JP2005088167A - Grinding method and grinding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grinding method and a grinding device capable of miniaturizing and simplifying a periphery of a main spindle and reducing influence of irregularity in an outer peripheral part dimension on a grinding surface dimension even if an inner peripheral surface or an outer peripheral surface is ground with the outer peripheral part dimension of work as a standard. <P>SOLUTION: The grinding device has an upper roll 2a, a lower roll 2b, a shoe 3 as a holding means for holding and rotating the substantially circular work W, a grinding means abutting on a peripheral surface of the work W and capable of making a cut along a diameter direction of the work W, and a measuring means 4 for obtaining difference between the outer peripheral part dimension as the standard of the work W and a preset master value. A correction value is obtained by the measuring means 4, and an amount of movement (cut) of the grinding means is corrected based on the correction value. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a grinding method and a grinding device for grinding a grinding surface such as an outer peripheral portion and an inner peripheral portion of a substantially annular workpiece.

2. Description of the Related Art Conventionally, a grinding apparatus that grinds a grinding surface (for example, an inner periphery) of a substantially annular workpiece has been widely known (see, for example, Patent Document 1). In addition, although an annular | circular shaped workpiece | work mainly points out that a diameter is larger than an axial length here, a diameter may be the same as an axial length or a cylindrical thing whose diameter is smaller than an axial length is also contained.
Further, examples of the grinding surface of the substantially annular workpiece include an inner ring surface and an outer ring surface of the outer ring and inner ring constituting the bearing, an outer ring groove of the outer ring, an inner ring groove of the inner ring, and the like.

  In this grinding apparatus, when grinding the inner peripheral surface, which is a grinding surface of a workpiece, the workpiece is supported and rotated by, for example, a two-roll one shoe or a shoe centerless method using a magnet chuck and a plurality of shoes, And while inserting the surrounding surface of a rotating grindstone into the inner side of a workpiece | work and contacting an inner peripheral surface, a rotating grindstone is cut along the radial direction of a workpiece | work.

This grinding apparatus cuts the rotating grindstone while directly measuring the inner diameter of the inner peripheral surface, which is the grinding surface of the workpiece, with an in-process gauge inserted inside the workpiece.
If the dimensions of the ground surface before grinding are varied, a command based on the measured value of the in-process gauge is given to a drive means such as a servomotor that moves (cuts) the rotating grindstone. In this way, the inner diameter of the inner peripheral surface (grinding surface) after grinding is not varied.
JP-A-4-310368

  However, in Patent Document 1 described above, in order to directly measure the inner diameter dimension of the ground surface, it is necessary to insert an in-process gauge inside the workpiece, which disadvantageously increases the size and complexity of the spindle.

In order to eliminate such an inconvenience, a method of grinding an inner peripheral surface which is a grinding surface based on the outer peripheral portion dimension of the work is considered. In this case, the stop position of the rotating grindstone that grinds the inner peripheral surface is fixed at the position from the outer peripheral portion (for example, the outer peripheral surface and the groove). In other words, the moving amount (cutting amount) of the rotating grindstone is constant.
In this method, since the dimension from the outer peripheral part to the ground surface after grinding is constant, when processing a large number of workpieces in succession, if the outer peripheral dimension used as a reference for each work is the same, The inner diameter of the ground surface after processing is the same.

However, the method of grinding the inner peripheral surface based on the outer diameter dimension has the following problems when a large number of workpieces are sequentially processed.
That is, in this method, it is assumed that the outer peripheral dimensions used as references for each workpiece are all the same specified value, but in reality, the outer peripheral dimensions of each workpiece are within the allowable error range with respect to the specified value. Randomly large or small diameter. In other words, these workpieces are individually dispersed in the range of the permissible error with respect to the predetermined value in the outer peripheral dimension.
Therefore, when the inner peripheral surface is ground with the stop position of the rotating grindstone fixed as a reference based on the outer peripheral portion dimensions of these workpieces, the dimension from the outer peripheral portion to the inner peripheral surface after processing is constant, but the outer peripheral portion dimensions There is a problem that the size of the ground surface (inner peripheral surface) after processing varies from workpiece to workpiece due to the variation of the workpiece.

  Further, when the outer peripheral portion is ground on the basis of the outer peripheral dimension before processing of the substantially annular workpiece, the above-described problem is similarly caused if the stop position of the rotating grindstone is fixed.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to reduce the size and simplification of the main shaft for grinding a grinding surface of a substantially annular workpiece, and to provide an outer peripheral portion of the workpiece. It is an object of the present invention to provide a grinding method and a grinding apparatus capable of reducing the influence of variation in the outer peripheral dimension serving as a reference even when the workpiece is ground on the basis of the dimension.

  In order to achieve the above-described object, the grinding method of the present invention cuts the grinding means that is in contact with the grinding surface of the workpiece along the radial direction of the workpiece while rotating the substantially annular workpiece. A grinding method for grinding the peripheral surface by determining the difference between the outer peripheral dimension serving as a reference of the workpiece and a preset master value by the measuring means, and measuring the measuring means The cutting amount of the grinding means is corrected based on the value.

  Further, the grinding apparatus of the present invention includes a holding means for holding and rotating a substantially annular workpiece, and a grinding means that comes into contact with a grinding surface of the workpiece and can be cut along a radial direction of the workpiece. A grinding device having a measuring means for measuring a dimension of an outer peripheral portion serving as a reference of the workpiece, and cutting the grinding means based on a difference between a measured value of the measuring means and a preset master value. It is characterized by correcting the loading amount.

Here, as the outer peripheral portion dimension, the diameter dimension of the outer peripheral surface of the annular workpiece may be employed, but for example, the diameter dimension at the bottom of the groove formed along the circumferential direction of the outer peripheral surface may be employed. In short, it is the diameter of the outside of the workpiece that serves as a reference when processing the ground surface of the workpiece.
On the other hand, the grinding surface includes an outer peripheral surface, an inner peripheral surface, and a groove formed along the circumferential direction of the outer peripheral surface or the inner peripheral surface.
That is, in the present invention, for example, when the workpiece is an outer ring or an inner ring of a bearing, a groove is preliminarily processed by a machine tool such as a lathe along the circumferential direction of the inner circumferential surface or outer circumferential surface of the workpiece. It is also applicable to.

In the grinding method and the grinding machine configured as described above, in order to correct the cutting amount of the grinding means based on the difference between the outer peripheral dimension serving as a workpiece reference and the master value, for example, a large number of workpieces. Even in the case where the outer peripheral part dimensions vary individually, the dimensions of the ground surface are not affected as in the prior art.
Further, in the grinding method and the grinding device as described above, it is not necessary to insert an in-process gauge inside the workpiece as in the prior art, so that the size around the main shaft can be reduced and simplified.

Next, the grinding method of the present invention is characterized in that the workpiece is held by two rolls and one shoe, and the moving amount of the two rolls whose position is not fixed is measured by the measuring means. To do.
In the grinding apparatus of the present invention, the holding means is a two-roll one shoe, and the measuring means measures a movement amount of the two rolls whose position is not fixed. .

According to the present invention, since there is no need to insert an in-process gauge inside the workpiece, the periphery of the main shaft can be reduced in size and simplified.
Further, according to the present invention, since the cutting amount of the grinding means is corrected based on the difference between the outer peripheral dimension serving as a reference of the workpiece and a preset master value, the outer peripheral dimension of the workpiece varies. The influence of the variation in the outer peripheral dimension of the workpiece can be reduced with respect to the radial dimension of the ground surface (inner diameter surface, outer peripheral surface) after the workpiece is ground.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, the grinding device according to the first embodiment of the present invention includes an upper roll 2 a that contacts an outer peripheral surface of a workpiece W in order to grind a grinding surface of a substantially annular workpiece W. A shoe centerless system having a two-roll one-shoe structure including a lower roll 2b and a shoe 3 is employed.
The upper roll 2a whose position is not fixed moves to the lower roll 2b and the shoe 3 by moving in a radial direction shifted by an angle α with respect to a line passing through the center of the upper roll 2a and the center of the lower roll 2b. On the other hand, it is possible to approach and separate.

The position of the work W is fixed in a state where the outer peripheral surface is pressed against the lower roll 2b and the shoe 3 by the upper roll 2a, and the work W is rotated by driving the lower roll 2b.
The workpiece W mainly refers to a workpiece having a diameter larger than the axial length, but also includes a cylindrical workpiece having a diameter that is the same as the axial length or a diameter that is smaller than the axial length.
Further, the grinding surface of the workpiece W can be exemplified by, for example, when the workpiece is an outer ring and an inner ring constituting a bearing, an inner ring surface and an outer ring surface of the outer ring and the inner ring, an outer ring groove of the outer ring, an inner ring groove of the inner ring, and the like. .

The grinding apparatus supports a work W by an upper roll 2a, a lower roll 2b, and a shoe 3 and rotates the grindstone, which is a grinding means that is brought into contact with an inner peripheral surface that is a grinding surface of the work W. The inner peripheral surface, which is a grinding surface, is ground by cutting a not shown) to a predetermined stop position along the radial direction of the workpiece W.
In addition, in this 1st Embodiment, although the internal peripheral surface is illustrated as a grinding surface, as a grinding surface in this invention, along the circumferential direction of the internal peripheral surface of the workpiece | work W with a machine tool, such as a lathe, previously. A pre-processed groove is also applicable.

Here, in the first embodiment, for example, a measuring instrument (measuring means) 4 such as an electric micrometer is installed so as to contact a guide member that guides the movement of the upper roll 2a.
The measuring device 4 measures the moving distance along the moving direction of the upper roll 2a.

Then, the grinding device calculates a difference between the outer peripheral dimension of the workpiece W and a preset master value by the measuring device 4 in a state where the workpiece W is supported by the upper roll 2a, the lower roll 2b, and the shoe 3. .
Here, as the outer peripheral portion dimension in the first embodiment, for example, the diameter dimension of the outer peripheral surface of the workpiece W may be adopted, but for example, the bottom of a groove (inner ring groove) formed along the circumferential direction of the outer peripheral surface. In other words, it is a diameter dimension on the outer side of the workpiece that serves as a reference when the grinding surface (inner peripheral surface) of the workpiece W is processed.
As a result, the variation amount or approximate value of the total error of the outer peripheral dimension of the workpiece W with respect to the preset master value is calculated.

In addition, the following can be considered as a specific method for setting a master value and a method for calculating a variation amount or an approximate value of the total error of the outer peripheral dimension of the workpiece W.
For example, as shown in FIG. 2, a measuring instrument is mounted in a state in which a master work MW that has been machined to a desired outer peripheral dimension without error is mounted on a grinding apparatus and the upper roll 2 a is in contact with the outer peripheral part of the master work MW. 4 (not shown) is set to 0, and then the master work MW is removed from the grinding apparatus, and then the work W to be ground is actually mounted on the grinding apparatus. If the upper roll 2a is brought into contact with the outer peripheral portion, the outer diameter of the work W to be ground on the grinding surface (inner peripheral surface) is larger or smaller than the master value. Is obtained by the measuring device 4 as a positive value or a negative value.
Then, a command based on a correction value calculated from the positive value or the negative value described above is given to a driving means such as a servomotor that moves (cuts) the rotating grindstone as a grinding means. Control may be performed to cut to the stop position.

For example, as a result of measuring the workpiece W having a diameter larger than the master value with the measuring device 4, whether the difference from the master value is a positive value or a negative value is determined by the measuring device 4 It depends on the installation form (location, orientation, etc.).
For this reason, what is necessary is just to select the installation form of the measuring device 4 arbitrarily.

  In addition, as another method of calculating the variation amount or approximate value of the total error of the outer peripheral portion dimension of the workpiece W, when grinding the grinding surfaces (inner circumferential surfaces) of many workpieces one after another, the first workpiece From the n + 1th workpiece to the nth workpiece (for example, the 10th workpiece), the average value of the outer circumference is measured as the master value. Grinding may be applied to the ground surface (inner peripheral surface) based on the correction value calculated according to the difference between the two.

Further, a plurality of workpieces that have been previously ground from the n-th workpiece to be ground, that is, in the case of 10 workpieces (for example, the n-10th workpiece to the (n-1) th workpiece). You may grind to the grinding surface (inner peripheral surface) of a workpiece | work by making the average value of an outer peripheral part dimension into a master value. In this case, the master value is not constant but fluid.
This method has an effect that it can flexibly cope with the temperature of the grinding apparatus itself, the ambient temperature, humidity and the like.

The measurement value obtained by the measuring instrument 4 directly shows the variation amount or approximate value of the outer peripheral dimension of the workpiece W, and the correction value for the movement amount of the grinding means can be obtained by, for example, | k × measurement value | (k: correction coefficient). .
In accordance with the variation amount or approximate value of the total error calculated as described above, a correction value for correcting the movement amount (cutting amount) of the grinding means is obtained, and this correction value is output to the drive circuit of the moving mechanism of the grinding means. . Thereby, even if the outer peripheral dimension of each workpiece W varies individually, the movement amount (cutting amount) of the grinding means, in other words, the cutting end point (stop position) is individually set according to these variations. The

Specifically, when the outer peripheral dimension of the workpiece W is larger than the master value, the moving amount (cutting amount) of the grinding means is set small. Accordingly, although the dimension from the outer peripheral portion serving as a reference to the ground surface (inner peripheral surface) is increased, the size of the ground surface that is extremely close to a desired value can be obtained.
On the other hand, when the outer peripheral dimension of the workpiece W is smaller than the master value, the movement amount (cutting amount) of the grinding means is set to be large. Therefore, although the dimension from the outer peripheral portion serving as a reference to the ground surface (inner peripheral surface) becomes small, the size of the ground surface that is extremely close to the desired value can be obtained.

  According to the above-described grinding apparatus, the measuring device 4 performs grinding by correcting the movement amount (cutting amount) of the grinding means based on the difference between the outer peripheral dimension which is the reference of the workpiece W and a preset master value. Since the machined surface (inner peripheral surface) is ground, it is not necessary to insert an in-process gauge inside the workpiece W as in the prior art, thereby eliminating the inconvenience of increasing the size and complexity of the spindle.

In addition, this grinding apparatus uses the measuring device 4 to calculate the grinding surface, that is, the inner peripheral surface of the workpiece W based on the correction value calculated based on the variation amount or approximate value of the total error of the outer peripheral portion dimension of the workpiece W with respect to the master value. Alternatively, the moving mechanism of the grinding means for grinding the outer peripheral surface is controlled.
Therefore, even when there is variation in the outer peripheral dimension that is the reference for the workpiece W, the movement amount (cutting amount) of the grinding means, in other words, the cutting end point (stop position) is individually set according to this variation. Thus, it is possible to reduce the possibility that the variation occurring in the outer peripheral dimension serving as a reference affects the dimension of the ground surface (inner peripheral surface).

(Example)
Next, when the grinding device of FIG. 1 is used to grind the inner circumferential surface, which is a grinding surface, with a rotating grindstone on the basis of the outer circumferential portion dimensions for 100 annular workpieces W, the correction of the present invention is performed. A comparative example and an example will be described with respect to the difference in variation width generated on the ground surface (inner peripheral surface) depending on whether or not there is.
That is, in the comparative example, the correction of the present invention was not performed, that is, the moving amount (cutting amount) of the rotating grindstone was made constant, and the grinding process of the inner peripheral surface was completed with the cutting end position (stop position) fixed. The result is shown in FIG.
On the other hand, in the embodiment, the correction of the present invention was performed, that is, the movement amount (cutting amount) of the rotating grindstone was individually set based on the outer peripheral portion dimension, and the grinding of the inner peripheral surface was completed. The result is shown in FIG.

  The variation referred to here is the amplitude from the maximum value to the minimum value of the inner diameter of the inner peripheral surface, which is a grinding surface, and is not directly related to the target size (desired value in design).

  As is apparent from FIGS. 7 and 8, the embodiment of FIG. 8 in which the correction of the present invention is corrected is significantly less varied and stable than the comparative example of FIG. 7 in which the correction of the present invention is not performed. You can see that

  The grinding apparatus of the present invention is not limited to the above-described embodiment, and appropriate modifications and improvements can be made.

With reference to FIG. 3 and FIG. 4, the grinding apparatus which is the 2nd and 3rd embodiment which concerns on this invention is demonstrated.
In each embodiment described below, members and the like already described in FIG. 1 are given the same or corresponding reference numerals in the drawing to simplify or omit the description.

As shown in FIG. 3, grinding apparatus according to a second embodiment of the present invention, the upper roll 2a is turning upper roll 2a is pivotally supported by the arm 5 and an intermediate portion of the arm 5 as a fulcrum O ₁ This is an example of exercise.
In this case, the measuring instrument 4 is installed on the opposite side of the upper roll 2 a with the fulcrum O ₁ in the arm 5 interposed therebetween.
And the outer peripheral part dimension which is the reference | standard of the workpiece | work W is measured with the measuring device 4 in the state which pressed the workpiece | work W against the upper roll 2a and the shoes 3 with the upper roll 2a, and the preset master value and the measured value of the measuring device 4 Based on the difference, the moving amount (cutting amount) of the rotating grindstone as the grinding means is corrected.

In the second embodiment, the diameter Db of the workpiece W is sufficiently smaller than the diameter Da of the upper roll 2a, and the plus or minus error of the inner diameter dimension of the grinding surface of the workpiece W with respect to a preset master value. since sufficiently smaller than the diameter Da of the upper roll 2a, the fulcrum O ₁ - between the centers of the upper roll 2a distance L ₁ and the fulcrum O ₁ - from the ratio of the measurement point distance L ₂ of the measuring device 4 of the grinding means The correction value for the movement amount = | (L ₁ / L ₂ ) × measured value × k |.
In addition, about an effect, since it is substantially the same as 1st Embodiment, description is abbreviate | omitted.

As shown in FIG. 4, in the grinding apparatus according to the third embodiment of the present invention, the upper roll 2 a is supported by the arm 6 so as to be able to turn, and the upper roll 2 a turns around the fulcrum O _{2 of the} arm 6. This is an example in which the measurement point arm 7 protrudes downward from the lower surface of the arm 6 at a position slightly moving from the fulcrum O _{2 of the} arm 6 toward the upper roll 2a side.

In this case, the measuring instrument 4 is installed on the surface on the side away from the lower roll 2b of the lower end of the measuring point arm 7.
Then, with the workpiece W pressed against the lower roll 2b and the shoe 3, the outer peripheral dimension serving as a reference of the workpiece W is measured by the measuring instrument 4, and the difference between the preset master value and the measured value of the measuring instrument 4 is determined. Based on this, the movement amount of the rotating grindstone as the grinding means is corrected.

Also in the case of the third embodiment, the diameter Db of the workpiece W is sufficiently smaller than the diameter Da of the upper roll 2a, and the master value of the diameter of the workpiece W after processing is the same as in the second embodiment described above. error dimension from, because enough compared to the diameter Da of the upper roll 2a small, the fulcrum O ₂ - center distance of the workpiece W L ₃ and the fulcrum O ₂ - interval measurement point distance L ₄ and the fulcrum O ₂ - measurement points correction value from between the distance L ₅ Noto ratio _{= | L 3 / {(L} 4) 2 + (L 5) 2} -1/2 × measured value × k | in sought.

Further, when L ₅ is sufficiently longer than L ₄ , sin θ (θ: rotation angle of arm 7) = measured value / L ₅ , correction value = | sin θ × L ₃ × k | = | (L ₃ / L ₅ ) × measured value × k | can be approximated. The correction value is a positive value or a negative value depending on the position and orientation of the measuring device 4.
In addition, about an effect, since it is substantially the same as 1st Embodiment, description is abbreviate | omitted.

Note that FIG. 5 is a shoe centerless type internal grinding machine using a magnet chuck and a plurality of shoes 3, for example, and the contact or non-contact type measuring device 4 is used to measure the outer circumference of the reference workpiece W. Then, the measured value is compared with a preset master value to obtain a correction value, and the moving amount of the rotating grindstone 10 as a grinding means is corrected.
The measurement value obtained by the measuring instrument 4 shows the variation in the outer peripheral part size of the workpiece W as it is, and the correction value for the movement amount of the rotating grindstone 10 of the grinding means can be obtained by | k × measured value |.

FIG. 6 is a shoe centerless type outer surface grinding machine using a magnet chuck and a plurality of shoes 3, and measures the outer peripheral portion dimension of a reference workpiece W with a contact type or non-contact type measuring instrument 4. The measured value is compared with a preset master value to obtain a correction value, and the movement amount of the rotating grindstone 10 as a grinding means is corrected to grind the outer peripheral surface as a grinding surface.
Also in this case, the measurement value obtained by the measuring instrument 4 shows the variation in the outer peripheral portion dimension of the workpiece W as it is, and the correction value for the movement amount of the grindstone 11 of the grinding means can be obtained by | k × measurement value |.

The present invention can also be applied to a case where a groove (inner ring groove) formed along the outer peripheral surface of the inner ring constituting the bearing is ground by a shoe centerless system having a two-roll one-shoe structure.
In addition, the materials, shapes, dimensions, forms, numbers, placement locations, etc. of the rotating shaft, the pair of rolls, the workpiece, the grinding means, the measuring means, the shoe, etc., exemplified in the above-described embodiments can achieve the present invention. It is arbitrary and is not limited.

It is explanatory drawing for demonstrating the grinding device which is 1st Embodiment which concerns on this invention. It is a figure which shows an example which sets a master value. It is explanatory drawing for demonstrating the grinding device which is 2nd Embodiment which concerns on this invention. It is explanatory drawing for demonstrating the grinding device which is 3rd Embodiment which concerns on this invention. It is explanatory drawing for demonstrating the example in the case of measuring the outer peripheral part dimension of the workpiece | work used as a reference | standard with a contact-type or non-contact-type measuring device in the internal-grinding machine of the structure by a magnet chuck and a some shoe. It is explanatory drawing for demonstrating the example in the case of measuring the outer peripheral part dimension of the workpiece | work used as a reference | standard with a contact-type or non-contact-type measuring device in the outer surface grinding machine of a structure by a magnet chuck and a some shoe. It is a graph which shows the relationship of the internal diameter dimension after a process with respect to the number of process of a workpiece | work and a master value in a comparative example (no correction | amendment). It is a graph which shows the relationship of the internal diameter dimension after a process with respect to the number of process of a workpiece | work and a master value in a comparative example (with correction | amendment).

Explanation of symbols

2a Upper roll 2b Lower roll 3 Shoe 4 Measuring instrument (measuring means)
W Work

Claims (4)

A grinding method for grinding a grinding surface by rotating a substantially annular workpiece while cutting a grinding means in contact with the grinding surface of the workpiece along a radial direction of the workpiece. Because
Grinding characterized in that a difference between an outer peripheral dimension serving as a reference of the workpiece and a preset master value is obtained by a measuring means, and a cutting amount of the grinding means is corrected based on a measured value of the measuring means. Processing method.   2. The grinding method according to claim 1, wherein the workpiece is held by two rolls and one shoe, and a moving amount of the two rolls whose position is not fixed is measured by the measuring unit. A grinding apparatus having a holding means for holding and rotating a substantially annular workpiece, and a grinding means that comes into contact with a grinding surface of the workpiece and can be cut along a radial direction of the workpiece,
A measuring means for measuring an outer peripheral dimension serving as a reference of the workpiece; and correcting a cutting amount of the grinding means based on a difference between a measured value of the measuring means and a preset master value. To grind.   The grinding apparatus according to claim 3, wherein the holding means is a two-roll one shoe, and the measuring means measures a movement amount of the two rolls whose position is not fixed.

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