JP2982485B2 - Wire electrode recovery device in wire electric discharge machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for cutting a so-called used wire electrode after electric discharge machining in a wire electric discharge machine to an appropriate length and collecting it.

[0002]

2. Description of the Related Art Conventionally, a wire electrode collecting apparatus for cutting and collecting used wire electrodes in a short length is disclosed in
As disclosed in JP-A-89441 and JP-A-3-49831, a wire electrode is inserted between a fixed blade body and a rotary blade body, and the rotary blade body is rotated by a drive motor so that the wire electrode is rotated. Some are cut into appropriate lengths and collected in a collection box.

[0003]

However, when the clearance between the fixed blade and the rotary blade is not appropriate or when the cutting blade blocks of the rotary blade and the fixed blade are worn due to long use, The wire electrode which is not cut but remains in a long state is sent to the collecting device. If the electric discharge machining is continued in such a state, the long wire electrode that is not cut and is bent in a complicated manner protrudes from the collection box and comes into contact with the main body of the electric discharge machine and is electrically short-circuited. There is a problem that a wire electrode disconnection accident or the like occurs.

[0004] It is an object of the present invention to solve such a problem and to provide a highly reliable wire electrode recovery device free from failure.

[0005]

In order to achieve the above object, a wire electrode collecting apparatus according to the present invention comprises a feeding means for feeding a wire electrode after electric discharge machining, a fixed blade and a fixed blade. Cutting means comprising a moving blade body moving in and out, a collecting box disposed below the cutting means, and a contact detector located between the cutting means and the collecting box and in contact with an uncut wire electrode; It comprises a contact detector and detection means capable of detecting the state of electrical contact with the wire electrode on the upstream side of feeding.

[0006]

Next, an embodiment of the present invention will be described with reference to FIGS. A machining tank 2 is mounted on a base 1 of the wire electric discharge machine, and a workpiece W fixed on a work table 3 is immersed in a machining fluid in the machining tank 2. An insulating working fluid 5 is supplied from the working fluid supply device 4, and the contaminated working fluid 5 is collected in the working fluid supply device 4, filtered through a filter or the like, and then circulated again to be 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. A lower guide 13 is disposed on a lower arm 12 supported at a lower portion of the column 7. The wire electrode 8 pulled out from the wire bobbin 9 is stretched substantially vertically from the upper guide section 11 to the lower guide section 13 via the workpiece W, 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 portion (electric discharge machining portion) between the wire electrode 8 and the workpiece W, which pass a pulse current and pass vertically downward. In addition, the machining fluid 5 is jetted toward the electric discharge machining portion from a nozzle portion (not shown) of the upper guide portion 11 and / or the lower guide portion 13 to remove metal scraps and electric discharge machining. Perform part cooling. The feeding speed (moving speed) of the wire electrode 8 varies depending on the electric discharge machining conditions, the thickness of the workpiece W, and the like, but is generally about 50 to 300 mm / sec. On the order of seconds.

The direction changing pulley 14 is connected to the lower guide portion 13.
And the used wire electrode 8 whose feeding direction has been changed in the lateral direction by the direction changing pulley 14.
Is forcibly nipped and fed by a feeding means including a pair of rollers 15 and 16 disposed behind the direction changing pulley 14. The outer circumference of the pair of upper and lower rollers 15 and 16 in the feeding means of the present invention is covered with an electrically insulating member. One of the rollers 15 is driven by a drive motor 17 (FIG. 3).
(See Reference). As shown in FIG. 2, the guide member 18 is disposed behind the pair of rollers 15 and 16 in the feeding direction, and a cutting device 19 as cutting means of the present invention is provided behind the guide member 18. The wire electrode 8a arranged and cut by the cutting device 19 to about 1 cm to 3 cm.
Is deposited on the collection box 20 arranged below.

FIGS. 2 and 3 show an embodiment of the recovery apparatus of the present invention. The drive motor 17 and the cutting motor 21 of the cutting device 19 are fixed to a base body 22 and are connected to the roller 15 and the cutting rotor 23, respectively. It is connected and transmits its rotational force. The other roller 16 is pivotally supported by the base body 22 via a pinch lever 24 so as to be vertically rotatable. The roller 16 is pressed against the roller 15 by a spring 25 and a screw 26 for adjusting the pressing force. Wire electrode 8
Is sandwiched.

The fixed blade 27 in the cutting device 19 is fixed to a fixed base 28 with an eccentric pin 29 for mounting. The fixed base 28 is fixed to the base 22 via an electric insulating member 30. A notch groove 31 is formed in the fixing base 28, and a clearance adjustment screw 32 for adjusting the width of the notch groove 31 is adjusted so as to adjust a gap dimension with a rotary blade body 33 described later. .

The cutting rotor 23 is made of an electrically insulating material. The cutting rotor 23 supports a tip holder 34 for holding a rotary blade 33. Collection box 20
The rotation speed of the cutting motor 21 and the driving motor 17 of the roller 15 are increased in order to increase the collection density of the wire electrode pieces 8a.
A control device 35 described later so as to synchronize with the rotation speed of
Is controlled by. Thus, even if the feeding speed (moving speed) of the wire electrode 8 changes, the used wire electrode 8 can be cut into wire electrode pieces 8a having substantially the same length.
In this embodiment, the wire electrode piece 8a is approximately 15 mm.

The detector 36 for detecting the limit of deposition of the wire electrode piece 8a on the collection box 20 is formed of a non-contact type, for example, a light reflection type detector. As shown in FIGS. 2 and 3, the detector 36 is detachably attached to an attachment base 37 attached to a lower portion of the base body 22 via screws (not shown). Further, as shown in FIG. 3, the detector 36 is mounted on the mounting base 37 so that the light projecting direction of the detector 36 is obliquely downward toward the inside of the collection box 20 at the lower position.

Then, by detecting the light reflected on the upper surface of the wire electrode piece 8a deposited in the collection box 20, the amount of the wire electrode piece 8a deposited, that is, the collection limit can be detected. Usually, 70 to 70 times the volume of the collection box 20
The position and sensitivity of the detector 36 are adjusted so that the collection limit is reached at a deposition amount of about 80%. The cutting device 1
A cover body 38 guided to the collection box 20 is detachably disposed on the front face of the device 9 and the like so that the wire electrode pieces 8a after cutting are not scattered.

A contact detector 40 for detecting a disconnection failure of the wire electrode is disposed substantially below the fixed blade 27 and, as shown in FIG. 4, a front side of a mounting table 37 on which the detector 36 is mounted. Are attached via electrical insulating members 41 and 42. In this embodiment, the contact detector 40 is formed in a shape in which a metal plate is bent into a substantially U-shape in a plan view, as shown in FIGS. Etc. can be set arbitrarily.

A control device 3 for the wire electric discharge machine
5 will be described with reference to FIG. The control device 35
A central processing unit (CPU) 50 which is a detecting unit of the present invention;
Read-only memory (RO) storing a control program
M) 52, a readable / writable memory (RAM) 54 for storing various data, and a computer having a bus connecting them as main components, which are provided inside the base 1.

The central processing unit (CPU) 50 has an alarm such as a buzzer for notifying that the accumulation amount of the drive motor 17, the cutting motor 21, the detector 36, and the wire electrode piece 8a of the collection box 20 has reached a limit. The device 39 is connected and the CPU 5
Controlled by 0. Further, the CPU 50 is provided with the contact detector 40 and a power supply 43 for supplying current by slidingly contacting the wire electrode 8 below the lower guide portion 13 (see FIG. 1).
And are electrically connected. When the CPU 50 detects that the contact detector 40 and the power supply 43 are electrically conductive, the CPU 50 determines that the wire electrode 8 is not properly cut.

Next, the operation of cutting and collecting the used wire electrode 8 in the wire electric discharge machine configured as described above will be described. First, the CPU 50 sets the drive motor 17
Is driven, the used wire electrode 8 after the electric discharge machining is used.
Is fed from a pair of rollers 15 and 16 to guide body 1
8 and is guided to the position of the trailing edge while contacting the fixed blade 27. Then, the cutting motor 2 is
1 is driven and cut by the rotary blade 33 that rotates upward in the direction of arrow A in FIG. Then, the wire electrode piece 8a cut to a predetermined length is deposited on the lower collection box 20 by its own weight. When the accumulation amount reaches a predetermined limit, that is, when the reflectance detected by the detector 36 becomes equal to or greater than the value stored in the ROM 52, the CPU 50
To notify the worker by a buzzer or an alarm device 39 on the display unit.

On the other hand, when the wire electrode 8 fed by the pair of rollers 15 and 16 cannot be completely cut by the cutting device 19, a part of the long wire electrode 8 which is bent due to defective cutting or the like. However, as shown by a chain line in FIG.
Until the contact detector 40 comes into contact with the contact detector 40 and is completely disconnected, the power supply 43 and the contact detector 40 are electrically connected via the wire electrode 8.

In this state, the CPU 50 determines that a cutting failure has occurred and activates an alarm device 39 such as a buzzer and a display unit to notify the worker of the cutting failure. It should be noted that the electric discharge machining operation may be stopped and the drive motor 17 and the cutting motor 21 may be stopped almost simultaneously with this warning.

[0020]

As described above in detail, according to the present invention, the used wire electrode after the electric discharge machining is bulked in the collection box by cutting the wire electrode into a suitable length by the cutting means. It can be collected without. A contact detector is provided below the cutting means, and the contact detector is provided with a detecting means capable of detecting an electrical contact state between the contact detector and a wire electrode on the upstream side of feeding. It is easy to detect that the cutting operation of the wire electrode is defective. Therefore, it is possible to prevent the collection box from overflowing due to the long length of the wire electrode being accommodated due to the poor cutting of the wire electrode, and the overflowed wire electrode contacts the main body of the electric discharge machine and is electrically short-circuited. Further, it is possible to prevent an accident that the wire electrode is inadvertently disconnected during the electric discharge machining.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a wire electric discharge machine.

FIG. 2 is a front view of the wire electrode collecting device.

FIG. 3 is a view taken in the direction of arrows III-III in FIG. 2;

FIG. 4 is a cross-sectional view taken along a line IV-IV in FIG. 2;

FIG. 5 is a block diagram of a control device.

[Explanation of symbols]

 Reference Signs List 8 wire electrode 8a wire electrode piece 15, 16 roller 18 guide body 19 cutting device 20 collection box 27 fixed blade body 33 rotating blade body 24 collection box 35 control device 36 detector 39 alarm device 40 contact detector 43 power supply 50 CPU

Claims (1)

(57) [Claims] 1. A cutting means comprising a feeding means for feeding a wire electrode after electrical discharge machining, a fixed blade body and a movable blade body moving in and out of the fixed blade body, and a collecting means disposed below the cutting means. A box, a contact detector located between the cutting means and the collection box and in contact with an uncut wire electrode, and electrical contact between the contact detector and a wire electrode upstream from the contact detector. A recovery device for a wire electrode in a wire electric discharge machine, comprising: a detection means capable of detecting a state.