JP3170113B2 - Method and apparatus for dressing grindstone of grinder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for dressing a grinding wheel of a grinding machine.

[0002]

2. Description of the Related Art Generally, in a grinding machine, grinding powder of a member to be ground is clogged in a concave portion (chip pocket) formed between abrasive grains on an outer peripheral grinding surface of a grinding wheel, and abrasive grains are worn.
When the grinding cannot be performed smoothly, a so-called dressing operation for removing the grinding powder and the like is performed. Conventionally, in such dressing work, a dressing grindstone cut out in a block shape is clamped to a rod end of a cylinder and pressed against the outer peripheral grinding surface of a rotationally driven grinding grindstone at a low pressure.

[0003]

However, in the conventional dressing operation, since the dressing grindstone is manually clamped each time, there is a problem that the working efficiency is low. In particular, if the grinding wheel uses a superabrasive having a high hardness, the dressing wheel (usually a white stone is used) in one dressing operation.
However, the above problem has been remarkable because it is necessary to carry out this dressing operation twice a day.

For this reason, it has been considered that the dressing grindstones are arranged in advance, and then automated by sequentially clamping and using the grinding wheels. However, the generated grinding powder adheres to the clamp portion, and is applied to a new dressing grindstone. It could not be adopted because of problems such as generation of scratches and insufficient clamping. In view of the above problems, an object of the present invention is to provide a method and an apparatus for dressing a grindstone of a grinding machine, which can efficiently perform dressing work and can be automated.

[0005]

According to the present invention, in order to achieve the above object, a grinding wheel having a substantially cylindrical shape is rotated, and a sharpening wheel is pressed against an outer peripheral grinding surface of the grinding wheel to perform sharpening. In the method for dressing a grindstone of a grinding machine, the dressing grindstone is formed in a cup shape having an annular dressing surface at an end surface, and a radial direction of the dressing substantially coincides with a grindstone width center line of the grinding grindstone. In addition, by arranging a sharpening surface of the sharpening whetstone with respect to the outer periphery of the grinding wheel, sharpening is performed while indexing and rotating the sharpening whetstone by a predetermined angle, the sharpening time is measured, and the sharpening time is measured. If it is determined that the dressing is completed, the dressing is terminated.If it is determined that the dressing is insufficient, the dressing is continued until it is determined that the dressing is completed. If in any of the regions, in which so as to cancel the dressing.

[0006]

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic view of a grinding machine provided with a dressing grindstone. In this grinding machine, a grindstone holding table 2 is mounted on a cutting feed device 1. The cutting feed device 1 is configured to reciprocate in a direction perpendicular to the plane of FIG. 1 by driving the cutting motor 3. Whetstone holder 2
A grinding wheel 4 is rotatably held in the grinding wheel 4, and the grinding wheel 4 is rotationally driven by a drive motor 5.

A dressing whetstone 6 is disposed above the grinding whetstone 4. As shown in FIG. 2, the dressing grindstone 6 has a cup shape in which the outer peripheral edge of a disk is extended in a substantially right angle direction, and the distal end surface of the extended portion faces the outer peripheral grinding surface of the grinding wheel 4. It is a dressing surface 6a. That is, the dressing surface 6a of the dressing grindstone 6 is arranged on the outer periphery of the grinding wheel 4 so that the radial direction of the dressing surface 6a substantially coincides with the grinding wheel width center line A of the grinding wheel 4. (See FIG. 7). Further, the length of the extended portion is larger than the cut depth at the time of dressing.

The dressing grindstone 6 is rotatably held by a holding member 8 attached to a support plate 7 so as to be movable up and down in the direction of the arrow in FIG. More specifically, the dressing grindstone 6 is clamped by screwing a screw portion of a mounting plate 10 a to a tip of a rotating shaft 10 rotatably held by a holding member 8 via a bearing 9. Guide pins 11a and 11b are screwed to the holding member 8, and the guide pins 11a and 11b are slidably held by a cylindrical holding portion 12 attached to the support plate 7 via a bearing 13. A detection piece 14 is provided at an end of the guide pin 11b, and a tip of the detection piece 14 is
Are respectively detected by detection sensors 15a and 15b attached at predetermined intervals. The dressing grindstone 6 moves up and down together with the holding member 8 by driving a cylinder 16 fixed to the support plate 7.

As shown in FIG. 3, a pinion 18 is connected to an intermediate outer peripheral portion of the rotary shaft 10 through a one-way clutch 17.
Is provided. A rack 19 meshes with the pinion 18. The rack 19 is slidably accommodated in a cylinder 20 and reciprocates by increasing air pressure (or hydraulic pressure) in the first chamber 20a or the second chamber 20b. Therefore, if the rack 19 is moved upward in FIG. 3 by increasing the air pressure in the first chamber 20a, the dressing grindstone 6 is rotated through the pinion 18 by a predetermined angle in the direction of the dotted arrow. However, the opposite direction, that is, the rack 19
Is moved downward in FIG. 3, the rotation shaft 10 does not rotate due to the function of the one-way clutch 17.

As shown in FIG. 4, an index plate 2 formed at the lower end of the rotating shaft 10 is provided at the center of the end surface of the holding member 8.
1 is provided, and an engagement concave portion 22 is formed in an outer peripheral portion thereof. On the other hand, an outer peripheral wall 23 is provided on the outer peripheral edge of the end surface of the holding member 8 in parallel with the outer peripheral surface of the index plate 21. A lock lever 25 is attached between the outer peripheral surface of the index plate 21 and the outer peripheral wall 23 so as to be rotatable about a support shaft 24. The lock lever 25 has an engaging portion 26 at the distal end that engages with and disengages from the engaging recess 22. Also,
The lock lever 25 is provided with a positioning pin 27 urged in a protruding direction by a spring 27a.
The rotation of the lock lever 25 in the counterclockwise direction is restricted by a detent pin 28, as shown by a solid line in FIG. 4, and the end of the positioning pin 27 is By pressing against the outer peripheral wall 24,
It is designed to be positioned. As shown by the two-dot chain line in FIG. It is possible to loosen the screws.

The raising and lowering of the dressing whetstone 6 is as follows.
As shown in FIG. 1, the switching valve 30 b is switched by a control signal from the control device 29 to increase the air pressure in the upper chamber 16 a or the lower chamber 16 b of the lifting cylinder 16 of the sharpening whetstone 6. . The indexing rotation of the dressing grindstone 6 is performed by switching the switching valve 30 a according to a control signal from the control device 29, and the indexing cylinder 2.
This is performed by increasing the air pressure in the first chamber 20a or the second chamber 20b. The control device 29
Sends control signals to the cutting motor 3 and the rotation motor 5 of the grinding wheel 4 to control the rotation of these.

Next, the dressing operation of the grinding machine provided with the dressing whetstone will be described with reference to the flowchart of FIG. This dressing operation is performed, for example, when the chip pockets of the grinding wheel 4 are clogged with grinding powder. The determination of the necessity of the dressing operation is performed by the control device 29 based on the grinding time, the number of times of grinding, and the like.

First, in step S1, the cutting motor 3 is driven to move the grinding wheel 4 from the grinding position to the dressing position. In this case, the grinding wheel 4 is kept rotating. Then, in step S2, the sharpening grindstone 6 is lowered, and the rotating grinding grindstone 4 is cut to a predetermined depth B to perform sharpening. Also, counting is started in step S3.

Subsequently, in step S4, the dressing whetstone 6
Is determined to have reached the descent position. If you have reached
In step S5, it is determined whether the first abnormal time has elapsed. If not, it is determined in step S6 whether the second abnormal time has elapsed.

In step S5, if the first abnormal time has not elapsed, or if the second abnormal time has elapsed in step S6, an abnormality is notified by a buzzer, a lamp or the like in step S7, and the grinding machine is notified. After stopping, the dressing work is finished. Here, the reason that the first abnormal time has not elapsed is in the first abnormal region (see a dashed line in FIG. 6).
This is the case where the dressing grindstone 6 is not set, or where the dressing has already been performed. The second abnormal time has passed within the second abnormal region (see the two-dot chain line in FIG. 6), and the rotation of the grinding wheel 4 has stopped due to the belt being cut or the like. And when the chip pocket is completely clogged with grinding powder.

Therefore, if it is determined in step S4 that the dressing grindstone 6 is at the lowered position, and if it is determined in step S5 that the first abnormal time has elapsed, the dressing work is performed normally. Because
In step S8, the dressing grindstone 6 is raised.
Then, when the dressing grindstone 6 reaches the raised position in step S9, the raising is stopped in step S10.

When the first dressing operation is completed in this way, it is determined in step S11 whether the dress is completed. If the dressing time is not within the dress completion area, it is determined that the dress is insufficient, and the process returns to step S2 to repeat this dressing operation until the dress is completed in step S11.

As described above, in this embodiment, by measuring the dressing time, not only abnormality detection but also determination of whether or not the dressing is properly performed is performed. The operation time can be greatly reduced, and automation is possible. Alternatively, the sharpening time may be monitored at the sharpening speed instead. In the above embodiment, a cup-shaped grindstone 6 was used as the dressing grindstone 6.
A configuration in which an annular grindstone 6c is bonded to b may be adopted. Also,
In the above embodiment, the one-way clutch 17 used as the indexing mechanism is not limited to the one shown in the drawing, and other, for example, the gear transmission means in which the gears are meshed with each other is indexed and rotated by the drive motor. A configuration may be adopted.

[0020]

As is apparent from the above description, according to the method and apparatus for dressing a grinding wheel of a grinding machine according to the present invention,
Since the dressing work was performed by indexing and rotating a dressing whetstone provided with a dressing surface on the circumference,
The dressing operation can be performed continuously, automation can be performed, and the operation time can be significantly reduced. Further, if the dressing operation is controlled based on the measured dressing time, the abnormality can be easily detected. Further, the dressing state (tip pocket depth) can be easily managed.

[Brief description of the drawings]

FIG. 1 is a schematic view of a grinding machine provided with a grindstone dressing apparatus according to the present embodiment.

FIG. 2 is a sectional view showing a holding structure of the dressing grindstone of FIG. 1;

FIG. 3 is a sectional view showing the indexing rotation mechanism of FIG. 2;

FIG. 4 is a front view showing the lock handle of FIG. 2;

FIG. 5 is a flowchart of a dressing operation.

FIG. 6 is a graph showing a relationship between a sharpening time and a cutting depth.

FIG. 7 is a local bottom view showing the arrangement of the dressing surface of the dressing grindstone with respect to the grinding wheel.

[Explanation of symbols]

 4 ... Whetstone for grinding, 6 ... Whetstone for dressing.

Continuation of front page (56) References JP-A-5-38676 (JP, A) JP-A-2-135160 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B24B 53 / 00-53/12

Claims (2)

(57) [Claims] 1. A method of dressing a grinding machine in which a grinding wheel having a substantially cylindrical shape is rotated and a sharpening grindstone is pressed against an outer peripheral grinding surface of the grinding wheel to sharpen the grinding wheel. Is formed in a cup shape having an annular sharpening surface, and the sharpening of the sharpening grindstone with respect to the outer periphery of the grinding wheel such that the radial direction of the sharpening line substantially coincides with the centerline of the grinding wheel width of the grinding wheel. By arranging a surface, sharpening is performed while indexing and rotating the sharpening grindstone by a predetermined angle, the sharpening time is measured, and if it is determined that the sharpening time is the dress complete area, the sharpening is terminated. If it is determined that the dressing is insufficient, the dressing is continued until it is determined that the dressing is complete. If not, the dressing is stopped. Grinder grindstone sharpening method characterized. 2. A grindstone dressing apparatus for a grinder, which rotates a substantially cylindrical grinding wheel and presses a sharpening grindstone against an outer peripheral grinding surface of the grinding wheel, wherein the sharpening wheel is an end face. Is formed in a cup shape having an annular sharpening surface, and the sharpening of the sharpening grindstone with respect to the outer periphery of the grinding wheel such that the radial direction of the sharpening line substantially coincides with the centerline of the grinding wheel width of the grinding wheel. While arranging the surface, an indexing mechanism for indexing and rotating the sharpening grindstone by a predetermined angle, indexing and rotating by the indexing mechanism, measuring the sharpening time, and determining that the sharpening time is the dressing complete area. If it is determined, the dressing is terminated. If it is determined that the dressing is insufficient, the dressing is continued until it is determined that the dressing is completed. A grindstone dressing apparatus for a grinding machine, further comprising control means for stopping the dressing if necessary.