JPS608910B2 - Spot welding gun equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spot welding gun device suitable for welding operations using industrial robots.

As a secondary spot welding gun device, there is a structure shown in FIGS. 1 and 2, for example.

In the figure, reference numeral 1 denotes a frame fixed to an arm 2 of an industrial robot, and a pair of slide shafts 3, 3 are constructed on this frame 1. 4 is a pair of arms 5a, 5b
A bearing part 6 of this body 4 is guided by the slide shaft 3, so that the frame and the body 4 can be slid relative to each other. There is.

Further, the body 4 has a built-in cylinder 7, and the one arm 5b is fixed to a piston rod 7a of the cylinder 7.

In the state shown in FIG.
The tip of the stopper bolt 8 attached to the frame 1 rests against a part of the frame 1, so that the arms 5a and 5b are separated from each other and are in an open state. Therefore, in the above configuration, if air is supplied to the chamber R of the cylinder 7 from the state shown in FIG. 1 to extend the piston rod 7a prior to spot welding, the arm 5b including the tip 9b, which is an electrode, While compressing the spring 10, it moves forward along the slide shaft 3 in the direction of arrow P and comes into contact with the workpiece W to be welded.

When air is further supplied to the chamber R of the cylinder 7 while the tip 9b is in contact with the object W to be welded, the other arm 5a containing the tip 9a, which is the other electrode, moves along with the body 4 as shown in the arrow The tip 9a also supports the workpiece W by retreating in the Q direction. As a result, the workpiece W to be welded is pressed and brought into contact with both tips 9a and gb, and a predetermined spot weld is performed. Conventionally, such spot welding gun devices have been used differently depending on the type of workpiece W to be welded, as described below.

That is, when the workpiece W to be welded is a reinforcing member for an automobile door, for example, where it is acceptable to leave a welding impression, welding is performed by directly contacting the workpiece with both tips 9a and 9b. Do the following.

However, if the workpiece W to be welded is something that constitutes the outer panel of an automobile door, for example, the quality of the product will be affected if an indentation is generated due to the pressing force of both chips 9a, 9b, so the indentation should be It is necessary to prevent this from occurring. In such a case, a backup member (not shown) is applied to the surface of the welded object W, which is the surface of the outer plate, and welding is performed to prevent pressurizing force from being directly applied to the welded object W. For example, in an automatic welding line using a robot, a backup member that is moved by the side of the drive machine is provided on the sash or base, and when the workpiece W is positioned to pick up odor, the workpiece W is moved at a predetermined timing. It was supposed to be applied to the workpiece W to be welded. However, according to such a method, it is necessary to install the backup member at a position where it does not interfere with the movement of the robot, and setting the installation position is not easy.

Further, when the aforementioned spot welding gun device is used as a portable type (manual type), an operator has to use a special jig or the like to fix a backup member to the object to be welded before welding.

However, in this case as well, it is necessary to prepare special jigs and the like, and the number of man-hours is increased. This invention was made in view of the above-mentioned conventional problems, and solves the above problems by attaching a backup member and this drive mechanism to the gun device itself, and is suitable for both robots and portable types. The purpose of the present invention is to provide a gun device for robot welding.

Embodiments of the present invention will be described below based on the drawings.

3 to 6 show an embodiment of the spot welding gun according to the present invention, the basic components of which are as follows:
Since it is almost the same as that shown in FIGS. 1 and 2, the common parts will be given the same reference numerals, detailed explanation will be omitted, and only the different parts will be explained.

In FIG. 3, the piston of the air cylinder 20 is an air cylinder fixed vertically to one side of the frame via a bracket 21. A rack 22 is integrally attached to the stud 20a. Also, 25
is a rotation shaft disposed horizontally below the air cylinder 20, and this rotation shaft 25 is rotatably supported by support members 23 and 26 provided on the negative side of the frame, and A pinion 27 that meshes with the rack 22 is provided at the end. As a result, by expanding and contracting the air cylinder 20, the rotation shaft 25 is rotated via the rack 22 and the pinion 27. An arm 28 is attached to the tip of the rotation shaft 25.

This arm 28 is configured such that its rotation in the circumferential direction with respect to the rotation shaft 25 is restricted, but can be slid slightly in the axial direction, and is also provided with a coil spring 29 on the side of the arm 5a in FIG. is being energized towards.
Further, as shown in FIGS. 4 and 5, a support hole 24 is formed at the tip of the arm 28, and a circular backup member 30 is inserted into the support hole 24 so as to be freely movable. . And this backup member 30
The support hole 24 is fixed by the screws 31 inserted from all sides of the G center.
The chip 9b is supported so that it can flow freely within the chip 9, and the surface 30a facing the object W to be welded has a larger area than the chip 9b. Next, the operation of the spot welding gun device having the above configuration will be explained mainly with reference to the movement of the backup member.

First, when the welding gun device is in the standby position, an operating signal is output from the control system to the robot to operate the air cylinder 20.

Then, as the piston rod 20a retracts, the rack 22 rises, and the engagement between the rack 22 and the pinion 27 causes the arm 28 to swing through the rotation shaft 25 and enter between the tips 9a and 9b. That is, as shown in the operation explanatory diagram of FIG. 6 (the illustration has been simplified for clarity of explanation), the arm 28 swings approximately 90 degrees from the position shown by the dashed line to the position shown by the solid line, and the backup member The tip 30 stops when it enters the gap between the chips 9a and 9b. Next, the arm 20 of the robot moves forward to bring the welding gun device to the welding position. At this time, the backup member 30 assists the workpiece W, but does not damage the workpiece due to the coil spring 29 and the floating function of the backup member 30 itself described above. When the backup member 30 is set at a predetermined position in this way, both arms 5a and 5b move forward with respect to the workpiece W by the function of the gun itself described above, and the workpiece W is connected between both tips 5a and 5b. Backup member 3
0 are sandwiched between them, and in this state, electricity is applied to perform spot welding.

According to this welding method, the backup member 30 is interposed between at least one tip 9b and the workpiece W, and as described above, the contact area of the backup member 30 is large, so that the nugget during welding is There is no biting into the object W to be welded when it is formed, and no impression is created on the surface of the object W after welding. After welding is completed, the welding gun itself returns to the standby position, and the back bar arm 28 returns to its initial position (the state indicated by the dashed line in Fig. 6) by the reverse operation of the air cylinder 20 (from between the tips 9a and 9b). However, in this state, the back bar arm 28 does not interfere with the direct welding work between the chips 9a and 9b, so next time we will leave it in this state and normally (as mentioned above, weld the workpiece W). This enables spot welding (where indentation is acceptable).

Here, the air cylinder 20, the rack 22, the pinion 27, the rotation shaft 25, the arm 28, etc. constitute a drive mechanism for the backup member 30. FIG. 7 shows another embodiment of the present invention, which differs from the first embodiment in that the arm is actuated by a rack and pinion, whereas this embodiment In this example, the drive mechanism is driven by a link.

That is, the piston rod 2 of the air cylinder 20 has a link member 40 attached to one end of the rotating shaft 25 and is swingably attached to the frame via a bracket 39.
0a, and an arm 28 is connected to the other end of the rotating shaft 26, and the rotating shaft 25 is used as a fulcrum to swing between the two states shown by the dashed line and the solid line. Also, the same effects as in the above embodiment can be obtained. Note that, in FIG. 8, illustration of the welding gun device itself is omitted for clarity of explanation. Further, in the above embodiment, the backup member 30 is arranged to flow between the workpiece W and the chip 9b, but it may be held between the workpiece W and the chip ga.

Furthermore, when the present invention is applied to a portable type device, a manual drive mechanism such as a handle may be used as the drive mechanism for moving the backup member in and out.

As is clear from the above explanation, according to the present invention, the spot welding gun device itself is provided with a backup member and a drive mechanism. Therefore, when used in an automated line using a robot, the backup member and drive mechanism etc. are provided in the spot welding gun device itself. There is no need to obstruct the movement of the welding gun device itself by the robot.

Furthermore, when a portable type is used, there is no need for a special jig to attach the backup member to the object to be welded, which has the effect of reducing the number of steps for the operator. Furthermore, in the above-described embodiment, the backup member 3 is in a floating state with respect to the arm 28, and the arm 28 itself is also movable with respect to the rotation axis 25, so that the work to be welded W It goes without saying that there will be no damage when assisting, but when used in the above-mentioned automated line, even if the workpiece W to be welded is changed, three backup parts need to be changed. There is an advantage that there is no

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the configuration of a conventional spot welding gun device, FIG. 2 is a side view thereof, FIG. 3 is a side view showing the configuration of the spot welding gun device according to the present invention, and FIG. FIG. 3 is an enlarged front view of part A in FIG. 3, FIG. 5 is a full sectional view, FIG. 6 is an explanatory diagram of the operation of the backup member in FIG. 3, and FIG. 7 is an explanation showing another embodiment of the present invention. It is a diagram. 1... Frame, 4... Aircraft, 20...
... Air cylinder, 22 ... Rack, 25.
...Rotation axis, 27...Pinion, 28...Arm, 3
0...Backup member, 40...Link. Figure 1 Figure 2 Figure 4 Figure 5 Figure 3 Figure 6 Blind Figure 7

Claims (1)

[Claims] 1. A spot welding gun device characterized in that a backup member is provided in the spot welding gun body so that it can enter and exit between two electrodes, and a drive mechanism that moves the backup member to enter and exit.