JPH049110Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention prevents deflection and displacement of the electrode tip during shaping in an automatic electrode shaping machine that shapes the electrode tip attached to the tip of the welding machine arm using a grinding tool. The present invention relates to an electrode tip holding device for holding an electrode tip.

BACKGROUND ART Conventionally, in an automatic electrode shaping machine, an electrode tip is shaped by bringing a rotating grinding tool into contact with the electrode tip. However, for welding machines in which the electrode tip is attached to a shank provided at the tip of the welding machine arm (hereinafter referred to as the arm), the electrode tip must be shaped using the conventional automatic electrode shaping device described above. In particular, the following problems arose.

Problems that the invention aims to solve: An electrode chip is provided at the tip of the arm,
Since the grinding tool that rotates on the electrode tip applies upward or downward pressing force to the grinding surface of the tip, the arm itself to which the tip is attached is distorted upward or downward, and the arm itself, along with the tip, is distorted upward or downward. The movement in the pressing direction causes the amount of grinding of the tip to become unstable, and the tip vibrates together with the arm, resulting in a decrease in machining accuracy.

Also, JP-A-60-12289 and JP-A-60-
Japanese Utility Model Publication No. 12288 and Japanese Utility Model Publication No. 58-36460 disclose a chip holding device having respective chip holding mechanisms for holding chips. but,
None of them are equipped with a chip holding mechanism composed of a fixed claw and a movable claw as in the present invention.
Therefore, each of the disclosed examples has inconvenient problems, such as not being able to securely hold the chip, and the arm to which the chip is attached may break when the chip is carried into and out of the grinding position.

The present invention was devised in view of the above-mentioned problems.The purpose of this invention is to use a chip clamping mechanism consisting of a fixed jaw and a movable jaw to securely clamp chips and to ensure vibration during grinding. In an automatic electrode shaping machine, the movable claw is opened to a retracted position when the chip is carried into and out of the grinding position, and no resistance or shock is applied to the movement of the arm on which the chip is attached. An electrode tip holding device is provided.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a mounting base equipped with a grinding tool on the shaping machine body so that it can be raised and lowered, and the mounting base is raised or lowered to be attached to the tip of the welding machine arm. A grinding tool is brought into contact with the tip of the electrode chip, and the tip of the chip is ground.A chip holding mechanism is disposed in the main body of the shaping machine to hold the chip at the position where the grinding tool contacts the chip. In an electrode chip holding device for an automatic electrode shaping machine in which the chip is held by a chip holding mechanism, the chip holding mechanism is composed of a fixed claw and a movable claw corresponding to the fixed claw, and the fixed claw is welded. It is equipped with a chip receiving part that receives an electrode chip carried into a position facing above or below the grinding tool by the rotation of the machine arm, and the movable claw faces the fixed claw and is fixed to the support rod, The movable claw is connected to the piston rod of the cylinder for driving the movable claw via a rod, and when the piston rod is extended, the movable claw opens the tip receiving part. The electrode tip is always resiliently biased in the pushing direction into the formed recess, and when the electrode tip is displaced by the upward or downward pressing force of the grinding tool, it engages with the stepped part of the recess to prevent the displacement. It is characterized in that the chip holding mechanism is provided with a protruding and retracting piece that prevents the chip from moving in and out.

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

FIG. 1 shows a side view of the shaping machine, and A is the shaping machine main body, which consists of a pedestal 1 and a frame 2. The frame body 2 is made up of a pair of upper and lower plates 3 and 4 framed by a plurality of support posts 5. The frame body 2 is provided with a pair of guide rods 6, 6 as shown in the plan view in FIG. It is fixed to the piston rod 9 of the cylinder 8. Reference numeral 10 indicates a grinding tool having a grinding surface having the same shape as the tip end shape of the electrode chip to be ground. The grinding tool 10 is held by a cylindrical holder 12 that protrudes from the frame 2 in the direction of the turning locus K of arms 50, 51 to which chips 52, 53 are attached. The grinding tool 10 is configured to rotate around a vertical axis by a rotary drive source 14 such as an air motor built in a case 13 that is integrally provided behind the mounting base 11.

The case 13 described above is attached to the metal fitting 7 by a fixture 15. Therefore, when the cylinder 8 is operated to extend and retract the piston rod 9, the mounting base 11 along with the case 13 moves up and down within a predetermined range. At this time, since the metal fitting 7 is accurately guided by the guide rods 6, 6, the mounting base 1
The grinding tool 10 attached to the grinding tool 1 reliably moves up and down along a predetermined vertical path without lateral vibration. Further, the cylinder 8 is capable of two-step expansion and contraction operations, and when set at the neutral position shown in FIG.
The electrode chips 52 and 53 attached to the tips of the grinding tool 10 are allowed to be carried into the upper and lower surfaces of the grinding tool 10 so as to face each other by the rotation of the arms 50 and 51. In addition, 16
is a cover that covers the periphery of the grinding tool 10.

17 indicates a chip holding mechanism. This mechanism 17 holds the upper and lower electrode chips 52 and 53 at opposite positions, facing the upper and lower surfaces of the grinding tool 10, and includes a fixing claw 18 that is U-shaped in side view, and a fixing claw 18 provided on the top of the fixing claw 18. an upper movable claw 19;
Lower movable claw 2 provided below the fixed claw 18
Consists of 0. Further, as shown in FIG. 2, the fixing claw 18 is relatively rotatably supported by a support rod 21 rotatably provided on the frame 2.
It is fixed to a support plate 2a erected on the frame 2. The upper protruding piece 18a and the lower protruding piece 18b of the fixed claw 18 are both formed with a chip receiving part 23 which receives arms 50 and 51 having V-shaped chips attached thereto. On the other hand, the upper movable claw 19 is fixed to the support rod 21 in a state opposite to the upper protruding piece 18a of the fixed claw 18, and a protruding rod 22 extending from the base end thereof is installed in the frame 2. The piston rod 24a of the movable pawl driving cylinder 24 is connected to the piston rod 24a. and,
When the piston rod 24a of the cylinder 24 is extended and the upper movable claw 19 is opened to the unloading position shown by the imaginary line in FIG. allowed to be brought in. The lower movable claw 20 is fixed to the support rod 21 in a state opposite to the lower protruding piece 18b of the fixed claw 18, and is connected to the cylinder 24 in the same way as the upper movable claw 19.

Next, as shown in FIG.
Retractable pieces 25 are provided at two locations in the center of each side of the V-shaped concave portion formed on the upper protruding piece 18a, and at one location on the movable claw 19 facing the upper protruding piece 18a. The arm to which the chip is attached is reliably supported at three points.

FIG. 4 shows the configuration of the retractable piece 25 provided on the upper protruding piece 18a. As is clear from the figure, the retractable piece 25 is attached to the outer circumferential surface of the recess 54 formed in the shank 55 of the arm 50 to which the chip is attached by the spring 26 stretched between it and the upper protruding piece 18a. It is constantly biased so that it protrudes from the opposite direction.
In other words, the protruding and retracting piece 25
3, the recess 54 formed between the upper electrode chip 52 and the shank 55 is constantly biased in the pushing direction. Also, the recess 5
4 is the upper electrode chip 5 as explained at the beginning.
2 is a shank 55 provided at the tip of the arm 50.
It is formed by attaching it to the Above, the retractable piece 25 provided on the upper protruding piece 18a has been explained, but the upper movable claw 19
The same applies to the retractable pieces provided on the lower movable claw 20, and when the chip holding mechanism 17 clamps the shank 55 of the arm 50 to which the electrode chip 53 is attached, these three retractable pieces 25 move. As shown in FIG. 2, it is configured to be pushed into the recess 54 shown in FIG. 4 while maintaining a reliable three-point support state at three equiangularly spaced locations.

Next, the operation will be explained.

The upper and lower electrode tips 52 and 53 are carried into opposing positions on the upper and lower surfaces of the grinding tool 10 by the rotation of the arms 50 and 51 during a short period of time when they are not used for spot welding, and the shaping is completed within that time. Then, the arms 50 and 51 are rotated to carry it out from the opposing position, and it is again used for welding work. If there is a request to shape a pair of upper and lower electrode chips 52, 53 at the same time, a chip holding mechanism 17 is provided for each of the electrode chips 52, 53 as in this embodiment. It is also advantageous that the grinding tool is mounted on a mounting base 11 that can be raised and lowered. Although the arms 50 and 51 are normally rotated together, they may be rotated separately to stagger the timing of shaping the upper and lower electrode tips 52 and 53. When the arms 50 and 51 with the electrode chips 52 and 53 attached thereto are carried in and out, the upper movable claw 19 and the lower movable claw 20 are rotated open by the cylinder 24, and the carrying in and out route is changed. not be hindered.

For example, the upper electrode tip 52 is carried into a position facing the grinding tool 10, and while pushing the retractable piece 25 provided on the fixed claw 18 against the bias of the spring 26, the tip receiving part 23 of the upper protruding piece 18a is pressed. When the retractable piece 25 is received by the spring 26, it is pushed into the recess 54 between the electrode chip 52 and the shank 55 as shown in FIG. It rotates in a direction approaching the fixing claw 18 as indicated by arrow B in FIG. 2 and moves to a position where it presses the shank 55 of the arm 50 to which the upper electrode chip 52 is attached. Furthermore, by pressing the recess 54 with the biasing force of the retractable piece 25, the upper electrode chip 52 is reliably held by the chip holding mechanism 17 via the shank 55 by three-point support. From this state, the mounting base 11, which had been set at the neutral position, is pushed up by the cylinder 8,
The grinding tool 10 comes into contact with the upper electrode chip 52, and then the upper electrode chip 52 is ground by the grinding tool 10 which is rotated by the rotary drive source 14 and shaped into an appropriate state. During grinding, the upper electrode tip 5
The shank 55 of the arm 50 to which the electrode chip 52 is attached is securely held by the chip holding mechanism 17 through three-point support.
is prevented from vibrating or idling against the shank 55 during grinding, and a stable machining state is maintained. After the shaping is completed, the mounting base 11 is lowered by the cylinder 8 and the upper movable claw is moved back by the cylinder 24, and the arm 50 is rotated to carry out the electrode chip 52.

In the series of operations described above, the upper electrode tip 52 is positioned with respect to the grinding tool 10 by a teaching machine (not shown), but as in this embodiment, the upper electrode tip 52 is By pressing the arm 50 to which the upper electrode chip 52 is attached with the upper movable claw 19 against the chip receiver 23 by means of the chip receiver 23 recessed in a V-shape, the reliability of positioning the upper electrode chip 52 can be increased. There are further advantages. Furthermore, when the pushing force of the cylinder 8 acts in the upward direction on the electrode tip 52 during tip shaping, this force causes the electrode tip 52 to slide while being held by the tip holding mechanism 17, as shown in FIG. There is a possibility that it will escape upwards as shown by arrow C. When such a situation occurs, the grinding tool 10 against the electrode tip 52
The amount of grinding is insufficient and the depth of cut during grinding cannot be maintained sufficiently, resulting in unstable machining conditions. However, in this embodiment, even if the electrode chip 52 escapes upward as shown by arrow C in the same figure, the protruding and retracting piece 25 is disposed on the upper end surface of the electrode chip 52, that is, the stepped portion 54a of the recess 54.
to prevent its movement. Therefore, no more electrode chips 52 escape, and a stable processing condition is maintained.

When shaping the lower electrode chip 53, the mounting base 11 in the neutral position is lowered by the cylinder 8, and the grinding tool 10 is brought into contact with the lower electrode chip 52. The other steps are the same as those for shaping the upper electrode chip 52.

Effects of the invention As explained above, according to the invention, since the electrode tip is attached to the tip of the arm, the electrode tip is in a state where it is easily vibrated by rotating it in contact with the grinding tool. However, since the electrode chip is reliably held by the chip holding mechanism composed of a fixed claw and a movable claw, it is possible to reliably prevent the vibration of the chip during grinding. Moreover, when carrying the chip in and out of the grinding position, by opening the movable claw,
There is no resistance or impact to the pivoting movement of the arm to which the tip is attached, and therefore, there is an effect of preventing the arm to be broken or bent when the arm to which the tip is attached is moved. .

Furthermore, if the chip holding mechanism is provided with a retractable piece,
Above the chip due to the raising and lowering of the grinding tool, or
Since downward displacement can be reliably prevented, problems such as insufficient grinding amount can be resolved, and a stable predetermined shaping state can be obtained, which can further improve the machining accuracy of electrode chips in automatic electrode shaping machines. Accompanied by the effect that can be done.

[Brief explanation of the drawing]

Fig. 1 is a side view showing an automatic electrode shaping machine according to an embodiment of the present invention, Fig. 2 is a plan view taken along the line FIG. 4 is an enlarged plan view showing the main parts; FIG. 4 is a cross-sectional view for explaining the retractable piece provided on the fixed claw;
The figure is a partially enlarged sectional view for explaining the operation of the retractable piece. A...Main body of shaping machine, 8...Cylinder, 10...
Grinding tool, 11...Mounting base, 14...Rotary drive source for the grinding tool, 17...Chip clamping mechanism, 18...
Fixed claw, 19... Upper movable claw, 20... Lower movable claw, 21... Support rod, 24... Cylinder, 2
5... Retractable piece, 26... Spring, 50, 51... Arm, 52, 53... Electrode chip, 54... Recess, 54a... Stepped portion.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A mounting base equipped with a grinding tool is provided on the shaping machine body so that it can be raised or lowered, and the mounting base is raised or lowered to apply the grinding tool to the electrode tip attached to the tip of the welding machine arm. While grinding the tip of the chip, a chip clamping mechanism is disposed in the shaping machine body to clamp the chip at a position where the grinding tool contacts the chip, and the chip clamping mechanism holds the chip during chip grinding. In an electrode tip holding device for an automatic electrode shaping machine, which is designed to hold the tip between
The chip holding mechanism is composed of a fixed claw and a movable claw corresponding to the fixed claw, and the fixed claw holds the electrode chip carried into a position facing above or below the grinding tool by the rotation of the welding machine arm. The movable claw is provided with a chip receiving part for receiving the tip, and the movable claw is fixed to a support rod opposite to the fixed claw, and is connected to a piston rod of a movable claw driving cylinder via a protruding rod, so that the movable claw is caused to pick up the chip by extension of the piston rod. An electrode tip holding device for an automatic electrode shaping machine, characterized in that a receiving part is open. 2. When the recess formed in the attachment part of the welding machine arm and the electrode tip is constantly elastically biased in the pushing direction, and the electrode chip is displaced by the upward or downward pressing force of the grinding tool, the recess is pressed into the recess. The electrode chip in the automatic electrode shaping machine according to claim 1, wherein the chip holding mechanism is provided with a retractable piece that engages with the stepped portion of the chip and prevents its displacement. holding device.