Tool changing device

Abstract

The purpose of the present invention is to prevent an external force from being applied to the spindle during machining by the spindle. This tool exchange device includes an arm and a gripper locking mechanism or coupling mechanism. The arm has a gripping member and, using the gripping member, removes a previously used tool from a spindle and then attaches a next-used tool to the spindle. The gripper locking mechanism includes: a spindle-side cam; an arm axis; a release cam arranged at a position farther from the spindle than the spindle-side cam; and a release axis. While the arm is moved in a predetermined direction to a predetermined position with respect to the spindle, the arm axis is displaced according to the profile of the spindle-side cam and rotates the gripper member toward one side of the release angle.As the arm is further moved from the prescribed position in the prescribed direction with respect to the spindle, a release axis is displaced according to the profile of the release cam, the gripping member further rotates toward the side of the release angle and causes the arm axis to separate from the spindle-side cam.

Description

TECHNICAL FIELDThe present disclosure relates to a tool changing device that changes a tool attached to a spindle of a machine tool.BACKGROUND ARTSome tool changing devices detach a previously used tool as one of a plurality of tools from a spindle and fix a subsequently used tool as a tool different from the previously used tool to the spindle.List of ReferencesPatent DocumentPatent Document 1: Japanese Unexamined Patent Application, Publication No. 2008-132555DISCLOSURE OF THE INVENTIONProblems to be Solved by the InventionThe inventors of the present invention have considered a structure of a tool changing apparatus including an arm having a grip member and a grip locking mechanism for rotating the grip member along with movement of the arm with respect to a spindle. The gripping element is rotatable into a gripping angle for gripping the tool and into a release angle for releasing the gripping of the tool. The arm releases the previously used tool from the spindle by means of the gripping element and fixes the subsequently used tool to the spindle.The gripper locking mechanism comprises a cam and an axis that moves together with the arm with respect to the cam. The axle comes into contact with the cam and displaces according to the profile of the cam. The gripping member rotates based on the displacement.The present inventors have focused on the following problem in such a configuration: In order for the axis to be able to slide according to the profile of the cam, the axis must be biased toward the cam by the weight of the gripping member, a spring, a weight, or the like, and constantly contact the cam.Therefore, even when the gripping member is disposed at the releasing angle during the machining of a workpiece by the spindle, a force is constantly applied from the axis to the cam. A portion of this force is also transmitted to the spindle as an external force, which can have a disadvantageous effect on the machining accuracy and the surface quality of the spindle.The present disclosure is made in view of the above circumstances, and an object of the present disclosure is to suppress application of an external force to a spindle during machining by the spindle.Means for Solving the ProblemsA tool replacing apparatus for detaching a previously used tool as one of a plurality of tools from a spindle of a machine tool and for fixing a subsequently used tool different from the previously used tool to the spindle includes:an arm having a gripping member rotatable into a gripping angle for gripping the tool and a releasing angle for releasing gripping of the tool, the arm configured such that the gripping member can release the previously used tool from the spindle and fix the subsequently used tool to the spindle; anda gripper lock mechanism that rotates the gripping member along with movement of the arm with respect to the spindle,wherein the gripper lock mechanism includes a spindle-side cam, an arm axis fixed to the gripping member and moving together with the arm with respect to the spindle-side cam, a separating cam provided at a position farther from the spindle than the spindle-side cam, and a separating axis fixed to the gripping member and moving together with the arm with respect to the separating cam when the arm moves in a predetermined direction to a predetermined position with respect to the spindle, the arm axis is displaced according to a profile of the spindle-side cam to rotate the gripping member in the direction of the releasing angle, andwhen the arm moves further from the predetermined position with respect to the spindle in the predetermined direction, the separating axis is displaced according to a profile of the separating cam to further rotate the gripping member in the direction of the releasing angle, so that the arm axis is separated from the spindle-side cam.Effects of the InventionAccording to the present disclosure, it is possible to suppress application of an external force to a spindle during machining by the spindle.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a perspective view showing a tool changing device according to a first embodiment; FIG. 2 is a front view showing the tool changing device; FIG. 3 is a front view showing an arm and a slot locking mechanism; FIG. 4 is a front view showing a tool storage place at a storage angle and a tool; FIG. 5 is a front view showing the tool receiving space at a replacement angle and the tool; FIG. 6 is a perspective view showing the tool receiving space; FIG. 7 is a side view showing a holding portion of the tool receiving space; FIG. 8 is a perspective view showing an arm, an arm lifting device, and an arm pivoting device; FIG. 9 is a planar cross-sectional view showing a gripping portion of a gripping member; FIG. 10 is a front view showing the arm; FIG. 11 is a bottom view showing the arm; FIG. 12 is a plan view schematically showing the arm; FIG. 13 is a front view schematically showing the arm; FIG. 14 is a front view schematically showing a state in which the grip member is rotated to a release angle; FIG. 15 is a front view schematically showing two gripping members displaced in a second direction; FIG. 16 is a front view schematically showing an initial state of a turning operation of the grip member on the spindle side; FIG. 17 is a front view schematically showing a subsequent turning operation; FIG. 18 is a front view schematically showing a subsequent turning operation; FIG. 19 is a front view schematically showing a subsequent turning operation; FIG. 20 is a front view schematically showing a subsequent turning operation; FIG. 21 is a front view showing an initial state of a tool changing operation; FIG. 22 is a front view showing a subsequent operation; FIG. 23 is a front view showing a subsequent operation; FIG. 24 is a front view showing a subsequent operation; FIG. 25 is a front view showing a subsequent operation; FIG. 26 is a front view showing a subsequent operation; FIG. 27 is a front view showing a subsequent operation; FIG. 28 is a front view showing a subsequent operation; FIG. 29 is a front view showing a subsequent operation; FIG. 30 is a front view showing a subsequent operation; FIG. 31 is a front view showing a subsequent operation; FIG. 32 is a front view showing a subsequent operation; FIG. 33 is a front view schematically showing an initial state of a turning operation according to the second embodiment; FIG. 34 is a front view schematically showing a subsequent turning operation; FIG. 35 is a front view schematically showing a subsequent turning operation; FIG. 36 is a front view schematically showing a subsequent turning operation; FIG. 37 is a front view schematically showing a subsequent turning operation; FIG. 38 is a plan view schematically showing a tool changing device according to a third embodiment; FIG. 39 is a plan view schematically showing a state in which an arm is pivoted to an access angle; FIG. 40 is a configuration diagram showing a control system of a tool changing device; FIG. 41 is a flowchart showing a procedure of tool change; FIG. 42 is a configuration diagram showing a control system of a tool changing device according to a fourth embodiment; FIG. 43 is a flowchart showing a flow of controlling the moving speed of an arm; and FIG. 44 is a flowchart showing another example of a flow of controlling the moving speed of the arm.PREFERRED MODE FOR CARRYING OUT THE INVENTIONHereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, the present disclosure is by no means limited to the following embodiments and may be appropriately modified and implemented without departing from the gist of the present disclosure.[First Embodiment]A tool changing device 100 shown in FIG. 1 is installed in a machine tool 200 as shown in FIG. 2. Hereinafter, three predetermined mutually orthogonal directions are referred to as "X direction from left to right", "Y direction from front to rear", and "Z direction from top to bottom".As shown in FIG. 2, the machine tool 200 includes a spindle assembly 210. The spindle assembly 210 includes a spindle 215 installed with its axial longitudinal direction in the Z direction from top to bottom, and a housing 211 covering the spindle 215 and configured to be movable in the Z direction from top to bottom.As shown in FIG. 2, one of a plurality of tools T is fixed to a lower end portion of the spindle 215. Hereinafter, the tool T of the plurality of tools T thus far attached to the spindle 215 is referred to as "previously used tool Tp", and the tool T to be next attached to the spindle 215 of the plurality of tools T is referred to as "subsequently used tool Tn".The tool changing device 100 automatically releases the previously used tool Tp from the spindle 215 and fixes the subsequently used tool Tn to the spindle 215. The tool changing apparatus 100 includes a magazine 30, an arm 50, a slot locking mechanism 40, and a gripper locking mechanism 60.First, the magazine 30 will be described. As shown in FIG. 1, the magazine 30 has a magazine body 39 and a plurality of tool receiving places 33.The magazine body 39 is configured to be rotatable about the X direction from left to right. The plurality of tool receiving places 33 are fixed to the magazine body 39. By the rotation of the magazine body 39, one of the plurality of tool receiving places 33 is placed at a "replacement position P" as a lowermost standby position for tool replacement.As shown in FIG. 7, each of the tool receiving places 33 has a holding portion 34 to which the tool T can be attached. The tool receiving space 33 is connected to the magazine body 39 via the holding portion 34 so as to be rotatable about the Y direction from front to rear. This means that the holding section 34 for fastening the tool T also serves as an axis of rotation of the tool receiving location 33. By the holding portion 34, the tool receiving space 33 is configured to be rotatable between a storage angle Pa shown in FIG. 5 and a replacement angle Pb in the replacement position P shown in FIG. 4. As shown in FIG. 4, the storage angle Pa is an angle at which the tool receiving place 33 tilts downward from left to right in the X direction. As shown in FIG. 5, the exchange angle Pb is an angle at which the tool receiving place 33 is standing from top to bottom in the Z direction.As shown in FIG. 6, each of the tool receiving places 33 has a bottomed cylindrical shape that is open downward in the state of the exchange angle Pb. In each of the tool receiving places 33, the tool T is fixed by inserting the upper end portion of the tool T into the holding portion 34 from the lower side. Specifically, as shown in FIG. 7, the upper end portion of each of the tools T is provided with an annular upper engagement groove Ga extending from top to bottom about the Z direction. The holding portion 34 includes a pair of biasing members 34 aand 34 athat can engage with the upper engagement groove Ga from both sides in the Y direction from front to rear, and biasing springs 34 band 34 bthat bias the biasing members 34 aand 34 atoward each other. With these structures, the holding portion 34 is configured to be able to fix the tool T.Each of the holding portions 34 has a pair of cylindrical storage members 34c and 34c for storing the tension springs 34b and 34b. At least an outer peripheral portion of each of the storage members 34 cis axially symmetric. Each of the tool receiving places 33 is rotatably fixed to the magazine body 39 by the pair of storing members 34c and 34c. As shown in FIG. 6, a notch 38 is provided in an outer peripheral portion of the tool receiving space 33 on the side in a direction from the storage angle Pa to the exchange angle Pb. The function of the notch 38 will be described later.Hereinafter, as shown in FIG. 5, the tool receiving place 33 disposed at the replacement position P at the replacement angle Pb will be referred to simply as "tool receiving place 33 at the replacement angle Pb". The detachment of the subsequently used tool Tn from the "holding portion 34 of the tool receiving place 33" is simply referred to as detachment of the subsequently used tool Tn from the "tool receiving place 33". The fastening of the previously used tool Tp to the "holding portion 34 of the tool receiving place 33" is simply referred to as fastening of the previously used tool Tp to the "tool receiving place 33".Next, the arm 50 shown in FIG. 2 will be described. The arm 50 disengages the subsequently used tool Tn from the tool receiving place 33 at the exchange angle Pb and fixes the subsequently used tool Tn to the spindle 215, and disengages the previously used tool Tp from the spindle 215 and fixes the previously used tool Tp at the exchange angle Pb to the tool receiving place 33.As schematically illustrated in FIG. 15, the arm 50 includes an arm main body 59, a first gripping member 51, and a second gripping member 52. Hereinafter, the first gripping member 51 and the second gripping member 52 will be collectively referred to as "gripping members 51 and 52". Hereinafter, as schematically illustrated in FIG. 12, a predetermined horizontal direction with respect to the arm main body 59 is referred to as "first direction Ya", and a horizontal direction orthogonal thereto is referred to as "second direction Xa". In the basic state of the arm 50, the first direction Ya is the Y direction from front to rear, and the second direction Xa is the X direction from left to right.As schematically illustrated in FIG. 12, the first gripping member 51 and the second gripping member 52 are arranged to be displaced from each other in the first direction Ya as viewed from the top to the bottom in the Z direction. As schematically illustrated in FIG. 13, when viewed in one side in the first direction Ya, the first gripping member 51 has an inverted L shape extending downward and then in the second direction Xa to one side, and the second gripping member 52 has an L shape extending downward and then in the second direction Xa to the other side. The upper end portions of the gripping members 51 and 52 are fixed to the arm main body 59 so as to be rotatable about the first direction Ya by respective shaft members 55. A gripping portion 54 is provided at a tip portion as an end portion in the second direction Xa of each of the first gripping members 51 and the second gripping members 52.That is, as schematically illustrated in FIG. 12, when viewed from top to bottom in the Z direction, the first gripping member 51 and the second gripping member 52 are supported so as to be rotatable about the first direction Ya with the gripping portions 54 facing each other in the second direction Xa. By the rotation, each of the gripping members 51 and 52 is displaced by a gripping angle Qb shown in FIG. 13 for gripping the tool T and a releasing angle Qa shown in FIG. 14 for releasing the gripping of the tool T. As shown in FIGS. 13 and 14, the first gripping member 51 and the second gripping member 52 partially overlap each other as viewed in the first direction Ya.As shown in FIG. 9, the grip portion 54 has a U-shape that opens toward the tip end side, that is, toward a side in the second direction Xa, and is configured such that the upper portion of the tool T is insertable therein. Specifically, an engagement recessed portion Gc and a lower engagement groove Gb are provided below the upper engagement groove Ga in the upper portion of the tool T. The grip portion 54 includes a projecting engaging portion 54c, a pair of engaging members 54a and 54a, and a pair of engaging springs 54b and 54b. The engagement protruding portion 54 cis provided at a portion of the grip portion 54 opposite to the tip end side, protrudes toward the tip end side, and is configured to be engageable with the engagement recessed portion Gc. The pair of engagement members 54 aand 54 aare configured to be engageable with the lower engagement groove Gb from both sides in the first direction Ya on the tip side with respect to the center line of the tool T. The pair of engaging springs 54 band 54 bpresses the pair of engaging members 54 aand 54 atoward each other. With the configuration described above, each of the gripping portions 54 is configured to be able to grip the tool T in place at three points.The arm main body 59 schematically illustrated in FIG. 13 is configured to be slidable in the Z direction from top to bottom and pivotable about the Z direction from top to bottom. Hereinafter, among the first gripping member 51 and the second gripping member 52, the gripping member whose gripping portion 54 is located on the magazine 30 side will be referred to as "the gripping member 51 on the magazine 30 side" or "the gripping member 52 on the magazine 30 side" as appropriate with reference to the drawings. Among the first gripping member 51 and the second gripping member 52, the gripping member whose gripping portion 54 is located on the spindle 215 is referred to as a "spindle 215-side gripping member 52" or a "spindle 215-side gripping member 51" with reference to the drawings as appropriate.Next, the slot locking mechanism 40 shown in FIG. 3 will be described. The slot locking mechanism 40 rotates the tool slot 33 at the replacement position P along with lowering of the arm 50 with respect to the magazine 30 from the storage angle Pa to the replacement angle Pb, and then rotates the tool slot 33 again to the storage angle Pa. Moreover, the receiving place locking mechanism 40 rotates the tool receiving place 33 at the replacement position P from the storage angle Pa to the replacement angle Pb along with the raising of the arm 50 with respect to the magazine 30, and then rotates the tool receiving place 33 again to the storage angle Pa.The slot locking mechanism 40 includes an arm-side cam 41, a hinge axis 45, a hinge mechanism 46, and a slot axis 48. The hinge shaft 45 is fixed to an upper end portion of the hinge mechanism 46. When the hinge axis 45 is displaced toward the magazine 30 side, the lower end portion of the hinge mechanism 46 rises, and when the hinge axis 45 is displaced toward the arm 50 side, the lower end portion of the hinge mechanism 46 lowers. the arm-side cam 41 is provided on the arm main body 59 and is in contact with the hinge axis 45. the hinge axis 45 is biased toward the arm-side cam 41 by the weight of the hinge mechanism 46, a return spring (not shown) of the tool receiving space 33, other return springs, a weight, and the like.The tool receiving place axis 48 is fixed to a portion of each of the tool receiving places 33 separated from the holding portion 34, that is, a portion away from the rotation axis. When the lower end portion of the link mechanism 46 is raised, the receiving place axis 48 is pushed upward from the lower end portion. As a result, the tool receiving space 33 rotates in the direction of the exchange angle Pb. The above-described return spring (not illustrated) is fixed to each of the tool storage places 33, and is biased toward the storage angle Pa side by the biasing force of the return spring.The arm-side cam 41 rotates the tool receiving place 33 via the joint axis 45, the joint mechanism 46, and the receiving place axis 48 by being displaced from top to bottom in the Z direction together with the arm 50 with respect to the joint axis 45.Specifically, as shown in FIG. 22, when the arm 50 is lowered with respect to the magazine 30, the lower portion of the arm-side cam 41 displaces the hinge axis 45 toward the magazine 30 side to raise the lower end portion of the hinge mechanism 46, thereby rotating the tool receiving place 33 toward the exchange angle Pb side. As shown in FIG. 24, when the arm 50 is further lowered with respect to the magazine 30, the upper portion of the arm-side cam 41 displaces the hinge axis 45 toward the arm 50 side to lower the lower end portion of the hinge mechanism 46, thereby returning the tool receiving place 33 to the storage angle Pa side.As shown in FIG. 29, when the arm 50 is raised with respect to the magazine 30, the upper portion of the arm-side cam 41 displaces the hinge axis 45 toward the magazine 30 side to raise the lower end portion of the hinge mechanism 46, thereby rotating the tool receiving slot 33 in the direction of the exchange angle Pb. Further, as shown in FIG. 31, when the arm 50 is further raised with respect to the magazine 30, the lower portion of the arm-side cam 41 displaces the hinge axis 45 toward the arm 50 side to lower the lower end portion of the hinge mechanism 46, thereby returning the tool receiving place 33 to the storage angle Pa side.Next, the gripper locking mechanism 60 shown in FIG. 3 will be described. The gripper lock mechanism 60 rotates the gripping member 51 on the magazine 30 side toward the gripping angle Qb side along with the lowering of the arm 50 with respect to the magazine 30, and moreover, the gripper lock mechanism 60 rotates the gripping member 52 on the spindle side toward the gripping angle Qb side along with the lowering of the arm 50 with respect to the spindle 215. Moreover, the gripper lock mechanism 60 rotates the gripping member 51 on the spindle side toward the release angle Qa side along with the raising of the arm 50 with respect to the spindle 215. Moreover, the gripper lock mechanism 60 rotates the gripper member 52 on the magazine 30 side toward the release angle Qa side along with the raising of the arm 50 with respect to the magazine 30.As schematically shown in FIG. 15, the gripper locking mechanism 60 includes a magazine-side cam 61, a spindle-side cam 62, and arm shafts 64. Although in FIG. 15 the two gripping elements 51 and 52 are shown displaced in the second direction Xa for better visibility, the two gripping elements 51 and 52 in practice partially overlap in the first direction Ya as described above. However, when there is space in the second direction Xa, the two gripping members 51 and 52 may actually be arranged to be displaced in the second direction Xa as shown in FIG. 15.The magazine-side cam 61 is fixed to a frame, a housing, or the like of the tool changing device 100. The spindle-side cam 62 is fixed to the frame, the housing 211, or the like of the spindle assembly 210. An arm axle 64 is attached to each of the gripping members 51 and 52. Therefore, the arm shaft 64 moves from top to bottom together with the arm 50 with respect to the magazine side cam 61 and the spindle side cam 62 in the Z direction. Each of the gripping members 51 and 52 is biased toward the release angle Qa side by a return spring, a weight thereof, or the like. Therefore, the arm axis 64 of the grip member 51 on the magazine 30 side is biased by the magazine side cam 61, and the arm axis 64 of the grip member 52 on the spindle 215 side is biased by the spindle side cam 62.As schematically shown in FIG. 16, the gripper locking mechanism 60 further includes a separating cam 63 and a separating axis 65. The separation cam 63 is provided at a position farther from the spindle 215 than the spindle-side cam 62, and is fixed to a frame, a housing, or the like of the tool changing device 100, in particular. A separating axle 65 is fastened to each of the gripping elements 51 and 52. The separating axis 65 moves together with the arm 50 in the Z direction from top to bottom with respect to the separating cam 63.As shown in FIG. 23, the arm axis 64 is displaced toward the magazine 30 side according to the profile of the magazine side cam 61 along with the lowering of the arm 50 with respect to the magazine 30, so that the grip member 51 on the magazine 30 side rotates toward the grip angle Qb side. Further, as shown in FIG. 31, the arm axis 64 is displaced toward the arm 50 side according to the profile of the magazine-side cam 61 along with the raising of the arm 50 with respect to the magazine 30, so that the grip member 51 on the magazine 30 side rotates toward the release angle Qa side.Further, as schematically shown in FIG. 17, the arm axis 64 is displaced toward the spindle 215 according to the profile of the spindle-side cam 62 along with the lowering of the arm 50 with respect to the spindle 215, so that the grip member 52 on the spindle 215 side rotates toward the grip angle Qb side. Further, as schematically shown in FIG. 19, the arm axis 64 is displaced toward the arm 50 side according to the profile of the spindle-side cam 62 along with the raising of the arm 50 to the predetermined position with respect to the spindle 215, so that the grip member 52 on the spindle 215 side rotates toward the release angle Qa side.As shown in FIG. 20, the separation axis 65 is displaced toward the arm 50 side according to the profile of the separation cam 63 along with the further lifting of the arm 50 from the predetermined position with respect to the spindle 215, so that the grip member 52 on the spindle 215 side further rotates toward the release angle Qa side. By this rotation, the arm shaft 64 is separated from the spindle-side cam 62.As shown in FIG. 2, the tool changing device 100 further includes a magazine rotating device 73, an arm lifting device 75, an arm pivoting device 76, and a control device 80. The magazine rotating device 73 rotates the magazine 30 around the X direction from left to right. The arm lifting device 75 moves the arm 50 up and down in the Z direction. The arm pivot 76 pivots the arm 50 about the Z direction from top to bottom. The magazine rotating device 73, the arm lifting device 75, and the arm pivoting device 76 are each an actuator, for example, a motor. In the tool changing device 100, the control device 80 controls each device including these actuators.Next, with reference to FIGS. 21 to 32, a concrete procedure of tool change based on the control by the control device 80 will be described. As shown in FIG. 21, the arm 50 is arranged in the "standby position W" as an uppermost part in the stroke in the Z direction from top to bottom in the initial state. At this time, the gripping members 51 and 52 are disposed at the releasing angle Qa.From this state, as shown in FIG. 22, the arm 50 is lowered. Along with the lowering, the tool receiving space 33 at the exchange position P rotates in the exchange angle Pb direction, and the grip member 51 on the magazine 30 side rotates in the grip angle Qb side. Then, as shown in FIG. 23, the tool receiving space 33 is disposed at the exchange position P at the exchange angle Pb, the grip member 51 on the magazine 30 side is disposed at the grip angle Qb, and the grip member 51 grips the upper portion of the subsequently used tool Tn of the tool receiving space 33.From this state, as shown in FIG. 24, when the arm 50 is further lowered, the grip member 51 on the magazine 30 side releases the subsequently used tool Tn from the tool receiving space 33 at the replacement angle Pb. Thereafter, the tool receiving space 33 rotates at the replacement position P along with the arm 50 being further lowered toward the storage angle Pa side. At this time, the upper portion of the subsequently used tool Tn passes through the notch 38. Thereafter, as shown in FIG. 25, when the tool receiving place 33 rotates to the storage angle Pa, the magazine 30 starts rotating and starts an operation of moving a desired tool receiving place 33 for storing the previously used tool Tp to the replacement angle Pb.In parallel with these operations, as shown in FIG. 25, when the arm 50 is lowered and the spindle assembly 210 is raised, the arm 50 is lowered with respect to the spindle 215. Along with the relative lowering, the grip member 52 on the spindle 215 side rotates toward the grip angle Qb side and grips the upper portion of the previously used tool Tp of the spindle 215.From this state, as shown in FIG. 26, the spindle-side gripping member 52 releases the previously used tool Tp from the spindle 215 when the spindle assembly 210 is further raised, that is, when the arm 50 is further lowered with respect to the spindle 215.Next, as shown in FIG. 27, the arm 50 pivots 180° about the Z direction from top to bottom. By the pivoting, the grip member 51 on the magazine 30 side and the grip member 52 on the spindle 215 side are interchanged. As a result, the previously used tool Tp is on the magazine 30 side and the subsequently used tool Tn is on the spindle 215 side. Thereafter, as shown in FIG. 28, when the spindle assembly 210 is lowered, i.e., when the arm 50 is raised with respect to the spindle 215, the gripping member 51 on the spindle 215 side fixes the subsequently used tool Tn to the spindle 215.Thereafter, as shown in FIG. 29, when the spindle assembly 210 is further lowered and the arm 50 is raised, the arm 50 is further raised with respect to the spindle 215. Along with the relative raising, the grip member 51 on the spindle 215 side rotates toward the release angle Qa side to release the gripping of the subsequently used tool Tn.Further, when the arm 50 is raised at this time, the arm 50 is raised with respect to the magazine 30, as shown in FIG. 29. Along with the relative raising, the tool receiving space 33 rotates in the direction of the exchange angle Pb at the exchange position P. At this time, the operation of moving the desired tool receiving space 33 to the replacing position P is already completed. Therefore, the desired tool receiving space 33 is disposed at the replacing position P. When the tool receiving place 33 rotates in the direction of the exchange angle Pb, the upper portion of the previously used tool Tp passes through the notch 38 of the rotating tool receiving place 33.Then, as shown in FIG. 30, the tool receiving place 33 is placed at the exchange position P at the exchange angle Pb, and the grip member 52 on the magazine 30 side fixes the previously used tool Tp to the tool receiving place 33.Thereafter, as shown in FIG. 31, along with the further raising of the arm 50, the tool receiving place 33 is rotated at the replacement position P toward the storage angle Pa side, and the grip member 51 on the magazine 30 side is rotated toward the release angle Qa side. By these rotations, the gripping member 52 on the magazine 30 side releases the gripping of the previously used tool Tp. Thereafter, the tool receiving space 33 returns to the storage angle Pa at the replacement position P as shown in FIG. 32 along with the arm 50 being raised to the original standby top position W.The configuration and effects of the present embodiment will be summarized below.As shown in FIG. 7, the tool receiving place 33 is rotatably fixed to the magazine body 39 by the holding portion 34 for fixing the tool T, and the holding portion 34 also serves as a rotation axis of the tool receiving place 33.The slot locking mechanism 40 shown in FIG. 3 rotates the tool slot 33 at the replacement position P along with the movement of the arm 50 with respect to the magazine 30, and therefore, it is possible to rotate the tool slot 33 to the replacement angle Pb and the storage angle Pa without a drive source provided for rotating the tool slot 33.Further, the slot locking mechanism 40 rotates the tool slot 33 from the storage angle Pa to the replacement angle Pb along with lowering of the arm 50 with respect to the magazine 30 to the predetermined position. Thereafter, the slot lock mechanism 40 rotates the tool slot 33 from the exchange angle Pb along with further lowering of the arm 50 from the predetermined position with respect to the magazine 30 to the storage angle Pa. Therefore, it is possible to perform a series of operations in which the tool receiving place 33 is rotated from the storage angle Pa to the replacement angle Pb while the arm 50 is lowered with respect to the magazine 30, and then rotated back to the storage angle Pa. Similarly, it is possible to perform the series of operations while the arm 50 is being raised with respect to the magazine 30.As shown in FIG. 6, the notch 38 is provided in an outer peripheral portion of the tool receiving space 33 in a direction from the storage angle Pa to the replacement angle Pb. During the movement of the arm 50 with respect to the magazine 30, the tool receiving space 33 rotates, and the upper portion of the tool T passes through the notch 38. This allows the movement of the arm 50 with respect to the magazine 30 and the turning operation of the tool receiving place 33 to be largely overlapped, so that the cycle time of tool change is shortened. When the tool receiving space 33 is rotated from top to bottom along with the movement of the arm 50 with respect to the magazine 30 in the Z direction, even if the stroke of the relative movement of the arm 50 in the Z direction from top to bottom is small, a sufficiently large stroke of the rotation of the tool receiving space 33 can be secured by the above-described substantial overlap. Therefore, it is possible to suppress the stroke of the relative movement of the arm 50 with respect to the magazine 30 in the Z direction from top to bottom.As shown in FIGS. 13 and 14, the first gripping member 51 and the second gripping member 52 are configured to be independently rotatable about the Y direction from front to rear, and perform gripping and releasing of the tool T by being independently rotated. Therefore, compared to a case where the tool T can be gripped and released only at the same time, it is possible to facilitate other operations in parallel with the operation by the arm 50.Specifically, as shown in FIG. 24, the control unit 80 allows the gripping member 51 on the magazine 30 side to release the subsequently used tool Tn from the tool receiving place 33 at the replacement position P, and then allows the gripping member 52 on the spindle 215 side to release the previously used tool Tp from the spindle 215. In parallel with the detachment of the used tool Tp, the magazine 30 is rotated to advance the operation for arranging the desired tool storage place 33 for storing the used tool Tp at the replacement position P. This makes it possible to quickly store the previously used tool Tp in the desired tool receiving place 33.As schematically illustrated in FIG. 12, the first and second gripping members 51 and 52 are arranged to be displaced from each other in the first direction Ya as viewed from the top to the bottom in the Z direction, and arranged such that the gripping portions 54 face opposite sides to each other in the second direction Xa. Therefore, as shown in FIG. 13, when viewed in the first direction Ya, the first and second gripping members 51 and 52 may be disposed so as to partially overlap each other. Thus, it is possible to compactly assemble the arm 50 in the second direction Xa while avoiding interference between the first gripping member 51 and the second gripping member 52.When the gripping portion 54 is pressed against the tool T to grip the tool T or is pulled away from the tool T from the top to the bottom by slightly pivoting the arm 50 shown in FIG. 2 about the Z direction to release the gripping of the tool T, the following problem occurs. That is, it is necessary to move the arm 50 in the Z direction from top to bottom with respect to the magazine 30 and the spindle 215 after the swing of the arm 50 is firmly stopped. Therefore, it is difficult to cause the acceleration / deceleration operation for gripping and releasing the gripping of the tool T to overlap with other operations such as raising and lowering of the arm 50. Therefore, it is difficult to shorten the cycle time of tool change.In this regard, in the present embodiment, as shown in FIG. 13, each of the gripping members 51 and 52 is configured to be rotatable about the first direction Ya orthogonal to the axial longitudinal direction of the spindle 215, and moreover, the gripper locking mechanism 60 schematically shown in FIG. 15 is provided. The gripper lock mechanism 60 rotates the gripping member 51 on the magazine 30 side along with the movement of the arm 50 with respect to the magazine 30 in the Z direction from top to bottom to grip and release the tool T. Moreover, the gripper lock mechanism 60 rotates the gripping member 52 on the spindle 215 side along with the movement of the arm 50 with respect to the spindle 215 in the Z direction from top to bottom to grip and release the gripping of the tool T. Therefore, it is not necessary to swing the arm 50 from top to bottom about the Z direction to grip the tool T or release the gripping. Therefore, it is not necessary to move the arm 50 from top to bottom in the Z direction with respect to the magazine 30 and the spindle 215 after the swing is firmly stopped. Therefore, it is possible to overlap other operations of the arm 50, such as raising and lowering of the arm 50, with the turning operations of the gripping members 51 and 52, that is, to overlap the accelerating and decelerating operations for gripping and releasing the gripping of the tool T. Therefore, it is possible to shorten the cycle time of tool change.As schematically illustrated in FIG. 16, the gripper locking mechanism 60 includes the spindle-side cam 62, the arm axis 64, the separating cam 63, and the separating axis 65. As schematically shown in FIG. 19, when the arm 50 is raised to a predetermined position with respect to the spindle 215, the arm axis 64 is displaced according to the profile of the spindle-side cam 62 to rotate the grip member 52 toward the release angle Qa side. As schematically shown in FIG. 20, when the arm 50 is further raised from the predetermined position with respect to the spindle 215, the separating axis 65 is displaced according to the profile of the separating cam 63 to further rotate the gripping member 52 in the direction of the releasing angle Qa. Thereby, the arm shaft 64 is separated from the spindle-side cam 62. Therefore, when the grip member 52 is positioned at the release angle Qa, the spindle-side cam 62 does not receive force from the arm axis 64, at which time, although the separation axis 65 is in contact with the separation cam 63, since the separation cam 63 is farther from the spindle 215 than the spindle-side cam 62, an external force is less likely to be applied to the spindle 215 than in the case where the arm axis 64 is in contact with the spindle-side cam 62. Therefore, it is possible to suppress the external force applied to the spindle 215 during machining by the spindle 215, and it is possible to suppress the adverse effect of the external force on the machining accuracy and the quality of the machined surface.[Second Embodiment]Next, a second embodiment will be described with reference to Figs. 33 to 37. Moreover, the following embodiments including the present embodiment will be described based on predetermined embodiments described above, centering on points different therefrom, and descriptions of points identical or similar to those of the embodiment based thereon will be omitted as appropriate. The present embodiment will be described based on the first embodiment.In the present embodiment, as shown in FIG. 33, the gripper locking mechanism 60 includes a spring 67, a grip-side stopper 68 a, a release-side stopper 68 b, and a rotation mechanism 69. In the present embodiment, only the gripping member 52 will be described, but the same applies to the gripping member 51.One end of the spring 67 is fixed to the arm main body 59 and the other end is fixed to the gripping member 52, and a change from the natural state is maximized at a predetermined intermediate point between the release angle Qa and the gripping angle Qb of the gripping member 52. Therefore, as shown in FIG. 35, in a state where the grip member 52 is closer to the grip angle Qb side than the intermediate point, the spring 67 biases the grip member 52 toward the grip angle Qb side. The grip-side stopper 68 bconvents the grip member 52 from rotating further as it rotates to the grip angle Qb. On the other hand, as shown in FIG. 37, in a state where the grip member 52 is closer to the release angle Qa side than the center, the spring 67 urges the grip member 52 toward the release angle Qa side. The release-side stopper 68 aconvents the grip member 52 from rotating further when rotating to the release angle Qa.Specifically, in the present embodiment, the spring 67 is a tension spring and has a maximum length at the intermediate point. Instead, however, the spring 67 may be, for example, a compression spring so that the length reaches a minimum at the intermediate point.As shown in FIG. 33, the gripper lock mechanism 60 includes, instead of the spindle-side cam 62 in the first embodiment, a gripping cam 62 band a releasing cam 62 aarranged in the first direction Ya. The gripper lock mechanism 60 includes, instead of the arm axis 64 and the separating axis 65 described in the first embodiment, a gripping axis 64 band a releasing axis 64 aarranged side by side in the Y direction from front to rear. The rotating mechanism 69 includes the gripping cam 62 b, the releasing cam 62 a, the gripping shaft 64 b, and the releasing shaft 64 a.The gripping axis 64 band the releasing axis 64 aare fixed to the gripping member 52, and move from top to bottom in the Z direction together with the arm 50 with respect to the gripping cam 62 band the releasing cam 62 a.As shown in FIG. 34, when the arm 50 is lowered with respect to the spindle 215, the gripping axis 64 bcomes in contact with the gripping cam 62 bto rotate the gripping member 52 toward the gripping angle Qb side from the above-described intermediate point. Thereafter, the gripping member 52 is rotated by the gripping angle Qb by the biasing force of the spring 67. At this time, as shown in FIG. 35, the gripping member 52 is biased toward the gripping-side stopper 68 b, and the gripping axis 64 band the releasing axis 64 aare separated from the gripping cam 62 band the releasing cam 62 a, respectively.As shown in FIG. 36, when the arm 50 is raised with respect to the spindle 215, the release axis 64 acomes in contact with the release cam 62 ato further rotate the grip member 52 from the intermediate point toward the release angle Qa side. Thereafter, the grip member 52 is rotated to the release angle Qa by the biasing force of the spring 67. At this time, as shown in FIG. 37, the gripping member 52 is biased toward the release-side stopper 68 a, and the gripping axis 64 band the release axis 64 aare separated from the gripping cam 62 band the release cam 62 a, respectively.The gripper lock mechanism 60 also includes a gripping cam and a releasing cam similar to the above-described gripping cam 62 band the releasing cam 62 ain place of the magazine-side cam 61 on the magazine side described in the first embodiment. However, for example, the grip cam on the magazine 30 side may be referred to as a "magazine side cam", and the grip cam 62 bon the spindle 215 side may be referred to as a "spindle side cam". The gripping axis may be referred to as an "arm axis.". That is, also in the present embodiment, similarly to the case schematically shown in FIG. 15, a configuration is established in which the "arm axis" of the grip member 51 on the magazine side comes into contact with the "magazine side cam" and the "arm axis" of the grip member 52 on the spindle 215 side comes into contact with the "spindle side cam".As described above, according to the present embodiment, as shown in FIG. 37, when the gripping member 52 is disposed at the release angle Qa, the gripping member 52 is biased toward the release-side stopper 68 b. Therefore, the gripping cams 62 band the releasing cams 62 ado not receive force from the gripping axis 64 band the releasing axis 64 a. Therefore, it is possible to suppress the external force applied to the spindle 215 by the spindle 215 during machining, and it is possible to suppress the adverse effect of the external force on the machining accuracy and the machining surface quality.[Third EmbodimentNext, a third embodiment based on the first embodiment will be described with reference to Figs. 38 to 41. However, the present embodiment may be implemented based on the second embodiment. As schematically shown in FIG. 38, the tool changing apparatus 100 of the present embodiment includes a housing 90 in a front side of which an opening 95 is provided. The magazine 30, the slot locking mechanism 40, the arm 50, the gripper locking mechanism 60, the spindle assembly 210, and the like are stored in the housing 90. A flap 96 is fastened to the opening 95.Hereinafter, a process in which a tool T different from all tools mounted on the tool storage locations 33 and the tool T mounted on the spindle 215 is stored in the tool changing device 100 will be referred to as "loading". Further, the operation of taking out one of these tools from the tool changing apparatus 100 is referred to as "unloading". In the following description, the performing of the "loading" and the "unloading" using the gripping member 52 will be described. However, the "loading" and the "unloading" may be performed using the gripping member 51.As schematically illustrated in FIG. 39, the control device 80 pivots the arm 50 to a predetermined access angle A at the time of "loading", and arranges the gripping member 52 that does not grip a tool T at a position closer to the opening 95 than the position before pivoting. On the other hand, at the time of "unloading", the gripping members 52 are caused to grip the tool T to be unloaded on the outside of the tool changing apparatus 100. Thereafter, the arm 50 is pivoted by the predetermined access angle A, and the tool T is disposed at a position closer to the opening 95 than before the pivoting.Specifically, as illustrated in FIG. 40, the tool changing device 100 includes a display unit 120 and an input unit 130. The input unit 130 includes a tool release / attachment mode selection button 131, a slot number selection button 132, a load / unload selection button 133, and a work completion button 134. The tool release / fastening mode selection button 131 is a tool release / fastening mode selection button. The slot number selection button 132 is a button for selecting one of the plurality of tool slots 33 included in the magazine 30. The load / unload selection button 133 is a button for selecting "load" or "unload".Next, with reference to FIG. 41, a flow for performing "charge" and "discharge" will be described. Moreover, the letter S appended with the reference numerals denotes "step".First, when the user presses the tool release / attachment mode selection button 131, the control device 80 causes the display unit 120 to display the slot number selection button 132 in S 1. The user selects the slot number by pressing the slot number selection button 132 to select one of the plurality of tool slots 33. Thereafter, in S 2, the control device 80 causes the display unit 120 to display the load / unload selection button 133. The user selects "load" or "unload" by operating the load / unload select key.When the user selects "loading", the control device 80 rotates the arm 50 to the access angle A in S 11. Next, in S 12, the control device 80 causes the display unit 120 to display the button 134 for completing the work. Thereafter, the user fixes the "load" tool T to the gripping portion 54 of the gripping member 52 from the opening 95 and then presses the button 134 to finish the works. Thereafter, in S 13, the control device 80 stores the tool T attached to the arm 50 in the selected tool storage place 33. After that, in S 14, the control device 80 moves the arm 50 to the standby position W. As described above, the "loading" is completed.On the other hand, in S 2, when the user selects "unloading", the control device 80 causes the gripping member 52 to grip the tool T of the tool receiving place 33 selected in S 21. Next, in S 22, the control device 80 rotates the arm 50 to the access angle A to place the tool T in the vicinity of the opening 95. Next, in S 23, the control device 80 causes the display unit 120 to display the button for completing the work. Thereafter, the user takes out the tool T gripped by the gripping member 52 from the opening 95 and then presses the button 134 to finish the work. Thereafter, in S 24, the control device 80 moves the arm 50 to the standby position W. Thus, the "unloading" is completed.According to the present embodiment, as shown in FIG. 38, even in the case where the opening 95 is provided at the front side in the housing 90 and there is no opening near the magazine 30, it is possible for the user to easily load the tool T from the opening 95 and unload the tool T from the opening 95.[Fourth Embodiment]Next, a fourth embodiment based on the first embodiment will be described with reference to Figs. 42 to 44. However, the present embodiment may be implemented based on the second embodiment or the third embodiment.In the present embodiment, as shown in FIG. 42, the control device 80 includes a weight detection unit 85 and a speed control unit 88. The weight acquisition unit 85 acquires the weight of the previously used tool Tp and the subsequently used tool Tn. The speed control unit 88 controls the moving speed of the arm 50 based on the detected weight. Specifically, when the detected weight is less than a predetermined value, the speed control unit 88 sets the moving speed of the arm 50 to be higher than that when the detected weight is greater than the predetermined value.The control device 80 further includes a weight storage unit 81. The weight storage unit 81 stores the weight of the tool T and the slot number of the tool slot 33 associated with each other. The weight acquisition unit 85 calculates the weight of the previously used tool Tp and the subsequently used tool Tn based on the storage. In this case, for example, as shown in FIG. 43, first, in S 51, the weight acquisition unit 85 calculates the weight data of the previously used tool Tp and the subsequently used tool Tn to calculate the weight. Next, in S 52, the speed control unit 88 controls the moving speed of the arm 50 based on the calculated weight.Instead of or in addition to the weight storage unit 81 described above, the control device 80 may include a load detection unit 82. The load detection unit 82 monitors the load of the arm lifting device 75 and / or the arm pivoting device 76. the weight detection unit 85 calculates the weight of the previously used tool Tp and the subsequently used tool Tn based on the load. In this case, for example, as shown in FIG. 44, first, in S 61, the load detection unit 82 detects the load of the arm lifting device 75 or the arm pivoting device 76. next, in S 62, the weight acquisition unit 85 calculates, based on the load, the weight of the previously used tool Tp and the subsequently used tool Tn. Next, the speed control unit 88 controls the moving speed of the arm 50 based on the calculated weight.According to the present embodiment, the following problems can be solved. It is necessary to move the arm 50 within a range in which no excessive load is applied to the arm lifting device 75 and the arm pivoting device 76. On the other hand, if the moving speed of the arm 50 is set on the assumption of the maximum weight that the tool Tn used subsequently and the tool Tp used previously may have, the moving speed of the arm 50 becomes unnecessarily slow and the cycle time of the tool change becomes unnecessarily long. In this regard, in the present embodiment, when the weight of the subsequently used tool Tn and the previously used tool Tp is small, the moving speed of the arm 50 is set to be higher than that of the large weight. Accordingly, the moving speed of the arm 50 can be increased within a range in which no excessive load is applied to the arm lifting device 75 or the arm pivoting device 76. This makes it possible to efficiently shorten the cycle time of tool change.[Other Embodiments]The above-described embodiments may be modified as follows, for example. Further, in each of the embodiments, when the complicated structure of the tool receiving place 33 does not pose a great problem, the holding portion 34 and a shaft can be separately provided as a rotation axis in the tool receiving place 33.Further, in each of the embodiments, the first gripping member 51 or the second gripping member 52 may be omitted, and only the gripping member 52 may be provided. In this case, it may be configured such that only the one gripping member 52 releases the previously used tool Tp from the spindle 215 and fixes the previously used tool Tp to a predetermined tool container 33, and releases the subsequently used tool Tn from another tool container 33 and fixes the subsequently used tool Tn to the spindle 215.According to the above-described embodiments, it is possible to realize the tool changing devices described below in Supplementary Notes 1 and 2.[Supplementary Note 1]A tool changing device (100) for releasing a previously used tool (Tp) as one of a plurality of tools (T) from a spindle (215) of a machine tool (200) and fixing a subsequently used tool (Tn) as a tool (T) different from the previously used tool (Tp) to the spindle (215), the tool changing device (100) comprising:an arm (50) having a gripping member (51, 52) rotatable into a gripping angle (Qb) for gripping the tool (T) and a releasing angle (Qa) for releasing gripping of the tool (T), the arm being configured to allow the gripping member (51, 52) to release the previously used tool (Tp) from the spindle (215) and to attach the subsequently used tool (Tn) to the spindle (215); anda gripper lock mechanism (60) that rotates the gripping member (51, 52) along with movement of the arm (50) with respect to the spindle (215);wherein the gripper lock mechanism (60) includes a spindle-side cam (62), an arm shaft (64) fixed to the gripping member (51, 52) and moving together with the arm (50) with respect to the spindle-side cam (62), a separating cam (63) provided at a position farther from the spindle (215) than the spindle-side cam (62), and a separating shaft (65) fixed to the gripping member (51, 52) and moving together with the arm (50) with respect to the separating cam (63),when the arm (50) moves to a predetermined position with respect to the spindle (215) in a predetermined direction, the arm axis (64) is displaced according to a profile of the spindle-side cam (62) to rotate the gripping member (51, 52) in the direction of the release angle (Qa), andwhen the arm (50) further moves from the predetermined position with respect to the spindle (215) in the predetermined direction, the separating axis (65) is displaced according to a profile of the separating cam (63) to further rotate the gripping member (51, 52) in the direction of the releasing angle (Qa), so that the arm axis (64) is separated from the spindle-side cam (62).[Supplementary Note 2]In the tool changing device (100) described in Supplementary Note 1, the arm (50) has, as the gripping member (51, 52), a first gripping member (51) and a second gripping member (52), the gripper locking mechanism (60) has, for each of the gripping members (51, 52), the arm axis (64) and the separating axis (65), and the arm axis (64) of one of the gripping members (51, 52) adjacent to the spindle (215) comes into contact with the spindle-side cam (62), and the separating axis (65) of one of the gripping members (51, 52) adjacent to the spindle (215) comes into contact with the separating cam (63).LIST OF REFERENCE NUMERALS50 Arm 51 First gripping member 52 Second gripping member 59 Arm main body 60 Gripper lock mechanism 62 Spindle-side cams 63 Separating cams 64 Arm axis 65 Separating axis 100 Tool changing device 200 Machine tool 215 Spindle P Replacement position Pa Storage angle Pb Replacement angle T Tool Tn Subsequently-used tool Tp Previously-used toolReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedJP 2008-132555

[0003]

Claims

A tool replacing apparatus for releasing a previously used tool as one of a plurality of tools from a spindle of a machine tool and for fixing a subsequently used tool as a tool different from the previously used tool to the spindle, the tool replacing apparatus comprising: an arm having a gripping member rotatable into a gripping angle for gripping the tool and a releasing angle for releasing gripping of the tool, the arm being configured to allow the gripping member to release the previously used tool from the spindle and fix the subsequently used tool to the spindle; and a gripper locking mechanism rotating the gripping member along with movement of the arm with respect to the spindle, wherein the gripper lock mechanism includes a spindle-side cam, an arm axis fixed to the gripping member and moving together with the arm with respect to the spindle-side cam, a separating cam provided at a position farther from the spindle than the spindle-side cam, and a separating axis fixed to the gripping member and moving together with the arm with respect to the separating cam when the arm moves relative to the spindle in a predetermined direction to a predetermined position, the arm axis is displaced according to a profile of the spindle-side cam to rotate the gripping member in the direction of the release angle, and when the arm moves further relative to the spindle in the predetermined direction from the predetermined position, the separating axis is displaced according to a profile of the separating cam, to further rotate the gripping member in the direction of the release angle so that the arm axis is separated from the spindle-side cam.The tool changing device according to claim 1, wherein the arm includes, as the gripping member, a first gripping member and a second gripping member, the gripper locking mechanism includes, for each of the gripping members, the arm axis and the separating axis, and the arm axis of one of the gripping members adjacent to the spindle comes into contact with the spindle-side cam, and the separating axis of one of the gripping members adjacent to the spindle comes into contact with the separating cam.

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