Kitagawa NPG3 User manual

INSTRUCTION
MANUAL
MODEL NPG3
3-jaw Shield Gripper
・This Instruction Manual has been prepared for intended use for
production engineers and maintenance persons who operate this
product. When the beginners use this product, be sure to receive the
guidance from skilled persons, sales agents, or us in advance.
・Before installing, using, or maintaining this product, read carefully the
safety precautions given in this manual so as to understand them
completely. If you do not heed given instructions or safety
precautions, serious human accidents, death, or physical damage
may occur.
・Store this manual with care in the specified place at hand, and reread
it as necessary for correct use of the product.
・Please contact the sales agent if you have any uncertainty or doubt
about this manual.
DANGER
MA1381YHG2
Version1.02(20221226)

1
Preface
This manual provides detailed information on the 3-jaw shield gripper (model NPG3) so that
you can understand its performance and functions and use it safely and correctly.
Before using this gripper, read this manual carefully to understand how to use the gripper
correctly. Always follow the instructions and warnings given in “Important Safety
Precautions” and “Precautions for Use”. Failure to follow these precautions could result
in serious human accidents.
Terms and Symbols Used for Safety
Messages
In this manual, handling precautions that are considered especially important are classified
and displayed as shown below according to the degree of risk (seriousness of harm) that
could result. Please completely understand the meaning of these terms and follow the
instructions for safe operation.
Safety Alert Symbol
This triangle is a safety alert symbol used to alert you to potential safety hazards. To avoid
death or injuries that could occur, follow the safety messages given with this safety alert
symbol.
Failure to follow the safety precautions below will result
in death or serious injuries.
Failure to follow the safety precautions below could
result in death or serious injuries.
Failure to follow the safety precautions below may result
in minor or moderate injuries.
Indicates instructions which, if you do not heed given
instructions, could result in damage to the product or
shortened service life, or damage to peripheral
equipment.

2
Disclaimer and How to Use Instruction
Manual
This product is suitable for gripping a conveyed workpiece by being installed on the robot or
loader. The product is equipped with the jaws to grip the conveyed workpiece and they are
operated by air pressure. For any other applications, please contact us.
Kitagawa Corporation shall not be held liable for human accidents, death, damage, or loss
that occurred due to a failure to follow the safety precautions given in this manual.
This manual does not predict all potential hazards in operation, inspection, and
maintenance under all environmental conditions. There will be an infinite number of matters
that cannot or must not be done, and it is impossible for the manual to cover all of them.
Therefore, the matters, unless otherwise mentioned clearly as “can be done” or “may be
done” in this manual, should be considered as “cannot be done” or “must not be done”.
Please contact us or our agents if you have an uncertainty about safety when you try to
perform operation, inspection, or maintenance not mentioned in this manual.
Warranty and Disclaimer
The product is warranted for one year after the date of delivery.
All parts used shall be those delivered by Kitagawa Corporation. Kitagawa Corporation
shall not be held liable for human accidents, death, damage, or loss that occurred due to
the use of parts which are not genuine parts manufactured by Kitagawa. Also, the use of
parts other than Kitagawa’s genuine parts will void the warranty.

3
Contents
1. Structural Drawing and Parts List 4
1-1.Model indication
1-2.Structural drawing
1-3.Seal list
1-4.Parts list
2. Important Safety Precautions 6
3. Specifications 10
3-1.Specification table
3-2.Gripping force
4. Use 13
5. Design of Jaws 14
5-1. Designing jaws to be installed on the gripper
6. Installation 15
6-1.Installing the gripper
6-2.Installing the jaws
6-3. Connecting the air piping
6-4.Installing the switches
7. Maintenance and Checking 20
7-1.Periodic checking
7-2.Maintenance interval
7-3.Grease
7-4. Disassembly and assembly procedure
8. Troubleshooting 25
8-1.Problems and countermeasures
8-2.Contact address in case of trouble
9. Others 26
9-1.Standards and directives to which the gripper conforms
9-2.Disposal of gripper

4
1. Structural Drawing and Parts List
1-1. Model indication
The model indication is as follows:
NPG3 10
1-2. Structural drawing
1-3. Seal list
No.
型式
206
207
208
209
210
NPG310
O-ring SS5
O-ring S75
X-ring X126
X-ring X232
Seal washer 10S1
Series
Size
NPG3
NBR Seal
10
Master jaw
Plunger
Cover Seal
Rear cover
Piston
Cover
Body

5
１-４．Parts List
No.
部品名称
個数
No.
部品名称
個数
1
Body
1
202
Cover fixing bolt
6
2
Rear cover
1
203
Rear cover fixing bolt
3
3
Master jaw
3
204
Set screw
2
4
Plunger
1
205
Spring pin
1
5
Piston
1
206
O-ring Ａ
2
6
Cover
1
207
O-ring Ｂ
1
7
Cover seal
1
208
Jaw packing
3
8
Positioning bushing
12
209
Piston packing
1
210
Seal washer
1
201
Piston fixing bolt
1
211
Seal cap bolt
3
202
6
7
1
8
211
3
4
5
201
2
208
206
205
209
210
207
204
203
203
NPG310

6
2. Important Safety Precautions
Important safety precautions that particularly you should know or follow are summarized
below. Please read them before starting to use the product.
DANGER
Failure to follow the safety precautions below will result
in death or serious injuries.
Be sure to turn off the main power supply when installing, checking,
oiling, or replacing the gripper.
Also, shut down the air pressure in the work area.
●During work, the robot or gripper
could move abruptly and collide
with your body.
●After shutting down the air
pressure, release the air
pressure remaining inside the
gripper.
When installing, checking, oiling, or replacing the gripper, post a sign or
notice, or provide a fence, and so on to notify people around the machine
that work is in progress.
●Notify people around the machine that work is in progress and take measures to keep
people other than the operator out of the work area.
Machine motion not predicted by a third party could cause serious danger.
Take safety measures so that the operator is not injured even if the
conveyed workpiece flies out due to the reduced air pressure.
●Observe the legal safety
standards defined by each
country, such as installation of
safeguards or fall prevention
covers.
！
Main power
OFF
Air pressure
Close

7
DANGER
Failure to follow the safety precautions below will result
in death or serious injuries.
Do not modify the gripper.
●Not only the gripper is
damaged but also the
gripper and fixed workpiece
may fly out.
If using the gripper as a workpiece fixture when the workpiece is drilled,
deburred, welded, or modified additionally, confirm the specifications.
●If the gripper is used out of
the specifications, not only
the gripper is damaged but
also the fixed workpiece may
fly out.
Be sure to tighten the bolts with the specified torque.
●Lack of bolt quantity or
tightening torque, or
excessive torque could
damage the bolt, causing the
gripper or conveyed work
piece to fly out.
●When tightening the bolts, fix
the gripper so that it will not
rotate. Failure to do so may
result in injury by slipping
your hands when tightening
the bolts.
Gripper body fixing bolt
Boltsize
Tightening torque
M5
5.5
N･m
M6
10.8
N･m
M8
26.5
N･m
Piston fixing bolt
Boltsize
Tightening torque
M6
10.8
N･m
M8
26.5
N･m
Cover fixing bolt
Boltsize
Tightening torque
M4
2
N･m
M5
3.5
N･m
Rear body fixing bolt
Boltsize
Tightening torque
M5
4.8
N･m
M6
8.6
N･m

8
DANGER
Failure to follow the safety precautions below will result
in death or serious injuries.
Use the gripper in accordance with the legal safety standards.
●Use the gripper in accordance
with the legal safety standards
defined by each country, such as
installation of safeguards or
safety covers.

9
WARNING
Failure to follow the safety precautions below will
result in death or serious injuries.
Do not operate the machine after drinking alcohol or taking medicine.
●Impaired judgment or operation mistake
may cause serious hazards.
Do not wear clothing or accessories such as a necktie, necklace, etc.
which are easy to be caught in.
●You may be caught in the gripper.
Use the gripper within the range of specification values.
●When selecting a gripper, select the
model by referring to "Model selection"
in page 14.
●Have the gripper grip the conveyed
workpiece at the position of its center of
gravity.
●If not, not only the gripper is damaged
but also the conveyed workpiece may
fly out.
Alcohol
Medicine

10
3. Specifications
3-1. Specification table
Model
NPG
310
Fluid used
Air pressure
Operating air pressure
(MPa)
0.2～0.8
Ambient temperature
range
(℃)
5～60
Jaw stroke in diameter
(mm)
20
Cylinder internal volume
(reciprocation)
(cm3)
139.7
Repeatability
(mm)
±0.01
Body Mass
(kg)
2.1
Ambient humidity range
(%)
30～95
Storage temperature
range
(℃)
5～60
Noise level
(dB)
61
*Noise level is measured at a distance of 1m at four locations on
the front, rear, left, and right of the gripper.

11
3-2. Gripping force
①Standard for selecting a model
Perform the following calculation and select the model that provides a gripping force
exceeding the calculation result, though a gripping force varies depending on the
shapes of jaws created by the customer and conveyed workpiece or the friction
coefficient.
F=m（g+a）/μ
(Example) When mass of conveyed workpiece = 8 kg, friction coefficient = 0.1,
and robot acceleration = 10m/s2:
F=8（9.8+10）/0.1＝1584（N）
②Gripping force
●External gripping ●Internal gripping
Ｌ：Distance up to a grip point(mm)
●Expression of gripping force
A gripping force F shown in graph is actually
measured gripping force per jaw F1 x the number of
jaws.
(F=F1×3)
F = Gripping force (N)
m = Mass of conveyed workpiece (kg)
g = Gravitational acceleration (m/s2)
a = Acceleration of robot/loader (m/s2)
μ = Friction coefficient of gripping part
Internal gripping
External gripping
F1
F1
F1

12
●Determine the distance up to a grip point L as short as possible when designing
the jaws. Also, the distance up to a grip point L should be used within a range
shown in graph. If it is used out of the range, not only the specified gripping
force may not be obtained but also the wear of sliding parts may be increased.
■NPG310

13
4. Use
This product supplies pneumatic pressure to the unit to move the jaws in the open or
close direction for gripping the conveyed workpiece and transfers the conveyed
workpiece up to any location. After transfer, the jaws are moved in the close or open
direction for removing the conveyed workpiece.
●Do not modify the gripper. Using the modified product could cause unexpected
accidents. Kitagawa shall not be held liable for human accidents, death,
damage, or loss that occurred due to the modification.
●If using the gripper as a workpiece fixture when the workpiece is drilled,
deburred, welded, or modified additionally, confirm the specifications. If the
gripper is used out of the specifications, not only the gripper is damaged but
also the fixed workpiece may fly out.
●Wear appropriate clothing suitable for the work and wear gloves, safety
glasses, safety shoes, and helmet.
・Wearing inappropriate clothing causes the clothing to be stuck,
resulting in danger.
・Appropriate clothing will be preventive measures to prevent hazards
due to the carelessness or unexpected accidents during work.
●Do not use the product in the environment of corrosive chemicals, corrosive
gas, dust, and vibration, avoiding high temperature or direct sunlight.
●When storing the product, apply antirust treatment and then store it in a place
free from water leakage, dew condensation, or freeze.
●Increase the maintenance frequency when gripper is used in an environment
directly exposed to water or oil because the seal life will be reduced.

14
5. Design of Jaws
5-1. Designing jaws to be installed on the gripper
When designing jaws to be installed on the gripper, form the installation face to the
master jaw as shown below.
型式
A
B
C
D
E
F
G
H
NPG310
22.5
22.5
φ33.5
45.6
56.7
φ8
2
10
型式
Ｊ
Ｋ
Ｌ
Mounting bolt size
NPG310
12
4.5
3.5
M5

15
6. Installation
6-1. Installing the gripper
①Front face installation
Install the gripper body using
three fixing bolt holes and two
positioning pin holes.
The gripper fixing adapter, gripper
fixing bolts, and positioning pins
are to be prepared by the
customer.
【Note】
Interference may occur between the adapter and reed switch during installation.
Take measures such as making holes in the adapter to prevent interference.
Model
NPG
310
Gripper fixing bolt size
M6
Positioning
pin hole
Diameter
(0+0.025）
(mm)
φ5
Depth
(mm)
12(18.6)
* Dimensions in ( ) indicate the depth from the mounting surface.
②Rear face installation
Install the gripper body using
three fixing bolt holes and two
positioning pin holes.
The gripper fixing adapter, gripper
fixing bolts, and positioning pins
are to be prepared by the
customer.
【Note】
Interference may occur between the adapter and reed switch during installation.
Take measures such as making holes in the adapter to prevent interference.
Gripper fixing adapter
（To be prepared
by the customer）
Positioning pin
（To be prepared by
the customer）
Gripper fixing bolt
（To be prepared by the
customer）
Gripper fixing adapter
（To be prepared by the
customer）
Positioning pin
（To be prepared by the
customer）
Fixing bolt
（To be prepared by the customer）

16
Model
NPG
310
Gripper
fixing bolt
Size
M8
Thread
depth
(mm)
14(20.6)
Positioning
pin hole
Diameter
(0+0.025）
(mm)
φ6
Depth
(mm)
12(18.6)
* Dimensions in ( ) indicate the depth from the mounting surface.
③Center surface installation
Install the gripper body using the
six fixing bolt holes and two
positioning pin holes.
The gripper fixing adapter, gripper
fixing bolts, and positioning pins
are to be prepared by the
customer.
【Note】
Interference may occur between the adapter and reed switch during installation.
Take measures such as making holes in the adapter to prevent interference.
Model
NPG
310
Gripper fixing bolt
M5
Positioning
pin hole
Diameter
(0+0.025）
(mm)
φ5
Depth
(mm)
7
* Dimensions in ( ) indicate the depth from the mounting surface.
●Be sure to tighten the bolts with the specified torque. Lack of tightening torque
or excessive torque could break the bolts, causing the gripper or conveyed
workpiece to fly out.
Gripper fixing adapter
（To be prepared by the customer）
Positioning pin
（To be prepared by the customer）
Fixing bolt
（To be prepared by the customer）

17
6-2. Installing the jaws
Install the jaws using four mounting bolt holes, spigot joint and positioning bushing
holes. The jaws, jaw fixing bolts, and positioning bushings are to be prepared by the
customer.
Model
NPG
310
Mounting
bolt
Size
M5
Thread
depth
A(mm)
10
Positioning
pin hole
Diameter
（H8）
B(mm)
φ8
Depth
C(mm)
2
●Be sure to tighten the bolts with the specified torque. Be sure to tighten the
bolts with the specified torque. Lack of tightening torque or excessive torque
could break the bolts, causing the jaws or conveyed workpiece to fly out.
●Before installing the jaws, disconnect the air piping.

18
6-3. Connecting the air piping
The air pressure supply ports to open and close the gripper jaws are provided on
the side face and rear face of the body.
When using the supply port on the side face of the body, connect the air piping
directly.
When using the supply port on the rear face of the body, remove the setscrew,
which is attached at the delivery to prevent air leakage, and supply air from the
adapter to fix the gripper.
The screws to close the open/close ports on the side face of the body are to be
prepared by the customer.
Model
NPG
310
Port size on body side face
M5
Port size on body rear face
M5
●The setscrews in the air pressure supply ports on the body rear face are
mounted with adhesive applied to them to prevent air leakage, so it is very
difficult to remove them. Therefore, when removing the setscrews, be careful
not to damage them.
●After removing the setscrews, take away adhesive fixed to the body screw hole
clearly. Be careful not to drip the adhesive into the cylinder.
●Be sure to shut off the air pressure before connecting the air piping.
Open port
Body
Rear Cover
Close port