JPH08243847A - Wire electric discharge machining device - Google Patents

Abstract

PURPOSE: To surely remove a wire electrode left to be cut, by providing a moving means moved so as to make a wire feed means distant from a wire cutting means, in the case of generating abnormality in a wire from the wire feed means. CONSTITUTION: In the case that a wire electrode 8 is cut in order to insert it through a machining start hole of a workpiece and in the case that the wire electrode 8 is disconnected during machining, a wire electrode 8a is surely left to be cut between wire collecting rollers 15, 16 and a wire cutting blade 22 of a wire cutting device 17. In the case of providing this wire electrode 8a left to be cut, when the wire cutting device 17 is once moved in a direction of separating distant from the wire collection rollers 15, 16 by a slide mechanism 6, the wire electrode 8a left to be cut is dropped down to a wire collecting case 23 as shown by an arrow mark A. Thereafter, the wire cutting device 17 is moved in a right direction to be returned back to the original position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire cutting device for a wire electric discharge machine.

[0002]

2. Description of the Related Art FIGS.
It is a figure which shows the conventional wire electric discharge machining apparatus described in No. 212627. In the figure, a machining tank 2 is placed on a base 1 of a wire electric discharge machine, and a workpiece W fixed on a work table 3 is immersed in the machining liquid in the machining tank 2. As described above, the insulating working liquid (fresh water or a mixed liquid of fresh water and oil) 5 is supplied from the working liquid supply device 4, and the contaminated working liquid 5 is collected by the working liquid supply device and filtered through a filter or the like. After that, it is recirculated and supplied.
A wire bobbin 9 around which a wire electrode 8 is wound is provided on the upper portion of the column 7, and an upper guide portion 11 is formed on an upper arm 10 supported on the upper portion of the column 7. In addition, the lower arm 12 supported at the bottom of the column 7
The lower guide portion 13 is arranged in the. Wire bobbin 9
The wire electrode 8 drawn out from the upper guide portion 11 is stretched in a substantially vertical shape on the lower guide portion 13 via the workpiece W, and a pulse current is applied to the wire electrode 8 and the workpiece W from a power source (not shown). Is applied, and electric discharge machining is performed in a minute gap portion (electric discharge machining portion) between the wire electrode 8 passing vertically downward and the workpiece W. It should be noted that the machining liquid 5 is jetted toward the electric discharge machining portion from a nozzle portion (not shown) in both or one of the upper guide portion 11 and the lower guide portion 13 to remove metal scraps in the electric discharge machining and perform electric discharge machining. Cool down the section and execute. The transport speed (moving speed) of the wire electrode 8 varies depending on the electric discharge machining conditions, the plate thickness of the workpiece W, etc., but is generally about 50 to 300 mm / sec. For example, when the plate thickness is 50 mm, 100 mm / sec. It is a degree. The direction-changing pulley 14 is arranged below the lower guide portion 13, and is used to forcefully sandwich and carry the processed wire electrode 8 whose lateral carrying direction has been changed by the direction-changing pulley 14. At least one of the pair of rollers 15 and 16 is rotationally driven by a drive motor (not shown). The guide body 17 includes the pair of rollers 15 and 16
The cutting means 18 is arranged at the rear of the guide body 17 in the conveying direction. Cutting means 18
Is a fixed blade body 20 fixed to the rear portion of the guide body 17 with bolts 19 and the like, and an upward rotating rotary blade body 21 in which a blade portion 21a is arranged so as to face the rear end blade portion 20a of the fixed blade body 20. Consists of. As shown in FIGS. 8 to 10, the guide body 17 is formed by a pair of left and right side plates 17b and 17b and a top plate 17a into a downward U-shaped cross section, and the pair of left and right side plates 17 is formed.
The ends of b and 17b are cut out in an arc shape along the outer circumference of the lower roller 15 so that the front edge of the top plate 17a can be approached above the transport path of the wire electrode 8. Then, the top plate 17a of the guide body 17 is arranged so as to be inclined downward as it moves away from the transport direction. The top plate 17a
The inclination angle θ of the lower surface with respect to the horizontal axis is set in consideration of the cantilever elastic bending characteristics of the processed wire electrode 8. The material and diameter of the wire electrode 8 to be used, the pair of rollers 15,
It is determined by the length of protrusion of the wire electrode 8 sandwiched by 16 in the direction of the guide body 17, and is set to an inclination angle θ larger than the natural bending angle of the tip of the wire electrode 8. With these configurations, the upper surface of the wire electrode 8 protruding from the pair of rollers 15 and 16 is in contact with the lower surface of the top plate 17a of the guide body 17 and the fixed blade body 20 by the elastic force of the wire electrode 8 while the rear end blade is being abutted. The rotary blade 21 guided to the portion 20a and rotating upward in the direction of arrow A in FIG. 8 can reliably cut. FIG. 11 is an enlarged view of a wire cutting device used in a conventional wire cutting device. In FIG. 11, 15 and 16 are wire collecting rollers, which are driven by a collecting motor 26. Wire collection rollers 15, 16
On the wire electrode outlet side of the
The wire cutting device 17 is connected to the tip of the
Is a compressed air outlet. The wire cutting device 17 includes a wire cutting motor 21, a wire cutting blade 22, and a fixed blade 2.
It is composed of 7. A wire collection box 23 is placed below the wire cutting device 17. Reference numeral 8 is a wire electrode.

Next, the operation of the prior art will be described. The processed wire electrode 8 discharged from the wire collecting rollers 15 and 16 is guided to the hose 28 and sent to the wire cutting device 17. Wire electrode 8 sent to wire cutting device 17
Is finely cut by the wire cutting blade 22 and the fixed blade 27 in the wire cutting device 17 and discharged into the wire recovery box 23. Further, the wire electrode 8 is connected to the wire collecting roller 15,
If it is bitten in 16, wire collection rollers 15, 16
The rotation of the wire electrode 8 sends the wire electrode 8 to the wire cutting device 17. However, when the wire electrode 8 is broken during processing, the right end of the wire electrode 8 is located at the wire collecting roller 1
When the wire electrode 8 is deviated from 5, 16, the wire electrode 8 is forcibly sent to the wire cutting device 17 by the compressed air discharged from the compressed air discharge port 29.

[0004]

The conventional wire cutting device is constructed as described above, and when the wire electrode remains in the hose, compressed air is sent to forcibly send the wire electrode to the wire cutting device. However, some of the broken wire electrodes could not be reliably sent to the wire collection box.

Further, if the wire cutting blade of the wire cutting device wears and cannot be cut, the wire cutting blade may be locked by pinching the wire electrode between the wire cutting blade and the fixed blade. At this time, since the wire electric discharge machine itself continues machining, the wire electrode may stick out of the hose or get caught in the roller, causing the wire electric discharge machine body to abnormally stop.

Further, since the feed rate of the wire electrode changes depending on the processing conditions and the like, the wire cutting rate must always be adjusted to the highest wire electrode feed rate. For this reason, when the wire electrode feeding speed is slow, the wire electrode is cut unnecessarily short, which is a factor of shortening the life of the wire cutting blade.

These inventions have been made to solve the above problems, respectively. In claims 1, 2 and 3, there is provided a wire electric discharge machine capable of reliably removing a broken wire electrode. . Moreover, in Claim 5, the wire electric discharge apparatus which can extend the life of the wire cutting blade of a wire cutting device is provided. Still another object of the present invention is to obtain a wire cutting device which can promptly control the cutting operation of the wire electric discharge machining device to easily resume machining when an abnormality occurs in the wire cutting device.

[0008]

According to a first aspect of the present invention, there is provided a wire electric discharge machine, a wire feeding means for feeding a wire electrode, and a wire cutting means for cutting the wire fed from the wire feeding means into a predetermined length. And a moving means for moving the wire feeding means and the wire cutting means away from each other when an abnormality occurs in the wire from the wire feeding means.

The wire electric discharge machine according to the second aspect of the present invention comprises a removing means for removing the wire electrode between the wire feeding means and the wire cutting means.

A wire electric discharge machine according to a third aspect of the present invention comprises a traveling route detecting means for detecting a traveling route of a wire electrode between the wire feeding means and the wire cutting means.

According to a fourth aspect of the present invention, there is provided a wire electric discharge machine which comprises wire feeding means for feeding a wire electrode, and wire cutting means for cutting a wire fed from the wire feeding means into a predetermined length by rotating a motor. In the load detection means for detecting the load of the motor of the wire cutting means, and in the detection result of the load detection means, when an abnormality occurs in the load of the motor,
Stop control means for stopping the cutting operation of the wire cutting means.

According to a fifth aspect of the present invention, there is provided a wire electric discharge machine which comprises a wire feeding means for feeding a wire electrode by rotating a roller and a wire for cutting the wire fed from the wire feeding means into a predetermined length by rotating a motor. Cutting means,
A rotation cycle means for synchronizing the rotation speed of the motor of the wire cutting means and the rotation speed of the roller of the wire feeding means is provided.

[0013]

In the wire electric discharge machine according to the first aspect of the present invention configured as described above, when an abnormality occurs in the wire from the wire feeding means, the wire feeding means and the wire cutting means are moved away from each other. Therefore, it is possible to reliably remove the remaining wire electrodes and the like.

In the wire electric discharge machining apparatus according to the second aspect of the present invention configured as described above, the moving means moves the wire feeding means and the wire cutting means away from each other, and the wire electrode between the wire feeding means and the wire cutting means. Since the removing means removes the wire electrode and the like, the wire electrode and the like left uncut can be removed more reliably.

In the wire electric discharge machine according to the third aspect of the present invention configured as described above, the traveling path detecting means detects the traveling path of the wire electrode between the wire feeding means and the wire cutting means. Is.

In the wire electric discharge machining apparatus according to the present invention configured as described above, when the load of the motor of the wire cutting means is abnormal, the stop control means stops the cutting operation of the wire cutting means. , It is possible to minimize troubles.

According to a fifth aspect of the wire electric discharge machining apparatus configured as described above, the rotation synchronizing means synchronizes the rotation speed of the motor of the wire cutting means and the rotation speed of the roller of the wire feeding means, whereby the wire electrode. It is possible to always cut a fixed length without cutting it more than necessary.

[0018]

【Example】

Example 1. Examples embodying the present invention will be described. In FIG. 1, a machining tank 2 is placed on a base 1 of a wire electric discharge machine, and a workpiece W fixed on a work table 3 is immersed in the machining liquid in the machining tank 2. As described above, the insulating working liquid (fresh water or a mixed liquid of fresh water and oil) 5 is supplied from the working liquid supply device 4, and the contaminated working liquid 5 is collected by the working liquid supply device and filtered through a filter or the like. After that, it is circulated again and supplied. A wire bobbin 9 around which a wire electrode 8 is wound is provided on the upper portion of the column 7, and an upper guide portion 11 is formed on an upper arm 10 supported on the upper portion of the column 7. Further, a lower guide portion 13 is arranged on the lower arm 12 supported on the lower portion of the column 7. The wire electrode 8 pulled out from the wire bobbin 9 is stretched from the upper guide portion 11 to the lower guide portion 13 via the workpiece W in a substantially vertical shape, and is connected to the wire electrode 8 and the workpiece W from a power source (not shown). Electric discharge machining is performed in a minute gap (electric discharge machining section) between the workpiece W and the wire electrode 8 passing vertically downward by passing a pulse current. A nozzle portion (not shown) in both or one of the upper guide portion 11 and the lower guide portion 13
The machining liquid 5 is ejected from the discharge nozzle toward the electric discharge machining unit to remove metal scraps from the electric discharge machining and cool the electric discharge machining unit.
The transport speed (moving speed) of the wire electrode 8 varies depending on the electrical discharge machining conditions, the plate thickness of the workpiece W, etc., but is generally 5
It is about 0 to 300 mm / sec, for example, about 100 mm / sec when the plate thickness is 50 mm. Next, FIG. 2 shows a detailed view of the wire cutting device of the present invention. In FIG. 2, 15 and 16 are wire collecting rollers. A wire cutting device 17 is provided on the wire electrode exit side of the wire collecting rollers 15 and 16.
Is connected, and 18 is its slide mechanism. In addition, 19 is a wire guide, 20 is a control device of a wire electric discharge machine, 21, 22, and 23 are a wire cutting motor, a wire cutting blade, and a wire collection box, respectively.

Next, the operation will be described. The wire electrode 8 discharged from the wire collecting rollers 15 and 16 is connected to the wire guide 19 mounted in front of the wire cutting device 17.
And is finely cut by the wire cutting blade 22. The wire electrode 8 cut by the wire cutting blade 22 is the wire collection box 2
Dropped in 3. When the wire electrode 8 is cut in order to pass the wire electrode 8 through a processing start hole (not shown) of the workpiece or the wire electrode 8 is broken during processing, the wire collecting rollers 15 and 16 and the wire cutting device 17 The wire electrode 8a is always left between the wire cutting blades 22a and 22b. If there is this uncut wire electrode 8a, the wire cutting device 17 is once moved by the slide mechanism 6 in the direction away from the wire collection rollers 15 and 16 (leftward in FIG. 1), and the uncut wire electrode 8a is indicated by an arrow. Like A, it falls into the wire collection box 23. After that, the wire cutting device 17 is moved rightward in the figure and returned to the original position. Since the slide mechanism 6 functions to move the wire cutting device 3 away from the wire collecting roller 1, the moving direction may be horizontal or vertical. With the above, the discharging operation of the wire electrode 8 is completed. When machining is performed again, the wire electrode 8 is stretched from the wire guide 19 to the wire cutting device 17 by using an automatic wire feeder (not shown) mounted on the wire electric discharge machine.
In order to determine whether there is any uncut wire electrode 8a, an optical sensor or the like is installed between the wire collecting rollers 15 and 16 and the wire cutting device, or the contact of the wire electrode is judged by the electric resistance. can do. Alternatively, since the wire collecting rollers 15 and 16 are displaced depending on whether or not the wire electrode 8 is sandwiched, it is possible to judge by the displacement amount. Further, when the wire electrode is cut using the automatic wire feeder, the wire electrode is always left uncut.
Therefore, after the wire electrode is cut, the wire collecting rollers 15 and 16 may be rotated for a certain period of time to eject the wire electrode 8, and then the wire cutting device may be forcibly moved.

Example 2. FIG. 3 shows another embodiment. FIG.
Reference numeral 24 is a compressed air discharge port. Other configurations are the same as those in FIG. The compressed air discharge port is provided in the vicinity of the wire collecting rollers 15 and 16 for sending out the wire electrode 8a.

Next, the operation will be described. In order to drop the uncut wire electrode 8a, the wire cutting device 17 once moves (retracts) to the left, and then the air is discharged from the compressed air discharge port 24 to remove the uncut wire electrode 8a in the wire collection box 23. Blow it away. After that, by moving (advancing) the wire cutting device 17 to the right, the wire cutting device is returned to the original position, whereby the discharging work of the wire electrode 8a is completed. Since the wire cutting device functions to move away from the wire collecting rollers 15 and 16,
The direction of moving away can be either horizontal or vertical.

Example 3. FIG. 4 shows another embodiment. FIG.
In the figure, 25a, 25b, 25c are gears, which connect the wire collecting rollers 15, 16 and the wire cutting blade 22. The recovery motor 26 also serves as the wire cutting motor 21. Others are the same as in FIG.

Next, the operation will be described. Since the wire cutting blade 22 is connected to the wire collecting rollers 15 and 16, the wire cutting blade 22 can be rotated in synchronization with the wire collecting rollers 15 and 16. Gear 25 if needed
You can also set the optimum gear ratio with. Also, without using a gear, by connecting the drive motor and the encoder to the wire collecting rollers 15 and 16 and the wire cutting blade 22, respectively,
The rotation speed may be controlled.

Example 4. FIG. 5 shows another embodiment. Figure 5
26 is a load detector. Others are the same as in FIG. The load detector 26 is provided in the vicinity of the wire cutting blade 22 and detects whether or not an excessive load is generated on the wire cutting blade.

Next, the operation will be described. When the wire cutting motor 21 stops due to the wire electrode 8 biting into the gap between the wire cutting blade 22 and the fixed blade 27, the load detector 26 sends a signal to the controller 20 to immediately stop the wire electric discharge machine. Further, the wire cutting blade 22 is rotated in the reverse direction to remove the wire electrode 8 that has been bitten. When removing the wire electrode, compressed air may be blown. Then, the processing is restarted.

Example 5. FIG. 6 shows the next embodiment. Figure 6
Reference numeral 27 denotes a wire electrode detector, which is located between the wire collecting rollers 15 and 16 and the wire cutting device 17.
Other configurations are the same as those in FIG.

Next, the operation will be described. If the wire cutting blade 22 is worn out and the wire electrode 8 cannot be cut, or if the tip of the wire electrode 8 is bent, the wire electrode 8 is cut by the wire cutting blade 22.
I won't go in. Therefore, the wire electrode 8 deviates from the traveling path and the wire electrode 8 (8 ') bends like 8'.
This deflection is detected by the wire electrode detector 27 to determine the abnormality of the wire cutting device 17. If it is determined to be abnormal, the wire cutting device 17 is immediately retracted (moved to the left), and the wire electrode 8 is directly cut into the wire recovery box 23 as shown by the alternate long and short dash line in FIG. 6 without being cut. Further, when the wire electrode 8 deviates from the traveling path, the wire electrode detector 27 determines that the wire cutting device 17 is abnormal, and sends a signal to the control device 20 of the wire electric discharge machining device to stop the machining. Then, the wire cutting device 17 is slid to drop the wire electrode 8 ′ into the wire collection box 23. As a result, if the wire electrode 8'is removed, the processing is restarted. To remove the wire electrode 8 ′, compressed air may be blown as in the second embodiment. It is also possible to rotate the recovery rollers 15 and 16 in the reverse direction and then to rotate the recovery rollers 15 and 16 in the forward direction to return the wire electrode 8 ′ to the normal path. Therefore, it is possible to obtain an electric discharge machine that can operate smoothly.

[0028]

As described above, according to the first, second and third aspects of the invention, when an abnormality occurs in the wire from the wire feeding means, the wire feeding means and the wire cutting means are moved so as to move away from each other. Since this is done, the wire electrode can be reliably removed. Therefore, it is possible to smooth the operation after the occurrence of the abnormality.

Further, according to the invention of claim 4, when the load of the motor is abnormal due to the detection result of the load detecting means, the cutting operation of the wire cutting means is stopped, so that the trouble is minimized. It is possible to suppress. Therefore, it is possible to smoothly and promptly perform the operation after the load abnormality occurs.

As described above, according to the fifth aspect of the invention, by synchronizing the rotation speed of the motor of the wire cutting means and the rotation speed of the roller of the wire feeding means, it is possible to always cut a predetermined length. become. Therefore, it is possible to extend the life of the cutting blade without cutting the wire electrode into finer pieces than necessary.

[Brief description of drawings]

FIG. 1 is a side view of a wire electric discharge machine showing an embodiment of a first invention.

FIG. 2 is a configuration diagram of a wire electric discharge machine showing an embodiment of the present invention.

FIG. 3 is a configuration diagram of a wire electric discharge machine showing another embodiment of the present invention.

FIG. 4 is a configuration diagram of a wire electric discharge machine showing another embodiment of the present invention.

FIG. 5 is a configuration diagram of a wire electric discharge machine showing another embodiment of the present invention.

FIG. 6 is a configuration diagram of a wire electric discharge machine showing another embodiment of the present invention.

FIG. 7 is a schematic side view of a conventional wire electric discharge machine.

FIG. 8 is a side sectional view of a main part of a conventional wire electrode recovery device.

9 is an enlarged view taken along the line III-III of FIG.

FIG. 10 is a perspective view of a conventional guide body and a fixed blade body.

FIG. 11 is a configuration diagram of a conventional wire electric discharge machine.

[Explanation of symbols]

8 wire electrode, 15, 16 wire collecting roller, 17
Wire cutting device, 18 slide mechanism, 22 wire cutting blade, 24 compressed air discharge port, 25 gear, 26 load detector, 27 wire detector.

Claims (5)

[Claims] 1. A wire electric discharge machine for processing an object to be machined by generating an electric discharge between the wire electrode and the object to be machined, and cutting and collecting the wire electrode. The wire feeding means, the wire cutting means for cutting the wire fed from the wire feeding means to a predetermined length, and when the wire from the wire feeding means has an abnormality, the wire feeding means and the wire cutting means are separated from each other. A wire electric discharge machine. 2. The removing means for removing the wire electrode between the wire feeding means and the wire cutting means while the moving means moves away from the wire feeding means and the wire cutting means. The wire electric discharge machine according to claim 1. 3. The wire electric discharge machine according to claim 1, further comprising a traveling path detecting means for detecting a traveling path of the wire electrode between the wire feeding means and the wire cutting means. 4. A wire for sending the wire electrode in a wire electric discharge machine for processing the work piece by generating an electric discharge between the wire electrode and the work piece and cutting and collecting the wire electrode. A feed means, a wire cutting means for cutting the wire fed from the wire feeding means into a predetermined length by rotation of a motor, a load detecting means for detecting a load on the motor of the wire cutting means, and a load detecting means for the load detecting means. An electric discharge machine comprising: a stop control means for stopping the cutting operation of the wire cutting means when an abnormality occurs in the load of the motor in the detection result. 5. A wire electric discharge machine for processing the work piece by generating an electric discharge between the wire electrode and the work piece, and cutting and collecting the wire electrode. Wire feeding means for feeding by rotation, wire cutting means for cutting the wire fed from the wire feeding means to a predetermined length by rotation of a motor,
A wire electric discharge machine comprising: a rotation cycle means for synchronizing a rotation speed of a motor of the wire cutting means and a rotation speed of a roller of the wire feeding means.