JP3321996B2 - Tool changer gripper 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 gripper device for an automatic tool changer of a machine tool, and more particularly, to a gripper at a tip end of a hollow exchange shaft supported slidably and pivotably in an axial direction. With the axial movement of the pull rod,
It relates to a mechanism for opening and closing.

[0002]

2. Description of the Related Art A gripper device of the type described above can be found, for example, in Japanese Patent Application Laid-Open No. 1-188246. According to this, the hollow exchange shaft is slidably and pivotably supported in the axial direction on the support body, and the gripper composed of a pair of gripping arms is attached to the exchange head provided at the lower end of the exchange shaft in opposite directions. A pull rod that is protruded, one end of which is supported at the upper end of the replacement arm, and is axially movable with a gap between the replacement shaft and the center hole of the replacement shaft is moved in the axial direction. When the gripping arm is opened and closed by the engagement of the fitting portion of the gripping arm base, one of the two grippers completely grips the tool and the other gripper does not grip the tool completely. By further retracting, the arm opening / closing member is slightly moved around the upper end of the replacement arm toward the gripper which does not completely grip the tool by the elasticity of the pull rod itself, thereby completely gripping the tool. Even grippers have not been realized floating structure which can be completely grip the tool.

[0003]

In the above prior art,
The floating structure of the arm opening / closing member is realized by utilizing the elasticity of the pull rod itself. Therefore, during long-term use, as a result of the repeated bending force being applied, the pull rod may be fatigued and may not be able to exhibit the initial grip function. It is an object of the present invention to provide a gripper structure of a tool changing device that can exhibit an initial grip function for a long time without causing such fatigue on a pull rod.

[0004]

In order to solve the above problems, in the present application, a hollow exchange shaft is supported on a support so as to be slidable and pivotable in the axial direction, and an exchange head provided at the tip of the exchange shaft. In a gripper device of a tool changing device, a gripper comprising a pair of gripping arms is projected in opposite directions to each other, and the gripping arm is opened and closed by an axial movement of a pull rod inserted through an exchange shaft. The guide rod is slidably guided in the axial direction.
An arm opening / closing member is attached so as to be tiltable in the linear direction via a support pin orthogonal to a straight line connecting the tool gripping centers of the two grippers, and a pull rod protruding portion projecting forward from the arm opening / closing member is axially slid to the exchange head. The arm opening / closing member is movably supported, and an operating pin is protruded from the arm opening / closing member toward each gripping arm base, and a gripping arm opening / closing cam groove for engaging with the operating pin is formed in each gripping arm base. The opening and closing cam groove is characterized in that it is set to have a shape that allows the gripping arm to open and close by the movement of the operating pin due to the axial movement of the pull rod.

[0005]

According to the gripper device of the present invention, when one gripper completely grips the tool and the other gripper does not grip the tool completely, the arm opening / closing member moves the support pin by the retraction of the pull rod. The tool is tilted toward the center of the gripper that does not securely grip the tool, so that the operating pin moves further along the grip arm opening / closing cam groove, and the gripper that does not grip the tool securely grips the tool. . The pull rod is supported by the replacement head and the replacement shaft before and after the arm opening / closing member, and therefore does not bend as in the related art.

[0006]

1, a vertical guide rail 2 is attached to a front surface of a moving column 1 which is moved only left and right on a bed (not shown), and a saddle 3 is guided up and down by the guide rail 2. ing. The saddle 3 has a spindle head 4
Are guided by a guide rail 5 in a front-rear direction (a direction perpendicular to the paper surface of FIG. 1) so as to be movable back and forth. The moving column 1, the saddle 3, and the spindle head 4 are each moved left and right, up and down, and back and forth by a feed screw mechanism connected to a feed motor (not shown). Spindle head 4
, A main shaft 6 is rotatably supported, and is rotationally driven by a main shaft motor (not shown).

A gate-shaped support frame 9 is further raised from the bed across the movable column 1. A tool changing device 10 is provided on the support frame 9. Tool changer 10
Divides a number of tool holders T1 provided with tools into indexing bodies 11a.
In a state in which the tool magazine 11 is held in an annular shape and detachably in the tool axis direction, and one of them is indexed to a predetermined preparation position P, and the saddle 3 is at the rising end on the movable column 1, The tool holder T2 at the tip of the main spindle 6 when the main spindle 6 is located immediately below the exchange position P and the main spindle 6 is located at the tool exchange position Q of the most retreated main spindle 6; It consists of a gripper device 20 for exchanging with the tool holder T1.

Next, the gripper device 20 according to the present application will be described. A support 21 is integrally fixed to the support frame 9, and a hollow exchange shaft 22 is supported on the support 21 so as to be axially movable and pivotable. The exchange shaft 22 is linked to a not-shown front-rear movement device and a turning drive device, and has a retracted end that holds the preparation position P and the tool holders T1 and T2 at the tool exchange position Q by grippers 25A and 25B described later at the time of tool exchange. From the position (the state shown in FIG. 2), each of the tool holders T1 and T2 is axially advanced to the forward end position where the tool holders T1 and T2 are withdrawn from the indexing body 11a and the main shaft 6, and is turned 180 degrees around the axis at the forward end position. Then, the tool is retracted in the axial direction to the retracted end position, the positions of the tool holders T1 and T2 are exchanged, and tool exchange is performed between the spindle 6 and the tool magazine 11.

An exchange head 23 is fixed to the tip of the exchange shaft 22. The exchange head 23 has the accommodation space 2
3A, grippers 25A, 25B each comprising a pair of gripping arms 24a, 24b on both sides of the pivot axis CL.
However, they protrude in opposite directions. Each gripping arm 24a, 2
4b, the base portion 24c is supported by the exchange head 23 so as to be rotatable around an axis parallel to the swivel axis CL.
4c is formed by projecting the turning shaft portion 24d to the rear of the exchange head 23, and the arm portion 24e (24f) is integrally fixed to the turning shaft portion 24d.
b can be opened and closed. On the other hand, a pull rod 26 is slidably guided in the hollow hole 22a of the exchange shaft 22 so as to be movable in the axial direction, and is constantly urged rearward in the axial direction by a clamp spring (not shown). An arm opening / closing member 27 is loosely fitted to the pull rod 26 at a distal end located in the accommodation space 23A in the exchange head 23 with a gap between the pull rod 26 and the pivot axis CL and the grippers 25A and 25A.
A support pin 28 orthogonal to a straight line L2 connecting the gripping centers C1 and C2 of B is attached so as to be tiltable in the straight line L2 direction. A protruding portion 26 a of the pull rod 26 that protrudes further forward than the arm opening / closing member 27 is guided and supported by a front portion of the exchange head 23 so as to be slidable in the axial direction.

From the arm opening / closing member 27, the grip arm 24
The operating pins 30 project from the pivot axis L1 radially toward the bases 24c of the a and 24b. Each base 24c
The grip arm opening / closing cam groove 3 engaged with the operating pin 30
1 is formed. The grip arm opening / closing cam groove 31 has a shape shown in FIG. 4, and when the pull rod 26 is pulled backward by the clamp spring and the arm opening / closing member 27 is at the clamp position S1 shown in FIG. Is closed (the operating pin 30 with respect to the grip arm opening / closing cam groove 31 at this time is closed).
Is a position A), the pull rod 26 is pushed forward by an unclamping mechanism (not shown) at its axial rear end,
When the arm opening / closing member 27 is located at the unclamping position S2 shown in FIG. 2, the gripping arms 24a and 24b are opened (at this time, the position of the operating pin 30 with respect to the gripping arm opening / closing cam groove 31 is the position B, and the gripping at this time. The opening angle between the arms 24a and 24b is
When the gripper is at the above-described retracted end position, even if the tool magazine 11 pivots and indexes the tool holder, the angle is such that the tool holder and the gripping arms 24a and 24b do not interfere with each other. I have.

[0011] The horizontal movement of the movable column 1, the raising and lowering of the saddle 3,
In addition, the spindle 6 performs predetermined processing on the workpiece on the front side of the spindle by the forward and backward movement of the spindle head 4. When predetermined processing by the tool holder T2 mounted on the main shaft 6 is completed,
The main spindle 6 is positioned at the tool change position Q. By this time, the tool magazine 11 has indexed the tool holder T1 having the tool to be used for the next machining to the preparation position P. Main shaft 6
Is at the tool change position Q, the change head 23 is at the retreat end position, the pull rod 26 has the arm opening / closing member 27 at the forward end position S2 by the unclamping mechanism, and the gripping arms 24a and 24b are in the open state. ing. Next, the forward pushing of the pull rod 26 by the unclamping mechanism is released, and the arm opening / closing member 27 retreats from the forward end position S2 toward the retreat end position S1 by the spring force of the clamp spring. As a result, the operating pin 30 of the arm opening / closing member 27 moves from the position B to the position A in the gripping arm opening / closing cam groove 31, and the gripping arm 24
a, 24b are closed, and the tool holders T1, T2 are gripped.

At this time, one gripper, for example, gripper 25A firmly grips the corresponding tool holder T1 first, and the other gripper 25B grips the corresponding tool holder 2 first.
When the grip 5B is not firmly gripped, the pull rod 26 receives the retraction force of the clamp spring in the retreating direction, and the arm opening / closing member 27 is tilted around the support pin 28. Does not prevent the pull rod 26 from retreating even if the corresponding tool holder T1 is firmly gripped. Even after the gripper 25A holds the corresponding tool holder T1, the pull rod 26 retreats while tilting the arm opening / closing member 27. , Whereby the other gripper 25B is further closed, and the corresponding tool holder T
Hold 2 firmly. Thus, both grippers 25
When A and 25B hold the corresponding tool holders T1 and T2, respectively, the exchange shaft 22 advances to the forward end position, and removes the tool holders T1 and T2 from the tool magazine 11 and the main shaft 6. Next, the exchange shaft 22 is turned by 180 degrees, the positions of the tool holders T1 and T2 are switched, the exchange shaft 22 is retracted to the retracted end position, and the tool T1 is mounted on the main shaft 6 and the tool T2 is mounted on the tool magazine 11.

As described above, in the present application, the tool holders T1, T
When the gripper 2 is held, when one gripper firmly grips the tool holder prior to the other gripper, the arm opening / closing member 27 is tilted around the support pin 28 as described above, so that the other gripper Is a floating structure that is further closed, compared to the floating structure based on the elastic deformation of the pull rod itself as before.
The pull rod can be prevented from being fatigued, and the initial grip function can be maintained for a long time.

[0014]

As described above, according to the gripper apparatus of the present invention, a hollow exchange shaft is slidably and pivotably supported in the axial direction on the support, and the exchange head provided at the tip of the exchange shaft is provided. In a gripper mechanism of a tool changing device, a gripper comprising a pair of gripping arms is projected in opposite directions to each other, and the gripping arm is opened and closed by an axial movement of a pull rod inserted through the replacement shaft. The guide rod is slidably guided in the axial direction.
An arm opening / closing member is attached so as to be tiltable in the linear direction via a support pin orthogonal to a straight line connecting the tool gripping centers of the two grippers, and a pull rod projecting portion projecting forward from the arm opening / closing member is axially attached to the exchange head. It is slidably supported, and an operating pin protrudes from the arm opening / closing member toward the base of each gripping arm.
A grip arm opening / closing cam groove that engages with the operating pin is formed in each grip arm base, and the grip arm opening / closing cam groove is set to a shape that opens and closes the grip arm by movement of the operating pin due to axial movement of the pull rod. When holding the tool holder,
When one gripper grips the tool holder firmly prior to the other gripper, the arm opening / closing member is tilted around the support pin, thereby realizing a floating function that further closes the other gripper. The bending force is not applied to the pull rod itself, and the pull rod can be prevented from being fatigued by such bending force.
The initial grip function can be exhibited.

[Brief description of the drawings]

FIG. 1 is a front view of a machine tool equipped with a gripper of the present invention.

FIG. 2 is a longitudinal sectional view of the gripper of the present invention.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is a diagram showing a grip arm opening / closing cam groove.

[Explanation of symbols]

21 support, 22 exchange shaft, 23 exchange head,
24a, 24b gripping arm, 24c base, 25A,
25B gripper, 26 pull rod, 26a projection, 27 arm opening / closing member, 28 support pin, 30 operating pin, 31 gripping arm opening / closing cam groove

Claims (1)

(57) [Claims] 1. A hollow exchange shaft is slidably and pivotably supported in an axial direction on a support, and a gripper comprising a pair of gripping arms is mounted on an exchange head provided at the end of the exchange shaft in opposite directions. In a gripper device of a tool changing device, which protrudes and opens and closes a gripping arm by an axial movement of a pull rod inserted through an exchange shaft, the pull rod is guided and supported slidably in the axial direction on the exchange shaft. The arm opening / closing member is attached to the portion via a support pin orthogonal to the straight line connecting the tool gripping centers of the two grippers so that the arm opening / closing member can be tilted in the linear direction. Slidably supported in the axial direction,
The arm opening / closing member has an operating pin protruding toward each gripping arm base, and each gripping arm base has a gripping arm opening / closing cam groove that engages with the operating pin. A gripper device for a tool changing device, wherein the gripper device is configured to open and close a gripping arm by movement of an operating pin due to axial movement of a pull rod.