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 center separation-distance obtaining part 53b, a target movement-amount determining part 53d and a driving part 53e. The center separation-distance obtaining part 53b obtains a center separation-distance ΔC between a center position Pmc of a master work-piece M and a center position Pwc of a work-piece W in the axial direction. The target movement-amount determining part 53d determines a first target movement amount Ew1 by correcting a first reference movement amount Dm1 of when the first grindstone 30 is moved from a first movement start position to the master work-piece M in the axial direction, on the basis of the center separation-distance ΔC. The target movement-amount determining part 53d determines a second target movement amount Ew2 by correcting a second reference movement amount Dm2 of when the second grindstone 40 is moved from a second movement start position to the master work-piece M in the axial direction, on the basis of the center separation-distance ΔC.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 that grinds both end faces of a workpiece arranged on the outer periphery of a rotating carrier with a pair of grinding wheels is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, in a ceramic package, when it is required to keep the distances between the metal members arranged on the surface and the respective end faces within a predetermined range, it is necessary to separately adjust the replacement at each of the end faces.

[0005] However, in a conventional grinding machine, the replacement at each of the end faces of the workpiece cannot be adjusted separately.

[0006] An object of the present disclosure is to provide a grinding machine and a grinding method capable of separately adjusting the replacement at each of the end faces of a workpiece.

Means for Solving the Problems

[0007] The grinding machine according to this disclosure comprises a carrier, a first grinding wheel, a second grinding wheel, and a controller. The carrier is rotatable about its axis while holding a master work and an unprocessed work on its outer circumference. The first grinding wheel is movable in an axial direction parallel to the axis from a first starting position toward the master work or the unprocessed work. The second grinding wheel is movable in the axial direction toward the master work or the unprocessed work from a second starting position opposite to the first starting position relative to the carrier. The controller controls the positions of the first grinding wheel and the second grinding wheel in the axial direction. The controller has a center separation distance acquisition unit, a target movement amount determination unit, and a drive unit. The center separation distance acquisition unit acquires the center separation distance between the center position of the master work and the center position of the unprocessed work in the axial direction. The target movement amount determination unit determines a first target movement amount by correcting a first reference movement amount when the first grinding wheel is moved from the first starting position toward the master work in the axial direction based on the center separation distance. The target movement amount determination unit determines the second target movement amount by correcting the second reference movement amount when the second grinding wheel is moved in the axial direction from the second movement start position to the master workpiece based on the center separation distance. The drive unit moves the first grinding wheel toward the unprocessed workpiece by the first target movement amount from the first movement start position, and moves the second grinding wheel toward the unprocessed workpiece by the second target movement amount from the second movement start position, thereby grinding both end faces of the unprocessed workpiece with the first and second grinding wheels. [Effects 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 masterwork according to the embodiment. [Figure 4] A schematic diagram showing an example of the surface of a workpiece according to the embodiment. [Figure 5] Partial enlarged view of Figure 1 [Figure 6] Block diagram showing the configuration of the controller according to the embodiment. [Figure 7] A schematic diagram showing an example of an image captured from a masterwork according to the embodiment. [Figure 8] A schematic diagram showing an example of an image of a workpiece according to the embodiment. [Figure 9] Flowchart illustrating the grinding method according to the embodiment [Figure 10] Schematic diagram illustrating the grinding method according to the embodiment. [Figure 11] Schematic diagram 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 master work M. Figure 4 is a schematic diagram showing an example of the surface of the workpiece W.

[0011] As shown in Figures 1 and 2, the 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] Grinding machine 1 is a so-called double-ended surface grinding machine. Grinding machine 1 uses a master workpiece M to grind both end faces of the workpiece W.

[0013] The master workpiece M has the target shape after the desired grinding process has been performed on the workpiece W. Therefore, the master workpiece M has dimensions that do not require grinding. In this embodiment, a machined workpiece, in which the workpiece W has been ground to the desired design dimensions, is used as the master workpiece M. However, a replica of the machined workpiece may also be used as the master workpiece M.

[0014] As shown in FIG. 3, the master workpiece M has a surface Sm, a first end face Tm1, and a second end face Tm2. A plurality of via conductors Cm filled in via holes Vm are arranged on the surface Sm. The arrangement of the via conductors Cm in the master workpiece M is the same as the arrangement of the via conductors Cw in the workpiece W described later. In the present embodiment, the via conductors Cm are arranged in two rows, but the positions and numbers of the via conductors Cm can be changed as appropriate.

[0015] The distance a between the via conductor Cm on the first end face Tm1 side and the first end face Tm1 among the plurality of via conductors Cm is a predetermined value. The distance b between the via conductor Cm on the second end face Tm2 side and the second end face Tm2 among the plurality of via conductors Cm is a predetermined value. The distance a and the distance b may be the same value as each other or different values. In the present embodiment, each of the distances a and b is based on the center of the via conductor Cm in the axial direction, but other parts of the via conductor Cm may be used as a reference.

[0016] When using a replica having the same shape as the processed workpiece as the master workpiece M, a mark having the same shape as the via conductor Cm may be printed on the surface Sm instead of the via conductor Cm.

[0017] The workpiece W is an unprocessed workpiece member. In the present embodiment, a ceramic package is assumed as the workpiece W. However, the workpiece W may be a member made of a material that can be ground by a grindstone.

[0018] As shown in FIG. 4, 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.

[0019] The distance A between the via conductor Cw on the first end face Tw1 and the first end face Tw1 is usually a different value for each workpiece. The distance B between the via conductor Cw on the second end face Tw2 and the second end face Tw2 is usually a different value for each workpiece. The distance A in workpiece W is greater than the distance a in master workpiece M by the amount of material removal at the first end face Tw1. The distance B in workpiece W is greater than the distance b in master workpiece M by the amount of material removal at the second end face Tw2. In this embodiment, the distances A and B are 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 references.

[0020] [Career 10] The carrier 10 has a disc 11, a first holding portion 12, and a second holding portion 13.

[0021] The disc 11 is a plate-like member formed in a nearly perfect circular shape. The disc 11 is rotatable in the circumferential direction around the axis A0 (an example of a "predetermined axis"). The disc 11 is rotationally driven by a drive motor (not shown). On the outer circumference of the disc 11, a first recess 11a where the first retaining portion 12 is located and a second recess 11b where the second retaining portion 13 is located are formed.

[0022] The first retaining portion 12 is positioned in the first recess 11a formed on the outer circumference of the disc 11. The second retaining portion 13 is positioned in the second recess 11b formed on the outer circumference of the disc 11. The first retaining portion 12 and the second retaining portion 13 are positioned 180 degrees apart in the circumferential direction. However, the number and position of the retaining portions can be changed as appropriate.

[0023] In Figures 1 and 2, the master workpiece M is held in the first holding section 12, and the workpiece W is held in the second holding section 13.

[0024] Here, Figure 5 is an enlarged view of the second retaining part 13 shown in Figure 1. In this embodiment, the second retaining part 13 has the same configuration as the first retaining part 12, so the configuration of the second retaining part 13 will be described below.

[0025] The second holding section 13 is composed of a fixed clamp section 61, a reference section 62, a movable clamp section 63, and a biasing member 64.

[0026] 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.

[0027] 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 Figures 6 and 7), 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.

[0028] 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.

[0029] 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.

[0030] When the operator holds the workpiece W in the second holding part 13, 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.

[0031] When the worker removes the workpiece W from the second holding part 13, 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.

[0032] In this embodiment, the workpiece W is held when the second holding unit 13 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.

[0033] Furthermore, in this embodiment, the workpiece W is removed when the disc 11 rotates further, the second holding part 13 passes between the first grinding wheel 30 and the second grinding wheel 40, and the first holding part 12 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.

[0034] The holding and removal of the workpiece W in the second holding section 13 has been described above, but the holding and removal of the master workpiece M in the first holding section 12 are performed in the same manner.

[0035] However, the first holding part 12 holds the master workpiece M only once. After removing the master workpiece M from the first holding part 12, the first holding part 12 can hold the workpiece W, and the first holding part 12 and the second holding part 13 can be used to grind the workpiece W.

[0036] [Imaging device 20] The imaging device 20 is positioned in a fixed location relative to the carrier 10.

[0037] The imaging device 20 images the surface Sm of the masterwork M 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 masterwork M, the imaging device 20 transmits the imaging data to the controller 50.

[0038] The imaging device 20 images the surface Sw of the workpiece W held in the second holding unit 13. The imaging range of the imaging device 20 is set to include the reference unit 62 of the second holding unit 13. After imaging the workpiece W, the imaging device 20 transmits the imaging data to the controller 50.

[0039] [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.

[0040] 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).

[0041] 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 master workpiece M is held in the first holding unit 12, the first grinding wheel 30 moves axially from the first starting position toward the master workpiece M. When the workpiece W is held in the second holding unit 13, 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).

[0042] 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 master work M is held in the first holding unit 12, the second grinding wheel 40 moves axially from the second starting position toward the master work M. When the workpiece W is held in the second holding unit 13, 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).

[0043] [Controller 50] Figure 6 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.

[0044] <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.

[0045] 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.

[0046] 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 holding operation of the master work M. 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 holding operation of the work W.

[0047] <Imaging device control unit 52> The imaging device control unit 52 controls the imaging device 20 to image the master work M and the work W, respectively.

[0048] Specifically, the imaging device control unit 52 causes the first holding unit 12 to pause at its highest position, and after the master work M is held in the first holding unit 12, it causes the imaging device 20 to image the master work M. Subsequently, the imaging device control unit 52 causes the second holding unit 13 to pause at its highest position, and after the work W is held in the second holding unit 13, it causes the imaging device 20 to image the work W. The imaging timing of the imaging device 20 can be set to just before the disc 11 resumes rotation.

[0049] The imaging device control unit 52 acquires imaging data for both the master work M and the work W from the imaging device 20 and outputs it to the grinding wheel control unit 53.

[0050] <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.

[0051] As shown in Figure 6, the grinding wheel control unit 53 includes a reference distance acquisition unit 53a, a center separation distance acquisition unit 53b, a reference movement amount acquisition unit 53c, a target movement amount determination unit 53d, and a drive unit 53e.

[0052] ·Reference distance acquisition unit 53a The reference distance acquisition unit 53a acquires image data of master work M and work W based on the respective imaging data of master work M and work W. Figure 7 is a schematic diagram showing an example of an image of master work M. Figure 8 is a schematic diagram showing an example of an image of work W.

[0053] In Figures 7 and 8, 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).

[0054] The reference distance acquisition unit 53a acquires distances Zm0, Zm1, and Zm2 from the captured image of the masterwork M shown in Figure 7. Distance Zm0 is the axial distance between the origin position Pr and the reference position Ps. Distance Zm1 is the axial distance between the origin position Pr and the first end face Tm1. Distance Zm2 is the axial distance between the origin position Pr and the second end face Tm2.

[0055] The reference distance acquisition unit 53a calculates the total width Wm of the masterwork M by subtracting the distance Zm1 from the distance Zm2. The reference distance acquisition unit 53a calculates the axial distance Zmc between the origin position Pr and the center position Pmc of the masterwork M by adding the distance Zm1 and half of the total width Wm (i.e., Wm / 2).

[0056] The reference distance acquisition unit 53a calculates the master reference distance gm by subtracting the distance Zmc from the distance Zm0. The master reference distance gm is the axial distance between the center position Pmc and the reference position Ps of the master workpiece M.

[0057] The reference distance acquisition unit 53a acquires distances Zw0, Zw1, Zw2, Zw3, and Zw4 from the captured image of the workpiece W shown in Figure 8. Distance Zw0 is the axial distance between the origin position Pr and the reference position Ps. Distance Zw0 is the same as distance Zm0 shown in Figure 7. 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, similar to spacings a and b, other parts of the via conductor Cw may also be used as reference points.

[0058] The reference distance acquisition unit 53a calculates the total width Ww of the workpiece W by subtracting distance Zw1 from distance Zw2. The reference 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).

[0059] The reference distance acquisition unit 53a calculates the workpiece reference distance gw, which is the difference between distance Zw0 and distance Zwc. The workpiece reference distance gw is the axial distance between the center position Pwc and the reference position Ps of the workpiece W.

[0060] Furthermore, the reference 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 gap a from the distance Zw3. The gap a is the distance between the via conductor Cw and the first end face Tw1, and is a predetermined value. 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.

[0061] The reference 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 interval b is the distance between the via conductor Cw and the second end face Tw2, and is a predetermined value. 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.

[0062] The reference distance acquisition unit 53a outputs the master reference distance gm and the workpiece reference distance gw to the center separation distance acquisition unit 53b. The reference distance acquisition unit 53a outputs the first cutting allowance x and the second cutting allowance y to the drive unit 53e.

[0063] • Center separation distance acquisition unit 53b The center separation distance acquisition unit 53b acquires the center separation distance ΔC between the center position Pmc of the master workpiece M and the center position Pwc of the workpiece W in the axial direction. In this embodiment, the center separation distance acquisition unit 53b acquires the center separation distance ΔC based on the master reference distance gm and the workpiece reference distance gw.

[0064] In the example shown in Figures 7 and 8, the center position Pmc of the master workpiece M is located on the opposite side of the center position Pwc of the workpiece W, relative to the reference position Ps. Therefore, the sum of the master reference distance gm and the workpiece reference distance gw is the center separation distance ΔC. The center separation distance acquisition unit 53b outputs the center separation distance ΔC to the target movement amount determination unit 53d.

[0065] ·Reference movement amount acquisition unit 53c The reference movement amount acquisition unit 53c acquires the first reference movement amount Dm1 when the drive unit 53e moves the first grinding wheel 30 from the first movement start position to the master work M, as will be described later. The first reference movement amount Dm1 can be acquired based on the amount of rotation of the servo motor that moves the first grinding wheel 30 in the axial direction. The reference movement amount acquisition unit 53c outputs the first reference movement amount Dm1 to the target movement amount determination unit 53d.

[0066] The reference movement amount acquisition unit 53c acquires the second reference movement amount Dm2 when the drive unit 53e moves the second grinding wheel 40 from the second movement start position to the master work M, as will be described later. The second reference movement amount Dm2 can be acquired based on the amount of rotation of the servo motor that moves the second grinding wheel 40 in the axial direction. The reference movement amount acquisition unit 53c outputs the second reference movement amount Dm2 to the target movement amount determination unit 53d.

[0067] ·Target movement amount determination unit 53d The target displacement determination unit 53d obtains the center separation distance ΔC from the center separation distance acquisition unit 53b and obtains the first reference displacement amount Dm1 and the second reference displacement amount Dm2 from the reference displacement amount acquisition unit 53c.

[0068] The target movement amount determination unit 53d determines the first target movement amount Ew1 by correcting the first reference movement amount Dm1 based on the center separation distance ΔC. The first target movement amount Ew1 is the amount by which the first grinding wheel 30 is moved axially when grinding the workpiece W. In the example shown in Figures 7 and 8, the workpiece W is shifted toward the second grinding wheel 40 side from the master workpiece M, so the first target movement amount Ew1 is obtained by adding the center separation distance ΔC to the first reference movement amount Dm1. The target movement amount determination unit 53d outputs the first target movement amount Ew1 to the drive unit 53e.

[0069] The target movement amount determination unit 53d determines the second target movement amount Ew2 by correcting the second reference movement amount Dm2 based on the center separation distance ΔC. The second target movement amount Ew2 is the amount by which the second grinding wheel 40 is moved axially when grinding the workpiece W. In the example shown in Figures 7 and 8, the workpiece W is shifted toward the second grinding wheel 40 side from the master workpiece M, so the second target movement amount Ew2 is obtained by subtracting the center separation distance ΔC from the second reference movement amount Dm2. The target movement amount determination unit 53d outputs the second target movement amount Ew2 to the drive unit 53e.

[0070] • Drive unit 53e When the master work M held by the first holding unit 12 is located between the first grinding wheel 30 and the second grinding wheel 40, the drive unit 53e moves the first grinding wheel 30 from the first starting position to the master work M. At this time, the drive unit 53e stops the movement of the first grinding wheel 30 when it comes into contact with the master work M, or just before it comes into contact with the master work M. As described above, the reference movement amount acquisition unit 53c acquires the first reference movement amount Dm1 from the first starting position to the master work M.

[0071] When the master workpiece M held by the first holding unit 12 is located between the first grinding wheel 30 and the second grinding wheel 40, the drive unit 53e moves the second grinding wheel 40 from the second starting position to the master workpiece M. At this time, the drive unit 53e stops the movement of the second grinding wheel 40 when it comes into contact with the master workpiece M, or just before it comes into contact with the master workpiece M. As described above, the reference movement amount acquisition unit 53c acquires the second reference movement amount Dm2 from the second starting position to the master workpiece M.

[0072] When the workpiece W held in the second holding unit 13 is located between the first grinding wheel 30 and the second grinding wheel 40, the drive unit 53e moves the first grinding wheel 30 toward the workpiece W by a first target movement amount Ew1 from the first starting position, thereby grinding the first end face Tw1 of the workpiece W with the first grinding wheel 30.

[0073] When the workpiece W held in the second holding unit 13 is located between the first grinding wheel 30 and the second grinding wheel 40, the drive unit 53e moves the second grinding wheel 40 toward the workpiece W by a second target movement amount Ew2 from the second starting position, thereby grinding the second end face Tw2 of the workpiece W with the second grinding wheel 40.

[0074] In this way, by moving the first grinding wheel 30 by a first target movement amount Ew1 and the second grinding wheel 40 by a second target movement amount Ew2, both end faces of the workpiece W are ground. The first target movement amount Ew1 is obtained by correcting the first reference movement amount Dm1 of the master workpiece M based on the center separation distance ΔC between the master workpiece M and the workpiece W. The second target movement amount Ew2 is obtained by correcting the second reference movement amount Dm2 of the master workpiece M based on the center separation distance ΔC between the master workpiece M and 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 the distance a in the master workpiece M (see Figure 3), and the distance between the via conductor Cw and the second end face Tw2 becomes the distance b in the master workpiece M (see Figure 3). 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.

[0075] Furthermore, it is preferable that the drive unit 53e 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 reference distance acquisition unit 53a, thereby aligning the timing at which the first grinding wheel 30 and the second grinding wheel 40 contact the workpiece W.

[0076] Specifically, the drive unit 53e calculates the first forward movement Fw1 by subtracting the first material removal x from the first target movement Ew1, and calculates the second forward movement Fw2 by subtracting the second material removal y from the second target movement Ew2. The drive unit 53e then 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 second holding unit 13.

[0077] (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.

[0078] In step S1, the operator holds the master workpiece M in the first holding unit 12.

[0079] In step S2, the imaging device 20 images the surface Sm of the masterwork M held in the first holding unit 12.

[0080] In step S3, the reference distance acquisition unit 53a of the controller 50 acquires the master reference distance gm from the captured image of the master work M shown in Figure 7. The master reference distance gm indirectly indicates the center position Pmc of the master work M.

[0081] In step S4, the carrier control unit 51 of the controller 50 rotates the disc 11.

[0082] In step S5, as shown in Figure 10, the drive unit 53e of the controller 50 moves the first grinding wheel 30 from the first starting position to the master work M, and moves the second grinding wheel 40 from the second starting position to the master work M, when the master work M passes between the first grinding wheel 30 and the second grinding wheel 40.

[0083] In step S6, the reference movement amount acquisition unit 53c of the controller 50 acquires the first reference movement amount Dm1 of the first grinding wheel 30 from the first movement start position to the master work M, and the second reference movement amount Dm2 of the second grinding wheel 40 from the second movement start position to the master work M, as shown in Figure 10.

[0084] In step S7, the operator removes the master workpiece M from the first holding unit 12 and holds the workpiece W in the second holding unit 13.

[0085] In step S8, the imaging device 20 images the surface Sw of the workpiece W held in the second holding unit 13.

[0086] In step S9, the reference distance acquisition unit 53a of the controller 50 acquires the workpiece reference distance gw, the first material removal amount x on the first end face Tw1 side of the workpiece W, and the second material removal amount y on the second end face Tw2 side of the workpiece W from the captured image of the workpiece W shown in Figure 8. The workpiece reference distance gw indirectly indicates the center position Pwc of the workpiece W.

[0087] In step S10, the center separation distance acquisition unit 53b of the controller 50 acquires the center separation distance ΔC based on the master reference distance gm and the workpiece reference distance gw. The center separation distance ΔC represents the distance between the center position Pmc of the master workpiece M and the center position Pwc of the workpiece W in the axial direction.

[0088] In step S11, the target movement amount determination unit 53d of the controller 50 determines the first target movement amount Ew1 by correcting the first reference movement amount Dm1 based on the center separation distance ΔC, and determines the second target movement amount Ew2 by correcting the second reference movement amount Dm2 based on the center separation distance ΔC.

[0089] In step S12, the carrier control unit 51 of the controller 50 rotates the disc 11.

[0090] In step S13, as shown in Figure 11, the drive unit 53e of the controller 50 moves the first grinding wheel 30 toward the workpiece W by a first target movement amount Ew1 from the first starting position, and moves the second grinding wheel 40 toward the workpiece W by a second target movement amount Ew2 from the second starting position, as the workpiece W passes between the first grinding wheel 30 and the second grinding wheel 40. As a result, both end faces of the workpiece W are ground, and the first and second material removal amounts x and y on each end face of the workpiece W are adjusted separately.

[0091] In step S13, it is preferable for the drive unit 53e of the controller 50 to bring the timing of the first grinding wheel 30 contacting the workpiece W closer to the timing of the second grinding wheel 40 contacting the workpiece W. Specifically, the drive unit 53e calculates the first forward movement amount Fw1, which is obtained by subtracting the first material removal amount x from the first target movement amount Ew1, and the second forward movement amount Fw2, which is obtained by subtracting the second material removal amount y from the second target movement amount Ew2. The drive unit 53e 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 amount Fw1 is equal to the time it takes for the second grinding wheel 30 to move the second forward movement amount Fw2. This makes it possible to suppress the axial displacement of the holding position of the workpiece W in the second holding unit 13.

[0092] (Modified version 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.

[0093] [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 workpieces W.

[0094] [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 even when grinding the remaining two end faces, the amount of material removed from the remaining two end faces can be adjusted separately by using the master workpiece M as described above.

[0095] [Difference 3] In the above embodiment, the center spacing distance acquisition unit 53b of the controller 50 acquires the center spacing distance ΔC based on the master reference distance gm and the workpiece reference distance gw, but it is not limited to this. For example, the center spacing distance acquisition unit 53b may acquire the center spacing distance ΔC based on the distance Zmc at the master workpiece M (see Figure 7) and the distance Zwc at the workpiece W (see Figure 8).

[0096] [Differentiation Example 4] 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.

[0097] 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 second holding section 13 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 second holding section 13 enters the imaging range of the imaging device 20.

[0098] In this case, when the target movement amount determination unit 53d determines the first target movement amount Ew1 for the next unprocessed workpiece W, it corrects the first reference movement amount Dm1 based on the center separation distance ΔC and the first displacement amount Δx to determine the first target movement amount Ew1. 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 53d determines the second target movement amount Ew2 for the next unprocessed workpiece W, it corrects the second reference movement amount Dm2 based on the center separation distance ΔC and the second displacement amount Δy to determine the second target movement amount Ew2. This allows the second material removal amount y to be accurately removed from the second end face Tw2. [Explanation of Symbols]

[0099] 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...Reference distance acquisition unit, 53b...Center separation distance acquisition unit, 53c...Reference movement amount acquisition unit, 53d...Target movement amount determination unit, 53e...Drive unit, M...Masterwork, Tm1...First end face, Tm2...Second end face, 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 the masterwork and unprocessed workpieces on its outer circumference, A first grinding wheel that can move from a first starting position toward the master work or the unprocessed work in an axial direction parallel to the axis, A second grinding wheel that is movable in the axial direction toward the master work or the unprocessed work, with respect to the carrier in the axial direction, from a second starting position opposite to the first starting position, 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 center separation distance acquisition unit acquires the center separation distance between the center position of the master workpiece and the center position of the unprocessed workpiece in the axial direction, A target movement amount determination unit determines a first target movement amount by correcting a first reference movement amount when the first grinding wheel is moved in the axial direction from the first starting position to the master work based on the center separation distance, and determines a second target movement amount by correcting a second reference movement amount when the second grinding wheel is moved in the axial direction from the second starting position to the master work based on the center 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, Having, Grinding machine.

2. The system further comprises an imaging device capable of imaging the surfaces of the master workpiece and the unprocessed workpiece held on the carrier, The controller has a reference distance acquisition unit that acquires the master reference distance in the axial direction between the center position of the master workpiece and a reference position set to a fixed position relative to the carrier from an image of the master workpiece, and acquires the workpiece reference distance in the axial direction between the center position of the unprocessed workpiece and the reference position from an image of the unprocessed workpiece. The center separation distance acquisition unit acquires the center separation distance based on the master reference distance and the unprocessed workpiece reference distance. The grinding machine according to claim 1.

3. The reference distance acquisition unit acquires the first material removal by the first grinding wheel and the second material removal 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. The grinding machine according to claim 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 center separation distance and the first displacement amount, and corrects the second reference movement amount based on the center 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, A step of holding the master work on the outer circumference of the carrier, A step of obtaining the center position of the master work in the axial direction, A step of obtaining a first reference movement amount when the first grinding wheel is moved in the axial direction from a first starting position to the master workpiece, and a second reference movement amount when the second grinding wheel is moved in the axial direction from a second starting position opposite to the first starting position with respect to the carrier to the master workpiece, The process of holding an unprocessed workpiece on the outer circumference of the carrier, A step of obtaining the center position of the unprocessed workpiece in the axial direction, A step of obtaining the distance between the centers of the unprocessed workpiece and the center of the master workpiece in the axial direction, The process involves determining a first target displacement by correcting the first reference displacement based on the center separation distance, and determining a second target displacement by correcting the second reference displacement based on the center 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 toward the unprocessed workpiece by a first target movement amount from the first starting position and moving the second grinding wheel toward the unprocessed workpiece by a second target movement amount, A grinding method comprising the following features.

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