Gear processing device

Abstract

To provide a gear processing device capable of performing both skiving and hobbing with high accuracy.SOLUTION: A gear processing device 101 for forming a gear on a workpiece 1 with a processing tool 10 comprises: a tool main spindle 133b that rotatably holds the processing tool 10; a tool main spindle motor 134 that rotary-drives the tool main spindle 133b; and a control unit 140 that controls the tool main spindle motor 134. The processing tool 10 performs processing selected from a plurality of processes including skiving and hobbing. The control unit 140 sets, when one of the skiving and the hobbing is selected, a gain parameter for the tool main spindle motor 134 on the basis of processing type information indicating one of the skiving and the hobbing and the number of times of using the tool main spindle 133b during processing.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a gear machining device. [Background technology]

[0002] The following Patent Document 1 discloses a gear finishing method, which describes changing the response to commands by changing the speed gain (control parameter) of a control motor in at least one of the control systems for a control motor that drives a workpiece or a machining tool (a cutter or a grinding wheel). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-231013 A Summary of the Invention [Problem to be solved by the invention]

[0004] In designing this type of gear cutting device, there is a demand for a technology that enables both skiving and hobbing. To meet such demands, it is important to satisfy the desired machining accuracy required for each process. For example, if the control parameters (servo gain, etc.) of one of the skiving and hobbing processes are used as the control parameters of the other process, it may be difficult to satisfy the desired machining accuracy in both processes.

[0005] The present invention has been made in consideration of such problems, and aims to provide a gear machining device that can perform both skiving and hobbing with high precision. [Means for solving the problem]

[0006] One aspect of the present invention is A gear machining device for creating a gear on a workpiece using a machining tool, comprising: A tool spindle that rotatably holds the machining tool; a tool spindle motor that rotates the tool spindle; A control unit for controlling the tool spindle motor; Equipped with The machining tool performs machining selected from a plurality of types of machining including skiving and hobbing, a gear machining device, wherein the control unit sets a gain parameter of the tool spindle motor based on machining type information indicating either the skiving machining or the hob machining and a usage rotation speed of the tool spindle during the machining when the skiving machining or the hob machining is selected; is located. Effect of the Invention

[0007] According to the gear machining device of the above aspect, the gain parameters of the tool spindle motor that rotates the tool spindle that holds the machining tool can be set to appropriate values ​​based on the type of machining, skiving or hobbing, and the rotational speed of the tool spindle used during machining, and then a gear can be generated on the workpiece with the machining tool. This makes it possible to satisfy the desired machining accuracy in both skiving and hobbing.

[0008] As described above, according to the above-described aspect, it is possible to provide a gear machining device capable of performing both skiving and hobbing with high precision. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing a gear machining device according to a first embodiment. [Diagram 2] FIG. 2 is a perspective view of a first cutting blade tool which is one embodiment of a machining tool. [Diagram 3] FIG. 4 is a side view of a second cutting blade tool as one embodiment of the machining tool. [Figure 4] FIG. 2 is a block diagram showing the configuration of a control device in FIG. [Diagram 5] 5 is a flowchart of a motor control process performed by the control device of FIG. 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of a gear machining device will be described with reference to the drawings.

[0011] In the drawings explaining this embodiment, unless otherwise specified, the horizontal direction is the X-axis direction, the up-down direction perpendicular to the X-axis direction is the Y-axis direction, and the direction perpendicular to both the X-axis direction and the Y-axis direction is the Z-axis direction.

[0012] (Embodiment 1) 1. Configuration of gear processing device 101 As shown in FIG. 1, the gear machining device 101 of the first embodiment is a device for machining the workpiece 1 with the machining tool 10 by moving the workpiece 1 and the machining tool 10 relative to each other while rotating them synchronously. The gear machining device 101 of this embodiment is a machining center. The machining center is configured so that the machining tool 10 is replaceable, and machining according to the attached machining tool 10 is possible. In this embodiment, the machining tool 10 performs machining selected from a plurality of types of machining including skiving and hobbing, which will be described later. For convenience of explanation, a tool exchanger and a tool magazine that stores a plurality of machining tools 10 are omitted in FIG. 1.

[0013] The gear machining device 101 of this embodiment is basically configured as a horizontal machining center. However, if necessary, other configurations such as a vertical machining center can be applied as the configuration of this gear machining device 101.

[0014] 1, the gear machining device 101 has, for example, three linear drive axes (X-axis, Y-axis, and Z-axis) that are perpendicular to each other. The gear machining device 101 is configured to be capable of relatively moving the workpiece 1 and the machining tool 10 in the X-axis direction, the Y-axis direction, and the Z-axis direction.

[0015] Furthermore, the gear machining device 101 has one rotation drive shaft (B-axis) for changing the relative posture between the workpiece 1 and the machining tool 10. In this embodiment, the B-axis is a rotation drive shaft that rotates about an axis Yw parallel to the Y-axis direction. The gear machining device 101 also has a rotation drive shaft (Ct-axis) for rotating the machining tool 10, and a rotation drive shaft (Cw-axis) for rotating the workpiece 1.

[0016] In this embodiment, the Ct axis is a rotation drive axis about the rotation axis Zt of the machining tool 10, which is parallel to the Z-axis direction. The Cw axis is a horizontal axis and is a rotation drive axis about the rotation axis Zw of the workpiece 1, which can be angled with respect to the Z-axis direction according to the B-axis angle. However, the rotation axis Zt of the machining tool 10 may be configured to be angled with respect to the Z-axis direction and the X-axis direction.

[0017] In the gear machining device 101, the configuration for relatively moving the workpiece 1 and the machining tool 10 can be appropriately selected. In the following, an example will be given in which the machining tool 10 is capable of linear movement in the Y-axis direction and the Z-axis direction, the workpiece 1 is capable of linear movement in the X-axis direction, and the workpiece 1 is capable of rotating about the B-axis.

[0018] The gear machining apparatus 101 includes a bed 110, a workpiece holding device 120, a tool holding device 130, and a control unit 140. The bed 110 is installed on an installation surface and formed into a shape corresponding to the shape of the workpiece holding device 120 and the shape of the tool holding device 130. In this embodiment, the bed 110 has a rectangular shape when viewed from the Y-axis direction, for example. A pair of X-axis guide rails 111 and a pair of Z-axis guide rails 112 are provided on the upper surface of the bed 110. Both of the pair of X-axis guide rails 111 extend in the X-axis direction with the Y-axis direction as the thickness direction. Both of the pair of Z-axis guide rails 112 extend in the Z-axis direction with the Y-axis direction as the thickness direction.

[0019] The workpiece holding device 120 mainly includes an X-axis moving table 121, a B-axis rotating table 122, and a workpiece spindle device 123. The X-axis moving table 121 is configured to be driven by a driving device such as a linear motor or a ball screw mechanism (not shown) so as to move in the X-axis direction while being guided by the X-axis guide rail 111 of the bed 110.

[0020] The B-axis rotating table 122 is placed on the upper surface of the X-axis moving table 121, and is configured to move in the X-axis direction together with the X-axis moving table 121. The B-axis rotating table 122 is provided so as to be rotatable about the B-axis relative to the X-axis moving table 121. The B-axis rotating table 122 is provided with a rotation motor and a rotation angle detector (not shown). Therefore, the B-axis rotating table 122 can rotate about the B-axis by driving the rotation motor.

[0021] The workpiece spindle device 123 is provided on the B-axis rotating table 122, and is configured to rotate about the B-axis integrally with the B-axis rotating table 122. The workpiece spindle device 123 rotatably holds the workpiece 1. The workpiece spindle device 123 includes a housing 123a, a workpiece spindle 123b, a workpiece spindle motor 124 that rotationally drives the workpiece spindle 123b, and an encoder 125 (see FIG. 4) that detects the rotation angle of the workpiece spindle motor 124.

[0022] A housing 123a of the work spindle device 123 is fixed to the B-axis rotating table 122, and a work spindle 123b of the work spindle device 123 is rotatably supported by the housing 123a. The workpiece 1 is attached to the tip of the work spindle 123b. In other words, the workpiece 1 is cantilevered by the work spindle 123b of the work spindle device 123. The work spindle motor 124 is a servo motor controlled by the control unit 140. The work spindle device 123 is capable of rotating the workpiece 1 about the Cw axis by driving the work spindle motor 124. In this way, the workpiece holding device 120 allows the workpiece 1 to move in the X-axis direction, rotate about the B axis, and rotate about the Cw axis relative to the bed 110.

[0023] The tool holding device 130 mainly includes a column 131, a saddle 132, and a tool spindle device 133. The column 131 is driven by a driving device such as a linear motor or a ball screw mechanism (not shown) to move in the Z-axis direction while being guided by a Z-axis guide rail 112 of the bed 110. A Y-axis guide rail 131a is formed on a side surface (left surface in FIG. 1) of the column 131 that extends in the vertical direction. The saddle 132 is driven by a driving device such as a linear motor or a ball screw mechanism (not shown) to move in the Y-axis direction while being guided by the Y-axis guide rail 131a of the column 131.

[0024] The tool spindle device 133 is provided on the saddle 132 and moves in the Y-axis direction integrally with the saddle 132. The tool spindle device 133 rotatably holds the machining tool 10. The tool spindle device 133 includes a housing 133a, a tool spindle 133b, a tool spindle motor 134 that rotationally drives the tool spindle 133b, and an encoder 135 (see FIG. 4) that detects the rotation angle of the tool spindle motor 134.

[0025] A housing 133a of the tool spindle device 133 is fixed to the saddle 132, and a tool spindle 133b of the tool spindle device 133 is rotatably supported by the housing 133a. The machining tool 10 is attached to this spindle 33b. The tool spindle motor 134 is a servo motor controlled by the control unit 140. The tool spindle device 133 is driven by the tool spindle motor 134 to rotate the machining tool 10 about the Ct axis. In this way, the tool holding device 130 holds the machining tool 10 so that it can move in the Y-axis direction and the Z-axis direction relative to the bed 110 and can rotate about the Ct axis.

[0026] The control unit 140 includes a processor (arithmetic processing unit) and a storage device, and controls each driving device by executing a machining program. That is, the control unit 140 controls the Ct-axis rotation of the machining tool 10, the Cw-axis rotation of the workpiece 1, the relative movement between the workpiece 1 and the machining tool 10, and the like.

[0027] In detail, the control unit 140 sets the rotation axis Zt of the machining tool 10 to a state in which the rotation axis Zw of the workpiece 1 has an axis crossing angle α. In this embodiment, the control unit 140 rotates the B-axis rotating table 122 to position the workpiece 1 and the machining tool 10 to a state in which the axis crossing angle α is formed.

[0028] 2. Configuration of machining tool 10 The gear machining device 101 is for generating a gear on a workpiece 1 with a machining tool 10. For this reason, the machining tool 10 in this embodiment includes a first cutting blade tool 10A shown in Fig. 2 and a second cutting blade tool 10B shown in Fig. 3. Examples of other machining tools that can be replaced with the first cutting blade tool 10A and the second cutting blade tool 10B include tools such as a shaper cutter, an end mill, a milling tool, a drill, a tapping tool, a chamfering tool, a turning tool, a threading tool, and a grinding tool.

[0029] As shown in FIG. 2, the first cutting blade tool 10A is called a "gear skiving cutter" or "skiving tool" and includes a tool body 11A that is driven to rotate around a rotation axis Zt, and a plurality of cutting blades 12A provided in a circumferential direction D on the outer periphery of the tool body 11A. Each cutting blade 12A is formed in a convex shape. Each cutting blade 12 includes a rake face 13 that is the surface on the tip side in the extension direction, a front clearance face 14 that is the radial outer surface, and a side clearance face 15 that is the circumferential outer surface. All of the plurality of cutting blades 12A have the same twist angle with respect to the rotation axis Zt (there may be cases where they do not have a twist angle).

[0030] The process of generating a gear on the workpiece 1 using the first cutting blade tool 10A is called "gear skiving." In this gear skiving, the first cutting blade tool 10A is supported in a cantilever manner on the tool spindle 133b of the tool spindle unit 133. In this gear skiving, the workpiece 1 and the first cutting blade tool 10A are rotated synchronously while the rotation axis Zt of the first cutting blade tool 10A is inclined at an axis crossing angle α with respect to the rotation axis Zw of the workpiece 1 (see FIG. 1), and the first cutting blade tool 10A is repeatedly operated in the tool feed direction at a predetermined feed speed.

[0031] As shown in Fig. 3, the second cutting blade tool 10B is called a "hob cutter" and includes a tool body 11B that is driven to rotate about a rotation axis Zt and a plurality of cutting blades 12B provided on the outer periphery of the tool body 11B. Each cutting blade 12B is formed as a convex strip. The plurality of cutting blades 12B are configured by arranging a group of cutting blades 12B, each of which is formed continuously in the axial direction, at equal intervals in the circumferential direction.

[0032] The process of generating a gear on the workpiece 1 using the second cutting blade tool 10B is called "hobbing". In this hobbing, the second cutting blade tool 10B is supported at one end by the tool spindle 133b of the tool spindle unit 133. If necessary, a dedicated attachment (not shown) for supporting at both ends may be attached to the second cutting blade tool 10B so that the second cutting blade tool 10B is supported at both ends. In this hobbing, the workpiece 1 and the second cutting blade tool 10B are moved relative to each other while rotating synchronously with the rotation axis Zt of the second cutting blade tool 10B inclined at an axis crossing angle α with respect to the rotation axis Zw of the workpiece 1 (see FIG. 1). In the case of the second cutting blade tool 10B, the axis crossing angle α of the rotation axis Zt with respect to the rotation axis Zw of the workpiece 1 is set to approximately 90°. In contrast, in the case of the first cutting blade tool 10A, the axis crossing angle α is set to approximately 20°.

[0033] In the case of skiving using the first cutting blade tool 10A, the workpiece 1 is machined at a higher rotation speed than in the case of hobbing using the second cutting blade tool 10B. In contrast, in the case of hobbing using the second cutting blade tool 10B, the workpiece 1 is machined at a lower rotation speed than in the case of skiving using the first cutting blade tool 10A. Skiving is suitable for machining with a low machining load, and hobbing is suitable for machining with a high machining load. In this embodiment, conditions are set such that the machining load by the second cutting blade tool 10B is higher than the machining load by the first cutting blade tool 10A.

[0034] 3. Configuration of the control unit 140 4, control unit 140 includes first control unit 141, second control unit 142, gain parameter storage unit 143, gain parameter instruction unit 144, data input unit 145, gain parameter selection unit 146, and gain parameter input unit 147. Gain parameters are used to adjust servo gains, control gains, etc., and are parameters that adjust position control, speed control, current control, filter adjustment, etc.

[0035] The first control unit 141 includes a workpiece position command unit 141a for the workpiece spindle motor 124, and a spindle position command unit 141b for the tool spindle motor 134. When a synchronization condition is met, the workpiece position command unit 141a and the spindle position command unit 141b perform a synchronous phase calculation. The second control unit 142 includes a position control processing unit 142a, a speed control processing unit 142b, a current control processing unit 142c, and a subtractor SW for the workpiece spindle motor 124. The second control unit 142 also includes a position control processing unit 142d, a speed control processing unit 142e, a current control processing unit 142f, and a subtractor SS for the tool spindle motor 134.

[0036] The first control unit 141 is a CNC (Computerized Numerical Control) device, and the second control unit 142 corresponds to a servo amplifier. In the first control unit 141, a control command for the workpiece spindle motor 124 is created (calculated) by a workpiece position command unit 141a, and a control command for the tool spindle motor 134 is created (calculated) by a spindle position command unit 141b. The NC program includes a dedicated G code. The machining type can be determined from this G code.

[0037] The second control unit 142 corresponds to a servo amplifier and is configured to include at least one of proportional control (P control), proportional integral control (PI control), proportional differential control (PD control), and proportional integral differential control (PID control).

[0038] The first control unit 141 and the second control unit 142 may be one control unit, or may be separate control units connected by a communication cable. Also, the workpiece position command unit 141a for the workpiece spindle motor 124, the processing units 142a, 142b, and 142c, the spindle position command unit 141b for the tool spindle motor 134, and the processing units 142d, 142e, and 142f may be separate control devices or may be one integrated control device.

[0039] The gain parameter storage unit 143 stores table data (not shown) of gain parameters in which the gain parameters of each motor corresponding to the machining conditions are set for each machining type. Therefore, the gain parameters Pa of the workpiece spindle motor 124 for each machining type and the gain parameters Pb of the tool spindle motor 134 for each machining type are stored in the gain parameter storage unit 143. The gain parameters Pa, Pb stored in the gain parameter storage unit 143 include at least a parameter of a proportional gain (P gain). The gain parameters Pa, Pb may further include at least one parameter of an integral gain (I gain) and a differential gain (D).

[0040] The gain parameter instruction unit 144 instructs the gain parameter selection unit 146 with a gain parameter selection command input by an operator, i.e., a command to select standard gain parameters, a gain parameter selection command based on machining conditions such as the specifications of the machining tool 2 written in the NC program, the operation of the machining tool 2, and the operation of the workpiece 1, or a gain parameter selection command based on the above machining conditions input by the operator from the data input unit 145. This makes it possible to select the gain parameters optimal for machining. Note that the specifications of the workpiece 1, which are among the machining conditions, are wirelessly transmitted to the gain parameter selection unit 146 by the operator having a reader read an IC tag attached to the workpiece 1 to be machined stored in a warehouse.

[0041] The gain parameter selection unit 146 selects standard gain parameters or gain parameters corresponding to the above-mentioned machining conditions from the gain parameter storage unit 143 in accordance with a gain parameter selection command input from the gain parameter instruction unit 144, and sends the selected gain parameters to the gain parameter input unit 147, which then distributes and sets the gain parameters to the position control processing units 142a and 142d, the speed control processing units 142b and 142e, and the current control processing units 142c and 142f.

[0042] Examples of the machining condition items for setting the gain parameters include the specifications of the machining tool 10, the specifications of the workpiece 1, the operating conditions of the machining tool 10, and the operating conditions of the workpiece 1. The specifications of the machining tool 10 include the shape (diameter, etc.) and inertia (weight) of the machining tool 10. The specifications of the workpiece 1 include the material, shape (diameter, etc.) and inertia (weight) of the workpiece 1. The operating conditions of the machining tool 10 include the rotation speed (rotational speed) of the machining tool 10, the feed amount, the cutting amount, and the like. The operating conditions of the workpiece 1 include the rotation speed (rotational speed) of the workpiece 1. For each type of machining, gain parameters related to the position control (e.g., PID control), speed control (e.g., PID control), and current control (e.g., PID control) of the workpiece spindle motor 124 and the tool spindle motor 134, which are the control targets, are determined and stored as table data.

[0043] When the gain parameters stored in the gain parameter storage unit 143 are not used, the gain parameter input unit 147 allocates and sets the gain parameters input by the operator to the position control processing units 142a and 142d, the speed control processing units 142b and 142e, and the current control processing units 142c and 142f. This allows the machining desired by the operator to be performed with high accuracy. Also, by setting the cutting speed (cutting depth, rotation speed) to be increased, highly efficient machining can be achieved.

[0044] The workpiece position command unit 141a reads a rotational position command for the workpiece spindle motor 124 written in the NC program and inputs it to the subtractor SW. The subtractor SW calculates the difference between the rotational position command for the workpiece spindle motor 124 and the detected rotational position detected by the encoder 125, i.e., the amount of position deviation. The position control processing unit 142a calculates a speed command based on the amount of position deviation and gain parameter Pa calculated by the subtractor SW and inputs it to the speed control processing unit 142b. The speed control processing unit 142b calculates a current command based on the speed command and gain parameter Pa calculated by the position control processing unit 142a and inputs it to the current control processing unit 142c. The current control processing unit 142c controls the rotation of the workpiece spindle motor 124 based on the current command and gain parameter Pa calculated by the speed control processing unit 142b.

[0045] The spindle position command unit 141b reads a rotational position command of the tool spindle motor 134 written in the NC program and inputs it to the subtractor SS. The subtractor SS calculates the difference between the rotational position command of the tool spindle motor 134 and the detected rotational position detected by the encoder 135, i.e., the amount of position deviation. The position control processing unit 142d calculates a speed command based on the amount of position deviation calculated by the subtractor SS and a gain parameter Pb, and inputs it to the speed control processing unit 142e. The speed control processing unit 142e calculates a current command based on the speed command and gain parameter Pb calculated by the position control processing unit 142d, and inputs it to the current control processing unit 142f. The current control processing unit 142f controls the rotation of the tool spindle motor 134 based on the current command and gain parameter Pb calculated by the speed control processing unit 142e.

[0046] 4. Setting the gain parameters Here, with reference to FIG. 4, a specific example of setting the gain parameters in this embodiment will be described.

[0047] 4-1.When skiving or hobbing When skiving or hobbing is selected, the gain parameter selection unit 146 sets the gain parameter Pb of the tool spindle motor 134 based on the machining type information E indicating either skiving or hobbing and the rotation speed Nb used for the tool spindle 133b during the selected machining, or changes the setting so that the already set standard gain parameter is switched to the gain parameter Pb. In other words, for the control of the tool spindle motor 134, a dedicated gain parameter Pb is used during each of skiving and hobbing.

[0048] The machining type information E is obtained, for example, from a G code indicating the machining type in an NC program. The machining type information E may also be obtained from a tool number written in an M code indicating a tool change in an NC program. The machining type information E may also be input by an operator from the data input unit 145. This machining type information E makes it possible to determine whether the machining is skiving or hobbing. The working speed Nb of the tool spindle 133b is the number of rotations (rotational speed) per unit time that is the target during machining. This working speed Nb is input, for example, by an operator from the data input unit 145. This working speed Nb differs between skiving and hobbing, and is usually a larger value for skiving than for hobbing.

[0049] Further, the gain parameter selection unit 146 sets the gain parameter Pa of the workpiece spindle motor 124 based on the machining type information E and the used rotation speed Na of the workpiece spindle 123b during the machining, or changes the setting so that the already set standard gain parameter is switched to the gain parameter Pa. In other words, for the control of the workpiece spindle motor 124, a dedicated gain parameter Pa is used during each of the skiving machining and the hobbing machining.

[0050] The usable rotational speed Na of the workpiece spindle 123b is the target rotational speed (rotational speed) per unit time during machining. This usable rotational speed Na is automatically determined by the usable rotational speed Nb of the tool spindle 133b and the gear ratio of the gear to be generated on the workpiece 1. This usable rotational speed Na is input from the gain parameter instruction unit 144, for example.

[0051] 4-2. When machining other than skiving and hobbing When a machining other than skiving and hobbing is selected, the gain parameter selection unit 146 sets the gain parameters Pb of the tool spindle motor 134 based on the machining type information F indicating the other machining and the rotation speed Nb used for the tool spindle 133b during the selected machining, or changes the setting so that the already set standard gain parameters are switched to the gain parameters Pb. In other words, during the other machining, the gain parameters Pb dedicated to the other machining are used for control of the tool spindle motor 134, as in the case of skiving and hobbing.

[0052] The machining type information F is obtained, for example, from the G code of the NC program. According to this machining type information F, it is possible to determine whether the machining is a type other than skiving or hobbing.

[0053] Further, the gain parameter selection unit 146 sets the gain parameter Pa of the workpiece spindle motor 124 based on the machining type information F and the used rotation speed Na of the workpiece spindle 123b during the machining, or changes the setting so that the already set standard gain parameter is switched to the gain parameter Pa. In other words, during another machining, the gain parameter Pa dedicated to the other machining is used for control of the workpiece spindle motor 124, as in the case of skiving and hobbing.

[0054] 5.Motor control processing The motor control processing by the control unit 140 will be described with reference to Fig. 5. Here, for convenience, only the motor control processing of the tool spindle motor 134 will be described, but the motor control processing of the workpiece spindle motor 124 is similar. It is also assumed that the gain parameter storage unit 143 stores table data of the above-mentioned gain parameters in advance, and that the gain parameter selection unit 146 has workpiece information input from an IC tag attached to the workpiece 1 (the workpiece information may be input from the data input unit 145 by the operator).

[0055] 5, the motor control process of this embodiment sequentially executes steps S101 to S112. Note that in this motor control process, one step may be divided into multiple steps, multiple steps may be integrated into one, or another step may be added, as necessary.

[0056] Step S101 is a step of reading an NC program. In this embodiment, the information of the NC program read in this step S101 includes the above-mentioned machining type information E, F. Step S102 is a step of selecting a gain parameter Pb based on the information of the NC program read in step S101. In this step S102, the gain parameter selection unit 146 selects a gain parameter Pb from the gain parameter storage unit 143 based on the machining conditions and machining type information E, F written in the NC program and the used rotation speed Nb of the tool spindle 133b input from the data input unit 145. Step S103 is a step of setting the gain parameter Pb selected in step S102 to each processing unit 142d, 142e, 142f.

[0057] Step S104 is a step in which a spindle position command is read out from a machining program (such as an NC program), and this spindle position command is input from the first control unit 141 to the second control unit 142. Step S105 is a step in which the second control unit 142 inputs a spindle detected position from the encoder 135 of the tool spindle motor 134. Step S106 is a step in which a position deviation amount is calculated from the spindle position command input in step S104 and the spindle detected position input in step S105. Specifically, in this step S106, the spindle position command unit 141b reads a rotational position command of the tool spindle motor 134 written in the NC program and inputs it to the subtractor SS. The subtractor SS inputs the detected rotational position detected by the encoder 135, and calculates the difference between the rotational position command of the tool spindle motor 134 and the detected rotational position as the position deviation amount.

[0058] Step S107 is a step of performing a position control process. Specifically, in this step S107, the position control processing unit 142d calculates a speed command based on the position deviation amount calculated by the subtractor SS and the gain parameter Pb, and inputs the speed command to the speed control processing unit 142e. Step S108 is a step of performing a speed control process. Specifically, in this step S108, the speed control processing unit 142e calculates a current command based on the speed command and the gain parameter Pb calculated by the position control processing unit 142d, and inputs the current command to the current control processing unit 142f. Step S109 is a step of performing a current control process. Specifically, in this step S109, the current control processing unit 142f controls the rotation of the tool spindle motor 134 based on the current command and the gain parameter Pb calculated by the speed control processing unit 142e. In this manner, the spindle rotation control is performed (step S110).

[0059] Step S111 is a step for judging whether the position deviation amount calculated in step S106 has reached a target deviation amount (a value close to 0 (zero) is set) (whether it is greater than the target deviation amount). If the position deviation amount has not reached the target deviation amount (is greater than the target deviation amount), the process returns to step S105 and repeats the above-mentioned processing. On the other hand, if the position deviation amount has reached the target deviation amount, the process proceeds to step S112.

[0060] Step S112 is a step for judging whether the NC program has ended. If the program has not ended, the process returns to step S105 and repeats the above-mentioned processing. On the other hand, if the NC program has ended, all processing of the motor control processing is ended.

[0061] According to the above-described motor control process, the operator does not need to manually adjust the gain parameters to match the machining conditions, and the gain parameters can be automatically set to match the machining conditions. This not only shortens the machining time, but also prevents erroneous adjustments and improves machining accuracy.

[0062] 6. Effects Next, the effects of the above-mentioned embodiment 1 will be described.

[0063] According to the gear machining device 101 of the first embodiment, the gain parameter Pb of the tool spindle motor 134 that rotates and drives the tool spindle 133b that holds the machining tool 10 is set to an appropriate value based on the machining type (skiving or hobbing) and the rotation speed Nb used of the tool spindle 133b during machining, and then a gear can be generated on the workpiece 1 by the machining tool 10. This makes it possible to satisfy the desired machining accuracy in both skiving and hobbing.

[0064] Therefore, according to the above-mentioned first embodiment, it is possible to provide a gear machining device 101 capable of performing both skiving and hobbing with high accuracy.

[0065] According to the gear machining device 101 of the first embodiment, it is possible to improve the machining accuracy during each machining operation by changing the settings of both the gain parameter Pa of the workpiece spindle motor 124 and the gain parameter Pb of the tool spindle motor 134. On the other hand, a standard gain parameter may be used for the gain parameter Pa of the workpiece spindle motor 124, and only the gain parameter Pb of the tool spindle motor 134 may be changed, or only the gain parameter Pa of the workpiece spindle motor 124 may be changed (changing the setting of only one of the gain parameters (Pa, Pb)). In detail, by changing the setting of only the gain parameter Pb of the tool spindle motor 134, it is possible to set the parameter taking into consideration the structure of the gear machining tool (machining method), improving the controllability (response, synchronism, no vibration, etc.) of the tool (machining), and enabling high-precision machining. Furthermore, by changing only the gain parameter Pa of the workpiece spindle motor 124, it is possible to set it taking into consideration the structure of the gear (workpiece 1), improving the controllability (responsiveness, synchronism, no vibration, etc.) of the gear (machining), and enabling high-precision machining. By changing the gain parameter Pb of the tool spindle motor 134 and the gain parameter Pa of the workpiece spindle motor 124, it is possible to set it taking into consideration the gear machining tool (machining method) and the structure of the gear (workpiece 1), improving the controllability (responsiveness, synchronism, no vibration, etc.) of machining, and enabling even higher-precision machining.

[0066] 7. Transformation Although the present invention has been described based on the above embodiment, it is understood that the present invention is not limited to the embodiment or structure. The present invention also includes various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, and other combinations and forms including only one element, more than one, or less than one, are also within the scope and spirit of the present invention.

[0067] In the above embodiment, the gear cutting device 101 is exemplified as a horizontal machining center, but it may be a vertical machining center instead. Furthermore, the main structure of the gear cutting device 101 can be similarly applied to a dedicated gear cutting machine, if necessary. [Explanation of symbols]

[0068] 1: workpiece, 10: machining tool, 10A: first cutting edge tool (machining tool), 10B: second cutting edge tool (machining tool), 101: gear machining device, 123b: workpiece spindle, 124: workpiece spindle motor, 133b: tool spindle, 134: tool spindle motor, 140: control unit, E, F: machining type information, Na: workpiece spindle rotation speed in use, Nb: tool spindle rotation speed in use, Pa: workpiece spindle motor gain parameter, Pb: tool spindle motor gain parameter

Claims

1. A gear machining device for creating a gear on a workpiece using a machining tool, comprising: A tool spindle that rotatably holds the machining tool; a tool spindle motor that rotates the tool spindle; A control unit for controlling the tool spindle motor; Equipped with The machining tool performs machining selected from a plurality of types of machining including skiving and hobbing, When the skiving or hobbing is selected, the control unit sets a gain parameter of the tool spindle motor based on machining type information indicating either the skiving or the hobbing and the used rotational speed of the tool spindle during the machining.

2. A workpiece spindle that rotatably holds the workpiece; a workpiece spindle motor that rotates the workpiece spindle; Equipped with 2. The gear machining device according to claim 1, wherein the control unit controls the workpiece spindle motor and sets a gain parameter of the workpiece spindle motor based on the machining type information and the used rotational speed of the workpiece spindle during the machining.

3. 3. The gear machining device according to claim 1, wherein when a machining operation other than the skiving operation and the hobbing operation is selected, the control unit switches a gain parameter of the tool spindle motor based on machining type information indicating the other machining operation and a usage speed of the tool spindle during the selected machining operation.

4. The gear machining device according to claim 1 , wherein the gain parameter is a proportional gain parameter.

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