Amada MH-1201A User manual

Z09M0612E-07
OPERATION MANUAL
RESISTANCE WELDING HEAD
MH-1201A

MH-1201A
1
Thank you for purchasing our Resistance Welding Head MH-1201A.
・This operation manual explains its method of operation and precautions for use.
・Before using, read this operation manual carefully; after reading, save it in a proper place
where you can easily access.
Contents
1. Special Precautions ................................................1-1 to 1-4
2. Features ...................................................................2-1
3. Specifications and Accessories.............................3-1 to 3-2
4. Name and Functions of Each Section ...................4-1 to 4-5
5. Piping System Diagrams ........................................5-1
6. Installation and Connection ...................................6-1 to 6-8
7. User’s Maintenance.................................................7-1 to 7-3
8. Outline Drawing ....................................................... 8-1 to 8-4

MH-1201A
1. Special Precautions
1-1
1. Special Precautions
(1) Safety Precautions
Before using, read "Safety Precautions"
carefully to understand the correct method
of use.
■These precautions are shown for safe use
of our products and for prevention of
damage or injury to operators or others.
Be sure to read each of them, since all of
them are important for safety.
■The meaning of the words and symbols is
as follows.
These symbols denote
"prohibition".
They are warnings about
actions out of the scope of the
warranty of the product.
These symbols denote actions
which operators must take.
Each symbol with a triangle
denotes that the content gives
notice of DANGER, WARNING
or CAUTION to the operator.
Denotes operations and practices that
may imminently result in serious injury
or loss of life if not correctly followed.
Denotes operations and practices that
may result in serious injury or loss of
life if not correctly followed.
Denotes operations and practices that
may result in personal injury or damage
to the equipment if not correctly followed.
Never disassemble, repair or modify the Welding Head
These actions can cause electric shock and fire. Do not do anything other than
the maintenance described in the operation manual.
Never burn, destroy, cut, crush or chemically decompose the Welding Head
This product incorporates parts containing gallium arsenide (GaAs).
DANGER
！
WARNING
！
CAUTION
！
DANGER
！

MH-1201A
1. Special Precautions
1-2
Do not put your hands between the electrodes
When welding, keep your fingers and hands away from the electrodes.
Do not touch any welded part or electrodes during welding and just after
welding finished
The welded part of a workpiece, electrodes and electrode holder are very hot.
Do not touch them; otherwise you may be burnt.
Do not touch electrode when supplying or exhausting high-pressure air
Upper electrode may move forcefully. Be careful not to have your finger and tool
pinched.
Use proper tools (wire strippers, pressure wire connectors, etc) for
termination of the connecting cables
Do not cut the conductor of wire. A flaw on it can cause fire and electric shock.
Do not damage the power cable and connecting cables
Do not tread on, twist or tense any cable. The power cable and connecting
cables may be broken, and that can cause electric shock and fire.
When you need any repair or replacement, consult us or your distributor.
Connect the specified cables securely
Cables of insufficient current capacities and loose connections can cause fire
and electric shock.
Stop the operation if any trouble occurs
Continuous operation after occurrence of a trouble such as burning smell,
abnormal sound, abnormal heat, smoke, etc. can cause electric shock and fire.
If such a trouble occurs, immediately consult us or your distributor.
Persons with pacemakers must stay clear of the welding machine
A person who uses a pacemaker must not approach the welding machine or
walk around the welding shop while the welding machine is in operation, without
being permitted by his/her doctor. The welding machine generates a magnetic
field and has effects on the operation of the pacemaker while it is turned on.
Wear protective glasses
If you look at the surface flash and expulsion directly during welding, your eyes
may be damaged.
WARNING
！

MH-1201A
1. Special Precautions
1-3
Apply the specified source voltage
Application of a voltage out of the specified range can cause fire and electric
shock.
Do not splash water on the Welding Head
Water splashed over the electric parts can cause electric shock and short
circuits.
Install the Welding Head on firm, level surface.
If the Welding Head falls or drops, injury may result.
Keep combustible matter away from the welding machine.
Surface flash and expulsion can ignite combustible matter. If it is impossible to
remove all combustible matter, cover them with non-combustible material.
Do not cover the Welding Head with a blanket, cloth, etc.
If such a cover is used, it may be overheated and burn.
Keep a fire extinguisher nearby.
Keep a fire extinguisher in the welding shop in case of fire.
Maintain and inspect the Welding Head periodically.
Maintain and inspect the Welding Head periodically, and repair any damage
nearby before starting operation.
Protective gear must be worn
Put on protective gear such as protective gloves, long-sleeve jacket, leather
apron, etc. Surface flash and expulsion can burn the skin if they touch the skin.
Do not use this Welding Head for purposes other than welding
Use of this Welding Head in a manner other than specified can cause electric
shock and fire.
CAUTION
！

MH-1201A
1. Special Precautions
1-4
(2) Precautions for Handling
■Do not install this Welding Head in the following:
・Damp places where humidity is 90% or higher,
・Dusty places,
・Places where chemicals are handled,
・Places near a high noise source,
・Hot or cold places where temperatures are above 40°C or below 5°C, and
・Places where water will be condensed.
■ Clean the outside of the Welding Head with a soft, dry cloth or one wet with a
little water. If it is very dirty, use diluted neutral detergent or alcohol. Do not use
paint thinner, benzine, etc., since they can discolor or deform the Welding Head.
■ Do not put anything other than a workpiece, e.g., a tool, a screw, etc., between
the electrodes. It can cause serious trouble.
■Do not put a screw, a coin, etc., in the Welding Head, since they can cause a
malfunction.
■Operate the Welding Head according to the method described in this operation
manual.
(3) On Disposal
This product incorporates parts containing gallium arsenide (GaAs). At the time of
disposal, separate it from general industrial waste or domestic waste and carry out
the disposal in accordance with applicable laws and regulations.

MH-1201A
2. Features
2-1
2. Features
The MH-1201A Precision Resistance Welding Head has the following features:
■Since the electrode force can be adjusted continuously, parameter setting can
be made finely.
■Since the response (follow-up) of the electrode is fast, explosive flashes and
indentation are not produced, and the workpiece surfaces are finished clean.
■The durable construction provides high reliability and stable weld quality.
■100
V AC- and 24 V DC-rated solenoid valve are available.

MH-1201A
3. Specifications and Accessories
3-1
3. Specifications and Accessories
(1) Specifications
Items
MH-1201A
-00
MH-1201A
-41
MH-1201A
-10
MH-1201A
-20
MH-1201A
-50
Electrode Force 300 to 1200
N (Approx. 30 to 120 kgf) (Continuously adjustable)
Forcing Method Spring
Electrode Provided None
Electrode Diameter φ8
mm φ12 mm *1
Electrode Stroke 35
mm
Throat Depth 74
mm ―74 mm
Electrode-Driving
Method
Air Cylinder
Solenoid Valve
Operating Voltage
(Power Consumption)
100 V AC
(0.9
W)
24
V DC
(0.5
W) ―*2 100
V AC
(0.9
W)
Welding Current 10000
A (at 2% Duty Cycle) *3
Load Cell Not mountable Mounted Not mountable
Frame Provided None Provided
Mass 30
kg 11 kg 30 kg
Air Supply Pressure 0.5 to 0.7
MPa (Fluid: Air)
(2) Accessories
Check that all of the following accessories are provided.
Accessory
Name Specification
MH-1201A
-00
MH-1201A
-41
MH-1201A
-10
MH-1201A
-20
MH-1201A
-50
Electrode φ8
mm 2 pcs 1 pc None *1
Hexagon
Socket Head
Bolt
M8 x 35 4 pcs None 4 pcs
Plain
Washer
For M8 8 pcs None 8 pcs
Spring
Washer
For M8 4 pcs None 4 pcs
T-Nut ST TST8 (Imao
Corp.-made) 4 pcs None 4 pcs
Hexagon
Socket
Screw Key
For M8
(Nominal size
6)
1 pc
Single
Open-Ended
Spanner
Nominal size
6 1 pc None
Operation
Manual
―1 copy
Digital
Indicator
NTS-4231 None 1 pc None

MH-1201A
3. Specifications and Accessories
3-2
*1: The Electrode of the MH-1201A-50 is user provided.
*2: The solenoid and regulator of the MH-1201A-20 are user provided. For the
recommendation, see 6. Installation and Connection.
*3: See “Welding Current vs. Duty Cycle” (p.3-2) for details of current and duty cycle.
(3) Welding Current vs. Duty Cycle
[Cable and copper wire]
・Air-cooled cable: 180
mm2x 1000 mm (1 cable)
・Flat-braided copper wire (1): 200
mm2x 1000 mm (2 wires)
・Flat-braided copper wire (2): 200
mm2x 1000 mm (1 wire)
[Measurement condition]
・Welding power supply: IS-800A (400
V AC power supply)
・Welding transformer: ITH-1050C6W
・Cooling water: 20°C (1
L/min.)
Flat-braided
copper wire (1)
Water-cooled cable
1
05432
2
4
6
8
10
Welding Current
(%)
(kA)
Duty Cycle
Flat-braided
copper wire (2)

MH-1201A
4. Name and Functions of Each Section
4-1
4. Name and Functions of Each Section
NOTE: Hose, tube, etc. are not shown in
figures.
①Electrode (Material: CrCu)
For spot welding.
②Water-Cooled Shank
Water-cooled
holder to secure the Elec-
trode.
③Electrode Holder (A)
Secures the Water-Cooled Shank.
④Fixing Screw for Electrode Holder (A)
Secures the Electrode Holder (A).
⑤Electrode Holder (B)
Secures the Water-Cooled Shank.
⑥Water-Cooled Shank-Fixing Screw
Secures the Water-Cooled Shank. Loosen
for Electrode height adjustment.
⑦Head-Fixing Channel
For securing the MH-1201A onto work-
bench.
Figure 4-1
CAUTION
When operating, do not place any metallic
items around the Welding Head. If a
screwdriver, a wire, etc., touches the
metallic
parts of ○
1
to ○
4during operation,
it ma
y
be welded to the Weldin
g
Head.
①
⑥
⑦
⑥
Front View
④
③
②
⑤

MH-1201A
4. Name and Functions of Each Section
4-2
⑧Speed Controller 1
Adjusts Electrode-Up speed.
⑨Speed Controller 2
Adjusts Electrode-Down
speed.
⑩Solenoid Valve
Changeover valve to control
the flow of air.
⑪Cooling Water Intake
Accepts the cooling water.
Tube Specifications
Model No.
MH-1201A
-00/-41/-10/
-20
MH-1201A
-50
Outer Dia. φ6 mm φ10 mm
Inner Dia. φ4 mm φ6.5 mm
Material Nylon, Soft Nylon,
Polyurethane
⑫Cooling Water Outlet
Exhausts the cooling water.
(The tube specifications are
same as ○
11 )
⑬[IN] Port
Intake of the high-pressure air.
Connects the primary tubing.
Tube Specifications
(Common to all models)
Outer Dia. φ10 mm
Inner Dia. φ6.5 mm
Material Nylon, Soft Nylon,
Polyurethane
⑭Regulator
Decreases the pressure to
necessary value, adjusting
the weld force.
⑮Lock Nut
Secures the Knob.
⑯Knob
Adjusts the air pressure,
setting the necessary force.
⑰Feeder Bar (Upper) (φ11 mm secondary-cable-connecting hole)
Terminal plate to connect the secondary cable. Feeds current to the upper
electrode.
⑱Feeder Bar (Lower) (φ11 mm secondary-cable-connecting hole)
Terminal plate to connect the secondary cable. Feeds current to the lower
electrode.
⑫
⑪
⑲
⑫
⑱
⑰
⑭
⑬
⑩
⑧
⑨
Side View
⑲
⑪
⑯
⑮
⑲
Figure 4-2

MH-1201A
4. Name and Functions of Each Section
4-3
⑲Frames
Support the Welding Head.
The welding current flows through
the Frames. Do not place metallic
items, such as watches, tools around
the Frames during operation since
they may be broken and may injure
you.
⑳Solenoid Valve Cable
Feeds power to the solenoid valve.
MH-1201A-10 has red cable (+) and black cable
(-).
Other models have no polarity.
○
21 Fixing Screw for Electrode Holder (B)
Secures the Electrode Holder (B).
○
22 Connecting Threaded Holes
Connects Voltage-Detecting Cable (see p.6-3).
M3 and 8
mm in depth.
Figure 4-3
Figure 4-4
CAUTION
！
Rear View
⑳
21
22

MH-1201A
4. Name and Functions of Each Section
4-4
Figure 4-5
○
23 Load Cell Cable
Connects to the indicator.
This is attached to the MH-1201A-41.
23

MH-1201A
4. Name and Functions of Each Section
4-5
○
24 Head-Mounting Hole
M6 and 15 mm in depth.
○
25 Feeder Terminal
Connects the secondary cable.
Figure 4-6
30 30
31
MH-1201A-20 Rear View

MH-1201A
5. Piping System Diagrams
5-1
5. Piping System Diagrams
Air Piping System Diagram
Do not touch the Electrode when feeding and exhausting
high-pressure air
The upper electrode may move forcefully; be careful not to have your
hand and tools pinched.
Cooling Water Piping System Diagram
CAUTION
！
Regulator
ＡＢ
Water-cooled shank
Cooling Water Intake
Cooling Water Outlet
Cooling Water Outlet
Cooling Water Intake

MH-1201A
6. Installation and Connection
6-1
6. Installation and Connection
Before using your MH-1201A, install it according to the following procedures.
When using, secure the Welding Head firmly.
If you use it not secured, it may cause injury due to its fall and degraded weld
quality.
(1) Determining Where to Install
Determine where to install the MH-1201A, welding power supply and welding
transformer.
(2) Drilling Mounting Holes
Drill mounting holes on the workbench to secure the MH-1201A. When drilling, see
the Head-Mounting Dimensions (Figure 6-2).
(3) Positioning T-Nuts
Place the T-Nuts at the determined positions referring to the drawing below.
Figure 6-1
CAUTION
！
(30)
Front Side
Slip T-Nut into channel
while turning
Threaded
Hole
Check direction of threaded hole
T-Nut
240 (30)

MH-1201A
6. Installation and Connection
6-2
(4) Installing the MH-1201A
Install the MH-1201A to the workbench with the attached hexagon socket head bolts,
plain washers and spring washers. Use a proper tool suitable for the bolts to secure
the Head.
Figure 6-2
(5) Connecting the Welding Power Supply and Welding Transformer
After finishing the installation above, connect the Welding Power Supply and Welding
Transformer, and connect the transformer secondary cable to the MH-1201A (see
Figure 6-3).
The Feeder Bars do not have polarities; connect either one of the transformer
secondary cables to either Feeder Bar.
When connecting, use tools of correct sizes for the screws, bolts and nuts to secure
cables.
(6) Connecting the Solenoid Valve Cables
After connecting the Welding Power Supply and Welding Transformer, connect the
MH-1201A Solenoid Valve Cables (see Figure 6-3).
MH-1201A-00/-41/-02/-43/-50: Solenoid Valve Cables have no polarities.
MH-1201A-10: Connect the RED cable to positive (+) pole; BLACK
to minus (-).
When connecting, use tools of correct sizes for the screws to secure cables.
23
Workbench
240 (30)
80
φ9mm Head Mounting Holes
Center of Electrode
Front Head Mounting Holes
(
Drillings on workbench
)
Rear
Hexagon Socket Head Bolt
Spring Washer
Plain Washer
(30)
ATTENTION
The attached bolts are for installing the MH-1201A on our Workbench
MA-11A. When using another workbench, prepare bolts suitable for it.

MH-1201A
6. Installation and Connection
6-3
Figure 6-3
(7) Connecting the Voltage-
Detecting Cables
When using the voltage-
detecting function of Transistor
Welding Power Supply
MD-A4000A, Weld Checker, etc.,
connect the Voltage-Detecting
Cables ([SENS] cable) using the
Connecting Threaded Holes.
Figure 6-4
ATTENTION
The Secondary Cables are sold separately. Please provide them.
See operation manuals for power supply, transformer and secondary cable
connections, respectively.
ATTENTION
The Voltage-Detecting Cables
([SENS] cable) are not attached
to the MH-1201A.
Please provide them.
Hexagon Socket Head Bolt
Plain Washer
Secondary Cable
To Transformer
Spring Washer
Nut
Plain Washer Secondary Cable
To Transformer
Voltage-
Detecting
Cable
Connecting Threaded Hole
Connecting Threaded Hole

MH-1201A
6. Installation and Connection
6-4
(8) Connecting the Cooling Water Hoses and Air Tubes
[Cooling Water Hose Connection]
Figure 6-5
[Air Tube Connection]
Figure 6-6
Cut hose end right!
Do Don't
Regulator
Cut hose end right!
Do Don't
ATTENTION
The Cooling Water
Hoses (for feed and
exhaust) are sold
separately. Please
provide them.

MH-1201A
6. Installation and Connection
6-5
When inspecting, decrease the pressure setting to zero and shut off the air supply
completely. When feeding and exhausting high-pressure air, the upper electrode may
move forcefully; take care not to have your hand and tools pinched.
Figure 6-7
If the high-pressure air contains residue or dust, the regulator will malfunction.
Clean the air using an air filter or a mist separator.
Do not use a lubricator; it will cause regulator to malfunction.
It is normal that air exhausts all the time from
the Air Bleed Hole (Figure 6-7).
After adjusting the pressure, be sure to
tighten the lock nut.
WARNING
！
Air Bleed Hole
Rear
Regulator
CAUTION
！
[Recommendation]
Air filter: AF3000 (SMC CORPORATION-made)
Mist se
p
arato
r
:
A
FM3000
(
SMC CORPORATION-made
)
CAUTION
！