Machine tool, control method for machine tool, and program

Abstract

To provide a machine tool capable of exchanging a collet without moving the spindle. 【Solution means】The machine tool 100 includes a spindle MS and a collet exchange mechanism CE capable of exchanging a first collet CL1 attached to the spindle MS with a second collet CL2. The collet exchange mechanism CE has a base BP movable along a moving axis DX extending parallel to the axial direction of the spindle MS, and an arm portion AP extending radially outward from the base BP around a circle centered on the moving axis DX. The arm portion AP is configured to be swingable around the moving axis DX. A collet attachment / detachment mechanism EM is attached to the tip of the arm portion AP.

Description

Technical Field

[0001] The present disclosure relates to a machine tool, a control method for a machine tool, and a program.

Background Art

[0002] Conventionally, an inverted lathe (machine tool) equipped with an automatic collet changer mechanism that is gripped by a chuck of a spindle has been known (see Patent Document 1). This automatic changer mechanism is configured to be able to replace the chuck by moving the spindle in a direction perpendicular to the axial direction of the spindle.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described automatic changer mechanism, since it is necessary to move the spindle when replacing the collet, the structure becomes complicated.

[0005] Therefore, it is desired to provide a machine tool capable of replacing the collet without moving the spindle.

Means for Solving the Problems

[0006] A machine tool according to an embodiment of the present disclosure includes a spindle and a collet changer mechanism capable of replacing a first collet attached to the spindle with a second collet. The collet changer mechanism has a base movable along a moving axis extending parallel to the axial direction of the spindle, and an arm portion extending radially outward from the base around the moving axis. The arm portion Using the moving axis that extends parallel to the axial direction of the main shaft as a swing axis is configured to be swingable around the moving axis, and a collet attachment / detachment mechanism is attached to the tip of the arm portion.

Advantages of the Invention

[0007] The above-mentioned machine tool can replace the collet without moving the spindle.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0009] Hereinafter, a machine tool 100 according to an embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a perspective view of the machine tool 100. Specifically, the upper diagram in FIG. 1 is a perspective view of the machine tool 100 with the cover CR attached, and the lower diagram in FIG. 1 is a perspective view of the machine tool 100 with the cover CR removed.

[0010] In FIG. 1, X1 represents one direction of the X-axis that constitutes a three-dimensional orthogonal coordinate system, and X2 represents the other direction of the X-axis. Also, Y1 represents one direction of the Y-axis that constitutes a three-dimensional orthogonal coordinate system, and Y2 represents the other direction of the Y-axis. Similarly, Z1 represents one direction of the Z-axis that constitutes a three-dimensional orthogonal coordinate system, and Z2 represents the other direction of the Z-axis. In FIG. 1, the X1 side of the machine tool 100 corresponds to the front side (front face side) of the machine tool 100, and the X2 side of the machine tool 100 corresponds to the rear side (rear face side) of the machine tool 100. Also, the Y1 side of the machine tool 100 corresponds to the left side of the machine tool 100, and the Y2 side of the machine tool 100 corresponds to the right side of the machine tool 100. Further, the Z1 side of the machine tool 100 corresponds to the upper side of the machine tool 100, and the Z2 side of the machine tool 100 corresponds to the lower side of the machine tool 100. The same applies to other figures.

[0011] The machine tool 100 is a device that processes a bar material held by a rotating spindle MS with a cutting tool. In the illustrated example, as shown in the lower figure of FIG. 1, the machine tool 100 has a spindle MS with a collet attached to its tip and a collet exchange mechanism CE for exchanging the collet.

[0012] Also, as shown in the upper figure of FIG. 1, the machine tool 100 has a controller CTR that controls the movement of the machine tool 100. In the illustrated example, the controller CTR is configured to include a computer (microcomputer) equipped with a CPU, a volatile memory device, a non-volatile memory device, an input / output interface, and the like. Specifically, the controller CTR can output a control command to the collet exchange mechanism CE and operate the collet exchange mechanism CE by the CPU executing a program stored in a storage medium such as a non-volatile memory device.

[0013] Next, referring to FIGS. 2 and 3, the collet exchange mechanism CE will be described. FIG. 2 is a schematic diagram of the collet exchange mechanism CE. Specifically, the upper figure of FIG. 2 is a front view of the collet exchange mechanism CE, and the lower figure of FIG. 2 is a plan view of the collet exchange mechanism CE. FIG. 3 is a right side view of the spindle MS with the collet CL attached and the collet exchange mechanism CE.

[0014] The collet exchange mechanism CE includes a first actuator AC1 to a fourth actuator AC4, an arm portion AP, a base portion BP, a collet holder CH, a collet attachment / detachment mechanism EM, a lid portion LD, a movable pedestal MP, and a pushing mechanism PM. In FIG. 3, for clarity of explanation, the illustration of the lid portion LD is omitted.

[0015] The first actuator AC1 is an actuator that moves a movable part including the arm portion AP, the base portion BP, the collet attachment / detachment mechanism EM, and the pushing mechanism PM along a movement axis DX parallel to the axis direction (Y-axis direction) of the main spindle MS with respect to the frame of the machine tool 100. In the illustrated example, the first actuator is an electric actuator driven by a ball screw. However, the first actuator may be any other actuator.

[0016] The second actuator AC2 is an actuator that swings the arm portion AP around the movement axis DX with respect to the base portion BP. In the illustrated example, the second actuator is an electric stepping motor. However, the second actuator may be any other actuator.

[0017] The third actuator AC3 is an actuator that moves the collet holder CH in a direction perpendicular to the movement axis DX with respect to the movable pedestal MP. In the illustrated example, the third actuator is an electric actuator driven by a ball screw. However, the third actuator may be any other actuator.

[0018] The fourth actuator AC4 is an actuator that moves the movable pedestal MP along the movement axis DX with respect to the frame of the machine tool 100. In the illustrated example, the fourth actuator is a pneumatic cylinder. However, the fourth actuator may be any other actuator.

[0019] The arm portion AP is a member swingably connected to the base portion BP, and the collet attachment / detachment mechanism EM and the pushing mechanism PM are fixed to the tip portion.

[0020] The base BP is a member configured to be movable along the axial direction of the spindle MS with respect to the frame of the machine tool 100. In the illustrated example, a second actuator AC2 is fixed to the base BP, and a lid LD is fixed to the tip of the base BP.

[0021] The collet holder CH is a member capable of holding a plurality of collets CL and is configured to be movable in a direction perpendicular to the moving axis DX. In the illustrated example, as shown in FIG. 3, the collet holder CH has four holder parts HP (first holder part HP1 to fourth holder part HP4) and is configured to be able to hold four collets CL. In the example shown in FIG. 3, the second collet CL2 is fitted and held in the first holder part HP1, and no collet CL is fitted in the remaining three holder parts HP (second holder part HP2 to fourth holder part HP4). Further, the collet holder CH is arranged such that the moving direction is inclined by an angle α with respect to the X-axis direction in a right side view in order to improve the space efficiency inside the machine tool 100. However, the collet holder CH may be arranged such that the moving direction is parallel or perpendicular to the X-axis direction.

[0022] The collet attachment / detachment mechanism EM is a mechanism for attaching the collet CL to a collet receiving part such as the chuck part of the spindle MS or the holder part HP of the collet holder CH and for detaching the collet CL from the collet receiving part. In the illustrated example, the collet attachment / detachment mechanism EM is a mechanism driven by a hydraulic cylinder and is configured to be able to attach and detach the collet CL used in a quick change collet chuck system to and from the collet receiving part. Specifically, the collet attachment / detachment mechanism EM is configured to be able to attach and detach the collet CL to and from the collet receiving part using a plurality of parallel pins 20. However, the collet attachment / detachment mechanism EM may be configured to be able to attach and detach the collet CL used in any other collet chuck system to and from the collet receiving part.

[0023] The cover part LD is a member attached to the tip (right end part) of the base part BP, and is a member for protecting the collet exchange mechanism CE from chips generated during cutting of a bar by the machine tool 100, or cleaning liquid or the like used for cleaning a workpiece, a cutting tool, or the like. In the illustrated example, the cover part LD is configured as a member that closes a through hole HL provided in a partition wall PW (see the lower figure in FIG. 1) that separates the inside and outside of the machining space SP of the machine tool 100. The first actuator AC1 can cover the through hole HL with the cover part LD by moving the base part BP, to the tip of which the cover part LD is fixed (projecting into the machining space SP), to the Y1 side (left side). In FIG. 2, for clarity, the position of the partition wall PW is represented by a two-dot chain line.

[0024] The movable pedestal MP is a movable member for supporting the third actuator AC3 and the collet holder CH, and is configured to be movable along the Y-axis direction with respect to the frame of the machine tool 100.

[0025] The pushing mechanism PM is a mechanism for pushing a bar gripped by the main shaft MS into the inside of the main shaft MS. The pushing mechanism PM is configured to be able to insert and remove a pushing pin 10 for pushing a bar gripped by the main shaft MS into the inside of the main shaft MS. In the illustrated example, the pushing pin 10 is a rod of a single-rod type hydraulic cylinder.

[0026] Further, in the right side view shown in FIG. 3, the collet exchange mechanism CE is configured such that the rotation axis MX of the main shaft MS, the central axis EX of the collet attachment / detachment mechanism EM, the central axis PX of the pushing pin 10, and the central axis CX of the collet CL (the central axis CX1 of the first collet CL1 in the illustrated example) attached to the main shaft MS are each located on the circumference of a circle RG1 having a radius RD centered on the moving axis DX. Further, the collet exchange mechanism CE is configured such that the central axis CX of each collet CL (the central axis CX2 of the second collet CL2 in the illustrated example) held by the holder part HP of the collet holder CH is positioned on the circumference of the circle RG1.

[0027] Next, referring to FIGS. 4 to 10, the movement of the collet exchange mechanism CE will be described. Each of FIGS. 4 to 9 is a perspective view of the collet exchange mechanism CE and the main spindle MS, and FIG. 10 is a cross-sectional view of the main spindle MS and the pushing mechanism PM. In FIGS. 4 to 9, for clarity of explanation, the illustration of the lid portion LD is omitted. Specifically, FIG. 4 shows four states (the first state ST1 to the fourth state ST4) of the machine tool 100, FIG. 5 shows four states (the fifth state ST5 to the eighth state ST8) of the machine tool 100, and FIG. 6 shows four states (the ninth state ST9 to the twelfth state ST12) of the machine tool 100. Further, FIG. 7 shows four states (the thirteenth state ST13 to the sixteenth state ST16) of the machine tool 100, FIG. 8 shows three states (the seventeenth state ST17 to the nineteenth state ST19) of the machine tool 100, and FIG. 9 shows two states (the twentieth state ST20 and the twenty-first state ST21) of the machine tool 100. FIG. 10 is a cross-sectional view of the main spindle MS and the pushing mechanism PM in the twenty-first state.

[0028] In the illustrated example, when exchanging the first collet CL1 mounted on the main spindle MS for the second collet CL2 held by the collet holder CH, the state of the collet exchange mechanism CE transitions in the order of the first state ST1, the second state ST2, ···, the eighteenth state ST18, and the nineteenth state ST19. Also, when pushing the bar stock gripped by the main spindle MS into the main spindle MS by the pushing mechanism PM, the state of the collet exchange mechanism CE transitions in the order of the first state ST1, the twentieth state ST20, and the twenty-first state ST21.

[0029] In the first state ST1 as the initial state, the base BP of the collet exchange mechanism CE is retracted to the Y1 side (left side) of the partition wall PW so that the through hole HL formed in the partition wall PW (see the lower figure in FIG. 1) can be closed by the lid portion LD. Further, the first collet CL1 is mounted on the main spindle MS, and the second collet CL2 is held in the first holder portion HP1 of the collet holder CH.

[0030] Thereafter, when the collet exchange mechanism CE exchanges the first collet CL1 mounted on the main spindle MS for the second collet CL2, as indicated by the arrow AR1 in the second state ST2, the first actuator AC1 is driven to move the base BP to the Y2 side (right side).

[0031] Thereafter, as indicated by the arrow AR2 in the third state ST3, the collet exchange mechanism CE drives the second actuator AC2 to swing the arm portion AP downward about the moving axis DX. Specifically, the collet exchange mechanism CE swings the arm portion AP downward about the moving axis DX until the central axis EX of the collet attachment / detachment mechanism EM fixed to the tip of the arm portion AP coincides with the rotation axis MX of the main spindle MS (is positioned on the same straight line).

[0032] Thereafter, as indicated by the arrow AR3 in the fourth state ST4, the collet exchange mechanism CE drives the first actuator AC1 to move the base BP to the Y1 side (left side). As a result, the parallel pin 20 (see the upper figure in FIG. 2) in the collet attachment / detachment mechanism EM is inserted into the corresponding hole in the first collet CL1. Then, the collet attachment / detachment mechanism EM removes the first collet CL1 from the chuck of the main spindle MS using the force generated by the hydraulic cylinder.

[0033] Thereafter, as indicated by the arrow AR4 in the fifth state ST5 in FIG. 5, the collet exchange mechanism CE drives the first actuator AC1 to move the base BP to the Y2 side (right side). As a result, the first collet CL1 mounted on the main spindle MS is separated from the main spindle MS and moves to the Y2 side (right side) together with the collet attachment / detachment mechanism EM.

[0034] Thereafter, as indicated by arrow AR5 in the sixth state ST6, the collet exchange mechanism CE drives the second actuator AC2 to swing the arm portion AP upward about the movement axis DX. Specifically, the collet exchange mechanism CE swings the arm portion AP upward about the movement axis DX until the central axis EX (central axis CX1 of the first collet CL1) of the collet attachment / detachment mechanism EM fixed to the tip of the arm portion AP coincides with the central axis HX of the holder portion HP of the collet holder CH (is positioned on the same straight line).

[0035] Thereafter, as indicated by arrow AR6 in the seventh state ST7, the collet exchange mechanism CE drives the third actuator AC3 to move the collet holder CH toward the X1 side (front). Specifically, the collet exchange mechanism CE moves the collet holder CH toward the X1 side (front) until the central axis EX (central axis CX1 of the first collet CL1) of the collet attachment / detachment mechanism EM coincides with the central axis HX2 of the second holder portion HP2 of the collet holder CH (is positioned on the same straight line).

[0036] Thereafter, as indicated by arrow AR7 in the eighth state ST8, the collet exchange mechanism CE drives the fourth actuator AC4 to move the movable pedestal MP toward the Y2 side (right). As a result, the third actuator AC3 and the collet holder CH fixed to the movable pedestal MP also move toward the Y2 side (right).

[0037] Thereafter, as indicated by arrow AR8 in the ninth state ST9 of FIG. 6, the collet exchange mechanism CE drives the first actuator AC1 to move the base BP toward the Y1 side (left). As a result, the first collet CL1 held by the collet attachment / detachment mechanism EM is fitted into the second holder portion HP2 of the collet holder CH. Then, the collet attachment / detachment mechanism EM attaches the first collet CL1 to the second holder portion HP2 using the force generated by the hydraulic cylinder.

[0038] Thereafter, as indicated by arrow AR9 in the 10th state ST10, the collet exchange mechanism CE drives the fourth actuator AC4 to move the movable pedestal MP to the Y1 side (left side). As a result, the first collet CL1 held by the collet attachment / detachment mechanism EM is separated from the collet attachment / detachment mechanism EM and moves to the Y1 side (left side) together with the collet holder CH.

[0039] Thereafter, as indicated by arrow AR10 in the 11th state ST11, the collet exchange mechanism CE drives the third actuator AC3 to move the collet holder CH to the X2 side (rear). Specifically, the collet exchange mechanism CE moves the collet holder CH to the X2 side (rear) until the central axis EX of the collet attachment / detachment mechanism EM coincides with the central axis HX1 of the first holder portion HP1 of the collet holder CH (the central axis CX2 of the second collet CL2) (is positioned on the same straight line).

[0040] Thereafter, as indicated by arrow AR11 in the 12th state ST12, the collet exchange mechanism CE drives the fourth actuator AC4 to move the movable pedestal MP to the Y2 side (right side). As a result, the parallel pin 20 (see the upper figure in FIG. 2) in the collet attachment / detachment mechanism EM is inserted into the corresponding hole in the second collet CL2 held by the first holder portion HP1 of the collet holder CH. Then, the collet attachment / detachment mechanism EM removes the second collet CL2 from the first holder portion HP1 using the force generated by the hydraulic cylinder.

[0041] Thereafter, as indicated by arrow AR12 in the 13th state ST13 in FIG. 7, the collet exchange mechanism CE drives the fourth actuator AC4 to move the movable pedestal MP to the Y1 side (left side). As a result, the second collet CL2 held by the first holder portion HP1 of the collet holder CH is separated from the first holder portion HP1.

[0042] After that, as indicated by arrow AR13 in the 14th state ST14, the collet exchange mechanism CE drives the first actuator AC1 to move the base BP to the Y2 side (right side). As a result, the second collet CL2 moves to the Y2 side (right side) together with the collet attachment / detachment mechanism EM.

[0043] After that, as indicated by arrow AR14 in the 15th state ST15, the collet exchange mechanism CE drives the second actuator AC2 to swing the arm portion AP downward around the movement axis DX. Specifically, the collet exchange mechanism CE swings the arm portion AP downward around the movement axis DX until the central axis EX of the collet attachment / detachment mechanism EM (the central axis CX2 of the second collet CL2) fixed to the tip of the arm portion AP coincides with the rotation axis MX of the main spindle MS (is positioned on the same straight line).

[0044] After that, as indicated by arrow AR15 in the 16th state ST16, the collet exchange mechanism CE drives the first actuator AC1 to move the base BP to the Y1 side (left side). As a result, the second collet CL2 is fitted into the chuck of the main spindle MS. Then, the collet attachment / detachment mechanism EM attaches the second collet CL2 to the chuck of the main spindle MS using the force generated by the hydraulic cylinder.

[0045] After that, as indicated by arrow AR16 in the 17th state ST17 of FIG. 8, the collet exchange mechanism CE drives the first actuator AC1 to move the base BP to the Y2 side (right side). As a result, the collet attachment / detachment mechanism EM is separated from the second collet CL2 attached to the chuck of the main spindle MS and moves to the Y2 side (right side).

[0046] After that, as indicated by arrow AR17 in the 18th state ST18, the collet exchange mechanism CE drives the second actuator AC2 to swing the arm portion AP upward around the movement axis DX.

[0047] After that, as indicated by arrow AR18 in the 19th state ST19, the collet exchange mechanism CE drives the first actuator AC1 to move the base BP to the Y1 side (leftward). That is, the state of the collet exchange mechanism CE returns to the first state (see FIG. 4) as the initial state. As a result, the lid LD (see FIG. 2) fixed to the tip of the base BP closes the through-hole HL formed in the partition wall PW, and it is possible to prevent the collet exchange mechanism CE from being exposed to chips or cleaning liquid or the like.

[0048] In this way, the collet exchange mechanism CE can replace the first collet CL1 mounted on the spindle MS with the second collet CL2 accommodated in the collet holder CH. Also, the collet exchange mechanism CE can accommodate the first collet CL1 mounted on the spindle MS in the collet holder CH.

[0049] Also, when the collet exchange mechanism CE in the initial state pushes the bar material held by the spindle MS into the spindle MS by the pushing mechanism PM, as indicated by arrow AR19 in the 20th state ST20 of FIG. 9, the first actuator AC1 is driven to move the base BP to the Y2 side (rightward).

[0050] After that, as indicated by arrow AR20 in the 20th state ST20, the collet exchange mechanism CE drives the second actuator AC2 to swing the arm portion AP downward about the moving shaft DX. Specifically, the collet exchange mechanism CE swings the arm portion AP downward about the moving shaft DX until the central axis PX of the pushing mechanism PM fixed to the tip of the arm portion AP coincides with the rotation axis MX of the spindle MS (is positioned on the same straight line).

[0051] After that, as indicated by arrow AR21 in the second state ST21, the collet exchange mechanism CE drives the first actuator AC1 to move the base BP to the Y1 side (left side). As a result, the pushing pin 10 (see the upper figure in FIG. 2) in the pushing mechanism PM can come into contact with the tip of the bar held by the main shaft MS, and the bar can be pushed into the main shaft MS. Specifically, as shown in FIG. 10, the pushing mechanism PM can project the pushing pin 10 to the Y1 side (left side) and push the bar held by the first collet CL1 attached to the chuck of the main shaft MS to the Y1 side (left side).

[0052] In this way, the collet exchange mechanism CE can push the bar held by the main shaft MS into the main shaft MS by the pushing mechanism PM. After pushing the bar, the pushing mechanism PM can retract the pushing pin 10 to the Y2 side (right side) until the tip of the pushing pin 10 (the end on the Y1 side) exits from the first collet CL1. After that, the collet exchange mechanism CE drives the second actuator AC2 to swing the arm portion AP upward around the moving axis DX, and drives the first actuator AC1 to move the base BP to the Y1 side (left side), thereby returning to the first state ST1 (see FIG. 4) as the initial state.

[0053] Next, referring to FIG. 11, a process (hereinafter referred to as "collet exchange process") in which the controller CTR exchanges the first collet CL1 attached to the main shaft MS with the second collet CL2 will be described. FIG. 11 is a flowchart showing an example of the flow of the collet exchange process. The controller CTR repeatedly executes this collet exchange process at a predetermined control cycle.

[0054] First, the controller CTR determines whether a collet exchange command has been received (step PR1). In the illustrated example, the controller CTR determines whether a collet exchange command has been received from the outside through communication. Note that the collet exchange command may be input by an operator around the machine tool 100 through an input device such as a touch panel attached to the controller CTR.

[0055] When it is determined that no collet replacement command has been received (NO in step PR1), the controller CTR ends the current collet replacement process. On the other hand, when it is determined that a collet replacement command has been received (YES in step PR1), the controller CTR determines whether the old collet is holding the workpiece (bar BR) (step PR2). The "old collet" is the collet CL before replacement that was mounted on the main spindle MS, and in the illustrated example, it is the first collet CL1.

[0056] When it is determined that the old collet is holding the bar BR (YES in step PR2), the controller CTR executes the pushing of the bar BR into the main spindle MS (step PR3). In the illustrated example, the controller CTR outputs an operation command to the pushing mechanism PM, and as shown in FIG. 10, the pushing pin 10 protrudes to the Y1 side (left side), and the bar held by the first collet CL1 mounted on the chuck of the main spindle MS is pushed to the Y1 side (left side). As a result, the pushing mechanism PM can achieve a state where the first collet CL1 is not holding the bar BR.

[0057] Thereafter, the controller CTR removes the old collet from the main spindle MS (step PR4). When it is determined that the old collet is not holding the bar BR (NO in step PR2), the controller CTR executes step PR4 without executing step PR3. In the illustrated example, in step PR4, the controller CTR operates the collet exchange mechanism CE as shown from the first state ST1 in FIG. 4 to the fifth state ST5 in FIG. 5, and removes the first collet CL1 as the old collet from the main spindle MS.

[0058] Thereafter, the controller CTR determines whether or not the holder portion HP of the collet holder CH is empty (step PR5). In the illustrated example, the controller CTR determines whether or not a collet CL is already fitted in a first holder portion HP1 that is on the extension line of the central axis EX of the collet attachment / detachment mechanism EM in the sixth state ST6 of FIG. 5. In the illustrated example, since a second collet CL2 is fitted in the first holder portion HP1, the controller CTR determines that the holder portion HP of the collet holder CH is not empty. Conversely, if the collet CL is not fitted in the first holder portion HP1, the controller CTR determines that the holder portion HP of the collet holder CH is empty. Note that the controller CTR determines which of the four holder portions HP of the collet holder CH is located on the extension line of the central axis EX of the collet attachment / detachment mechanism EM based on information stored in a volatile memory device, a non-volatile memory device, or the like. The same applies to whether or not a collet CL is fitted in each of the four holder portions HP of the collet holder CH. Also, the information stored in a volatile memory device, a non-volatile memory device, or the like includes information such as the position of the collet holder CH, the rotation angle of the arm portion AP, the position of the base portion BP, and whether or not the collet attachment / detachment mechanism EM is gripping the collet CL.

[0059] And when it is determined that the holder portion HP of the collet holder CH is not empty (NO in step PR5), the controller CTR moves the collet holder CH (step PR6). In the illustrated example, as shown in the seventh state ST7 of FIG. 5, the controller CTR moves the collet holder CH along the X-axis direction so as to position a second holder portion HP2 in which the collet CL is not fitted on the extension line of the central axis EX of the collet attachment / detachment mechanism EM.

[0060] Then, after positioning the second holder part HP2 in which the collet CL is not fitted on the extension line of the central axis EX of the collet attachment / detachment mechanism EM, the controller CTR stores the old collet (step PR7). In the illustrated example, the controller CTR operates the collet exchange mechanism CE as shown in the eighth state ST8 of FIG. 5 and the ninth state ST9 of FIG. 6, and fits the first collet CL1 as the old collet into the second holder part HP2 of the collet holder CH. When it is determined that the holder part HP of the collet holder CH is empty (YES in step PR5), the controller CTR executes step PR7 without executing step PR6.

[0061] Thereafter, the controller CTR moves the collet holder CH (step PR8). In the illustrated example, the controller CTR moves the collet holder CH as shown in the tenth state ST10 and the eleventh state ST11 of FIG. 6. Then, the controller CTR positions the holder part HP in which the new collet is fitted on the extension line of the central axis EX of the collet attachment / detachment mechanism EM. The "new collet" is the collet CL after being newly attached to the main spindle MS, and in the illustrated example, it is the second collet CL2.

[0062] Thereafter, the controller CTR picks up the new collet (step PR9). In the illustrated example, the controller CTR operates the collet exchange mechanism CE as shown in the twelfth state ST12 of FIG. 6 and the thirteenth state ST13 of FIG. 7. As a result, the collet attachment / detachment mechanism EM can pick up the second collet CL2 accommodated in the first holder part HP1 of the collet holder CH as the new collet.

[0063] Thereafter, the controller CTR attaches the new collet to the main spindle MS (step PR10). In the illustrated example, the controller CTR operates the collet exchange mechanism CE as shown from the fourteenth state ST14 to the sixteenth state ST16 of FIG. 7. As a result, the collet attachment / detachment mechanism EM can attach the second collet CL2 to the main spindle MS as the new collet.

[0064] In this way, the controller CTR can replace the old collet (first collet CL1) attached to the main shaft MS with a new collet (second collet CL2).

[0065] As described above, the machine tool 100 according to the embodiment of the present disclosure includes, as shown in FIG. 4, a main shaft MS and a collet exchange mechanism CE capable of exchanging a first collet CL1 attached to the main shaft MS with a second collet CL2. The collet exchange mechanism CE has a base BP movable along a moving axis DX extending parallel to the axial direction (Y-axis direction) of the main shaft MS, and an arm portion AP extending radially outward from the base BP around the moving axis DX. The arm portion AP is configured to be swingable around the moving axis DX. A collet attachment / detachment mechanism EM is attached to the tip of the arm portion AP.

[0066] This configuration has the effect of being able to replace the collet CL without moving the main shaft MS. Therefore, this configuration has the effect of suppressing the complication of the structure of the machine tool 100.

[0067] Further, as shown in the lower diagram of FIG. 2, the collet exchange mechanism CE may have a collet holder CH capable of holding a plurality of collets CL such that a plurality of collets including the second collet CL2 are arranged along a first direction (X-axis direction) perpendicular to the axial direction (Y-axis direction) of the main shaft MS, and an actuator (third actuator AC3) capable of transporting the plurality of collets CL along the first direction.

[0068] This configuration has the effect of being able to automatically exchange the collet CL attached to the main shaft MS with one of the plurality of collets CL held by the collet holder CH. Therefore, this configuration has the effect of enhancing the versatility of the machine tool 100 compared to a configuration in which the collet holder CH can hold only one collet CL. This is because the collet CL attached to the main shaft MS can be exchanged with one of the plurality of collets CL corresponding to a plurality of bar materials having different diameters.

[0069] Also, as shown in FIG. 3, the collet exchange mechanism CE may be configured such that when viewed along the axial direction (Y-axis direction) of the main shaft MS, the distance (radius RD) between the central axis CX2 of the second collet CL2 held by the collet holder CH and the moving axis DX is the same as the distance (radius RD) between the central axis CX1 of the first collet CL1 attached to the main shaft MS and the moving axis DX, so that the second collet CL2 can be positioned.

[0070] This configuration has the effect of simplifying the structure of the collet exchange mechanism CE because there is no need to make the arm portion AP extendable and retractable.

[0071] Further, as shown in FIG. 10, a pushing mechanism PM for pushing a bar (not shown) gripped by the main shaft MS into the main shaft MS may be attached to the tip of the arm portion AP.

[0072] Specifically, as shown in FIG. 10, the pushing mechanism PM may be configured to be able to insert and remove a pushing pin 10 for pushing a bar (not shown) gripped by the main shaft MS into the main shaft MS. And, as shown in FIG. 3, the pushing pin 10 may be arranged such that the distance (radius RD) between the central axis PX of the pushing pin 10 and the moving axis DX is the same as the distance (radius RD) between the central axis CX1 of the first collet CL1 attached to the main shaft MS and the moving axis DX.

[0073] This configuration has the effect of simplifying the machine tool 100 (collet exchange mechanism CE) compared to the case where the pushing mechanism PM is attached to an arm portion different from the arm portion AP to which the collet attachment / detachment mechanism EM is attached. Also, for the same reason, this configuration has the effect of improving the space efficiency inside the machine tool 100.

[0074] Further, the machine tool 100 may have a computer (controller CTR) that controls the movement of the collet changer CE. Then, as shown from the first state ST1 in FIG. 4 to the fifth state ST5 in FIG. 5, the controller CTR may operate the collet changer CE to remove the first collet CL1 from the spindle MS. Further, as shown from the sixth state ST6 in FIG. 5 to the ninth state ST9 in FIG. 6, the controller CTR may operate the collet changer CE to store the removed first collet CL1 in a predetermined position (second holder portion HP2). Further, as shown from the tenth state ST10 in FIG. 6 to the thirteenth state ST13 in FIG. 7, the controller CTR may operate the collet changer CE to pick up the second collet CL2 stored in another predetermined position (first holder portion HP1). Further, as shown from the fourteenth state ST14 to the sixteenth state ST16 in FIG. 7, the controller CTR may operate the collet changer CE to mount the picked-up second collet CL2 on the spindle MS.

[0075] With this configuration, the machine tool 100 can automatically operate the collet changer CE and automatically exchange the collet CL (first collet CL1) mounted on the spindle MS with another collet CL (second collet CL2) accommodated in the collet holder CH. Further, the machine tool 100 can automatically accommodate the collet (first collet CL1) mounted on the spindle MS in the collet holder CH.

[0076] Further, as shown in FIG. 10, the computer (controller CTR) may operate the collet changer CE (pushing mechanism PM) to push the bar stock held by the first collet CL1 mounted on the spindle MS into the spindle MS.

[0077] With this configuration, the machine tool 100 can remove the collet (first collet CL1) that is not holding the bar stock from the main spindle MS. In other words, even when the collet (first collet CL1) is currently holding the bar stock, the machine tool 100 can replace that collet (first collet CL1) with another collet (second collet CL2).

[0078] Also, as shown in FIG. 11, the control method of the machine tool 100 according to the embodiment of the present disclosure includes steps in which the controller CTR operates the collet changer mechanism CE to remove the first collet CL1 from the main spindle MS (see step PR4), the controller CTR operates the collet changer mechanism CE to store the removed first collet CL1 at a predetermined position (see step PR7), the controller CTR operates the collet changer mechanism CE to pick up the second collet CL2 stored at another predetermined position (see step PR9), and the controller CTR operates the collet changer mechanism CE to attach the picked-up second collet CL2 to the main spindle MS (see step PR10).

[0079] This control method has the effect of enabling the replacement of the collet CL without operating the machine tool 100 to move the main spindle MS of the machine tool 100. Therefore, this control method has the effect of enabling the machine tool 100 to execute the function of automatically replacing the collet CL while suppressing the complication of the structure of the machine tool 100.

[0080] In addition, as shown in FIG. 11, the program used in the machine tool 100 according to the embodiment of the present disclosure causes a computer to execute a process of operating the collet changer CE to remove the first collet CL1 from the spindle MS (see step PR4), a process of operating the collet changer CE to store the removed first collet CL1 at a predetermined position (see step PR7), a process of operating the collet changer CE to pick up the second collet CL2 stored at another predetermined position (see step PR9), and a process of operating the collet changer CE to mount the picked-up second collet CL2 on the spindle MS (see step PR10).

[0081] This program brings about the effect that the collet CL can be exchanged without moving the spindle MS of the machine tool 100 while using the machine tool 100. Therefore, this program brings about the effect that the machine tool 100 can be made to execute the function of automatically exchanging the collet CL while suppressing the complication of the structure of the machine tool 100.

[0082] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments. Various modifications, substitutions, etc. can be applied to the above-described embodiments without departing from the scope of the present invention. Also, each of the features described with reference to the above embodiments may be appropriately combined as long as there is no technical contradiction.

Explanation of Reference Numerals

[0083] 10 ··· Press-in pin 20 ··· Parallel pin 100 ··· Machine tool AC1 ··· First actuator AC2 ··· Second actuator AC3 ··· Third actuator AC4 ··· Fourth actuator AP ··· Arm part BP ··· Base part CE ··· Collet exchange mechanism CH ··· Collet holder CL ··· Collet CL1 ··· First collet CL2 ··· Second collet CL3 ··· Third collet CL4 ··· Fourth collet CTR ··· Controller CX, CX1~CX4 ··· Central axis CR ··· Cover DX ··· Moving axis EM ··· Collet attachment / detachment mechanism EX ··· Central axis HL ··· Through hole HP ··· Holder part HP1 ··· First holder part HP2 ··· Second holder part HP3 ··· Third holder part HP4 ··· Fourth holder part LD ··· Cover part MP ··· Movable pedestal MS ··· Spindle MX ··· Rotating axis PM ··· Press-in mechanism PX ··· Central axis PW ··· Partition RG1 ··· Circle RD ··· Radius SP ··· Machining space

Claims

1. A spindle, and a collet exchange mechanism for detachably replacing a first collet attached to the spindle with a second collet, wherein the collet exchange mechanism has a base movable along a moving axis extending parallel to the axis of the spindle, and an arm portion extending radially outward from the base in a direction perpendicular to the axis of the moving axis, the arm portion is configured to be swingable around the moving axis with the moving axis extending parallel to the axis of the spindle as a swing axis, and a collet attachment / detachment mechanism is attached to the tip of the arm portion. A machine tool characterized by the above.

2. The collet exchange mechanism has a collet holder capable of holding a plurality of collets including the second collet so that the plurality of collets are arranged along a first direction perpendicular to the axis of the spindle, and an actuator capable of transporting the plurality of collets along the first direction. The machine tool according to Claim 1.

3. A machine tool comprising a spindle, and a collet exchange mechanism for detachably replacing a first collet attached to the spindle with a second collet, wherein the collet exchange mechanism has a base movable along a moving axis extending parallel to the axis of the spindle, and an arm portion extending radially outward from the base in a direction perpendicular to the axis of the moving axis, the arm portion is configured to be swingable around the moving axis, a collet attachment / detachment mechanism is attached to the tip of the arm portion, the collet exchange mechanism has a collet holder capable of holding a plurality of collets including the second collet so that the plurality of collets are arranged along a first direction perpendicular to the axis of the spindle, and an actuator capable of transporting the plurality of collets along the first direction, and the collet exchange mechanism positions the second collet so that the distance between the central axis of the second collet held by the collet holder and the moving axis is the same as the distance between the central axis of the first collet attached to the spindle and the moving axis when viewed along the axis of the spindle. A machine tool characterized by the above.

4. A machine tool comprising a spindle, and a collet exchange mechanism for detachably replacing a first collet attached to the spindle with a second collet, wherein the collet exchange mechanism has a base movable along a moving axis extending parallel to the axis of the spindle, and an arm portion extending radially outward from the base in a direction perpendicular to the axis of the moving axis, The arm portion is configured to be swingable around the moving axis, a collet attachment / detachment mechanism is attached to the tip of the arm portion, a pushing mechanism for pushing the bar material held by the main shaft into the main shaft is attached to the tip of the arm portion, A machine tool characterized by the above.

5. The pushing mechanism is configured to insert and remove a pushing pin for pushing the bar material held by the main shaft into the main shaft, the pushing pin is arranged such that the distance between the central axis of the pushing pin and the moving axis is the same as the distance between the central axis of the first collet attached to the main shaft and the moving axis, The machine tool according to claim 4.

6. It has a computer for controlling the movement of the collet exchange mechanism, the computer, operates the collet exchange mechanism to remove the first collet from the main shaft, operates the collet exchange mechanism to store the removed first collet in a predetermined position, operates the collet exchange mechanism to pick up the second collet stored in another predetermined position, and operates the collet exchange mechanism to attach the picked-up second collet to the main shaft. The machine tool according to claim 1.

7. A main shaft, a collet exchange mechanism capable of exchanging a first collet attached to the main shaft with a second collet, a computer for controlling the movement of the collet exchange mechanism, a machine tool comprising: the collet exchange mechanism has a base portion movable along a moving axis extending parallel to the axial direction of the main shaft, and an arm portion extending radially outward from the base portion around the moving axis, the arm portion is configured to be swingable around the moving axis, a collet attachment / detachment mechanism is attached to the tip of the arm portion, the computer, operates the collet exchange mechanism to push the bar material held by the first collet attached to the main shaft into the main shaft, operates the collet exchange mechanism to remove the first collet from the main shaft, operates the collet exchange mechanism to store the removed first collet in a predetermined position, operates the collet exchange mechanism to pick up the second collet stored in another predetermined position, and Operating the collet exchange mechanism so as to attach the picked-up second collet to the spindle. A machine tool characterized by the above.

8. A control method for a machine tool, wherein the machine tool comprises a spindle and a collet exchange mechanism capable of exchanging a first collet attached to the spindle with a second collet. The collet exchange mechanism has a base movable along a moving axis extending parallel to the axial direction of the spindle, and an arm portion extending radially outward from the base about the moving axis. The arm portion is configured to be swingable about the moving axis with the moving axis extending parallel to the axial direction of the spindle as a swing axis. A collet attachment / detachment mechanism is attached to the tip of the arm portion. The control method includes the computer operating the collet exchange mechanism to remove the first collet from the spindle, the computer operating the collet exchange mechanism to store the removed first collet at a predetermined position, the computer operating the collet exchange mechanism to pick up the second collet stored at another predetermined position, and the computer operating the collet exchange mechanism to attach the picked-up second collet to the spindle. A control method for a machine tool.

9. A program used in a machine tool, wherein the machine tool comprises a spindle and a collet exchange mechanism capable of exchanging a first collet attached to the spindle with a second collet. The collet exchange mechanism has a base movable along a moving axis extending parallel to the axial direction of the spindle, and an arm portion extending radially outward from the base about the moving axis. The arm portion is configured to be swingable about the moving axis with the moving axis extending parallel to the axial direction of the spindle as a swing axis. A collet attachment / detachment mechanism is attached to the tip of the arm portion. The program includes a process of operating the collet exchange mechanism to remove the first collet from the spindle, a process of operating the collet exchange mechanism to store the removed first collet at a predetermined position, a process of operating the collet exchange mechanism to pick up the second collet stored at another predetermined position, and A process of operating the collet exchange mechanism so as to mount the picked-up second collet on the main shaft, causing a computer to execute the process. Program.

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