Grinding machine

Abstract

A grinding machine (1, 101, 201) has: a grinding wheel (T) that grinds a workpiece (W); a motion motor (12, 15) that moves the grinding wheel relative to the workpiece; a motion motor (12a, 15a) that moves the moving body; a manual rotary handle (21, 31) that controls a position of the moving body; a reaction motor (26, 36, 226, 236) that is mounted on the manual rotary handle and configured to apply a reaction torque (Tb1, Tb2) to the manual rotary handle when the manual rotary handle is rotated; and a control device (3, 103, 203) that controls the motion motor according to a rotation angle (θ1, θ2) of the manual rotary handle and controls the reaction motor to generate the reaction torque according to a magnitude of the grinding resistance during grinding.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to grinding machines. STATE OF THE ART

[0002] There are the following types of grinding machines: automatic grinding machines, which perform grinding automatically according to a program, and manual grinding machines, whose manual rotary handle is operated by an operator to perform the grinding manually. There are also grinding machines that have the functions of both automatic and manual grinding machines.

[0003] Manually operated grinding machines are known to use a configuration in which a manual rotary handle is operated to apply hydraulic oil directly to a moving body, thus moving a grinding wheel relative to a workpiece. In this case, the operator directly receives a load acting on the rotating body when operating the manual rotary handle. This allows the operator to perceive the contact between the workpiece and the grinding wheel through the torque applied to the manual rotary handle, enabling precise grinding.

[0004] Patent document 1 describes a configuration of a manually operated grinding machine in which a movable body is moved according to the magnitude of the rotation of a manual rotary handle based on an electrical signal, instead of using hydraulic oil. The manual rotary handle is provided with a torque-modifying device to change the torque required to rotate the manual rotary handle, and the torque-modifying device is controlled according to the proximity condition between the workpiece and the grinding wheel.

[0005] Therefore, even in the configuration that does not use hydraulic oil, the torque at the manual rotary handle is increased when the workpiece and the grinding wheel come into contact. This allows the operator to perceive the contact between the workpiece and the grinding wheel, enabling precise grinding.

[0006] In patent document 1, the device for changing the running torque is configured to increase the running torque at the manual rotary handle by pressing a pressing element against a plate integral with the manual rotary handle. The flow rate of compressed air is adjusted by controlling a solenoid valve for pressure regulation according to the proximity between the workpiece and the grinding wheel, and a pressing force corresponding to the flow rate of compressed air is exerted on the pressing element. DOCUMENTS OF THE STATE OF TECHNOLOGY Patent documents

[0007] Patent document 1: Japanese unfiled patent application Publication No. 2015-157345 (JP 2015 - 157 345 A) SUMMARY OF THE INVENTION Problem that the invention is intended to solve

[0008] In patent document 1, the device for changing the running torque, based on a proximity detection signal, determines whether the workpiece and the grinding wheel are in contact or not, and switches the torque applied to the manual rotary handle depending on whether the workpiece and grinding wheel are in contact or not. The applied torque is kept constant when they are in contact. Alternatively, the cutting depth of the grinding wheel is determined based on a proximity detection signal when they are in contact, and the applied torque is controlled according to the cutting depth.

[0009] In a configuration using hydraulic oil, the force exerted on the manual rotary handle can vary even at the same cutting depth if the workpiece material, the sharpness of the grinding wheel, etc., change. Therefore, conventional methods for adjusting the operating torque are in need of improvement compared to a configuration using hydraulic oil.

[0010] The present disclosure was made with regard to the aforementioned problem, and one objective of the present disclosure is to provide a grinding machine that makes it possible to apply a load to a manual rotary handle with high accuracy, such as a manually operated machine that uses hydraulic oil, and which can increase the flexibility in applying the load to the manual rotary handle. Means to solve the problem

[0011] One aspect of the present disclosure is a grinding machine comprising: a grinding wheel that grinds a workpiece; a movable body that moves the grinding wheel relative to the workpiece; a motion motor that moves the movable body; a manual rotary handle that controls a position of the movable body; a reaction motor that is attached to the manual rotary handle and configured to exert a reaction torque on the manual rotary handle when the manual rotary handle is rotated; and a control device that controls the motion motor according to a rotation angle of the manual rotary handle and controls the reaction motor to generate the reaction torque according to a magnitude of the grinding resistance during grinding. Effects of the invention

[0012] From the above perspective, the reaction torque is exerted on the hand grip by the reaction motor mounted on the hand grip. Therefore, controlling the reaction motor allows for a high degree of flexibility in applying the reaction torque to the manual hand grip.

[0013] Furthermore, the control device regulates the reaction motor to generate the reaction torque according to the magnitude of the grinding resistance during grinding. Therefore, when an operator operates the manual rotary handle, they can feel a load corresponding to the grinding resistance. The grinding resistance varies depending on the workpiece material, the sharpness of the grinding wheel, and the cutting depth. In other words, the reaction torque varies depending on the workpiece material, the sharpness of the grinding wheel, and the cutting depth. Therefore, the load felt by the operator at the manual rotary handle, corresponding to the grinding resistance, can be similar to that of a manually operated hydraulic machine, or it can be designed as a load further refined from that of a manually operated hydraulic machine.In this way, a load can be applied with high accuracy to the manual rotary handle operated by the operator, and precise grinding can be carried out using the manual rotary handle.

[0014] From the perspective described above, it is possible to provide a grinding machine that allows a load to be applied with high accuracy to a manual rotary handle, similar to a manually operated machine using hydraulic oil, and that can increase the flexibility in applying the load to the manual rotary handle.

[0015] The reference numerals placed in brackets in the claims indicate conformity with, in particular, the means described in the following embodiments and are not intended to limit the technical scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a top view of a grinding machine according to a first embodiment. Fig. Figure 2 is a diagram showing the configurations of grip units and a control device in the grinding machine of the first embodiment. Fig. Figure 3 is a front view of the handle unit. Fig. Figure 4 is a flowchart showing a reaction force control process performed by a reaction force control unit of the control device in the first embodiment. Fig. Figure 5 is a flowchart illustrating an initial reaction torque generation process in Fig. 4 shows. Fig. Figure 6 is a flowchart illustrating a continuous reaction torque generation process in Fig. 4 represents. Fig. Figure 7 is a diagram showing relationship information for determining the reaction torque, where the diagram shows the reaction torque according to a drive current of a motion motor and a gain value. Fig. Figure 8 is a diagram showing the behavior of the rotational speed of a manual rotary handle, the movement speed of a disc head, and the reaction torque when the manual rotary handle is operated. Fig. Figure 9 is a diagram showing the configurations of grip units and a control device in a grinding machine of a second embodiment. Fig. Figure 10 is a flowchart showing a continuous reaction torque generation process in a reaction force control process performed by a reaction force control unit of the control device in the second embodiment. Fig. Figure 11 is a diagram showing relationship information used to determine the reaction torque, where the diagram shows the reaction torque according to a detection value from an AE sensor and a gain value. Fig. Figure 12 is a diagram showing the configurations of grip units and a control device in a grinding machine of a third embodiment. Fig. Figure 13 is a flowchart showing a reaction force control process performed by a reaction force control unit of the control device in the third embodiment. Fig. Figure 14 is a flowchart illustrating an initial reaction torque generation process in Fig. 13 shows. Fig. Figure 15 is a flowchart showing a reaction force control process carried out by a control unit of a control device in a fourth embodiment. Fig. Figure 16 is a diagram with relationship information used to determine the reaction torque, where the diagram shows the reaction torque according to a drive current of a motion motor and a gain value. OPERATING MODES FOR EXECUTING THE INVENTION (First embodiment) 1. Configuration of the grinding machine 1

[0016] The configuration of a grinding machine 1 according to the present embodiment is described with reference to Fig. 1 described. As it appears Fig. As can be seen in Figure 1, the grinding machine 1 grinds a workpiece W with a grinding wheel T by moving the workpiece W and the grinding wheel T relative to each other while rotating the workpiece W and also rotating the grinding wheel T: (a) grinding the outer circumferential surface of the workpiece W while the grinding wheel T is moved relative to the radial direction (X-axis direction) of the workpiece W; (b) grinding an axial end face of a flange-like section of the workpiece W while the grinding wheel T is moved relative to the axial direction of the workpiece W; and (c) grinding the outer circumferential surface of the workpiece W while the grinding wheel T is moved relative to the radial direction (X-axis direction) of the workpiece W and then the grinding wheel T is moved relative to the axial direction of the workpiece W.

[0017] The present embodiment represents an example where the grinding machine 1 is a cylindrical grinding machine. However, other configurations are also possible, such as a cam grinding machine or a surface grinding machine. The present embodiment represents an example where the grinding machine 1 is a bench grinder. However, a disc grinding machine is also applicable.

[0018] As can be seen from the Fig. As can be seen in Figure 1, the grinding machine 1 has a grinding machine body 2 and a control device 3. The grinding machine body 2 has a bed 11, a table 12, a headstock 13, a tailstock 14, a grinding wheel head 15, a Z-axis gripping unit 16, and an X-axis gripping unit 17. In the present embodiment, the table 12 is a Z-axis motion body that moves the grinding wheel T relative to the workpiece W in the direction of the Z-axis. The grinding wheel head 15 is an X-axis movable body that moves the grinding wheel T relative to the workpiece W in the X-axis. Although not shown in the figure, the grinding machine body 2 may have a calibration device, a storage device, a dressing device for the grinding wheel, etc.

[0019] The bed 11 is installed on an installation surface. A Z-axis guide 11a, extending in the direction of the Z-axis, and an X-axis guide 11b, extending in the direction of the X-axis, are formed on the top of the bed 11. In the present embodiment, the Z-axis guide 11a is formed on the front side in the direction of the X-axis (lower side in Fig. 1), i.e., on the front of the machine. The X-axis guide 11b is located on the back of the machine (top side) in relation to the Z-axis guide 11a. Fig. 1) trained.

[0020] The table 12 (Z-axis motion body) is positioned on the top of the bed 11 such that it can move along the Z-axis while being guided on the bed 11 by the Z-axis guide 11a. The table 12 is configured to move via a ball screw when driven by a motor 12a (Z-axis motion motor) mounted on the bed 11. That is, the motor 12a moves the table 12 along the Z-axis. The table 12 can also be driven by a linear motor instead of the motor 12a and ball screw.

[0021] The headstock 13 has a headstock body 13a, a spindle 13b, a motor 13c, and a central element 13d. The headstock body 13a is attached to the upper surface of the table 12. The spindle 13b is held by the headstock body 13a so that it can rotate about the Z-axis. The motor 13c is mounted on the headstock body 13a and drives the spindle 13b to rotate. The central element 13d is attached to the distal end of the spindle 13b and supports one end of the workpiece W. That is, the rotary drive of the motor 13c drives the workpiece W so that it rotates about the central axis of the workpiece W. Fig. Figure 1 shows an example in which the headstock 13 is configured to support one end of the workpiece W through the central element 13d. However, a chuck can also be used instead of the central element 13d.

[0022] The tailstock 14 is positioned on the top of the table 12 such that it faces the headstock 13 in the Z-axis direction. The tailstock 14 holds the other axial end of the workpiece W and supports the workpiece W in such a way that the tailstock 14 is rotatable about the Z-axis. The tailstock 14 comprises a tailstock body 14a, a ram 14b, and a central element 14c. The tailstock body 14a is attached to the top surface of the table 12. The ram 14b is positioned within the tailstock body 14a to be movable in the Z-axis direction. Specifically, the ram 14b is positioned so that the circumference of its projection from the tailstock body 14a can be adjusted. The central element 14c is attached to the distal end of the ram 14b and supports the other end of the workpiece W. The workpiece W is thus rotatably held at both ends by the headstock 13 and the tailstock 14.The workpiece W can also be held cantilevered solely by the headstock 13. The tailstock 14 can be configured such that the tailstock body 14a is movable relative to the table 12 in the direction of the Z-axis. In this case, the ram 14b is not required.

[0023] The grinding head 15 (X-axis motion body) is positioned on the top of the bed 11 such that it can move along the X-axis while being guided on the bed 11 by the X-axis guide 11b. The grinding head 15 is configured to move via a ball screw when driven by a motor 15a (X-axis motion motor) mounted on the bed 11. That is, the motor 15a moves the grinding head 15 along the X-axis. The grinding head 15 can also be driven by a linear motor instead of the motor 15a and ball screw. The grinding head 15 has the grinding wheel T, which is rotatably mounted. The grinding wheel T is rotated via a belt 15c when driven by a motor 15b mounted on the grinding head 15.The grinding wheel T is a tool for grinding the workpiece W and consists of a multitude of abrasive grains held together by a bonding agent.

[0024] The Z-axis handle unit 16 is mounted on the front of the bed 11 and, in the present embodiment, to the left of center in the left-right direction. The Z-axis handle unit 16 has a manual Z-axis rotary handle 21. The manual Z-axis rotary handle 21 is an element that can be manually operated by an operator and manually controls the position of the table 12, which serves as the Z-axis motion body. The Z-axis handle unit 16 also has a Z-axis response gain adjustment unit 22. The Z-axis response gain adjustment unit 22 can be manually operated by an operator and is configured to adjust a gain value G1 for the response torque acting on the manual Z-axis rotary handle 21.

[0025] The X-axis handle unit 17 is mounted on the front of the bed 11 and, in the present embodiment, to the right of center in the left-right direction. The X-axis handle unit 17 has a manual X-axis rotary handle 31. The manual X-axis rotary handle 31 is an element that can be manually operated by an operator and manually controls the position of the disk head 15, which serves as the X-axis motion body. The X-axis handle unit 17 also has an X-axis response rate adjustment unit 32. The X-axis response rate adjustment unit 32 can be manually operated by an operator and is configured to adjust a rate of change G2 for the response torque acting on the manual X-axis rotary handle 31.

[0026] The control device 3 controls each drive unit that forms the grinding machine body 2. In particular, the control device 3 controls the motor 12a (Z-axis drive motor) according to the rotation angle of the manual Z-axis handle 21 to control the position of the table 12 (rotating body of the Z-axis) along the Z-axis. The control device 3 controls the motor 15a (X-axis drive motor) according to the rotation angle of the manual X-axis handle 31 to control the position of the grinding wheel head 15 (rotating body of the X-axis) along the X-axis. 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 the moving bodies for the movement of the grinding wheel T relative to the workpiece W. The control device 3 also 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 disc head 15 to control the rotation of the grinding wheel T. 2. Detailed configuration of handle units 16, 17

[0027] The detailed configurations of the handle units 16, 17 are described with reference to the Fig. 2 and Fig. 3 described. As can be seen from the Fig. As can be seen in Figure 2, the grip unit 16 for the Z-axis and the grip unit 17 for the X-axis have the same components and differ only in the element to be actuated. The following description applies to the components of both grip units if no axis name is specified.

[0028] The handle units 16, 17 each have the manual rotary handles 21, 31, the reaction rate adjustment units 22, 32, input shaft elements 23, 33, output shaft elements 24, 34, torsion bars 25, 35, reaction motors 26, 36, angle detection sensors 27, 37, and torque sensors 28, 38.

[0029] The manual rotary handles 21, 31 are elements for controlling the position of the table 12 or the disc head 15, each serving as a movable body. As can be seen from the Fig. 2 and Fig. As can be seen in Figure 3, the manual rotary handles 21, 31 each have, for example, an annular section and a handle attached to the section. An operator can hold the handle sections and rotate the manual rotary handles 21, 31. The manual rotary handles 21, 31 can have any configuration as long as they are rotatable. For example, they can use a rod-shaped arm that extends radially instead of the annular section of the body. In this case, the manual rotary handles 21, 31 are, for example, L-shaped.

[0030] The input shaft sections 23, 33 are each integrally formed with the manual rotary handles 21, 31 and are rotatably held by the bed 11 or by parts attached to the bed 11. The central axes of the input shaft sections 23, 33 are the same as the central axes of the manual rotary handles 21, 31. The output shaft elements 24, 34 are held by the bed 11 or the elements attached to the bed 11 such that they are rotatable relative to the input shaft elements 23, 33. The central axes of the output-side shaft parts 24, 34 are the same as the central axes of the input-side shaft parts 23, 33. One end of the torsion bars 25, 35 is connected to the input-side shaft elements 23, 33, the other ends are connected to the output-side shaft elements 24, 34.Therefore, when the drive-side shaft elements 23, 33 are rotated, the torsion bars 25, 35 are twisted, causing the output-side shaft elements 24, 34 to rotate.

[0031] The reaction motors 26, 36 are each mounted on the output-side shaft elements 24, 34. Specifically, the reaction motors 26, 36 are connected to the manual rotary handles 21, 31 via the output-side shaft elements 24, 34, the torsion bars 25, 35, and the input-side shaft elements 23, 33. The reaction motors 26, 36 are configured to exert reaction torques Tb1, Tb2 on the manual rotary handles when the manual rotary handles are rotated. In particular, when driving the reaction motors 26, 36, the reaction torques Tb1, Tb2 are applied to the output-side shaft elements 24, 34, which are attached to the drive shafts of the reaction motors 26, 36, and the reaction torques Tb1, Tb2 are transmitted via the torsion bars 25, 35 and the input-side shaft elements 23, 33 to the manual rotary handles 21, 31.

[0032] The angle sensors 27, 37 are installed on the reaction motors 26, 36 and detect the angles θ1, θ2 of the drive shafts of the reaction motors 26, 36. That is, the angle sensors 27, 37 essentially detect the rotation angles θ1, θ2 of the manual rotary handles 21, 31. The angle sensors 27, 37 are, for example, encoders.

[0033] The torque sensors 28, 38 detect the operating torques Ta1, Ta2 applied by the operator to the manual rotary handles 21, 31. In the present embodiment, the torque sensors 28, 38 can detect the operating torques Ta1, Ta2 by sensing the rotational states of the torsion bars 25, 35. The torque sensors 28, 38 are, for example, Hall-effect IC torque sensors mounted on the drive-side shaft elements 23, 33 and the output-side shaft elements 24, 34. Since Hall-effect IC torque sensors are well-known in the art, a detailed description of these sensors is omitted. The torque sensors 28, 38 can be torque sensors with other configurations. As described above, the

[0034] The reaction rate adjustment units 22, 32 are manually operated by an operator and are configured to adjust the rate of change G1, G2 for the reaction torques Tb1, Tb2 acting on the manual rotary handles 21, 31. The reaction torques Tb1, Tb2 are controlled by the control device 3. The reaction rate adjustment units 22, 32 are, for example, manually operated adjustment knobs. As can be seen from the Fig. As can be seen in Figure 3, each adjustment knob is, for example, of the type of scale and has a multitude of settings. Each adjustment knob element can be an adjustment knob, an adjustment lever, etc. The adjustment knob consists of a multitude of knobs. The adjustment lever, for example, is configured to make a multitude of settings. 3. Configuration of the control device 3

[0035] The configuration of the control device 3 is described with reference to Fig. 2 described. In particular, the control of the operation of the manual rotary handles 21, 31 by the control device 3 is described.

[0036] The control device 3 comprises, as components relating to the operation of the manual rotary handles 21, 31, 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. The Z-axis control unit 41 controls the motor 12a (movement motor of the Z-axis) according to the rotation angle θ1 of the manual rotary handle 21 of the Z-axis in order to control the position in the Z-axis direction of the table 12 (movable body of the Z-axis).

[0037] The Z-axis control unit 42 controls the Z-axis response motor 26 to generate the Z-axis response torque Tb1 according to the magnitude of the grinding resistance during grinding. In the present embodiment, the Z-axis control unit 42 uses the magnitude of a drive current I1 of the motor 12a during grinding as the magnitude of the grinding resistance and controls the Z-axis response motor 26 such that the Z-axis response motor 26 generates the Z-axis response torque Tb1 according to the magnitude of the drive current I1 of the motor 12a. When the manual Z-axis rotary handle 21 is turned while grinding is not taking place, the Z-axis control unit 42 also causes the Z-axis reaction motor 26 to generate the Z-axis reaction torque Tb1 according to the magnitude of the drive current I1 of the motor 12a while grinding is not taking place.

[0038] More precisely, the Z-axis control unit 42 obtains the rotation angle θ1 of the manual Z-axis rotary handle 21, which is detected by the Z-axis angle sensing sensor 27, the Z-axis response torque Ta1, which is detected by the Z-axis torque sensor 28, the slew rate G1, which is set by the Z-axis response slew rate adjustment unit 22, and the drive current I1 of the motor 12a. The Z-axis control unit 42 controls the Z-axis response motor 26 to generate the Z-axis response torque Tb1 at the manual Z-axis rotary handle 21, based on the information obtained.

[0039] The control device 3 is triggered by the detection of the operating torque Ta1 by the Z-axis torque sensor 28 to cause the Z-axis response motor 26 to generate the Z-axis response torque Tb1. At this point, the control device 3 determines the direction of rotation of the manual Z-axis rotary handle 21 based on the detection value of the angle detection sensor 27 for the Z-axis. The control device 3 then controls the Z-axis response motor 26 to generate the Z-axis response torque Tb1 in a direction opposite to the determined direction of rotation of the manual Z-axis rotary handle 21. When the Z-axis operating torque Ta1 drops to a predetermined value or less, the control device 3 causes the Z-axis response motor 26 to stop generating the Z-axis response torque Tb1.

[0040] The control device 3 also controls the Z-axis response motor 26 to generate the Z-axis response torque Tb1, which is based on the magnitude of the grinding resistance during grinding and the slope value G1, which is adjusted by the Z-axis response adjustment unit 22.

[0041] The control unit 51 for the X-axis controls the motor 15a (movement motor of the X-axis) according to the rotation angle θ2 of the manual rotary handle 31 of the X-axis, in order to control the position of the disk head 15 (rotating body of the X-axis) in the X-axis direction.

[0042] The X-axis reaction force control unit 52 controls the X-axis reaction motor 36 to generate the X-axis reaction torque Tb2 according to the magnitude of the grinding resistance during grinding. In the present embodiment, the X-axis reaction force control unit 52 uses the magnitude of a drive current I2 of the motor 15a during grinding as the magnitude of the grinding resistance and controls the X-axis reaction motor 36 such that the X-axis reaction motor 36 generates the X-axis reaction torque Tb2 according to the magnitude of the drive current I2 of the motor 15a. When the X-axis hand-operated rotary handle 31 is rotated while grinding is not taking place, the X-axis reaction force control unit 52 also causes the X-axis reaction motor 36 to generate the X-axis reaction torque Tb2 according to the magnitude of the drive current I2 of the motor 15a while grinding is not taking place.

[0043] More precisely, the X-axis reaction force control unit 52 obtains the rotation angle θ2 of the manual X-axis rotary handle 31, which is detected by the X-axis angle sensing sensor 37, the X-axis operating torque Ta2, which is detected by the X-axis torque sensor 38, the slope value G2, which is set with the X-axis reaction slope adjustment unit 32, and the drive current I2 of the motor 15a. The X-axis reaction force control unit 52 controls the X-axis reaction motor 36 to generate the X-axis reaction torque Tb2 at the manual X-axis rotary handle 31, based on the information obtained.

[0044] The control device 3 is triggered by the detection of the operating torque Ta2 by the X-axis torque sensor 38 to cause the X-axis response motor 36 to generate the X-axis response torque Tb2. At this point, the control device 3 determines the direction of rotation of the manual X-axis rotary handle 31 based on the detection value of the X-axis angle detection sensor 37. The control device 3 then controls the X-axis response motor 36 to generate the X-axis response torque Tb2 in a direction opposite to the determined direction of rotation of the manual X-axis rotary handle 31. When the operating torque Ta2 of the X-axis drops to a predetermined value Th1 or less, the control device 3 causes the X-axis reaction motor 36 to stop generating the X-axis reaction torque Tb2.

[0045] The control device 3 also controls the X-axis reaction motor 36 to generate the X-axis reaction torque Tb2, which is based on the magnitude of the grinding resistance during grinding and the rise value G2 adapted by the reaction rise value adjustment unit 32.

[0046] 4. Processes of the reaction force control units 42, 52 of the control device 3 The processes carried out by the reaction force control units 42, 52 of the control device 3 are described with reference to the Fig. Sections 4 to 7 are described. The reaction force control units 42 and 52 determine whether the operating mode is manual (S1). If the operating mode is not manual (S1: No), the process returns to normal.

[0047] If the operating mode is manual (S1: Yes), the reaction force control units 42, 52 determine whether the reaction motors 26, 36 are stopped (S2). If the reaction motors 26, 36 are stopped (S2: Yes), the reaction force control units 42, 52 perform an initial reaction force control process (S3), and the process returns. The process of initial reaction torque generation S3 is described later.

[0048] If the reaction motors 26, 36 are not stopped (S2: No), the reaction force control units 42, 52 attain the operating torques Ta1, Ta2 (S4). The reaction force control units 42, 52 then determine whether the operating torques Ta1, Ta2 are equal to or less than the predetermined value Th1 (S5). If the operating torques Ta1, Ta2 are not equal to or less than the predetermined value Th1 (S5: No), the reaction force control units 42, 52 perform a continuous reaction torque generation process (S6). The continuous reaction torque generation process S6 is described later.

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

[0050] As can be seen from the Fig. As can be seen in Figure 5, the reaction force control units 42, 52 acquire the operating torques Ta1, Ta2 (S11) in the initial reaction force control process S3. The reaction force control units 42, 52 then determine whether the operating torques Ta1, Ta2 are greater than a predetermined value Th2 (S12). S11 is repeated until the operating torques Ta1, Ta2 become greater than the predetermined value Th2 (S12: No).

[0051] If the operating torques Ta1, Ta2 become greater than the predetermined value Th2 (S12: Yes), the reaction force control units 42, 52 determine the reaction torques Tb1, Tb2 (S13). At this point, the reaction torques Tb1, Tb2 have a preset value A, as can be seen from the Fig. 7 is evident.

[0052] The reaction force control units 42, 52 then acquire the rotation angles θ1, θ2 (S14). Based on these rotation angles, the reaction force control units 42, 52 calculate the directions of rotation of the manual rotary handles 21, 31 (S15). Finally, the reaction force control units 42, 52 generate the determined reaction torques Tb1, Tb2 in a reaction force direction that is the opposite direction to the calculated direction of rotation (S16). This completes the process.

[0053] As can be seen from the Fig. As can be seen in Figure 6, the reaction force control units 42, 52 obtain the drive currents I1, I2 of the motors 12a, 15a in the continuous reaction torque generation process S6 (S21). Next, the reaction force control units 42, 52 obtain the slope values ​​G1, G2 (S22). The reaction force control units 42, 52 then determine the reaction torques Tb1, Tb2 based on the magnitude of the drive currents I1, I2 of the motors 12a, 15a and the slope values ​​G1, G2 (S23).

[0054] As can be seen from the Fig. As can be seen in Figure 7, the values ​​of the reaction torques Tb1, Tb2 increase with increasing magnitude of the drive currents I1, I2 of the motors 12a, 15a. The present embodiment provides that the reaction torques Tb1, Tb2 increase monotonically with respect to the magnitudes of the drive currents I1, I2, like a line in a line graph. However, the reaction torques Tb1, Tb2 can also be set to increase monotonically with respect to the magnitudes of the drive currents I1, I2.

[0055] Furthermore, as can be seen from the Fig. As can be seen in Figure 7, the reaction torques Tb1, Tb2 are set to different values ​​according to the slope values ​​G1, G2. For example, the reaction torques Tb1, Tb2 are set such that the reaction torques Tb1, Tb2 are smaller the smaller the slope value G1, G2 is, and that the reaction torques Tb1, Tb2 are larger the larger the slope value G1, G2 is.

[0056] The reaction force control units 42, 52 then acquire the rotation angles θ1, θ2 (S24). Subsequently, the reaction force control units 42, 52 calculate the directions of rotation of the manual rotary handles 21, 31 based on the rotation angles θ1, θ2 (S25). Finally, the reaction force control units 42, 52 generate the determined reaction torques Tb1, Tb2 in a reaction force direction that is the opposite direction to the calculated direction of rotation (S26). The process is thus completed. 5. Behavior of the reaction torque

[0057] The behavior of the rotational speeds of the manual rotary handles 21, 31 over time, the behavior of the movement speed of the grinding wheel head 15 over time, and the behavior of the reaction torques Tb1, Tb2 over time during grinding of the workpiece W with the grinding wheel T are described with reference to Fig. 8 described.

[0058] The operator manually turns the rotary handles 21, 31 to move the workpiece W and the grinding wheel T relative to each other, thus grinding the workpiece W with the grinding wheel T. It is assumed that the grinding wheel T is initially positioned away from the workpiece W in the X-axis direction, that the grinding wheel T is then brought into contact with the workpiece W to perform the grinding operation, and that the grinding wheel T is moved away from the workpiece W after the grinding operation is complete. Although the grinding is described in the X-axis direction, the behavior is essentially the same when grinding in the Z-axis direction.

[0059] As can be seen from the Fig. As can be seen in Figure 8, at time T1 the operator begins to rotate the manual rotary handle 31 of the X-axis at low speed in one direction. Accordingly, the control unit 51 for the X-axis controls the motor 15a according to the rotation angle θ2 detected by the angle sensor 37. Subsequently, the disc head 15 begins to move at low speed towards the workpiece W in the direction of the X-axis.

[0060] At this point, the torque sensor 38 detects the operating torque Ta2 at the manual rotary handle 31 immediately after the operator begins to rotate the manual X-axis rotary handle 31 in one direction. The X-axis reaction force control unit 52 controls the reaction motor 36 to generate the reaction torque Tb2. In other words, since the operating torque Ta2 detected by the torque sensor 38 triggers the control of the reaction motor 36, the reaction torque Tb2 can be generated in the short time between the operator beginning to rotate the manual rotary handle 31 and the start of the movement of the disc head 15.

[0061] Once the disk head 15 has started moving, the reaction torque Tb2 is determined based on the drive current I2 of the motor 15a, the rise value G2 set for the X-axis with the reaction rate adjustment unit 32, and the Fig. The X-axis reaction motor 36 is then controlled in such a way that it generates the determined X-axis reaction torque Tb2.

[0062] Then, at time T2, the operator gradually increases the rotational speed of the manual rotary handle 31 of the X-axis in one direction. As a result, the disc head 15 moves at high speed along the X-axis towards the workpiece W. At this time, the X-axis control unit 51 controls the motor 15a, causing the disc head 15 to move at high speed along the X-axis towards the workpiece W. Simultaneously, the X-axis reaction force control unit 52 controls the X-axis reaction motor 36, so that the reaction torque Tb2 is applied according to the value shown in the diagram. Fig. The relationship shown in Figure 7 acts on the manual rotary handle 31. As the speed of the disc head 15 increases, the load on the motor 15a, which moves the disc head 15, increases accordingly. Therefore, the drive current I2 of the motor 15a increases, so that the reaction torque Tb2 generated by the X-axis reaction motor 36 increases. As a result, the reaction torque Tb2 of the X-axis, which acts on the manual rotary handle 31 of the X-axis, increases.

[0063] Subsequently, at time T3, the operator reduces the rotational speed of the manual rotary handle 31 of the X-axis. As a result, the movement speed of the disk head 15 and the reaction torque Tb2 generated by the X-axis reaction motor 36 also decrease accordingly.

[0064] When the grinding wheel head 15 moves at low speed along the X-axis, the grinding wheel T comes into contact with the workpiece W, and the grinding wheel T begins grinding the workpiece W at time T4. The grinding resistance in this state increases the load on the motor 15a, which moves the grinding wheel head 15. At the moment of contact, the load on the motor 15a increases suddenly, leading to a sudden increase in the reaction torque Tb2 in the X-axis, which is generated by the reaction motor 36 in the X-axis. Therefore, the reaction torque Tb2 of the X-axis, which acts on the manual rotary handle 31 of the X-axis, increases suddenly.

[0065] If the reaction torque Tb2 applied to the manual X-axis rotary handle 31 suddenly increases, the rotational speed of the operator-turned manual X-axis rotary handle 31 drops instantaneously. The operator then turns the manual X-axis rotary handle 31 again at the same rotational speed as before. Accordingly, the movement speed of the disk head 15 and the reaction torque Tb2 generated by the X-axis reaction motor 36 also change.

[0066] Then, at time T5, the operator stops the rotation of the manual rotary handle 31 of the X-axis. This means that the operating torque Ta2 acting on the manual rotary handle 31 of the X-axis becomes zero, and the rotational speed of the manual rotary handle 31 of the X-axis becomes zero. Then, firing is started. At this point, the movement speed of the disc head 15 becomes zero, and the reaction torque Tb2 exerted on the manual rotary handle 31 of the X-axis also becomes zero.

[0067] At time T6, firing is complete, and the operator begins to rotate the manual X-axis rotary handle 31 in the opposite direction. The operator initially rotates it at low speed and then at high speed. The movement speed of the disc head 15 and the reaction torque Tb2 generated by the X-axis reaction motor 36 behave as expected from the Fig. 8 is evident. At time T7, the operator stops the rotation of the manual rotary handle 31 of the X-axis. 6. Effects

[0068] The above embodiment is configured such that the reaction torques Tb1, Tb2 are applied to the manual handles 21, 31 by the reaction motors 26, 36 mounted on the manual handles 21, 31. Therefore, the control of the reaction motors 26, 36 allows for a high degree of flexibility in applying the reaction torques Tb1, Tb2 to the manual handles 21, 31.

[0069] Furthermore, the control device 3 controls the reaction motors 26, 36 to generate the reaction torques Tb1, Tb2 according to the magnitude of the grinding resistance during grinding. Therefore, when the operator operates the manual rotary handles 21, 31, they can feel a load from the manual rotary handles 21, 31 during grinding, corresponding to the magnitude of the grinding resistance. The magnitude of the grinding resistance varies depending on the material of the workpiece W, the sharpness of the grinding wheel T, and the cutting depth. In other words, the reaction torques Tb1, Tb2 vary depending on the material of the workpiece W, the sharpness of the grinding wheel T, and the cutting depth.Therefore, the load felt by the operator at the manual rotary handles 21, 31, corresponding to the magnitude of the grinding resistance, can be made similar to the load of a manually operated machine using hydraulic oil, or a load can be generated that is further adapted to the load of a manually operated machine using hydraulic oil. In this way, a load can be applied with high accuracy to the manual rotary handles 21, 31 operated by the operator, thus enabling precise grinding with the manual rotary handles 21, 31.

[0070] According to the above embodiment, it is therefore possible to provide a grinding machine that makes it possible to apply a load with high accuracy to the manual rotary handles 21, 31, such as a manually operated machine that uses hydraulic oil, and which can increase the flexibility in applying the load to the manual rotary handles 21, 31.

[0071] The control device 3 uses the magnitudes of the drive currents I1, I2 of motors 12a, 15a during grinding as the magnitude of the grinding resistance and controls the reaction motors 26, 36 such that the reaction motors 26, 36 generate the reaction torques Tb1, Tb2 according to the magnitudes of the drive currents I1, I2 of motors 12a, 15a. The desired control can therefore be achieved simply and reliably via the magnitudes of the drive currents I1, I2 of motors 12a, 15a.

[0072] When the manual rotary handles 21, 31 are turned while grinding is not taking place, the control device 3 causes the reaction motors 26, 36 to generate the reaction torques Tb1, Tb2 according to the magnitudes of the drive currents I1, I2 of the motors 12a, 15a, while grinding is not taking place. In other words, the reaction torques Tb1, Tb2 can be applied to the manual rotary handles 21, 31 not only during grinding but also when at rest. This allows the operator to feel the reaction torques Tb1, Tb2 while operating the manual rotary handles 21, 31.

[0073] The grinding machine 1 also has torque sensors 28, 38 that detect the operating torques Ta1, Ta2 acting on the manual rotary handles 21, 31. The control device 3 is triggered by the detection of the operating torques Ta1, Ta2 by the torque sensors 28, 38, causing the reaction motors 26, 36 to generate the reaction torques Tb1, Tb2. Since the detection of the operating torques Ta1, Ta2 by the torque sensors 28, 38 is used as a trigger, the reaction torques Tb1, Tb2 can be applied to the manual rotary handles 21, 31 in a highly responsive manner. In other words, the sensitivity of the manual rotary handles 21, 31 can be improved.

[0074] When the operating torques Ta1, Ta2 drop to the predetermined value Th1 or less, the control device 3 causes the reaction motors 26, 36 to stop generating the reaction torques Tb1, Tb2. Since, as described above, the operating torques Ta1, Ta2 are used, the generation of the reaction torques Tb1, Tb2 can be stopped when the manual rotary handles 21, 31 are stopped. In other words, the sensitivity of the manual rotary handles 21, 31 can be improved.

[0075] The grinding machine 1 also has angle sensors 27, 37, which detect the rotation angles θ1, θ2 of the manual rotary handles 21, 31. The control device 3 determines the directions of rotation of the manual rotary handles 21, 31 based on the detected values ​​θ1, θ2 from the angle sensors 27, 37 and controls the reaction motors 26, 36 to generate the reaction torques Tb1, Tb2 in a direction opposite to the determined directions of rotation of the manual rotary handles 21, 31. This ensures that the directions in which the reaction torques Tb1, Tb2 are to be generated are reliably achieved. The grinding machine 1 also has the

[0076] Reaction rate adjustment units 22, 32 are configured to adjust the gain values ​​G1, G2 for the reaction torques Tb1, Tb2. The control device 3 controls the reaction motors 26, 36 to generate the reaction torques Tb1, Tb2, which are based on the magnitude of the grinding resistance during grinding and the rate values ​​G1, G2 adjusted by the reaction rate adjustment units 22, 32. The operator can, for example, adjust the reaction torques Tb1, Tb2 to their desired value. Thus, the reaction torques Tb1, Tb2 to be applied to the manual rotary handles 21, 31 can be adjusted as desired.

[0077] Each response rate adjustment unit 22, 32 preferably has at least one of the following manually operable elements: an adjustment knob, an adjustment knob, and an adjustment lever. The rate rates G1, G2 can be easily adjusted using one of these elements. (Second embodiment)

[0078] The present embodiment of a grinding machine 101 according to the present embodiment is described with reference to Fig. 9 described. In the present embodiment, the same configurations as in the grinding machine 1 of the first embodiment are designated with the same symbols. The grinding machine 101 has a grinding machine body 102 and a control device 103. The grinding machine body 102 has an acoustic emission (AE) sensor 110. The AE sensor 110 is, for example, mounted on the headstock 13 and detects an AE signal, which is an elastic wave (acoustic signal). However, the position of the AE sensor 110 can also be on the table 12, the tailstock 14, the grinding wheel head 15, etc., instead of on the headstock 13.

[0079] The control device 103 comprises, as components relating to the operation of the manual rotary handles 21, 31, the Z-axis control unit 41, a Z-axis reaction force control unit 142, the X-axis control unit 51, and an X-axis reaction force control unit 152. The Z-axis control unit 142 controls the Z-axis reaction motor 26 to generate the Z-axis reaction torque Tb1 according to the magnitude of the grinding resistance during grinding. In the present embodiment, the Z-axis control unit 142 uses the magnitude of the AE signal AEs as the magnitude of the grinding resistance and controls the Z-axis reaction motor 26 such that the Z-axis reaction motor 26 generates the Z-axis reaction torque Tb1 according 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 the X-axis reaction torque Tb2 according to the magnitude of the grinding resistance during grinding. In the present 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 such that the X-axis reaction motor 36 generates the X-axis reaction torque Tb2 according to the magnitude of the AE signal AEs.

[0081] In the present embodiment, the reaction force control units 142, 152 receive the rotation angles θ1, θ2 of the manual rotary handles 21, 31 detected by the angle detection sensors 27, 37, the operating torques Ta1, Ta2 detected by the torque sensors 28, 38, the rise values ​​G1, G2 set by the reaction rate adjustment units 22, 32, and the AE signal AEs. The reaction force control units 142, 152 then control the reaction motors 26, 36 using this information. This control method is the same as in the first embodiment.

[0082] Next, the processes performed by the reaction force control units 142, 152 of the control device 3 will be described with reference to the Fig. 10 and Fig. 11 described. Of the processes carried out by the reaction force control units 142, 152, one reaction force control process and one initial reaction torque generation process are the same as the one described in Fig. 4 evident reaction force control process and the one in Fig. 5. The initial reaction torque generation process of the first embodiment is evident. The continuous reaction torque generation process S6, which is carried out by the reaction force control units 142, 152, is derived from the Fig. 10 is evident.

[0083] As can be seen from the Fig. As can be seen in section 10, the reaction force control units 142, 152 achieve in the from the Fig. 4. In the continuous reaction torque generation process S6, the AE signal AEs, which is a detection value from the AE sensor 110 (S31), is obtained. Next, the reaction force control units 142, 152 acquire the slope values ​​G1, G2 (S32). The reaction force control units 142, 152 then determine the reaction torques Tb1, Tb2 based on the magnitude of the AE signal AEs and the slope values ​​G1, G2 (S33).

[0084] As can be seen from the Fig. As can be seen in Figure 11, the values ​​of the reaction torques Tb1 and Tb2 increase with increasing magnitude of the AE signal AEs. The present embodiment provides that the reaction torques Tb1 and Tb2 increase monotonically with respect to the magnitude of the AE signal AEs, like a line in a line graph. However, the reaction torques Tb1 and Tb2 can also be set to increase monotonically with respect to the magnitude of the AE signal AEs.

[0085] Furthermore, the reaction torques Tb1, Tb2 are set to different values ​​according to the slope values ​​G1, G2. For example, the reaction torques Tb1, Tb2 are set such that the reaction torques Tb1, Tb2 are smaller the smaller the slope value G1, G2 is, and that the reaction torques Tb1, Tb2 are larger the larger the slope value G1, G2 is.

[0086] The reaction force control units 142, 152 then acquire the rotation angles θ1, θ2 (S34). Subsequently, the reaction force control units 142, 152 calculate the directions of rotation of the manual rotary handles 21, 31 based on the rotation angles θ1, θ2 (S35). Finally, 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 direction of rotation (S36). The process is thus completed.

[0087] The present embodiment provides that, even when using the AE signal detected by the AE sensor 110, the reaction motors 26, 36 can be controlled arbitrarily according to the grinding resistance during grinding.

[0088] The AE sensor 110 primarily detects an elastic wave generated by the grinding resistance. Therefore, the AE sensor 110 detects almost no elastic wave when the disc head 15 moves with the grinding wheel T, which is not in contact with the workpiece W. Accordingly, as can be seen from the Fig. As can be seen in Figure 11, the relationship between the reaction torques Tb1 and Tb2 is such that the reaction torques Tb1 and Tb2 are the preset torque A when the AE signal AEs is zero. In other words, when the manual rotary handles 21 and 31 are turned while grinding is not taking place, the control units 142 and 152 for the reaction force control units cause the reaction motors 26 and 36 to generate the torque A as the preset reaction torques Tb1 and Tb2. (Third embodiment)

[0089] The configuration of a grinding machine 201 according to the present embodiment is described with reference to Fig. 12. In the present embodiment, the same configurations as in the grinding machine 1 of the first embodiment are designated with the same reference numerals. The grinding machine 201 has a grinding machine body 202 and a control device 203. The grinding machine body 202 has a Z-axis gripping unit 216 and an X-axis gripping unit 217.

[0090] The handle units 216, 217 each have the manual rotary handles 21, 31, the reaction rate adjustment units 22, 32, the shaft elements 223, 233, the reaction motors 226, 236, and the angle detection sensors 227, 237. The shaft elements 223, 233 are integrally formed with the manual rotary handles 21, 31 and are rotatably held by the bed 11 or by elements attached to the bed 11. The reaction motors 226, 236 are each mounted on the shaft elements 223, 233. When the reaction motors 226, 236 are driven, the reaction torques Tb1, Tb2 are transmitted to the shaft elements 223, 233 which are attached to the drive shafts of the reaction motors 226, 236, and the reaction torques Tb1, Tb2 are transmitted to the manual rotary handles 21, 31.

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

[0092] The control device 203 comprises, as components relating to the operation of the manual rotary handles 21, 31, the Z-axis control unit 41, a Z-axis reaction force control unit 242, the X-axis control unit 51 and an X-axis reaction force control unit 252. The reaction force control units 242, 252 control the reaction motors 226, 236 to generate the reaction torques Tb1, Tb2 according to the magnitude of the grinding resistance during grinding. In the present embodiment, the reaction force control units 242, 252 receive the rotation angles θ1, θ2 of the manual rotary handles 21, 31 detected by the angle detection sensors 227, 237, the rise values ​​G1, G2 set by the reaction rate adjustment units 22, 32, and the drive currents I1, I2 of the motors 12a, 15a. The reaction force control units 242, 252 then control the reaction motors 226, 236 using this information.

[0093] The processes carried out by the reaction force control units 242, 252 of the control device 3 are described with reference to the Fig. 13 and Fig. 14 described. The reaction force control units 242, 252 determine whether the operating mode is manual mode (S41). If the operating mode is not manual mode (S41: No), the process returns.

[0094] If the operating mode is manual (S41: Yes), the reaction force control units 242, 252 determine whether the reaction motors 226, 236 are stopped (S42). If the reaction force motors 226, 236 are stopped (S42: Yes), the reaction force control units 242, 252 perform an initial reaction torque generation process (S43), and the process returns. The initial reaction torque generation process S43 is described later.

[0095] In Fig. 13. The reaction force control units 242, 252 obtain the rotation angles θ1, θ2 (S44) when the reaction motors 226, 236 are not stopped (S42: No). The reaction force control units 242, 252 then determine whether the changes Δθ1, Δθ2 in the rotation angles θ1, θ2 are equal to or less than a predetermined value Th3 (S45). If the changes 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 carry out a continuous reaction torque generation process (S46). The continuous reaction torque generation process S46 is the same as the one in Fig. 6 evident process in the first embodiment.

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

[0097] As can be seen from the Fig. As can be seen in Figure 14, the reaction force control units 242, 252 attain the rotation angles θ1, θ2 (S51) during the initial reaction torque generation process S43. The reaction force control units 242, 252 then 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 become greater than the predetermined value Th4 (S52: No).

[0098] If the change rates Δθ1, Δθ2 in the rotation angles θ1, θ2 become greater than the predetermined value Th4 (S52: Yes), the reaction force control units 242, 252 determine the reaction torques Tb1, Tb2 (S53). At this point, the reaction torques Tb1, Tb2 have the preset value A, as can be seen from the Fig. 7 is evident.

[0099] The reaction force control units 242, 252 then calculate the directions of rotation of the manual rotary handles 21, 31 based on the rotation angles θ1, θ2 (S54). Subsequently, 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 direction of rotation (S45). The process is thus completed.

[0100] The present embodiment provides that the control device 3, based on the detection values ​​of the angle detection sensors 227, 237, determines that the manual rotary handles 21, 31 are being rotated, and, by determining that the manual rotary handles 21, 31 are being rotated, causes the reaction motors 226, 236 to generate the reaction torques Tb1, Tb2. This simplifies the configuration of the handle units 216, 217. (Fourth embodiment)

[0101] The grinding machine 201 of the present embodiment differs from the third embodiment in the processes carried out by the reaction force control units 242, 252. The processes carried out by the reaction force control units 242, 252 are described with reference to Fig. 15 and Fig. 16 described. The present embodiment provides that the reaction force control units 242, 252 always determine the reaction torques Tb1, Tb2 on the basis of the drive currents I1, I2 of the motors 12a, 15a and the slope values ​​G1, G2.

[0102] As can be seen from the Fig. As can be seen in Figure 15, the reaction force control units 242 and 252 determine whether the operating mode is a manual mode (S61). If the operating mode is not manual (S61: No), the process returns to normal.

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

[0104] As can be seen from the Fig. As can be seen in Figure 16, the values ​​of the reaction torques Tb1, Tb2 increase with increasing magnitude of the drive currents I1, I2 of the motors 12a, 15a. The present embodiment provides that the reaction torques Tb1, Tb2 increase monotonically with respect to the magnitudes of the drive currents I1, I2, like a line in a line graph. However, the reaction torques Tb1, Tb2 can also be set to increase monotonically and in a curved manner with respect to the magnitudes of the drive currents I1, I2.

[0105] Furthermore, as can be seen from the Fig. As can be seen in Figure 16, the reaction torques Tb1, Tb2 are set to different values ​​according to the slope values ​​G1, G2. For example, the reaction torques Tb1, Tb2 are set such that the reaction torques Tb1, Tb2 are smaller the smaller the Lv of the slope values ​​G1, G2, and that the reaction torques Tb1, Tb2 are larger the larger the Lv of the slope values ​​G1, G2.

[0106] The reaction force control units 242, 252 then acquire the rotation angles θ1, θ2 (S65). Subsequently, the reaction force control units 242, 252 calculate the directions of rotation of the manual rotary handles 21, 31 based on the rotation angles θ1, θ2 (S66). Finally, 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 direction of rotation (S67). The process is thus completed.

[0107] The present embodiment provides that the control device 3 always has the reaction torques Tb1, Tb2, which were determined on the basis of the drive currents I1, I2 of the motors 12a, 15a and the ramp values ​​G1, G2, generated by the reaction motors 226, 236. This simplifies the configurations of the handle units 216, 217. (Other)

[0108] In the third and fourth embodiments, the reaction force control units 242, 252 can use the magnitude of the AE signal AEs in the embodiment instead of the magnitudes of the drive currents I1, I2 of the motors 12a, 15a. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2015-157345

[0007] JP 2015 - 157 345 A

[0007]

Claims

[1] Grinding machine (1, 101, 201), with: a grinding wheel (T) that grinds a workpiece (W); a movable body (12, 15) which moves the grinding wheel relative to the workpiece; a movement motor (12a, 15a) which moves the movable body; a manual rotary handle (21, 31) that controls a position of the moving body; a reaction motor (26, 36, 226, 236) attached to the manual twist handle and configured to apply a reaction torque (Tb1, Tb2) to the manual twist handle when the manual twist handle is rotated; and a control device (3, 103, 203) that controls the movement motor according to a rotation angle (θ1, θ2) of the manual rotation handle and controls the reaction motor to generate the reaction torque according to a magnitude of the grinding resistance during grinding. [2] The grinding machine (1, 201) according to claim 1, wherein the control device uses a magnitude of a drive current of the moving motor during grinding as the magnitude of the grinding resistance and controls the reaction motor to cause the reaction motor to generate the reaction torque according to the magnitude of the drive current of the moving motor. [3] The grinding machine (1, 201) according to claim 2, wherein, when the manual turning handle is turned while grinding is not in progress, the control device causes the reaction motor to generate the reaction torque according to the magnitude of the drive current of the moving motor while grinding is not in progress. [4] The grinding machine (101) according to claim 1, further comprising an AE sensor (110) that detects an acoustic emission signal (AEs) associated with grinding, wherein the controller uses a magnitude of the AE signal as a magnitude of the grinding resistance, and the controller controls the reaction motor to cause the reaction motor to generate the reaction torque according to the magnitude of the AE signal. [5] The grinding machine (101) according to claim 4, wherein when the manual turning handle is turned while not grinding, the control device causes the reaction motor to generate the reaction torque set in advance. [6] A grinding machine (1, 101) according to any one of claims 1 to 5, further comprising a torque sensor (28, 38) which detects the operating torque (Ta1, Ta2) applied to the manual turning handle, wherein the control device is triggered by detecting the operating torque by the torque sensor to cause the reaction motor to generate the reaction torque. [7] A grinding machine (1, 101) according to claim 6, wherein the control device, when the operating torque drops to a predetermined value (Th1) or less, causes the reaction motor to stop generating the reaction torque. [8] A grinding machine (1, 101) according to any one of claims 1 to 5, further comprising a torque sensor (28, 38) which detects the operating torque (Ta1, Ta2) applied to the manual turning handle, wherein, when the operating torque drops to a predetermined value (Th1) or less, the control device causes the reaction motor to stop generating the reaction torque. [9] The grinding machine (1, 101) according to any one of claims 6 to 8, further comprising an angle detection sensor (27, 37) that detects a rotation angle of the manual handle, wherein the control device determines a rotation direction of the manual handle based on a detection value from the angle detection sensor and controls the reaction motor to generate the reaction torque in a direction opposite to the determined rotation direction of the manual handle. [10] The grinding machine (201) according to any one of claims 1 to 5, further comprising an angle detection sensor (227, 237) that detects a rotation angle of the manual rotation handle, wherein the control device determines that the manual rotation handle is rotated based on a detection value from the angle detection sensor, and is triggered by the determination that the manual rotation handle is rotated to cause the reaction motor to generate the reaction torque. [11] The grinding machine (1, 101, 201) according to any one of claims 1 to 10, further comprising a reaction increase value adjusting unit (22, 32) configured to be capable of adjusting a increase value (G1, G2) for the reaction torque, wherein the control device controls the reaction motor to generate the reaction torque obtained based on the magnitude of the grinding resistance during grinding and the increase value adjusted by the reaction increase value adjusting unit. [12] The grinding machine (1, 101, 201) according to claim 11, wherein the reaction increase value adjusting unit has at least one of a manually operable adjusting knob member, an adjusting knob, and an adjusting lever. [13] The grinding machine (1, 101, 201) according to any one of claims 1 to 12, wherein the movable body (12, 15), the movement motor (12a, 15a), the manual rotation handle (21, 31), and the reaction motor (26, 36, 226, 236) are each provided as a configuration (15, 15a, 31, 36, 236) that moves the grinding wheel relative to the workpiece in a radial direction of the workpiece, and a configuration (12, 12a, 21, 26, 226) that moves the grinding wheel relative to the workpiece in an axial direction of the workpiece.

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