JPH0126808B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to the improvement of electric discharge machining equipment, and in particular, to prevent the processing machine body from being deformed due to the thermal influence of machining energy, in order to enable precision machining. The present invention relates to an electrical discharge machining device.

[Prior art]

As a conventional electrical discharge machining apparatus of this type, the one shown in FIG. 1 is known. FIG. 1 is a schematic diagram showing the configuration and operating mode of a conventional electrical discharge machining device. In the figure, 2 is a machining fluid, 1 is a machining tank in which the machining fluid 2 is stored and electrical discharge machining is performed therein, 3 is an electrode, and 4 is a main shaft for machining and feeding the electrode 3;
5 is a workpiece; 6 is the processing tank 1 and the workpiece 5;
This is a table for attaching the holder, and is movable in the direction of the arrow X in FIG. 7 is a saddle, which moves the table 6 along the arrow Y in FIG.
direction. 8 is a head attached to guide the main shaft 4; 9 is a column that supports the head 8; 9a is an inner surface of the column; 9b is an outer surface of the column; 10 is a ped that is attached to and supports the column 9; is a cooling fan attached to the top of the column 9.

Next, the operation of this conventional electric discharge machining apparatus will be explained. Electric discharge is generated by supplying discharge energy from a power source (not shown) between the electrode 3 and the workpiece 5 in the machining liquid 2 stored in the machining tank 1, and the workpiece 5 is heated. It performs electrical discharge machining. At this time, the temperature of the machining fluid 2 rises due to the discharge energy, and the machining bath 1 and the table 6 are heated by this fluid temperature.
The temperature of the table 6 rises higher than the air temperature around the electric discharge machine main body, and this temperature rise gradually increases depending on the amount of machining energy from the start of machining, and becomes the largest heat source in the electric discharge machine main body. Radiant heat 11 shown by the arrow in FIG. 1 is generated from the upper surface machining tank 1 and table 6 of the machining fluid 2 whose temperature has increased, and the column inner surface 9a facing the heat source is heated by this radiant heat 11. and their surface temperature increases. Furthermore, the temperature distribution in each part of the processing machine changes due to changes in the atmosphere such as room temperature.

Since the conventional electric discharge machining apparatus is configured as described above, as the workpiece 5 is subjected to electric discharge machining, the surface temperature of the main body of the machine, that is, the column 9, the bed 10, etc. facing the heat generation source increases. When the surface temperature of the part increases compared to the surface temperature of the part, the column inner surface 9a and the main shaft 4 undergo thermal deformation, as shown by the two-dot chain line in FIG. A positional shift shown by ε in the figure occurs. For this reason, there was a drawback that the processing accuracy of the workpiece 5 deteriorated. In addition, similar positional deviations occur due to changes in room temperature, etc., and processing accuracy deteriorates. As a countermeasure for this, in conventional electrical discharge machines, a cooling fan 12 is installed at the top of the column 9 or at the rear of the bed 10.
Although the main body of the processing machine was cooled by blowing in outside air, the ventilation inside the processing machine was insufficient because the ventilation path was not clear. FIG. 2 shows the state of ventilation inside the processing machine, and the length of the arrow indicates the wind speed. Furthermore, FIG. 3 shows the actual measurement results of the processing machine temperature distribution and the amount of displacement when the room temperature changes when ventilation inside the processing machine is insufficient. Also,
FIG. 4 shows a temporal change in relative displacement occurring between the electrode 3 and the workpiece 5 due to a change in room temperature.

[Summary of the invention]

The present invention is provided with a means for sucking in surrounding outside air other than the outside air above the upper part of the electrical discharge machine and blowing it into the inside of the electrical discharge machine, and further provided with a ventilation duct serving as an air path for passing the surrounding outside air inside the electrical discharge machine. The purpose of this is to obtain an electrical discharge machining device that cools the machine body from inside the machine body, reduces thermal deformation of the machine body, and prevents relative positional deviation between the electrode and the workpiece. be.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The electrical discharge machining apparatus of the present invention will be explained below based on an embodiment shown in the drawings. FIG. 5 is a vertical cross-sectional view of the electric discharge machining apparatus of the present invention, omitting parts that are the same as those of the conventional apparatus, and showing a configuration in which a ventilation duct is installed inside the processing machine, which is a feature of the present invention, and its operating mode. It is. In the figure, reference numeral 10 is a bed, 9 is a column, 12 is a cooling fan provided at the rear of the bed, and 13 is a ventilation duct, which is a feature of the present invention, and is installed inside the bed 10, that is, the processing machine.

Next, the operation of the embodiment shown in FIG. 5 will be explained. Although illustration is omitted, in the same way as already explained in FIG. When performing electrical discharge machining in step 5, machining fluid 2,
Radiant heat 11 radiated from heat sources such as the processing tank 1 and the table 6 heats the column 9 and the bed 10, but by installing the ventilation duct 13 inside the processing machine, the entire bed 10 and column 9 can be sufficiently ventilated and cooled. Since it is possible to apply
The temperature distribution of the column 9 is kept uniform, and as a result, thermal deformation of the column 9 due to an increase in the temperature of the machining fluid 2 does not occur. Furthermore, similar effects can be obtained with respect to environmental temperature changes such as room temperature and sunlight. Therefore, electrical discharge machining of the workpiece 5 can be performed with extremely high precision.

FIG. 6 shows another embodiment of the present invention, which is characterized in that the ventilation duct 13 is branched inside the processing machine. As a result, the column 9 and the bed 10 can be cooled by almost the same amount of ventilation.

FIG. 7 shows yet another embodiment of the present invention,
In this embodiment, by making the column ventilation and bed ventilation systems independent, column 9 and bed 1
It is possible to perform ventilation cooling almost equivalent to that of 0.
In the figure, 13a is a ventilation duct installed inside the column 9, 12a is a cooling fan installed at the top of the column 9, 13b is a ventilation duct installed inside the bed 10, and 12b is a ventilation duct installed at the rear of the bed 10. A cooling fan is installed.

Further, the ventilation duct 13a shown in FIG. 7 is provided with a large number of small holes 14, thereby increasing the amount of ventilation hitting the inner surface of the column 9 and enhancing the ventilation cooling effect.

In the embodiments shown in FIGS. 5 to 7, the cooling fan 12 is installed in either or both of the column 9 and the bed 10, but in the embodiment shown in FIG. This is an example of supplying from an external blower. In the figure, 9 is a column, 10 is a bed, 13 is a ventilation duct, 15 is an external blower, 16
is the wind conduit.

〔Effect of the invention〕

As described above, according to the electrical discharge machining apparatus according to the present invention, heat radiation from heat sources such as machining fluid, a machining tank storing this machining fluid, a table on which this machining tank and a workpiece are attached, room temperature, sunlight, etc. In response to environmental temperature changes, a ventilation duct is installed inside the processing machine to provide smooth ventilation cooling to the inner surface of the processing machine, thereby minimizing the thermal influence from the heat source to the machine structure. Therefore, it is possible to eliminate relative positional deviation between the electrode and the workpiece due to thermal deformation of the processing machine main body. This has the effect that electrical discharge machining of the workpiece can be performed with extremely high precision.

[Brief explanation of drawings]

Figure 1 is a schematic cross-sectional view showing the configuration of a conventional electric discharge machining device and its operating mode, Figure 2 is a cross-sectional view showing the ventilation condition inside a conventional electric discharge machine, and Figure 3 is a diagram showing insufficient ventilation inside the machine. Fig. 4 is a perspective view of the device showing the actual measurement results of the processing machine temperature distribution and displacement amount when the room temperature changes. Diagrams shown separately, FIG. 5 is a longitudinal cross-sectional view showing the internal structure and internal ventilation state of an electric discharge machining apparatus which is one embodiment of the present invention, and FIGS. FIG. 2 is a vertical cross-sectional view showing the internal structure of the electrical discharge machining apparatus, the internal ventilation state, and the cooling outside air blowing state. In the figure, 1...processing tank, 2...processing liquid, 3
...Electrode, 4...Spindle, 5...Workpiece, 6...
Table, 7...Saddle, 8...Head, 9...
Column, 9a...Column inner surface, 9b...Column outer surface, 10...Bed, 11...Radiant heat, 1
2, 12a, 12b...Cooling fan, 13, 13
a, 13b...Ventilation duct, 14...Small hole, 15
. . . External blower, 16 . . . Air guiding pipe. In addition,
In FIG. 2 and FIGS. 5 to 8, arrows indicate flow velocity vectors, and the length of the arrow corresponds to the flow velocity. In addition, the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. In an electric discharge machining device for machining a workpiece by generating electric discharge between electrodes and a workpiece disposed opposite to each other, the electric discharge machining device is disposed in the bed of the electric discharge machining device, and one end is a ventilation duct fixed to a side wall of the bed and connected to a cooling device provided outside the machine, the other end of which opens near the side wall of the bed opposite to the side wall; the ventilation duct allows ventilation from the cooling device to the bed; A ventilation path is formed in which outside air blown into the duct is sent into the bed from the opening, turned around, guided in the opposite direction along the inner wall of the bed, and then exhausted outside the machine. Electrical discharge machining equipment. 2. The electric discharge machining apparatus according to claim 1, wherein the outside air outlet is provided in a side wall to which the ventilation duct is fixed. 3. The electrical discharge machining apparatus according to claim 1, wherein a passage is provided between the bed and the column, and the outlet for the outside air is provided at the upper part of the column. 4. The electric discharge machining apparatus according to claim 1 or 3, wherein the passage provided between the bed and the column and the ventilation duct are connected by a branch pipe. 5. In an electric discharge machining device that processes a workpiece by generating an electric discharge between electrodes and a workpiece arranged opposite to each other, the electric discharge machining device is disposed within a bed of the electric discharge machining device, and one end is fixed to a side wall of the bed. a ventilation duct which is connected to a cooling device provided outside the machine and whose other end opens near a side wall opposite to the side wall; and a ventilation duct connected to a cooling device provided outside the machine, the other end of which opens near the bottom plate of the column, and these ventilation ducts allow the outside air blown from the cooling device to each ventilation duct to An electric discharge machining apparatus characterized in that a ventilation path is formed in which air is sent into the bed and column from an opening, turned back, guided in opposite directions along the inner walls of the bed and column, and then discharged to the outside of the machine. 6. The electric discharge machining apparatus according to claim 5, wherein an outlet for the outside air of the column is provided in the ceiling of the column. 7. The electrical discharge machining apparatus according to claim 1 or 5, characterized in that a large number of small holes are provided near the opening of the ventilation duct.