JPS637472Y2 - - Google Patents

Description

[Detailed description of the invention] Technical field This invention applies a voltage to the machining gap between the wire electrode and the workpiece that is continuously supplied to generate an electric discharge, and the workpiece is stimulated by the discharge energy. The present invention relates to a wire-cut electric discharge machine for machining, and particularly to a wire-cut electric discharge machine capable of detecting disconnection and vertical alignment of the wire electrode.

Prior Art Conventional wire-cut electrical discharge machines of this type include, for example, Japanese Patent Laid-Open No. 53-68496 and Japanese Patent Laid-Open No. 58
As described in Japanese Patent No. 126025, there is a device equipped with a detection circuit for detecting disconnection or vertical extension of the wire electrode. However, if a detection circuit is provided to perform both of these detections, it is necessary to provide not only the detection circuit but also a signal transmission line between the detection circuit and the control device separately for disconnection detection and vertical output detection. At the same time, each signal transmission line must be protected against noise generated during electrical discharge machining by using fiber optic cables, coaxial cables, etc., making the circuit configuration complex and expensive. .

Purpose of the invention This invention eliminates the defects in the prior art as described above, and simplifies the circuit configuration by eliminating the need to provide separate detection circuits and signal transmission lines for detecting disconnection and vertical extension of wire electrodes. It is an object of the present invention to provide a wire cut electric discharge machine that can be manufactured at low cost.

Structure of the Device In order to achieve the above object, this device supports the workpiece by relatively moving upper and lower electrode guides that guide and support continuously supplied wire electrodes above and below the workpiece. an electrode guide adjustment device that adjusts the angle of the wire electrode between the upper and lower electrode guides with respect to the top surface of the table; a discharge circuit that applies a voltage to generate a discharge in the machining gap between the wire electrode and the workpiece; In a wire-cut electric discharge machine equipped with a control device for controlling a transfer device that relatively transfers a wire electrode and a workpiece between upper and lower electrode guides, the wire electrode is moved along the movement path of the wire electrode. A disconnection detection device including a detection unit that detects disconnection, and a detection circuit that is connected to the detection unit via a first connection path and generates a detection signal when the wire electrode is disconnected; provided on the top surface of the table and comes into contact with the wire electrode between the upper and lower electrode guides as the transfer device operates;
It has a detection piece that detects the angle of the wire electrode with respect to the table top surface, and is connected to the detection circuit via a second connection path so that the detection circuit generates a detection signal when the wire electrode comes into contact with the detection piece. a connected wire electrode angle detection device; and a wire electrode angle detection device connected to the first and second connection paths, which operates a disconnection detection device when the discharge circuit is activated, and when the electrode guide adjustment device is adjusted. The switch is provided with a changeover switch for opening and closing the first and second connection paths so as to operate the first and second connection paths.

Embodiment Hereinafter, an embodiment of this invention will be described in detail with reference to the drawings.

Now, as shown in FIG. 1, in the wire-cut electric discharge machine of this embodiment, the frame 1 includes a base 2, a saddle 3 disposed on the base 2, and an upper surface of one side of the saddle 3. It is composed of a column 4 which is fixed upright and has a substantially inverted L-shape from the front. A machining tank 6 is supported on the saddle 3 so as to be movable in a horizontal plane via a transfer device 5, and a machining liquid L is provided inside the tank 6.
The workpiece W can be supported on a table 7 protruding from the inner surface of the bottom wall in a state where the conditions are satisfied. The transfer device 5 includes a first movable platen 9 that is moved in the left and right direction in a horizontal plane by a first air cylinder 8 on the saddle 3, and a second air cylinder on the first movable platen 9. The workpiece W in the processing tank 6 is moved in any direction within the horizontal plane by the operation of both moving plates 9 and 11. It is becoming more and more common.

Above the processing tank 6, an upper arm 12 is attached to the tip of the column 4 so as to be movable in the vertical direction, and an electrode guide adjustment device 13 is attached to the lower end of the upper arm 12.
Upper electrode guide 1 consisting of a conductive roller
4 is supported in an insulated manner on the upper arm 12. A lower arm 15 made of a cylindrical body is protruded from the side of the column 4 so as to penetrate the side wall of the processing tank 6 and extend horizontally to a position below the workpiece W. A lower electrode guide 16 made of a roller is supported in an insulated manner with respect to the lower arm 15. Then, the electrode guide adjustment device 1
3 is equipped with a driving means (not shown) consisting of a pair of pulse motors, etc., and by the action of the driving means, the upper electrode guide 14 is moved relative to the lower electrode guide 16 back and forth and left and right in a horizontal plane, thereby moving the workpiece. W
The angle of the wire electrode 17 between the upper and lower electrode guides 14 and 16 with respect to the upper surface of the table 7 that supports it can be adjusted.

A mounting plate 18 is provided on one side of the frame 1, and a supply reel 19 and a tension roller 20 for supplying the wire electrode 17 made of metal wire are attached to the upper part of the front surface of the mounting plate 18. Wire electrode 17 being fed out
is continuously supplied under tension onto the workpiece W between the upper and lower electrode guides 14 and 16 via the tension roller 20 and the guide roller 21 on the column 4. A guide roller 22, a pair of collection rollers 23 that are rotationally driven by a motor (not shown), and a take-up reel 24 that is rotationally driven by a motor (not shown) are provided at the lower front of the mounting plate 18. The wire electrode 17 is transferred from the machining gap between the wire electrode 17 and the workpiece W to the take-up reel 24 via the guide roller 22 and the collection roller 23.
It is designed to be wound up and collected. Note that the frame 1 is provided with a translucent cover (not shown) that covers the components on the mounting plate 18.

A discharge circuit 25 is connected between the upper electrode guide 14 and the workpiece W, and applies a voltage to the machining gap between the wire electrode 17 and the workpiece W to generate an electric discharge. There is. In this embodiment, the discharge circuit 25, the transfer device 5
The electrode guide adjustment device 13 is configured to be operated and controlled by a control circuit 26 as a control device, and the workpiece W is moved in a horizontal plane by the operation of the discharge circuit 25 and the transfer device 5 based on the control circuit 26. Electric discharge machining can be performed while being transported in any direction.

Next, a disconnection detection device 27 for detecting disconnection of the wire electrode 17 between the upper and lower electrode guides 14 and 16, which is the main part of this invention, and the wire electrode 1
The wire electrode angle detection device 28 for detecting the angle of the wire electrode 17 with respect to the upper surface of the table 7 to vertically bring out the wire electrode 17 will be described in detail.

Now, the wire electrode 1 on the column 4
A detection section 29 made of a conductive cylindrical body is disposed along the movement path of the electrode 7, and the wire electrode 17 is normally inserted into this detection section 29 under tension with a slight gap between the upper and lower electrode guides. When the wire electrode 17 between the wire electrodes 14 and 16 is disconnected and loosened, the wire electrode 17 comes into contact with the inner surface of the detection part 29. A detection circuit 31 is connected between the detection section 29 and the upper electrode guide 14 via a first connection path 30, and the detection circuit 31 includes a detection power source 32, a light emitting diode 33, and a resistor 34.
is provided. When the wire electrode 17 is disconnected and comes into contact with the detection section 29, a current flows through the wire electrode 17 to the detection circuit 31, and the light emitting diode 33 generates light as a detection signal.

A phototransistor 36 to which a reference voltage is applied is connected to the control circuit 26 via a resistor 35, and an optical fiber cable 37 as a signal transmission line is connected between the phototransistor 36 and the light emitting diode 33. It is provided. When the light emitting diode 33 emits light due to a disconnection of the wire electrode 17, the light reaches the phototransistor 36 via the optical fiber cable 37, and the operation of the phototransistor 36 causes the discharge circuit 25 to stop via the control circuit 26. It is controlled so that electrical discharge machining is stopped immediately.

On the other hand, a pair of detection pieces 3 are placed on the table 7.
As shown in FIG. 2, a pair of perpendicular detection surfaces 38a, 38b, 39a, 39a, 39a, 39a, 39a, 39a, 39b, 39a, 39a, 39b, 39a, 39a, 39b, 39b, 39a, 39a, 39a, 39a, 39a, 39b, and 8, 39 are provided at the tips of both the detection pieces 38, 39, as shown in FIG. 39b are formed respectively. Each detection piece 38 of the detector 40,
39 is connected to the detection circuit 3 via a second connection path 41.
1, and when the wire electrode 17 comes into contact with the detection pieces 38 and 39 when detecting the angle of the wire electrode 17, the detection circuit 31
A current flows through the light emitting diode 33 to generate light as a detection signal.

The control circuit 26 includes three relays CR1 and CR.
2, CR3 is connected, and the relay switch CR1-1 of relay CR1 is connected to the first connection path 30, and the relay switches of relays CR2 and CR3 are connected.
CR2-1 and CR3-1 are connected to the second connection path 41 in correspondence with the detection pieces 38 and 39, respectively. In this embodiment, the relay switch CR1-
1, CR2-1 and CR3-1 constitute a changeover switch, and when the discharge circuit 25 is activated, the relay switch CR1-1 is closed by the excitation of the relay CR1 under the control of the control circuit 26, and the disconnection detection device is activated. 27 is switched to the operating state, and when adjusting the electrode guide adjustment device 13, the relay switches CR2-1 and CR3 are selectively energized by relays CR2 and CR3 under the control of the control circuit 26.
-1 is arbitrarily closed to switch the wire electrode angle detection device 28 into the operating state.

The operation of the wire cut electric discharge machine configured as described above will be explained next.

Now, in this electric discharge machine, normally, the electric discharge circuit 25 and the transfer device 5 are operated based on the control of the control circuit 26, and the workpiece W supported on the table 7 in the machining tank 6 is moved freely in the horizontal plane. While being transferred in the direction of , the workpiece W and the wire electrode 1
The workpiece W is machined by the energy of the electric discharge generated in the machining gap between the workpiece W and the workpiece W. When the discharge circuit 25 is in operation, the control circuit 2
The relay switch CR1-1 is closed by the excitation of the relay CR1 based on the control in step 6, and the disconnection detection device 27 is switched to the operating state. Therefore,
When the wire electrode 17 is disconnected and loosened during electrical discharge machining of the workpiece W, the wire electrode 17 contacts the detection section 29, current flows through the detection circuit 31, and the light emitting diode 33 emits light. As a result, the phototransistor 36 is activated via the optical fiber cable 37, and the control circuit 26 controls the discharging circuit 25 to stop, thereby immediately stopping the electrical discharge machining.

Also, prior to this electric discharge machining etc., the wire electrode 1
7. When performing vertical alignment, first
A detector 4 supported on a table 7 is used to detect and adjust the inclination of the wire electrode 17 with respect to the direction.
One detection surface 38a of the detection pieces 38, 39 on 0,
With 39a corresponding to the wire electrode 17,
By operating the electrode guide adjusting device 13, the wire electrode 17 is arranged in an inclined state such that the upper electrode guide 14 side approaches the detection pieces 38 and 39, as shown in FIG. 3a. In this state, the relay CR3 is energized under the control of the control circuit 26 to turn on the relay switch.
CR3-1 is closed and the wire electrode angle detection device 28 is switched to the operating state, and then the transfer device 5 is operated by the control circuit 26 to detect the detector 4.
0 detection pieces 38 and 39 are brought close to the wire electrode 17.

As a result of this operation, as shown in FIG. 3b, when the detection surfaces 38a and 39a of both detection pieces 38 and 39 come into contact with the wire electrode 17, a current flows into the detection circuit 31 via the lower detection piece 39 and the wire electrode 17. ,
The phototransistor 36 is activated by the light emitted from the light emitting diode 33. As a result, the control circuit 2
6, the operation of the transfer device 5 is stopped, and the relay is further activated under the control of its control circuit 26.
CR3 is demagnetized and relay switch CR3-1 is opened, and relay CR2 is energized and relay switch CR2-1 is closed. Then, in this state, the control circuit 26 operates the electrode guide adjustment device 13, and the upper electrode guide 14 is moved to the detection piece 3.
8, 39.

As a result of this movement, as shown in FIG. 3c, the wire electrode 17 between the upper and lower electrode guides 14 and 16 becomes perpendicular to the top surface of the table 7 in the X direction of FIG.
When the electrode guide adjusting device 13 is separated from the detection surface 38a, the light emitting diode 33 of the detection circuit 31 is extinguished, and the phototransistor 36 is stopped, so that the operation of the electrode guide adjustment device 13 is immediately stopped via the control circuit 26. Therefore, the wire electrode 17 between the upper and lower electrode guides 14 and 16 is adjusted to be perpendicular to the upper surface of the table 7 in the X direction in FIG.

Next, the wire electrode 1 in the Y direction in FIG.
7, the other detection surfaces 38b, 39b of the detection pieces 38, 39 on the detector 40
in the Y direction of FIG. is adjusted to the right angle state. Therefore, wire electrode 1
The detection circuit 31 of the disconnection detection device 27 detects the vertical extension of 7.
This can be done accurately using .

It should be noted that this invention is not limited to the configuration of the above-mentioned embodiments, and it is also possible to embody the invention by changing the configuration of each part arbitrarily within a range that does not depart from the spirit of this invention.

Effects of the invention As detailed above, this invention eliminates the need to provide separate detection circuits and signal transmission lines for wire electrode disconnection detection and perpendicular extension detection, and simplifies the circuit configuration. It has the excellent effect of being able to be manufactured at low cost.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway front view of a wire-cut electrical discharge machine that embodies this idea, Figure 2 is an enlarged perspective view of the detector, and Figures 3 a, b, and c are vertical extensions of the wire electrodes. FIG. 3 is a partially enlarged sectional view for explaining the operation. 1 is a frame, 5 is a transfer device, 6 is a processing tank, 7
13 is a table, 13 is an electrode guide adjustment device, 14 is an upper electrode guide, 16 is a lower electrode guide, 17 is a wire electrode, 25 is a discharge circuit, 26 is a control circuit as a control device, 27 is a disconnection detection device, and 28 is a wire Electrode angle detection device, 29 is a detection section, 30 is a first connection path, 31 is a detection circuit, 41 is a second connection path, CR1-1, CR2-1, CR3-1 are relay switches as changeover switches, W is a workpiece.

Claims (1)

[Claims for Utility Model Registration] A table that supports a workpiece W by relatively moving upper and lower electrode guides 14 and 16 that guide and support a continuously supplied wire electrode 17 above and below the workpiece W. an electrode guide adjustment device 13 that adjusts the angle of the wire electrode 17 between the upper and lower electrode guides 14 and 16 with respect to the upper surface of the workpiece W; A wire cut electric discharge machine equipped with a discharge circuit 25 for applying voltage, and a control device 26 for controlling a transfer device 5 for relatively transferring a wire electrode 17 and a workpiece W between upper and lower electrode guides 14 and 16, a detection unit 29 that detects a disconnection of the wire electrode 17 along the movement path of the wire electrode 17;
and a detection circuit 31 connected to the detection unit 29 via a first connection path 30 and generating a detection signal when the wire electrode 17 is broken; The transfer device 5 is provided on the top surface of the table 7.
When the wire electrode 17 is in contact with the wire electrode 17 between the upper and lower electrode guides 14 and 16,
The wire electrode 17 is connected to the detection piece 3.
8, 39, the wire electrode angle detection device 28 is connected to the detection circuit 31 via a second connection path 41 so that the detection circuit 31 generates a detection signal when the wire electrode angle detection device 28 comes into contact with the first and second wire electrodes 8 and 39; When the discharge circuit 25 is activated, the disconnection detection device 27 is activated, and the electrode guide adjustment device 13 is connected to the second connection path 30, 41.
When adjusting the wire electrode angle detection device 28
the first and second connecting paths 3 so as to actuate the
Selector switch CR1- for opening and closing 0,41
1. A wire cut electric discharge machine characterized by having CR2-1 and CR3-1.