JPH0555255B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electrical discharge machining apparatus in which a worktable on which a workpiece is attached is stationary, and electrodes are controlled and operated along at least two axes.

[Conventional technology]

Conventional electric discharge machining equipment is placed on the bed,
A workpiece is placed on a table that moves in X-axis and Y-axis directions perpendicular to each other, and side walls are erected around the table to form a machining tank, into which machining fluid is poured. The electrode that processes the workpiece is supported by a ram that slides on the sliding surface of a column that is fixed and erected on the side of the bed, and is supported by a head that moves vertically opposite the table. It is attached to the tip of a spindle that is rotatably and slidably supported, and is controlled in one vertical axis direction. In this way, the workpiece and the electrode are opposed to each other, a machining gap is provided, and a machining voltage pulse is applied between the two while moving the workpiece and the electrode relatively to perform electrical discharge machining.

[Problem that the invention seeks to solve]

This conventional electric discharge machining equipment has a table inside the machining tank, so when setting a workpiece on the table, the side wall of the machining tank must be opened or the entire side wall of the machining tank must be lowered below the table. This is inconvenient, and the size of the workpiece that can be placed on the table is controlled by the table size and the amount of movement. It must be processed while being supplied. The electrode for machining the workpiece placed on the table in this way is attached to the spindle in the above-mentioned complex configuration and faces the workpiece, so a machining voltage pulse is applied between the workpiece and the electrode. When electric discharge machining is performed by applying electric current, the electrode and the discharge point become a kind of heat generation source.
This heat generation and changes in room temperature cause the column to deform and the bed to become convex, changing the position and orientation of the electrode relative to the workpiece. In other words, conventional electrical discharge machining equipment uses an electrode that moves in a reciprocating manner in the vertical Z-axis direction, and when it moves in a controlled manner on the X and Y planes, it approaches and confronts the workpiece from a remote location through a complex structure. Therefore, the deformation of the structure due to a small amount of heat generation causes the relative positional relationship between the electrode and the workpiece to be distorted, reducing machining accuracy. Furthermore, electrical discharge machining performed in this manner can only be performed within the specifications of the electrical discharge machine, and there is a restriction that it can only be performed at a specific location where the electrical discharge machine is installed.

[Means for solving problems]

Therefore, the present invention provides an electrode head having an electrode attached to the tip of a hanging spindle, a workpiece stand for positioning and fixing a workpiece, an electrode stand for holding the electrode head opposite to the workpiece stand, and an electrode stand for holding the electrode head opposite to the workpiece stand. an auxiliary support member that engages with the electrode or spindle and is attached to the electrode head so as to restrict displacement in a direction perpendicular to the spindle axial direction; They were provided as a pair on both sides and at a plurality of locations on the plane in the perpendicular direction so as to be able to move close to each other and separate in opposite directions while remaining parallel to each other and guided by fitting and sliding into each other. a guide device, a feeding mechanism in the opposing direction provided in each guide device, and each drive device thereof;
It consists of a feeding mechanism that attaches and holds the electrode head with the electrode attached thereto so as to be movable in two horizontal and perpendicular axes directions perpendicular to the opposing direction with respect to the electrode stand, and drive devices for each of the two-axis feeding mechanisms. It is characterized in that it is transported and installed in a machining tank in which a liquid is stored to perform electrical discharge machining.

That is, the electrode stand or the workpiece table is controlled to move toward and away from one or more servo motors, and the electrode head, in which the electrode is attached to the tip of the hanging spindle, is placed at right angles to the electrode stand, It is capable of controlled feeding in the Y direction, and the electrode stand or workpiece table assembled in this way can be lifted up and placed in a processing tank, moved back and forth in the processing liquid, and used for processing. Since electrical discharge machining is performed while the machining liquid is flowing through the machining gap by reciprocating the tank, displacement of the electrode and the support spindle in the direction perpendicular to the spindle axis direction is likely to occur. In order to improve this point, the electrode or spindle is reinforced with an auxiliary support member.

[Effect]

A simple structure in which the workpiece table with the workpiece attached and the electrode table with the electrode attached are linked by a guide device that guides them by fitting and sliding, and maintains thermal equilibrium. With this structure, the workpiece and electrode can be attached accurately in a place fully equipped with measuring instruments and jigs, such as an electrode outside the processing tank and a workbench for attaching and detaching the workpiece. . Once the combination of the electrode stand and workpiece stand with the workpiece and electrode attached is lifted and immersed in the machining fluid in the machining tank, the electrode and workpiece are connected to the machining power supply and control device. Then, while supporting the electrode with an auxiliary support member, a control operation including a reciprocating operation is performed in the Z-axis direction, and electrical discharge machining is performed while controlling the electrode stand in the X-axis and Y-axis directions.

That is, the auxiliary support member for the electrode has a configuration in which the electrode head supported via the electrode spindle is held movable in a controlled manner in two directions of the X and Y axes with respect to the electrode stand, and the electrode is immersed in the machining liquid in the machining tank. With it inserted,
By performing the above-mentioned controlled movement, the electrode is prevented from being displaced in the horizontal direction using the electrode head portion as a fulcrum.

With this configuration, even if the machine unit is tilted a little when placed in the processing tank, the relative position of the workpiece and electrode remains unchanged as it is held by the guide, resulting in extremely high accuracy. Good electrical discharge machining can be performed.

As long as you have this simple-configured electric discharge machining unit, a machining power source, a control device, and a machining tank, you can perform electric discharge machining anywhere.For example, you can place this small electric discharge machining unit on a desk. It can be used for machining of various sizes, such as storing it in a small machining liquid box for machining watch parts and chips, or placing this large electric discharge machining unit in a large machining tank like a pool to perform electric discharge machining. Electrical discharge machining can be performed on objects.

〔Example〕

In FIG. 1, a shaft 5 is fixed to a cylindrical guide 4 by welding or caulking to each hole 3 provided at the four corners of a workpiece table 2 on which a workpiece 1 is positioned and fixed.
Insert and secure it with screw 6. A cylindrical guide 7 that slides using the outer periphery of this guide 4 as a guide.
are fixed to corresponding locations on the electrode stand 8, and the two constitute a guide device. In this guide 7, a threaded hole formed in the guide 4 and a threaded screw 9 are rotatably supported by a bearing 10, and the end thereof is connected to a synchronized motor 11 fixed to an electrode stand 8 and a coupling 12. By connecting and providing them, a feeding mechanism and a driving device for the opposing direction between the electrode table 8 and the workpiece table 2 are constructed. FIG. 2 is a view of FIG. 1 viewed from above, and as shown in FIG. 3, which is a cross-sectional view taken along line A-A in FIG. . A screw 16 screwed onto the slide 15 is pivotally supported by the electrode stand 8, and its end is connected to a drive device 17 such as a servo motor fixed to the electrode stand 8. Slide 1
An electrode head 19 such as a table is pivotally supported on a pair of guide shafts 18 provided in the electrode 5.
The screw 20 is screwed together. The screw 20 is pivotally supported by brackets 21 and 22 fixed to the slide 15, and one end is connected to a servo motor 23 fixed to the bracket 22. With this configuration, the electrode 24 is fixed to the tip of the spindle which is suspended and supported by the electrode head 19 which can move in any direction.

Now, loosen the screw 6 at the electrode outside the machining tank 25, the work station for attaching and detaching the workpiece, etc., which will be described later, and use a crane, jig, etc. to remove the shaft 5 from the workbench 2 and place it on the workbench, etc. However, workpiece 1 is placed on workpiece table 2.
, an electrode 24 is attached to the electrode head 19 of the electrode stand 8,
Install accurately using measuring instruments and jigs. Electrode stand 8
An auxiliary support member 41 is provided on a chuck 40 for attaching an electrode 24 fixed to the electrode head 19 of the device via a spindle. The auxiliary support member 41 illustrated here includes a plurality of links 42 provided radially from a chuck 40 integrated with the electrode head 19, a link 43 hanging down from the tip of the link 42,
It consists of a support link 44 extending from the lower end of this link 43 toward the electrode 24, and the connecting portion of each link is structured so that it can be rotated by loosening a wing nut, etc., and then fixed by loosening it. electrode 24
to fix the joints of each link.
Once the electrode 24 is accurately fixed to the electrode stand 8 using a measuring device or jig in this way, the shafts 5 of the guide devices 4 and 7 are inserted into the holes 3 of the workpiece stand 2 and fixed with screws 6. do. The electric discharge machining machine unit, in which the workpiece table 2 and the electrode table 8 are integrally connected by the guide devices 4 and 7, is carried by a crane, jig, etc., and the machining tank 25 is opened. It is inserted into the machining fluid 26 and connected to a control device and a machining power source for electric discharge machining installed around the machining tank 25 (not shown) through a connector to complete the preparation. Next, the four screws 9 are rotated synchronously by the synchro motor 11, and the workpiece 1 and the electrode 24 are brought closer together, while maintaining an appropriate machining gap.
Electrical discharge machining is performed by applying a machining voltage pulse to. As shown in FIG. 2, the electrode 24 is controlled to move in the directions of arrows a and b by a servo motor 17, and controlled to move in directions c and d perpendicular to the directions shown by arrows a and b by a servo motor 23. This makes it possible to perform processing using a desired translational movement, as well as profiling processing using a rod-shaped electrode.

The apparatus shown in FIG. 4 is a machine unit for electric discharge machining according to the present invention, which is carried into a machining tank by suspended conveyance, and is suspended and carried out.
A column 28 that can stand upright and rotate is provided, and an arm 29 is pivotally supported on this column 28. A screw 30 is screwed onto this arm 29, and the screw 30 is pivotally supported on a bracket 31 fixed to the column 28, and its end is connected to a motor 32 fixed to the bracket 31. The screw 30 is rotated by this motor 32, and an arm 29 is screwed thereto.
Move up and down. The electrode stand 8 is removably connected to this arm 29 via a joint 33,
The workpiece 1 and the electrode 24 are suspended in the machining tank 25 and immersed in the machining liquid 26 . On the other hand, the machining tank 25 is slightly moved up and down on a lifter 34 provided on the bed 27, so that the machining liquid in the machining gap flows. 3
5 is a cover provided to prevent the machining fluid from scattering.

〔Effect of the invention〕

In the electrical discharge machining machine unit of the present invention, the workpiece stand on which the workpiece is installed and the electrode stand that holds the electrode head on which the electrode is attached are integrally connected by a plurality of guide devices that guide both in opposite directions. This type of equipment unit is inserted into the machining fluid of the machining tank, and during electrical discharge machining,
Since processing is performed while horizontally translating the electrode head relative to the electrode stand, or while swinging the unit and processing tank, the present invention provides an auxiliary support member to prevent the electrode and spindle from being displaced by the liquid. is provided on the electrode head and engaged with the electrode to provide reinforcement and support.

Therefore, since the electrode and the workpiece can be constructed in a symmetrically balanced manner, the present machine unit for electrical discharge machining can maintain a balance both mechanically and thermally. When a conventional cantilevered electrode is servo-driven at one support point, the accuracy fluctuates by l ³ for the length l from the support point, but the electrode stand of the present invention has both ends connected to multiple It is more stable because it is driven by a servo motor. Furthermore,
Furthermore, even in the case of left-right drive, it can be reinforced with a reinforcing support member, and extremely accurate electrical discharge machining can be performed. Moreover, since it can be transported and moved freely by hanging, etc., when installing the workpiece and electrode,
It can be carried out to a detachable station equipped with measuring instruments and jigs, and electrical discharge machining can be carried out at any location as long as it has a machining tank and a power source. Moreover, since both the machining tank and the power source can be transported, electrical discharge machining can now be performed at any location. For example, you can place a small machining box on a desk and perform electrical discharge machining on chips, etc. in it, and conversely, you can use a crane or the like to move the electric discharge machining unit of the present invention into a large machining tank like a pool. It is possible to carry in and perform electrical discharge machining on extremely large workpieces, and with excellent accuracy and one processing tank, it is not limited to the conventional electrical discharge machine that consists of a bed, column, table, processing tank, etc. This has the effect that electrical discharge machining can be carried out with an extremely high degree of freedom, such as by carrying in a plurality of electrical discharge machining machine units and performing electrical discharge machining.

[Brief explanation of the drawing]

Figure 1 is a front view of the present invention, Figure 2 is a plan view, and Figure 3 is a front view of the present invention.
The figure is a sectional view taken along the line A--A in FIG. 2, and FIG. 4 is an embodiment of the apparatus of the present invention suspended. 1... Workpiece, 2... Work table, 8... Electrode stand, 24... Electrode, 41... Processing tank.

Claims (1)

[Scope of Claims] 1. An electrode head with an electrode attached to the tip of a hanging spindle, a workpiece table for positioning and fixing a workpiece, and an electrode table for holding the electrode head opposite to the workpiece table. an auxiliary support member that is engaged with the electrode or the spindle and attached to the electrode head so as to restrict displacement of the electrode in a direction perpendicular to the spindle axis direction; While keeping parallel along the plane of
a pair of guide devices provided at a plurality of locations on the plane in the perpendicular direction to each other so as to be able to move close to each other and separate from each other in opposing directions, and to guide each other in sliding contact with each other; a feeding mechanism in the opposing direction and its respective driving devices; a feeding mechanism that attaches and holds the electrode head to which the electrode is attached so as to be movable in two horizontal and perpendicular axes directions perpendicular to the opposing direction with respect to the electrode stand; What is claimed is: 1. A machine unit for electric discharge machining, which comprises drive devices for each of the two-axis feed mechanisms, and is conveyed and installed in a machining tank in which machining fluid is stored to perform electric discharge machining. 2. The electrical discharge machining machine unit according to claim 1, wherein the front auxiliary support member is comprised of a link mechanism.