JPS6327942Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to the configuration of an electroforming or press forming electrode for electrical machining that three-dimensionally processes a workpiece into a cavity shape.

Traditionally, in order to create electrodes for electrical machining such as electric discharge machining with complex three-dimensional shapes, it is necessary to produce an electroformed shell of the electrode material by electroforming and press it from a plate-shaped body using a pressing method such as discharge pressure forming. Molding is carried out, but as a three-dimensional shaped processing electrode, it naturally includes a variety of irregular shapes, such as large and small, sharp protrusions, etc., and in particular protruding sharp parts. etc. are subjected to stress due to strain, and when used as an electrode for electrical machining such as electrical discharge machining, there is a risk that heat will concentrate on the relevant part and cause the electrode to lose its shape. If even one of the protruding sharp parts loses its shape, the electrode becomes unusable, and a new electrode must be created again by electroforming or press molding. As a countermeasure to such a case, cooling the electrode is described, for example, in Japanese Patent Publication No. 46519/1983.

That is, the above-mentioned publication discloses that a molded object such as a press-formed plate, cylinder, etc., or an electroformed molded object is used as a machining electrode, and the electrode is brought close to the back surface of the machined surface and shaped into the shape of the machined surface. A cooling liquid flow pipe formed into an approximate spiral shape, serpentine curved shape, etc. is provided, the liquid inflow and outflow ports of the pipe are made to protrude from the back side, and the pipe is filled with a low melting point alloy and fixed. However, in this method of cooling the entire electrode evenly, it is difficult to sufficiently cool the sharp protrusion of the electrode where heat is concentrated. Furthermore, in Japanese Patent Application Laid-Open No. 55-70528, a heat pipe is used, and the end of the heat pipe is placed in contact with an insulator in the middle of a spindle on which a processing electrode is attached and supported. It has also been proposed to prevent temperature rise, but attaching a heat pipe to the part connected to the electrode in this way is unlikely to prevent heat from concentrating on the tip of the processing electrode, especially its protruding sharp end. It is not used in time and its shape collapses.

In view of the above points, the present invention selectively and locally cools the surface protrusion of a shell-shaped electrode formed into a desired three-dimensional shape by electroforming or press working, and also reduces the temperature of the surface protrusion. The purpose of this is to detect and reliably prevent deformation due to overheating, and the end of the heat pipe is placed in close contact with the recessed part on the back surface corresponding to the protruding part on the surface of the shell-like electrode. At the same time, a filler is filled on the back side of the shell-shaped electrode with the heat dissipation end of the heat pipe protruding, and a cooling means for the heat dissipation end of the heat pipe protruding from the filler is provided, and the heat dissipation The heat pipe is characterized by being provided with a temperature detector that detects the temperature of the heat pipe near the end.

The present invention will be explained in detail below based on the drawings.
1, 2 and 3 of the drawings are side sectional views showing embodiments of the present invention.

In Fig. 1, reference numeral 1 denotes an electrode for electrical machining consisting of an electroformed shell with a three-dimensional overall shape produced by electroforming using copper, nickel, etc. as a material, and in Fig. 1, an electroforming mold 2 is shown. It shows the state that it has not been removed yet. Reference numeral 3 denotes a heat pipe having a not-shown heat pipe inside the body, and one end of the heat pipe 3a is inserted into the inner recess corresponding to the vicinity of the protrusion 1a on the machined surface of the electrode 1, and is placed in close contact with the heat pipe. A low melting point alloy is poured and fixed, and the other end heat radiation part 3b is placed in a cooling pipe 6 through which cooling water and air flow. Reference numeral 4 denotes a low melting point alloy or synthetic resin that is filled into the recess on the back of the machined surface created by electroforming of the shell electrode 1, and is used to reinforce the shell electrode 1. Install and arrange as shown. Reference numeral 5 designates a mounting plate for the shell electrode 1, which is mounted via an appropriate mounting mechanism (not shown) on the tip end side of a spindle 7, which is connected to an electrode feed servo mechanism for electric machining using a motor, hydraulic pressure, etc., as shown in FIG. In addition, in FIG. 2, the direction in which the shell electrode 1 is viewed is changed to show the complexity of its form, and the shell electrode 1 is peeled off from the electroforming mold 2.
The cooling fins 3c of the heat pipe 3 are attached to the plate 5 by screws. Further, as shown in FIG. 3, the electrode for electrical processing of the present invention is equipped with a temperature detector 8 that detects the temperature of the heat pipe near the heat radiation part 3b, and 9 detects the temperature detected by the temperature detector 8. A discriminating device for discriminating, 10 is a discriminating device 9
This is the output terminal for the discrimination signal.

By arranging the endothermic end 3a of the heat pipe 3 in close contact with the recess on the back surface corresponding to the surface protrusion 1a of the shell-like electrode 1, the protrusion 1a can be sufficiently cooled selectively and locally. Therefore, even if high current is applied and machining is performed under high load, the protruding part 1a of the electrode will not overheat and be thermally deformed.
It becomes possible to perform highly accurate machining.

In addition, the heat pipe has a heat absorption part 3a as its characteristic.
Since the heat dissipation section 3b and the heat dissipation section 3b have approximately the same temperature, a temperature detector 8 is provided to detect the temperature of the heat pipe near the heat dissipation section, thereby detecting the temperature of the protruding section 1a of the electrode that is in close contact with the heat absorption section. Therefore, the temperature of the protruding portion 1a can be maintained at a desired temperature by changing and controlling the flow rate of water or air for cooling the heat radiating portion 3b according to the temperature detected by the detector 8. If the detected temperature exceeds the specified value even if the flow rate of water or air is increased,
By reducing the machining load by temporarily stopping the machining, reducing the machining current, or slowing down the machining feed, the temperature of the protruding portion 1a can be lowered to a desired temperature. These controls can be performed manually by an operator, or automatically using an output signal from a discrimination device 9 that discriminates the temperature detected by the temperature detector 8.

Furthermore, by being able to control the temperature of the electrode protrusion 1a, it is possible not only to prevent the protrusion from deforming due to heat, but also to prevent the occurrence of arc discharge and wear of the electrode in the case of electrical discharge machining, for example. This enables efficient machining with high precision. In other words, when the temperature of the electrode reaches 300 to 600℃, arc discharge occurs, which reduces the machining speed and damages the machined surface.Also, it is difficult to perform machining under machining conditions with low or no electrode consumption. However, if the temperature of the electrode drops below a certain temperature, which varies depending on the materials of the electrode and workpiece, machining pulses, machining fluid, etc., the electrode will wear out and reduce machining accuracy. However, according to the present invention, the electrode protrusion 1a can be sufficiently cooled and not overcooled, and the temperature can be maintained at a desired temperature, so that accurate machining can be performed efficiently. Also, in the case of electrolytic machining and electrolytic grinding, if the temperature of the electrode protrusion is high, for example, about 200 to 400°C, the machining fluid will evaporate, gasify, and even discharge will occur, making the machining state unstable. However, according to the present invention, the electrode protrusion can be sufficiently cooled, so even when performing high-load machining with a high electrolytic current, the electrode protrusion can be kept at the desired level. It is possible to maintain and control the temperature at a good level, allowing efficient processing with high precision.

The shell electrode 1 has been described above as manufactured by electroforming, but for example,
As described in the publication, electrode materials for electrical machining, such as plate-shaped bodies or blocks made of copper, nickel, brass, etc., can be made by electric discharge pressure forming method, other appropriate sheet metal press forming method, or It will be further explained in detail that it can be similarly applied to the case of a shell-like electrode 1 having a three-dimensional overall shape formed by cold or hot forging, and that the same effects as in the above case can be achieved. It goes without saying.

Further, the shape of the shell electrode 1 may be a cylindrical electrode with a three-dimensional machined surface formed on the outer peripheral side surface, or a cylindrical electrode with a tapered shape. may be inserted into a machining fluid in a machining tank in which a workpiece of an electric machining machine is disposed, and may be cooled by a fluid machining fluid that is circulated and supplied from a machining fluid supply device. It is also possible to create a hole in the electrode that is cut out from a block of electrode material alloy by milling, etc., and to insert a heat pipe into the hole, which would produce a certain effect. However, compared to shell-shaped electrodes, this type of electrode generally has an extremely large heat capacity and a heat conduction path to the supporting side such as the spindle, so it often withstands considerably high-load processing. In many cases, it is not necessary.

As described above, according to the present invention, it is possible to selectively and locally sufficiently cool the surface protrusion of a shell-like electrode having a three-dimensional overall shape produced by electroforming or press processing, and Since the temperature of the surface protrusion can be detected and controlled to maintain it at a desired temperature, it is possible to reliably prevent the shell-shaped electrode protrusion, on which heat acts intensively, from deforming due to overheating, and also to allow for high processing speed. Even when performing high-load machining with electric current, machining can be performed in a stable machining state, and highly accurate machining can be performed efficiently.

[Brief explanation of the drawing]

1, 2, and 3 are side sectional views showing an embodiment of the present invention. In the figure, 1 is an electroformed shell electrode, 3 is a heat pipe, 4 is a reinforcing filler filled part, 5 is a mounting plate, and 6 is a cooling fluid distribution pipe.

Claims (1)

[Scope of utility model registration request] The heat-absorbing end of the heat pipe is placed in close contact with the recess on the back surface corresponding to the surface protrusion of the shell-like electrode formed into a desired three-dimensional shape by electroforming or press processing, and the back side of the shell-like electrode is is filled with a filler with the heat dissipation end of the heat pipe protruding, a cooling means for the heat dissipation end of the heat pipe protruding from the filler is provided, and the temperature of the heat pipe near the heat dissipation end is detected. Electrode for electrical processing equipped with a temperature detector.