JP2000296440A - Grinding equipment - Google Patents

Abstract

(57) [Problem] In a conventional grinding apparatus, since a burdock and a dog are used, there is a problem that time and labor are required for work. A headstock provided with a headstock, and a headstock and a headstock are provided.
Tailstock 4 for holding the workpiece W between them, and a grinding wheel 5
, A grinding wheel head driving means 7 for driving the grinding wheel head 6 forward and backward, a spindle load detecting means 8 for detecting a rotational load of the spindle 1, and a grinding wheel based on a detection signal from the spindle load detecting means 8. This is a grinding apparatus provided with a grinding control means 9 for controlling the table drive means 7, and has a simple structure for holding the workpiece W, but the cutting amount of the grinding wheel 5 according to the rotational load of the spindle 1. Is automatically adjusted to enable high-precision grinding, and the time and labor required for work are reduced by eliminating the need for conventional burrs and dogs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding apparatus used for grinding an outer peripheral surface of a roughly cylindrical workpiece including a cylindrical body, an eccentric cylindrical body or a non-circular cylindrical body. Things.

[0002]

2. Description of the Related Art FIG. 10 shows an example of this type of grinding apparatus. The illustrated grinding apparatus includes a headstock 102 provided with a rotationally driven spindle 101.
And a tailstock 104 provided with a rotatable center 103.
And a grindstone table 106 provided with a grinding wheel 105, and the workpiece W is held rotatably around the axis by the spindle 101 of the headstock 102 and the center 103 of the tailstock 104. At this time, the headstock 102 is provided with a knurl 107 that rotates with the spindle 101, and the workpiece W
There is a dog 108 that engages with the button 107,
The workpiece W is rotated by the knurls 107 and the dogs 108. The grindstone head 106 includes a motor 109 serving as a rotation drive source, and a housing 110 containing a rotation transmission mechanism and a grindstone rotation shaft. The grindstone head driving means 111 controls the headstock 102 and the tailstock 1.
The workpiece W is driven in a direction in which the workpiece W is moved forward and backward (vertical direction in the figure) and an axial direction of the workpiece W (horizontal direction in the figure).

The above-mentioned grinding apparatus rotates the workpiece W and the grinding wheel 105 in the same direction or in opposite directions,
The workpiece W is moved while moving the grindstone table 106 in an appropriate direction.
Grinding is performed on the outer peripheral surface of the.

[0004]

However, in the conventional grinding apparatus as described above, since the dog 108 is attached to the workpiece W in advance, it takes time to set up before machining, and the dog Since it is not possible to grind the portion to which the workpiece 108 has been attached, in order to grind this portion, the workpiece W after the other portions have been ground is once removed, and the attachment position of the dog 108 and the workpiece W It is necessary to reverse the direction and set again. For this reason, the conventional grinding apparatus has a problem that much time and labor is required for work, and it has been a problem to solve such a problem.

Conventionally, the headstock is provided with a chuck for gripping the end of the workpiece W, and there is also a type which does not use burrs or dogs. However, in this case, the structure of the apparatus becomes complicated. In addition, since the portion gripped by the chuck cannot be ground, there is a problem similar to the case where a dog is used.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and simplifies the apparatus by eliminating the use of conventional burrs, dogs or chucks, thereby reducing work time and labor. It is an object of the present invention to provide a grinding apparatus capable of performing high-precision grinding automatically.

[0007]

According to a first aspect of the present invention, there is provided a grinding apparatus for rotatably holding a workpiece between a headstock provided with a spindle driven to rotate and a headstock. A tailstock, a grindstone provided with a rotationally driven grinding grindstone, a grindstone drive means for driving the grindstone head forward and backward with respect to the sandwiched workpiece, and a spindle for detecting a rotational load of the spindle of the headstock. A load detecting means, and a grinding control means for controlling the wheel head driving means based on a detection signal from the spindle load detecting means, wherein the grinding control means comprises: When the fluctuation of the detection signal from the detecting means exceeds a reference value, the means is a means for outputting a wheel head retreat command to the wheel head driving means. As a third aspect, the rotational speed of the spindle of the head stock is adjusted. Spindle rotation adjusting means and whetstone A grinding wheel load detecting means for detecting a rotational load of the grinding wheel, wherein the grinding control means is means for controlling the spindle rotation adjusting means based on a detection signal from the grinding wheel load detecting means, wherein The grinding control means outputs a spindle deceleration command to the spindle rotation adjusting means when the detection signal from the grinding wheel load detecting means during the grinding processing is equal to or less than a reference value, and thereafter, determines the cutting amount of the grinding wheel. The configuration is a means for increasing a certain amount, and the above configuration is a means for solving the conventional problem.

The grinding apparatus according to the present invention is characterized in that a headstock provided with a rotationally driven spindle is provided as claim 5,
A tailstock that rotatably holds a workpiece between the headstock, a center driving unit that drives at least the center of the tailstock with respect to the headstock, and a grindstone provided with a rotationally driven grinding wheel A table, a grinding wheel head driving means for driving the grinding wheel head forward and backward with respect to the clamped workpiece, a spindle load detecting means for detecting a rotational load of the spindle of the headstock, and a detection signal from the spindle load detecting means. And a grinding control means for controlling the center driving means. The grinding control means is provided when the fluctuation of the detection signal from the spindle load detecting means during the grinding processing exceeds a reference value. And a means for outputting a center advance command to the center drive means. Claim 7 includes a grinding wheel load detecting means for detecting a rotational load of the grinding wheel of the grinding wheel stand, and the grinding control means detects the wheel load detection. hand The grinding control means is configured to control the wheel head driving means based on the detection signal from the grinding wheel, and the grinding control means determines that a fluctuation of a detection signal from the grinding wheel load detecting means during grinding exceeds a reference value. In this case, the grindstone control means outputs a command to retract the grinding wheel head to the grinding wheel head driving means. When the detection signal from the detecting means becomes equal to or less than the reference value, the center driving means outputs a center retreat command to the center driving means, and the above structure is used as means for solving the problem.

[0009]

In the grinding apparatus according to the first aspect of the present invention, the workpiece is rotatably held between the spindle of the headstock and the tailstock, and the workpiece and the grinding wheel are moved in the same direction. Alternatively, the outer peripheral surface of the workpiece is ground by rotating in the opposite direction. At this time, in the grinding device, the spindle load detecting means detects the rotational load of the spindle, and the grinding control means controls the wheel head driving means based on the detection signal from the spindle load detecting means. In accordance with the change in the rotational load, the grindstone table is driven forward and backward to change the cutting amount of the grinding wheel with respect to the workpiece. That is, if the workpiece is held between the headstock and the tailstock with a predetermined force, the grinding wheel for the workpiece is maintained so that the holding state between the spindle and the workpiece is maintained well. Is adjusted.

[0010] In the grinding apparatus according to the second aspect of the present invention, when the fluctuation of the detection signal from the spindle load detecting means during the grinding processing exceeds a reference value, that is, the cutting amount of the grinding wheel with respect to the workpiece is reduced. When the slip is generated between the spindle of the headstock and the workpiece due to being excessively large, the rotational load of the spindle decreases, and the slip of the workpiece is detected by detecting the decrease in the rotational load. Judgment is made, and the grinding control means outputs a grindstone retreat command to the grindstone driving means to reduce the cutting amount of the grinding wheel with respect to the workpiece.

In the grinding apparatus according to a third aspect of the present invention, the amount of cutting of the grinding wheel is reduced with a decrease in the rotational load of the spindle, while the rotational load of the grinding wheel on the grinding wheel table is reduced by the wheel load detecting means. Detecting and controlling the spindle rotation adjusting means based on the detection signal from the grinding wheel load detecting means by the grinding processing control means, and changing the rotation speed of the spindle of the headstock according to the change in the rotating load of the grinding wheel. .

In the grinding apparatus according to a fourth aspect of the present invention, when the cutting amount of the grinding wheel is reduced with a decrease in the rotational load of the spindle of the headstock, the grinding wheel load detecting means during the grinding process is used. When the detection signal becomes equal to or less than the reference value, the grinding processing control means outputs a spindle deceleration command to the spindle rotation adjusting means to decelerate the spindle, and thereafter,
The cutting amount of the grinding wheel is increased by a certain amount to prevent the cutting amount from becoming zero, and the optimum conditions are automatically determined.

In the grinding apparatus according to a fifth aspect of the present invention, the workpiece is rotatably held between the spindle of the headstock and the tailstock, and the workpiece and the grinding wheel are moved in the same direction or opposite to each other. To grind the outer peripheral surface of the workpiece. At this time, in the grinding device, the rotational load of the spindle is detected by the spindle load detecting means, and the grinding control means is used by the grinding control means.
The center drive means is controlled based on a detection signal from the spindle load detection means, and according to a change in the rotational load of the spindle,
The center of the tailstock is driven forward and backward to change the clamping force of the work piece between the spindle and the center, so that the holding state between the work spindle and the center and the work piece is always kept good.

In the grinding apparatus according to a sixth aspect of the present invention, when the fluctuation of the detection signal from the spindle load detecting means during the grinding processing exceeds a reference value, that is, when the cutting amount of the grinding wheel with respect to the workpiece is reduced. When the slip is generated between the spindle of the headstock and the workpiece due to being excessively large, the rotational load of the spindle decreases, and the slip of the workpiece is detected by detecting the decrease in the rotational load. Judgment is made, and a center advance command is output to the center driving means by the grinding control means to increase the clamping force of the workpiece by the spindle and the center.

In the grinding apparatus according to a seventh aspect of the present invention, the center of the tailstock is advanced with a decrease in the rotational load of the spindle of the headstock, and the grinding wheel of the grinding wheel is detected by the grinding wheel load detecting means. By detecting the rotational load, the grinding control means controls the grinding wheel head driving means based on the detection signal of the rotating load of the grinding wheel, and drives the grinding wheel head forward and backward according to the change in the rotating load of the grinding wheel. To change the cutting depth of the grinding wheel with respect to the workpiece.

In the grinding apparatus according to claim 8 of the present invention, when the center of the tailstock is advanced with a decrease in the rotational load of the spindle, the detection signal of the detection signal from the grinding wheel load detecting means during the grinding processing is obtained. When the fluctuation exceeds the reference value, the grinding control means outputs a grinding wheel head retreat command to the grinding wheel drive means to reduce the cutting amount of the grinding wheel with respect to the workpiece.

In the grinding apparatus according to the ninth aspect of the present invention, when the center of the tailstock is advanced with a decrease in the rotational load of the main shaft, the fluctuation of the detection signal from the grinding wheel load detecting means is equal to the reference value. When the detection signal from the grinding wheel load detecting means becomes equal to or less than the reference value after outputting the grinding wheel head retracting command to the grinding wheel drive means, the grinding processing control means causes the center driving means to retreat the center to the center driving means. Is output to reduce the holding force of the workpiece between the spindle and the center.

[0018]

According to the grinding apparatus according to the first aspect of the present invention, there is provided a headstock having a spindle, a tailstock, a grindstone head, a grindstone drive means, a spindle load detecting means, and a grinding control means. By adopting the configuration described above, the work piece can be securely held and the work piece can be rotated with a simple structure in which the work piece is sandwiched between the headstock and the tailstock,
This eliminates the need for conventional burrs, dogs, or chucks, and eliminates the need to re-set the work as in the past, saving time and labor. In addition, it is possible to realize automatic setting and unloading of a workpiece, improvement in the degree of freedom of a workpiece that can be ground, and the like. Also,
By automatic control using the wheel head drive means, the spindle load detecting means, and the grinding processing control means, the cutting amount of the grinding wheel with respect to the workpiece is adjusted so that the press-contact state between the spindle and the workpiece is favorably maintained. Since the workpiece can be adjusted to an optimum one, high-precision grinding can be automatically performed while having a simple structure in which the workpiece is held between the headstock and the tailstock.

According to the grinding apparatus according to the second aspect of the present invention, the same effect as that of the first aspect can be obtained, and in particular, slip occurs between the spindle of the headstock and the workpiece. In such a case, the cutting amount of the grinding wheel with respect to the workpiece is automatically reduced by a certain amount, so that the occurrence of a subsequent slip can be suppressed.

According to the grinding apparatus according to the third aspect of the present invention, the same effects as those of the first and second aspects can be obtained, and in particular, the automatic processing using the spindle rotation adjusting means and the grinding wheel load detecting means. The control is to cover the control of the cutting amount by the grinding wheel drive means and the spindle load detecting means, and by changing the rotation speed of the spindle of the headstock according to the change of the rotation load of the grinding wheel, the rotation load of the grinding wheel is changed. Can be adjusted to the optimal one.

According to the grinding apparatus of the fourth aspect of the present invention, the same effect as that of the third aspect can be obtained, and in particular, the grinding wheel is reduced in accordance with a decrease in the rotational load of the spindle of the headstock. When the depth of cut is reduced to a certain amount or less, the rotational load of the grinding wheel is reduced by a certain amount by decelerating the spindle of the headstock, and the occurrence of slip of the workpiece is more reliably prevented, and again the grinding wheel By giving a cut of
It is possible to prevent the cutting amount of the grinding wheel from being excessively reduced with respect to the workpiece.

According to the grinding apparatus according to the fifth aspect of the present invention, a headstock having a spindle, a tailstock, a center driving means, a grinding wheel head, a grinding wheel head driving means, a spindle load detecting means, and a grinding control means are provided. By adopting the configuration provided with the above, the work piece can be securely held and the work piece can be rotated with a simple structure in which the work piece is sandwiched between the headstock and the tailstock. This eliminates the need for conventional burrs, dogs or chucks, and eliminates the need to re-set the work piece as in the past, saving time and labor. Further, it is possible to realize the automation of setting and unloading of the workpiece, the improvement of the degree of freedom of the workpiece which can be ground, and the like. A center driving unit, a spindle load detecting unit,
And by automatic control using the grinding control means, according to the change of the rotational load of the spindle, the press-contact state between the spindle and the center and the workpiece can always be kept good, for example, the cutting amount of the grinding wheel If it is desired to increase, the clamping force of the workpiece by the spindle and center can be increased, and if it is desired to reduce the cutting depth, the clamping force can be controlled to be small. It can prevent the workpiece from being deformed and prevent the workpiece from being deformed.It has a simple structure in which the workpiece is sandwiched between the headstock and tailstock. Can be done.

According to the grinding apparatus of the sixth aspect of the present invention, the same effect as that of the fifth aspect can be obtained, and in particular, slip occurs between the spindle of the headstock and the workpiece. In this case, the gripping force of the workpiece by the spindle and the center is automatically increased by a certain amount, so that the occurrence of a subsequent slip can be suppressed.

According to the grinding apparatus according to the seventh aspect of the present invention, the same effects as those of the fifth and sixth aspects can be obtained, and especially, the automatic processing using the grinding wheel drive means and the grinding wheel load detecting means. As the control covers the control of the clamping force by the center driving means and the spindle load detecting means, the cutting amount of the grinding wheel with respect to the workpiece is adjusted to an optimum value in accordance with a change in the rotational load of the grinding wheel. Can be.

According to the grinding apparatus of the present invention, the same effect as that of the seventh aspect can be obtained, and in particular, the center of the tailstock is reduced with a decrease in the rotational load of the main shaft. When advancing more than a certain amount, the cutting amount of the grinding wheel with respect to the workpiece is reduced to more reliably prevent the occurrence of slip of the workpiece, and further clamping force is applied to the workpiece. Can be prevented. Accordingly, even when the workpiece has a relatively small diameter, the clamping force between the main shaft and the center can be made appropriate to prevent deformation of the workpiece, and high-precision grinding can be performed. .

According to the grinding apparatus according to the ninth aspect of the present invention, the same effect as that of the eighth aspect can be obtained, and especially, the center of the tailstock is reduced with the decrease in the rotational load of the main shaft. When the workpiece is advanced by more than a certain amount, and when the cutting amount of the grinding wheel to the workpiece is reduced, the clamping force of the workpiece by the spindle and the center is reduced, and the clamping force more than necessary It can be more reliably prevented from being added.

[0027]

1 to 3 are views for explaining an embodiment of a grinding apparatus according to the present invention.

The grinding apparatus shown in FIG. 1 includes a headstock 2 provided with a spindle 1 driven to rotate, a tailstock 4 provided rotatably having a center 3, and a grinding wheel 5 driven in rotation. A grinding wheel head 6; a grinding wheel head driving means 7 for driving the grinding wheel head 6 forward and backward with respect to the sandwiched workpiece W; a spindle load detecting means 8 for detecting a rotational load of the spindle 1 of the headstock 2; A grinding control means 9 for controlling the wheel head driving means 7 based on a detection signal from the detection means 8 is provided. The workpiece W of this embodiment is a substantially cylindrical body having a large diameter portion in the middle.

The headstock 2 incorporates a spindle motor 10 for driving the spindle 1 to rotate. Headstock 2 and tailstock 4
Is arranged on a bed (not shown), which allows the tailstock 4 to move forward and backward with respect to the stationary headstock 2, and rotates the workpiece W about the axis between the spindle 1 and the center 3. Hold as much as possible. Here, the main shaft 1 and the center 3 have a pointed tip. On the other hand, the workpiece W has conical tapered holes formed coaxially at both ends thereof, and the pointed tip of the main shaft 1 and the center 3 is engaged with both tapered holes. In a state, it is held rotatably.

The grinding wheel head 6 includes a grinding wheel motor 11 as a rotary drive source and a housing 12 containing a rotation transmitting mechanism and a grinding wheel rotating shaft. The rotating shaft of the grinding wheel 5 is parallel to the axis of the main shaft 1 and the center 3. It is arranged so that it becomes. The grindstone drive means 7 drives the grindstone 6 forward and backward with respect to the workpiece W sandwiched between the main shaft 1 and the center 3 by a slide mechanism using a slide motor 13 as a drive source, and another motor (not shown). The wheel head 6 is also reciprocated in the axial direction of the workpiece W by the slide mechanism.

The spindle load detecting means 8 uses a current detector or a current / voltage detector attached to the spindle motor 10 of the headstock 2 as an input source, and based on the detected current or the current and the voltage. The rotational load of the main shaft 1 is detected.

The grinding control means 9 is driven by an arithmetic unit 14 to which a detection signal from the spindle load detecting means 8 is inputted, and by a slide motor 13 of the grinding wheel head driving means 7 based on a command signal from the arithmetic unit 14. Control device 15 that outputs commands
It has. Here, when the fluctuation of the detection signal from the spindle load detecting means 8 during the grinding processing exceeds the reference value, the grinding control means 9 retreats the grinding wheel head 6 to the sliding motor 13 of the wheel head driving means 7. Output command. In this embodiment, in particular, the arithmetic unit 14 monitors the fluctuation of the rotational load of the spindle 1, and when the fluctuation amount exceeds a preset reference value, the grinding wheel head 6 is kept constant by a command from the control unit 15. Retract amount.

The operation of the grinding machine having the above configuration will be described with reference to the flowchart of FIG.

The grinding apparatus holds the workpiece W with a constant holding force between the spindle 1 of the headstock 2 and the center 3 of the tailstock 4 by advancing and positioning the tailstock 4.
The spindle motor 10 is operated to rotate the workpiece W together with the spindle 1. That is, the workpiece W is rotated by the frictional force with the main shaft 1. Then, the grinding wheel motor 11 is operated to rotate the grinding wheel 5 in the same or opposite direction as the rotation direction of the workpiece W, and further, the grinding wheel table 6 is moved by the grinding wheel table driving means 7 to process the workpiece. Object W
Of the outer peripheral surface of the workpiece is started (step S1,
S2).

At the same time as the start of the grinding, the grinding apparatus always detects the rotational load of the spindle 1 by the spindle load detecting means 8, and continues to monitor the fluctuation of the rotational load by the grinding control means 9 (step). S3). Here, for example, when the force received from the grinding wheel 5 on the workpiece W increases and a slip occurs between the main spindle 1 and the workpiece W, as shown in FIG. The load of the motor 10 for use rapidly decreases.

At this time, when the grinding device determines in the arithmetic unit 14 of the grinding means 9 that the fluctuation amount of the rotational load exceeds the reference value (No in step S3),
When it is determined that a slip has occurred between the main spindle 1 and the workpiece W, a command signal is output to the control device 15.
, The cutting amount of the grinding wheel 5 with respect to the workpiece W is reduced by a certain amount by retracting (raising) the grinding wheel base 6 by a certain amount (steps S4 to S7).

As a result, the load on the workpiece W is reduced, the subsequent slip of the workpiece W is prevented, and good grinding is continued. If the workpiece W slips again, the above-mentioned control for reducing the cutting amount of the grinding wheel 5 by a certain amount is repeated to make the load on the workpiece W appropriate.

When the arithmetic unit 14 of the grinding means 9 determines that the variation of the rotational load of the spindle 1 is within the range of the reference value (Yes in step S3), it confirms the end of the grinding. Subsequently, it is determined whether or not all the machining steps have been completed. If it is determined that the processing steps have not been completed (No in step S9), the above control flow is repeated, and it is determined that the processing steps have been completed (in step S9). If Yes), the operation ends (steps S8 to S10).

As described above, the grinding machine of the above embodiment does not require the use of a conventional tool, a dog or a chuck, and can grind the entire set workpiece W. Thus, there is no need to reset the workpiece W partially ground, and it is easy to automate the setting and removal of the workpiece W. In addition, despite the simple structure of holding the workpiece W, the spindle 1
When the workpiece W slips, the grinding wheel 5
Thus, automatic control for preventing slippage by reducing the cutting amount of the grinding wheel 5 is performed. In other words, the optimum cutting condition of the grinding wheel 5 can be automatically determined.

FIGS. 4 and 5 are views for explaining another embodiment of the grinding apparatus according to the present invention. The same components as those in the previous embodiment are denoted by the same reference numerals, and detailed description is omitted.

The grinding apparatus shown in FIG. 4 has, in addition to the configuration of the apparatus of the previous embodiment (see FIG. 1), a spindle rotation adjusting means 21 for adjusting the rotation speed of the spindle 1 of the headstock 2, and a grinding wheel head. 6
Wheel load detecting means 2 for detecting the rotational load of the grinding wheel 5
And the grinding control means 9 controls the grinding wheel head driving means 7 based on the detection signal from the spindle load detection means 8, and also controls the spindle based on the detection signal from the grinding wheel load detection means 22. The rotation adjusting means 21 is controlled.

As the spindle rotation adjusting means 21, an inverter for adjusting the rotation speed of the spindle motor 10 is used, and the operation of the inverter adjusts the rotation speed of the spindle 1. The grinding wheel load detecting means 22 uses a current detector or a current / voltage detector attached to the grinding wheel motor 11 as an input source, and detects the rotational load of the grinding wheel 5 based on the detected current or the current and the voltage. To detect.

The grinding control means 9 performs a control to reduce the cutting amount of the grinding wheel 5 as the rotational load of the spindle 1 decreases during the grinding process, and then detects a detection signal from the grinding wheel load detecting means 22. Is smaller than or equal to the reference value, a spindle deceleration command is output to the spindle rotation adjusting means 21, and thereafter, the cutting amount of the grinding wheel 5 is increased by a certain amount.

The operation of the grinding apparatus having the above configuration will be described with reference to the flowchart of FIG. Steps S21 to S27 and steps S32 to S32 in FIG.
S34 is the same as steps S1 to S7 and S8 to S10 in the operation of the previous embodiment (see FIG. 2).

That is, in the grinding machine, a slip occurs between the main spindle 1 and the workpiece W, thereby reducing the rotational load of the main spindle 1. In step 23, the amount of fluctuation of the rotational load of the main spindle 1 is reduced. When it is determined that the value exceeds the reference value (No), control for reducing the cutting amount of the grinding wheel 5 by a certain amount is performed (Steps S24 to S27). Thereafter, the arithmetic unit 14 of the grinding control means 9 detects the grinding wheel load. Based on the detection signal from the means 22, it is determined whether the rotational load of the grinding wheel 5 is equal to or less than a reference value (step S2).
8).

If the rotational load of the grinding wheel 5 is not less than the reference value (No), the process returns to step S23,
When the rotational load of the grinding wheel 5 is equal to or less than the reference value (Yes), the control unit 15 outputs a command signal to the control unit 15, and outputs a deceleration command of the spindle 1 to the spindle rotation adjusting unit 21. The number of revolutions of the spindle 1 (spindle motor 10) is reduced by a fixed amount, and thereafter, the grinding wheel 5 is moved forward together with the grindstone table 6 to give a constant cut (steps S29 to S29).
33).

In other words, the grinding apparatus of the above embodiment performs control to reduce the cutting amount of the grinding wheel 5 by a fixed amount as the rotational load of the spindle 1 decreases. Since there is a possibility that the cutting amount may be remarkably reduced, the grinding wheel 5 is advanced by automatically moving the spindle 1 after decelerating the spindle 1 by the automatic control using the spindle rotation adjusting means 21 and the grinding wheel load detecting means 22. give,
The rotational load of the grinding wheel 5 is adjusted to an optimum one, whereby the occurrence of slip of the workpiece W is more reliably prevented,
Further, the cutting amount of the grinding wheel 5 into the workpiece W is prevented from being excessively reduced.

FIGS. 6 and 7 are views for explaining still another embodiment of the grinding apparatus according to the present invention. In addition,
The same components as those in the previous embodiment are denoted by the same reference numerals, and detailed description is omitted.

The grinding apparatus shown in FIG. 6 comprises a headstock 2 provided with a spindle 1, a tailstock 4 for rotatably holding a workpiece W between the headstock 2, and a tailstock 4. Center driving means 2 for driving at least the center 3 forward and backward with respect to the headstock 2
3, a grinding wheel base 6 provided with a grinding wheel 5 that is driven to rotate,
Based on a detection signal from the wheel head drive means 7 for driving the wheel head 6 forward and backward with respect to the clamped workpiece W, a spindle load detection means 8 for detecting a rotational load of the spindle 1, and a spindle load detection means 8. And a grinding control means 9 for controlling the center driving means 23.

The center driving means 23 has a driving section 25 for driving the center 3 forward and backward via a spring mechanism 24.
The grinding control means 9 outputs a command to advance the center 3 to the center driving means 23 when the fluctuation of the detection signal from the spindle load detecting means 8 during the grinding processing exceeds a reference value.

The operation of the grinding apparatus having the above configuration will be described with reference to the flowchart of FIG. Steps S41 to S43 and steps S47 to S47 in FIG.
S49 is the same as steps S1 to S7 and S8 to S10 in the operation of the previous embodiment (see FIG. 2).

That is, in the above-described grinding apparatus, a slip occurs between the main spindle 1 and the workpiece W during the grinding processing, whereby the rotational load of the main spindle 1 decreases, and the grinding control means 9 When the arithmetic unit 14 determines that the amount of change in the rotational load of the main shaft 1 has exceeded the reference value (No in step S43), it outputs a command signal to the control unit 15 and issues a forward command from the control unit 15 to the center drive unit 23. Then, the center 3 of the tailstock 4 is advanced by a fixed amount, and the clamping force of the workpiece W by the spindle 1 and the center 3 is increased by a fixed amount (steps S44 to S46). That is, since the area of the contact portion with the workpiece W increases, the main shaft 1 and the workpiece W
And the frictional force between the workpiece W and the center 3 are increased, and the subsequent slip of the workpiece W is prevented.

Further, the grinding apparatus of the above embodiment can control the gripping force of the workpiece W between the spindle 1 and the center 3 according to a change in the rotational load of the spindle 1 so as to be optimal. In addition to the slip prevention described above,
The clamping force can be controlled to an optimum value according to the type of the grinding process. Specifically, when roughing is performed by increasing the depth of cut of the grinding wheel 5, the roughening process is performed according to the load. When finishing work is performed by increasing the holding force of the workpiece W and reducing the cutting depth of the grinding wheel 5, control can be performed to reduce the holding force. The center driving means may drive the tailstock 4 as a whole.

FIGS. 8 and 9 are views for explaining still another embodiment of the grinding apparatus according to the present invention. In addition,
The same components as those in the previous embodiment are denoted by the same reference numerals, and detailed description is omitted.

The grinding apparatus shown in FIG. 8 includes, in addition to the configuration of the previous embodiment (see FIG. 6), a grinding wheel load detecting means 22 for detecting the rotational load of the grinding wheel 5 of the grinding wheel base 6, and a grinding machine. The machining control means 9 controls the center driving means 23 based on the output signal from the spindle load detecting means 8 and also controls the grinding wheel head driving means 7 based on the detection signal from the grinding wheel load detecting means 22. .

During the grinding process, the grinding control means 9 controls the rotation of the spindle 1 and the center 3 with the reduction of the rotational load of the spindle 1.
Is performed, and when the fluctuation of the detection signal from the grinding wheel load detecting means 22 exceeds the reference value, that is, the fluctuation of the rotational load of the grinding wheel 5 When the amount exceeds a predetermined reference value, a retreat command of the wheel head 6 is output to the wheel head driving means 7.

The operation of the grinding apparatus having the above configuration will be described with reference to the flowchart of FIG. Steps S51 to S56 and steps S62 to S56 in FIG.
S64 is the same as steps S41 to S46 and S47 to S49 in the operation of the previous embodiment (see FIG. 7).

That is, in the grinding machine, a slip occurs between the main spindle 1 and the workpiece W, thereby reducing the rotational load of the main spindle 1. In step 53, the fluctuation amount of the rotational load of the main spindle 1 is reduced. When it is determined that the reference value has been exceeded (No), the center 3 is advanced to perform a control for increasing the clamping force by a certain amount (steps S54 to S56). Based on the detection signal from the load detecting means 22, it is determined whether or not the fluctuation amount of the rotational load of the grinding wheel 5 exceeds a reference value (step S57).

If the fluctuation amount of the rotational load of the grinding wheel 5 is within the reference value (Yes), step S53 is performed.
When the amount of change in the rotational load exceeds the reference value (No), it is determined whether the currently performed grinding is finishing (step S58). At this time,
If it is not the finish processing (No), that is, if it is the rough processing, a large cutting depth of the grinding wheel 5 is necessary, so the process returns to step S53 to continue the grinding processing.

When the grinding process is a finishing process (Yes), a command signal is output to the control device 15, and the control device 15 outputs a retreat command of the grindstone head 6 to the grindstone drive means 7. The cutting amount of the grinding wheel 5 with respect to the workpiece W is reduced by a certain amount (steps S59 to S61).

In other words, the grinding apparatus of the above embodiment performs control for moving the center 3 forward with a decrease in the rotational load of the main shaft 1 and increasing the clamping force of the workpiece W by a certain amount. If the repetition is performed, the clamping force may become excessive and deform the workpiece W. Therefore, the rotation load of the grinding wheel 5 is automatically controlled using the grinding wheel load detection unit 22 and the grinding wheel head driving unit 7. When the variation exceeds the reference value, that is, when the variation of the load is large due to the deformation of the workpiece W, the slip of the workpiece W is reduced by reducing the cutting depth of the grinding wheel 5. The generation is more reliably prevented, and the clamping force on the workpiece W is prevented from becoming unnecessarily large.

In order to determine whether the current grinding processing is rough processing or finishing processing, the grinding wheel 5 is used.
Is used as the initial cutting amount (movement amount from the origin). In this case, in the grinding control means 9, a signal for determining the cutting depth may be input from the control device 15 to the arithmetic device 14.

Further, in addition to the above operation, the grinding apparatus of this embodiment outputs a command to retract the grindstone 6 to the grindstone drive means 7 to reduce the cutting depth of the grindstone 5. Since the load on the workpiece W is also reduced, the grinding control means 9 outputs a retract command of the center 3 to the center driving means 23 so that the clamping force on the workpiece W returns to the initial value. As a result, it is possible to more reliably prevent the workpiece W from being subjected to an excessive clamping force.

In the grinding apparatus of this embodiment, the optimum clamping force that does not affect the workpiece W can be automatically determined by the above-described automatic control. Even a small, easy-to-bend one can perform high-precision grinding. Further, when it is determined based on a detection signal from the grinding wheel load detecting means 22 whether or not the variation of the rotational load of the grinding wheel 5 exceeds a reference value, the variation is extremely large, and a predetermined upper limit value is set. If it exceeds
It is also possible to determine that the workpiece W has been deformed, and to perform control to interrupt the grinding.

In the grinding apparatus according to the present invention, specific examples of each component are not limited to the above embodiments. In addition, it is also possible to control the grinding apparatus by using a configuration in which various means are combined in addition to the above embodiments.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a grinding apparatus according to the present invention.

FIG. 2 is a flowchart illustrating the operation of the grinding apparatus shown in FIG.

FIG. 3 is a graph showing a change in load of a spindle motor over time, illustrating a state in which a slip has occurred between a spindle and a workpiece.

FIG. 4 is an explanatory view showing another embodiment of the grinding apparatus according to the present invention.

FIG. 5 is a flowchart illustrating an operation of the grinding apparatus shown in FIG. 4;

FIG. 6 is an explanatory view showing still another embodiment of the grinding apparatus according to the present invention.

FIG. 7 is a flowchart illustrating the operation of the grinding apparatus shown in FIG. 6;

FIG. 8 is an explanatory view showing still another embodiment of the grinding apparatus according to the present invention.

FIG. 9 is a flowchart illustrating an operation of the grinding apparatus shown in FIG. 8;

FIG. 10 is an explanatory view showing a conventional grinding apparatus. Reference Signs List 1 spindle 2 headstock 3 center 4 tailstock 5 grinding wheel 6 grinding wheel table 7 grinding wheel drive means 8 spindle load detection means 9 grinding processing control means 21 spindle rotation adjusting means 22 grinding wheel load detection means 23 center drive means W Workpiece

Claims (9)

[Claims] A headstock provided with a rotationally driven spindle;
A tailstock that rotatably clamps a workpiece between a headstock, a grindstone table provided with a grinding wheel that is driven to rotate, and a grindstone table that drives the grindstone table forward and backward with respect to the clamped workpiece Driving means, spindle load detecting means for detecting a rotational load of the spindle of the headstock, and grinding control means for controlling the wheel head driving means based on a detection signal from the spindle load detecting means. Grinding equipment. 2. The grinding control means outputs a grinding wheel head retreat command to the grinding wheel head driving means when a fluctuation of a detection signal from the spindle load detecting means during the grinding processing exceeds a reference value. The grinding apparatus according to claim 1, wherein: 3. A grindstone rotation adjusting means for adjusting a rotation speed of a spindle of a headstock, and a grindstone load detecting means for detecting a rotational load of a grinding wheel on a grindstone head. 3. A grinding apparatus according to claim 1, wherein said means is a means for controlling said spindle rotation adjusting means based on said detection signal. 4. The grinding control means outputs a spindle deceleration command to the spindle rotation adjusting means when a detection signal from the grinding wheel load detecting means during the grinding processing becomes equal to or less than a reference value. 4. The grinding apparatus according to claim 3, wherein the grinding device is a means for increasing a cutting amount of the workpiece by a predetermined amount. 5. A headstock provided with a rotationally driven spindle,
A tailstock that rotatably holds a workpiece between the headstock, a center driving unit that drives at least the center of the tailstock with respect to the headstock, and a grindstone provided with a rotationally driven grinding wheel A table, a grinding wheel head driving means for driving the grinding wheel head forward and backward with respect to the clamped workpiece, a spindle load detecting means for detecting a rotational load of the spindle of the headstock, and a detection signal from the spindle load detecting means. A grinding process control means for controlling a center driving means by means of a grinding machine. 6. A grinding processing control means for outputting a center advance command to a center driving means when a fluctuation of a detection signal from a spindle load detection means during a grinding processing exceeds a reference value. The grinding apparatus according to claim 5, characterized in that: 7. A grinding wheel load detecting means for detecting a rotational load of a grinding wheel of the grinding wheel head, wherein the grinding processing control means controls the wheel head driving means based on a detection signal from the grinding wheel load detecting means. 7. The method according to claim 5, wherein
2. The grinding apparatus according to claim 1. 8. A grinding machine control means for outputting a grindstone head retreat command to a grinding wheel head driving means when a fluctuation of a detection signal from a grinding wheel load detecting means during grinding processing exceeds a reference value. The grinding apparatus according to claim 7, wherein: 9. A grinding process control means outputs a grinding wheel head retreat command to a grinding wheel head driving means, and when the detection signal from the grinding wheel load detecting means becomes equal to or less than a reference value, the center driving means retreats the center. 9. The grinding apparatus according to claim 8, wherein the means is a means for outputting a command.