JPH049111Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is an automatic electrode shaping machine that shapes an electrode tip attached to the tip of a welding machine arm using a grinding tool. This invention relates to an electrode tip holding device for preventing displacement.

[Conventional technology]

Initially, automatic electrode shaping machines shaped the electrode chips by bringing a rotating grinding tool into contact with the electrode tips. However, for welding machines in which the electrode tip is fitted into 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 automatic electrode shaping machine described above. The following problems arose.

That is, an electrode chip is provided at the tip of the arm,
In addition, since a rotating grinding tool is brought into contact with the electrode tip, the electrode tip vibrates during grinding, which tends to make the state during the grinding process (hereinafter referred to as the "machining state") unstable, resulting in reduced machining accuracy. There were some problems that could easily lead to a decline. In addition, since the grinding tool contacts and rotates the electrode tip that is only fitted into the shank, the electrode tip may idle relative to the shank, which may result in insufficient cutting depth or machining accuracy. This was causing a decline in

To deal with this problem, a conventional mechanism for holding the electrode tip in the grinding position was developed
−12289, Publication No. 60-12288, Publication No. 1988−
It is proposed in each publication of No. 36460.

[Problem that the invention attempts to solve]

However, JP-A-60-12289 and JP-A-60-12289
The electrode chip holding mechanism disclosed in No. 12288 has a basic configuration in which a hole for holding an electrode chip is provided in a base plate, and this hole is opened toward the direction in which the electrode chip is carried in and out. Since a bush for positioning the tip is provided, or a stopper for preventing the electrode tip from being removed is provided in the open part of the hole so as to be biased to protrude by a bullet, there are the following disadvantages.

That is, in the above configuration, neither the tip positioning bush nor the stopper pin for preventing removal of the tip actively holds the electrode tip. Therefore, in order to hold the electrode tip in the holding hole, the electrode tip must be held at all times. The robot must continue to be driven to press against the base plate. In addition, since electrode chips come in various sizes, it is necessary to replace the holding mechanism each time a different size is set. However, in the conventional configuration described above, the base plate for holding the chips is large and it is difficult to replace it. It's hard to do.

On the other hand, Japanese Utility Model Publication No. 58-36460 discloses a mechanism in which an electrode chip is clamped by a clamp driven by an air actuator, but in this prior art, by replacing the electrode chip, The entire clamp, including the air actuator, must be replaced, resulting in high replacement costs.Also, it is necessary to prepare as many clamps as there are types of electrode chips, making storage cumbersome. be.

The present invention solves these problems by reliably preventing vibration and idling of the electrode tip during grinding, and at the same time, the chip clamping mechanism can accommodate electrode chips of different sizes and shapes. It is an object of the present invention to provide an electrode tip holding device having a structure that allows easy replacement.

[Means for solving problems]

In order to achieve the above object, the electrode chip holding device in the automatic electrode shaping machine of the present invention is provided with a mounting base equipped with a grinding tool that can be raised and lowered in the shaping machine body, and also allows the grinding tool to be removed by raising or lowering the mounting base. A chip clamping mechanism is installed in the shaping machine body that clamps the chip at the position where it contacts the electrode chip attached to the tip of the welding machine arm, and the grinding tool is brought into contact with the electrode chip by raising or lowering the mounting base. In an electrode chip holding device in an automatic electrode shaping machine that grinds the tip end of the chip by grinding the tip, the chip holding mechanism
It includes a fixed claw that restricts movement of the electrode chip from the surrounding area except for the carrying in/out route, and a movable claw that comes into contact with the electrode chip so as to close the carrying in/out route,
The fixed claw is detachably attached to the frame of the shaping machine body, the movable claw is detachably attached to a rotating block provided on the shaping machine body so as to be rotatable around a vertical axis, and the rotating block is movable. The gist is that the tip is connected to the piston rod of the pawl driving cylinder by a protruding rod, and the tip receiving portion is closed and opened by moving the piston rod back and forth.

[Effect]

In this electrode chip holding device, a fixed claw and a movable claw that match the size and shape of the electrode chip are attached to the frame body or rotating block with bolts, etc. in advance, and the fixed claw and movable claw are used to hold the electrode chip. While holding the electrode tip, the grinding tool is raised or lowered to come into contact with the electrode tip to perform grinding.

Furthermore, if the shape or size of the electrode chip is different, the most suitable fixed claw or movable claw should be used.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a 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 plate bodies 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.
A metal fitting 7 guided by the piston rod 9 is fixed to a piston rod 9 of a cylinder 8 installed upward on the pedestal 1. Reference numeral 10 denotes a grinding tool having the same configuration as the grinding surface of the tip of the electrode chip which is the object to be ground. This grinding tool 10 is mounted on a mount 11 that projects forward from the frame 2, and is held by a cylindrical holder 12 shown in FIG. The holder 12 is rotated 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 mount 11.

The case 13 is attached to the metal fitting 7 by a fitting 15. Therefore, cylinder 8
When the piston rod 9 is moved up and down by operating the piston rod 9, the mounting base 11 is moved up and down together with the case 13 within a certain range. At this time, the guide rod 6,
Since the metal fitting 7 is guided by 6, the grinding tool 1 is accurately made and attached to the mounting base 11.
0 reliably ascends and descends along a fixed path without lateral vibration. Further, the cylinder 8 is capable of moving in and out in two steps, and when it is set at the neutral position shown in FIG. The electrode chips 52 and 53 thus formed are allowed to be carried into both the upper and lower sides of the grinding tool 10 by the rotation of the arms 50 and 51.

17 indicates a chip holding mechanism. This chip holding mechanism 17 holds the upper and lower electrode chips 52, 53.
are held at opposite positions of the grinding tool 10, and are U-shaped in side view, and are connected to the chip loading/unloading path B.
It consists of upper and lower fixed claws 18 that open in the direction, and upper and lower movable claws 19 and 20 that are provided to close the chip loading/unloading path B side, which is the opening direction, with respect to the upper and lower fixed claws 18. The base of the fixed claw 18 is
As clearly shown in FIG. 2, it is detachably attached to an upper support plate 2a and a lower support plate 2b formed on the frame 2 using two bolts 21a. The upper protruding piece 18a of the fixed claw 18 is formed with a chip receiving part 23 recessed in a V-shape. Further, although not shown, a similar chip receiving portion is also formed on the lower protruding piece 18b (see FIG. 1) of the fixed claw 18. On the other hand, as described above, the upper movable claw 19 and the lower movable claw 20 are in a state where their distal ends face the upper protruding piece 18a and the lower protruding piece 18b of the fixed claw 18, respectively.
The rotary block 28 is rotatably installed on the support rod 22, and is detachably attached using two bolts 21b. The rotating block 28 is connected to the piston rod 25a of the movable pawl driving cylinder 25 installed on the frame 2 and the protruding rod 2.
3, and the piston rod 25
By moving forward and backward a, the tips of the upper movable pawl 19 and the lower movable pawl 20 rotate about the support rod 22, thereby closing and opening the tip receiving portion 24. Therefore, the piston rod 25a of the cylinder 25 is pulled in and the movable claw 1
9 is set in the retracted position shown by the imaginary line in FIG.

Next, as shown in FIG.
Retractable pieces 26 are provided at two locations on the upper protruding piece 18a and at one location on the movable claw 19, respectively.
FIG. 4 shows a retractable piece 26 provided on the upper protruding piece 18a among them. As is clear from the figure, the protruding/retracting piece 26 is supported by the tip receiving part 24 by the spring 27 stretched between the upper protruding piece 18a and the upper protruding piece 18a.
It is constantly biased in the direction of protrusion. In other words, the protruding and retracting piece 26
upper electrode chip 52 and arm 5 received in
It is always elastically biased in the pushing direction into a recess 54 formed in the attachment part with 0. The recess 54
As explained at the beginning, the upper electrode chip 52
is formed by being fitted into a shank 55 provided at the tip of the arm 50. Although the above configuration has been described with respect to the retractable piece 26 provided on the upper protruding piece 18a, the same applies to the retractable piece provided on the upper movable claw 19 and the lower movable claw 20, and in the illustrated example, the tip When the electrode chip 53 is held by the holding mechanism 17, these three retractable pieces 26 are pushed into the recesses 54 at three positions spaced at equal angles.

Next, the operation will be explained.

The upper and lower electrode chips 52 and 53 are carried into the position facing the grinding surface 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. By the rotation of the arms 50 and 51, it is carried out from the opposing position and subjected to welding again. 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, and It is advantageous if the grinding tool 10 is mounted on a mount that can be raised and lowered.
Further, when the electrode chips 52, 53 are carried in and out, the upper movable claw 19 and the lower movable claw 20 are moved to the retracted position by the cylinder 25, and the carrying in/out path B is opened.

For example, when the upper electrode tip 52 is carried to a position facing the grinding tool 10 and pushes away the retractable piece 26 provided on the fixed claw 18 against the bias of the spring 27, the tip receiving part 24 of the upper protruding piece 18a is pushed away. When the retractable piece 26 is received by the spring 27, it is pushed into the recess 54 between the electrode tip 52 and the shank 55 as shown in FIG. As a result, it is rotated in a direction approaching the fixing claw 18 as indicated by arrow C in FIG. 2, and is moved to a pressing position where it presses the upper electrode chip 52. As a result, the upper electrode chip 52
is held by the chip holding mechanism 17. From this state, the cylinder 8 pushes up the mounting base 11 which had been set at the neutral position, and the grinding tool 1
0 fits into the upper electrode tip 52, and then the upper electrode tip 52 is ground by the action of 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 52 is held by the chip holding mechanism 17, so that the electrode tip 52 is prevented from vibrating or idling with respect to the shank 55, and a stable processing state is maintained. Ru. After the shaping is completed, the mounting base 11 is lowered by the cylinder 8 and the upper movable claw 19 is moved back by the cylinder 25, 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 positioned on the protruding piece 18a of the fixed claw 18. The upper electrode chip 52 is received by the chip receiving part 24 recessed in a V-shape, and the upper electrode chip 52 thus received is transferred to the upper movable claw 19.
If the upper electrode tip 52 is pressed against the tip receiving portion 24, there is an advantage that the reliability in positioning the upper electrode tip 52 is further increased. In addition, when the extrusion force of the cylinder 8 is applied to 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.
There is a possibility that it will escape upwards as shown by arrow D in the figure. If this situation occurs, the electrode tip 5
The pressing force of the grinding tool 10 against the grinding tool 2 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 tip 52 escapes upward as indicated by arrow D in the figure, the retractable piece 26 touches the upper end surface of the electrode tip 52 in the middle of the escape.
It engages with the stepped portion 54a of the recess 54 to prevent its displacement. 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.

By the way, the upper fixing claw 18a and the lower fixing claw 1
8b is a support plate 2 erected on the frame body 2, respectively.
a, 2b with bolts 21a, and the upper movable claw 19 and lower movable claw 20 are removably screwed into the rotating body 28, which is rotatably installed, with bolts 21b. , when the dimensions are different, loosen or remove the bolts 21a, 21b and replace the upper fixed claw 18a, lower fixed claw 18b, upper movable claw 19, and lower movable claw 20 to change the shape of the chip receiving part 24. can be easily changed.

Therefore, even if the electrode chips 52 and 53 are eccentric, for example, the fixed claw 18 and the movable claw 1
9 and 20 can be easily replaced, making it possible to configure various electrode tip holding devices with one automatic electrode shaping machine.
A single chip holding mechanism can be used in a plurality of automatic electrode shaping machines, which has the effect of reducing wasted time in the manufacturing process and reducing the amount of incidental equipment.

[Effect of idea]

Since the present invention is configured as described above, it has the following effects.

Since the electrode tip can be ground while being directly held, the electrode tip can be ground while vibration is prevented.

The chip holding mechanism holds the electrode chip being ground between a fixed claw that restricts the movement of the electrode chip from the surrounding area except for the loading/unloading route, and a movable claw that contacts the electrode chip so as to close the loading/unloading route. Because of this structure, the electrode chip is securely held between the fixed claw and the movable claw so that it does not move in any direction. Therefore, there is no need to keep driving the robot to constantly press the electrode tip against the holding part as in the conventional case, and the robot can be stopped during grinding.

When loading and unloading electrode chips into the automatic electrode shaping machine, the rotary block can be rotated to change the position of the movable claw to open the chip loading/unloading path, allowing smooth loading and unloading of electrode chips. can.

The fixed claw is removably attached to the frame of the shaping machine body, and the movable claw is detachably attached to the rotating block, so if the type of electrode chip is different, there is no need to replace the entire chip holding mechanism. However, since only the fixed claw and movable claw need to be replaced, the replacement work is easy, and in terms of parts management, it is only necessary to have fixed claws and movable claws according to the type of electrode chip. , which is very advantageous in terms of cost and space.

[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 sectional view taken along the line FIG. 4 is a cross-sectional view for explaining the retractable piece provided on the fixed claw, and FIG. 5 is a partially enlarged cross-sectional view for explaining the operation of the retractable piece. A...Main body of the shaping machine, B...Chip loading route, 8
... Cylinder, 10 ... Grinding tool, 11 ... Mounting base, 14 ... Rotating drive source, 17 ... Chip clamping mechanism, 18 ... Fixed claw, 19 ... Upper movable claw, 20
... Lower movable claw, 21a, 21b ... Bolt, 2
2...Support rod, 25...Cylinder, 26...
Exit piece, 27... Spring, 50, 51... Arm,
52, 53...electrode chip, 54...recess, 54
a...Stepped part.

Claims (1)

[Scope of Claim for Utility Model Registration] A mounting base equipped with a grinding tool is provided on the main body of the shaping machine so that it can be raised or lowered, and when the mounting base is raised or lowered, the grinding tool is attached to an electrode tip attached to the tip of a welding machine arm. An electrode in an automatic electrode shaping machine, in which a chip clamping mechanism that clamps the chip at the contact position is disposed in the shaping machine body, and a grinding tool is brought into contact with the electrode chip by raising or lowering the mounting base to grind the tip of the chip. In the chip holding device, the chip holding mechanism includes a fixed pawl that restricts the movement of the electrode chip from the circumference except for the loading/unloading path thereof, and a movable pawl that abuts the electrode chip so as to close the loading/unloading path. , the fixed claw is removably attached to the frame of the shaping machine body, the movable claw is detachably attached to a rotating block that is rotatably provided on the shaping machine body about a vertical axis, and the rotating block is An electrode tip in an automatic electrode shaping machine, characterized in that the tip is connected to a piston rod of a cylinder for driving a movable claw by a protruding rod, and the movable claw closes and opens a chip receiving part by retracting the piston rod. holding device.