Grinding machine and grinding method

Abstract

To provide a grinder and a grinding method which can separately adjust respective machining allowances on both end faces of a work-piece.SOLUTION: A grinder 1 comprises a controller 50 that controls respective positions of a first grindstone 30 and of a second grindstone 40 in an axial direction. The controller 50 has a separation-distance obtaining part 52a, a target movement-amount determining part 53c and a driving part 54d. The separation-distance obtaining part 53a obtains a separation distance gw between a center position Pwc and a reference position Ps of a work-piece M. The target movement- amount determining part 53c determines a first target movement amount L1a by correcting a first reference movement amount L1 on the basis of the separation distance gw, and determines a second target movement amount L2a by correcting a second reference movement amount L2 on the basis of the separation distance gw. The driving part 54d moves the first grindstone 30 from a first movement start position toward the work-piece W by the first target movement amount L1a, and moves the second grindstone 40 from a second movement start position toward the work-piece W by the second target movement amount L2a.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to a grinding machine and a grinding method.

Background Art

[0002] Conventionally, a grinding machine for grinding both end faces of a workpiece arranged on the outer periphery of a rotating carrier with a pair of grindstones is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0008] According to this disclosure, it is possible to provide a grinding machine and a grinding method that can adjust the amount of material removed from each end face of a workpiece separately. [Brief explanation of the drawing]

[0009] [Figure 1] Side view of a grinding machine according to an embodiment [Figure 2] Top view of the grinding machine according to the embodiment [Figure 3] A schematic diagram showing an example of the surface of a workpiece according to the embodiment. [Figure 4] Partial enlarged view of Figure 1 [Figure 5] Block diagram showing the configuration of the controller according to the embodiment. [Figure 6] A schematic diagram showing an example of an image of a workpiece according to the embodiment. [Figure 7] Schematic diagram to explain the reference displacement. [Figure 8] Schematic diagram to explain the target displacement. [Figure 9] Flowchart illustrating the grinding method according to the embodiment [Modes for carrying out the invention]

[0010] (Grinding machine 1) Figure 1 is a side view of the grinding machine 1 according to this embodiment. Figure 2 is a top view of the grinding machine 1 according to this embodiment. Figure 3 is a schematic diagram showing an example of the surface of the workpiece W.

[0011] Grinding machine 1 is a so-called double-ended surface grinding machine. As shown in Figures 1 and 2, grinding machine 1 comprises a carrier 10, an imaging device 20, a first grinding wheel 30, a second grinding wheel 40, and a controller 50.

[0012] Workpiece W is an unprocessed component to be processed. In this embodiment, a ceramic package is assumed as workpiece W. However, workpiece W can be any component made of a material that can be ground with a grinding wheel.

[0013] As shown in FIG. 3, the workpiece W has a surface Sw, a first end face Tw1, and a second end face Tw2. A plurality of via conductors Cw filled in via holes Vw are arranged on the surface Sw.

[0014] Among the plurality of via conductors Cw, the distance A between the via conductor Cw on the first end face Tw1 side and the first end face Tw1 is usually a different value for each workpiece. Among the plurality of via conductors Cw, the distance B between the via conductor Cw on the second end face Tw2 side and the second end face Tw2 is usually a different value for each workpiece. In the present embodiment, each of the distances A and B is based on the center of the via conductor Cw in the axial direction, but other parts of the via conductor Cw may also be used as a reference.

[0015] [Carrier 10] The carrier 10 has a disk 11, a first holding portion 12, and a second holding portion 13.

[0016] The disk 11 is a plate-like member formed in a substantially perfect circular shape. The disk 11 is rotatable in the circumferential direction about an axis A0 (an example of "a predetermined axis"). The disk 11 is rotationally driven by a drive motor (not shown). On the outer periphery of the disk 11, a first recess 11a in which the first holding portion 12 is arranged and a second recess 11b in which the second holding portion 13 is arranged are formed.

[0017] ​​​​​​​​​​​

[0020] The first holding section 12 is composed of a fixed clamp section 61, a reference section 62, a movable clamp section 63, and a biasing member 64.

[0021] The fixing clamp portion 61 is fixed to the outer circumference of the disc 11. The fixing clamp portion 61 can be fixed to the disc 11 by screws or the like. The fixing clamp portion 61 has a locking portion 61a and a mounting surface 61b. One end of the workpiece W in the circumferential direction is inserted into the locking portion 61a. The workpiece W is placed on the mounting surface 61b.

[0022] The reference section 62 is positioned on the fixed clamp section 61. As shown in Figure 2, the reference section 62 has a notch 62a. The notch 62a is used to determine the reference position Ps (see Figure 6), which will be described later. The notch 62a is positioned within the imaging range of the imaging device 20. In this embodiment, the reference section 62 is fixed to the fixed clamp section 61, but it is sufficient that it is fixed so as not to move relative to the imaging device 20, and it may be fixed to a member other than the fixed clamp section 61 (for example, the imaging device 20). Also, in this embodiment, the reference section 62 is a thin plate-shaped member, but the shape and material of the reference section 62 are not particularly limited.

[0023] The movable clamp portion 63 is attached to the support portion 11c of the disc 11. The movable clamp portion 63 is pivotable about a shaft portion 11d that penetrates the support portion 11c. The shaft portion 11d is arranged along an axial direction parallel to the axis A0. The movable clamp portion 63 is biased toward the fixed clamp portion 61 by a biasing member 64. The biasing member 64 is connected to the disc 11 and the movable clamp portion 63. An elastic member such as a spring can be used as the biasing member 64.

[0024] The movable clamping portion 63 has a locking portion 63a and a pushing portion 63b. The other end of the workpiece W in the circumferential direction is inserted into the locking portion 63a. The pushing portion 63b is operated by the operator when clamping or unclamping the workpiece W.

[0025] When the operator holds the workpiece W in the first holding part 12, they press the push part 63b, insert one end of the workpiece W into the locking part 61a, and place the workpiece W on the mounting surface 61b. Then, they release the push part 63b and insert the other end of the workpiece W into the locking part 63a. This fixes the workpiece W not only in the circumferential direction but also in the axial direction.

[0026] When the worker removes the workpiece W from the first holding part 12, they first release the other end of the workpiece W from the locking part 63a by pressing the push part 63b, and then remove the workpiece W by taking the workpiece W and pulling one end out of the locking part 61a.

[0027] In this embodiment, the workpiece W is held when the first holding unit 12 reaches its highest position and the disc 11 temporarily stops. However, the workpiece W only needs to be held before the workpiece W is imaged by the imaging device 20.

[0028] Furthermore, in this embodiment, the workpiece W is removed when the disc 11 rotates further, the first holding part 12 passes between the first grinding wheel 30 and the second grinding wheel 40, and the second holding part 13 passes between the first grinding wheel 30 and the second grinding wheel 40. However, the workpiece W removal operation only needs to be performed before the next workpiece W holding operation.

[0029] The holding and removal of the workpiece W in the first holding section 12 has been described above, but the holding and removal of the workpiece W in the second holding section 13 are performed in the same manner.

[0030] [Imaging device 20] The imaging device 20 is positioned in a fixed location relative to the carrier 10.

[0031] The imaging device 20 images the surface Sw of the workpiece W held in the first holding unit 12. The imaging range of the imaging device 20 is set to include the reference unit 62 of the first holding unit 12. After imaging the workpiece W, the imaging device 20 transmits the imaging data to the controller 50.

[0032] [First grinding wheel 30 and second grinding wheel 40] As shown in Figure 2, the first grinding wheel 30 and the second grinding wheel 40 face each other in the axial direction. A carrier 10 is positioned between the first grinding wheel 30 and the second grinding wheel 40 in the axial direction.

[0033] The first grinding wheel 30 is rotatable about an axis A1 parallel to axis A0. The second grinding wheel 40 is rotatable about an axis A2 parallel to axis A0. Axes A1 and A2 are coaxial with each other. The first grinding wheel 30 and the second grinding wheel 40 are each driven by a drive motor (not shown).

[0034] The first grinding wheel 30 is movable in the axial direction. In Figure 2, the first grinding wheel 30 is positioned at the first starting position. When the workpiece W is held in the first holding part 12, the first grinding wheel 30 moves axially from the first starting position toward the workpiece W. The position of the first grinding wheel 30 in the axial direction can be adjusted by a servo motor (not shown).

[0035] The second grinding wheel 40 is movable in the axial direction. In Figure 2, the second grinding wheel 40 is positioned at the second starting position. The second starting position is located in the axial direction, with respect to the carrier 10, on the opposite side from the first starting position of the first grinding wheel 30. When the workpiece W is held in the first holding part 12, the second grinding wheel 40 moves axially from the second starting position toward the workpiece W. The position of the second grinding wheel 40 in the axial direction can be adjusted by a servo motor (not shown).

[0036] [Controller 50] Figure 5 is a block diagram showing the configuration of the controller 50. The controller 50 includes a carrier control unit 51, an imaging device control unit 52, and a grinding wheel control unit 53.

[0037] <Carrier control unit 51> The carrier control unit 51 adjusts the rotation speed of the disc 11 by controlling the drive motor for the disc 11.

[0038] Specifically, the carrier control unit 51 rotates the disc 11 at a predetermined feed rate when the first holding unit 12 and the second holding unit 13 are positioned between the first grinding wheel 30 and the second grinding wheel 40. When the first holding unit 12 and the second holding unit 13 are not positioned between the first grinding wheel 30 and the second grinding wheel 40, the carrier control unit 51 rotates the disc 11 at a predetermined rapid traverse speed. The rapid traverse speed may be faster than the feed rate.

[0039] The carrier control unit 51 pauses the disc 11 when the first holding unit 12 reaches its highest position. While the disc 11 is paused, the first holding unit 12 performs the workpiece W holding operation. The carrier control unit 51 pauses the disc 11 when the second holding unit 13 reaches its highest position. While the disc 11 is paused, the second holding unit 13 performs the next workpiece W holding operation.

[0040] <Imaging device control unit 52> The imaging device control unit 52 controls the imaging device 20 to image the workpiece W.

[0041] Specifically, the imaging device control unit 52 causes the first holding unit 12 to pause at its highest position, and after the workpiece W is held by the first holding unit 12, it causes the imaging device 20 to image the workpiece W. The imaging timing of the imaging device 20 can be set to just before the disc 11 resumes rotation.

[0042] The imaging device control unit 52 acquires imaging data of the workpiece W from the imaging device 20 and outputs it to the grinding wheel control unit 53.

[0043] <Grinding wheel control unit 53> The grinding wheel control unit 53 adjusts the rotational speed of the first grinding wheel 30 and the second grinding wheel 40 by controlling their respective drive motors. The grinding wheel control unit 53 also adjusts the axial position of the first grinding wheel 30 and the second grinding wheel 40 by controlling their respective servo motors.

[0044] As shown in Figure 5, the grinding wheel control unit 53 includes a distance acquisition unit 53a, a storage unit 53b, a target movement amount determination unit 53c, and a drive unit 53d.

[0045] ·Separation distance acquisition unit 53a The separation distance acquisition unit 53a acquires an image of the workpiece W based on the imaging data of the workpiece W. Figure 6 is a schematic diagram showing an example of an image of the workpiece W.

[0046] In Figure 6, the origin position Pr is the camera origin position of the imaging device 20 in the axial direction, and the reference position Ps is the position specified in the axial direction by the notch 62a of the reference section 62. In this embodiment, the reference position Ps is specified by the deepest part of the notch 62a, but it may also be specified by a part other than the deepest part (for example, one end of the reference section 62).

[0047] The separation distance acquisition unit 53a acquires distances Zw0, Zw1, Zw2, Zw3, and Zw4 from the captured image of the workpiece W shown in Figure 6. Distance Zw0 is the axial distance between the origin position Pr and the reference position Ps. Distance Zw1 is the axial distance between the origin position Pr and the first end face Tw1. Distance Zw2 is the axial distance between the origin position Pr and the second end face Tw2. Distance Zw3 is the axial distance between the via conductor Cw on the first end face Tw1 side of the multiple via conductors Cw and the origin position Pr. Distance Zw4 is the axial distance between the via conductor Cw on the second end face Tw2 side of the multiple via conductors Cw and the origin position Pr. In this embodiment, distances Zw3 and Zw4 are based on the center of the via conductor Cw in the axial direction, but other parts of the via conductor Cw may be used as references, similar to intervals a and b.

[0048] The separation distance acquisition unit 53a calculates the total width Ww of the workpiece W by subtracting distance Zw1 from distance Zw2. The separation distance acquisition unit 53a calculates the axial distance Zwc between the origin position Pr and the center position Pwc of the workpiece W by adding distance Zw1 and half of the total width Ww (i.e., Ww / 2).

[0049] The separation distance acquisition unit 53a calculates the separation distance gw, which is the difference between distance Zw0 and distance Zwc. The separation distance gw is the axial distance between the center position Pwc and the reference position Ps of the workpiece W.

[0050] Furthermore, the separation distance acquisition unit 53a obtains spacing a and spacing b by referring to the storage unit 53b. Spacing a is the distance between the via conductor Cw and the first end face Tw1, and is a default value. Spacing b is the distance between the via conductor Cw and the second end face Tw2, and is a default value.

[0051] The separation distance acquisition unit 53a calculates the first material removal amount x on the first end face Tw1 side by subtracting the distance Zw1 and the interval a from the distance Zw3. The first material removal amount x is the width that needs to be removed by grinding the first end face Tw1 with the first grinding wheel 30.

[0052] The separation distance acquisition unit 53a calculates the second material removal amount y on the second end face Tw2 side by subtracting the distance Zw4 and the interval b from the distance Zw2. The second material removal amount y is the width that needs to be removed by grinding the second end face Tw2 with the second grinding wheel 40.

[0053] The separation distance acquisition unit 53a outputs the separation distance gw to the center separation distance acquisition unit 53c. The separation distance acquisition unit 53a outputs the first removal amount x and the second removal amount y to the drive unit 53d.

[0054] ·Storage unit 53b The memory unit 53b has pre-stored intervals a and b as shown in Figure 6.

[0055] The memory unit 53b pre-stores the first reference displacement L1 and the second reference displacement L2 shown in Figure 7.

[0056] The first reference movement amount L1 is the amount of movement when the first grinding wheel 30 is moved from the first starting position toward the workpiece W in order to machine the workpiece W to a desired dimension, assuming that the center position Pwc of the workpiece W coincides with the reference position Ps, as shown in Figure 7.

[0057] The second reference movement amount L2 is the amount of movement when the second grinding wheel 40 is moved from the second movement start position toward the workpiece W in order to machine the workpiece W to a desired dimension, assuming that the center position Pwc of the workpiece W coincides with the reference position Ps, as shown in Figure 7.

[0058] In Figure 7, a workpiece W is shown for reference, but the first reference travel amount L1 and the second reference travel amount L2 are predetermined values ​​regardless of the shape and dimensions of the workpiece W. The first reference travel amount L1 and the second reference travel amount L2 may be the same value or may be different values.

[0059] ·Target movement amount determination unit 53c The target movement amount determination unit 53c obtains the separation distance gw from the separation distance acquisition unit 53a. The target movement amount determination unit 53c obtains the first reference movement amount L1 and the second reference movement amount L2 by referring to the storage unit 53b.

[0060] The target movement amount determination unit 53c determines the first target movement amount L1a by correcting the first reference movement amount L1 based on the separation distance gw. In the example shown in Figure 6, the center position Pwc of the workpiece W is shifted from the reference position Ps toward the second grinding wheel 40, so the first target movement amount L1a is obtained by adding the separation distance gw to the first reference movement amount L1.

[0061] Similarly, the target movement amount determination unit 53c determines the second target movement amount L2a by correcting the second reference movement amount L2 based on the separation distance gw. In the example shown in Figure 6, the center position Pwc of the workpiece W is shifted from the reference position Ps toward the second grinding wheel 40, so the second target movement amount L2a is obtained by subtracting the separation distance gw from the second reference movement amount L2.

[0062] The target movement amount determination unit 53c outputs the first target movement amount L1a and the second target movement amount L2a to the drive unit 53d.

[0063] • Drive unit 53d When the workpiece W held by the first holding unit 12 is located between the first grinding wheel 30 and the second grinding wheel 40, the drive unit 53d moves the first grinding wheel 30 toward the workpiece W by a first target movement amount L1a from the first starting position, as shown in Figure 8, thereby grinding the first end face Tw1 of the workpiece W with the first grinding wheel 30.

[0064] When the workpiece W held by the first holding unit 12 is located between the first grinding wheel 30 and the second grinding wheel 40, the drive unit 53d moves the second grinding wheel 40 toward the workpiece W by a second target movement amount L2a from the second starting position, as shown in Figure 8, thereby grinding the second end face Tw2 of the workpiece W with the second grinding wheel 40.

[0065] In this way, by moving the first grinding wheel 30 by a first target movement amount L1a and the second grinding wheel 40 by a second target movement amount L2a, both end faces of the workpiece W are ground. The first target movement amount L1a is obtained by correcting the first reference movement amount L1 based on the distance gw between the center position Pwc and the reference position Ps of the workpiece W. The second target movement amount L2a is obtained by correcting the second reference movement amount L2 based on the distance gw between the center position Pwc and the reference position Ps of the workpiece W. Therefore, both end faces of the workpiece W can be ground until the distance between the via conductor Cw and the first end face Tw1 becomes distance a (see Figure 6), and the distance between the via conductor Cw and the second end face Tw2 becomes distance b (see Figure 6). Thus, according to the grinding machine 1 of this embodiment, the first and second material removal amounts x and y on each end face of the workpiece W can be adjusted separately.

[0066] Furthermore, it is preferable that the drive unit 53d adjusts the moving speed of the first grinding wheel 30 and the second grinding wheel 40 based on the first material removal amount x and the second material removal amount y obtained from the separation distance acquisition unit 53a, thereby aligning the timing of contact between the first grinding wheel 30 and the second grinding wheel 40 with the workpiece W.

[0067] Specifically, the drive unit 53d calculates the first forward movement T1 by subtracting the first material removal x from the first target movement L1a, and calculates the second forward movement T2 by subtracting the second material removal y from the second target movement L2a. Then, the drive unit 53d adjusts the movement speeds of the first grinding wheel 30 and the second grinding wheel 40 so that the time it takes for the first grinding wheel 30 to move the first forward movement Fw1 is equal to the time it takes for the second grinding wheel 30 to move the second forward movement Fw2. As a result, the timing at which the first grinding wheel 30 contacts the workpiece W can be brought closer to the timing at which the second grinding wheel 40 contacts the workpiece W, thereby suppressing axial displacement of the workpiece W's holding position in the first holding unit 12.

[0068] (Grinding method) The grinding method for workpiece W using grinding machine 1 will be explained with reference to the drawings. Figure 9 is a flowchart illustrating the grinding method.

[0069] In step S1, the worker holds the workpiece W in the first holding unit 12.

[0070] In step S2, the imaging device 20 images the surface Sw of the workpiece W held in the first holding unit 12.

[0071] In step S3, the distance acquisition unit 53a of the controller 50 acquires the distance gw from the captured image of the workpiece W shown in Figure 6. The distance gw is the axial distance between the center position Pwc and the reference position Ps of the workpiece W.

[0072] In step S4, the distance acquisition unit 53a of the controller 50 acquires the first removal amount x and the second removal amount y from the captured image of the workpiece W shown in Figure 6. The first removal amount x and the second removal amount y are the removal widths at both end faces Tw1 and Tw2 of the workpiece W.

[0073] In step S5, the target movement amount determination unit 53c of the controller 50 determines the first target movement amount L1a shown in Figure 8 by correcting the first reference movement amount L1 shown in Figure 7 based on the separation distance gw.

[0074] In step S6, the target movement amount determination unit 53c of the controller 50 determines the second target movement amount L2a shown in Figure 8 by correcting the second reference movement amount L2 shown in Figure 7 based on the separation distance gw.

[0075] In step S7, the drive unit 53d of the controller 50 moves the first grinding wheel 30 toward the workpiece W by a first target movement amount L1a from the first starting position, and moves the second grinding wheel 40 toward the workpiece W by a second target movement amount L2a from the second starting position. As a result, both end faces Tw1 and Tw2 of the workpiece W are ground by the first and second grinding wheels 30 and 40.

[0076] In step S7, it is preferable that the drive unit 53d adjusts the moving speed of the first and second grinding wheels 30 and 40 based on the first material removal x and second material removal y, thereby aligning the timing of contact between the first and second grinding wheels 30 and 40 and the workpiece W. This prevents the holding position of the workpiece W in the first holding unit 12 from shifting in the axial direction. However, if it is not necessary to align the contact timing, this step, along with step S4, can be omitted.

[0077] (Modified examples of the embodiment) The present invention is not limited to the embodiments described above, and various modifications or alterations are possible without departing from the scope of the present invention.

[0078] [Example 1] In the above embodiment, the case of grinding only one workpiece W was described, but by using the first holding part 12 and the second holding part 13 alternately, it is possible to continuously grind the next new workpiece W.

[0079] [Differentiation 2] In the above embodiment, the case of grinding the first end face Tw1 and the second end face Tw2 of the workpiece W was described, but the amount of material removed can also be adjusted separately when grinding the remaining two end faces.

[0080] [Difference 3] Preferably, the grinding wheel control unit 53 of the controller 50 further includes a displacement amount acquisition unit that acquires a first displacement amount Δx of the first material removal amount x and a second displacement amount Δy of the second material removal amount y in the workpiece W after grinding. The first displacement amount Δx is the difference between the distance between the via conductor Cw and the first end face Tw1 after grinding and the distance a. The second displacement amount Δy is the difference between the distance between the via conductor Cw and the second end face Tw2 after grinding and the distance b.

[0081] The first displacement Δx and the second displacement Δy can be obtained from an image of the surface of the grinding workpiece W (i.e., the processed product). The image of the grinding workpiece W may be obtained using an imaging device other than the imaging device 20, or it may be obtained using the imaging device 20. When using the imaging device 20, after grinding the workpiece W held in the first holding unit 12 with the first and second grinding wheels 30 and 40, the carrier 10 can be rotated and imaged until the ground workpiece W held in the first holding unit 12 enters the imaging range of the imaging device 20.

[0082] In this case, when the target movement amount determination unit 53c determines the first target movement amount L1a for the next unprocessed workpiece W, it corrects the first reference movement amount L1 based on the separation distance gw and the first displacement amount Δx to determine the first target movement amount L1a. This allows the first material removal amount x to be accurately removed from the first end face Tw1. Similarly, when the target movement amount determination unit 53c determines the second target movement amount L2a for the next unprocessed workpiece W, it corrects the second reference movement amount L2 based on the separation distance gw and the second displacement amount Δy to determine the second target movement amount L2a. This allows the second material removal amount y to be accurately removed from the second end face Tw2. [Explanation of symbols]

[0083] 1...Grinding machine, 10...Carrier, 11...Disc, 12...First holding unit, 13...Second holding unit, 20...Imaging device, 30...First grinding wheel, 40...Second grinding wheel, 50...Controller, 51...Carrier control unit, 52...Imaging device control unit, 53...Grinding wheel control unit, 53a...Separation distance acquisition unit, 53b...Memory unit, 53c...Target movement amount determination unit, 53d...Drive unit, W...Workpiece, Tw1...First end face, Tw2...Second end face, Cw...Via conductor

Claims

1. A carrier that can rotate around its axis while holding an unprocessed workpiece on its outer circumference, A first grinding wheel that can move from a first starting position toward the unprocessed workpiece in an axial direction parallel to the axis, A second grinding wheel that is movable in the axial direction toward the unprocessed workpiece, with respect to the carrier in the axial direction, from a second starting position opposite to the first starting position, and A controller that controls the positions of the first grinding wheel and the second grinding wheel in the axial direction, Equipped with, The aforementioned controller, A separation distance acquisition unit that acquires the separation distance between the center position of the unprocessed workpiece in the axial direction and a reference position set at a fixed position relative to the carrier, A target movement amount determination unit determines a first target movement amount by correcting a first reference movement amount when moving the first grinding wheel toward the unprocessed workpiece to process the unprocessed workpiece to a desired dimension, assuming that the center position coincides with the reference position, based on the separation distance, and determines a second target movement amount by correcting a second reference movement amount when moving the second grinding wheel toward the unprocessed workpiece to process the unprocessed workpiece to a desired dimension, assuming that the center position coincides with the reference position, based on the separation distance. A drive unit that moves the first grinding wheel toward the unprocessed workpiece by a first target movement amount from the first starting position, and moves the second grinding wheel toward the unprocessed workpiece by a second target movement amount from the second starting position, thereby grinding both end faces of the unprocessed workpiece with the first and second grinding wheels, A grinding machine having a grinding function.

2. The system further comprises an imaging device capable of imaging the surface of the unprocessed workpiece held on the carrier, The controller obtains the separation distance from the captured image of the unprocessed workpiece. The grinding machine according to claim 1.

3. The separation distance acquisition unit acquires the first material to be removed by the first grinding wheel and the second material to be removed by the second grinding wheel from the image of the unprocessed workpiece. The drive unit adjusts the moving speeds of the first grinding wheel and the second grinding wheel based on the first and second material removal amounts, thereby bringing the timing at which the first grinding wheel contacts the unprocessed workpiece closer to the timing at which the second grinding wheel contacts the unprocessed workpiece. A grinding machine according to claim 1 or 2.

4. The controller further includes a displacement amount acquisition unit that acquires a first displacement amount of the first material removal amount and a second displacement amount of the second material removal amount in the workpiece after grinding. When the target movement amount determination unit acquires the first target movement amount and the second target movement amount for the next unprocessed workpiece, it corrects the first reference movement amount based on the separation distance and the first displacement amount, and corrects the second reference movement amount based on the separation distance and the second displacement amount. The grinding machine according to claim 3.

5. A grinding method using a carrier rotatable about an axis, a first grinding wheel movable in an axial direction parallel to the axis, and a second grinding wheel facing the first grinding wheel in the axial direction and movable in the axial direction, The process of holding an unprocessed workpiece on the outer circumference of the carrier, A step of obtaining the distance between the center position of the unprocessed workpiece in the axial direction and a reference position set at a fixed position relative to the carrier, The steps include: determining a first target movement amount by correcting a first reference movement amount when moving the first grinding wheel toward the unprocessed workpiece to process the unprocessed workpiece to a desired dimension, assuming that the center position coincides with the reference position, based on the separation distance; and determining a second target movement amount by correcting a second reference movement amount when moving the second grinding wheel toward the unprocessed workpiece to process the unprocessed workpiece to a desired dimension, assuming that the center position coincides with the reference position, based on the separation distance; A step of grinding both end faces of the unprocessed workpiece with the first grinding wheel and the second grinding wheel by moving the first grinding wheel from a first starting position toward the unprocessed workpiece by a first target movement amount, and moving the second grinding wheel toward the unprocessed workpiece by a second target movement amount from a second starting position opposite to the first starting position relative to the carrier in the axial direction, and A grinding method comprising the following features.

Images