TECHNICAL DATA
AND
SERVICE MANUAL
COIL NAILER
NV 50AF3
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
LIST No.: E019 Jan. 2005
N
MODEL
NV 50AF3
Hitachi
Power Tools
CONTENTS
Page
1. PRODUCT NAME ............................................................................................................................ 1
2. MARKETING OBJECTIVE .............................................................................................................. 1
3. APPLICATIONS ............................................................................................................................... 1
4. SELLING POINTS ........................................................................................................................... 1
4-1. Selling Point Descriptions ................................................................................................................ 2
5. SPECIFICATIONS ........................................................................................................................... 3
5-1. Specifications ....................................................................................................................................3
5-2. Nail Selection ....................................................................................................................................4
5-3. Nail Driving Force .............................................................................................................................6
5-4. Optional Accessory ...........................................................................................................................7
6. PRECAUTIONS IN SALES PROMOTION ...................................................................................... 8
6-1. Safety Instructions ............................................................................................................................8
6-2. Related Laws and Regulations .........................................................................................................9
6-3. Precautions in Sales Promotion ........................................................................................................ 9
7. MECHANISM AND OPERATION PRINCIPLE .............................................................................. 10
7-1. Mechanism .....................................................................................................................................10
7-2. Operation Principle .........................................................................................................................12
8. TROUBLESHOOTING................................................................................................................... 14
8-1. Troubleshooting and Correction......................................................................................................14
8-2. Possible Causes and Corrections for Air Leakage ......................................................................... 19
9. DISASSEMBLY AND REASSEMBLY ........................................................................................... 21
9-1. General Precautions in Disassembly and Reassembly ..................................................................21
9-2. Disassembly and Reassembly of the Output Section .....................................................................22
9-3. Disassembly and Reassembly of the Control Valve Section ..........................................................24
9-4. Disassembly and Reassembly of the Cap and the Magazine Section ...........................................27
9-5. Disassembly and Reassembly of the Driving Section ....................................................................29
10. INSPECTION AND CONFIRMATION AFTER REASSEMBLY ................................................... 33
11. STANDARD REPAIR TIME (UNIT) SCHEDULES ....................................................................... 34
Assembly Diagram for NV 50AF3
--- 1 ---
1. PRODUCT NAME
Hitachi Coil Nailer, Model NV 50AF3
2. MARKETING OBJECTIVE
The Model NV 50AF3 is a lightweight coil nailer that can handle wire-collated nails with lengths of 27 mm
(1-1/16") to 50 mm (2") and sheet-collated nails with lengths of 25 mm (1") to 45 mm (1-3/4"). This model's
outstanding features are as follows.
Small and lightweight [1.4 kg (3.1 lbs)]
Exhaust muffler for reduction of exhaust noise and dust disturbance
New magazine with a tilt bottom for easy top loading
Nailing depth adjustment mechanism with an easy-to-see calibrated dial
3. APPLICATIONS
* General nailing for construction such as nailing of a variety of backing materials, such as plywood or drywall.
* Fastening of a variety of interior finishing materials
* Nailing of a variety of architectural metals, such as reinforcing brackets [0.35 m (0.014") or less in thickness]
for joining frames or rafters of wooden buildings
4. SELLING POINTS
Newly designed magazine
for easy nail top loading
with tilt bottom
Continuous nailing/single
nailing changeover capability
[For Europe, by turning the
lever with the accessory hex.
bar (allen) wrench]
Exhaust muffler:
Reduces exhaust noise
Flings up less dust
Top cover swivels 360 for
precise, one-touch exhaust
air control
Nailing depth adjustment
mechanism with an easyto-see calibrated dial
Equipped with a handle grip
Protector
Small and lightweight
1.4 kg (3.1 lbs)
Automatic changeover between
wire-collated nails and sheet-collated
nails for stabler nail driving
--- 2 ---
The nailing depth can be changed by 0.5 mm per click.
The adjustable range of nailing depth is from 0 mm to 0.5 mm.
4-1. Selling Point Descriptions
(1) Magazine
(a) Tiltable
The nail holder can be tilted for easy nail loading.
[Reference]
Adjust the nail holder according to the length of nails to be used
as shown below.
1 Turn the nail holder about 90 counterclockwise.
2 Adjust the upper surface of the nail holder to a desired mark on
the inside of the magazine according to the length of nails to be
used by sliding the nail holder vertically.
3 Turn the nail holder clockwise until a click is heard (about 90 ).
(2) Nailing depth adjustment mechanism
The Model NV 50AF3 is equipped with a nailing depth adjustment mechanism that enables adjustment of
nailing depth by turning the adjuster dial.
However, an air pressure which exceeds the proper level for the driving resistance of the nails can shorten the
service life of the coil nailer. Be sure to instruct customers to adjust both the air pressure level and the
adjuster dial by referring to the table below.
Adjust the adjuster dial and the air pressure level referring to the
table below.
Perform a test driving. When the nail head is sunk below the
wood surface, adjust the adjuster dial clockwise (Up).
When the nail head is left above the wood surface, adjust the air
pressure level to higher.
Proper
Nail head is
lower than the
surface. (Turn
the adjuster dial
clockwise (Up).)
Nail head is
higher than the
surface. (Turn the
adjuster dial
counterclockwise
(Down).)
Adjuster dial
Up
Down
Nail holder
Magazine
Magazine
cover
Nail holder
For 27 mm
For 32, 38 mm
For 45, 50 mm
Magazine
Nail
Reference of air pressure and adjuster dial setting
Nail length Air pressure Adjuster dial
27 mm to 32 mm
38 mm to 50 mm
4.9 bar (5 kgf/cm2,, 70 psi)
6.9 bar (7 kgf/cm2, 98 psi)
Fully turn the adjuster
dial counterclockwise
for the lowermost level.
--- 3 ---
Sequential fire parts set (Code No. 881012)
Pneumatic tool lubricant [30 cc (1 oz) oil feeder] (Code No. 877153)
Pneumatic tool lubricant [120 cc (4 oz) oil feeder] (Code No. 872042)
Pneumatic tool lubricant [1 ltr (1 quart) can] (Code No. 876212)
Grease (ATTOLUB No. 2) [500 g (1.1 lbs.)] (Code No. 317918)
5. SPECIFICATIONS
5-1. Specifications
Model
Driving system
Applicable pressure
Driving speed
Product weight
Main body dimensions
(Length x Height x Width)
Nail feed system
Nail capacity
Air consumption
Air inlet
Packaging
Package dimensions
(Length x Height x Width)
Standard accessories
Optional accessories
NV50AF3
Reciprocating piston type
4.9 --- 8.3 bar (5 --- 8.5 kgf/cm2, 70 --- 120 psi) (Gauge pressure)
3 pcs./sec
1.4 kg (3.1 lbs)
252 mm x 269 mm x 112 mm
(9-15/16" x 10-19/32" x 4-13/32")
Reciprocating piston type
0.80 liter/cycle at 6.9 bar
(0.80 liter/cycle at 7 kgf/cm2)
(0.28 ft3/cycle at 100 psi)
3/8 NPT thread
Corrugated cardboard box (Sleeve type)
310 mm x 350 mm x 135 mm
(12-3/16" x 13-25/32" x 5-5/16")
Safety glasses (Code No. 875769)
•••••••••••••••••••••••••••••••••••••••••••••••••••
1
Hex. bar wrench for M4 screw (Code No. 943277)
•••••••••••••••••••••••••••
1
Hex. bar wrench for M5 screw (Code No. 944458)
•••••••••••••••••••••••••••
1
Hex. bar wrench for M6 screw (Code No. 944459)
••••••••••••••• ••••••••••••
1
Oiler (30 cc) (Code No. 877153)
•••••••••••••••••••••••••••••••••••••••••••••••••••••
1
Case (Code No. 881849)
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
1
Nose cap (A) (Code No. 881092)
••••••••••••••••••••••••••••••••••••••••••••••••••••
1
Nose cap (B) (Code No. 881093)
••••••••••••••••••••••••••••••••••••••••••••••••••••
1
200 --- 400 nails
--- 4 ---
Wire-collated nails
Min.
Max.
Fig. 1 Dimensions of nails
5-2. Nail Selection
The Model NV 50AF3 utilizes common round-head nails collated by wire or sheet into coils from 200 to 400
pieces. Applicable nail dimensions are shown below. However, it is recommended to use genuine HITACHI nails
to ensure satisfactory driving quality.
CAUTION: Ensure that nails are as specified in Figs. 1, 2 and 3. Other nails will cause clogging of nails
and subsequent damage to the nailer.
NOTE: Aluminum nails may bend when driven into a hard workpiece. Test before use.
4.6 mm
(0.181")
4.8 mm
(0.189")
2.3 mm
(0.091")
1.8 mm
(0.071")
27 mm (1-1/16")
50 mm (2")
Sheet-collated nails
Min.
Max.
4.6 mm
(0.181")
5.2 mm
(0.205")
2.0 mm
(0.079")
1.6 mm
(0.063")
25 mm (1")
45 mm (1-3/4")
--- 5 ---
L
d
1
27 --- 50
(1-1/16 --- 2)
12
(0.472)
Unit: mm (inch)
dL
1
L
2
D
1
D
2
H
1.8 --- 2.3
(0.071 --- 0.091)
24
(0.98)22(0.866)
100
(3.937)72(2.835)
0.6
(0.024)
Fig. 2 Dimensions of wire-collated nails
Fig. 3 Dimensions of sheet-collated nails
4.5
(0.177)
0.8
(0.031)
12.5
(0.492)
9.7
(0.382)
14
(0.551)
6
(0.236)
6
(0.236)
L
25 --- 45
(1 --- 1-3/4)
dD1 D2 H
1.6 --- 2.0
(0.063 --- 0.079)25(1)98(3.858)47(1.85)
--- 6 ---
5-3. Nail Driving Force
Figure 4 shows the energy required to drive a nail flush and the output energy of the NV 50AF3 nailer.
When the supplied pressure is adjusted so that the output energy of the nailer equals the energy required for
driving a nail, the nail can be completely driven.
For example, in driving wire-collated nails of 2.1 mm dia. x 50 mm length (0.080" dia. x 2" length) into Hemlock
below a 12 mm plywood sheet with the Model NV 50AF3, a force of about 5.3 bar (5.6 kgf/cm2, 79.8 psi) is
required to drive the nail flush with the surface of the plywood. If the nail is driven with a force more than 5.5 bar
(5.6 kgf/cm2, 79.8 psi), the nail head will be sunk below the wood surface. Please use Fig. 4 as a rough guide
only, because figures vary according to the workpiece materials, moisture content, and grain of the wood.
--- 7 ---
Fig. 4 Required nailing energy and nailer output energy
5-4. Optional Accessory
Sequential fire parts set:
The sequential fire parts set is provided as an optional accessory for the Model NV 50AF3. By using this optional
accessory, a nail is driven by pressing the pushing lever first against a workpiece and then pulling the trigger, and
no nail is driven when pulling the trigger first and then pressing the pushing lever against a workpiece (single-shot
operation). Please recommend the sequential fire parts set to the customers who want to use it. Salespersons
must instruct the customers to read the Handling Instructions attached to the sequential fire parts set and also the
Handling Instructions of the Model NV 50AF3 thoroughly for correct use.
4 5 6 7 8
4 5 6 7 8
60 70 80 90 100 110 120
Air pressure setting to drive nail flush
with NV50AF3
Nail: d x L
(
mm x mm
)
d
L
2.3 mm x 50 mm
(0.091" x 2")
bar
kgf/cm
2
PSi
2.1 mm x 50 mm
(0.083" x 2")
1.8 mm x 27 mm
(0.071" x 1-1/16")
Size of nail
40 60 80 100 120 140
mm
2
in
2
50
40
30
20
10
50
40
30
20
10
500
400
300
200
100
500
400
300
200
100
40
30
20
10
40
30
20
10
(ft-Ibs)
(J)
(kgf cm)
(ft-Ibs)
(J)
(kgf cm)
Nailer output energy
Required nailing energy
0.05 0.1 0.15 0.2
Hemlock + 12mm (0.47") plywood
Output range of
NV50AF3
--- 8 ---
6. PRECAUTIONS IN SALES PROMOTION
6-1. Safety Instructions
In the interest of promoting the safest and most efficient use of the Model NV 50AF3 Nailer by all of our
customers, it is very important that at the time of sale the salesperson carefully ensures that the buyer seriously
recognizes the importance of the contents of the Handling Instructions, and fully understands the meaning of the
precautions listed on the Warning Label attached to each tool.
(1) Handling Instructions
Although every effort is made in each step of design, manufacture and inspection to provide protection against
safety hazards, the dangers inherent in the use of any pneumatic tool cannot be completely eliminated.
Accordingly, specific precautions and suggestions for the use of the pneumatic nailer are listed in the Handling
Instructions to enhance the safe and efficient use of the tool by the customer. Salespersons must be
thoroughly familiar with the contents of the Handling Instructions to be able to offer appropriate guidance to the
customer during sales promotion.
(2) Warning Label
Each Model NV 50AF3 unit is provided with a Warning Label (illustrated below) which lists basic safety
precautions in its use. Carefully ensure that the customer fully understands and follows these precautions
before using the tool.
GEFAHR Vor Gebrauch die BETRIEBSANLEITUNG LESEN. Ein Nichtbeachten
der Betriebsanleitung KANN ZU ERNSTHAFTEN VERLETZUNGEN FÜHREN.
Anwender und andere Personen, die sich im Arbeitsbereich aufhalten, MÜSSEN
DIE ERFORDERLICHEN SCHUTZBRILLEN TRAGEN.
NIEMALS FLASCHENGASE BENUTZEN. Ausschließlich regulierte Druckluft benutzen.
ÜBERSCHREITEN SIE NIEMALS 120 psi/8.3 bar. TRAGEN SIE DIE MASCHINE
NIEMALS MIT DEM FINGER AM SCHALTER. Vor Service-und Reparaturarbeiten,
sowie wenn das Gerät nicht benutzt wird, DRUCKSCHLAUCH ABKLEMMEN.
DANGER LISEZ LE MANUEL D'UTILISATION avant usage. VOUS POUVEZ
VOUS BLESSER GRAVEMENT en ne suivant pas les instructions. L'opérateur ainsi
que toute personne à aproximité DOIT PORTER DES LUNETTES DE SECURITE
AGREES. NE JAMAIS UTILISER DU GAZ EMBOUTEILLE. Utiliser uniquement de
l'air règlé. NE PAS DEPASSER 12 psi/8.3 bar. NE JAMAIS PORTER AVEC LE
DOIGT SUR LA GACHETTE. DEBRANCHEZ L'AIR avant de commencer l'entretien,
le règlade ou avant d'arrêter le travail.
C316007
--- 9 ---
6-2. Related Laws and Regulations
As nailers and staplers are designed to instantaneously drive nails and staples, there is an ever-present danger of
misfiring and subsequent possible serious injury. Accordingly, close attention in handling is absolutely necessary
at all times. Carefully ensure that the customer is fully aware of the precautions listed in the Handling Instructions
provided with each unit.
While there are no specific safety regulations, there are related items in various general safety regulations with
which the salespersons should be familiar in order to advise the customer properly. Please check your national
and/or local regulations for applicable items.
Some applicable items are outlined below.
(1) Europe
EUROPEAN STANDARD EN792-13 JUNE 2000
HAND-HELD NON-ELECTRIC POWER TOOLS---SAFETY REQUIREMENTS
Part 13: Fastener driving tools
(2) The U.S.A.
OSHA 1926.102 Eye and Face Protection
1926.302 Power-Operated Hand Tools
ANSI SNT-101-2002 Portable, Compressed-Air-Actuated,
Fastener Driving Tools---Safety Requirements for
6-3. Precautions in Sales Promotion
The salespersons must instruct customers to observe the following precautions.
(1) An air pressure less than 4.4 bar (4.5 kgf/cm2, 63 psi) or more than 7.8 bar (8 kgf/cm2, 112 psi) can affect the
performance, service life and safety of the Model NV 50AF3. Pay special attention to the pressure level,
capacity and piping of the air compressor. [If using an air compressor capable of high air pressure [9.8 bar
(10 kgf/cm2, 140 psi) or more], be sure to install a pressure reducing valve on the air compressor and limit the
pressure to 7.8 bar (8 kgf/cm2, 112 psi) or less.]
(2) To protect the Model NV 50AF3 against rust, apply oil and perform idle driving two or three times to spread the
applied oil fully inside this nailer when it is not used for a long time. Also coat the steel parts with oil.
(3) Rust inside this nailer can cause performance degradation or failure. The salespersons must instruct the
customers to drain the air compressor tank without fail.
(4) The salespersons must instruct the customers, especially those who use the Model NV 50AF3 frequently, to
check and maintain this nailer without fail.
(5) The salespersons must instruct the customers to clean and apply the provided oil to the sliding sections of the
pushing lever regularly.
--- 10 ---
7. MECHANISM AND OPERATION PRINCIPLE
7-1. Mechanism
Most of the parts of the Model NV 50AF3 have been newly designed, though the basic construction is the same
as that of the Model NV 38AB2. Features of the main parts are described below.
Output section .................. Most of the parts have been newly designed, though the basic construction is the same
as that of the Model NV 38AB2.
The muffler has been added to reduce air exhaust force.
Control valve section ........ This section is common to that of the Model NV 38AB2.
Driving section.................. The adjuster, nose, nail guide and other parts have been newly designed for
improvement of operability in nailing depth adjustment.
Magazine section ............. Most of the parts have been newly designed for easier nail loading.
--- 11 ---
Top cover
Cylinder
Piston bumper
Pushing lever (A)
Head valve
Exhaust cover
Control valve ass'y
Plunger spring
Plunger (A)
Valve
bushing (B)
Valve bushing (A)
Control valve ass'y
Feeder (Feed claw)
Nail guide
Feed piston
Nail holder
Magazine cover
Guide lock
A
Fig. 5 Construction
Cross section A --- A
Exhaust port
Head ring
Muffler
Protector(A)
Piston
(Driver blade)
Body
Feeder
(Feed chuck)
Adjuster
Nose
Ejection port
Vinyl cover
(Dust proof cover)
Magazine
Hook
Valve piston (B)
Change knob (B)
Trigger (A)
Magazine section
Output section
Driving section
--- 12 ---
(1) Prior to nailing (See Fig. 6.)
1. When compressed air is supplied to the main body,
it fills the accumulator (see diagram).
2. At the same time, the compressed air flows into the
valve piston lower chamber of the control valve
section, and pushes up the valve piston. Also, the
compressed air flows from the air supply vent,
through air passage (A), and into the head valve
upper chamber where it simultaneously pushes
down the head valve and the head valve spring to
seal the upper surface of the head valve and the
cylinder.
(2) During nailing (I) (See Fig. 7.)
1. When plunger (A) is pushed up by operating both
the pushing lever and trigger (A), the compressed
air in the valve piston lower chamber is exhausted
from the lower part of plunger (A). Then, the valve
piston is pushed down by the compressed air from
the accumulator so that it shuts off the air supply
vent and releases the exhaust valve.
2. When the exhaust valve opens, the compressed air
in the head valve upper chamber is exhausted into
the atmosphere through air passage (A).
3. The air pressure applied against the lower surface
of the head valve soon exceeds the force of the
head valve spring, and pushes the head valve up.
The head valve is pushed fully upward by the
compressed air, and seals the upper surface of the
exhaust cover and the head valve.
4. When the head valve is pushed up, the
compressed air flows rapidly into the cylinder and
pushes down the piston to drive a nail. At this time,
the compressed air flows through the cylinder hole,
into the return air chamber, through air passage (B),
and into the chamber at the left side of the feed
piston in the nail feeder section. When the air
pressure exceeds the force of the feed spring, the
feeder moves to the right.
7-2. Operation Principle
Cylinder
Head valve spring
Air passage (A)
Head valve
Accumulator
Valve piston (B)
Control
valve
section
Air supply vent
Pushing
lever (A)
Fig. 6 Prior to nailing
Air supply vent
Fig. 7 During nailing (I)
Exhaust valve
Accumulator
Exhaust cover
Air passage (A)
Head valve spring
Head valve
Cylinder
hole
Piston
Cylinder
[Return air
chamber]
Air passage
(B)
Plunger (A)
Trigger (A)
Pushing
lever (A)
Valve piston
Nail feeder
section
Feed spring
Feed piston
Feeder
Pushing lever (B)
--- 13 ---
(3) During nailing (II) (See Fig. 8.)
1. When the piston moves down inside the cylinder,
the air below the piston flows through air passage
(C) under the cylinder and is accumulated in the
return air chamber together with the compressed air
flowing through the cylinder hole.
2. When the compressed air in the left chamber of the
feed piston moves the feed piston fully to the right,
the nail feeder (feed pawl) engages the next nail.
(4) After nailing (See Fig. 9.)
1. When the trigger is released, the plunger goes
down, the air supply vent opens, the valve piston
goes up, and the compressed air in the
accumulator passes through air passage (A) into
the head valve upper chamber. The head valve is
then pushed down by the head valve spring and the
air pressure against the upper surface of the head
valve. At the same time, the exhaust valve opens
and the upper chamber of the cylinder is opened to
the atmosphere.
2. When the head valve seals the upper surface of the
cylinder, the compressed air accumulated in the
return air chamber passes through air passage (C),
presses on the lower surface of the piston, and
forces the piston to return upward to its original
position. Also, the compressed air above the piston
is exhausted through the head valve hole.
3. The compressed air accumulated in the left
chamber of the feed piston passes through air
passage (B), goes into the return air chamber, and
is then exhausted through the nose hole. The feed
piston is then moved to the left by the force of the
feed spring, and the feed pawl feeds the next nail
into the ejection port. This completes one full
nailing cycle.
Cylinder
[Return air
chamber]
Air passage
(C)
Piston
Nail feeder
Cylinder hole
Fig. 8 During nailing (II)
[Return air
chamber]
Piston
Head valve spring
Head valve
Cylinder
Air passage (A)
Fig. 9 During return
Feed piston
Nail feeder
Air passage (C)
Feed piston
Feed spring
Plunger (A)
Trigger
Valve piston
Air supply vent
[Accumulator]
--- 14 ---
* The air passage is jammed
(with pieces of broken
piston bumper etc.).
* The feed piston chamber
contains foreign matter
such as pieces of broken
bumper etc.
Remove foreign matter.
Replace the piston bumper
with new one.
Body....Remove foreign matter
in the return air chamber.
Nose....Remove foreign
matter in the air passage and
the feed piston chamber.
8. TROUBLESHOOTING
8-1. Troubleshooting and Correction
Fault
Cause
(
The mark * refers to main causes.
)
Inspection method Remedy
(1)
Nails fail to
eject.
< Nail >
The nailer is loaded with
nails not approved by
Hitachi.
The nailer is loaded with
abnormal nails (bent nails,
nail heads too large, or too
small, abnormally collated
nails, deformed wire).
Nails or link pieces are
jammed.
Deformation and breaking
of collated nails
Check whether or not the
nailer is normally loaded with
nails approved by Hitachi.
Use specified nails.
Remove abnormal nails and
load the nailer with proper
nails.
< Nail feeding section:
nose, feeder,
feed piston, etc. >
The sliding resistance of
the feed piston is too great.
The nail guide face of the
nose is abnormal
(deformed, jagged,
damaged and/or worn).
The feed spring and/or
feeder spring is abnormal
(damaged and/or fatigued).
The feeder is abnormal
(damaged and/or worn).
Remove the feed piston, and
examine the feed piston slide
surface of the nose.
Apply grease.
Polish the scratched section
with abrasive paper.
Replace parts.
Check whether or not the nail
feeding section is abnormal
(jagged, deformed, damaged
or worn).
Replace parts.
Smooth jagged areas.
Correct the deformed part.
The nose is not correctly
loaded with nails in the
groove.
Check whether or not the
nailer is correctly loaded with
nails in the specified groove.
Load the nailer with nails in
the correct position in the
nose.
Insufficient oil and/or dust
sticking in the chuck
groove's slide of the nose.
Remove dust and then apply
oil.
Air pressure is too low. Adjust air pressure in a range
of 4.9 --- 8.3 bar (5 --- 8.5
kgf/cm2, 70 --- 120 psi).
Open the nail guide and inject
air to check the feeder's
action.
--- 15 ---
Replace parts.
Apply grease.
Replace the piston bumper
with new one.
Pushing lever (A)
* The piston bumper is
abnormal.
The inner face of the
cylinder is abnormal (
packed
with dust and/or worn
).
The sliding face of the head
valve is abnormal (seized,
damaged, and/or oil has
depleted).
Examine the action of pushing
lever (A).
Reassemble or replace the
O-ring with new one.
< Nail guide section >
The nail guide face of the
nail guide is abnormal
(deformed, jagged,
damaged and/or worn).
Air leaks from a gap
between the body and the
nose.
Fault
Cause
(
The mark * refers to main causes.
)
Inspection method Remedy
(1)
Nails fail to
eject.
(Continued)
Open the nail guide and inject
air to check feeder's action.
Tighten screws and examine
the O-rings (1AP-3).
O-rings are worn and
deformed.
Check whether or not the nail
guide is abnormal (jagged,
deformed and/or damaged).
Examine the O-ring.
Examine the action of nail
stopper (A) and nail stopper
(B).
Remove dust and then apply
oil.
Replace abnormal parts.
Collate the nails normally and
reload the nailer with normally
collated nails.
Remove burrs and deformed
parts and replace parts.
Adjust the height of the nail
holder correctly.
< Magazine section >
< Pushing lever (A) >
Magazine
Check whether or not a nail
catches on another nail in the
magazine.
Check whether or not a nail
catches on some part of the
magazine.
Check the nail holder for the
height.
Correct or replace parts.
< Output section: Piston,
driver blade, etc. >
Air pressure is low. Adjust air pressure in the
range of 4.9 --- 8.3 bar (5 ---
8.5 kgf/cm2, 70 --- 120 psi).
* Piston rings are worn.
Open the nail guide and inject
air to examine whether or not
the driver blade is reset.
Replace the piston ring with
new one.
Examine whether or not nails
can be driven at a pressure of
4.9 bar (5 kgf/cm2, 70 psi).
Correct the driver blade or
replace it with new one.
The O-ring in the cylinder
section is abnormal (off,
jagged and/or damaged).
Inject air to check nail driving
action.
Remove dust and then apply
oil. Or replace the cylinder
with new one.
The driver blade is
abnormal (
deformed, jagged,
damaged and/or worn
).
The O-rings need oil.
Apply grease or oil.
Correct and replace part.
Dust is stuck to the inside of
the nail guide groove, and
the oil in the groove has
depleted.
* A spring is abnormal (off,
damaged and/or fatigued).
The claw ridge section of
the nail stopper is abnormal
(damaged, worn and/or
jagged).
--- 16 ---
Disassemble the output
section and check whether or
not the piston ring, the O-ring
and the cylinder are normal.
* The piston ring is
abnormal (worn and/or
damaged).
The inner face of the
cylinder is abnormal (worn
and/or rough).
Inject air to check whether or
not the driver blade is left
lowered.
Nails are not completely fed
in the injection port.
Nails not approved by
Hitachi are used.
Replace parts.The spring of the head
valve is abnormal (fatigued
and/or damaged).
Inject air to check whether or
not the driver blade is left
lowered.
Fault
Cause
(
The mark * refers to main causes.
)
Inspection method Remedy
(1)
Nails fail to
eject.
(Continued)
< Control valve section >
Plunger (A), valve piston
(B), valve bushing (A) and
valve bushing (B) are
abnormal (seized and/or
damaged).
Disassemble the control valve
and check the O-rings.
Apply grease or replace it.
Refer to Item 1.
Refer to Item 1.
Check whether or not the
driver blade head is
abnormally worn.
Replace it.
Nails not approved by
Hitachi are used.
Check whether or not the nail
is appropriate for metal
reinforcing plates.
Use nails approved by Hitachi.
Adjust air pressure in the range
of 4.9 --- 8.3 bar (5 --- 8.5 kgf/
cm2, 70 --- 120 psi)
.
Replace the abnormal parts.
(2)
Nails are
driven bent.
The wood being nailed is
very hard.
Check whether or not the nail
is bent, even when it is driven
into soft wood.
The nailer cannot be used
because the material is
beyond its applicable range.
(3)
Nails cannot
be driven
into the
wood
completely:
the heads
cannot be
made flush.
The adjuster is incorrectly
set.
Try to drive nails with the
adjuster set to maximum
depth.
Adjust the adjuster to the
optimum depth.
Check whether or not the nail
heads are flush with the
surface when driven into soft
wood.
The nailer cannot be used
because the material is
beyond its applicable range.
Inject air and check whether
or not the driver blade sticks
out from the nose.
Replace it.
Replace abnormal parts.
O-rings are worn.
When driving a short nail,
the adjuster set for
insufficient depth.
Check whether or not the
adjuster is set for insufficient
depth.
Use the nailer with the
adjuster set to greater depth.
(Decrease the pressure.)
* The driver blade is worn.
Air pressure is low.
The wood being nailed is
excessively hard.
* The driver blade is worn.
Check whether or not the
sliding face is abnormal and
oil has depleted.
The sliding face of the head
valve is abnormal (seized,
damaged, and/or oil has
depleted).
The cylinder plate or the
O-ring is abnormal
(dislocated, deformed
and/or broken).
Disassemble the cylinder
plate section and check for
abnormality.
Replace the abnormal parts.
Replace the abnormal parts.
Apply grease.
--- 17 ---
Fault
Cause
(
The mark * refers to main causes.
)
Inspection method Remedy
(4)
Nail
jamming
< Nail >
*Nails not approved by
Hitachi are used.
* Abnormal nails are mixed.
* The collation sheet is
abnormal (deformed and/or
broken). (Sheet collation
nails)
Nails fall off.
(Sheet collation nails)
Nails are missing from the
sheet. (Sheet collation
nails)
Abnormality in wire collation
nails (Breakage, wrong
welding, deformation and/or
wrong welding position)
(Wire collation nails)
* Wire collated nails are
deformed.
(Deformation in collation
angle, collation pitch, etc.)
* The diameter of nail head is
too small.
(Wire collation nails whose
head diameter is 4.3 mm
(0.17") or less are liable to
cause jamming)
Check whether or not nails
approved by Hitachi are used.
Check nails referring to the
following figures.
Use the nails approved by
Hitachi.
Remove abnormal nalis and
refill the nailer with normal
nails.
6 mm
(0.24")
(Wire collation nails)
L1
D
16
L2
Dimension L2
19.2
(0.76")
24
(0.94")
Dimension D
4.6 --- 4.7
(0.18" --- 0.19")
4.8
(0.19")
Dimension L1
7.6
(0.30")
12
(0.47")
Unit : mm
(Sheet collation nails)
--- 18 ---
Check whether or not when
injecting air or actually
injecting nails, the driver blade
is completely returned.
Open the nail guide to check
the position of the feeder
claw.
Check whether or not the
chuck of the feeder holds a
nail, and the first nail is
positioned in the injection
port.
(Check that the second claw
chucks the nail shaft and
feeds it.)
Disassemble the control valve
section to check the O-rings
of plunger (A) and valve
piston (B).
Check for the abnormality
(wear, damage and/or
deformation) in each part.
Check where the single shot/
continuous shot change knob
is positioned.
* The O-ring of plunger (A)
is worn.
* The O-ring of valve piston
(B) is worn.
The sliding face of plunger
(A) of valve piston (B) is
abnormal (seized and/or
deformed).
Plunger (A), trigger (A) and
pushing lever (B) are
abnormal (worn and/or
deformed).
The single shot/continuous
shot switch lever is
positioned incorrectly.
Replace abnormal parts.
Nose…Remove the foreign
matter in the feed piston
chamber.
< Body: Nail feeding is
incomplete. >
The feeder is worn, and the
sliding section is abnormal.
The nail guide face of the
nose and the sliding
section of the feeder are
abnormal (deformed,
warped and/or damaged).
The nail guide face of the
nail guide is worn.
The driver blade head is
worn.
The feed spring and the
feeder spring are abnormal
(damaged, fatigued and/or
damaged).
* The feed piston chamber
contains foreign matter
such as piston bumper
pieces.
Fault
Cause
(
The mark * refers to main causes.
)
Inspection method
Remedy
(4)
Nail
jamming
(Continued)
Adjust the air pressure in a
range of 4.9
---
8.3 bar (5
---
8.5
kgf/cm2, 70
---
120 psi).
Replace the abnormal parts.
Set the single shot/continous
shot change knob to a correct
position.
< The driver blade is not
completely returned. >
Refer to Item 1.
< Output section: Piston,
driver blade, etc.>
< Output section: Piston,
driver blade, etc. >
(5)
Single
shot is
impossible.
Air pressure is too high. When nails are driven at a
high pressure and speed,
nails can cause jamming.
Check pressure and driving
speed.
< Body: Abnormality in nail guide section > Refer to Item 1 < Nail guide section >
--- 19 ---
(A)
(H)
(C)
(a)
(b)
(c)
(B)
(D)
(d)
(e)
(f)
A
A
Looseness of the Hex. Socket Hd.
Bolt M5 X 20 [7]
Damage of Gasket (A) [9]
Abnormality in the sealed faces of
the Body Ass'y [22], Exhaust Cover
[8] and the Cylinder [20]
8-2. Possible Causes and Corrections for Air Leakage
Air leakage repairing position
Repairing step
(1) Check for abnormality in the
parts marked *(asterisk) out of
the following parts.
(2) Check for wear, scratches and
damage in the parts marked
(circle).
(3) Next, examine other portions.
(The numbers in [Bold]
correspond to the item numbers
in Parts List and the exploded
assembly diagrams.)
Control valve section
(E)
(g)
(h)
(G)
(F)
Cross section A --- A
Air leakage portion
(A) Exhaust port
Cause
When the trigger is turned off
When the trigger is turned on
Abnormality in Head Valve (A) [12]
and the Cylinder [20] [Wear and
deformation of the sealed face of the
(b) section]
Abnormality in the Head Valve O-ring
(I.D 16.8) [11] or wear, deformation
and/or breakage of Head Valve (A)
[12]
Abnormality (damage) in the Exhaust
Cover [8]
Abnormality in Head Valve (A) [12]
[Wear, deformation and/or breakage
of the section (a)]
* Abnormality in the inner face [the
section (a)] in the Exhaust Cover [8]
[Deformation and dust clogging in
the section (a)]
(B) Exhaust cover
(C) Nose 1
(Feed piston passage)
Looseness of the Hex. Socket Hd.
Bolt M6 X 20 [34]
Scratched and/or broken O-ring
(1AP-3) [32]
Abnormality in the sealed faces of
the Body Ass'y [22] and the Nose
[33]
(F)(G)
--- 20 ---
Abnormality (wear, breakage and/or scratches) in the O-ring (I.D 37.2) [45]
Looseness of the Cap [46]
Abnormality (damage, deformation and/or scratches) in the sealed faces of the
Body Ass'y [22] and Cap [46]
Air leakage portion
(D) Nose 2
Cause
When the trigger is turned off
When the trigger is turned on
* Abnormality (breakage and/or
scratches) in the O-Ring (1AS-50)
[16] of the Cylinder Plate [17]
Abnormality in the sealing faces [the
sections (c) and/or (d)] of the
Cylinder Plate [17], Body Ass'y [22]
and/or the Cylinder [20]
Abnormality (wear, breakage and/or
scratches) in the O-ring (I.D 11) [61]
of Valve Piston (B) [60]
Abnormality (wear, breakage and/or
scratches) in the O-ring (I.D 8.8) [58]
(lower side) of Valve Piston (B) [60]
Abnormality (breakage and/or
scratches) in the O-ring (S-18) [57] of
Valve Bushing (B) [56]
* Abnormality in the inner face [the
section (h)] of the valve chamber of
the Body Ass'y [22]
Abnormality [deformation, crack
and/or damage of the sections (e)
and (f)] in the Piston Bumper [21]
Deformation of the Piston [15]
(The deformation of driver blade
abnormality in sealed faces)
The deformation of the face (f) of the
Body Ass'y [22]
Abnormality (wear, deformation,
breakage and/or scratches) in the
O-Ring (S-12) [24]
(E) Feed piston
(F) Control valve 1
Abnormality (wear, breakage and/or
scratches) in the O-ring (P-18) [73] of
the Feed Piston [72], or wear and/or
deformation of the Nose [33] on the
sliding face
Abnormality (wear, breakage and/or
scratches) in the O-ring (P-9) [71] of
the Nose [33], or wear, deformation
and/or scratches of the Feed Piston
[72] on the sliding face
(G) Control valve 2
Abnormality (wear, breakage and/or
scratches) in the O-ring (I.D 8.8) [58]
(upper side) of Valve Piston (B) [60]
Abnormality (breakage and/or
scratches) in the Head Valve O-ring
(I.D 16.8) [11] of Valve Bushing (B)
[56]
* Abnormality in the upper face [the
section (g)] of the valve chamber of
the Body Ass'y [22]
(H) Cap
Abnormality (wear, breakage and/or
scratches) in the O-ring (I.D 1.8) [64]
of Plunger (A) [63]
Abnormality (deformation and/or
scratches of the sliding face of
Plunger (A) [63] in Valve Bushing (A)
[65]
Abnormality (wear, breakage and/or
scratches) in the O-ring (S-4) [59]
inside Valve Piston (B) [60]
Abnormality (deformation and/or
scratches of the sliding face of
Plunger (A) [63] in Valve Piston (B)
[60]
--- 21 ---
9. DISASSEMBLY AND REASSEMBLY
The following describes procedures considered essential for proper disassembly and reassembly.
The numbers in [Bold] correspond to the item numbers in the Parts List and the exploded assembly diagrams.
The structure of the Model NV50AF3 can be generally divided into four sections: the output section, the control
valve section, the driving section and the magazine section.
NOTE: Prior to disassembling and reassembling, be sure to remove the hose with your finger off the trigger
and exhaust the internal compressed air completely.
When reassembling O-rings, be careful not to scratch them and not to let dust enter the tool.
Apply grease to the O-rings and O-ring sliding sections.
9-1. General Precautions in Disassembly and Reassembly
Apply grease [Nippeco SEP-3A (Code No. 930035) or Multemp PS No. 2 (Code No. 939536)] to the O-rings
and the O-ring sliding area.
When installing the O-rings, exercise care to avoid scratches and dust.
Lubricants required: Hitachi pneumatic tool lubricant
1 oz. (30 cc) Oil feeder (Code No. 877153)
4 oz. (120 cc) Oil feeder (Code No. 874042)
1 quart (1 liter) Can (Code No. 876212)
Replace gasket (A) if broken, and make sure that there is no air leak after installation.
Exercise care to protect the valve area from any foreign substance.
Lubricate the sliding area of the feeder unit.
Rated tightening torque for bolts and screws
Bolt/Screw
Hex. Socket Hd. Bolt M6 x 20 .....................[34]
Hex. Socket Hd. Bolts M5 ...........................[1] [7]
Nylock Hex. Socket Hd. Bolt M4 x 10 ......... [104]
Machine Screw (W/Washers) M5 x 30 ....... [49]
Cap.............................................................. [46]
Tightening torque [N•m (kgf•cm, ft-lbs)]
12.7 0.8 (130 8, 9.4 0.6)
6.4 0.5 ( 65 5, 4.7 0.4)
4.4 0.3 ( 45 3, 3.2 0.2)
2.0 0.5 ( 20 5, 1.4 0.4)
24.5 4.9 (250 50, 18.0 3.6)
Before replacing the Piston Bumper [21], make sure that anything, such as broken chips of the old Piston
Bumper [21], are not stuffed in the passages of the Body Ass'y [22] or the Nose [33].
--- 22 ---
9-2. Disassembly and Reassembly of the Output Section
(1) Disassembly and reassembly of the Exhaust Cover [8], Head Valve (A) [12], the Piston [15] and the
Cylinder [20]
Hex. Socket Hd. Bolt
M5 x 10 [1]
Washer [2]
Top Cover [3]
Hex. Socket Hd. Bolt
M5 x 20 [7]
Protector (A) [6]
Gasket (A) [9]
Exhaust Cover [8]
Head Valve Spring [10]
Cylinder Plate [17]
Body Ass'y [22]
Body Ass'y [22]
Stopper
portion of the
Cylinder Plate
[17]
Fig. 10 Disassembly and reassembly of piston,
cylinder and exhaust cover
[Tool required] 4 mm hex. bar wrench
(a) Disassembly (See Fig. 10.)
Loosen the Hex. Socket Hd. Bolt M5 x 10 [1]. Then the Top
Cover [3], the Head Ring [4], the Muffler [5] and Protector
(A) [6] can be removed.
Loosen the four Hex. Socket Hd. Bolts M5 x 20 [7] to remove
the Exhaust Cover [8]. Then the parts forming the output
section, such as the Piston [15], the Cylinder [20] and the
Piston Bumper [21], can be removed.
(b) Reassembly
Proceed in reverse to the disassembly procedure, while taking
care to observe the following procedures.
Apply Shell Tonna Oil S32 to the Piston Ring [13], the Piston
O-Ring [14] and the inside of the Cylinder [20].
Apply grease to the O-Ring (S-36) [18] and the Cylinder
O-Ring [19] and then install them.
Mount the Cylinder Plate [17] to the Cylinder [20] facing the
stopper portion of the Cylinder Plate [17] towards the Piston
Bumper [21]. Locate the assembled Cylinder [20] so that the
stopper portion of the Cylinder Plate [17] is positioned
between the ribs of the Body Ass'y [22]. (Figs. 11 and 12)
Fig. 11
Head Ring [4]
Muffler [5]
Head Valve O-Ring
(I.D 16.8) [11]
Head Valve (A) [12]
Piston Ring [13]
Piston O-Ring [14]
Piston [15]
O-Ring (1AS-50) [16]
O-Ring (S-36) [18]
Cylinder O-Ring [19]
Cylinder [20]
Piston Bumper [21]
Ribs of the
Body Ass'y
[22]
Fig. 12
Face the stopper portion
of the Cylinder Plate [17]
towards the Piston
Bumper [21].
--- 23 ---
Before reassembly, apply grease to the sliding
portion (A) of the Exhaust Cover [8] and Head
Valve (A) [12], lip portions (B) and (C) of Head
Valve (A) [12], and charge about 0.5 g of grease
into the groove of the Exhaust Cover [8] (Fig. 13).
Push Head Valve (A) [12] in the Exhaust Cover [8]
together with the Head Valve O-Ring (I.D 16.8) [11].
Matching the cut side of the Muffler [5] to the Top
Cover [3], mount the Muffler [5] without curling it
(Fig. 14).
Apply Shell Tonna Oil S32 to the inside of the
Cylinder [20] and mount the Cylinder [20].
Mount Gasket (A) [9] so that its hole matches the
blowhole of the Body Ass'y [22].
Apply grease to the O-Ring (1AS-50) [16] and its
sealing surface and mount it.
Fit the convex portion of the Exhaust Cover [8] in
the concave portion of the Top Cover [3].
Head Valve Spring [10]
Head Valve
O-Ring (I.D 16.8) [11]
(A)
Fig. 13
Exhaust
Cover [8]
Head
Valve (A) [12]
Groove of
the Exhaust
Cover [8]
(C)
(B)
Cut side of the
Muffler [5]
Exhaust Cover [8]
Muffler [5]
Fig. 14
Convex portion of
the Exhaust Cover [8]
Top Cover [3]
Concave portion of
the Top Cover [3]
--- 24 ---
[Tool required]
Roll pin puller (3 mm dia. and 2.5 mm dia.)
9-3. Disassembly and Reassembly of the Control Valve Section
(1) Disassembly and reassembly of the
control valve unit
(a) Disassembly (See Fig. 15.)
Remove the Retaining Ring (E-Type) for D6
Shaft [23]. Trigger (A) [25] and Change Knob
(B) [54] can then be removed. The Pushing
Lever Guide [28] can be removed by pulling
off the Roll Pin D3 x 25 [51] and the Roll Pin
D3 x 18 [50].
Pull off the Roll Pins D3 x 18 [50] with a roll pin
puller (3 mm dia.) and remove the control
valve unit following the procedures below.
(i) Remove the Exhaust Cover [8] as indicated in
item 9-2-(1).
(ii) Insert a small rod from top of the Body Ass'y
[22] and push the top surface of Valve Piston
(B) [60] as illustrated in Fig. 16, and then the
parts forming the control valve unit excluding
Valve Bushing (B) [56], the O-ring (S-18) [57]
and the Head Valve O-ring (I.D 16.8) [11] can
be removed.
(iii) Valve Bushing (B) [56] can be pulled out
using a wire by hooking a bent end into the
hole of Valve Bushing (B) [56]. Exercise care
not to cause any damage to Valve Bushing
(B) [56] interior with such a wire hooked
portion.
Exercise care not to damage Valve Piston (B)
[60] and Valve Bushing (B) [56].
Do not pull off plunger (A) end with pliers or a
similar tool.
Grip Tape [43]
Steel Ball D3.97 [52]
Spring (C) [53]
Change Knob (B) [54]
Trigger (A)
[25]
Fig. 15 Disassembly and reassembly of the control valve
section
Body Ass'y [22]
Rod
Fig. 16
Tape [44]
Valve Bushing (B) [56]
O-Ring (S-18) [57]
O-Ring
(
I.D
8.8) [58]
O-Ring (S-4) [59]
Valve Piston (B) [60]
O-Ring (I.D 11) [61]
Plunger Spring [62]
Plunger (A) [63]
O-Ring (I.D 1.8) [64]
Valve Bushing (A) [65]
Head Valve
O-Ring (I.D 16.8)
[11]
Roll Pin D3 x 25 [51]
Roll Pin D3 x 18 [50]
Retaining
Ring (EType) for
D6 Shaft
[23]
Roll Pin D3 x 18 [50]
Pushing
Lever Guide
[28]
--- 25 ---
(b) Reassembly
Proceed in reverse to the disassembly procedure, taking
care of the following points.
Exercise enough care to keep the control valve unit away
from foreign substances.
Apply enough lubricant to Plunger (A) [63], the O-ring
(I.D 1.8) [64] and the O-ring (I.D 8.8) [58], O-ring (S-4)
[59], O-ring (I.D 11) [61] of Valve Piston (B) [60].
Fig. 17
Fit Valve Bushing (A) [65] into the Body Ass'y [22] so that its roll pin groove is aligned with the roll pin hole of
the Body Ass'y [22] as illustrated in Fig. 18. First insert a roll pin puller (3 mm dia.) and hammer in the Roll Pin
D3 x 18 [50] after making sure that it can pass through the roll pin hole.
(If the roll pin is hammered in with the roll pin groove of Valve Bushing (A) [65] out of alignment with the roll pin
hole at the Body Ass'y [22], the circumferential area of Valve Bushing (A) [65] may be damaged, resulting in
difficulty of reassembly and disassembly.)
Valve Bushing (B) [56]
Hole
Wire
Roll pin hole
Body Ass'y [22]
Roll pin groove
Valve Bushing (A) [65]
Valve Bushing (A) [65]
Plunger (A) [63]
Fig. 18
Roll Pin D3 x 18 [50]
Make sure that Plunger (A) [63] moves smoothly after reassembly.
Charge grease in the O-ring groove.
Apply grease to the shaft.
--- 26 ---
Fig. 19
Tape [44]
Roll pin hole
Body Ass'y [22]
Wound end of the
Grip Tape [43]
(2) Winding the Grip Tape [43] and the Tape [44]
The Grip Tape [43] and the Tape [44] are self-adhesive. Peel the backing sheets off the Grip Tape [43] and
the Tape [44] before adhering them to the Body Ass'y [22]. First, adhere the end of the Grip Tape [43] near
the roll pin hole of the Body Ass'y [22] and start to wind it around the Body Ass'y [22]. When the winding is
completed, fix both wound ends of the Grip Tape [43] with the Tape [44] (Fig. 19). Be careful that the Grip
Tape [43] and the Tape [44] cannot be peeled off once they are adhered.
Tape [44]
Grip Tape [43]
Wound end of the Grip
Tape [43]
Overlapping amount
1.5 --- 3 mm
--- 27 ---
9-4. Disassembly and Reassembly of the Cap and the Magazine Section
[Tools required]
21 mm-width wrench Phillips head screwdriver Roll pin pullers (2.5 mm dia. and 4 mm dia.)
(1) Disassembly and reassembly of the cap unit
(a) Disassembly
The cap [46], united with the M42 screw, can be removed by gripping and turning it with a wrench.
(b) Reassembly
Proceed in reverse to the disassembly procedure, with lubricant applied to the O-ring (I.D 37.2) [45].
Fig. 20 Disassembly and reassembly of the cap and the magazine section
Nylon Nut M5 [42]
Cap [46]
Pin [81]
Pin [81]
Protector (B) [79]
Feeder Shaft Ring [82]
O-Ring (I.D 37.2) [45]
Hook [48]
Machine Screw (W/Washers)
M5 x 30 [49]
Magazine [83]
Feeder Shaft Ring [82]
Holder Cap (A) [85]
Magazine Cover [84]
Ratchet Spring [86]
Nail Holder [87]
Roll Pin D2.5 x 12 [88]
Holder Shaft [89]
Spring [90]
Convex
portion
Engaged
--- 28 ---
(2) Disassembly and reassembly of the Magazine Ass'y [105]
(a) Disassembly
Loosen the Machine Screw (W/Washers) M5 x 30 [49] securing the Body Ass'y [22]. Then the Magazine
Ass'y [105], the Hook [48] and Protector (B) [79] can be removed.
(b) Reassembly
Proceed in reverse to the disassembly procedure, fitting the convex portion of the Magazine [83] into the
Nose [33].
(3) Disassembly and reassembly of the Nail Holder [87], the Holder Shaft [89], etc.
(a) Disassembly
Remove the two Pins [81] with a roll pin puller (4 mm dia.). Then the Magazine [83] and the Magazine
Cover [84] can be removed. Remove Holder Cap (A) [85], and remove the Roll Pin D2.5 x 12 [88] with a
roll pin puller (2.5 mm dia.). Then the Nail Holder [87], the Holder Shaft [89] and the Spring [90] can be
removed.
(b) Reassembly
Proceed in reverse to the disassembly procedure, taking care of the following points.
Check that the Spring [90] is inserted between the concave portion of the Magazine [83] and the convex
portion of the Holder Shaft [89]. Then insert the Pin [81] when mounting the Holder Shaft [89] to the
Magazine [83] (Fig. 21).
Check that the Feeder Shaft Rings [82] (2 pcs.) are fitted in the grooves of the Pins [81] (2 pcs.). Be
careful not to lose the Feeder Shaft Rings [82].
Check the following after reassembly.
The Nail Holder [87] tilts when the Magazine Cover [84] is opened.
The Nail Holder [87] moves smoothly in the Magazine [83] when the Magazine Cover [84] is closed.
Nail Holder [87]
Convex portion of the
Holder Shaft [89]
Concave portion of
the Magazine [83]
Pin [81]
Spring [90]
Fig. 21
--- 29 ---
[Tools required]
5 mm hex. bar wrench
Roll pin puller (1.5 mm dia. and 4 mm dia.)
Retaining ring drawer for C type hole
9-5. Disassembly and Reassembly of the Driving Section
Fig. 22 Disassembly and reassembly of the driving section
(1) Disassembly and reassembly of the Nose [33] and Pushing Lever (A) [40]
(a) Disassembly
Remove the two Hex. Socket Hd. Bolts M6 x 20 [34]. Then the Nose [33] and Pushing Lever (A) [40] can
be removed.
Body Ass'y [22]
O-Ring (S-12) [24]
Adjuster Shaft [26]
Bolt Washer M4 [66]
Roll Pin D1.6 x 12 [68]
Adjuster
Knob [69]
Pushing Lever Guide [28]
Bumper [75]
Spring [74]
O-Ring (P-18) [73]
Feed Piston [72]
O-Ring (P-9) [71]
Latch [27]
Spring [29]
Pushing Lever (B) [30]
Adjuster [70]
Nose [33]
Hex. Socket Hd. Bolt M6 x 20
[34]
Needle Roller [35]
Roll Pin D4 x 14 [36]
Feeder Arm [37]
Feeder [39]
Feeder Spring [38]
Pushing Lever (A) [40]
Feed Piston Cover [76]
Retaining Ring for D24 Hole [77]
Magazine Bushing [78]
Adjuster Spring [67]
--- 30 ---
Fig. 24
Latch [27]
Window of Pushing
Lever (B) [30]
End surface of Pushing Lever (A) [40]
(b) Reassembly
Proceed in reverse to the disassembly procedure, taking care of the following points.
Before reassembly, check that the end surface of Pushing Lever (A) [40] is fitted in the opening of the
Pushing Lever Guide [28] (Fig. 23).
After reassembly, check that Pushing Lever (A) [40] operates smoothly.
Fig. 23
Opening of the Pushing Lever
Guide [28]
(2) Disassembly and reassembly of the adjuster
(a) Disassembly
Remove the Roll Pin D1.6 x 12 [68]. Then the Adjuster Knob [69], the Adjuster Spring [67], the Bolt Washer
M4 [66], the Latch [27], the Adjuster Shaft [26], the Spring [29], Pushing Lever (B) [30] and the Adjuster
[70] can be removed.
(b) Reassembly
Proceed in reverse to the disassembly procedure, taking care of the following points.
Align the dihedral width portion and the radius portion of the Latch [27] to the window of Pushing Lever (B)
[30] when reassembling (Fig. 24).
Mount the Adjuster [70] and the Adjuster Knob [69] as shown below (Fig. 25).
Apply the provided oil (SHELL TONNA S32 Oil) to Pushing Lever (B) [30] and the Bolt Washer M4 [66]
before reassembly.
After reassembly, check that the Adjuster [70] and Pushing Lever (B) [30] operate smoothly.
Adjuster [70]
Mount the Adjuster
Knob [69] in this
orientation.
Fig. 25
Radius
portion
Dihedral
width
portion
--- 31 ---
(3) Disassembly and reassembly of the Feeder [39] and the Feed Piston [72]
(a) Disassembly
Remove the Magazine [83] from the Body Ass'y [22] as indicated in item 9-4-(2).
Remove the Retaining Ring for D24 Hole [77] to take out the Feed Piston Cover [76], the Bumper [75]
and the Spring [74].
Pull out the Roll Pin D4 x 14 [36] to remove the Feed Piston [72] and the Feeder Arm [37].
Remove the Needle Roller [35] to remove the Feeder Arm [37] and the Feeder [39].
(b) Reassembly
Proceed in reverse to the disassembly procedure, taking care of the following points.
Broken chips from the Piston Bumper [21], if caught in the air passage of the Nose [33] and the feed
piston chamber, may make the movement of the Feed Piston [72] dull. Carefully clean with a clean rag
before reassembly.
Lubricate the O-Ring (P-9) [71] and the O-Ring (P-18) [73] before reassembly.
Move the O-Ring (P-18) [73] of the Feed Piston [72] toward right and fill the channel with lubricant.
Apply grease to the O-ring sliding surfaces of the Feed Piston [72] and the Nose [33] before reassembly,
though too much lubricant may make the feed piston movement sluggish.
Make sure that the Retaining Ring for D24 Hole [77] is completely received in the Nose [33] groove.
Push in the Roll Pin D4 x 14 [36] with its split end facing the magazine as indicated in Fig. 27.
Feed Piston [72]
O-Ring (P-18) [73]
Roll Pin D4 x 14 [36]
Split side
Feeder Arm [37]
Feed Piston [72]
Nose [33]
Groove
Retaining
Ring for
D24 Hole [77]
Fig. 27
Fig. 26
Apply grease.
Magazine
--- 32 ---
(3) Disassembly and reassembly of the Nail Guide [96] (See Fig. 28.)
(a) Disassembly
Remove the feeder unit from the output section as indicated in item 9-5-(1).
Remove the Nail Guide [96] by pulling up the Nail Guide Shaft [31] beyond the Nose [33].
Remove the Nylock Hex. Socket Hd. Bolt M4 x 10 [104] with the 3 mm dia. hex. bar wrench and remove the
Nail Guide Cover [101], the Cover [102] and the Springs [98] [100].
Then pull the Guide Lock [94] out of the Nail Guide [96] to remove Nail Stopper (A) [97] and Nail Stopper
(B) [99].
(b) Reassembly
Proceed in reverse to the disassembly procedure, taking care of the following points.
Carefully remove any dust stuck in the Nail Guide [96] before reassembly.
Degrease the Nail Guide [96] screw before tightening the Nylock Hex. Socket Hd. Bolt M4 x 10 [104].
After reassembly, push Nail Stopper (A) [97] and Nail Stopper (B) [99] with a finger and make sure that
they quickly return to position.
Mount the Nail Guide Shaft [31] facing the chamfered side upward.
O-Ring (P-4) [93]
Guide Lock [94]
Spring [98]
Nail Guide [96]
Nail Stopper (A) [97]
Spring [100]
Nail Stopper (B) [99]
Nail Guide Cover [101]
Cover [102]
Sleeve (B) [103]
Nylock Hex. Socket
Hd. Bolt M4 x 10 [104]
Nail Guide Shaft [31]
Nose [33]
[Tool required]
3 mm hex. bar wrench
Fig. 28 Disassembly and reassembly of the nail guide
Spring [95]
--- 33 ---
10. INSPECTION AND CONFIRMATION AFTER REASSEMBLY
Make sure that:
Plunger (A) [63] moves smoothly.
Pushing Lever (A) [40] moves smoothly.
Nail Stopper (A) [97] and Nail Stopper (B) [99] pushed with a finger completely return to position.
There is no air leak at any part of the assembly.
The main body is brought into operation by a simple pull on Trigger (A) [25] and by light pressure on
Pushing Lever (A) [40].
The Feed Piston [72] reliably operates with an air pressure of 4.9 bar (5 kgf/cm2, 70 psi). (Open the Nail
Guide and perform a nailing operation with no nail being fed.)
Nails do not jam and are not bent when nailed with an air pressure of 4.9 bar (5 kgf/cm2, 70 psi).
Note: Perform test-nailing with the Adjuster Knob [69] turned to the lowermost position.
The tightening torque for each screw is proper.
--- 34 ---
11. STANDARD REPAIR TIME (UNIT) SCHEDULES
MODEL 10 20 30 40 50 60 min.
Fixed
Variable
NV 50AF3
Work Flow
Exhaust Cover
Gasket (A)
Head Valve
Spring
Head Valve
O-Ring
Head Valve
(A)
Pushing
Lever (A)
Pushing Lever
Guide
Spring
Pushing
Lever (B)
Adjuster
Valve Bushing
(B)
Head Valve
O-ring
O-Ring x 6
Valve Piston
(B)
Plunger Spring
Plunger (A)
Valve Bushing
(A)
Adjustment
(
Cylinder, Body
and Valve)
Body Ass'y
Feed Piston
O-Ring x 2
Spring
Bumper
Feed Piston
Cover
Piston
Piston O-Ring
Piston Ring
Change Knob
(B)
Spring (C)
Feeder Arm
Feeder Spring
Feeder
Cylinder
O-Ring x 3
Cylinder Plate
Cylinder O-ring
Piston Bumper
Nose
Magazine Ass'y
Magazine Cover
Nail Holder
Guide Lock
Nail Guide
Nail Stopper (A)
Nail Stopper (B)
Nail Guide
Cover
General Assembly
PNEUMATIC TOOL PARTS LIST
LIST NO. E019
COIL NAILER
Model NV 50AF3
2005 • 1 •20
(E1)
Hitachi Power Tools
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45 46
47
48
49
50
51
52
53
54
11
56
57
58
59
60
61
62
63
64
65
66
67
68
69
50
70
71
72
73
74
75
76
77
78
79
81
82
81
82
83
84
85
86
87
88
89
90
93
94
95
96
97
98
99
105
501 502
503
504
505
506
507
55
80
91
92
100
101
102
103
104
*
ALTERNATIVE PARTS--- 2 ---
ITEM
NO.
CODE NO.
DESCRIPTION REMARKS
NO.
USED
PARTS
1 -- 05
NV 50AF3
1 949-819 HEX. SOCKET HD. BOLT M5X10 (10 PCS.) 1
2 944-260 WASHER 1
3 881-841 TOP COVER 1
4 881-840 HEAD RING 1
5 881-835 MUFFLER 1
*6 881-838 PROTECTOR (A) 1
*6 881-883 PROTECTOR (A) 1 FOR H/V
7 949-757 HEX. SOCKET HD. BOLT M5X20 (10 PCS.) 4
*8 881-879 EXHAUST COVER 1
*8 881-865 EXHAUST COVER 1 FOR H/V
9 881-839 GASKET (A) 1
10 881-851 HEAD VALVE SPRING 1
11 877-699 HEAD VALVE O-RING (I.D 16.8) 2
12 881-837 HEAD VALVE (A) 1
13 881-834 PISTON RING 1
14 881-833 PISTON O-RING 1
15 881-832 PISTON 1
16 990-067 O-RING (1AS-50) 1
17 881-831 CYLINDER PLATE 1
18 984-483 O-RING (S-36) 1
19 881-864 CYLINDER O-RING 1
20 881-829 CYLINDER 1
21 881-830 PISTON BUMPER 1
*22 881-877 BODY ASS’Y 1 INCLUD. 43, 44
*22 881-878 BODY ASS’Y 1 INCLUD. 43, 44 FOR H/V
23 955-479
RETAINING RING (E-TYPE) FOR D6 SHAFT
1
24 875-638 O-RING (S-12) 1
25 880-674 TRIGGER (A) 1
26 881-846 ADJUSTER SHAFT 1
27 881-847 LATCH 1
28 316-389 PUSHING LEVER GUIDE 1
29 881-882 SPRING 1
30 881-843 PUSHING LEVER (B) 1
31 881-811 NAIL GUIDE SHAFT 1
32 873-093 O-RING (1AP-3) 1
33 881-810 NOSE 1
34 949-660 HEX. SOCKET HD. BOLT M6X20 (10 PCS.) 2
35 983-545 NEEDLE ROLLER 1
36 949-770 ROLL PIN D4X14 (10 PCS.) 1
37 878-132 FEEDER ARM 1
38 878-340 FEEDER SPRING 1
39 881-818 FEEDER 1
40 881-819 PUSHING LEVER (A) 1
41 881-092 NOSE CAP (A) 1
42 877-371 NYLON NUT M5 1
43 880-408 GRIP TAPE 1
44 880-407 TAPE 2
45 880-183 O-RING (I.D 37.2) 1
*46 880-379 CAP 1
*46 882-162 CAP 1 FOR H/V
47 872-035 DUST CAP 1
*
ALTERNATIVE PARTS --- 3 ---
ITEM
NO.
CODE NO.
DESCRIPTION
REMARKS
NO.
USED
PARTS
1 -- 05
NV 50AF3
48 881-827 HOOK 1
49 880-881
MACHINE SCREW (W/WASHERS) M5X30 (BLACK)
1
50 949-518 ROLL PIN D3X18 (10 PCS.) 2
51 949-539 ROLL PIN D3X25 (10 PCS.) 1
52 959-155 STEEL BALL D3.97 (10 PCS.) 1
53 982-454 SPRING (C) 1
54 880-086 CHANGE KNOB (B) 1
*55 NAME PLATE 1 EXCEPT FOR H/V
56 878-881 VALVE BUSHING (B) 1
57 878-885 O-RING (S-18) 1
58 878-925 O-RING (I.D 8.8) 2
59 981-317 O-RING (S-4) 1
60 880-672 VALVE PISTON (B) 1
61 878-887 O-RING (I.D 11) 1
62 878-884 PLUNGER SPRING 1
63 880-673 PLUNGER (A) 1
64 878-888 O-RING (I.D 1.8) 1
65 880-671 VALVE BUSHING (A) 1
66 949-429 BOLT WASHER M4 (10 PCS.) 1
67 881-853 ADJUSTER SPRING 1
68 878-222 ROLL PIN D1.6X12 1
69 881-848 ADJUSTER KNOB 1
70 881-845 ADJUSTER 1
71 872-645 O-RING (P-9) 1
72 880-168 FEED PISTON 1
73 873-570 O-RING (P-18) 1
74 880-409 SPRING 1
75 877-476 BUMPER 1
76 880-170 FEED PISTON COVER 1
77 983-748 RETAINING RING FOR D24 HOLE 1
78 880-177 MAGAZINE BUSHING 1
79 881-850 PROTECTOR (B) 1
*80 878-183 WARNING LABEL 1 EXCEPT FOR H/V
81 881-825 PIN 2
82 877-826 FEEDER SHAFT RING 2
83 884-090 MAGAZINE 1
84 881-822 MAGAZINE COVER 1
85 881-003 HOLDER CAP (A) 1
86 880-398 RATCHET SPRING 1
87 881-824 NAIL HOLDER 1
88 878-791 ROLL PIN D2.5X12 1
89 881-823 HOLDER SHAFT 1
90 881-826 SPRING 1
*91 884-070 WARNING LABEL 1 EXCEPT FOR H/V
*92 883-513 WARNING LABEL(A) 1 EXCEPT FOR H/V
93 874-436 O-RING (P-4) 1
94 878-103 GUIDE LOCK 1
95 880-446 SPRING 1
96 881-812 NAIL GUIDE 1
97 881-813 NAIL STOPPER (A) 1
98 881-817 SPRING 1
*
ALTERNATIVE PARTS
--- 4 --- 1 -- 05
OPTIONAL ACCESSORIES
ITEM
NO.
CODE NO.
DESCRIPTION
REMARKS
NO.
USED
PARTS
ITEM
NO.
CODE NO.
DESCRIPTION REMARKS
NO.
USED
NV 50AF3
STANDARD ACCESSORIES
ITEM
NO.
CODE NO.
DESCRIPTION
REMARKS
NO.
USED
Printed in Japan
(050120N)
99 881-814 NAIL STOPPER (B) 1
100 880-393 SPRING 1
101 881-815 NAIL GUIDE COVER 1
102 881-816 COVER 1
103 878-337 SLEEVE (B) 1
104 880-413 NYLOCK HEX. SOCKET HD. BOLT M4X10 1
105 881-820 MAGAZINE ASS’Y 1 INCLUD. 81-90
501 944-459 HEX. BAR WRENCH 5MM 1
502 944-458 HEX. BAR WRENCH 4MM 1
503 943-277 HEX. BAR WRENCH 3MM 1
504 881-093 NOSE CAP (B) 1
505 877-153 PNEUMATIC TOOL LUBRICANT (30CC) 1
506 875-769 SAFETY GLASSES 1
* 507 881-849 CASE 1
* 507 881-881 CASE 1 FOR H/V
601 881-012 SEQUENTIAL TRIP MECHANISM SET 1
Loading...