JPH0929458A - Electrode tip exchanging device for spot welding gun - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely pull out an electrode tip mounted freely mountable/ demountable to a spot welding gun. SOLUTION: Link members 21, 22, which are pivotally supported to a housing oscillatably, are oscillated by a cylinder device 30. Tip pulling out pieces 25, 26 are pivotally supported to link members 21, 22 oscillatably as taking its reference end for an oscillating center O. The tip pulling out pieces 25, 26 have at its tip side claw parts 25c, 26c, which enter into the clearance C between a shank 13 and electrode tip 14 in the tip mounting/demounting direction, while the oscillating center O is moved in a circular arc state by the oscillation of link members 21, 22, the claw parts 25c, 26c are entered into the clearance C while oscillating in the direction of the electrode tip 14 separating from the shank 13, the electrode tip 14 is pulled out from the shank 13 with the claws 25c, 26c.

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 device for a spot welding gun for automatically extracting an electrode tip attached to the spot welding gun.

[0002]

2. Description of the Related Art In a welding gun used for spot welding, an electrode tip is removably attached to a tapered portion of a shank tip of the welding gun by fitting, and the electrode tip is appropriately replaced according to wear or the like. . When exchanging the electrode tip, for example, in a welding gun of a spot welding robot used in a vehicle body assembly line or the like, as shown in FIG. 12, an electrode tip 92 fitted to a tapered portion 91a of a shank 91 is used. A two-forked fork-shaped tip extracting jig 94 having a wedge-shaped claw portion 94a which can enter a gap 93 in the electrode tip fitting / removing direction between the shank 91 and becomes thinner toward the tip is used. A method of replacing the electrode tip 92 is adopted (see Japanese Patent Laid-Open No. 6-170553). This is different from the chip extracting jig 94 described above.
After the spot welding robot is moved so that the claw portion 94a of the is located in the gap 93 between the shank 91 and the electrode tip 92 in the electrode tip fitting / removing direction, the tip extracting jig 94 is horizontally moved with a predetermined stroke. (Electrode tip 92
By moving the claw portion 94a of the tip extracting jig 94 into the clearance 93, the electrode tip 92 is extracted from the shank 91.

[0003]

However, in the above-mentioned conventional method, it is difficult to reliably remove the electrode tip 92. That is, since the size of the gap 93 in the electrode tip fitting / removing direction between the shank 91 and the electrode tip 92 varies depending on the accuracy variation among the electrode tips 92, etc., when the gap 93 is too large, the tip extracting jig 94 is The electrode tip 92 may not be extracted due to insufficient insertion stroke.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an electrode tip exchanging device for a spot welding gun capable of reliably extracting an electrode tip attached to the spot welding gun. This is a technical issue that should be addressed.

[0005]

An electrode tip exchanging device for a spot welding gun according to claim 1, which solves the above-mentioned problems, comprises:
A spot welding gun electrode tip exchanging device for automatically exchanging an electrode tip fitted to a shank tip tapered portion of a spot welding gun, comprising: The tip side has a claw part that can enter the gap in the electrode tip fitting / removing direction, the base end side is movable in an arc shape, and the tip side having the claw part swings around the base end side as a swing center. It is made possible, and the claw portion on the distal end side moves into the gap while swinging in the direction away from the shank of the electrode tip as the swing center on the proximal end side moves in an arc shape. By
It is characterized by comprising a tip extractor capable of extracting the electrode tip from the shank with the claw portion, and a drive means for moving the swing center of the tip extractor in an arc shape.

In a preferred mode, the drive means includes a swingable link member for swingably supporting the base end side of the tip extractor, and stroke amount detection means for swinging the link member. And a cylinder device. The electrode tip exchanging device for a spot welding gun according to claim 3, which solves the above problems, is an electrode tip exchanging device for a spot welding gun for automatically exchanging an electrode tip fitted to a taper portion of a shank tip of the spot welding gun. A swingable pivotally supported link member, and a gap in the electrode tip fitting / removing direction between the shank and the electrode tip that is swingably pivotally supported by the link member with the base end side as a swing center. Has a claw portion that can enter into the front end side, and the claw portion on the tip side moves from the shank of the electrode tip as the swing center moves in an arc shape due to the swing of the link member. By inserting into the gap while swinging in the separating direction, the tip extractor capable of extracting the electrode tip from the shank by the claw portion and a slide means as a drive means for swinging the link member. A cylinder device provided with a rooke amount detecting means, a tip mounting means for fitting an electrode tip to a taper portion of the shank tip, a cooling water supplied to a flow passage provided in the spot welding gun and the electrode tip. And a sensor for detecting the water pressure of.

[0007]

In the electrode tip exchanging device for the spot welding gun according to the first aspect of the present invention, the tip end side of the tip extractor is moved as the swing center of the tip extractor on the base end side is moved in an arc shape by the driving means. The claw portion of the electrode tip oscillates in the direction away from the shank of the electrode tip, and enters the gap in the electrode tip fitting / removing direction between the shank and the electrode tip. In this way, the claw portion swings in the direction in which the electrode tip is pulled out from the shank and enters the gap, whereby the electrode tip at the tip of the claw portion comes into contact with the electrode tip, and the electrode tip is pulled away from the shank. Since the force acts, the electrode tip can be reliably removed from the shank.

The driving means for moving the swing center of the tip extractor in an arc shape swings the swingable link member for swingably supporting the base end side of the tip extractor and the link member. In the case of the cylinder device having the stroke amount detecting means for moving, the completion of extraction of the electrode tip can be detected as described below. That is, when the link member is rocked by the operation of the cylinder device, the rocking center on the base end side of the tip extractor pivotally supported by the link member moves in an arc shape, and accordingly. The claw portion on the tip side of the tip extractor moves into the gap while swinging. At this time, if the stroke amount detecting means of the cylinder device is set so as to detect the stroke amount at the time when the electrode tip is extracted from the shank by the tip extracting tool, the signal of the stroke amount detecting means detects the electrode tip The completion of extraction can be detected. Further, if the stroke amount detecting means does not generate a detection signal even after a lapse of a predetermined time after the operation of the cylinder device, the electrode tip is abnormally attached to the taper portion of the shank tip, and the electrode tip can be removed from the shank. It is possible to detect the absence.

According to another aspect of the present invention, there is provided an electrode tip exchanging device for a spot welding gun, further comprising a tip mounting means for fitting an electrode tip to a tapered portion of a shank tip, and a passage provided in the spot welding gun and the electrode tip. Since it is equipped with a sensor for detecting the water pressure of the cooling water supplied to the electrode, the electrode tip is pulled out from the shank by the tip pulling tool via the link member by the operation of the cylinder device, and the electrode tip is detected by the stroke amount detecting means. After detecting the completion of the extraction, the electrode mounting means fits the electrode tip to the taper portion of the shank tip. Then, cooling water is supplied to the flow path provided in the spot welding gun and the electrode tip. At this time, if the electrode tip is normally attached to the taper portion of the shank tip by the tip attaching means, the water pressure of the cooling water supplied to the spot welding gun and the flow path in the electrode tip rises to a predetermined pressure. By detecting this water pressure with a sensor, it is possible to detect that the electrode tip has been normally mounted on the shank from the detection signal from the sensor.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The electrode tip exchanging device for a spot welding gun according to the present invention will be specifically described below with reference to embodiments. As shown in the wiring system diagram of FIG. 1 and the piping system diagram of FIG. 2, the electrode tip exchanging device of the spot welding gun according to the present embodiment is a tip exchanging device for the spot welding robot 7, and is a tip extractor main body. 1, a chip mounting machine main body 2 and a chip feeder main body 3. The chip extractor main body 1, the chip mounting machine main body 2 and the chip feeder main body 3 are controlled by a chip extracting controller 4, a chip mounting machine controller 5 and a chip feeder controller 6, respectively. Further, the spot welding gun 8, the chip extractor main body 1, the chip mounter main body 2 and the chip feeder main body 3 of the spot welding robot 7, the main valve 10, the robot controller 9, the chip extractor controller 4, the chip mounter controller, respectively. 5 and valves 11a, 11b controlled by the chip feeder controller 6,
It is activated by the supply of pressurized air from the air source 12 via 11c and 11d.

The spot welding robot 7 is equipped with a spot welding gun 8. The spot welding gun 8 has a pair of upper and lower shanks 13, 13, and electrode tips 14, 14 are provided at the tip tapered portions of the shanks 13, 13. Are detachably attached. A cooling water supply passage (not shown) is provided in the spot welding gun 8, the shanks 13, 13 and the electrode tips 14, 14. The supply of the cooling water to this flow path is controlled by the robot controller 9 from the cooling water supply source 15 via the cooling water supply valve 16. In addition, a flow switch 17 as a water pressure sensor for detecting the water pressure of the cooling water supplied into the flow passage is arranged in the flow passage. It has been confirmed that the water pressure of the cooling water supplied into the flow path increases to about 2 kg / cm ² if the electrode tip 14 is normally attached to the shank 13, so The flow switch 17 has a water pressure of 2 kg /
It is set to be turned on when it reaches cm ² , and an ON signal from this flow switch 17 is sent to the general controller 18 via the robot controller 9.

The tip removing controller 4,
The chip mounting machine controller 5, the chip feeder controller 6, and the robot controller 9 are comprehensively controlled by a general controller 18. As shown in the side view of FIG. 3 and the plan view of FIG. 4, the chip extractor main body 1 includes a housing 19 and a pair of upper and lower link members 21 pivotally supported by a shaft 20 held by the housing 19. , 22 and a pair of upper and lower tip extractors 2 pivotally supported by shafts (swing centers O) 23, 24 held at the tips of the upper and lower link members 21, 22 respectively.
5 and 26.

As shown in FIG. 5 for the upper and lower link members 21 and 22, the upper and lower link members 21 and 22 have shaft holes 21a and 22a through which the shaft 20 held in the housing 19 is inserted. Pierced bases 21b and 22b,
The upper and lower tip extractors 25 and 26 are respectively constituted by swinging portions 21d and 22d having shaft holes 21c and 22c through which shafts 23 and 24 for swingably pivoting are inserted. The base portion 21 of the upper and lower link members 21, 22
In b and 22b, the base portion 21b of the upper link member 21
Is sandwiched between the forked base portions 22b of the lower link member 22. In addition, the upper and lower link members 21, 22
Has a return spring 27 whose one end is fixed to the housing 19.
The other ends of are fixed.

The upper and lower tip extractors 25 and 26 are provided with base end portions 25b and 2b having shaft holes 25a and 26a through which the shafts 21b and 22b held by the upper and lower link members 21 are inserted.
6b and fork-shaped claw portions 25c, 26c on the tip side
And (see FIG. 7). Claw part 25
c and 26c have a wedge shape whose wall thickness decreases toward the tip, and the first inclined surface 2 on the tip side of the claw portions 25c and 26c.
5d, 26d and first inclined surfaces 25e, 26e on the base end side of the claw portions 25c, 26c. The second inclined surfaces 25e and 26e are slightly steeper than the first inclined surfaces 25d and 26d. Also, the claw portions 25c and 26c are
The shank 13 of the spotch welding gun 8 and the shank 13
It is possible to enter into a gap C (see FIG. 3) in the electrode tip fitting / removing direction between the tip and the electrode tip 14 fitted to the tapered portion. Further, the upper and lower chip extractors 25, 26 are provided with a return spring 28 whose one end side is fixed to the housing 19.
The other end side of each is fixed.

In this way, the bases 21b, 22 of the upper and lower link members 21, 22 are attached to the shaft 20 held by the housing 19.
b is pivotably supported, and the vertical link member 2
Shafts 23 held by the swinging parts 21d and 22d of
24 includes base parts 25 of upper and lower chip extractors 25 and 26.
When b and 26b are pivotally supported, the shafts 23 and 24 as the swing center O move in an arc shape due to the swing of the upper and lower link members 21 and 22, and the upper and lower chip extractors are accompanied by this. Claws 25c and 26c of 25 and 26 enter the gap C while swinging in the direction of separation of the electrode tip 14 from the shank 13, whereby the claws 25c and 26c extract the electrode tip 14 from the shank 13. It is possible.

An inclination prevention plate 29 of the electrode tip 14 is fixed to one end of the housing 19 (left side in FIGS. 3 and 4). This tilt prevention plate 29 is used for the electrode chip 1
4, the tip end side of the electrode tip 14 is prevented from inclining to the tip extractor body 1 side, and the shank 13 is removed.
Is for smoothly extracting the electrode tip 14 from the taper portion of the tip, and when the spot welding robot 7 is positioned at the electrode tip extracting position, the upper and lower ends of the tilt prevention plate 29 are the tips of the upper and lower electrode tips 14, 14, respectively. It is arranged so as to be located in the vicinity. On the other hand, housing 1
On the other end side of 9, there is provided a cylinder device 30 as a driving means for swinging the link members 21, 22. This cylinder device 30 is a chip extraction controller 4
It is operated by being controlled by the integrated controller via. The cylinder device 30 has a rod portion 31 that moves back and forth with a predetermined stroke amount, and the tip end of the rod portion 31 includes swinging portions 21d and 22d of the vertical link members 21 and 22.
The roller holding member 34, which holds the upper and lower rollers 32, 33 that come into contact with the rotatably, is fixed. The cylinder device 30 is also provided with a reed switch (not shown) as a stroke amount detecting means for detecting a predetermined stroke amount of the rod portion 31. The reed switch is arranged so as to detect the stroke position of the rod portion 31 at the time when the electrode tip 14 is pulled out from the tip tapered portion of the shank 13. And the detection signal from the reed switch is the chip extraction controller 4
Is sent to the integrated controller 18 via. Therefore, when the cylinder device 30 is operated by the control of the general controller 18 via the chip extracting controller 4 and the rod portion 31 of the cylinder device 30 moves, the upper and lower rollers 32 and 33 held by the roller holding member 34 are moved to the upper and lower link members. The oscillating portions 21d and 22d of the ridges 21 and 22 are pressed, whereby the oscillating portion 2 of the upper and lower link members 21 and 22 is pressed.
1d and 22d are configured to swing.

As shown in FIGS. 8 to 10, the chip mounting machine main body 2 is provided on the side surface of the housing 19 and has a disk table 36 which is rotated by a drive motor 35 at a predetermined angle. Eight electrode chip holding holes 37 are provided on the upper and lower surfaces of the outer periphery of the disk table 36, respectively, at regular intervals along the circumferential direction corresponding to the rotation angle of the disk table 36. The electrode tip 14 is attached to the shank 13 through the electrode tip holding hole 37a (see FIG. 8) at the electrode tip attachment position. Further, the disk table 36 is provided with a photoelectric switch 36a for detecting the presence or absence of the electrode chip 14 in the electrode chip holding hole 37a at the electrode chip mounting position. The detection signal of the photoelectric switch 36a is sent to the general controller 18 via the chip mounting machine controller 5, and the drive motor 35 for rotating the disc table 36 by a predetermined angle is controlled by the general controller 18 via the chip mounting machine controller 5. It

An electrode tip 14 is attached to the tip mounting machine body 2.
The chip feeder main body 3 for automatically supplying the liquid has a chip storage box 38, an upper and lower feeder tubes 39, and an upper and lower feeder rods 40 (see FIG. 1). The chip storage box 38 has a chip alignment function, and the aligned electrode chips 14 are fed one by one by air blow inside the feeder tube 39 and chucked to the feeder rod 40 at the tip of the feeder. In this state, the feeder rod 40 travels forward and the chuck is released at the position of the holding hole 37, so that the upper and lower feeder tubes 39 and the upper and lower feeder rods 40 move from the chip storage box 38 to the electrode chip holding hole 3 of the disk table 36.
It is possible to automatically supply the electrode tip 14 in the inside 7. The chip feeder main body 3 is controlled by the general controller 18 via the chip feeder controller 6.

The electrode tip exchanging device for the spot welding gun according to the present embodiment thus constructed can automatically exchange the electrode tip 14 of the spot welding gun 8 of the spot welding robot 7 as shown below. it can. That is, when it is necessary to replace the electrode tip 14, the spot welding robot 7 causes the upper and lower tip extractors 25, 26 of the tip extractor main body 1 to operate according to an operation program previously incorporated in the robot controller 9.
The claw portions 25c and 26c of the tip extractors 25 and 26 are moved so as to be located in the gap C portion between the shank 13 and the electrode tip 14 in the electrode tip fitting / removing direction (see FIG. 3). Even if the welding gun 8 of the spot welding robot 7 is different and the position of the gap C in the electrode tip fitting / removing direction between the shank 13 and the electrode tip 14 is different, the operation programs should be individually set accordingly. Can be dealt with. When the spot welding robot 7 moves to the electrode tip extraction position in this way, the operation completion signal of the spot welding robot 7 is generated from the robot controller 9 to the general controller 18, and the general controller 18 which receives this signal causes the tip extraction controller 4 to An operation signal of the chip extractor body 1 is emitted.

In the chip extractor main body 1 which receives an operation signal from the general controller 18 through the chip extractor controller 4, the cylinder device 30 is driven and the rod portion 31 moves. As a result, the upper and lower rollers 32 and 33 arranged on the tip end side of the rod portion 31 press the swing portions 21d and 22d of the upper and lower link members 21 and 22 to swing. By swinging the upper and lower link members 21 and 22, FIG.
As shown in FIG.
Shafts 23 and 2 serving as swing centers O on the base end sides of the upper and lower chip extractors 25 and 26 swingably supported by d and 22d.
4 moves in an arc shape, and accordingly, the claw portions 25c, 26c on the tip side of the upper and lower tip extractors 25, 26 swing into the direction away from the shank 13 of the electrode tip 14 and enter the gap C. .

As described above, the electrode tip 14 has the shank 1
When the claws 25c and 26c swing into the space C while swinging in the direction of being pulled out from the claw 25c,
With the swinging of 26c, the claws 25c, 2c
Since the leverage is applied to the portion of the tip of 6c that contacts the electrode tip 14, the electrode tip 14 can be reliably pulled out from the shank 13. Further, in this embodiment, the tilt prevention plate 29 is positioned so as to be located near the tip of the electrode tip 14.
Is provided, the tip of the electrode tip 14 is prevented from tilting toward the tip extractor body 1 when the electrode tip 14 is pulled out, and the electrode tip 14 is smoothly pulled out from the tip tapered portion of the shank 13. It is possible. Therefore, in the electrode tip exchanging device according to the present embodiment, the electrode tip 14 can be extracted with almost no load on the spot welding robot 7 itself, so that the spot welding robot 7 is not damaged when exchanging the electrode tip 14. It can be effectively prevented.

Further, in the electrode tip exchanging device of the present embodiment, the stroke amount of the rod portion 31 is set so that the stroke position of the rod portion 31 at the time when the electrode tip 14 is pulled out from the tip tapered portion of the shank 13 is detected. Since the reed switch as the stroke amount detecting means for detecting is installed in the cylinder device 30, the completion of extraction of the electrode tip 14 can be detected by this, and this detection signal is sent via the tip extraction controller 4 to the general controller. Sent to 18. If a detection signal is not generated by the stroke amount detecting means even after a lapse of a predetermined time after the operation of the cylinder device 30, the shank 1
It is possible to detect that the electrode tip 14 is abnormally attached to 3 and the electrode tip 14 cannot be removed from the shank 13. In addition, the electrode tip 14 is attached to the shank 13.
If the shank 13 or the electrode tip 14 is deformed or damaged when the tip of the abnormally mounted electrode tip 14 is removed, the cylinder device 30 is provided with a pressure control valve to By setting the operating pressure of the device 30 to a predetermined pressure, the shank 13
Shank 13 when the electrode tip 14 is abnormally attached to the
It is also possible to take protective measures such as.

In the cylinder device 30, the rod portion 31 moves back by a predetermined stroke amount and then retreats.
Along with this, the upper and lower link members 2 of the chip extractor body 1
1, 22 and the tip extractors 25, 26 are returned to their original positions by return springs 27, 28, respectively. Upon receiving the detection signal of the completion of extraction of the electrode tip 14 from the stroke amount detection means through the tip extraction controller 4, the general controller 18 sends a signal to the robot controller 9 to move the spot welding robot 7 to the tip mounting position. . As a result, the spot welding robot 7 moves to the tip mounting position of the tip mounting machine body 2. That is, the spot welding robot 7 moves so that the shank 13 of the spot welding gun 8 is located in the electrode tip holding hole 37a at the tip mounting position of the disk table 36 of the tip mounting machine body 2. In this way, when the spot welding robot 7 moves to the electrode tip mounting position,
Robot controller 9 to total controller 18
An operation completion signal of the head spot welding robot 7 is issued,
Receiving this signal, the general controller 18 sends an operation signal to the robot controller 9 to pressurize the spot welding gun 8 of the spot welding robot 7.

The spot welding robot 7 which receives an operation signal from the general controller 18 through the robot controller 9 pressurizes the welding gun 8, whereby the shank 13 enters into the electrode tip holding hole 37a of the disk table 36, The shank 1 is fitted with the electrode tip 14 previously held at the concentric position in the electrode tip holding hole 37a.
The attachment of the electrode tip 14 to 3 is completed. In addition, the welding gun 8 is controlled by the program control of the robot controller 9.
The pressing force of is released. The photoelectric switch 36a indicates that the electrode tip 14 is not held in the electrode tip holding hole 37a at the tip mounting position of the disk table 36.
Is detected, and this detection signal is sent to the general controller 18 via the chip mounting machine controller 5. As a result, it is detected that the attachment of the electrode tip 14 to the shank 13 of the spot welding gun 8 is completed, and this tip attachment completion signal is output from the general controller 18 to the robot controller 9 and the tip attachment machine controller 5 and Chip feeder controller 6
Is output to

Upon receiving the tip mounting completion signal from the general controller 18, the tip mounting machine controller 5 drives the drive motor 35 to rotate the disk table 36 by a predetermined angle, and the electrode tip holding hole 3 in which the electrode tip 14 is held.
7 is moved to the chip mounting position. Further, the chip feeder controller 6 which receives the chip mounting completion signal from the general controller 18 is the upper and lower feeder tubes 3.
9 and the upper and lower feeder rods 40 are operated to automatically supply the electrode tip 14 from the tip storage box 38 to the empty electrode tip holding hole 37. Further, the robot controller 9 receiving the tip mounting completion signal from the general controller 18 supplies the cooling water from the cooling water supply source 15 to the cooling water supply passages provided in the spot welding gun 8, the shank 13 and the electrode tip 14. Supply. Then, the flow switch 17 as a water pressure sensor installed in the cooling water supply flow path sends an ON signal to the robot controller 9 if the electrode tip 14 is normally attached to the shank 13.
To the integrated controller 18 via. in this way,
In the present embodiment, it can also be determined that the electrode tip 14 is normally attached to the shank 13. If the ON signal is not sent from the flow switch 17 to the robot controller 9 even after a lapse of a predetermined time from the start of supplying the cooling water from the cooling water supply source 15, the robot controller 9 attaches the electrode tip 14 to the robot chip 9. Judge it as a mistake,
A retry command for mounting the electrode tip 14 can also be output to the general controller 18.

Flow switch 1 as the water pressure sensor
The overall controller 18 receiving the ON signal from 4 issues a command to the robot controller 9 to move the spot welding robot 7 to a predetermined welding work position, whereby all steps of the electrode tip exchange are completed. Since the spot welding robot 7 maintains the servo ON state during this electrode tip replacement, even in a line involving a plurality of spot welding robots 7 such as a station line,
The electrode tip replacement work can be performed even while another adjacent spot welding robot is performing the welding work. Therefore, according to the present embodiment, it is possible to suppress the decrease in the operating rate of the station line due to the replacement of the electrode tip as much as possible.

In the above embodiment, the link members 21, 22 and the link members 21, 22 are used as driving means for moving the shafts 23, 24 as the swing centers O of the tip extractors 25, 26 in an arc shape. Although the cylinder device 30 including the rollers 32 and 33 for swinging is adopted,
The drive means is not limited to this configuration, and other configurations can be adopted. For example, by driving with a motor and a ball screw, driving with a rack and a pinion, or using a rotary actuator instead of the motor, the swing center O of the tip extractors 25, 26 can be changed. It is also possible to move the shafts 23, 24 in an arc shape.

[0028]

As described above, in the electrode tip exchanging device for the spot welding gun according to the first aspect of the invention, the claw portion on the tip side of the tip extractor is swung in the direction away from the shank of the electrode tip. , The shank and the electrode tip are configured to be inserted into the gap in the electrode tip fitting / removing direction, so that the electrode tip is shanked by the claw portion by utilizing the force generated by the swing of the claw portion. Can be reliably pulled out. In addition, when replacing the electrode tip in the spot welding robot, it is possible to suppress the load on the spot welding robot itself when extracting the electrode tip, and prevent damage to the spot welding robot when extracting the electrode tip. Is possible.

In the electrode tip exchanging device for a spot welding gun according to a second aspect of the present invention, the drive means for moving the swing center of the tip extractor in an arc shape is pivotally supported so as to swing the base end side of the tip extractor. Since it is composed of a swingable link member and a cylinder device having a stroke amount detecting means for swinging the link member, the extraction of the electrode tip is completed by a signal from the stroke amount detecting means,
It is possible to detect a tip extraction error when the electrode tip is abnormally attached.

Further, in the electrode tip exchanging device for a spot welding gun according to a third aspect of the invention, there is provided tip mounting means for fitting the electrode tip to the taper portion of the shank tip, and the flow provided in the spot welding gun and the electrode tip. Since it is equipped with a sensor that detects the water pressure of the cooling water supplied to the passage, after the tip extraction is completed, the electrode tip is fitted to the taper part of the shank tip by the tip mounting means, and then the spot welding gun. Further, by supplying the cooling water to the flow path provided in the electrode tip and detecting the water pressure with the sensor, it is possible to detect that the electrode tip is normally attached to the shank.

[Brief description of drawings]

FIG. 1 is a wiring system diagram of an electrode tip exchanging device for a spot welding gun according to an embodiment.

FIG. 2 is a piping system diagram of the electrode tip exchanging device for the spot welding gun according to the present embodiment.

FIG. 3 is a side view of the tip extractor main body according to the electrode tip exchanging device for the spot welding gun of the present embodiment.

FIG. 4 is a plan view of a tip extractor main body according to the electrode tip exchanging device for the spot welding gun of the present embodiment.

FIG. 5 is a side view of the upper link member of the electrode tip exchanging device for the spot welding gun according to the present embodiment.
(B) is a view on arrow A of (a), and (c) is a view on arrow B of (a).

FIG. 6 is a side view of a lower link member of an electrode tip exchanging device for a spot welding gun according to the present embodiment, FIG.
(B) is a view on arrow A of (a), and (c) is a view on arrow B of (a).

FIG. 7 is a side view of a tip extractor of an electrode tip exchanging device for a spot welding gun according to the present embodiment, FIG.
(B) is an arrow A view of (a).

FIG. 8 is a plan view showing a tip mounting machine main body relating to the electrode tip exchanging device for the spot welding gun of the present embodiment.

9 is a view of the tip mounting machine body of the electrode tip exchanging device for the spot welding gun according to the present embodiment, which is a view as seen from the arrow A in FIG.

10 is a view of the tip mounting machine body of the electrode tip exchanging device for the spot welding gun of the present embodiment, which is a view taken in the direction of arrow B in FIG.

FIG. 11 is an explanatory view showing a manner of extracting the electrode tip by the tip extractor main body of the electrode tip exchanging device for the spot welding gun according to the present embodiment.

FIG. 12 shows a conventional electrode tip exchanging device for a spot welding gun, in which (a) is a side view thereof and (b) is a plan view thereof.

[Explanation of symbols]

1 is the chip extractor main body, 2 is the chip mounting machine main body, 3
Is a tip feeder main body, 4 is a tip extracting controller, 5 is a tip mounting machine controller, 6 is a tip feeder controller, 7 is a spot welding robot, 7 is a spot welding gun, 9 is a robot controller, 13 is a shank, 14 is an electrode tip, 17 is a flow switch as a water pressure sensor, 19 is a housing, 2
Reference numerals 1 and 22 are link members, 23 and 24 are shafts as swing centers O, 25 and 26 are tip extractors, and 25b and 26b.
Is a base end portion, 25d and 26d are claw portions, 27 and 28 are return springs, 19 is a tilt prevention plate, 30 is a cylinder device, 31 is a rod portion, 32 and 33 are rollers, 36 is a disk table,
37 is a chip holding hole, 38 is a chip storage box, 39 is a feeder tube, and 40 is a feeder rod.

Claims (3)

[Claims] 1. An electrode tip exchanging device for a spot welding gun for automatically exchanging an electrode tip fitted to a taper portion of a shank tip of a spot welding gun, comprising: an electrode tip fitted to the taper portion of the shank tip. The front end side has a claw portion that can enter into the gap in the electrode tip fitting / removing direction with the shank, the base end side is movable in an arc shape, and the claw portion is formed with the base end side as a swing center. The tip side has a swingable center, and the claw portion on the tip side swings in a direction away from the shank of the electrode tip as the swing center on the base side moves in an arc shape. It is characterized by including a tip extractor capable of extracting the electrode tip from the shank by the claw portion by entering the gap, and a drive means for moving the swing center of the tip extractor in an arc shape. Electrode tip exchange device of the spot welding gun to. 2. A swingable link member for swingably supporting a base end side of the tip extractor, the drive means comprising:
2. An electrode tip replacement device for a spot welding gun according to claim 1, further comprising a cylinder device having a stroke amount detecting means for swinging the link member. 3. An electrode tip exchanging device for a spot welding gun for automatically exchanging an electrode tip fitted to a taper portion of a shank tip of the spot welding gun, comprising a link member pivotably supported so as to be swingable. The member is pivotally supported about the base end side so as to be swingable, and has a claw portion at the tip end side that can enter a gap in the electrode tip fitting / removing direction between the shank and the electrode tip,
As the center of the swing moves in an arc shape due to the swing of the link member, the claw portion on the tip end side moves into the gap while swinging in the direction away from the shank of the electrode tip. Thus, a tip extractor capable of extracting the electrode tip from the shank by the claw portion, a cylinder device having a stroke amount detecting means as a driving means for swinging the link member, and a taper portion at the tip of the shank. A spot welding gun comprising: a tip mounting means for fitting an electrode tip, a spot welding gun, and a sensor for detecting a water pressure of cooling water supplied to a flow path provided in the electrode tip. Electrode tip replacement device.