JP5251429B2 - Grinder - Google Patents

Description

  The present invention relates to a grinding machine that sequentially grinds a plurality of substantially cylindrical workpieces.

A conventional grinding machine that carries in a substantially cylindrical workpiece, grinds the workpiece of the workpiece to a target dimension, unloads the finished workpiece, and grinds the workpiece one after another. A workpiece measuring means (so-called sizing device) for measuring the dimensions of the machining location is provided.
In general, the processing accuracy of the grinding machine is very high such as several tens of μm, and the sensitivity of the workpiece measuring means is also set very high in order to ensure the processing accuracy. However, if workpieces are ground one after another after starting grinding on the grinding machine, the environmental temperature will gradually rise and temperature drift will occur, and the error of the measurement value by the workpiece measuring means will gradually increase. Tend. As shown in FIG. 4A, the measurement error due to the temperature drift has a large change at the beginning, gradually decreases, and finally tends to be saturated.
Therefore, in a conventional grinding machine, a workpiece measurement unit measures a previously prepared master workpiece at a predetermined timing before the error exceeds the allowable value Emax (see FIG. 7A), and measures the workpiece. So-called zeroing is performed to correct the error of the means (see FIG. 7B).
Hereinafter, measuring a master workpiece by the workpiece measuring means and performing zeroing is referred to as “mastering”.

For example, in the prior art described in Patent Document 1, a master work prepared outside the grinding machine is carried into the grinding machine instead of the work at a predetermined time interval, and after mastering, the master work is taken out. The work to be processed next is carried in. In this way, mastering is performed at predetermined time intervals before the error of the measurement value of the workpiece measurement means exceeds the allowable value.
As another conventional technique, every time a predetermined number of workpieces are processed, a master work prepared outside the grinding machine is carried into the grinding machine instead of the work, and after mastering, the master work is taken out, There is also a method of carrying in a workpiece to be processed next (for example, mastering is performed every first, second, fifth, tenth, and tenth).
JP 61-65771 A

If the number of times of mastering increases, the processing cycle time becomes longer and the processing efficiency decreases. Therefore, it is preferable that the number of mastering times is small.
However, in the conventional technique described in Patent Document 1, since mastering is performed at a predetermined time interval, there is a possibility that mastering is performed even though mastering is not yet required, and processing efficiency is reduced. there is a possibility.
Also, the method of performing mastering every time a predetermined number of workpieces are processed, as in Patent Document 1, there is a possibility of performing mastering even though it is not necessary to perform mastering yet, which may reduce the processing efficiency. is there.
The present invention was devised in view of such points, and appropriately avoids mastering more than necessary by appropriately determining the timing at which mastering is necessary, and shortens the time for performing mastering. It is an object of the present invention to provide a grinding machine that can further improve the processing efficiency.

As means for solving the above problems, a first invention of the present invention is a grinding machine as set forth in claim 1.
The grinding machine according to claim 1 is configured to grind the workpiece by moving the workpiece support means when the workpiece grinding process is completed (when the measurement value by the workpiece measurement means reaches a target value). Or when the position of the processing tool (when the processing tool moves to grind the workpiece) is out of the allowable position range, it is determined that mastering is necessary and mastering is performed.

The second invention of the present invention is a grinding machine as set forth in claim 2.
In the grinding machine according to claim 2, before or after grinding a new workpiece, a position at which the previous or current workpiece has been ground and a position at which the workpiece has been ground immediately after the previous mastering is performed. It is determined whether or not the mastering is necessary. In an ideal state, even if the workpiece is ground one after another, it should end at the same position almost every time. However, the error of the measured value of the workpiece measuring device 40 gradually increases due to the environmental temperature gradually increasing. When changing, the position at the completion of grinding of the workpiece also changes gradually. This positional shift is used for determining the mastering timing.

The third invention of the present invention is a grinding machine as set forth in claim 3.
In the grinding machine according to claim 3, the master work is not provided outside the grinding machine but is provided at one of the work supporting means inside the grinding machine and at a position coaxial with the work. .

Moreover, the 4th invention of this invention is a grinding machine as described in Claim 4.
In the grinding machine according to claim 4, when the first workpiece is ground immediately after turning on the power of the grinding machine, or the power is turned on, the workpiece is left without being processed for a while and the environmental temperature is lowered. Mastering is performed when grinding the first workpiece from the state.

  If the grinding machine according to claim 1 is used, the position of the workpiece support means (when the workpiece support means moves and the workpiece is measured when the workpiece grinding is completed (when the measurement value by the workpiece measurement means reaches the target value)). Or the position of the machining tool (when the machining tool moves to grind the workpiece), the timing at which mastering is required compared to a predetermined time interval, a predetermined number of machining operations, etc. Can be determined more appropriately, and it is possible to avoid the mastering more than necessary and further improve the processing efficiency.

  According to the grinding machine of the second aspect, the current or next workpiece is ground from the amount of change between the position when the previous mastering is performed and the position when the previous or current workpiece is completely ground. It can be appropriately determined whether or not mastering is necessary before.

  Further, according to the grinding machine of the third aspect, since the master work is close to the work and coaxial with the work, the moving distance of the work measuring means can be greatly shortened when performing mastering. Therefore, the mastering time can be made very short, and the processing efficiency can be further improved.

In addition, according to the grinding machine of the fourth aspect, the mastering timing is determined using the position when the grinding of the workpiece is completed. Mastering can be done.
In addition, although it is not the first workpiece, the mastering can be appropriately performed even when grinding of the workpiece is resumed from a state where the ambient temperature is lowered after being left for a while.

The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 shows a plan view (FIG. 1 (A)) and a perspective view (FIG. 1 (B)) of an example of a workpiece W in an embodiment of a grinding machine 1 of the present invention.
Hereinafter, a first embodiment which is an example of a grinding machine for grinding a cylindrical surface of a substantially cylindrical workpiece W, and a grinding machine for grinding an end surface (a surface orthogonal to the workpiece rotation axis) of the substantially cylindrical workpiece W. A second embodiment as an example will be described.
In all drawings in which the X axis, Y axis, and Z axis are described, the X axis, the Y axis, and the Z axis are orthogonal to each other, and the X axis direction (corresponding to the intersecting direction) is the workpiece rotation axis WZ. An orthogonal horizontal direction is shown, the Y-axis direction is a vertically upward direction, and the Z-axis direction (corresponding to a parallel direction) is the direction of the workpiece rotation axis WZ.
In the following description, the X-axis direction is a direction orthogonal to the workpiece rotation axis WZ, but the X-axis direction may be a direction that intersects without crossing the workpiece rotation axis WZ.

●● [First embodiment (FIGS. 1 to 4)]
● [Schematic configuration of the grinding machine 1 and the part of the workpiece W to be processed (FIGS. 1 and 2)]
The configuration of the grinding machine 1 according to the first embodiment will be described with reference to FIG. An example of a workpiece W to be ground by the grinding machine 1 is shown in FIG. The workpiece W has a substantially cylindrical shape, and in the first embodiment, the part to be processed of the workpiece W is the cylindrical surface KE, and the cylindrical surface KE is ground using the processing tool T.

As shown in FIG. 1A, the grinding machine 1 includes a spindle device 10, a tailstock device 20, a tool device 30, a workpiece measuring device 40 (a so-called sizing device, corresponding to a workpiece measuring means), and a control device 50. (Corresponding to control means).
The spindle device 10 includes a center member 10 a and a spindle 12 coaxially with respect to the workpiece rotation axis WZ. The center member 10 a supports the workpiece W, and the spindle 12 is accommodated in the spindle stock 11. The main shaft 12 and the center member 10a rotate based on a control signal from the control device 50. The rotation of the main shaft 12 is transmitted to the workpiece W via the connecting member 13.
The tailstock device 20 includes a center member 20a, a ram 22 that accommodates the center member 20a and can reciprocate in the Z-axis direction, and a tailstock 21 that accommodates the ram 22. The center member 20a is a workpiece. It can freely rotate around the rotation axis WZ.
In the example of FIG. 1A, a master work MW is provided on the center member 20a coaxially with the work rotation axis WZ.
The workpiece W is supported by a pair of spindle devices 10 and tailstock devices 20 (corresponding to a pair of workpiece support means) provided with a pair of center members 10a and 20a at both ends, and rotates around the workpiece rotation axis WZ. Be made.
In the example of FIG. 1A, the spindle device 10 and the tailstock device 20 are attached to the base 2 (see FIG. 2A).
The control device 50 includes a numerical control device 51, a sequencer 52, a sizing amplifier 53, a Z-axis servo amplifier 54, and an X-axis servo amplifier 55. The sequencer 52 (PLC, etc.) The description will be omitted, and others will be described later.

The tool device 30 can be reciprocated in the Z-axis direction on the base 2 (see FIG. 2A) by a ball screw NZ provided in the Z-axis direction that is rotated by a motor M31 (corresponding to a relative movement means). Tool table 31, motor M32 (corresponding to relative movement means) provided on tool table 31, and ball screw NX provided in the X-axis direction rotated by motor M32, in the X-axis direction on tool table 31 A cutting table 32 capable of reciprocating movement and a grinding wheel T (corresponding to the processing tool T) provided on the cutting table 32 and rotating around the grinding wheel rotation axis TZ are configured.
The control device 50 (numerical control device 51) takes in a detection signal from an encoder or the like (corresponding to position detection means) provided in the motor M31 via the Z-axis servo amplifier 54, and the position of the grindstone T in the Z-axis direction. Can be detected, and a control signal can be output to the motor M31 via the Z-axis servo amplifier 54 to move the position of the grindstone T in the Z-axis direction to an arbitrary position. Further, a detection signal from an encoder or the like (corresponding to position detection means) provided in the motor M32 can be taken in via the X-axis servo amplifier 55 to detect the position of the grindstone T in the X-axis direction. A control signal can be output to the motor M32 via the servo amplifier 55 to move the position of the grindstone T in the X-axis direction to an arbitrary position.

Next, the workpiece | work measuring apparatus 40 is demonstrated using FIG. 1 (A) and FIG. 2 (A). The workpiece measuring device 40 is a device that measures the dimension of the workpiece W of the workpiece W. In the first embodiment, the workpiece W of the workpiece W is the cylindrical surface KE, so the diameter of this cylindrical surface is measured. It is a device to do.
As shown in FIG. 2A, the workpiece measuring device 40 can move forward and backward in the X-axis direction by the arm 43 attached to the tool table 31, the cylinder 44 provided at the end of the arm 43, and the cylinder 44. The measurement main body 41, a pair of fingers 42 extending from the measurement main body 41, and a pair of contacts 42s provided at the tips of the fingers 42 and in contact with the workpiece W are provided.
The control device 50 (numerical control device 51) takes in the detection signal of the opening (angle) of the pair of fingers 42 when the workpiece W is sandwiched between the pair of fingers 42 via the sizing amplifier 53. The diameter can be recognized. Further, the control device 50 can output a control signal to the cylinder 44 to move the measurement main body 41 forward and backward, and move the measurement main body 41 forward and backward to recognize the largest detected diameter as the diameter of the workpiece W. To do.
2B, the arm 43 may be attached to the base 2 without being attached to the tool table 31. In this case, it is preferable that the arm 43 can be moved to an arbitrary position in the Z-axis direction. In the present embodiment shown in FIGS. 2A and 2B, the workpiece measuring device 40 can reciprocate in the Z-axis direction and can be moved to the position of the master workpiece MW. In addition, the diameter of the master work MW is made into the ideal diameter of the cylindrical surface KE which is the processed part of the work W.

● [Processing and mastering processing procedures (Fig. 3)]
Next, a procedure of processing for grinding and mastering the workpiece W will be described using the flowchart shown in FIG. A program based on the flowchart shown in FIG. 3 is stored in the numerical controller 51.
When the processing is started, the numerical controller 51 carries in the unprocessed workpiece W (the workpiece W to be processed next) in step S10, and supports the workpiece W by the pair of workpiece support means. The process proceeds to step S20.

  Then, in step S20, the numerical controller 51 determines whether or not it is immediately after the power to the grinding machine 1 is turned on (when the grinding machine 1 is started). For example, it is determined whether or not the state has changed from a state where the power is not turned on to a state where the power is turned on. If it is determined that it is immediately after the power is turned on (Yes), the process proceeds to step S40, and if it is determined that it is not immediately after the power is turned on (No), the process proceeds to step S30.

  When it progresses to step S30, it is determined whether it is the process after a long time stop. For example, the elapsed time from the time when the machining of the previous workpiece is completed to the step S30 is obtained, and whether or not the obtained elapsed time is equal to or longer than a predetermined time (at the start of workpiece machining after stopping for a predetermined time or longer). Whether or not there is). If it is determined that the processing is after a long stop (Yes), the process proceeds to step S40. If it is determined that the processing is not a long time stop (No), the process proceeds to step S70.

When the process proceeds to step S40, a flag Fm for instructing execution of mastering is set, and the process proceeds to step S50.
In step S50, a processing number counter N that stores the number of processed workpieces is initialized, and the process proceeds to step S60. In the flowchart of FIG. 3, the machining number counter only counts the number of workpieces W that have been machined, and is not particularly used for mastering or the like.
In step S60, the reference position Db indicating the position where the grinding of the workpiece W is completed immediately after the mastering is initialized, and the grinding completion position Dn indicating the position where the grinding of the workpiece W is completed each time the workpiece W is ground. Is initialized, and the process proceeds to step S100.

When the process proceeds to step S70, it is determined whether or not the difference between the reference position Db and the grinding completion position Dn (the position where the previous grinding of the workpiece W has been completed) is out of the allowable position range. In this case, it is determined whether or not −α <Dn−Db <α. Here, the threshold value α is set to a value smaller than the allowable maximum value Emax of the error of the workpiece W that has been processed. When it is determined that the difference between the reference position Db, which is the position where the workpiece has been ground immediately after the previous mastering, and the grinding completion position Dn, which is the position where the previous workpiece has been ground, is outside the allowable position range ( If Yes), the process proceeds to step S80, and if it is determined that the difference between the reference position Db and the grinding completion position Dn is not outside the allowable position range (No), the process proceeds to step S100.
When the process proceeds to step S80, the flag Fm for instructing execution of mastering is set, and the process proceeds to step S100.

In step S100, it is determined whether or not the flag Fm is set. If it is determined that the flag Fm is set (Yes), the process proceeds to step S110. If it is determined that the flag Fm is not set (No), the process proceeds to step S120.
When it progresses to step S110, the workpiece measuring apparatus 40 is mastered using the master workpiece MW, and it progresses to step S120. In the mastering, a master workpiece MW (a master gauge formed with high precision so as to have an ideal dimension) prepared in advance or inside the grinding machine 1 is measured by the workpiece measuring device 40, and the measurement is performed. The result is stored as a target value.
In the grinding machine 1 shown in FIG. 1A, since the master work MW is coaxially attached to the work W and attached to the center member 20a of the tailstock device 20, the work measuring device 40 is moved to a position facing the master work MW. It is moved in the Z-axis direction, the master work MW is sandwiched between the fingers 42, and the measurement result is stored as a target value. The master work MW may be prepared anywhere inside and outside the grinding machine 1. If the workpiece measuring device 40 is within the moving range, the workpiece measuring device 40 may be moved to perform mastering. If not within the moving range of the workpiece measuring device 40, the master workpiece MW is replaced with the grinder 1 instead of the workpiece W. After the main workpiece MW is supported by the spindle device 10 and the tailstock device 20 and mastering is performed, the master workpiece MW is unloaded and the workpiece W to be processed next is loaded. When the master workpiece MW is carried into the grinding machine 1 in place of the workpiece W and supported by the spindle device 10 and the tailstock device 20, the unmachined workpiece W is not carried in at the position of step S10 and is shown in FIG. It may be the position of step S115.

In step S120, the part to be processed of the workpiece W is ground. In this case, grinding is performed until the result measured by the workpiece measuring device 40 reaches the target value stored at the time of mastering. When the grinding is completed, the process proceeds to step S130.
In step S130, it is determined whether or not the flag Fm is set. If the flag Fm is set (Yes), the process proceeds to step S140. If the flag Fm is not set (No), the process proceeds to step S150.
When the process proceeds to step S140, the position when the grinding of the workpiece W performed in step S120 is completed (in this case, the position of the grindstone T in the X-axis direction) is stored in the reference position Db. The reference position Db is a position where the grinding of the workpiece W immediately after the mastering is completed.

When the process proceeds to step S150, the machining number counter N is counted up and the process proceeds to step S160.
In step S160, the position when the grinding of the workpiece W performed in step S120 is completed (in this case, the position of the grindstone T in the X-axis direction) is stored in the grinding completion position Dn, and the process proceeds to step S170.
In step S170, the flag Fm is cleared (initialized), and the process proceeds to step S180.
In step S180, the workpiece W for which grinding has been completed is carried out, and the process proceeds to step S190.
In step S190, the presence / absence of the workpiece W to be ground next is determined. When there is a workpiece W to be ground next (Yes), the process returns to step S10, and when there is no workpiece W to be ground next (No), the processing is terminated.
In the above description, it is determined whether or not mastering should be performed based on the difference between the reference position Db and the grinding completion position Dn of the previous workpiece before grinding the new workpiece. You may make it determine whether it should master by the difference of Db and the grinding completion position Dn of this workpiece | work.

[Comparison of processing procedure of this embodiment (FIG. 3) and conventional processing procedure (FIG. 6), and change in measurement error of this embodiment (FIG. 4) and conventional (FIG. 7) due to mastering]
Next, the difference between the processing procedure of the present embodiment described with reference to FIG. 3 and the example of the conventional processing procedure (FIG. 6) will be described.
In the conventional processing procedure shown in the example of FIG. 6, the timing for setting the flag Fm instructing execution of mastering is determined only by whether or not the machining number counter in step S75 is a predetermined value. For example, the predetermined value is set so that Fm is set for each of the first, second, fifth, tenth and tenth.
When performing mastering in step S110, the master work MW is carried in from the outside of the grinding machine and the master work MW is supported by the spindle device 10 and the tailstock device 20 instead of the work W. The workpiece W is brought in at the position of step S115.

FIGS. 4A and 7A are graphs showing changes in the measurement error (vertical axis) of the workpiece measuring apparatus 40 with respect to the number of workpieces processed (horizontal axis) when mastering is not performed. Both are the same graph. In both cases, mastering is performed immediately before the first machining is performed, and the process starts from a state where there is no error. Emax is the allowable maximum value of the error of the workpiece W that has been processed, and α is the threshold value of step S70 in the flowchart of the present embodiment shown in FIG. This is a threshold value for determining whether or not to perform mastering from the difference from the workpiece grinding completion position (α <Emax).
If mastering is not performed, as the workpiece W is ground one after another, the environmental temperature gradually increases and approaches asymptotically toward a predetermined temperature. The measurement error of the workpiece measurement device also shows a characteristic that asymptotically approaches a predetermined value due to a temperature drift caused by an increase in the environmental temperature (FIGS. 4A and 7A).

Here, in the conventional mastering method in which mastering is performed for each predetermined number, as shown in FIG. 7B, the measurement error is not so large in the tenth and subsequent pieces where the slope of the measurement error of the workpiece measuring device 40 becomes small. Regardless of mastering, mastering is more than necessary.
On the other hand, in the mastering method described in the present embodiment, as shown in FIG. 4B, mastering is performed when the measurement error reaches α regardless of the magnitude of the measurement error inclination of the workpiece measuring device 40. Since the number of mastering operations can be reduced without performing unnecessary mastering, the machining efficiency can be further improved.
Further, as shown in FIG. 1A, the position of the master work MW is always provided in the vicinity of the work W, so that loading and unloading of the master work MW at the time of mastering becomes unnecessary and the work measuring device 40 The moving distance can be reduced, and the processing efficiency can be further improved.
In the description of the present embodiment, the example in which the master work MW is provided on the center member 20a of the tailstock device 20 and coaxially with the work rotation axis WZ has been described. However, the spindle device that is the other work support means. Ten center members 10a may be provided coaxially with the workpiece rotation axis WZ.

●● [Second Embodiment (FIG. 5)]
Next, a second embodiment will be described with reference to FIG. In contrast to the first embodiment in which the cylindrical surface KE (see FIG. 1B) of the workpiece W is ground, in the second embodiment, the end surfaces KA and KB (surfaces orthogonal to the workpiece rotation axis) of the workpiece W. ).

● [Schematic configuration of the grinding machine 1 and the machining location of the workpiece W (Fig. 5)]
The configuration of the grinding machine 1 of the second embodiment shown in FIG. 5A is different from that of the grinding machine 1 of the first embodiment shown in FIG. Other configurations are the same. In addition, the position of the grindstone T and the workpiece | work W and the moving direction at the time of grinding differ.
In the grinding machine 1 according to the second embodiment shown in FIG. 5A, the end surface of the grindstone T (surface orthogonal to the grindstone rotation axis TZ) is brought into contact with the end surfaces KA and KB which are the processing points of the workpiece W. Then, the grindstone T is moved in the Z-axis direction to grind the processed portion of the workpiece W.
In the grinding machine 1 shown in FIG. 5A, the workpiece measuring device 40 determines the position of the measurement main body 41A and finger 42A for measuring the position in the Z-axis direction on the end face KA side, and the position in the Z-axis direction on the end face KB side. Each of the workpiece measuring devices has a measurement main body 41B and a finger 42B to be measured. In addition, each workpiece | work measuring apparatus is provided with the contactor at the front-end | tip of a finger similarly to 1st Embodiment, and the cylinder etc. (illustration omitted) which move forward / backward toward the workpiece | work W are also provided.

As in the first embodiment, the control device 50 stores the target value of the measured value by the workpiece measuring device 40, and moves the grindstone T to Z until the measured value by the workpiece measuring device 40 reaches the target value. The part to be processed of the workpiece W is ground by moving in the axial direction.
The processing procedure for machining and mastering the workpiece is the same as that in the first embodiment shown in FIG. However, the mastering method is different from the point that the reference position Db and the grinding completion position Dn are not positions in the X-axis direction of the grindstone T but positions in the Z-axis direction of the grindstone T.
In the second embodiment, the position of the master workpiece MW and the mastering position that is the position of the workpiece measuring device at the time of mastering are set with high accuracy in advance, and the measured value at the position at the time of mastering is set as the target value. That's fine.
Note that the change in measurement error is the same as that in FIG. 4B of the first embodiment, and a description thereof will be omitted.

The grinding machine 1 of the present invention is not limited to the appearance, configuration, processing, and the like described in the present embodiment, and various modifications, additions, and deletions can be made without changing the gist of the present invention.
Further, the configuration, structure, and the like of the workpiece measuring device 40 are not limited to the workpiece measuring device 40 described in the present embodiment.
In the description of the present embodiment, an example in which the processing tool is the grindstone T has been described. However, a cutting tool or the like may be used as the processing tool, and the processing tool is not limited to the grindstone T.
In the description of the present embodiment, an example of a pair of center members that support both end surfaces of the workpiece W as a pair of workpiece support means for supporting the workpiece W has been described. However, the cylindrical surface at the end of the workpiece W is gripped. The vicinity of both ends may be supported by the chuck, or one end may be supported by the center member and the vicinity of the other end may be supported by the chuck.
In the description of the present embodiment, the example of the configuration in which the machining tool is moved in the X-axis direction and the Z-axis direction has been described. However, the spindle device 10 and the tailstock device 20 are moved in the X-axis direction and the Z-axis direction. It may be placed on a possible table. Accordingly, any configuration is possible as long as the machining tool can move relative to the workpiece W in the X-axis direction and the Z-axis direction.
The numerical values used in the description of the present embodiment are examples, and are not limited to these numerical values.

It is a figure explaining the example of schematic structure of the grinding machine 1 in 1st Embodiment, and the example of the processed part of the workpiece | work W. FIG. It is a figure explaining the example of a structure of the workpiece | work measuring apparatus. It is a flowchart explaining the example of the procedure of the process which performs the process of a workpiece | work and mastering in this Embodiment. It is a figure explaining the change of the measurement error by mastering in this Embodiment. It is a figure explaining the example of schematic structure of the grinding machine 1 in 2nd Embodiment, and the example of the processed part of the workpiece | work W. FIG. It is a flowchart explaining the example of the procedure of the process which performs the process of the conventional workpiece | work, and mastering. It is a figure explaining the change of the measurement error by the conventional mastering.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Grinding machine 10 Main axis | shaft apparatus 10a Center member 11 Main spindle stand 12 Main axis | shaft 13 Connection member 20 Tailstock apparatus 20a Center member 21 Tailstock 22 Ram 30 Tool apparatus 31 Tool table 32 Cutting table 40 Work measuring apparatus (work measuring means)
41 Measurement Main Body 42 Finger 42s Contact 50 Control Device (Control Unit)
51 Numerical Control Unit T Machining Tool (Whetstone)
TZ Wheel rotation axis W Work WZ Work rotation axis MW Master work

Claims (4)

A pair of workpiece support means for supporting the vicinity of both ends of the substantially cylindrical workpiece and rotating the supported workpiece around the workpiece rotation axis;
A processing tool for grinding a workpiece portion of a workpiece supported by the workpiece support means;
The machining tool is moved relative to the workpiece supported by the workpiece support means in the intersecting direction that intersects the workpiece rotation axis or in the parallel direction that is parallel to the workpiece rotation axis. Relative movement means for causing
Position detecting means for detecting the position of the workpiece support means or the processing tool in the crossing direction or the parallel direction by the relative movement means;
Workpiece of end surface, which is a surface perpendicular to the workpiece rotation axis, formed at an arbitrary position of the workpiece supported on the cylindrical surface of the workpiece supported by the workpiece support means A workpiece measuring means capable of measuring the position of the part in the parallel direction;
In a grinding machine comprising a diameter or position measured by the workpiece measuring means, and a control means for controlling the relative movement means based on the position detected by the position detecting means,
The control means includes
Grinding the workpiece by controlling the relative movement means until the diameter or position measured by the workpiece measurement means reaches a preset target value,
If the position detected by the position detecting means when the measured value by the work measuring means reaches the target value is out of the allowable position range, an error of the work measuring means is determined using a master work prepared in advance. Perform mastering to correct,
Grinder. The grinding machine according to claim 1,
The control means includes
Based on the difference between the position when grinding of the workpiece immediately after the previous mastering was performed and the position when grinding of the previous or current workpiece was completed before or after grinding a new workpiece. Determine whether it is out of the allowable position range,
Grinder. The grinding machine according to claim 1 or 2,
The master work is provided on one of the pair of work support means and coaxially with respect to the work rotation axis.
Grinder. A grinding machine according to any one of claims 1 to 3,
The control means includes
Furthermore, when the state changes from the state where the power is not turned on to the state where the power is turned on, or when grinding of a new workpiece is started after stopping for a predetermined time or more in the state where the power is turned on Do the mastering,
Grinder.

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