JPH0616971B2 - Drilling electric discharge machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electric discharge machining apparatus that simultaneously performs a large number of drilling processes on a workpiece using a large number of linear electrodes.

[Conventional technology]

2. Description of the Related Art An apparatus has heretofore been proposed in which a large number of linear electrodes are simultaneously used to perform a large number of holes in a workpiece by electric discharge machining.

An example of this type of device is shown in FIG.

In FIG. 1, 1a, 1b, 1c ... 1n are linear electrodes such as a plurality of solid rods or pipes, and 2 and 3 are guides having a large number of guide holes. The guide holes of the guide 3 and the guide 3 are coaxially formed in the same arrangement. The linear electrodes face the workpiece 4 while being inserted into the guide holes of the guides 2 and 3 and being fixedly supported by the guide 2. 6x, 6y, 6z are motors for feeding the guide 2 in the X, Y, Z axial directions. Further, 9 is a machining power source, which is an independent machining voltage pulse between each linear electrode 1a, 1b, 1c ... 1n and the workpiece 4 by using a guide as an insulator or by insulating coating each linear electrode. Is applied. Then, while a machining voltage pulse is being applied by the machining power source 9, a machining feed in the Z-axis direction facing the workpiece 4 is applied by the motor 6z to perform a large number of drilling operations simultaneously. Also, prior to processing, the motor 6x, 6
Positioning adjustment of the processing position of the workpiece 4 is performed by y, and motors 6x and 6y may give a machining feed on the XY plane as needed. Also, in some cases,
A motor 6v that rotates the guide 2 about the X axis and a motor 6w that rotates about an axis parallel to the Z axis are provided. The operations of these motors 6x, 6y, 6z, 6v, 6w are numerical values. It is controlled by the control (NC) device 8. The distance between the guides 2 and 3 is adjustable, and the guide 3 is arranged close to or in contact with the workpiece 4.

Further, although the device for supplying the working liquid to the working gap is not shown, when the linear electrode is a solid body, the working liquid is jetted from a nozzle arranged facing the working part or the working part is surrounded. A processing tank is provided, and when the processing portion is immersed in the processing liquid in the tank, processing is performed by using a jet flow from a nozzle together as necessary. When the linear electrode has a pipe shape, the working liquid is jetted and supplied to the tip processing portion through the internal passage of the pipe electrode.

Further, motors 5a, 5b, 5c ... 5n for rotating each of the linear electrodes 1a, 1b, 1c ... 1n are provided, and each linear electrode is continuously rotated in one direction or has a rotation angle of about 50 to 360 °. By performing the forward and reverse rotation, it is possible to satisfactorily eliminate the discharge of the machining chips generated in the machined hole tip machining part, prevent the occurrence of arcs and short circuits, and perform drilling efficiently. Can be done. In this case, the rotation speed is about 50.
0 to 2000 rpm is used, and each linear electrode is supported by the guide 2 so as to be able to rotate and prevent movement in the axial direction. An axial machining feed is provided integrally with all of the electrodes.

[Problems to be solved by the invention]

In such a conventional device, a large number of linear electrodes 1a, 1b, 1c ...
The guide holes of the guide 3 for supporting and guiding 1n are normally formed in a straight line at a predetermined interval (the same applies to the guide 2) as shown in FIG. 2 (a). For this reason,
Although it is possible to machine a large number of holes at the same time, only a large number of holes arranged linearly can be machined.
Further, in the case of processing a large number of holes arranged in a shape other than a straight line, for example, a circular shape, the guide 3 having a large number of guide holes arranged in a circular shape as shown in FIG. 2B is used. However, it is necessary to prepare the guide 3 in which the guide holes are arranged and formed in accordance with the required arrangement shape, and the conventional apparatus cannot easily and efficiently process a large number of holes having an arbitrary arrangement shape at the same time. It was

In view of such problems, an object of the present invention is to provide a drilling electric discharge machining apparatus that can easily and efficiently machine a large number of holes having arbitrary arrangement shapes at the same time.

[Means for solving problems]

In order to achieve this object, the drilling electric discharge machining apparatus of the present invention has a large number of linear electrodes arranged in parallel with a predetermined interval facing a workpiece through a minute gap, and the facing gap With a machining liquid interposed, a machining voltage pulse is applied between the linear electrode and the workpiece, and a relative machining feed in the opposite direction is applied between the two to simultaneously perform a number of drilling processes. In a drilling electric discharge machine, a machining power source capable of applying a machining voltage pulse to each electrode of a large number of linear electrodes and an object to be machined, and a unidirectional rotation or positive rotation to each of the electrodes. A rotating device that imparts reverse rotation and a guide hole that individually inserts each electrode have a spread in the X and Y biaxial directions on an XY plane orthogonal to the axial direction of each electrode. Formed in multiple locations in close proximity to or in contact with the work piece Of a plurality of the above-mentioned respective electrodes by drivingly controlling the guide device provided with a plurality of guide holes, a feeding device for independently feeding each of the electrodes inserted into the plurality of guide holes of the guide in the axial direction, And a control device for selectively feeding a desired electrode in the axial direction.

[Work]

A position corresponding to the required arrangement shape among the plurality of guide holes having a spread in the X and Y biaxial directions by driving and controlling the feeding device by the control device according to the required arrangement shape of the plurality of machined holes. Of the guides through which the selected linear electrodes are inserted by selecting a linear electrode to be inserted into the guide hole of the The multiple holes corresponding to the holes are simultaneously subjected to the drilling of the required arrangement shape.
Further, by causing the linear electrode to rotate on its own axis by means of the rotating device, it is possible to satisfactorily discharge and eliminate the machining chips generated in the machining portion at the machining hole tip, and to prevent the occurrence of arcs and short circuits. Well drilling is performed well, and especially many thin and deep drilling is also performed efficiently.

〔Example〕

 An embodiment of the present invention will be described with reference to FIG.

The apparatus of the embodiment shown in FIG. 3 is configured so that a desired linear electrode among the large number of linear electrodes 1a, 1b, 1c ... 1n in the apparatus of FIG. 1 can be selectively fed in the axial direction. In addition, as guides, guide holes for individually inserting a large number of respective linear electrodes are formed on an XY plane orthogonal to the axial direction of each linear electrode, for example, as in a grid pattern shown in FIG. 2 (c). X in
By using the guides 3 formed dispersedly in a large number of positions having a spread in the Y biaxial direction (the guide hole of the guide 2 is also formed in the same arrangement shape as the guide hole of the guide 3 coaxially). The guide 3 is provided in the vicinity of or in contact with the workpiece, and the same reference numerals as in FIG. 1 in FIG. 3 indicate the same components. Although not shown,
Also in the apparatus shown in FIG. 3, the linear electrodes 1a, 1b, shown in FIG.
Motors 5a, 5b, 5c ... 5n for rotating 1c ... 1n and motors 6x, 6y, 6z, 6v, 6w for driving the guide 2 are provided, and these motors are NC devices 8 respectively. Is controlled by. In FIG. 3, 10a, 10b, 10c ... 10n are rollers for independently feeding the linear electrodes 1a, 1b, 1c ... 1n in the axial direction, and 11a, 11b, 11c ... 11n are motors for rotating each roller, and these motors are also N
The drive is controlled by the C device 8.

NC program corresponding to the required layout shape of a large number of machined holes
It is input to the device 8 and the NC output signal is used to select a linear electrode corresponding to the required arrangement shape from a large number of linear electrodes 1a, 1b, 1c ... 1n, and the motors 11a, 11b, 11c. Among them, the motors that feed the selected plurality of linear electrodes are selectively driven and controlled, and the plurality of linear electrodes corresponding to the required arrangement shape are fed out by a predetermined length in the axial direction, and each fed linear electrode The ends of the are aligned and face the workpiece 4. By the machining voltage pulse supplied from the machining power supply 9, independent pulse discharges are generated in the respective machining gaps between the respective (selected) linear electrodes sent out and the workpiece by the machining liquid. At the same time, drilling is performed by giving a machining feed in the axial direction to each of the selected linear electrodes. For the machining feed in the axial direction (opposite direction to the workpiece), a motor that feeds the guide 2 in the Z-axis direction by feeding the selected linear electrode a predetermined length according to the required depth of the machining hole. 6z can be performed by performing servo control according to the detection signal of the discharge state of the machining gap. Further, the movement of the guide 2 in the Z-axis direction is utilized when the selected linear electrodes are opposed to the workpiece 4 at the start of processing, and the machining feed is performed independently for each selected linear electrode. It is also possible to perform servo control of each motor that feeds in the axial direction according to the detection signal of the discharge state of each machining gap. If such a machining feed is performed until each selected linear electrode penetrates the workpiece,
A large number of through holes can be machined into the required arrangement shape at the same time, and if the machining feed is stopped before penetrating, a large number of bottomed holes can be simultaneously formed into the required arrangement shape. Thus, by using a guide having guide holes at a large number of positions spread in the XY plane and appropriately selecting each linear electrode to be inserted into each guide hole, the linear electrodes can be fed in the axial direction. It is possible to simultaneously perform a large number of drilling processes at arbitrary positions on the workpiece.

During machining, the drive control of the motor corresponding to each linear electrode selected in the motors 5a, 5b, 5c, ... 5n causes each of the selected linear electrodes to operate in the same manner as the device of FIG. The rotation of the machine makes it possible to satisfactorily eliminate the discharge of machining chips and generated gas generated at the machined part of the machining hole by this rotation, preventing the occurrence of arcs and short circuits, and Also disappears and disappears due to the rotational movement, and the renewed flow of the working fluid is well performed, and by maintaining the stable working state, thin and deep drilling can be efficiently performed.

When a pipe-shaped electrode is used to jet a machining fluid from the tip of the electrode, a hydraulic pressure of about 10 kg / cm ² or more is used. In such a case, the pipe-shaped electrode is continuous in one direction. Since a liquid seal is required to rotate the electrodes and such a large number of electrodes complicates the apparatus, it is usually preferable to rotate each electrode forward and backward within an angle of 360 °. By doing so, it is possible to increase the supply pressure of the processing liquid without the need for a seal, to remove the processing waste and to enhance the cooling action of the processing portion, thereby improving the processing speed.

Further, the machining feed may be given to the workpiece 4 side.

The processing results are as follows.

When 22 rod-shaped brass electrodes with a diameter of 0.35 mmφ are used to drill holes in stainless steel with a plate thickness of 10 mm, 5% of surfactant and 5 μmφ of graphite particles are added to the water base as a working fluid.
% Using a liquid mixed with a specific resistance of 5 × 10 ⁴ Ωcm,
When electric discharge machining was performed while rotating at 000 rpm, the machining speed was about 16 mm / min and the electrode wear ratio was about 8%.

Next, when 22 pipe-shaped brass electrodes having an outer diameter of 0.3 mmφ were used for drilling on the same workpiece as the above, the electrodes were rotated at a rotation speed of 750 rpm and a rotation angle of 270 ° in the forward and reverse directions. Apply the same working fluid as above and apply pressure from the tip of the pipe-shaped electrode.
When electrical discharge machining was performed while jetting at 60 kg / cm ² , the machining speed was about 26 mm / min. Moreover, according to the experiment, the maximum is 100.
Simultaneous processing up to this level was possible.

Further, by controlling the driving of the X-axis motor 6x and the Y-axis motor 6Y by the NC device 8 to move the guide 2 circularly on the XY plane or move it to an arbitrary shape to bring it closer to the linear electrodes, Holes with a large diameter or holes of any shape can be machined, and if necessary, a machining feed on the XY plane that is equal to or larger than the interval between the selected linear electrodes is provided to the side walls of the plurality of holes. It is also possible to form a shape in which the two are communicated with each other, or to control the delivery length of each selected linear electrode individually to form the tip envelope surface of each linear electrode in the target shape.

〔The invention's effect〕

As described above, according to the present invention, a guide having guide holes at a large number of positions extending in the XY plane is used, and the guide is arranged close to or in contact with the workpiece 4, and Depending on the required arrangement shape of the machining hole, it is configured so that an appropriate electrode can be selected from the respective linear electrodes that are inserted into the respective guide holes and can be fed in the axial direction. By providing the rotating device for performing the movement, it is possible to easily and efficiently simultaneously process a large number of holes having an arbitrary arrangement shape, particularly a large number of thin and deep holes, in the workpiece 4.

[Brief description of drawings]

FIG. 1 is a simplified configuration diagram illustrating a conventional device, and FIG. 2 (a).
(B) and (c) are perspective views showing the arrangement shape of the guide holes of the guide, and FIG. 3 is a simplified configuration diagram for explaining the position embodiment of the present invention. 1a, 1b, 1c ... 1n are linear electrodes, 2 and 3 are guides, 4 is a workpiece, 5a, 5b, 5c ... 5n, 6x, 6y, 6z, 6v, 6w, and 11a, 11b,
11c ... 11n is a motor, 8 is an NC device, 9 is a machining power supply, 10
a, 10b, 10c …… 10n is Laura.

Claims (2)

[Claims] 1. A plurality of linear electrodes, which are arranged in parallel at a predetermined interval, are opposed to an object to be processed with a minute gap therebetween, and the machining liquid is interposed in the opposed gap to form the linear electrode. In a drilling electric discharge machining apparatus, which applies a machining voltage pulse between an electrode and a workpiece and gives a relative machining feed in the opposite direction between them to perform many drilling simultaneously, A machining power source capable of applying an independent machining voltage pulse between each electrode of the electrode and the object to be machined, and a rotation device for imparting unidirectional rotation or normal and reverse rotation to each of the electrodes, Guide holes for individually inserting the respective electrodes are formed dispersedly at a large number of positions having a spread in the XY biaxial directions on an XY plane orthogonal to the axial direction of the respective electrodes. A guide provided close to or in contact with
A feed device that gives independent axial feed to each of the electrodes that are inserted through the multiple guide holes of the guide, and a drive device that drives and controls the feed device to selectively select a desired electrode of the multiple electrodes. A drilling electric discharge machine, comprising: 2. The drilling electric discharge machining apparatus according to claim 1, wherein the linear electrode is a pipe-shaped electrode.