JP2000343396A - Traverse polishing method and traverse polishing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep a peripheral speed constant at a portion regardless of radius of rotation by making the rotating speed of a workpiece proportional to the radius of a grinding wheel surface position contacting the end face of the workpiece, and making the traverse feed speed of a grinding wheel proportional to the rotating speed of the workpiece. SOLUTION: In a numerical value control device 30, a spindle servo motor 11 is driven, and the rotating speed N=A db/da of a workpiece W is computed. A is a coefficient and a constant value. That is, the rotating speed N of the workpiece W is varied according to the ratio of the diameter da changed by traverse feed to the maximum diameter db of the tapered surface to perform traverse polishing. To make polishing resistance (work amount p) constant, that is to make the traverse speed per one rotation of the workpiece 1 constant, in the numerical value control device 30, a feed servo motor 9 is driven, that is, the feed speed F=BN in the direction of Z-axis is computed. B is a coefficient and a constant value. By this operation, traverse polishing is performed according to the rotating speed N of the workpiece W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traverse grinding method and a traverse grinding device.

[0002]

2. Description of the Related Art In a conventional grinding apparatus, as shown in FIG. 3, a grinder for grinding an inclined surface of an umbrella-shaped portion of a workpiece, for example, a tapered surface of a pulley of a continuously variable transmission, is provided.
A grinding wheel (angular grindstone or flat grindstone) with a grindstone surface wider than the radius of the bevel is mounted on the grindstone axis perpendicular to the direction of advance and retreat of the grindstone head, and the slope of the workpiece to grind the grindstone surface. The direction of the grindstone head is set so as to be parallel to the above, the grindstone head is moved forward and backward, and the slope of the umbrella-shaped portion of the workpiece is ground by so-called plunge cutting.

[0003]

The inclined surface of the umbrella-shaped portion of the work, for example, the tapered surface of the pulley of the continuously variable transmission, is rotated about the axis of the work spindle in the grinding device. The peripheral speed or the amount of grinding differs for each radial position, that is, the peripheral speed or the amount of grinding increases from the inner peripheral area (small diameter side) to the outer peripheral area (large diameter side).

Therefore, when the conventional grinding machine is used for grinding, the larger the diameter of the workpiece, the greater the grinding amount and the higher the peripheral speed. Therefore, the amount of wear on the grindstone surface of the grinding wheel corresponding thereto increases, and the grinding wheel wears unevenly, and it is difficult to maintain the straightness and the inclination angle of the inclined surface of the workpiece. The present invention solves the above-mentioned problems of the prior art when grinding the inclined surface of the umbrella-shaped portion of a workpiece.

[0005]

SUMMARY OF THE INVENTION A traverse grinding method according to the present invention is characterized in that the traverse grinding method is carried out in a radial direction of the end face along an end face of the work which intersects with the axis of rotation, for example, an end face of the work which is a conical surface around the axis of rotation. When traversing the end surface with the grinding wheel surface of the outer peripheral surface of the grinding wheel being traversed,
The rotational speed of the workpiece is proportional to the radius of the position of the grinding wheel surface in contact with the end surface of the workpiece, and the traverse feed speed of the grinding wheel is proportional to the rotational speed of the workpiece.

A traverse grinding apparatus for carrying out the method includes a workpiece rotation drive device, a grinding wheel whose outer peripheral grinding wheel faces the end face of the workpiece and is driven to rotate. A traverse feed drive for traversing the grinding wheel in the radial direction of the end face, a plunge feed drive for plunge-feeding the grinding wheel in a direction to reciprocate with respect to the end face of the workpiece, and a workpiece rotation drive, a traverse feed drive; It comprises a control device for controlling the plunge feed drive device.

The control device keeps a constant product of the ratio of the diameter of the position of the grinding wheel on the end face of the workpiece to the diameter of the maximum diameter position of the traverse feed multiplied by the rotation speed of the workpiece rotation drive device. In addition to controlling the workpiece rotation drive,
The traverse feed drive is controlled so as to maintain a constant ratio between the feed speed of the traverse feed drive and the rotational speed of the workpiece rotary drive. as a result,
In the traverse grinding of the end face, the peripheral speed of the grinding location is kept constant and the grinding amount is kept constant regardless of the turning radius of the grinding location on the end face.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A traverse grinding apparatus for performing a traverse grinding method according to an embodiment of the present invention will be described with reference to the drawings. In FIG. 1, on a bed 1 is placed a table 2 which can be indexed around a central axis perpendicular to the bed surface and can be slid in the U-axis direction. A work headstock 3 and a tailstock 4 which are opposed to each other on the longitudinal work spindle axis are provided. A traverse feed guide 5 having a guide surface in the Z-axis direction at an appropriate angle with respect to the U-axis is provided on the bed 1.
Is placed.

In the embodiment of the present invention, since the workpiece is a pulley of a continuously variable transmission, and a grinding portion is an inclined tapered surface of the pulley, the Z axis is parallel to the tapered surface. That is, if the traverse feed guide table 5 is provided so that the angle between the Z axis and the U axis is 90 degrees- (the inclination angle θ of the tapered surface), the table 2 becomes 0.
In this position, the grinding can be performed while the work spindle axis is in the U-axis direction. For example, since the inclination angle θ of the tapered surface is, for example, 11 degrees, the angle between the Z axis and the U axis is 79 degrees.

On the traverse feed guide 5, a cut feed guide 6 having a guide surface in the X axis direction orthogonal to the Z axis is provided along the guide surface of the traverse feed guide 5 in the traverse feed direction (Z axis direction). ) Is slidably mounted. Then, on the cutting feed guide table 6, a grindstone table 7 is provided along the guide surface of the cutting feed guide table 6 in the cutting feed direction (X).
(In the axial direction).

The table 2 is a feed servo motor 8 provided on the bed 1, and the cut feed guide table 6 is a feed servo motor 9 provided on the traverse feed guide table 5.
The wheel head 7 is moved in the U-axis direction, the Z-axis direction, and the X-axis direction by a ball screw mechanism driven by a feed servo motor 10 provided on the cutting feed guide table 6.

In the work headstock 3, a center 12 is provided at the tip of the work spindle which is rotationally driven by a spindle servomotor 11.
The work W is supported by the center 12 and the center 13 of the tailstock 4, and is rotated by the rotation transmitting member.

The grindstone table 7 is provided with a grindstone shaft that is orthogonal to the X-axis direction, that is, protrudes toward the table 2 in the X-axis direction, and is rotated by a grindstone motor. The grindstone surface on the outer peripheral surface of the grinding wheel 14 attached to the tip of the grindstone shaft becomes a tapered surface with an appropriate taper angle on the base end side of the grindstone shaft, a tapered angle of 10 degrees in the example shown in the figure, and a subsequent grindstone shaft. On the tip side, it has a cylindrical surface.

Thus, a cut is made at the tapered portion,
Finishing is performed in the cylindrical part. The taper angle may be appropriately changed according to the feed amount in the X-axis direction. The width DH0 of the grinding wheel 14 is the width D of the tapered surface.
Use a thinner than H1. In the present invention, the straightness and the surface roughness of the tapered surface can be more accurately finished by using a grinding wheel whose DH0 is as thin as possible.

The feed servomotors 8, 9, 10 and the spindle servomotor 11 are controlled and driven by a numerical controller 30. The control unit 30 will be described. The numerical control device 30 includes a ROM 31, a RAM 32, a rotation speed control means 33 and a traverse speed control means 34 each having an arithmetic function, and feeds servo motors 8, 9, 10 and a spindle servo motor 11 via an interface 35.
Drive circuits 36, 37, 38, 39 of the numerical controller 3
A connection is made so that a command signal from 0 is input, and a CRT display 40 and an operation panel 41 for inputting a control command for grinding are connected.

Then, each feed servo motor 8, 9, 10
And the spindle servomotor 11 includes drive circuits 36, 37, 3
8 and 39, which are driven by an input therefrom, and are connected so as to input the rotational speed to the numerical controller 30 via the interface 35.

The traverse grinding method according to the embodiment of the present invention will be described together with the operation and operation of the above-described grinding apparatus. First, a workpiece W is supported on the center 12 of the work headstock 3 and the center 13 of the tailstock 4. Workpiece W is
It is a pulley of a continuously variable transmission, and a grinding portion is an inclined tapered surface of the pulley.

The table 2 is indexed and positioned such that the tapered surface is in the Z-axis direction. As described above, when the angle formed by the Z axis with respect to the U axis is 90 degrees-(the inclination angle θ of the tapered surface), for example, 79 degrees, the table 2 is at the 0 position and the work spindle is not positioned. The axis is in the U axis direction. The point of intersection between the cylindrical surface and the tapered surface of the grinding wheel 14 on the XZ plane is point P, and the point of intersection between the cylindrical surface and the tip surface is point Q. (See Fig. 3)

The following data is input to the numerical controller 30 by operating the operation panel 40. Feed coordinates Ua, Za, Xa by feed servo motors 8, 9, 10 at the start of plunge grinding Feed coordinates Ua, Za, Xb by feed servo motors 8, 9, 10 at the end of plunge grinding / traverse grinding At the end of traverse grinding Feed servo motor 8,
Feed coordinates by 9 and 10 Ua, Zb, Xb Diameter of traverse grinding start point of tapered surface da Maximum diameter of tapered surface db Coefficient for determining rotational speed N (peripheral speed of workpiece) A Traverse speed Coefficient for determination B

The operation will be described below with reference to the flowchart of FIG. 2 and the explanatory diagram of FIG. The control operation is started. (Step 1) Data is read in the numerical controller 30. (Step 2) Spindle servomotor 11, initial rotational speed N0 of workpiece W = A · db / da and feed servomotor 9
, The initial traverse feed speed F0 = B
× N operations are performed. (Step 3)

The grinding wheel 14 is driven to rotate by the driving of the grinding wheel motor 7, and the spindle servomotor 11 is driven at an initial rotation speed by the drive circuit 39 based on a command signal from the numerical controller 30. Initial rotation speed N0
Is driven to rotate.

The feed servo motors 8, 9 and 10 are driven by drive circuits 36, 37 and 38 based on a command signal from the numerical controller 30, and the table 4, the cutting feed guide table 6 and the grinding wheel table 7 are used as grinding wheels. Until the point Q of No. 14 comes to a position Q0 close to the position in contact with the minimum diameter side of the sheep surface in the X-axis direction and the point P reaches the position P0, that is, the U-axis feed coordinate is Ua, and the X-axis feed coordinate is Xa Then, the feed is rapidly performed in the U-axis direction, the Z-axis direction, and the X-axis direction until the Z-axis feed coordinate becomes Za. (Step 4)

When the completion of step 4 is confirmed, plunge grinding starts. That is, the feed servomotor 10 is driven by an output from the drive circuit 38 based on a command signal from the numerical controller 30, and the grinding wheel head 7 is cut and fed at a predetermined cutting speed via a ball screw mechanism. 1
Infeed grinding is performed on the grinding wheel surface of the cylindrical surface and the tapered surface of No. 4. (Step 5)

Since only the feed servomotor 10 is driven based on the command signal from the numerical controller 30 and the feed servomotors 8 and 9 are stopped, the U-axis feed coordinates Ua
And the Z-axis feed coordinate Za does not change, only the X-axis feed coordinate changes, the X-axis feed coordinate becomes Xb, and the grinding wheel 14 reaches a predetermined cutting position of the minimum diameter d1 of the sheep surface, that is, the grinding wheel 14 The cutting feed is continued until the point P changes from the position P0 to the position P1 and the point Q changes from the position Q0 to the position Q1, the feed servomotor 10 stops, and the cutting feed stops. (Step 6)

When the completion of Step 6 is confirmed, traverse grinding starts. That is, the feed servomotor 9 is driven by the output from the drive circuit 37 based on the command signal from the numerical control device 30, and the cutting feed guide table 6 and the grinding wheel table 7 are moved to the outer peripheral edge of the tapered surface. Traverse feed is performed only in the axial direction. Thus, traverse grinding is performed on the tapered surface of the grinding wheel 14 and finish grinding is performed on the cylindrical surface. (Step 7)

During the traverse feed, the diameter da of the tapered surface at the point P of the grinding wheel 14 gradually increases. At this time, if the rotational speed N of the workpiece W is constant, the peripheral speed of the tapered surface to be ground is different at each radial position, and the peripheral speed at the point P is changed from the inner peripheral area (small diameter side) to the outer peripheral area. (Large diameter side) gradually increases. Therefore, the rotational speed of the workpiece W is changed in accordance with the position P of the grinding wheel 14 which is changed by the traverse feed of the grinding wheel 14 in order to keep the grinding speed in the circumferential direction of the grinding portion, that is, the peripheral speed constant.

Therefore, in the numerical controller 30, the drive of the spindle servomotor 11 and the rotation speed N of the workpiece W = A ·
The calculation of db / da is performed. (A is a constant value with a coefficient.) That is, traverse grinding is performed by changing the rotation speed N of the workpiece W in accordance with the ratio of db changed by traverse feed to the maximum diameter da of the tapered surface.

Further, by controlling the rotational speed N of the work W by the above equation, the peripheral speed of the work (which becomes slower as the point P moves toward the larger diameter side) becomes constant, but the work moves toward the larger diameter side. Accordingly, the removal amount increases. That is, the workload p (p = F /
If the speed F of traversing the grinding wheel 14 in the Z-axis direction is constant as before despite the increase in N), the load (or grinding resistance) applied to the grinding wheel gradually increases. Therefore, only by controlling the rotational speed of the workpiece W, there are still problems such as a sharp wear of the grindstone and a difference in the finished surface roughness of the workpiece between the large diameter side and the small diameter side.

Further, if the traverse feed amount per one rotation of the workpiece is equal to or larger than the grinding wheel width, uncut parts will be left out, so that a grinding wheel having a too small width cannot be used. Therefore, in order to keep the grinding resistance (work p) constant, that is, the traverse speed per one rotation of the workpiece, the numerical controller 30 drives the feed servomotor 9, that is, the Z-axis direction feed speed F = BN. An operation is performed. (B is a constant value with a coefficient) By this calculation, the traverse feed speed F is changed according to the rotation speed N of the workpiece W to perform traverse grinding. (Step 8)

Since only the feed servo motor 9 is driven based on the command signal from the numerical controller 30 and the feed servo motors 8 and 10 are stopped, the U-axis feed coordinates Ua
The X-axis feed coordinate Xb does not change, and only the Z-axis feed coordinate changes. The traverse feed is continued until the Z-axis feed coordinate becomes Zb, that is, until the diameter da of the tapered surface at the point P during the traverse feed reaches a position P3 exceeding the maximum diameter of the tapered surface. (Step 9)

When the Z-axis feed coordinate reaches Zb, the feed servomotor 9 is stopped based on a command signal from the control device 30, and the traverse feed is stopped. Numerical control unit 3
The spindle servomotor 11 is stopped by the drive circuit 39 based on the command signal from 0, and the feed servomotors 8, 9, and 10 are driven, and the table 4, the cut feed guide table 6, and the grindstone table 7 are moved to their original positions. Return to

In the above-described embodiment, the U-axis is used to change the truer 15 when the grinding wheel 14 is dressed.
Although the axis is used when it is located on the front surface of No. 4, the U axis may not be provided if it can be replaced by the Z axis and the X axis. Further, in the above embodiment, the table 2 is supported so as to be able to turn around an axis perpendicular to the bed surface, but the traverse feed guide table 5 is supported so as to be able to turn around the vertical axis with respect to the bed 1. You may. (Step 10)

[0033]

According to the traverse grinding method carried out by the traverse grinding apparatus of the present invention, the grinding wheel is traversed in the radial direction of the workpiece, and the grinding portion on the end face of the rotating workpiece moves in the radial direction. However, regardless of the radius of gyration, the peripheral speed at the location is kept constant, and the grinding amount and the grinding resistance are kept constant.

Accordingly, the wear of the grinding wheel surface, which is the outer peripheral surface of the grinding wheel, is not biased, so that the life of the grinding wheel is extended, and the straightness and the inclination angle of the inclined surface of the workpiece are accurately maintained over the entire surface. Is done. In addition, since the surface roughness of the ground surface of the workpiece becomes uniform in addition to the uniformity of the straightness and the inclination angle, the processing accuracy is improved.

[Brief description of the drawings]

FIG. 1 is a plan view of a traverse grinding device and a block diagram of a numerical control device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a control operation of the traverse grinding device according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram of an operation of a grinding wheel of the traverse grinding device according to the embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 bed 2 table 3 work headstock 4 tailstock 5 traverse feed guide table 6 cutting feed guide table 7 grinding wheel table 8, 9, 10, 11 feed servo motor 12, 13 center 14 grinding wheel 30 numerical controller 31 ROM 32 RAM 33 rotation speed control means 34 traverse speed control means 35 interface 36,37,38,39 drive circuit 40 CRT display 41 operation panel W workpiece

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Yoshihiro Soake, 1-1-1, Asahi-machi, Kariya-shi, Aichi, Japan Toyota Machine Works Co., Ltd. (72) Takami Yoshimi 1-1-1, Asahi-cho, Kariya-shi, Aichi Toyoda Machine F term within the company (reference) 3C034 AA01 BB32 CB02 3C049 AA03 AA11 AB06 BA02 BA04 BB02 BB06 BB08 BB09 BC02 CB01

Claims (4)

[Claims] 1. A rotating speed of a workpiece when traversing said end face with a grinding wheel surface on an outer peripheral surface of a grinding wheel which is traversely fed in a radial direction of the end face along an end face of the workpiece which intersects with the rotation axis. A traverse grinding method in which the traverse feed speed of a grinding wheel is proportional to the radius of the position of the grinding wheel surface in contact with the end surface of the workpiece, and the traverse feed speed of the grinding wheel is proportional to the rotation speed of the workpiece. 2. A workpiece rotation driving device, a grinding wheel whose outer peripheral surface is grinded and opposed to an end face of the workpiece, and a traverse feed of the grinding wheel in a radial direction of the end face along the end face of the workpiece. Traverse feed drive device, plunge feed drive device for plunge-feeding the grinding wheel in the direction to advance and retreat with respect to the end face of the workpiece, and control device for controlling the workpiece rotation drive device, traverse feed drive device and plunge feed drive device The control device is configured to maintain a constant product of the ratio of the diameter of the position of the grinding wheel on the end surface of the workpiece to the diameter of the maximum diameter position of the traverse feed multiplied by the rotation speed of the workpiece rotation drive device. The traverse feed drive device is controlled so that the ratio of the feed speed of the traverse feed drive device to the rotation speed of the work rotary drive device is kept constant. A traverse grinding device characterized by controlling. 3. The traverse grinding method according to claim 1, wherein the end surface of the workpiece is a conical surface around the rotation axis. 4. The traverse grinding device according to claim 2, wherein the end surface of the workpiece is a conical surface around the rotation axis.