Working machinery

Abstract

Provided is a machine tool that can set an appropriate delivery position which corresponds to the weight and length of a workpiece and at which the workpiece is transferred between a Cartesian coordinate robot and a partner device.　A machine tool comprises: a partner device capable of holding a workpiece; a Cartesian coordinate robot that includes a holding member for holding the workpiece and that transfers the workpiece, which is held by the holding member, between the Cartesian coordinate robot and the partner device; and a control device that controls the Cartesian coordinate robot. The control device executes: an acquisition process for acquiring the weight and length of the workpiece in the transfer between the Cartesian coordinate robot and the partner device; and a setting process for setting a delivery position, which is the position of the Cartesian coordinate robot in the transfer of the workpiece between the Cartesian coordinate robot and the partner device, on the basis of the weight and length of the workpiece that have been acquired in the acquisition process.

Description

[Technical Field]

[0001] The present disclosure relates to a technique for setting a transfer position where a workpiece is transferred between a Cartesian robot and a mating device. [Background technology]

[0002] Various devices for transferring workpieces have been proposed in the past. For example, Patent Document 1 below describes a vertical articulated robot that transports sheet-like workpieces. Experimental data is stored in the control box of the vertical articulated robot. This experimental data includes detection values ​​of strain gauges attached to the base ends of the arms and jaws of each axis, and the deformation amounts of each arm and jaw corresponding to the detection values ​​of each strain gauge. During workpiece transport, the control box calculates the deformation amount based on the detection values ​​input from the strain gauges and the experimental data. The control box inserts the workpiece into a magazine by driving the hand cylinder with a position correction signal that matches the calculated deformation amount. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 08-150580 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned vertical articulated robot, the amount of deformation caused by the weight of the workpiece is detected by strain gauges. For this reason, it is necessary to install strain gauges on each arm and claw, process the detection signals of the strain gauges during the workpiece transfer operation, and detect the amount of change. Then, the detection signals output from the strain gauges must be processed by the control box for each workpiece transfer operation.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a machine tool that can set an appropriate transfer position for transferring a workpiece between an orthogonal robot and a mating device according to the weight and length of the workpiece. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, this specification provides a method for controlling a Cartesian robot, the method comprising: a mating device capable of holding a workpiece; a Cartesian robot having a holding member for holding the workpiece and executing transfer of the workpiece held by the holding member between the mating device and the Cartesian robot; and a control device for controlling the Cartesian robot, the control device executing an acquisition process for acquiring a weight and length of the workpiece when transferring the workpiece between the mating device and the Cartesian robot; and a setting process for setting a transfer position, which is a position of the Cartesian robot when transferring the workpiece between the mating device and the Cartesian robot, based on the weight and length of the workpiece acquired by the acquisition process. the control device is capable of calculation using a correction formula, and the correction formula is capable of calculating a correction value by substituting values ​​of the weight and length of the workpiece held by the holding member into variables, and is capable of calculating, as the correction value, an amount of change in position that occurs in the workpiece held by the Cartesian robot according to the weight and length of the workpiece; the control device, in the setting process, calculates the correction value based on the weight and length of the workpiece acquired by the acquisition process and the correction formula, and corrects the delivery position with the correction value; the Cartesian robot has a head provided with the holding member, and is capable of holding a contact detection device by the holding member; the contact detection device outputs a contact detection signal in response to contact to the control device; the correction formula is an amount of change in the head in each axial direction in which the head can move, and is an equation derived from the relationship between the measured amount of change and the weight of the measurement weight, the amount of change in the head due to the weight of a measurement weight attached to the head being measured in advance based on the position of the head when the contact detection signal was output from the contact detection device held by the holding member. A machine tool is disclosed. [Effects of the Invention]

[0007] According to the machine tool disclosed herein, the transfer position between the mating device and the Cartesian robot is set based on the acquired weight and length of the workpiece. This allows an appropriate transfer position to be set using a correction formula, database, etc. depending on the weight and length of the workpiece. Unlike conventional technology, it is no longer necessary to provide sensors such as strain gauges in each drive unit of the Cartesian robot and to detect and process the sensor detection signals for each transfer operation. By executing a process to acquire the weight and length of the workpiece, the transfer position can be set more quickly. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a front view of a machine tool according to an embodiment of the present invention. [Figure 2] Block diagram of a machine tool. [Figure 3] FIG. 2 is a perspective view showing a main body of the machine tool with the device cover removed. [Figure 4]FIG. 4 is a right side view of the machine tool in the state shown in FIG. 3 . [Figure 5] FIG. [Figure 6] 10A and 10B are diagrams showing the state of the left spindle device and the head when setting the reference position and when transferring the workpiece. [Figure 7] FIG. 10 is a diagram showing a reception screen of the operation panel. [Figure 8] FIG. 10 is a diagram showing a state in which a contact detection device and a measurement weight are attached to a head. [Figure 9] FIG. 10 is a diagram for explaining tilt of the head due to a workpiece. [Figure 10] 10A and 10B are diagrams showing the state of the stocker device and the head when the reference position is set and when the workpiece is transferred. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of a machine tool according to the present disclosure will be described in detail below with reference to the drawings. FIG. 1 shows a front view of machine tool 1 according to this embodiment. FIG. 2 shows a block diagram of machine tool 1. FIG. 3 shows a perspective view of the main body of machine tool 1 with equipment cover 2 (see FIG. 1) removed. In the following description, the direction of machine tool 1 viewed from the front as shown in FIG. 1 will be used as a reference, and the rightward direction in the machine width direction and parallel to the installation surface of the equipment will be referred to as the Z direction, the forward direction parallel to the installation surface of the equipment and perpendicular to the Z direction will be referred to as the Y direction, and the upward direction perpendicular to the Z and Y directions will be referred to as the X direction. In the following description, the letter "L" will generally be added to the reference numerals of equipment located on the left side of machine tool 1, and the letter "R" will be added to the reference numerals of equipment located on the right side.

[0010] (Configuration of machine tool 1) As shown in Figures 1 and 2, the front of machine tool 1 is covered by equipment cover 2, and a movable operation panel 3 is provided on the front of the machine. The operation panel 3 is movable in the Z direction from the center of the front of the machine to the right edge along a rail 6 provided on the lower right of the front of equipment cover 2. The equipment cover 2 has a left front door 5L on the left side of the machine tool 1 and a right front door 5R on the right side. The left and right front doors 5L, 5R are, for example, sliding doors, and opening the doors allows access to the machining space behind the doors.

[0011] As shown in FIGS. 1 to 3, the machine tool 1 includes a control panel 3, a left-side machining device 11L, a right-side machining device 11R, a stocker device 9, a workpiece transport device 14, and a control device 15. A machining space for the left-side machining device 11L is provided behind the left-side front door 5L. The left-side machining device 11L is, for example, a turret-type lathe, and includes a left-side spindle unit 12L and a left-side turret 13L. The left-side spindle unit 12L has, for example, multiple child jaws for chucking a workpiece. The child jaws grip the workpiece and rotate the workpiece around a spindle parallel to the Z direction. The left-side turret 13L has a tool post to which multiple tools (rotary tools and cutting tools) can be attached, and performs tool indexing. The left-side turret 13L performs machining (such as cutting or drilling) on ​​the workpiece gripped by the left-side spindle unit 12L using the indexed tools. A user can check the machining status of the workpiece or replace worn tools through the left-side front door 5L.

[0012] The right-side machining device 11R has the same configuration as the left-side machining device 11L, except for the orientation of the spindle (device). Therefore, the description of the right-side machining device 11R will omit the same details as those of the left-side machining device 11L. Behind the right-side front door 5R, a machining space for the right-side spindle device 12R and right-side turret 13R of the right-side machining device 11R is provided. The spindle of the right-side spindle device 12R is parallel to the Z direction and opposes (faces) the spindle of the left-side spindle device 12L of the left-side machining device 11L in the left-right direction. Therefore, the left-side and right-side machining devices 11L, 11R are so-called opposed two-spindle lathes, arranged symmetrically. The left-side and right-side machining devices 11L, 11R do not have to be symmetrical. Furthermore, the right-side machining device 11R does not have to have the same configuration as the left-side machining device 11L. For example, at least one of the left-side processing device 11L and the right-side processing device 11R may be another type of processing device such as a machining center.

[0013] Furthermore, the machine tool 1 is a multi-tasking machine equipped with the functions of both an NC lathe and a machining center. Fig. 4 is a right side view of the machine tool 1 in the state shown in Fig. 3. As shown in Figs. 2 to 4, a tool spindle unit 21 is provided approximately in the center of the machine tool 1 in the left-right direction. The tool spindle unit 21 performs machining that is difficult to perform with the left and right machining units 11L, 11R, which are lathes. For example, the tool spindle unit 21 can perform lathe machining as well as drilling on workpieces held by the left and right spindle units 12L, 12R, respectively, and enables workpiece machining at depths and angles that are difficult to perform with the left and right turrets 13L, 13R.

[0014] The machine tool 1 includes a multitasking machine equipped with left and right machining units 11L, 11R and a tool spindle unit 21 mounted on a single bed 22. The left and right spindle units 12L, 12R rotate a workpiece W (see FIG. 4) driven by spindle motors 14L, 14R mounted outside the units. The left and right spindle units 12L, 12R, including the spindle motors 14L, 14R, are slidable in a direction parallel to the Z direction along an inclined surface 23 on the bed 22, which has a slant-bed structure. The left and right spindle units 12L, 12R move in a direction parallel to the Z direction, for example, by driving a ball screw mechanism (not shown) by a Z-axis servo motor 17 (see FIG. 4) mounted below the bed. The left and right turrets 13L, 13R and the tool spindle unit 21 are all movable in the machine body's front-to-rear and up-to-down directions, which are perpendicular to the spindles. For example, the movement direction of the tool spindle device 21 is the horizontal Y direction and the vertical X direction, while the movement directions of the left and right turrets 13L, 13R are the YL direction and the XL direction, which are inclined 45 degrees from the Y direction and the X direction.

[0015] An automatic tool changer 25 is provided in front of the tool spindle unit 21. The tool spindle unit 21 is capable of exchanging tools T (spindle head tools) with the automatic tool changer 25. The automatic tool changer 25 has a tool magazine 25A storing multiple tools T at its top, and a tool changer 25B, provided opposite the tool spindle unit 21, transports a tool T to be replaced from the tool magazine 25A to a tool changing position on the tool spindle unit 21. The machine tool 1 can also change tools on the tool spindle unit 21 while machining a workpiece W (see FIG. 4) with each of the left and right machining devices 11L and 11R. The machine tool 1 is equipped with, for example, separation shutters (not shown) disposed on both the left and right sides of the tool spindle unit 21 in the Z direction. The machine tool 1 is capable of moving the two separation shutters individually in the Y direction by a drive mechanism (not shown). FIG. 3 shows the separation shutters in a retracted state. In the machine tool 1, two separation shutters separate the machining spaces of the left-side machining unit 11L and the right-side machining unit 11R from the tool changing space of the tool spindle unit 21. This prevents each unit from being affected by coolant or chips. Furthermore, by closing only one of the separation shutters, the space including the tool changing space can be expanded to include the machining space of one of the turrets or the tool spindle unit 21.

[0016] The workpiece transport device 14 transfers the workpiece W between the left and right processing devices 11L, 11R and each device for carrying in, discharging, inspecting, etc. the workpiece. The left and right processing devices 11L, 11R and each device that transfers the workpiece W are examples of counterpart devices of the present disclosure. The machine tool 1 is equipped with a stocker device 9 as one of the counterpart devices. As shown in FIG. 1, the stocker device 9 has a plurality of pallets 10 on which the workpieces W can be stacked, and swaps the pallets 10 at the work position based on the control of the control device 15. The workpiece transport device 14 receives the workpiece W before machining and transfers the workpiece W after machining between the pallets 10 at the work position. Details of the workpiece transport device 14 will be described later.

[0017] 1 and 2, the operation panel 3 is provided on the front surface of the device cover 2 and includes a touch panel 3A and an operating device 3B. The operating device 3B includes, for example, an operating switch, a push button, a dial, and an indicator lamp. The operation panel 3 receives operation input from the user via the touch panel 3A or the operating device 3B, and outputs a signal corresponding to the received operation input to the control device 15. The operation panel 3 also changes the display content of the touch panel 3A and the lighting state of the indicator lamps of the operating device 3B based on the control of the control device 15. A pendant 8 for operating the machine tool 1 can be suspended below the center of the device cover 2.

[0018] As shown in FIG. 2, the control device 15 of the machine tool 1 is a processing device that includes a CPU 15A and a storage device 15B and is primarily a computer. The storage device 15B includes, for example, RAM, ROM, and flash memory. The control device 15 is electrically connected to each device (such as the left-side machining device 11L and the workpiece transport device 14) and is capable of controlling each device. Various control programs 16 are stored in the storage device 15B. The control programs 16 include, for example, NC programs that control the operation of the left-side and right-side machining devices 11L and 11R when machining a workpiece, a program that controls the operation of the workpiece transport device 14, and ladder circuit programs that process various signals. The control program 16 also stores, in association with each other, the X, Y, and Z coordinates of the transfer position where the workpiece transport device 14 transfers the workpiece W, the name of the process to be performed at the transfer position, and identification information for identifying the process. In the following description, the coordinates in the X, Y, and Z directions will be referred to as the X coordinate, Y coordinate, and Z coordinate. This coordinate system is used for convenience of explanation and can be changed as appropriate. The setting of each coordinate is not limited to the above setting, and for example, the left-right direction (Z direction) may be set as the X coordinate, the front-rear direction as the Y coordinate, and the up-down direction (X direction) as the Z coordinate. Furthermore, the storage device 15B stores correction formula data 19. The correction formula data 19 stores a plurality of correction formulas for correcting the XYZ coordinates of the transfer position of the workpiece W of the workpiece transport device 14. Details of the correction formulas will be described later.

[0019] (Regarding the workpiece transport device 14) Next, the workpiece transport device 14 will be described in detail. As shown in Figures 1, 3, and 4, the workpiece transport device 14 is, for example, a gantry-type transport device, and is capable of moving the gripped workpiece W in three directions, the X, Y, and Z directions. Note that Figure 1 shows in one diagram the workpiece transport device 14 moving to multiple positions.

[0020] The machine tool 1 includes a tower-shaped frame structure 31 having beams connected to front, rear, left, and right pillars erected to match the width of the bed 22. The front sides of the devices on the bed 22, such as the tool spindle device 21, the automatic tool changer 25, and the workpiece transportation device 14, are covered by a device cover 2 supported by the frame structure 31. As shown in FIGS. 3 and 4 , the workpiece transportation device 14 includes a rail base 32 and a traveling table 33. The rail base 32 is provided on the frame structure 31, on the front side of the device. Two traveling rails 34 parallel to the Z direction and one traveling rack 35 are provided on the rail base 32. The traveling table 33 is slidable along the traveling rails 34. A traveling motor 37 is fixed to the traveling table 33. The traveling table 33 is movable in the Z direction when a pinion fixed to the rotation shaft of the traveling motor 37 meshes with the traveling rack 35. The control device 15 controls the travel motor 37 to move the workpiece transport device 14 to any position in the Z direction.

[0021] A slide base 39 is provided on the upper surface of the traveling table 33 so as to be slidable in the Y direction. A rack is provided on the side of the slide base 39 for moving it in the Y direction. A front-rear motor 41 is fixed to the traveling table 33. A pinion fixed to the rotation shaft of the front-rear motor 41 is engaged with the rack of the slide base 39. The control device 15 can move the slide base 39 to any position in the Y-axis direction (front-rear direction) by controlling the front-rear motor 41. The slide base 39 protrudes forward from the frame structure 31, and a lifting arm 43 that moves up and down is provided at its tip.

[0022] A support column 45 equipped with a lifting rail is fixed to the front end of the slide base 39 in a position parallel to the X direction. A lifting arm 43 is provided in front of the support column 45. The lifting arm 43 is movable in the X direction along the lifting rail of the support column 45. A lifting motor 47 is provided at the top of the support column 45. A pulley is fixed to the rotation shaft of the lifting motor 47. A belt is stretched between the pulley of the lifting motor 47 and a pulley journaled at the bottom of the support column 45. The lifting arm 43 is connected to the belt, and its position in the X direction is changed in response to the driving of the lifting motor 47. The control device 15 controls the lifting motor 47 to change the position of the lifting arm 43 in the X-axis direction (up and down direction). A head 51 for gripping the workpiece W is provided at the lower end 43A of the lifting arm 43. Therefore, the control device 15 can move the head 51 to any position in the X, Y and Z directions by controlling the travel motor 37, the front-rear motor 41 and the lift motor 47.

[0023] The head 51 is attached to the rear surface of the lower end 43A and is positioned rearward relative to the lift arm 43. FIG. 5 shows a perspective view of the lift arm 43 and the head 51. The head 51 has two gripping portions: a first gripping portion 52 and a second gripping portion 53. The second gripping portion 53 has the same configuration as the first gripping portion 52. Therefore, in the following explanation, the explanation of the second gripping portion 53 will be omitted as appropriate.

[0024] As shown in FIG. 5, the head 51 includes a support member 56, a first claw member 57, and a second claw member 58. The support member 56 is attached to the rear of the lower end 43A of the lifting arm 43. The support member 56 is a generally rectangular plate having a predetermined thickness. A first gripper 52 and a second gripper 53 are provided on each side of the support member 56 that face each other in the thickness direction (from the front left to the rear right in FIG. 5). The support member 56 is rotatably attached to the lower end 43A. The control device 15 rotates the head 51 around a rotation axis 62 (see FIGS. 4 and 5) parallel to the Y direction, for example, by driving a rotation motor (not shown) provided in the lower end 43A. As a result, the support member 56 rotates in a rotation direction 61 (see FIGS. 4 and 5), causing the first and second grippers 52, 53 to face in different directions.

[0025] The head 51 rotates in a rotation direction 61 (clockwise or counterclockwise) by 90 degrees increments, for example, in response to the driving of the rotation motor. The head 51 rotates to a total of four rotation positions: a rotation position (two rotation positions including a position rotated 180 degrees) in which each of the first and second grippers 52, 53 faces both sides in the Z direction (left and right sides), and a rotation position (two rotation positions including a position rotated 180 degrees) in which each of the first and second grippers 52, 53 faces both sides in the X direction (up and down sides). In the following description, the rotation positions at which the first gripper 52 faces left, up, right, and down, respectively, are referred to as first to fourth rotation positions RP1 to RP4. For example, when transferring the workpiece W between the first gripper 52 and the left spindle unit 12L as shown in FIG. 6 (described later), the control device 15 sets the head 51 to the first rotation position RP1. 10, for example, when transferring the workpiece W between the first gripper 52 and the stocker device 9, the control device 15 rotates the head 51 to a fourth rotation position RP4 where the first gripper 52 faces downward. Note that the rotation angle and rotation position of the head 51 described above are merely examples. For example, the head 51 may be configured to rotate at intervals of an angle greater than 90 degrees (such as 180 degrees) or at intervals of a smaller angle (such as 45 degrees), or may be configured to rotate at any rotation angle.

[0026] For example, three first claw members 57 can be attached to the first gripping unit 52. Each of the three first claw members 57 has the same shape and is attached at positions offset from each other by 120 degrees in the circumferential direction. The three first claw members 57 are detachably attached to the support member 56 and can be replaced with different types of first claw members 57 depending on the type of workpiece W, etc. The three first claw members 57 slide radially (open and close) in response to the driving of a hydraulic cylinder (not shown) provided in the head 51. As a result, the control device 15 drives the hydraulic cylinder to close the three first claw members 57 to clamp the workpiece W, or open the three first claw members 57 to release the clamping. Similarly, the second gripping unit 53 can detachably attach, for example, three second claw members 58, and can open and close the three second claw members 58.

[0027] (Setting and correcting the delivery position) Next, the setting of the transfer position for transferring the workpiece W between the head 51 and the mating device and the correction process using the correction formula will be described. The control device 15 performs machining on the workpiece W based on the control program 16. The workpiece W to be machined is transported, for example, from the stocker device 9 to the left spindle device 12L or the right spindle device 12R by the work transfer device 14. After transferring the workpiece W to each spindle device, the control device 15 performs predetermined machining using the left and right turrets 13L, 13R and the tool spindle device 21. The control device 15 receives the machined workpiece W from the left spindle device 12L, etc. to the work transfer device 14 and transports it to the stocker device 9.

[0028] For example, the NC program of the control program 16 includes X, Y, and Z coordinates of a transfer position, which is the position of the head 51 where the workpiece W is transferred between the workpiece transport device 14 and each of the other devices. The control device 15 positions the head 51 at the transfer position (X, Y, and Z coordinates) set in the NC program and rotates the head 51 to a predetermined rotation position to transfer the workpiece W between the head 51 and the other device. The machine tool 1 can set a reference position, which serves as a reference for setting the transfer position, using a contact detection device. The machine tool 1 of this embodiment receives input values ​​such as the weight and length of the workpiece W to be machined, sets the transfer position based on the reference position and length, and corrects the set transfer position based on the weight, length, and the correction formula of the correction formula data 19. In the following description, as an example, the left spindle unit 12L is used as the other device, and a case will be described in which the workpiece W is transferred from the first gripper 52 of the head 51 to the left spindle unit 12L. Note that, as will be described later with reference to FIG. 10, similar transfer position setting and the like can be performed for other transfer positions as well.

[0029] In FIG. 6, the upper diagram shows the state of the left spindle unit 12L and head 51 when the reference position is set, and the lower diagram shows the state of the left spindle unit 12L and head 51 when a workpiece is transferred. As shown in the upper diagram of FIG. 6, when the reference position is set, a master workpiece 63 is attached to the left spindle unit 12L. This master workpiece 63 is used as a member that comes into contact with the contact detection device 65 when setting the reference position P1 and is also used as a member for checking misalignment of the spindle during spindle centering work. The master workpiece 63 has, for example, a disk-shaped clamped portion 63A and a generally cylindrical convex portion 63B that protrudes from the center of the clamped portion 63A. The shape of the master workpiece 63 shown in FIG. 6 is an example.

[0030] The left spindle unit 12L can be fitted with a plurality of (e.g., three) child jaws 67 that can clamp, for example, the workpiece W or the master workpiece 63. Each of the plurality of child jaws 67 has, for example, the same shape and is fitted at positions that are offset in the circumferential direction by a predetermined rotation angle (e.g., 120 degrees). Furthermore, the plurality of child jaws 67 move in the radial direction based on the drive of a drive source (e.g., hydraulic cylinder) provided in the left spindle unit 12L, and clamp the workpiece W or the master workpiece 63. Note that the member that holds the workpiece W or the master workpiece 63 is not limited to a jaw member such as the child jaw 67, and may be another member such as a collet chuck.

[0031] In the setting operation of the reference position P1 using the contact detection device 65, the master workpiece 63 is clamped by the multiple child jaws 67. For example, the user operates the operation panel 3 to open the child jaws 67 and seat the master workpiece 63 on the left spindle unit 12L. The user operates the operation panel 3 to close the child jaws 67 and clamp the clamped portion 63A of the master workpiece 63 between the child jaws 67. The master workpiece 63 contacts the abutment portion 67A formed on the child jaws 67 and is positioned in a state in which movement toward the base end side (the left side in FIG. 6 ) of the left spindle unit 12L is restricted. Furthermore, the centers of the clamped portion 63A and the convex portion 63B of the master workpiece 63 are aligned on the spindle 69. In other words, when the master workpiece 63 is positioned in the correct position for measurement, movement toward the base end side is restricted and the center of rotation is aligned on the spindle 69. The operation of placing the master workpiece 63 on the left spindle device 12L may be performed automatically using the head 51 of the workpiece transport device 14. For example, in response to an instruction to start measurement, the control device 15 may cause the head 51 to grip the master workpiece 63 placed on the stocker device 9, transport the master workpiece 63 to the left spindle device 12L, and hand over the master workpiece 63 from the head 51 to the left spindle device 12L.

[0032] When the user places the master workpiece 63 on the left spindle unit 12L, the user clamps the contact detection device 65 with the first gripping portion 52 of the head 51. As with the master workpiece 63, the user may operate the operation panel 3 to clamp the contact detection device 65 with the head 51, or the contact detection device 65 may be disposed in a stocker device 9, a workstation, or the head 51 may automatically grasp the contact detection device 65. In the example shown in FIG. 6, first jaw members 57 of different shapes are used when setting the reference position (upper diagram) and when transferring the workpiece (lower diagram). It is preferable that the first jaw members 57 be changed to ones suitable for clamping the contact detection device 65 and clamping the workpiece W, but the same type of first jaw members 57 may be used when setting the reference position and when transferring the workpiece.

[0033] The contact detection device 65 is, for example, a touch probe. When the tip of the stylus 65A comes into contact with another member, the contact detection device 65 transmits a contact detection signal indicating the occurrence of contact via wireless communication. As shown in FIG. 2, the control device 15 includes a wireless device 18 capable of wireless communication with the contact detection device 65. The control device 15 is capable of receiving the contact detection signal SI via wireless communication from the contact detection device 65 held by the first claw member 57 of the head 51. The contact detection method used by the contact detection device 65 (touch probe) is not particularly limited, and may be a movable contact method, a pressure sensor method, an optical sensor method, or the like. Therefore, the contact detection device of the present disclosure is not limited to a touch probe, and may also be one that uses a push button switch with a movable contact or a pressure sensor. The method of transmitting the contact detection signal SI to the control device 15 is not limited to wireless communication, and may also be a method using infrared rays or electromagnetic induction. The contact detection signal SI may also be transmitted via wired communication.

[0034] After clamping the contact detection device 65 to the head 51, the user operates the operation panel 3 to issue an instruction to start measuring the reference position P1. Upon receiving the instruction to start measurement, the control device 15 positions the head 51 at a predetermined measurement start position P2 (see FIG. 6 ). This measurement start position P2 is the position at which the head 51 is positioned when starting measurement of the reference position P1. For example, if a centering operation or the like is performed in advance and the head 51 is positioned at the measurement start position P2 in FIG. 6 , the X coordinate in the X direction and the Y coordinate in the Y direction of the head 51 at the measurement start position P2 will match the X and Y coordinates of the spindle 69 of the left spindle unit 12L. For example, based on the user's operation instruction, the control device 15 brings the stylus 65A of the contact detection device 65 into contact with multiple points on the convex portion 63B of the master workpiece 63, detects the center position of the convex portion 63B, and corrects the amount of misalignment with the spindle 69 to perform centering. After placing the head 51 at the measurement start position P2, the control device 15 moves the head 51 in the Z direction and sets the Z coordinate in the Z direction based on the detection of the contact detection device 65. The control device 15 can use the X and Y coordinates of the spindle 69 for the X and Y coordinates. Therefore, the control device 15 sets the X and Y coordinates of the spindle 69 determined by performing the centering operation (the X and Y coordinates of the measurement start position P2) as the X and Y coordinates of the reference position P1.

[0035] After positioning the head 51 at the measurement start position P2, the control device 15 keeps the X and Y coordinates constant and moves the head 51 toward the left spindle device 12L in a direction parallel to the Z direction (see the arrow indicating the measurement start position P2 in Figure 6). The control device 15 controls the travel motor 37 to move the head 51 in a direction parallel to the Z direction. The contact detection device 65 transmits a contact detection signal SI when the stylus 65A contacts the surface of the convex portion 63B facing the head 51. When the control device 15 receives the contact detection signal SI from the contact detection device 65, the control device 15 sets the Z coordinate of the reference position P1. For example, the control device 15 corrects the delay time required for transmitting the contact detection signal SI from the contact detection device 65 to the control device 15 relative to the time when the contact detection signal SI was received, and calculates the output time when the contact detection signal SI was output. The control device 15 then sets the Z coordinate at which the head 51 was positioned at the output time as the Z coordinate of the reference position P1. The Z coordinate of the head 51 can be detected based on the position information of the drive motor 37. The control device 15 does not need to perform the delay correction of the transmission time. For example, the control device 15 may set the Z coordinate of the head 51 at the time when the contact detection signal SI is input as the Z coordinate of the reference position P1.

[0036] The control device 15 sets the reference distance L1, for example, to the distance along the Z direction from the origin position P3 to the reference position P1 shown in FIG. 6. This origin position P3 is a reference (origin) position for determining the transfer position. The origin position P3 may be set to a position other than the left spindle unit 12L (such as a predetermined position on the frame structure 31). In other words, the origin position P3 is not limited to the position of the left spindle unit 12L and can be set to any position on the machine tool 1. When the control device 15 completes setting the reference distance L1, it displays on the operation panel 3 that the reference position setting process has been completed. After confirming the completion display, the user detaches the contact detection device 65 from the head 51, removes the master workpiece 63 from the left spindle unit 12L, and replaces the first jaw member 57 with one that matches the workpiece W to be machined.

[0037] The control device 15 receives input values ​​required for setting the transfer position and for the correction formula, for example, on a predetermined setting screen or a screen for receiving a start instruction before starting processing of the workpiece W. FIG. 7 shows an example of an input value reception screen 73. As shown in FIG. 7, the control device 15 receives, as input values, for example, the position name, the weight of the workpiece W, the length of the workpiece W, the rotation position, and information on whether or not a transfer is to be performed. Note that the input values ​​shown in FIG. 7 are merely examples.

[0038] For example, consider a case where machining of a workpiece W held by the left spindle unit 12L (first machining process) and machining of a workpiece W held by the right spindle unit 12R (second machining process) are executed in that order as machining processes. In this case, the workpiece W is transferred, for example, six times. The control device 15 sets position names NO1 to NO6 as names of transfer positions for these six transfers and identifies the transfer positions. Specifically, the head 51 receives the workpiece W from the stocker device 9 to the first gripper 52 at position name NO1, and transfers the workpiece W from the first gripper 52 to the left spindle unit 12L at NO2. The head 51 also receives the workpiece W after the first machining process from the left spindle unit 12L to the first gripper 52 at NO3, and transfers the workpiece W from the first gripper 52 to the right spindle unit 12R at NO4. Then, the head 51 receives the workpiece W after the second machining process from the right spindle device 12R at NO5, and delivers the workpiece W to the stocker device 9 at NO6.

[0039] At the top of the reception screen 73 in FIG. 7, input value names 75 are displayed to explain each input value. Below each input value name 75, an input field 76 is provided for inputting each input value for each position name (transfer position). In the example shown in FIG. 7, transfer positions NO1 to NO6 are set in order from top to bottom. The top position name NO1 is the transfer position where the unmachined workpiece W is transferred from the stocker device 9 to the first gripper 52. For this reason, the user inputs the weight of the unmachined workpiece W as the input value weight X1 and the length of the unmachined workpiece W as the input value length Y1 in the input field 76. For example, when inputting the weight X2 and length Y2 after the first processing step of NO3, the user inputs the weight X2 that has been reduced by the first processing step and the length Y2 that has been shortened by the first processing step. Similarly, for example, when inputting the weight and length after the second processing step of NO5, the user inputs the weight X3 that has been further reduced by the second processing step and the length Y3 that has been shortened by the second processing step. In the example shown in FIG. 7, since the second gripping unit 53 does not grip the workpiece W, the input fields 76 for the weight and length of the workpiece W in the second gripping unit 53 are left blank.

[0040] Furthermore, the control device 15 identifies, for example, the first to fourth rotation positions RP1 to RP4 as "RP1 to RP4." The user selects the fourth rotation position RP4, at which the first gripper 52 faces downward, as the rotation position for the position name No. 1. Furthermore, at the delivery position for the position name No. 1, the head 51 receives the workpiece W from the stocker device 9. Therefore, the user selects information indicating "receive" as information on whether or not a delivery is to be made for the position name No. 1 and inputs it into the input field 76. When the setting button 77 on the reception screen 73 is touched, the control device 15 stores the input values ​​on the reception screen 73 in the storage device 15B and uses them to correct the delivery position, which will be described later. When the cancel button 78 on the reception screen 73 is touched, the control device 15 discards the information received on the reception screen 73. Note that the method for acquiring the input values ​​is not limited to the method of inputting them using the operation panel 3 described above. For example, a setting file containing the input values ​​may be read into the control device 15.

[0041] The following explanation will mainly focus on position No. 2 (see FIG. 7) where the workpiece W is transferred from the first gripper 52 of the head 51 shown in the lower diagram of FIG. 6 to the left spindle unit 12L. In this case, the control device 15 accepts the length L2 of the unmachined workpiece W (see FIG. 6) as the length Y1 of the workpiece W at position No. 2. The user may input, for example, a value on the drawing (design) of the unmachined workpiece W as length L2, or may input an actual measurement value of the workpiece W before machining. The control device 15 sets the transfer position for position No. 2 using the accepted length L2 of the workpiece W. For example, as shown in the lower diagram of FIG. 6, the control device 15 calculates a design position P5, which is the design position of the head 51 during transfer, based on the accepted length L2 of the workpiece W. The design position P5 is a calculated position that takes into account, for example, the design lengths of each component and does not include errors in the Z direction due to component assembly errors. As shown in the diagram below, the workpiece W transferred from the first gripping unit 52 is seated against the abutment portion 67A of the child jaws 67 and is clamped by the multiple child jaws 67. The X and Y coordinates of the design position P5 are the same as those of the reference position P1, for example, because they have been adjusted by a centering operation. Meanwhile, the distance L3 in the Z direction from the origin position P3 to the design position P5 is, for example, the sum of the distance L4 from the origin position P3 to the abutment portion 67A of the child jaw 67, the length L2 of the workpiece W, and the distance L5 from the workpiece W to the design position P5 (L3 = L4 + L2 + L5).

[0042] Distance L4 is the distance to the workpiece W held by the sub-jaw 67 of the left spindle unit 12L and can be set in advance depending on the structure of the sub-jaw 67, etc. Distance L5 is, for example, the distance from the end of the workpiece W held by the first jaw member 57 on the support member 56 side to the center of the head 51 and can be set in advance depending on the structure of the head 51, etc. After calculating distance L3, the control device 15 calculates a correction distance L6, which is the difference between distance L3 and the reference distance L1 calculated when setting the reference position. Here, component assembly errors specific to the device occur in the workpiece transportation device 14, the left spindle unit 12L, etc. As a result, there is a risk that the designed transfer position will deviate from the actual transfer position including the assembly error, making it difficult to perform the transfer operation with precision. When setting the reference distance L1 described above, the contact detection device 65 is used to set the reference distance L1, which is a distance that includes errors in the assembly accuracy of the components of the left spindle unit 12L and the workpiece transportation device 14, i.e., the actually measured distance. The control device 15 then sets the transfer position of the head 51 based on this reference distance L1, thereby correcting the error and setting the transfer position. Specifically, for example, as shown in FIG. 6, the control device 15 sets the Z coordinate of the transfer position P6 to a position obtained by adding the correction distance L6 to the reference distance L1 in the Z direction. In the example shown in FIG. 6, the transfer position P6 is located to the right of the reference position P1, but the positional relationship changes depending on the contact detection device 65 and the length of the workpiece W. Furthermore, the control device 15 sets the same values ​​as the spindle 69 as the X and Y coordinates of the transfer position P6. In this way, the control device 15 sets the transfer position P6 based on the input length L2 of the workpiece W.

[0043] Then, the control device 15 corrects the delivery position P6 set by the above-mentioned process using a correction value calculated from the correction formula. The control device 15 inputs each input value received on the reception screen 73 into a correction formula for correcting the XYZ coordinates, and calculates the correction value. An example of the correction formula for the X coordinate (coordinate in the up and down direction) is shown below. X=A11*[{B11+B12...}*C11+{B21+B22...}*C21] (formula) Among the above equations, the first equation (B11 to C11) on the front side is a correction equation whose value is reflected when the workpiece W is gripped by both the first and second gripping units 52, 53, and the second equation (B21 to C21) on the back side is a correction equation whose value is reflected when the workpiece W is gripped by one of the first and second gripping units 52, 53. The variable A11 is a value that is changed depending on the state of the head 51 (such as whether the workpiece W is present in each of the first and second gripping units 52, 53). For example, the control device 15 changes the variable A11 depending on whether values ​​are entered in the input fields 76 for the weight and length of the workpiece W at each position on the reception screen 73. When values ​​are entered in the input fields 76 for the weight and length for the first gripping unit 52 at each position, the control device 15 determines that the workpiece W will be gripped by the first gripping unit 52 at that position. Similarly, when a value is input in the input field 76 for the weight or length for the second gripping unit 53 at each position, the control device 15 determines that the workpiece W will be gripped by the second gripping unit 53 at that position. The control device 15 sets a variable A11 according to the result of the determination of gripping of the workpiece W.

[0044] The variables B11, B12, B21, and B22 are values ​​that change depending on the input weight and length of the workpiece W, and reflect values ​​that take into account correction for the tilt of the head 51 (referred to as correction (1)) and correction for differences due to the length of the workpiece W (referred to as correction (2)). The variables C11 and C21 are values ​​that change depending on the input weight and length of the workpiece W, and reflect values ​​that take into account correction for deformation due to moments (referred to as correction (3)). The applicant conducted experiments in which, as shown in FIG. 8, a contact detection device 65 was placed on the first gripper 52 and a measurement weight 83 was placed on the second gripper 53, or measurement weights 83 were placed on both the first and second grippers 52 and 53. The applicant successfully derived the above-mentioned correction formula by using the contact detection device 65 to measure the amount of change in the X, Y, and Z directions of the head 51 due to the weight of the measurement weight 83. Therefore, the above-mentioned correction formulas and variables are the amount of change in the position of the head 51 depending on the weight and length of the workpiece W, and are formulas that represent the amount of change in each direction obtained through experiments. The control device 15 derives a correction value for the delivery position P6 from the correction formula and the weight and length of the workpiece W to be processed. The relationship between the experimental results and the correction formula will be explained below. Note that the first jaw member 57 is not shown in Figure 8.

[0045] (X coordinate correction) First, the correction (1) of the X coordinate (vertical coordinate) will be described. As shown in FIG. 6, the workpiece W is clamped and held by the three sub-jaws 67 while abutting (seated) against the abutment portion 67A. The above-described correction formula corresponds to this method of setting the workpiece W. More specifically, in the case of transfer from the head 51, the correction formula corrects the amount of change in the position of the head 51, which changes due to the weight of the workpiece W, and variables are set so that the center 82 at the tip of the workpiece W is the center of the area surrounded by the three sub-jaws 67 on the main spindle 69. The center 82 is the center of the surface (circular surface) on the tip side of the cylindrical workpiece W. Thus, by correcting the transfer position P6 using the correction value calculated by the correction formula, for example, the center of the workpiece W held by the multiple sub-jaws 67 and the center 82 of the tip of the workpiece W held by the head 51 coincide with each other, and the main spindle 69 is aligned. In other words, by positioning the head 51 at the corrected delivery position, the center 82 of the workpiece W held by the head 51 coincides with the center of the area surrounded by the three child jaws 67. For example, the control device 15 positions the head 51 at the corrected delivery position P6, and then causes the child jaws 67 to clamp the workpiece W. This avoids interference between the child jaws 67 and the workpiece W, and allows the workpiece W to be satisfactorily seated on the abutment portion 67A.

[0046] For example, in an experiment using the contact detection device 65, assuming a situation in which the workpiece W is held only by the second gripper 53, and attaching a weight 83 to the second gripper 53, the head 51 tilts more in the direction of arrow 85 shown in FIG. 8 as the weight 83 of the second gripper 53 increases. The applicant, for example, changed the weight of the weight 83 and contacted the stylus 65A of the contact detection device 65 held by the head 51 tilted by the weight 83 with the center of the convex portion 63B to confirm the difference (amount of change) in the X coordinate of the head 51. Then, the variables B11, B12, etc. in the first correction formula were calculated from the proportional relationship between the amount of change in the weight of the weight 83 and the amount of change in the X coordinate of the head 51. Therefore, by using the correction value of the correction formula, for example, when the first gripper 52 receives the workpiece W while the second gripper 53 holds the workpiece W, the X coordinate can be corrected downward to correct the upward tilt of the head 51. As a result, the center of the surface on the tip side (head 51 side) of the workpiece W held by the left spindle unit 12L can be aligned with the centers of the three first jaw members 57 of the first gripping unit 52. Conversely, as shown in FIG. 9, when the workpiece W held by the first gripping unit 52 is handed over without the workpiece W being held by the second gripping unit 53, the head 51 tilts in the direction of arrow 86. In this case, the X coordinate is corrected upward using a correction formula. As a result, the center 82 of the surface on the tip side of the workpiece W held by the first gripping unit 52 can be aligned with the centers of the three sub-jaws 67 of the left spindle unit 12L.

[0047] Additionally, assuming a case in which a workpiece W is held by both the first and second gripping units 52, 53 and then handed over to either one of the first or second gripping units 52, 53, the applicant conducted an experiment by attaching weights 83 to both gripping units. In this case, the position of the head 51 shifts downward as the weight of the workpiece W held by both gripping units increases. The variables B21 and B22 in the second correction formula reflect the values ​​of the variables, thereby correcting the X coordinate, which would otherwise change downward in such a case of double-holding, upward.

[0048] The correction formula also takes into account the correction (2) described above. As shown by arrow 87 in FIG. 9, the longer the axial length L2 of the workpiece W held by head 51, the greater the change in center 82 caused by the tilt described above. For example, as shown in FIG. 8, when first gripper 52 tilts upward, even if the head 51 is tilted while holding a weight 83 of the same weight in second gripper 53, the longer length L2 increases the upward shift of the X coordinate of center 82 of the adjustment target. Therefore, the longer the length L2 of the workpiece W, the greater the shift in the X coordinate caused by the tilt. Therefore, variables B11, B12, B21, B22, etc. in the correction formula are set to correct the error caused by the length L2 of the workpiece W. For example, when the workpiece W is displaced downward as shown in FIG. 9, the longer the length L2 of the workpiece W, the greater the downward shift of center 82. For this reason, when values ​​are reflected in variables B11, B12, B21, B22, etc., coefficients, etc. are set such that the amount of upward correction of the X coordinate increases relatively as the length L2 increases. Furthermore, in the case where the head 51 tilts upward as shown in FIG. 8 , the longer the length L2 of the workpiece W, the more downward correction is made to the X coordinate of the head 51 receiving the workpiece W held by the left spindle unit 12L. Alternatively, when a workpiece W is held by both the first and second grippers 52, 53 and the workpiece W held by the second gripper 53 is heavier than the workpiece W held by the first gripper 52, the workpiece W held by the first gripper 52 will tilt upward. In such a case, the longer the length L2 of the workpiece W, the more downward correction is made to the X coordinate of the head 51 so that the center 82 of the workpiece W held by the first gripper 52 coincides with the center of the left spindle unit 12L. This allows the user to perform tilt correction according to the length L2 by inputting the length Y1 before processing, the length Y2 after the first processing step, and the length Y3 after the second processing step on the reception screen 73 of Figure 7.

[0049] The correction formula also takes into account the above correction (3). As indicated by arrow 89 in FIG. 9, a moment (torque attempting to rotate head 51) that rotates head 51 occurs in the workpiece W held by head 51 depending on its length and weight. This moment increases, for example, as the weight of the workpiece W increases. The moment generated in the workpiece W also increases, for example, as the length L2 increases and the distance 93 from the center of rotation (transfer position P6 in FIG. 9) to the center of gravity 91 of the workpiece W increases. Therefore, the variables C11 and C21 in the correction formula are set with coefficients and the like that correct for deviations due to this moment. For example, when the workpiece W is held by the first gripper 52, the variables C11 and C21 relatively increase the amount of upward correction of the X coordinate as the weight and length of the held workpiece W increase. Furthermore, for example, when a workpiece W is held by the second gripping unit 53 and received by the first gripping unit 52, the heavier and longer the workpiece W held by the second gripping unit 53, the larger the downward correction amount for correcting the X coordinate is set to. This allows the user to correct errors due to the moment by inputting the weights X1, X2, X3 and lengths Y1, Y2, Y3 before and after machining on the reception screen 73 of Fig. 7. Whether or not such first and second correction formulas are reflected in the correction value of the calculation result is adjusted by the variable (A11), i.e., depending on the presence or absence of the workpiece W on the first and second gripping units 52, 53, etc.

[0050] (Y coordinate correction) Similarly, a correction formula can be set for the Y direction (front-rear direction) as well, and correction can be performed. For example, in correction (1), when the head 51 grips the workpiece W in one or both of the first and second gripping parts, it tilts downward with the lower end 43A as the fulcrum, as shown by arrow 95 in FIG. 5. As a result, the Y coordinate fluctuates toward the lower end 43A (in the direction of arrow 97 in FIG. 5). The amount of change (error) in this Y coordinate increases as the weight of the workpiece W increases. Therefore, in the Y coordinate correction formula, a variable is set that increases the amount of correction for correcting the Y coordinate in the direction away from the lower end 43A (in the opposite direction to arrow 97) as the weight of the workpiece W increases.

[0051] (Z coordinate correction) Similarly to the X direction, a correction formula can be set for the Z direction (left-right direction) and correction can be performed. For example, in the case of correction (1), in the case shown in FIG. 9, the heavier the workpiece W in the first gripping unit 52, the more the workpiece W tilts downward. The greater the tilt, the farther the center 82 is from the convex portion 63B. Therefore, in the correction formula for the Z coordinate, for example, in the case of FIG. 9, a variable is set that increases the amount of correction to correct the Z coordinate to the left as the weight of the workpiece W increases.

[0052] The above correction content is merely an example. For example, variables that take into account the moment of correction (3) may be set for the YZ coordinate correction formula. For example, since the tilt of the head 51 increases as the moment increases, the correction value of the YZ coordinate may be increased. Alternatively, the distance 93 to the center of gravity 91 of the workpiece W may be input as an input value in FIG. 7, and correction values ​​corresponding to the center of gravity 91 and the distance 93 to the center of gravity 91 may be calculated as variables C11 and C21. Furthermore, in correcting the Z coordinate, the center 82 shown in FIG. 9 becomes farther away from the convex portion 63B as the workpiece W becomes heavier and the tilt increases. Furthermore, the amount of change (distance) caused by this tilt increases as the length L2 of the workpiece W increases. In other words, even with the same rotation angle, the longer the workpiece W, the greater the change in the Z coordinate before and after rotation. Therefore, in the correction formula for the Z coordinate, for example, the longer the length L2 of the workpiece W, the larger the amount of correction for correcting the Z coordinate to the left in the state shown in FIG.

[0053] The control device 15 then sets the transfer position P6 corrected using the correction value calculated using the above-described correction formula in, for example, an NC program, and controls the position at which the head 51 is positioned. This allows the transfer position P6 to be set with errors due to the weight and length of the workpiece W corrected, enabling the transfer of the workpiece W with high precision. Specifically, for example, when transferring the workpiece W from the first gripper 52 to the left spindle unit 12L, the control device 15 positions the head 51 gripping the workpiece W at the corrected transfer position P6. The center 82 of the workpiece W coincides with the center 82 of the three sub-jaws 67. The control device 15 controls the left spindle unit 12L to clamp the workpiece W with the sub-jaws 67 (see FIG. 6). The control device 15 releases the chuck of the first jaw member 57, retracts the head 51, and then rotates the left spindle unit 12L to start machining.

[0054] As described above, the control device 15 of this embodiment is capable of calculations using a correction formula. This correction formula can calculate the amount of position change that occurs in the workpiece W held by the head 51 according to the weight and length L2 of the workpiece W as a correction value by substituting the values ​​of the weight and length L2 of the workpiece W held by the first jaw member 57 into variables. The control device 15 then calculates the correction value based on the weight and length L2 of the workpiece W obtained from the user and the correction formula, and corrects the delivery position P6 with the correction value. As a result, the X, Y, and Z coordinates of the workpiece W, which are affected by the weight and length L2 of the workpiece W, can be corrected to appropriate positions by substituting values ​​into the correction formula, calculating the correction value, and correcting the position of the head 51.

[0055] Furthermore, the correction formula of this embodiment can calculate correction values ​​for correcting the coordinates of the head 51 in the X and Y directions. These X and Y directions are directions perpendicular to the axial direction of the workpiece W held by the left spindle unit 12L. This makes it possible to perform correction using the perpendicular direction as the adjustment direction, and to adjust the position of the center 82 of the workpiece W on the spindle 69 of the left spindle unit 12L in the X and Y directions. This allows for smooth transfer of the workpiece W.

[0056] The correction formula also includes a variable A11 that indicates whether or not a workpiece W is being held by each of the first and second jaw members 57, 58. The control device 15 acquires information indicating whether or not a workpiece W is being held by each of the first and second jaw members 57, 58 on the reception screen 73, and sets the variable A11. Specifically, the control device 15 determines whether or not a workpiece W is being held by each of the first and second gripping units 52, 53 based on whether or not a value is entered in the input field 76 for the weight and length of the workpiece W, and sets the variable A11. The control device 15 sets the delivery position P6, based on the correction formula in which the variable A11 is set, by correcting the tilt of the head 51 due to the weight of the workpiece W held by at least one of the first and second gripping units 52, 53. This allows the head 51, which has multiple gripping units, to correct tilt errors caused by the gripped workpiece W. This reduces interference between the workpiece W and the other device.

[0057] Furthermore, the correction formula sets variables A11, B11, B12, B21, B22, C11, and C21 for calculating a correction value for correcting delivery position P6 when transferring workpiece W from head 51 to left spindle unit 12L to be at delivery position P6 where center 82 of the tip of workpiece W held by head 51 is on spindle 69. This makes it possible to use the calculated correction value to align center 82 of the tip of workpiece W with the centers of the three child jaws 67. The left spindle unit 12L on the receiving side can hold the workpiece W well with the child jaws 67.

[0058] The first and second jaw members 57, 58 are positioned opposite each other in the thickness direction of the support member 56. When the first jaw member 57 receives the workpiece W from the left spindle unit 12L while the second jaw member 58 is gripping the workpiece W, the control device 15 corrects the transfer position P6 in the vertical direction of the head 51 based on the correction formula. Furthermore, the heavier the workpiece W on the second jaw member 58, the more the head 51 corrects the transfer position P6 to a lower position. This allows the head 51, which has the first and second jaw members 57, 58 on both sides of the support member 56, to correct tilt errors that occur when the workpiece W is held by the second jaw member 58 on the side opposite to the side that receives the workpiece W. By correcting errors that occur when the first jaw member 57 faces upward, the head 51 can successfully receive the workpiece W from the left spindle unit 12L. This prevents the workpiece W from falling off.

[0059] Furthermore, the control device 15 brings the contact detection device 65 held by the head 51 into contact with the master workpiece 63 of the left spindle device 12L, and sets the reference position P1 of the head 51 at the time of contact based on the contact detection signal SI obtained from the contact detection device 65. This makes it possible to set the reference position P1 taking into account errors in the assembly accuracy of parts such as the head 51. Furthermore, when setting the reference position P1, it is not necessary to provide a sensor or the like on the mating device. Then, the control device 15 corrects the set delivery position P6 from this reference position P1 using the correction value of the correction formula. This makes it possible to set the delivery position P6 by correcting not only the amount of change due to weight and length, but also the assembly error of the part. This allows for more accurate delivery of the workpiece W.

[0060] Furthermore, as described above, through experiments by the applicant, the amount of movement of the head 51 in the X, Y, and Z directions in which the head 51 can move, that is, the amount of movement of the head 51 due to the weight of the measurement weight 83 attached to the head 51, was measured in advance based on the position of the head 51 when the contact detection signal SI was output from the contact detection device 65 held by the first claw member 57. The correction formula is an equation derived from the relationship between the measured amount of change and the weight of the weight 83. This makes it possible to reflect in the correction formula the inclination of the head 51 caused by the weight of the workpiece W and the amount of change in the center 82 of the workpiece W that is displaced due to that inclination and the length L2 of the workpiece W. By using the correction formula, it is possible to accurately calculate a correction value that corresponds to the structure of the actual device (workpiece transport device 14).

[0061] In the above example, the transfer of the workpiece W between the head 51 and the left spindle unit 12L has been mainly described, but similar corrections can also be made for transfers with other partner devices. FIG. 10 shows, as an example, a case where the workpiece W is transferred between the head 51 and the stocker unit 9. The pallet 10 in FIG. 10 is disposed at the work position of the stocker unit 9. The pallet 10 of the stocker unit 9 is provided with multiple positioning pins 10A. The workpiece W placed on the upper surface of the pallet 10 is placed with its axial direction aligned in the vertical direction by the multiple positioning pins 10A. The head 51 transfers the workpiece W to and from the pallet 10, for example, at a fourth rotation position RP4 where the first gripper 52 faces downward. In this case, the control unit 15 corrects the X coordinate in the X direction when setting the transfer position P6 using the reference position P1 and the length of the workpiece W. As shown in the upper diagram of FIG. 10 , the control device 15 can set a reference position P1 in the X direction and a reference distance L1 in the X direction based on the position of the head 51 when the contact detection device 65 held by the head 51 is brought into contact with, for example, the upper surface of the pallet 10. The control device 15 receives, for example, the length of the unmachined workpiece W as the length required for the head 51 to receive the workpiece W from the pallet 10. The control device 15 calculates the distance L3 and the correction distance L6 in the X direction based on the received length and sets the delivery position P6. In the example shown in FIG. 10 , if the workpiece W is held by the second gripper 53, the heavier the workpiece W, the more the X coordinate of the head 51 is displaced downward. Furthermore, the heavier the workpiece W, the more the Y coordinate of the head 51 is displaced toward the lower end 43A (see FIG. 5 ). Even in such a case, by setting a correction formula in advance based on experimental results, the control device 15 can correct the transfer position P6 to an appropriate position according to the weight and length of the workpiece W using the correction value calculated by the correction formula, just like the left-side spindle device 12L described above.

[0062] Incidentally, the stocker device 9 is an example of a counterpart device or a mounting table. The left and right spindle devices 12L, 12R are examples of counterpart devices or spindle devices. The work transport device 14 is an example of an Cartesian robot. The first claw member 57 is an example of a first holding member. The second claw member 58 is an example of a second holding member. The X direction and the Y direction are examples of adjustment directions that are perpendicular to the axial direction of the workpiece W when it is held by the counterpart device. The variable A11 is an example of a work state variable.

[0063] As described above, the present embodiment provides the following effects. In one aspect of this embodiment, the control device 15 acquires the weight and length L2 of the workpiece W on the reception screen 73 of FIG. 7 (an example of an acquisition process of the present disclosure). The control device 15 sets the transfer position P6 based on the acquired weight and length L2 of the workpiece W and a correction formula (an example of a setting process of the present disclosure). This allows an appropriate transfer position P6 to be set using the correction formula according to the weight and length L2 of the workpiece W. Furthermore, calculation of the correction formula allows the transfer position P6 to be set more quickly. Furthermore, with the above-mentioned configuration, the same reference position P1 and reference distance L1 can be used for different types of workpiece W. Even if the types of workpiece W are different, the same reference position P1 can basically be reused, with only the distance between the mating device and the head 51 varying.

[0064] It goes without saying that the present disclosure is not limited to the above-described embodiments, and various improvements and modifications are possible within the scope of the present disclosure. For example, in the above embodiment, the weight and length of the workpiece W input by the user were substituted into a correction formula, and the correction values ​​were calculated to correct the X, Y, and Z coordinates of the transfer position P6. However, the transfer position P6 may be set using a method other than the correction formula. For example, the control device 15 may have a database in the storage device 15B in which the weight and length of the workpiece W and the corresponding X, Y, and Z coordinates of the transfer position P6 are set. The machine tool 1 may then acquire the corresponding X, Y, and Z coordinates from the database based on the weight and length of the workpiece W acquired via the touch panel 3A or the like, and set the transfer position P6. In this case, too, an appropriate transfer position P6 can be set using the database depending on the weight and length of the workpiece W. Alternatively, the database may contain correction values ​​for each coordinate instead of the X, Y, and Z coordinates of the delivery position P6. The control device 15 may then detect correction values ​​corresponding to the weight and length of the workpiece W obtained from the user from the database and correct the delivery position P6 set based on the reference position P1. In this case, too, the database can be used to set an appropriate delivery position P6 according to the weight and length of the workpiece W. Furthermore, the control device 15 may inquire about the correction formula, the corrected XYZ coordinates, the correction values, etc. via the network from a server on the local network or a server of the vendor of the machine tool 1. For example, the control device 15 may transmit the values ​​of the weight and length of the workpiece W obtained from the user to the server via the network, obtain the corrected XYZ coordinates and the correction values, and set the delivery position P6.

[0065] Although not specifically mentioned in the above embodiment, the machine tool 1 may be configured to include (permanently install) the contact detection device 65. For example, the contact detection device 65 may be permanently installed on a table for the workpiece W or on a station for placing tools. In this case, the control device 15 may retrieve the contact detection device 65 using the workpiece transport device 14 when measurement or the like is required, and perform the measurement. Alternatively, as shown by the dashed line in Fig. 5, contact detection device 165 may be attached to head 51. Contact detection device 165 may be configured, for example, to enable stylus 65A to be extended and retracted, and may be configured to cause stylus 65A to protrude forward beyond first claw member 57 during measurement under the control of control device 15. Furthermore, contact detection device 165 may be configured to store stylus 65A within support member 56 when measurement is not being performed and is not required. In this way, machine tool 1 may be provided with contact detection device 165 as part of the device. Furthermore, the configuration of the head 51 in the above embodiment is one example. For example, although the second gripping portion 53 has the same structure as the first gripping portion 52, it may have a different structure. The number of second claw members 58 may be greater than the number of first claw members 57. Furthermore, although the first and second gripping portions 52, 53 are provided at positions rotated 180 degrees, this is not limiting. For example, the second gripping portion 53 may be provided at a position rotated 90 degrees from the first gripping portion 52. Furthermore, the head 51 may include only the first gripping portion 52, and not the second gripping portion 53.

[0066] Furthermore, the master workpiece 63 does not have to be used when setting the reference position shown in FIG. 6 . For example, the reference position P1 may be set by bringing the contact detection device 65 into contact with the center of the face of the left spindle unit 12L facing the head 51 (the center surrounded by multiple child jaws 67, a position on the spindle 69). Therefore, in the above embodiment, the master workpiece 63 is used as the component of the mating device with which the contact detection device 65 comes into contact, but this is not limited thereto. For example, if the left spindle unit 12L has a stopper that seats the workpiece W and grips the workpiece W between it and the child jaws 67, the component with which the contact detection device 65 comes into contact may be the stopper. Furthermore, if the left spindle unit 12L has a master jaw that is arranged opposite the child jaws 67 and grips the workpiece W between it and the child jaws 67, the component with which the contact detection device 65 comes into contact may be the master jaw. Furthermore, if the chuck of the left spindle unit 12L is a collet chuck, the component with which the contact detection device 65 comes into contact may be the collet chuck. Furthermore, the mating devices are not limited to the left and right spindle devices 12L, 12R and the stocker device 9, but may also be, for example, a workpiece inversion device that inverts the orientation of the workpiece W, a temporary table on which the machined workpiece W is placed so that the user can check it, or a discharge chute that discharges defectively machined workpieces W. Furthermore, although the machine tool 1 is provided with a plurality of mating devices (the left and right spindle devices 12L, 12R, and the stocker device 9) as the mating devices of the present disclosure, it may also be configured to have only one mating device (for example, only one spindle device). Furthermore, the control device 15 may execute the reference position setting process for each different type of workpiece W (for each setup change). Furthermore, the control device 15 may correct only one of the X, Y and Z directions for the delivery position P6 using a correction formula. The correction formula does not need to include variable A11. For example, separate correction formulas may be prepared depending on whether or not the workpiece W is held by each of the first and second gripping units 52, 53. For example, four patterns of correction formulas may be prepared: when the workpiece W is not held by both gripping units, when the workpiece W is held by only the first gripping unit 52, when the workpiece W is held by only the second gripping unit 53, and when the workpiece W is held by both gripping units. Then, the control device 15 may select the correction formula to use depending on the holding state of the workpiece W. The left and right machining devices 11L, 11R are not limited to lathes with two opposing axes, but may be lathes with two parallel axes. The left and right machining devices 11L, 11R may be various types of devices, such as a horizontal lathe, a face lathe, a vertical lathe, a machining center, a milling machine, or a drill press. [Explanation of symbols]

[0067] 1 machine tool, 9 stocker device (counter device, stand), 12L left side spindle device (counter device, spindle device), 12R right side spindle device (counter device, spindle device), 15 control device, 14 workpiece transport device (Cartesian robot), 51 head, 52 first gripping unit, 53 second gripping unit, 56 support member, 57 first jaw member (first holding member), 58 second jaw member (second holding member), 65 contact detection device, 69 spindle, 82 center, 83 weight, A11 variable (workpiece status variable), L2 length, P6 delivery position, SI contact detection signal, W workpiece.

Claims

1. A mating device capable of holding a workpiece; a Cartesian robot including a holding member for holding the workpiece, the Cartesian robot executing delivery of the workpiece held by the holding member to the mating device; a control device for controlling the Cartesian robot; Equipped with The control device an acquisition process for acquiring the weight and length of the workpiece when transferring the workpiece to the counterpart device; a setting process for setting a transfer position, which is a position of the Cartesian robot when transferring the workpiece between the Cartesian robot and the counterpart device, based on the weight and length of the workpiece acquired by the acquisition process; Run The control device Calculation using a correction formula is possible, The correction formula is A correction value can be calculated by substituting values ​​of the weight and length of the workpiece held by the holding member into variables, and a change in position of the workpiece held by the Cartesian robot according to the weight and length of the workpiece can be calculated as the correction value, The control device In the setting process, the correction value is calculated based on the weight and length of the workpiece acquired in the acquisition process and the correction formula, and the delivery position is corrected using the correction value. The Cartesian robot is a head provided with the holding member, the holding member being capable of holding the contact detection device; The contact detection device outputting a contact detection signal corresponding to the contact to the control device; The correction formula is A machine tool, wherein the amount of change of the head in each axial direction along which the head can move is determined by measuring the amount of change of the head due to the weight of a measuring weight attached to the head in advance based on the position of the head when the contact detection signal is output from the contact detection device held by the holding member, and the formula is derived from the relationship between the measured amount of change and the weight of the measuring weight.

2. When the direction perpendicular to the axial direction of the workpiece held by the mating device is set as the adjustment direction, The correction formula is The machine tool according to claim 1 , wherein the correction value for correcting the position of the head in the adjustment direction can be calculated.

3. A mating device capable of holding a workpiece; a Cartesian robot including a holding member for holding the workpiece, the Cartesian robot executing delivery of the workpiece held by the holding member to the mating device; a control device for controlling the Cartesian robot; Equipped with The control device an acquisition process for acquiring the weight and length of the workpiece when transferring the workpiece to the counterpart device; a setting process for setting a transfer position, which is a position of the Cartesian robot when transferring the workpiece between the Cartesian robot and the counterpart device, based on the weight and length of the workpiece acquired by the acquisition process; Run The control device Calculation using a correction formula is possible, The correction formula is A correction value can be calculated by substituting values ​​of the weight and length of the workpiece held by the holding member into variables, and a change in position of the workpiece held by the Cartesian robot according to the weight and length of the workpiece can be calculated as the correction value, The control device In the setting process, the correction value is calculated based on the weight and length of the workpiece acquired in the acquisition process and the correction formula, and the delivery position is corrected using the correction value. The Cartesian robot is a head provided with the holding member; The head The holding members include a first holding member and a second holding member that hold the workpiece, The correction formula includes: a work state variable that is changed depending on whether or not the first holding member and the second holding member are holding the workpiece is set, The control device In the acquisition process, information indicating whether the workpiece is held by each of the first holding member and the second holding member is acquired, In the setting process, the work state variable is set based on the information acquired in the acquisition process, and the correction value that corrects the tilt of the head due to the weight of the work held by at least one of the first holding member and the second holding member is calculated based on the correction formula, thereby correcting the transfer position.

4. A mating device capable of holding a workpiece; a Cartesian robot including a holding member for holding the workpiece, the Cartesian robot executing delivery of the workpiece held by the holding member to the mating device; a control device for controlling the Cartesian robot; Equipped with The control device an acquisition process for acquiring the weight and length of the workpiece when transferring the workpiece to the counterpart device; a setting process for setting a transfer position, which is a position of the Cartesian robot when transferring the workpiece between the Cartesian robot and the counterpart device, based on the weight and length of the workpiece acquired by the acquisition process; Run The Cartesian robot is a head provided with the holding member; The head As the holding members, a first holding member and a second holding member that hold the workpiece; a support member on which the first holding member and the second holding member are provided; and The first holding member and the second holding member are are provided at positions facing each other in the thickness direction of the support member, The control device In the acquisition process, a weight of the workpiece held by the second holding member is acquired when the workpiece is received by the first holding member from the counterpart device while the second holding member is holding the workpiece; In the setting process, when the workpiece is received by the first holding member from the opposing device while the second holding member is holding the workpiece, the transfer position in the vertical direction of the Cartesian robot is corrected based on the weight of the workpiece held by the second holding member, and the heavier the workpiece held by the second holding member, the more the transfer position is corrected to a lower position.

5. A mating device capable of holding a workpiece; a Cartesian robot including a holding member for holding the workpiece, the Cartesian robot executing delivery of the workpiece held by the holding member to the mating device; a control device for controlling the Cartesian robot; Equipped with The control device an acquisition process for acquiring the weight and length of the workpiece when transferring the workpiece to the counterpart device; a setting process for setting a transfer position, which is a position of the Cartesian robot when transferring the workpiece between the Cartesian robot and the counterpart device, based on the weight and length of the workpiece acquired by the acquisition process; Run The Cartesian robot is The contact detection device can be held by the holding member, The contact detection device outputting a contact detection signal corresponding to the contact to the control device; The control device In the setting process, the Cartesian robot is moved while the contact detection device is held by the holding member of the Cartesian robot, the contact detection device is brought into contact with the opposing device, the contact detection signal when contact with the opposing device is detected is obtained from the contact detection device, and the transfer position is set based on the position of the Cartesian robot at the time of contact based on the obtained contact detection signal and the weight and length of the workpiece.

6. The other device is a spindle device that rotates the held workpiece around a spindle, The control device 6. The machine tool according to claim 1, wherein in the setting process, the transfer position when transferring the workpiece from the Cartesian robot to the spindle device is set so that the center of the tip of the workpiece held by the Cartesian robot is on the spindle.

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