Tool rest and machine tool

Abstract

To provide a tool rest that can suppress hydraulic oil of a clamp mechanism from blowing out to a periphery thereof, and a machine tool provided with the tool rest.SOLUTION: The tool rest comprises: a tool holder having a clamp mechanism for clamping a tool, which is operated by oil pressure; an attachment part (52), provided with a hole (212) to which hydraulic oil of the clamp mechanism is supplied, to which the tool holder is detachably attached; a valve body (312), arranged in the hole (212), which can operate between a first state where when the tool holder is not attached thereto, the valve body restricts hydraulic oil from being distributed by receiving pressure of hydraulic oil and a second state where when the tool holder is attached thereto, the valve body allows hydraulic oil to be distributed; and an elastic member (361), arranged in the hole (212), which makes elastic force act on the valve body (312) so that the valve body is operated from the second state toward the first state.SELECTED DRAWING: Figure 13

Description

[Technical field]

[0001] The present invention relates to a tool rest and a machine tool. [Background technology]

[0002] For example, Japanese Patent Application Laid-Open No. 2022-20366 (Patent Document 1) discloses a machine tool including a tool rest, a magazine, and an automatic tool changer for changing tools attached to the tool rest and the magazine. The tool rest has a turret that can rotate around a central axis of rotation, and a plurality of tool holders that are attached to the turret and arranged in a circumferential direction of the central axis of rotation and hold tools. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-20366 Summary of the Invention [Problem to be solved by the invention]

[0004] As disclosed in the above-mentioned Patent Document 1, in a turret-type tool rest, various kinds of tool holders are prepared according to the posture, position, type, etc. of the tool to be held. A user selects multiple tool holders from among them according to the content of the workpiece machining, and mounts them on multiple mounting parts of the tool rest, respectively.

[0005] Meanwhile, the tool holder has a built-in clamping mechanism for clamping a tool. The clamping mechanism operates when hydraulic oil is supplied to the tool holder from a mounting part on the turret side. However, if the tool holder is replaced while the oil pump is running, or if a mounting part to which a tool holder is not attached is left due to carelessness of an operator, hydraulic oil from the clamping mechanism may spurt out from the mounting part to which a tool holder is not attached, toward the periphery of the tool post.

[0006] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a tool rest capable of reducing the amount of hydraulic oil from the clamp mechanism spraying out to the surrounding area, and a machine tool equipped with such a tool rest. [Means for solving the problem]

[0007] According to one aspect of the present invention, a tool post includes a tool holder operated hydraulically and having a clamping mechanism for clamping a tool, a mounting portion provided with a hole through which hydraulic oil for the clamping mechanism is supplied and to which the tool holder is detachably mounted, a valve body disposed in the hole and operable between a first state in which the hydraulic oil pressure is applied to restrict the flow of hydraulic oil when the tool holder is not attached and a second state in which the hydraulic oil is allowed to flow when the tool holder is attached, and an elastic member disposed in the hole and applying an elastic force to the valve body in a direction to move the valve body from the second state toward the first state.

[0008] According to another aspect of the present invention, a tool rest includes a base portion having a plurality of mounting portions, and a plurality of tool holders that are detachably mounted to the respective mounting portions and that hold tools. The tool holder has a clamp mechanism that operates by hydraulic pressure and clamps a tool. The mounting portion includes a seating surface on which the tool holder is seated. The mounting portion is provided with a valve body insertion hole that opens into the seating surface, and an oil circulation hole that communicates with the valve body insertion hole and through which hydraulic oil of the clamp mechanism flows. The tool rest further includes a valve body that is inserted into the valve body insertion hole and is movable between a first state in which the valve body protrudes from the seating surface when the tool holder is not attached by receiving pressure of hydraulic oil from the oil circulation hole and restricts the flow of hydraulic oil, and a second state in which the valve body is pushed back into the valve body insertion hole by the tool holder when the tool holder is attached and allows the flow of hydraulic oil, and an elastic member that is disposed in the valve body insertion hole and applies an elastic force to the valve body in a direction that moves the valve body from the second state to the first state.

[0009] A machine tool according to the present invention includes the above tool rest. Effect of the Invention

[0010] According to the invention, it is possible to provide a tool rest capable of reducing the hydraulic oil of the clamp mechanism from spraying out to the surroundings, and a machine tool equipped with such a tool rest. [Brief description of the drawings]

[0011] [Figure 1] 1 is a perspective view showing a machine tool equipped with a tool rest in an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view showing a tool rest in FIG. [Diagram 3] 1. FIG. 4 is another perspective view showing the tool rest in FIG. [Figure 4] 4 is a perspective view showing the tool rest (mounting portion) in the area surrounded by the two-dot chain line IV in FIG. [Diagram 5] FIG. 2 is a cross-sectional view showing a tool rest in FIG. [Figure 6] 2 is a circuit diagram showing a mechanism for confirming seating of a tool holder in the tool rest in FIG. 1. [Figure 7] 1. FIG. 4 is another cross-sectional view showing the tool rest in FIG. [Figure 8] 1. FIG. 4 is still another cross-sectional view showing the tool rest in FIG. [Figure 9] FIG. 3 is a perspective view showing a piping block in FIG. 2. [Figure 10] 3 is a cross-sectional view showing the internal structure of the piping block of FIG. 2. [Figure 11] 5 is a cross-sectional view showing the mounting portion, the valve body, and the elastic member when the tool holder is mounted. FIG. [Figure 12] FIG. 12 is a perspective view showing the valve body in FIG. [Figure 13] 5 is a cross-sectional view showing the mounting portion, the valve body, and the elastic member when the tool holder is not mounted. FIG. [Figure 14] FIG. 14 is a perspective view showing the valve body in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described with reference to the accompanying drawings, in which the same or corresponding components are designated by the same reference numerals.

[0013] Fig. 1 is a perspective view showing a machine tool equipped with a tool rest according to an embodiment of the present invention. In the drawing, the internal structure of the machine tool is shown by seeing through a cover body that forms the exterior of the machine tool. Fig. 2 is a perspective view showing the tool rest in Fig. 1.

[0014] 1 and 2, machine tool 100 is a lathe that machines a workpiece by bringing a tool into contact with a rotating workpiece. Machine tool 100 is provided with a milling function that machines a workpiece by bringing a rotating tool into contact with a stationary workpiece.

[0015] Machine tool 100 is an NC (Numerically Controlled) machine tool in which various operations for machining a workpiece are automated by numerical control using a computer.

[0016] In this specification, an axis that is parallel to the left-right direction (width direction) of machine tool 100 and extends horizontally is referred to as the "Z-axis," an axis that is parallel to the front-to-back direction (depth direction) of machine tool 100 and extends horizontally is referred to as the "Y-axis," and an axis that extends up-down is referred to as the "X-axis."

[0017] For the convenience of explaining the structure of machine tool 100 and tool rest 50 provided on machine tool 100, the X-axis, Y-axis, and Z-axis are set as described above, but these do not necessarily coincide with the X-axis, Y-axis, and Z-axis defined for a lathe.

[0018] First, there will be described the structure of the machine tool 100. The machine tool 100 has a bed 11, a first headstock 21, a second headstock 26, a tool rest 50, a magazine 110, and an automatic transfer device 130.

[0019] The bed 11 is a base member for supporting the first headstock 21, the second headstock 26, the tool rest 50, the magazine 110, the automatic transport device 130, etc., and is installed on the floor of a factory, etc. The bed 11 is made of metal such as cast iron.

[0020] The first headstock 21 and the second headstock 26 are attached to the bed 11. Each of the first headstock 21 and the second headstock 26 has a work spindle (not shown). A chuck for removably holding a workpiece is provided at the tip of the work spindle. The work spindle of the first headstock 21 is driven to rotate about a rotation center axis 106 parallel to the Z axis. The work spindle of the second headstock 26 is driven to rotate about a rotation center axis 107 parallel to the Z axis. The first headstock 21 and the second headstock 26 are disposed opposite each other in the Z axis direction so that the rotation center axis 106 and the rotation center axis 107 extend in a straight line.

[0021] The tool rest 50 is provided in the machining area. The machining area is a space where the workpiece is machined, and is substantially sealed by a cover body so that foreign matter such as chips or cutting oil resulting from the machining of the workpiece does not leak out of the machining area. The tool rest 50 is configured to be able to hold a plurality of tools. The tool rest 50 is a turret type tool rest that moves the held tools in the circumferential direction of a central axis of rotation 101 to index the tool to be used for machining. The central axis of rotation 101 extends in the Z-axis direction.

[0022] The tool rest 50 has a base portion 51. The base portion 51 has an overall disk-like appearance with its thickness direction being in the axial direction of the central pivot shaft 101. The base portion 51 is attached to a tool rest base 58.

[0023] The base portion 51 has a swivel portion 63 and a plurality of mounting portions 52. The swivel portion 63 has a cylindrical shape centered on a central swivel axis 101 as a whole. The swivel portion 63 is capable of rotating about the central swivel axis 101 by inputting rotation from a motor 64 (not shown).

[0024] The multiple mounting parts 52 are provided on the swivel part 63 and aligned in the circumferential direction of the swivel central axis 101. The multiple mounting parts 52 are provided integrally with the swivel part 63. The multiple mounting parts 52 are provided on the outer circumferential surface of the swivel part 63. The multiple mounting parts 52 are provided at equal intervals in the circumferential direction of the swivel central axis 101. The multiple mounting parts 52 are capable of rotating together with the swivel part 63 around the swivel central axis 101. In this embodiment, the base part 51 has twelve mounting parts 52.

[0025] The tool rest 50 further has a plurality of tool holders 61. The tool holder 61 is a device for holding tools in the tool rest 50. The plurality of tool holders 61 are detachably attached to the plurality of mounting parts 52, respectively. The plurality of tool holders 61 are fastened to the plurality of mounting parts 52, respectively, using bolts.

[0026] The multiple tool holders 61 are arranged side by side in the circumferential direction of the turning center axis 101. The tool holders 61 are configured to be able to hold tools. When classified based on the tool insertion direction, the multiple tool holders 61 include a first tool holder 61S into which a tool is inserted in the axial direction of the turning center axis 101 and a second tool holder 61T into which a tool is inserted in the radial direction of the turning center axis 101.

[0027] The tool holder 61 has a clamping mechanism 79 (see FIG. 6 described later) that operates hydraulically and clamps a tool. The shank standard of a tool that can be held by the tool holder 61 is, for example, CAPTO. The tool holder 61 may incorporate a rotation mechanism that rotates the tool by inputting rotation from the base part 51 side.

[0028] There may be cases where the user determines that it is not necessary to mount the tool holder 61 on a particular mounting portion 52. In this case, a lid 62 shown in FIG.

[0029] As the swivel part 63 rotates about the central axis 101, the tool held by the tool holder 61 moves in the circumferential direction of the central axis 101. When machining a workpiece held by the workpiece spindle of the first headstock 21 or the second headstock 26, the tool holder 61 is positioned at a workpiece machining position W. When exchanging tools with the automatic transport device 130 described below, the tool holder 61 is positioned at a tool rest-side tool exchange position K. The workpiece machining position W and the tool rest-side tool exchange position K are positioned adjacent to each other in the circumferential direction of the central axis 101.

[0030] The tool rest base 58 is supported by the bed 11 via a saddle 57 and a cross slide (not shown). The saddle 57 can be moved in the Z-axis direction by various feed mechanisms, guide mechanisms, servo motors, etc. The cross slide (not shown) can be moved in an axial direction (referred to as the "Xa-axis direction") that is perpendicular to the Z-axis and inclined with respect to the X-axis and Y-axis by various feed mechanisms, guide mechanisms, servo motors, etc. The saddle 57 and the cross slide (not shown) move in the Z-axis direction and the Xa-axis direction, respectively, to move the machining position of the workpiece by the tool held by the tool holder 61 within the Z-axis-Xa-axis plane.

[0031] The magazine 110 is provided outside the machining area. The magazine 110 is provided at a position separated in the Z-axis direction from the tool rest 50. The tool rest 50 is disposed between the first headstock 21 and the magazine 110 in the Z-axis direction.

[0032] Magazine 110 is a device for storing a plurality of tools so as to sequentially supply the tools to the machining area according to the machining purpose. Magazine 110 stores rotary tools such as drills, end mills, milling cutters, etc., which are attached to tool holders 61 in tool rest 50, and fixed tools such as external cutting tools, internal cutting tools, grooving tools, etc.

[0033] The magazine 110 has a support plate 111, a plurality of tool pots 120, and a motor (not shown). The support plate 111 has a disk shape centered on a central rotation axis 103 parallel to the Y axis. The plurality of tool pots 120 are attached to the support plate 111. The plurality of tool pots 120 are arranged at regular intervals along a circumferential path centered on the central rotation axis 103.

[0034] The support plate 111 can be rotated around the central axis 103 by a motor (not shown). When the support plate 111 rotates around the central axis 103, the tool pot 120 is transported in the circumferential direction of the central axis 103. When tools are exchanged with an automatic tool changer 31 (described later), the tool pot 120 is disposed at a magazine-side tool exchange position.

[0035] The automatic transfer device 130 is a device for transferring tools. The automatic transfer device 130 is supported by a support frame 14. The support frame 14 extends in the Z-axis direction above the second headstock 26. The automatic transfer device 130 transfers tools between the tool rest 50 in the machining area and the magazine 110 outside the machining area by moving in the Z-axis direction.

[0036] The automatic transfer device 130 has a first base 15 and a second base 16. The first base 15 is movable in the Z-axis direction relative to the support frame 14 by various feed mechanisms, guide mechanisms, servo motors, etc. The second base 16 is movable in the Y-axis direction relative to the first base 15 by various feed mechanisms, guide mechanisms, servo motors, etc. With this configuration, the automatic transfer device 130 is configured to be movable in both the Y-axis direction and the Z-axis direction.

[0037] The automatic transfer device 130 further includes a tool exchange unit 140. The tool exchange unit 140 exchanges tools with the tool holder 61 positioned at the tool-rest-side tool exchange position K in the tool rest 50, and exchanges tools with the tool pot 120 positioned at the magazine-side tool exchange position in the magazine 110.

[0038] The tool exchange unit 140 has a gripping portion 146. The gripping portion 146 detachably grips a tool. The gripping portion 146 has a claw shape capable of gripping a tool. The tool exchange unit 140 has a pair of gripping portions 146 as the gripping portion 146, and is of a double arm type capable of holding two tools at the same time. The tool exchange unit 140 may be of a single arm type capable of holding one tool at the same time.

[0039] The tool exchange unit 140 is configured to be rotatable about a central axis extending in the X-axis direction in order to change the attitude of the gripper 146 in accordance with the insertion direction of the tool into the tool holder 61.

[0040] Next, a more specific structure of the tool rest 50 will be described. Fig. 3 is another perspective view showing the tool rest in Fig. 1. In Fig. 3, a part of the internal piping of the tool rest 50 is shown by seeing through the tool rest 50. Fig. 4 is a perspective view showing the tool rest (mounting part) in the range surrounded by the two-dot chain line IV in Fig. 3. Fig. 5 is a cross-sectional view showing the tool rest in Fig. 1.

[0041] 3 to 5, tool rest 50 further includes a housing 65 and a motor 64. Housing 65 is fixed inside swivel unit 63. While swivel unit 63 is a rotating side that is rotatable about a central swivel axis 101, housing 65 is a fixed side.

[0042] The motor 64 is a milling motor for rotating a tool held in the tool holder 61. The motor 64 is disposed inside the swivel unit 63. The motor 64 is disposed radially inside the swivel central axis 101 with respect to the multiple mounting units 52. The stator of the motor 64 is fixed to the housing 65. The rotor of the motor 64 is supported by the housing 65 so as to be rotatable around a rotation central axis 102. The rotation central axis 102 of the motor 64 intersects with the swivel central axis 101 at an angle of 90°.

[0043] The tool rest 50 further has an axis portion 69 and a cover portion 66. The axis portion 69 has an axis (shaft) shape centered on a central axis of rotation 101. The axis portion 69 is connected to a housing 65. The axis portion 69 is provided at a position protruding from the rotating portion 63 (mounting portion 52) in the axial direction of the central axis of rotation 101.

[0044] The lid part 66 is connected to an end of the swivel part 63 in the axial direction of the swivel central axis 101. The lid part 66 is connected to an end of the swivel part 63 that opens toward the axial direction of the swivel central axis 101. The lid part 66 is provided facing the housing 65 and the motor 64 in the axial direction of the swivel central axis 101. The lid part 66 is rotatable together with the swivel part 63 about the swivel central axis 101.

[0045] The lid portion 66 is fitted onto the outer periphery of the shaft portion 69. The lid portion 66 is provided so as to close an opening portion occurring between the shaft portion 69 and the rotating portion 63 in the radial direction of the central axis of rotation 101. The lid portion 66 rotates around the central axis of rotation 101 while sliding relative to the shaft portion 69.

[0046] The cover portion 66 has a housing portion 67 and a tapered portion 68. The housing portion 67 has a cylindrical shape centered on the central axis 101 of rotation. The housing portion 67 is provided at a position away from the rotating portion 63 in the axial direction of the central axis 101 of rotation. As the rotating portion 63 rotates, an inner peripheral surface 67t of the housing portion 67 comes into sliding contact with an outer peripheral surface 69u of the shaft portion 69.

[0047] The tapered portion 68 protrudes from the housing portion 67 in the axial direction of the swivel central axis 101 toward the swivel portion 63. The tapered portion 68 has a cylindrical shape centered on the swivel central axis 101. The tapered portion 68 has a tapered shape with a peripheral surface that is inclined with respect to the axial direction of the swivel central axis 101. The diameter of the tapered portion 68 centered on the swivel central axis 101 increases from the housing portion 67 toward the swivel portion 63 in the axial direction of the swivel central axis 101. The end of the tapered portion 68 on the small diameter side is connected to the housing portion 67, and the end of the tapered portion 68 on the large diameter side is connected to the swivel portion 63.

[0048] The mounting portion 52 has a seating surface 53. The tool holder 61 is seated on the seating surface 53. The tool holder 61 mounted on the mounting portion 52 is in surface contact with the seating surface 53. The seating surface 53 is a flat surface. The seating surface 53 corresponds to each side surface of a regular polygonal prism (a regular dodecagon in this embodiment) corresponding to the number of the multiple mounting portions 52.

[0049] 4, the mounting portion 52 is provided with a first hole 211, a second hole 212, a third hole 213, a fourth hole 214, a fifth hole 215, and a sixth hole 216. The first hole 211, the second hole 212, the third hole 213, the fourth hole 214, the fifth hole 215, and the sixth hole 216 open to the seating surface 53. Each of the first hole 211, the second hole 212, the third hole 213, the fourth hole 214, the fifth hole 215, and the sixth hole 216 has a circular opening shape.

[0050] Air flows through the first hole 211 to confirm whether the tool holder 61 (lid 62) is seated on the seating surface 53. When the tool holder 61 (lid 62) is attached to the mounting portion 52, the opening 211a of the first hole 211 on the seating surface 53 is blocked by the tool holder 61. This restricts the air flow through the first hole 211. On the other hand, when the tool holder 61 (lid 62) is not attached to the mounting portion 52, the opening 211a of the first hole 211 on the seating surface 53 is open to the atmosphere. This allows the air flow through the first hole 211.

[0051] Hydraulic oil flows through the second hole 212 for clamping the clamp mechanism 79 built into the tool holder 61. Hydraulic oil flows through the third hole 213 for unclamping the clamp mechanism 79 built into the tool holder 61. A valve body 312 for reducing the blowing out of hydraulic oil is inserted into each of the second hole 212 and the third hole 213. The valve body 312 will be described in detail later.

[0052] Either coolant or air for tapered air blowing selectively flows through the fourth hole 214 and the fifth hole 215. The coolant supplied to the tool holder 61 through the fourth hole 214 and the fifth hole 215 passes through the inside of the tool held in the tool holder 61 and is discharged from the cutting edge of the tool. The air supplied to the tool holder 61 through the fourth hole 214 and the fifth hole 215 is sprayed toward the tapered surface of the tool holder 61 that receives the shank portion of the tool.

[0053] 1 at tool change position K on the tool rest side and at workpiece machining position W, air flows through the sixth hole 216 to check the clamping of the tool. Air supplied to the tool holder 61 through the sixth hole 216 is discharged from an opening that opens into the holder end face of the tool holder 61. When a tool is clamped in the tool holder 61, the opening is closed by the end face of the shank of the tool.

[0054] The mounting portion 52 is further provided with a seventh hole 217. The seventh hole 217 opens to the seating surface 53. The seventh hole 217 has a circular opening shape. The opening area of ​​the seventh hole 217 is larger than the opening area of ​​each of the first hole 211, the second hole 212, the third hole 213, the fourth hole 214, the fifth hole 215, and the sixth hole 216. The first hole 211, the second hole 212, the third hole 213, the fourth hole 214, the fifth hole 215, and the sixth hole 216 are aligned around the seventh hole 217 in the circumferential direction of the seventh hole 217.

[0055] 5, the multiple tool holders 61, when classified according to whether or not a tool can be rotated, include a third tool holder 61U capable of holding a rotating tool and a fourth tool holder 61V capable of holding a fixed tool. The third tool holder 61U has a clutch shaft 41. The clutch shaft 41 is inserted into the seventh hole 217. When the third tool holder 61U is positioned at the workpiece machining position W in FIG. 1, the tip of the clutch shaft 41 is connected to the rotor shaft of the motor 64.

[0056] Next, a mechanism for checking whether the tool holder 61 is seated on the seating surface 53 will be described in more detail.

[0057] 3 and 5, the lid portion 66 is provided with a plurality of first radial holes 240. The plurality of first radial holes 240 extend radially from the central axis of rotation 101. When the lid portion 66 is viewed in the axial direction of the central axis of rotation 101, the plurality of first radial holes 240 extend in the radial direction of the central axis of rotation 101 while being spaced apart from one another in the circumferential direction of the central axis of rotation 101.

[0058] The plurality of first radial holes 240 includes a first section 241 and a second section 242. The first section 241 is located on the upstream side of the air flow in the plurality of first radial holes 240, and the second section 242 is located on the downstream side of the air flow in the plurality of first radial holes 240. The first section 241 is provided in the housing portion 67. The second section 242 is provided across between the housing portion 67 and the tapered portion 68.

[0059] The first section 241 extends from the inner circumferential surface 67t of the housing part 67 toward the radially outward direction of the swirl central axis 101. The second section 242 extends toward the radially outward direction of the swirl central axis 101 while approaching the swirl part 63 from the housing part 67 in the axial direction of the swirl central axis 101. An end of the second section 242 on the upstream side of the air flow communicates with the first section 241, and an end of the second section 242 on the downstream side of the air flow communicates with the first hole 211 in the mounting part 52.

[0060] A first annular groove 224 is provided between the shaft portion 69 and the cover portion 66 in the radial direction of the turning center shaft 101. The first annular groove 224 extends in the circumferential direction of the turning center shaft 101. A plurality of first radial holes 240 (first section portions 241) are connected to the first annular groove 224.

[0061] The cover portion 66 and the shaft portion 69 are provided with a recess 67g and a recess 69g, respectively. The recess 67g is recessed from an inner peripheral surface 67t of the housing portion 67 and extends in the circumferential direction of the turning center axis 101. The recess 69g is recessed from an outer peripheral surface 69u of the shaft portion 69 and extends in the circumferential direction of the turning center axis 101 while facing the recess 67g in the radial direction of the turning center axis 101. The first annular groove 224 is defined and formed by the recess 67g and the recess 69g.

[0062] With this configuration, a rotary joint is formed in which the first annular groove 224 and the multiple first radial holes 240 are maintained in communication with each other when the lid portion 66 rotates around the central rotation axis 101.

[0063] A first pipe 221 is connected to the housing 65. The first pipe 221 is connected to the housing 65 from the side opposite to the shaft portion 69 in the axial direction of the central axis of rotation 101. The housing 65 is provided with a hole 222 communicating with the first pipe 221. The shaft portion 69 is provided with a hole 223 extending between the hole 222 and the first annular groove 224. Air is supplied to the first pipe 221 from an air compressor (not shown). The air is supplied to the first hole 211 in the mounting portion 52 through the hole 222, the hole 223, the first annular groove 224, and the plurality of first radial holes 240 in the listed order.

[0064] Fig. 6 is a circuit diagram showing a mechanism for confirming seating of a tool holder in the tool rest in Fig. 1. Referring to Fig. 6, the tool rest 50 has a first air flow passage 71 and a plurality of second air flow passages 72. Air is supplied to the first air flow passage 71. The plurality of second air flow passages 72 branch off from the first air flow passage 71. The plurality of second air flow passages 72 extend toward the plurality of mounting portions 52, respectively. The second air flow passages 72 open to the seating surface 53.

[0065] The first air flow path 71 is formed by the first pipe 221, the hole 222, the hole 223, and the first annular groove 224 in Fig. 5. The second air flow path 72 is formed by the first radial holes 240 and the first hole 211 in Fig. 5.

[0066] Since the motor 64 for rotating the tool is built inside the swivel part 63, there is a large space restriction. In this embodiment, by providing the first radial holes 240 in the cover part 66 connected to the end of the swivel part 63 in the axial direction of the swivel central axis 101, it is possible to configure the second air flow passage 72 for supplying air to each mounting part 52 while avoiding the above-mentioned space restriction. In addition, by providing the first annular groove 224 in the shaft part 69 having an axial shape centered on the swivel central axis 101 and having the cover part 66 fitted on its outer periphery, it is possible to configure the first air flow passage 71 that maintains a state of communication with the multiple second air flow passages 72 regardless of the swivel operation of the cover part 66.

[0067] As a means for checking whether the tool holder 61 is seated on the seating surface 53, there is a method of providing each mounting portion 52 with a switch to be pressed by the tool holder 61. In this case, a rotary joint that maintains electrical contact when the cover portion 66 is turned is provided between the shaft portion 69 and the cover portion 66 in the radial direction of the turning central axis 101, and electrical wiring is routed in the same path as the first air flow path 71 and the multiple second air flow paths 72. On the other hand, in this embodiment, air piping is used as a mechanism for checking whether the tool holder 61 is seated on the seating surface 53, so that such a mechanism can be constructed simply and inexpensively.

[0068] The tool rest 50 further has a detection unit 76. The detection unit 76 is provided on the path of the first air flow passage 71. The detection unit 76 is connected to, for example, the first piping 221. The detection unit 76 is capable of detecting the state of air flow in the first air flow passage 71. The detection unit 76 is a differential pressure sensor capable of detecting the difference between the air pressure on the upstream side (primary side) of the air flow in the first air flow passage 71 from the detection unit 76 and the air pressure on the downstream side (secondary side) of the air flow in the first air flow passage 71 from the detection unit 76.

[0069] When the tool holder 61 is attached to all of the multiple mounting parts 52, the opening of the second air flow passage 72 in the seating surface 53 (the opening 211a of the first hole 211) is blocked by the tool holder 61. In this case, the detection unit 76 detects a pressure difference between the primary side and the secondary side of the first air flow passage 71 that is equal to or greater than a predetermined threshold value. On the other hand, when there is at least one mounting part 52 to which the tool holder 61 is not attached among the multiple mounting parts 52, air flows out of that mounting part 52 through the opening of the second air flow passage 72 in the seating surface 53 (the opening 211a of the first hole 211). In this case, the detection unit 76 does not detect a pressure difference between the primary side and the secondary side of the first air flow passage 71 that is equal to or greater than a predetermined threshold value.

[0070] The detection unit 76 is not limited to a differential pressure sensor, and may be, for example, a flow rate sensor capable of detecting the air flow rate in the first air flow path 71.

[0071] Machine tool 100 further has a control unit 77. Detection unit 76 outputs to control unit 77 the detected state of air flow in first air passage 71 (differential pressure between the primary side and secondary side).

[0072] The control unit 77 judges whether or not there is any mounting part 52 to which the tool holder 61 is not attached, among the multiple mounting parts 52, based on the state of the air flow detected by the detection unit 76. That is, the control unit 77 judges that the tool holder 61 is attached to all of the multiple mounting parts 52 when the detection unit 76 detects a differential pressure between the primary side and the secondary side of the first air flow path 71 that is equal to or greater than a predetermined threshold. The control unit 77 judges that there is any mounting part 52 to which the tool holder 61 is not attached, among the multiple mounting parts 52, when the detection unit 76 does not detect a differential pressure between the primary side and the secondary side of the first air flow path 71 that is equal to or greater than a predetermined threshold.

[0073] When the control unit 77 determines that any of the mounting parts 52 has no tool holder 61 attached thereto, the control unit 77 restricts the operation of the clamping mechanism 79. More specifically, even when execution of automatic tool change (ATC) is commanded based on the description of the NC program, the control unit 77 does not operate the oil pump 78 for supplying hydraulic oil to the clamping mechanism 79. When the control unit 77 determines that any of the mounting parts 52 has no tool holder 61 attached thereto, the control unit 77 may perform control to stop execution of the NC program.

[0074] In the present embodiment, the detection unit 76 is provided on the path of the first air flow path 71. With this configuration, it is possible to detect the absence of attachment of the tool holder 61 to the attachment portion 52 with a simpler configuration than when the detection unit 76 is provided on each of the paths of the multiple second air flow paths 72.

[0075] Also, by detecting that the tool holder 61 is not attached to the attachment portion 52, it is possible to prevent the hydraulic oil of the clamp mechanism 79 from spurting out from the second hole 212 and the third hole 213 opening into the seating surface 53. Furthermore, it is possible to prevent chips, coolant, etc. from entering the inside of the tool rest 50 through the seventh hole 127, etc. opening into the seating surface 53.

[0076] Next, there will be described a piping structure for supplying various fluids to the tool holder 61. Figures 7 and 8 are other cross-sectional views showing the tool rest in Figure 1.

[0077] 7, the cover portion 66 is further provided with a plurality of second radial holes 250. The plurality of second radial holes 250 are provided in the same form as the plurality of first radial holes 240. The plurality of second radial holes 250 are provided at angular positions offset from the plurality of first radial holes 240 in the circumferential direction of the central axis of rotation 101.

[0078] A second annular groove 234 is further provided between the shaft portion 69 and the cover portion 66 in the radial direction of the swivel central shaft 101. The second annular groove 234 is provided in the same form as the first annular groove 224. The second annular groove 234 is provided at a position shifted from the first annular groove 224 in the axial direction of the swivel central shaft 101. A plurality of second radial holes 250 are connected to the second annular groove 234. The second annular groove 234, together with the plurality of second radial holes 250, constitute a rotary joint.

[0079] A second pipe 231 is connected to the housing 65. The second pipe 231 is connected to the housing 65 from the side opposite to the shaft portion 69 in the axial direction of the swivel central shaft 101. The housing 65 is provided with a hole 232 communicating with the second pipe 231. The shaft portion 69 is provided with a hole 233 extending between the hole 232 and the second annular groove 234. The second pipe 231 is supplied with hydraulic oil from the oil pump 78 in FIG. 6. The hydraulic oil is supplied to an internal pipe (not shown) of the swivel portion 63 through the hole 232, the hole 233, the second annular groove 234, and the plurality of second radial holes 250 in the listed order.

[0080] A switching valve 80 (see FIG. 6) is built into the swivel part 63. The second radial holes 250 communicate with the second hole 212 and the third hole 213 in FIG. 4 via the switching valve 80 through internal piping of the swivel part 63. The switching valve 80 switches the flow path of the hydraulic oil so that the hydraulic oil is supplied to the second hole 212 in FIG. 4 when the tool is clamped, and is supplied to the third hole 213 in FIG. 4 when the tool is unclamped.

[0081] 8, the cover portion 66 is further provided with a plurality of third radial holes 260. The plurality of third radial holes 260 are provided in the same form as the plurality of first radial holes 240. The plurality of third radial holes 260 are provided at angular positions offset from the plurality of first radial holes 240 and the plurality of second radial holes 250 in the circumferential direction of the swirl central axis 101.

[0082] A third annular groove 239 is further provided between the shaft portion 69 and the cover portion 66 in the radial direction of the swivel central shaft 101. The third annular groove 239 is provided in the same form as the first annular groove 224. The third annular groove 239 is provided at a position shifted from the first annular groove 224 and the second annular groove 234 in the axial direction of the swivel central shaft 101. A plurality of third radial holes 260 are connected to the third annular groove 239. The third annular groove 239, together with the plurality of third radial holes 260, constitute a rotary joint.

[0083] A third pipe 236 is connected to the housing 65. The third pipe 236 is connected to the housing 65 from the side opposite to the shaft portion 69 in the axial direction of the central axis of rotation 101. The housing 65 is provided with a hole 237 communicating with the third pipe 236. The shaft portion 69 is provided with a hole 238 extending between the hole 237 and the third annular groove 239.

[0084] As the clamping mechanism 79 performs clamping and unclamping operations, hydraulic oil is discharged from the clamping mechanism 79. The hydraulic oil is guided to the third radial holes 260 through the internal piping of the swivel part 63. The hydraulic oil passes through the third radial holes 260, the third annular groove 239, the hole 238, the hole 237, and the third piping 236 in the listed order, and is collected in an oil tank (not shown).

[0085] Fig. 9 is a perspective view showing the piping block in Fig. 2. Fig. 10 is a cross-sectional view showing the internal structure of the piping block in Fig. 2.

[0086] 2, 9 and 10, the tool rest 50 further includes a piping block 81 and a plurality of piston mechanisms 86 (86A, 86B, 86C, 86D).

[0087] The piping block 81 is provided at a position radially outwardly away from the swirl central axis 101 and at a predetermined angular position in the circumferential direction of the swirl central axis 101. The piping block 81 is provided on the opposite side of the cover portion 66 with the swirl portion 63 in between in the axial direction of the swirl central axis 101. The piping block 81 faces the swirl portion 63 with a gap therebetween in the axial direction of the swirl central axis 101.

[0088] The piping block 81 is attached to the tool rest base 58. The swivel unit 63 is the rotating side that can rotate about a central axis of rotation 101, whereas the piping block 81 is the fixed side.

[0089] The piston mechanism 86 is built into the piping block 81. The piston mechanism 86 is provided to be movable forward and backward in the axial direction of the swivel central axis 101 so as to be separated from the swivel part 63 when the swivel part 63 swivels and to be connected to the swivel part 63 when the swivel part 63 stops (when the swivel stops).

[0090] More specifically, the piping block 81 has an opposing surface 82. The opposing surface 82 is formed of a plane perpendicular to the swirl central axis 101, and faces the swirl section 63 with a gap therebetween in the axial direction of the swirl central axis 101. The piping block 81 is provided with a piston insertion hole 83. The piston insertion hole 83 extends in the axial direction of the swirl central axis 101 and opens to the opposing surface 82.

[0091] The piston mechanism 86 has a piston 87. The piston 87 is inserted into the piston insertion hole 83. The piston 87 protrudes from the opposing surface 82. The piston 87 slides in the axial direction of the swivel central axis 101 by fluid pressure such as air pressure or hydraulic pressure. The piston 87 is provided with a flow path 88. Various fluids are supplied to the flow path 88 through the internal piping of the piping block 81. The flow path 88 opens at the tip of the piston 87 on the side facing the swivel part 63 in the axial direction of the swivel central axis 101.

[0092] When the swivel part 63 rotates around the central axis 101, the piston mechanism 86 contracts so that the length of the piston 87 protruding from the opposing surface 82 becomes smaller. By moving the piston 87 away from the swivel part 63, interference between the rotating swivel part 63 and the piston 87 can be avoided. When the swivel part 63 stops rotating, the piston mechanism 86 expands so that the length of the piston 87 protruding from the opposing surface 82 becomes larger. By connecting the piston 87 to the swivel part 63, the flow path 88 and the internal piping 91 of the swivel part 63 are communicated with each other.

[0093] The piston mechanism 86A supplies air for taper air blow toward the swivel part 63. The piston mechanism 86B supplies air toward the swivel part 63 for checking the clamping of a tool in the tool holder 61 positioned at the tool post side tool changing position K in Fig. 1. The piston mechanism 86C supplies coolant toward the swivel part 63. The piston mechanism 86D supplies air toward the swivel part 63 for checking the clamping of a tool in the tool holder 61 positioned at the workpiece machining position W in Fig. 1.

[0094] The tool rest 50 further has a piston mechanism 96. The piston mechanism 96 has a piston 97. The piston mechanism 96 has a similar structure to the piston mechanism 86 except that the piston 97 is not provided with a flow path 88. The piston mechanism 96 extends to press a switch 92 for switching the switching valve 80. When the switch 92 is pressed, the switching valve 80 switches the flow path of hydraulic oil for tool clamping toward the second hole 212 in FIG. 4 to the flow path of hydraulic oil for tool unclamping toward the third hole 213 in FIG. 4.

[0095] As described above, in this embodiment, various fluids are supplied to the tool holder 61 using two types of fluid paths: a fluid path extending radially from the axial center of the turning central axis 101 in the radial direction thereof, and a fluid path provided at a specific angular position in the circumferential direction of the turning central axis 101 and extending in the axial direction of the turning central axis 101. In particular, air for checking the seating of the tool holder 61 (cover body 62) on the seating surface 53 needs to be continuously supplied to all of the multiple tool holders 61, so the upstream fluid path that enables such a continuous supply of fluid is used.

[0096] According to such a configuration, it is possible to supply various types of fluid to the tool holder 61 in accordance with the application of the fluid used in the tool holder 61 while avoiding space restrictions in the tool rest 50.

[0097] The tool rest 50 in this embodiment is provided with a mechanism for reducing the amount of hydraulic oil from the clamp mechanism 79 spraying out from the mounting portion 52 when the tool holder 61 is not mounted. This mechanism will be described in detail below.

[0098] Fig. 11 is a cross-sectional view showing the mounting portion, the valve body, and the elastic member when the tool holder is mounted. Fig. 12 is a perspective view showing the valve body in Fig. 11. Fig. 13 is a cross-sectional view showing the mounting portion, the valve body, and the elastic member when the tool holder is not mounted. Fig. 14 is a perspective view showing the valve body in Fig. 13.

[0099] 11 to 14, the mounting portion 52 is provided with a second hole 212 (corresponding to the “valve body insertion hole” of the present invention) and an oil circulation hole 311.

[0100] The second hole 212 extends around the specified axis 301. The specified axis 301 is an imaginary straight line extending in the radial direction of the turning center axis 101 in FIG. 2. The second hole 212 is a bottomed hole that opens to the seating surface 53. The oil circulation hole 311 communicates with the second hole 212. The oil circulation hole 311 opens to a side wall of the second hole 212. The length between the opening of the oil circulation hole 311 and the hole bottom 212c of the second hole 212 in the axial direction of the specified axis 301 is smaller than the length between the opening of the oil circulation hole 311 and the seating surface 53 in the axial direction of the specified axis 301.

[0101] Hydraulic oil for the clamp mechanism 79 flows through the oil circulation hole 311. The oil circulation hole 311 extends between the switching valve 80 and the second hole 212 in Fig. 6. Hydraulic oil supplied from the switching valve 80 toward the clamp mechanism 79 flows through the oil circulation hole 311.

[0102] The tool rest 50 further has a valve element 312. The valve element 312 is inserted into the oil circulation hole 311. The valve element 312 has an axis (shaft) shape extending in the axial direction of the specified axis 301 as a whole. The valve element 312 is provided so as to be slidable in the axial direction of the specified axis 301.

[0103] When the tool holder 61 is not attached to the mounting portion 52, the valve body 312 protrudes from the seating surface 53 due to the pressure of the hydraulic oil from the oil flow hole 311, and is capable of sliding between a first state (state shown in Figures 13 and 14) in which the flow of hydraulic oil is restricted, and when the tool holder 61 is attached to the mounting portion 52, the valve body 312 is pushed back into the valve body insertion hole 311 by the tool holder 61, and is capable of sliding between a second state (state shown in Figures 11 and 12) in which the flow of hydraulic oil is permitted.

[0104] The valve body 312 has a first member 351 and a second member 331. The first member 351 has a cylindrical shape centered on a specific axis 301 inside the second hole 212. The first member 351 is fixed to the side wall of the second hole 212 so as not to slide in the axial direction of the specific axis 301.

[0105] The second member 331 is provided so as to be slidable in the axial direction of the specified shaft 301 relative to the first member 351. The second member 331 has a top portion 332, a large diameter portion 334, a small diameter portion 341, and a bottom portion 345. The top portion 332, the large diameter portion 334, the small diameter portion 341, and the bottom portion 345 are provided side by side in the axial direction of the specified shaft 301 in the listed order. The second member 331 is configured so as to be separable between the large diameter portion 334 and the small diameter portion 341.

[0106] 11 and 12, the top portion 332 faces the tool holder 61 in the axial direction of the predetermined axis 301. A seal member 333 that comes into contact with the tool holder 61 is provided on the top surface of the top portion 332. In the first state shown in FIGS. 13 and 14, the top portion 332 protrudes from the seating surface 53.

[0107] The large diameter portion 334 is inserted into the inside of the second hole 212. When the valve body 312 slides in the axial direction of the specified axis 301, the large diameter portion 334 comes into sliding contact with the side wall of the second hole 212. A seal member 335 is provided on the outer circumferential surface of the large diameter portion 334, which comes into contact with the side wall of the second hole 212 in the radial direction of the specified axis 301. The small diameter portion 341 has a smaller diameter than the large diameter portion 334. The small diameter portion 341 is inserted into the inside of the first member 351. When the valve body 312 slides in the axial direction of the specified axis 301, the small diameter portion 341 comes into sliding contact with the inner wall of the first member 351.

[0108] The bottom 345 faces the hole bottom 212c of the second hole 212 at a distance in the axial direction of the predetermined axis 301. An oil distribution space 371, through which hydraulic oil supplied toward the tool holder 61 flows, is provided between the bottom 345 and the hole bottom 212c. The oil distribution space 371 is a part of the space within the second hole 212. The oil distribution hole 311 communicates with the oil distribution space 371.

[0109] The second member 331 slides relative to the first member 351 so that the distance between the large diameter portion 334 and the first member 351 in the axial direction of the specified axis 301 in the second state is greater than the distance between the large diameter portion 334 and the first member 351 in the axial direction of the specified axis 301 in the first state.

[0110] The second member 331 is provided with a first in-valve passage 342 and a plurality of second in-valve passages 343. The first in-valve passage 342 extends on the axis of the specified axis 301. The first in-valve passage 342 extends between the small diameter portion 341, the large diameter portion 334, and the top portion 332 in the axial direction of the specified axis 301. In the second state shown in Figures 11 and 12, the first in-valve passage 342 opens facing the tool holder 61. The first in-valve passage 342 communicates with an internal pipe 313 extending inside the tool holder 61 toward the clamp mechanism 79.

[0111] The multiple second in-valve flow paths 343 are provided in the small diameter portion 341. The multiple second in-valve flow paths 343 are provided at an end of the small diameter portion 341 in the axial direction of the specified axis 301, which forms a boundary with the bottom portion 345. The second in-valve flow paths 343 extend in the radial direction of the specified axis 301. The multiple second in-valve flow paths 343 are provided at intervals from one another in the circumferential direction of the specified axis 301.

[0112] The small diameter portion 341 has a cylindrical shape centered on the specified axis 301. An end of the second in-valve flow path 343 on the radially inner side of the specified axis 301 opens into the inner circumferential surface of the small diameter portion 341 that forms the first in-valve flow path 342. An end of the second in-valve flow path 343 on the radially outer side of the specified axis 301 opens into the outer circumferential surface of the small diameter portion 341. The opening area of ​​each second in-valve flow path 343 is smaller than the opening area of ​​the first in-valve flow path 342 in the small diameter portion 341.

[0113] The first member 351 has a first opposing surface 356. The first opposing surface 356 is made of a conical surface centered on the specified axis 301. The diameter (inner diameter) of the first opposing surface 356 centered on the specified axis 301 increases as it approaches the hole bottom 212c of the second hole 212 in the axial direction of the specified axis 301. The second member 331 has a second opposing surface 346. The second opposing surface 346 is made of a conical surface centered on the specified axis 301. The diameter (outer diameter) of the second opposing surface 346 centered on the specified axis 301 increases as it approaches the hole bottom 212c of the second hole 212 in the axial direction of the specified axis 301. The second opposing surface 346 faces the first opposing surface 356 in the axial direction of the specified axis 301.

[0114] 13 and 14, when the tool holder 61 is not attached to the attachment portion 52, the hydraulic oil in the oil circulation space 371 applies pressure (for example, a pressure of 10 MPa or more) to the bottom portion 345, causing the second member 331 to slide in the axial direction of the specified axis 301 in a direction away from the hole bottom 212c. The second opposing surface 346 comes into contact with the first opposing surface 356 in the axial direction of the specified axis 301, and the multiple second in-valve flow paths 343 are closed by the first member 351. This blocks the oil circulation space 371 from the first in-valve flow paths 342, achieving a first state in which the flow of hydraulic oil is restricted.

[0115] 11 and 12, when the tool holder 61 is attached to the attachment portion 52, the tool holder 61 seated on the seating surface 53 presses the top portion 332, causing the second member 331 to slide in the axial direction of the specified axis 301 toward the hole bottom 212c. The second opposing surface 346 moves away from the first opposing surface 356, and the multiple second in-valve passages 343 open into the gap between the first opposing surface 356 and the second opposing surface 346 in the axial direction of the specified axis 301. As a result, the oil distribution space 371 communicates with the first in-valve passage 342 via the multiple second in-valve passages 343, and a second state is obtained in which the flow of hydraulic oil is permitted.

[0116] The tool rest 50 further has an elastic member 361. The elastic member 361 is disposed in the second hole 212. The elastic member 361 applies an elastic force to the valve body 312 in a direction to move the valve body 312 from the second state shown in Figures 11 and 12 toward the first state shown in Figures 13 and 14.

[0117] The elastic member 361 is disposed in the oil distribution space 371. The elastic member 361 is made of a coil spring. The elastic member 361 extends in a spiral shape centered on the specified axis 301. The elastic member 361 is shortened and deformed between the hole bottom 212c and the bottom portion 345 in the axial direction of the specified axis 301. The elastic member 361 is provided at a position overlapping the first opposing surface 356 and the second opposing surface 346 when viewed in the axial direction of the specified axis 301. The pressure acting on the bottom portion 345 by the elastic force of the elastic member 361 is smaller than the pressure acting on the bottom portion 345 by the hydraulic oil in the oil distribution space 371.

[0118] 6 malfunctions and pumps hydraulic oil when the tool holder 61 is not attached to the attachment portion 52. In this case, a small time lag occurs between the timing when the hydraulic oil fills the oil circulation space 371 and the timing when the sliding movement of the second member 331 is completed by the pressure of the hydraulic oil, and therefore high-pressure hydraulic oil may momentarily gush out from the second hole 212. In this embodiment, the elastic force of the elastic member 361 is applied to the second member 331 in addition to the pressure of the hydraulic oil, thereby suppressing the occurrence of the time lag and reducing the phenomenon of hydraulic oil gush-out.

[0119] In particular, in the tool rest 50 of this embodiment, a mechanism for confirming the seating of the tool holder 61 on the seating surface 53 is added, which makes it possible to more effectively reduce the phenomenon of hydraulic oil spraying out when the tool holder 61 is not attached.

[0120] Furthermore, even when oil pump 78 is not operating, the piping leading to second hole 212 is filled with hydraulic oil. In mounting part 52 in which second hole 212 opens facing downward, such hydraulic oil may drip from second hole 212. In this embodiment, by applying the elastic force of elastic member 361 to second member 331, a first state in which oil distribution space 371 is blocked from first in-valve flow path 342 is obtained, and the phenomenon of hydraulic oil dripping can be reduced.

[0121] Furthermore, by bringing first opposing surface 356 and second opposing surface 346, which are conical surfaces centered on predetermined axis 301, into contact with each other, a first state is obtained in which oil distribution space 371 is blocked from first in-valve flow path 342. With this configuration, by utilizing the wedge force generated between first opposing surface 356 and second opposing surface 346, the oil distribution space 371 and first in-valve flow path 342 can be blocked more reliably.

[0122] Furthermore, the elastic member 361 is provided at a position overlapping with the first opposing surface 356 and the second opposing surface 346 when viewed in the axial direction of the predetermined axis 301. With this configuration, the elastic force of the elastic member 361 is more efficiently transmitted to the first opposing surface 356 and the second opposing surface 346, thereby more reliably blocking the gap between the oil distribution space 371 and the first in-valve flow path 342.

[0123] In the above, the mechanism for preventing hydraulic oil from being sprayed out has been described with focus on the second hole 212 in FIG. 4 through which hydraulic oil flows for clamping the clamp mechanism 79. However, a similar mechanism is also provided for the third hole 213 in FIG. 4 through which hydraulic oil flows for unclamping the clamp mechanism 79.

[0124] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0125] 11 bed, 14 support frame, 15 first base, 16 second base, 21 first headstock, 26 second headstock, 31 automatic tool changer, 41 clutch shaft, 50 tool rest, 51 base portion, 52 mounting portion, 53 seating surface, 57 saddle, 58 tool rest base, 61 tool holder, 61S first tool holder, 61T second tool holder, 61U third tool holder, 61V fourth tool holder, 62 cover, 63 swivel portion, 64 motor, 65 housing, 66 cover portion, 67 housing portion, 67g, 69g recess, 67t inner peripheral surface, 68 tapered portion, 69 shaft portion, 69u outer peripheral surface, 71 first air flow path, 72 second air flow path, 76 detection portion, 77 control portion, 78 oil pump, 79 Clamping mechanism, 80, switching valve, 81, piping block, 82, opposing surface, 83, piston insertion hole, 86, 86A, 86B, 86C, 86D, 96, piston mechanism, 87, 97, piston, 88, flow path, 91, 313, internal piping, 92, switch, 100, machine tool, 101, 103, swivel axis, 102, 106, 107, rotation axis, 110, magazine, 111, support plate, 120, tool pot, 130, automatic transfer device, 140, tool exchange unit, 146, gripping unit, 211, first hole, 211a, opening, 212, second hole, 212c, hole bottom, 213, third hole, 214, fourth hole, 215, fifth hole, 216, sixth hole, 217, seventh hole, 221 First pipe, 222, 223, 232, 233, 237, 238 hole, 224 First annular groove, 231 Second pipe, 234 Second annular groove, 236 Third pipe, 239 Third annular groove, 240 First radial hole, 241 First section, 242 Second section, 250 Second radial hole, 260 Third radial hole, 301 Predetermined axis, 311 Oil circulation hole, 312 Valve body, 331 Second member, 332 Top, 333, 335 Seal member, 334 Large diameter portion, 341 Small diameter portion, 342 First valve internal flow passage, 343 Second valve internal flow passage, 345 Bottom, 346 Second opposing surface, 351 First member, 356 First opposing surface, 361 Elastic member, 371 Oil circulation space, K Tool change position on tool rest side, W Workpiece machining position.

Claims

1. a tool holder having a clamping mechanism that is hydraulically operated to clamp a tool; a mounting portion provided with a hole through which hydraulic oil for the clamp mechanism is supplied and to which the tool holder is detachably mounted; a valve body that is disposed in the hole and that is operable between a first state in which the hydraulic oil is restricted from flowing when the tool holder is not attached, and a second state in which the hydraulic oil is permitted to flow when the tool holder is attached; and a tool rest including an elastic member disposed in the hole and configured to apply an elastic force to the valve body in a direction to move the valve body from the second state to the first state.

2. A machine tool comprising the tool rest according to claim 1.

Images