JP3042597B2 - Machine tool tool changer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool changer of a machine tool for mutually exchanging a tool on a spindle and a tool on a tool magazine, which are located at a tool change position.

[0002]

2. Description of the Related Art Conventionally, a large tool magazine for storing a tool in a horizontal direction through a plurality of tool pots connected to an endless chain and rotating a chain to index an arbitrary tool to a tool delivery position has been known. Place it on the side of the machine,
The number of tools stored in the tool magazine has been increased, the space for the tool magazine has been reduced, and the storage of tools in the tool magazine has been facilitated. When such a tool magazine is arranged on the side of the machine, the moving direction of the main spindle and the storing direction of the tool are often different, so that it is necessary to directly exchange the tool between the main spindle and the tool magazine. difficult.

For this reason, for example, in a horizontal machining center in which a main shaft is supported in a horizontal direction, a swing arm which can swing around a vertical axis and has a tool exchange arm for gripping a tool at its tip is provided in a tool magazine. The tool indexed to the delivery position is gripped by the tool change arm, and the swing arm is swung 90 ° about the vertical axis to separate the tool from the tool pot and transferred to the tool change position. The tool is exchanged with the tool mounted on the spindle by the tool exchange arm.

On the other hand, in a vertical machining center whose main spindle is supported vertically, when the aforementioned tool magazine is arranged on the side of the machine, the tool magazine is stored in the tool magazine like a horizontal machining center due to the structure of the machine. It is difficult to transfer the tool to the tool change position so as to separate the tool from the tool pot and change the tool with the main spindle by the tool change arm. To this end, a tool transfer device is interposed between the tool magazine and the tool magazine, and the tool indexed to the tool delivery position of the tool magazine is pulled out of the tool magazine together with the tool pot by the tool transfer device and the posture is changed from a horizontal state to a vertical state. The tool is transferred to a tool change position, and the tool is exchanged with a tool mounted on the spindle by a tool change arm of a tool changer provided on the machine tool.

In the vertical machining center, the tool transferred from the tool magazine to the tool change position by the tool transfer device together with the tool pot is exchanged between the tool mounted on the main spindle and the tool exchange arm of the tool exchange device. To do so, the tool changer must perform the following operations. (1) Opening / closing operation of the gripper portion of the tool change arm that holds the tool transferred to the tool change position and the tool mounted on the spindle. (2) Lowering operation of the tool change arm for removing the tool from the tool pot and the spindle. (3) The turning operation of the tool change arm for changing the tool transferred to the tool change position and the tool mounted on the spindle. (4) The raising operation of the tool change arm for mounting and clamping the tool on the tool pot and the spindle.

Accordingly, the tool changing device requires actuators such as cylinders and motors corresponding to the respective operations of tool gripping, removing, turning, and mounting, and the tool changing device is increased in size, leading to an increase in cost. In addition, since the following operations are executed after confirming that the respective actuators have been operated correctly in each of the operations of tool gripping, removing, turning, and mounting, the actuators corresponding to the respective operations can be operated in synchronization. Difficult, tool gripping ~ removal ~
Each operation from turning to mounting must be performed sequentially, and the time required for tool change must be long.

As a prior art for solving such a problem, there is a cam type automatic tool changer disclosed in Japanese Utility Model Publication No. 4-17312. This device is provided with an arm shaft having a tool changing arm, a roller gear cam which engages with a flange provided annularly around the arm shaft on a shaft provided rotatably in the vertical direction, and an arm shaft. A cam having a cam groove engaged with the flange portion is mounted, and a roller gear cam and a cam are rotated by a motor to cause a tool change arm to execute a series of operations necessary for tool gripping, removal, turning, and mounting. It is to try. Further, the gripping of the tool by the tool exchange arm is performed by pivotally moving the tool exchange arm, engaging the engagement notch with the tool, and pushing the engagement member by a spring.
Therefore, the rotation of the roller gear cam and the rotation of the cam can cause the tool change arm to perform the pivoting movement and the vertical reciprocating movement required for tool change, and the tool change device can be simplified because the actuator required for tool change is minimized. Structure.

[0008]

In recent years, it has been desired to shorten the tool change time as a part of shortening the machining time.
For this purpose, the timing of the unclamping operation of the tool from the main spindle and the timing of the tool gripping-withdrawing-turning-mounting operation by the tool changing arm is adjusted. In other words, the unclamping of the tool immediately before the main spindle moves to the tool changing position is performed. Unclamp type tool change is being performed.

[0009] Here, the tool changer disclosed in Japanese Patent Publication No. 4-17312 discloses a tool changer which pivots a tool transferred to a tool change position and a tool mounted on a spindle to a tool change arm. In order to perform the tool change of the preceding unclamping method, the tool change arm pivots to move the tool, moves the main spindle to the tool change position, and releases the tool from the main spindle. It is necessary to match the timing of the three operations of the clamp, and the operation control of the tool change becomes very complicated. Also,
If the tool is to be replaced by the preceding unclamping method, a temporary holding device for the tool or the like may be provided on the spindle, but the structure becomes more complicated. In addition, the operation of elevating the tool change arm for mounting the tool on the tool pot and the spindle is performed by elevating the lever by the cam and the cam follower. However, in this case, a considerable load is applied to the cam and the cam follower. There is such a problem.

Further, in order to shorten the tool change time, it is necessary to speed up the operations of tool holding, removing, turning and mounting by the tool changing arm. However, Tokuhei 4
The tool changer disclosed in US Pat.
Since the tool is held on the tool changing arm only by the force of the spring, the tool changing arm is rotated at a high speed to exchange the tool transferred to the tool changing position with the tool mounted on the spindle. Then, there is a fear that the tool held by the tool changing arm may fall off due to centrifugal force.

As a conventional technique for solving such problems, there is a tool changing apparatus disclosed in Japanese Patent Application Laid-Open No. 64-51247. This device is a tool changing device in the above-mentioned horizontal machining center, and a shaft that allows a claw to perform a turning operation when a tool transferred from a tool magazine and held by a tool changing arm is mounted on a main shaft at a tool changing position. Is engaged with a concave portion formed on the inner peripheral surface of the cam attached to the rotating shaft, and the shaft is moved toward the pawl, thereby allowing the pawl opening operation. In addition, while the tool change arm is turning, the shaft is not moved toward the pawl to prevent the pawl opening operation.

However, the tool changing device disclosed in Japanese Patent Application Laid-Open No. 64-51247 prevents the pawl opening operation only while the tool changing arm is turning.
In order to shorten the time of tool change, not only the tool change arm's swing movement but also the swing arm's swing movement need to be accelerated.When the swing arm is moved at a high speed, the tool held by the tool change arm can be moved. There is a risk of falling off.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a tool changer for a machine tool which can shorten a tool change time and can reliably hold a tool with a tool change arm during a tool change operation.

[0014]

According to the present invention, there is provided, in accordance with the present invention, a tool change arm, ie, a pair of grippers for gripping a tool, extending along a vertical axis. There is provided a tool changing device provided with a tool changing arm which is provided on an arm shaft and rotates around a vertical axis together with the arm shaft and reciprocates in the vertical axis direction. The tool changer is provided with gripper locking means for preventing the gripped tool from dropping when the tool change arm rotates around the vertical axis and reciprocates in the vertical axis direction. The gripper locking means includes a pair of rod members provided in parallel with the arm axis as described below, and an engagement member provided on the pair of grippers so as to be able to engage with the rod members. ing.

That is, the arm shaft is provided upright from a housing attached to a fixed portion of the machine tool, and the pair of bar members is provided between a tool changing arm and the housing around an axis of the arm shaft. It is arranged so that it can revolve. A concave groove is formed in the rod member, and an engaging member of the gripper is provided so as to be able to engage with the concave groove. More specifically, the engagement member engages with the concave groove when the pair of grippers of the tool change arm is opened to grip the tool, and the tool change arm rotates about a vertical axis and When it reciprocates in the vertical axis direction, it engages with the outer peripheral surface of the rod member.

Further, the present invention relates to a tool changing device for a machine tool for mutually exchanging the tools indexed to the tool changing position, wherein a housing provided at a fixing portion of the machine tool and a housing perpendicular to the housing are provided. A sleeve rotatably supported around an axis, a drive shaft supported by the housing and rotated by rotary drive means, an arm shaft engaged with the sleeve and movable relative to the sleeve in a vertical axis direction, A gear cam portion fixed to the drive shaft and a first cam follower fixed to the sleeve and engaged with the gear cam portion, wherein rotation around the axis of the drive shaft is converted into rotation around a vertical axis of the arm shaft. Arm shaft rotating means, a groove cam portion fixed to the drive shaft, a second cam follower engaging with the groove cam portion, and a shifter engaging with the arm shaft. An arm shaft reciprocating means for converting rotation of the drive shaft about an axis into reciprocal movement in a vertical axis direction of the arm shaft, and a pair of grippers for gripping the tool, provided on the arm shaft. A tool change arm that rotates about a vertical axis and reciprocates in the vertical axis direction together with the arm axis, and a groove that is provided between the tool change arm and the housing to be rotatable about the axis of the arm axis, A pair of bar members formed with a pair of grippers, and the pair of grippers of the tool exchange arm engage with a groove formed in an outer peripheral portion of the bar member when gripping and releasing the tool; A tool changer for a machine tool, comprising: a gripper lock means comprising: an engagement member that engages with the outer peripheral surface of the rod member when the arm rotates around the vertical axis and reciprocates in the vertical axis direction. The gist of the location.
Elastic means for reducing the load on the rotary drive means may be further provided between the housing and the tool changing arm.

[0017]

[Function] The tool transferred together with the tool pot to the tool change position on the tool magazine side, and the tool mounted on the spindle,
The tool is exchanged by gripping with a pair of grippers of a tool exchange arm provided at the upper end of the arm shaft, and causing the tool exchange arm to reciprocate up and down and swing by arm axis rotating means and arm axis reciprocating movement means.

More specifically, when the drive shaft supported by the housing is rotated by the rotary drive means, the gear cam portion fixed to the drive shaft rotates about a horizontal axis, and the first cam follower engaged with the gear cam portion. Thus, the rotation of the gear cam portion about the horizontal axis is converted into the rotation of the arm shaft about the vertical axis via the sleeve.

When the drive shaft supported by the housing is rotated by the rotary drive means, the groove cam portion fixed to the drive shaft rotates about a horizontal axis and engages with the groove cam portion.
The rotation of the groove cam around the horizontal axis is converted into swinging movement of the shifter around the horizontal axis by the cam follower, and the shifter is engaged with the annular groove of the arm shaft. The swing of the shifter is converted into a reciprocating movement in the direction of the vertical axis of the arm shaft while being allowed to rotate.

When the tool is gripped and released by the pair of grippers of the tool change arm during the tool change operation, the tool is engaged with the concave groove formed on the outer peripheral portion of the rod member provided between the tool change arm and the housing. The engagement with the mating member allows the pair of grippers to open. Thereafter, when the tool change arm is rotated around the vertical axis and reciprocated in the vertical axis direction to remove the tool from the tool pot and the main shaft, the outer peripheral surface of the rod member engages with the engaging member, and the pair of grippers is closed. Become.

[0021]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, referring to FIG. 5, a tool changer 10 according to an embodiment of the present invention is disposed between a vertical machining center 40 and a tool magazine 70. The vertical machining center 40 includes a bed 42 installed on the floor of a factory or the like, and a column base 44 fixed to the upper surface of the bed 42. A column 46 is provided on the upper surface of the column base 44 in the X-axis direction, In FIG. 5, it is provided so as to be able to reciprocate in the left-right direction. Bed 42
A table 52 on which a work is placed is provided on the upper side so as to be able to reciprocate in a direction (Y direction) perpendicular to the plane of the paper of FIG. A spindle head 48 is mounted on the front surface of the column 46. The spindle head 48 rotatably supports the spindle 50 about a vertical axis and is capable of reciprocating in the vertical axis direction, that is, the Z-axis direction. . Further, a tool 78 is mounted on the tip of the spindle 50 via a tool holder 76.

The tool magazine 70 is a vertical tool magazine having a magazine base 72 vertically mounted on the left end face of the bed 42 of the vertical machining center 40.
A pair of sprockets (not shown) is rotatably attached to both upper and lower ends of the magazine base 72, and a chain 80 is stretched over the pair of sprockets.
A plurality of holders 82 are connected to the chain 80, and a tool 78 is attached to each holder 82.
Is held through. Preferably, the magazine base 72
The sprocket attached to the lower end of the is connected to the rotating shaft of a tool magazine drive motor (not shown),
A series of tools are connected to the magazine base 72 via the chain 80.
Is rotated in both the forward and reverse directions, and a desired tool is indexed at the tool transfer position A.

The tool transfer device 100 includes a tool magazine 70
A plate cam 102 attached to the magazine base 72 so as to be able to reciprocate in a direction perpendicular to the direction in which the tool 78 is stored, that is, in a direction perpendicular to the plane of FIG. 5, and a rotation fixed vertically to the plate cam 102. Shaft 106 and the rotating shaft 1
A bracket 104 having a substantially L-shape is provided so as to be rotatable around a position 06 in a direction indicated by an arrow R in FIG. The bracket 104 is provided with a guide rail 104a extending linearly as shown in FIG.
A guide 108b which engages with the guide rail 104a on a pot gripper 108 provided so as to be able to grip the tool pot 74.
Is mounted so as to be able to reciprocate with respect to the bracket 104 along the guide rail 104a.

The plate cam 102 is formed with a cam groove 102a, and the pot gripper 108 is rotatably mounted with a roller-like turning cam follower 108a which engages with the cam groove 102a. L-shaped bracket 104
A turning cylinder 110 is attached to the end opposite to the guide rail 104a, and the piston rod of the turning cylinder 110 extends parallel to the guide rail 104a and is attached to a pot gripper 108.

The tool 78 indexed to the tool transfer position A
Is gripped together with the tool pot 74 by the pot gripper 108 of the tool transfer device 100 as shown in FIG. Next, when the rotation cylinder 110 is extended, the pot gripper 108 is rotated by the rotation cam follower 108a and the plate cam 102.
Guide rail 104a while rotating in the direction of arrow R together with the bracket 104 by engagement with the cam groove 102a.
And the guide 108b engages to move linearly relative to the bracket 104 and move to the tool change position B.
As a result, the tool 78 is transferred to the tool change position B while being mounted on the tool pot 74.

The tool changing device 10 disposed at the tool changing position B includes a base 12 as a housing mounted on a bed 42 of a vertical machining center 40, an arm shaft 18 erected on the base 12, It has a pair of grippers 30 attached to the tip of the arm shaft 18 via an arm base 28. As will be described in detail later, the arm shaft 18 is provided so as to be capable of reciprocating in a vertical direction indicated by an arrow ZZ in FIG. 5 and rotatable about a longitudinal axis as indicated by an arrow RR.

Tool change position B by tool transfer device 100
Is held by the gripper 30 of the tool changing device 10 and waits until the start of the tool changing operation on the vertical machining center 40 side.

When the tool change operation of the vertical machining center 40 starts, the column 4 of the vertical machining center 40
6 moves leftward along the X-axis from the state shown in FIG. 5 to above the gripper 30 that does not hold the tool 78 of the tool changer 10, the main shaft 50 moves down in the Z-axis direction, and the main shaft 50 moves. Is transported toward the tool change position B. By this operation, the spindle 50
Is held by the other gripper 30 of the tool changer 10. Next, the arm shaft 18 rotates in the direction of the arrow RR and moves up and down in the ZZ direction, so that the old tool 78 is removed from the tip of the main shaft 50, and the new tool 78 is mounted on the main shaft 50 to perform tool change. Will be

Next, the tool changing device 10 according to the present embodiment will be described in more detail with reference to FIGS. In addition,
FIG. 1 is a front sectional view taken along the line II of FIG. The tool changing device 10 according to the present embodiment includes a base 12 formed of a hollow member attached to an upper surface of a bed 42 of a vertical machining center 40 by a fixing bolt 12d, the base 12 being a bush 12g, and the adjusting bolt 1
2e, the nut 12f is attached to the bed 42 so that the position can be finely adjusted.

The base 12 has an opening 12c in an upper wall portion, and a lower bearing case 20 formed in a substantially cylindrical hollow shape is attached to the opening 12c, and an inner periphery of the lower bearing case 20 is provided. A vertically extending arm shaft 18 is rotatably supported via a sleeve 32 by a pair of ball bearings 20a and 20b disposed at the upper and lower ends of the surface. The arm shaft 18 has a spline portion 18a formed on the outer peripheral surface of a lower portion, and a spline portion 32b fitted on the inner peripheral surface of the sleeve 32. This allows the arm shaft 18 to rotate together with the sleeve 32 and reciprocate in a direction perpendicular to the sleeve 32. As shown, the arm shaft 18 is formed of a hollow, substantially cylindrical member, and a spring 1 for urging the arm shaft 18 upward therein.
8c, the upper end opening of the arm shaft 18 is closed by a bush 18b, while the lower end opening is a bottom surface of the internal space 12a of the base 12 so as to be slidably inserted into the arm shaft 18. Is closed by a spring fixed shaft 18e erected from above. The load applied to the shifter 16 when the arm shaft 18 moves upward is reduced by the spring 18c.

On the lower bearing case 20, an upper bearing case 22 having a hollow substantially frustoconical shape is mounted. A sleeve bearing 24a is provided between the upper bearing case 22 and the arm shaft 18 so that the arm bearing 18 can rotate around the axis and slide in the axial direction. Thus, the upper part of the arm shaft 18 is supported. Upper bearing case 2
A pair of right and left rods 26 are erected from the upper end surface of the upper part 2 via a ball bearing 22a, and a fixed rod base 24 is rotatably supported on the upper part. The rod 26 is formed of a substantially columnar member, and has an annular concave groove 26a formed in an upper portion.

A flange portion 18e for attaching and fixing the arm base 28 is formed near the upper end portion of the arm shaft 18, and the arm base 28 has a substantially rectangular shape as understood with reference to FIG. Grippers 30 which are made of a plate member and which can be engaged with an engaging portion of the tool holder 76 as a pair of left and right grips are provided at both ends. Each of the pair of grippers 30 is provided with a pair of gripper claws 30a erected on the arm base 28 and rotatably mounted on a fixed gripper shaft 28a. A pair of grippers 30
A gripping spring 30d is arranged between the rear ends of the gripper claws 30a, and the gripper claws 30a are urged by the gripping spring 30d so that the tip ends thereof approach. Further, at the rear end of each gripper claw 30a, an engagement pin 30c provided substantially horizontally is projected and provided.
A rotatably provided engagement roller 30b is attached to be able to engage with the outer peripheral surface of the rod 26. A guide key 28b for positioning the tool 78 with the tool holder 76 when the tool 78 is gripped by the gripper 30 is fixed between the gripper claws 30a. The tool 78 is a pair of grippers 3
2 enters from the direction shown by the arrow S in FIG. 2 and is held by the gripper 30 by the engagement between the engagement portion formed of an annular groove formed in the tool holder 76 and the gripper claw 30a.

Referring to FIGS. 1 and 3, in the internal space 12a of the base 12a, a roller gear cam 14 rotates at both ends together with a horizontal rotating shaft 14a rotatably supported by the base 12 via ball bearings 14c. Attached to. A plurality of cam followers 32a that engage with the roller gear cam 14 are provided at the lower end of the sleeve 32, and rotation of the roller gear cam 14 is transmitted to the sleeve 32 by engaging with the cam follower 32a. Preferably, the roller gear cam 14 is
The sleeve 32 is halved around the vertical axis during one revolution of
It is formed to rotate, that is, rotate by 180 °. A worm wheel 36b is attached to one end of the rotating shaft 14a, and a worm 36a that meshes with the worm wheel 36b is attached to a drive shaft 34a of the drive motor 34. As described below, an annular cam groove 14b is formed on one end surface of the roller gear cam 14 to reciprocate the arm shaft 18 in the vertical direction.

Referring to FIGS. 1 and 4, a shifter shaft 16a projects horizontally from the side wall of the base 12 toward the internal space 12a, and a shifter 16 formed of a plate-like member is shifted via a sleeve bearing 16d. It is rotatably supported by a shaft 16a. A cam groove 14 of the roller cam gear 14 is provided on a surface of the shifter 16 facing the roller gear cam 14.
A reciprocating cam follower 16b that engages with a is rotatably mounted. Cam groove 1 of roller gear cam 14
4b is engaged with the reciprocating cam follower 16b.
While the roller gear cam 14 makes one rotation, the shifter 16 rotates so that the tip portion makes one reciprocation while drawing an arc in the vertical direction about the shifter shaft 16a. Further, in the shifter 16, a shifter roller 16c is rotatably attached to an end opposite to the shifter shaft 16a.
8 is engaged with an annular groove 18d provided at the lower end.
Therefore, the engagement between the shifter roller 16c and the annular groove 18d,
The arm shaft 18 makes one reciprocation in the vertical axis direction while the roller gear cam 14 makes one rotation and engages with the cam follower 32a provided at the lower end of the sleeve 32 and the roller gear cam 14 by one rotation. Rotate.

As described above, the tool 78 indexed to the tool transfer position A by the tool magazine 70 is gripped by the pot gripper 108 while being mounted on the tool pot 74. Next, the piston rod of the turning cylinder 110 of the tool transfer device 100 extends, and the pot gripper 1
The bracket 104 and the pot gripper 108 are engaged by the engagement of the rotation cam follower 108a attached to the cam 08 with the cam groove 102a of the plate cam 102, and the engagement of the guide 108b of the pot gripper 108 and the guide rail 104a of the bracket 104. The tool 78 is transferred to the tool change position B by turning around the rotation shaft 106 in the direction indicated by the arrow R in FIG. 5 and moving the pot gripper 108 linearly relative to the bracket 104.

At this time, the tool changer 10 is in a state in which the arm shaft 18 has been moved upward to the highest position as shown in FIG. 1, and the engaging rollers 30a of the pair of left and right grippers 30 and the concave grooves 26a of the rod 26 are provided. Are engaged. At this time, the gripper claws 30a rotate around the gripper shaft 28a in directions in which the respective distal ends are separated from each other. As described above, since the engaging roller 30a of the gripper 30 is at the position of the concave groove 26a of the rod 26, the gripper 30a can rotate until the engaging roller 30a contacts the surface of the concave groove 26a. ing. When the tool 78 is transferred to the tool change position B, the tool magazine 7 is
The gripper 30 enters the gripper 30 on the 0 side, that is, the gripper 30 on the left side in FIG. 5 in the direction indicated by the arrow S in FIG.

Next, the motor 34 rotates, and this rotation is transmitted to the roller gear cam 14 via the worm 36a and the worm wheel 36b. As described above, during one rotation of the roller gear cam 14, the arm shaft 18
The tool 78 is vertically moved downward while rotating by 0 ° and then moved upward and reciprocally, and the tool 78 is removed from the tool pot 74. When the arm shaft 18 moves down, the engaging roller 30b is disengaged from the concave groove 26a of the rod 26 and engages with the cylindrical outer peripheral surface of the rod 26,
The gripper claw 30a rotates around the gripper shaft 28a to grip the tool 78. Therefore, the tool 78 is prevented from falling off the gripper 30 due to the centrifugal force based on the rotation operation of the arm shaft 18.

When the roller gear cam 14 makes two rotations, the arm shaft 18 makes two reciprocations in the vertical direction while rotating by 360 °, and returns to the position shown in FIG. The above-described process is performed while the machining process of the vertical machining center 40 is being performed, and a new tool 78 to be used in the next process is gripped by the gripper 30 on the tool magazine 70 side of the tool changer 10. You may make it stand by until the start of the tool change operation of the vertical machining center 40.

When the tool changing operation of the vertical machining center 40 is started, the used old tool 7 is used as described above.
8 is transferred to the tool change position B, and is mounted on the gripper 30 on the vertical machining center 40 side of the tool change device 10. At this time, the engagement roller 30a provided at the rear end of the gripper claw 30a engages with the concave groove 26a of the rod 26, and the gripper claw 30a rotates around the gripper shaft 28a in a direction away from each other. State and the old tool 78
Can enter the gripper 30.

Next, the motor 34 rotates, and this rotation is transmitted to the roller gear cam 14 via the worm 36a and the worm wheel 36b. The roller gear cam 14 makes one rotation and the arm shaft 18 rotates 180 °, and the vertical axis extends. Make one reciprocating movement along the downward and upward movements. Before the arm shaft 18 moves up and returns to the position shown by the solid line in FIG. 1, the tool transfer device 100 is turned and moved to the tool changing position B, and the gripper 30 is moved by the arm shaft 18 moving down. While holding the tool 78, the old tool 78 attached to the main shaft 50 of the vertical machining center 40 is removed from the main shaft 50, and the old and new tools 78 are replaced by the arm shaft 18 rotating by 180 °, and the arm shaft 1
When the tool 8 is moved upward, a new tool 78 is mounted on the main shaft 50 of the vertical machining center 40, and the old tool 78 is mounted in the tool pot 74 held by the pot holder 108 of the tool transfer device 100, so that the tool can be changed. Done.

While one embodiment of the present invention has been described with reference to the accompanying drawings, this is merely an example, and it goes without saying that the present invention is not limited to this embodiment. (1) For example, in the above-described embodiment, the gripper 30 of the tool changing device 10 has a generally U-shape including a pair of gripper claws 30a. It may be substantially C-shaped. (2) In the above-described embodiment, the vertical machining center 40 has been described as a machine tool to which the tool changing device of the present invention is applied. However, a horizontal machining center may be used. (3) In the above-described embodiment, the cam groove 14b is formed integrally with the roller gear cam 14 on the side surface of the roller gear cam 14, but the cam groove 14b may be formed as a separate member from the roller gear cam 14.

[0042]

According to the present invention, when the tool change arm starts to descend at the time of tool change, a lock mechanism acts on the gripper for gripping the tool, so that the gripper is unlocked at the moment when the tool change arm is rotated by 180 ° and raised. Since the gripper is locked and unlocked by the tool change operation itself, the tool can be securely gripped, so that the tool can be prevented from dropping from the gripper, and the reliability and safety of the tool change operation are improved. In addition, the tool change time can be reduced.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a tool changing device of a machine tool according to an embodiment of the present invention.

FIG. 2 is a plan sectional view taken along the line II-II of FIG. 1, showing a tool changing arm of the tool changing device of the machine tool according to the embodiment of the present invention.

FIG. 3 is a diagram illustrating a relationship between a gear cam portion and an arm shaft in the tool changing device of the machine tool according to the embodiment of the present invention;
FIG. 3 is a plan sectional view taken along a line III.

FIG. 4 is a plan sectional view along IV-IV in FIG. 1 showing a relationship between a shifter, a groove cam portion, and an arm shaft in the tool changing device of the machine tool according to the embodiment of the present invention.

FIG. 5 is a front view of a machine tool including the tool changing device according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Tool changer 12 ... Base 14 ... Roller gear cam 14a ... Rotary shaft 14b ... Cam groove 16 ... Shifter 16b ... Reciprocating cam follower 18 ... Arm shaft 18c ... Spring 26 ... Rod 26a ... Depressed groove 28 ... Arm base 30 ... Gripper 30a ... Gripper claw 30b ... engagement roller 30c ... engagement pin 32 ... sleeve 32a ... cam follower 34 ... motor 40 ... vertical machining center 42 ... bed 70 ... tool magazine 78 ... tool 100 ... tool transfer device A ... tool transfer position B ... tool exchange position

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B23Q 3/157

Claims (2)

(57) [Claims] 1. A tool changer for a machine tool for mutually exchanging tools indexed to a tool change position, comprising: a housing provided on a fixed portion of the machine tool; and a housing rotatable about a vertical axis. A supported sleeve, a drive shaft supported by the housing and rotated by rotary drive means, an arm shaft engaged with the sleeve and movable relative to the sleeve in a vertical axis direction, and fixed to the drive shaft. Arm shaft rotating means for converting the rotation of the drive shaft around the axis to the rotation of the arm shaft around a vertical axis, the arm cam rotating means comprising a gear cam portion and a first cam follower fixed to the sleeve and engaged with the gear cam portion. The drive shaft, comprising: a groove cam portion fixed to the drive shaft; a second cam follower engaging with the groove cam portion; and a shifter engaging with the arm shaft. Arm shaft reciprocating means for converting rotation about the axis of the arm shaft into reciprocal movement in the vertical axis direction of the arm shaft; and a pair of grippers for gripping the tool, and provided on the arm shaft and a vertical axis together with the arm shaft. A tool change arm that rotates around and reciprocates in the vertical axis direction, and a pair of grooves provided between the tool change arm and the housing so as to be rotatable around the axis of the arm shaft and formed with a concave groove in the outer peripheral portion. When the bar member and the pair of grippers of the tool change arm grip and release the tool, they engage with a concave groove formed on the outer periphery of the bar member, and the tool change arm rotates around a vertical axis. Gripper lock means comprising: an engaging member that engages with the outer peripheral surface of the rod member when reciprocating in the vertical axis direction. Location. 2. The tool changer for a machine tool according to claim 1, further comprising elastic means for reducing a load on said rotary drive means between said housing and said tool change arm.