JPH04300160A - Method of controlling compensation for taper - Google Patents

Abstract

PURPOSE:To shorten the cycle time by setting the initial position of each taper correction to a position which is retracted by a predetermined distance, and by displacing a housing for a preparatory side magnetic shaft in the advance direction at the retracted position so as to always shorten the taper compensation stroke by a constant value. CONSTITUTION:When a servo-motor 22 is rotated so as that an elevatable slide member 27 is elevated by a predetermined value by means of ball-and- screw mechanisms 24, 25, a coupling part 19 of a slide member 15 is elevated by means of a shaft pin 28, and accordingly, a link 18 is rotated. Further, a grindstone shaft housing 7 is pushed forward by means of a linear guide 13. Accordingly, the grindstone shaft housing 7 is tilted about a resilient flexible part 11 as a fulcrum, and accordingly, one end part of a grindstone shaft 5 near to the grindstone shaft housing 7 is displaced by a compensating value corresponding to the degree of rotation of the servemotor 22. Accordingly, the grindstone shaft 5 is tilted reversely by a value corresponding to the degree of a taper so that a taper during cutting is removed. In this phase, the position of each initiation of correction for the taper is set at a position which is retracted from the taper sizing position of a workpiece before processing.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a taper correction control method in a taper correction device for a grinding machine.

0002

[Prior Art] Grinding on a grinding machine, especially when grinding a long workpiece on a cylindrical grinder or a different diameter workpiece on a multi-wheel grinder, involves mounting errors in the workpiece, grinding wheel wear, and heat in each part of the grinder. When a taper occurs on the machined surface due to deformation or other factors, there is a problem that the workpiece becomes tapered.

[0003] As a means of correcting the taper to prevent the workpiece from becoming tapered, the grinding wheel axis is tilted by slightly displacing the grinding wheel shaft housing at the end of the grinding wheel shaft in a direction perpendicular to the grinding wheel axis during the grinding process. A means for adjusting is described, for example, in Japanese Patent Publication No. 19635/1983.

0004

The conventional means described above is a taper correction stroke that starts each time from a fixed original position, stops at the taper sizing OK signal point, and returns to the fixed original position again.

[0005] In a thermally unstable machine such as a multi-wheel grinder having a long grinding wheel spindle span, the tendency of the workpiece to taper changes over time. Therefore, in the taper correction described above, it is difficult to make the taper correction stroke constant according to changes in the taper, and the taper correction is completed with a variable stroke from a fixed position, which increases the cycle time and increases the time. Along with this, the cycle time changes, the machining allowance for taper correction changes, and the accuracy is unstable.

[0006]

[Means for Solving the Problems] The present invention is a taper correction control method devised to solve the above-mentioned conventional problems. A taper correction device for a grinding machine, in which the lower surface of at least one of the grinding wheel shaft housings is attached to the grinding wheel head via an elastic flexible part, and the adjustment side grinding wheel shaft housing can be adjusted in displacement in the front and back direction by an NC-controlled moving device. , the taper correction start position each time is set back a certain amount from the taper fixed size position of the pre-processed workpiece, and at this fixed amount back position, the adjustment side grindstone shaft housing is adjusted based on the signal of the amount of taper generated in the workpiece. This feature is characterized in that the taper is corrected by being displaced in the forward direction.

[0007]

[Operation] According to the method of the present invention, the taper correction stroke during continuous cycles is always substantially constant and short, so that the cycle time can be shortened and the taper machining allowance can be made uniform.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. 1 and 2 show a taper correction device for a grinding machine used in the method of the present invention. Its configuration will be explained below. In FIG. 1, reference numeral 9 denotes a whetstone head provided on a bed (not shown). Reference numeral 7 denotes a grindstone shaft housing mounted opposite to the front step portion 12 of this grindstone head 9, and rotatably supports both ends of the grindstone shaft 5, on which a plurality of grinding wheels 6 are mounted, by means of hydrodynamic bearings.

One lower surface of the grindstone shaft housing 7 is
An elastic flexible section 11 is formed by the opposing notches 10 and 10, and the elastic flexible section 11 is attached to the front step section 12 of the grindstone head 9. A vertical linear guide 13 is fixed to the back surface of the grinding wheel shaft housing 7.
A fork-shaped sliding member 15 on which a linear member 14 having a cross-sectional shape that holds a member 3 is fixed is guided by the linear guide 13 so as to be slidable in the vertical direction.

As shown in FIG. 2, inside the cavity 16 formed in the grindstone head 9 behind the grindstone shaft housing 7,
A link 18 whose base end is parallel to the grinding wheel shaft 5 and is rotatably connected in the vertical direction by a shaft pin 17 is provided, and both sides of the tip of this link 18 fit into the sliding member 15, It is rotatably pivoted. Further, the sliding member 15 has a connecting portion 19 integrally formed in a fork shape.
is provided.

A servo motor 22 is mounted on the upper surface of the grindstone head 9 in the vertical axial direction above a cylindrical bracket 21 which is mounted in the vertical axial direction. The lower end of the threaded rod 24 is coupled to the upper end of the threaded rod 24 of the ball screw mechanism provided in the vertical axial direction and screwed into the nut member 25.
It is engaged with the lower end surface of the nut member 25 via a disc spring 26 for removing backlash.

Inside the cylindrical bracket 21 is an upper recess 27a to which a nut member 25 of a ball screw mechanism is fixed.
An elevating sliding member 27 having a lower end portion 27b having a parallel surface is attached so as to be slidable in the vertical direction and rotationally restrained.

The upper end portion of the fork-shaped connecting portion 19 with the notch fits into both sides of the lower end portion 27b of the elevating sliding member 27, and the lower end portion 27b of the elevating sliding member 27 is separated from the grinding wheel shaft 5.
It is rotatably connected by a shaft pin 28 which is inserted vertically into a horizontally elongated hole 27c drilled in parallel with the shaft pin 27c without any play.

[0014] When the link 18 is in its original position without being subjected to taper correction, it is in an inclined position, for example, tilted forward. That is, the center point O2 of the shaft pin 20 is located at a position somewhat lower than the center point O1 of the shaft pin 17. Various conditions such as the length of the link 18 are set so that the horizontal component of the displacement until the center point O2 rotates around the center point O1 and becomes parallel to the center point O1 is somewhat larger than the maximum correction range. .

The operation of the above configuration will be explained. When the servo motor 22 rotates a predetermined amount, the ball screw mechanism (24
, 25), the lifting/lowering sliding member 27 is raised by a predetermined amount. As a result, the connecting portion 19 of the sliding member 15 rises via the shaft pin 28, and the link 18 accordingly rotates counterclockwise in FIG. 1, and the sliding member 15 slides upward on the linear guide 13. do. At that time, shaft pin 2
The center point O2 of the shaft pin 17 rotates around the center point O1 of the shaft pin 17, and the sliding member 15 moves forward in the direction of the grindstone shaft 5 by the horizontal component of the displacement, moving the grindstone shaft housing 7 forward via the linear guide 13. to press.

As a result, the grinding wheel shaft housing 7 is tilted using the elastic flexible portion 11 as a fulcrum, and the grinding wheel shaft 5 is tilted accordingly.
The end on the grindstone shaft housing 7 side is displaced by a correction amount corresponding to a predetermined amount of rotation of the servo motor 22 with respect to the end of the other grindstone shaft housing, and the grindstone shaft 5 is tilted in the opposite direction by the amount of the taper. As a result, the taper in the grinding process is eliminated. It is easily understood that the taper correction in the opposite direction described above can be similarly performed by reversing the operating direction.

The taper correction device for a grinding machine capable of performing taper correction operation as described above enables the following control method according to the present invention. That is, as shown in the cycle diagram of FIG. 3, the taper correction total stroke L is defined as the taper correction total stroke L, and within this taper correction total stroke L, the position retreated by a certain amount L1 from the taper sizing correct position T of the pre-processed workpiece is set for each taper correction stroke L. Let it be the correction start position C. Taper correction is performed by displacing the grindstone shaft housing 7 in the forward direction based on the signal of the amount of taper generated in the workpiece at this fixed amount L1 retreat position. With this method, as shown by the trajectory line E of the fixed size and fixed amount retreat position in Fig. 3, the stroke for taper correction during continuous cycles can be shortened, the cycle time can be shortened, and the taper correction can be performed easily. Since there is less variation in the thickness, it becomes easier to achieve grinding accuracy.

Further, the taper correction start position B at the time of starting the first machining and the first time after the machining is stopped for a predetermined time is a fixed position behind the taper correction start position C, and the process is started from this position. This eliminates the effect that the sizing position of the pre-processed workpiece changes due to machine interruption or the like due to the interruption time.

When correcting the grinding wheel after several times of machining, the grinding wheel head 9 is moved backward with the grinding wheel correction position D set at the rear of the first taper correction start position B at the time of starting and after stopping the machining for a predetermined period of time. It is done by doing this. This results in
The relationship between the grindstone shaft 5 and the grindstone correction becomes constant, and highly accurate grindstone correction can be obtained.

[0020]

[Effects of the Invention] As described above, the method of the present invention has the advantage of shortening the cycle time of taper correction every time during continuous cycles, reducing changes in the machining allowance of taper correction, and stabilizing grinding accuracy. However, it has the practical benefit of solving all the conventional problems at once.

[Brief explanation of drawings]

[Fig. 1] A partially sectional side view of a taper correction device adopted in the present invention.

[Figure 2] Cross-sectional view taken along line A-A in Figure 1

[Figure 3] Cycle diagram of the method of the present invention

[Explanation of symbols]

5 Grinding wheel shaft 6 Grinding wheel 7 Grinding wheel shaft housing 9. Whetstone stand 11 Elastic flexible part 13 Linear guide 14 Linear moving parts 15 Sliding member 18 Link 22 Servo motor 24 Threaded rod 25 Nut member 27 Lifting sliding member

Claims (1)

[Claims] Claim 1: A lower surface of at least one of the grindstone shaft housings, which are provided facing each other so as to rotatably support both ends of the grindstone shaft, is attached to the grindstone head via an elastic flexible part, and the adjustment side grindstone shaft housing In a taper correction device for a grinding machine, the displacement of which can be adjusted in the back and forth direction by an NC-controlled moving device, the taper correction start position each time is set back a certain amount from the correct taper size position of the pre-processed workpiece, and this constant A taper correction control method, characterized in that the adjusting side grindstone shaft housing is displaced in the forward direction based on a signal of the amount of taper generated in the workpiece at a retracted position to perform taper correction.