JP2024055571A - Processing position setting method, grinding device, and forming device - Google Patents

Abstract

[Problem] To accurately determine the machining start position when performing grinding. [Solution] A number of machining points are extracted for a workpiece W, and a grinding wheel is brought into contact with each machining point while rotating at a low speed, and the contact position at each machining point is determined. Based on the distribution of contact positions at each machining point, the machining start position is determined from the contact position with the minimum amount of cutting, and the machining end position is determined from the contact position with the maximum amount of cutting. [Selected Figure] Figure 1A

Description

This disclosure relates to a method for setting a processing position when performing grinding using a grinding wheel, a grinding device, and a forming device.

When grinding a workpiece using a rotating grinding wheel, it is necessary to properly determine the start and end positions of the process.

For example, if machining is started with the grinding wheel away from the workpiece, excessive cutting can be prevented, but the machining time will be longer. On the other hand, if machining is started with the grinding wheel too close to the workpiece, excessive cutting will occur.

Similarly, if the end of the process is too shallow, unmachined areas will remain and additional machining will be required. On the other hand, if the end of the process is too deep, the machining time will be longer.

JP 2016-150402 A

This disclosure has been made in consideration of these points, and aims to provide a processing position setting method, a grinding device, and a forming device that can correctly set the processing start position and processing end position.

The present disclosure relates to a processing position setting method for setting a processing position when a rotating grinding wheel is used to grind a workpiece, the processing position setting method comprising the steps of: extracting a plurality of processing points when the grinding wheel is used to grind the workpiece; contacting each processing point of the workpiece while rotating the grinding wheel at a slower speed than during grinding to determine the contact position of the grinding wheel at each processing point; and determining a processing start position and a processing end position based on the distribution of the contact positions at each processing point.

This disclosure is a method for setting machining positions that sets the smallest cutting depth as the machining start position and the largest cutting depth as the machining end position based on the distribution of contact positions at each machining point.

This disclosure is a method for setting processing positions in which the number of processing points is set to 5 to 20.

The present disclosure relates to a processing position setting method for setting processing positions when a rotating forming wheel is used to form a grindstone, the processing position setting method comprising the steps of: extracting a plurality of processing points when forming processing of the grindstone is started using the forming wheel; contacting each processing point of the grindstone while rotating the forming wheel at a slower speed than during forming processing, and determining the contact position of the forming wheel at each processing point; and determining the processing start position and processing end position based on the distribution of the contact positions at each processing point.

This disclosure provides a method for setting machining positions that determines the machining start position and the machining end position with the smallest amount of cutting based on the distribution of contact positions at each machining point.

This disclosure is a method for setting processing positions in which the number of processing points is set to 5 to 20.

The present disclosure relates to a grinding device that includes a rotating grindstone, a drive mechanism for driving the grindstone relative to a workpiece, and a control unit, the control unit including a processing point extraction unit that extracts multiple processing points when grinding the workpiece using the grindstone, a contact position detection unit that rotates the grindstone at a slower speed than during grinding to bring the grindstone into contact with each processing point of the workpiece and determines the contact position of the grindstone at each processing point, and a processing start position and processing end position determination unit that determines the processing start position and processing end point based on the distribution of contact positions at each processing point.

The present disclosure relates to a forming device that includes a rotating forming wheel, a drive mechanism that drives the forming wheel relative to a grindstone, and a control unit, the control unit including a processing point extraction unit that extracts multiple processing points when forming the grindstone using the forming wheel, a contact position detection unit that rotates the forming wheel at a slower speed than during forming while contacting each processing point of the grindstone and determines the contact position of the forming wheel at each processing point, and a processing start position and processing end position determination unit that determines the processing start position and processing end point based on the distribution of contact positions at each processing point.

According to the present disclosure, when a grinding process is performed on a workpiece using a grinding wheel, or when a shaping process is performed on a grinding wheel using a shaping wheel, the processing start position and processing end position can be appropriately determined.

FIG. 1A is a schematic diagram showing an example of a grinding apparatus according to a first embodiment of the present disclosure. FIG. 1B is a diagram showing details of the control unit. FIG. 2 is a perspective view showing the relative positions of the workpiece and the grinding wheel. FIG. 3 is a diagram showing the machining points of the grinding wheel on the workpiece. FIG. 4 is a diagram showing a specific operation of the processing position setting method. FIG. 5 is a diagram showing the principle of the grinding process. FIG. 6 is a diagram showing the distribution of contact positions at the contact confirmation processing points in the grinding process. FIG. 7 is a diagram showing the operation of the second embodiment of the present disclosure. FIG. 8 is a diagram showing the distribution of contact positions at contact confirmation processing points during molding.

First Embodiment
Hereinafter, a first embodiment of the present disclosure will be described with reference to the drawings.

First, a grinding device 1 that uses a rotating grinding wheel to perform grinding on a workpiece will be described with reference to Figures 1 and 2. As shown in Figure 1, the grinding device 1 mainly comprises a machine base 10, an X-axis table 12 provided on the machine base 10, a Y-axis column 13 provided on the X-axis table 12, a Y-axis table 14 attached to the Y-axis column 13, a support base 15 attached to the Y-axis table 14, and a tool spindle unit 20 provided on the support base 15. Of these, the tool spindle unit 20 has a tool spindle 20a and a tool spindle motor 20b.

The grinding wheel 22 is held on the tool spindle 20a, and the grinding wheel 22 is rotated by the tool spindle 20a.

The X-axis table 12 is provided on the machine base 10. The X-axis table 12 is capable of linear movement in the X-axis direction. The X-axis table 12 is driven, for example, by a servo motor (not shown).

A Z-axis table 16 is also provided on the machine base 10, and this Z-axis table 16 is capable of linear movement in the Z-axis direction. The Z-axis table 16 is driven in the Z-axis direction, for example, by a servo motor (not shown). The X-axis table 12, the Y-axis table 14, and the Z-axis table 16 constitute the drive mechanism 10A.

A work spindle unit 18 is mounted on the Z-axis table 16. The work spindle unit 18 has a rotatable work spindle 18a, a work spindle motor 18b, and a work holder 18c that is connected to the work spindle 18a and holds the workpiece W, which will be described later.

The work spindle 18a can rotate around the rotation axis A by an air bearing, and the work spindle 18a is driven to rotate by the work spindle motor 18b.

The workpiece holder 18c is fixed to the tip of the workpiece spindle 18a and holds the workpiece W. The workpiece spindle 18a also rotates the workpiece W around the rotation axis A at the desired rotation speed.

The Y-axis column 13 is fixed onto the X-axis table 12. The Y-axis column 13 supports the Y-axis table 14, and the Y-axis table 14 can move linearly in the Y-axis direction (vertical direction). The Y-axis table 14 is driven, for example, by a servo motor (not shown).

As described above, the tool spindle unit 20 is fixed to the Y-axis table 14 via the support base 15. The tool spindle unit 20 includes a tool spindle 20a and a tool spindle motor 20b.

As shown in Figures 1 and 2, the rotation axis A of the work spindle 18a and the rotation axis B of the tool spindle 20a are on the same horizontal plane and intersect with each other at a predetermined angle when viewed in a plan view.

The tool spindle 20a can rotate around the rotation axis B by means of an air bearing. The tool spindle 20a is driven to rotate by the tool spindle motor 20b.

A grinding wheel 22 is attached as a tool to the tip of the tool spindle 20a, and the grinding wheel 22 is rotated by the tool spindle 20a. The workpiece W is ground by the rotating grinding wheel 22.

The tool spindle 20a is indirectly connected to the X-axis table 12, which moves the grinding wheel 22 in the X-axis direction at the desired feed rate.

The grinding wheel 22 is, for example, disk-shaped and includes a resin-bonded grinding wheel in which diamond abrasive grains are bound with resin.

The workpiece W is made of, for example, a glass material having a free-form surface.

A control unit 24 is also connected to the X-axis table 12, the Y-axis table 14, the tool spindle motor 12b, the work spindle motor 18b, and the Z-axis table 16.

The control unit 24 includes, for example, a microcontroller. The microcomputer constituting the control unit 24 includes, for example, a CPU and a memory, and the memory stores an NC machining program.

The control unit 24 controls the X-axis table 12, the Y-axis table 14, and the Z-axis table 16 according to an NC machining program. In other words, the control unit 24 performs simultaneous three-axis control of the X-axis, Y-axis, and Z-axis.

For each of the control axes, the X-axis, Y-axis, and Z-axis, a linear scale (not shown) is provided, and position feedback control is performed using a fully closed system.

It is desirable to control the positions of the X-axis table 12, Y-axis table 14, and Z-axis table 16 with an accuracy of 1 nm or less in order to improve the machining accuracy of the aspheric surface.

The control unit 24 also controls the work spindle unit 18 and the tool spindle unit 20 according to the NC machining program. Specifically, the control unit 24 controls the rotation speed of the workpiece W by controlling the rotation of the work spindle motor 18b. The control unit 24 also controls the rotation speed of the grinding wheel 22 by controlling the rotation of the tool spindle motor 20b.

The rotation speed of the workpiece W is, for example, 10 rpm or more and 3000 rpm or less. The rotation speed of the workpiece W can be controlled as a function of the distance from the rotation axis A to the contact point (machining point) between the grinding wheel 22 and the workpiece W. It is desirable to control the rotation speed of the workpiece W with an accuracy of 0.01 rpm or less from the viewpoint of improving the machining accuracy of the aspheric surface.

The rotation speed of the grinding wheel 22 is, for example, 100 rpm or more and 80,000 rpm or less.

Next, we will explain the operation of this embodiment with such a configuration.

As shown in FIG. 3, first, a workpiece W made of glass material having a convex surface (free-form surface) is prepared. In this embodiment, the workpiece W is pre-processed in a pre-processing step, and the convex surface of the workpiece W has already been processed with a certain degree of precision. In this embodiment, the convex surface of the workpiece W is further subjected to grinding to finish the convex surface with high precision.

As shown in Figures 1 to 3, first, the workpiece W is rotated around the rotation axis A at a desired rotation speed. Also, the grinding wheel 22 is rotated around the rotation axis B.

Next, the outer periphery of the grinding wheel 22 is brought into contact with the outer peripheral edge of the convex portion of the workpiece W. Then, the grinding process of the workpiece W is performed while moving the grinding wheel 22 along the surface of the convex portion to the center of the convex portion at a desired feed rate. The feed rate of the grinding wheel 22 is, for example, 1 mm/min to 15 mm/min. The amount of cutting (grinding thickness) of the workpiece W by the grinding wheel 22 is, for example, 0.25 μm to 10 μm.

The relative movement of the workpiece W and the grinding wheel 22 is performed by the control unit 24 controlling the X-axis table 12, the Y-axis table 14, and the Z-axis table 16.

The contact point (machining point) between the grinding wheel 22 and the workpiece W is indicated by P in the figure (see Figure 3).

The grinding wheel 22 is rotated and brought into contact with the workpiece W, which is made of glass material having a free-form surface. In this way, the grinding process is performed on the workpiece W using the grinding wheel 22.

In this embodiment, before performing grinding on the workpiece W using the grinding wheel 22 described above, the grinding start position and grinding end position for the workpiece W are set in advance.

The following describes a method for setting the machining position, which sets the machining start and end positions of the grinding wheel 22 relative to the workpiece W.

First, referring to Figure 5, we will explain the principle of setting the processing position, which sets the processing start position and processing end position of the grinding wheel 22.

As shown in Figure 5, when grinding a workpiece W using a grinding wheel 22, the workpiece W is generally rotated while the grinding wheel 22 is rotated. For convenience, the rotating workpiece W in Figure 5 is shown moving horizontally.

While rotating the grindstone 22 in this manner, the workpiece W is also rotated, and in this state, the grindstone 22 is brought close to the workpiece W. Next, while the grindstone 22 is in contact with the workpiece W, grinding is performed on the workpiece W by the grindstone 22.

In this case, before performing the grinding process, it is necessary to set the processing start position and processing end position between the workpiece W and the grinding wheel 22 when starting the grinding process.

As shown in FIG. 5, if the workpiece W and the grinding wheel 22 are brought too close when starting the grinding process, it is necessary to make an excessive cut into the protrusion W1 formed on the workpiece W. In this case, it is possible that the grinding wheel 22 will apply excessive force to the workpiece W, which will hinder the machining accuracy of the workpiece W.

On the other hand, if the workpiece W and the grinding wheel 22 are separated too far when grinding begins, excessive cutting into the convex portion W1 of the workpiece W can be prevented, but the grinding wheel 22 may be separated too far from the workpiece W at the start of processing, which may increase the processing time.

Similarly, if the end position of the grinding process between the workpiece W and the grinding wheel 22 is too shallow, an unmachined portion such as the recess W2 will remain on the workpiece W, and additional machining may be required. On the other hand, if the end position of the grinding process between the workpiece W and the grinding wheel 22 is too deep, an unmachined portion such as the recess W2 will not remain on the workpiece W, but the machining time will be longer.

Therefore, in this embodiment, the starting position when starting the grinding process and the ending position when ending the grinding process are set as follows:

First, the control unit 24 extracts several points, 3 to 30 points, and preferably 5 to 20 points, on the surface of the workpiece W as machining points for contact confirmation (hereinafter also simply referred to as machining points). In this case, the control unit 24 extracts the corresponding tool axis from the data file of the built-in tool path generation program. Here, if the machining points for contact confirmation are set to less than three points, it becomes difficult to set the machining start position and machining end position with high precision. On the other hand, if the machining points for contact confirmation are set to 31 or more points, the machining start position and machining end position can be set with high precision, but the machining position setting process for setting the machining start position and machining end position takes a long time.

Next, the control unit 24 creates an automatic search program and automatically extracts the confirmation machining points from the above-mentioned data file. The extraction of machining points by the control unit 24 is performed by the machining point extraction unit 24A.

The control unit 24 then creates a program for checking the hit and automatically generates tool operations for checking the hit.

Next, the control unit 24 rotates the grinding wheel 22 at a rotation speed (100 rpm) that is significantly slower than the rotation speed during actual grinding (200 rpm to 8000 rpm).

In this case, as shown in FIG. 4, the control unit 24 manages the rotation speed of the tool spindle 20a using an encoder signal.

Specifically, the control unit 24 includes a driver 24a that drives and controls the tool spindle motor 20b at a desired rotation speed, and a high-speed counter 24b, and an encoder signal from the tool spindle 20a is sent to the driver 24a. Next, a pulse signal is sent from the driver 24a to the high-speed counter 24b, and the rotation speed of the tool spindle 20a is calculated by the high-speed counter 24b.

However, when the rotation speed of the tool spindle 20a obtained by the high-speed counter 24b falls below a reference value, the control unit 24 generates a trigger signal and performs a skip operation to retract the grinding wheel 22.

Then, the control unit 24 (1) moves the workpiece W and the grindstone 22 relative to each other, and brings the grindstone 22 to the vicinity of the above-mentioned machining point for checking the contact on the workpiece W. During this time, the grindstone 22 rotates at a low rotation speed.

(2) Next, the control unit 24 moves the grinding wheel 22 in the cutting direction at the machining point on the workpiece W for checking the contact.

(3) The control unit 24 then monitors the rotation speed of the tool spindle 20a using the high-speed counter 24b, and when the rotation speed of the tool spindle 20a falls below a reference value, it determines that the workpiece W and the grinding wheel 22 have come into contact. At this time, the control unit 24 causes a skip operation to occur in which the grinding wheel 22 retreats.

At this time, the control unit 24 can determine the contact position at the processing point for confirming the contact by using the built-in contact position detection unit 24B.

(4) The control unit 24 repeats the above-mentioned actions (1), (2), and (3) at all of the machining points for checking the contact.

This allows the contact position of the grinding wheel 22 to be determined at all machining points for checking the contact.

(5) In this way, the distribution of contact positions is obtained from the contact positions of the grindstone 22 at each contact confirmation processing point.

Figure 6 shows the distribution of contact positions of the grinding wheel 22 at each contact confirmation processing point on the workpiece W.

The contact position of the grindstone 22 at each contact confirmation processing point shown in Figure 6 corresponds to the amount of cutting of the grindstone 22 into the workpiece W. Based on the distribution of contact positions of the grindstone 22, the control unit 24 determines that the processing point where the amount of cutting of the grindstone 22 into the workpiece W is the smallest (the processing point with the smallest amount of cutting), i.e., the processing point with a cutting amount of -1.3 μm, is the processing point that protrudes the furthest outward. The control unit 24 determines the processing start position based on the cutting amount of the processing point with a cutting amount of -1.3 μm, using the built-in processing start position and processing end position determination unit 24C.

That is, the starting position between the workpiece W and the grinding wheel 22 when starting grinding is determined based on the cutting depth at the processing point where the cutting depth is -1.3 μm (see Figure 5).

Based on the distribution of contact positions of the grinding wheel 22, the control unit 24 determines that the machining point where the grinding wheel 22 cuts into the workpiece W is the largest (the machining point with the largest amount of cut), i.e., the machining point with a cut amount of -4.6 μm, is the machining point that recedes the furthest inward, based on the cut amount of this machining point with a cut amount of -4.6 μm, using the built-in machining start position and machining end position determination unit 24C, the control unit 24 determines the machining end position between the workpiece W and the grinding wheel 22 when grinding ends, based on the cut amount of this machining point with a cut amount of -4.6 μm (see Figure 5).

As shown in FIG. 6, in this embodiment, for example, nine machining points are set for checking the contact.

The control unit 24 determines the machining start position and machining end position in this manner using the machining start position and machining end position determination unit 24C, and then starts grinding the workpiece W with the grinding wheel 22 from this machining start position. Next, the control unit 24 continues the grinding process, and then ends the grinding process at the machining end position.

As described above, according to this embodiment, the machining points for contact confirmation on the workpiece W are determined in advance, and the contact position of the grinding wheel 22 with respect to the workpiece W can be determined for each of the machining points for contact confirmation. The control unit 24 then identifies the machining point with the smallest amount of cutting based on the distribution of the contact positions of the grinding wheel 22, and can appropriately determine the machining start position from the amount of cutting at this machining point. This prevents the workpiece W and the grinding wheel 22 from being brought too close together, which would cause the grinding wheel 22 to make excessive cuts into the workpiece W. In this way, excessive force is not applied to the workpiece W from the grinding wheel 22, and therefore the machining accuracy of the workpiece W is not reduced.

It also prevents the workpiece W and the grinding wheel 22 from being separated too far from each other, which increases the processing time.

The control unit 24 can also identify the machining point with the largest amount of cut based on the distribution of the contact position of the grinding wheel 22, and appropriately determine the machining end position from the amount of cut at this machining point. Therefore, by setting the machining end position between the workpiece W and the grinding wheel 22 too shallow, unmachined parts such as recesses W2 will not remain in the workpiece W, and additional machining will not be necessary. Similarly, the machining time will not be extended by setting the machining end position between the workpiece W and the grinding wheel 22 too deep.

The start and end positions of machining by the grinding wheel 22 on the workpiece W are all automatically determined by the control unit 24 as described above.

The control unit 24 then automatically determines the machining start position and machining end position, and starts grinding the workpiece W using the grinding wheel 22.

For this reason, for example, compared to conventional methods in which an on-site worker determines the starting position for grinding the workpiece W with the grinding wheel 22 while listening to the contact sound between the workpiece W and the grinding wheel 22, and then brings the grinding wheel 22 to this starting position for grinding the workpiece W to begin, or when the worker marks the position with a marker or the like or visually checks, determines the end position for grinding, and ends the grinding process, the start and end positions for grinding can be determined with high accuracy regardless of the skill level of the skilled person.

In addition, when determining the machining start position, the worker does not need to be involved, such as by listening to the contact sound between the workpiece W and the grinding wheel 22, which reduces the work risks at the work site. In addition, since the machining start position can be determined automatically without the involvement of the worker, the efficiency of the grinding work can be improved and the grinding work can be performed with high precision. In addition, when determining the machining end position, the worker does not need to visually check and determine the machining end position to end the grinding work. This reduces the work risks at the work site. In addition, since the machining end position can be determined automatically without the involvement of the worker, the efficiency of the grinding work can be improved and the grinding work can be performed with high precision.

In the above embodiment, an example is shown in which nine machining points for confirming the contact are provided, as shown in Fig. 6. However, the number of machining points for confirming the contact can be set to any number between 3 and 30, as described above.
Second Embodiment
Next, a second embodiment of the present disclosure will be described with reference to FIG.

The second embodiment shown in FIG. 7 sets the start and end positions of the forming process by the forming wheels 30A, 30B when forming the grinding wheel 32 using the rotating forming wheels 30A, 30B.

In the second embodiment shown in FIG. 7, the forming wheels 30A and 30B are both made of diamond wheels, and are used to form the grindstone 32 and precisely finish the shape of the grindstone 32. Of these, the forming wheel 30A is used to finish the side surface 32A of the grindstone 32, and the forming wheel 30B is used to finish the end surface 32B of the grindstone 32.

In the second embodiment shown in FIG. 7, the grindstone 32 and the forming wheels 30A, 30B are driven relatively along the three axial directions of the X-axis, Y-axis, and Z-axis by a drive mechanism 35 including an X-axis table, a Y-axis table, and a Z-axis table (not shown). The drive mechanism 35 is controlled by the control unit 34.

When forming the grindstone 32 using the forming wheels 30A and 30B to finish the side surface 32A and end surface 32B of the grindstone 32, the processing start and end positions of the forming wheels 30A and 30B relative to the grindstone 32 are set as follows:

In this embodiment, the start and end positions of the forming process using the forming wheels 30A and 30B are set in the same manner, so the forming wheel 30A that finishes the side surface 32A of the grindstone 32 will be used as an example for explanation.

First, the processing point extraction unit 24A built into the control unit 34 extracts several points, 3 to 20 points, preferably 3 to 10 points, on the surface of the side surface 32A of the grindstone 32 as processing points for confirming the contact (hereinafter also simply referred to as processing points). In this case, the control unit 34 extracts the corresponding tool axis from the data file of the built-in tool path generation program. Here, if the processing points for confirming the contact are set to less than 3 points, it becomes difficult to set the processing start position and processing end position with high precision. On the other hand, if the processing points for confirming the contact are set to 31 or more points, the processing start position and processing end position can be set with high precision, but the setting process of setting the processing start position and processing end position takes a long time.

Next, the control unit 34 creates an automatic search program and automatically extracts the confirmation processing points from the above-mentioned data file.

The control unit 34 then creates a program for checking the hit and automatically generates tool operations for checking the hit.

Next, the control unit 34 rotates the forming wheel 30A at a speed (100 rpm) that is significantly slower than the rotational speed during the actual forming process.

In this case, the control unit 34 manages the rotation speed of the forming wheel 30A using an encoder signal.

Specifically, when the control unit 34 drives and controls the forming wheel 30A at a desired rotation speed, the control unit 34 includes a high-speed counter, and an encoder signal from the forming wheel 30A is sent to the driver. Next, a pulse signal is sent from the driver to the high-speed counter, and the rotation speed of the forming wheel 30A is calculated by the high-speed counter.

Then, the control unit 34 (1) moves the grindstone 32 and the forming wheel 30A relative to each other, and brings the forming wheel 30A to the vicinity of the above-mentioned contact confirmation processing point on the side surface 32A of the grindstone 32. During this time, the forming wheel 30A rotates at a low rotation speed.

(2) Next, the control unit 34 moves the forming wheel 30A in the cutting direction at the machining point for checking the contact on the side surface 32A of the grinding wheel 32.

(3) The control unit 34 then monitors the rotation speed of the forming wheel 30A using a high-speed counter, and when the rotation speed of the forming wheel 30A falls below a reference value, it determines that the side surface 32A of the grindstone 32 and the forming wheel 30A have come into contact. At this time, the control unit 34 causes a skip operation to occur in which the forming wheel 30A retreats.

At this time, the control unit 34 can determine the contact position at the processing point for confirming the contact by using the built-in contact position detection unit 24B.

(4) The control unit 34 repeats the above-mentioned actions (1), (2), and (3) at all of the machining points for checking the contact.

This allows the contact position of the forming wheel 30A to be determined at all contact confirmation processing points.

(5) In this way, the distribution of contact positions is obtained from the contact positions of the forming wheel 30A at each contact confirmation processing point.

Figure 8 shows the distribution of contact positions of the forming wheel 30A at each contact confirmation processing point on the side surface 32A of the grinding wheel 32.

The contact position of the forming wheel 30A at each contact confirmation processing point shown in Figure 8 corresponds to the amount of cutting of the forming wheel 30A into the side surface 32A of the grindstone 32. Based on the distribution of the contact positions of the forming wheel 30A, the control unit 34 determines that the processing point with the smallest amount of cutting of the forming wheel 30A into the side surface 32A of the grindstone 32 (the processing point with the smallest amount of cutting), i.e., the processing point with a cutting amount of -1.3 μm, is the processing point that protrudes the furthest outward. The control unit 34 determines the processing start position based on the cutting amount of the processing point with a cutting amount of -1.3 μm using the built-in processing start position and processing end position determination unit 24C.

Based on the distribution of contact positions of the forming wheel 30A, the control unit 34 determines that the machining point with the largest amount of cutting into the side surface 32A of the grindstone 32 of the forming wheel 30A (the machining point with the largest amount of cutting), i.e., the machining point with an amount of cutting of -4.5 μm, is the machining point that recedes the furthest inward. The control unit 34 determines the machining end position based on the amount of cutting at the machining point with an amount of cutting of -4.5 μm using the built-in machining start position and machining end position determination unit 24C.

As shown in FIG. 8, in this embodiment, for example, nine machining points are set for checking the contact.

After determining the processing start position and processing end position in this manner, the control unit 34 starts forming processing using the forming wheel 30A on the side surface 32A of the grindstone 32 from this processing start position.

The control unit 34 then continues the molding process and ends it at the end of the process position.

As described above, according to this embodiment, the contact confirmation processing points on the side surface 32A of the grindstone 32 are obtained in advance, and the contact position of the forming wheel 30A with respect to the side surface 32A of the grindstone 32 can be obtained for each contact confirmation processing point. The control unit 34 then identifies the processing point with the smallest amount of cut based on the distribution of the contact positions of the forming wheel 30A, and can appropriately determine the processing start position from the amount of cut at this processing point. Therefore, the side surface 32A of the grindstone 32 and the forming wheel 30A are not excessively close to each other, and the forming wheel 30A does not make excessive cuts into the side surface 32A of the grindstone 32, and excessive force is not applied from the forming wheel 30A to the side surface 32A of the grindstone 32, so the processing accuracy of the side surface 32A of the grindstone 32 does not decrease.

In addition, it is possible to prevent the processing time from increasing by separating the side surface 32A of the grinding wheel 32 from the forming wheel 30A too far.

The control unit 34 can then identify the processing point with the largest amount of cut based on the distribution of contact positions of the forming wheel 30A, and appropriately determine the processing end position from the amount of cut at this processing point. Therefore, by setting the processing end position between the side surface 32A of the grindstone 32 and the forming wheel 30A shallow, no unprocessed portion such as the recess W2 remains on the side surface 32A of the grindstone 32, and additional processing is not required. Similarly, it is possible to prevent the processing time from being extended by setting the processing end position between the side surface 32A of the grindstone 32 and the forming wheel 30A too deep.

Furthermore, the start and end positions of the forming wheel 30A with respect to the side surface 32A of the grinding wheel 32 are all automatically determined by the control unit 34 as described above.

The control unit 34 then automatically determines the processing start position and processing end position, and starts the forming process using the forming wheel 30A on the side surface 32A of the grindstone 32.

For this reason, for example, compared to the conventional method in which an on-site worker determines the processing start position of the forming wheel 30A relative to the side surface 32A of the grindstone 32 while listening to the contact sound between the side surface 32A of the grindstone 32 and the forming wheel 30A, and then the worker brings the forming wheel 30A to this processing start position relative to the side surface 32A of the grindstone 32 and starts the forming process, the processing start position can be determined with high accuracy regardless of the skill level of the skilled person.

In addition, when determining the processing start position, the worker does not need to be involved in listening to the contact sound between the side surface 32A of the grindstone 32 and the forming wheel 30A, thereby reducing the work risk at the work site. In addition, since the processing start position can be determined automatically without the worker's involvement, the efficiency of the forming process can be improved and the forming process can be performed with high precision.

In addition, when determining the processing end position, there is no need for the worker to visually check and determine the processing end position and end the molding process, which reduces the work risk at the work site. Also, since the processing end position can be determined automatically without the involvement of the worker, the molding process can be made more efficient and the molding process can be carried out with high precision.

In the above embodiment, as shown in FIG. 8, an example is shown in which nine machining points are provided for checking the contact, but the number of machining points for checking the contact can be set to any number between 3 and 30, as described above.

REFERENCE SIGNS LIST 1 Grinding machine 10 Machine base 12 X-axis table 13 Y-axis column 14 Y-axis table 16 Z-axis table 18 Work spindle unit 18a Work spindle 18b Work spindle motor 18c Workpiece holder 20 Tool spindle unit 20a Tool spindle 20b Tool spindle motor 22 Grindstone 24 Control unit 24a Driver 24b High-speed counter 30A Forming wheel 30B Forming wheel 32 Grindstone 32A Side surface 32B End surface 34 Control unit 35 Drive mechanism

Claims (8)

A method for setting a processing position when performing grinding on a workpiece using a rotating grinding wheel, comprising:
A step of extracting a plurality of processing points when performing grinding on the workpiece using the grindstone;
A step of contacting each processing point of the workpiece with the grinding wheel while rotating at a slower speed than that during grinding, and determining a contact position of the grinding wheel at each processing point;
and determining a machining start position and a machining end position based on the distribution of contact positions at each machining point. The machining position setting method according to claim 1, in which the smallest amount of cut is set as the machining start position and the largest amount of cut is set as the machining end position based on the distribution of contact positions at each machining point. The machining position setting method according to claim 1 or 2, wherein the number of machining points is set to 5 to 20. A method for setting a processing position when performing a forming process on a grindstone using a rotating forming wheel, comprising:
A step of extracting a plurality of processing points when starting a forming process on the grindstone using the forming wheel;
A step of contacting each processing point of the grindstone with the forming wheel while rotating at a slower speed than during forming, and determining a contact position of the forming wheel at each processing point;
and determining a machining start position and a machining end position based on the distribution of contact positions at each machining point. The machining position setting method according to claim 4, in which the smallest amount of cut is set as the machining start position and the smallest amount of cut is set as the machining end position based on the distribution of contact positions at each machining point. The machining position setting method according to claim 4 or 5, wherein the number of machining points is set to 5 to 20. The grinding machine includes a rotating grinding wheel, a drive mechanism for driving the grinding wheel relative to a workpiece, and a control unit.
The control unit includes a processing point extraction unit that extracts a plurality of processing points when performing grinding on the workpiece using the grindstone;
a contact position detection unit that rotates the grindstone at a slower speed than during grinding to contact each processing point of the workpiece and determines a contact position of the grindstone at each processing point;
and a machining start position and machining end position determining unit that determines a machining start position and a machining end position based on a distribution of contact positions at each machining point. The forming apparatus includes a rotating forming wheel, a drive mechanism for driving the forming wheel relatively to a grindstone, and a control unit,
The control unit includes a processing point extraction unit that extracts a plurality of processing points when performing a forming process on the grindstone using the forming wheel;
a contact position detection unit that detects the contact position of the forming wheel at each processing point by contacting the forming wheel with the respective processing points of the grindstone while rotating the forming wheel at a slower speed than that during forming;
and a processing start position and processing end position determining unit that determines a processing start position and a processing end point based on a distribution of contact positions at each processing point.