JPH06246634A - Centerless grinding machine - Google Patents

Abstract

PURPOSE:To provide a centerless grinding machine which is capable of increasing the stiffness and precision of a dress device and reducing the number of the control shafts of the control device. CONSTITUTION:In a centerless grinding machine where a grinding wheel 5 and a regulating wheel 3 are arranged opposite to each other across a work rest 2, and a dress device 17 is arranged on a counter work rest side of the grinding wheel 5, the work rest 2 is mounted on the fixed position, both the grinding wheel 5 and the regulating wheel 3 are provided in a movable manner in the direction apart from or nearer to work rest 2, and control driving means 10, 9 to control the moving position are provided. A dress blade 22 of the dress device for the grinding wheel is mounted on a traverse slide 20 not through a cut-in slide, the working diameter of the work is controlled by controlling the advancing position of both the grinding wheel 5 and the regulating wheel 3, and the dress margin is controlled by controlling the retreating position of the grinding wheel 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centerless grinding machine used for grinding an outer periphery of a cylindrical work, and is characterized by a dressing device mounting structure for a grinding wheel and a control means for dressing the grinding wheel. It relates to a centerless grinder.

[0002]

2. Description of the Related Art In a centerless grinder, as shown in FIG. 7, a grinding wheel 5 and an adjusting wheel 3 face each other with a work rest 2 interposed therebetween.
Dressing devices 17 and 13 are arranged behind the grinding wheel 5 (opposite to the work rest) and above the adjusting wheel 3, and adjustment is provided behind the adjusting wheel 3 (opposite to the work rest) so that the adjusting wheel 3 can be tilted. A chassis 11 is usually arranged. In a conventional general centerless grinding machine, a grinding wheel 5 is pivotally supported by a spindle casing 16 fixed at a fixed position on a base 1, and a slide stand 4 having a work rest 2 fixed at an end on the grinding wheel side is mounted. It is mounted on the grinding wheel 5 so as to be close to and away from it, and the adjustment chassis 11 is mounted on the slide base 4 so as to be close to and away from the work rest 2, and the adjustment chassis 11 is provided around an axis parallel to the feed direction. Counter shaft casing 1 supported so as to be tiltable
2, the adjusting wheel 3 is pivotally supported, and the dressing device 13 for the adjusting wheel is supported on the auxiliary shaft casing 12 and arranged above the adjusting wheel 3.
The dressing device 17 for a grinding wheel has a structure in which the dressing device 17 is arranged on the side opposite to the workrest of the spindle casing 16 so as to be able to approach and separate toward the grinding wheel 5.

At the time of machining a workpiece, the adjusting wheel 3 is moved by a control motor 40 such as a servo motor or a pulse motor to control the distance between the grinding wheel 5 and the adjusting wheel 3, and the control motor 9 responds to the change in the distance. The position of the work rest 2 is adjusted by moving the slide base 4. In addition, the dressing of the grinding wheel 5 is performed by positioning the cutting slide 23 having the dressing blade 22 attached thereto by the control motor 41 according to the dressing allowance and advancing toward the grinding wheel 5 and positioning the cutting slide 23 and the control motor 41. The traverse slide 20 is traversed in parallel with the axis of the grinding wheel 5. Adjustment car 3
In the same manner, the dressing blade for the adjusting wheel is advanced by the control motor 42 toward the adjusting wheel 3 and positioned, and the dressing blade is traversed in parallel or slightly obliquely with the axis of the adjusting wheel 3. To do.

When irregularities are formed on the peripheral surface of the grinding wheel 5 (same for the adjusting wheel 3) in accordance with the shape of the work, as shown in FIG. 8, the dress blade 22 is placed on the traverse slide 20 for traversing. Further, a copying slide 21 is movably provided in a direction of moving closer to and away from the grinding wheel 5, and a cam follower 27 fixed to the copying slide 21 is pressed by a spring 28 against a template 26 fixed to a slide base 47 of the traverse slide 20 to move the traverse slide. 20
When the robot traverses, the copying slide 21 is moved back and forth along the template 26, and the grinding wheel 5 is dressed by the dressing blade 22 provided on the slit slide 23 mounted on the copying slide 21. In this case, the control motor 41 for adjusting the dressing allowance is attached to the copying slide 21.

On the other hand, in a particularly large centerless grinding machine having automatic work feeding / discharging devices before and after the centerless grinding machine, the work passage and the automatic feeding / discharging device of the centerless grinding machine when the diameter of the work changes. There is known a structure in which both the grinding wheel and the adjusting wheel are movably provided in order to prevent the work passage from being displaced. In this structure, the work rest is provided at a fixed position on the base, and the spindle casing 16 that pivotally supports the grinding wheel 5 is provided.
And the dressing device 17 behind it is mounted on a slide table provided so as to be able to approach and separate from the workrest 2.

[0006]

In the centerless grinding machine having the above-mentioned conventional structure, particularly in the structure provided with a dressing blade copying device as shown in FIG. 8, 2 in the direction perpendicular to the axis of the grinding wheel 5 is used. Dressing blade 2 through three sliding surfaces 43, 44 and a sliding surface 45 in the axial direction of the grindstone.
Since 2 is supported, there is a problem that the support rigidity and the position accuracy of the dress blade are lowered, and thus the processing accuracy of the work is also adversely affected.

Further, in the conventional apparatus, when it is attempted to numerically control the entire machining operation including dressing of the grinding wheel, the above-mentioned four control motors 9, 40, 41, 42 and a grinding wheel drive motor and an adjusting wheel (not shown) are used. A total of 6 axes of control device with drive motor is required. In particular, the centerless grinding machine has a problem that the installation area and cost of the control device are larger than those of the machine body as compared with other machine tools.

The present invention has been made to solve the above problems, and the rigidity and accuracy of the dressing device can be increased, and therefore the grinding wheel can be corrected with higher accuracy, and the cost can be reduced. An object of the present invention is to obtain a centerless grinding machine that can automate all processing operations including dressing of a grinding wheel by a small control device.

[0009]

In the centerless grinding machine according to the present invention, a grinding wheel 5 and an adjusting wheel 3 are opposed to each other with a work rest 2 interposed therebetween, and the grinding wheel 5 is provided on the side opposite to the work rest for the grinding wheel. In the centerless grinding machine in which the dressing device 17 is arranged, the work rest 2 is mounted at a fixed position, and the grinding wheel 5 and the adjusting wheel 3 are attached.
Both of which are movably provided in a direction in which they approach and separate from the work rest 2 and control the movement position thereof.
0 and 9 are provided, and the dressing device 1 for the grinding wheel is provided.
The dressing blade 22 of No. 7 is attached to the traverse slide 20 without passing through the cutting slide 23. By controlling the forward movement positions of both the grinding wheel 5 and the adjusting wheel 3, the machining diameter of the work is controlled, and the grinding wheel is cut. The dressing allowance is controlled by controlling the retracted position of No. 5.

[0010]

In the centerless grinding machine of the present invention, the dressing allowance of the grinding wheel is set by controlling the retracted position of the grinding wheel 5. Therefore, in order to set the dressing allowance, it is not necessary to move the dress blade 22 in a direction in which the dress blade 22 approaches and separates from the grinding wheel 5, and when the dress blade 22 is not copied, the position of the dress blade 22 in the direction perpendicular to the grindstone axis. Can be fixedly provided. That is, there is no need to set the dressing allowance by moving the dressing blade 22 close to and away from the grinding wheel 5, so that there is one sliding surface of the dressing device 17 (sliding surface 44 in FIG. 8).
It becomes unnecessary, the supporting rigidity of the dressing blade 22 is increased, and the positioning accuracy of the dressing blade, particularly the positioning accuracy in the radial direction of the grinding wheel can be improved. Therefore, the dressing accuracy of the grinding wheel (the diameter of the corrected grinding wheel Accuracy).

Accurate control of the moving position of the grinding wheel 5 is necessary in any case in order to control the machining diameter of the workpiece, while the dressing blade 22 is set in the grinding wheel 5 according to the set dressing allowance. Notch slide 2 for moving toward
Since the sliding surface 44 for 3 and the control system for controlling the movement thereof are not required, the number of control axes of the control device can be reduced by one.

Further, based on the same concept as that of the grinding wheel side, the dressing device 13 of the adjusting car is also provided behind the adjusting car 3 so as to traverse at a fixed position, and the dressing allowance of the adjusting car 3 is also set at the retracted position of the adjusting car 3. If it is set by controlling, the number of control axes of the control device can be reduced by two.
In this case, the auxiliary shaft casing 12 cannot be supported behind the adjusting wheel. Therefore, the auxiliary shaft casing 12 is tiltably supported by the circular arc sliding surface 31 provided below the adjusting wheel 3. adopt.

[0013]

EXAMPLE An example shown in the drawings will be described below. 1 to 3 show a first embodiment of the present invention. In FIG. 3, a work rest 2 is provided at the center of the base 1.
Is provided at a fixed position with its tip height adjustable, and a slide stand 4 on the adjusting wheel 3 side and a slide stand 6 on the grinding wheel 5 side are provided on the base 1 with the work rest 2 interposed therebetween. It is slidably mounted on rails 7 and 8 in the direction of approaching and separating from the work rest 2. On the slide bases 4 and 6, feed screws (not shown) axially supported by the base 1 in parallel with the rails 7 and 8 are screwed, and these feed screws are attached to both ends of the base 1 by a feed motor 9 respectively. It is driven to rotate by 10, and the slide bases 4 and 6 are moved toward and away from the work rest 2.

On the adjusting carriage 11 provided on the slide stand 4 on the adjusting car side, a counter shaft casing 12 is supported by a structure similar to the conventional one so as to be tiltable around an axis parallel to the moving direction of the slide stand 4. The adjusting wheel 3 is axially supported by the auxiliary shaft casing 12, and the adjusting wheel 3 is rotationally driven by an auxiliary shaft motor (not shown) arranged behind the base 1 via a belt transmission mechanism. The dressing device 13 for the adjusting wheel is mounted at a position above the adjusting wheel 3 by a support bracket 14 extending from the countershaft casing 12.

The dressing device 13 on the adjusting wheel side in the first embodiment has a structure similar to that of the conventional device, and the advancing position of the dressing blade toward the adjusting wheel 3 can be controlled by the control motor 42, and the dressing blade is mounted. The traverse slide is mounted so that it can travel in a direction perpendicular to the plane of the drawing and that the traveling direction of the traverse slide can be slightly tilted with respect to the axis of the adjusting vehicle 3.

On the other hand, a spindle casing 16 is fixed on the slide base 6, and a grinding wheel 5 is pivotally supported on the spindle casing. The grinding wheel 5 is belt-driven by a spindle motor (not shown) provided behind the base 1. It is driven to rotate through the device. As shown in FIG. 2, the dressing device 17 on the grinding wheel side is mounted on a gate-shaped guide frame 18 having both lower ends fixed to the base 1. That is, a traverse slide 20 is slidably mounted along a rail 19 parallel to the grindstone axis provided on the guide frame 18, and a slide 21 that follows the traverse slide is slidably moved in a direction in which the traverse slide 21 approaches and separates from the grinding wheel 5. The dressing blade 22 is mounted on the copying slide.

The traverse slide 20 is screwed onto a feed screw 24 mounted in parallel with the rail 19 of the portal frame, and the feed screw is rotationally driven by a traverse motor 25 provided at the end of the guide frame 18. Thereby, the traverse slide 20 reciprocates in a direction parallel to the grindstone axis. The copying slide 21 can be fixed to a predetermined position of the traverse slide 20 with a positioning pin or the like, and the fixing is released to guide the guide frame 18
The cam follower 27 fixed to the slide is pressed against the template 26 fixed to
Copy slide 2 along with traverse slide 20 traveling
1 is moved back and forth in the direction of approaching and separating from the grinding wheel 5, so that the peripheral surface of the grinding wheel 5 can be dressed in a shape along the shape of the template 26.

The spindle casing 16 is provided with an opening 48 at a position facing the dressing device 17 into which the dressing blade 22 enters, and this opening is closed when performing a grinding operation, so that the grinding fluid and grinding dust are transferred to the dressing device. I tried not to take it. As the grinding wheel 5, a grinding wheel using super abrasive grains such as CBN and DIA is used. The grinding wheel using such super-abrasive grains has a dressing interval of about one week, which is much longer than that of a grinding wheel using normal abrasive grains (dressing interval 2-3 hours), and the usage cost of the grinding wheel is 1 Approximately 3 mm, which is less than the usage cost (about 50 mm) of a normal whetstone. Therefore, when a grinding wheel using superabrasives is used, the machining position of the work is determined by setting the forward position of the grinding wheel 5 and the dressing cost of the grinding wheel is set by setting the retracted position of the grinding wheel 5. Even if the setting is made, the movement stroke of the grinding wheel 5 does not become so large, and therefore problems such as an increase in the size of the support structure of the dress blade 22 and the base 1 do not occur. On the other hand, when an ordinary grinding wheel is used as the grinding wheel 5, the movement stroke of the grinding wheel 5 is considerably increased in order to cover the range of workable diameters and the diameter difference of the grinding wheel at the beginning and end of use. However, there are cases in which there are disadvantages such as an increase in device size.

4 to 6 show a second embodiment of the present invention, in which the dressing device 13 on the adjusting vehicle side is also arranged behind the adjusting vehicle 3 to set the retracted position of the adjusting vehicle 3. Thus, the structure for setting the dressing allowance of the adjusting vehicle 3 is shown. Since the structure of the grinding wheel 5 side of the second embodiment is similar to that of the first embodiment, only the structure of the adjusting wheel side will be described below.

As shown in FIG. 6, the counter shaft casing 12 is mounted on the slide base 4 so as to be tiltable and fixable via an arcuate sliding surface 31. Adjust the adjustment wheel 3 to the circular arc sliding surface 3
By tilting along 1 and fixing, a desired feed angle (usually about 3 degrees) is given to the adjusting wheel 3. The dressing device 13 on the adjusting wheel side is mounted in the same structure as the dressing device on the grinding wheel side of the first embodiment described above. That is, the copying slide 34 is slidably mounted on the traverse slide 33 that traverses along the portal-shaped guide frame 32 fixed to the fixed position of the base 1 in the direction toward and away from the adjusting wheel 3, and the dressing slide is dressed on this copying slide. A blade 35 is mounted. The traverse drive device of the traverse slide 33 and the fixing or copying structure of the copying slide 34 are the same as those on the grinding wheel side, and the respective members constituting these are shown by the same reference numerals as in FIG.

When the work is through-ground, the adjusting wheel 3 is used.
In addition to providing a feed angle at the time of dressing,
The feed angle and the dress angle are slightly changed in order to slightly widen the inlet and outlet of the work passage formed between the grinding wheel 5 and the adjusting wheel 3. This angle difference is achieved by slightly changing the angle of the countershaft casing 12 on the circular arc sliding surface 31 when dressing the adjusting wheel 3.

As in the second embodiment, the setting of the dressing allowance of the grinding wheel 5 and the setting of the dressing allowance of the adjusting wheel 3 are performed by the grinding wheel 5
When the rear side position setting and the rear side position setting of the adjusting vehicle 3 are performed, two dressing devices 17 and 1 are provided.
Since both the support rigidity of No. 3 and the positional accuracy of the dress blades 22 and 35 can be made highly accurate, the work can be processed with higher accuracy. Further, both control axes for controlling the positions of the dress blades 22 and 35 in the advancing / retracting direction are not required, so that the number of control axes of the control device can be reduced by two compared with the conventional structure, and the price and size of the control device can be greatly reduced. Can be reduced to

[0023]

As described above, according to the present invention, the supporting rigidity of the dressing blade can be increased and the position of the dressing blade can be set with higher accuracy. Can be dressed exactly,
Therefore, there is an effect that the machining accuracy of the work is also improved.
Further, when automating all machining operations of the centerless grinding machine including dressing work, the number of control axes of the control device can be reduced, so that the control device can be made small and inexpensive,
The installation area of the entire device including the control device can also be reduced.

[Brief description of drawings]

FIG. 1 is a front view showing a grinding wheel and a dressing device therefor according to a first embodiment.

FIG. 2 is a side view of the dressing device according to the first embodiment.

FIG. 3 is a front view of the entire apparatus of the first embodiment.

FIG. 4 is a front view of the entire apparatus of the second embodiment.

FIG. 5 is a front view showing an adjusting vehicle and a dressing device therefor according to a second embodiment.

FIG. 6 is a sectional side view of a support structure for an adjusting vehicle according to a second embodiment.

FIG. 7 is a front view of the entire conventional centerless grinding machine.

FIG. 8 is a front view showing a grinding wheel of a conventional centerless grinding machine and a dressing device therefor.

[Explanation of symbols]

 2 Workrest 3 Adjusting wheel 5 Grinding wheel 9 Pulse motor 10 Pulse motor 12 Secondary shaft casing 17 Dressing device 20 Traverse slide 22 Dressing blade

Claims (1)

[Claims] 1. A grinding wheel (5) and an adjusting wheel (3) face each other with a work rest (2) interposed therebetween, and a dressing device (17) for the grinding wheel is provided on the side opposite to the work rest of the grinding wheel (5). In the centerless grinder that is placed, the work rest (2) is mounted in place,
Both the grinding wheel (5) and the adjusting wheel (3) are movable in the direction toward and away from the work rest (2), and control drive means (10), (9) for controlling the moving position are provided. The dressing blade (22) of the dressing device (17) for the grinding wheel is provided on the traverse slide (20) without the cut slide,
(5) and the adjusting wheel (3) are controlled to control the machining diameter of the work by controlling the forward movement position, and the retracting position of the grinding wheel (5) to control the dressing allowance. A heartless grinder.