JP2583843Y2 - Work holding device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work holding device, and more particularly to an improvement of a work holding device for transferring a work to and from a main shaft of a machine tool or the like.

[0002]

2. Description of the Related Art In recent years, at various machining sites where automation has been attempted, a number of loaders and unloaders for automatically attaching and removing a work to and from a machine tool have been introduced. Among them, a machine tool such as an NC lathe, which has a spindle and performs a predetermined machining with a tool or the like while rotating a workpiece attached to a chuck of the spindle, corresponds to each individual workpiece. A work gripping device having a gripping mechanism is disposed, for example, at the tip of the arm member, and after gripping the work at the loading position,
At the main spindle side, the workpiece is released and mounted at the attachment / detachment position, and when machining is completed, the work is gripped again, removed from the spindle, and released automatically at the unloading position. It has become. The work gripping device generally has a plurality of gripping claws driven to approach and separate from a gripping center, and grips a cylindrical outer circumferential surface or a cylindrical inner circumferential surface of a work with the gripping claws. Further, (a) a main body member and (b) a plurality of gripping claws which are disposed on the main body member so as to be able to approach and separate from the gripping center, respectively, and which are driven closer to grip a cylindrical workpiece from the outer peripheral side. (C) a pressing member that is disposed on the main body member so as to be movable in the center line direction of the gripping center, and is always urged forward by the urging means and held at the front moving end. When gripping a workpiece, the pressing member is pressed by the workpiece against the urging force of the urging means while being gripped by the gripping claws, and when the workpiece is delivered to a main shaft of a machine tool or the like. There has also been proposed a configuration in which the gripping state is released at a position where the gripping center is concentric with the main axis, whereby the workpiece is pressed against the main axis in accordance with the urging force of the urging means. The work gripping device described in Japanese Utility Model Application No. 3-111156 filed earlier by the present applicant is one example.

[0003]

However, in such a conventional work gripping device, during the delivery of the work, that is, from the start of the removal of the work after the processing to the completion of the mounting of the work before the processing, the work of the machine tool is not performed. The spindle had to be completely stopped. For this reason, it is necessary to calculate not only the actual processing time and the delivery time of the work holding device, but also the cycle time of the process including the time required for stopping and starting the spindle,
A large amount of power is consumed for stopping and starting the spindle every cycle, which is not always efficient.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a work holding device capable of mounting and removing a work without stopping a spindle. .

[0005]

In order to achieve the above object, a first aspect of the present invention is to provide a plurality of gripping claws which are driven to approach and separate from a gripping center, and the gripping claws move a workpiece. While holding the cylindrical outer peripheral surface or the cylindrical inner peripheral surface,
In a work gripping device that transfers the work between the gripping center and a main axis of a machine tool or the like at a position concentric with the main axis, the tip ends of the plurality of gripping claws may be arranged around an axis parallel to the gripping center. A rotatable gripping roller is provided, and the work is gripped via the gripping roller.

[0006]

[Operation and effect of the first invention] In such a work gripping device, the work is gripped via the gripping rollers provided at the tips of the gripping claws.
Even in the gripping state, the work is allowed to rotate around the axis. Therefore, it is possible to attach a workpiece to the spindle or receive a workpiece from the spindle while the spindle of the machine tool or the like is rotationally driven, and it is not necessary to stop the spindle one by one for mounting and removing the workpiece. As a result, the cycle time is shortened, and the power consumption due to the start / stop of the spindle is reduced.

[0007] The loading and unloading of the work with respect to the spindle is performed by 1
Although it can be performed by a single work holding device, loading and unloading can be performed by separate work holding devices. In that case, the present invention does not necessarily need to be applied to both work gripping devices.For example, while loading a work using the work gripping device according to the second invention, the work is also performed using the work gripping device according to the present invention. You may carry it out.

[0008]

In order to achieve the above object, a second aspect of the present invention is to provide (a) a main body member and (b) a main body member which can be moved toward and away from a gripping center. And a plurality of gripping claws for gripping the cylindrical workpiece from the outer peripheral side by being driven close to the outer peripheral side; and (c) being disposed on the main body member so as to be movable in a center line direction of the gripping center. A pressing member urged forward by the urging means toward the front side of the main body member and held at a moving end on the front side, and when the work is gripped, the pressing member applies the urging means by the work. While the workpiece is gripped by the gripping claws while being pressed against the force, when the work is transferred to a main shaft of a machine tool or the like, the gripping center grips the gripping claw at a position concentric with the main shaft. By releasing the state In a work gripping device that presses the work against its main shaft in accordance with the urging force of the urging means, (d) a contact shaft in which an end surface of the work is brought into contact with a fitting shaft portion fittable in a cylinder of the work. A core metal member integrally provided with a portion is provided at the gripping center portion of the pressing member so as to be rotatable around an axis and immovable in the axial direction. This second device is a utility model registration request.
This corresponds to the invention described in claim 1 of the scope.

[0009]

In such a work gripping device, the cylindrical work is fitted to the fitting shaft of the metal core member and the end face is brought into contact with the contact portion. In a state where the pressing member is pushed in through the core metal member against the urging force of the urging means, the pressing member is gripped from the outer peripheral side by the plurality of gripping claws. When the workpiece is transferred to a spindle of a machine tool or the like, the gripping state of the gripping claw is released at a position where the gripping center is concentric with the spindle, and the workpiece is attached via a metal core member. The main shaft is pressed by the urging force of the urging means. In this case, since the work is fitted to the fitting shaft portion of the cored bar member, the work is favorably held concentrically with the gripping center of the gripping device and further with the axis of the main shaft, and the work is pressed against the main shaft. Since the core metal member is disposed on the pressing member so as to be rotatable around the holding center, the work is allowed to rotate together with the main shaft when the main shaft is driven to rotate. Therefore, there is no need to stop the spindle one by one when attaching a workpiece to the spindle,
For example, if the work is carried out from the main spindle by using the work gripping device of the first invention, it becomes possible to perform attachment and detachment of the work while rotating the main spindle. The cycle time is reduced, and the power consumption due to starting and stopping of the spindle is reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 2 is a perspective view showing an NC lathe provided with a carry-in gripper 10 and a carry-out gripper 12 as a work holding device according to one embodiment of the present invention. A pair of grippers 10 and 12 are provided with an automatic loader / unloader device (hereinafter, referred to as a “loader / unloader device”) disposed on the front side of the spindle 14.
A pair of carry-in arms 18
And are attached to the distal end of the carry-out side arm 20, respectively. The loader device 16 includes a rotating shaft 22 to which the loading arm 18 and the unloading arm 20 are integrally fixed.
The motor-driven drive device 24 rotates around an axis parallel to the axis of the main shaft portion 14 and moves in the axial direction in a forward direction approaching the main shaft portion 14 and in a reverse direction opposite thereto. I have.

The operation of the loader device 16 will be briefly described. In FIG. 2, the work 26 carried into the carry-in chute 28 on the further front side of the loader device 16 is lifted to a predetermined height position by the lifter 30 and is carried in. The gripper 10 is moved forward and gripped to be gripped. And
The swivel shaft 22 is turned so that the carry-in arm 18 rotates toward the main shaft portion 14, and the carry-in gripper 10 is positioned concentrically with the main shaft portion 14. In this state, the carry-in gripper 10 approaches the main shaft portion 14. As described above, the turning shaft 22 is advanced, and the carry-in gripper 10 is released to drive the work 26 to the main shaft portion 14 side. Further, after the processing is completed, the unloading gripper 12 is concentric with the main shaft portion 14 by rotating the turning shaft 22 so that the unloading-side arm 20 rotates toward the main shaft portion 14,
The carry-out gripper 12 is approached and gripped and driven, and the processed work 26 is gripped by the carry-out gripper 12 and removed from the main shaft portion 14. Then, the unloading arm 20 is rotated to the receiving position of the unloading chute 32 disposed diagonally above the main shaft portion 14, and the unloading gripper 12 is driven to release to release the work 26 and discharge it. .

FIG. 3 shows a cylindrical work 26 at the center of gripping.
FIG. 1 is a cross-sectional view parallel to the axial direction, in which a cutting position is partially changed and a part of the gripper is omitted while FIG. The gripper main body 36 is integrally attached to the leading end of the carry-in side arm 18, and is connected to the carry-in side arm 18 via the intermediate member 38 shown in FIG. A second member 36b connected to the side opposite to the loading side arm 18 with respect to 36a, a third member 36c fixed to the second member 36b so as to substantially cover the front opening of the second member 36b, and The fourth member 36d is fixed to the front side of the third member 36c. Between the second member 36b and the third member 36c, gripping center line L, i.e. with the shaft 40 is fixed to the vertical center line on L to the plane passing through the gripping center O _G in FIG. 3, the The grip center line L is provided on the front side of the three members 36c.
In the plane perpendicular to the plane, three claw member holders 42 are provided in three directions divided into three at intervals of 120 ° about the grip center line L. In this embodiment, the gripper main body 36 corresponds to a main body member.

As shown in FIG. 4 which is a cross-sectional view taken along the line IV-IV in FIG. 1, the claw member holder 42
Member 36c integrally fixed to the sliding radial linearly move by fitting into a T-shaped guide groove 44 which is formed by hand, that is, the gripping center O _G each holder It is held so that it can approach and separate.
On the front side of the claw member holder 42, the gripping roller 4
6 are rotatably held around the pin 34 parallel to the grip center line L. The grip claws 48 are integrally fixed by bolting, and the three grip claws 48 work together to approach from the outer side to the inner side. When driven, the three gripping rollers 46
Are engaged with the cylindrical outer peripheral surface 50 of the work 26, respectively, and the work 26 is gripped in a state where rotation about the grip center line L is permitted. The gripping roller 46
The relative movement in the axial direction is prevented by the large diameter head of the pin 34. The claw member holder 42 is provided with a gripper claw 48.
On the back side opposite to the above, there is provided an engagement protrusion 52 projecting in the rear direction parallel to the grip center line L, that is, rightward in FIGS. 1 and 4. On the other hand, a cam groove 58 is formed on the front side of the cam member 54 rotatably disposed around the shaft 40, that is, on the left surface of the flange portion 56 in FIGS. 1 and 4. The above-mentioned engaging projection 52 is engaged.

As is apparent from FIG. 5, which shows a part of a cross section taken along the line VV in FIG. 1, the cam groove 58 is uniformly formed in the circumferential direction corresponding to the engaging projection 52 of the claw member holder 42. It is provided in a spiral shape at three spaced apart locations, and each of the cam grooves 58 is accurately formed by shifting the same spiral shape by a phase of 120 °. Therefore, the engagement projections 52 respectively engaged with the three cam grooves 58 are kept at the same radial position, and the cam members 5
When the shaft 4 is rotated counterclockwise of the shaft 40 in FIG. 5, the engagement protrusion 52 is pushed out to the outer peripheral side while sliding on the inner wall surface 60a of the cam groove 58, and the claw member is inserted through the engagement protrusion 52. While the holder 42 is moved to the outer peripheral side, the cam member 54 is rotated clockwise, whereby the engaging protrusion 52 is pulled in to the inner peripheral side while slidingly contacting the wall surface 60 b outside the cam groove 58, and the claw member The holder 42 is moved to the inner peripheral side. A bush 62 for smooth rotation is provided between the cam member 54 and the shaft 40.
Is inserted.

FIG. 6 is a cross-sectional view of the loading gripper 10 as viewed from the rear side. On the rear side of the cam groove 58 in the flange portion 56 of the cam member 54, a contact surface 64 parallel to the axis of the shaft 40 is provided. A pair of engaging portions 68 and 70 each having a hub portion 72 are provided integrally with the hub portion 72. The contact surfaces 64 and 66 are formed in a partial cylindrical curved surface having a predetermined curvature, and
8, 70 are symmetrically arranged in FIG. A pair of single-acting cylinders for rotating and driving the cam member 54 are provided in the opposite direction of the respective contact surfaces 64 and 66 of the pair of engagement portions 68 and 70, that is, above them in FIG. 74 and 76 are gripper bodies 3
6 and are disposed integrally.

The single-acting cylinder 74 on the side of the engaging portion 68 has an axis substantially parallel to the rotation locus of the engaging portion 68 when the cam member 54 rotates in a plane perpendicular to the axis of the shaft 40. Cylindrical member 80 having a cylinder bore 78 formed therein
And a piston 82 that is disposed in the cylinder bore 78 so as to be able to linearly reciprocate, and one end of which is brought into contact with the engagement portion 68. Further, the single-acting cylinder 76 on the engagement portion 70 side
A bottomed cylindrical member 86 formed with a cylinder bore 84 having an axis substantially parallel to the rotation locus of the engagement portion 70 when the cam member 54 rotates in a plane perpendicular to the axis of the shaft 40. And a piston 88 which is disposed in the cylinder bore 84 so as to be able to linearly reciprocate, and one end of which is brought into contact with the engaging portion 70. On the other hand, the oil passage 9 in the first member 36a
0 and 92, as shown in FIG.
Hydraulic oil is guided through the inside of each of the pipes 8, and hydraulic oil adjusted to a predetermined pressure by a hydraulic circuit (not shown) is selectively supplied by switching a switching valve. As a result, hydraulic oil is supplied through the oil passages 90 and 92 to the other end sides of the pistons 82 and 88, that is, the upper ends of the cylinder bores 78 and 84 in FIG.

As can be seen from FIGS. 4 and 1, the pistons 82 and 88 are located on the one end side, that is, on the lower side in FIG. 6, on the side adjacent to the flange portion 56 of the cam member 54. Is part of its flange 5
6 are respectively cut out with a gap therefrom, and slits 94 and 96 are respectively provided in a part of the outer peripheral surface along the axial direction, and the slits 94 and 96 are formed in the slits 94 and 96 from the outer peripheral side. The rotation of the pistons 82 and 88 around the axis is prevented by the engagement of the detent pins 100 formed at the tips of the bolts 98, respectively.

When the hydraulic oil is supplied to the single-acting cylinder 76, the piston 88 is moved in the cylinder bore 84 in a direction protruding toward one end thereof, that is, downward in FIG. Engaging part 7
At the same time, the cam member 54 is rotated counterclockwise to the shaft 40 by pushing 0, and at the same time, the piston 82 in contact with the engaging portion 68 on the single-acting cylinder 74 side is retracted and pushed back into the cylinder bore 78. Thereby, the claw member holder 42 is driven in the inner circumferential direction, the grip claws 48 are made to approach each other, and the work 26 is gripped from the outer circumferential side via the grip rollers 46. On the other hand, when the hydraulic oil is supplied to the single-acting cylinder 74 side, the piston 82 is moved in the cylinder bore 78 in a direction to protrude toward one end thereof, and the piston 8
2 pushes the engaging portion 68 of the cam member 54 and the cam member 5
4 is rotated clockwise of the shaft 40, and at the same time, the piston 88, which is in contact with the engaging portion 70 on the single-acting cylinder 76 side, is retracted to move the other end side within the cylinder bore 84, that is, the upward movement in FIG. Push back to the end. As a result, the claw member holder 42 is driven in the outer peripheral direction, the grip claws 48 are separated from each other, and the work 26 is released. Therefore, the above operation is alternately repeated by switching the operation state of the hydraulic oil pressure.

Returning to FIG. 1, a pressing plate 102 is provided on the further front side of the fourth member 36d. The pressing plate 102 has a disk shape and includes three notches 104 each having a predetermined gap from a radial movement space of the three gripping claws 48 as shown in FIG. ing. The pressing plate 102 has a fourth member 36d at three locations equally spaced in the circumferential direction between the notches 104.
And three guide pins 106 protruding from the third member 36c in parallel with the grip center line L, respectively, and are engaged via a bush 108 to maintain a constant posture perpendicular to the grip center line L. It is supported so that it can move forward and backward. Further, between the pressing plate 102 and the second member 36b, pressing pins 111 urged by a compression coil spring 110 are disposed at three positions further to the outer periphery from the position of the guide pin 106, and are always provided. The pressing plate 102 is urged forward of the gripper body 36.

[0020] The gripping center O _G portion of the pressing plate 102, the metal core member 114 via a bearing 112 gripping the center line L
It is provided so as to be rotatable around and incapable of relative movement in the axial direction. The cored metal member 114 having a stepped cylindrical shape is
A relatively small-diameter fitting shaft 116 that can be engaged in the cylinder of the work 26 is provided at the distal end side.
16 and one end face 118 of the workpiece 26.
Is provided with an abutting portion 120 to which the abutment is made to abut. In addition, an insertion hole 122 is formed in the shaft portion of the core member 114 so as to have a stepped portion so that a relatively large diameter is formed from the distal end opening of the fitting shaft portion 116 to a predetermined depth. And a stopper pin 12 extending forward from the shaft 40 and provided on the grip center line L in the insertion hole 122.
When the large-diameter head of the stopper pin 124 and the inner step of the insertion hole 122 are in contact with each other, the compression spring 4 is urged forward by the urging force of the compression coil spring 110. The front moving end of the pressing plate 102 is defined. The pressing plate 102 corresponds to a pressing member, and the compression coil spring 110 corresponds to a biasing unit.

FIG. 1 shows that the carrying-in side arm 18 is
The loading gripper 10 is moved toward the work 26 by the gripping claw 48 in a state in which the carry-in gripper 10 is brought close to the work 26 to a position where the pressing plate 102 is pushed by a predetermined amount against the urging force of the compression coil spring 110. In this state, the urging force of the compression coil spring 110 for separating the pressing plate 102 from the gripper body 36 is applied to the gripping roller 46 and the gripping claw 4.
8. The gripper body 36 itself is supported via the claw member holder 42. However, when the workpiece 26 is not gripped, the step of the insertion hole 122 abuts on the large-diameter head of the stopper pin 124 to prevent further separation between the pressing plate 102 and the gripper body 36. .

For this reason, when gripping the work 26,
The work 26 is formed by the fitting shaft 116 of the metal core member 114.
Are positioned substantially concentrically with the gripping center line L, and the pressing plate 102
Is pressed by a predetermined amount against the urging force of the compression coil spring 110, the gripping is performed by the gripping claw 48 that is driven close by the gripping roller 46, and when the workpiece 26 is transferred to the main shaft portion 14. When the gripping claw 48 is released in a state where the work 26 is positioned substantially concentric with the axis of the main shaft portion 14, the core metal member 114 causes the work 26 to engage the fitting shaft portion by the urging force of the compression coil spring 110. 1
An operation of pushing forward while positioning by 16 is performed.
As a result, the work 26 is pressed by the reference metal 142 while being held concentrically with the main shaft 140 of the main shaft portion 14 as shown in FIG.
The carry-in gripper 10 corresponds to both the work holding device of the first invention and the work holding device of the second invention.

On the other hand, like the carry-in gripper 10, the carry-out gripper 12 whose front view is shown in FIG. 7 has a gripper body 130 in which first to fourth members 130a, 130b, 13 are provided.
0c (not shown) and 130d, and the gripping center O _G in FIG.
6 comprising a shaft (not shown) pivotally supported on a gripping center line perpendicular to the plane of the drawing and a cam member (not shown) rotationally driven by a pair of single-acting cylinders (not shown).
The same drive unit is built in. A pair of claw member holders 132 and 134, which are the same members as the claw member holder 42, are provided on the front side of the gripper body 130.
But gripping center O _G are respectively movably disposed in the radial direction and located opposite each other with respect, the two spiral cam grooves provided on the engaging projection and the cam member (not shown) The engagement drives the actuator toward and away from the gripping center.

A gripping claw 136 holding the two gripping rollers 46 at its distal end so as to be rotatable about an axis parallel to the gripping center line is integrally fixed to one claw member holder 132 by bolt fastening. On the other hand, to the other claw member holder 134, a gripping claw 138, which similarly holds one gripping roller 46 at the tip, is integrally fixed by bolting. Two gripping rollers 46 on the gripping claw 136 side
Is a radial position equivalent from the gripping center O _G is and pivotally supported by the center from equal distances by the offset position of the claw member holder 132. For this reason, the outer peripheral surface 50 of the work 26 is formed at three places spaced unequally in the circumferential direction by the pair of gripping claws 136 and 138 being driven to approach from the outer peripheral side to the inner peripheral side in conjunction with each other. The three grip rollers 46 are gripped in a state where rotation about the grip center line is allowed.

Also in the case of the unloading gripper 12, by switching the supply state of the hydraulic oil guided through the oil passage in the unloading arm 20, the claw member holders 132, 1 are switched.
The gripping claws 136 and 138 which are driven in the inner circumferential direction and approach each other grip the work 26, and the gripping claws 136 and 138 in which the claw member holders 132 and 134 are driven in the outer circumferential direction and are separated from each other. 26 is released. The unloading gripper 12 corresponds to the work holding device of the first invention.

Next, the operation of the carry-in gripper 10 and the carry-out gripper 12 configured as described above will be described.

First, when the carry-in gripper 10 grips the work 26 on the carry-in chute 28 side, the operating oil on the oil passage 90 side is supplied to the single-acting cylinder 74, and the cam member 54 rotates clockwise to the shaft 40 in FIG. By being rotated, each claw member holder 42 is previously positioned on the outer peripheral side as shown by a dashed line in FIG. In this state, the carry-in side arm 18 is driven to the receiving position of the work 26, and the carry-in gripper 10 is approached in a posture where the axis of the work 26 and the grip center line L are aligned, and the rear (front of the apparatus).
The fitting shaft portion 116 of the cored bar member 114 fits inside the workpiece 26 and the abutting portion 120 abuts on the end surface 118 of the workpiece 26 in a state where the movement of the cored bar member 114 is stopped. Then, the pressing plate 102 is pushed in a predetermined amount against the urging force of the compression coil spring 110. And
By switching the switching valve of the hydraulic circuit, the oil passage 9 is switched.
When the hydraulic oil on the second side is supplied to the single-acting cylinder 76, the cam member 54 is rotated counterclockwise of the shaft 40 in FIG. 6, and the claw member holders 42 and the holding claws 48 are brought closer to each other. The workpiece 26 is gripped via the gripping rollers 46.

Next, when the carry-in gripper 10 transfers the workpiece 26 to the main shaft 140, the carry-in side arm 18 is positioned so that the axis of the main shaft 140 and the gripping center line L of the carry-in gripper 10 coincide. It is moved to the delivery position on the spindle 14 side. The delivery position is determined in consideration of a positioning accuracy error of the loader device 16, a dimensional error of the work 26, and the like.
Front end surface 126 of workpiece 26 and reference metal 142 of spindle 140
This is a position having a slight gap between them. Then, the supply state of the hydraulic oil is switched, the claw member holder 42 is separated, and the holding state by the holding claw 48 is released, so that the work 26 is biased by the compression coil spring 110 via the cored bar member 114. 8, the end surface 12 is pushed onto the reference metal 142 as shown in FIG.
6 is brought into contact.

At this time, since the work 26 is fitted to the fitting shaft 116 of the metal core member 114, the carry-in gripper 1
The core metal member 114, which is held substantially concentrically with the gripping center line L and the axis of the main shaft 140 and presses the end surface 118 of the work 26 with the contact portion 120,
The work 26 can be delivered while the main shaft 140 is being rotated, since the work 26 is rotatably disposed on the pressing plate 102. That is, the end surface 126 of the work 26
When the workpiece 26 comes into contact with the reference metal 142 and a rotational force is applied to the workpiece 26, the workpiece 26 starts to rotate together with the metal core member 114 and is synchronized with the rotation of the main shaft 140. After that, the work 26 is gripped by the chuck 144 of the main shaft 140, and the carry-in gripper 10 is moved to a retreat position separated from the main shaft portion 14. Since the gripping claw 48 grips the work 26 via the gripping roller 46, the gripping state is released, the work 26 is pushed out, and the gripping roller 46 starts rotating when it comes into contact with the reference metal 142.
Is still in contact with the work 26,
The rotation of 6 prevents the work 26 from being damaged. Further, the end face 1 is held while the work 26 is being gripped.
The loading gripper 1 reaches a position at which 26 comes into contact with the reference money 142.
Even when 0 is advanced, the work 26 is favorably rotated in synchronization with the rotation of the main shaft 140.

On the other hand, when the work 26 which has been processed is to be pulled out from the spindle 140 by the unloading gripper 12, the unloading arm 20 is driven and the unloading gripper 12 is driven by the unloading spindle 14.
It is positioned so that the axis of zero and the grip center line coincide with each other, and is advanced to a predetermined receiving position on the main shaft portion 14 side. This receiving position is a position where the gripping claws 136 and 138 can grip the work 26 without interfering with the main shaft portion 14, and the claw member holder 42 and the gripping claws 136 and 138 are brought closer by switching the hydraulic circuit. Thereby, the work 26 is gripped via the gripping rollers 46. Also in this case, the work 2 around the grip center O _G
6, the work 26 can be received while the main shaft 140 is rotated. Then, spindle 1
The gripping state of the chuck 144 on the 40 side is released, and the unloading arm 20 is driven to separate the unloading gripper 12 from the main shaft portion 14 and move to a predetermined release position corresponding to the unloading chute 32. The rotation of the work 26 released from the chuck 144 gradually decreases due to the rotational resistance of the gripping roller 46, and finally stops.

When the unloading gripper 12 releases the work 26 at the receiving port of the unloading chute 32, the shutter member 1 disposed above the unloading chute 32 is used.
46 is protruded downward by the air cylinder 148, and in a state where the position of the work 26 in the axial direction is positioned, the claw member holder 42 is driven to separate by switching the supply state of the hydraulic oil to separate the gripping claws 136, 138. FIG. 9 shows the state at this time.
Is in contact with the gripping roller 46 of the gripping claw 138, so that rolling is prevented. Then, unloading gripper 1
2 is retracted, so that the work 26 and the gripper 1
38 is released, and the work 26 is moved out of the unloading chute 3.
2. Rolled over and discharged.

As described above, the carry-in gripper 10 according to the present embodiment is
In the carry-out gripper 12, the gripping rollers 46 are rotatably provided on the gripping claws 48 and the gripping claws 136 and 138, and the workpiece 26 is gripped by the gripping rollers 46 in a state where the work 26 is allowed to rotate. In addition, since the metal core member 114 is disposed on the pressing plate 102 of the carry-in gripper 10 so as to be rotatable around the grip center line L, the work 26 is held between the main shaft 140 while the main shaft 140 is rotated. Can be delivered. Therefore, it is not necessary to stop the spindle 140 one by one for attaching and detaching the work 26 as in the related art, so that the cycle time is shortened and the power consumption due to the start / stop of the spindle 140 is reduced.

The core member 114 is provided with the work 2
6 is provided in the cylinder of FIG. 6, the gripping state by the gripping claws 48 is released at a position where the gripping center line L is concentric with the axis of the main shaft 140, and the work 26 is grippered. The main shaft 140 is pushed out of the main body 36.
When the workpiece 26 is pressed by the reference metal 142,
It is held concentrically with the axis of the shaft 40 to prevent poor rotation due to misalignment. Since the fitting shaft 116 is gripped while being fitted to the work 26, there is also an advantage that the work 26 is prevented from falling off during the transfer of the work 26, for example, when the arm is turned.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be implemented in other modes.

For example, the carry-in gripper 10 and the carry-out gripper 12 in the above-described embodiment are examples of the work gripping device for the work 26 whose cylindrical outer circumferential surface 50 is gripped from the outer circumferential side by the plurality of gripping rollers 46. Even in a workpiece gripping device configured for a workpiece whose inner peripheral surface is gripped from the inner peripheral side , a gripping roller is provided on a gripping claw.
The first invention, characterized in that it can be applied, can likewise be applied.

In the above-described embodiment, three gripping claws 48 are provided on the loading gripper 10 respectively.
6 are equally arranged at three positions at 120 ° intervals in the circumferential direction, and two gripping claws 13
In the case where the total of three gripping rollers 46 held by the grippers 46 and 138 are arranged at three uneven positions in the circumferential direction, the gripping claws 48 and the gripping claws 136 and 138 and the gripping rollers held by them are used. The number and arrangement position of the 46 can be changed as appropriate.

In the loading gripper 10 in the above-described embodiment, the gripping rollers 46 are provided on the gripping claws 48, respectively.
If the workpiece 26 is controlled so as not to come into contact with the reference metal 142 in the approaching state, it is not necessary to allow the rotation of the workpiece 26 in the gripping state on the loading gripper 10 side.
It is not always necessary to provide the gripping roller 46.

Further, the carry-in gripper 1 in the embodiment described above.
0 is provided with a cored metal member 114 having a fitting shaft portion 116, but the end face 126 of the work 26 is
When the gripping state is maintained until the end face 118 of the work 26 is brought into contact with the pressing plate 1,
02 may be simply arranged rotatably. Depending on the shape of the work, it is also possible to provide a cylindrical fitting portion fitted on the outer peripheral side.

In the above-described embodiment, the pressing plate 1
Although the compression coil spring 110 is used as the urging means for urging the 02 forward, the urging means may be constituted by another spring member such as a leaf spring or an urging device using air pressure or weight. good.

In the above-described embodiment, the stopper pin 12 provided in the insertion hole 122 of the cored member 114 is provided.
4, the front moving end of the pressing plate 102 is defined. In addition to this, the front end of the guide pin 106 has a large diameter and is configured to directly engage with the pressing plate 102. The moving end may be defined.

In the above-described embodiment, the carry-in gripper 10 and the carry-out gripper 12 are provided on the carry-in arm 18 and the carry-out arm 20 as work gripping devices dedicated to carry-in and carry-out, respectively. It is also possible to carry out the work 26 by using the gripper 12 or carry in the work 26 by using the carry-out gripper 12, and it is not always necessary to dispose a work holding device dedicated to carry-in and carry-out to a pair of arms. .

In the above-described embodiment, the gripping claws 48 and the gripping claws 136 and 138 are driven to approach and separate by switching the supply state of the hydraulic oil by the switching valve of the hydraulic circuit. Alternatively, the gripper body 36 and the gripper body 130 may be configured to include a drive unit that uses a pressure air, an electric motor, or the like as a drive source.

In the above-described embodiment, the mutual relationship between the gripping timing and the release timing of the carry-in gripper 10 and the carry-out gripper 12 is not described in detail. For example, the carry-in chute 28 and the carry-out chute 32, the carry-in arm 18 and unloading arm 20
By appropriately setting the positional relationship of the rotary shaft 22 with respect to the main shaft 140 and synchronizing the gripping timing and the release timing of the two grippers, the forward and backward movements of the rotary shaft 22 can be made common.

In the above embodiment, the carry-in gripper 10 and the carry-out gripper 12 provided at the leading end of the carry-in arm 18 and the carry-out arm 20 of the loader device 16 have been described. However, the turret head of the NC lathe has been described. The present invention can be similarly applied to other work gripping devices arranged in the above-described manner.

Although not specifically exemplified, the present invention can be embodied with various modifications and improvements based on the knowledge of those skilled in the art.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment for carrying in a work holding device according to an embodiment of the present invention.

2 is a perspective view showing a machine tool or the like provided with the carry-in work holding device of FIG. 1 and the carry-out work holding device of FIG. 7;

FIG. 3 is a front view of the work holding device of FIG. 1;

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a view showing a cross section taken along line VV in FIG. 1 with a part thereof omitted.

FIG. 6 is a cross-sectional view of the work holding device of FIG. 1 as viewed from the back side.

FIG. 7 is a work holding device according to another embodiment of the present invention;
It is a front view which shows one aspect for carrying out.

FIG. 8 is a side view showing an operation when a work is transferred to a main spindle by the work holding device of FIG. 1 and a part of which is omitted and a main part is cut away.

9 is a diagram illustrating an operation when the work is discharged from the machine tool of FIG. 2 by the work holding device of FIG. 7;

[Explanation of symbols]

 10: carry-in gripper (work holding device) 12: carry-out gripper (work holding device) 14: spindle 26: work 36: gripper body (main body member) 46: holding roller 48, 136, 138: holding claw 50: cylindrical outer peripheral surface 102: Pressing plate (pressing member) 110: Compression coil spring (biasing means) 114: Core member 116: Fitting shaft portion 118: End surface 120: Contact portion 140: Main shaft

Claims (1)

(57) [Scope of request for utility model registration] A main body member, a plurality of gripping claws disposed on the main body member so as to be able to approach and separate from a gripping center, and gripping a cylindrical work from an outer peripheral side by being driven to approach; A pressing member which is disposed on the main body member so as to be movable in a center line direction of a gripping center, and is always urged forward by the urging means and held at a front moving end, When gripping the workpiece, the pressing member is gripped by the gripping claw while being pressed by the workpiece against the urging force of the urging means, and the workpiece is transferred to a main shaft of a machine tool or the like. In a work gripping device, the gripping center is released at a position where the gripping center is concentric with the spindle, and the workpiece is pressed against the spindle according to the urging force of the urging means by releasing the gripping state of the gripping claw. Wa A core metal member integrally provided with a fitting shaft portion that can be fitted into the cylinder of the workpiece and a contact portion with which the end surface of the work is brought into contact is provided around the axis around the grip center portion of the pressing member. A work gripping device provided so as to be rotatable and immovable in an axial direction.