JP2005118834A - Chip exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chip removing mechanism which has a simpler structure and can be downsized and a chip exchanger having such chip removing mechanism. <P>SOLUTION: The chip removing mechanism 3 is equipped with a lever-operated lever 13 which is inserted bweeen a shank 9 of a welding gun 7 and a chip 11, a main unit 14 to which the lever is connected, and a movable supporting means 18 which is disposed between the lever and the main unit and oscillatably and slidably supports the lever with a single shaft. The movable supporting means 18 is equipped with a cam roller means including cam rollers 19 disposed at a ratio of one per side of the lever-operated lever and a cam groove means including cam grooves 21 disposed at a ratio of one per cam roller formed in the main unit. Also, the cam grooves extend in a linear form. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electrode tip exchange device for exchanging electrode tips of a spot welder.

  In general, spot welding presses the material to be welded with a pair of tips to ensure a current path, and as the number of welding points increases, the tip shape of the tip deforms due to heat generated by a large current during welding and pressure. As a result, it is worn out and sufficient welding quality cannot be obtained. Therefore, at an appropriate time, the production line is stopped and the chip is automatically polished, or it is removed and replaced with a new one or polished one to ensure the tip shape of the chip.

  By the way, in recent years, chemical treatment materials such as high rust prevention have come to be used for the materials to be welded, and there is a tendency for electrode tips to be worn out and to be replaced more frequently. It doesn't fit the current situation. In order to change the tip without stopping the production line, it must be performed from the end of the welding operation to the start of the next welding (for example, the workpiece transfer time). However, this time is short and can be several seconds. Therefore, an apparatus that can automatically replace the electrode tip has been devised.

  Japanese Patent Application Laid-Open No. 2002-79381 discloses a tip changer having a mechanism for removing a tip from a shank of a welding gun by swinging a lever lever (see Patent Document 1). Based on FIG. 7, this type of chip removal mechanism will be described. The tip removal mechanism 51 is provided with an air cylinder 53, a pair of left and right guide plates 55 provided to be slidable in the front-rear direction by the air cylinder 53, and swingable and slidable with respect to the guide plates 55. A lever lever 57 is provided. Each guide plate 55 is provided with a pair of front and rear cam grooves 59a and 59b. That is, the entire pair of guide plates 55 is provided with a total of four cam grooves 59a and 59b. Each cam groove 59a, 59b extends in an arc shape. In addition, a total of four cam rollers 61 a and 61 b are provided on the side surface of the lever lever 57, a pair of left and right. The pair of front cam rollers 61a are inserted into the pair of front cam grooves 59a, and the pair of rear cam rollers 61b are inserted into the pair of rear cam grooves 59b.

  The chip extraction operation of the chip extraction mechanism 51 having such a configuration will be described. As shown in FIG. 7A, the guide plate 55 is further directed toward the shank 9 by the action of the air cylinder 53 from the state in which the lever 57 is inserted between the shank 9 and the tip 11 of the welding gun. Move forward. As a result, the lever lever 57 receives a reaction force from the shank 9 or the like, and the cam rollers 61a and 61b move while being guided by the cam grooves 59a and 59b. As shown in FIG. Oscillate with respect to etc. Finally, the tip 11 is pushed up from the shank 9 by the swinging of the lever lever 57 and extracted.

JP 2002-79381 A

  However, in the tip extraction mechanism in the conventional tip changer described above, two cam rollers are provided on each of the left and right sides of the lever lever, so there are a large number of parts and two cams arranged in front and rear to correspond to them. Since the formation of the groove is also forced, the total length of the guide plate, and thus the total length of the apparatus, tends to be longer in the front and rear direction.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a chip extraction mechanism that has a simpler structure and can be made compact, and a chip changer having such a chip extraction mechanism. To do.

  In order to achieve the above-described object, the tip extracting mechanism according to claim 1 includes a lever lever inserted between a shank and a tip of a welding gun, a main body portion to which the lever lever is coupled, A lever is provided between the lever lever and the main body, and movable support means for supporting the lever lever slidably and slidably on one axis is provided.

  Further, the chip extraction mechanism according to claim 2 is characterized in that in claim 1, the movable support means includes cam roller means including a cam roller provided on one side of the lever lever, and the main body part. And a cam groove means including a cam groove prepared at a ratio of one to the cam roller.

  According to a third aspect of the present invention, there is provided the chip extracting mechanism according to the second aspect, wherein the cam groove extends linearly.

  The tip extraction mechanism according to claim 4 is the standby position according to any one of claims 1 to 3, wherein the lever lever waits for insertion between the shank and the tip, and the standby position. And a posture defining means for defining a predetermined posture of the lever lever at the standby position, and a position of the lever lever at the standby position. And urging means for urging to return to the position.

  According to a fifth aspect of the present invention, there is provided a chip exchanging device including the chip extracting mechanism according to any one of the first to fourth aspects.

  According to a sixth aspect of the present invention, there is provided the chip exchanging device according to the fifth aspect, wherein the main body of the chip extraction mechanism is fixed so as not to move at least in the front-rear direction.

  According to the present invention, the lever is pivoted and slid in a single axis so that the tip is extracted by the lever operation, so that the swing / slide fulcrum can be simplified. The cost can be reduced, and the total length of the lever lever in the moving direction of the tip extraction mechanism can be shortened.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Embodiment 1 FIG.
FIG. 1 schematically shows an outline of the chip exchange device according to the first embodiment. The chip changer 1 mainly includes a chip removal mechanism 3 and a replacement chip supply mechanism 5. Both mechanisms will be described with reference to FIG.

  First, the tip removal mechanism 3 includes a lever lever 13 for removing the tip 11 fitted to the tips of a pair of upper and lower shanks 9 of the welding gun 7, and a main body portion 14 of the tip removal mechanism to which the lever lever 13 is coupled. And have. The main body 14 is composed of a pair of left and right guide plates 15 that movably support the lever lever 13. A notch 17 having a U-shape in plan view is formed at the tip of the lever lever 13. Thereby, the tip of the lever lever 13 can be inserted between the shank 9 and the tip 11 of the welding gun 7.

  In addition, the chip removal mechanism 3 includes movable support means 18 that is provided between the lever lever 13 and the main body 14 and supports the lever lever 13 so as to be swingable and slidable on one axis. The movable support means 18 is provided at a ratio of one cam roller means including a cam roller provided on one side surface of the lever lever 13 and one main roller formed on the main body portion 14. Cam groove means including a cam groove. That is, in this embodiment, as the cam roller means, a pair of left and right cam rollers 19 are rotatably attached to the side surface of the base portion of the lever lever 13. On the other hand, as the cam groove means, each guide plate 15 is formed with a cam groove 21 that accommodates the corresponding cam roller 19 in a rollable manner. Each cam groove 21 has an elongated hole shape extending with a width slightly larger than the outer diameter of the cam roller 19. The extension axis CL (see FIG. 5A) of each cam groove 21 extends linearly. In addition, each cam groove 21 is provided to be inclined so as to be positioned higher toward the rear. In the description, it is assumed that the front and rear direction of the lever lever 13 is determined as the front side. With such a configuration, the lever lever 13 is swingably supported by a single shaft that passes through the rotation shafts of the pair of cam rollers 19. Further, the lever lever 13 is slidably supported by the cam roller 19 rolling in the cam groove 21 and the rotation axis of the cam roller 19 being guided along the extension axis CL of the cam groove 21. .

  In addition, as shown in FIG. 3, a torsion coil spring 22 is provided between the pair of left and right guide plates 15 as urging means. The torsion coil spring 22 is arranged so that the torsion axis is orthogonal to the guide plate 15. One arm 22 a of the torsion coil spring 22 is hooked to a pin 15 a that crosses the pair of guide plates 15, and the other arm 22 b is hooked to the rear end of the lever lever 13. With this configuration, the lever lever 13 is urged so as to return to a standby position described later by the elastic force of the torsion coil spring 22. Further, a guide 15b as a posture defining means is bridged between the pair of guide plates 15. The guide 15b is in surface contact with the lower surface of the lever lever 13 on the upper surface thereof to define and hold the lever lever 13 in a predetermined posture. With this configuration, the lever lever 13 is supported in a posture suitable for insertion between the shank 9 and the tip 11 at the standby position.

  Next, the replacement chip supply mechanism 5 will be described with reference to FIG. The replacement chip supply mechanism 5 mainly includes a rotation magazine 23, a feed mechanism 25, and an input member 27. The rotating magazine 23 has a cylindrical case 29 provided rotatably, and a plurality of replacement chips 31 are accommodated in the cylindrical case 29. The plurality of replacement chips 31 are arranged on the same radius circumference around the rotation center of the rotation magazine 23. A claw gear portion 33 is provided on the outer circumferential portion of the cylindrical case 29.

  The feed mechanism 25 includes a force transmission means 35 for transmitting a rotational force to the rotary magazine 23 and a coil spring 37 that functions as a restoring force applying means. The force transmission means 35 includes a slide plate 39, a claw 41, and a claw urging spring 43. The slide plate 39 is provided so as to be linearly slidable along the longitudinal direction thereof. The claw 41 is swingably attached to the slide plate 39 at its base end. Further, the tip portion of the claw 41 is disposed so as to mesh with the teeth of the claw gear portion 33 of the rotary magazine 23 at least in any position in the swinging state. One end of the claw urging spring 43 is connected to the slide plate 39, and the other end of the claw urging spring 43 is connected to the claw 41. As a result, the claw 41 is constantly urged in the direction of meshing with the teeth of the claw gear portion 33 by the elastic force of the claw urging spring 43.

  A member 45 having a substantially L-shape in plan view is provided on the rear end side of the slide plate 39, and one end of a coil spring 37 is connected to the member 45. On the other hand, the other end of the coil spring 37 is connected to a support bracket 47 that slidably supports the slide plate 39.

  The input member 27 is a flat plate-like member, and is attached to the front end of the slide plate 39 with its front and back surfaces oriented almost horizontally. Further, the input member 27 has an input surface 27a that comes into contact with the welding gun 7, and the input surface 27a is in a direction crossing the movement path S of the welding gun 7, that is, in a direction not at least parallel to the movement path, as will be described later. It is extended.

  Next, the movement path S of the tip replacement process of the welding gun 7 will be described. As shown in FIG. 2, the welding gun 7 comes into contact with the lever lever 13, pushes the lever lever 13 toward the guide plate 15, and then returns to the position before the contact with the lever. In this way, the worn tip 11 is removed from the welding gun 7 at the tip removal position A where the reciprocating operation along the longitudinal direction of the lever 13 is performed. Subsequently, the welding gun 7 moves from the tip removal position A to the tip receiving position B located in front of the replacement tip supply mechanism 5. At the tip receiving position B, the welding gun 7 approaches the cylindrical case 29 and receives the replacement tip 31 and then reciprocates away from the cylindrical case 29 again. When the replacement of the new tip is completed, the tip moves to a welding position (not shown) and is used for welding work.

  Furthermore, the chip exchange operation of the chip exchange apparatus according to the present embodiment having the above-described configuration will be described. At the time of tip replacement, the welding gun 7 moves along the moving path S as described above. First, the shank 9 and the tip 11 of the welding gun 7 move to the front front of the lever lever 13. At this time, in the chipping mechanism 3, the lever lever 13 is in the solid line state of FIG. 3 and the standby position shown in FIG. The shank 9 and the tip 11 are moved along the longitudinal direction of the lever lever 13 so that the lever 13 is inserted between the shank 9 and the tip 11 by operating. Since the notch 17 is formed at the tip of the lever lever 13, the insertion state is as shown in FIGS. 3 and 5B.

  From this state, the shank 9 and the like are moved so as to push the lever lever 13 backward. Here, since the guide plate 15 is fixed at least in the front-rear direction (completely fixed in the present embodiment), the lever lever 13 and the cam roller 19 are moved relative to the guide plate 15 that is not moved by the moving force of the welding gun 7. Move backward. Further, since the cam roller 19 is restricted to move along the cam groove 21, it moves rearward and upward. Further, the lever lever 13 moves rearward with its tip portion inserted between the shank 9 and the tip 11. Under the above conditions, the lever lever 13 and the cam roller 19 move rearward while raising the rear end thereof, and finally pass through the states (c) and (d) of FIG. Move to the tip removal position indicated by the dotted line. By such an inclination operation while the lever lever 13 is moving from the standby position to the tip removal position, the contact point between the lower end 11a of the tip 11 and the upper surface of the lever lever 13 is used as a lever, and the step of the shank 9 is performed. A lever operation is performed with the contact point between the attaching portion 9 a and the lower surface of the lever lever 13 as a fulcrum, and the tip 11 is removed from the shank 9.

  After pushing the lever lever 13 to the tip removal position, the welding gun 7 returns to the position before contact so that the shank 11 is separated from the lever lever 13. As a result, the lever lever 13 receives the elastic force of the torsion coil spring 22 and moves forward toward the standby position while maintaining the contact state with the shank 11, and the shank 11 is completely separated from the lever lever 13. At that time, it returns to the original horizontal standby position and prepares for the next chip removal operation.

  The welding gun 7 is sufficiently separated from the lever lever 13 at the tip removal position A, and then moves toward the tip receiving position B in front of the replacement tip supply mechanism 5 disposed next to the welding gun 7. At this time, the input surface 27a of the input member 27 is positioned between the chip removal position A and the chip receiving position B in the movement path S, and the input surface 27a extends in a direction intersecting the movement path S. Therefore, the welding gun 7 moves toward the tip receiving position B while being in contact with the input surface 27a and applying a force. That is, the input member 27 receives the moving force of the welding gun 7, and the slide plate 39 in the feed mechanism 25 moves along its longitudinal direction as shown in FIG. 4B while resisting the elastic force of the coil spring 37. Slide linearly. As the slide plate 39 slides, the claw 41 that slides with it applies a rotational force to the claw gear portion 33 to rotate the rotation magazine 23 by one arrangement pitch of the replacement chips 31.

  As the rotation of the rotating magazine 23 for one pitch is completed, the welding gun 7 starts to move closer to the rotating magazine 23 at the tip receiving position B, and the shaft center of the shank 9 is used for replacement. It moves to a position that coincides with the axis of the tip 31. Then, after inserting the shank 9 into the replacement tip 31 in the cylindrical case 29, the welding gun 7 moves away from the rotary magazine 23 with the replacement tip 31 attached to the shank 9. . In this way, a chip replacement operation is performed in which the old worn chip 11 at the tip of the shank 9 is removed and a new replacement chip 31 is attached.

  On the other hand, in the feed mechanism 25, the slide plate 39 that has been slid once to the feed completion position (position (b) in FIG. 4) against the elastic force of the coil spring 37 is applied by passing the welding gun 7. Due to the release of the moving force, this time, the elastic force of the coil spring 37 becomes a restoring force and starts moving toward the standby position (position (a) in FIG. 4) ((c) in FIG. 4). reference). At this time, the claw 41 swings in accordance with the tooth shape of the claw gear portion 33, and the slide plate 39 returns to the standby position without obstructing the engagement of the claw 41 and the claw gear portion 33 ((( d)).

  As described above, in the present embodiment, in the tip removal mechanism 3, the tip is removed by the lever operation by swinging and sliding the lever lever uniaxially. Accordingly, one cam roller as a swing / slide fulcrum is sufficient for one side of the lever lever, and the structure is simpler than the conventional configuration having two left and right cam rollers shown in FIG. There are such advantages. That is, by reducing the number of cam rollers, it is possible to reduce costs in terms of manufacturing, management, and maintenance. Further, as the number of cam rollers is reduced, the number of cam grooves required corresponding to the number of cam rollers is reduced, and the labor and cost required for forming the cam grooves can be reduced. Furthermore, since only one cam groove needs to be provided on one side of the guide plate corresponding to the cam roller, the front and rear of the guide plate are compared to the case where the cam grooves are arranged in two rows in the front and rear direction as shown in FIG. The overall length in the direction can be shortened, and as a result, the entire apparatus can be made compact.

  Further, in the embodiment in which there are two cam rollers and cam grooves on one side as shown in FIG. 7, the tilting posture of the lever lever is unambiguous depending on the positions of the cam grooves of the two cam rollers regardless of the position of the shank or tip. Will be determined. The tip of the lever lever always slides along a fixed path. On the other hand, in the present embodiment, since the lever lever is supported on one axis, the lever itself can always swing, and the inclination posture of the lever lever is determined by the positions of the shank and the tip. The In other words, the lever lever is moved by extracting the tip 11 having a relatively weak holding force against the reaction force from the shank 9 supported by a relatively strong holding force. Can be swung to escape. Therefore, as shown in FIG. 6, not only is the shank 9 swinging so that the shank 9 is below and biasing the tip 11 upward, but the shank 9 is swinging so that the tip 11 is upward and biases the tip 11 downward. It can also be applied to movements.

  Further, in the present embodiment, the linear cam groove 21 is used without using the two curved (arc-shaped) cam grooves on one side for uniquely determining the inclination posture of the lever lever. Therefore, the cam groove forming process is greatly simplified and the cost is reduced. Further, the relative movement between the lever lever 13 and the main body portion 14 of the tip removal mechanism 3 is not used with a dedicated driving means such as an air cylinder as in the prior art, and a welding gun that is indispensable in an automatic welding process. It is carried out using 7 movement forces. Therefore, the dedicated drive means such as an air cylinder is not necessary, and related components such as a control mechanism and a guide mechanism such as a rail are not required, and the apparatus is made compact and energy saving is achieved by reducing costs. It is possible.

  The present invention described above is not limited to the above-described embodiment, and can be implemented with various modifications. For example, in the present invention, the cam roller means only needs to include at least one cam roller provided on one side of the lever lever, and on both sides of the lever lever as in the above embodiment. Instead of a mode in which two cam rollers are prepared one by one, a mode in which the cam roller means is configured by only one cam roller provided on one side of the lever lever as long as sufficient strength and rigidity can be secured. Good. The same applies to the number of cam grooves of the cam groove means.

  Further, in the above-described embodiment, the structure is such that the lever 13 is pushed between the shank 9 and the tip 11 by the movement of the welding gun 7, but the relative movement between the welding gun and the tip removal mechanism is performed. Is not limited to such a structure. For example, the tip removal mechanism of the present invention may be moved by an air cylinder or the like as in the prior art. In that case, although the number of air cylinders and the components associated therewith increases, the advantage that the chip removal mechanism itself can be made more compact than the conventional one is still obtained by making the other configurations the same as in the above embodiment.

  Further, the lever-type lever movable support means is not limited to the mode composed of the cam roller means and the cam groove means as in the above-described embodiment, but is processed to ensure sufficient slidability and the same as the cam roller. A shaft support means including one or more protrusions prepared in a proportion of the aspect, and a long hole including one or more elongated holes that guide and hold the protrusion so as to rotate and slide and are prepared in the same aspect ratio as the cam groove. You may make it comprise from a means.

  Furthermore, the biasing means for the lever lever is not limited to the torsion coil spring 22, and other configurations such as a tension coil spring and an air spring may be used as long as the biasing action is obtained.

It is a figure showing the composition outline of the chip exchange device concerning an embodiment of the invention. It is a top view of the chip extraction mechanism and the chip supply mechanism for exchange in a chip exchange device. It is a figure which shows the plane and side surface of a chip | tip extraction mechanism. It is operation | movement explanatory drawing of the chip supply mechanism for replacement | exchange in a chip | tip exchange apparatus. It is operation | movement explanatory drawing of the chip | tip removal mechanism in a chip | tip exchange apparatus. It is a figure which shows the usage condition variation of a chip | tip removal mechanism. It is a figure which shows the chip | tip extraction mechanism in the conventional chip | tip exchange apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Tip change device, 3 Tip extraction mechanism, 7 Welding gun, 9 Shank, 11 Tip, 13 Lever lever, 14 Main body part, 15b Guide (attitude | position definition means), 18 Movable support means, 19 Cam roller, 21 Cam groove, 22 Torsion coil spring (biasing means).

Claims (6)

A lever lever inserted between the shank and tip of the welding gun;
A main body to which the lever lever is coupled;
A tip extraction mechanism for a tip changer, comprising: a movable support means provided between the lever lever and the main body and supporting the lever lever slidably and slidably on one axis.   The movable support means is prepared at a ratio of one cam roller means including a cam roller provided on one side of the lever lever and one cam roller formed on the main body. 2. A tip removal mechanism for a tip changer according to claim 1, further comprising cam groove means including a cam groove.   The tip removal mechanism of the tip changer according to claim 2, wherein the cam groove extends linearly. The lever lever is movable between a standby position waiting for insertion between the shank and the tip and a tip extraction position where the tip is pulled out in an inclined posture with respect to the standby position. ,
2. The apparatus according to claim 1, further comprising posture defining means for defining a predetermined posture of the lever lever at the standby position, and biasing means for biasing the lever lever to return to the standby position. The chip extraction mechanism of the chip change apparatus as described in any one of thru | or 3.   A chip exchanging device comprising the chip extraction mechanism according to claim 1.   6. The chip changer according to claim 5, wherein the main body of the chip extraction mechanism is fixed so as not to move at least in the front-rear direction.

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