JPS62162426A - Wire-cut electric discharge machine - Google Patents

Abstract

PURPOSE:To prevent a trouble such as that a wire electrode comes off from its path during inserting operation thereof, by providing an automatic wire insertion monitoring device composed of wire electrode detecting devices laid along the path of the wire electrodes and a wire insertion confirming circuit, in a wirecut electric discharge machining device. CONSTITUTION:A plurality of wire-electrode detecting devices which are successively arranged along wire electrodes, are each composed of detectors 29 through 35 and preamplifiers 36 through 42 associated with the former, and the output of each wire electrode detecting device is delivered to an insertion confirming circuit 43 which checks whether of not a wire electrode detecting device in the following stage issues a wire electrode detection signal within a predetermined time after a wire electrode detecting device in each stage issues a wire electrode detection signal, in accordance with a previously set sequence control program, and then delivers an output signal in accordance with the thus detected condition. The output signal from the insertion confirming circuit 43 is delivered to a control circuit for controlling a motor adapted to drive a feed roller 7, and therefore, the feed-out of the wire-electrode is controlled.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a wire cutter equipped with an automatic wire threading device that automatically inserts a wire electrode into a processing section including a workpiece so that it can be processed. This invention relates to electrical discharge machining equipment.

[Conventional technology]

When performing contour machining of a cutting die or the like using a wire-cut electrical discharge machining device, a pilot hole for starting machining is formed in advance for passing a wire electrode through the workpiece, the wire electrode is inserted into the pilot hole, and the workpiece is Position the body between two normal arms, apply appropriate tension between the pair of electrode guides provided at the tips of the two arms, and make the wire electrode into a straight line through the prepared hole for starting machining. During machining, machining fluid is supplied between the wire electrode and the workpiece, and intermittent voltage pulses are applied between the two to generate electrical discharge.
Further, a relative machining feed is applied between the wire electrode and the workpiece in a direction substantially perpendicular to the wire electrode axis between the guides, thereby performing desired contour machining.

In addition, when performing multiple contour machining on one workpiece in succession, after one machining is completed, the wire electrode inserted through the workpiece is cut and the used wire electrode is collected. After moving the workpiece to a predetermined position, the wire electrode is inserted into the next machining start hole, the wire electrode is sent along the predetermined path, and the machining is continued in the same manner as above. It is.

[Problem that the invention seeks to solve]

However, the wire electrode is an extremely thin wire with a diameter of 1n or less, usually about 0.05 to 0.4 mm, and is inserted into the machining start hole formed in the workpiece before each machining process starts. It is a very difficult task to automatically insert the wire into the guide and to ensure that it is stretched between the pair of guides.

With conventional equipment, the wire electrodes are sent out one after another during the above operation, so there are times when the wire electrode is not inserted properly into the pilot hole for starting machining, or even if the wire electrode is successfully inserted into the pilot hole, the wire electrode is not properly inserted in the subsequent path. There was a problem in that the wire electrodes got tangled in pigeonholes that strayed from the route, causing work to be interrupted and subsequent processing not only to be impossible but also to damage the feed rollers, their drive devices, and the like.

The present invention was made to solve the problem of ridges, and its purpose is to monitor the insertion of a wire electrode into a pre-formed hole for starting machining, and to ensure that the wire electrode When a problem such as deviation from the guide route occurs, it is immediately detected and the feeding of the wire electrode is stopped, thereby preventing the wire electrode from becoming tangled and allowing subsequent processing to be carried out promptly. The objective is to prevent damage to the feed roller, its drive device, etc.

[Means for solving problems]

The above problem can be solved by using a plurality of wire electrode detection devices sequentially provided along the wire electrode path and the outputs of these wire electrode detection devices as input, so that each stage of the wire electrode detection device detects the wire electrode. It consists of a wire continuity confirmation circuit that detects whether or not the wire electrode detection device in the subsequent stage has transmitted a wire electrode detection signal within a predetermined time after each signal is transmitted, and transmits an output signal according to the situation. This is achieved by providing an automatic line monitoring device.

[For production]

With the above configuration, the passage of the wire electrode is detected by a plurality of wire electrode detection devices sequentially provided along the wire electrode route, and their outputs are input to the wire continuity confirmation circuit. After the wire electrode detection device in each stage transmits a wire electrode detection signal, it is detected whether or not the wire electrode detection device in the subsequent stage has transmitted a wire electrode detection signal within a predetermined time period, and the output is output according to the situation. Signals are sent and automatic line routing is monitored.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.

Figures 1 to 5 show an embodiment of the wire-cut electric discharge machining apparatus according to the present invention, in which the wire electrode is inserted into the machining start hole and stretched along a predetermined path automatically. FIG. 1 is an explanatory diagram showing step-by-step the process carried out, of which FIG. 1 shows the state when one process on the workpiece is completed, FIG. 2 shows the work stage of cutting the wire electrode, Figure 3 shows the work stage of detecting the bending of the cut wire electrode, and Figures 4 and 5 show the work stage of inserting the wire electrode into the prepared hole for starting machining in preparation for the next machining. be.

In Figures 1 to 5, 1 is a column installed upright on a base (not shown), and 2 is a column that extends horizontally from column 1 and is attached so that it can be moved up and down and positioned and fixed. A processing arm, 3 is a processing head provided at the tip of the processing arm 2, 4 is a processing fluid injection nozzle, 5 is a wire electrode positioning die holder, 6 is a power supply die, 7 is a feed roller that also serves as a brake roller, 8 is a pinch roller,
9 is a guide roller, 10 is a wire electrode, 11 is a wire cutting device, 12 is a wire cutting arm, 13 is a cylinder,
14.14' is a wire bending detection device, 15.15' is a wire detection arm, 16 is a cylinder, 17.17' is a pair of wire electrode positioning guides that can be opened and closed, 18.18
' is a cylinder, 19 is a capstan, 20 is a pinch roller, 21 is a wire take-up device, 22.23 is a wire take-up roller that can be opened and closed as required, 24 is a wire guide body, 2
5. 25 is a feed roller, 26 is a pinch roller, 27 is a wire collection surface, 28 is a workpiece, 29 to 35 are detectors, 3
6 to 42 are preamplifiers, and 43 is a wiring confirmation circuit.

In addition, a power supply device that supplies machining voltage pulses to the wire electrode 10 via the power feeding die 6, a drive device that gives relative machining feed between the wire electrode and the workpiece, a control device that controls this, and a machining fluid. The supply device and the like are omitted in the figure.

First, the configuration of an embodiment of a wire-cut electric discharge machining apparatus according to the present invention will be briefly described with reference to FIG.

The processing arm 2 extends horizontally from the column 1 and is configured to be vertically movable by a drive device (not shown).

A die holder 5 having a wire electrode positioning die, a power supply die 6, a feed roller 7 which also serves as a brake roller, and a pinch roller 8 are provided in the processing head 3, which has a processing fluid injection nozzle 4 attached to its tip. A wire cutting device 11 and a wire bending detection device 14 are attached.

A pair of wire electrode positioning guides 17, 17' are provided at positions facing the processing head 3, sandwiching the workpiece 28, and a wire pulling device 21 is provided below them.

In this embodiment, the wire electrode detection device includes detectors 29 to 35.
and preamplifiers 36 to 42 corresponding to each of them, and the detectors 29 to 35 are connected to the wire detection arm 15, the wire electrode positioning guide 17, and the wire take-off roller of the wire take-off device 21 along the tensioning route of the wire electrode 10. 2
2, the feed roller 25, 25, and the pinch roller 26, and the output of each wire electrode detection device is input to the wire continuity confirmation circuit 43.

In accordance with a predetermined sequence control program, the wire connection confirmation circuit 43 transmits the wire electrode detection signal to the wire electrode detection device in the subsequent stage within a predetermined time after the wire electrode detection device in each stage transmits the wire electrode detection signal. It checks whether the signal has been transmitted or not, and transmits an output signal depending on the situation.

The output signal of the wire continuity confirmation circuit 43 is sent to a control device that controls the motor that drives the feed roller 7, and the wire electrode 1
The sending of 0 is controlled.

With reference to FIGS. 1 to 4 below, we will explain the process of automatically setting the wire electrode in preparation for the next machining after one machining is completed using the wire-cut electrical discharge machining apparatus according to the present invention. Explain in detail.

FIG. 1 shows the state when one process is completed. In this state, the wire electrode 10 is supplied from a wire supply drum (not shown), passes through the guide roller 9, and is connected to the feed roller 7, which also serves as a brake roller, in a pinch. roller 8
The wire passes through the power feeding die 6, the wire electrode positioning die, and its die holder 5, is pulled out from the tip of the machining fluid injection nozzle 4, passes through the machined hole 28a of the workpiece 28, and is inserted into a pair of Wire electrode positioning guide 17
．． 17', the wire take-up roller 22, the wire guide body 24, the feed roller 25, 25, and the pinch roller 2.
The wire collection surface 27 passes through the wire collection device 21 consisting of G.
It is laid out along the route leading to.

From this state, as shown in FIG. 2, after moving the pair of wire electrode positioning guides 17 and 17' to the open position,
The arm 2 is moved upward along the column 1, and the cutting edge 3 is moved to a position appropriately away from the workpiece 28 for processing.

At this position, the wire cutting arm 1 of the wire cutting device 11
2 is moved downward and rotated, and the wire electrode 10 is cut by a cutter 12a provided at the tip thereof.

Next, as shown in FIG. 3, the wire cutting arm 12 is moved upward and rotated to return to the original position shown in FIG. 15, 15' is moved downward and rotated, and the detectors 29, 29' provided at the tips thereof are placed opposite to each other with the wire electrode 10 sandwiched therebetween to detect the bending of the wire electrode 10.

This detector 29, 29' is of a contact type with a wire electrode 10
It may be configured to output an abnormal signal when it comes into contact with the wire, or it may be configured to output a normal detection signal when the wire electric wire +410 passes a predetermined position as an optical type.

Although only a portion of the wire bending detection device 14' is shown in FIG. 3 for convenience of illustration, a pair of wire bending detection devices 14 and 14' are provided facing the outer periphery of the processing head 3. When the arm 15.15' is set, the detector 29.29' provided at the tip thereof is configured to face the wire electrode 10 between them.

Also, at this time, the wire detection arm 15, 15' is set appropriately below the tip of the wire electrode 10 cut by the wire cutting device 11, and in this state, the feed roller 7, which also serves as a brake roller, is operated. The wire electrode 10 may be fed out slightly to detect whether the wire electrode 10 is fed out in a straight line.

In parallel with the above operation, the wire take-up device 21 is operated to remove the cut used wire electrode 10' from the wire collection surface 27.
At the same time, a drive device (not shown) is activated to start the next machining, so that the center of the machining start pilot hole 28b previously provided in the workpiece 28 and the axis of the position where the wire electrode 10 is stretched on the machining part. The workpiece 28 is moved so that the

Next, the arm 2 is gradually moved downward along the column 1, and the tip of the processing head 3 approaches the upper surface of the workpiece 28, as shown in FIG.

At this position, the feed roller 7, which also serves as a brake roller, is operated to slowly feed out the wire electrode 10, and the wire electrode 10 is inserted into the lower hole 28b of the workpiece 28.
A pair of wire electrode positioning guides 17 in the open position.
17' and further extends downward.

When the tip of the wire electrode 10 reaches the take-off rollers 22 and 23 of the wire take-off device 21, the wire electrode 10 either rotates the take-off roller 22 and the yoke directly or removes the take-off roller 22 and the yoke that have been separated. After closing and sandwiching the wire electrode 10, the wire guide body 24 is pulled out by rotational driving.
guided by.

The wire electrode 10 is sequentially sent by a feed roller 25 and a roller, passes through a pinch roller 26, and is collected on a wire collection surface 27.

In the above process, when the wire electrode 10 passes through the pair of wire electrode positioning guides 17.17', the optical detectors 30.30' and 31 provided on the wire electrode positioning guides 17.17' .Wire electrode by 31']
0 is detected, and at this time, by applying a weak voltage to the wire electrode 10 via the power supply die 6, the wire electrode 10 is connected to the take-up roller 22, the feed roller 25, .
25 successively, conduction occurs between the wire electrode 10 and each portion, and this is sequentially detected by the detectors 32 to 35.

The signals from the detectors 29 to 35 are amplified by preamplifiers 36 to 42 and sent to the wire continuity confirmation circuit 43. If the signal from the wire electrode detection device does not arrive within a predetermined time, a signal is sent to a control device (not shown) that controls the motor that drives the feed roller 7, the feed roller 7 is stopped, and the wire electrode 10 is stopped. This prevents the paper from getting tangled or wrapping around the feed roller, etc.

Furthermore, by knowing the location of the detectors 29 to 35 where this signal has stopped, it is possible to know where on the route the trouble has occurred.

The above operations complete the insertion of the wire electrode 10 into the machining start hole 28b in preparation for the next machining and the tensioning work along a predetermined route.

When the wire electrode 10 is stretched as shown in FIG. 5, the pair of wire electrode positioning guides 17.17
’ and connect the power supply die 6 from the power supply (not shown).
A machining voltage pulse is applied between the workpiece 28 and the wire electrode 10 through the machining part, and machining fluid is supplied to the machining part from the machining fluid jet nozzle 4 and the wire electrode positioning guide 17, 17'. A desired machining feed is applied between the workpiece 28 and the wire electrode 10 to perform the next machining.

Therefore, in the explanation on the ridge, the insertion work was explained after one machining is completed, but in this embodiment, it is also possible to perform the initial wire electrode tensioning work for one workpiece. In this case, it is sufficient to start the work from the state shown in FIG.

Note that the present invention is not limited to the embodiment on ridges.

That is, for example, the wire electrode detection device may be provided at any position along the wire electrode path, and the number thereof can be set freely. The structure of the wire pulling device etc. can be freely changed in design within the scope of the purpose of the present invention, and the present invention encompasses such modified embodiments.

〔Effect of the invention〕

Since the present invention is structured like a ridge, when the present invention is used, troubles such as the wire electrode coming off the predetermined guide path during the insertion work of the wire electrode into the pre-formed pilot hole for starting machining can be avoided. Even if this occurs, the wire electrodes are prevented from becoming tangled in the middle of the path, allowing subsequent processing to be carried out quickly, and damage to the feed roller, its driving device, etc. is also prevented.

[Brief explanation of drawings]

Figures 1 to 5 show an embodiment of the wire-cut electric discharge machining apparatus according to the present invention, in which the wire electrode is inserted into the machining start hole and stretched along a predetermined path automatically. FIG. 3 is an explanatory diagram showing step by step the process performed. 1−・−・−−−−・−・−−−1−−−Column 2−・
−・−・−・−・−−−−−m−Processing arm 3−・
−・・−−m−・・−・−−−−Ehead 4−・−
・・−・−・−−−−1・−Working fluid injection nozzle 5−・・
−・−・−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−1
−・−・−・Heeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeoooooooooooooooooooooooooooooooooooooooo!・−・Guide roller 10−・−
・−・−−−−・−・・−・Wire electrode 11−−−−−
---・-1111～-----Wire cutting device 12
---------1-----Wire cutting arm 12a--------m-----Force cutter 1
4.14'・---------Wire bending detection device 15.15'--1-----Wire detection arm 17.17'------- ...-A pair of wire electrode positioning guides that can be opened and closed

Claims (1)

[Claims] A plurality of wire electrode detection devices are sequentially provided along the wire electrode route, and the outputs of these wire electrode detection devices are input, and each wire electrode detection device at each stage transmits a wire electrode detection signal and then within a predetermined period of time. A wire cutting device equipped with an automatic wiring monitoring device consisting of a wiring confirmation circuit that detects whether or not a wire electrode detection device in a subsequent stage has transmitted a wire electrode detection signal, and transmits an output signal depending on the situation. Electrical discharge machining equipment.