JP2000108030A - Grinding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grinding device in which grinding work of a grinding wheel is not limited even while the other grinding wheel is dressed by a grinding wheel correcting device in a case where a workpiece is ground by a plurality of grinding wheels. SOLUTION: When grinding wheels 16, 18 grind a cranks shaft 12, abrasive grains are formed on the grinding surfaces of the grinding wheels 16, 18 by friction in grinding. Therefore, the grinding surfaces of the grinding wheels 16, 18 are dressed by grinding wheel correcting devices 74, 76. Since the grinding wheel correcting devices 74, 76 are arranged outside the grinding range W of the grinding wheels 16, 18, the grinding operation of the grinding wheel 18 is not limited even while the grinding surface of the grinding wheel 16 is dressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding apparatus provided with a grinding wheel correcting device for reshaping the grinding surface of a grinding wheel for grinding a workpiece.

[0002]

2. Description of the Related Art As shown in FIG.
Is a spindle device 14 that rotationally drives the crankshaft 12
A pair of grindstones 16 and 18 for grinding the pin journal P of the crankshaft 12, a pair of grindstone stands 20 and 22 for rotating the grindstones 16 and 18, and a grindstone correcting device 24 for re-grinding the grindstones 16 and 18. And a feed table 26 on which the grindstone stands 20 and 22 are arranged.

In such a grinding apparatus 11, the grinding wheel head 2
0 and 22 move on the feed table 26 in the X and Y axis directions, and simultaneously grind the pin journals P at different positions of the crankshaft 12 where the grindstones 16 and 18 are rotatably supported by the spindle device 14. Processing time can be shortened.

By the way, when the grindstones 16 and 18 grind the pin journal P for a predetermined time, abrasive grains are formed on the grinded surfaces of the grindstones 16 and 18 so that the grindstones 16 and 18 become uneven.
8 is moved to the grindstone correcting device 24, and then the grindstones 16 and 1 are moved.
The ground surface of No. 8 is modified.

[0007] However, as can be seen from FIG. 7, the grinding wheel correcting device 24 has a region (the grinding process of the crankshaft 12) where the grinding wheel heads 20 and 22 move when the grinding wheels 16 and 18 grind the pin journal P. Area), there is a problem as described below.

That is, when the grinding surfaces of the two grindstones 16 and 18 are sequentially reviewed by one grindstone correction device 24,
While the dressing of one of the grinding wheels 16 is being performed, the movement of the other grinding wheel base 22 is restricted because the grinding wheel correction device 24 is disposed in the grinding region of the crankshaft 12,
Grinding of the crankshaft 12 could not be performed.

[0007]

SUMMARY OF THE INVENTION Therefore, in order to solve the above-mentioned problems, the present invention provides a grinding method which does not limit the grinding operation of the other whetstone even while the other whetstone is being modified. It is an object to provide a device.

[0008]

According to a first aspect of the present invention, there is provided a grinding apparatus for rotating a workpiece, a pair of grindstones for grinding the workpiece, and rotating and rotating the grindstones.
A pair of grindstone heads, and moving means for moving the grindstone head toward or away from the workpiece or moving along the workpiece, and each provided with a grindstone correction device outside the grinding area of the workpiece. It is characterized by.

According to this configuration, the workpiece rotatably supported by the spindle device is ground by the grindstone turned by the grindstone table. Then, the work is ground into a predetermined shape by moving the grindstone head toward and away from the work or along the work by the moving means. On the other hand, when the grindstone grinds the workpiece, abrasive grains are formed on the grinding surface of the grindstone due to friction with the workpiece. Since the grinding surface of the grindstone becomes uneven due to the formation of the abrasive grains, it is necessary to modify the grinding surface of the grindstone in order to maintain the precision of the grinding surface of the workpiece. The dressing of the grinding surface is performed by a grindstone correcting device arranged outside a region where the grindstone table moves when the grindstone grinds the workpiece, that is, outside the grinding region.

[0010] In detail, the grindstone table moves out of the grinding area of the workpiece, and the grinding surface of one of the grindstones is adjusted by a grinding wheel correction device arranged outside the grinding area. When the grinding surface is being reworked, the grinding wheel head is not located in the grinding area, so even while the grinding surface of one whetstone is being reworked, the workpiece is ground by the other whetstone. The operation is not restricted, and the workpiece can be ground. Also,
Since each pair of the grindstone and the grindstone correction device is provided, the grindstone and the grindstone correction device can respectively correspond to simultaneously grind the grinding surfaces of both grindstones. Efficiency can be increased.

According to a second aspect of the present invention, there is provided a grinding apparatus comprising: a spindle device for driving a workpiece to rotate; a pair of grinding wheels for grinding the workpiece;
A moving means for moving the grindstone table toward or away from the workpiece, or moving the grindstone along the workpiece, and provided with a grindstone correction device for the other grindstone outside the grinding area of the other grindstone. I do.

According to this configuration, both wheel heads have their own grinding areas. Then, both grinding wheels grind the grinding points in the range of the separate grinding areas. At this time, since the grindstone correcting device for modifying the grinding surface of the grinding wheel of one of the grinding wheels is arranged outside the grinding area of the other grinding wheel, the grinding surface of one of the grinding wheels may be modified. Even
There is no restriction on the grinding operation of the other grindstone.

Therefore, even if a grindstone correction device for redressing the grindstone of one grindstone head is arranged in the grinding area of the workpiece, the grinding operation of the other grindstone stone can be performed without disturbing the grinding operation of the other grindstone grindstone. The ground surface can be modified.
For this reason, compared with the first aspect of the present invention, the degree of freedom can be increased in the location of the grindstone correcting device.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a grinding apparatus according to an embodiment of the present invention.

As shown in FIG. 2, the grinding apparatus 10 according to the present embodiment is provided with a feed table 26.

As shown in FIGS. 1 and 2, on a feed table 26, a spindle device 14 is disposed on both sides with a crankshaft 12 interposed therebetween as a workpiece. The spindle device 14 includes a headstock 14A and a tailstock 14B.

A spindle 28 is rotatably mounted on the headstock 14A. The main shaft 28 is provided with a hydraulic chuck 30, which grips the crankshaft 12.

On the other hand, a tailstock shaft 32 is rotatably mounted on the tailstock 14B. The tail shaft 32 moves in the axial direction according to the length of the crankshaft 12, and the main shaft 28
Together with the crankshaft 12.

The spindle 28 and tailstock 32 rotate the crankshaft 12 synchronously by a servomotor 31 built in the headstock 14A and tailstock 14B, respectively.

On the other hand, the feed table 26 has two guide rails 3 parallel to the axial direction of the crankshaft 12.
4 and 36 are provided.

On the guide rails 34, 36, the grinding wheel head 2
Two tables 38 and 40 constituting 0 and 22 are slidably mounted. Also, two tables 38,
40 is the grinding area W of the crankshaft 12
(See FIG. 3) ball screws 42, 4 extending to the outside
4 screwed.

These ball screws 42, 44 are turned by servo motors 46, 48, respectively,
8 and 40 are respectively moved in the X direction shown in FIG.

The tables 38 and 40 are provided with ball screws 50 and 52 extending in the Y direction, respectively.

To these ball screws 50, 52, two heads 54, 56 which form grinding wheel heads 20, 22 and move along guide rails 21, 23 are screwed. The ball screws 50 and 52 are both turned by the motors 58 and 60 to move the heads 54 and 56 in the Y direction, respectively.

The heads 54 and 56 have a motor 6
6 and 68 are arranged.
6, 18 are rotatably mounted.

The heads 54 and 56 are provided with a whetstone 1
Covers 70 and 72 that cover a part of the parts 6 and 18 are attached for the safety of workers.

The grindstones 16 and 18 are mounted on the crankshaft 12
And is rotated by motors 66 and 68.

On the side surfaces of the headstock 14A and the tailstock 14B, grindstone correcting devices 74 and 76 are provided, respectively. The grinding wheel correcting devices 74 and 76
Is located outside the grinding area W. Here, the grinding region W of the crankshaft 12 refers to a region where the grinding wheel heads 20, 22 move when the grinding wheels 16, 18 grind the pin journal P of the crankshaft 12, as shown in FIG.

The grindstone correcting devices 74, 76
8 includes crushers 78 and 80 for reshaping the grinding surface, and motors 82 and 84 for driving the crushers 78 and 80. The motors 82 and 84 are usually housed inside a housing.

The crushers 78 and 80 include a motor 82,
Drive shafts 84 and 88 for transmitting the drive of the drive shaft 84 and disc-shaped polishing portions 90 and 92 fitted on the outer periphery thereof are formed. As shown in FIGS. 1 and 3, the polishing portions 90 and 92 are formed.
Is in contact with the grinding surfaces of the grindstones 16 and 18 to perform dressing.

Note that the polishing sections 9 of the crushers 78 and 80
Reference numerals 0 and 92 are made of a hard material such as diamond, and are suitable for redressing the grinding surfaces of the grindstones 16 and 18.

Next, a control mechanism of the grinding device will be described.

As shown in FIGS. 2 to 5, encoders 33, 94, 96, 98, and 100 are connected to the motors 31, 46, 48, 58, and 60, respectively.

The machining operation of the wheel heads 20 and 22 is controlled by motor control circuits 104 and 105 based on a deviation between a feedback signal from the encoders 94, 96, 98 and 100 and a command value from the numerical controller 102. In addition,
The encoder 33 in FIG. 5 is connected to the servo motor 31.

Specifically, as shown in FIG. 5, the numerical controller 102 has two CPUs 110 and 112, a ROM 1
14, a RAM 116, an input / output device 118, and the like.

The ROM 114 stores a program for executing a grinding method such as fixed-size plunge grinding, indirect plunge grinding, and fixed-size traverse grinding, and a program as shown in the flowchart of FIG.

The RAM 116 stores the crankshaft 12
The grinding method for each grinding location and which grinding wheel 16, 18
Is stored, whether or not grinding is completed is stored.

The motor control circuit 104 includes a driver unit. The motors 46, 48, and 58 move the tables 38, 40 and the heads 54, 56 to target values in accordance with the deviation. , 60 are controlled. In addition, the servo motor 31 is controlled to adjust the rotation of the crankshaft 12.

Next, the operation of the grinding apparatus according to this embodiment will be described with reference to FIG.
This will be described based on the flowchart shown in FIG.

First, in step 200, the headstock 14A,
The crankshaft 12 is rotated by a servomotor 31 built in the tailstock 14B. Then, the program stored in the numerical controller 102 is executed to execute the grinding wheel head 2
The grinding wheels 16 and 18 are rotated by the motors 66 and 68 to simultaneously grind different grinding locations. Thereby, the pin journal P of the crankshaft 12 is ground into a predetermined shape. Then, as the grinding of the pin journal P is continued, it is assumed that, for example, the grinding surface of the grindstone 16 is worn down due to friction and abrasive grains are formed.

In order to judge this timing, in step 202, 1 is added to the parameter A every time the machining position of the crankshaft 12 is ground.

In step 204, it is determined whether or not this value exceeds the value of R indicating the timing at which the grindstone 16 is to be modified.

If this value is exceeded, the grinding surface of the grindstone 16 is redressed in step 206.
As shown in FIG.
Then, the table 38 is moved in the X direction by the motor 46, the grindstone table 20 is retracted from the grinding area W, and the grindstone 16 is moved on the extension of the polishing section 90.

Next, at step 208, the encoder 98
Then, the number of rotations of the motor 58 is controlled to move the grindstone table 38 in the Y direction (downward direction). Thus, even while the grinding surface of one grindstone 16 is being modified, the grinding operation of the other grindstone 18 is not limited, and the pin journal P of the crankshaft 12 can be ground.

Next, after resetting the parameter A to 0 in step 210, it is determined in step 212 whether or not all the processing positions of the crankshaft 12 have been processed.

If the machining of all machining locations has been completed, it is determined in step 214 whether or not there is a next crankshaft 12 (workpiece).

As a result, the crankshaft 1 to be ground
If there is 2, follow the machining program again and follow step
After setting another crankshaft 12 in step 6, grinding is performed in step 200. On the other hand, if there is no crankshaft 12 to be ground, this program ends.

If it is determined in step 212 that all the processing points have not been completed, in step 200, the next processing point is ground.

As another embodiment, in the above embodiment, the grindstone correcting devices 74 and 76 are provided on the side surfaces of the headstock 14A and the tailstock 14B.
If the wheels 6 and 18 are outside the grinding area W, the places where the grindstone correcting devices 74 and 76 are attached are not limited to this.

As an example of the above embodiment, the grinding wheel head 2
A case in which 0 and 22 have their own grinding regions W1 and W2 will be described.

As shown in FIG. 4, when the grinding areas W1 and W2 of the grindstones 16 and 18 of the grindstone heads 20 and 22 are separately and independently defined, the grindstone heads 20 and 22 are respectively positioned in the longitudinal direction of the crankshaft 12. It only moves halfway through.
In this embodiment, the grindstone correcting device 74 for redressing the grindstone 16 of one grindstone head 20 is provided with a grinding area W1 of the grindstone head 20.
May be arranged on the other hand, while the grindstone correcting device 76 may be arranged in the grinding area W2 of the grindstone table 22.
That is, as long as the grindstone correcting device 74 for reshaping the grindstone 16 of the grindstone head 20 is arranged outside the grinding region W2 of the grindstone head 22, even if the grindstone 16 of one grindstone head 20 is reshaped. The grinding operation of the other wheel head 22 is not affected at all. As a result, the same effect can be obtained for the grindstone correcting device 76 corresponding to the grindstone table 22.

[0052]

According to the grinding apparatus of the present invention, even while the grinding surface of one of the grinding wheels is being modified by the grinding wheel correcting device, the other grinding wheel can grind the workpiece without any limitation. can do. In addition, since the grinding surfaces of both grinding wheels can be simultaneously modified by both grinding wheel correction devices, the grinding surfaces of the grinding wheels can be efficiently modified and unnecessary time can be saved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a grinding device according to an embodiment.

FIG. 2 is a plan view of the grinding device according to the embodiment.

FIG. 3 is a plan view showing a state in which a grindstone of the grinding device according to the present embodiment is redressed.

FIG. 4 is a plan view showing another example of the grinding device according to the present embodiment.

FIG. 5 is a block diagram of a control device that controls each drive unit of the grinding device according to the present embodiment.

FIG. 6 is a flowchart for controlling a wheel head of the grinding device according to the present embodiment.

FIG. 7 is a plan view of a conventional grinding device.

[Explanation of symbols]

 12 Crankshaft (workpiece) 14 Spindle device 16, 18 Grindstone 20, 22 Grindstone 21, 23, 34, 36 Guide rail (moving means) 42, 44, 50, 52 Ball screw (moving means) 46, 48, 58, 60 motor (moving means) 74, 76 grinding wheel correction device W, W1, W2 grinding area

Claims (2)

[Claims] 1. A spindle device for driving a workpiece to rotate, a pair of grindstones for grinding the workpiece, a pair of grindstone tables for pivotally supporting and turning the grindstones, respectively, And a moving means for moving toward and away from the workpiece or moving along the workpiece, wherein a grinding wheel correcting device is provided outside each of a grinding area of the workpiece. 2. A spindle device for driving a workpiece to rotate, a pair of grinding wheels for grinding the workpiece, a pair of grinding wheels for pivotally supporting and turning each of the grinding wheels, and Moving means for moving toward or away from, or moving along the workpiece, grinding being provided outside the grinding area of one of the grinding wheels and a grindstone correcting device for the other of the grinding wheels provided. apparatus.