JPH0216871Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a spot welding electrode shaping device.

(Prior Art) In welding robots used in the manufacture of automobile bodies, the electrodes of spot welding guns may become deformed due to repeated welding operations, and unless the electrodes are shaped, they may become unusable. Conventionally, this electrode shaping work has been performed using a chip dresser having a rotating cutting tool, and the upper and lower electrodes are pressed against the rotating cutting tool at the same time to shape the electrodes. (For example, see Japanese Patent Application Laid-open No. 70982/1982). In this case, as a means of pressing the upper and lower electrodes against the rotary cutting tool, the air sent to the cylinder that pressurizes the upper and lower electrodes during welding is depressurized to obtain a pressing force suitable for shaping. Because it is used to obtain Ta.

(Problems to be Solved by the Invention) The present invention was made in an attempt to solve the problems pointed out in the section of the prior art described above. The object of the present invention is to provide an apparatus that can alternately perform polishing and shaping.

(Means for Solving the Problems) The present invention provides a chip dresser equipped with a rotating cutting tool configured to be able to shape the upper and lower electrodes of a spot welding gun supported by a robot. is supported on a dresser support provided on a base so as to be movable up and down, and the dresser support is constantly urged upward by a first cylinder with a force smaller than the total weight of the tip dresser and the dresser support. is supported by the dresser support and whose lower end is capable of contacting the base.
The tip dresser is held in an unloaded position in the extended position of the cylinder, and either one of the electrodes can be pressed against a rotating cutting tool of the tip dresser to shape the tip dresser.

(Function) In the present invention, the dresser support that supports the tip dresser is extended with two cylinders, that is, the first cylinder that constantly urges the dresser support upward with a force smaller than the total weight of the tip dresser and the dresser support. The tip dresser is supported by a second cylinder that holds the tip dresser in an unloaded position, and the tip dresser is floated in the vertical direction (in other words, in the direction in which it is pressed against the electrode). An effect is obtained in which the electrodes are alternately pressed against the rotating cutting tool of the tip dresser with an appropriate pressing force.

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

This shaping device is a device for polishing and shaping the upper and lower electrodes 3 and 4 of a spot welding gun 2 supported by a robot 1, and includes a chip dresser 5 equipped with a rotary cutting tool 6 for polishing and shaping the electrodes 3 and 4. , a dresser support 8 that supports the tip dresser 5 so as to be movable up and down with respect to the base 7; a first cylinder 9 that is constantly biased upward with a force F1;
The upper end is supported by a dresser support 8, and the lower end is able to come into contact with a base 7, and in the extended position, the chip dresser 5 is placed in an unloaded position (that is, the upper and lower electrodes 3 and 4 are not pressed together). The second cylinder 10 is provided with a second cylinder 10 for holding the second cylinder 10 in a position where the second cylinder 10 is held in a fixed position. Reference numeral 11 denotes a pressure cylinder for pressing the electrodes 3 and 4 against the workpiece during spot welding, and an air cylinder using compressed air is employed.

The tip dresser 5 includes a singing device that moves the rotating cutting tool 6 back and forth and left and right, and a singing device that moves the rotating cutting tool 6 back and forth and left and right.
A commercially available product equipped with a drive device (both not shown) is used.

The dresser support 8 is located between a pair of support columns 12, 12 constituting the base 7, and is arranged between rollers 13, 1.
3. It is said that it is freely movable in the vertical direction via...

Both the first and second cylinders 9 and 10 are air cylinders that use compressed air regulated by a regulator, and their output
The structure is such that the following relationship holds between F1 and F2 and the no-load load W.

W<F1+F2 However, W>F1, W>F2 In this embodiment, the stroke of the second cylinder 10 is half the stroke of the first cylinder 9.

In the above configuration, the tip dresser 5
The upper and lower electrodes 3 and 4 are supported floating in the vertical direction by the second cylinders 9 and 10, and the upper and lower electrodes 3 and 4 are alternately pressed downward and upward against the rotary cutting tool 6, with the upper and lower center positions as the origin. As a result, the electrodes 3 and 4 are polished and shaped by receiving an appropriate repulsive force.

The illustrated spot welding electrode shaping device operates as follows.

() When shaping the upper electrode 3, in the no-load state, as shown in Fig. 3A,
The second cylinder 10 has extended its full stroke, and the first cylinder 9 has extended its 1/2 stroke, and the no-load load W is resisted by both cylinders 9 and 10. Therefore, when the upper electrode 3 is pressed against the upper surface of the rotary cutter 6, the resultant force of the no-load load W and the pressing force W1 of the upper electrode 3 acts on both cylinders 9 and 10, resulting in the state shown in FIG. The repulsive force N1 that the upper electrode 3 receives is given by the following equation.

N1=(W1+W)-(F1+F2) Therefore, by appropriately setting F1 and F2, the desired repulsive force N1 can be obtained, and the polishing and shaping work can be performed smoothly. Then, when the pressing force W1 of the upper electrode 3 is released, the no-load state shown in FIG. 3A is restored.

() When shaping the lower electrode 4, in the no-load state, the procedure is the same as in the case of () above (see FIG. 4A). When the lower electrode 4 is pressed against the lower surface of the rotary cutter 6, the second cylinder 10 lifts up, and the pressing force W2 of the lower electrode 4 is obtained from the sum of the no-load load W on the first cylinder 9 only and the weight _W3 of the second cylinder 10. A force obtained by subtracting the amount of N2 acts, resulting in the state shown in FIG.

N2=(W2+F1)-(W+W3) Therefore, by setting F1 appropriately,
The desired repulsive force N2 can be obtained, and the polishing and shaping work can be carried out smoothly. Then, when the pressing force W2 of the lower electrode 4 is released,
It returns to the no-load state shown in FIG. 4A.

(Effect of the invention) As described above, according to the invention, the tip dresser for shaping the upper and lower electrodes of a spot welding gun is floatingly supported by two cylinders, and the upper and lower electrodes are lowered relative to the rotary cutting tool of the tip dresser. Since the structure is configured so that polishing and shaping can be performed by pressing the electrodes alternately in the direction and upward, the upper and lower electrodes are polished and shaped while receiving appropriate repulsion forces, and the rotary cutting tool does not dig in, resulting in smooth shaping. This has the practical effect of not only making the work easier but also reducing the amount of polishing.

[Brief explanation of drawings]

1 and 2 are front and side views of a spot welding electrode shaping device according to an embodiment of the present invention, and FIGS. 2 is a schematic diagram illustrating the operating state of the first and second cylinders when polishing and shaping the upper electrode and the lower electrode. FIG. 1...Robot, 2...Spot welding gun, 3
... upper electrode, 4 ... lower electrode, 5 ... chip dresser, 6 ... rotary cutter, 7 ... base, 8 ... dresser support, 9 ... first cylinder, 10 ... second cylinder.

Claims (1)

[Scope of utility model registration request] A chip dresser equipped with a rotary cutter configured to be able to shape the upper and lower electrodes of a spot welding gun supported by a robot; a dresser support that supports the chip dresser movably up and down on a base; and a first cylinder that is always biased upward with a force smaller than the total weight of the dresser support; and a second cylinder that can be lifted from the top of the tip dresser and holds the tip dresser in an unloaded position in the extended position by the resultant force of the biasing force of the first cylinder, and the second cylinder holds the tip dresser in an unloaded position by the combined force of the biasing force of the first cylinder. 1. A spot welding electrode shaping device, characterized in that it is configured to be able to shape the spot welding electrode by pressing it against a rotating cutting tool.