JPS6149050B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of an electric discharge machining apparatus previously disclosed by the present inventor in Japanese Patent Application No. 123280/1983.

In this electrical discharge machining device, an electrode unit attached to a machine arm has a plurality of guides forming a substantially U-shaped electrode guide path, and a wire electrode is guided through this substantially U-shaped guide path under the action of a desired tension. It is made to pass through a guide path and is configured to perform electrical discharge machining near the turning point at the tip.

Therefore, the specification of the above-mentioned Japanese Patent Application No. 123280/1983 states that
It is also disclosed that the positions of these wire guides are not necessarily fixed to the electrode unit, but can be changed at will, and the shape, dimensions, etc. of the guide route can be set appropriately. ,
They are set before the start of processing,
It was not something that could be controlled at any time during processing.

Although this previously disclosed method has been adopted for a wide range of applications, it has been found that the following problems arise because the shape and dimensions of the electrode path cannot be controlled during processing.

The first problem is that depending on the machining shape, the fluctuation range of the machining area during the machining period may become large, but it is impossible to reduce the fluctuation range, especially when the machining area is extremely small. In many cases, machining is forced, and in such cases, the average current is limited to a small value, resulting in a decrease in machining efficiency.

The second problem is that there are many restrictions on the shape and dimensions that can be machined, and when trying to machine something with a complex shape.
The NC program became complicated and redundant, and a long machining time was required.

The present invention has been made based on the above-mentioned viewpoints, and its purpose is to improve the machining area so that it can be freely controlled and set within a certain range during machining, and to improve the machining area during machining. Increase the degree of freedom,
The objective is to improve the ability to make higher-order selections during processing.

The gist of the present invention is to change the position of the sub-guide adjacent to the main guide, which forms the turning point of the U-shaped electrode path and constitutes the continuous machining section, to the main guide during electrical discharge machining. The object of the present invention is to configure the structure so that it can be freely controlled relative to the position of the object.

The present invention will be explained below with reference to the drawings.

1 and 2 are a partially cutaway front view and a partially cutaway side view of an electrode unit used in an electrical discharge machining apparatus according to the present invention, and FIGS. 3 to 5 illustrate the effects of the present invention. It is a diagram.

1 and 2, 1 is a substrate attached to an arm of a processing machine (not shown), 2 is a rotating part casing, 3 is a guide holder,
4 is a wire electrode supply reel, 5 is its shaft, 6 is the same collection reel, 7 is its shaft, 8 and 9 are split bearings, 10 and 11 are their hinges, 12 and 13 are locking devices, 14 is a wire electrode, 15 is a main guide, 17, 17' and 18 are sub guides, 19 is a hydraulic cylinder, 20 is an encoder, 2
1 is a piston rod, 22 and 23 are brake rollers, 24 is a capstan, 25 is a pinch roller,
26 is a pulse motor for rotating the guide holder, 27
is its encoder, 28 is the guide holder rotation axis,
29 and 30 are spur gears, 31 and 32 are bearings, 33 is a set screw, and in FIG.
35 is a brake torque device; 36 is a capstan drive motor; 37 is a connecting rod;
38 is a hydraulic four-way switching valve, 39 is an oil pump, 4
0 is Natsu.

The main holder 3 consists of a mounting flange 3a, a main frame 3b, and reel holding brackets 3c and 3d, and includes a rotating shaft 28 and bearings 31, 32 fixed to the center of the mounting flange 3a.
It is rotatably attached to the lower surface of the rotating part casing 2 and rotated around a rotating shaft 28 by a pulse motor 26 via spur gears 29 and 30.

One ends of the shafts 5 and 6 of the wire electrode supply reel 4 and the collection reel 6 are inserted into and supported by the rotation device 34,
The other end is supported by split bearings 8, 9 attached to the free ends of the brackets 3c, 3d by hinges 10, 11.

A main guide 15 is fixed to the free end of the main frame 3b, and sub guides 17, 17', brake rollers 22, 23, a capstan 24, and a pinch roller 25 are attached to the surface of the main guide 15, and a hydraulic Cylinder 19 is attached.

A sub-guide 18 is attached to the free end of the piston rod 21 of the hydraulic cylinder 19 via a connecting rod 37, and the wire electrode 14 is pulled out from the supply reel 4 and connected to the brake roller 22,
23, pass through the sub-guides 17 and 18, pass through the outer circumference of the main guide 15, turn back, pass through the sub-guide 17', the capstan 24, and the pinch roller 25, and then are wound onto the recovery reel 6.

The hydraulic four-way switching valve 38 is operated according to a predetermined program, and the hydraulic cylinder 19
is operated to appropriately move the sub-guide 18 between the rest position shown by the solid line in FIG. 1 and the position 18' shown by the dotted line. The amount of movement of the sub-guide 18 is detected by an encoder 20 and fed back to a processing control device (not shown).

This electrode unit is attached to a desired machine arm, and electrical discharge machining is performed between the wire electrode moving around the outer periphery of the main guide 15 and the desired workpiece.

Although the processing machine is not shown, the wire electrode unit and the workpiece are connected to a predetermined power supply, processing feed is performed so that a predetermined processing gap is maintained between them, and processing fluid is supplied.

The pulse motor 26 and the hydraulic switching valve 38 are controlled by, for example, a numerical control device together with a processing feed device (not shown).

Accordingly, in the structure previously disclosed by the present inventor, it was difficult to change the relative positions of the main guide 15 and the sub-guide 18.

Therefore, as shown in FIG. 3, for example, when attempting to excavate a shallow and narrow groove 41a on the surface of the workpiece 41, the machining area, that is, the electrode surface area corresponding to the part where electrical discharge machining is currently being performed, becomes extremely large. Sometimes it became narrow. That is, if processing is now carried out in the x direction in Fig. 3, the main guide 1
Only the area on the outer semicircumferential side surface of the wire electrode corresponding to the central angle α of 5, which is further below the surface of the workpiece 41, is an area where electrical discharge machining can be performed. Since it is desirable that .

In the device of the present invention, in such a case, the fourth
By moving the sub-guide 18 as shown in the figure and making the angle between the wire electrode between the main guide 15 and the sub-guide 18 and the surface of the workpiece a minute angle β, the wire that actually contributes to the processing The electrode length l can be set to any desired length, thereby increasing the processing area.
Since the concentrated occurrence of electric discharge is prevented, the average machining current can be increased and the required machining time can be shortened.

In addition, in this case, if the machining feed step in the x-axis direction is dx, the decrease in machining gap due to the progression of this one step is sinβ・dx, and
Since sinβ<1, changes in the machining gap during machining are extremely small, and stable machining is possible.

Furthermore, with the apparatus of the present invention, the position of the sub-guide can be controlled at any time depending on the purpose of processing such as cutting, grooving, etc. and the depth of the groove, so extremely efficient processing is possible.

Further, in the apparatus of the present invention, for example, a cylinder wall 41a, a spindle-shaped curved surface 41b, etc. as shown in FIG. 5 can be easily processed. That is,
In such a case, the workpiece 41 should be rotated around the z-axis in the figure, and the main guide 1 should be rotated.
5 sequentially from 15-1 to 15-2, 15-3, 15
-4 and machining feed in the z-axis direction, the sub guide position is sequentially changed from 18-1 to 18-1 in the xz plane.
2, 18-3, and 18-4 to perform electrical discharge machining. In this way, desired machining is possible without extremely reducing the machining area, which not only improves machining efficiency but also provides a good machined surface.

Since the present invention is constructed as described above, the present invention can further improve the efficiency of the electric discharge machining apparatus disclosed earlier by the present inventors.

Note that the configuration of the present invention is not limited to the embodiments described above, and for example, the configuration of the electrode unit, especially the shape and arrangement of each guide, the support of the sub-guide, the position control method, the moving device, etc. The design can be changed freely within the scope of the purpose of the invention, and the wire electrode supply and collection reels, brake rollers, capstans, pinch rollers, etc. can be used outside the electrode unit, for example, by extending the electrode unit onto the workpiece table. The wire electrode may be provided in a holding column of an arm that holds the electrode unit, and the wire electrode may be supplied to and discharged from the electrode unit, and the present invention encompasses all of them.

[Brief explanation of the drawing]

1 and 2 are a partially cutaway front view and a partially cutaway side view of an electrode unit used in an electrical discharge machining apparatus according to the present invention, and FIGS.
The figure is an explanatory view of the effects of the present invention. 1: Substrate, 2: Rotating part casing, 3: Guide holder, 4: Wire electrode supply reel, 6: Wire electrode collection reel, 14: Wire electrode, 15: Main guide, 17, 18: Sub guide, 19: Hydraulic pressure Cylinder, 22, 23: Brake roller, 24:
Capstan, 25: Pinch roller, 26: Pulse motor.

Claims (1)

[Claims] 1. A wire electrode is guided along a substantially U-shaped path by an electrode unit having a plurality of guides,
The wire electrode is moved under a desired tension action, and a relative machining feed is applied between the electrode unit and the workpiece, and the turning point of the U-shaped path is constituted by at least one main guide, and the wire electrode in the vicinity thereof is In a type of electrical discharge machining equipment in which electrical discharge machining is performed by The electrical discharge machining apparatus described above, further comprising a control device capable of controlling according to a predetermined program.