Hitachi NV 45AC Manual

POWER TOOLS
TECHNICAL DATA
AND
SERVICE MANUAL
COIL NAILER
NV 45AC
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
LIST No. 1098 Nov. 2000
N
MODEL
NV 45AC

Page
CONTENTS
1. PRODUCT NAME.............................................................................................................................. 1
2. MARKETING OBJECTIVE ................................................................................................................ 1
3. APPLICATIONS................................................................................................................................. 1
4. SELLING POINTS ............................................................................................................................. 1
5. SPECIFICATIONS ............................................................................................................................. 2
5-1. Specifications ......................................................................................................................................2
5-2. Nail Selection ......................................................................................................................................3
5-3. Nail Driving Force ...............................................................................................................................4
5-4. Optional Accessories ..........................................................................................................................5
6. COMPARISONS WITH SIMILAR PRODUCTS ................................................................................. 6
7. PRECAUTIONS IN SALES PROMOTION ........................................................................................ 7
7-1. Instruction Manual ..............................................................................................................................7
7-2. Warning Label .....................................................................................................................................7
7-3. Related Laws and Regulations ...........................................................................................................8
8. MECHANISM AND OPERATION PRINCIPLE .................................................................................. 8
8-1. Mechanism .........................................................................................................................................8
8-2. Operation Principle ...........................................................................................................................10
9. TROUBLESHOOTING GUIDE ........................................................................................................12
9-1. Troubleshooting and Correction ........................................................................................................12
9-2. Possible Causes and Corrections of Air Leakage .............................................................................17
10. DISASSEMBLY AND REASSEMBLY ........................................................................................... 19
10-1. General Precautions in Disassembly and Reassembly ..................................................................19
10-2. Disassembly and Reassembly of the Output Section .....................................................................20
10-3. Disassembly and Reassembly of the Control Valve Section ..........................................................22
10-4. Disassembly and Reassembly of the Driving Section ....................................................................25
10-5. Disassembly and Reassembly of the Cap and the Magazine Section ...........................................29
11. INSPECTION AND CONFIRMATION AFTER REASSEMBLY ..................................................... 32
12. STANDARD REPAIR TIME (UNIT) SCHEDULES ........................................................................ 33
[ Appendix]
Assembly Diagram for NV 45AC .............................................................................................................34

--- 1 ---
1. PRODUCT NAME
Hitachi 1-3/4" Coil Nailer, Model NV 45AC
2. MARKETING OBJECTIVE
The current Model NV 45AB coil nailer is well-reputed in the U.S.A. market as a roofing nailer suitable for roofing
asphalt shingles in building construction. However, competitively priced roofing nailers have been put on the
U.S.A. market recently. The newly developed Model NV 45AC is specifically designed for roofing asphalt shingles
and weighs just 1.7 kg (3.7 lbs.). Please expand our market share with the new Model NV 45AC.
The Model NV 45AC is a medium-duty roofing coil nailer capable of asphalt shingles with 25 --- 45 mm length nails
after heavy-duty Model NV 45AB for 22 --- 45 mm length nails.
3. APPLICATIONS
Installation of asphalt roofing shingles in building construction
4. SELLING POINTS
Nailing depth adjustment
mechanism with an easy-
to-see calibrated dial
Rubber grip for comfort and
temperature protection
Rubber protector protects
tool and prevents sliding
Exhaust direction easily
changeable
Lightweight 1.7 kg (3.7 lbs.) for easy one-handed operation

--- 2 ---
Optional accessories
Nail capacity
1.7 kg (3.7 lbs.)
1.0 ltr/cycle at 6.9 bar (1.0 ltr/cycle at 7 kgf/cm2) (0.035 ft3/cycle at 100 psi)
Corrugated cardboard box
3 nails/sec.
Driving speed
241 mm x 269 mm x 124 mm
(9-1/2" x 10-19/32" x 4-7/8")
120 nails (1 coil)
Dimensions
(Length x Height x Width)
Nail feed system
3/8 NPT thread
Standard accessories
Weight
Spiral spring
Air consumption
Air inlet
Package dimensions
(Length x Height x Width)
Packaging
280 mm x 290 mm x 150 mm
(11-1/32" x 11-13/32" x 5-29/32")
Eye protector (Code No. 875769) .............................................................. 1
Hex. bar wrench for M6 screw (Code No. 944459) .................................... 1
Hex. bar wrench for M5 screw (Code No. 944458) .................................... 1
Sequential trip mechanism kit (Single-shot) (Code No. 881973)
Muffler (Code No. 881835)
Shingle guide
Shingle guide (Code No. 878175)
Guide base (Code No. 878176)
Washer (Code No. 949424)
Plate nut (Code No. 878213)
Hexagon socket hd. bolt M5 x 16 (Code No. 949819)
Pneumatic tool lubricant (1 oz oil feeder) (Code No. 877153)
Pneumatic tool lubricant (4 oz oil feeder) (Code No. 872042)
Pneumatic tool lubricant (1 quart can) (Code No. 876212)
5. SPECIFICATIONS
5-1. Specifications
Reciprocating piston type
Model
Driving system
NV 45AC
Operating pressure 4.9 --- 8.3 bar (5 --- 8.5 kgf/cm2, 70 --- 120 psi) (Gauge pressure)

--- 3 ---
10.5 mm
(0.413")
5-2. Nail Selection
The Model NV 45AC utilizes roofing nails which are common round-head nails collated by wire into coils from 120
nails. Applicable nail dimensions are shown below. However, it is recommended to use genuine HITACHI nails to
ensure satisfactory driving quality. For nail length 22 mm (7/8"), recommend the Model NV 45AB instead of this
Model NV 45AC.
CAUTION: Ensure that nails are as specified in Fig. 1. Other nails will cause clogging of nails and
subsequent damage to the nailer.
3.05 mm
(0.120")
25 mm (1")
Min.
Wire-collated nails
Fig. 1 Dimensions of nails
Max.
10.5 mm
(0.413")
45 mm (1-3/4")
3.05 mm
(0.120")

--- 4 ---
Porter Cable RN175
Senco SCN40R
Hitachi NV 45AB
5-3. Nail Driving Force
Fig. 2 shows by type of wood and nail the nailer output energy provided by the supply pressure and the nailing
energy required for driving the nail flush. Air pressure which exceeds the intersecting point between the nailer
output energy and the required nailing energy for driving the nail allows the nail to be fully driven.
For example, when driving a nail of 3.05 mm dia. x 45 mm length (0.120" x 1-3/4") into a workpiece of hemlock
with the Model NV 45AC, a pressure of about 6.9 bar (7 kgf/cm2, 100 psi) allows the nailer to drive the nail flush
with the wood surface. A pressure beyond this value causes the nail head to be driven below the wood surface.
Fig. 2 should be used as a reference only because those values vary depending on the type of wood, moisture
content, and grain of wood.
Fig. 2 Required nailing energy and nailer output energy
Max CN450R
Bostitch N63CP
NV 45AC
Hemlock

--- 5 ---
5-4. Optional Accessories
(1) Sequential trip mechanism kit
The sequential trip mechanism kit is provided as an optional accessory for the Model NV 45AC. When using
this optional accessory, a nail is driven by pressing the push lever first against a workpiece and then pulling
the trigger, and no nail is driven when pulling the trigger first and then pressing the push lever against a
workpiece (single-shot operation). Please recommend the sequential trip mechanism kit to customers who
may want to use it. Salespersons must instruct the customers to read thoroughly the Instruction Manual
attached to the sequential trip mechanism kit and also the Handling Instructions of the Model NV 45AC for
correct use.
(2) Muffler
The muffler is provided as an optional accessory for the Model NV 45AC. By mounting this muffler, the
exhaust sound is reduced by about 10 dB (A). Please recommend the muffler to customers who may want to
use it. The muffler can be mounted according to the following procedure as shown in Fig. 3.
1. Remove the hex. socket hd. bolt M5 x 10.
2. Put the muffler in the head ring with the convex side facing the top cover.
3. Fit the convex portion of the exhaust cover in the concave portion of the top cover.
4. Secure it with the hex. socket hd. bolt M5 x 10.
Exhaust cover
Washer
Top cover
Concave portion of top cover
Muffler
Head ring
Convex portion of muffler
Convex portion of exhaust cover
Hex. socket hd. bolt
M5 x 10
Fig. 3 Mounting of muffer

--- 6 ---
Maker BOSTITCH
HITACHI SENCO PORTER CABLE MAX
Air consumption at 6.9
bar (7 kgf/cm2, 100 psi)
Operating pressure
Driving depth
adjustment mechanism
Direction change of
exhaust air
Magazine type
(Material)
Tool not required
Weight
Dimensions
(L x H x W)
Replaceable anti-slip
protector
Trigger lock mechanism
Exhaust muffler
Handle grip
Shank dia.
Applicable
nails
Head dia.
Collation
Length
4.9 --- 8.3 bar
(5 --- 8.5 kgf/cm2)
(70 --- 120 psi)
241 mm x 269 mm x 124 mm
(9-1/2" x 10-19/32" x 4-7/8")
250 mm x 264 mm x 124 mm
(9-27/32" x 10-13/32" x 4-7/8")
277 mm x 269 mm x 117 mm
(10-29/32" x 10-19/32" x 4-19/32")
248 mm x 264 mm x 117 mm
(9-3/4" x 10-13/32" x 4-19/32")
Model name
25 mm -- 45 mm
(1" -- 1-3/4")
NV 45AC NV 45AB RN45B SCN40R RN175 CN450R
4.9 --- 6.9 bar
(5 ---7 kgf/cm2)
(70 --100 psi)
4.9 --8.3 bar
(5 --8.5 kgf/cm2)
(70 --120 psi)
4.9 --8.3 bar
(5 --8.5 kgf/cm2)
(70 --120 psi)
4.5 -- 6.9 bar
(4.6 -- 7 kgf/cm2)
(65 --100 psi)
1.0 ltr/cycle
(0.035 ft3/cycle) 1.2 ltr/cycle
(0.042 ft3/cycle) 1.8 ltr/cycle
(0.064 ft3/cycle) 1.3 ltr/cycle
(0.046 ft3/cycle) 1.4 ltr/cycle
(0.049 ft3/cycle) 2.0 ltr/cycle
(0.070 ft3/cycle)
120 nails 120 nails 120 nails 120 nails 120 nails
Bottom loading
(Plastic) Top loading
(Plastic) Top loading
(Plastic) Top loading
(Plastic) Top loading
(Plastic)
Nail capacity
None Tool required None Tool not required None
Provided
None
Provided
Tool not required Tool not required Tool not required
Provided Provided None
None
None
Racket grip
(Comfortable grip)
Wire
10.5 mm (0.413")
3.05 mm (0.120")
None
Rubber
(Not elastic)
Wire
3.05 mm (0.120")
None
Provided
Foam rubber
(Apt to peel off)
Wire
None
None
Rubber
(Not elastic)
Wire
Provided
Provided
Rubber
(Not elastic)
Wire
10 mm (0.394")
3.05 mm (0.120")
19 mm --- 38 mm
(3/4" --- 1-1/2")
9.8 mm (0.385")
3.05 mm (0.120")
22 mm -- 45 mm
(7/8" -- 1-3/4")
10.5 mm (0.413")
3.05 mm (0.120")
19 mm -- 45 mm
(3/4" -- 1-3/4")
10.5 mm (0.413")
19 mm -- 45 mm
(3/4" -- 1-3/4")
22 mm -- 45 mm
(7/8" -- 1-3/4")
1.7 kg (3.7 lbs.) 2.5 kg (5.5 lbs.) 2.7 kg (6.0 lbs.) 2.4 kg (5.3 lbs.) 2.3 kg (5.1 lbs.) 2.5 kg (5.5 lbs.)
None
Optional
275 mm x 268 mm x 111 mm
(10-13/16" x 10-9/16" x 4-3/8")
300 mm x 257 mm x 110 mm
(11-13/16" x 10-1/8" x 4-11/32")
6. COMPARISONS WITH SIMILAR PRODUCTS
Tool not required Tool not required
None

--- 7 ---
7. PRECAUTIONS IN SALES PROMOTION
In the interest of promoting the safest and most efficient use of the Model NV 45 AC 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 Instruction Manual, and fully understands the meaning of the precautions
listed on the Warning Label attached to each tool.
7-1. Instruction Manual
Although every effort is made in each step of the 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, general precautions and suggestions for use of pneumatic tools, and specific precautions and
suggestions for the use of the pneumatic nailer are listed in the Instruction Manual to enhance the safe, efficient
use of the tool by the customer.
Salespersons must be thoroughly familiar with the contents of the Instruction Manual to be able to offer
appropriate guidance to the customers during sales promotion.
7-2. Warning Label
Each Model NV 45AC unit is provided with a Warning Label (illustrated below) which lists basic safety precautions
in its use. Carefully ensure that customers fully understand and follow these precautions before using the tool.

--- 8 ---
7-3. 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 Instruction Manual
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 properly advise the customer. Please check your national
and/or local regulations for applicable items. Some applicable items are outlined below.
The U.S.A:
OSHA 1926.102 Eye and face protection
1926.302 Power-operated hand tools
ANSI SNT-101-1993 Portable, Compressed-Air-Actuated,
Fastener Driving Tools-Safety Requirements for
8. MECHANISM AND OPERATION PRINCIPLE
8-1. Mechanism
As illustrated in Fig. 4, NV 45AC can be generally divided into four sections: output section, control valve section,
driving section and magazine section. Most of the parts of the above sections have been newly designed, though
its basic construction is the same as that of the Model NV 50AG. Primary differences from the Model NV 50AG
are described below.
Output section ................... Most of the parts have been newly designed, though its basic construction is the
same as that of the Model NV 50AG. The piston unit employs O-rings at the
sliding portion in the same manner as the Model NV 45AB instead of a piston
ring. The protector has been newly designed to prevent slipping of tool.
Control valve section .......... This section is common to the Models NR 90AC and NV 65AH.
Driving section .................... The adjuster has been newly designed to improve operability in nailing depth
adjustment.
The plastic guard shielding the pushing lever and the feed piston has been newly
designed to prevent adhesion of dust.
Magazine section ................ This section is common to the Model NV 45AB, though the shingle guide is not
provided. The shingle guide is interchangeable between the Model NV 45AB and
the Model NV 45AC.