JPH02139119A - Machining method for ball screw - Google Patents

Abstract

PURPOSE:To shorten a span of machining time by applying rough grind and fine grind to a ball rolling groove of a ball screw consisting of fragile material such as ceramics or the like by grinding wheel in order, and then heating it by means of a laser beam. CONSTITUTION:In a ceramics ball screw W supported between two centers 23 and 24, a grinding wheel 28 is rotated drived in an arrow B direction, this ball screw W is rotated and driven in an arrow A direction, and a wheel spindle stock 27 is advanced forward for infeed, then a table 13 is moved in an arrow C direction, thus a rolling groove Wa is roughly ground. When rough grind is all over, the wheel spindle stock 27 is advanced forward for infeed with a little infeed quantity as compared with the rough grind time, and the table 13 is advanced left in the axial direction of the ball screw W, thus the ball rolling groove Wa is finely ground. At final fine grind, a laser beam is irradiated to the ball rolling groove Wa from a laser torch 33, heating it. Whereby some cracks produced by the rough grind are reduced. Consequently, there is unnecessary to apply the fine grind for long.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for processing a ball screw made of a brittle material such as ceramics.

<Conventional technology> When grinding the ball rolling groove of a ceramic ball screw using a screw grinding device, the ball screw and the grindstone are both rotated, and each rotation of the ball screw rotates the ball screw by the pitch of the ball rolling groove. Processing is performed by moving in the direction. This processing is performed separately for rough grinding and equipment, and the crank is made smaller by making the equipment longer with a larger rack on the outer periphery of the ball screw generated during rough grinding.

<Problem to be solved by the invention> There was a problem that processing took time if the device was used for a long time.

Means for Solving the Problems> The present invention has been made to solve the above-mentioned problems, and the ball rolling groove of a ball screw is sequentially subjected to coarse grinding and fine grinding using a grindstone. The ball rolling grooves thus formed are heated by laser light. Further, the ball rolling groove of the ball screw is roughly ground with a grindstone, the roughly ground ball rolling groove is heated with a laser beam, and the heated ball rolling groove is finely ground with a grindstone.

Action> The ball rolling groove of the screw 7L/screw is sequentially rough-ground and fine-ground using a grindstone, and the fine-ground ball rolling groove is heated by laser light to eliminate cracks. In addition, the ball rolling grooves of the ball screw are roughly ground with a grindstone, the coarsely ground ball rolling grooves are heated with laser light to eliminate cranking, and the heated ball rolling grooves are finely polished with a grindstone. do.

<Example> Hereinafter, an example of the present invention will be described based on FIGS. 1 and 2. 1O is a bed, on which a table 13 is slidably guided in the left-right direction, and a movable base 14 is slidably guided in the front-back direction. table 13
is driven by a ball screw 15 and a servo motor 16, and the movable table 14 is driven by a ball screw 17 and a servo motor 18). A headstock 20 and a tailstock 21 are installed on the table 13 facing each other, and a rotary plate 22 is rotatably supported on the headstock 20, and this rotary plate 22 is rotationally driven by a motor of a circuit. It looks like this. Centers 23 and 24 that engage with the center hole of the ball screw W are removably attached to the headstock 20 and tailstock 21, respectively. The ball screw W is made of ceramics, and a rotating plate 22 is attached to the ball screw W.
A groove 26 is attached to which the drive bin 25 of the drive pin 25 engages.

Note that the ball screw W may be made of glass as long as it is a brittle material. A grindstone head 27 is installed on the movable table 14, and a whetstone 28 is rotatably supported on the whetstone head 27 around an axis inclined by the torsion angle of the ball rolling groove Wa with respect to the rotation axis of the ball screw W. There is. The grindstone 28 is rotationally driven by a grindstone drive motor of a circuit, and most of the grindstone 28 is covered with a grindstone cover 29 attached to the grindstone stand 27 except for the ball screw W side.

A block 32 is attached to the front surface of the bed 10 so as to extend upward, and this block 32 is attached to a position corresponding to the left side of the left end of the grindstone 28, that is, a ball rolling groove Wa immediately after being machined by the grindstone 28. A laser torch 33 is installed at a corresponding position. One end of the optical path tube 34 for guiding the laser light to the laser torch 33 is a block 32.
The other end of the optical path tube 34 is attached to a YAG laser oscillator 35. Note that the laser oscillator 35 is C
O! It may also be a laser oscillator. A mirror block 36 is provided in the middle of the optical path tube 34 to refract and reflect the laser beam.

Next, the operation will be explained based on the above-described configuration. The grindstone head 27 moves back and the small diameter part wb on the left side of the ball screw W
A ball screw W made of ceramics is supported between two centers 23 and 24 while the table 13 is moved to the right to a position corresponding to the grindstone 28. In this state, the grindstone 28 is driven to rotate in the direction of arrow A, the ball screw W is driven to rotate in the direction of arrow B, the grindstone head 27 is cut and advanced, and then, each revolution of the ball screw W is rotated by the pitch of the ball rolling groove Wa. The table 13 is moved leftward in the direction of arrow C to roughly grind the ball rolling groove Wa. When the table 13 moves to the left to the position where the grindstone 28 corresponds to the small diameter part wb on the right side of the ball screw W, the grindstone head 27 is moved backward, and the table 3 is moved to the position where the grindstone 28 corresponds to the small diameter part wb on the left side of the ball screw W. Move to the right.

The above-mentioned grindstone head 27 is cut and moved forward, and the ball screw W is
The table 13 is moved to the left in the axial direction of the ball screw W by the pitch of the ball rolling groove Wa per revolution, and the grindstone head 2
The operation of moving the table 13 backward and moving the table 13 to the right is repeated.

When the rough grinding process is completed, the grinding wheel head 27 is moved forward by holding the grindstone head 27 with a smaller cutting advance amount than during rough grinding, and the table 13 is moved by the pitch of the ball rolling groove Wa per one rotation of the ball screw W. Move left in the axial direction,
The operations of retracting the grindstone head 27 and moving the table 13 to the right are repeated to finely grind the ball rolling groove Wa. In the final fine polishing process, the ball rolling groove Wa is irradiated with laser light from the laser torch 33 to heat the ball rolling groove Wa, thereby reducing the size of cracks caused by the rough polishing process.

When the fine grinding described above is completed, the tailstock 21 is moved to the right and the workpiece W is taken out from the center 23, 24.

As another modification, the grindstone head 27 is moved backward, and the ball screw W
The table 13 moves to the right until the grinding wheel 28 corresponds to the small diameter portion wb on the left side of the table 13, and the grinding wheel head 27 is cut and moved forward with the ball screw W supported between the two centers 23 and 24, making one revolution of the ball screw W. The table 13 is moved to the left in the axial direction of the ball screw W by the pitch of the ball rolling groove Wa, the grinding wheel head 27 is retreated, and the table 13 is moved to the right by a repeated operation, and the ball rolling groove Wa is roughly ground. do. In the final rough grinding of the ball rolling groove Wa,
The ball rolling groove Wa is irradiated with laser light from the laser torch 33 to heat the ball rolling groove Wa, thereby reducing the size of cracks caused by rough grinding.

When the rough grinding process is completed, the grindstone head 27 is held at a Rfit before cutting, which is smaller than that during rough grinding, and is moved forward into the cut.
For each revolution of the ball screw W, the table 13 is moved leftward in the axial direction of the ball screw W by the pitch of the ball rolling groove Wa, the grindstone head 27 is retreated, and the table 13 is moved rightward, which are repeated. Finely polish Wa.

The operation of moving the table 13 and movable base 14 described above is performed by the NC control device. Further, the ball screw W having the above-mentioned path may be formed into a round bar with the ball rolling grooves Wa formed thereon. Further, rough ball rolling grooves may be formed in the baked and hardened state.

<Effects of the Invention> As described above, the present invention sequentially performs coarse grinding and fine grinding on the ball rolling grooves of a ball screw made of a brittle material using a grindstone, and then applies a laser beam to the finely polished ball rolling grooves. heated by. In addition, the ball rolling groove of the ball screw is roughly ground with a grindstone, the rough ground ball rolling groove is heated with a laser beam, and the heated ball rolling groove is finely polished with a grindstone. It is possible to eliminate the crank caused by the grinding process, and there is no need for long fine grinding processes, resulting in the effect of shortening the machining time.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a plan view of a screw grinding device, and FIG. 2 is a view seen from the direction (■) in FIG. 1. 10... Bed, 13... Table, 14... Movable base, 20... Headstock, 21... Tailstock, 22...
・Rotary plate, 27... Grinding wheel stand, 28... Grinding wheel, 29.
・・Whetstone cover 30・・Coolant nozzle, 33・
...Laser torch, 35...YAG laser oscillator, 3
7... Lever, W... Ball screw, Wa... Ball rolling groove.

Claims (2)

[Claims] (1) A ball screw processing method in which the ball rolling grooves of a ball screw made of a brittle material are sequentially rough-ground and fine-ground using a grindstone, and the fine-ground ball rolling grooves are heated by laser light. (2) Roughly grind the ball rolling groove of a ball screw made of brittle material with a grindstone, heat the roughly ground ball rolling groove with a laser beam, and finely polish the heated ball rolling groove with a grindstone. A method of processing a ball screw.