machine tool

Abstract

A machine tool for producing internal or external teeth on a cylindrical workpiece, comprising a workpiece holder, a column relatively movable to the workpiece holder, a rotating spindle rotatable relative to the column, a working tool held by the rotating spindle, and a phase detection unit, the phase detection unit detecting the phase of the working tool relative to the rotating spindle. The working tool comprises a tool portion having a tool, a holder portion, and a detected portion formed on the holder portion. The phase detection unit comprises a detection portion, the detection portion detecting the detected portion, and a calculation portion calculating the phase angle of the detected portion relative to a reference position of the rotating spindle based on the result detected by the detection portion.

Description

Technical Field

[0001] The present disclosure relates to machine tools. Background Art

[0002] JP H06-55341 A discloses a tool measuring device that measures the shape of a screw-shaped working tool used in gear processing. The tool measuring device disclosed in JP H06-55341 A measures the shape of the screw-shaped working tool by moving a measuring probe in the X-axis and Y-axis directions while rotating the working tool around an axis. On the other hand, JP 2018-001343 A discloses a gear cutting tool used in gear processing by skiving.

[0003] In gear processing by skiving, hard processing (processing of a high-hardness workpiece) is sometimes performed, in which a rough-processed workpiece is heat-processed by using another machine and then the workpiece is finely processed, or other processing is performed on a part of a workpiece such as a synchronizer sleeve by using multiple working tools. In such processing, when a gear cutting tool mounted on a rotating spindle is replaced with another gear cutting tool, it is necessary to perform phase matching between the gear cutting tool newly mounted on the rotating spindle and the workpiece forming the gear. In addition, as a preliminary stage of the phase matching between the gear cutting tool and the workpiece, it is necessary to determine the phase of the gear cutting tool newly mounted on the rotating spindle relative to the rotating spindle.

[0004] In the case of determining the phase of the gear cutting tool relative to the rotating spindle based on the shape of the cutter of the gear cutting tool, a long time is required. That is, the shape of the cutter of the gear cutting tool used in the scraping process is complicated, so it takes a lot of time and effort to know the shape of the cutter mounted on the rotating spindle. In the gear cutting tool, the helix angle of each cutter in the tool is changed by regrinding. Therefore, after each regrinding, the shape of the cutter must be measured again, and the shape data of the cutter used as a reference in phase determination needs to be corrected. In addition, in gear processing by scraping, the replacement frequency of the gear cutting tool is high, so there is a need to shorten the time required to determine the phase of the gear cutting tool relative to the rotating spindle. Summary of the invention

[0005] The present disclosure provides a machine tool that can shorten the time required to determine the phase of a work tool relative to a rotating spindle.

[0006] According to one aspect of the present disclosure, a machine tool for producing internal or external teeth on a cylindrical workpiece includes a workpiece holder for holding the workpiece in a rotatable manner, a column arranged to be relatively movable relative to the workpiece holder, a rotating spindle arranged to be rotatable relative to the column, a working tool held by the rotating spindle, and a phase detection unit configured to detect the phase of the working tool relative to the rotating spindle. The working tool includes: a tool portion having a plurality of tools for cutting a workpiece; a holder portion, the holder portion being arranged to be integrally rotatable with the tool portion and the holder portion being detachably mounted on the rotating spindle; and a detected portion formed on the holder portion. The phase detection unit includes a detection portion configured to detect the detected portion and a calculation portion configured to calculate the phase angle of the detected portion relative to a reference position of the rotating spindle based on a result detected by the detection portion.

[0007] According to one aspect of the present disclosure, a detection unit detects a detected portion provided in a retainer portion. Then, a calculation unit calculates a phase angle (displacement) of the detected portion relative to a reference position of a rotating spindle based on the detection result obtained by the detection unit, and determines the phase of a working tool. That is, the phase detection unit determines the phase of the working tool based on the position of the detected portion whose shape does not change due to regrinding, and therefore, even in the case of regrinding the tool, it is not necessary to know the shape of the tool. Therefore, in a machine tool, the time period required to determine the phase of the working tool relative to the rotating spindle can be shortened without depending on the shape of the tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a plan view of a machine tool according to an embodiment of the present disclosure.

[0009] Figure 2A is an enlarged side view of a portion of the cutter portion of the work tool shown in cross section.

[0010] Figure 2B It is along Figure 2A A cross-sectional view of the working tool taken along the line IIB-IIB in FIG. 8 , in which the detection portion 81 is shown by a dotted line.

[0011] Figure 3 2 are views showing the operation of the working tool.

[0012] Figure 4 It is a block diagram of a gear processing device.

[0013] Figure 5A This is the front view of the machine tool.

[0014] Figure 5B It shows that from Figure 5A The illustrated state is a front view of the machine tool in a state where a working tool accommodated in a tool magazine is started to be moved to a tool holding portion.

[0015] Figure 5C is a front view of the machine tool showing the steps of replacing a working tool using a change arm.

[0016] Figure 5D 1 is a front view of the machine tool showing a state in which a holder attachment portion of a working tool mounted on a rotating spindle is sensed by a detection portion.

[0017] Figure 6 is a flow chart illustrating a sensing process performed by the controller.

[0018] Fig. 7A is a graph showing detection results in the case where the rotation spindle is rotated in one direction while sensing is performed on the holder attachment portion.

[0019] Figure 7B is a graph showing the detection result in the case where the rotation spindle is rotated in the other direction while sensing is performed on the holder attachment portion. DETAILED DESCRIPTION

[0020] (1. Outline of machine tool 1)

[0021] Hereinafter, an embodiment of a machine tool to which the present disclosure is applied will be described with reference to the accompanying drawings. Figure 1 Describe the outline of machine tool 1. Figure 1 As shown, the machine tool 1 mainly includes a gear machining device 100 and a presetter 200 .

[0022] The gear processing device 100 is a machining center with three mutually orthogonal linear axes (X, Y, Z axes) and two rotation axes (A axis and C axis) as drive axes. The embodiment will be described by exemplifying the case where internal teeth are produced on a cylindrical workpiece W by using the gear processing device 100. However, the gear processing device 100 can also be used in the case where external teeth are produced on the workpiece W. In addition, the gear processing device 100 can also be used, for example, in the case of processing a spline provided in a synchronizer sleeve. The presetter 200 measures various dimensions of a working tool 40 used to process the workpiece W.

[0023] (2. Gear processing device 100)

[0024] like Figure 1 As shown, the machine tool 1 mainly includes a bed 10, a workpiece holder 20, a tool holding device 30, and a working tool 40. The bed 10 is formed in a substantially rectangular shape.

[0025] The workpiece holder 20 can rotatably hold the workpiece W. The workpiece holder 20 includes a worktable 21, a rotary worktable 22, and a rotating worktable 23. The worktable 21 is placed on the bed 10. The bed 10 is provided with a plurality of Figure 1 A pair of X-axis guide rails 11 extending in the lateral direction of the workbench (in the lateral direction of the workbench). The workbench 21 is driven by a screw feed mechanism not shown to reciprocate in the X-axis direction.

[0026] The rotary table 22 is provided on the table 21 so as to be rotatable about the B axis parallel to the Y axis direction. The rotary table 23 is provided on the rotary table 22 so as to be rotatable about the A axis orthogonal to the B axis. The workpiece W is held by the rotary table 23 so as to be rotatable integrally with the rotary table. The workpiece W held by the rotary table 23 rotates about the A axis as the rotary table 23 rotates.

[0027] The tool holding device 30 mainly includes a column 31, a saddle 32 and a rotating spindle 33. The column 31 is placed on the top surface of the bed 10. The bed 10 is provided with a plurality of axes extending in the Z-axis direction ( Figure 1 A pair of Z-axis guide rails 12 extending in the vertical direction (in the vertical direction) of the workpiece holder 20 are provided. The column 31 is driven by a screw feed mechanism not shown to reciprocate in the Z-axis direction. Therefore, the column 31 is configured to be relatively movable relative to the workpiece holder 20.

[0028] The saddle 32 is placed on the side of the column 31 parallel to the plane orthogonal to the Z-axis direction. Figure 1 A pair of Y-axis guide rails 34 extending in the direction perpendicular to the paper (in the paper). The saddle is driven by a screw feed mechanism (not shown) to reciprocate in the Y-axis direction.

[0029] The rotating spindle 33 is provided to be rotatable relative to the column 31 and the saddle 32. Specifically, the rotating spindle 33 is rotatably held by the saddle 32, and the rotating spindle 33 is rotated by a spindle motor (not shown) housed in the saddle 32. One of the working tools 40 is held to be rotatable integrally with the rotating spindle 33. The working tool 40 moves relative to the bed 10 in the Z-axis direction and the Y-axis direction as the column 31 and the saddle 32 move.

[0030] like Figure 2AAs shown, each of the working tools 40 includes a tool portion 41 and a holder portion 42, the tool portion 41 having a plurality of tools 43 for cutting a workpiece W, and the holder portion 42 being arranged to be rotatable integrally with the tool portion 41. The plurality of tools 43 have a helix angle relative to the central axis O of the working tool 40. The radial outer surface of each of the tools 43 has a clearance angle relative to the central axis O of the working tool 40. The end surface 43a of the tool 43 has a rake angle relative to a plane orthogonal to the central axis O of the working tool 40.

[0031] The holder portion 42 includes a holder attachment portion 44 and a tool holder 45. The holder attachment portion 44 is an annular portion formed integrally with the cutter portion 41. The tool holder 45 is a columnar member. The tool holder 45 has a side portion ( Figure 2A The tool holder 45 is attached to the holder attachment portion 44 in an integrally rotatable manner, and the tool holder 45 is attached to the holder attachment portion 44 in an integrally rotatable manner in the other side portion ( Figure 2A The working tool 40 is detachably mounted on the rotating spindle 33. Figure 1 ) rotates around the central axis O.

[0032] like Figure 2B As shown, the holder portion 42 further includes a detected portion 46 and two balancers 47, 48. The detected portion 46 and the two balancers 47, 48 are recessed portions recessed radially inwardly from the outer peripheral surface of the holder attachment portion 44.

[0033] As will be described later, the detected portion 46 serves as a reference in the case where the phase angle (displacement) of the working tool 40 relative to the rotating spindle 33 is to be detected. The two balancers 47, 48 are provided to offset the dispersion occurring in the centrifugal force generated in the retainer attachment portion 44 during the rotation of the working tool 40 and caused by the detected portion 46. In particular, the axial positions of the two balancers 47, 48 in the retainer attachment portion 44 are equivalent to the axial position of the detected portion 46, and the circumferential positions of the two balancers 47, 48 in the retainer attachment portion 44 are different from the circumferential position of the detected portion 46. In addition, the radial dimensions of the two balancers 47, 48 are smaller than the radial dimensions of the detected portion 46.

[0034] like Figure 3 As shown in FIG. 1 , when internal teeth are to be produced on the inner peripheral surface of the workpiece W, the gear machining device 100 performs cutting processing, wherein the working tool 40 and the workpiece W are fed in the direction of the rotation axis (A-axis direction) of the workpiece W while the working tool 40 and the workpiece W are rotated synchronously. In particular, when performing gear machining, the gear machining device 100 causes the rotary table 22 (see FIG. 1 ) to rotate synchronously with the workpiece W. Figure 1) is swung so as to achieve a state in which the center axis (A axis) of the workpiece W is tilted and twisted relative to the center axis (O axis) of the work tool 40. Thereafter, while maintaining the tilt angle of the rotary table 22, the gear machining device 100 moves the work tool 40 relatively in the A-axis direction while the work tool 40 rotates synchronously with the workpiece W. At this time, a relative speed difference is generated between the workpiece W and the work tool 40, and the inner peripheral surface of the workpiece W is cut out in the portion in contact with one of the cutters 43.

[0035] Back to Figure 1 , the gear machining device 100 will be described. The gear machining device 100 includes a tool magazine 50 and a tool changing device 60. The tool magazine 50 accommodates a plurality of working tools 40. Figure 1 In order to simplify the drawing, only two tools 40 are shown. A flat support plate 13 is fixed to the top surface of the tool 10, and a tool magazine 50 is rotatably arranged on the support plate 13.

[0036] The tool changing device 60 changes the working tool 40 mounted on the rotating spindle 33 by means of another tool 40 accommodated in the tool magazine 50. The tool changing device 60 is placed between the tool magazine 50 and the tool holding device 30 in the X-axis direction.

[0037] The tool changing device 60 mainly includes a device main unit 61, a changing arm 62, an arm motor 63, a frame portion 64, a door 65, a moving member 66, and a tool holding portion 67. The device main unit 61 is disposed on the bed 10. The changing arm 62 is rotatably disposed on the device main unit 61 around an axis parallel to the Z axis. Hook-shaped gripping portions 62a (see FIG. 6A ) capable of gripping the tool holder 45 are formed at both longitudinal ends of the changing arm 62. Figure 5A ) The arm motor 63 is a motor for generating a driving force for rotating the replacement arm 62 .

[0038] The frame portion 64 is placed at a position closer to the column 31 than the support plate 13 in the X-axis direction and is placed between the tool magazine 50 and the tool holding device 30. In the frame portion 64, an opening portion 64a is formed at a position opposite to the replacement arm 62 in the X-axis direction. The opening portion 64a is arranged between the column 31 and the device main unit 61 in the X-axis direction. A door 65 is provided on the frame portion 64 to open and close the opening portion 64a.

[0039] A spring not shown is provided in the frame portion 64. When the door 65 is tightened under the force of the spring, the opening portion 64a is opened. An actuator (not shown) coupled to the door 65 is provided in the frame portion 64. When the actuator is driven and the door 65 is unfolded against the force of the spring, the opening portion 64a is closed.

[0040] The moving member 66 is provided on the side of the support plate 13 opposite to the device main unit 61. In addition, a screw feed mechanism not shown is provided on the surface of the support plate 13 opposite to the surface on which the tool magazine 50 is mounted. The moving member 66 is provided so that the member can be relatively moved in the X-axis direction relative to the support plate 13 by the screw feed mechanism. The moving member 66 is formed integrally with the frame portion 64, and the device main unit 61 is connected to the frame portion 64 by a bracket 68. That is, the device main unit 61 and the frame portion 64 are arranged so as to be able to move integrally in the X-axis direction with the movement of the moving member 66.

[0041] The tool holding portion 67 is provided on the device main unit 61 and is movable integrally with the device main unit 61. The tool holding portion 67 holds one of the working tools 40 to be replaced by another tool 40 mounted on the rotating spindle 33. An actuator (not shown) is provided on the device main unit 61, and the tool holding portion 67 holds the working tool 40 taken out from the tool magazine 50 by the actuator.

[0042] The tool changing device 60 further includes a detection portion arm 69 which holds a detection portion 81 (see Figure 5A ). The detection section arm 69 is fixed to the arm motor 63 at a position farther from the apparatus main unit 61 than the replacement arm 62. The detection section arm 69 is extendable and retractable, and is telescopically driven by an actuator not shown.

[0043] like Figure 4 As shown, the gear machining device 100 further includes a tool shape storage unit 70 and a phase detection unit 80. The tool shape storage unit 70 stores at least one data related to the shape of the working tool 40. In particular, the measurement results (values ​​measured by the presetter 200) of the axial length H of the working tool 40 and the outer diameter D of the tool portion 41 measured by the presetter 200 are stored in the tool shape storage unit 70. The presetter 200 measures the distance such as the axial length H of each of the working tools 40, the distance from the edge tip of at least one of the tools 43 (the axial end of the working tool 40) to the detected portion 46. The presetter 200 can measure the helix angle of the tool 43 of the working tool 40. In this case, in the case of grinding the working tool 40, for example, the gear machining device 100 can calculate the phase angle (displacement) based on the tip position (angle) and the grinding amount.

[0044] The phase detection unit 80 detects the phase of the working tool 40 relative to the rotating spindle 33 (see Figure 1The phase detection unit 80 includes a detection unit 81 and a calculation unit 82. The detection unit 81 is a sensor for detecting the detected portion 46. The detection unit 81 is formed by a detection unit arm 69 (see Figure 1 ) is held. In the gear machining device 100, by extending the detection portion arm 69, the detection portion 81 can be brought close to the holder attachment portion 44 of the working tool 40 mounted on the rotating spindle 33. Although the detection portion 81 is a non-contact eddy current sensor in this embodiment, the detection portion may be, for example, a contact touch probe sensor.

[0045] Based on the detection result of the detection unit 81, the calculation unit 82 obtains the phase angle (displacement) of the detected portion 46 relative to the predetermined reference position of the rotation spindle 33 by calculation. The calculation unit 82 also obtains the phase angle (displacement) of the detected portion 46 relative to the predetermined reference position of the rotation spindle 33 based on the data stored in the tool shape storage unit 70 (see Figure 1 ) and obtain the tool 43 (see Figure 2A )’s tip position.

[0046] The controller 90 generally controls the gear machining device 100. The controller 90 implements, for example, the following controls: the positions of the column 31 and the saddle 32; the rotation of the rotary spindle 33, and controls related to the operation of the tool magazine 50 and the tool changing device 60; and performs sensing implemented by the detection portion 81 of the phase detection unit 80.

[0047] (3. Operation of the gear machining device 100 during replacement of the tool 40)

[0048] Next, refer to FIG. 5A to FIG. 5D , the operation performed by the gear machining device 100 when the working tools 40 are replaced with each other will be described. Figure 5A As shown, a plurality of sockets 51 are detachably mounted on the tool magazine 50 , and the working tools 40 are respectively accommodated in the sockets 51 .

[0049] Before the tool 40 is replaced by the tool changing device 60, the controller 90 rotates the tool magazine 50 to place the tool 40 to be used next at a position opposite to the tool holding portion 67. The tool changing device 60 is placed at a position that does not interfere with the column 31 when viewed from the Z-axis direction, and the changing arm 62 is held in a state where the longitudinal direction is oriented in the Y-axis direction.

[0050] At this time, the replacement arm 62 and the detection portion arm 69 are placed on the tool magazine 50 side of the frame portion 64, and the opening portion 64a is closed by the door 65. In the gear machining device 100, during gear machining, a machining area on the column 31 side and a non-machining area on the tool magazine 50 side are defined in this manner by the door 65. Therefore, in the gear machining device 100, it is possible to prevent chips, coolant, etc. attached to the working tool 40 mounted on the rotating spindle 33 from scattering toward the tool magazine 50 through the opening portion 64a, and thus it is possible to prevent chips, coolant, etc. from attaching to the detection portion 81 and the tool 49 accommodated in the tool magazine 50.

[0051] like Figure 5B As shown, the working tool 40 and the socket 51 introduced to the position opposite to the tool holding portion 67 are transferred to the tool holding portion 67 by an actuator not shown. Then, the working tool 40 transferred to the tool holding portion 67 is placed at a position where the tool can be grasped by the replacement arm 62.

[0052] Before starting to replace the working tool 40, the controller 90 moves the column 31 in a direction in which the column is separated from the workbench 21 ( Figure 1 The column 31 is retracted in the left direction in the process (in the left direction) and the column 31 is placed at a position where the column does not interfere with the tool changing device 60. When the column 31 is retracted to a position where it can avoid interfering with the tool changing device 60, the controller 90 makes the device main unit 61 face the processing area ( Figure 1 In addition, the controller 90 stops the rotation of the rotating spindle 33, moves the saddle 32, and places the working tool 40 mounted on the rotating spindle 33 at a position where it can be grasped by the replacement arm 62.

[0053] like Figure 5C As shown, the main unit 61 of the device stops at a position where the distance from the central axis O of the working tool 40 mounted on the rotating spindle 33 to the rotation axis of the replacement arm 62 is equal to the distance from the central axis O of the working tool 40 held by the tool holding portion 67 to the rotation axis of the replacement arm 62. Then, the controller 90 opens the door 65 and moves the replacement arm 62 along the rotation axis. Figure 5C The counterclockwise swing shown is 90 degrees.

[0054] Thereafter, the replacement arm 62 grasps both the working tool 40 mounted on the rotating spindle 33 and the working tool 40 held by the tool holding portion 67, and removes the working tools 40, 40 from the rotating spindle 33 and the tool holding portion 67, respectively. Figure 5CThe replacement arm 62 is swung counterclockwise in the middle of the tool holder 67 so as to move the working tool 40 removed from the tool holder 67 to the mounting position relative to the rotating spindle 33, and to move the working tool 40 removed from the rotating spindle 33 to the storage position relative to the tool holder 67. The working tools 40, 40 are respectively mounted on the rotating spindle 33 and the tool holder 67, and thereafter, the replacement arm 62 moves along the rotating spindle 33 and the tool holder 67. Figure 5C The clockwise swing shown is 90 degrees.

[0055] like Figure 5D As shown, after the replacement of the working tool 40 by the tool changing device 60 is completed, the controller 90 extends the detection portion arm 69. Then, the controller 90 places the detection portion 81 at a sensing position where the holder attachment portion 44 of the working tool 40 mounted on the rotating spindle 33 can be sensed. Thereafter, the controller 90 performs sensing by using the detection portion 81 while driving the rotating spindle 33 to rotate so as to rotate the working tool 40.

[0056] Accordingly, the calculation section 82 recognizes the position of the detected portion 46 based on the detection result performed by the detection section 81. Then, the calculation section 82 obtains the phase angle (displacement) of the detected portion 46 relative to the reference position of the rotation spindle 33 by calculation. The calculation section 82 obtains the position of the tip of the tool 43 of the working tool 40 mounted on the rotation spindle 33 by calculation based on at least one data related to the shape of the working tool 40 stored in the tool shape storage unit 70.

[0057] When the sensing performed by the detection unit 81 ends, the controller 90 retracts the detection unit arm 69 from the sensing position. In addition, the controller 90 moves the device main unit 61 toward the non-processing area ( Figure 1 The tool changer 60 is moved to the left side of the workbench 21, and the opening portion 64a is closed by the door 65. When the tool changer 60 is moved to a position where it does not interfere with the column 31 when viewed from the Z-axis direction, the controller 90 advances the column 31 to a position close to the worktable 21 and starts the cutting work.

[0058] (4. Phase detection process)

[0059] Next, refer to Figures 6 to 7B , a process of detecting the phase of the detected portion 46 by the phase detection unit 80 will be described with reference to an example. Figure 6 Referring to the flowchart shown in FIG. 1 , first, a sensing process performed by the controller 90 will be described. The sensing process is a process performed after the working tool 40 is mounted on the rotating spindle 33. In this process, the outer peripheral surface of the retainer attachment portion 44 is sensed by the detection portion 81, thereby detecting the position of the detected portion 46.

[0060] During the sensing process, Figure 6 As shown, the controller 90 first extends the detection portion arm 69 so as to place the detection portion 81 at a position where the outer peripheral surface of the holder attachment portion 44 can be subjected to a sensing process ( S1 ).

[0061] Next, the controller 90 causes the detection unit 81 to perform sensing while rotating the rotating spindle 33 in one direction at a constant speed for one revolution (S2). Then, the controller 90 causes the detection unit 81 to perform sensing while rotating the rotating spindle 33 in another direction (the opposite direction to that in the process of step S2) at a constant speed for one revolution (S3). Thereafter, the controller 90 causes the detection unit arm 69 to retract, thereby causing the detection unit 81 to retract from the sensing position and be placed in the non-processing area (S4), and then the process ends. In the sensing process, as described above, the controller 90 causes the detection unit 81 to perform sensing while rotating the working tool 40 in two directions.

[0062] Next, refer to Fig. 7A and Figure 7B , the calculation process implemented by the calculation unit 82 will be described later. Fig. 7A 3 is a graph showing a detection result when sensing is performed by the detection unit 81 while the rotation main shaft 33 is rotated in one direction during step S2 performed in the sensing process. Figure 7B 3 is a graph showing the detection result when the detection unit 81 performs the sensing while rotating the rotation main shaft 33 in the other direction during step S3 performed during the sensing process. Fig. 7A and Figure 7B In FIG. 8 , the detection result shows the sensor output value of the detection unit 81 .

[0063] When sensing is performed while rotating the rotation spindle 33, the distance between the holder attachment portion 44 and the detection portion 81 is substantially constant in a portion where the detected portion 46 and the two balancers 47 and 48 are not formed. Therefore, during the period when sensing is applied to a portion where the detected portion 46 and the two balancers 47 and 48 are not formed, the sensor output value of the detection portion 81 is substantially constant.

[0064] On the contrary, when the position sensed by the detection part 81 is transferred from one of the parts where the detected portion 46 and the balancers 47 and 48 are not formed to one of the parts where the detected portion 46 and the two balancers 47 and 48 are formed, the sensor output value of the detection part 81 decreases. Therefore, in the detection result obtained by the detection part 81, the calculation part 82 can judge that there are three periods (P, Q, R) when the sensor output value decreases during the period of performing the sensing while rotating the working tool 40 once. In other words, when the sensor output value decreases, the calculation part 82 can determine that the detected portion 46 and the balancers 47 and 48 of the retainer attachment part 44 are each at the position where the detection part 81 performs the sensing.

[0065] In addition, the width of the detected portion 46 in the circumferential direction is greater than the width of the two balancers 47, 48 in the circumferential direction. Therefore, when the detection portion 81 has no signal output, the calculation portion 82 can determine that the detected portion 46 is in the position where the sensing is implemented during the period (P) when the sensor output value decreases, and the period (P) is the longest of the three periods. In addition, the width of one of the two balancers 47, 48, that is, the balancer 47 in the circumferential direction is greater than the width of the other balancer 48 in the circumferential direction. Therefore, the calculation portion 82 can determine the positions where the two balancers 47, 48 are formed respectively.

[0066] In the case where the sensing is applied to the outer peripheral surface of the retainer attachment portion 44 by the detection portion 81 while rotating the working tool 40, the bottom surface of the detected portion 46 and the bottom surface of one balancer 47 pass through a position separated from the possible measurement range of the detection portion 81. Therefore, during the sensing of the detected portion 46 and the one balancer 47, the detection portion 81 has no sensor output. In contrast, the bottom surface of the other balancer 48 passes through the possible measurement range of the detection portion 81. Therefore, when sensing the other balancer 48, a decrease in the sensor output value can be observed, but the sensor output value does not decrease to zero. Therefore, the calculation portion 82 can recognize the position of the other balancer 48 according to the presence or absence of the sensor output value.

[0067] In the case where the rotating spindle 33 rotates faster, an error sometimes occurs between the position of the detected portion 46 known based on the signal output of the detection section 81 and the actual position of the detected portion 46. Therefore, the calculation section 82 obtains the first center position A1 and the second center position A2 of the detected portion 46 by calculation, the first center position A1 being identified by sensing performed by the detection section 81 while the rotating spindle 33 rotates once in one direction, and the second center position A2 being identified by sensing performed by the detection section 81 while the rotating spindle 33 rotates once in the other direction. Thereafter, the calculation section 82 obtains the intermediate position A (A=(A1+A2) / 2) between the first center position A1 and the second center position A2 by calculation, and sets the obtained position as the position 46 of the portion to be detected. Therefore, the phase detection unit 80 can correctly detect the position of the detected portion 46.

[0068] In the phase detection unit 80, when the phase of the working tool 40 is to be determined, as described above, the detected portion 46 provided in the holder attachment portion 44 is detected by the detection section 81. Then, the calculation section 82 calculates the phase angle (displacement) of the detected portion 46 relative to the reference position of the rotating spindle 33 based on the detection result performed by the detection section 81, and determines the phase of the working tool 40. That is, the phase detection unit 80 determines the phase of the working tool 40 based on the position of the detected portion 46 whose shape does not change due to regrinding, and therefore, even in the case where the tool 43 is regrinded, it is not necessary to know the shape of the tool 43. Therefore, in the machine tool 1, the period required to determine the phase of the working tool 40 relative to the rotating spindle 33 can be shortened.

[0069] In addition, the detected portion 46 is a recessed portion recessed radially inward from the outer peripheral surface of the holder attachment portion 44. Therefore, the calculation portion 82 can easily know the change in the sensor output value in the detection result obtained by the detection portion 81, and thus can reliably determine the position of the detected portion 46.

[0070] Furthermore, in the machine tool 1, the axial length H of the working tool 40 and the outer diameter D of the tool portion 41 are measured by the presetter 200. Therefore, even in the case of regrinding the tool 43, the axial length H of the working tool 40 and the outer diameter D of the tool portion 41 can be correctly measured. On the other hand, instead of measuring the shape of the tool 43 using the presetter 200, the machine tool 1 obtains the phase angle (displacement) of the detected portion 46 relative to the reference position of the rotating spindle 33 by calculation using the phase detection unit 80. In the machine tool 1, in this case, the time required to determine the phase of the working tool 40 relative to the rotating spindle 33 can be shortened compared to the case where the tool portion of the tool 43 is identified by the presetter 200 or the like and the phase of the working tool 40 is determined based on the edge position of the identified tool 43.

[0071] When the distance from the detected portion 46 to the edge of the cutter 43 is measured as the axial length H of the working tool 40 , the presetter 200 can correctly measure the axial length H of the working tool 40 .

[0072] The tool holder 45 is provided to be separated from the holder attachment portion 44 formed integrally with the cutter portion 41. When the working tool 40 is measured by the presetter 200 in a state where the tool holder 45 is detached from the holder attachment portion 44, the measurement by the presetter can be efficiently performed at a level corresponding to the reduced size of the measurement object.

[0073] (5. Others)

[0074] Although the present disclosure has been described with reference to the embodiment, the present disclosure is not limited to the embodiment, and it can be easily inferred that various modifications or improvements can be made to the embodiment without departing from the purpose of the present disclosure. For example, although an embodiment has been described in which the detected portion 46 is a recessed portion that is recessed radially inward from the outer peripheral surface of the retainer attachment portion 44, the detected portion 46 may be a convex portion that protrudes radially outward from the outer peripheral surface of the retainer attachment portion 44. In this case as well, the calculation section 82 can easily know the change in the sensor output value in the detection result obtained by the detection section 81, and thus can reliably determine the position of the detected portion 46.

[0075] Although an embodiment has been described in which the detected portion 46 is formed on the outer peripheral surface of the holder attachment portion 44, the detected portion 46 may be formed on the outer peripheral surface of the tool holder 45. Although an embodiment has been described in which the tool holder 45 is formed separately from the cutter portion 41 and the holder attachment portion 44 and is detachably mounted on the holder attachment portion 44, the present disclosure is not limited thereto, and the tool holder 45 may be formed integrally with the holder attachment portion 44.

[0076] Although an embodiment has been described in which the detection portion 81 is held by the detection portion arm 69 provided on the device main unit 61 of the tool changing device 60, the present disclosure is not limited thereto. For example, the detection portion 81 may be fixed to the column 31, the saddle 32, etc. of the tool holding device 30. In this case, the detection portion 81 is able to move integrally with the column 31. Therefore, in the gear processing device 100, after a new working tool 40 is mounted on the rotating spindle 33 and while the column 31 is subsequently moved from the tool changing position to the processing position, the detection portion 81 is able to sense the retainer attachment portion 44. Therefore, in the gear processing device 100, the time required from the completion of the replacement of the working tool 40 to the start of processing the workpiece W can be shortened.

[0077] Although an embodiment has been described in which the detected portion 46 is formed so that the width of the portion is larger than the widths of the two balancers 47, 48 in the circumferential direction, the detected portion 46 is required to have at least a shape different from that of the balancer, and this enables the calculation section 82 to recognize the position based on the detection result obtained by the detection section 81. For example, the detected portion 46 may be formed so that the width of the portion is smaller than that of the balancer in the circumferential direction, or the portion is different from the balancer in depth.

[0078] Although an embodiment in which the balancers 47, 48 are formed in the retainer attachment portion 44 has been described, the balancers 47, 48 may be omitted. In this case, the shape of the retainer portion 42 of the working tool 40 can be simplified. In this case, when the retainer attachment portion 44 is sensed while rotating the rotating spindle 33, it is not always necessary for the controller 90 to rotate the rotating spindle 33. In the case where a recess is formed in the retainer attachment portion 44 to which the sensing is applied, when the rotating spindle 33 rotates in one direction, that is, when the position of the recess can be identified (when it is confirmed that the sensor output value drops or the like), the rotation of the rotating spindle 33 in one direction can be stopped. Therefore, the controller 90 can shorten the time required to detect the phase angle of the working tool 40 relative to the rotating spindle 33.

[0079] Although an embodiment has been described in which the calculation section 82 identifies the position of the detected portion 46 based on the detection results generated by the detection section 81 performing sensing while the working tool 40 rotates in one direction and by the detection section 81 performing sensing while the working tool 40 rotates in another direction, the present disclosure is not limited thereto. That is, the calculation section 82 may identify the position of the detected portion 46 based only on the detection results of the sensing performed while rotating the working tool 40 in one direction or the other direction. Therefore, the controller 90 can shorten the time required to determine the phase angle of the working tool 40 relative to the rotating spindle 33.

[0080] Reference numerals list

[0081] 1: Machine tools

[0082] 20: Workpiece holder

[0083] 30: Tool holding device

[0084] 31: column

[0085] 33: Rotating spindle

[0086] 40: Work Tools

[0087] 41: Tool part

[0088] 42: Retainer part

[0089] 43: Knife

[0090] 44: Retainer attachment part

[0091] 45: Tool holder

[0092] 46: Detected part

[0093] 60: Tool changing device

[0094] 61: Device main unit

[0095] 62: Replacement arm

[0096] 64a: Opening

[0097] 65: Door

[0098] 69: Detection arm

[0099] 70: Tool shape storage unit

[0100] 80: Phase detection unit

[0101] 81: Inspection Department

[0102] 82: Computing Department

[0103] 90: Controller

[0104] 100: Gear processing device

[0105] 200: Presetter

[0106] D: outer diameter of tool part

[0107] H: Axial length of the working tool

[0108] O: Center axis of the working tool

[0109] W: Workpiece

Claims

1. A machine tool for producing internal or external teeth on a cylindrical workpiece, the machine tool comprising: a workpiece holder configured to rotatably hold the workpiece; a column arranged to be relatively movable relative to the workpiece holder; a rotating spindle, the rotating spindle being arranged to be rotatable relative to the column; a working tool held by the rotating spindle; as well as a phase detection unit configured to detect a phase of the working tool relative to the rotating spindle, Wherein, the working tool comprises: a tool portion, the tool portion having a plurality of tools for cutting the workpiece; a holder portion, the holder portion being arranged to be rotatable integrally with the cutter portion and being detachably mounted on the rotating spindle; and a detected portion formed on the holder portion, and Wherein, the phase detection unit comprises: a detection unit configured to detect the detected portion; and a calculation section configured to calculate a phase angle of the detected portion relative to a reference position of the rotation main axis based on a result detected by the detection section, The machine tool also includes: a tool shape storage unit configured to store at least one data related to the shape of the working tool; and a presetter configured to measure an axial length of the work tool and an outer diameter of the tool portion, wherein the tool shape storage unit stores the values ​​measured by the presetter, The presetter measures the distance from the detected portion to the tip of the edge of at least one of the tools, and the distance is measured as the axial length of the working tool.

2. A machine tool for producing internal or external teeth on a cylindrical workpiece by scraping, the machine tool comprising: a workpiece holder configured to rotatably hold the workpiece; a column arranged to be relatively movable relative to the workpiece holder; a rotating spindle, the rotating spindle being arranged to be rotatable relative to the column; a working tool held by the rotating spindle; as well as a phase detection unit configured to detect a phase of the working tool relative to the rotating spindle, Wherein, the working tool comprises: A tool portion, the tool portion having a plurality of tools for cutting the workpiece, and using the end faces of the tools as rake angles; a holder portion, the holder portion being arranged to be rotatable integrally with the cutter portion and being detachably mounted on the rotating spindle; and a detected portion formed on the holder portion, and Wherein, the phase detection unit comprises: a detection unit configured to detect the detected portion; and a calculation section configured to calculate a phase angle of the detected portion relative to a reference position of the rotating spindle based on a result detected by the detection section, and detect a phase of the working tool based on the calculation result, The retainer portion comprises: a holder attachment portion integrally formed with the cutter portion; and a tool holder formed separately from the holder attachment portion and detachably mounted on the rotating spindle, wherein the detected portion is formed on the holder attaching portion.

3. A machine tool for producing internal or external teeth on a cylindrical workpiece by scraping, the machine tool comprising: a workpiece holder configured to rotatably hold the workpiece; a column arranged to be relatively movable relative to the workpiece holder; a rotating spindle, the rotating spindle being arranged to be rotatable relative to the column; a working tool held by the rotating spindle; as well as a phase detection unit configured to detect a phase of the working tool relative to the rotating spindle, Wherein, the working tool comprises: A tool portion, the tool portion having a plurality of tools for cutting the workpiece, and using the end faces of the tools as rake angles; a holder portion, the holder portion being arranged to be rotatable integrally with the cutter portion and being detachably mounted on the rotating spindle; and a detected portion formed on the holder portion, and Wherein, the phase detection unit comprises: a detection unit configured to detect the detected portion; and a calculation section configured to calculate a phase angle of the detected portion relative to a reference position of the rotating spindle based on a result detected by the detection section, and detect a phase of the working tool based on the calculation result, The machine tool further comprises a controller configured to implement control related to the rotating spindle and the phase detection unit, and wherein, when the phase of the working tool relative to the rotating spindle is detected, the detecting portion detects the detected portion by controlling the working tool mounted on the rotating spindle to rotate in one direction, and Subsequently, the detection unit detects the detected portion again by controlling the working tool to rotate in another direction.

4. The machine tool according to any one of claims 1 to 3, wherein: The detected portion has a concave portion formed to be recessed inwardly from an outer peripheral surface of the holder portion in a radial direction of the working tool.

5. The machine tool according to any one of claims 1 to 3, wherein: The detected portion has a convex portion formed to protrude outward from an outer peripheral surface of the holder portion in a radial direction of the working tool.

6. The machine tool according to any one of claims 1 to 3, wherein: The detection portion is provided on the column.

7. The machine tool according to claim 4, wherein: The detection portion is provided on the column.

8. The machine tool according to claim 5, wherein: The detection portion is provided on the column.

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