JP2020203344A - Grinding method by centerless grinder and centerless grinder - Google Patents

Abstract

To provide a grinding method by a centerless grinder and a centerless grinder by which finished dimensions of respective work-pieces can be made uniform even if oscillation occurs on an outer peripheral surface of a regulating wheel during rotation.SOLUTION: In a grinding method by a centerless grinder comprising a grinding wheel 102 and a regulating wheel 104 which rotate around an axis while supporting an outer peripheral surface of a work-piece W from a longitudinal direction and a blade 20 which supports the outer peripheral surface of the work-piece from below, the regulating wheel is stopped in a same phase between the end of grinding the work-piece and the start of grinding a next work-piece. Since the phase of the regulating wheel at the start of grinding always matches, each work-piece is always ground to the same extent under the influence of oscillation even if oscillation occurs on an outer peripheral surface 104b of the regulating wheel during rotation. Therefore, finished dimensions of each work-piece can be made the same when grinding is terminated after a prescribed time has passed.SELECTED DRAWING: Figure 5

Description

The present invention relates to a grinding method using a centerless grinder and a centerless grinder capable of making the finished dimensions of each workpiece uniform even when the outer peripheral surface of a rotating adjusting wheel is shaken.

As a grinder that grinds the outer circumference of a work such as a columnar or cylindrical shape, when the longitudinal direction of the work is the front-back direction, the outer peripheral surface of the work is supported from the left and right by a grinding wheel and an adjusting wheel and attached to the work rest. A centerless grinder that is supported from below by a blade is known.
Since the finished size of the work is adjusted by adjusting the distance between the grinding wheel and the adjusting wheel, if the outer peripheral surface of the adjusting wheel during rotation is shaken, the finished size of the work will vary. Examples of causes of runout on the outer peripheral surface of the adjusting wheel include a defect in the bearing portion of the adjusting wheel, distortion of the outer peripheral shape of the adjusting wheel due to wear, and a defective dressing for the adjusting wheel.

For example, in Patent Document 1, the roundness of a plurality of workpieces after grinding is measured to obtain the degree of change in the roundness in the future, that is, the predicted curve of the roundness, and the predicted curve is the reference value of the roundness. A technique is disclosed in which the adjusting vehicle is dressed when the value is exceeded and the distortion of the outer peripheral shape of the adjusting vehicle is corrected.

Japanese Unexamined Patent Publication No. 11-277384

In Patent Document 1, the adjusting wheel is dressed at an appropriate timing. For example, dressing the adjusting wheel accurately to the extent that the outer peripheral surface is not shaken due to the non-uniformity of the internal structure of the adjusting wheel itself. There is a problem that it is difficult. Further, even if the adjusting wheel is dressed accurately, the rotation axis may shift due to a defect in the bearing portion of the adjusting wheel, for example, and runout may occur.
As described above, it is an unavoidable phenomenon that the outer peripheral surface of the adjusting wheel during rotation is shaken, and it is not easy to eliminate the variation in the finished dimensions of the workpiece due to this phenomenon.
Further, in general, the desired finished size is finished by spark-out in which the cutting is stopped for a certain period of time after the completion of grinding. Therefore, for example, if the spark-out is continued until the adjusting vehicle makes one rotation, it is possible to suppress variations in the finished dimensions due to the runout of the outer peripheral surface of the adjusting vehicle. However, it often takes several seconds for the adjusting vehicle to make one revolution, and there is a problem that the cycle time is extended if sparking out for several seconds.

In view of these problems, the present invention provides a grinding method using a centerless grinder and a centerless grinder capable of making the finished dimensions of each workpiece uniform even when the outer peripheral surface of the rotating adjusting wheel is shaken. The purpose is.

The grinding method using the centerless grinder of the present invention includes a grinding wheel and an adjusting wheel that rotate around an axis while supporting the outer peripheral surface of the work from the left and right, and a blade that supports the outer peripheral surface of the work from below. The grinding method using a grinder is characterized in that the adjusting wheel is stopped in the same phase between the end of grinding the work and the start of grinding the next work.
The grinding method using the centerless grinder of the present invention includes a grinding wheel and an adjusting wheel that rotate around an axis while supporting the outer peripheral surface of the work from the left and right, and a blade that supports the outer peripheral surface of the work from below. In the grinding method using a grinder, the cycle time from setting the work to a predetermined position on the blade, finishing grinding of the work, and setting the next work to a predetermined position on the blade is T1. It is a feature that T1 = n × T2 (n is an integer of 1 or more), where T2 is the time required for the adjusting wheel to make one rotation.

The heartless grinder of the present invention is a heartless grinder including a grinding wheel and an adjusting wheel that rotate around an axis while supporting the outer peripheral surface of the work from the left and right, and a blade that supports the outer peripheral surface of the work from below. , A control device that controls the drive of the grinding wheel and the adjusting wheel,
A phase detection device that detects the rotation phase of the adjusting wheel and outputs a phase signal is provided, and the control device outputs the phase signal between the end of grinding one of the workpieces and the start of grinding of the next workpiece. Based on this, the adjusting vehicle is stopped in the same phase.
The heartless grinder of the present invention is a heartless grinder including a grinding wheel and an adjusting wheel that rotate around an axis while supporting the outer peripheral surface of the work from the left and right, and a blade that supports the outer peripheral surface of the work from below. The grinding wheel and the control device for controlling the drive of the adjusting wheel are provided, and after one of the workpieces is set at a predetermined position on the blade, the grinding of the workpiece is completed and the next workpiece is subjected to the next workpiece. When the cycle time until the blade is set at a predetermined position is T1 and the time required for the adjusting wheel to make one rotation is T2, the control device has T1 = n × T2 (n is an integer of 1 or more). ) Satisfied, the driving of the grinding wheel and the adjusting wheel is controlled.

If the adjusting wheel is stopped in the same phase between the end of grinding the work and the start of grinding the next work, the phase of the adjusting wheel at the start of grinding always matches, so the rotating adjusting wheel Even if runout occurs on the outer peripheral surface of the work, each work is always ground while being affected by runout to the same extent. Therefore, the finished dimensions of each work at the time when the predetermined time elapses and the grinding is completed can be made the same. Rather than suppressing the runout of the outer peripheral surface of the adjusting wheel as in the past, the present invention is based on the reverse idea of making the finished dimensions of the work pieces the same by evenly affecting each work piece. is there.

Further, the drive of the grinding wheel and the adjusting wheel may be controlled so that T1 = n × T2 (n is an integer) is satisfied. By rotating the adjusting wheel an integral number of times during one cycle time T1, the phases of the adjusting wheel at the start of cutting of each workpiece are matched. Each workpiece is always ground to the same extent under the influence of the runout of the adjusting wheel, and the phase of the adjusting wheel at the end of cutting also matches. Therefore, the finished dimensions of each workpiece at the time when the cycle time elapses and the grinding is completed can be made the same. Similarly, the present invention is based on the reverse idea of making the finished dimensions of the workpieces the same by evenly affecting each workpiece with the influence of runout.

Front view of heartless grinder Block diagram showing a part of the configuration of a centerless grinder Partial enlarged view showing workpiece, grinding wheel, adjusting wheel and blade during grinding Partial enlarged view showing the state where the outer peripheral surface of the adjusting vehicle is shaken Figures (a) to (e) show the cycle time from when the workpiece is set in a predetermined position on the blade to when grinding is completed and when the next workpiece is set. Figures (a) to (d) showing the cycle time from when the workpiece is set in a predetermined position on the blade to when grinding is completed and when the next workpiece is set.

[First Embodiment]
The first embodiment of the heartless grinder of the present invention will be described.
As shown in FIG. 1, the heartless grinder 100 is a dressing device 106 that dresses the grinding wheel 102, the grinding wheel stand 103, the adjusting wheel 104, the adjusting chassis 105, the blade 20, the work rest 10, and the grinding wheel 102 on the bed 101. , The dressing device 107 for the adjusting wheel 104, the feeding device 108 for moving the grinding wheel base 103, the feeding device 109 for moving the adjusting wheel 105, and the like are provided. Since it is a well-known technique, detailed explanation is omitted, but in the grinding work, first, the grinding wheel base 103 and the adjusting chassis 105 are appropriately moved by driving the feed devices 108 and 109, and the work W is moved by the grinding wheel 102 and the adjusting wheel 104. Support from the left and right, and adjust the height of the blade 20 of the work rest 10 to support the work W from below. Then, the grinding wheel 102 and the adjusting wheel 104 are rotated around the axis to grind the work W. After the grinding process is completed, the work W is taken out and the next work W is supplied. The work W supply / discharge method may be any method.

As shown in FIG. 2, the centerless grinder 100 further includes a phase detection device 200, a control device 201, motors 202 and 203, a driver 204, a storage device 205, and the like.
The phase detection device 200 detects the rotational phase of the adjusting wheel 104 and outputs a phase signal to the control device 201. The method for detecting the rotation phase is not particularly limited, and a well-known method can be used. For example, as shown in FIG. 3, a dog 206 is attached to a part of the rotation shaft 104a of the adjusting wheel 104 or the bearing portion, and this dog is used. A method of reading the position of 206 with a proximity sensor can be mentioned. FIG. 4 shows the adjusting wheel 104 in which the outer peripheral surface 104b is shaken during rotation by a two-dot chain line.
The control device 201 is provided to control the drive of the adjusting wheel 104 via the driver 204 and the motor 203. The control device 201 may also control the drive of other mechanisms constituting the centerless grinder 100, for example, the grinding wheel base 103, the adjusting chassis 105, the dressing devices 106, 107 and the like.
Although a detailed description will be described later, the control device 201 stops the adjusting wheel 104 in the same phase based on the phase signal between the end of grinding the work W and the start of grinding the next work W. Since advanced control is required to stop the adjusting wheel 104 in the same phase, it is preferable to use an AC servomotor as the motor 203.

Next, the grinding method of the heartless grinder 100 of the present invention will be described.
In the centerless grinder 100, one work W1 is set at a predetermined position on the blade 20 as shown in FIG. 5 (a), and then grinding of the work W1 is started as shown in FIG. 5 (b). Grinding is completed as shown in FIG. 5 (c), and the next work W2 is set in a predetermined position on the blade 20 as shown in FIG. 5 (e). Note that FIGS. 5 (a) and 5 (e) show the same state.
During the period from the completion of grinding of one work W1 to the supply of the next work W2 and the start of grinding (between FIGS. 5 (c) and 5 (e)), in FIG. 5 (d). As shown, the control device 201 controls the drive of the AC servomotor 203 based on the phase signal output from the phase detection device 200 to rotate the adjusting wheel 104 to the same phase and stop it. When the dog 206 is attached to a part of the rotation shaft of the adjustment vehicle 104, the adjustment vehicle 104 is rotated and stopped so that the dog 206 is always in the same position (for example, the 12 o'clock position).
Since the phases of the adjusting wheel 104 at the start of grinding of the workpieces W1 and W2 are always the same, even if the outer peripheral surface 104b of the rotating adjusting wheel 104 is warped as shown in FIG. Since the workpieces W1 and W2 are always ground while being affected by the runout to the same extent, the finished dimensions of the workpieces W1 and W2 are the same when the grinding is completed after a predetermined time has passed (Fig. 5 (c)). become.

[Second Embodiment]
The second embodiment of the heartless grinder of the present invention and the grinding method thereof will be described, but the parts having the same configuration as the first embodiment are designated by the same reference numerals and the description thereof will be omitted. To do.
In the present embodiment, as shown in FIG. 6, the grinding wheel 102 and the adjusting wheel 104 continue to rotate even after the grinding of one work W3 is completed, and the grinding work of the next work W4 is started as it is.
After setting one work W3 in a predetermined position on the blade 20 as shown in FIG. 6 (a), grinding of the work W3 is started as shown in FIG. 6 (b), and FIG. 6 (c) shows. As shown in Fig. 6 (d), the cycle time until the next workpiece W4 is set in the predetermined position on the blade 20 is T1 (s), and the adjusting wheel 104 makes one rotation. When the required time is T2 (s), the driving of the grinding wheel 102 and the adjusting wheel 104 is controlled so that T1 = n × T2 (n is an integer of 1 or more) is established. Note that FIGS. 6 (a) and 6 (d) show the same state.

In the present embodiment, the adjusting wheel 104 rotates n times (integer times) during one cycle time T1. As a result, the phases of the adjusting wheels 104 at the start of grinding of the workpieces W3 and W4 are matched. The workpieces W3 and W4 are always ground to the same extent while being affected by the runout of the adjusting wheel 104, and the phases of the adjusting wheel 104 at the end of grinding also match. Therefore, when the cycle time T1 elapses and the grinding is completed, the finished dimensions of the workpieces W3 and W4 are the same.
In the case of the present embodiment, since the adjusting wheel 104 is continuously rotated from the completion of grinding of one work W3 to the start of grinding of the next work W4, it is compared with the first embodiment. There is an advantage that it is not necessary to use an expensive motor such as the AC servomotor 203 to drive the adjusting wheel 104.

The present invention relates to a grinding method using a centerless grinder and a centerless grinder capable of making the finished dimensions of each workpiece uniform even when the outer peripheral surface of a rotating adjusting wheel is shaken, and is used for industrial purposes. Has the potential.

T1 cycle time
Time required for the T2 adjustment vehicle to make one revolution
W, W1 to W4 work
10 Workrest
20 blades
100 coreless grinder
101 beds
102 Grinding wheel
103 Grinding wheel stand
104 Adjustment car
104a axis of rotation
104b Outer surface
105 Adjustment chassis
106,107 Dressing device
108,109 Feeder
200 phase detector
201 Control unit
202,203 motor
204 driver
205 Storage device
206 Dog

Claims (4)

In a grinding method using a heartless grinder equipped with a grinding wheel and an adjusting wheel that rotate around an axis while supporting the outer peripheral surface of the work from the left-right direction, and a blade that supports the outer peripheral surface of the work from below.
A grinding method using a centerless grinder, characterized in that the adjusting wheel is stopped in the same phase between the end of grinding of the work and the start of grinding of the next work.
In a grinding method using a heartless grinder equipped with a grinding wheel and an adjusting wheel that rotate around an axis while supporting the outer peripheral surface of the work from the left-right direction, and a blade that supports the outer peripheral surface of the work from below.
The cycle time from when the work is set at a predetermined position on the blade until the grinding of the work is completed and the next work is set at a predetermined position on the blade is T1, and the adjusting wheel makes one rotation. A grinding method using a heartless grinder, characterized in that T1 = n × T2 (n is an integer of 1 or more), where T2 is the time required for grinding.
In a heartless grinder provided with a grinding wheel and an adjusting wheel that rotate around an axis while supporting the outer peripheral surface of the work from the left and right direction, and a blade that supports the outer peripheral surface of the work from below.
A control device that controls the drive of the grinding wheel and the adjusting wheel, and
It is equipped with a phase detection device that detects the rotational phase of the adjusting wheel and outputs a phase signal.
The control device is a heartless grinder characterized in that the adjusting wheel is stopped in the same phase based on the phase signal between the end of grinding of one work and the start of grinding of the next work.
In a heartless grinder provided with a grinding wheel and an adjusting wheel that rotate around an axis while supporting the outer peripheral surface of the work from the left and right direction, and a blade that supports the outer peripheral surface of the work from below.
It is equipped with a control device that controls the driving of the grinding wheel and the adjusting wheel.
The cycle time from when one of the workpieces is set at a predetermined position on the blade until the grinding of the workpiece is completed and the next workpiece is set at a predetermined position on the blade is set to T1, and the adjusting wheel is used. When the time required for one rotation is T2, the control device controls the driving of the grinding wheel and the adjusting wheel so that T1 = n × T2 (n is an integer of 1 or more) is established. A featured heartless grinder.

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