JPH0679536A - Wire-cut electric discharge machining device - Google Patents

Abstract

PURPOSE:To prevent electric discharge machining from being affected by vibration in the wire running direction by providing a vibration absorbing section absorbing mechanical vibration in the vicinity of a wire which runs at a wire drive section but is close to a work. CONSTITUTION:Vibration in the running direction of a wire W is absorbed by a vibration absorbing mechanism which comprises a spring 34 and a damper 22a set in parallel. By this constitution, since there in no need for lowering working speed and dropping discharge voltage in order to attenuate wire vibration, productivity can be prevented from being lowered, and concurrently, constant tension can be stably applied to the wire W, so that electric discharge machining can thereby be enhanced in efficiency.

Description

Detailed Description of the Invention

 [Object of the Invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire cut electric discharge machine for damping vibration of a wire electrode due to electric discharge repulsion during machining.

[0002]

2. Description of the Related Art In a wire-cut electric discharge machine, as shown in FIG. 5, a fine wire 80 is used as an electrode. Therefore, the wire traveling system 81 prevents the wire from bending or sagging due to vibrations or electric discharge repulsion during electric discharge machining. It results in a drum shape 82. Further, as a result, the wire tension also changes, and the processing accuracy of the workpiece 83 deteriorates. Therefore,
In order to suppress such vibrations, conventionally, the processing conditions (current, voltage, etc.) and the processing speed are set so as to reduce the vibrations. Further, in the conventional wire-cut electric discharge machine, the wire tension is applied by applying friction to the roller shaft of the wire traveling system 81 so that the roller is prevented from rotating and tension is applied. adjust.).

However, in order to reduce wire vibration,
The processing speed must be reduced. Therefore, the productivity will be reduced. In addition, even under the processing conditions, it is unavoidable to perform processing with a large amount of energy (the larger this is, the larger the repulsive force of the electric discharge), which further reduces the productivity. In addition, in the tension, when the slack 84 is generated, the pulling force to reduce the slack 84 does not work, so that a certain tension is not applied.

[0004]

As described above, the conventional wire-cut electric discharge machining apparatus causes bending and sagging due to the vibration of the wire traveling system and the electric discharge repulsive force during electric discharge machining. The wire tension also fluctuates, and the processing accuracy deteriorates.

The present invention has been made in consideration of the above circumstances, and by absorbing the vibration in the traveling direction of the wire,
An object of the present invention is to provide a wire cut electric discharge machining apparatus capable of improving electric discharge machining efficiency and electric discharge machining accuracy. [Constitution of Invention]

[0006]

A wire-cut electric discharge machine according to the present invention absorbs vibration in the traveling direction of a wire by means of a vibration absorbing mechanism in which a spring and a damper are arranged in parallel.

[0007]

With the wire-cut electric discharge machine having such a structure, it is not necessary to reduce the machining speed or the electric discharge voltage in order to reduce the wire vibration, so that it is possible to prevent a decrease in productivity. In addition, it is possible to stably apply a constant tension to the wire W, which can contribute to the improvement of the electric discharge machining efficiency.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a wire cut electric discharge machine according to this embodiment. This wire-cut electric discharge machining device includes a table portion 1 for holding a workpiece M and positioning it in XY directions, a wire drive portion 2 for traveling a wire W,
A machining liquid supply unit 3 for supplying a machining liquid to a machining site, a voltage application unit 4 for applying a voltage for generating an electric discharge between a wire W and a workpiece M, a table unit 1, a wire drive unit 2, and a voltage. It comprises a processing control section 5 for electrically controlling the application section 4. Thus, the table unit 1 includes a cross table 6 movably provided in the X-axis direction and the Y-axis direction, an X-axis motor 7 that drives the cross table 6 in the X-axis direction, and the cross table 6 in the Y-axis direction. And a Y-axis motor 8 that is driven in the direction. In addition, the machining fluid supply unit 3 stores, for example, a machining fluid tank 10 that stores a machining fluid 9 such as water, and a nozzle 1 that sprays the machining fluid 9 onto a discharge site between the wire W and the workpiece M.
1, a liquid supply pipe 12 for guiding the processing liquid 9 from the processing liquid tank 10 to the nozzle 11, and a pump 13 provided in the middle of the liquid supply pipe 12 for pumping the processing liquid 9 to the nozzle 11. Further, the voltage applying section 4 includes a power feeding die 14 fixedly provided in a state of slidingly contacting the wire W, a connection terminal 15 electrically connected to the workpiece M, a power feeding die 14 and a connection terminal 15. And a machining power supply 16 for applying a discharge voltage therebetween. On the other hand, the wire drive unit 2 includes a supply reel 17 around which the wire W is wound, a take-up reel 18 around which the wire W from the supply reel 17 is wound, and a space between the take-up reel 18 and the workpiece M. And a supply reel 17 which is disposed on the winding roller 19 and drives the wire W to be wound at a constant speed.
And a workpiece M, and a brake roller 18 which applies a predetermined tension to the wire W, and a fixing which is provided directly above the workpiece M and guides the wire W to the workpiece M side smoothly. The pulley 19 and a pair of wire guides 2 arranged close to each other on the upper and lower surfaces of the workpiece M and slidably holding the wire W.
0 and 21, and a vibration absorbing mechanism 22 arranged between the wire guide 20 and the fixed pulley 19 to absorb mechanical vibration in the traveling direction of the wire W, which is generated accompanying the discharge. As shown in FIG. 2, the vibration absorbing mechanism 22 has a flat plate-like mounting member 24 attached to the processing apparatus main body 23.
A fixed pulley 25 rotatably provided near one side of the mounting bracket 24, and a pair of vibration absorbing columns 26, 26 standing parallel to each other near the other side of the mounting bracket 24.
The vibration absorbing columns 26, 26 include a support shaft 27 mounted between the support shafts 27 and a movable pulley 28 coaxially supported by the support shaft 27. Then, the vibration absorbing column 26 is coaxially connected to a cylinder portion 29 forming a cylinder, a disc-shaped piston portion 30 slidably fitted in the cylinder portion 29, and a back portion of the piston portion 30. The rod 31, the shaft stopper 32 connected to the tip of the rod 31, and the shaft stopper 32 interposed between the shaft stopper 32 and one end of the cylinder 29 elastically move in the direction of the arrow 33. And a spring 34 for urging. A small-diameter through hole 35 is formed in the piston portion 30. Further, the cylinder portion 29 is provided in a liquid-tight manner, and an internal space sandwiching the piston portion 30 is filled with a vibration damping liquid 36 such as silicone oil. The cylinder portion 29 and the piston portion 30 are the damper portion 2
It constitutes 2a. Then, the pair of vibration absorbing columns 26, 2
A support shaft 27 is fixed and laterally mounted on the shaft stoppers 32, 32 of 6. Movable pulley 2 pivotally supported by this support shaft 27
8 is stationary at the equilibrium position determined by the elastic coefficient of the spring 34 when no external force is applied. And
The wire W from the supply reel 17 passing through the fixed pulley 19 is turned around by the fixed pulley 25 and then guided vertically downward by the movable pulley 28. Next, the operation of the wire cut electric discharge machine having the above configuration will be described.

First, the workpiece M is held on the cross table 6, and is positioned and displaced by the X-axis motor 7 and the Y-axis motor 8 based on a machining program stored in advance in the machining controller 5. Next, the machining liquid 9 is jetted from the nozzle 11 to the machining site. And the wire drive unit 2
Causes the wire W to travel in the direction of arrow 38,
A discharge voltage (impulse voltage of about 60 to 300 V) is applied between the wire W and the workpiece M by the voltage application unit 4, and wire spark discharge machining is performed by the generated spark discharge. At this time, the wire W is supplied to the supply reel 17, the brake roller 18, the fixed pulleys 19 and 25, the movable pulley 28, the movable pulley 28, the wire guide 20, the workpiece M, the wire guide 21, the winding roller 19, and the winding reel. Drive in the order of 18. By the way, when spark discharge is generated between the wire W and the workpiece M, a complicated mechanical vibration is applied to the wire W. When vibration in the traveling direction of the wire W occurs in the mechanical vibration, this vibration propagates to the movable pulley 28, and the movable pulley 28 vibrates in the vertical direction via the spring 34. The vibration of the movable pulley 28 is absorbed by the damper portion 22a and is quickly attenuated. As a result, the straightness of the processed shape of the workpiece M and the processing accuracy at the bending angle are improved. Further, since the restoring force of the spring 34 can apply tension to the wire W in a direction opposite to the vibration direction, "deflection" and "slack" can be reduced. Especially, fine wire (φ0.3〜
In addition to 0.1 mm), it is possible to apply a slight tension to ultrafine wire (φ 0.1 mm or less),
The "deflection" can be reduced.

As described above, in the wire-cut electric discharge machine of this embodiment, the vibration of the wire W in the traveling direction is
The vibration is absorbed by the vibration absorbing mechanism 22, and the vibration does not adversely affect the electric discharge machining. As a result, it is not necessary to reduce the processing speed or the discharge voltage in order to reduce the wire vibration, so that the productivity is not reduced. Further, since it becomes possible to stably apply a constant tension to the wire W, it is possible to contribute to the improvement of the electric discharge machining efficiency. It should be noted that the damper portion 22a may be provided in a two-tiered manner without being limited to the vibration absorbing mechanism in the above-described embodiment. By doing so, the vibration absorbing effect can be enhanced.

Further, as shown in FIG. 4, the vibration absorbing mechanism 22
As a result, a spring 51 is built in the cylinder portion 50, and the spring 51 urges a piston 52 fitted and inserted in the cylinder portion 50. A bellows flam 54 filled with oil 53 may be provided to hold a support shaft on which the movable pulley 28 is pivotally supported at the tip of a rod connected to the piston 52.

[0013]

The wire-cut electric discharge machine of the present invention is
Since the vibration of the wire in the traveling direction is absorbed by the vibration absorbing mechanism in which the spring and the damper are arranged in parallel, the vibration of the wire in the traveling direction does not adversely affect the electric discharge machining. As a result, to reduce wire vibration,
Since it is not necessary to reduce the processing speed or the discharge voltage, it is possible to prevent the productivity from decreasing. Further, since it becomes possible to stably apply a constant tension to the wire W, it is possible to contribute to the improvement of the electric discharge machining efficiency.

[Brief description of drawings]

FIG. 1 is a perspective view showing an overall configuration of a wire cut electric discharge machine according to an embodiment of the present invention.

FIG. 2 is a front view of a main part of a wire cut electric discharge machine according to an embodiment of the present invention.

FIG. 3 is a side view of essential parts showing a part of a wire cut electric discharge machine according to an embodiment of the present invention.

FIG. 4 is a diagram showing a modification of the wire cut electric discharge machine according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

2: wire drive unit, 22: vibration absorbing mechanism, 22a: damper unit, 28: movable pulley, spring: 34, W: wire, M:
Workpiece.

Claims (4)

[Claims] 1. A table section for holding and positioning a work piece, a wire driving section for running a wire at the work piece position, and a voltage applied between the wire and the work piece. A voltage application unit for generating an electric discharge, a machining liquid supply unit for supplying a machining liquid to the electric discharge generation site, and a vibration absorbing unit for absorbing mechanical vibration of the wire running by the wire driving unit near the workpiece. And a wire cut electric discharge machine. 2. The vibration absorbing portion is provided between a pair of vibration absorbing columns, which have rods that are erected parallel to each other and are displaceable in the axial direction and absorb mechanical vibrations of the rods, and are axially mounted between the pair of rods. 2. The wire cut electric discharge machine according to claim 1, further comprising a support shaft and a movable pulley supported by the support shaft and around which a wire is wound. 3. The vibration absorbing column comprises a spring portion for elastically urging the rod and a damper portion for absorbing mechanical vibration of the rod urged by the spring portion. Item 2. The wire cut electric discharge machine according to Item 2. 4. The damper part comprises a piston connected to one end of the rod, a cylinder into which the piston is slidably inserted, and a vibration absorbing oil held inside the cylinder. The wire-cut electric discharge machine according to claim 3.