JP2002079381A - Tip exchanging device for welding gun - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the structure of an electrode tip exchanging device for welding gun, with which structure the time required to exchange tips 18 is shortened by removing and mounting a pair of the vertically mounted tips 18 in a state that a welding gun is fixed at a fixed position. SOLUTION: The structure is so composed that the welding gun is provided with a vertical pair of tip removing device 10 having a pair of tip removing tools 13 for removing a pair of the vertically mounted tips 18 fitted on the end of shanks 19 at a fixed position while the shanks of the welding guns are separated from each other, and with a vertical pair of tip fitting devices 11 which are located between the welding guns, and that the exchanging of the tips 18 is completed by single reciprocal motion of the tip removing tools 13 and single pressurization of the welding guns by connecting the tip removing devices 10 and the tip fitting devices 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode tip exchanging apparatus for exchanging electrode tips of a spot welding machine.

[0002]

2. Description of the Related Art Generally, in spot welding, a superposed workpiece is pressed with a pair of tips (pressing force of 2000 to 30).
00N) to secure a current path, and as the number of welding points increases, the tip shape of the tip is deformed and worn due to heat generated by a large current during welding and a pressing force, and sufficient welding quality cannot be obtained. Therefore, the welding current is stepped up according to the number of welding points. When the welding current reaches the upper limit, the production line is stopped and the chips are automatically polished, or the chips are removed and replaced with new or polished chips to secure the tip shape of the chips.

[0003] In recent years, the use of chemically treated materials such as highly rust-proofing has been used as the material to be welded, and the wear and tear of electrode tips has tended to increase and the frequency of replacement has increased. Replacing is not the case. In order to replace the chips without stopping the production line, the chips must be exchanged between the end of the welding operation and the start of the next welding (for example, the work transfer time). However, this time is short and can be several seconds.

[0004] For example, Japanese Patent Application Laid-Open No. H11-90646 discloses an automatic electrode tip changing apparatus. According to this, as shown in FIG. 11, just by positioning the shank tip 1A of the welding gun with the electrode tip at the clamping center O by the robot arm, the link mechanism 4 is swung within a predetermined range by the linear motion actuator 5. By doing so, the electrode tip is held between the chuck claws 2A and 2B, and the tip is loosened by rotating the chuck claws 2A and 2B, and is removed from the shank tip. Then the elastic body 6
The chip supply means 9 swings together with the support member 3 due to the repulsion force, and the chip is attached at the holding center O which is the positioning position. According to the tip exchanging device, there is an advantage that the removal of the tip and the attachment of the tip are performed at the same position, so that it does not take much time to move the position of the welding gun.

[0005]

However, Japanese Patent Application Laid-Open No.
In the method of 1-90646, when the tip and the shank tip are strongly fitted, the removal is uncertain and the rotation of the chuck pawl may take time. Further, there is a problem that it is difficult to finely adjust the pressure, and the pressure cannot be removed even if the pressure is too high or too low, and that the chip surface is damaged. Further, as a characteristic of the movement of the link mechanism and the elastic body, there is a problem that the swing position of the chip supply means is easily shifted. For these reasons, it took time to replace the chip.

Accordingly, an object of the present invention is to provide an electrode tip changing apparatus for a welding gun in which the time required for tip replacement is reduced by removing and mounting a pair of upper and lower tips while the welding gun is fixed at a fixed position. It is to provide a structure.

[0007]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, a pair of upper and lower tips fitted to the tip of the shank are removed at a fixed position with the welding gun separated from the shank. A gist comprising a pair of upper and lower tip removing devices having a tip removing tool, and a pair of upper and lower tip mounting devices located between the welding guns at the fixed position where the welding gun is separated from the shank. I do. According to the above structure, the tip removal tool is inserted into the gap between the tip and the shank by the advance of the tip removal device and the removal is performed at a fixed position with the welding gun separated from the shank. Further, after the retreat of the tip removing device is completed, the tip is mounted by pressing the welding gun to the tip. Thus, after the welding gun is fixed at a fixed position, the removal and mounting of the tip is completed by one reciprocating motion of the tip removal tool and one press of the welding gun.

According to a second aspect of the present invention, the gist is such that the chip removal device and the chip mounting device are connected.

According to the above structure, the chip can be removed and mounted by one reciprocating movement of the driving source.

According to the third aspect of the present invention, the tip mounting device is a gripper made of, for example, a leaf spring or a clip, and a pair of upper and lower chip supply devices for continuously supplying chips to the chip mounting device, for example, a parts feeder. The gist is that it is provided.

According to the above structure, the chips sent from the chip storage box by the feeder tube are supplied to the gripper of the chip mounting device, so that the chips can be continuously supplied.

[0012] In the invention according to claim 4, the chip supply device includes a chip transfer section, and the transfer section is a two-wavy leaf spring type gripper opened in the transfer direction. The tip mounting device includes a chip mounting portion, and the mounting portion is a two-wafer, leaf spring type gripper opened in the transfer direction.

According to the above structure, the movement of the chip from the chip supply device to the chip mounting device is performed by setting the gap between the two corrugated leaf springs and the chip in the delivery section of the chip supply device. The corrugated leaf spring of the mounting part is inserted to clamp the chip, and the chip is pulled out of the leaf spring of the delivery part while being clamped by the leaf spring of the mounting part, and moves to the mounting part. According to a fifth aspect of the present invention, the tip mounting device includes a storage section (cartridge) for storing a plurality of chips, and the chips are sequentially sent from the storage section to the mounting section. According to the structure,
First, the tip is fitted to the shank by pressing the welding gun against the tip, and the tip is removed from the mounting portion together with the shank by releasing the pressure of the welding gun.
Further, the chip is sent out from the storage section to the mounting section and is prepared for the next fitting.

According to a sixth aspect of the present invention, the gist is characterized in that the chip supply device includes a storage section (cartridge) for storing a plurality of chips.

According to the above structure, the chips stored in the storage section are sequentially sent out to the delivery section.

In the invention according to claim 7, the tip removing device is provided with a driving portion, a supporting portion moved by the driving portion, and a tiltably supported by the supporting portion, and a gap between the tip fitted to the shank tip and the shank. The gist comprises a detachable tool that can enter, and the remover penetrates into the gap between the tip and the shank and tilts by a reaction force received from the shank neck.

According to the above structure, the removal tool enters the gap between the tip and the shank by the driving force of the driving section. Further, when the removal tool hits the neck of the shank, the tip is tilted by receiving a reaction force from the neck of the shank, and the tip is removed by squeezing the shoulder of the tip in the removal direction. In the invention according to claim 8, the support portion constitutes a cam mechanism. The cam mechanism includes a pair of guide plates for guiding the chip removal tool, and two pairs of cam holes provided on the guide plate so that a tip removal rod as a chip removal tool is tilted with a tip shoulder as an action point. And a pair of cam engaging protrusions provided on the tip removal rod, and the two pairs of cam engaging protrusions are respectively engaged with the two pairs of cam holes. According to the above structure, the removal rod enters the gap between the tip and the shank, and the removal rod hits the neck of the shank. Further, the removal bar receives a reaction force from the shank neck portion, and the cam engagement protrusion 16 moves in the cam hole, whereby the removal bar tilts.

According to a ninth aspect of the present invention, the tip removing device is characterized in that the tip is a wedge tip removing tool. The gist of the invention is further characterized in that the tip of the tip remover has an elongated front-opening hole which can be fitted between the tip and the tip of the welding gun.

According to the above structure, the tip of the removal tool is inserted into the gap between the tip and the shank, and the tip is removed by gradually widening the gap between the tip and the tip of the welding gun by wedge action.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) (Structure) A first embodiment of the present invention will be described below with reference to FIGS. The chip exchanging device according to the first embodiment includes a chip removing device 10, a chip mounting device 11, and a chip supply device 12, and the chip removing device 10 and the chip mounting device 11 are connected. (Chip Removal Device) In the chip removal device 10,
Claw portion 13A of lever lever 13, which is a tip removal tool
A U-shaped groove formed in a U-shape in a plan view that can be inserted into the gap 20 between the shank 19 and the tip 18 is formed at the tip of the lever, and the side surface of the lever 13 is sandwiched by two guide plates 14. Have been. The guide plate 14 has two cam holes 1
5 provided on the lever 13
The two cam engaging projections 16 are engaged with the cam holes 15 so as to be movable in the respective cam holes. The two cam engaging projections 16 move in the two cam holes 15 respectively, so that the lever 13 is tilted. Further, as shown in FIG. 4A, the lever 13 is pressed on the upper portion of the cam hole 15 by a spring 38 which is an elastic member. Further, the cam mechanism 17 including the lever 13, the guide plate 14, and the spring 38 is mounted together with the support plate 27 on the tip of the piston rod 22 of the air cylinder 21 as a driving unit.
Reciprocation is possible by the expansion and contraction operation of 1.

The chip removing device 10 has a paired structure that is upside down in order to cope with the exchange of a pair of upper and lower chips 18. (Chip mounting device) Upper mounting portion 2 of chip mounting device 11
The 3A and the lower mounting portion 23B are gripping tools each including two corrugated leaf springs 24A and 24B. The leaf spring 24 sandwiches the substrate 26 connected to the support plate 27.
A and 24B are connected to the base 26 with the wide surfaces facing each other by two sets of screws 25 on the left and right sides.
The chip 18 is vertically sandwiched between A and 24B. The distal ends of the leaf springs 24A and 24B are connected to the upper delivery section 28A and the lower delivery section 2 of the chip supply device 12.
It is slightly opened in the figure 8 in the direction 8B. Like the chip removing device 10, the chip mounting device 11 also has a vertically inverted pair structure to cope with replacement of the pair of upper and lower chips 18. Upper mounting portion 23A and lower mounting portion 23 on substrate 26
A convex portion 26A for supporting the heads of the upper and lower chips 18 is provided at the boundary of B.

The chip mounting device 11 is overlapped and joined to one of the guide plates 14 of the chip removing device 10 by a support plate 27, whereby the chip mounting device 1
1 and the chip removing device 10 can reciprocate as a unit by sliding an air cylinder. (Chip Supply Device) Upper Delivery Unit 2 of Chip Supply Device 12
8A and the lower transfer portion 28B are, like the upper mounting portion 23A and the lower mounting portion 23B, two leaf springs 30A each having two waveforms.
And 30B. The leaf springs 30A and 30B are connected to the base 29 with four sets of left and right screws 25 facing each other across the supply-side substrate 29, and the chip 18 is located between the leaf springs 30A and 30B.
Are sandwiched in the vertical direction. Leaf spring 30A,
The tip of 30B is the upper mounting portion 23 of the chip mounting device 11.
A, and is slightly opened in the figure of eight in the direction of the lower mounting portion 23B. Further, the open width of the distal ends of the leaf springs 30A, 30B is larger than the open width of the distal ends of the leaf springs 24A, 24B of the upper mounting portion 23A and the lower mounting portion 23B. Similarly to the chip removing device 10, the chip supply device 12 has a pair structure in which the upper delivery part 28A and the lower delivery part 28B are turned upside down in order to cope with the exchange of a pair of upper and lower chips 18. At the boundary between the upper delivery part 28A and the lower delivery part 28B, a convex part 29A for regulating the position of the upper and lower chips 18 is provided. (Note that the tip mounting device 11
So that it does not come into contact with the convex portion 26A on the supply side.
9A is provided with a concave portion 29B so that the mounting device convex portion 26A and the supply device concave portion 29B do not come into contact with each other at the forward end of the cylinder, so that unnecessary impact does not occur. ) In the upper delivery section 28A and the lower delivery section 28B, a chip storage box (not shown), an upper feeder tube (not shown), and a lower feeder tube (not shown) are provided.
The chip 18 is fed by a parts feeder consisting of Specifically, a lower end of the upper chip supply pipe 32 provided in the substrate 29 in the vertical direction is opened in the upper transfer section 28A, and an upper feeder connection section is provided at an upper end of the upper chip supply pipe 32. One end of the upper feeder tube is connected via 39A.

An upper end of an ascending pipe 33 of a lower chip provided in the substrate 29 in the vertical direction is opened in the lower transfer section 28B, and an air cylinder 34 is installed at a lower end of the ascending pipe 33. ing. The rod head of the air cylinder 34 is movable in the riser 33. Further, a lower chip supply pipe 35 is obliquely connected to an intermediate portion of the riser pipe 33, and the other end of the lower chip supply pipe 35 is opened at an upper end of the base 29, and a lower feeder connection section is provided. One end of the lower feeder tube is continuous via 39B. The other ends of the upper feeder tube and the lower feeder tube are continuous with the chip storage box, and the chips 18 are sent out one by one from the chip storage box in a fixed direction.

It should be noted that some of the reference numerals in the drawings have been omitted from the parts where the upper and lower sides have a vertically inverted pair structure.

(Operation) Next, the operation of the chip exchange device of the first embodiment will be described. (Arrival of Welding Gun Position) When it becomes necessary to replace the electrode tip, a welding gun (not shown) is moved to a fixed position by a welding robot (not shown) so that the tip 18 is disposed in front of the lever 13. I do. At that time, the welding gun relieved the pressure and the shank 19 was opened.
(See FIGS. 1 and 4A). (Tip arrival) From the lower feeder tube to the ascending tube 33
The tip 18 sent to the ascending piston 34 of the inside chip is pushed up by the ascending piston 34 of the ascending chip air cylinder and reaches the lower delivery portion 28B of the chip supply device 12. Further, the chip 18 arrives at the upper delivery section 28A from the upper feeder tube. (Tip removal) The piston rod 22 of the air cylinder 21 moves forward, and as shown in FIGS. 2 and 4B, the tip claw portion 1 of the lever 13 attached to the cam mechanism 17.
3A is inserted into the gap 20 between the shank 19 and the tip 18 of the welding gun, and the tip claw 13A of the lever 13 is inserted.
The U-shaped groove hits the neck of the shank 19. Then, the lever 13 receives a reaction force from the neck of the shank 19.
The spring 38 is extended by this reaction force and the force of the piston rod 22 moving forward, and the two engagement protrusions 16
However, the lever 13 is tilted by moving in the cam hole 15, and the shoulder of the tip 18 is used as a lever acting point.
While the height of the tip 18 is kept constant, the inclination changes and the tip 18 is twisted. As a result, the tip 18 is removed from the shank 19. A cooling water flow path is provided in the shank 19 and the tip 18 to reduce the temperature of heat generated by a large current during welding. When the chip 18 is removed, the cooling water is switched to air so that the cooling water does not leak. A change in the pressure of the air is sensed by a sensor to confirm whether or not the chip 18 has been removed from the shank 19. (Tip Delivery) When the air cylinder 21 moves forward, the leaf springs 24A and 24B of the upper mounting portion 23A and the lower mounting portion 23B of the chip mounting device 11 are connected to the plates of the upper delivery portion 28A and the lower delivery portion 28B of the chip supply device 12. The springs 30A and 30B are pushed and expanded, respectively, to enter the leaf springs 30A and 30B.
Are inserted between the chips 18, and the leaf springs 30A and 30B completely grip the chip 18 at the forward end of the air cylinder 21. (Tip fixed position set) The leaf springs 24A and 24B of the upper mounting portion 28A and the lower mounting portion 28B
While holding the air cylinder 21, the leaf springs 24 </ b> A and 24 </ b> B convey the chip 18 to the retracted end of the air cylinder 21. (Tip mounting) As shown in FIG.
At the retreat end position, the welding gun releases the pressure and stands by in a state in which the shank 19 is separated, and the upper and lower shank 19 of the welding gun are pressed by the pressing operation of the upper mounting portion 23A and the lower mounting portion 23B of the welding gun. And the respective chips 18 are fitted. At this time, the structure is such that 26A is pressed by both chips 18.

(Effects) Next, the effects of the present embodiment will be described below. (1) After fixing the welding gun in a fixed position, one reciprocation of the tip removing device 10 and one press of the welding gun completes the removal and mounting of the pair of upper and lower tips 18 and replaces the tips 18. Can be shortened. (2) The chip removing device 10 and the chip mounting device 11 are connected and reciprocate, so that only one drive source can be used. Since the operation is simple in the front-rear direction, the power of the drive source is relatively small. Help me. Further, since the reciprocating motion is simple, there is an advantage that the positioning of the chip mounting device 11 is stabilized. (3) Since continuous supply is performed by the parts feeder composed of the storage box, the upper feeder tube, and the lower feeder tube, the number of chips 18 to be stored is not limited as in the case of a cartridge, and a large amount of chips 18 can be quickly replaced. It is possible.

Further, it is possible to function as a chip polishing machine for performing the following series of operations. First, chips 18 that need to be polished and deformed and worn by multipoint welding are collected from a line and put into a storage box of a parts feeder of the chip exchanging apparatus of the present embodiment. A pair of upper and lower chips 18 are sent from the storage box to the upper and lower transfer sections and the mounting section by the feeder tube, where they are attached to the shank 19 by pressurizing the welding gun. Further, the welding gun is moved from the fixed position to the second position, where the polishing is performed by a polishing machine. The polished tip 18 is again moved to the home position by the welding gun, removed by the removal device, and collected. (4) Delivery is performed by a leaf spring type gripper from the upper delivery section 28A and the lower delivery section 28B to the upper mounting section 23A and the lower mounting section 23B, which enables reliable delivery with a simple structure. It is. (5) According to the present embodiment, the lever is removed by tilting the lever 13 by the cam mechanism 17, so that the stroke of the piston is smaller than that in the case where the remover only moves forward like a wedge type, for example. Can be shortened, and the removal time can be shortened. Further, for example, Japanese Patent Application Laid-Open No. 11-906
Compared with the structure in which the tip 18 is pinched and rotated, there is no need for fine adjustment of the pressure for pinching the tip 18 and the configuration of the cam mechanism 17 is simple, but the reliability of removal is high.

(Second Embodiment) (Structure) A description will be given below with reference to FIGS. This embodiment includes a chip removing device 10 and a chip mounting device 11. In the first embodiment, the chip mounting device 11 is a leaf spring type gripper, and the chip supply device 12 is a parts feeder. In the present embodiment, the chip mounting device 11 is a cartridge 60 having a plurality of storage units. And the chip supply device 12 is not provided. Note that the chip removing device 10 is the same as that in the first embodiment, and a description thereof will be omitted.

In brief, the cartridge 60 shown in FIG. 5 includes a pair of upper and lower cylinders 61 which are rotated by the rotational force of a spiral spring 62, and includes three partition plates 64A, 64B,
It is incorporated between 64C and spacer 65.
The cylinder 61 is made of a metal material, and is a storage portion for the chip 18. In the present embodiment, the cylinder 61 has eleven chips 18 and a height and a diameter capable of being stored vertically along the inner peripheral surface of the cylinder 61. A spiral spring 62 is placed at the center of the cylinder 61. A center shaft 63 is attached to the center end of the spiral spring 62. The central axis 6
3 protrudes above the upper partition plate 64A, and a ratchet 70 that rotates clockwise to store the elastic energy of the spiral spring 62 at the protruding portion.
Is attached. Further, the upper partition plate 64A
A pawl 7 for regulating the rotation of the ratchet 70;
3 is attached, and is rotatable as the ratchet 70 moves. The spiral spring 62 urges and rotates the cylinder 61 clockwise by the elastic energy stored by rotating the ratchet 70.
Furthermore, the tip 18 is pressed against the inner peripheral surface of the cylinder 61 by the pressing force of the spiral spring 62 in the outer peripheral direction. The pressing force of the spiral spring 62 is such a strength that the tip 18 in the lower storage portion does not fall and the shank 19 to which the tip 18 is fitted can be removed from the upper mounting portion 23A and the lower mounting portion 23B. .

Upper partition plates 64A, 64B, 64C
Has a substantially square shape, and the upper partition plate 64
A and the middle partition plate 64B, the middle partition plate 6
Spacers 65 (eight in total) are sandwiched between the four corners between 4B and the lower partition plate 64C, and are fixed by bolts (not shown). Bolt is partition plate 6
The cartridge 60 is fixed through the bolt holes 69 of 4A, 64B and 64C and the inside of the spacer 65. Cylinder 61
Are the partition plates 64A, 64B, 64C and the spacer 65
It is rotatably assembled between. At this time, the height of the spacer 65 is higher than the height of the cylinder 61,
For this reason, even in the assembled state, the cylinder 61 remains
It is rotatable between 4A, 64B, 64C. (It should be noted that the cylinder 61 is fixed by appropriately adjusting the rotational force of the spiral spring 62 and the pressing force in the outer circumferential direction, so that only the internal chip 18 is pushed out by the spiral spring 62 and rotates. The upper partition plate 64A and the lower partition plate 64C can be connected to the outer periphery of each of the accommodated chips 18 along the fitting side of the accommodated chips 18 so that approximately two mounting openings for the chips 18 are provided. 66 are formed. An L-shaped chip stopper 67 is attached by a screw 68 in a clockwise direction of the mounting opening 66. After the tip 18 is removed together with the shank 19 by the tip stopper 67, the next tip 18 is attached to the upper mounting portion 23A.
And, it is stopped by the lower mounting portion 23B to be ready for the next mounting. The storage of the chip 18 in the cartridge 60
Is released to rotate the ratchet 70 to the loosening side, and then, while the spiral spring 62 is loosened, the tip 18
After completion of the insertion, the center shaft 63 is rotated by a tool to store elastic energy in the spiral spring 62, and the ratchet 70 is fixed by the claw 73. Further, as shown in FIG. 6, the cartridge 60 is housed in the cartridge storage container 74 and supported by the support rod 76, and is located between the welding guns at a fixed position with the shank 19 separated. . (In order to avoid the problem that the chip 18 removed by the chip removing device 10 falls on the cartridge 60,
The position of the cartridge 60 does not necessarily have to be fixed, and may be implemented as a movable structure so as to be positioned between the upper and lower welding guns when the chip is mounted. In addition, the reference numerals in the drawings partially omit the overlapping portions on the lower side of the drawings.

(Operation) The operation of the present embodiment is basically the same as that of the first embodiment in the operation of the chip removing device 10.
However, since the chip removing device 10 and the chip mounting device 11 are not connected to each other, they do not move integrally, and only the chip removing device 10 is mounted on the air cylinder 21.
To move forward. (Attachment of tip) When the air cylinder 21 is retracted, the tip 18 is removed, and the welding gun in a fixed position is moved to the tip 18 in the cartridge 60 with the shank 19 separated.
Pressurizing operation. Thereby, the shank 1 of the welding gun
9 and the chip 18 are fitted and attached. (Tip supply) When the tip 18 is pulled out of the cartridge 60 together with the welding gun, the rotating force of the spiral spring 62 causes the cylinder 61 to rotate and the tip 1 from the cartridge back.
8 arrive at the upper mounting portion 23A and the lower mounting portion 23B, respectively, and preparation for the next mounting is performed.

(Effects) The second embodiment has the following effects in addition to the effects (1) and (5) of the first embodiment. (1) Since the cartridge 60 is employed in the chip mounting device 11, unlike the parts feeder type of the first embodiment in which both the chip mounting device 11 and the chip supplying device 12 must be provided, the chip supplying device 12 is unnecessary. Therefore,
The structure is compact and inexpensive. In an actual line, the frequency of replacement of the tip 18 of one welding gun is 6
８8 / day, and the cartridge of this embodiment can accommodate 11 chips 18 and is therefore suitable for functioning as a chip exchange in a line.

(Third Embodiment) (Structure) A description will be given below with reference to FIG. This embodiment includes a chip removing device 10, a chip mounting device 11, and a chip supplying device 12, and the chip removing device 10 and the chip mounting device 11 are connected. In the first embodiment, the tip removing device 10 is a cam type, but in the present embodiment, the tip removing device 10 is a wedge type. The chip mounting device 11 and the chip supply device 12 (not shown) are the same as those in the first embodiment, and thus the description is omitted.

As shown in FIG. 7 (a), in the chip removing device 10, the chip removing tool is a wedge-type removing rod 51 having the tip of a wedge 51A. The inclined surfaces of the wedges 51A are provided such that the inclined surfaces of the upper and lower wedges 51A face each other. Thus, when the wedge 51 is inserted into the chip 18, the inclined surface of the upper wedge 51A contacts the shoulder of the upper chip 18, and the inclined surface of the lower wedge 51A contacts the shoulder of the lower chip 18. Further, as shown in FIG. 7 (b), the front end of the wedge 51A is formed with a long hole with an open front surface which can be fitted between the gap 20 between the tip 18 and the shank 19. Further, the rear end of the tip removing rod 51 is attached to a piston rod 22 of an air cylinder 21 as a driving means via a substantially T-shaped base 52. Thus, the wedge-type removal rod 51 can reciprocate by driving the air cylinder 21.

(Operation) The operation of the above configuration will be described below. The operations of the chip mounting device 11 and the chip supply device 12 are the same as in the first embodiment.

(Tip Removal) The air cylinder 21 advances, and the wedge 51A at the tip of the wedge-type removal rod 51 is inserted into the gap 20 between the shank 19 of the welding gun and the tip 18. The inclined surface of the wedge 51A contacts the shoulder of the chip 18, and as the wedge 51A advances, the upper chip 18 is pushed up by the inclined surface, and the lower chip 18 is pushed down by the inclined surface. Thereby, the inclined surface of the wedge 51A gradually widens the gap between the tip 18 and the shank 19, and the tip 18 is removed from the shank 19.

(Effects) The third embodiment has the following effects in addition to the effects of the first embodiment (1), (2), (3) and (4). (1) According to the present embodiment, the structure is simpler than the cam mechanism 17 because the wedge-type removal rod 51 is employed.

(Fourth Embodiment) (Structure) A description will be given below with reference to FIGS. This embodiment comprises a chip removing device 10, a chip mounting device 11, and a chip supply device 12, and the chip removing device 10
And the tip mounting device 11 are connected. In the first embodiment, the chip supply device 12 is a parts feeder,
In this embodiment, the chip supply device 12 is a cartridge 60. In the second embodiment, the chip mounting device 11 is the cartridge 60.
2 is a cartridge 60. Note that the structures of the chip removing device 10 and the chip mounting device 11 are the same as those of the first embodiment, and a description thereof will be omitted. As shown in FIG. 8, the cartridge 60 is accommodated in the cartridge accommodating container 74 and is fixed by the support rod 76, and is located forward of the chip removing device 10 and the chip mounting device 11 in the traveling direction. The basic structure of the cartridge 60 is the same as that of the second embodiment, but differs in the following points. First, in the second embodiment, the cylinder 61 rotates with the chip 18 stored therein, but in the present embodiment, the cylinder 61 is partitioned by the partition plates 64A, 64B and 64C.
Since the cylinder 61 itself is not rotated because it is fixed between the spacer and the spacer 65, only the internal chip 18 is rotated by the spiral spring 62.
And is moved clockwise along the outer periphery of the cylinder 61 by being pushed by the rotational force of the cylinder 61. FIG. 5 of the second embodiment.
9 is not formed. Instead, a through hole 75 for one chip is provided in the wall of the cylinder 61 in the direction of the chip mounting device 11 as shown in FIG. Further, the upper delivery portion 28A and the lower delivery portion 28B (not shown) are formed to extend outward in the cylindrical radial direction continuously from the through hole 75.
Is provided. Upper delivery part 28A and lower delivery part 2
8B is the same as the upper mounting portion 23A and the lower mounting portion 23B.
It is a gripping tool composed of a plurality of corrugated leaf springs 30A and 30B (not shown). The leaf springs 30A and 30B are fitted and welded along the left and right side surfaces of the through hole 75, respectively (this may be appropriately screwed). Is also possible). Thereby, the upper delivery part 28A and the lower delivery part 28B are formed so as to protrude outside the cylinder 61. Rotational force of the spiral spring 62 and the upper delivery portion 28A and the lower delivery portion 28B
By appropriately adjusting the holding force of the leaf springs 30A and 30B, the chips 18 are sent out from the inside of the cylinder 61 to the upper delivery portion 28A and the lower delivery portion 28B one by one.

(Operation) The operation of the above configuration will be described below. The operation of the chip removing device 10 and the chip mounting device 11 and the delivery of the chips by the spring type gripper are the same as those in the first embodiment. (Chip supply) When the chip 18 is taken out from the upper delivery section 28A and the lower delivery section 28B by the delivery of the chip and moves to the upper mounting section 23A, the lower mounting section, and so on, the upper delivery section 28A and the lower delivery section 28B Leaf spring 30A, 30
The tip 18 is spirally wound from the inside of the cylinder 61 during B.
It is pushed out and pinched by the rotational force of, and preparation for the next mounting is performed.

(Effects) According to the fourth embodiment, the following effects are obtained in addition to the effects (1), (2), (4) and (5) of the first embodiment. (1) Since the cartridge 60 is adopted in the chip supply device 12, the chip supply device 12 is compact, and is suitable when the chip supply device 12 does not have sufficient space. In addition, the structure is simpler than that of the parts feeder.

Fifth Embodiment (Structure) A description will be given below with reference to FIG. This embodiment comprises a chip removing device 10 and a chip mounting device 11, both of which are connected. In the first embodiment, the chip mounting device 11 is a gripper.
0, which is characterized in that the chip removing device 10 and the chip mounting device 11, which were independent in the second embodiment, are connected. As shown in FIG. 10, the chip mounting device 11 of the cartridge type is overlapped and joined to one of the guide plates 14 of the chip removing device 10 by the support plate 27. The structure of the chip removing device 10 is the same as that of the first embodiment, and the structure of the chip mounting device 11 is the same as that of the second embodiment.

(Operation) According to the above configuration, the operation of the chip removing device 10 is the same as that of the first embodiment, and the operation of the chip mounting device 11 is the same as that of the first embodiment. However,
The chip mounting device 11 and the chip removing device 10 can reciprocate as a unit by the expansion and contraction of the air cylinder 21.

(Effects) According to the fifth embodiment, in addition to the effects (1), (2) and (5) of the first embodiment, there are the effects of the second embodiment (1).

The embodiment of the present invention is not limited to the above embodiment, but may be modified as follows. In the first, third, and fourth embodiments, the chip removing device 10 and the chip mounting device 11 are connected, but the chip mounting device 11 is located at a position where the chip mounting device 11 does not hinder chip removal when the chip is removed. In some cases, if the tip mounting device 11 is provided between the upper and lower welding guns, a structure in which the both are not connected and can be moved independently is also possible. The form of the cartridge 60 is circular in the second, fourth, and fifth embodiments. However, the cartridge 60 can be similarly implemented by changing its shape such as a vertical shape in which the chips 18 are arranged and stored in series. The tip removing device 10 is a cam type or a wedge type in the embodiment, but is not limited to these structures.

[0045]

According to the present invention, the following effects can be obtained. According to the first aspect of the invention, after the welding gun is fixed at a fixed position, the removal and mounting of the pair of upper and lower tips is completed by one reciprocating motion of the tip removing device and one press of the welding gun. In addition, the time required for chip replacement can be reduced. According to the second aspect of the present invention, the tip removing device and the tip mounting device are connected and reciprocate, so that only one drive source can be used. Since the operation is simple in the front-rear direction, the power of the drive source can be relatively small. Further, since the reciprocating motion is simple, the positioning of the chip mounting device becomes stable. According to the third aspect of the present invention, continuous supply is performed by the parts feeder including, for example, the storage box, the upper feeder tube, and the lower feeder tube, so that it is possible to cope with a large amount and rapid replacement of chips. According to the fourth aspect of the present invention, the delivery by the leaf spring type gripper can be achieved by a simple structure. According to the fifth and sixth aspects of the present invention, since the cartridge is employed in the chip mounting device or the chip supply device, the structure is compact and inexpensive as compared with the case of the parts feeder. According to the seventh and eighth aspects of the present invention, the removal tool is tilted (for example, the removal is performed by the tilting of the lever, which is the removal tool by the cam mechanism). The stroke of the piston can be shorter than in the case where the removal tool only moves forward, and the removal time can be shortened.

According to the ninth aspect of the present invention, since the wedge-type detaching rod is employed, the structure is simpler than that of the cam mechanism.

[Brief description of the drawings]

FIG. 1 is a perspective view of an automatic tip changer in Embodiment 1 when the welding gun reaches a home position.

FIG. 2 is a perspective view of the automatic chip changer at the time of chip removal and chip delivery in the first embodiment.

FIG. 3 is a perspective view of the automatic chip changer at the time of chip attachment in the first embodiment.

FIG. 4 is an explanatory diagram of an operation of a cam mechanism in the first embodiment. (A) is when the welding gun arrives at the home position. (B) is when the chip is removed and the chip is delivered.

FIG. 5 is a perspective view of a cartridge part of the automatic chip changer according to the second embodiment.

FIG. 6 is a perspective view of an automatic chip changer according to a second embodiment.

FIG. 7 is a diagram relating to an automatic chip changer according to a third embodiment. (A) is a side view, and (B) is a view of the wedge portion of (A) as viewed from above.

FIG. 8 is a perspective view of an automatic chip changer according to a fourth embodiment.

FIG. 9 is a plan view of an automatic tip changer according to a fourth embodiment.

FIG. 10 is a perspective view of an automatic tip changer according to a fifth embodiment.

FIG. 11 is a perspective view of an exchange device in the related art.

[Explanation of symbols]

10 chip removing device, 11 chip mounting device,
12 tip supply device 13 lever lever, 14 guide plate, 15 cam hole, 17 cam mechanism, 18 tip, 19 shank, 20 gap, 21 air cylinder, 22 piston rod, 23 mounting part, 28
Delivery part, 51 wedge type removal rod, 60 cartridge, 61 cylinder, 62 spiral spring, 63
Center axis, 64 partition, 65 spacer, 66
Mounting mouth, 67 chip stop, 70 ratchet,
73 claws, 76 support rods.

Claims (9)

[Claims] In a tip changing device for a welding gun for exchanging a pair of upper and lower tips fitted to a tip of a shank of the welding gun, the welding gun is fitted to a tip of the shank at a fixed position with the shank being separated. A pair of upper and lower tip removal devices having a tip removal tool for removing the tip,
A tip exchanging device comprising: a pair of upper and lower tip mounting devices located between the welding guns at the fixed position in a state where the welding gun is separated from the shank. 2. The chip exchanging device according to claim 1, wherein said chip removing device and said chip mounting device are connected. 3. The chip exchange device according to claim 1, wherein said chip mounting device is a gripper.
A chip exchange device further comprising a pair of upper and lower chip supply devices for continuously supplying chips to the chip mounting device. 4. The chip exchanging device according to claim 3, wherein the chip delivery unit of the chip supply device is a gripper made of two corrugated leaf springs, and a tip end of the leaf spring is opened in the delivery direction. The tip mounting portion of the tip mounting device is also a gripper made of two corrugated leaf springs, and the tip of the leaf spring is opened in the delivery direction, and the tip of the leaf spring of the delivery portion is A tip exchanging device, wherein an opening width is larger than an opening width of a tip end portion of the leaf spring of the mounting portion. 5. The chip exchanging device according to claim 1, wherein said chip mounting device includes a storage unit for sequentially sending out a plurality of chips. 6. A chip exchange device according to claim 1, wherein said chip supply device includes a storage section for sequentially sending out a plurality of chips. 7. The chip exchanging device according to claim 1, wherein said chip removing device has a driving part, a supporting part moved by said driving part, and a tip and a shank tiltably supported by said supporting part. A chip exchange device comprising a detachable tool which can enter a gap between the tip and the shank, wherein the detachable tool is tilted by a reaction force received from a shank neck portion by entering the gap between the tip and the shank. 8. A chip exchanging device according to claim 7, wherein said supporting portion is a pair of guide plates for guiding said chip removing device, and said chip removing bar is tilted on said guide plate with a tip shoulder as an action point. And two pairs of cam holes are provided on the tip removal bar, and the two pairs of cam holes are respectively engaged with the two pairs of cam holes. And a resilient member that presses the removal rod against the front end of the cam hole. 9. A tip exchanging device according to claim 1, wherein the tip removing device has a tip portion having a wedge shape, and further has a tip and a shank attached to the tip portion of the wedge. A chip exchanging device comprising a detachable tool having a long hole with an open front surface that can be fitted into a gap.