JPH074699B2 - Electric discharge machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electric discharge machining apparatus suitable for manufacturing a pin having a small diameter that is difficult to machine.

2. Description of the Related Art Electric discharge machining is often used for machining pins with a diameter of 1 mm or less, which are difficult to cut or grind. For example, in an apparatus for fine machining by electric discharge as described in Japanese Patent Laid-Open No. 57-33922, a fine hole electric discharge machining technique and an electric machining technique Vol. A method of machining by performing electric discharge by facing the side of the machining electrode to the molding block, or improving the precision of micro electric discharge machining, using the running wire described in the proceedings of the Annual Meeting of the Precision Machinery Society of 1984 (Masawa). A method of processing by using is known. Hereinafter, each of the above conventional methods will be described with reference to the drawings.

FIG. 5 is an explanatory diagram of a system in which the side surface of the workpiece is opposed to the molding block and machining is performed by electric discharge. In the figure, 101 is a cylinder to be a workpiece, 102 is a holder of the workpiece 101, 103
Is a forming block, and the forming block 103 and the workpiece 1
01 is immersed in the working fluid. Then, a machining voltage is applied between the workpiece 101 and the molding block 103, and the molding block 103 is gradually moved to the workpiece 101 while the position of the workpiece 101 is fixed.
When the distance is closer to the side, and the distance between them approaches within the discharge gap length, the discharge starts, and the discharge area A of the workpiece 101 decreases in the radial direction. When the forming block 103 is brought closer to the workpiece 101 while maintaining a constant discharge gap, the radial machining (reduction) of the workpiece 101 progresses in proportion to the feed amount, and the workpiece 101 becomes the desired shape. Repeat feeding until the diameter is reached.

FIG. 7 and FIG. 8 are an overall view of a processing apparatus using traveling wires and an explanatory view of a processing method, respectively. The workpiece 201 is discharged between the wire 201 and the workpiece 202, and the workpiece 202 is processed from the upper side to the lower side while the wire 201 running has a weight allowance for the machining allowance Δd and the outer periphery is processed. Wire 20
In No. 1, the traveling area on the guide roller 203 is always low, so that the discharge area of the wire 201 is updated.

Problems to be Solved by the Invention However, in the former processing method in which the side surface of the workpiece 101 faces the molding block 103, only the workpiece 101 side is not consumed by electric discharge, and the molding block 1 has a small proportion.
03 also wears out, and as shown in FIG.
04 is formed. For this reason, it is necessary to shift the molding block 103 and use a new surface when performing repeated machining. Therefore, when the groove 104 is formed from one end of the forming block 103 to the end, the life is reached, and the forming block 103
Will be replaced anew, resulting in a decrease in work efficiency.
Further, since the replacement work of the molding block 103 is required, it is extremely difficult to support unmanned operation by NC control. Further, since the electric discharge area is equal to the machining length, electric discharge is generated on the entire facing surface, so that electric discharge is concentrated at the tip portion, and as the machining allowance is increased, the workpiece 101 is tapered so that the tip portion becomes thinner. It has problems such as being formed.

On the other hand, in the latter machining with the traveling wire 201, since the wire 201 is traveling, a new surface (in the case of a cylindrical wire, it approaches the line) and the work piece 202 are always discharged. As described above, the problem that the workpiece is tapered does not occur. The wire 201 runs at a low speed of 50 mm / MIN, and the reel is wound with the wire 201 of several thousand m, so there is no problem in terms of life. However, as a whole processing device, the traveling device of the wire 201, the brake,
Since a follow-up mechanism for following the movement of the stage is required, the device becomes complicated and the cost becomes high.

Therefore, the present invention is to solve the above-mentioned problems of the conventional example, the molding surface of the molding block can always be kept flat even after repeated machining, and the workpiece can be machined with good straightness. Can be even easier with NC
It is intended to provide an electric discharge machine that can be automated.

Means for Solving the Problems And technical means of the present invention for solving the above-mentioned problems include means for vertically moving a work piece, and an electric discharge machining solution arranged below the work piece. A processing tank filled with
The processing block is fixed in the processing tank, and has a protruding portion having a width narrower than the processing length of the workpiece, and the processing tank is orthogonal to the forming block in which a flat forming surface is formed on the protruding portion. A means for moving in two directions, a machining power source for causing an electric discharge between the work piece and the forming block, and a moving speed of the work piece in the vertical direction and a moving speed of the forming block in the horizontal plane are proportional. It is equipped with a control means for controlling the movement.

Effect The present invention has the above-described configuration and controls the feed in the length direction of the work piece and the feed of the forming block at the same time and at a single running ratio, so that the work in the length direction of the work piece is protruded from the forming block. Since it can be performed while sequentially changing the position of the molding surface over the entire length, the shape of the molding surface after consumption of the molding block can be kept flat even after repeated machining, and the processed workpiece has already been processed. Since the part of is separated from the molding surface,
The workpiece can be processed without being processed with good straightness.

Examples Hereinafter, examples of the present invention will be described in detail with reference to the drawings.

1 to 4 show an electric discharge machining apparatus according to an embodiment of the present invention, FIG. 1 is an overall perspective view, FIG. 2 is an enlarged perspective view of a workpiece and a block, FIG. 3 (a), (b) and FIG. 4 are explanatory views of the machining operation.

The work piece 1 is held by a holder 2 as shown in FIG.
The holder 2 is rotatably held by the rotating means 3. The rotating means 3 is supported by a support base 4, and the support base 4 is continuous with the vertical (Z-axis) moving means 5. In the vertical direction moving means 5, a movable table 7 is supported on a column 6 so that the movable table 7 can be discharged in the vertical direction, and the movable table 7 is discharged in the vertical direction by driving means including a motor 8 and a feed screw 9. A machining tank 10 is provided below the work piece 1, the machining tank 10 is filled with an electric discharge machining liquid 11, and a forming block 12 is fixed in the machining tank 10 and immersed in the electric discharge machining liquid 11. As is particularly apparent from FIG. 2, the molding block 12 has a horizontal projection 12a formed at the upper end thereof, and the tip end surface of the projection 12a is formed as a flat molding surface 12b. In this embodiment, the width d of the molding surface 12b is set to about 1/10 of the processing length l of the workpiece 1. The processing tank 10 is mounted on moving means 13 and 14 in two directions (X axis and Y axis) orthogonal to each other in a horizontal plane. The Y-axis moving means 14 has a movable base 16 on a fixed base 15.
Is movably supported in the Y-axis direction, and the movable table 16 is used for the motor 1
7. It is moved in the Y-axis direction by driving means such as a feed screw (not shown). In the X-axis moving means 13, a fixed base 18 is mounted on a movable base 16 of the Y-axis moving means 14, a movable base 19 is supported on the fixed base 18 so as to be movable in the X-axis direction, and the movable base 19 is a motor 20. , X by a driving means such as a feed screw (not shown)
Moved axially. A machining power supply 21 is connected to the holder 2 holding the work piece 1 and the forming block 12 with the work piece as a primary electrode and the forming block 12 as a secondary electrode.
The motor 8 of the vertical (Z-axis) moving means 5 is a Z-axis driver.
22, the motor 20 of the X-axis moving means 13 and the motor 17 of the Y-axis moving means 14 are connected to the X and Y axis drivers 23, and the Z axis driver 22 and the X and Y axis drivers 23 are connected to the control means 24. The moving speed of the workpiece 1 in the vertical direction (Z axis) and the moving speed of the forming block 12 in the horizontal plane (X axis) are proportionally controlled.

Next, the processing operation of the above embodiment will be described.

FIG. 3 (a) is a front view for explanation when processing the workpiece 1 while rotating it, and FIG. 3 (b) is a bottom view thereof.

Now, the processing length of the work piece 1 is 1, and the machining allowance in the radial direction is ΔD.
(2 × ΔD in diameter). Therefore, first, the workpiece 1 is lowered by the operation of the vertical moving means 5 from the upper surface of the forming block 12 by the same length d ′ as the width d of the forming surface 12b of the forming block 12 and the X-axis moving means 13 is operated. The working tank 10 and the molding block 12 are moved in the X-axis direction by the operation,
The molding block 12 is set at a position away from the side end surface of the molding block by ΔD. Then, the processing tank 10, that is, the forming block
When the X-axis moving means 13 is operated, 12 is moved to a relative position where electric discharge is started between the workpiece 1 and the forming block 12, and a constant velocity Vb
Then move. Then, after the machining power is supplied from the machining power source 21 to the workpiece 1 and the molding block 12 to start the discharge,
While moving the forming block 12 at the same speed, the workpiece 1 is sent to the forming block 12 side at a speed of Ve by the operation of the vertical (Z-axis) moving means 5 while being rotated by the rotating means 3. That is, the workpiece 1 is simultaneously reduced in the radial direction and machined in the length direction. Naturally, the forming block 12 side is also consumed, but in this embodiment, when the ratio of Vb to Ve is the length 1 of the workpiece 1 and the length L of the forming block 12,
It is controlled by the control means 24 so that Vb / Ve = L / l. Therefore, when the length machining of the work piece 1 is completed, the movement to the right end of the forming surface 12b of the forming block 12 is completed, and the state becomes, and the forming surface 12b of the forming block 12 moves from the left end to the right end at a ratio of one run. Since it is consumed, a groove is not formed unlike the conventional example even if it is repeatedly processed, and a flat surface is always maintained. In addition, at the part where the radial processing is finished, the forming surface 12
Since it separates to the lower side of b and no discharge occurs, it is possible to perform machining with good straightness over the entire length in the length direction. In FIG. 4, the shape of the forming block 12 before processing is shown by a broken line, and the shape after processing is shown by a solid line.

In the above embodiment, the case where the workpiece 1 is rotated to be processed into a perfect circle has been described. However, even when the workpiece 1 is not rotated, processing is performed with the end surface of the molding block 12 kept flat. Is possible.

Also, when machining is performed by NC control, the molding block 12
Molding block 12
By detecting the side surface position of the machining tank 10 by moving the machining tank 10 in the Y direction or determining ΔD by detecting the coordinates of the discharge start point, machining can be performed without causing the wear of the molding block 12 to be a problem.

As described above, according to the present invention, the feed in the longitudinal direction of the workpiece by the vertical moving means and the feed of the forming block by the moving means in the horizontal plane are controlled simultaneously and at a constant ratio, Since the workpiece can be machined in the longitudinal direction while the position of the projecting portion of the molding block is sequentially changed over the entire length, the shape of the molding surface after consumption of the molding block even after repeated machining Can be kept flat, and since the forming surface of the forming block is narrower than the processing length of the work piece, the processed part of the work piece separates from the forming surface and is not processed. Can be processed with good straightness. Furthermore, since it is not necessary to provide a special accessory mechanism, NC automation is possible with a simple configuration.

[Brief description of drawings]

1 to 4 show an electric discharge machine in one embodiment of the present invention. FIG. 1 is an overall perspective view, FIG. 2 is an enlarged perspective view of essential parts, and FIGS. 3 (a), (b) and 4 is a machining operation explanatory view, FIG. 5 is an explanatory perspective view showing an example of a conventional electric discharge machining method,
FIG. 6 is a perspective view showing the consumption pattern of the molding block after machining by the electric discharge machining method shown in FIG. 5, FIG. 7 is an overall view of a conventional traveling wire type machining apparatus, and FIG. 8 is its machining method. FIG. 1 ... Workpiece, 3 ... Rotating means, 5 ... Vertical moving means, 10 ... Machining tank, 11 ... EDM fluid, 12 ... Molding block, 12a ... Projection, 12b ... Molding Surface, 13 ... X-axis moving means, 14 ... Y-axis moving means, 24 ... Control means.

Front Page Continuation (72) Inventor Akemi Tanaka 3-10-1 Higashisanda, Tama-ku, Kawasaki City, Kanagawa Matsushita Giken Co., Ltd. (56) Reference JP-A-61-203226 (JP, A) JP-A-62 -114824 (JP, A)

Claims (3)

[Claims] 1. A means for moving a workpiece vertically, a machining tank disposed below the workpiece and filled with an electric discharge machining fluid, and fixed in the machining tank, A molding block having a protrusion having a width narrower than the machining length, and a flat molding surface formed on the protrusion; a means for moving the machining tank in two directions orthogonal to each other in a horizontal plane; and the workpiece. A machining power source for discharging between the molding blocks; and a control means for proportionally controlling the moving speed of the workpiece in the vertical direction with respect to the molding block and the moving speed of the molding block in the horizontal plane. EDM equipment. 2. The ratio of the vertical moving speed Ve of the workpiece to the moving speed Vb of the forming block is Vb /, where the processing length of the workpiece is l and the forming surface length of the forming block is L. The electric discharge machine according to claim 1, which is given by Ve = L / l. 3. The electric discharge machining apparatus according to claim 1, wherein the workpiece is rotated by a rotating means.