Grinding wheel dressing device, grinding wheel dressing method, and control program

Abstract

To provide a grindstone dressing device, a grindstone dressing method, and a control program for obtaining a more uniform sharpness over the entire grindstone surface. [Solution] The dressing device includes a grinding wheel holding unit 30 capable of rotating the grinding wheel 12, a dresser holding unit 40 capable of holding a dresser 36 for dressing the grinding wheel 12, a moving mechanism unit 70 that moves at least one of the grinding wheel holding unit 30 and the dresser holding unit 40 so that the dresser 36 and the grinding wheel 12 are scanned relatively to each other, and a control device 51 that controls the moving mechanism unit 70 so that when the dresser 36 contacts the large diameter portion 210 of the grinding wheel surface 21, the dresser 36 and the grinding wheel 12 are scanned relatively to each other at a first speed, and when the dresser 36 contacts the small diameter portion 220 of the grinding wheel surface 21, the dresser 36 and the grinding wheel 12 are scanned relatively to each other at a second speed greater than the first speed.

Description

[Technical field]

[0001] The present invention relates to a grinding wheel dressing device, a grinding wheel dressing method, and a control program. [Background technology]

[0002] For example, JP 2023-55160 A (Patent Document 1) discloses a grinding machine equipped with a circular grinding wheel rotated by an electric motor and a diamond dresser for dressing the outer peripheral surface of the grinding wheel which functions as a grinding surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-55160 A Summary of the Invention [Problem to be solved by the invention]

[0004] As disclosed in the above-mentioned Patent Document 1, a grinding wheel is used to grind a workpiece. In such a grinding wheel, when the diameter of the grinding wheel surface centered on the rotation axis of the grinding wheel changes along the axial direction of the rotation axis, the peripheral speed of the small diameter part of the grinding wheel surface becomes smaller than the peripheral speed of the large diameter part of the grinding wheel surface. This makes the sharpness of the small diameter part of the grinding wheel surface worse than that of the large diameter part of the grinding wheel surface, resulting in a rough surface of the workpiece ground by the small diameter part, or a chatter vibration occurring easily during grinding by the small diameter part.

[0005] An object of the present invention is to provide a grinding wheel dressing device, a grinding wheel dressing method, and a control program that can provide a more uniform sharpness over the entire grinding wheel surface. [Means for solving the problem]

[0006] A grinding wheel dressing device according to the present invention includes a grinding wheel holding unit capable of holding a grinding wheel having a grinding wheel surface extending about a predetermined axis and having a diameter that varies about the predetermined axis, and capable of rotating the grinding wheel about the predetermined axis; a dresser holding unit capable of holding a dresser for dressing the grinding wheel; a movement mechanism unit that moves at least one of the grinding wheel holding unit and the dresser holding unit so that the dresser and the grinding wheel are scanned relatively to each other; and a control device that controls the movement mechanism unit so that the dresser and the grinding wheel are scanned relatively to each other at a first speed when the dresser comes into contact with the large diameter portion of the grinding wheel surface, and so that the dresser and the grinding wheel are scanned relatively to each other at a second speed greater than the first speed when the dresser comes into contact with the small diameter portion of the grinding wheel surface.

[0007] A method for dressing a grinding wheel according to the present invention is a method for dressing a grinding wheel having a wheel surface that extends around a predetermined axis and whose diameter around the predetermined axis varies, using a dresser. The method for dressing a grinding wheel includes the steps of rotating the grinding wheel around the predetermined axis and scanning the dresser and the grinding wheel relatively at a first speed while bringing the dresser into contact with a large diameter portion of the grinding wheel surface, and rotating the grinding wheel around the predetermined axis and scanning the dresser and the grinding wheel relatively at a second speed that is greater than the first speed while bringing the dresser into contact with a small diameter portion of the grinding wheel surface.

[0008] A control program according to the present invention is a control program for a dressing device that uses a dresser to dress a grinding wheel having a grinding wheel surface that extends around a predetermined axis and whose diameter around the predetermined axis varies. The control program causes the dressing device to execute a step of rotating the grinding wheel around the predetermined axis and relatively scanning the dresser and the grinding wheel at a first speed while bringing the dresser into contact with a large diameter portion of the grinding wheel surface, and a step of rotating the grinding wheel around the predetermined axis and relatively scanning the dresser and the grinding wheel at a second speed higher than the first speed while bringing the dresser into contact with a small diameter portion of the grinding wheel surface. Effect of the Invention

[0009] According to the invention, it is possible to provide a grindstone dressing device, a grindstone dressing method, and a control program that enable uniform dressing of the grindstone surface. [Brief description of the drawings]

[0010] [Figure 1] 1 is a front view showing a dressing device according to an embodiment of the present invention. [Diagram 2] 2 is a block diagram showing a control system related to dressing of a grinding wheel in the dressing device in FIG. 1. FIG. [Diagram 3] 2 is an enlarged front view showing the dressing process in the dressing device in FIG. 1. [Figure 4] 4 is a graph showing a change in dressing speed in the dressing process in FIG. 3. [Diagram 5] FIG. 2 is a cross-sectional view showing abrasive grains of a grinding wheel (large diameter portion) after dressing. [Figure 6] FIG. 2 is a cross-sectional view showing abrasive grains of a grinding wheel (small diameter portion) after dressing. [Figure 7] 4 is a graph showing a modified example of the change in dressing speed in the dressing process in FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described with reference to the accompanying drawings, in which the same or corresponding components are designated by the same reference numerals.

[0012] Fig. 1 is a front view showing a dressing device in an embodiment of the present invention, Fig. 2 is a block diagram showing a control system related to dressing of a grinding wheel in the dressing device in Fig. 1.

[0013] 1 and 2, a dressing device 100 is an apparatus capable of dressing a grinding wheel 12 used in grinding a workpiece.

[0014] The grinding wheel 12 has a grinding wheel portion 16 and a shank portion 17. The shank portion 17 is made of metal and extends axially as a whole, centered on a predetermined axis 160. The predetermined axis 160 is an imaginary straight line corresponding to the central axis of rotation of the grinding wheel 12. The grinding wheel portion 16 is composed of high-hardness granular abrasive grains that function as a grinding wheel, and a binder that functions to bind the abrasive grains together. The grinding wheel portion 16 is connected to one end of the shank portion 17 in the axial direction to the predetermined axis 160.

[0015] The grindstone portion 16 has a grindstone surface 21. The grindstone surface 21 is the surface of the grindstone portion 16 that is brought into contact with the workpiece when the workpiece is ground by the grindstone 12. The grindstone surface 21 extends about a predetermined axis 160. The diameter of the grindstone surface 21 about the predetermined axis 160 varies along the axial direction of the predetermined axis 160. The grindstone surface 21 (each of a first grindstone surface 21A and a second grindstone surface 21B described below) is made of a conical surface centered about the predetermined axis 160. The grindstone surface 21 extends while curving along the axial direction of the predetermined axis 160, and may have a shape that protrudes radially outward from the predetermined axis 160.

[0016] The grindstone surface 21 includes a first grindstone surface 21A and a second grindstone surface 21B. The first grindstone surface 21A and the second grindstone surface 21B are continuous in the axial direction of the specified axis 160. The second grindstone surface 21B is disposed between the first grindstone surface 21A and the shank portion 17 in the axial direction of the specified axis 160. The diameter of the first grindstone surface 21A centered on the specified axis 160 becomes smaller as it moves away from the second grindstone surface 21B in the axial direction of the specified axis 160. The diameter of the second grindstone surface 21B centered on the specified axis 160 becomes larger as it approaches the first grindstone surface 21A in the axial direction of the specified axis 160.

[0017] The diameter of the grindstone surface 21 centered on the specified axis 160 is maximum at the boundary between the first grindstone surface 21A and the second grindstone surface 21B. As an example, the length of the first grindstone surface 21A in the axial direction of the specified axis 160 is greater than the length of the second grindstone surface 21B in the axial direction of the specified axis 160. Each of the first grindstone surface 21A and the second grindstone surface 21B is inclined at 45° with respect to the specified axis 160.

[0018] The dressing device 100 has a grindstone holding unit 30, a dresser holding unit 40, and a movement mechanism unit 70. The grindstone holding unit 30 can hold the grindstone 12. The grindstone holding unit 30 can rotate the grindstone 12 about a predetermined axis 160. The dresser holding unit 40 can hold a dresser 36 for dressing the grindstone 12. The movement mechanism unit 70 moves at least one of the grindstone holding unit 30 and the dresser holding unit 40 so that the dresser 36 and the grindstone 12 are scanned relatively to each other.

[0019] In this embodiment, the dressing device 100 is composed of a multi-tasking machine 101 equipped with both a milling function for machining a workpiece by bringing a rotating tool into contact with a stationary workpiece, and a turning function for machining a workpiece by bringing a tool into contact with a rotating workpiece.

[0020] In the following, a more specific configuration of the dressing device 100 will be described in light of the configuration of the multi-tasking machine 101.

[0021] The multitasking machine 101 is an NC (Numerically Controlled) machine tool in which various operations for machining a workpiece are automated by computer numerical control.

[0022] In this specification, for the convenience of explaining the configuration of the multi-tasking machine 101, the axis that is parallel to the rotation axis of the workpiece and extends horizontally will be referred to as the "Z-axis," the axis that is perpendicular to the Z-axis and extends horizontally will be referred to as the "Y-axis," and the axis that extends vertically will be referred to as the "X-axis."

[0023] The multitasking machine 101 has a work spindle 41, a tool spindle (upper tool rest) 31, and a tool rest (lower tool rest) not shown. The work spindle 41, the tool spindle 31, and the tool rest (not shown) are arranged in a working area 105. The working area 105 is a space where the workpiece is machined, and is sealed by a cover body (not shown) so that foreign matter such as cutting chips or cutting oil resulting from the workpiece machining does not leak out of the working area 105.

[0024] The workpiece spindle 41 is capable of holding a workpiece. The workpiece spindle 41 is driven by a motor to rotate about a central rotation axis 110 extending in the Z-axis direction.

[0025] The workpiece spindle 41 has a chuck 42. The chuck 42 detachably holds a workpiece. The chuck 42 has a chuck body 43 and a plurality of jaws 44. The chuck body 43 has a cylindrical shape centered on the central rotation axis 110. The chuck body 43 has an end surface 43a. The end surface 43a is a plane perpendicular to the central rotation axis 110.

[0026] The multiple claw portions 44 are attached to the chuck body 43 at intervals from one another in the circumferential direction of the rotation central shaft 110. The multiple claw portions 44 protrude in the Z-axis direction from the end face 43a. Each of the claw portions 44 is driven to slide in the radial direction of the rotation central shaft 110 by hydraulic pressure or the like. The multiple claw portions 44 grip the outer peripheral surface of the workpiece by sliding radially inwardly of the rotation central shaft 110, and grip the inner peripheral surface of the workpiece by sliding radially outwardly of the rotation central shaft 110.

[0027] The workpiece spindle 41 holds the dresser 36. In this embodiment, the dresser holding portion 40 is formed by the workpiece spindle 41.

[0028] The dresser 36 is attached to the chuck body 43 via a dresser attachment base 37. The dresser attachment base 37 is attached to an end surface 43a of the chuck body 43. The dresser attachment base 37 is disposed radially outward of the rotation center axis 110 relative to the multiple claws 44.

[0029] The dresser 36 is a point dresser having a tip curved into a semicircular shape. The dresser 36 is made of diamond, for example. The dresser 36 includes a first dresser 36A and a second dresser 36B. The first dresser 36A protrudes from the dresser mounting base 37 toward the outside in the radial direction of the rotation center axis 110. The second dresser 36B protrudes from the dresser mounting base 37 along the Z-axis direction. The first dresser 36A is used for dressing the first grinding wheel surface 21A. The second dresser 36B is used for dressing the second grinding wheel surface 21B.

[0030] The multitasking machine 101 may further include an opposing work spindle at a position opposing the work spindle 41 in the Z-axis direction. The dresser 36 is not limited to being held by the work spindle 41, and may be held, for example, by the opposing work spindle, by a cover body surrounding the machining area 105, or by a tool rest (not shown).

[0031] The tool spindle 31 can hold a tool. The tool spindle 31 is driven by a motor to rotate about a rotation center axis 120 parallel to the X-axis in a reference posture described later. A clamp mechanism (not shown) for detachably holding a tool is built into the tool spindle 31.

[0032] The tool spindle 31 is further provided so as to be rotatable about a central axis of rotation 130 parallel to the Y axis (B-axis rotation). The central axis of rotation 130 intersects with the central axis of rotation 120. The rotation range of the tool spindle 31 is, for example, a range of ±120° based on a reference posture in which the spindle end surface 31a of the tool spindle 31 faces downward. Fig. 1 shows the tool spindle 31 rotated 45° clockwise from the reference posture about the central axis of rotation 130.

[0033] The tool spindle 31 can further hold the grinding wheel 12. In this embodiment, the dresser holding portion 40 is configured by the tool spindle 31. The grinding wheel 12 is held by the tool spindle 31 as the shank portion 17 is clamped by a clamping mechanism built into the tool spindle 31. When the grinding wheel 12 is held by the tool spindle 31, the rotation center axis 120 and the predetermined axis 160 extend in a straight line.

[0034] The tool spindle 31 can be moved in the X-axis, Y-axis and Z-axis directions by a movement mechanism 70. The movement mechanism 70 is made up of various feed mechanisms, guide mechanisms and a servo motor (tool spindle feed motor 62 in FIG. 2).

[0035] The tool rest (not shown) can hold tools. The tool rest is a so-called turret type, and a plurality of tools are attached radially and rotated for indexing. The tool rest can be moved in the Z-axis direction and the X-axis direction by various feed mechanisms, guide mechanisms, and servo motors. Therefore, when the dresser 36 is held by the tool rest, the dresser 36 can be moved within the Z-axis-X-axis plane.

[0036] The multitasking machine 101 also functions as a grinding device that grinds a workpiece. As an example of grinding, the tool spindle 31 is rotated 45° clockwise from the reference position around the pivot central axis 130 to grind the outer circumferential surface of a cylindrical workpiece held by the workpiece spindle 41 using the first grindstone surface 21A. The tool spindle 31 is rotated 45° counterclockwise from the reference position around the pivot central axis 130 to grind the end surface of a cylindrical workpiece held by the workpiece spindle 41 using the second grindstone surface 21B.

[0037] The multi-tasking machine 101 (dressing apparatus 100) further includes a control device 51. The control device 51 controls the operation of the multi-tasking machine 101.

[0038] Each component of the control device 51 is realized by hardware including arithmetic units such as a CPU (Central Processing Unit) and various computer processors, storage devices such as memory or storage, and wired or wireless communication lines connecting them, and software stored in the storage devices and supplying processing instructions to the arithmetic units. The computer programs may be configured by device drivers, operating systems, various application programs located at higher layers thereof, or libraries that provide common functions to these programs.

[0039] The control device 51 has a program storage unit 52 , a program execution unit 53 , a tool spindle control unit 54 , and a workpiece spindle control unit 55 .

[0040] The program storage unit 52 stores an execution program for machining a workpiece (a control program for the multi-tasking machine 101) created by an operator of the multi-tasking machine 101. The program storage unit 52 is, for example, a flash memory.

[0041] The program execution unit 53 executes the execution program stored in the program storage unit 52. The program execution unit 53 reads instructions of the execution program, and outputs control signals to the tool spindle control unit 54 and the workpiece spindle control unit 55, respectively.

[0042] The tool spindle control unit 54 controls a tool spindle turning motor 61 for turning the tool spindle 31 along the B axis, a tool spindle feed motor 62 for moving the tool spindle 31 in the X-axis, Y-axis and Z-axis directions, and a tool spindle rotating motor 63 for rotating the tool spindle 31 about the rotation central axis 120, in accordance with a control signal from the program execution unit 53. The work spindle control unit 55 controls a work spindle rotating motor 64 for rotating the work spindle 41 about the rotation central axis 110, in accordance with a control signal from the program execution unit 53.

[0043] Fig. 3 is an enlarged front view showing the dressing process in the dressing device in Fig. 1. Fig. 4 is a graph showing the change in dressing speed in the dressing process in Fig. 3.

[0044] In the present invention, the dressing speed means the speed at which the dresser and the grindstone are scanned relative to each other. In this embodiment, the dressing speed corresponds to the feed speed of the tool spindle 31 (grindstone 12) in the Z-axis direction.

[0045] 1 to 4, the control device 51 controls the moving mechanism 70 so that when the dresser 36 contacts the large diameter portion 210 of the grinding wheel surface 21, the dresser 36 and the grinding wheel 12 are scanned relatively at a first speed, and when the dresser 36 contacts the small diameter portion 220 of the grinding wheel surface 21, the dresser 36 and the grinding wheel 12 are scanned relatively at a second speed higher than the first speed.

[0046] In addition, the method for dressing the grinding wheel in this embodiment includes a step of rotating the grinding wheel 12 around a predetermined axis 160 and scanning the dresser 36 and the grinding wheel 12 relatively at a first speed while bringing the dresser 36 into contact with the large diameter portion 210 of the grinding wheel surface 21, and a step of rotating the grinding wheel 12 around the predetermined axis 160 and scanning the dresser 36 and the grinding wheel 12 relatively at a second speed higher than the first speed while bringing the dresser 36 into contact with the small diameter portion 220 of the grinding wheel surface 21.

[0047] In addition, the control program in this embodiment causes the multi-tasking machine 101 (dressing device 100) to execute a step of rotating the grinding wheel 12 around a predetermined axis 160 and scanning the dresser 36 and the grinding wheel 12 relatively at a first speed while bringing the dresser 36 into contact with the large diameter portion 210 of the grinding wheel surface 21, and a step of rotating the grinding wheel 12 around the predetermined axis 160 and scanning the dresser 36 and the grinding wheel 12 relatively at a second speed that is greater than the first speed while bringing the dresser 36 into contact with the small diameter portion 220 of the grinding wheel surface 21.

[0048] 3 shows a process of dressing the first grinding wheel surface 21A of the grinding wheel part 16 using the first dresser 36A. Hereinafter, the method of dressing the grinding wheel in this embodiment will be described using the dressing process of the first grinding wheel surface 21A using the first dresser 36A as an example.

[0049] As shown in Fig. 3, the first grindstone surface 21A extends between a first position Pa and a second position Pb in the axial direction of the specified axis 160. The first position Pa is the position where the diameter of the first grindstone surface 21A centered on the specified axis 160 is the largest, and the second position Pb is the position where the diameter of the first grindstone surface 21A centered on the specified axis 160 is the smallest. The first grindstone surface 21A is divided into two in the axial direction of the specified axis 160, and the region including the first position Pa is shown as a large diameter portion 210, and the region including the second position Pb is shown as a small diameter portion 220. The diameter of the large diameter portion 210 centered on the specified axis 160 is larger than the diameter of the small diameter portion 220 centered on the specified axis 160.

[0050] As shown in Figures 1 to 4, in dressing processing of the first grinding wheel surface 21A, first, the tool spindle control unit 54 controls the tool spindle turning motor 61 so that the tool spindle 31 is turned 45° clockwise around the turning central axis 130 from the reference posture.

[0051] Next, the tool spindle control unit 54 controls the tool spindle feed motor 62 so that the tip of the first dresser 36A approaches the first position Pa of the first grinding wheel surface 21A. The tool spindle control unit 54 controls the tool spindle rotation motor 63 so that the grinding wheel 12 rotates about the specified axis 160. Next, the tool spindle control unit 54 controls the tool spindle feed motor 62 so that the grinding wheel 12 moves in the Z-axis direction. The grinding wheel 12 rotates about the specified axis 160, and the tip of the first dresser 36A moves from the first position Pa to the second position Pb of the first grinding wheel surface 21A while the first dresser 36A is in contact with the first grinding wheel surface 21A, thereby dressing the first grinding wheel surface 21A. (Hereinafter, the position where the dresser 36 contacts the grinding wheel surface 21 is also referred to as the "dressing position".) At this time, the tool spindle control unit 54 controls the tool spindle feed motor 62 so that the dressing speed (the feed speed of the tool spindle 31 in the Z-axis direction) when the first dresser 36A comes into contact with the small diameter portion 220 of the first grinding wheel surface 21A is greater than the dressing speed (the feed speed of the tool spindle 31 in the Z-axis direction) when the first dresser 36A comes into contact with the large diameter portion 210 of the first grinding wheel surface 21A.

[0052] 4, in this embodiment, the dressing speed when the dressing position is the first position Pa in the large diameter portion 210 is Va, and the dressing speed when the dressing position is the second position Pb in the small diameter portion 220 is Vb, which is higher than Va. The dressing speed increases as the dressing position moves from the first position Pa to the second position Pb.

[0053] Next, the effect of providing the above-mentioned magnitude relationship in the dressing speed between the large diameter portion 210 and the small diameter portion 220 will be described. Fig. 5 is a cross-sectional view showing abrasive grains of the grindstone (large diameter portion) after dressing. Fig. 6 is a cross-sectional view showing abrasive grains of the grindstone (small diameter portion) after dressing.

[0054] Since the diameter of the small diameter portion 220 centered on the specified axis 160 is smaller than the diameter of the large diameter portion 210 centered on the specified axis 160, when the workpiece is ground using the grindstone 12, the peripheral speed of the small diameter portion 220 is smaller than the peripheral speed of the large diameter portion 210. As a result, the sharpness of the small diameter portion 220 becomes poorer than that of the large diameter portion 210.

[0055] In contrast, in this embodiment, the dressing speed when the first dresser 36A contacts the small diameter portion 220 is set to be relatively high. As shown in Fig. 5, when the dressing speed is high, the interval H and height T of the cutting edge shape formed on the abrasive grains 91 of the grindstone 12 by the dresser 36 become relatively large, so that the sharpness of the grindstone 12 improves but the processing accuracy during grinding deteriorates.

[0056] Also, the dressing speed when the first dresser 36A contacts the large-diameter portion 210 is set to be relatively small. As shown in FIG. 6, when the dressing speed is small, the intervals h and heights t of the cutting-edge shapes formed on the abrasive grains 91 of the grinding wheel 12 by the dresser 36 become relatively small (h < H, t < T), so the sharpness of the grinding wheel 12 deteriorates while the machining accuracy during grinding improves.

[0057] Therefore, by making the dressing speed when the first dresser 36A contacts the small-diameter portion 220 greater than the dressing speed when the first dresser 36A contacts the large-diameter portion 210, it becomes possible to dress the first grinding-wheel surface 21A so that the sharpness of the grinding wheel 12 at the small-diameter portion 220 increases more than the sharpness of the grinding wheel 12 at the large-diameter portion 210. By performing the grinding process of the workpiece using such a grinding wheel 12, it is possible to suppress the variation in sharpness caused by the difference in the peripheral speed of the grinding-wheel surface 21 described above, and to obtain a uniform sharpness over the entire first grinding-wheel surface 21A.

[0058] Also, in the present embodiment, during the above-described dressing process, the position (dressing position) of the first grinding-wheel surface 21A that contacts the grinding wheel 12 is shifted from the large-diameter portion 210 to the small-diameter portion 220. According to such a configuration, since it becomes possible to bring the large-diameter portion 210 into contact with the dresser 36 immediately after the start of the dressing process, it is possible to preferentially obtain a desired dressing effect at the large-diameter portion 210 where the frequency of contact with the workpiece is high in the grinding process.

[0059] FIG. 7 is a graph showing a modification of the change in the dressing speed in the dressing process in FIG. 3. Referring to FIG. 5, in this modification, the dressing speed is increased stepwise while the dressing position moves from the first position Pa to the second position Pb. The dressing speed may be increased in a plurality of steps other than two steps.

[0060] The second grinding wheel surface 21B can be dressed by the second dresser 36B by rotating the tool spindle 31 counterclockwise from the reference posture around the rotation central axis 130 and moving the tool spindle 31 in the X-axis direction. In this case, the feed speed of the tool spindle 31 may be controlled so that the dressing speed when the second dresser 36B contacts the small diameter portion of the second grinding wheel surface 21B is higher than the dressing speed when the second dresser 36B contacts the large diameter portion of the second grinding wheel surface 21B.

[0061] In the present embodiment, the dressing device 100 is configured from the multi-tasking machine 101, but is not limited to this. The dressing device in the present invention may be configured from, for example, a device dedicated to dressing, or may be configured from a grinding device equipped with a dressing function.

[0062] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0063] 12 Grindstone, 16 Grindstone section, 17 Shank section, 21 Grindstone surface, 21A First grindstone surface, 21B Second grindstone surface, 30 Grindstone holder, 31 Tool spindle, 31a Spindle end surface, 36 Dresser, 36A First dresser, 36B Second dresser, 37 Dresser mounting stand, 40 Dresser holder, 41 Work spindle, 42 Chuck, 43 Chuck body, 43a End surface, 44 Jaw section, 51 Control device, 52 Program memory section, 53 Program execution section, 54 Tool spindle control section, 55 Work spindle control section, 61 Tool spindle swivel motor, 62 Tool spindle feed motor, 63 Tool spindle rotation motor, 64 Work spindle rotation motor, 70 Movement mechanism section, 91 Abrasive grain, 100 Dressing device, 101 Multi-tasking machine, 105 working area, 110,120 central rotation axis, 130 central turning axis, 160 specified axis, 210 large diameter section, 220 small diameter section.

Claims

1. a grindstone holding portion that holds a grindstone having a grindstone surface that extends around a predetermined axis and whose diameter about the predetermined axis varies in an axial direction of the predetermined axis, and that is capable of rotating the grindstone around the predetermined axis; a dresser holder capable of holding a dresser for dressing the grindstone; a moving mechanism for moving at least one of the grindstone holder and the dresser holder so that the dresser and the grindstone are scanned relative to each other; a control device that controls the moving mechanism so that the dresser and the grinding wheel are scanned relatively at a first speed when the dresser contacts the large diameter portion of the grinding wheel surface, and the dresser and the grinding wheel are scanned relatively at a second speed that is higher than the first speed when the dresser contacts the small diameter portion of the grinding wheel surface, A grinding wheel dressing device, wherein the control target of the movement mechanism unit by the control device is linear movement in a single direction.

2. The grindstone dressing device according to claim 1 , wherein the control device controls the movement mechanism unit so that a contact position of the dresser with respect to the grindstone surface moves from a large diameter portion of the grindstone surface to a small diameter portion of the grindstone surface.

3. 1. A method for dressing a grinding wheel using a dresser, the grinding wheel having a wheel surface extending about a predetermined axis between a first position and a second position in an axial direction of the predetermined axis, the wheel surface having a diameter about the predetermined axis that is largest at the first position and smallest at the second position, and that continuously decreases from the first position to the second position in the axial direction of the predetermined axis, the method comprising: rotating the grindstone about the predetermined axis; and scanning the dresser and the grindstone relative to one another such that a contact position of the dresser with respect to the grindstone surface is shifted between the first position and the second position; When the contact position transitions from the first position to the second position, a scanning speed of the dresser and the grindstone is minimum when the contact position is at the first position, is maximum when the contact position is at the second position, and continuously increases with the transition of the contact position from the first position to the second position; a scanning speed of the dresser and the grinding wheel that is maximum when the contact position is at the second position, that is minimum when the contact position is at the first position, and that is continuously decreased as the contact position transitions from the second position toward the first position when the contact position transitions from the second position toward the first position.

4. A control program for a dressing device that uses a dresser to dress a grinding wheel having a grinding wheel surface that extends around a predetermined axis between a first position and a second position in an axial direction of the predetermined axis, the diameter of the wheel surface being largest at the first position and smallest at the second position, and continuously decreasing from the first position to the second position in the axial direction of the predetermined axis, The control program causes the dressing apparatus to rotating the grindstone about the predetermined axis; and scanning the dresser and the grindstone relative to each other so that a contact position of the dresser with respect to the grindstone surface is shifted between the first position and the second position. When the contact position transitions from the first position to the second position, a scanning speed of the dresser and the grindstone is minimum when the contact position is at the first position, is maximum when the contact position is at the second position, and continuously increases with the transition of the contact position from the first position to the second position; a control program for controlling the scanning speed of the dresser and the grinding wheel when the contact position transitions from the second position toward the first position, the scanning speed being maximum when the contact position is at the second position, being minimum when the contact position is at the first position, and continuously decreasing with the transition of the contact position from the second position toward the first position.

Images