JP2570177Y2 - Robot hand - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to a robot which has a pair of upper and lower horizontal work gripping claws, is mounted on a machine spindle of a vertical machining center, and grips and moves a work or the like with the two claws. Regarding the hand.

[0002]

2. Description of the Related Art First, an entire automatic work exchanging system using the robot hand will be described with reference to FIG. The vertical spindle type machining center is provided with a vertical machine spindle 1 for tool mounting rotatably, and a work magazine 3 and an index table (or an inclined rotary table or the like) 5 are fixed on a machine table 2 of the machining center. The machining center is controlled by an N / C (numerical control) device, and the mechanical table 2 is operated to move back and forth and left and right. The work magazine 3 includes a rotating plate 8 rotatably supported, and the rotating plate 8 holds a plurality of work holders 6. Each work holder 6 has a tapered handle 9 and a detachable bolt 10, and an enlarged end of the bolt 10 is locked by a lock pin 11 of the work magazine 3. The lock pin 11 is urged toward the bolt by a spring 12. A work mounting jig 14 is fixed to each work holder 6, and a work W is fixed to the jig 14. At the center of the work holder 6, there is an annular V for holding by the robot hand T.
A flange 13 having a groove 15 is formed. The robot hand T has a handle 16 which is detachably mounted in the spindle 1.
And an annular V-groove (grip portion) 17 for an ATC (automatic tool change) device, which can be replaced with a tool in a tool magazine by a manipulator of the ATC device.

FIG. 7 shows a conventional robot hand in the above-mentioned automatic workpiece exchange system. A robot hand main body 51 has a pair of horizontal claws 52 and 53 at the top and bottom. , Each of which is rotatably supported by upper and lower support pins 54, 55 provided on the main body 51, and a biasing spring 56 is contracted between the rear ends, and the spring 56 closes to the closed position. By being urged and coming into contact with the upper and lower stopper pins 57, 58, the closed position is maintained. When gripping the work holder 6,
The claws 52 and 53 are pushed and expanded against the elastic force of the spring 56,
The work holder 6 is gripped as shown.

[0004]

However, when the upper and lower claws 52 and 53 are of a movable type which opens against the spring 56 as shown in FIG. 7, the work holder 6 is included. When the work becomes heavy, the lower claw 53 is opened by its weight. That is, the weight of the work including the work holder 6 is limited by the load of the spring 56,
It is not suitable for replacing heavy workpieces. In addition, in a shocking operation accompanied by a large acceleration or a high moving speed, a gripping state becomes unstable and a work or the like becomes unstable, so that the moving operation and the moving speed are greatly limited.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has a pair of upper and lower horizontal work gripping claws, and is provided on a machine spindle of a vertical machining center to vertically move a work or the like. In the robot hand which is gripped and moved by the claws, the lower claws are fixed to the robot hand body as fixed claws, and the upper claws are rotatable upward as movable claws so that the support pins 25 A retaining member urged to the closed position by a pawl biasing spring and biased upward by the retaining member biasing spring at the distal end of the lower fixed type pawl. It has.

[0006]

[0007]

[Function] The work is held in the work holder, the work holder is gripped by the robot hand, and the work is automatically exchanged between the work magazine and the index table, etc. Insert the work holder between the nails while pushing and expanding, and after insertion,
Due to the spring, the upper movable claw returns to the closed position side, and presses and holds the work holder 6. That is, the lower fixed claw supports the weight of the entire work including the work holder, and is pressed down by the upper movable claw to stabilize the gripping state.

When the tip of the lower fixed claw is provided with a retaining member which is biased and supported by a spring in an upwardly projecting manner, the upper movable claw and the retaining stopper are provided when the work holder is gripped. Insert against each spring force of the member. After gripping,
The lower fixed claw supports the weight of the work holder and the like, and the pressing action of the retaining member and the upper movable claw stabilizes the gripping state of the work holder and prevents the work holder from falling off.

[0009]

FIG. 1 is an enlarged side view of a robot hand T to which the invention of claim 1 of the present invention is applied. A handle portion 16 removably mounted in a spindle 1 is provided above a robot hand main body 21. And an annular V-groove (grip portion) 17 for an ATC (automatic tool change) device, and the manipulator of the ATC device allows the main shaft 1 to be replaced with a tool in a tool magazine.

The robot hand body 21 is provided with a pair of upper and lower lateral claws 22 and 23 in parallel, and the two claws 22 and 23 are respectively attached to the robot hand body 21 by horizontal support pins 25 and 26. It is supported and extends substantially horizontally out of the robot hand. The lower surface of the upper claw 22 and the upper surface of the lower claw 23 are formed in a partial arc shape corresponding to the outer periphery of the collar portion 13 of the work holder 6 and correspond to the annular V-groove 15 of the work holder 6. Arc-shaped projections 22a and 23a are formed. Each nail 22,
The rear end portion of 23 extends rearward in the robot hand body 21, and between the rear end portions of both claws 22 and 23, a claw biasing spring 30 which is vertically expandable and contractible is contracted.

The upper claw 22 is configured as a movable claw and the lower claw 23 is configured as a fixed claw as follows. The upper movable claw 22 is rotatably supported by the support pin 25, a notch 28 is formed on the upper surface of the rear end, and the rear end of the upper movable claw 22 is formed by the claw biasing spring 30. Is pushed upward, and the notch 28 is
Is in contact with The stopper pin 27 is fixed above the rear end of the robot hand body 21. That is, the rear end of the upper movable claw 22 abuts against the stopper pin 27 to maintain the closed position as shown in the figure. It can be opened in any direction. On the other hand, the lower fixed claw 2
3 is provided with a fixing pin 33 penetrating the rear end portion,
The lower fixed claw 23 is fixed by the fixing pin 33 so that it cannot rotate vertically. A retaining pin 35 is provided at the tip (front end) of the lower fixed claw 23 as a retaining member according to the second aspect of the present invention so as to protrude upward.

FIG. 3 is an enlarged partial view of the lower fixed claw 23. A through hole 37 is formed at the front end of the lower fixed claw 23 so as to penetrate substantially vertically. A retaining pin 35 is inserted therein so as to be vertically slidable. In FIG. 4, an upper end of the retaining pin 35 is formed in a hemispherical shape, and a locking flange 35a and a guide rod 35b extending downward are integrally formed at the lower end. A female screw 37b is formed in the lower half of the through hole 37, and an adjusting bolt 38 in the form of a cap bolt is screwed into the female screw 37b. A retaining pin biasing spring 36 is contracted between the bottom of the adjusting bolt 38 and the flange 35a of the retaining pin 35, and the retaining pin 35 is urged upward by the spring 36 to form a flange 35a. Is seated on the step 37a. When seated, the retaining pin 3
5, the upper end of the hemisphere 5 projects upward from the upper end surface of the projection 23a of the lower fixed claw 23. The cross-sectional shape of the projection 23a is trapezoidal.

Next, the operation will be described. First, the automatic work changing operation will be described. In FIG. 6, a plurality of work holders 6 to which works W are mounted are mounted on a work magazine 3 in advance. The N / C device causes the robot hand T to move relative to the work magazine 3 and the index table 5 in the three-dimensional direction by moving the machine table 2 back and forth and left and right, and moving the machine spindle 1 up and down. Then, the work holder 6 on the work magazine 3 is gripped, carried to the index table 5, and mounted in the mounting hole of the rotating shaft of the index table 5. The robot hand T of the machine spindle 1 is replaced with a tool for cutting or the like by a tool exchanging manipulator (not shown), and the work on the index table 5 is machined. After machining is completed, spindle 1
Is replaced with a robot hand T by a tool changing manipulator. Then, by the relative movement of the robot hand T similar to the above, the holder 6 of the work W after the processing on the index table 5 is gripped, removed from the index table 5, and returned to the work magazine 3. Next, the holder 6 of the new work W is gripped from the work magazine 3 and moved to the index table 5 as described above.

During the above exchange work, when the work holder 3 of the work magazine 3 or the index table 5 is gripped by the robot hand T, first,
The robot hand T is on the side of the work holder 6,
The robot hand T is positioned at a position corresponding to the annular V-shaped groove 15 of the work holder 6, and the robot hand T is horizontally moved to the work holder 6 side, and the protrusions 22a,
a is engaged with the annular V-groove 15 of the work holder 6. During the gripping operation, the upper movable claw 22 is temporarily pushed upward by the work holder 6 against the elastic force of the spring 30, and the retaining pin 35 is pushed downward. When the grip is completed, the upper movable claw 2
The work holder 6 is returned to the closed position by the spring
From above, and the retaining pin 35 projects into the annular V-groove 15 as shown by a virtual line in FIG. The rear end of the collar portion 13 of the work holder 6 is in contact with the arc-shaped contact surface 21 a of the robot hand body 21.

That is, in the gripping state, the weight of the work holder 6 is supported by the lower fixed claws 23, pressed down by the upper movable claws 22, and from the lower front by the retaining pins 35. It is held down and cannot be dropped off.

[0016]

[Another embodiment]

(1) FIG. 5 shows a modification of the retaining pin 35,
The retaining pin 35 is inclined such that the upper end side is forward. The inclination angle is set within 45 ° with respect to the vertical line. (2) Instead of the retaining pin 35, a steel ball may be used as a retaining member, and may be urged upward by a spring.

[0017]

Advantages of the Invention In a robot hand in which a pair of claws 22 and 23 are vertically arranged, the lower claw 23 is fixed.
The upper claw 22 is movable, and is biased to a closed position by a spring 30. The structure of the upper movable claw 22 is configured to rotate upward (rotate) around the support pin 25. Since the weight of the work is supported by the lower fixed claw 23 and a heavy object can be firmly supported, and the upper movable claw 22 only presses the work from above, so the detent mechanism ( Even if there is no stiffness maintaining mechanism such as a ratchet mechanism), the work can be reliably held down by the force of the spring 30 and can be pinched so as not to fall off. In other words, while maintaining the smoothness of the operation of gripping the work,
The gripping state of the heavy workpiece is stabilized. Further, since the lower fixed claw 23 does not rattle and the gripping state is stabilized, it can sufficiently cope with a shocking operation with a large acceleration and a high moving speed, and the use range is widened in this respect as well.

The retaining member (retaining pin 35)
Since the lower fixed claw 23 is provided so as to protrude upward and is located at the distal end of the fixed claw 23, the spring 36 for urging the retaining member moves the work between the upper and lower claws 22, 23. It exerts the function of pushing it into the back and can hold the work more firmly and stably. In particular, when gripping a cylindrical work, the effect is remarkable.

[Brief description of the drawings]

FIG. 1 is a side view of a robot hand to which the invention according to claims 1 and 2 of the present application is applied.

FIG. 2 is a view taken in the direction of the arrow II in FIG.

FIG. 3 is a partially enlarged side view of the lower fixed nail shown in FIG. 1;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

5 shows a modification of the retaining member, and is an enlarged side view of the same portion as FIG. 3. FIG.

FIG. 6 is a front view of the entire automatic workpiece exchange system.

FIG. 7 is a side view of a conventional robot hand.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 machine main shaft 21 robot hand body 22 movable claw 23 fixed claw 30 claw biasing spring 35 retaining pin (retaining member) 36 retaining spring

Claims (1)

(57) [Scope of request for utility model registration] 1. A robot hand which has a pair of upper and lower horizontal grippers for gripping a workpiece and is mounted on a machine spindle of a vertical machining center and grips and moves a workpiece or the like with upper and lower nails. Is fixed to the robot hand body as a fixed claw, and the upper claw is supported on the robot hand body via a support pin 25 so as to be rotatable upward as a movable claw, and the closed position is set by a claw biasing spring. A retaining member urged upward by a retaining member urging spring at a distal end portion of the lower fixed claw.