JPH06134622A - Wire electric discharge machine - Google Patents

Abstract

PURPOSE:To provide a wire electric discharge machine which can keep the moving accuracy of a table at excellent accuracy independently of machining liquid and the weight of a workpiece. CONSTITUTION:A wire electric discharge machine is composed of a bed 1, a lower XY table mounted on the bed 1, a lower wire guide device 4 mounted on the lower XY tables 2, 3, a machining bath 9 which is fixed to the bed 1 and has a hole 10 on its bottom, an upper wire guide device 16, and upper XY tables 17, 18 on which the upper wire guide device 16 is mounted, and the upper wire guide device 16 is arranged on the upper side of the machining bath 9, and the lower wire guide device 4 is arranged on the lower side of the machining bath 9, and the surface of the lower wire guide device 4 is almost sticked fast to the lower face of the bottom of the machining bath 9.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire electric discharge machine having good machining accuracy.

2. Description of the Related Art Generally, since a machining fluid of a wire electric discharge machine uses ion-exchanged water, when a workpiece is a steel material, rust may be generated on the surface of the workpiece during machining. Further, in order to improve the machining accuracy, it is necessary to minimize the temperature fluctuation of the workpiece. Therefore, so-called dipping processing is performed in which the entire workpiece is submerged in a machining fluid whose temperature is controlled to a constant temperature, and the workpiece is immersed in the machining fluid for machining. ◆ There are various types of devices for performing the above dipping process. For example, in Japanese Unexamined Patent Publication No. 60-5223, a workpiece is supported on a machining tank movable in XY directions, and a lower wire guide for guiding a wire is supported on an arm penetrating a wall surface of the machining tank. Then, a seal member is arranged between the arm and the wall surface to reduce the working fluid leaking from the working tank. Further, in Japanese Patent Application Laid-Open No. 2-256422,
The X-table placed on the bed holds the column on which the upper wire guide device and the lower wire guide device are placed, and the Y-table placed on the bed holds the processing tank having a hole at the bottom. The distance between the surface of the processing tank and the bottom surface of the bottom of the processing tank is reduced to reduce the processing liquid leaking from the processing tank.

However, in the former case of the prior art described above, the arm is deformed due to the frictional resistance between the arm and the seal member during the movement of the table, and high precision machining cannot be performed. Further, in a state where the processing tank is filled with the processing liquid and a heavy work piece is loaded on the table, it is difficult to accurately position and control the feed rate. On the other hand, the latter of the above-mentioned prior arts can perform high-precision processing because it does not use the seal member like the former. In general,
When the size and weight of the work piece are large, the weight of the working fluid filled in the working tank is also large. However, when the processing tank and the work are placed on the table, the rigidity of the table needs to be commensurate with the total weight thereof, and the weight of the table itself becomes large. As a result, as in the former case, it was difficult to accurately position and control the feed rate in a state where the processing tank was filled with the processing liquid and the heavy workpiece was loaded on the table. An object of the present invention is to solve the above-mentioned problems and to provide a wire electric discharge machine capable of keeping the movement accuracy of a table with high accuracy regardless of the working fluid or the weight of a workpiece.

Means for Solving the Problems The above-mentioned problems are solved by a bed, a lower XY table placed on the bed, a lower wire guide device placed on the lower XY table, and a machining process which is fixed to the bed and has a hole at the bottom. A tank, an upper wire guide device, and an upper XY table on which the upper wire guide device is placed. The upper wire guide device is placed above the processing tank.
The problem can be solved by disposing the lower wire guide device on the lower side of the processing tank so that the surface of the lower wire guide device and the lower surface of the bottom of the processing tank are substantially in close contact with each other. Further, the wall surface of the processing tank is configured to be movable in the vertical direction with respect to the bottom portion, and this is more effectively solved.

[Operation] Since the bed supports the weight of the machining fluid and the work piece and the surface of the lower wire guide device and the bottom surface of the bottom of the machining tank do not contact each other, no frictional resistance is generated between the two when moving. , The table can be moved with high accuracy.

FIG. 1 is a sectional view of a wire electric discharge machine showing a first embodiment of the present invention. ◆ In the figure, 1 is a bed. The lower X table 2 is placed on the bed 1. The lower Y table 3 is placed on the lower X table 2. A lower wire guide device 4 is placed on the lower Y table 3. Depressions 5 and 6 are provided on the upper surface 7 of the lower wire guide device 4. Reference numeral 8 denotes a lower guide, which is arranged at the center of the lower wire guide device 4 and holds a wire guide and a conducting tip inside (not shown). Reference numeral 9 is a processing tank having a hole 10 at the bottom, which is fixed to the bed 1. The lower wire guide device 4
There is a slight gap between the upper surface 7 and the outer surface 11 of the bottom of the processing tank 9. Moreover, the hole 10 is sized so as not to interfere with the lower guide 8 in the entire range in which the lower guide 8 moves. A work 12 is fixed to the inner surface 13 of the bottom of the processing tank 9. 14 is a working fluid. Reference numeral 15 denotes an upper guide, which holds a wire guide and a current-carrying tip inside (not shown) and is movable in the vertical direction with respect to the upper wire guide device 16. 17 is an upper X on which the upper wire guide device 16 is mounted.
The table is mounted on the upper Y table 18. The upper Y table 18 is mounted on the ceiling of U-shaped columns 19 fixed to both sides of the bed 1. Reference numeral 20 denotes a wire, which is taken out from the wire bobbin 21, passes through the upper guide 15, the work piece 12, and the lower guide 8 via the feed rollers 22 and 23 which give tension to the wire 20, and then to the lower wire guide device 4. It is wound up by the winding rollers 24 and 25 provided and collected in a collection box 26 installed in the bed 1. 30 is a processing liquid tank. 31 is a pump connected to the processing liquid tank 30. Three
2 is a pipe connecting the pump and the processing tank 9. Reference numeral 33 is a valve for adjusting the flow rate of the processing liquid 14 supplied to the processing tank 9. Reference numeral 34 is a pipe for keeping the liquid level of the processing tank 9 constant, and returns the processing liquid 14 overflowing during processing to the processing liquid tank 30. Reference numeral 35 is a pipe that connects the inner surface 13 of the bottom portion and the working liquid tank 30 via a valve 36, and collects the working liquid 14 inside the working tank 9 into the working liquid tank 30 at the end of the working. 37 is a pipe connecting the recess 5 and the processing liquid tank 30. Reference numeral 38 is a pipe connecting the recess 6 and the working liquid tank 30 via a valve 39. Reference numeral 40 denotes a hole provided in the bed 1, which connects the upper surface 41 of the bed 1 and the processing liquid tank 30. The operation will be described below. ◆ Lower X table 2, lower Y table 3 and upper X table 17, upper Y table 1 by a controller (not shown)
By moving 8 the wire 20 is moved relative to the work piece 12. At this time, the workpiece 12 and the processing tank 9
Is fixed to the bed 1 and has a top surface 7 and a bottom outer surface 1
Since there is a slight gap with 1, frictional resistance does not occur. ◆ The machining fluid 14 slightly leaks from the gap between the top surface 7 and the bottom outer surface 11.
It is collected in the working liquid tank 30 through the holes 7, 38 and the holes 40. Further, the above-mentioned leakage of the working fluid 14 is negligible compared with the capacity of the working fluid pump. FIG. 2 is a sectional view of a wire electric discharge machine showing a second embodiment of the present invention, which further improves the workability of the first embodiment. The same parts as those in FIG. 1 are designated by the same reference numerals. In the figure, 51 is a processing tank, which is composed of a bottom portion 52 and a wall surface 53. And the wall surface 53 is a U-shaped pillar 5
It is possible to move in the vertical direction by the moving device 55 arranged at No. 4. 56 to 58 are seals arranged between the bottom portion 52 and the wall surface 53. ◆ With the above configuration, by lowering the wall surface 53,
The work of attaching / detaching the workpiece 12 to / from the processing tank 51 is facilitated.
The other operations are the same as those in the first embodiment and will not be described. FIG. 3 is a front sectional view of a wire electric discharge machine showing a third embodiment of the present invention, and FIG. 4 is a side view in which a part thereof is sectioned. In the figure, 61 is an L-shaped column, which is fixed to the side surface of the lower wire guide device 4 and is formed into a C-shape as a whole. The upper guide 15 is arranged on the upper arm 62 of the column 61 in alignment with the lower guide 8. 6
Reference numeral 3 denotes a U-shaped column, which is fixed to the bed 1. The operation is the same as that of the first embodiment, and will be omitted. Further, in this embodiment, the L-shaped column 61 is used.
Is fixed to the side surface of the lower wire guide device 4, but it may be integrally formed. Further, similarly to the second embodiment, it may be configured to be movable up and down on the wall surface 52 of the processing tank.

As described above, according to the present invention,
Even if the size or weight of the workpiece is large, the positioning between the workpiece and the wire and the feed rate can be accurately controlled, and the machining accuracy is improved. Further, there is an effect that the rigidity of the table can be made smaller than the conventional one with respect to the size or weight of the workpiece.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a wire electric discharge machine showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a wire electric discharge machine showing a second embodiment of the present invention.

FIG. 3 is a front sectional view of a wire electric discharge machine showing a third embodiment of the present invention.

FIG. 4 is a side view of FIG.

[Explanation of symbols]

 1 Bed 2 Lower X Table 2 3 Lower Y Table 4 Lower Wire Guide Device 7 Upper Surface 8 Lower Guide 9,51 Processing Tank 10 Hole 11 Bottom Outer Surface 15 Upper Guide 16 Upper Wire Guide Device 17 Upper X Table 18 Upper Y Table 19,54 Pillar 53 Wall surface 61 Column 63 Post

Claims (3)

[Claims] 1. A bed, a lower XY table mounted on the bed, a lower wire guide device mounted on the lower XY table, a processing tank fixed to the bed and having a hole at the bottom, and an upper wire guide device, An upper XY table on which the upper wire guide device is placed, the upper wire guide device is arranged on the upper side of the processing tank, the lower wire guide device is arranged on the lower side of the processing tank, and the surface of the lower wire guide device and the processing tank are A wire electric discharge machine characterized in that the bottom surface is almost in close contact with the bottom surface. 2. A bed, an XY table mounted on the bed, a C-shaped column mounted on the XY table, a lower wire guide device mounted on the C-shaped column, and a hole fixed to the bed at the bottom. And the upper wire guide device mounted on the column. The upper wire guide device and the lower wire guide device are arranged in the upper and lower parts of the processing tank, and the surface of the lower wire guide device and the processing tank are arranged. A wire electric discharge machine characterized in that the bottom surface of the bottom surface of the wire is almost in close contact. 3. The wire electric discharge machine according to claim 1, wherein the wall surface of the machining tank is configured to be vertically movable with respect to the bottom.