JP2582164Y2 - Thermal deformation prevention device for electric discharge machine - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for preventing thermal deformation of an electric discharge machine which performs machining using electric discharge.

[0002]

2. Description of the Related Art A Die-sinker EDM as shown in FIG.
A table 3 is fixed to an appropriate height on a bottom plate 1a of a machine base 1 via a cylindrical lower base 2, an electrode 4 facing a workpiece W is gripped by a main shaft 5, and the main shaft 5 is XY. -It can be moved and positioned along the Z-axis guides 7, 8, 9. The electric discharge machining is performed in a machining fluid having an insulating property. The machining fluid is sent from the lower side of the lower base 2 so as to constantly circulate, overflows from the upper surface of the machining tank 6, and flows into the machining fluid reservoir a in the machine base. It falls down and is returned to the working fluid storage tank 23 communicating with the storage part a via the pipe 22.

[0003]

Since the electric discharge machine described in the prior art has a machining fluid reservoir a inside the machine base, the bottom plate 1a is thermally deformed due to a change in room temperature or a change in the temperature of the machining fluid. I do. FIG. 3A is an exaggerated view showing the thermal deformation of the bottom plate 1a when the room temperature changes to a higher temperature relative to the liquid temperature and the change in the position of the table due to this.
FIG. 5 is an exaggerated view showing a change in a case where the room temperature is relatively lower than the liquid temperature. As described above, when the table position changes, the relative position between the electrode and the workpiece changes, and the processing gap changes, resulting in a problem that the processing efficiency decreases and the processing accuracy decreases. The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object the purpose of which is that the relative position between the workpiece and the electrode is small even when the working fluid or room temperature changes. It is an object of the present invention to provide a thermal deformation preventing mechanism.

[0004]

According to a first aspect of the present invention, a thermal deformation preventing mechanism for an electric discharge machine is provided in an electric discharge machine having a portion in which a machining fluid is stored inside a machine base. the outer peripheral portion corresponding to the working fluid reservoir inside the machine base providing a container for soaking by the working fluid, before
A hole communicating between the working fluid reservoir inside the machine stand and the container
At least one or more are provided, and means for circulating the working fluid inside and outside the machine base is provided. Also, the present invention
The thermal deformation preventing mechanism of the electric discharge machine according to claim 2 is a machining fluid
With a liquid temperature controller added to the means for circulating
is there.

[0005]

According to the first aspect of the present invention, since the machining fluid reservoir inside the machine and the corresponding outside of the machine are immersed in the circulating machining fluid, they are directly affected by changes in room temperature. No change, and even if the temperature of the machining fluid changes, the inside and outside of the bottom plate of the machine change at the same time at the same time, so the temperature distribution in the thickness direction changes symmetrically on the inside and outside surfaces, and the bottom plate warps. Does not appear. Further, if the automatic control of the temperature of Sonoue working fluid in claim 2 by the liquid temperature adjusting device, without changing the temperature distribution Most machine base bottom plate, can be suppressed very small thermal deformation, processing table the position change <br/> amount can be minimized.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. In the sinker electric discharge machine shown in FIG.
A cylindrical lower base 2 is erected on a, and a processing table 3 is fixed on the lower base 2, and a workpiece W is mounted on the processing table 3. On the outer periphery of the lower base 2, a bottom hole of a processing tank 6 forming a container around the table 3 is formed on a sliding surface which can move up and down, and a seal member is attached around the bottom hole to prevent leakage of processing liquid. There is prevented, and is movable up and down through the chain 14 by the driving device 13 is machining bath 6 substantially <br/> serial. Machine stand 1 side after is a trapezoidal having an X-axis direction of the guide 7 on the upper surface, are front and wall formed on both lateral and the lower base 2 is mounted substantially at the center of the recess surrounded by the tetrahedron I have.

A saddle 15 is movably mounted on the X-axis guide 7, and the saddle 15 is moved and positioned by a servo motor 10 via a ball screw (not shown). Saddle 15
A guide 8 in the Y-axis direction is provided on the upper side, and a column 16 is movably mounted on the Y-axis guide 8,
Is moved and positioned by a servo motor 11 via a ball screw (not shown). Further, a guide 9 in the Z-axis direction is provided on the front side surface of the column. The main shaft 5 is movably mounted on the Z-axis guide 9, and the main shaft 5 is moved and positioned by a servo motor 12 via a ball screw (not shown). Is done. The electrode 4 is detachably gripped at the lower end of the main shaft 5 so as to face the workpiece W, and the electrode 4 can be accurately moved and positioned with respect to the workpiece W by NC control.

Outside the machine, a machining fluid storage tank 2 is located near the machine base 1.
3 are installed, and the tank 23 has two tanks 23 inside.
a first tank 23a is communicated with a recess of the machine base 1 by a relatively thick return pipe 22. A pump 18 is attached to the first tank 23a, and a pump 19 is attached to the other second tank 23b.
At the discharge port of the pump 18, a filter device 24 for removing sludge and a liquid temperature adjusting device 25 are arranged in series. The working fluid discharged from the fluid temperature adjusting device 25 is
It is sent to the tank 23b. Pump 19
Is connected to a supply pipe 26 which opens under the hole 2a of the lower base 2 through the inside of the machine base 1, and the working fluid fed into the hole 2a is pushed up by the pump pressure, and It overflows from the upper surface, falls into the processing liquid storage part a in the concave part, and returns to the first tank 23 a of the tank 23 through the return pipe 22.

A machining fluid container 27 is provided below the machine base 1 so as to completely wrap the outer periphery including the bottom surface. The container 27 communicates with a machining fluid storage portion a in the machine base through at least one or more holes. . Therefore, the level of the processing liquid in the container 27 is always kept at the same level as the storage part a and the first tank 23a. Circulation paths 27a and 27b are provided along the outer periphery of the machine base in the upper part of the processing liquid container 27. When the processing liquid is supplied to the circulation path from the discharge port 28 branched from the pipe 26, the circulation path It flows into the container along the machine wall from a slight gap provided below, and is collected in the first tank 23a of the tank 23 without being retained.

Next, the operation of the present embodiment will be described.
During the processing, the processing liquid is constantly supplied to the lower surface of the lower base 2 via the supply pipe 26, and is also supplied from the discharge port 28 to the circulation paths 27a and 27b of the container 27 at the same time. The working fluid sent to the lower base 2 is pushed up to the working tank 6 by the pressure of the pump 19, cools the workpiece W and the electrode 4, removes sludge generated by electric discharge machining, and overflows from the upper surface of the working tank 6. After dropping into the processing liquid storage part a of the concave part, it is returned to the first tank 23a of the tank 23 via the return pipe 22.
On the other hand, the processing liquid sent into the circulation paths 27a and 27b from the discharge port 28 enters the container 27 along the machine base wall surface, flows along the side and bottom surfaces of the machine base 1, and passes through the return pipe 22 to the first tank. 23a.

The returned working fluid is sent to a filter device 24 by a pump 18 where sludge is separated and removed. The working fluid is continuously adjusted to a constant temperature by a fluid temperature adjusting device 25. , And is sent out to the supply pipe 26 again by the pump 19. As described above, the lower side of the machine base 1 is immersed in the working fluid on both the inner and outer surfaces, so that the bottom plate 1a is not directly affected by the change in the room temperature even if the temperature of the working fluid changes.
Since the inner and outer surfaces of the bottom plate 1a simultaneously change in the same manner, the temperature distribution in the thickness direction changes symmetrically between the inner and outer surfaces, and the phenomenon that the bottom plate 1a warps does not appear.

In addition, since the working fluid is maintained at a constant temperature by the fluid temperature adjusting device 25, the temperature of the lower portion of the machine immersed in the working fluid is always constant, and the temperature distribution of the bottom plate 1a is almost changed. without suppressing to a minimum the amount of positional change of the working table 3 to occupy a large element of the thermal deformation.
Note that the present invention is not limited to electric discharge machine, so as to dip with cutting fluid both inner and outer surfaces of the machine under the base side of the machine tool, the thermal deformation due to temperature and room temperature change in the cutting fluid Can of course be prevented.

[0013]

[Effects of the Invention] Since the present invention is configured as described above, the following effects can be obtained. Regarding claim 1 , since a container is provided around the lower portion of the machine base and the inner and outer surfaces are immersed in the working fluid, the temperature of the inner and outer surfaces of the machine becomes the same, and the conventional electric discharge machining The relative position between the workpiece and the electrode can be maintained better than that of the machine, and high-precision machining can be realized without deterioration in machining efficiency due to a change in machining gap. According to the second aspect, a device for adjusting the temperature of the working fluid is provided.
The temperature distribution on the bottom plate of the machine changes little because of the addition
And minimizes the thermal deformation of the bottom plate
Therefore, the amount of change in the position of the processing table can be minimized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an electric discharge machine of the present embodiment.

FIG. 2 is a configuration diagram of a conventional electric discharge machine.

FIG. 3 is an exaggerated view showing a deformation state of a machine base due to a change in a machining liquid temperature or a room temperature of a conventional electric discharge machine,
(A) shows the case where the room temperature changes relatively to the working fluid temperature, and (b) shows the case where the room temperature changes relatively to the working fluid temperature. .

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Machine stand 1a Bottom plate 2 Lower stand 3 Processing table 4 Electrode 6 Processing tank 18, 19 Pump 23 Processing liquid storage tank 25 Liquid temperature adjusting device 27 Processing liquid container W Workpiece

Claims (2)

(57) [Scope of request for utility model registration] 1. A machine base of electric discharge machine inside the working fluid has a portion reservoir, the container for soaking provided an outer periphery corresponding to the working fluid reservoir inside the machine base by the working fluid, the Communication between the machining fluid reservoir inside the machine stand and the container
A heat deformation preventing mechanism for an electric discharge machine, characterized in that at least one or more holes are provided and means for circulating the working fluid inside and outside the machine base are provided. 2. A mechanism for preventing thermal deformation of an electric discharge machine according to claim 1, wherein a liquid temperature adjusting device is added to the means for circulating the machining liquid.