JPH0230812B2 - - 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 the improvement of electric discharge machining equipment, in order to enable precision machining, it is possible to prevent the main structure from deforming due to the thermal influence of machining energy. 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, reference numeral 2 denotes a machining fluid, 1 a machining tank in which the machining fluid 2 is stored and electrical discharge machining is performed therein, and 3
4 is an electrode, 4 is a main shaft for processing and feeding the electrode 3, 5 is a workpiece, and 6 is a table for attaching the workpiece 5 to the processing tank 1, which can be moved in the direction of the arrow X in FIG. It is like that. Reference numeral 7 denotes a saddle, which allows the table 6 to be moved in the direction of arrow Y in FIG. 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 bed that attaches and supports the column 9; This 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 between the electrode 3 and the workpiece 5 in the machining fluid 2 stored in the machining tank 1 by supplying discharge energy from a power source (not shown), 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 ambient temperature of the electrical discharge machine main body. This temperature rise gradually increases depending on the amount of machining energy from the start of machining.
It is the largest source of heat in the electrical discharge machine body. Radiant heat 11 shown by the arrow in FIG. 1 is generated from the upper surface of the machining fluid 2, the machining tank 1, and the table 6 whose temperature has increased, and this radiant heat 11 causes the inner surface 9a of the column facing the heat source to be heated. They are heated and their surface temperature increases. Furthermore, the temperature distribution of each part of the processing machine also 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 main body of the machine, that is, the main structure, such as the column 9 and the bed 10, face the heat generation sources. When the surface temperature of the electrode 3 increases compared to the surface temperature of the other portion, the column inner surface 9a and the main shaft 4 undergo thermal deformation, as shown by the two-dot chain line in FIG.
Compared to the initial stage of machining, the position deviates as shown by ε in FIG. 1, resulting in disadvantages such as deterioration of the machining accuracy of the workpiece 5. Further, a similar positional shift occurs due to changes in room temperature, etc., and processing accuracy deteriorates. For this reason, in the conventional main structure, a cooling fan 12 was installed at the top of the column 9 or at the rear of the bed 10 to cool the main structure by feeding outside air, but since the ventilation path was not clear,
Ventilation inside the processing machine was insufficient. Second
The figure shows the state of ventilation inside the processing machine, and the length of the arrow is drawn in proportion to the wind speed. Moreover, FIG. 3 shows the actual measurement results of the processing machine temperature distribution and displacement amount when the room temperature changes when ventilation inside the processing machine is insufficient. Further, FIG. 4 shows a temporal change in the 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 has been made in order to eliminate the drawbacks of the conventional electric discharge machining equipment as described above, and a dividing rib is provided in the column and bed, which are integrated with these, thereby creating a smooth inside of the column 9 and bed 10. By effectively uniformizing the temperature distribution throughout the main structure by providing ventilation, it is possible to reduce machining errors caused by relative positional deviations between the electrode and workpiece due to thermal deformation of the main structure. It is an object of the present invention to provide an electric discharge machining device that can perform highly accurate machining.

[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 longitudinal cross-sectional view of the electric discharge machining apparatus of the present invention, omitting the parts that have the same configuration as the conventional apparatus, and showing the configuration of the main structures, namely the column 9 and the bed 10, and their operating mode, which are featured in the present invention. It is a front view. 9c is a ventilation division rib formed inside the column 9, and 10a is a ventilation division rib formed inside the bed 10.
These ventilation dividing ribs 9c and 10a are integrally cast with the column 9 and bed 10, respectively. Reference numeral 12 denotes a ventilation fan, which is installed at the top of the column 9 and at the rear of the bed 10, respectively. Arrow 13 indicates ventilation. 12 is a ventilation fan provided at the top of the column 9 and at the rear of the bed 10, and 13 is a ventilation fan. Note that FIG. 6 shows the bed 10 in this embodiment.
FIG. 2 is a cutaway perspective view showing the structure of ventilation ribs 10a formed inside.

Next, the operation shown in FIG. 5 will be explained. Although illustration is omitted, as already explained in Fig. 1,
When electrical discharge is generated between the electrode 3 and the workpiece 5 in the machining fluid 2 stored in the machining tank 1 to perform electrical discharge machining on the workpiece 5, the machining fluid 2, the machining tank 1, and the table are Radiant heat 11 radiated from a heat generating source such as 6 heats the inner surface 9a of the column 9 and the upper surface of the bed 10, but divided ribs 9c and 10a for ventilation are integrally formed inside these main structures, respectively. As a result, outside air is supplied to the space between the ventilation rib and the structure by the ventilation fan 12.
The entire structure is cooled. Therefore, the temperature distribution of the main structure is kept uniform, and as a result, thermal deformation of the column 9, bed 10, etc. due to an increase in the temperature of the machining fluid 2 does not occur. Furthermore, relative positional displacement between the electrode and the workpiece does not occur even with environmental changes such as room temperature and sunlight. FIG. 7 is a cutaway perspective view showing the structure of the ventilation dividing rib 10a inside the bed 10 in another embodiment of the present invention. Even in the case of this other embodiment, the same functions and effects as those of the embodiment shown in FIGS. 5 and 6 can be obtained.

〔Effect of the invention〕

As explained above, the electric discharge machining apparatus of the present invention is capable of absorbing radiant heat from heat sources such as the machining fluid, the machining tank that stores the machining fluid, the workpiece, and the table on which the workpiece is attached, as well as environmental temperatures such as room temperature and sunlight. In response to these changes, a dividing rib is formed inside the main structure that is integrated with the main structure to provide smooth ventilation cooling to the inner surface of the processing machine, effectively making the temperature distribution uniform throughout the main structure. By doing so, it is possible to reduce as much as possible the thermal influence from the heat generation source to the mechanical structure, which has been a drawback of conventional devices. Therefore, it is possible to eliminate relative positional deviation between the electrode and the workpiece due to thermal deformation of the processing machine body,
This has the effect that electrical discharge machining of a workpiece can be performed with extremely high precision.

[Brief explanation of drawings]

Figure 1 is a schematic diagram showing the configuration of a conventional electrical discharge machine and its operating mode, Figure 2 is a sectional view showing the ventilation condition inside the conventional electrical 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 in the case of . Diagrams shown in each Z direction, FIG. 5 is a longitudinal sectional view showing the configuration and operating mode of the main structure of the electrical discharge machining apparatus of the present invention,
FIG. 6 is a cutaway perspective view showing the structure of the divided rib for ventilation inside the bed in the same embodiment, and FIG. 7 is a cutaway view showing the structure of the divided rib for ventilation inside the bed in another embodiment of the present invention. FIG. 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, 9c...Divided rib for ventilation inside the column, 10
... Bed, 10a... Divided rib for ventilation inside the bed, 12... Cooling fan, 13... Ventilation.
Note that in FIGS. 2 and 5, 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 that processes a workpiece by generating an electric discharge between opposing electrodes and the workpiece, the electric discharge machining device is disposed within a bed of the electric discharge machining device, and the outer wall is connected to the bed. The base is connected to the inner wall of the bed by a plurality of ribs, and the base is connected to the side wall of the bed and formed integrally with the bed, and the base is connected to a cooling device provided outside the machine and the other end is connected to the bed. a ventilation pipe that opens near a side wall of the bed opposite to the side wall;
disposed within a column of the electric discharge machining apparatus, an outer wall is connected to an inner wall of the column by a plurality of ribs, and a base is connected to a ceiling of the column and formed integrally with the column; The base portion is connected to a cooling device provided outside the machine, and the other end is provided with a ventilation pipe that opens near the bottom plate of the column, and these ventilation pipes and the ribs allow air to be blown from the cooling device into each ventilation pipe. A ventilation space is formed in which outside air is sent from the opening into the bed and column, turned around, guided in opposite directions along the inner walls of the bed and column, and then discharged to the outside of the machine. Electrical discharge machining equipment. 2. The electric discharge machining apparatus according to claim 1, wherein an outlet for the outside air of the bed is provided in a side wall to which the base of the ventilation pipe is connected. 3. The electric discharge machining apparatus according to claim 1, wherein an outlet for the outside air of the column is provided in the ceiling of the column.