JPS6361132B2 - - Google Patents

Description

Detailed Description of the Invention [Technical field to which the invention pertains] The present invention relates to an electric discharge process for a roll that finishes the outer peripheral surface of a roll-shaped workpiece (hereinafter simply referred to as a roll) with a constant surface roughness by electric discharge machining. This relates to processing methods.

[Prior art]

Conventionally, when finishing the surface of steel strip rolling rolls, especially cold rolling rolls, with a satin finish, a method has been adopted in which hard metal particles such as shots and grit are projected onto the polished roll surface to form impressions on the roll surface. It was getting worse.

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, and periodically applying a pulse voltage between the electrode and the workpiece to generate an electric discharge. This is a method of processing a workpiece by

By repeating such electrical discharge machining on the roll surface, rotating the roll in the circumferential direction, and at the same time gradually moving the electrode in the direction of the rotation axis of the roll, the roll surface will undergo a continuous spiral satin finish.
The roll surface can be covered with discharge marks. This is a method of uniformly applying a satin finish to the surface of the roll using electrical discharge machining.

The pear surface obtained in this way not only has a larger difference in unevenness and a much more regular shape than mechanical impressions made by metal particle projection, but the shape is also influenced by the manufacturing method and hardness of the roll. Zumata,
It 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.

Fig. 1 is for explaining the roll electric discharge machining method. In Fig. 1, 1 is the bed, 3 is the roll of the workpiece, 4 is the celery that chucks one end of the roll 3, and 5 is the roll rotation. A drive device rotates the celery 4 and rotates the roll 3. Reference numeral 6 denotes a base, which is configured to be slidable on the bed 1 from side to side in the figure by the action of a column lateral feed drive device 7 and a feed screw 8. 9 is a head column fixed on the base 6, 10 is an electrode holder attached to the head column 9, and 11 is a plurality of electrodes attached to the holder 10 at equal pitches through an insulating plate. 11 is formed of a copper plate having a shape shown in a perspective view in FIG. 2, facing the roll 3 through a machining gap, and is also formed in the same shape. 13 is a machining tank held on the roll 3; 14 is a machining fluid supplied into the machining tank 13 by a pump (not shown); the machining fluid 14 overflowing from the machining tank 13 is passed through and returned to the machining tank 13; It is configured to be supplied to Further, reference numeral 15 denotes a pulse power supply device, which is connected to form a discharge between each of the electrodes 11 and the roll 3. In the figure, the positive electrode is connected to the electrode 11, and the negative electrode is connected to the roll 3, but processing can also be performed in the reverse direction. Further, the spindle feed of the electrode 11 in the direction perpendicular to the machined surface of the roll 3 is carried out by the servo head 16.
It will be held in 17 and 18 are the headstock 19 respectively
A spindle-side center and a tailstock-side center provided on the tailstock 20 are inserted into center holes at both ends of the roll 3 to position the roll in the electric discharge machining apparatus. Conventionally, when installing a roll in an electric discharge machining device with such a configuration, an operator lowers the roll from above while inching a roll carrier such as a hoist of a crane, and places the roll on the spindle side center 17 and the center at an appropriate position. The roll was positioned by inching the push-side center 18 and inserting it into center holes at both ends of the roll. Since the weight of the roll is 2 to 7 tons, this operation requires great skill, is dangerous, and takes a long time.

[Summary of the invention]

The present invention has been made in view of the above circumstances, and provides a method for electrical discharge machining of rolls that allows the transport and positioning of rolls to be carried out safely and in a short period of time, and further enables automation of the process. It is something.

In order to achieve the above object, the method according to the present invention lowers a roll-shaped workpiece having a center hole at both ends of the rotating shaft from above, and inserts a spindle-side center and a center hole into the center holes at both ends. Insert the push side center and position the roll-shaped workpiece,
In an electrical discharge machining device for a roll-shaped workpiece that finishes the outer circumferential surface of the roll-shaped workpiece with a satin finish, a detector is provided so that the center holes at both ends of the roll-shaped workpiece are connected to the spindle side and the center. After detecting that the push side center is in a position where it can be inserted and that the center of the center hole is located below the line connecting the centers of the spindle side center and tailstock side center, The push-side center is inserted into the center hole.

[Embodiments of the invention]

A method according to an embodiment of the present invention will be described below with reference to FIGS. 3A to 3D. In the same figure, 30
31 is a rope, 31 is a hole for the center, 32 is the center of the center hole, 33 is a line connecting the center of the spindle side center and the center of the tailstock side, and 34 is a detector of the present invention.

FIG. 3A and FIG. 3B are diagrams showing an example of poor roll mounting, in which the center holes 31 at both ends of the roll 3
is in a position where it can be inserted into the spindle side center 17 and the tailstock side center 18, but the center 32 of the center hole is connected to the line 33 connecting the centers of the spindle side center and the tailstock side center.
It shows a state that is higher up. FIG. 3B shows the case where both centers 17 and 18 are inserted from that state. As can be seen from Figure 3B, roll 3
is pushed down by the forces of both centers 17 and 18, and an unreasonable downward force is applied to the hoist and crane (not shown) suspending the roll 3.
This is very dangerous as there is a possibility of damage to the rope 30, damage to the crane or hoist, damage to the electric discharge machining equipment, etc.

3C and 3D are diagrams showing an example of roll mounting according to the method according to the present invention. Figure 3C shows
Due to the function of the detector 34, the roll both end center holes 31 are aligned with the spindle side center 17 and the tailstock side center 18.
The center hole 32 is located below a line 33 connecting the centers of the spindle side center and the tailstock side center. Third
Figure D shows both centers 1 from the state shown in Figure 3C.
7 and 18 are inserted. As can be seen from FIG. 3D, the roll 3 is pushed upward by the forces of both centers 17 and 18 during installation, so
No force is applied to the hoist, crane, etc. that is suspending the roll 3, and a gap is created between the hoist, crane, etc. that is suspending the roll 3, and a gap is created between the roll 3 and the rope 30, etc., by the amount that has been pushed upward, so that it is difficult to remove the rope, etc. This is easy, and it is also possible to keep the roll on standby and rotate it.

As described above, if the roll is set in the state shown in Fig. 3C and then mounted as shown in Fig. 3D, it can be mounted safely and in a short time.

〔Effect of the invention〕

According to the present invention, when installing a roll, the force applied to the roll by each center acts upward, and no unreasonable force is applied to the hoist, crane, etc. Therefore, the roll can be installed safely and in a short time. Carrying in and positioning is possible, and automation is also becoming possible.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing an electrical discharge machine for explaining the electric discharge machining method for a roll-shaped workpiece, Fig. 2 is a perspective view of an electrode, and Figs. 3A and 3B show a bad example of the roll machine. 3C and 3D are diagrams showing an example of mounting a roll by a method according to an embodiment of the present invention. In the figure, 1 is a bed, 3 is a roll, 17 is a spindle side center, 18 is a tailstock side center, 19 is a headstock, 20 is a tailstock, and 34 is a detector. In addition,
In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1 Lower the roll-shaped workpiece that has a center hole at the center of the rotating shaft at both ends from above, insert the spindle side center and tailstock side center into the center holes at both ends, and position the roll-shaped workpiece. conduct,
In the electric discharge machining method for a roll-shaped workpiece in which the outer peripheral surface of the roll-shaped workpiece is finished with a satin finish, a detector is provided so that the center holes at both ends of the roll-shaped workpiece are connected to the spindle side and the center. After detecting that the pushing side center is in a position where it can be inserted and that the center of the center hole is located below a line connecting the centers of the spindle side center and the tailstock side center, A method for electric discharge machining of a roll-shaped workpiece, characterized by inserting a center into the center hole.