Grinding machine

Abstract

A grinding machine (1, 101, 201) comprises: a grinding wheel (T) for grinding a workpiece (W); moving bodies (12, 15) that move the grinding wheel relative to the workpiece; movement motors (12a, 15a) that move the moving bodies; manual rotary handles (21, 31) used to manipulate the positions of the moving bodies; reaction force motors (26, 36, 226, 236) attached to the manual rotary handles and configured to apply reaction torques (Tb1, Tb2) to the manual rotary handles when the manual rotary handles are rotating; and a control device (3, 103, 203) which controls the movement motors according to rotation angles (θ1, θ2) of the manual rotary handles and which controls the reaction force motors so as to generate the reaction torques in accordance with the magnitude of the grinding resistance during grinding.

Description

Grinding machine

[0001] The present disclosure relates to grinding machines.

[0002] There are two types of grinding machines: automatic machines that grind automatically according to a program, and manual machines that require an operator to operate a manual rotary handle to perform grinding. There are also grinding machines that combine the functions of both automatic and manual machines.

[0003] Conventionally, manually operable grinding machines have been configured to apply hydraulic oil directly to a moving body that moves the grinding wheel relative to the workpiece when the manual rotating handle is operated. In this case, the operator can directly bear the load on the moving body when operating the manual rotating handle. Therefore, the operator can grasp the contact between the workpiece and the grinding wheel by the torque of the manual rotating handle, enabling high-precision grinding.

[0004] Patent Document 1 describes a manually operable grinding machine in which a moving body is moved based on an electrical signal corresponding to the amount of rotation of a manual rotary handle without using hydraulic oil. The manual rotary handle is provided with a rotational torque variable means for varying the torque required for rotation, and the rotational torque variable means is controlled according to the proximity state between the workpiece and the grinding wheel. Therefore, even in a configuration that does not use hydraulic oil, by increasing the torque of the manual rotary handle when the workpiece and the grinding wheel come into contact, the operator can grasp the contact between the workpiece and the grinding wheel, thereby enabling high-precision grinding.

[0005] In Patent Document 1, the rotational torque varying means is configured to increase the rotational torque of the manual rotating handle by pressing a pressure member against a plate integrated with the manual rotating handle. The flow rate of compressed air is adjusted by controlling a pressure regulating electromagnetic valve according to the proximity state of the workpiece and the grinding wheel, and a pressing force according to the flow rate of compressed air is applied to the pressing member.

[0006] Japanese Patent Application Laid-Open No. 2015-157345

[0007] In Patent Document 1, the rotational torque varying means determines whether the workpiece and grinding wheel are in contact or not by a proximity detection signal, and switches the torque applied to the manual rotation handle depending on whether the workpiece and grinding wheel are in contact or not. Also, the torque applied in the contact state is kept constant, or the amount of cutting of the grinding wheel is detected based on the proximity detection signal in the contact state, and the torque applied is controlled according to the amount of cutting.

[0008] In a configuration using hydraulic oil, even if the cutting depth is the same, the load acting on the manual rotating handle may vary depending on the material of the workpiece, the sharpness of the grinding wheel, etc. Therefore, there is room for improvement in conventional rotational torque varying means compared to a configuration using hydraulic oil.

[0009] The present disclosure has been made in consideration of such problems, and aims to provide a grinding machine that is capable of applying a load to a manual rotating handle with the same high precision as a manually operated machine that uses hydraulic oil, and that can increase the degree of freedom in the load that can be applied to the manual rotating handle.

[0010] One aspect of the present disclosure is a grinding machine comprising: a grinding wheel for grinding a workpiece; a moving body for moving the grinding wheel relatively to the workpiece; a moving motor for moving the moving body; a manual rotation handle for manipulating the position of the moving body; a reaction motor attached to the manual rotation handle and configured to apply a reaction torque to the manual rotation handle when the manual rotation handle is rotating; and a control device that controls the moving motor in accordance with the rotation angle of the manual rotation handle, and controls the reaction motor to generate the reaction torque in accordance with the magnitude of grinding resistance during grinding.

[0011] According to the above aspect, the reaction torque is applied to the manual rotation handle by the reaction motor attached to the manual rotation handle, and therefore, by controlling the reaction motor, there is a high degree of freedom in applying the reaction torque to the manual rotation handle.

[0012] Furthermore, the control device controls the reaction motor to generate a reaction torque corresponding to the magnitude of the grinding resistance during grinding. Therefore, when the operator operates the manual rotary handle, the operator can feel a load corresponding to the magnitude of the grinding resistance during grinding from the manual rotary handle. The magnitude of the grinding resistance varies depending on the cutting depth as well as the material of the workpiece and the sharpness of the grinding wheel. In other words, the reaction torque varies depending on the cutting depth as well as the material of the workpiece and the sharpness of the grinding wheel. Therefore, the load corresponding to the magnitude of the grinding resistance felt by the operator from the manual rotary handle can be the same as that of a manual machine using hydraulic oil, or can be a load further adjusted from that of a manual machine using hydraulic oil. In this way, the operator can apply a load with high precision to the manual rotary handle while operating it, allowing for high-precision grinding using the manual rotary handle.

[0013] As described above, according to the above aspect, it is possible to provide a grinding machine that can apply a load to a manual rotating handle with high precision, similar to a manually operated machine that uses hydraulic oil, and that can increase the degree of freedom in the load that can be applied to the manual rotating handle.

[0014] It should be noted that the reference symbols in parentheses in the claims indicate the correspondence with the specific means described in the embodiments to be described later, and do not limit the technical scope of the present invention.

[0015] 4 is a plan view of a grinding machine of embodiment 1. FIG. 5 is a diagram showing the configuration of a handle unit and a control device in the grinding machine of embodiment 1. FIG. 6 is a front view of the handle unit. FIG. 7 is a flowchart showing reaction torque control processing by a reaction force control unit of the control device in embodiment 1. FIG. 8 is a flowchart showing initial reaction torque generation processing in FIG. 4. FIG. 9 is a flowchart showing reaction torque continuous generation processing in FIG. 4. FIG. 10 is a graph showing relationship information used to determine reaction torque, the graph representing reaction torque depending on the drive current and gain value of a movement motor. FIG. 11 is a diagram showing behavior of the rotation speed of the manual rotation handle, the movement speed of the wheel head, and reaction torque when the manual rotation handle is operated. FIG. 12 is a diagram showing the configuration of a handle unit and a control device in a grinding machine of embodiment 2. FIG. 13 is a flowchart showing reaction torque continuous generation processing of the reaction torque control processing by a reaction force control unit of the control device in embodiment 2. FIG. 14 is a graph showing relationship information used to determine reaction torque, the graph representing reaction torque depending on the detection value of an AE sensor and a gain value. FIG. 15 is a diagram showing the configuration of a handle unit and a control device in a grinding machine of embodiment 3. FIG. 16 is a flowchart showing reaction torque control processing by a reaction force control unit of the control device in embodiment 3. Fig. 14 is a flowchart showing the initial reaction torque generation process in Fig. 13. Fig. 15 is a flowchart showing the reaction torque control process by the reaction force control unit of the control device in embodiment 4. Fig. 16 is a graph showing relation information used to determine the reaction torque, and is a graph showing the reaction torque according to the drive current and gain value of the movement motor.

[0016] (Embodiment 1) 1. Configuration of Grinding Machine 1 The configuration of the grinding machine 1 of this embodiment will be described with reference to Fig. 1. As shown in Fig. 1, the grinding machine 1 rotates the workpiece W and also rotates the grinding wheel T, while moving the workpiece W and the grinding wheel T relative to each other, thereby grinding the workpiece W with the grinding wheel T. Grinding modes include (a) a mode in which the grinding wheel T is moved relative to the workpiece W in the radial direction (X-axis direction) while grinding the outer peripheral surface of the workpiece W, (b) a mode in which the grinding wheel T is moved relative to the workpiece W in the axial direction while grinding the axial end face of the flange portion of the workpiece W, and (c) a mode in which the grinding wheel T is moved relative to the workpiece W in the radial direction (X-axis direction) and then the grinding wheel T is moved relative to the workpiece W in the axial direction while grinding the outer peripheral surface of the workpiece W.

[0017] In this embodiment, a cylindrical grinding machine is taken as an example of the grinding machine 1, but various configurations are applicable, such as a cam grinding machine, a surface grinding machine, etc. Also, in this embodiment, a table traverse type grinding machine is taken as an example of the grinding machine 1, but a wheelhead traverse type grinding machine can also be applied.

[0018] As shown in Fig. 1, the grinding machine 1 includes a grinding machine main body 2 and a control device 3. The grinding machine main body 2 includes a bed 11, a table 12, a headstock 13, a tailstock 14, a grinding wheel head 15, a Z-axis handle unit 16, and an X-axis handle unit 17. In this embodiment, the table 12 constitutes a Z-axis movable body that moves the grinding wheel T in the Z-axis direction relative to the workpiece W. The grinding wheel head 15 constitutes an X-axis movable body that moves the grinding wheel T in the X-axis direction relative to the workpiece W. Although not shown, the grinding machine main body 2 may also include a sizing device, a rest device, a grinding wheel dressing device, etc.

[0019] The bed 11 is placed on an installation surface. On the upper surface of the bed 11, a Z-axis guide 11a extending in the Z-axis direction and an X-axis guide 11b extending in the X-axis direction are formed. In this embodiment, the Z-axis guide 11a is formed on the front side of the machine in the X-axis direction (lower side in FIG. 1). The X-axis guide 11b is formed further back from the machine than the Z-axis guide 11a (upper side in FIG. 1).

[0020] Table 12 (Z-axis movable body) is disposed on the upper surface of bed 11 so as to be movable in the Z-axis direction while being guided by Z-axis guides 11a of bed 11. Table 12 is configured to be movable via a ball screw device by driving a motor 12a (Z-axis movement motor) provided on bed 11. In other words, motor 12a moves table 12 in the Z-axis direction. Table 12 may be driven by a linear motor instead of motor 12a and a ball screw device.

[0021] The headstock 13 includes a headstock body 13a, a spindle 13b, a motor 13c, and a center member 13d. The headstock body 13a is fixed to the upper surface of the table 12. The spindle 13b is supported by the headstock body 13a so as to be rotatable about the Z axis. The motor 13c is provided on the headstock body 13a and drives the spindle 13b to rotate. The center member 13d is attached to the tip of the spindle 13b and supports one end of the workpiece W. In other words, by driving the motor 13c to rotate, the workpiece W is driven to rotate about the central axis of the workpiece W. Note that while FIG. 1 shows an example of a configuration in which the headstock 13 supports one end of the workpiece W by the center member 13d, a chuck may be used in place of the center member 13d.

[0022] The tailstock 14 is disposed on the upper surface of the table 12 in a position facing the headstock 13 in the Z-axis direction. The tailstock 14 supports the other axial end of the workpiece W and supports the workpiece W rotatably around the Z-axis. The tailstock 14 includes a tailstock body 14a, a ram 14b, and a center member 14c. The tailstock body 14a is fixed to the upper surface of the table 12. The ram 14b is attached to the tailstock body 14a so as to be movable in the Z-axis direction. In other words, the ram 14b is attached so as to be able to change the amount of protrusion relative to the tailstock body 14a. The center member 14c is attached to the tip of the ram 14b and supports the other end of the workpiece W. In this way, the workpiece W is rotatably supported at both ends by the headstock 13 and the tailstock 14. Note that the workpiece W may also be cantilevered by the headstock 13 alone. Furthermore, the tailstock 14 may be configured so that the tailstock body 14a is movable in the Z-axis direction relative to the table 12. In this case, the ram 14b is not necessary.

[0023] The wheel head 15 (X-axis movable body) is disposed on the upper surface of the bed 11, and is movable in the X-axis direction while being guided by the X-axis guide 11b of the bed 11. The wheel head 15 is configured to be movable via a ball screw device by driving a motor 15a (X-axis moving motor) provided on the bed 11. In other words, the motor 15a moves the wheel head 15 in the X-axis direction. The wheel head 15 may be driven by a linear motor instead of the motor 15a and the ball screw device. The wheel head 15 is equipped with a rotatable grinding wheel T. The grinding wheel T rotates via a belt 15c by driving a motor 15b provided on the wheel head 15. The grinding wheel T is a tool for grinding a workpiece W, and is configured by a plurality of abrasive grains fixed with a binder.

[0024] The Z-axis handle unit 16 is provided on the front side of the bed 11, and in this embodiment, is provided to the left of the center in the left-right direction. The Z-axis handle unit 16 includes a Z-axis manual rotation handle 21. The Z-axis manual rotation handle 21 is configured to be manually operable by the operator and is a member for manually operating the position of the table 12 as a Z-axis movable body. The Z-axis handle unit 16 further includes a Z-axis reaction force gain value adjuster 22. The Z-axis reaction force gain value adjuster 22 is configured to be manually operable by the operator and is configured to adjust a gain value G1 related to the reaction torque to be applied to the Z-axis manual rotation handle 21.

[0025] The X-axis handle unit 17 is provided in front of the bed 11, and in this embodiment, is provided to the right of the center in the left-right direction. The X-axis handle unit 17 includes an X-axis manual rotation handle 31. The X-axis manual rotation handle 31 is configured to be manually operable by the operator and is a member for manually operating the position of the grinding head 15, which serves as the X-axis movable body. The X-axis handle unit 17 also includes an X-axis reaction force gain value adjuster 32. The X-axis reaction force gain value adjuster 32 is configured to be manually operable by the operator and is configured to adjust a gain value G2 related to the reaction torque to be applied to the X-axis manual rotation handle 31.

[0026] The control device 3 controls each driving device constituting the grinding machine main body 2. Specifically, the control device 3 controls the motor 12a (Z-axis movement motor) in accordance with the rotation angle of the Z-axis manual rotation handle 21 to control the position of the table 12 (Z-axis movable body) in the Z-axis direction. The control device 3 controls the motor 15a (X-axis movement motor) in accordance with the rotation angle of the X-axis manual rotation handle 31 to control the position of the grinding wheel head 15 (X-axis movable body) in the X-axis direction. In other words, the control device 3 controls the motors 12a and 15a to control the positions of the table 12 and the grinding wheel head 15, which serve as movable bodies that move the grinding wheel T relative to the workpiece W. Furthermore, the control device 3 controls the motor 13c of the headstock 13 to control the rotation of the workpiece W. The control device 3 controls the motor 15b of the grinding wheel head 15 to control the rotation of the grinding wheel T.

[0027] 2. Detailed Configuration of Handle Units 16, 17 The detailed configuration of the handle units 16, 17 will be described with reference to Figures 2 and 3. As shown in Figure 2, the Z-axis handle unit 16 and the X-axis handle unit 17 have the same components, except for the members that are operated. In the following, unless a specific axis name is given, both elements will be described.

[0028] The handle units 16, 17 include manual rotation handles 21, 31, reaction force gain value adjustment units 22, 32, input side shaft members 23, 33, output side shaft members 24, 34, torsion bars 25, 35, reaction force motors 26, 36, angle detection sensors 27, 37, and torque sensors 28, 38.

[0029] The manual rotation handles 21, 31 are members for manipulating the position of the table 12 or the grinding wheel head 15 as a movable body. As shown in FIGS. 2 and 3 , the manual rotation handles 21, 31 include, for example, an annular main body and a grip portion fixed to the main body. An operator can rotate the manual rotation handles 21, 31 by grasping the grip portion. Note that the manual rotation handles 21, 31 only need to be configured to be rotatable, and instead of the annular main body, for example, a rod-shaped arm extending in the radial direction can be used. In this case, the manual rotation handles 21, 31 would be formed, for example, in an L-shape.

[0030] The input-side shaft members 23, 33 are integrally provided with the manual rotation handles 21, 31 and are rotatably supported by the bed 11 or a member fixed to the bed 11. The rotation center axis of the input-side shaft members 23, 33 is coaxial with the rotation center axis of the manual rotation handles 21, 31. The output-side shaft members 24, 34 are supported by the bed 11 or a member fixed to the bed 11 so as to be rotatable relative to the input-side shaft members 23, 33. The rotation center axis of the output-side shaft members 24, 34 is coaxial with the rotation center axis of the input-side shaft members 23, 33. One end of the torsion bar 25, 35 is connected to the input-side shaft member 23, 33, and the other end is connected to the output-side shaft member 24, 34. Therefore, when the input-side shaft members 23, 33 are rotated, the torsion bar 25, 35 twists, causing the output-side shaft members 24, 34 to rotate.

[0031] The reaction motors 26, 36 are attached to the output-side shaft members 24, 34. That is, the reaction motors 26, 36 are attached to the manual rotation handles 21, 31 via the output-side shaft members 24, 34, the torsion bars 25, 35, and the input-side shaft members 23, 33. The reaction motors 26, 36 are configured to apply reaction torques Tb1, Tb2 to the manual rotation handles when the manual rotation handles are rotating. That is, when the reaction motors 26, 36 are driven, reaction torques Tb1, Tb2 are applied to the output-side shaft members 24, 34 fixed to the drive shafts of the reaction motors 26, 36, and the reaction torques Tb1, Tb2 are transmitted to the manual rotation handles 21, 31 via the torsion bars 25, 35 and the input-side shaft members 23, 33.

[0032] The angle detection sensors 27, 37 are attached to the reaction motors 26, 36 and detect angles θ1, θ2 of the drive shafts of the reaction motors 26, 36. In other words, the angle detection sensors 27, 37 essentially detect the rotation angles θ1, θ2 of the manual rotation handles 21, 31. The angle detection sensors 27, 37 are, for example, encoders.

[0033] The torque sensors 28, 38 detect that the operator is applying operation torques Ta1, Ta2 to the manual rotary handles 21, 31. In this embodiment, the torque sensors 28, 38 can detect the operation torques Ta1, Ta2 by detecting the torsion state of the torsion bars 25, 35. In detail, the torque sensors 28, 38 use, for example, Hall IC torque sensors and are provided on the input-side shaft members 23, 33 and the output-side shaft members 24, 34. Hall IC torque sensors are well known, so a detailed description will be omitted. Torque sensors having other configurations can also be used for the torque sensors 28, 38.

[0034] As described above, the reaction force gain value adjusters 22, 32 are configured to be manually operable by the operator and are configured to adjust the gain values ​​G1, G2 related to the reaction force torques Tb1, Tb2 to be applied to the manual rotation handles 21, 31. The reaction force torques Tb1, Tb2 are controlled by the control device 3. The reaction force gain value adjusters 22, 32 are, for example, manually operable adjustment knob members. As shown in FIG. 3 , the adjustment knob members are, for example, dial-type and configured to be settable in multiple stages. The adjustment knob members may be configured with an adjustment button, an adjustment lever, or the like. The adjustment button is configured with multiple buttons. The adjustment lever is configured to be able to assume, for example, multiple positions.

[0035] 3. Configuration of the Control Device 3 The configuration of the control device 3 will be described with reference to Fig. 2. In particular, the control of the control device 3 relating to the operation of the manual rotary handles 21 and 31 will be described.

[0036] The control device 3 includes a Z-axis control unit 41, a Z-axis reaction force control unit 42, an X-axis control unit 51, and an X-axis reaction force control unit 52 as elements related to the operation of the manual rotation handles 21, 31. The Z-axis control unit 41 controls the motor 12a (Z-axis movement motor) in accordance with the rotation angle θ1 of the Z-axis manual rotation handle 21, and controls the position of the table 12 (Z-axis mover) in the Z-axis direction.

[0037] The Z-axis reaction force control unit 42 controls the Z-axis reaction motor 26 to generate a Z-axis reaction torque Tb1 corresponding to the magnitude of the grinding resistance during grinding. In this embodiment, the Z-axis reaction force control unit 42 controls the Z-axis reaction motor 26 to generate a Z-axis reaction torque Tb1 corresponding to the magnitude of the drive current I1 of the motor 12a during grinding, using the magnitude of the drive current I1 of the motor 12a during grinding as the magnitude of the grinding resistance. Furthermore, when the Z-axis manual rotation handle 21 is rotating during non-grinding, the Z-axis reaction force control unit 42 controls the Z-axis reaction motor 26 to generate a Z-axis reaction torque Tb1 corresponding to the magnitude of the drive current I1 of the motor 12a during non-grinding.

[0038] More specifically, the Z-axis reaction force control unit 42 acquires the rotation angle θ1 of the Z-axis manual rotation handle 21 detected by the Z-axis angle detection sensor 27, the Z-axis operation torque Ta1 detected by the Z-axis torque sensor 28, the gain value G1 set by the Z-axis reaction force gain value adjustment unit 22, and the drive current I1 of the motor 12a. Based on the acquired information, the Z-axis reaction force control unit 42 controls the Z-axis reaction force motor 26 so as to generate a Z-axis reaction force torque Tb1 in the Z-axis manual rotation handle 21.

[0039] The control device 3 is triggered by the detection of the operation torque Ta1 by the Z-axis torque sensor 28 to cause the Z-axis reaction motor 26 to generate a Z-axis reaction torque Tb1. At this time, the control device 3 determines the rotation direction of the Z-axis manual rotation handle 21 based on the detection value of the Z-axis angle detection sensor 27. The control device 3 then controls the Z-axis reaction motor 26 to generate the Z-axis reaction torque Tb1 in the direction opposite to the determined rotation direction of the Z-axis manual rotation handle 21. Furthermore, when the Z-axis operation torque Ta1 falls below a predetermined value, the control device 3 causes the Z-axis reaction motor 26 to stop generating the Z-axis reaction torque Tb1.

[0040] Furthermore, the control device 3 controls the Z-axis reaction motor 26 to generate a Z-axis reaction torque Tb1 obtained based on the magnitude of the grinding resistance during grinding and the gain value G1 adjusted by the Z-axis reaction gain value adjustment unit 22.

[0041] The X-axis control unit 51 controls the motor 15a (X-axis movement motor) in accordance with the rotation angle θ2 of the X-axis manual rotation handle 31, and controls the position of the wheel head 15 (X-axis movement body) in the X-axis direction.

[0042] The X-axis reaction force control unit 52 controls the X-axis reaction motor 36 to generate an X-axis reaction torque Tb2 corresponding to the magnitude of the grinding resistance during grinding. In this embodiment, the X-axis reaction force control unit 52 controls the X-axis reaction motor 36 to generate an X-axis reaction torque Tb2 corresponding to the magnitude of the drive current I2 of the motor 15a during grinding, using the magnitude of the drive current I2 of the motor 15a during grinding as the magnitude of the grinding resistance. Furthermore, when the X-axis manual rotation handle 31 is rotating during non-grinding, the X-axis reaction force control unit 52 controls the X-axis reaction motor 36 to generate an X-axis reaction torque Tb2 corresponding to the magnitude of the drive current I2 of the motor 15a during non-grinding.

[0043] More specifically, the X-axis reaction force control unit 52 acquires the rotation angle θ2 of the X-axis manual rotation handle 31 detected by the X-axis angle detection sensor 37, the X-axis operation torque Ta2 detected by the X-axis torque sensor 38, the gain value G2 set by the X-axis reaction force gain value adjustment unit 32, and the drive current I2 of the motor 15a. Based on the acquired information, the X-axis reaction force control unit 52 controls the X-axis reaction force motor 36 so as to generate an X-axis reaction torque Tb2 in the X-axis manual rotation handle 31.

[0044] The control device 3 is triggered by the detection of the operation torque Ta2 by the X-axis torque sensor 38 to cause the X-axis reaction motor 36 to generate an X-axis reaction torque Tb2. At this time, the control device 3 determines the rotation direction of the X-axis manual rotation handle 31 based on the detection value of the X-axis angle detection sensor 37. The control device 3 then controls the X-axis reaction motor 36 to generate the X-axis reaction torque Tb2 in the direction opposite to the determined rotation direction of the X-axis manual rotation handle 31. Furthermore, when the X-axis operation torque Ta2 falls below a predetermined value Th1, the control device 3 causes the X-axis reaction motor 36 to stop generating the X-axis reaction torque Tb2.

[0045] Furthermore, the control device 3 controls the X-axis reaction motor 36 to generate an X-axis reaction torque Tb2 obtained based on the magnitude of the grinding resistance during grinding and the gain value G2 adjusted by the X-axis reaction gain value adjustment unit 32.

[0046] 4. Processing of the reaction force control units 42, 52 of the control device 3 Processing of the reaction force control units 42, 52 of the control device 3 will be described with reference to Figures 4 to 7. The reaction force control units 42, 52 determine whether or not the vehicle is in manual driving mode (S1). If the vehicle is not in manual driving mode (S1: No), the process returns.

[0047] If the vehicle is in the manual driving mode (S1: Yes), the reaction force control unit 42, 52 determines whether the reaction force motor 26, 36 is stopped (S2). If the reaction force motor 26, 36 is stopped (S2: Yes), the reaction force control unit 42, 52 executes an initial reaction force torque generation process (S3) and returns the process. The initial reaction force torque generation process S3 will be described later.

[0048] If the reaction force motors 26, 36 are not stopped (S2: No), the reaction force control units 42, 52 acquire the operation torques Ta1, Ta2 (S4). Next, the reaction force control units 42, 52 determine whether the operation torques Ta1, Ta2 are equal to or less than a predetermined value Th1 (S5). If the operation torques Ta1, Ta2 are not equal to or less than the predetermined value Th1 (S5: No), the reaction force control units 42, 52 execute a reaction torque continuation generation process (S6). The reaction torque continuation generation process S6 will be described later.

[0049] If the operation torques Ta1 and Ta2 are equal to or less than the predetermined value Th1 (S5: Yes), the reaction force control units 42 and 52 execute a reaction torque stopping process (S7). The reaction torque stopping process S7 is a process for stopping the generation of the reaction torques Tb1 and Tb2 by the reaction force motors 26 and 36.

[0050] 5, in the initial reaction torque generation process S3, the reaction force control units 42, 52 acquire the operation torques Ta1, Ta2 (S11). Next, the reaction force control units 42, 52 determine whether the operation torques Ta1, Ta2 are greater than a predetermined value Th2 (S12). S11 is repeated until the operation torques Ta1, Ta2 are greater than the predetermined value Th2 (S12: No).

[0051] When the operation torques Ta1 and Ta2 become greater than the predetermined value Th2 (S12: Yes), the reaction force control units 42 and 52 determine the reaction torques Tb1 and Tb2 (S13). The reaction torques Tb1 and Tb2 at this time are set to a preset value A, as shown in FIG.

[0052] Next, the reaction force control unit 42, 52 acquires the rotation angles θ1, θ2 (S14). Then, the reaction force control unit 42, 52 calculates the rotation direction of the manual rotation handle 21, 31 based on the rotation angles θ1, θ2 (S15). Next, the reaction force control unit 42, 52 generates the determined reaction torque Tb1, Tb2 in a reaction force direction that is the opposite direction to the calculated rotation direction (S16). Then, the processing ends.

[0053] 6, in the reaction torque continuous generation process S6, the reaction force control units 42, 52 acquire the drive currents I1, I2 of the motors 12a, 15a (S21). Subsequently, the reaction force control units 42, 52 acquire gain values ​​G1, G2 (S22). Subsequently, the reaction force control units 42, 52 determine reaction torques Tb1, Tb2 based on the magnitudes of the drive currents I1, I2 of the motors 12a, 15a and the gain values ​​G1, G2 (S23).

[0054] 7, the reaction torques Tb1 and Tb2 increase as the magnitude of the drive currents I1 and I2 of the motors 12a and 15a increases. In this embodiment, the reaction torques Tb1 and Tb2 are set to monotonically increase in a broken line with the magnitude of the drive currents I1 and I2. However, the reaction torques Tb1 and Tb2 may also be set to monotonically increase in a curved line with the magnitude of the drive currents I1 and I2.

[0055] 7, the reaction torques Tb1 and Tb2 are set to have different values ​​depending on the gain values ​​G1 and G2. For example, the reaction torques Tb1 and Tb2 are set to be smaller as the Lv of the gain values ​​G1 and G2 decreases, and the reaction torques Tb1 and Tb2 are set to be larger as the Lv of the gain values ​​G1 and G2 increases.

[0056] Next, the reaction force control unit 42, 52 acquires the rotation angles θ1, θ2 (S24). Then, the reaction force control unit 42, 52 calculates the rotation direction of the manual rotation handle 21, 31 based on the rotation angles θ1, θ2 (S25). Next, the reaction force control unit 42, 52 generates the determined reaction torque Tb1, Tb2 in a reaction force direction that is the opposite direction to the calculated rotation direction (S26). Then, the processing ends.

[0057] 5. Behavior of Reaction Torque When the workpiece W is ground by the grinding wheel T, the behavior over time of the rotation speed of the manual rotation handles 21, 31, the behavior over time of the movement speed of the grinding wheel head 15, and the behavior over time of the reaction torques Tb1, Tb2 will be described with reference to FIG. 8 .

[0058] The operator manually rotates the manual rotation handles 21, 31 to move the workpiece W and the grinding wheel T relative to each other, and the workpiece W is ground by the grinding wheel T. Here, the initial state is one in which the grinding wheel T is separated from the workpiece W in the X-axis direction, and then the grinding wheel T is brought into contact with the workpiece W to perform grinding, and when grinding is completed, the grinding wheel T is moved away from the workpiece W. Note that although grinding in the X-axis direction will be described, substantially the same behavior occurs when grinding in the Z-axis direction.

[0059] 8, at time T1, the operator starts rotating the X-axis manual rotation handle 31 in one direction at a low speed. Then, the X-axis control unit 51 controls the motor 15a in accordance with the rotation angle θ2 detected by the angle detection sensor 37. As a result, the wheel head 15 starts moving in the X-axis direction toward the workpiece W at a low speed.

[0060] At this time, immediately after the operator starts to rotate the X-axis manual rotation handle 31 in one direction, the torque sensor 38 detects an operation torque Ta2 of the manual rotation handle 31. The X-axis reaction force control unit 52 controls the reaction motor 36 to generate torque A as reaction torque Tb2. In other words, by controlling the reaction motor 36 using the operation torque Ta2 detected by the torque sensor 38 as a trigger, reaction torque Tb2 can be generated in the short time between when the operator starts to rotate the manual rotation handle 31 and when the wheel head 15 starts to move.

[0061] After the wheel head 15 starts to move, the X-axis reaction torque Tb2 is determined based on the drive current I2 of the motor 15a, the gain value G2 set by the X-axis reaction force gain value adjuster 32, and the relationship shown in Fig. 7. The X-axis reaction motor 36 is then controlled to generate the determined X-axis reaction torque Tb2.

[0062] Next, at time T2, the operator gradually increases the speed of rotation of the X-axis manual rotation handle 31 in one direction. This causes the wheel head 15 to move at high speed in the X-axis direction toward the workpiece W. At this time, the X-axis control unit 51 controls the motor 15a, causing the wheel head 15 to move at high speed in the X-axis direction toward the workpiece W. At the same time, the X-axis reaction force control unit 52 controls the X-axis reaction motor 36, applying a reaction torque Tb2 to the X-axis manual rotation handle 31 according to the relationship shown in FIG. 7 . As the wheel head 15 moves at a higher speed, the load on the motor 15a, which moves the wheel head 15, increases. Therefore, the drive current I2 of the motor 15a increases, and the X-axis reaction torque Tb2 generated by the X-axis reaction motor 36 increases. As a result, the X-axis reaction torque Tb2 applied to the X-axis manual rotation handle 31 increases.

[0063] Next, at time T3, the operator reduces the rotation speed of the X-axis manual rotation handle 31. This reduces the movement speed of the wheel head 15 and the X-axis reaction torque Tb2 generated by the X-axis reaction motor 36.

[0064] As the wheel head 15 moves slowly in the X-axis direction, at time T4, the grinding wheel T comes into contact with the workpiece W, and grinding of the workpiece W by the grinding wheel T begins. Grinding resistance in this state increases the load on the motor 15a that moves the wheel head 15. At the moment of contact, the load on the motor 15a increases sharply, causing a sharp increase in the X-axis reaction torque Tb2 generated by the X-axis reaction motor 36. Therefore, the X-axis reaction torque Tb2 applied to the X-axis manual rotation handle 31 increases sharply.

[0065] When the X-axis reaction torque Tb2 applied to the X-axis manual rotation handle 31 suddenly increases, the rotation speed of the X-axis manual rotation handle 31 by the operator momentarily decreases. After that, the operator again rotates the X-axis manual rotation handle 31 at the same rotation speed as the original speed. In response to this behavior, the movement speed of the wheel head 15 and the X-axis reaction torque Tb2 generated by the X-axis reaction motor 36 also change.

[0066] Next, at time T5, the operator stops rotating the X-axis manual rotation handle 31. In other words, the operating torque Ta2 applied to the X-axis manual rotation handle 31 becomes zero, and the rotation speed of the X-axis manual rotation handle 31 becomes zero. This starts spark-out. At this time, the movement speed of the wheel head 15 becomes zero, and the X-axis reaction torque Tb2 applied to the X-axis manual rotation handle 31 also becomes zero.

[0067] At time T6, the spark-out ends, and the operator starts rotating the X-axis manual rotation handle 31 in the other direction. The operator rotates it at a low speed at first, and then at a high speed. The movement speed of the wheel head 15 and the X-axis reaction torque Tb2 generated by the X-axis reaction motor 36 behave as shown in FIG. 8. Then, at time T7, the operator stops the rotation of the X-axis manual rotation handle 31.

[0068] 6. Effects According to this embodiment, the reaction torques Tb1, Tb2 are applied to the manual rotation handles 21, 31 by the reaction motors 26, 36 attached to the manual rotation handles 21, 31. Therefore, by controlling the reaction motors 26, 36, a high degree of freedom is achieved in applying the reaction torques Tb1, Tb2 to the manual rotation handles 21, 31.

[0069] Furthermore, the control device 3 controls the reaction motors 26, 36 to generate reaction torques Tb1, Tb2 corresponding to the magnitude of the grinding resistance during grinding. Therefore, while the operator is operating the manual rotary handles 21, 31, the operator can feel a load corresponding to the magnitude of the grinding resistance during grinding from the manual rotary handles 21, 31. The magnitude of the grinding resistance varies not only depending on the cutting depth but also on the material of the workpiece W and the sharpness of the grinding wheel T. In other words, the reaction torques Tb1, Tb2 vary not only depending on the cutting depth but also on the material of the workpiece W and the sharpness of the grinding wheel T. Therefore, the load corresponding to the magnitude of the grinding resistance felt by the operator from the manual rotary handles 21, 31 can be the same as that of a manual machine using hydraulic oil, or can be a load further adjusted to that of a manual machine using hydraulic oil. In this way, the operator can apply a load with high precision to the manual rotary handles 21, 31 while operating them, thereby enabling high-precision grinding using the manual rotary handles 21, 31.

[0070] Therefore, according to the above aspect, it is possible to provide a grinding machine that can apply a load to the manual rotating handles 21, 31 with high precision, similar to a manually operated machine that uses hydraulic oil, and that can increase the degree of freedom in the load that can be applied to the manual rotating handles 21, 31.

[0071] Furthermore, the control device 3 uses the magnitude of the drive currents I1, I2 of the motors 12a, 15a during grinding as the magnitude of the grinding resistance and controls the reaction motors 26, 36 to generate reaction torques Tb1, Tb2 corresponding to the magnitude of the drive currents I1, I2 of the motors 12a, 15a. In this way, by using the magnitude of the drive currents I1, I2 of the motors 12a, 15a, desired control can be performed easily and reliably.

[0072] Furthermore, when the manual rotary handles 21, 31 are rotating during non-grinding, the control device 3 causes the reaction motors 26, 36 to generate reaction torques Tb1, Tb2 according to the magnitude of the drive currents I1, I2 of the motors 12a, 15a during non-grinding. In other words, the reaction torques Tb1, Tb2 can be applied to the manual rotary handles 21, 31 not only during grinding but also during non-grinding. Therefore, the operator can feel the reaction torques Tb1, Tb2 while operating the manual rotary handles 21, 31.

[0073] The grinding machine 1 further includes torque sensors 28, 38 that detect the application of operation torques Ta1, Ta2 to the manual rotary handles 21, 31. The control device 3 is triggered by the torque sensors 28, 38 detecting the operation torques Ta1, Ta2 to cause the reaction motors 26, 36 to generate reaction torques Tb1, Tb2. By using the detection of the operation torques Ta1, Ta2 by the torque sensors 28, 38 as a trigger, the application of the reaction torques Tb1, Tb2 to the manual rotary handles 21, 31 can be performed with high responsiveness. In other words, the sensitivity of the manual rotary handles 21, 31 can be improved.

[0074] Furthermore, when the operation torques Ta1, Ta2 fall below a predetermined value Th1, the control device 3 causes the reaction motors 26, 36 to stop generating the reaction torques Tb1, Tb2. By using the operation torques Ta1, Ta2 in this way, when the manual rotation handles 21, 31 are stopped, the generation of the reaction torques Tb1, Tb2 can be stopped with high response. In other words, the sensitivity of the manual rotation handles 21, 31 can be improved.

[0075] The grinding machine 1 further includes angle detection sensors 27, 37 that detect rotation angles θ1, θ2 of the manual rotation handles 21, 31. The control device 3 determines the rotation direction of the manual rotation handles 21, 31 based on the detected values ​​θ1, θ2 of the angle detection sensors 27, 37, and controls the reaction motors 26, 36 to generate reaction torques Tb1, Tb2 in the direction opposite to the determined rotation direction of the manual rotation handles 21, 31. Therefore, the direction in which the reaction torques Tb1, Tb2 are generated can be reliably obtained.

[0076] The grinding machine 1 further includes reaction force gain value adjusters 22, 32 that are configured to adjust gain values ​​G1, G2 related to the reaction torques Tb1, Tb2. The control device 3 controls the reaction force motors 26, 36 to generate reaction torques Tb1, Tb2 based on the magnitude of the grinding resistance during grinding and the gain values ​​G1, G2 adjusted by the reaction force gain value adjusters 22, 32. For example, the operator can adjust the magnitude of the reaction torques Tb1, Tb2 to their desired values. In this way, the reaction torques Tb1, Tb2 generated in the manual rotary handles 21, 31 can be freely adjusted.

[0077] Furthermore, it is preferable that the reaction force gain value adjusters 22 and 32 include at least one of an adjustment knob member, an adjustment button, and an adjustment lever that are configured to be manually operable, which allows for easy adjustment of the gain values ​​G1 and G2.

[0078] (Embodiment 2) The configuration of a grinding machine 101 of this embodiment will be described with reference to Figure 9. In this embodiment, the same components as those of the grinding machine 1 of embodiment 1 are designated by the same reference numerals. The grinding machine 101 includes a grinding machine main body 102 and a control device 103. The grinding machine main body 102 includes an acoustic emission (AE) sensor 110. The AE sensor 110 is attached to, for example, the headstock 13 and detects an AE signal AEs as an elastic wave (acoustic signal). However, the AE sensor 110 can also be attached to the table 12, tailstock 14, grinding wheel head 15, etc., in addition to the headstock 13.

[0079] The control device 103 includes a Z-axis control unit 41, a Z-axis reaction force control unit 142, an X-axis control unit 51, and an X-axis reaction force control unit 152 as elements related to the operation of the manual rotary handles 21, 31. The Z-axis reaction force control unit 142 controls the Z-axis reaction force motor 26 to generate a Z-axis reaction torque Tb1 corresponding to the magnitude of the grinding resistance during grinding. In this embodiment, the Z-axis reaction force control unit 142 uses the magnitude of the AE signal AEs as the magnitude of the grinding resistance and controls the Z-axis reaction force motor 26 to generate a Z-axis reaction torque Tb1 corresponding to the magnitude of the AE signal AEs.

[0080] The X-axis reaction force control unit 152 controls the X-axis reaction motor 36 to generate an X-axis reaction torque Tb2 corresponding to the magnitude of the grinding resistance during grinding. In this embodiment, the X-axis reaction force control unit 152 uses the magnitude of the AE signal AEs as the magnitude of the grinding resistance and controls the X-axis reaction motor 36 to generate an X-axis reaction torque Tb2 corresponding to the magnitude of the AE signal AEs.

[0081] In this embodiment, the reaction force control units 142, 152 acquire the rotation angles θ1, θ2 of the manual rotation handles 21, 31 detected by the angle detection sensors 27, 37, the operation torques Ta1, Ta2 detected by the torque sensors 28, 38, the gain values ​​G1, G2 set by the reaction force gain value adjustment units 22, 32, and the AE signal AEs. Then, the reaction force control units 142, 152 use this information to control the reaction force motors 26, 36. This control method is the same as in the first embodiment.

[0082] Next, the processing of the reaction force control units 142, 152 of the control device 3 will be described with reference to Figures 10 and 11. Of the processing of the reaction force control units 142, 152, the reaction force control processing shown in Figure 4 and the initial reaction torque generation processing shown in Figure 5 in the first embodiment are common. The reaction torque continuous generation processing S6 by the reaction force control units 142, 152 is as shown in Figure 10.

[0083] 4, as shown in FIG. 10, the reaction force control units 142, 152 acquire the AE signal AEs, which is the detection value of the AE sensor 110 (S31). Next, the reaction force control units 142, 152 acquire gain values ​​G1, G2 (S32). Next, the reaction force control units 142, 152 determine reaction torques Tb1, Tb2 based on the magnitude of the AE signal AEs and the gain values ​​G1, G2 (S33).

[0084] 11, the reaction torques Tb1 and Tb2 increase as the magnitude of the AE signal AEs increases. In this embodiment, the reaction torques Tb1 and Tb2 are set to monotonically increase in a broken line with respect to the magnitude of the AE signal AEs. However, the reaction torques Tb1 and Tb2 may also be set to monotonically increase in a curved line with respect to the magnitude of the AE signal AEs.

[0085] Furthermore, the reaction torques Tb1 and Tb2 are set to have different values ​​depending on the gain values ​​G1 and G2. For example, the reaction torques Tb1 and Tb2 are set to be smaller as the Lv of the gain values ​​G1 and G2 decreases, and the reaction torques Tb1 and Tb2 are set to be larger as the Lv of the gain values ​​G1 and G2 increases.

[0086] Next, the reaction force control units 142, 152 acquire the rotation angles θ1, θ2 (S34). Then, the reaction force control units 142, 152 calculate the rotation direction of the manual rotation handles 21, 31 based on the rotation angles θ1, θ2 (S35). Next, the reaction force control units 142, 152 generate the determined reaction torques Tb1, Tb2 in a reaction force direction that is the opposite direction to the calculated rotation direction (S36). Then, the processing ends.

[0087] According to this embodiment, even when the AE signal AEs detected by the AE sensor 110 is used, the reaction motors 26, 36 can be controlled as desired in accordance with the grinding resistance during grinding.

[0088] Here, the AE sensor 110 mainly detects elastic waves generated by grinding resistance. Therefore, when the grinding wheel T is not in contact with the workpiece W and the grinding head 15 is moving, the AE sensor 110 detects almost no elastic waves. Therefore, as shown in FIG. 11 , the relationship between the reaction torques Tb1 and Tb2 is such that when the AE signal AEs is zero, the reaction torques Tb1 and Tb2 become a preset torque A. In other words, when the manual rotary handles 21 and 31 are rotating during non-grinding, the reaction force control units 142 and 152 cause the reaction motors 26 and 36 to generate torque A as the preset reaction torques Tb1 and Tb2.

[0089] (Embodiment 3) The configuration of a grinding machine 201 of this embodiment will be described with reference to Fig. 12. In this embodiment, the same components as those of the grinding machine 1 of embodiment 1 are designated by the same reference numerals. The grinding machine 201 includes a grinding machine main body 202 and a control device 203. The grinding machine main body 202 includes a Z-axis handle unit 216 and an X-axis handle unit 217.

[0090] The handle units 216, 217 include manual rotation handles 21, 31, reaction force gain value adjusters 22, 32, shaft members 223, 233, reaction force motors 226, 236, and angle detection sensors 227, 237. The shaft members 223, 233 are integrally provided with the manual rotation handles 21, 31, and are rotatably supported on the bed 11 or a member fixed to the bed 11. The reaction force motors 226, 236 are attached to the shaft members 223, 233. In other words, when the reaction force motors 226, 236 are driven, reaction force torques Tb1, Tb2 are applied to the shaft members 223, 233 fixed to the drive shafts of the reaction force motors 226, 236, and the reaction force torques Tb1, Tb2 are transmitted to the manual rotation handles 21, 31.

[0091] The angle detection sensors 227, 237 are attached to the reaction motors 226, 236 and detect angles θ1, θ2 of the drive shafts of the reaction motors 226, 236. In other words, the angle detection sensors 227, 237 essentially detect the rotation angles θ1, θ2 of the manual rotation handles 21, 31. The angle detection sensors 227, 237 are, for example, encoders.

[0092] The control device 203 includes a Z-axis control unit 41, a Z-axis reaction force control unit 242, an X-axis control unit 51, and an X-axis reaction force control unit 252 as elements related to the operation of the manual rotary handles 21, 31. The reaction force control units 242, 252 control the reaction force motors 226, 236 to generate reaction torques Tb1, Tb2 corresponding to the magnitude of the grinding resistance during grinding. In this embodiment, the reaction force control units 242, 252 acquire the rotation angles θ1, θ2 of the manual rotary handles 21, 31 detected by the angle detection sensors 227, 237, the gain values ​​G1, G2 set by the reaction force gain value adjusters 22, 32, and the drive currents I1, I2 of the motors 12a, 15a. The reaction force control units 242, 252 then use this information to control the reaction force motors 226, 236.

[0093] The processing of the reaction force control units 242, 252 of the control device 3 will be described with reference to Figures 13 and 14. The reaction force control units 242, 252 determine whether or not the vehicle is in manual driving mode (S41). If the vehicle is not in manual driving mode (S41: No), the process returns.

[0094] If the vehicle is in the manual driving mode (S41: Yes), the reaction force control unit 242, 252 determines whether the reaction force motor 226, 236 is stopped (S42). If the reaction force motor 226, 236 is stopped (S42: Yes), the reaction force control unit 242, 252 executes an initial reaction torque generation process (S43) and returns the process. The initial reaction torque generation process S43 will be described later.

[0095] 13 , if the reaction force motors 226, 236 are not stopped (S42: No), the reaction force control units 242, 252 acquire the rotation angles θ1, θ2 (S44). Subsequently, the reaction force control units 242, 252 determine whether the change amounts Δθ1, Δθ2 in the rotation angles θ1, θ2 are equal to or less than a predetermined value Th3 (S45). If the change amounts Δθ1, Δθ2 in the rotation angles θ1, θ2 are not equal to or less than the predetermined value Th3 (S45: No), the reaction force control units 242, 252 execute a reaction torque continuation generation process (S46). The reaction torque continuation generation process S46 is the same as the process shown in FIG. 6 in the first embodiment.

[0096] If the change amounts Δθ1 and Δθ2 of the rotation angles θ1 and θ2 are equal to or smaller than the predetermined value Th3 (S45: Yes), the reaction force control units 242 and 252 execute a reaction torque stopping process (S47). The reaction torque stopping process S47 is a process for stopping the generation of the reaction torques Tb1 and Tb2 by the reaction force motors 226 and 236.

[0097] 14, in the initial reaction torque generation process S43, the reaction force control units 242, 252 acquire the rotation angles θ1, θ2 (S51). Next, the reaction force control units 242, 252 determine whether the changes Δθ1, Δθ2 in the rotation angles θ1, θ2 are greater than a predetermined value Th4 (S52). S51 is repeated until the changes Δθ1, Δθ2 in the rotation angles θ1, θ2 are greater than the predetermined value Th4 (S52: No).

[0098] When the change amounts Δθ1 and Δθ2 in the rotation angles θ1 and θ2 become larger than a predetermined value Th4 (S52: Yes), the reaction force control units 242 and 252 determine the reaction torques Tb1 and Tb2 (S53). The reaction torques Tb1 and Tb2 at this time are set to a predetermined value A, as shown in FIG.

[0099] Next, the reaction force control unit 242, 252 calculates the rotation direction of the manual rotation handle 21, 31 based on the rotation angles θ1, θ2 (S54). Next, the reaction force control unit 242, 252 generates the determined reaction torque Tb1, Tb2 in a reaction force direction that is the opposite direction to the calculated rotation direction (S45). Then, the processing ends.

[0100] According to this embodiment, the control device 3 determines that the manual rotation handles 21, 31 are rotating based on the detection values ​​of the angle detection sensors 227, 237, and uses the determination that the manual rotation handles 21, 31 are rotating as a trigger to cause the reaction motors 226, 236 to generate reaction torques Tb1, Tb2. This simplifies the configuration of the handle units 216, 217.

[0101] (Embodiment 4) A grinding machine 201 of this embodiment differs from embodiment 3 in the processing of reaction force control units 242, 252. The processing of the reaction force control units 242, 252 will be described with reference to Figures 15 and 16. In this embodiment, the reaction force control units 242, 252 constantly determine reaction torques Tb1, Tb2 based on the drive currents I1, I2 and gain values ​​G1, G2 of the motors 12a, 15a.

[0102] 15, the reaction force control units 242, 252 determine whether or not the vehicle is in the manual driving mode (S61). If the vehicle is not in the manual driving mode (S61: No), the process returns.

[0103] If the operation mode is manual (S61: Yes), the drive currents I1 and I2 of the motors 12a and 15a are acquired (S62). The reaction force control units 242 and 252 then acquire gain values ​​G1 and G2 (S63). The reaction force control units 242 and 252 then determine reaction torques Tb1 and Tb2 based on the magnitudes of the drive currents I1 and I2 of the motors 12a and 15a and the gain values ​​G1 and G2 (S64).

[0104] 16, the reaction torques Tb1 and Tb2 increase as the magnitude of the drive currents I1 and I2 of the motors 12a and 15a increases. In this embodiment, the reaction torques Tb1 and Tb2 are set to monotonically increase in a broken line with the magnitude of the drive currents I1 and I2. However, the reaction torques Tb1 and Tb2 may also be set to monotonically increase in a curved line with the magnitude of the drive currents I1 and I2.

[0105] 16, the reaction torques Tb1 and Tb2 are set to have different values ​​depending on the gain values ​​G1 and G2. For example, the reaction torques Tb1 and Tb2 are set to be smaller as the Lv of the gain values ​​G1 and G2 decreases, and the reaction torques Tb1 and Tb2 are set to be larger as the Lv of the gain values ​​G1 and G2 increases.

[0106] Next, the reaction force control units 242, 252 acquire the rotation angles θ1, θ2 (S65). Then, the reaction force control units 242, 252 calculate the rotation direction of the manual rotation handles 21, 31 based on the rotation angles θ1, θ2 (S66). Next, the reaction force control units 242, 252 generate the determined reaction torques Tb1, Tb2 in a reaction force direction that is the opposite direction to the calculated rotation direction (S67). Then, the processing ends.

[0107] According to this embodiment, the control device 3 constantly causes the reaction motors 226, 236 to generate reaction torques Tb1, Tb2 determined based on the drive currents I1, I2 and gain values ​​G1, G2 of the motors 12a, 15a. This simplifies the configuration of the handle units 216, 217.

[0108] (Others) In the third and fourth embodiments, the reaction force control units 242 and 252 may use the magnitude of the AE signal AEs in the embodiments instead of the magnitude of the drive currents I1 and I2 of the motors 12a and 15a.

Claims

1. A grinding wheel (T) for grinding a workpiece (W); A moving body (12, 15) that moves the grinding wheel relatively to the workpiece; A moving motor (12a, 15a) for moving the moving body; A manual rotating handle (21, 31) for manipulating the position of the moving body; a reaction motor (26, 36, 226, 236) attached to the manual rotation handle and configured to apply a reaction torque (Tb1, Tb2) to the manual rotation handle when the manual rotation handle is rotated; a control device (3, 103, 203) for controlling the movement motor in response to a rotation angle (θ1, θ2) of the manual rotation handle and for controlling the reaction motor so as to generate the reaction torque; Equipped with The control device includes: When a drive current of the movement motor accompanying the movement of the movement motor or an acoustic emission (AE) signal (AEs) accompanying grinding is not detected, the reaction motor is controlled so as to generate the reaction torque set in advance but not zero in the reaction motor; When detecting a drive current or an AE signal of the moving motor accompanying the movement of the moving motor, the grinding machine (1, 101, 201) controls the reaction motor so as to generate the reaction torque in the reaction motor according to the magnitude of the drive current of the moving motor or the magnitude of the AE signal.

2. The grinding machine (1, 201) according to claim 1, wherein when the control device detects a drive current of the movement motor accompanying the movement of the movement motor during grinding, the control device controls the reaction motor so as to cause the reaction motor to generate the reaction torque corresponding to the magnitude of the drive current of the movement motor during grinding.

3. The grinding machine (1, 201) according to claim 2, wherein when the control device detects the drive current of the movement motor accompanying the movement of the movement motor when not grinding, the control device causes the reaction motor to generate the reaction torque corresponding to the magnitude of the drive current of the movement motor when not grinding.

4. Further, an AE sensor (110) is provided for detecting the AE signal (AEs) accompanying grinding, The control device includes: When the manual rotating handle is rotating during non-grinding, the reaction motor is controlled so as to generate the reaction torque set in advance, which is not zero, in the reaction motor by not detecting the AE signal; 2. The grinding machine (101) according to claim 1, wherein the reaction motor is controlled to generate the reaction torque corresponding to the magnitude of the AE signal by detecting the AE signal accompanying grinding during grinding.

5. Further, a torque sensor (28, 38) is provided for detecting that an operating torque (Ta1, Ta2) is applied to the manual rotating handle, The control device includes: when the drive current of the movement motor accompanying the movement of the movement motor or the AE signal is not detected and the torque sensor detects the operation torque, controlling the reaction motor so as to generate the reaction torque that is set in advance and not zero in the reaction motor; The grinding machine (1, 101) according to any one of claims 1 to 4, wherein when the drive current of the moving motor accompanying the movement of the moving motor or the AE signal is not detected and when the torque sensor does not detect the operating torque, the reaction torque is not generated in the reaction motor.

6. 6. The grinding machine (1, 101) according to claim 5, wherein the control device causes the reaction motor to stop generating the reaction torque when the operating torque falls below a predetermined value (Th1).

7. Further, a torque sensor (28, 38) is provided for detecting that an operating torque (Ta1, Ta2) is applied to the manual rotating handle, The grinding machine (1, 101) according to any one of claims 1 to 4, wherein the control device causes the reaction motor to stop generating the reaction torque when the operating torque falls below a predetermined value (Th1).

8. Further, an angle detection sensor (27, 37) is provided for detecting a rotation angle of the manual rotation handle, The grinding machine (1, 101) according to any one of claims 5 to 7, wherein the control device determines a rotation direction of the manual rotation handle based on a detection value of the angle detection sensor, and controls the reaction motor so as to generate the reaction torque in a direction opposite to the determined rotation direction of the manual rotation handle.

9. Further, an angle detection sensor (227, 237) is provided for detecting a rotation angle of the manual rotation handle, The control device includes: determining whether the manual rotation handle is rotating based on a detection value of the angle detection sensor; When it is determined that the manual rotation handle is rotating, and a drive current of the movement motor accompanying the movement of the movement motor or the AE signal is not detected, a non-zero preset reaction torque is generated in the reaction motor; The grinding machine (201) according to any one of claims 1 to 4, wherein when it is determined that the manual rotation handle is not rotating, the reaction torque is not generated in the reaction motor.

10. Further, a reaction force gain value adjustment unit (22, 32) configured to be able to adjust a gain value (G1, G2) related to the reaction force torque is provided, The control device includes: The grinding machine (1, 101, 201) according to any one of claims 1 to 9, wherein when detecting the drive current or the AE signal of the moving motor accompanying the movement of the moving motor, the reaction motor is controlled so as to generate the reaction torque obtained based on the magnitude of the drive current or the magnitude of the AE signal of the moving motor and the gain value adjusted by the reaction force gain value adjustment unit.

11. The grinding machine (1, 101, 201) according to claim 10, wherein the reaction force gain value adjustment unit includes at least one of an adjustment knob member, an adjustment button, and an adjustment lever configured to be manually operable.

12. The grinding machine (1, 101, 201) according to any one of claims 1 to 11, wherein the moving body (12, 15), the moving motor (12a, 15a), the manual rotating handle (21, 31) and the reaction motor (26, 36, 226, 236) are provided as a configuration (15, 15a, 31, 36, 236) for moving the grinding wheel relative to the workpiece in the radial direction of the workpiece, and a configuration (12, 12a, 21, 26, 226) for moving the grinding wheel relative to the workpiece in the axial direction of the workpiece, respectively.

13. The control device includes: A grinding machine (1, 101, 201) according to any one of claims 1 to 12, wherein when detecting the drive current or the AE signal of the movement motor accompanying the movement of the movement motor, the reaction motor is controlled so that the reaction torque generated in the reaction motor monotonically increases linearly or curvedly with respect to the magnitude of the drive current or the magnitude of the AE signal.