JPH06258050A - Profile measuring apparatus for grinding wheel - Google Patents

Abstract

PURPOSE:To measure the curved outline of a grinding wheel and subject the grinding wheel to truing when the error exceeds a predetermined level. CONSTITUTION:In a dressing unit comprising a rotating grinding wheel 36 provided with an outer peripheral grinding plane and a rotating dresser for dressing the outer peripheral plane, light is projected from a projector 37a toward the grinding wheel 36. A light receiving unit 37b is disposed on the optical path 12 of the projected light and ON/OFF position is measured when the light 12 impinges on the light receiving unit 37b thus measuring the outline of the grinding wheel 36.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grindstone shape measuring device. For more details, ultrafine diamond wheel, CBN
The present invention relates to a grindstone shape measuring device capable of measuring the shape of a grindstone after molding by truing and dressing the curved surface of a grinding wheel such as a wheel with a rotary dresser.

[0002]

2. Description of the Related Art As new materials such as fine ceramics are used, there is an increasing need to grind these materials with high efficiency and accuracy. For processing high hardness materials such as fine ceramics, diamond wheel, CB
A grindstone with hard abrasive grains such as N wheel is used.

When the grindstone is clogged or the shape of the grindstone is lost due to the processing of these materials, the sharpness of the grindstone is deteriorated.
It is necessary to perform truing and dressing in the same manner as a normal grindstone. For this dressing, conventional dressing methods such as rotary dressing and point dressing, and truing methods are used.

However, since the abrasive grains of diamond and CBN grindstones are hard, truing and dressing are difficult with conventional methods. There is an increasing demand for truing and dressing of diamond wheels with high precision and efficiency.

On the other hand, it is also known that after the grindstone is shaped into an arc, the shape of the outer circumference of the arc of the grindstone is measured. For example,
As in Japanese Patent Publication No. 4-71667, there is a grindstone measuring device in which a contact piece is brought into contact with the outer circumference of a grindstone to obtain an arc radius and a center position, and correct the deviation when it is out of a target. However, since this measuring device is of the contact type as described, there is a problem that wear occurs each time the contactor makes contact. In addition, since the measuring device is separate from the dressing and truing device, the periphery of the grindstone is occupied by both devices, resulting in poor operability.

On the other hand, there is also known a grindstone shape measuring device for measuring a non-contact trued grinding surface such as Japanese Utility Model Laid-Open No. 4-125565. However, since the projection direction of the laser beam for measurement is irrelevant to the moving method of the truing device, there are problems such as inaccurate measurement and complicated coordinate calculation.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a grinding wheel shape measuring device equipped with a truing and dressing device (hereinafter simply referred to as a truing device) capable of measuring the outer shape of a grinding wheel with a simple structure and control device. To provide.

Another object of the present invention is to measure the R shape of the outer circumference of a grindstone, and if an error of a predetermined value or more occurs, truing the grindstone shape with a truing device so that the optical path coincides with the turning axis for truing. To provide a measuring device.

[0009]

[Means for Solving the Problems] To solve the above problems, the following means are adopted.

According to the present invention, in a truing device provided with a turning shaft for truing the outer peripheral surface of a grinding wheel, a projector for projecting light along the turning axis to project light on the grinding wheel. A light receiver arranged on the optical path of the light for receiving the light and having a distance on the turning axis, and detecting ON / OFF when the light receiver receives the light, A grindstone shape measuring device comprising: a grindstone shape detecting means for detecting the on / off coordinate position.

[0011]

In the truing device for truing the outer peripheral surface of the grinding wheel, light is projected from the light projector to the grinding wheel along the axis of rotation. A light receiver is arranged on the optical path of this light, and the ON / OFF position when the light is received by the light receiver is measured by the grindstone shape detecting means to measure the outer peripheral surface shape of the grinding grindstone.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The following embodiment is an example in which the present invention is applied to a truing device for cylindrical grinding. Figure 1
FIG. 2 is a plan view of the truing device, FIG. 2 is a side view showing a partial cross section of the truing device, and FIG. 3 is a sectional view showing an upper support structure of a revolving frame.

The machine base 2 of the truing device 1 is fixed to a table 3 provided on a bed of a grinder (not shown). The table 3 is moved in the Z-axis direction by a servo motor (not shown) in the horizontal plane. A grindstone (not shown) is driven and controlled by a servomotor (not shown) in an X-axis direction orthogonal to the Z-axis direction. The machine base 2 includes a column portion 4, and an upper plate 5 and a lower plate 6 provided on the upper and lower portions of the column portion 4.

A swivel frame 7 is arranged between the upper plate 5 and the lower plate 6. The turning frame 7 is provided with turning shafts 8 and 9 in the upper and lower portions, and the turning shafts 8 and 9 are supported by the upper plates 5 and 6 via bearings 10 and 11. As a result, the swivel frame 7 can swivel around the vertical swivel axis 12.

The servo motor 13 provided on the upper plate 5 is
This is for turning the turning frame 7. The revolving frame 7 includes toothed pulleys 15 and 16 provided on the output shaft 14 of the servomotor 13 and the upper revolving shaft 8, respectively.
And a toothed belt 17 provided between the toothed pulleys 15 and 16 (see FIG. 3).

A slider 18 is provided on the revolving frame 7 so as to be movable up and down via a guide member (not shown). Both ends of a link 21 are pivotally supported by an upper pin 22 and a lower pin 23 between a face plate 20 provided on the output shaft of the servo motor 19 and the slider 18. The slider 18 is moved up and down by the drive of the servomotor 19 so that the upper pin 22 pivots around the output shaft. Servo motor 19
Is for aligning the grindstone 32 with the axial center of the grindstone 36.

A ball screw 24 is horizontally provided on the slider 18. A housing 27 is fixed to a nut 25 screwed to the ball screw 24 via a bracket 26. The housing 27 is movable in the horizontal direction with respect to the slider 18 via a guide member (not shown). The ball screw 24 is connected to a servo motor (not shown) via a toothed pulley 28 and a toothed belt (not shown). Ball screw 24 by the drive of the servo motor
Rotates, and the housing 27 moves in the horizontal direction (X-axis direction), that is, in the direction toward or away from the grinding wheel 6.

A spindle 29 is rotatably supported in the housing 27 via a bearing 30. A grindstone 32 for truing is fixed to one end of the spindle 29 via a grindstone fixing plate 31. The other end of the spindle has pulleys 33a and 33b and a timing belt 34.
Is connected to the servomotor 35 via. The grinding wheel 32 for truing is rotated by the drive of the servo motor 35.

In the above structure, the grinding wheel 36
According to the shape, the grindstone 32 turns and horizontally moves to truing and dressing the grindstone 36 into a desired arc shape. Prior to this truing and dressing work, the servomotor 19 is driven to align the grindstone 32 with the axis center of the grindstone 36.

The truing apparatus 1 is provided with detection means for detecting the outer shape of the grinding wheel 36.
The shape detecting means is an optical type, and is used for the revolving frame 7
37a and light receiver 37b provided on the inner surfaces of the upper and lower parts of the
It consists of The projector 37a is a laser projector in which a semiconductor laser is used as a light source in this embodiment, and is arranged so that its optical axis coincides with the swivel axis 12 of the swivel frame 7.

That is, the laser light emitted from the light projector 37a passes on the turning axis 12 and is received by the light receiver 37b. Then, whether or not the grinding wheel 36 blocks the laser beam, in other words, the outer circumference of the grinding wheel 36 is the turning axis 1
2 depending on whether or not it is ON-OF
Output F signal.

FIG. 4 is a functional block diagram showing a control device 60 for measuring and correcting the shape of the grinding wheel.

The CPU 40 is a central processing unit that controls the entire measuring device. The CPU 40 is connected to various memories, arithmetic means, etc. via a bus line 41. Data is input to the CRT from the keyboard 42 in various memories, and each data is displayed on the CRT.

The X-axis servomotor 43 is a motor for moving the grindstone in the X-axis direction, and the position detection signal and the speed detection signal are the X-axis position control means 44 and the amplifier 4.
5 is fed back to the X-axis servo motor 4
The operation of 3 is controlled. Similarly, the Z-axis servo motor 46 is a motor for moving the table 3 in the Z-axis direction, and the position detection signal and the speed detection signal are the Z-axis position control means 4.
7 and amplifier 48, respectively, and Z
The operation of the axis servo motor 46 is controlled.

The measurement program memory 49 stores a program for measuring the grindstone shape, that is, a program for driving the X-axis servomotor 43 and the Z-axis servomotor 46 to detect the grindstone by laser light. Has been done. The laser grindstone detecting means 37 is specifically a light projector 37a and a light receiver 37b, and is connected to the bus 42 via an interface 50.

The grindstone shape calculating means 51 is the grindstone detecting means 3
This is for calculating the shape of the grindstone based on the current position in the X-axis and Z-axis directions when the detection signal 7 is output.
The grindstone shape measurement memory 52 is for temporarily storing data of each point of the grinding grindstone 36 detected by the grindstone detecting means 37. The laser light projected from the light projector 37a is received by the light receiver 37b, but cannot be received when blocked by the grinding wheel 36. This received light,
The position where the light cannot be received, that is, the on / off position is detected, and the coordinate position is stored in the grindstone shape measurement memory 52. The whetstone shape reference memory 53 stores a whetstone shape that is a reference necessary for grinding a workpiece.

The tolerance memory 54 stores the allowable tolerance between the measured whetstone shape and the reference whetstone shape. The truing judging means 55 compares the reference grindstone shape stored in the grindstone shape reference memory 53 with the measured grindstone shape stored in the grindstone shape measuring memory 52, and judges whether or not the difference is within the tolerance. Is.

In the truing program memory 56,
A program for truing, that is, a grindstone 3
A program for raising, lowering, moving horizontally, rotating, etc. is stored. This truing program is executed when the difference between the reference grindstone shape and the measured grindstone shape deviates from the tolerance.

The operation of the grindstone shape measuring apparatus will be described below with reference to the flow chart shown in FIG. After the grinding of the workpiece by the grinding wheel 36 is completed, it is determined in step P ₁ whether the reference shape is set in the wheel shape reference memory 53. If the reference shape is not set, the data is input to the reference memory 53 via the keyboard 42 in step P ₂ . When the reference shape is set, the program in the measurement program 49 is executed in step P ₃ . This measurement is performed in the following procedure (see FIG. 6).

The grinding wheel 36 is rotationally driven at the same rotational speed as during grinding during shape measurement. The truing device 1 is moved in the Z-axis direction by a predetermined pitch Z _n -Z _n-1 by driving the Z-axis servo motor 46, and is driven in the X-axis direction by driving the X-axis servo motor 43 every time the predetermined pitch is moved. The grinding wheel 36 moves in the direction of the wheel 32. The position of each point is connected by a straight line or a curved line is the shape of the grinding wheel stored in the above-mentioned grinding wheel shape reference memory 53,
That is, the shape is close to the cross-sectional shape (X-Z axis).

Along with that, the laser light also moves in the same manner,
Each time the laser beam is blocked at each point on the outer peripheral surface of the grindstone 36,
The grindstone detecting means 37 outputs a signal. The laser light at this time moves in the X-axis direction around each of the above points and moves to the grinding wheel 3
Measure the on / off position while exploring the outer shape of 6. Then, in step P ₄ , the coordinate position of the laser beam that generated these output signals is the coordinate position (X ₁ , Z ₁ ), (X ₂ , Z ₂ ), ... (At each point on the outer peripheral surface of the grindstone 36. X _n , Z
_n ) is stored in the grindstone shape measurement memory 52.

Next, in step P ₅ , the grindstone shape calculation means 51 causes the coordinate position (X ₁ , Z ₂ ), (X ₂ , Z ₂ ) ...
The shape of the grindstone 36 is calculated from (X _n , Z _n ). At the same time, when there is an R shape, the center of curvature (X _c , Z _c ) and the radius of curvature r are also calculated. Next, in step P ₆ , the truing determination means 55 determines whether or not the measured whetstone shape is within the tolerance. If the shape of the grindstone is greater than the tolerance, the program stored in the truing program memory 56 is executed in step P ₆ . If it is within the tolerance, truing is not performed.

[0033]

Other Embodiments The grindstone shape measuring device is applied to a cylindrical grinder, but can be applied to other grinders such as a surface grinder. Although the dressing grindstone is the rotating grindstone 32, it may be a non-rotating grindstone such as a point dresser. Furthermore, although the dressing device is a dressing device for arcs, it may be a dressing device having another curved surface. The servomotors 13 and 35 are
A drive motor of a type that cannot be normally controlled may be used.

[0034]

【The invention's effect】

a. Even if an error such as a thermal deformation occurs in the truing device due to a change in room temperature or the like, since the optical path is on the turning axis of the truing device, an error is unlikely to occur in the outer shape of the trued wheel.

B. Since the central axis of rotation of the truing device and the optical path (axis) are coincident, it becomes easy to find the relative position of the coordinates of the grinding wheel and the coordinates of the truing device, and the measurement results can be fed back accurately, and truing was performed. The precision of the whetstone shape is improved.

C. The time required to shift from shape measurement to truing can be minimized.

[Brief description of drawings]

FIG. 1 is a plan view of a truing device.

FIG. 2 is a partially cutaway view of FIG.

FIG. 3 is a sectional view taken along line II-II of FIG. 1.

FIG. 4 is a functional block diagram of a grindstone shape control device.

FIG. 5 is a diagram showing a flowchart of an operation of the grindstone shape control device.

FIG. 6 is a diagram showing a measuring operation at the time of measuring a grindstone shape.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Truing device 3 ... Table 8, 9 ... Swivel axis 36 ... Grinding grindstone 37a ... Emitter 37b ... Photoreceiver 40 ... CPU 43 ... X-axis servo motor 46 ... Z-axis servo motor 51 ... Grindstone shape calculation means 52 ... Grindstone shape measurement Memory 53 ... Grindstone reference memory 54 ... Tolerance memory 56 ... Truing program memory

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[Procedure amendment]

[Submission date] April 13, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Figure 3]

[Figure 6]

[Fig. 2]

[Figure 5]

[Figure 4]

Claims (1)

[Claims] 1. A truing apparatus having a turning axis for truing an outer peripheral surface of a grinding wheel, comprising: a light projector for projecting light along the turning axis to project light on the grinding wheel. A light receiver arranged to have a distance on the optical path of the light for receiving light and on the turning axis, and detecting ON / OFF when the light receiver receives the light and the ON A grindstone shape measuring device comprising: a grindstone shape detecting means for detecting an off coordinate position.