Machine tool

Abstract

The purpose of the present invention is to provide a machine tool for which it is possible to set a parameter corresponding to inertia of a tool rest as a parameter for controlling a drive source.　A machine tool according to the present disclosure comprises: a drive source; a tool rest to which a plurality of tools can be attached; a cam mechanism that rotates the tool rest on the basis of the drive force of the drive source; and a control device that controls the drive source and indexes the tools of the tool rest to predetermined index positions. The control device executes a test operation for rotating the tool rest by controlling the drive source, and sets a parameter for controlling the drive source on the basis of a value related to the inertia of the tool rest estimated from the drive torque of the drive source in the test operation.

Description

machine tools

[0001] The present disclosure relates to a machine tool that rotates a tool post using a cam mechanism.

[0002] Conventionally, in machine tools equipped with a tool post, a tool used for machining a workpiece is switched by rotating the tool post to which multiple tools are attached. Patent Document 1 below describes a machine tool equipped with a tool post to which a rotating tool and a fixed tool are attached. The machine tool in Patent Document 1 includes an indexing member that rotates the tool post, a roller gear cam that meshes with a roller provided on the outer circumferential surface of the indexing member, and a reduction mechanism that rotates the roller gear cam.

[0003] Japanese Patent Application Laid-Open No. 2002-086302

[0004] In machine tools that rotate a tool post using a cam mechanism, such as the machine tool disclosed in Patent Document 1, it is necessary to set appropriate values ​​for parameters such as the rotation speed of the tool post and the gain of the motor. For example, the faster the rotation speed, the shorter the tool indexing time. However, the weight of the tool post varies depending on the tool attached, and if the tool post has a large inertia, rotating it at high speed can cause abnormal noise.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a machine tool that can set a parameter corresponding to the inertia of the tool post as a parameter for controlling a drive source.

[0006] In order to solve the above problems, this specification discloses a machine tool comprising a drive source, a tool post to which a plurality of tools can be attached, a cam mechanism that rotates the tool post based on the driving force of the drive source, and a control device that controls the drive source and indexes the tool in the tool post to a predetermined index position, wherein the control device controls the drive source to perform a test operation that rotates the tool post, and sets parameters that control the drive source based on a value related to the inertia of the tool post that is estimated from the driving torque of the drive source during the test operation.

[0007] According to the machine tool of the present disclosure, the control device executes a test operation and sets parameters for controlling the drive source based on a value relating to the inertia of the tool post estimated from the drive torque of the drive source. This allows the machine tool to execute the test operation and automatically set parameters according to the inertia of the tool post.

[0008] 1 is a front view of a machine tool according to the present embodiment. A block diagram of the machine tool. A perspective view of a first processing device, a second processing device, and a bed. A front view of a Y-axis drive device, showing a partial cross section and an internal structure. A perspective view of a roller gear cam and an indexing member. A plan view showing a state in which a cam groove is developed in a plane. A schematic view showing a roller gear cam and an indexing member during indexing. A schematic view showing a roller gear cam and an indexing member after indexing. A diagram showing the relationship between the rotation angle of an input shaft and the rotation angle of an output shaft. A diagram showing an adjustment screen. A diagram showing correspondence data. A graph showing the drive torque when the first tool post is rotated with weights of different weights attached.

[0009] A machine tool 10, which is one embodiment of a machine tool according to the present disclosure, will be described below with reference to the drawings. Fig. 1 shows a front view of the machine tool 10 of this embodiment. Fig. 2 shows a block diagram of the machine tool 10. Fig. 3 shows a perspective view of a first machining device 11, a second machining device 12, and a bed 18 provided on the machine tool 10. In the following description, the direction viewed from the front of the machine tool 10 as shown in Fig. 1 is used as a reference, and the machine width direction of the machine tool 10 will be referred to as the left-right direction, a direction parallel to the installation surface 7 of the machine tool 10 and perpendicular to the left-right direction will be referred to as the front-rear direction, and a direction perpendicular to the left-right direction and the front-rear direction will be referred to as the up-down direction.

[0010] As shown in FIGS. 1 to 3 , the machine tool 10 includes a first machining device 11, a second machining device 12, a loader 13, an operation panel 15, an opening / closing sensor 16, a control device 17, a bed 18, and the like. The first and second machining devices 11 and 12 are disposed in a machining chamber 6 of the machine tool 10. The first and second machining devices 11 and 12 are devices for machining a workpiece (not shown). A front door 19A for opening and closing the machining chamber 6 is provided in front of an equipment cover 19 of the machine tool 10. A user accesses the machining chamber 6 by opening the front door 19A and performs operations such as replacing cutting tools for the first and second machining devices 11 and 12. The opening / closing sensor 16 is a sensor for detecting whether the front door 19A is open or closed, and outputs a detection signal to the control device 17 at a different signal level depending on whether the front door 19A is open or closed. The control device 17 can detect whether the front door 19A is open or closed based on the detection signal from the opening / closing sensor 16.

[0011] The loader 13 is, for example, a gantry-type workpiece transport device that is provided on top of the machine tool 10 and slides a head (not shown) that grips the workpiece in left-right, up-down, and front-rear directions to transfer the workpiece between each device. The operation panel 15 is a user interface and includes a touch panel 15A, operation switches 15B, etc. Note that the configuration of the user interface provided in the machine tool 10 is not limited to the configuration described above, and may include, for example, a liquid crystal panel and operation switches, without the touch panel 15A.

[0012] (Regarding the First and Second Machining Devices 11, 12) As shown in FIGS. 2 and 3 , the first and second machining devices 11, 12 are placed on a bed 18 and arranged side by side in the left-right direction. The first and second machining devices 11, 12 are so-called parallel two-axis lathes whose main axis direction (Z-axis direction) is the front-to-rear direction. The first machining device 11 and the second machining device 12 are configured symmetrically in the left-right direction. For this reason, the following description will mainly focus on the first machining device 11, and description of the second machining device 12 will be omitted as appropriate. Note that the configuration of the machine tool 10 shown in FIGS. 1 to 3 is merely an example. For example, the first and second machining devices 11, 12 may be opposing two-axis lathes whose main axes face each other in the left-right direction. The machine tool 10 may also be configured to include only one machining device (turret).

[0013] The first processing device 11 includes a first spindle device 21, a first turret device 22, a first X-axis slide device 24, and a first Z-axis slide device 25. The first spindle device 21 is provided to the rear and right side of the first turret device 22. A chuck mechanism (not shown) for gripping a workpiece can be attached to the front surface of the first spindle device 21. The first spindle device 21 grips the workpiece with the chuck mechanism and drives a first spindle motor 21A (see FIG. 2) based on the control of the control device 17 to rotate the workpiece.

[0014] The first Z-axis sliding device 25 is disposed on the bed 18 and includes, for example, a ball screw mechanism, and drives a first Z-axis motor 25A (see FIG. 2) under the control of the control device 17 to move the first X-axis sliding device 24 in a direction parallel to the front-rear direction. The first X-axis sliding device 24 also includes a ball screw mechanism, and drives a first X-axis motor 24A (see FIG. 2) under the control of the control device 17 to move the first turret device 22 in a direction parallel to the left-right direction. Thus, the control device 17 controls the first X-axis sliding device 24 and the first Z-axis sliding device 25 to slide the first turret device 22 in the left-right direction and the front-rear direction.

[0015] The first turret device 22 includes a first turret motor 22A (see FIG. 2 ), a first tool rest 22B to which multiple cutting tools 73 can be attached, and a Y-axis encoder 22C (see FIG. 2 ) that outputs encoder information such as the rotational position of the first turret motor 22A. The first turret motor 22A is, for example, a servo motor. The first turret motor 22A is not limited to a servo motor and may be another type of motor, such as a stepping motor. The same applies to the first spindle motor 21A, the first X-axis motor 24A, and the first Z-axis motor 25A. The first turret motor 22A is an example of a drive source according to the present disclosure. The drive source according to the present disclosure is not limited to a motor, but may also be a fluid pressure cylinder, such as an air cylinder or a hydraulic cylinder, or a drive source using electromagnetic induction, such as a linear motor. Similarly to the first processing device 11, the second processing device 12 includes a second spindle device 31 (second spindle motor 31A), a second turret device 32 (second turret motor 32A, Y-axis encoder 32C), a second X-axis slide device 34 (second X-axis motor 34A), and a second Z-axis slide device 35 (second Z-axis motor 35A) (see FIG. 2).

[0016] The control device 17 performs feedback control to control the rotational speed, rotational direction, acceleration, etc. of the first turret motor 22A based on encoder information (such as rotational position information) from the Y-axis encoder 22C. The first tool rest 22B rotates in a swing direction 77 around a rotation axis 75 parallel to the front-to-rear direction based on the rotation of the first turret motor 22A. The first turret unit 22 drives the first turret motor 22A based on the control of the control device 17 and indexes an arbitrary cutting tool 73 from among the multiple cutting tools 73 attached to the first tool rest 22B to an index position 79. This index position 79 is a swing position at which the cutting tool 73 used to machine the workpiece gripped by the first spindle unit 21 is indexed. The first turret unit 22 performs machining on the workpiece gripped by the first spindle unit 21 using the cutting tool 73 indexed to the index position 79. Similarly, the second turret unit 32 drives the second turret motor 32A to index the cutting tool 73 on the second tool post 32B. Note that the first and second turret units 22, 32 may each use the first and second turret motors 22A, 32A as a drive source for rotating a rotary tool (such as an end mill) attached to the first and second tool posts 22B, 32B.

[0017] The first tool rest 22B has a predetermined thickness in the front-to-rear direction and, for example, forms a substantially regular decagon in a front view. Ten holders 81 are provided on each side (position). Each of the ten holders 81 has a female-threaded screw hole formed therein, and a holding member 82 is attached by threading a fastening member (not shown) such as a bolt into the screw hole. The holding member 82 is a member that holds cutting tools 73. The cutting tools 73 are an example of a tool of the present disclosure, such as a turning tool 73A with a tip at the cutting edge, or a rotary tool 73B such as an end mill or drill. Therefore, the first tool rest 22B can mount a maximum of ten cutting tools 73. Similarly, the second tool rest 32B can mount a maximum of ten cutting tools 73. Note that FIG. 3 illustrates a state in which some of the cutting tools 73 that can be attached to the first and second tool rests 22B and 32B are attached. The number of cutting tools 73 that can be attached to the first and second tool rests 22B, 32B is not limited to 10, and may be any other multiple number. Furthermore, the tools disclosed herein are not limited to cutting tools 73, and may be other tools that are attached to the first and second tool rests 22B, 32B and used, such as pushers that push the workpieces held by the first and second spindle units 21, 31 to adjust their seating positions.

[0018] 2, the control device 17 includes a numerical control device 41 and a PLC 43. The numerical control device 41 includes a CPU 44 and a storage device 45. The storage device 45 includes, for example, RAM, ROM, flash memory, and HDD. An NC program 46, a control program 48, and corresponding data 49 are stored in the storage device 45. The storage device 45 is not limited to the above-described devices, and may include an SSD instead of an HDD, or may be an external storage device such as a USB memory. The storage device 45 may also be a storage medium such as a DVD-RAM, or a combination of these.

[0019] The machine tool 10 also includes a control device 17 and a plurality of drive circuits 20 that connect each of the above-mentioned devices (first and second machining devices 12, loader 13, operation panel 15, and open / close sensor 16). The numerical control device 41 can control each device via the drive circuits 20 by executing an NC program 46 stored in a storage device 45 using a CPU 44. The drive circuit 20 is, for example, a driver circuit (servo amplifier). The PLC 43 is a programmable logic controller. The PLC 43 executes, for example, a ladder program and performs sequence processing of various signals using the ladder circuit. The PLC 43 is connected to the numerical control device 41 via a communication bus 47 and performs signal input / output between the numerical control device 41 and the PLC 43.

[0020] The control program 48 also includes a program for executing a test operation, which will be described later, and a program for controlling the pendant panel 15. The numerical control device 41 executes the control program 48 with the CPU 44 to execute the test operation and determine parameters. The numerical control device 41 also executes the control program 48 with the CPU 44 to change the display content of the touch panel 15A and perform input processing based on the screen displayed on the touch panel 15A. The correspondence data 49 is data used to determine parameters from the results of the test operation. Details of the test operation and the correspondence data 49 will be described later. The storage device that stores the control program 48 and the correspondence data 49 is not limited to the storage device 45, and may be another storage device such as a server or network storage.

[0021] In the following description, the control of each device by the control device 17 executing programs such as the NC program 46 and the control program 48 may be described simply by the device name. For example, "the control device 17 controls the first turret motor 22A" means "the control device 17 executes the NC program 46 in the CPU 44 and controls the first turret motor 22A based on the NC program 46."

[0022] The control device 17 controls each device using the above-described configuration to perform machining on the workpiece. For example, the control device 17 transfers the workpiece received by the loader 13 from the previous process device to the first spindle device 21 of the first processing device 11. The first spindle device 21 rotates the first spindle motor 21A under the control of the control device 17 to rotate the gripped workpiece. The control device 17 also controls the first turret motor 22A to rotate the first tool rest 22B and appropriately index the desired cutting tool 73 to the index position 79. The control device 17 also controls the first X-axis motor 24A to appropriately change the position of the first tool rest 22B in the left-right direction. The control device 17 also controls the first Z-axis motor 25A to appropriately change the position of the first tool rest 22B in the front-rear direction. As a result, the control device 17 changes the left-right and front-rear position of the cutting tool 73 indexed to the index position 79, and the workpiece can be machined into a desired shape by the cutting tool 73. The control device 17 also controls the second processing device 12 in the same way, and performs processing on the workpiece machined by the first processing device 11 and the workpiece carried in by the loader 13.

[0023] (Y-Axis Drive Unit) As described above, the control device 17 controls the first turret motor 22A to perform indexing of the cutting tool 73. Figure 4 shows a front view of the Y-axis drive unit 91 provided in the first turret unit 22, partially showing a cross section and the internal structure. The Y-axis drive unit of the second turret unit 32 has a similar configuration, and therefore its description will be omitted.

[0024] The Y-axis drive unit 91 is a unit that rotates the first tool rest 22B in the rotation direction 77. As shown in FIG. 4 , the Y-axis drive unit 91 includes a pulley 93 and a cam mechanism 92 in addition to the first turret motor 22A described above, and these components are attached to a device case 99. The cam mechanism 92 includes an input shaft 95, an output shaft 97, a roller gear cam 107, and an indexing member 115. A belt 103 is wound around the pulley 93 and a motor output shaft 101, which is the output shaft of the first turret motor 22A. Therefore, the pulley 93 rotates in conjunction with the rotation of the first turret motor 22A. The pulley 93 is attached to one end (the left end in FIG. 4 ) of the input shaft 95. Therefore, the input shaft 95 is connected to the first turret motor 22A via the belt 103, and the rotational driving force of the first turret motor 22A is transmitted via the motor output shaft 101, the belt 103, and the pulley 93. Note that the method for transmitting the output of the first turret motor 22A to the input shaft 95 is not limited to the method using the belt 103, and other transmission mechanisms, for example, methods using gears, may also be used.

[0025] The input shaft 95 is held in the device case 99 via a plurality of bearing members 105 and is rotatably attached to the device case 99. The bearing members 105 are, for example, ball bearings. A roller gear cam 107 of the cam mechanism 92 is attached to the input shaft 95. The roller gear cam 107 is, for example, a substantially cylindrical member (see FIG. 5 ), into which the input shaft 95 is inserted and which rotates coaxially with the input shaft 95 as the input shaft 95 rotates. A screw-shaped (or helical) cam rib 111 is formed on the outer circumferential surface 107A of the roller gear cam 107. The cam rib 111 protrudes outward from the outer circumferential surface 107A of the cylindrical roller gear cam 107 in the radial direction (a direction perpendicular to the rotation axis of the input shaft 95), has a predetermined height, and is a member having a predetermined thickness in a direction parallel to the rotation axis of the input shaft 95 (the left-right direction in FIG. 4 ). The cam rib 111 is a wall-shaped member that extends along the outer peripheral surface 107A, and is formed so as to wrap around the outer peripheral surface 107A of the roller gear cam 107, forming a cam groove 113 that extends in one direction. The outer peripheral surface 107A forms the bottom of this cam groove 113.

[0026] The output shaft 97 is held by the device case 99 via a bearing member (not shown) and is rotatably attached to the device case 99. An indexing member 115 of the cam mechanism 92 is attached to the output shaft 97. The indexing member 115 rotates coaxially with the output shaft 97 as the output shaft 97 rotates. A plurality of cam followers 115A are provided on the outer peripheral surface of the indexing member 115. FIG. 5 shows a perspective view of the roller gear cam 107 and the indexing member 115. In this embodiment, the indexing member 115 is provided with, for example, ten cam followers 115A. Therefore, the number of the cam followers 115A is the same as the maximum number of cutting tools 73 (the number of holders 81) that can be attached to the first tool rest 22B. Each of the ten cam followers 115A corresponds one-to-one to each of the ten holders 81 (cutting tools 73). The number of cam followers 115A may be greater than or less than the number of cutting tools 73 (holders 81). The number of cam followers 115A provided in the indexing member 115 is changed as appropriate depending on the outer diameter of the indexing member 115, the shape of the cam groove 113, the number of cutting tools 73 that can be attached to the first tool rest 22B, etc. Also, Fig. 5 shows only the roller gear cam 107 with the shaft portion of the input shaft 95 removed.

[0027] The indexing member 115 has, for example, a thick plate shape that forms a substantially regular decagon when viewed from the axial direction of the output shaft 97. The multiple cam followers 115A are provided, for example, at equal intervals in the circumferential direction on the outer periphery of the indexing member 115 and protrude radially outward in the radial direction. The ten cam followers 115A are provided at 36-degree intervals in the circumferential direction. Each cam follower 115A has a cylindrical shape and is a roller cam attached rotatably around an axis along the radial direction of the indexing member 115. Note that the cam followers 115A may be configured to be non-rotatable, may be configured to be arranged at unequal intervals in the circumferential direction, or may have a shape other than a cylindrical shape.

[0028] The roller gear cam 107 and the indexing member 115 are disposed at a position where the cam groove 113 and the cam follower 115A mesh with each other. The roller gear cam 107 meshes any one of the cam followers 115A with the cam groove 113 and guides the cam follower 115A along the cam groove 113. The indexing member 115 rotates in accordance with the rotation of the roller gear cam 107 by moving any one of the cam followers 115A along the cam groove 113 as the roller gear cam 107 rotates. The rotation axis of the output shaft 97 (indexing member 115) is perpendicular to the rotation axis of the input shaft 95 (roller gear cam 107). Note that the rotation axis of the output shaft 97 (indexing member 115) and the rotation axis of the input shaft 95 (roller gear cam 107) may be configured to have an angle other than 90 degrees.

[0029] A portion of the output shaft 97 protrudes outside the device case 99. The first tool rest 22B is connected to the protruding portion of the output shaft 97. Therefore, the first tool rest 22B rotates in the turning direction 77 as the input shaft 95 and the output shaft 97 rotate in accordance with the rotation of the first turret motor 22A. As a result, the control device 17 can index the cutting tool 73 by controlling the rotation of the first turret motor 22A.

[0030] Fig. 6 is a plan view showing the cam groove 113 developed on a plane. Fig. 7 is a schematic diagram showing the roller gear cam 107 and the indexing member 115 during indexing. Fig. 8 is a schematic diagram showing the roller gear cam 107 and the indexing member 115 after indexing. "During indexing" here refers to a state in which the first tool rest 22B is being rotated and the cutting tool 73 to be indexed to the index position 79 is being replaced. "After indexing" refers to a state after the desired cutting tool 73 has been placed at the index position 79.

[0031] 6 , the cam groove 113 has, within the entire range of the groove, an indexing range 113A, a retention range 113B, and a pair of insertion ranges 113C. The indexing range 113A is a range in which the output shaft 97 is rotated in conjunction with the rotation of the input shaft 95 to index the cutting tool 73, and is a range in which the cam rib 111 (an example of an indexing wall of the present disclosure) contacts the cam follower 115A only from one side of the axial direction 95A of the input shaft 95. For example, the indexing range 113A is provided within a range of 280 degrees (40 degrees to 320 degrees) of the 360 ​​degrees of the rotation direction 95B.

[0032] The cam rib 111 in the indexing range 113A is inclined at a predetermined angle relative to the input shaft 95. As shown in FIG. 7 , during indexing, the cam follower 115A is pushed by the cam rib 111 from one side in the axial direction 95A and moves to one side in the axial direction 95A. This causes the indexing member 115 to rotate and index (replace) the cutting tool 73. Note that, depending on the structure, the outer side of the cam rib 111 in the stopping range 113B or the insertion range 113C (outside in the axial direction 95A) may also function as the indexing range 113A that brings the cam rib 111 into contact with the cam follower 115A only from one side in the axial direction 95A of the input shaft 95. However, in FIG. 6 , the positional relationship of each range is illustrated aligned in the rotational direction 95B to avoid cluttering the drawing. Further, the range outside the stopping range 113B and the insertion range 113C in the axial direction 95A is a range other than the stopping range 113B of the present disclosure.

[0033] FIG. 9 shows the relationship between the rotation angles of the input shaft 95 and the output shaft 97. The horizontal axis of FIG. 9 represents the rotation angle of the input shaft 95, and the vertical axis represents the rotation angle of the output shaft 97. When ten cam followers 115A are provided at equal intervals on the outer periphery of the indexing member 115, two adjacent cam followers 115A in the circumferential direction are positioned at positions rotated 36 degrees apart. The roller gear cam 107, for example, has only one stop range 113B in the circumferential direction. Therefore, by rotating the roller gear cam 107 by 360 degrees, the state in which any cam follower 115A is positioned in the stop range 113B changes to the state in which the cam follower 115A positioned adjacent to that cam follower 115A in the circumferential direction is positioned in the stop range 113B. As shown in FIG. 9, the output shaft 97 (indexing member 115) rotates 36 degrees every time the input shaft 95 (roller gear cam 107) rotates 360 degrees.

[0034] The first tool rest 22B switches from a state in which a given cutting tool 73 is positioned at the index position 79 to a state in which the cutting tool 73 positioned adjacent to that cutting tool 73 in the circumferential direction is positioned at the index position 79 every time the indexing member 115 rotates by 36 degrees. For example, in the first tool rest 22B shown in FIG. 3 , which has 10 cutting tools 73 attached thereto, the first tool rest 22B rotates by 36 degrees in the pivot direction 77 every time the indexing member 115 rotates by 36 degrees. Note that the first tool rest 22B may be coupled to the output shaft 97 via a gear mechanism including multiple gears, and the relationship between the rotation angles of the cam follower 115A and the first tool rest 22B may be changed by the gear ratio of the gear mechanism. For example, the gear ratio may be set so that when the cam follower 115A is rotated by 36 degrees, the first tool rest 22B rotates by 72 degrees (corresponding to two holders 81).

[0035] As shown in FIG. 6 , a pair of retaining walls 111A are provided in the retaining range 113B. The pair of retaining walls 111A are part of the cam rib 111, and are portions of the cam rib 111 that face each other in the axial direction 95A. The retaining range 113B (the pair of retaining walls 111A) is provided in a predetermined range in the rotational direction of the cam follower 115A, i.e., the rotational direction 95B of the input shaft 95. As shown in FIG. 9 , the cam follower 115A has the retaining range 113B in a range of, for example, 60 degrees (0 to 30 degrees and 330 to 360 degrees) out of 360 degrees in the rotational direction 95B. The inner walls 111B of the pair of retaining walls 111A that face each other in the axial direction 95A are formed, for example, parallel to each other and parallel to the rotational direction 95B. The groove width 119 of the pair of inner walls 111B is set to match the thickness (outer diameter) of the cam follower 115A.

[0036] In the stopping range 113B, for example, even if the roller gear cam 107 is rotated, the cam follower 115A is sandwiched between the pair of stopping walls 111A and does not move in the axial direction 95A, and the indexing member 115 does not rotate. In other words, the position of the cutting tool 73 in the rotation direction 77 at the index position 79 does not change. By ensuring a constant length of the stopping range 113B, even if the rotation control accuracy of a drive source such as a motor is somewhat low, rapid indexing is possible by stopping the cam follower 115A within the stopping range 113B. The cam follower 115A does not have to be completely stopped in the stopping range 113B. The inner walls 111B of the pair of stopping walls 111A may be parallel to each other and inclined with respect to the rotation direction 95B.

[0037] As shown in Figure 8, after indexing, any one of the multiple cam followers 115A is positioned in the retention range 113B and is sandwiched from both sides in the axial direction 95A by the inner walls 111B of the pair of retention walls 111A. The rotation of the indexing member 115 is restricted by sandwiching the cam follower 115A between the pair of retention walls 111A. As a result, when a load (reaction force) is applied from the workpiece to the cutting tool 73 during machining of the workpiece, the pair of retention walls 111A restricts the rotation of the indexing member 115, thereby suppressing positional deviation of the cutting tool 73 in the pivot direction 77. In other words, machining accuracy can be improved.

[0038] As shown in FIG. 6 , a pair of insertion ranges 113C are provided at both ends of the stopping range 113B in the direction along the cam groove 113, and are provided between the indexing range 113A and the stopping range 113B. The insertion range 113C is a portion where the cam follower 115A is inserted from the indexing range 113A to the stopping range 113B, or where the cam follower 115A is ejected from the stopping range 113B to the indexing range 113A. The insertion range 113C has a shape that makes it easier to insert the cam follower 115A, for example, by widening the groove width 119 of a pair of inner walls 111B facing each other in the axial direction 95A compared to the stopping range 113B. As shown in FIG. 9 , for example, the insertion range 113C is provided in a range of 20 degrees (30 to 40 degrees and 320 to 330 degrees) out of 360 degrees in the rotational direction 95B. The average value of the inclination angle of the pair of inner walls 111B with respect to the rotational direction 95B in the insertion range 113C is smaller than, for example, the average value of the inclination angle of the cam rib 111 with respect to the rotational direction 95B in the indexing range 113A. In other words, when the input shaft 95 is rotated by the same rotation angle, the amount of movement of the cam follower 115A in the axial direction 95A in the indexing range 113A is greater than the amount of movement of the cam follower 115A in the axial direction 95A in the insertion range 113C. Also, the size of the indexing range 113A in the rotational direction 95B (280 degrees in this embodiment) is greater than the sum of the sizes of the pair of insertion ranges 113C (20 degrees).

[0039] 4 to 9 are merely examples. For example, the roller gear cam 107 may be configured to have multiple combinations of the indexing range 113A, the stopping range 113B, and the insertion range 113C. In this case, multiple cam followers 115A can be switched and multiple cutting tools 73 can be indexed during one rotation of the roller gear cam 107. The roller gear cam 107 may also be configured without the insertion range 113C. The roller gear cam 107 may also be configured to sandwich the cam followers 115A from both sides in the axial direction 95A over the entire range of the cam groove 113.

[0040] (Regarding the Test Operation) Here, the machine tool 10 needs to adjust parameters such as the rotation speed and acceleration for rotating the first tool rest 22B in the rotation direction 77, and the gain of the first turret motor 22A. For example, the faster the rotation speed and acceleration, the faster the first tool rest 22B rotates during indexing, thereby reducing the time required to index the cutting tool 73. However, the weight of the first tool rest 22B varies depending on the type and number of cutting tools 73 attached, and the total weight M of the first tool rest 22B becomes heavier. The total weight M here refers to the sum of the weight of the first tool rest 22B and the weight of the cutting tools 73 attached to the first tool rest 22B. As the total weight M increases, the inertia of the first tool rest 22B increases, which can cause abnormal noise and vibrations when the first tool rest 22B is rotated. The inertia referred to here is, for example, the moment of inertia acting on the first tool rest 22B during rotation, and is a value proportional to the weight of the cutting tool 73 attached to the first tool rest 22B. If the machine tool 10 is continued to be used in a state where abnormal noise and vibration are generated, excessive wear and breakdowns may occur, and the usable life of the machine tool 10 may be shortened.

[0041] Furthermore, the weight of the cutting tools 73 attached to the first tool post 22B, i.e., the number and type of cutting tools 73, varies depending on the shape of the workpiece to be machined, etc. Therefore, the total weight M of the first tool post 22B may vary depending on the user and the workpiece to be machined, and the appropriate parameters will also vary. Therefore, the machine tool 10 of this embodiment automatically sets parameters for controlling the drive source of the machine tool 10 based on the results of the test operation and the correspondence data 49. In the following explanation, a case where the maximum swivel speed V, which is the maximum speed at which the tool post is rotated during the workpiece machining operation, is used as the parameter to be set will be described. To avoid complication of explanation, a case where the maximum swivel speed V of the first turret unit 22 is set will be described. The maximum swivel speed V of the second turret unit 32 can be set in the same manner as the first turret unit 22.

[0042] Fig. 10 shows an adjustment screen 121 that accepts an instruction to execute a test operation of the first turret device 22. When the control device 17 accepts a predetermined operational input on the touch panel 15A, the control device 17 executes the control program 48 in the CPU 44 and displays the adjustment screen 121 shown in Fig. 10 on the touch panel 15A. The control device 17 displays an execute button 122, an adjustment result display section 123, and a close button 124 on the adjustment screen 121.

[0043] When the control device 17 receives an operation input to the execute button 122, it executes the NC program 46 for the test operation and executes the test operation of the first turret device 22. The control device 17 displays the maximum rotation speed V set by the test operation on the display unit 123. Furthermore, when the control device 17 receives an operation input to the close button 124, it ends the display of the adjustment screen 121.

[0044] When the control device 17 starts the test operation, it controls the first turret motor 22A to rotate the first tool post 22B, detects the driving torque of the first turret motor 22A, and sets the maximum rotation speed V based on a value related to the inertia of the first tool post 22B estimated from the detected driving torque.

[0045] In the test operation, the control device 17 rotates the first tool rest 22B by one index in the clockwise rotation direction 77 (hereinafter referred to as the forward rotation direction) when the machine tool 10 is viewed from the front, and then rotates the first tool rest 22B by one index in the counterclockwise rotation direction 77 (hereinafter referred to as the reverse rotation direction). One index is the amount of rotation by which the first tool rest 22B is rotated by the amount of one adjacent cutting tool 73 in the rotation direction 77 (36 degrees in this embodiment). Therefore, in the test operation, the control device 17 rotates the first tool rest 22B in the forward direction by the amount of one cutting tool 73 (holder 81), and then rotates the first tool rest 22B in the reverse direction by the amount of one cutting tool 73.

[0046] The control device 17 detects the drive torque T of the first turret motor 22A in the above-described test operation. For example, the control device 17 detects the maximum drive torque during forward rotation and the maximum drive torque during reverse rotation, calculates the sum of the two maximum drive torques, and determines the calculated sum as the drive torque T. The control device 17 determines the maximum rotation speed V based on the determined drive torque T and the corresponding data 49.

[0047] The method for detecting the drive torque T (maximum drive torque) is not particularly limited. For example, a method can be employed in which the drive torque is estimated from the current value of the current flowing through the drive circuit 20 (servo amplifier) ​​that drives the first turret motor 22A. The control device 17 may monitor the current value, etc., of the current supplied from the drive circuit 20 to the first turret motor 22A, and detect the maximum drive torque based on the current value. Alternatively, the machine tool 10 may be provided with a torque sensor that detects the drive torque of the first turret motor 22A using a strain gauge or the like. The control device 17 may then detect the maximum drive torque based on the value detected by the torque sensor.

[0048] FIG. 11 shows an example of data set in the correspondence data 49. As shown in FIG. 11, the correspondence data 49 registers a plurality of combinations of the above-described drive torque T, total weight M of the tool post, and set maximum rotation speed V, which are associated with each other. Different values ​​of drive torque (T1 to T8, etc.) are set in the column for drive torque T. The total weight M indicates the weight of the first tool post 22B including the attached cutting tool 73. Each value in the column for drive torque T corresponds to the sum of the maximum drive torque when the cutting tool 73 corresponding to each value (M1 to M8, etc.) in the column for total weight M is attached to the first tool post 22B and rotated forward by one index, and the maximum drive torque when the cutting tool 73 is rotated reversely.

[0049] More specifically, the correspondence data 49 is set to values ​​obtained by pre-measurement using the machine tool 10. In the pre-measurement, for example, a weight representing the cutting tool 73 is attached to the first tool rest 22B, and the first tool rest 22B is rotated using a fixed test swing speed as the measurement swing speed (hereinafter referred to as the test swing speed). The drive torque T is measured under different conditions with different weights of the weight. This test swing speed is the same as the speed at which the first tool rest 22B is rotated during the test operation. Based on the results of the pre-measurement, the sum of the two maximum drive torques is set as the drive torque T in the correspondence data 49, and the weight of the first tool rest 22B including the attached weight is set as the total weight M. Note that the pre-measurement may be performed by attaching the cutting tool 73 to the first tool rest 22B without using a weight. Therefore, the drive torque T may be measured with a cutting tool 73 corresponding to each condition attached to the first tool rest 22B.

[0050] Furthermore, in the preliminary measurement, for example, the first turret motor 22A is rotated with the weights of each condition attached to the first tool rest 22B, and abnormal noise and vibration of the first tool rest 22B are checked. Reference values ​​are set for the allowable noise level (noise level) and vibration level of the first tool rest 22B during operation. These reference values ​​are values ​​that allow the machine tool 10 to continue operating at a desired availability rate or higher if the abnormal noise and vibration levels are below the reference values. In other words, the reference values ​​are values ​​that reduce the probability of occurrence of breakdowns and allow stable continuation of production. For example, the person in charge of the preliminary measurement measures the abnormal noise and vibration with the weights of each condition attached to the first tool rest 22B. With the weights of each condition attached and the abnormal noise and vibration levels below the reference values, the person in charge verifies the maximum rotation speed at which the first turret motor 22A can be rotated, and sets the verified maximum rotation speed as the maximum rotation speed V. The person in charge sets the set maximum rotation speed V in the correspondence data 49 in association with the driving torque T and total weight M of the corresponding conditions.

[0051] This makes it possible to create correspondence data 49 that allows the maximum swing speed V to be set based on the total weight M estimated from the drive torque T. As shown in Fig. 11, the correspondence data 49 sets correspondence data between the drive torque T and the maximum swing speed V for each total weight M (weight of the cutting tool 73). The control device 17 calculates the drive torque T (total value of the maximum drive torque in the forward and reverse directions) of the first turret motor 22A in the above-mentioned test operation, detects the maximum swing speed V corresponding to the calculated drive torque T from the correspondence data 49, and sets it as the maximum swing speed V.

[0052] As shown in FIG. 10 , the display unit 123 displays the maximum swing speed V before adjustment (pre-adjustment maximum speed in FIG. 10 ), the maximum swing speed V after adjustment (post-adjustment maximum speed in FIG. 10 ), and the date and time when the test operation was performed (implementation date and time in FIG. 10 ), one per line. The control device 17 performs a test operation each time the execute button 122 is operated, displays the maximum swing speed V and other execution results in the top line, and displays past execution results sequentially down the line. The control device 17 displays the value set as the maximum swing speed V before the test operation in the pre-adjustment maximum swing speed V column, and displays the maximum swing speed V determined in the test operation in the post-adjustment maximum swing speed V column. The control device 17 also displays, for example, the time when an instruction to start the test operation was received in the implementation date and time column. The control device 17 also displays past execution results in response to an operation of the scroll button 125 displayed on the display unit 123. In this way, the operator can set the maximum rotation speed V corresponding to the weight (inertia) of the cutting tool 73 attached to the first tool rest 22B simply by pressing the execute button 122.

[0053] After executing the test operation, the operator causes the machine tool 10 to perform a machining operation on the workpiece. For example, when rotating the first tool rest 22B to switch the cutting tool 73 during machining, the control device 17 sets the maximum rotation speed V set in the test operation as the target speed and executes control to rotate the first tool rest 22B. This makes it possible to rotate the first tool rest 22B at a speed faster than that corresponding to the total weight M without generating abnormal noise or the like, and to switch the cutting tool 73.

[0054] 11 , the control device 17 of this embodiment sets the maximum swing speed V from the drive torque T based on correspondence data 49 that associates the drive torque T, the total weight M of the first tool post 22B, and the maximum swing speed V. This makes it possible to uniformly set the maximum swing speed V from the drive torque T based on the preset correspondence data 49. Note that if a value that completely matches the drive torque T detected in the test operation does not exist in the column of drive torque T in the correspondence data 49, the control device 17 may set, as the parameter to be used, the maximum swing speed V associated with the drive torque T that is closest to the detected drive torque T.

[0055] Furthermore, during the test operation, the control device 17 sets the maximum swing speed V based on the total weight M estimated from the maximum drive torque when the first tool rest 22B is rotated forward and the maximum drive torque when the first tool rest 22B is rotated reversely. For example, even if the total weight M is the same, the balance (center of gravity, etc.) of the first tool rest 22B varies depending on the position and orientation of the holder 81 to which the cutting tool 73 is attached. Therefore, during the test operation in which the first tool rest 22B is rotated only in one direction (the swing direction 77), the imbalance of the first tool rest 22B may affect the estimation of the inertia, potentially reducing the accuracy of the determined maximum swing speed V. Therefore, by using drive torques for both the forward and reverse rotations, the control device 17 can offset the influence of the imbalance of the first tool rest 22B between the forward and reverse rotations. As a result, the accuracy of the determined maximum swing speed V can be improved.

[0056] Furthermore, during the test operation, the control device 17 sets the maximum swing speed V based on the total weight M estimated from the sum of the maximum drive torque when the first tool post 22B is rotated forward by one index and the maximum drive torque when it is rotated reversely by one index. This makes it possible to complete the test operation and determine the maximum swing speed V more quickly than in a method in which the first tool post 22B is rotated one full rotation during the test operation. In particular, by rotating the first tool post 22B forward and reverse by one index rather than rotating it multiple indexes, the maximum swing speed V can be determined with a shorter test operation and adverse effects of balance can be reduced.

[0057] In the above description, the parameter for controlling the drive source of the present disclosure is the maximum rotation speed V when rotating the first tool rest 22B to replace the cutting tool 73 during a workpiece machining operation. The maximum rotation speed V set in the correspondence data 49 is the speed verified when the first tool rest 22B is rotated with the cutting tool 73 (or a weight representing the cutting tool 73) attached to the first tool rest 22B so that the total weight M corresponds to the maximum rotation speed V in the correspondence data 49. For example, the person in charge of the preliminary measurement sets in the correspondence data 49 the maximum rotation speed V at which the magnitude of the abnormal noise generated by the rotation of the first tool rest 22B and the magnitude of the vibration generated in the first tool rest 22B due to the rotation are below predetermined reference values.

[0058] According to this, by detecting and setting the maximum rotation speed V corresponding to the drive torque T of the test operation from the correspondence data 49, it is possible to set the maximum rotation speed V that is less likely to generate abnormal noise or vibration and that corresponds to the total weight M. During machining operations, the first tool post 22B can be rotated faster without generating abnormal noise or vibration. Note that when setting the maximum rotation speed V from the correspondence data 49, the maximum rotation speed V may be set so that at least one of the abnormal noise and vibration is below a reference value.

[0059] (Regarding the Test Swing Speed) Next, the test swing speed, which is the swing speed in the test operation and the swing speed when the correspondence data 49 is set, will be described. FIG. 12 shows the drive torque when the first tool post 22B is rotated with weights of different weights attached. The vertical axis of FIG. 12 indicates, for example, the drive torque during forward rotation as a positive value and the drive torque during reverse rotation as a negative value. The vertical axis scale of 0, 50, 100, and 150 indicates the ratio of the drive torque to the maximum torque of the first turret motor 22A (hereinafter referred to as maximum motor torque). Therefore, a value of 100 on the vertical axis indicates a state in which the measured drive torque matches the maximum motor torque. The horizontal axis indicates time.

[0060] The graphs for weights 3 to 9 in Figure 12 show graphs in which drive torque was measured by attaching weights weighing several kilograms each to the first tool rest 22B and increasing the number of weights attached from three to nine. Furthermore, measurements for each graph were performed using a predetermined fixed value for the rotation speed. As shown in the enlarged view of Figure 12, the maximum drive torque value for each graph approaches 100% as the weight is increased. Therefore, as the weight is increased, the maximum drive torque momentarily coincides with the maximum motor torque, or the graph maintains the maximum motor torque value for a predetermined period of time and remains stuck at the maximum motor torque.

[0061] If the maximum drive torque measured using different weights always equals the maximum motor torque, it becomes difficult to estimate (classify) the weight of the weight from the maximum drive torque measured. As a result, even if such measurement result correspondence data 49 is set, it becomes difficult to estimate the total weight M including the cutting tool 73 from the maximum drive torque detected in the test operation. For example, when a cutting tool 73 having a total weight M equal to or greater than a certain upper limit is attached, the drive torque T detected in the test operation in all cases corresponds to the maximum motor torque, making it difficult to estimate the total weight M and therefore difficult to change the maximum rotation speed V according to the total weight M.

[0062] Therefore, in this embodiment, the test rotation speed used to create the correspondence data 49 is set to a speed at which the measured maximum drive torque is less than the maximum motor torque of the first turret motor 22A, or a speed at which the maximum drive torque does not remain at the maximum motor torque for a predetermined period of time or longer, regardless of which weight, assumed to be a cutting tool 73, is attached to the first tool rest 22B. Specifically, the test rotation speed is set to a speed at which the measured maximum drive torque is less than the maximum motor torque (an example of the maximum drive source torque in the present disclosure) when the first tool rest 22B is rotated with weights attached that correspond to the combination of cutting tools 73 with the heaviest total weight among the combinations of cutting tools 73 that can be attached to the first tool rest 22B.

[0063] Using this test swing speed, the maximum drive torque is measured while changing the weight (total weight M) and set as correspondence data 49. Furthermore, the maximum swing speed V for each total weight M is set to a maximum swing speed V at which abnormal noise is minimal or does not occur. This test swing speed is then used not only when creating correspondence data 49 but also as the swing speed in test operations. As a result, regardless of the combination of cutting tools 73 attached, the maximum drive torque will not be the maximum motor torque, and the total weight M (maximum swing speed V) can be uniquely determined from the drive torque T.

[0064] The test swing speed may be a speed at which the measured maximum drive torque does not stick to the maximum motor torque value for a predetermined period of time or more when the first tool rest 22B is rotated with weights corresponding to the heaviest combination of cutting tools 73 attached. For example, if the detected maximum drive torque becomes the maximum motor torque only when a weight corresponding to the heaviest total weight M among the multiple total weights M set in the correspondence data 49 is attached, then the drive torque T and the total weight M (maximum swing speed V) can be associated one-to-one. Therefore, the test swing speed may be a value that sticks to the maximum motor torque to some extent, as long as the measured maximum drive torque becomes the maximum motor torque only when the heaviest combination of cutting tools 73 is attached.

[0065] Furthermore, the test swing speed was set to a speed at which the maximum drive torque was less than the maximum motor torque when the heaviest combination of cutting tools 73 was attached, but this is not limiting. For example, the control device 17 may estimate the total weight M based on the time during which the maximum drive torque remains at the maximum motor torque during the test operation. The time during which the maximum drive torque remains at the maximum motor torque (100% in FIG. 12 ) is proportional to the total weight M (the weight of the cutting tools 73). Therefore, when the control device 17 executes the test operation and the detected maximum drive torque becomes the maximum motor torque, the control device 17 may set the maximum swing speed V based on the time during which the detected drive torque remains at the maximum motor torque (the time during which the drive torque remains at 100% in FIG. 12 ). In this case, the speed at which the maximum motor torque remains may be used as the test swing speed.

[0066] In the above description, the total weight M of the first tool post 22B including the attached cutting tools 73 is used as the value relating to the inertia of the present disclosure, but this is not limited thereto. The value relating to the inertia of the present disclosure may also be the total weight M of the cutting tools 73 attached to the first tool post 22B, i.e., the weight of only the tools excluding the tool posts. Alternatively, the value relating to the inertia of the present disclosure may also be the value of the moment of inertia acting on the first tool post 22B.

[0067] Furthermore, the above-described method of setting the maximum swing speed V is merely an example and can be modified as appropriate. For example, as shown in FIG. 11 , the value of the total weight M is set in the correspondence data 49, but the correspondence data 49 may not have a value for the total weight M. When determining the maximum swing speed V, the maximum swing speed V can be determined from the drive torque T, so the total weight M does not need to be set in the correspondence data 49. Furthermore, the control device 17 may display the total weight M estimated in the test operation on the adjustment screen 121 as reference information.

[0068] Furthermore, for example, the sum of the maximum drive torques in the forward and reverse directions is used as the drive torque T, but this is not limiting. The control device 17 may determine the maximum rotation speed V using the difference between the maximum drive torques in the forward and reverse directions. Alternatively, the control device 17 may rotate the first tool rest 22B once during the test operation and determine the maximum rotation speed V based on the maximum drive torque obtained during the one rotation. Furthermore, the control device 17 may rotate the first tool rest 22B forward and reverse a predetermined number of indexes (two or more) during the test operation and determine the maximum rotation speed V from the sum of the maximum drive torques obtained during each rotation. The number of indexes during the forward and reverse rotations may be different from each other. Furthermore, the control device 17 may rotate the first tool rest 22B forward for multiple indexes and determine the maximum rotation speed V based on the maximum drive torque during the forward rotation. Furthermore, the control device 17 may determine the maximum rotation speed V based on the average value of the drive torque, rather than the maximum drive torque, during the test operation. Therefore, the operation content of the test operation described above can be modified as appropriate.

[0069] Furthermore, in the above embodiment, the maximum rotation speed V is used as a parameter for controlling the drive source of the present disclosure, but this is not limiting. For example, the gain of a servo motor may be used as a parameter for controlling the drive source of the present disclosure. The gain of a servo motor is, for example, a value that determines the responsiveness of the servo motor, and is a parameter that determines the strength of correction (input / output gain) for zeroing the error of the detected value relative to the target value. For example, the larger the gain setting value, the better the tracking ability to the position command, but the more likely overshooting occurs. The gain value of the first turret motor 22A may be associated with the total weight M instead of the maximum rotation speed V and set in the correspondence data 49. This allows the gain of the servo motor to be changed according to the weight (inertia) of the cutting tool 73, thereby automatically adjusting the tracking ability. If the number of cutting tools 73 increases and the total weight M increases, the tracking ability in motor control may decrease. Therefore, by increasing the gain to an extent that does not cause overshooting as the total weight M increases, the tracking ability can be improved, thereby appropriately controlling the rotation of the first turret motor 22A.

[0070] Alternatively, the parameter for controlling the drive source may be the acceleration value of the rotation speed at which the first tool rest 22B is rotated. Furthermore, the parameter may be a combination of at least two of the above-described maximum rotation speed V, gain, and acceleration. The control device 17 may set two or more types of parameters based on the drive torque T in the test operation.

[0071] In the above embodiment, the maximum turning speed V is determined from the driving torque T based on the preset correspondence data 49, but this is not limiting. For example, the control device 17 may determine the maximum turning speed V from the driving torque T by an arithmetic formula using a relational expression between the driving torque and the moment of inertia (driving torque = moment of inertia * angular acceleration) or the like.

[0072] (Regarding the Rotational Speeds in the Retention Range 113B and the Indexing Range 113A) As described above, the maximum rotation speed V at which the first tool post 22B rotates is preferably as fast as possible from the viewpoint of switching the cutting tools 73, but this may result in increased noise and vibration. Furthermore, for example, when the first tool post 22B is rotated with the front door 19A open, the magnitude of the maximum rotation speed V is limited for reasons such as safety standards. For example, a standard may be established that requires that the rotation speed of the tip of the cutting tool that is longest in the radial direction among the cutting tools attached to the tool post be set to a predetermined upper limit value or less.

[0073] 6 and 9 , the rotation range of the input shaft 95 in this embodiment includes an indexing range 113A in which the output shaft 97 rotates in conjunction with the rotation of the input shaft 95 to index the cutting tool 73, and a stopping range 113B in which the indexed cutting tool 73 is stopped. The stopping range 113B is a range in which the indexing member 115 on the output side does not rotate even if the roller gear cam 107 on the input side rotates. Furthermore, the machine tool 10 defines a state in which the desired cutting tool 73 is indexed to the index position 79 when the cam follower 115A is positioned at a center position 127 (see FIG. 6 and the 0-degree position in FIG. 9 ) of the stopping range 113B in the rotation direction 95B.

[0074] Therefore, when switching from the indexed cutting tool 73 to another cutting tool 73, even if the roller gear cam 107 rotates from the 0-degree position to the 30-degree position at the start of indexing, the cam follower 115A remains within the stop range 113B and does not move in the axial direction 95A. After switching of the cutting tool 73 begins, even if the roller gear cam 107 (input shaft 95) rotates within the range of 0 to 30 degrees, the first tool rest 22B does not rotate. Similarly, even if the roller gear cam 107 rotates from the 330-degree position to the 360-degree (0-degree) position at the end of indexing, the cam follower 115A remains within the stop range 113B and does not move in the axial direction 95A. After the cam follower 115A enters the stop range 113B, even if the roller gear cam 107 (input shaft 95) rotates within the range of 330 to 360 degrees, the first tool rest 22B does not rotate. Therefore, the stopping range 113B is not subject to the above-mentioned limitations because the first tool post 22B does not rotate. Also, even if the inner wall 111B of the stopping range 113B is slightly inclined with respect to the rotation direction 95B, if the inclination angle of the inner wall 111B is smaller than the inclination angle of the cam rib 111 of the indexing range 113A, the stopping range 113B is not subject to the same limitations as the indexing range 113A.

[0075] Therefore, the control device 17 increases the rotational speed of the input shaft 95 in the stopping range 113B compared to the rotational speed of the input shaft 95 in the indexing range 113A. For example, the control device 17 increases the target rotational speed of the first turret motor 22A in the stopping range 113B compared to the target rotational speed in the indexing range 113A. This increases the rotational speed of the input shaft 95 while the cam follower 115A is in the stopping range 113B, thereby shortening the indexing time required to switch the cutting tool 73. The indexing time can be reduced while complying with the safety standards described above. Furthermore, because the first tool rest 22B does not rotate in the stopping range 113B, the indexing time can be reduced without generating abnormal noise or vibration. The control device 17 may increase the rotational speed in the stopping range 113B compared to the indexing range 113A only at the start or end of indexing.

[0076] A method for increasing the rotational speed in the stopping range 113B can be, for example, by setting the rotational speed in the NC program 46. The NC program 46, which is executed during machining or with the front door 19A open, may be set to increase the rotational speed for a predetermined time from the start of indexing. Alternatively, the NC program 46 may be set to increase the rotational speed from a predetermined time before the end of indexing until the end of indexing. This predetermined time is the time required for the cam follower 115A to move from the center position 127 to the end of the stopping range 113B. Alternatively, the control device 17 may detect the rotational angles of the first turret motor 22A or the input shaft 95 based on encoder information from the Y-axis encoder 22C, and increase the rotational speed from the start of indexing to a predetermined rotational angle (e.g., 0 to 30 degrees in FIG. 9 ).

[0077] 6, the cam groove 113 in the indexing range 113A is inclined at a predetermined angle with respect to the rotation direction 95B of the roller gear cam 107. The inclination angle of the cam groove 113 in the indexing range 113A is larger than the inclination angle (zero degrees in this embodiment) of the cam groove 113 in the stopping range 113B. This allows the rotation speed of the input shaft 95 to be increased in the stopping range 113B, where the inclination angle is smaller, thereby shortening the indexing time.

[0078] Furthermore, the stopping range 113B is a range where a pair of stopping walls 111A are provided that sandwich the cam follower 115A from both sides in the axial direction 95A of the input shaft 95. Furthermore, the indexing range 113A is a range where a cam rib 111 (an example of an indexing wall of the present disclosure) that contacts the cam follower 115A from one side in the axial direction 95A is provided. As a result, in the stopping range 113B where the cam follower 115A is sandwiched between the pair of stopping walls 111A, the rotational speed of the input shaft 95 can be increased, thereby shortening the indexing time.

[0079] Furthermore, the rotation range of the input shaft 95 in this embodiment includes an insertion range 113C that is located between the indexing range 113A and the dwelling range 113B and connects the two ranges. The groove width 119 of the cam groove 113 in the insertion range 113C is larger than the groove width 119 of the cam groove 113 in the dwelling range 113B. The control device 17 may also set the rotation speed of the input shaft 95 in this insertion range 113C to be faster than the rotation speed in the indexing range 113A. The insertion range 113C is a range that facilitates movement of the cam follower 115A between the indexing range 113A, where the inclination angle of the cam rib 111 (cam groove 113) is large, and the dwelling range 113B, where the inclination angle is zero. For this reason, the insertion range 113C is formed with a groove width 119 wider than that of the dwelling range 113B. The inclination angle of the cam rib 111 in the insertion range 113C is larger than the inclination angle in the stopping range 113B (zero degrees in this embodiment) and is smaller than the inclination angle in the indexing range 113A.

[0080] When the roller gear cam 107 is rotated at the same speed, the speed at which the cam follower 115A moves in the axial direction 95A within the insertion range 113C, which has a gentle slope, is slower than the speed at which it moves in the axial direction 95A within the indexing range 113A, which has a steep slope. Therefore, even if the rotational speed of the input shaft 95 in the insertion range 113C is made faster than the rotational speed of the input shaft 95 in the indexing range 113A, the rotational speed does not exceed the maximum rotational speed V. This also allows the speeds stipulated by the safety standards to be observed, and the occurrence of abnormal noise and vibration can be suppressed. Therefore, the control device 17 makes the rotational speed of the input shaft 95 in the insertion range 113C faster than the rotational speed in the indexing range 113A.

[0081] For example, the control device 17 sets the target rotation speed of the first turret motor 22A in the insertion range 113C to be faster than the target rotation speed of the first turret motor 22A in the indexing range 113A. This makes it possible to increase the rotation speed of the input shaft 95 in the insertion range 113C within a range in which the turning speed does not exceed the maximum turning speed V, thereby shortening the indexing time.

[0082] Furthermore, while the cam ribs 111 in the stopping range 113B are not inclined with respect to the rotation direction 95B, the cam ribs 111 in the insertion range 113C are inclined to some extent. Therefore, the cam follower 115A moves a certain amount in the axial direction 95A in the insertion range 113C. Therefore, the control device 17 slows the rotational speed at which the input shaft 95 rotates in the insertion range 113C compared to the rotational speed at which the input shaft 95 rotates in the stopping range 113B. By setting the rotational speed in the insertion range 113C to be equal to or lower than the rotational speed in the stopping range 113B, it is possible to prevent the swing speed from exceeding the maximum swing speed V, prevent abnormal noise, and the like.

[0083] Furthermore, the control device 17 executes the above-described control when the front door 19A is open. The machine tool 10 is equipped with an opening / closing sensor 16 that detects whether the front door 19A is open or closed. When the control device 17 detects that the front door 19A is open based on the detection signal from the opening / closing sensor 16 and rotates the first turret motor 22A, the control device 17 makes the rotational speed at which the input shaft 95 rotates in the stopping range 113B faster than the rotational speed in the indexing range 113A. This allows the above-described rotational speed control to be executed when an operator opens the front door 19A to replace the cutting tool 73, for example. This allows the indexing time to be shortened while complying with safety standards, etc.

[0084] For example, when the control device 17 rotates the first tool rest 22B while the opening / closing sensor 16 detects that the front door 19A is open, the control device 17 sets the rotational speed of the input shaft 95 (first turret motor 22A) in the indexing range 113A to a speed equivalent to several percent of the maximum rotation speed V (an example of the first ratio in the present disclosure). The control device 17 also sets the rotational speed of the input shaft 95 in the stopping range 113B to a speed equivalent to 50 to 60% of the maximum rotation speed V (an example of the second ratio in the present disclosure). In other words, the second ratio in the stopping range 113B is set to a ratio greater than the first ratio in the indexing range 113A. By setting the first ratio and the second ratio in this way, the indexing time can be shortened while complying with safety standards, etc.

[0085] The control device 17 also performs the above-described control during machining. When the opening / closing sensor 16 detects that the front door 19A is closed, the control device 17 sets the rotational speed of the input shaft 95 in the indexing range 113A to a speed corresponding to the maximum swing speed V set in the test operation. The control device 17 also sets the rotational speed of the input shaft 95 in the stopping range 113B to a speed corresponding to a speed faster than the maximum swing speed V set in the test operation. That is, the rotational speed of the first turret motor 22A in the stopping range 113B is set to be faster than the speed at which the first turret motor 22A is rotated so as to achieve the maximum swing speed V in the indexing range 113A. By rotating the first tool rest 22B in the indexing range 113A at the maximum swing speed V set in the test operation, the first tool rest 22B can be rotated at the maximum swing speed V corresponding to the total weight M while suppressing the generation of abnormal noise and vibration. Furthermore, in the stopping range 113B where the first tool rest 22B does not rotate, the indexing time can be shortened by rotating the input shaft 95 at a rotational speed faster than the rotational speed at the set maximum rotational speed V. For example, the target rotational speed of the first turret motor 22A in the stopping range 113B may be set to one or several times the target rotational speed in the indexing range 113A.

[0086] Note that the speed control according to each range described above is one example. For example, the control device 17 may execute only one of the control executed when the front door 19A is open and the control executed when the front door 19A is closed (during machining). Alternatively, the control device 17 may be configured to execute neither of the controls according to whether the front door 19A is open or closed. In this case, the control device 17 may rotate the first turret motor 22A at the same target rotation speed (corresponding to the maximum rotation speed V) in all of the indexing range 113A, the stopping range 113B, and the insertion range 113C.

[0087] Incidentally, the correspondence between the terms used in this embodiment and those used in the claims will be explained below. The front door 19A in this embodiment is an example of a door. The first and second turret motors 22A, 32A are an example of a drive source. The first and second tool rests 22B, 32B are an example of a tool rest. The cutting tool 73 is an example of a tool. The total weight M is an example of a value related to the inertia of the tool rest, and is an example of the weight of the tool rest. The cam rib 111 is an example of an indexing wall. The maximum rotation speed V is an example of a parameter for controlling the drive source.

[0088] As described above, the present embodiment provides the following advantages. The control device 17, which is one aspect of the present embodiment, controls the first turret motor 22A to index the cutting tool 73 of the first tool post 22B to a predetermined index position 79 using the Y-axis drive device 91 having the cam mechanism 92. Furthermore, when the execute button 122 in FIG. 10 is operated, the control device 17 controls the first turret motor 22A to execute a test operation that rotates the first tool post 22B. The control device 17 sets the maximum rotation speed V of the first tool post 22B (an example of a parameter for controlling the drive source) based on the total weight M of the cutting tool 73 (an example of a value related to the inertia of the tool post) estimated from the drive torque T of the first turret motor 22A during the test operation. This allows the operator to automatically set the maximum rotation speed V according to the weight of the cutting tool 73 attached to the first tool post 22B by causing the machine tool 10 to execute the test operation. This can suppress the generation of abnormal noise and vibrations during rotation of the first tool rest 22B, thereby reducing the probability of malfunction.

[0089] The present disclosure is not limited to the above-described embodiments, and various improvements and modifications are possible without departing from the spirit and scope of the present disclosure. For example, while the machine tool 10 in the above-described embodiments is configured to perform test operations, it may be configured not to perform such operations. Therefore, the machine tool of the present disclosure may be configured not to set parameters for controlling the drive source through test operations. The machine tool 10 may be configured to rotate the input shaft 95 at a rotational speed faster in the dwell range 113B than in the indexing range 113A. Furthermore, the maximum swivel speed V set in the correspondence data 49 is the speed at which at least one of the magnitude of abnormal noise generated by the rotation of the tool post and the magnitude of vibration generated in the tool post due to the rotation is below a predetermined reference value. However, this is not limiting. For example, the maximum swivel speed V may be the speed at which either the abnormal noise or the vibration is below a predetermined reference value.

[0090] Furthermore, in the above embodiment, the roller gear cam 107 is configured to have one stop range 113B in the cam groove 113, but may be configured to have two or more stop ranges 113B. The configurations of the first and second machining devices 11, 12 in the above embodiment are merely examples. For example, the machine tool 10 may be configured to have only one machining device, i.e., one set of a turret device and a spindle device. The first machining device 11 may have a different configuration from the second machining device 12. The machining device included in the machine tool 10 is not limited to a front-facing two-spindle lathe, but may also be a counter-facing two-spindle lathe, a horizontal lathe, or a vertical lathe. The machining device is not limited to a lathe, but may also be a machining center, a milling machine, a drill press, or another type of machining device. The machine tool 10 may also be a composite machining device equipped with multiple types of machining devices, such as a lathe and a machining center.

[0091] The scope of the present disclosure is not limited to the dependency relationships set forth in the claims. For example, this specification also discloses a technical idea in claim 5 where "the machine tool according to claim 1 or claim 2" is changed to "the machine tool according to any one of claims 1 to 4." For example, this specification also discloses a technical idea in claim 6 where "the machine tool according to claim 2" is changed to "the machine tool according to any one of claims 3 to 5 dependent on claims 2 and 1." For example, this specification also discloses a technical idea in claim 7 where "the machine tool according to claim 1 or claim 2" is changed to "the machine tool according to any one of claims 1 to 6." For example, this specification also discloses a technical idea in claim 8 where "the machine tool according to claim 1 or claim 2" is changed to "the machine tool according to any one of claims 1 to 7." For example, this specification also discloses a technical idea in claim 11 where "the machine tool according to claim 9" is changed to "the machine tool according to claim 9 or claim 10." For example, this specification also discloses a technical idea in which "the machine tool according to claim 8" in claim 12 is changed to "the machine tool according to any one of claims 8 to 11." For example, this specification also discloses a technical idea in which "the machine tool according to claim 8" in claim 14 is changed to "the machine tool according to any one of claims 8 to 13."

[0092] 6 Machining chamber, 10 Machine tool, 16 Opening / closing sensor, 17 Control device, 19A Front door (door), 22A, 32A First and second turret motors (drive sources), 22B, 32B First and second tool rests (tool rests), 49 Corresponding data, 73 Cutting tool (tool), 79 Indexing position, 92 Cam mechanism, 95 Input shaft, 95B Rotation direction, 97 Output shaft, 107 Roller gear cam, 111 Cam rib (indexing wall), 111A Retaining wall, 113 Cam groove, 113A Indexing range, 113B Retaining range, 113C Insertion range, 115 Indexing member, 115A Cam follower, 119 Groove width, T Drive torque, M Total weight (value related to the inertia of the tool rest, weight of the tool rest), V Maximum turning speed (parameter for controlling the drive source).

Claims

1. A machine tool comprising: a drive source; a tool post capable of mounting a plurality of tools; a cam mechanism that rotates the tool post based on the driving force of the drive source; and a control device that controls the drive source and indexes the tool on the tool post to a predetermined index position, wherein the control device controls the drive source to perform a test operation that rotates the tool post, and sets parameters that control the drive source based on a value related to the inertia of the tool post that is estimated from the driving torque of the drive source during the test operation.

2. The machine tool of claim 1, wherein the value relating to the inertia is the weight of the tool post including the tool attached to the tool post, and the control device sets parameters for controlling the drive source from the drive torque based on correspondence data that associates the drive torque, the weight of the tool post, and parameters for controlling the drive source.

3. A machine tool as described in claim 1 or claim 2, wherein the control device sets parameters for controlling the drive source based on a value relating to the inertia of the tool post estimated from the drive torque when the tool post is rotated forward and the drive torque when the tool post is rotated reverse during the test operation.

4. The machine tool of claim 3, wherein the control device sets parameters for controlling the drive source based on a value relating to the inertia of the tool post estimated from the sum of the drive torque when the tool post is rotated forward by a predetermined number of indexes and the drive torque when the tool post is rotated reversely by a predetermined number of indexes during the test operation.

5. A machine tool according to claim 1 or claim 2, wherein the test rotation speed at which the tool post is rotated in the test operation is a speed at which the drive torque becomes less than the maximum drive source torque of the drive source when the tool post is rotated with the combination of tools that has the heaviest total weight attached to it out of the combinations of tools that can be attached to the tool post, or a speed at which the drive torque does not stick to the value of the maximum drive source torque of the drive source for a predetermined period of time or more.

6. A machine tool as claimed in claim 2, wherein the parameter for controlling the drive source, which is set based on the value relating to the inertia, is a maximum rotation speed when rotating the tool post to change the tool during workpiece machining operations, and the corresponding data is set to the maximum rotation speed as a parameter for controlling the drive source, and the maximum rotation speed set in the corresponding data is set to a speed at which, when the tool post is rotated with the tool attached to it, at least one of the magnitude of abnormal noise generated by the rotational movement of the tool post and the magnitude of vibration generated in the tool post by the rotational movement is below a predetermined reference value, so that the maximum rotation speed becomes the weight of the tool post associated with the maximum rotation speed and the corresponding data.

7. A machine tool according to claim 1 or claim 2, wherein the drive source is a servo motor, and the parameter for controlling the drive source, which is set based on the value related to the inertia, is a gain value that determines the responsiveness of the servo motor.

8. A machine tool according to claim 1 or claim 2, wherein the cam mechanism has an input shaft to which the drive source is connected and an output shaft to which the tool post is connected, the rotation range of the input shaft including an indexing range in which the output shaft is rotated in accordance with the rotation of the input shaft to index the tool, and a parking range in which the indexed tool is parked, and the control device makes the rotational speed at which the input shaft is rotated in the parking range faster than the rotational speed at which the input shaft is rotated in the indexing range.

9. A machine tool as described in claim 8, wherein the cam mechanism comprises: a roller gear cam attached to the input shaft and rotating as the input shaft rotates; and an indexing member attached to the output shaft and having a plurality of cam followers that mesh with cam grooves of the roller gear cam; wherein the cam grooves in the indexing range are inclined at a predetermined angle with respect to the direction of rotation of the roller gear cam, and the inclination angle of the cam grooves in the indexing range is larger than the inclination angle of the cam grooves in the stationary range.

10. A machine tool as set forth in claim 9, wherein the stopping range is a range in which a pair of stopping walls are provided to sandwich the cam follower from both sides in the axial direction of the input shaft, and the indexing range is a range in which an indexing wall is provided that contacts the cam follower from one side in the axial direction of the input shaft.

11. A machine tool as described in claim 9, wherein the rotation range of the input shaft includes an insertion range that is provided between the indexing range and the dwell range and connects the two ranges, the groove width of the cam groove in the insertion range is larger than the groove width of the cam groove in the dwell range, and the control device sets the rotational speed at which the input shaft is rotated in the insertion range to a speed that is faster than the rotational speed at which the input shaft is rotated in the indexing range and slower than the rotational speed at which the input shaft is rotated in the dwell range.

12. A machine tool as described in claim 8, further comprising: a machining chamber in which a workpiece is machined by the tool; a door for opening and closing the machining chamber; and an opening / closing sensor for detecting the opening / closing of the door, wherein the control device, when rotating the tool post in a state in which the opening / closing sensor detects that the door is open, makes the rotational speed at which the input shaft rotates in the stopping range faster than the rotational speed at which the input shaft rotates in the indexing range.

13. The machine tool according to claim 12, wherein the parameter for controlling the drive source, which is set based on the value related to the inertia, is a maximum rotation speed when rotating the tool post to change the tool during a workpiece machining operation, and the control device, when rotating the tool post while the open / close sensor detects that the door is open, sets the rotation speed at which the input shaft rotates in the indexing range to a speed equivalent to a first ratio of the maximum rotation speed, and sets the rotation speed at which the input shaft rotates in the dwelling range to a speed equivalent to a second ratio of the maximum rotation speed, and the second ratio is a ratio greater than the first ratio.

14. A machine tool according to claim 8, further comprising: a machining chamber in which a workpiece is machined by the tool; a door for opening and closing the machining chamber; and an opening / closing sensor for detecting the opening and closing of the door, wherein the parameter for controlling the drive source set based on the value related to the inertia is a maximum rotation speed when rotating the tool post to change the tool in a workpiece machining operation, and wherein the control device, when it detects that the door is closed by the opening / closing sensor, sets the rotation speed at which the input shaft is rotated in the indexing range to a speed equivalent to the maximum rotation speed set in the test operation, and sets the rotation speed at which the input shaft is rotated in the dwell range to a speed equivalent to a speed higher than the maximum rotation speed set in the test operation.

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