JPS5921731B2 - Electric discharge machining method and device for roll-shaped workpieces - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses electrical discharge to finish the outer circumferential surface of a roll-shaped workpiece with a satin finish with a constant surface roughness (makes the roll-shaped workpiece a satin-like uneven surface).

) This relates to a method and device for electric discharge machining of roll-shaped workpieces (hereinafter simply referred to as rolls), and in particular, relates to a novel method capable of machining even crown-shaped rolls and a device for carrying out the method. It is something. Conventionally, for example, when finishing the surface of a steel strip rolling roll, especially a cold rolling roll, with a satin finish, there has been a method of projecting hard metal grains such as shots or grids onto the polished roll surface to create impressions on the roll surface. However, in recent years, attempts have been made to perform this type of machining by electrical discharge machining. As is well known, electric discharge machining involves interposing an insulating liquid, such as kerosene, in the narrow discharge gap between the electrode and the workpiece.
This is a method of machining the surface of a workpiece by periodically applying a pulse voltage between an electrode and the workpiece to cause discharge. This kind of waste electrical processing is a waste of money =;=;:! t″′shinji+=: As the roll continues to move, the roll surface is continuously subjected to a spiral satin finish, and the roll surface can be covered with discharge marks.

This is a method of uniformly applying a satin finish to the surface of a roll using electrical discharge machining. The resulting satin surface not only has a larger difference in unevenness and a much more regular shape than mechanical impressions made by metal particle projection, but also has a shape that is independent of the manufacturing method and hardness of the roll. It also has many advantages, such as the metal structure on the roll surface being hardened by electrical discharge, making it ideal for use as a rolling roll. By the way, rolling rolls are divided into straight rolls, which are completely cylindrical in shape, and crown rolls, in which the outer diameter of the center part is larger or smaller than that of both ends.
Further, the crown shape of the crown roll varies depending on conditions such as the thickness of the thin plate to be rolled. Processing of such various roll shapes is currently performed using a roll grinder, and after the grinding process, a matte finish is further applied using another device. However, such a two-step processing method of grinding and satin finishing is very time-consuming and requires a long processing time, and has many drawbacks, such as requiring two processing devices.

Therefore, the present invention focuses on the above-mentioned drawbacks, and uses a single electric discharge machining device to compare the outer diameter of the roll to be machined with the outer diameter of the desired roll, and to provide machining conditions for a power supply device that supplies discharge energy. By processing the roll while controlling it, the roll surface can be finished with a satin finish and at the same time be finished with the desired outer diameter.

That is, the present invention provides a method and apparatus for shortening the processing time of a satin-finished roll (a matte-finished roll) and further reducing the processing cost. Hereinafter, the present invention will be explained using figures.

FIG. 1 shows an embodiment of the apparatus of the present invention for carrying out the method of the present invention, in which 1 is a roll as a workpiece, 2 and 7 are roll supports for supporting the roll 1, 3 is a burr, and 4 is a roll support. A roll rotation drive device, 5 is a detection device for detecting the roll outer diameter, 6 is an electrode, 7 is a spindle head, 8 is a base that supports the detection device 5 and the spindle head 7, and 9 is a supply of waste electrical energy between poles. Pulse power supply device, 10 roll 1 the above base 8
11 is a drive device for rotating the feed screw 10; 12 is a storage device for storing the desired outer diameter of the roll; 13 is the detection device 5;
This is a change control device that controls changing of the machining conditions of the power supply device 9 based on a comparison signal between the roll outer diameter detected by and the output signal of the storage device 12. FIG. 2 is a detailed view of the processed portion, and FIG. 3 is a diagram showing an example of the processed crown roll shape.

Next, to explain the method of the present invention using the device of the present invention, first, the roll 1 is rotated at a constant speed, and the electrode is moved from either the left or right end of the mouth ring 1 in the axial direction of the roll 1 at a constant speed. The roll outer diameter of the machined portion at that time is detected by the detection device 5. Then, the processing conditions of the power supply device 9 are controlled by the change control device 12 by comparing the detected roll outer diameter and the roll outer diameter at the desired position of the roll outer diameter. That is, when the difference is large, the machining conditions are set to a high machining speed, and when the difference is small, the machining conditions are set to a low machining speed. In this case, there is no particular problem because the relationship between the processing speed and the amount of change in the outer diameter of the roll after passing through the electrode can be known experimentally in advance. By performing processing over the entire length of the roll while controlling the processing conditions of the power supply device 9, that is, the processing speed, in the manner described above, it is possible to simultaneously process the roll surface with a satin finish and to obtain the desired roll shape.

FIG. 4 shows another embodiment of the apparatus for carrying out the method of the present invention. In this figure, 14 is a program control apparatus, and this apparatus 14 has information on the outer diameter of the desired roll-shaped workpiece and the machine to be machined. The outer diameters of the roll-shaped workpieces to be processed are compared, and the manner in which the machining conditions of the power supply device 9 are changed based on the comparison is programmed in advance.

The machining conditions of the power supply device 9 are changed and controlled by the output signal of the program control device 14. According to this embodiment, there is no need to measure the small diameter of the roll during machining. In other words, the power supply 9 is configured such that the machining speed is high at positions where the difference between the outside diameter before machining and the desired roll outside diameter is large in the direction of the roll rotation axis, and the machining speed is low at positions where the difference is small. All you have to do is program the machining conditions.

The rest of the configuration is the same as that shown in FIG. 1, so the explanation thereof will be omitted. In summary, the present invention compares the outer diameter of the roll to be processed with the outer diameter of the desired roll and processes the roll while controlling the processing conditions of the power supply device, thereby giving the roll surface a satin finish and at the same time achieving the desired outer diameter. The present invention provides a finishing method and apparatus, and the effects of its implementation are extremely large.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an embodiment of the apparatus of the present invention for carrying out the method of the present invention, Fig. 2 is a detailed view showing the processing portion of the apparatus shown in Fig. 1, and Fig. 3 is a diagram of the processed crown roll shape. FIG. 4 is a diagram showing another embodiment of the apparatus of the present invention for carrying out the method of the present invention. Note that the same reference numerals in the figures indicate the same or equivalent parts. 1 is a roll-shaped workpiece, 4 is a roll rotation drive device, 5 is a detection device, 6 is an electrode, 8 is a base, 9 is a pulse power supply device, 10 is a feed screw, 11 is a drive device, 12 is a storage device,
13 is a change control device, and 14 is a program control device.

Claims (1)

[Claims] 1. While rotating the roll-shaped workpiece, an electrode is moved in the direction of the rotation axis of the roll-shaped workpiece, and a pulse power supply device is connected between the electrode and the roll-shaped workpiece. In the method for processing the surface of the roll-shaped workpiece into a matte finish, the outer diameter of the roll-shaped workpiece before the electrode passes;
Compare the outer diameters of the desired roll-shaped workpieces, and if the difference is large, control the pulse pause width of the pulse power supply device to be small, and if the difference is small, control the pulse pause width of the pulse power supply device to be large. A method for electric discharge machining of a roll-shaped workpiece, characterized in that the surface of the roll-shaped workpiece is finished with a satin finish and at the same time has a desired outer diameter. 2. While rotating the roll-shaped workpiece, move the electrode in the direction of the rotation axis of the roll-shaped workpiece, and connect a pulse power supply device between the electrode and the roll-shaped workpiece to rotate the roll-shaped workpiece. A storage device that stores the outer diameter of a desired roll-shaped workpiece; a detection device that detects the outer diameter of the roll-shaped workpiece before the electrode passes through; If the difference signal between the output signal of the storage device and the detection signal of the detection device is large, the pulse pause width of the pulse power supply device is controlled to be small, and if the difference is small, the pulse pause width of the pulse power supply device is controlled to be increased. An electric discharge machining apparatus for a roll-shaped workpiece, comprising a change control device for controlling. 3 While rotating the roll-shaped workpiece, move the electrode in the rotational direction of the roll-shaped workpiece, and connect a pulse power supply device between the electrode and the roll-shaped workpiece to increase the speed of the roll-shaped workpiece. For those whose surface is processed into a satin finish,
The roll-shaped workpiece is equipped with a program control device that compares the outer diameter of the desired roll-shaped workpiece with the outer diameter of the roll-shaped workpiece to be machined, and preprograms the pulse pause width of the pulse power supply device based on the comparison. Electrical discharge machining equipment for workpieces.