JPS6229195Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention uses a robot or the like to automatically move the welding gun to the welding part of the workpiece, and the workpiece is sandwiched between a pair of electrodes arranged oppositely on the movable frame of the welding gun. This relates to a welding gun unit that performs welding.

Conventionally, this type of welding gun unit is attached to a robot or the like, and the robot or the like moves the welding gun unit to the welding part of the workpiece to perform welding.
Lighter weight is desired. By the way, in a conventional welding gun unit, a movable frame of the welding gun is equipped with a pair of electrodes, a pressurizing mechanism, etc., the movable frame is supported by a main body frame containing a welding transformer, and this main body frame is used by a robot, etc. The structure is such that it is integrally fixed to the As a result, since the main body frame is integrally fixed to a robot or the like, the welding gun unit itself becomes large in size, making it difficult to reduce its weight and causing high manufacturing costs.

The purpose of this invention is to reduce the size and weight of the welding gun unit, reduce manufacturing costs, and improve welding quality by making it possible to bring both electrodes into contact with the workpiece almost simultaneously. It is an object of the present invention to provide a welding gun unit which is designed to improve the performance of the welding gun.

Therefore, the configuration of the present invention includes a welding transformer having a movable frame support member on one side and a welding gun unit mounting means on the other side, one end supporting the movable frame, and the other end sliding on the movable frame support member. The movable frame support member has a lock mechanism that cooperates with one of the pair of guide members to suppress forward and backward movement of the movable frame, and the other of the pair of guide members. The present invention is characterized in that an electrode response mechanism is provided for cooperating to cause the other of the pair of electrodes to immediately respond to one of the pair of electrodes.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. 1 is a welding gun unit, 2 is a welding transformer, and the welding transformer 2 has a presser plate 3,
4, and projections 6a, 6b and 7a, 7b are formed on the upper parts of the presser plates 3 and 4. The holding plates 3 and 4 are connected through a tie rod 8 and tightened together with a nut 9. Presser plate 3, 4
A movable frame support member 12 having support parts 10 and 11 is provided on the upper part of the support part 10 and 11.
Protrusions 13a, 13b and 14a, 14b protruding from
are fixed to the projections 6a, 6b and 7a, 7b. A mounting plate 15 serving as a welding gun unit mounting means is fixedly provided at the lower part of the holding plates 3 and 4, and a robot or the like (not shown) can be mounted on the mounting plate 15.

16 is a movable frame disposed in front of the movable frame support member 12, and on the front side of the movable frame 16 (the left side in FIGS. 1 and 2) there is approximately L.
A letter-shaped arm 17 is fixedly provided, and an electrode 18 is attached to the front end of the arm 17 so as to face the movable frame 16 side. Further, a pressurizing cylinder 19 as a pressurizing mechanism is installed inside the movable frame 16, and a power supply arm 20 is connected to the cylinder rod side (the left side in FIG. 2) of the pressurizing cylinder 19, which is not shown. . An electrode 23 is attached to the power supply arm 20 via a screw adapter 21 and a shank 22, and the electrode 23 is disposed opposite to the electrode 18.

24 and 25 are a pair of guide bars (guide members) arranged in parallel to each other on both left and right sides (in FIG. 2, both upper and lower sides) of the movable frame support member 12;
Guide bars 24 and 25 are movable frame support members 1
It is slidably attached to the support parts 10 and 11 of No. 2. The guide bars 24, 25 support protrusions 26a, 26b and 27a, 27b protruding from the movable frame 16.

The support portion 11 of the movable frame support member 12 includes
As shown in FIG. 2, a cylinder portion 28 is provided as a locking mechanism. This cylinder part 28
is a cylinder hole 29 bored in the rear part of the support part 11.
and a guide bar 2 extending into the cylinder hole 29.
5, a piston 30 fixed to the rear end of the guide bar 25, a stopper 31 for suppressing the forward movement of the piston 30, and a stopper 31 for suppressing the backward movement of the piston 30. lid member)
It is composed of 32.

The support portion 10 of the movable frame support member 12 includes:
As shown in FIG. 2, a spring portion 33 is provided as an electrode response mechanism. This spring part 33 has a spring hole 34 bored in the rear part of the support part 10, a rear end part of the guide bar 24 extending into the spring hole 34, and a rear end of the guide bar 24 (to the right in FIG. 2). a spring 35 that urges the spring 35 toward the side); a spring receiver 36 that is fixed to the rear end of the guide bar 24 and locks the rear end of the spring 35; A spring 35 is installed inside.
Spring stopper (button) 3 that locks the front end of
It consists of 7. This spring stopper 3
7 and the spring receiver 36 is set to be larger than the stroke amount of the piston 30.

In addition, 38 is a solenoid valve for supplying air to the pressurizing cylinder 19, and 39 is a spline for preventing the piston (not shown) of the pressurizing cylinder 19 from rotating.

The welding gun unit 1 constructed as described above is attached to the robot via the attachment plate 15 and is on standby. First, when the robot moves toward the workpiece W set at a predetermined position, air is simultaneously supplied to the cylinder head side of the cylinder portion 28 and the cylinder rod side of the pressurizing cylinder 19.

When air is supplied to the cylinder head side of the cylinder portion 28, the piston 30 moves forward and comes into contact with the stopper 31. Air continues to be supplied even after the piston 30 contacts the stopper 31, and the air pressure generated at this time locks the cylinder portion 28 in the state in which the piston 30 contacts the stopper 31 at the forward rear end position. On the other hand, the movable frame 16 moves forward in response to the forward movement of the piston 30 and is locked at its front end position. Therefore, when the welding gun unit 1 moves to the welding parts X and X' of the workpiece W, the movable frame 16 is held locked via the cylinder part 28, so that the pair of electrodes 18 and 23 are moved in the front-back direction ( This reliably prevents movement in directions B and B' in Fig. 1.

On the other hand, in the spring portion 33, the guide bar 24 also moves forward in response to the forward movement of the movable frame 16, and as a result, the spring receiver 36 approaches the spring stop 37 and contracts, so the spring 35 moves the guide bar 24 backward. side (right side in Fig. 1). Also, the air is in the cylinder part 2.
Not only the cylinder head side of 8 but also the pressurized cylinder 1
Since it is also supplied to the cylinder rod side of No.9,
The piston of the pressurizing cylinder 19 and the electrode 23 connected thereto are displaced backward by the air pressure. Therefore, the electrode 23 is maintained at a constant distance from the electrode 18.

Next, while maintaining this state, the welding gun unit 1 is moved by the robot to the welded portions X and X of the workpiece W.
X', as shown in FIG.
When the welding portions X and X' of the workpiece W are placed between and 23, the air supply is switched. That is, the supply of air to the cylinder portion 28 is stopped, and air is supplied to the cylinder head side of the pressurizing cylinder 19.

When the air supply to the cylinder portion 28 is stopped, the air pressure to the piston 30 is released and the piston 30 becomes free. When the piston 30 becomes free, the movable frame 16 moves backward via the guide bar 24 due to the biasing force of the spring 35 . As a result, the electrodes 18, 23 in FIG.
The electrode 18 moves in the B′ direction, and the workpiece W
approach to the vicinity of the welded part X'.

On the other hand, since air is supplied to the cylinder head side of the pressurizing cylinder 19, the piston of the pressurizing cylinder 19 moves forward, and then the electrode 23 comes into contact with the welding part X of the workpiece W. The welded portion X is pressurized. When the electrode 23 applies pressure to the welding part X of the workpiece W, the back pressure generated by the pressure causes the movable frame 16 to move the electrode 18 into contact with the welding part X' of the workpiece W. is moved backward (moved in the direction B' in FIG. 1) until the pressing force of the electrode 23 becomes equal. On the other hand, the welding part X of the workpiece W,
X' tends to bend in the direction B in FIG. 1 due to the pressing force of the electrode 23, but as mentioned above, the electrode 18 approaches the welding part X' of the workpiece W, so the electrode 23 The response time of the electrode 18 after coming into contact with the welding part X is extremely short, and the electrode 18 comes into contact with the welding part X' and pressurizes it before the welding parts X and X' are bent in the direction B.

Note that after the electrode 23 comes into contact with the welding part X of the workpiece W, the movable frame 16 applies the pressing force between the electrode 23 and the electrode 18 due to the back pressure generated by the pressing force of the electrode 23 and the urging force of the spring 35. Move in the B′ direction until they become equal.

In this way, the welding part X of the workpiece W,
X' is held between both electrodes 18 and 23 from both sides and welded under appropriate pressure. Therefore, the welded parts X and X' of the workpiece W are welded without being bent by the pressing force of the electrode 23, so that extremely good welding quality can be obtained.

As described above, the welding part X of the workpiece W,
When welding of X' is completed, the air supply is switched again. That is, air is supplied to the cylinder head side of the cylinder section 28 and the cylinder rod side of the pressurizing cylinder 19, and the welding gun unit 1 is moved by the robot to the next welding section X, X'. After this, welding parts X and X' are welded in the same manner as above,
When the target welding parts X and X' are completely welded, the welding gun unit 1 returns to the initial position and the welding process is completed.

As explained above, according to the present invention, the structure of the welding gun unit is simplified, so that the welding gun unit can be made smaller and lighter, and maintenance can be facilitated and manufacturing costs can be reduced. Moreover, when the welding gun unit moves to the welding part of the workpiece, the lock mechanism reliably prevents the movable frame from moving, and the pair of electrodes welds almost simultaneously from both sides of the welding part. Since welding can be carried out under appropriate pressure by contacting the parts, there is also the effect of improving welding quality without causing bending deformation of the welded object.

[Brief explanation of the drawing]

Figure 1 is a front view showing one embodiment of the present invention;
The figure is a partial cross-sectional plan view of FIG. 1, and FIG. 3 is a cross-sectional view taken along line A--A in FIG. 1. DESCRIPTION OF SYMBOLS 1... Welding gun unit, 2... Welding transformer, 12... Movable frame support member, 15... Mounting plate (welding gun unit mounting means), 16... Movable frame, 18, 23... Electrode, 19... Pressure Cylinder (pressure mechanism), 24, 25... Guide bar (guide member), 28... Cylinder part (lock mechanism), 33... Spring part (electrode response mechanism),
W...Object to be welded.

Claims (1)

[Scope of utility model registration request] A welding gun unit in which a pair of electrodes are arranged opposite to each other on a movable frame of a welding gun, and one of the pair of electrodes is equipped with a pressurizing mechanism, in which a movable frame support member is provided on one side and the welding gun unit is mounted on the other side. a welding transformer provided with means; and a pair of guide members, one end of which supports the movable frame and the other end of which is slidably attached to the movable frame support member, and the movable frame support member includes: a lock mechanism that cooperates with one of the pair of guide members to suppress forward and backward movement of the movable frame;
A spring receiver is formed at one end of the other of the pair of guide members, and a spring is resiliently biased and installed between the spring stop and the spring receiver through which the guide member is slidably inserted, and A welding gun unit comprising: an electrode response mechanism for causing the other of the pair of electrodes to immediately respond to one of the pair of electrodes in cooperation with one of the pair of guide members.