Tool clamping device and machine tool

Abstract

The tool holder (31) includes a clamping mechanism (131) and a first piston (61). The first piston (61) includes a first relative portion (63) and a second relative portion (64), and the clamping mechanism (131) includes a rod (135). The first piston (61) reciprocates between a first position and a second position. At the first position, the rod (135) contacts the first relative portion (63), causing the clamping mechanism (131) to move to a clamped state. At the second position, the rod (135) contacts the second relative portion (64), causing the clamping mechanism (131) to move to an unclamped state. The tool holder (31) includes a second piston (71) that moves the first piston (61) to a third position between the first position and the second position. When the first piston (61) is at the third position, the rod (135) is separated from the first relative portion (63) and the second relative portion (64).

Description

Technical Field

[0001] The invention relates to a tool clamping device and a machine tool. Background Art

[0002] For example, Japanese Patent Application Laid-Open No. 58-149151 (Patent Document 1) discloses a turret tool post, which includes a tool holder mounting portion, an unclamping cylinder mechanism, and a clamping cylinder mechanism so that a tool for a machining center can be mounted as a tool for a lathe.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 58-149151 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] As disclosed in the above-mentioned Patent Document 1, there is a known tool clamping device having a function of clamping a tool, such as a tool holder and a tool spindle. As a structure of the tool clamping device, there is a structure having a clamping mechanism part capable of clamping a tool and a piston for causing the clamping mechanism part to perform a clamping action and an unclamping action. If the rotation of the clamped tool is to be achieved in such a tool clamping device, there is a case where the contact between the piston on the stop side and the clamping mechanism part on the rotating side that rotates with the tool becomes a problem depending on the structure of the clamping mechanism part.

[0008] Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a tool clamping device capable of rotating a clamped tool and a machine tool including such a tool clamping device.

[0009] Solutions for solving problems

[0010] The tool clamping device according to the present invention is a tool clamping device for installing a rotating tool in a detachable manner. The tool clamping device comprises: a clamping mechanism portion; and a first piston, which reciprocates in the axial direction of the predetermined axis with a predetermined axis as the center. The clamping mechanism portion has a first relative portion and a second relative portion that are opposite to each other in the axial direction of the predetermined axis, and any one of a locking portion arranged between the first relative portion and the second relative portion. The first piston has a first relative portion and a second relative portion, and the other of the locking portions. The first piston reciprocates between a first position and a second position, and at the first position, the locking portion contacts the first relative portion, so that the clamping mechanism portion moves to a clamped state in which the rotating tool is clamped, and at the second position, the locking portion contacts the second relative portion, so that the clamping mechanism portion moves to an unclamped state in which the rotating tool is not clamped. In addition, the tool clamping device comprises a second piston that moves the first piston to a third position located between the first position and the second position in the axial direction of the predetermined axis. When the first piston is positioned at the third position, the clamp mechanism is maintained in the clamped state, and the locking portion is separated from the first opposing portion and the second opposing portion.

[0011] In addition, preferably, the clamping mechanism has a rod, which extends outward in the radial direction of the predetermined axis and corresponds to the locking portion. The first piston is provided with a recessed portion, which is in a concave shape recessed outward in the radial direction of the predetermined axis and is provided for the rod to be arranged. The first piston has a first wall surface and a second wall surface, which constitute the wall surface of the recessed portion and correspond to the first opposing portion and the second opposing portion, respectively.

[0012] In addition, it is preferred that the tool clamping device further comprises a cylinder, the first piston and the second piston are engaged with the cylinder, and the cylinder is divided into: a first hydraulic chamber to which hydraulic pressure is supplied when the first piston is moved to the first position; and a second hydraulic chamber to which hydraulic pressure is supplied when the first piston is moved to the second position. The first piston and the second piston divide and form a third hydraulic chamber to which hydraulic pressure is supplied in order to move the first piston to the third position. The third hydraulic chamber is provided at a position radially inner than the first hydraulic chamber and the second hydraulic chamber in the predetermined axis.

[0013] Preferably, the tool clamping device further includes a locking member provided on the first piston and locked with the second piston when the hydraulic pressure is supplied to the third hydraulic chamber, thereby holding the first piston at the third position.

[0014] Furthermore, it is preferable that when the hydraulic pressure is supplied to the second hydraulic chamber, the second piston is locked to the second piston by the locking member and moves integrally with the first piston.

[0015] A machine tool according to the present invention comprises: the tool clamping device described in any one of the above; and an automatic tool changing device for changing a rotary tool mounted on the tool clamping device.

[0016] Effects of the Invention

[0017] According to the present invention, it is possible to provide a tool clamping device capable of rotating a clamped tool and a machine tool including such a tool clamping device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a perspective view showing a machine tool in the embodiment of the present invention.

[0019] Figure 2 This is a side view showing the automatic replacement position of the tool in the tool holder.

[0020] Figure 3 This is a side view showing the workpiece machining position of the tool in the tool holder.

[0021] Figure 4 It is a cross-sectional view showing the tool holder.

[0022] Figure 5 is another cross-sectional view showing the tool holder.

[0023] Figure 6 It is a perspective view showing a first tool holder for a rotary tool.

[0024] Figure 7 It is a perspective view showing a second tool holder for fixing the tool.

[0025] Figure 8 Yes means Figure 6 A cross-sectional view of the first tool holder in FIG.

[0026] Fig. 9 Yes means Figure 7 A cross-sectional view of the second tool holder in FIG.

[0027] Fig.10 It is a cross-sectional view showing the tool holder (when clamped) to which the first tool holder is mounted.

[0028] Fig.11 It is a cross-sectional view showing the tool holder to which the first tool holder is mounted (when a workpiece is being machined).

[0029] Fig.12 It is a cross-sectional view showing the tool holder to which the first tool holder is mounted (when not clamped).

[0030] Fig.13 It is a cross-sectional view showing the tool holder (when clamped) to which the second tool holder is mounted.

[0031] Fig.14 It is magnified Figure 4 A cross-sectional view of the retainer mounting portion in the range surrounded by the double-dashed chain line XIV.

[0032] Fig.15 It means along Fig.11 A cross-sectional view of the tool holder viewed in the direction of the XV-XV line in FIG.

[0033] Fig.16 It is magnified Fig.10 A sectional view of the tool holder in the range surrounded by the double-dotted chain line XVI.

[0034] Fig.17 It means along Fig.16 FIG. 1 is a diagram of the tool holder viewed in the direction shown in FIG. XVII.

[0035] Fig.18 It means in Fig.15 A cross-sectional view of a process for removing and attaching a first tool holder relative to a holder mounting portion in a tool holder. DETAILED DESCRIPTION

[0036] Embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings referred to below, the same or corresponding components are denoted by the same reference numerals.

[0037] Figure 1 1 is a perspective view showing a machine tool in an embodiment of the present invention. Figure 1 In the figure, the internal structure of the machine tool is shown by seeing through the cover that constitutes the appearance of the machine tool.

[0038] Reference Figure 1 The machine tool 10 in this embodiment is a lathe that processes a workpiece by bringing a tool into contact with a rotating workpiece. The machine tool 10 is provided with a milling function that processes a workpiece by bringing a rotating tool into contact with a stopped workpiece.

[0039] The machine tool 10 is an NC (Numerically Controlled) machine tool that automates various operations for machining a workpiece by numerical control performed by a computer.

[0040] First, the overall structure of the machine tool 10 is described. The machine tool 10 includes a machine base 11, a spindle head 21, a tool rest 31, and an automatic tool changer 18 (see the following). Figure 2 ).

[0041] The machine bed 11 is a base member for supporting the main spindle head 21, the tool rest 31, the automatic tool changer 18, etc., and is installed on the floor of a factory, etc. The machine bed 11 is formed of metal such as cast iron.

[0042] The spindle table 21 is mounted on the machine base 11. The spindle table 21 has a spindle (not shown). The spindle is driven to rotate around a central axis 101 parallel to the Z axis extending in the horizontal direction. A chuck mechanism capable of holding a workpiece in a detachable manner is provided at the top end of the spindle. The workpiece held in the chuck mechanism rotates around the central axis 101 as the spindle is driven to rotate.

[0043] The tool rest 31 is installed in a processing area defined by a cover (not shown). The tool rest 31 is a turret-type tool rest, and can rotate around a central axis (rotation central axis) 102 parallel to the Z axis.

[0044] The tool rest 31 includes a tool rest base 32, a turret 33, and a plurality of tool holders 121. A motor or the like for rotationally driving the tool rest 31 is mounted on the tool rest base 32. The tool rest base 32 is attached to a lateral conveyance table to be described later.

[0045] The turret 33 is provided so as to protrude from the tool rest base 32 in the Z-axis direction toward the spindle head 21. The turret 33 has a disk shape with the axial direction of the rotation center axis 102 being the thickness direction. The turret 33 is rotatable about the rotation center axis 102.

[0046] The plurality of tool holders 121 are attached to the turret 33. The plurality of tool holders 121 are fastened to the turret 33 using bolts. The plurality of tool holders 121 are arranged in a row in the circumferential direction of the rotation center axis 102. Each tool holder 121 is configured to be able to hold a tool.

[0047] The tool holder 31 is mounted on the machine base 11 by means of a saddle 16 and a transverse conveyor table (not shown). The saddle 16 can be moved in the Z-axis direction by various conveying mechanisms, guide mechanisms, servo motors, etc. The transverse conveyor table can be moved in the X-axis direction which is orthogonal to the Z-axis and inclined relative to the vertical direction by various conveying mechanisms, guide mechanisms, servo motors, etc. The saddle 16 and the transverse conveyor table can move the processing position of the tool held in the tool holder 121 on the workpiece in the Z-axis-X-axis plane by moving in the Z-axis direction and the X-axis direction respectively.

[0048] Figure 2 This is a side view showing the automatic replacement position of the tool in the tool holder. Figure 3 This is a side view showing the workpiece machining position of the tool in the tool holder.

[0049] Reference Figure 1 to Figure 3Since the turret 33 rotates around the rotation center axis 102, the tool held by the tool holder 121 moves in the circumferential direction of the rotation center axis 102. The automatic tool changer (ATC: Automatic Tool Changer) 18 has a double arm capable of holding a tool, and is configured to be able to change tools between the tool holder 31 in the processing area and a tool magazine (not shown) outside the processing area.

[0050] like Figure 2 As shown, the automatic tool changer 18 is provided on the front side of the machine tool of the tool rest 31. When the tool in the tool rest 31 is replaced by the automatic tool changer 18, the tool holder 121 holding the tool to be replaced is positioned at the automatic tool replacement position J in the figure. Figure 3 As shown, when the workpiece W is machined using the tool in the tool holder 31 , the tool holder 121 that holds the tool used for machining is positioned at the workpiece machining position K in the figure.

[0051] In addition, the positions of the automatic tool change position J and the workpiece processing position K are not particularly limited. For example, when the automatic tool changer 18 is arranged at the rear side of the machine tool, the automatic tool change position J may also be relative to Figure 3 The workpiece processing position K shown is offset by 180°.

[0052] Next, the structure of the tool post 31 on the turret 33 side will be described. Figure 4 and Figure 5 is a cross-sectional view showing the tool holder. Figure 4 and Figure 5 2 shows the tool holder 31 in a state where the tool holder 121 is removed. Figure 4 The cross section shown is similar to that along Figure 2 It corresponds to the cross section of the tool holder 31 at the tool automatic changing position J viewed in the direction on the IV-IV line in FIG. Figure 5 The cross section shown is similar to that along Figure 3 It corresponds to the cross section of the tool holder 31 at the workpiece processing position K viewed in the viewing direction on the VV line in FIG.

[0053] Reference Figure 4 and Figure 5 The tool holder 31 (turret 33) further includes a ring member 34. The ring member 34 has a ring shape centered on the central axis of rotation 102. A surrounding groove 35 is provided in the ring member 34. The surrounding groove 35 has a groove shape that is recessed inward in the radial direction toward the central axis of rotation 102 and surrounds the central axis of rotation 102 as the center.

[0054] The tool holder 31 also has an air supply unit 41. The air supply unit 41 is provided at Figure 4The cross-sectional position of the tool rest 31 at the tool automatic changing position J is shown. The air supply unit 41 is provided with a first air flow path 43. The first air flow path 43 is supplied with air from an air supply source 46.

[0055] The ring member 34 is also provided with a nozzle insertion hole 44. The nozzle insertion hole 44 is a bottomed hole that is recessed from the groove bottom of the surrounding groove 35 toward the inner side in the radial direction of the rotation center axis 102. The air supply unit 41 has an air nozzle 42. The air nozzle 42 is provided with a through hole 43h. The through hole 43h constitutes an air ejection port from the first air flow path 43.

[0056] The tool holder 31 also has a motor 36. The motor 36 is arranged at Figure 5 The cross-sectional position of the tool rest 31 at the workpiece machining position K is shown. The motor 36 is built into the turret 33 .

[0057] The motor 36 has a rotor shaft 37. The rotor shaft 37 extends in an axial shape along a central axis 106 extending in a radial direction of the rotation center axis 102. The rotor shaft 37 is supported so as to be rotatable around the central axis 106. An engaging groove 38 is provided at the top end of the rotor shaft 37. The engaging groove 38 has a groove shape that is recessed from the end surface of the top end of the rotor shaft 37 and extends in one direction. The engaging groove 38 is provided continuously with the surrounding groove 35 in the circumferential direction of the rotation center axis 102.

[0058] Although described in detail later, the air supply unit 41 performs air purging when the tool attached to the tool holder 31 is automatically replaced. When the rotary tool is attached to the tool holder 31, the motor 36 outputs rotation to the rotary tool.

[0059] Next, the structure of the tool holder 121 will be described. Figure 6 It is a perspective view showing a first tool holder for a rotary tool. Figure 7 It is a perspective view showing a second tool holder for fixing the tool.

[0060] Figure 8 Yes means Figure 6 A cross-sectional view of the first tool holder in FIG. Fig. 9 Yes means Figure 7 A cross-sectional view of the second tool holder in FIG.

[0061] In addition, the tool holder 121 is Figure 4 The tool holder is inserted into the retainer insertion hole 58 in the tool holder 31 in the direction indicated by the arrow 201 in FIG. Figure 6 to Figure 9 The center axis 106 shown in FIG. 1 is aligned with the center axis 106 when the tool holder 121 is mounted to the tool holder 31. Figure 4 and Figure 5 The central axis 106 shown in FIG.

[0062] In the following description, the inner side direction of the tool holder 121 relative to the insertion direction of the holder insertion hole 58 is also referred to as "axially rearward of the center axis 106", and the front side direction of the tool holder 121 relative to the insertion direction of the holder insertion hole 58 is also referred to as "axially forward of the center axis 106".

[0063] Reference Figure 6 to Figure 9 The tool holder 31 includes a first tool holder 121A and a second tool holder 121B as tool holders 121. The first tool holder 121A is a tool holder for holding a rotating tool, and the second tool holder 121B is a tool holder for holding a fixed tool.

[0064] Rotary tools are tools that process workpieces while rotating, such as drills, end mills, or reamers. Fixed tools are tools that process rotating workpieces, such as outer diameter cutting blades, inner diameter cutting blades, end face cutting blades, or cut-off blades.

[0065] The first tool holder 121A and the second tool holder 121B each include a clamping mechanism 131. The clamping mechanism 131 is configured to be able to clamp a tool.

[0066] The clamp mechanism 131 includes a pull rod 132 , a collet 136 , and a sliding member 134 .

[0067] The pull rod 132 is provided on the axis of the central axis 106. The pull rod 132 is provided so as to be able to slide in the axial front-rear direction of the central axis 106. The collet 136 is attached to the front end of the pull rod 132. The collet 136 is deformed in a manner of expanding or reducing the diameter around the central axis 106 as the pull rod 132 slides in the axial front-rear direction of the central axis 106.

[0068] The tie rod 132 is provided with an insertion hole 132h. The insertion hole 132h extends along the axis of the central axis 106 and opens toward the rear in the axial direction of the central axis 106. The sliding member 134 is arranged in parallel with the tie rod 132 in the axial direction of the central axis 106. The sliding member 134 is inserted into the insertion hole 132h.

[0069] The sliding member 134 has a rod (locking portion) 135. The rod 135 has a rod shape extending toward the radial outer side of the central axis 106. The sliding member 134 has a plurality of rods 135. The sliding member 134 has three rods 135. The plurality of rods 135 are arranged in a manner of being spaced apart from each other in the circumferential direction of the central axis 106. The plurality of rods 135 are arranged at equal intervals in the circumferential direction of the central axis 106 (see the following description). Fig.15 ).

[0070] If an external force in the axial direction rearward of the central axis 106 is applied to the plurality of rods 135, the sliding member 134 slides in the axial direction rearward of the central axis 106. At this time, the pull rod 132 slides in the axial direction rearward of the central axis 106 together with the sliding member 134, and the collet 136 deforms in a manner of expanding the diameter around the central axis 106. The tool is held by the collet 136 and pulled in in the axial direction rearward of the central axis 106, thereby obtaining a clamped state of the tool.

[0071] If an external force in the axial direction forward of the central axis 106 is applied to the plurality of rods 135, the sliding member 134 slides in the axial direction forward of the central axis 106. At this time, the pull rod 132 slides in the axial direction forward of the central axis 106 together with the sliding member 134, so that the collet 136 is deformed in a manner of reducing the diameter around the central axis 106. By releasing the grip of the collet 136 on the tool, the tool is pushed out in the axial direction forward of the central axis 106, and the tool is in an unclamped state.

[0072] The pull rod 132 has a wedge mechanism 133. When the tool is clamped, if the slide member 134 slides in the axial direction rearward of the center axis 106, a force in the radial direction outward of the center axis 106 acts on the wedge mechanism 133 from the slide member 134, and a wedge effect is generated in the wedge mechanism 133. Thus, even when the force in the axial direction rearward of the center axis 106 is eliminated from being applied to the plurality of rods 135, the clamped state of the tool is maintained.

[0073] Reference Figure 6 and Figure 8 The first tool holder 121A further includes an outer housing (second housing member) 141 , an inner housing 143 , a first bearing 142 , and a rear member 151 .

[0074] The inner housing 143 has a cylindrical shape centered on the central axis 106. The clamping mechanism 131 is provided inside the inner housing 143. The inner housing 143 is provided with a tool insertion hole 145. The tool insertion hole 145 opens toward the front in the axial direction of the central axis 106. The pull rod 132 and the collet 136 in the clamping mechanism 131 are arranged in the tool insertion hole 145. The rotating tool clamped by the clamping mechanism 131 is inserted into the tool insertion hole 145.

[0075] The inner housing 143 is provided with a plurality of openings 144. The openings 144 penetrate the inner housing 143 in the radial direction of the central axis 106. The plurality of openings 144 are respectively provided at phase positions corresponding to the plurality of rods 135 with the central axis 106 as the center. The plurality of rods 135 extend to the outside of the inner housing 143 through the plurality of openings 144 (see the following description). Fig.15).

[0076] The outer housing 141 has a cylindrical shape centered on the central axis 106. The outer housing 141 is disposed on the outer periphery of the inner housing 143. The outer housing 141 is disposed near the front end of the first tool holder 121A in the axial direction of the central axis 106. When the first tool holder 121A is mounted to the tool holder 31, the outer housing 141 is fastened to the inner housing 143. Figure 4 and Figure 5 The front housing 57 that then appears is shown.

[0077] The first bearing 142 is inserted between the inner housing 143 and the outer housing 141. The first bearing 142 is provided at a position close to the front end of the first tool holder 121A in the axial direction of the central axis 106. The clamping mechanism 131 is supported by the first bearing 142 via the inner housing 143 so as to be rotatable about the central axis 106. The first bearing 142 is an angular contact ball bearing.

[0078] The rear member 151 is provided at the rear end portion of the first tool holder 121A. The rear member 151 is fastened to the inner housing 143. The rear member 151 is provided so as to close the opening of the inner housing 143 which is open toward the rear in the axial direction of the central axis 106.

[0079] The rear member 151 has a first connection portion 152. The first connection portion 152 extends on the axis of the central axis 106 and protrudes toward the rear in the axial direction of the central axis 106. The first connection portion 152 has a key shape having a rectangular cross section when cut along a plane perpendicular to the central axis 106.

[0080] The second air flow path 153 is provided in the first connection portion 152. The second air flow path 153 extends on the axis of the central axis 106 and opens toward the rear in the axial direction of the central axis 106. The second air flow path 153 extends from the first connection portion 152 in the rear member 151 and the inner housing 143 in sequence and opens at the inner peripheral surface of the predetermined tool insertion hole 145 of the inner housing 143.

[0081] Reference Figure 7 and Fig. 9 The second tool holder 121B further includes a housing 171 and a rear member 161 .

[0082] The housing 171 has a cylindrical shape centered on the central axis 106. The clamping mechanism 131 is provided inside the housing 171. The housing 171 is provided with a tool insertion hole 175. The tool insertion hole 175 opens toward the front in the axial direction of the central axis 106. The pull rod 132 and the collet 136 in the clamping mechanism 131 are arranged in the tool insertion hole 175. The fixed tool clamped by the clamping mechanism 131 is inserted into the tool insertion hole 175.

[0083] The housing 171 is provided with a plurality of openings 174. The plurality of openings 174 are provided in the same form as the plurality of openings 144 in the inner housing 143 of the first tool holder 121A.

[0084] The rear member 161 is provided at the rear end portion of the second tool holder 121B. The rear member 161 is fastened to the housing 171. The rear member 161 is provided so as to close the opening of the housing 171 which is open to the rear in the axial direction of the central axis 106.

[0085] The rear member 161 has a second connection portion 162. The second connection portion 162 extends on the axis of the central axis 106 and protrudes toward the rear in the axial direction of the central axis 106. The second connection portion 162 has a pin shape having a circular cross section when cut along a plane perpendicular to the central axis 106.

[0086] The third air flow path 163 is provided in the second connection portion 162. The third air flow path 163 extends on the axis of the central axis 106 and opens toward the rear in the axial direction of the central axis 106. The third air flow path 163 extends from the second connection portion 162 inside the rear member 161 and the housing 171 and opens at the inner peripheral surface of the predetermined tool insertion hole 175 of the housing 171.

[0087] Reference Figure 6 to Figure 9 The first tool holder 121A and the second tool holder 121B have substantially the same appearance. The first tool holder 121A and the second tool holder 121B have an appearance in which the diameter decreases from the front side toward the rear side in the axial direction of the central axis 106 as a whole.

[0088] Next, the structure of the holder mounting portion 50 to which the tool holder 121 (121A, 121B) is mounted will be described.

[0089] Fig.10 It is a cross-sectional view showing the tool holder (when clamped) to which the first tool holder is attached. Fig.11 It is a cross-sectional view showing the tool holder (when machining a workpiece) to which the first tool holder is attached. Fig.12 It is a cross-sectional view showing the tool holder (unclamped) to which the first tool holder is attached.

[0090] exist Fig.10 The figure shows a rotating tool clamped Figure 2 The cross section of the tool holder 31 at the tool automatic change position J in . Fig.11 The figure shows the case where a workpiece is machined by a rotating tool. Figure 3 The cross section of the tool rest 31 at the workpiece processing position K in FIG. Fig.12 The figure shows that the rotating tool is not clamped. Figure 2 The cross section of the tool holder 31 at the tool automatic changing position J in FIG.

[0091] Fig.13 2 is a cross-sectional view showing the tool holder (when clamped) with the second tool holder installed. Fig.13 The following is a typical example of a fixed tool clamping. Figure 2 The cross section of the tool holder 31 at the tool automatic changing position J in FIG.

[0092] Reference Figure 4 and Figure 5 as well as Figure 10 to Figure 13 The tool holder 31 also has a plurality of retaining member mounting portions 50 .

[0093] The plurality of holder mounting parts 50 are provided on the outer peripheral surface of the turret 33. The plurality of holder mounting parts 50 are arranged in a row in the circumferential direction of the rotation center axis 102. The plurality of holder mounting parts 50 have the same structure as each other.

[0094] The holder mounting portion 50 is configured so that either the first tool holder 121A or the second tool holder 121B can be selectively mounted. That is, the user can mount the first tool holder 121A for holding a rotating tool to each holder mounting portion 50, or the second tool holder 121B for holding a fixed tool to each holder mounting portion 50, depending on the content of workpiece processing performed in the machine tool 10.

[0095] Fig.14 It is magnified Figure 4 A cross-sectional view of the retainer mounting portion in the range surrounded by the double-dashed chain line XIV.

[0096] Reference Figure 4 and Fig.14 The holder mounting portion 50 includes a cylinder 52 , a front housing (first housing member) 57 , and a bearing housing 56 .

[0097] The cylinder 52 has a cylindrical portion 53 and a rear wall portion 54. The cylindrical portion 53 has a cylindrical shape centered on the central axis 106.

[0098] The cylindrical portion 53 has a first inner peripheral surface 53p, a second inner peripheral surface 53q, and a third inner peripheral surface 53r. The first inner peripheral surface 53p, the second inner peripheral surface 53q, and the third inner peripheral surface 53r are arranged in the order listed from the front side to the rear side in the axial direction of the central axis 106. The second inner peripheral surface 53q has an inner diameter larger than the inner diameter of the third inner peripheral surface 53r. The first inner peripheral surface 53p has an inner diameter larger than the inner diameter of the second inner peripheral surface 53q.

[0099] The rear wall portion 54 is in a wall shape that blocks the opening of the cylindrical portion 53 at the rear of the central axis 106 in the axial direction. A communication hole 55 is provided in the rear wall portion 54. The communication hole 55 is composed of a through hole that penetrates the rear wall portion 54 in the axial direction of the central axis 106. The communication hole 55 is provided in a manner that allows the inside and outside of the cylindrical portion 53 to communicate.

[0100] The front housing 57 is connected to the front end (cylindrical portion 53) of the cylinder 52. The front housing 57 is fitted inside the first inner peripheral surface 53p. The bearing housing 56 is connected to the rear end (rear wall portion 54) of the cylinder 52. The bearing housing 56 is fitted into the communication hole 55 from the inside of the cylindrical portion 53.

[0101] The holder mounting portion 50 is provided with a holder insertion hole 58. The holder insertion hole 58 extends on the axis of the central axis 106 and opens toward the front in the axial direction of the central axis 106. The holder insertion hole 58 is provided in the front housing 57. The tool holder 121 (the first tool holder 121A, the second tool holder 121B) mounted on the holder mounting portion 50 is inserted into the holder insertion hole 58. Figure 4 The direction indicated by the arrow 201 in is the insertion direction of the tool holder 121 (the first tool holder 121A, the second tool holder 121B) into the holder insertion hole 58 .

[0102] The holder mounting portion 50 further includes a second bearing 91. The second bearing 91 is provided at the rear end portion of the holder mounting portion 50. The second bearing 91 is fitted inside the bearing housing 56. The second bearing 91 is arranged inside the cylindrical portion 53.

[0103] Reference Figure 10 to Figure 12 A first tool holder 121A for holding a rotary tool is mounted on the holder mounting portion 50 . An outer housing 141 of the first tool holder 121A is fitted inside the front housing 57 of the holder mounting portion 50 .

[0104] The rear member 151 is inserted into the inner side of the second bearing 91. The second bearing 91 is arranged at a position closer to the first tool holder 121A than the first bearing 142 in the insertion direction of the holder insertion hole 58. The second bearing 91 is arranged opposite to the turret 33 in the axial direction of the central axis 106. The diameter D2 of the second bearing 91 centered on the central axis 106 is smaller than the diameter D1 of the first bearing 142 centered on the central axis 106 (refer to Figure 4 and Figure 8 ).

[0105] The second bearing 91 is a needle roller bearing and includes an outer ring 92 and a plurality of rollers 93 .

[0106] The outer ring 92 has a cylindrical shape centered on the central axis 106. The outer ring 92 is fitted into the inner side of the bearing housing 56. The plurality of rollers 93 are supported by the outer ring 92. Each roller 93 extends in an axial direction of the central axis 106 in an axial shape. The plurality of rollers 93 are arranged in a manner of setting intervals between each other in the circumferential direction of the central axis 106. The plurality of rollers 93 are in contact with the first tool holder 121A. The plurality of rollers 93 are in contact with the outer peripheral surface of the rear member 151.

[0107] The second bearing 91 supports the first tool holder 121A so as to be rotatable about the central axis 106. The first tool holder 121A is rotatably supported by the first bearing 142 on the front side in the insertion direction of the first tool holder 121A relative to the holder insertion hole 58, and is rotatably supported by the second bearing 91 on the back side in the insertion direction of the first tool holder 121A.

[0108] The first connection portion 152 moves inside the surrounding groove 35 as the turret 33 rotates. Fig.10 and Fig.12 In the cross section of the tool holder 31 at the tool automatic changing position J shown in , the first connecting portion 152 is connected to the air supply portion 41. The first connecting portion 152 is positioned opposite to the air nozzle 42 in the nozzle insertion hole 44. Thus, the first air flow path 43 on the turret 33 side is communicated with the second air flow path 153 on the first tool holder 121A side.

[0109] When the rotary tool held in the first tool holder 121A is automatically replaced, the air from the air supply source 46 flows sequentially in the first air flow path 43 and the second air flow path 153. The air flowing in the second air flow path 153 is ejected toward the gap between the rotary tool inserted and pulled out of the tool insertion hole 145 and the inner peripheral surface of the predetermined tool insertion hole 145 of the inner housing 143.

[0110] exist Fig.11In the cross section of the tool rest 31 at the workpiece processing position K shown in FIG. 1 , the first connection portion 152 is disposed in the engagement groove 38 of the rotor shaft 37. At this time, the first connection portion 152 has a rectangular cross section and is therefore engaged with the engagement groove 38. Thus, the rotation output by the motor 36 is transmitted from the rotor shaft 37 to the rear member 151, so that the rotary tool held by the first tool holder 121A can be rotated.

[0111] Reference Fig.13 A second tool holder 121B for holding a fixed tool is mounted on the holder mounting portion 50 . A housing 171 of the second tool holder 121B is fitted inside the front housing 57 of the holder mounting portion 50 .

[0112] The rear member 161 is inserted into the inner side of the second bearing 91. The second tool holder 121B is supported by the front housing 57 at the front side in the insertion direction of the second tool holder 121B relative to the holder insertion hole 58, and is supported by the second bearing 91 at the back side in the insertion direction of the second tool holder 121B.

[0113] The second connection portion 162 moves inside the surrounding groove 35 as the turret 33 rotates. Fig.13 In the cross section of the tool holder 31 at the tool automatic replacement position J shown in , the second connection portion 162 is positioned opposite to the air nozzle 42 in the nozzle insertion hole 44. Thus, the first air flow path 43 on the turret 33 side communicates with the third air flow path 163 on the second tool holder 121B side.

[0114] When the fixed tool held in the second tool holder 121B is automatically replaced, the air from the air supply source 46 flows sequentially in the first air flow path 43 and the third air flow path 163. The air flowing in the third air flow path 163 is ejected toward the gap between the fixed tool inserted and pulled out of the tool insertion hole 175 and the inner peripheral surface of the predetermined tool insertion hole 175 of the housing 171.

[0115] When the second tool holder 121B is positioned at the workpiece processing position K, the second connection portion 162 is arranged in the engagement groove 38 of the rotor shaft 37, similarly to the case where the first tool holder 121A is positioned at the workpiece processing position K. At this time, the second connection portion 162 has a circular cross section and is therefore not engaged with the engagement groove 38. Therefore, even if rotation is output from the motor 36, the rotation is not transmitted to the second tool holder 121B.

[0116] Next, the hydraulic cylinder mechanism portion 51 for operating the clamp mechanism portion 131 will be described.

[0117] Reference Figure 10 to Figure 13The holder mounting portion 50 has a hydraulic cylinder mechanism 51. The hydraulic cylinder mechanism 51 is supplied with hydraulic pressure to operate the clamping mechanism 131 in the tool holder 121 (first tool holder 121A, second tool holder 121B) to a clamped state in which the tool is clamped and an unclamped state in which the tool is unclamped.

[0118] Reference Figure 4 and Fig.14 The hydraulic cylinder mechanism 51 includes a first piston 61 and a second piston 71 in addition to the cylinder 52 already described.

[0119] The first piston 61 and the second piston 71 have a cylindrical shape centered on the central axis 106. The first piston 61 and the second piston 71 are fitted in the cylinder 52. The first piston 61 and the second piston 71 are provided so as to be slidable in the axial direction of the central axis 106.

[0120] The first piston 61 and the second piston 71 are arranged side by side in the axial direction of the central axis 106. The second piston 71 is arranged further back than the first piston 61 in the insertion direction of the tool holder 121 with respect to the holder insertion hole 58.

[0121] The first piston 61 includes a front portion 65 , a first middle portion 66 , a second middle portion 67 , and a rear portion 68 .

[0122] The front section 65, the first middle section 66, the second middle section 67, and the rear section 68 are arranged in the order listed from the front side toward the back side of the tool holder 121 in the insertion direction of the holder insertion hole 58. The front section 65 is provided at the front end of the first piston 61. The rear section 68 is provided at the rear end of the first piston 61.

[0123] The front section 65, the first middle section 66, the second middle section 67, and the rear section 68 are formed in a stepped shape on the outer peripheral surface of the first piston 61. The first middle section 66 has the largest outer diameter (diameter) in the first piston 61. The front section 65 and the second middle section 67 have an outer diameter (diameter) smaller than the outer diameter (diameter) of the first middle section 66. The rear section 68 has an outer diameter (diameter) smaller than the outer diameter (diameter) of the front section 65 and the second middle section 67. The rear section 68 has the smallest outer diameter (diameter) in the first piston 61.

[0124] The outer peripheral surface of the first intermediate portion 66 is in sliding contact with the second inner peripheral surface 53q of the cylinder 52. The outer peripheral surface of the front portion 65 is in sliding contact with the inner peripheral surface of the front housing 57.

[0125] The second piston 71 has a front section 72, a middle section 73, and a rear section 74. The front section 72, the middle section 73, and the rear section 74 are arranged in the order listed from the front side to the back side of the tool holder 121 in the insertion direction of the holder insertion hole 58. The front section 72 is provided at the front end of the second piston 71. The rear section 74 is provided at the rear end of the second piston 71.

[0126] The front section 72, the middle section 73, and the rear section 74 are stepped on the inner circumferential surface of the second piston 71. The middle section 73 has the smallest inner diameter in the second piston 71. The rear section 74 has an inner diameter larger than that of the middle section 73. The front section 72 has an inner diameter larger than that of the rear section 74. The front section 72 has the largest inner diameter in the second piston 71. The middle section 73 has a convex shape that protrudes from the rear section 74 and the front section 72 toward the inner side in the radial direction of the central axis 106.

[0127] The outer circumferential surface of the second piston 71 (the front section 72, the middle section 73, and the rear section 74) is in sliding contact with the third inner circumferential surface 53r of the cylinder 52. The inner circumferential surface of the front section 72 is in sliding contact with the outer circumferential surface of the second middle section 67 of the first piston 61. The inner circumferential surface of the middle section 73 is in sliding contact with the outer circumferential surface of the rear section 68 of the first piston 61.

[0128] The retaining member mounting portion 50 (hydraulic cylinder mechanism portion 51) also has a locking block (locking member) 76. The locking block 76 is provided on the first piston 61. The locking block 76 is provided on the rear end portion (rear section 68) of the first piston 61. The locking block 76 is fastened to the first piston 61 by bolts 77. The locking block 76 is provided in a manner protruding outward in the radial direction of the central axis 106 relative to the outer peripheral surface of the rear section 68. The portion of the locking block 76 protruding outward in the radial direction of the central axis 106 is opposite to the second middle section 67 of the first piston 61 in the axial direction of the central axis 106 in a manner that a gap is provided with the second middle section 67 of the first piston 61.

[0129] The middle section 73 of the second piston 71 is disposed between a portion of the locking block 76 that protrudes radially outward from the center axis 106 and the second middle section 67 of the first piston 61 in the axial direction of the center axis 106 .

[0130] The distance H1 between the locking block 76 and the second middle section 67 in the axial direction of the central axis 106 is greater than the length H2 of the middle section 73 in the axial direction of the central axis 106. According to such a structure, the second piston 71 can slide relative to the first piston 61 within the range in which the middle section 73 moves between the locking block 76 and the second middle section 67. The locking block 76 is provided as a mutual anti-slip member for the first piston 61 and the second piston 71.

[0131] The cylinder 52 defines a first hydraulic chamber 81 and a second hydraulic chamber 82. The first piston 61 and the second piston 71 define a third hydraulic chamber 83.

[0132] Each of the first hydraulic chamber 81, the second hydraulic chamber 82, and the third hydraulic chamber 83 is connected to a hydraulic supply source 87 via a valve 86. By opening and closing the control valve 86, the hydraulic pressure from the hydraulic supply source 87 is supplied to the first hydraulic chamber 81, the second hydraulic chamber 82, or the third hydraulic chamber 83 (see Figure 4 and Figure 5 ).

[0133] The first hydraulic chamber 81 is formed between the first piston 61 (front section 65) and the cylinder 52 (second inner peripheral surface 53q) in the radial direction of the central axis 106. The first hydraulic chamber 81 is formed between the front housing 57 and the first piston 61 (first middle section 66) in the axial direction of the central axis 106. When hydraulic pressure is supplied to the first hydraulic chamber 81, the first piston 61 slides from the front side to the back side in the insertion direction of the tool holder 121 with respect to the holder insertion hole 58.

[0134] The second hydraulic chamber 82 is formed between the first piston 61 (second middle section 67) and the cylinder 52 (second inner peripheral surface 53q) in the radial direction of the central axis 106. The second hydraulic chamber 82 is formed between the first piston 61 (first middle section 66) and the cylinder 52 (step portion between the second inner peripheral surface 53q and the third inner peripheral surface 53r) and the second piston 71 (front section 72) in the axial direction of the central axis 106. The first hydraulic chamber 81 and the second hydraulic chamber 82 are arranged with the first middle section 66 interposed therebetween in the axial direction of the central axis 106. When hydraulic pressure is supplied to the second hydraulic chamber 82, the first piston 61 slides and moves from the inner side to the front side in the insertion direction of the tool holder 121 relative to the holder insertion hole 58.

[0135] The third hydraulic chamber 83 is formed between the first piston 61 (rear section 68) and the second piston 71 (front section 72) in the radial direction of the central axis 106. The third hydraulic chamber 83 is formed between the first piston 61 (second middle section 67) and the second piston 71 (middle section 73) in the axial direction of the central axis 106.

[0136] The first piston 61 is provided with a plunger insertion hole 84 . The plunger insertion hole 84 extends from the end surface of the front end portion (front stage portion 65 ) of the first piston 61 in the axial direction of the central axis 106 and communicates with the third hydraulic chamber 83 .

[0137] The holder mounting portion 50 (hydraulic cylinder mechanism portion 51) further includes a plunger 85. The plunger 85 extends cylindrically in the axial direction of the central axis 106. The plunger 85 is inserted into the plunger insertion hole 84. The plunger 85 can slide and move in the axial direction of the central axis 106 in the plunger insertion hole 84. The plunger 85 protrudes from the plunger insertion hole 84 to the front side of the insertion direction of the tool holder 121 relative to the holder insertion hole 58. The plunger 85 is connected to the front housing 57.

[0138] The hydraulic pressure from the hydraulic supply source 87 is supplied to the third hydraulic chamber 83 through the plunger 85 and the plunger insertion hole 84. When the hydraulic pressure is supplied to the third hydraulic chamber 83, the first piston 61 and the second piston 71 slide relative to each other in a direction in which the second intermediate portion 67 and the intermediate portion 73 move apart from each other.

[0139] The first hydraulic chamber 81 , the second hydraulic chamber 82 , and the third hydraulic chamber 83 are arranged in the listed order from the front side to the back side in the insertion direction of the tool holder 121 with respect to the holder insertion hole 58 .

[0140] The third hydraulic chamber 83 is provided at a position radially inward of the central axis 106 relative to the first hydraulic chamber 81 and the second hydraulic chamber 82. The outer peripheral wall of the third hydraulic chamber 83 is located at the same radial position as the radial position of the inner peripheral wall of the second hydraulic chamber 82 with the central axis 106 as the center. The outer peripheral wall of the third hydraulic chamber 83 is located radially inward of the central axis 106 relative to the inner peripheral wall of the first hydraulic chamber 81.

[0141] Fig.15 It means along Fig.11 The cross-sectional view of the tool holder viewed from the XV-XV line in the figure. Fig.11 and Fig.15 The first piston 61 has a first relative portion 63 and a second relative portion 64 .

[0142] The first opposing portion 63 and the second opposing portion 64 oppose each other with a space therebetween in the axial direction of the central axis 106. The first opposing portion 63 is located closer to the second opposing portion 64 in the insertion direction of the first tool holder 121A into the holder insertion hole 58.

[0143] The first piston 61 is provided with a recessed portion 62. The recessed portion 62 has a concave shape that is recessed from the inner peripheral surface of the first piston 61 toward the radially outer side of the central axis 106. The recessed portion 62 is an annular groove extending in the circumferential direction of the central axis 106.

[0144] The first piston 61 has a first wall surface 62m and a second wall surface 62n. The first wall surface 62m and the second wall surface 62n correspond to the wall surface of the recessed portion 62. The first wall surface 62m and the second wall surface 62n are formed by planes orthogonal to the central axis 106. The first wall surface 62m faces the inner side of the insertion direction of the first tool holder 121A relative to the holder insertion hole 58. The second wall surface 62n faces the front side of the insertion direction of the first tool holder 121A relative to the holder insertion hole 58. The first wall surface 62m corresponds to the first relative portion 63. The second wall surface 62n corresponds to the second relative portion 64.

[0145] The plurality of rods 135 are disposed between the first relative portion 63 (first wall surface 62m) and the second relative portion 64 (second wall surface 62n). The distance between the first relative portion 63 (first wall surface 62m) and the second relative portion 64 (second wall surface 62n) in the axial direction of the central axis 106 is greater than the length (thickness) of the rods 135 in the axial direction of the central axis 106.

[0146] Reference Figure 10 to Figure 12 and Fig.14 , the first piston 61 is in the first position ( Fig.10 Position shown) and position 2 ( Fig.12 In the first position, the rod 135 contacts the first relative portion 63 (the first wall surface 62m), so that the clamping mechanism portion 131 is actuated into a clamped state for clamping the rotating tool. In the second position, the rod 135 contacts the second relative portion 64 (the second wall surface 62n), so that the clamping mechanism portion 131 is actuated into an unclamped state for unclamping the rotating tool.

[0147] The second piston 71 moves the first piston 61 to the first position ( Fig.10 Position shown) and position 2 ( Fig.12 The third position ( Fig.11 When the first piston 61 is positioned to the third position ( Fig.11 In the case of the position shown in the figure), the clamping mechanism portion 131 is maintained in the clamped state, and the rod 135 is separated from the first relative portion 63 (first wall surface 62m) and the second relative portion 64 (second wall surface 62n).

[0148] More specifically, when the rotary tool is mounted on the first tool holder 121A, the clamping mechanism 131 is moved from the unclamped state to the clamped state. Fig.10 As shown, the hydraulic supply from the hydraulic supply source 87 to the second hydraulic chamber 82 is stopped, and the hydraulic supply source 87 supplies the hydraulic pressure to the first hydraulic chamber 81. When the hydraulic pressure is supplied to the first hydraulic chamber 81, the first piston 61 slides and moves rearward in the axial direction of the central axis 106.

[0149] As a result, the first piston 61 moves to the sliding end on the axial rear side of the central axis 106 where the bolt 77 abuts against the rear wall portion 54 of the cylinder 52. The second piston 71 also moves together with the first piston 61 to the sliding end on the axial rear side of the central axis 106 where the rear section 74 abuts against the rear wall portion 54 of the cylinder 52. The locking block 76 and the middle section 73 of the second piston 71 are separated from each other in the axial direction of the central axis 106.

[0150] As the first piston 61 slides, the first relative portion 63 (first wall surface 62m) contacts the plurality of rods 135. The first relative portion 63 (first wall surface 62m) pushes the plurality of rods 135 toward the rear of the axial direction of the central axis 106, and an external force toward the rear of the axial direction of the central axis 106 is applied to the plurality of rods 135. Thus, a clamping state in which the clamping mechanism portion 131 clamps the rotary tool is obtained.

[0151] After obtaining the clamping state of the clamped rotating tool, as Fig.11 As shown, the hydraulic supply from the hydraulic supply source 87 to the first hydraulic chamber 81 is stopped, and the hydraulic supply source 87 supplies the hydraulic pressure to the third hydraulic chamber 83. When the hydraulic pressure is supplied to the third hydraulic chamber 83, the first piston 61 slides forward in the axial direction of the central axis 106.

[0152] Thus, the first piston 61 moves to a position where the locking block 76 contacts the middle portion 73 of the second piston 71. The second piston 71 stops at a sliding end on the rear side of the central axis 106 in the axial direction where the rear portion 74 contacts the rear wall portion 54 of the cylinder 52.

[0153] As the first piston 61 slides, the first relative portion 63 (first wall surface 62m) and the rod 135 are separated. The rod 135 does not contact the first relative portion 63 (first wall surface 62m) and the second relative portion 64 (second wall surface 62n). That is, the moving length of the first piston 61 in this process is shorter than Fig.10 The length of the gap between the rod 135 and the second facing portion 64 (second wall surface 62n) in the axial direction of the central axis 106 shown is small.

[0154] The clamping mechanism 131 maintains the clamped state of the rotary tool due to the wedge effect of the wedge mechanism 133 described above. The rotary tool held by the first tool holder 121A is rotated while the workpiece is milled. At this time, the rotary tool can be rotated without the plurality of rods 135 coming into contact with the first opposing portion 63 (first wall surface 62m) and the second opposing portion 64 (second wall surface 62n).

[0155] When the rotary cutter is removed from the first cutter holder 121A, the clamping mechanism 131 is moved to the unclamped state. Fig.12 As shown, the hydraulic pressure supply from the hydraulic pressure supply source 87 to the third hydraulic chamber 83 is stopped, and the hydraulic pressure is supplied to the second hydraulic chamber 82. When the hydraulic pressure is supplied to the second hydraulic chamber 82, the first piston 61 slides forward in the axial direction of the central axis 106.

[0156] Thus, the first piston 61 moves to the sliding end on the axial front side of the center axis 106 where the front section 65 abuts against the outer housing 141 and the front housing 57. The second piston 71 also moves integrally with the first piston 61 because the locking block 76 is locked with the second piston 71 (middle section 73).

[0157] As the first piston 61 slides, the second relative portion 64 (second wall surface 62n) contacts the plurality of rods 135. The second relative portion 64 (second wall surface 62n) pushes the rods 135 forward in the axial direction of the central axis 106, and an external force forward in the axial direction of the central axis 106 is applied to the plurality of rods 135. Thus, an unclamped state in which the clamping mechanism portion 131 does not clamp the rotary tool is obtained.

[0158] Furthermore, the above description is about the operation of the clamp mechanism 131 when the first tool holder 121A is mounted on the holder mounting portion 50 , but the operation of the clamp mechanism 131 when the second tool holder 121B is mounted on the holder mounting portion 50 is also the same.

[0159] Next, the mounting structure of the tool holder 121 ( 121A, 121B) to the holder mounting portion 50 will be described.

[0160] Fig.16 It is magnified Fig.10 A sectional view of the tool holder in the range surrounded by the double-dotted chain line XVI. Fig.17 It means along Fig.16 FIG. 1 is a diagram of the tool holder viewed in the direction shown in FIG. XVII.

[0161] Reference Fig.16 and Fig.17 A plurality of recessed portions 181 ( 181J, 181K) are provided in the outer housing 141 of the first tool holder 121A and the front housing 57 of the holder mounting portion 50 . The plurality of recessed portions 181 are arranged at intervals from each other in the circumferential direction of the central axis 106 .

[0162] The recessed part 181 is provided across the outer housing 141 and the front housing 57. The recessed part 181 has a concave shape that is recessed from the front side toward the back side in the insertion direction of the first tool holder 121A. The outer housing 141 is provided with a recessed part 181J. The front housing 57 is provided with a recessed part 181K. The recessed part 181J and the recessed part 181K are connected in the radial direction of the central axis 106 to form the recessed part 181.

[0163] The tool holder 31 further includes a plurality of block members 186. The plurality of block members 186 are respectively fitted into the plurality of recessed portions 181. The end faces of the block members 186 are flush with the end faces of the outer housing 141 and the front housing 57 in the axial direction of the central axis 106. The block members 186 are fastened to the front housing 57 by bolts 187.

[0164] In addition, the fastening structure between the holder mounting portion 50 and the second tool holder 121B is the same as the fastening structure between the holder mounting portion 50 and the first tool holder 121A described above. Figure 7 As shown, in the second tool holder 121B, a recessed portion 181J constituting the recessed portion 181 is provided in the housing 171 .

[0165] Fig.18 It means in Fig.15 A cross-sectional view of a process for attaching and detaching a first tool holder relative to a holder mounting portion in a tool holder.

[0166] Reference Fig.12 , Fig.15 as well as Fig.18 The first piston 61 is further provided with a plurality of notches 69. The notches 69 extend from the recess 62 in the axial direction of the central axis 106 and open. The notches 69 open toward the front of the axial direction of the central axis 106. The notches 69 are connected to the bottom wall of the recess 62 at the rear of the axial direction of the central axis 106.

[0167] The plurality of notches 69 are arranged at intervals from each other in the circumferential direction of the central axis 106. The plurality of notches 69 are arranged at intervals equal to the intervals of the plurality of rods 135 in the circumferential direction of the central axis 106. Between the notches 69 adjacent to each other in the circumferential direction of the central axis 106, a wall portion 70 having a first opposing portion 63 (first wall surface 62m) is provided.

[0168] When removing the first tool holder 121A from the holder mounting portion 50, first, remove the bolt 187 and the block member 186 (see FIG. 1 ) that fasten the holder mounting portion 50 and the first tool holder 121A. Fig.16 and Fig.17). Next, the hydraulic supply from the hydraulic supply source 87 is turned off. Next, in order to allow the first tool holder 121A to rotate in the circumferential direction of the center axis 106, the first tool holder 121A is pulled out to the front side in the axial direction of the center axis 106 by a predetermined stroke.

[0169] Next, the first tool holder 121A is rotated 60 degrees around the central axis 106. As a result, the rod 135 is moved from a position opposite to the wall portion 70 in the axial direction of the central axis 106 to a position opposite to the notch 69. Next, the first tool holder 121A is pulled out toward the front side in the axial direction of the central axis 106, thereby completing the removal of the first tool holder 121A.

[0170] When the first tool holder 121A is mounted on the holder mounting portion 50 , the above steps are preferably performed in reverse order. The mounting and removal of the second tool holder 121B to the holder mounting portion 50 is similar to the mounting and removal of the first tool holder 121A to the holder mounting portion 50 .

[0171] In the present embodiment, the hydraulic cylinder mechanism 51 is not provided on the tool holder 121 side but on the holder mounting portion 50 side, so even if the tool holder 121 is removed from the holder mounting portion 50, the hydraulic cylinder mechanism 51 remains on the holder mounting portion 50. Thus, when the tool holder 121 is replaced, the hydraulic path in the hydraulic cylinder mechanism 51 is not disconnected between the holder mounting portion 50 and the tool holder 121, so that the operability when replacing the tool holder 121 can be improved.

[0172] In addition, in this embodiment, the tool holder 121 is described in which the tool is installed in a manner extending radially outward from the rotation center axis 102 of the tool holder 31, but it is not limited to this. The tool holder 121 may also be installed in a manner extending axially from the rotation center axis 102 of the tool holder 31.

[0173] The following summarizes the structures and effects of the tool rest 31 and the machine tool 10 in this embodiment.

[0174] The tool holder 31 in this embodiment is a tool clamping device for mounting a rotating tool in a detachable manner. The tool holder 31 includes: a clamping mechanism 131; and a first piston 61, which reciprocates in the axial direction of the central axis 106 with the central axis 106 as the predetermined axis as the center. The clamping mechanism 131 has a rod 135 as a locking portion arranged between the first relative portion 63 and the second relative portion 64. The first piston 61 has a first relative portion 63 and a second relative portion 64 that are opposite to each other in the axial direction of the central axis 106. The first piston 61 reciprocates between a first position and a second position, and at the first position, the rod 135 contacts the first relative portion 63, so that the clamping mechanism 131 is operated to a clamped state in which the rotating tool is clamped, and at the second position, the rod 135 contacts the second relative portion 64, so that the clamping mechanism 131 is operated to an unclamped state in which the rotating tool is not clamped. The tool holder 31 further includes a second piston 71 for moving the first piston 61 to a third position between the first position and the second position in the axial direction of the central axis 106. When the first piston 61 is positioned at the third position, the clamping mechanism 131 is maintained in the clamped state, and the rod 135 is separated from the first relative portion 63 and the second relative portion 64.

[0175] According to such a configuration, by moving the first piston 61 to the third position by the second piston 71 , the clamped rotary tool can be rotated without causing the rod 135 to come into contact with the first opposing portion 63 and the second opposing portion 64 .

[0176] In addition, the clamping mechanism 131 has a rod 135, which extends outward in the radial direction of the central axis 106 and corresponds to the locking portion. The first piston 61 is provided with a recessed portion 62, which is a concave shape recessed outward in the radial direction of the central axis 106, for the rod 135 to be arranged. The first piston 61 has a first wall surface 62m and a second wall surface 62n, which constitute the wall surface of the recessed portion 62 and correspond to the first relative portion 63 and the second relative portion 64, respectively.

[0177] According to such a configuration, by moving the first piston 61 to the third position by the second piston 71, the clamped rotary tool can be rotated without causing the rod 135 to come into contact with the first wall surface 62m and the second wall surface 62n.

[0178] In addition, the tool holder 31 further includes a cylinder 52, and the first piston 61 and the second piston 71 are engaged with the cylinder 52, and the cylinder 52 is divided into: a first hydraulic chamber 81, to which hydraulic pressure is supplied when the first piston 61 is moved to the first position; and a second hydraulic chamber 82, to which hydraulic pressure is supplied when the first piston 61 is moved to the second position. The first piston 61 and the second piston 71 divide and form a third hydraulic chamber 83 to which hydraulic pressure is supplied in order to move the first piston 61 to the third position. The third hydraulic chamber 83 is provided at a position radially inward of the center axis 106 than the first hydraulic chamber 81 and the second hydraulic chamber 82.

[0179] According to such a structure, the third hydraulic chamber 83 is provided at a position radially inward of the center axis 106 relative to the first hydraulic chamber 81 and the second hydraulic chamber 82, so that the diameter of the second piston 71 that defines the third hydraulic chamber 83 together with the first piston 61 can be set smaller than the diameter of the first piston 61 that is actuated by the hydraulic pressure supplied to the first hydraulic chamber 81 and the second hydraulic chamber 82. Thus, the size of the tool holder 31 in the radial direction of the center axis 106 can be suppressed from increasing due to the addition of the second piston 71.

[0180] The tool holder 31 further includes a locking block 76 as a locking member, which is provided on the first piston 61 and is locked with the second piston 71 when hydraulic pressure is supplied to the third hydraulic chamber 83 , thereby holding the first piston 61 at the third position.

[0181] According to such a configuration, when hydraulic pressure is supplied to the third hydraulic chamber 83 , the first piston 61 can be held at the third position against the hydraulic pressure.

[0182] Furthermore, when the hydraulic pressure is supplied to the second hydraulic chamber 82 , the second piston 71 is locked to the second piston 71 by the locking block 76 , and moves integrally with the first piston 61 .

[0183] According to such a structure, when the hydraulic pressure is supplied to the first hydraulic chamber 81, the second piston 71 moves integrally with the first piston 61, so that the required amount of the first piston 61 and the second piston 71 in the axial direction of the central axis 106 can be set shorter. Thus, the dimension of the tool holder 31 in the axial direction of the central axis 106 can be suppressed to be smaller.

[0184] The machine tool according to the present invention includes: a tool post 31 ; and an automatic tool changing device 18 for changing a rotary tool attached to the tool post 31 .

[0185] According to such a configuration, in the tool holder 31 in which the rotary tool is automatically replaced by the automatic tool changer 18 , the clamped rotary tool can be rotated without causing the rod 135 to come into contact with the first opposing portion 63 and the second opposing portion 64 .

[0186] In addition, in this embodiment, the structure in which the clamping mechanism has the locking portion and the first piston has the first relative portion and the second relative portion is described, but the structure in which the clamping mechanism has the first relative portion and the second relative portion and the first piston has the locking portion may also be used. In addition, the tool clamping device in the present invention is not limited to the tool holder, for example, it can also be applied to the tool spindle in a machining center or a combination machine tool.

[0187] The embodiments disclosed this time should be considered in all points as illustrative and non-restrictive. The scope of the present invention is indicated by the claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0188] Industrial Applicability

[0189] The present invention is suitable for use in, for example, a tool post mounted on a machine tool and the machine tool.

[0190] Description of Reference Numerals

[0191] 10. Machine tool; 11. Machine base; 16. Saddle; 18. Automatic tool changer; 21. Spindle head; 31. Tool rest; 32. Tool rest base; 33. Turret; 34. Ring member; 35. Surrounding groove; 36. Motor; 37. Rotor shaft; 38. Engaging groove; 41. Air supply unit; 42. Air nozzle; 43. First air flow path; 43h. Through hole; 44. Nozzle insertion hole; 46. Air supply source; 50. Holder mounting unit; 51. Hydraulic cylinder mechanism unit; 52. Cylinder; 53. Cylinder unit; 53p, first inner peripheral surface; 53q, second inner peripheral surface; 53r, third inner peripheral surface; 54, rear wall; 55, communicating hole; 56, bearing housing; 57, front housing; 58, retainer insertion hole; 61, first piston; 62, recess; 62m, first wall surface; 62n, second wall surface; 63, first relative portion; 64, second relative portion; 65, 72, front section; 66, first middle section; 67, second middle section; 68, 74, rear section; 70, wall; 71, second piston; 73, middle section 76, locking block; 77, 187, bolt; 81, first hydraulic chamber; 82, second hydraulic chamber; 83, third hydraulic chamber; 84, plunger insertion hole; 85, plunger; 86, valve; 87, hydraulic supply source; 91, second bearing; 92, outer ring; 93, roller; 101, 106, center axis; 102, rotation center axis; 121, tool holder; 121A, first tool holder; 121B, second tool holder; 131, clamping mechanism; 132, pull rod; 132h , insertion hole; 133, wedge mechanism; 134, sliding member; 135, rod; 136, collet; 141, outer shell; 142, first bearing; 143, inner shell; 144, 174, opening; 145, 175, tool insertion hole; 151, 161, rear member; 152, first connecting portion; 153, second air flow path; 162, second connecting portion; 163, third air flow path; 171, shell; 181, 181J, 181K, recessed portion; 186, block member.

Claims

1. A tool clamping device, which is a tool clamping device for a rotating tool to be mounted in a detachable manner, wherein: The tool clamping device has: a clamping mechanism portion; and The first piston reciprocates in the axial direction of the predetermined axis with the predetermined axis as the center. The clamp mechanism has one of a first opposing portion and a second opposing portion opposing each other in the axial direction of the predetermined axis, and a locking portion disposed between the first opposing portion and the second opposing portion. The first piston has the first relative portion, the second relative portion, and the other of the locking portion. The first piston reciprocates between a first position and a second position, wherein at the first position, the locking portion contacts the first opposing portion, causing the clamping mechanism portion to be operated in a clamped state in which the rotary tool is clamped, and at the second position, the locking portion contacts the second opposing portion, causing the clamping mechanism portion to be operated in an unclamped state in which the rotary tool is not clamped, and, The tool clamping device includes a second piston that moves the first piston to a third position located between the first position and the second position in the axial direction of the predetermined axis. When the first piston is positioned at the third position, the clamp mechanism portion is maintained in the clamped state, and the locking portion is separated from the first opposing portion and the second opposing portion.

2. The tool clamping device according to claim 1, wherein: The clamping mechanism has a rod extending outward in the radial direction of the predetermined axis and corresponding to the locking portion. The first piston is provided with a recessed portion, which is in a concave shape recessed toward the outside in the radial direction of the predetermined axis, for the rod to be arranged. The first piston has a first wall surface and a second wall surface, and the first wall surface and the second wall surface constitute wall surfaces of the recessed portion and correspond to the first opposing portion and the second opposing portion, respectively.

3. The tool clamping device according to claim 1 or 2, wherein: The tool clamping device further comprises a cylinder, in which the first piston and the second piston are engaged, and the cylinder is divided into: a first hydraulic chamber, to which hydraulic pressure is supplied when the first piston is moved to the first position; and a second hydraulic chamber, to which hydraulic pressure is supplied when the first piston is moved to the second position, The first piston and the second piston define a third hydraulic chamber to which hydraulic pressure is supplied in order to move the first piston to the third position. The third hydraulic chamber is provided at a position radially inward of the predetermined axis relative to the first hydraulic chamber and the second hydraulic chamber.

4. The tool clamping device according to claim 3, wherein: The tool clamping device further includes a locking member provided on the first piston and locked with the second piston when the hydraulic pressure is supplied to the third hydraulic chamber, thereby holding the first piston at the third position.

5. The tool clamping device according to claim 4, wherein: When the hydraulic pressure is supplied to the second hydraulic chamber, the second piston is locked to the second piston by the locking member and moves integrally with the first piston.

6. A machine tool comprising: The tool clamping device according to any one of claims 1 to 5; and An automatic tool changing device is used to change a rotating tool installed on the tool clamping device.

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