Tool changing mechanism and machine tool provided with the same

Abstract

Provided are a tool changing mechanism that has a small load on a turret at the time of tool changing of a machine tool, and a machine tool provided with the tool changing mechanism. A pushing member (210) of a tool release unit (200) pushes against a rear end of a tool holding unit (100) to release a pulled-in state of a tool holder (Th) of a tool (T) by a tool holder holding portion (150) of the tool holding unit (100), and a locking lever (220) of the tool release unit (200) is freely engaged with an engagement protrusion (112a) formed on the rear end side of the tool holding unit (100).

Description

TECHNICAL FIELD

[0001] The present application relates to a tool changing mechanism and a machine tool provided with the tool changing mechanism. BACKGROUND

[0002] In the past, as a tool changing mechanism in a turret in which a tool spindle unit that fixes a tool that processes a workpiece to be free to rotate is installed, a mechanism is known in which a pushing member that pushes the tool spindle unit is pushed from the outside, a rod that abuts against the front end of the pushing member is advanced, and a tool installed at the front end of the rod is removed (see, for example, Patent Literature 1).

[0003] Patent Literature 1: Japanese Patent Application Publication No. 2019-188499

[0004] In such a tool changing mechanism, because the back surface side of the tool spindle unit is pushed, an excessive bending moment is applied to the unit holding portion of the turret, an excessive load is applied to the turret, and the improvement of the durability of the turret has room for further improvement. SUMMARY

[0005] Therefore, the present application solves the problems of the prior art described above, and the object of the present application is to provide a tool changing mechanism in which the load on a turret is small when a tool is changed in a machine tool, and a machine tool provided with the tool changing mechanism.

[0006] First, the present application is a tool changing mechanism of a machine tool, provided with: a turret in which a tool holding unit that holds a tool to be free to attach and detach is installed, the tool being composed of a rotary tool that processes a workpiece and a tool holder that holds the rotary tool to be free to attach and detach; and a turret support body that has a tool detachment unit that detaches the tool installed in the tool holding unit from the tool holding unit, the tool changing mechanism of the machine tool being characterized in that the tool holding unit installed in the turret has a tool holder holding portion that installs the tool holder of the tool in a state in which the tool holder is drawn in, the tool detachment unit of the turret support body has a pushing member that freely advances and retreats toward the rear end of the tool holding unit and a locking rod that freely advances and retreats in parallel with the advancing and retreating direction of the pushing member, the pushing member of the tool detachment unit pushes the rear end of the tool holding unit to free the tool holder holding portion of the tool holding unit from the drawn-in state of the tool holder of the tool, the locking rod of the tool detachment unit freely locks with a locking protrusion formed on the rear end side of the tool holding unit, after the pushing member of the tool detachment unit abuts against the rear end of the tool holding unit, the locking rod of the tool detachment unit locks with the locking protrusion of the tool holding unit, and the pushing member of the tool detachment unit advances to free the tool holder holding portion of the tool holding unit from the drawn-in state of the tool holder of the tool, and the tool is freely changed.

[0007] Second, the tool detachment unit has an elastic body that applies a force to the tool detachment unit itself toward the turret.

[0008] Third, the pushing member of the tool detachment unit receives a reaction force from the rear end of the tool holding unit after the pushing member abuts against the rear end, and the reaction force is greater than the force of the elastic body.

[0009] Fourth, the tool exchange mechanism, a spindle that holds the workpiece so as to be freely rotatable, and a tool storage device that stores the tool are provided, and when the turret rotates to a predetermined tool exchange position, the pushing member of the tool detachment unit pushes the rear end side of the tool holding unit toward the front, and the locking lever of the tool detachment unit pulls the engagement protrusion of the tool holding unit toward the rear.

[0010] The present application can achieve the following effects.

[0011] (1) After the pushing member of the tool detachment unit abuts against the rear end of the tool holding unit, the locking lever of the tool detachment unit engages with the engagement protrusion of the tool holding unit, and the pushing member of the tool detachment unit advances to release the pulled-in state of the tool holder of the tool holding unit against the tool holder of the tool, thereby freely exchanging the tool. Thus, the pushing member of the tool detachment unit pushes the rear end side of the tool holding unit toward the front, and the locking lever of the tool detachment unit pulls the engagement protrusion of the tool holding unit toward the rear, so that the bending moment applied to the turret is canceled, and the load on the turret can be reduced during tool exchange.

[0012] (2) The tool detachment unit has an elastic body that applies a force to the tool detachment unit itself toward the turret, so that before the pushing member of the tool detachment unit abuts against the rear end of the tool holding unit, the locking lever of the tool detachment unit is held in a state of being located further forward than the engagement protrusion of the tool holding unit, and thus the locking lever of the tool detachment unit can be prevented from contacting the engagement protrusion of the tool holding unit due to vibrations and the like generated during machining of the workpiece.

[0013] (3) The pushing member of the tool detachment unit receives a reaction force from the rear end of the tool holding unit after the pushing member abuts against the rear end, and the reaction force is greater than the force of the elastic body, so that after the pushing member of the tool detachment unit abuts against the rear end of the tool holding unit, the locking lever of the tool detachment unit engages with the engagement protrusion of the tool holding unit, and the pushing member of the tool detachment unit advances while maintaining this state, and thus the pulled-in state of the tool holder of the tool can be released while the bending moment applied to the turret is canceled.

[0014] (4) The tool changer mechanism, the main shaft that holds the workpiece so as to freely rotate, and the tool storage device that stores the tool, when the turret rotates to a prescribed tool changing position, the pushing member of the tool detachment unit pushes the rear end side of the tool holding unit toward the front and the locking lever of the tool detachment unit pulls the engaging protrusion of the tool holding unit toward the rear, whereby the tool is freely changed by the tool changer mechanism and the tool is changed between the tool storage device, so the bending moment applied to the turret is canceled and the load applied to the turret is reduced, and the tool can be changed in a state where the load applied to the turret is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a perspective view of a machine tool equipped with a tool changer mechanism as an embodiment of the present application.

[0016] Figure 2 is a front view of the turret shown in Figure 1

[0017] Figure 3 is a partial cross-sectional perspective view of the tool shown in Figure 1

[0018] Figure 4 is an IV-IV cross-sectional view of Figure 2

[0019] Figure 5 is a plan view of the turret and the turret support body viewed from the V direction of Figure 2

[0020] Figure 6A is an explanatory view that explains the tool changing step of the tool changer mechanism.

[0021] Figure 6B is an explanatory view that explains the tool changing step of the tool changer mechanism.

[0022] Figure 6C is an explanatory view that explains the tool changing step of the tool changer mechanism.

[0023] Figure 6D is an explanatory view that explains the tool changing step of the tool changer mechanism. DETAILED DESCRIPTION

[0024] ​​​​The present application is a tool changing mechanism of a machine tool, comprising: a turret having a tool holding unit that holds a tool freely attachable and detachable, the tool being composed of a rotating tool that processes a workpiece and a tool holder that holds the rotating tool freely attachable and detachable; and a turret support body having a tool detachment unit that detaches the tool attached to the tool holding unit from the tool holding unit, wherein the tool holding unit attached to the turret has a tool holder holding portion that holds the tool holder in a state in which the tool holder is pulled in, the tool detachment unit of the turret support body has a push member that freely advances and retreats toward a rear end of the tool holding unit and a locking lever that freely advances and retreats in parallel with the advancing and retreating direction of the push member, the push member of the tool detachment unit pushes the rear end of the tool holding unit to release the pulling-in state of the tool holder holding portion of the tool holding unit on the tool holder, the locking lever of the tool detachment unit freely engages with an engagement protrusion formed on the rear end side of the tool holding unit, after the push member of the tool detachment unit abuts against the rear end of the tool holding unit, the locking lever of the tool detachment unit engages with the engagement protrusion of the tool holding unit, and the push member of the tool detachment unit advances to release the pulling-in state of the tool holder holding portion of the tool holding unit on the tool holder, thereby freely changing the tool, and as long as the load on the turret at the time of changing the tool of the machine tool is small, the detailed embodiment can be any.

[0025] Embodiment

[0026] Hereinafter, a tool changing mechanism as an embodiment of the present application and a machine tool provided with the tool changing mechanism will be described based on Figures 1 to 6D

[0027] <1. Outline of Machine Tool>

[0028] First, an outline of the machine tool 10 will be described based on Figure 1 and Figure 2

[0029] Figure 1 is a perspective view of a machine tool assembled with a tool changing mechanism as an embodiment of the present application, Figure 2 is Figure 1 a front view of the turret shown in

[0030] The machine tool 10 is an automatic lathe having a processing chamber 10a that processes a workpiece W.

[0031] As shown in Figure 1 , the processing chamber 10a has, inside thereof: a spindle 11 that holds the workpiece W freely rotatable and freely attachable and detachable; a turret 12 disposed opposite to the spindle 11; a turret support body 13 that supports the turret 12 freely indexable and revolvable; and a tool storage device 14 that stores and changes a tool attached to the turret 12. ​​

[0032] As Figure 2 shown, the turret 12 is an 8-sided polygon in a front view.

[0033] Further, tool holders H each holding a tool for machining are freely attached to and detached from the peripheral surface of the turret 12, i.e., the turret surface 12a.

[0034] Further, a tool holding unit 100 that holds the tool holder T freely is installed in one of the turret surfaces 12a.

[0035] On the other hand, the turret support 13 is freely linearly moved in the front-rear, left-right, and up-down directions by a support moving mechanism not shown.

[0036] Therefore, the turret 12 is also freely linearly moved in the front-rear, left-right, and up-down directions integrally with the turret support 13.

[0037] As such, the machine tool 10 is capable of bringing the turret 12 close to the workpiece W held by the spindle 11 by the support moving mechanism, and performing machining of the workpiece W by a tool selected by indexing of the turret 12.

[0038] In addition, the turret support 13 is provided with a tool release unit 200 that releases the tool holder T from the tool holding unit 100.

[0039] Further, the tool storage device 14 described above is disposed on the same side as the spindle 11 and is freely moved in the axial direction of the spindle 11, i.e., the front-rear direction, and has a shutter 14a on the front surface.

[0040] A plurality of tool holders are housed inside the tool storage device 14, and a plurality of tool holders T held by the tool holding unit 100 can also be housed.

[0041] Further, the machine tool 10 is provided with a tool exchange mechanism 15 that releases the tool holder T in order to automatically exchange the tool holder housed in the tool storage device 14 and the tool holder T installed in the tool holding unit 100.

[0042] The tool exchange mechanism 15 is composed of the tool holding unit 100 installed in the turret 12 and the tool release unit 200 provided to the turret support 13.

[0043] <2. Configuration of tool>

[0044] Here, based on Figure 3 The tool holder T installed in the tool holding unit 100 will be described.

[0045] Figure 3 is Figure 1 a partial cross-sectional perspective view of the tool shown.

[0046] The tool T is provided with a rotary tool Tb such as a drill bit for machining a workpiece; a tool holder Th for freely attaching and detaching the rotary tool Tb; and a draw pin Tp attached to the rear end of the tool holder Th.

[0047] The tool holder Th is tapered toward the rear end side, i.e., is formed with a taper toward the rear end side.

[0048] The draw pin Tp is inserted and fixed in a through hole formed in the rear end of the tool holder Th, and is formed of a head Tp1 on the rear end side, and a neck portion Tp2 connected to the front side of the head Tp1 and smaller in diameter than the head Tp1.

[0049] <3. Configuration of tool holding unit>

[0050] Next, the tool holding unit 100 will be described based on Figure 3 and Figure 4

[0051] Figure 4 is an IV-IV sectional view of the tool holding unit 100. Figure 2

[0052] The tool holding unit 100 is provided with a housing 110; a first rotary drive force transmission shaft 120 engaged with a rotary drive force transmission shaft 12b protruding from the turret 12; a transmission gear 130 engaged with the first rotary drive force transmission shaft 120; a second rotary drive force transmission shaft 140 engaged with the transmission gear 130; and a tool holder holding portion 150 attached to the front end of the second rotary drive force transmission shaft 140.

[0053] As shown in Figure 4 , the housing 110 is formed of a base portion 111 extending in the front-rear direction and attached to the turret 12, and a standing portion 112 standing from the base portion 111 in a direction away from the rotation axis of the turret 12, and has an inverted L shape in side view.

[0054] A fitting protrusion 112a protruding in a direction away from the rotation axis of the turret 12 is formed on the upper portion of the rear end side of the standing portion 112.

[0055] The first rotary drive force transmission shaft 120 is provided to freely rotate inside the base portion 111 of the housing 110 and extends in the front-rear direction.

[0056] A bevel gear is formed on the front end side of the first rotary drive force transmission shaft 120, and is engaged with a bevel gear formed on the front end of the rotary drive force transmission shaft 12b.

[0057] In addition, a gear engaged with the transmission gear 130 is formed on the rear end side of the first rotary drive force transmission shaft 120.

[0058] ​​The transmission gear 130 is freely rotatable about an axis parallel to the swivel axis of the turret 12.

[0059] The second rotary drive force transmission shaft 140 is a cylindrical hollow shaft freely rotatable inside the raised portion 112 of the housing 110 on the rear end side and extending in the front-rear direction.

[0060] The tool holder holding portion 150 is held freely rotatable with respect to the raised portion 112 of the housing 110 by a bearing 160 provided inside the raised portion 112 of the housing 110.

[0061] Further, the tool holder holding portion 150 has a cylindrical holding frame 151 coupled to the second rotary drive force transmission shaft 140, a drawbar 152 inserted into the rear end of the cylindrical holding frame 151, a flange 153 fixed to the drawbar 152, and a drawbar urging spring 154 urging the flange 153.

[0062] The cylindrical holding frame 151 has a tool holder Th of a tool T inserted into a tool insertion portion 151a, an intermediate portion 151b communicating with the rear end of the tool insertion portion 151a and extending toward the rear end side with the same diameter, and a drawbar insertion portion 151c communicating with the rear end of the intermediate portion 151b and into which the drawbar 152 is inserted.

[0063] The tool insertion portion 151a is tapered toward the rear end side on the inside, that is, a taper is formed toward the rear end side.

[0064] Further, the taper of the tool holder Th of the tool T is formed to coincide with the taper of the tool insertion portion 151a.

[0065] The diameter of the intermediate portion 151b is slightly larger than the diameter of the rear end of the tool holder Th of the tool T.

[0066] The diameter of the drawbar insertion portion 151c is smaller than the diameter of the intermediate portion 151b.

[0067] The drawbar 152 is a cylindrical rod having a concave tool housing region 152a formed at the front end thereof.

[0068] In addition, a plurality of engagement ball housing holes into which a plurality of engagement balls 152b are fitted are formed at intervals around the outer peripheral wall of the tool housing region 152a.

[0069] The engagement ball housing holes have different hole diameters on the outer peripheral side and the inner peripheral side, the hole diameter on the outer peripheral side being substantially equal to the diameter of the engagement ball 152b, and the hole diameter on the inner peripheral side being smaller than the diameter of the engagement ball 152b.

[0070] In this state, the inner diameter of the front end of the pull rod 152 is smaller than the diameter of the head portion Tp1 of the pull pin Tp of the jig T and larger than the diameter of the necked portion Tp2 of the pull pin Tp of the jig T.

[0071] In addition, when the front end of the pull rod 152 is positioned at the pull rod insertion portion 151c of the tubular holder 151, the engagement ball 152b abuts against the wall surface that forms the pull rod insertion portion 151c, and thus becomes a state in which the engagement ball 152b protrudes toward the inside of the pull rod 152.

[0072] In this state, the inner diameter of the front end of the pull rod 152 is smaller than the diameter of the head portion Tp1 of the pull pin Tp of the jig T and larger than the diameter of the necked portion Tp2 of the pull pin Tp of the jig T.

[0073] Therefore, in a case where the jig T is to be held to the tool holder holding portion 150, the jig T is inserted into the jig insertion portion 151a in a state in which the pull rod 152 is pushed in until the front end of the pull rod 152 is positioned at the middle portion 151b of the tubular holder 151.

[0074] At this time, the engagement ball 152b temporarily protrudes toward the outside of the pull rod 152 due to the head portion Tp1, and thereafter becomes a position that opposes the necked portion Tp2, and the head portion Tp1 of the pull pin Tp of the jig T is accommodated in the jig accommodation region 152a.

[0075] If the pull rod 152 is retracted in this state until the front end of the pull rod 152 is positioned at the pull rod insertion portion 151c of the tubular holder 151, the engagement ball 152b protrudes toward the inside of the pull rod 152 and abuts against the necked portion Tp2 of the pull pin Tp of the jig T.

[0076] Thus, as long as the pull rod 152 is not pushed in until the front end of the pull rod 152 is positioned at the middle portion 151b of the tubular holder 151, the jig T is held to the tool holder holding portion 150.

[0077] The pull rod urging spring 154 urges the pull rod 152 to the rear via the flange 153.

[0078] That is, the pull rod 152 pulls in the jig T in a state in which the pull pin Tp of the jig T is sandwiched by the urging force of the pull rod urging spring 154.

[0079] Therefore, the tool holder holding portion 150 mounts the tool holder Th in a state in which the tool holder Th of the jig T is pulled in.

[0080] <4. Configuration of Jig Disengagement Unit>

[0081] Next, the jig disengagement unit 200 will be described based on Figure 4 and Figure 5 The jig disengagement unit 200 will be described.

[0082] Figure 5 is from Figure 2 a plan view of the turret and the turret support viewed in a V direction of

[0083] The tool detachment unit 200 has a push member 210 which is freely movable toward the rear end of the tool holding unit 100, a locking lever 220 which is freely movable in parallel with the direction of movement of the push member 210, a link plate 230 which links the push member 210 and the locking lever 220, a base 240 which is mounted to the turret support 13 and serves as a fixed end, and a coil spring (elastic body) 250 which exerts a force toward the front on the link plate 230.

[0084] As shown in Figure 4 , the push member 210 is composed of a piston rod 211 which is inserted through the turret support 13, a cylinder rod 212 which is connected to the rear end of the piston rod 211, and a cylinder 213 which moves the cylinder rod 212.

[0085] The piston rod 211 is opposed to the rear end of the pull rod 152 of the tool holding unit 100 when the turret 12 is indexed to rotate until the tool holding unit 100 reaches a position (tool exchange position) P which is opposed to the tool storage device 14.

[0086] The cylinder 213 is a hydraulic cylinder which is filled with working oil in a cylinder chamber 213a.

[0087] The cylinder 213 adjusts the amount of working oil in the cylinder chamber 213a by means of a pump which is not shown, thereby freely moving the cylinder rod 212 (i.e., the piston rod 211).

[0088] By constituting the push member 210 in this way, the push member 210 pushes the rear end of the pull rod 152 of the tool holding unit 100, thereby releasing the pull-in state of the tool holder holding portion 150 of the tool holding unit 100 to the tool holder Th of the tool T.

[0089] On the other hand, as shown in Figure 4 , the locking lever 220 has a lever main body 221 which is inserted through the turret support 13 and the link plate 230, a protruding member 222 which is mounted to the front end of the lever main body 221, a spring receiving member 223 which is in abutment with the coil spring 250, and a sleeve 224 in which the rear end of the lever main body 221 is inserted.

[0090] The lever main body 221 is a stepped round bar which extends in the same direction as the piston rod 211 of the push member 210.

[0091] The protruding member 222 is provided so as to protrude toward the axis of rotation of the turret 12 more than the lever main body 221.

[0092] Further, the protruding member 222 opposes the engagement protrusion 112a of the tool holding unit 100 when the turret 12 is indexed until the tool holding unit 100 reaches the tool change position P.

[0093] As shown in Figure 4 and Figure 5 , the spring receiving member 223 is assembled to the rod main body 221 and is integrated with the rod main body 221.

[0094] Further, as shown in Figure 4 , the rear end of the spring receiving member 223 abuts against the coil spring 250 and is urged toward the front.

[0095] As shown in Figure 4 , the left end of the sleeve 224 abuts against the right side shoulder 221a that constitutes the step on the right side of the rod main body 221, and the right end abuts against the base 240.

[0096] By configuring the stopper rod 220 like this, the stopper rod 220 freely engages with the engagement protrusion 112a formed on the rear end side of the tool holding unit 100.

[0097] The link plate 230 is one plate, as shown in Figure 4 , through which the cylinder rod 212 of the pusher member 210 and the rod main body 221 of the stopper rod 220 are inserted.

[0098] The cylinder 213 of the pusher member 210 is installed on the rear surface 231 of this link plate 230.

[0099] Further, the link plate 230 is sandwiched by the left side shoulder 221b that is the step on the left side of the rod main body 221 and the spring receiving member 223.

[0100] Therefore, the cylinder 213 of the pusher member 210 and the stopper rod 220 are integrated with the link plate 230 and advance and retreat in the front-rear direction.

[0101] As shown in Figure 5 , the base 240 is fixed to the turret support 13 by a fixing bolt B.

[0102] Further, this base 240 is separated from the cylinder 213 of the pusher member 210.

[0103] As shown in Figure 4 , the coil spring 250 covers the outer periphery of the sleeve 224 of the stopper rod 220 and urges the tool detachment unit 200 itself toward the front via the link plate 230.

[0104] With this coil spring 250, the stopper rod 220 that moves integrally with the tool detachment unit 200 is urged toward the front.

[0105] <5. Tool change step>

[0106] Next, based on Figure 2 , Figures 6A to 6D , Figures 6A to 6D , the tool changing step of the machine tool 10 and the tool changing mechanism 15 thus configured will be described.

[0107] Figure 2 is a view that explains the tool changing step of the tool changing mechanism.

[0108] First, the turret 12 is indexed to bring the tool holding unit 100 holding the tool T to the tool changing position P (refer to Figure 6A ).

[0109] Figure 6A is a view that schematically shows this state.

[0110] At this time, the link plate 230 is urged forward by the coil spring 250, and the link plate 230 abuts against the turret support 13.

[0111] Therefore, when the tool holding unit 100 reaches the tool changing position P, the engaging protrusion 112a of the tool holding unit 100 and the protruding member 222 of the stopper rod 220 reliably come apart in opposition as shown in Figure 6A .

[0112] From this Figure 6B state, the working oil is caused to flow into the cylinder chamber 213a by a pump not shown to push the cylinder rod 212 forward.

[0113] If the cylinder rod 212 is pushed forward, the piston rod 211 coupled to the cylinder rod 212 also advances.

[0114] If the piston rod 211 advances, the front end of the piston rod 211 abuts against the rear end of the pull rod 152 of the tool holding unit 100 as shown in Figure 4 .

[0115] If the cylinder rod 212 is further pushed forward from this state, the pull rod 152 does not advance because the force of the coil spring 250 acting on the link plate 230 (i.e., the force pushing the link plate 230 forward) is smaller than the force of the pull rod urging spring 154 (refer to Figure 6C ) acting on the pull rod 152 (i.e., the force exerted on the pull rod 152 rearward).

[0116] The reaction force from the pull rod 152 at this time is transmitted to the cylinder chamber 213a via the piston rod 211, and since the working oil of the cylinder chamber 213a pushes the rear wall of the cylinder chamber 213a rearward, the cylinder 213 retreats relative to the cylinder rod 212.

[0117] Since the cylinder 213 and the link plate 230 are integrated, the link plate 230 retreats as the cylinder 213 retreats.

[0118] Since the link plate 230 and the locking lever 220 are integrated, the locking lever 220 retreats as the link plate 230 retreats.

[0119] Therefore, after the abutting of the push member 210 of the tool detachment unit 200 and the rear end of the tool holding unit 100, the reaction force received by the push member 210 from the tool holding unit 100 is greater than the force of the coil spring 250.

[0120] If the locking lever 220 retreats, as shown in Figure 4 , the protruding member 222 of the locking lever 220 abuts and engages with the engagement protrusion 112a of the tool holding unit 100.

[0121] If the cylinder rod 212 is further pushed forward from this state, since the turret 12 cannot move forward and backward with respect to the turret support 13 except for the engagement of the protruding member 222 of the locking lever 220 with the engagement protrusion 112a of the tool holding unit 100, the link plate 230 cannot further retreat.

[0122] Furthermore, since the pushing force of the push member 210 on the pull rod 152 is greater than the force of the pull rod biasing spring 154 (refer to Figure 4 ) on the pull rod 152, the push member 210 engages with the engagement protrusion 112a of the tool holding unit 100, and the pull rod 152 advances.

[0123] If the pull rod 152 advances and the front end of the pull rod 152 reaches the intermediate portion 151b (refer to ​ ) of the cylindrical holder 151, the engagement of the engagement ball 152b of the pull rod 152 with the draw pin Tp of the tool T is released, and the pull-in state of the tool holder holding portion 150 of the tool holding unit 100 to the tool holder Th of the tool T is released.

[0124] In the state where the pull-in state of the tool holder Th is released, the tool storage device 14 and the turret 12 move close to each other, and the shutter 14a of the tool storage device 14 opens to store the tool T in the tool storage device 14.

[0125] Next, a desired tool is selected from the plurality of tools located inside the tool storage device 14.

[0126] Further, the tool holder holding portion 150 of the turret 12 pulls in and holds the new tool selected in the tool storage device 14.

[0127] As described above, the tool T is exchanged between the tool storage device 14 and the turret 12.

[0128] Further, the tool storage device 14 is separated from the turret 12, and the turret 12 is transferred to the next processing step or the like.

[0129] <6. Effects of the machine tool of the present embodiment>

[0130] As explained above, according to the machine tool 10 and the tool exchange mechanism 15 as an embodiment of the present application, after the abutment of the push member 210 and the rear end of the tool holding unit 100, the protruding member 222 provided to the locking lever 220 is engaged with the engagement protrusion 112a, and the push member 210 is advanced to release the pull-in state of the tool holder holding portion 150 to the tool holder Th of the tool T, and the tool T is freely exchanged, whereby the push member 210 pushes the rear end side of the tool holding unit 100 toward the front, and the locking lever 220 pulls the engagement protrusion 112a toward the rear, and the bending moment applied to the turret 12 is canceled, and the load to the turret 12 at the time of tool exchange can be reduced.

[0131] Further, the tool disengagement unit 200 has an elastic body, i.e., a coil spring 250, which applies a force to the tool disengagement unit 200 itself toward the turret 12, whereby before the abutment of the push member 210 and the rear end of the tool holding unit 100, the locking lever 220 is held in a state of being located further forward than the engagement protrusion 112a, and thus the locking lever 220 can be prevented from contacting the engagement protrusion 112a due to vibration or the like generated in the processing of the workpiece W.

[0132] Further, the reaction force received by the push member 210 from the tool holding unit 100 after the abutment of the push member 210 and the rear end of the tool holding unit 100 is greater than the force of the coil spring 250, whereby after the abutment of the push member 210 and the rear end of the tool holding unit 100, the locking lever 220 is engaged with the engagement protrusion 112a, and the push member 210 is advanced while maintaining this state, and thus the pull-in state of the tool holder Th of the tool T can be released in a state in which the bending moment applied to the turret 12 is canceled.

[0133] The above describes an embodiment of the present application, but the present application is not limited to the above-described embodiment.

[0134] For example, in the present embodiment, eight turret faces 12a are formed in the turret 12, but the number of turret faces formed in the turret is not limited thereto.

[0135] Explanation of Reference Numerals

[0136] 10…machine tool; 10a…processing chamber; 11…spindle; 12…turret; 12a…turret face; 12b…rotary drive power transmission shaft; 13…turret support body; 14…tool storage device; 14a…shutter; 15…tool changing mechanism; 100…tool holding unit; 110…housing; 111…base; 112…upright portion; 112a…engagement protrusion; 120…first rotary drive power transmission shaft; 130…transmission gear; 140…second rotary drive power transmission shaft; 150…tool holder holding portion; 151…cylindrical holding bracket; 151a…tool insertion portion; 151b…intermediate portion; 151c…drawbar insertion portion; 152…drawbar; 152a…tool storage area; 152b…engagement ball; 153…flange; 154…drawbar force spring; 160…bearing; 200…tool disengagement unit; 210…pushing member; 211…piston rod; 212…cylinder rod; 213…cylinder; 213a…cylinder chamber; 220…locking rod; 221…rod main body; 221a…right side shoulder portion; 221b…left side shoulder portion; 222…protruding member; 223…spring receiving member; 224…sleeve; 230…link plate; 231…rear surface; 240…base; 250…coil spring (elastic body); T…tool; Tb…rotary tool; Th…tool holder; Tp…drawn nail; Tp1…head portion; Tp2…necked portion; W…workpiece; H…tool holder; B…fixing bolt; P…tool changing position.

Claims

1. A tool changing mechanism of a machine tool, comprising: a turret having a tool holding unit that holds a tool freely attachable and detachable, the tool being composed of a rotary tool that processes a workpiece and a tool holder that holds the rotary tool freely attachable and detachable; and a turret support body having a tool detachment unit that detaches the tool attached to the tool holding unit from the tool holding unit, wherein the tool holding unit attached to the turret has a tool holder holding portion that holds the tool holder of the tool in a state in which the tool holder is drawn in, the tool detachment unit of the turret support body has a push member that is freely movable toward a rear end of the tool holding unit and a locking lever that is freely movable in parallel with a direction of movement of the push member, the push member of the tool detachment unit pushes the rear end of the tool holding unit to release the state in which the tool holder holding portion of the tool holding unit holds the tool holder of the tool, the locking lever of the tool detachment unit freely engages with an engagement protrusion formed on the rear end side of the tool holding unit, after the push member of the tool detachment unit abuts against the rear end of the tool holding unit, the locking lever of the tool detachment unit engages with the engagement protrusion of the tool holding unit, and the push member of the tool detachment unit advances to release the state in which the tool holder holding portion of the tool holding unit holds the tool holder of the tool, and the tool is freely changed.

2. The tool changing mechanism of a machine tool according to claim 1, wherein the tool detachment unit has an elastic body that applies a force to the tool detachment unit itself toward the turret.

3. The tool changing mechanism of a machine tool according to claim 2, wherein a reaction force that the push member of the tool detachment unit receives from the tool holding unit after the push member abuts against the rear end of the tool holding unit is greater than a force of the elastic body.

4. A machine tool comprising: the tool changing mechanism according to any one of claims 1 to 3; a spindle that holds the workpiece freely rotatable; and a tool storage device that stores the tool, wherein when the turret revolves to a prescribed tool changing position, the push member of the tool detachment unit pushes the rear end side of the tool holding unit toward the front, and the locking lever of the tool detachment unit pulls the engagement protrusion of the tool holding unit toward the rear. ​ ​ ​ ​ ​ ​ ​ ​ ​ 4. A machine tool, characterized by ​ ​ ​ ​ ​

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