JPH106266A - Hand mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hand mechanism which permits decrease in the number of hands, reduction of the cost, and shortening of the intermittent time by introducing such an arrangement that one hand can deal with various sorts of works. SOLUTION: A differential mechanism 4 is supported on bearing brackets 2 fixed to a base 1, and an actuator 6 to drive the differential mechanism 4 is mounted on one of the brackets 2. Ball nuts 18 and pawl arms 5 fastened thereto are installed on a left and a right ball screw 3 coupled with the mechanism 4, and the pawl arms 5 are operated in the X-direction with the rotation of the ball screws 3. The driving force of the actuator 6 is transmitted to the ring gear of the mechanism 4, and the pawl arms 5 are closed by the ball screws 3, and when a work is contacted with one pawl arm 5, the driving force is transmitted only to that pawl arm 5 which is not in contact, so that it is possible to grasp the work without moving it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hand mechanism, more specifically, a hand for automatic assembly or movement by a single hand, a hand for gripping and moving various kinds of workpieces, a HES (Hand Eye System). The present invention relates to a hand mechanism suitable for a robot cell-compatible component supply system, a sorting robot according to a shape for recycling, a crane, and the like, for hands for bin picking and the like.

[0002]

2. Description of the Related Art In a conventional robot used for transferring and assembling a work, a special hand is prepared for a work (a target part) unless a work having a similar size is handled. In a so-called work-intensive robot or the like, which handles many types of works (parts), a hand for each work (part) is replaced by a tool changer or the like.

[0003] In addition, when a relative displacement between the work and the hand occurs, the hand is provided with compliance or the deformation of the gripping portion of the claw is increased to increase the grippable range. I was

However, in the conventional method as described above, hand replacement time and hand cost for each component increase, and when a workpiece is gripped, "prying" or movement of the workpiece to the center of the hand is required. There was a problem that excessive force was applied to the device.

To solve such a problem, see, for example,
In the device disclosed in Japanese Patent Application Laid-Open No. -10794, a projection member having a plurality of projections to be engaged with an end of a work is attached to each claw of a hand, and each claw is attached to an arbitrary position with respect to the hand body. By providing fixing means for fixing, it is possible to hold various kinds of works.

[0006]

However, the above-mentioned Japanese Patent Application Laid-Open No.
In Japanese Patent No. -10794, the brake is used to fix the gripping position even if the stroke of the claw is variable. Therefore, the continuous gripping force after gripping is only the elastic reaction force of the projection member, When the contact area to each nail is different, there is a problem that the gripping position is delicately moved and the position is not easily reproduced and is weak against disturbance.

[0007] Further, when handling an aligned part supply work, the above-described hand function is not required, and another hand having a centering function is required.
In a parallel opening / closing hand with individual claw strokes,
There were problems that the continuous gripping force could not be adjusted and the stroke range could not be adjusted.

On the other hand, a hand provided with a radial cylinder has a drawback that the overall size of the hand increases with an increase in the stroke that can be gripped. If the position of the work on the hand cannot be recognized, such as if the work is held by the hand, and the position shifts due to disturbance, there is a problem that accurate transfer and assembly cannot be performed.

The present invention has been made in view of the above circumstances, and a hand mechanism capable of reducing the number of hands, reducing costs and shortening tact time by handling many types of workpieces with one hand. The purpose of this is to provide.

[0010]

According to a first aspect of the present invention, there is provided a hand mechanism used for equipment such as a robot or a crane for transferring or assembling a work, wherein at least two gripping claws for gripping the work are provided. Driving means for driving the gripping claws, characterized in that each gripping claw operates independently and with a variable stroke.By handling many types of workpieces with one hand, the number of hands can be reduced. In this way, the cost and tact time can be reduced.

According to a second aspect of the present invention, in the first aspect of the present invention, there is provided a detecting means for detecting a three-dimensional or two-dimensional work position, and each of the gripping claws is operated based on a detection result of the detecting means. Even if the shape and posture of the work are different, the work is held while holding the state, and the work is grasped in a state recognized by the sensor without applying excessive force to the work. It is something that can be done.

According to a third aspect of the present invention, in the first or second aspect, the driving means comprises at least one actuator and a differential mechanism for transmitting power from the actuator to each of the gripping claws. In this method, the gripping force is maintained after gripping, and has a gripping position holding force.

According to a fourth aspect of the present invention, in the third aspect of the present invention, a locking means is provided between each power transmission shaft from the differential mechanism to each of the gripping claws, and the locking action of the locking means causes It is characterized in that each gripping claw operates integrally, so that the hand function and the centering function can be switched manually or remotely with one touch, so that it is possible to respond with one hand It was done.

According to a fifth aspect of the present invention, in the first or second aspect of the present invention, the driving means comprises an air cylinder and a link mechanism for connecting the air cylinder and the gripping claws. Thus, the gripping claws perform a fulcrum opening / closing chucking operation via the link mechanism, whereby the gripping force can be changed by a simple operation, and the frontage of the gripping claws is widened. Is made possible.

According to a sixth aspect of the present invention, in the first or second aspect, the driving means comprises a rotary actuator, a pulley disposed on an output shaft of the rotary actuator, the pulley, and each of the gripping claws. The gripping claws perform a chucking operation by driving the rotary actuator, and the gripping force can be changed by a simple operation. The frontage can be widened.

According to a seventh aspect of the present invention, in the sixth aspect of the invention, an encoder for detecting an amount of movement of each of the gripping claws is disposed on the rotary actuator. The robot can reliably recognize the presence / absence and the position of the gripped work.

According to an eighth aspect of the present invention, in the seventh aspect of the present invention, the driving means comprises at least one actuator and a clutch disposed on an output shaft of the actuator and provided for each of the gripping claws. The said at least one
The gripping claws are operated by one actuator, and the hand can be reduced in cost and weight by reducing the number of actuators for driving the gripping claws.

According to a ninth aspect of the present invention, there is provided a hand mechanism used for equipment such as a robot or a crane for transferring or assembling a work, wherein at least three gripping claws which operate by drawing a scroll-like locus for gripping the work. And an actuator provided for each gripping claw to drive each gripping claw, so that the length of the hand itself is reduced as much as possible, and the stroke of the gripping claw is reduced. It is designed to be as large as possible.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a view showing a main part of a hand mechanism according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a base, 2 denotes a bearing bracket, 3 denotes a ball screw, and 4 denotes a difference. The moving mechanism, 5 is a claw arm, 6 is an actuator, 18 is a ball nut, and X is the operation direction of the claw arm 5.

In the embodiment shown in FIG. 1, a differential mechanism 4 is supported by a bearing bracket 2 attached to a base 1 with a hand attached to a robot or a hoist, and one of the bearing brackets 2 An actuator 6 for driving the differential mechanism 4 is attached, and a ball nut 18 and a claw arm 5 (grip claw) fastened to the ball nut 18 are attached to the ball screw 3 connected to the differential mechanism 4. The claw arm 5 moves left and right (X direction in the figure), and the driving force of the actuator 6 is transmitted to the ring gear of the differential mechanism 4,
Each of the claw arms 5 is closed by the left and right ball screws 3, and when a work (not shown) touches one of the claw arms 5, the driving force is transmitted to only the claw arm 5 which is not in contact with the claw arm 5, so that the work is not moved. This allows the workpiece to be gripped by the user.

The differential mechanism 4 shown in FIG. 1 is a differential gear used for an automobile or the like, but it goes without saying that a differential mechanism such as a viscous type may be used.

FIG. 2 is a view showing a main part of another embodiment of the hand mechanism according to the present invention. In FIG. 2, reference numeral 3a denotes a left ball screw, 3b denotes a right ball screw, 7 denotes a lock mechanism, and FIG. Parts having the same functions as in FIG. 1 are denoted by the same reference numerals as in FIG.

In the embodiment shown in FIG. 2, a manual or solenoid driven lock mechanism 7 is provided between the left ball screw 3a-side shaft and the right ball screw 3b-side shaft of the differential mechanism 4, and this lock mechanism 7 is provided. By using, left ball screw 3
a and the right ball screw are connected to the axis of 3b, whereby
This is a normal parallel opening / closing type chuck, and can be a chuck capable of centering a work.

FIGS. 3A and 3B are main part structural diagrams for explaining another embodiment of the hand mechanism according to the present invention. FIG. 3A is a plan view, and FIG. 3B is a plan view of FIG. 8 is a view taken in the direction of arrows BB, in which 8 is a pivot portion, 9 is a linear actuator,
Is a mounting hole, 11 is a small end, Y is an operation direction of the linear actuator 9, and other portions having the same operation as in FIG. 1 or FIG. 2 are denoted by the same reference numerals as in FIG. 1 or FIG.

In the embodiment shown in FIG. 3, three claw arms 5 are mounted on a base 1 mounted on a robot or a hoist via a pivot portion 8, and a linear actuator 9 is mounted on each claw arm 5 for driving. As shown by X and Y in the figure, when the linear actuator 9 is extended, the claw arm 5 operates to the closing side, and when the linear actuator 9 contracts, the claw arm 5 operates to the opening side. When the linear actuator 9 is an air cylinder, it can be gripped in a form according to the state of the work by using the same system of air.

The claw arm 5 has a mounting hole 1
A plurality of zeros are provided, and the gripping force and the opening / closing stroke can be changed by changing the mounting position of the pivot portion 8 and the small end 11. Further, by providing the linear actuator 9 with an auto switch, a linear encoder, or the like, it is possible to grasp the presence / absence of the work and the holding state.

FIGS. 4A and 4B are main part structural diagrams for explaining another embodiment of the hand mechanism according to the present invention. FIG. 4A is a plan view and FIG. 4B is a plan view of FIG. In the drawing, as indicated by arrows BB, 12 is a wire, 13 is a pulley, 14 is a rotary actuator, 15 is a rotary actuator base, Z is a rotation direction of the pulley 13, and the other operations are the same as those in FIGS. Portions are given the same reference numerals as in FIGS.

In the embodiment shown in FIG. 4, a claw arm 5 in which a preload is always applied to each of three bearing brackets 2 mounted on a base 1 by a coil spring (not shown) on a side to be opened is pihot. Joined, base 1
Rotary actuator 1 evenly arranged at the center of
A pulley 13 on which a wire 12 connected to the claw arm 5 is wound is provided at the tip of the claw arm 4 so that tension can be applied to the claw arm 5 as shown by X and Z in the figure. And the rotary actuator 14
When the wire 12 is fed (loosen), the claw arm 5 that is always preloaded on the open side by the coil spring
Is opened, and when the wire 12 is wound up, the claw arm 5 operates in the closing direction.

The claw arm 5 is provided with a mounting hole 10 for raising and lowering the mounting position of the wire 12 and raising and lowering the rotary actuator 14 with the rotary actuator base 15 to keep the wire 12 as horizontal as possible. Thus, the lever ratio of the claw arm 5 changes, and the chuck characteristics can be easily changed.

When the rotary actuator 14 is driven by the same pressure air, the claw arm 5 which comes into contact with the work is stopped and the other claw arm 5 is closed, so that the work can be held while holding the position of the work. Can be.

FIG. 5 is a view showing the construction of a main part of another embodiment of the hand mechanism according to the present invention. In FIG. 5, reference numeral 16 denotes an encoder, and other parts which operate in the same manner as in FIGS. 1 to 4 are denoted by the same reference numerals.

The embodiment shown in FIG. 5 is different from the embodiment shown in FIG. 4 in that an encoder 16 is provided for each rotary actuator 14. By grasping the relative position between the workpiece and the gripped workpiece, sending the data to the robot, and merging the deviation from the center position with the robot address, the workpiece can be transferred to the correct position and assembled. It was done.

FIG. 6 is a view showing the construction of a main part of another embodiment of the hand mechanism according to the present invention. In FIG. 6, reference numeral 17 denotes a clutch pulley, and Z 'denotes a rotation direction of the clutch pulley.
Other parts having the same functions as those in FIGS. 1 to 5 are denoted by the same reference numerals as those in FIGS.

The embodiment shown in FIG.
The clutch pulley 17 is mounted on one rotary actuator 14, and the torque of the clutch pulley 17 is first minimized. When the claw arm 5 is gradually closed from the open state, the claw arm that comes into contact with the work is started. When the clutch pulley 17 slides in order from 5 and all the claw arms 5 come into contact with the workpiece, the clutch pulley 17 is turned on to grip the workpiece, so that the workpiece can be gripped while maintaining the state of the workpiece. It is. The clutch pulley 17 is a torque clutch such as a picus coupling.

FIG. 7 is a view for explaining another embodiment of the hand mechanism according to the present invention. FIG. 7 (A) is a plan view, and FIG. 7 (B) is BB of FIG. 7 (A). In the view as viewed in the direction of the arrow, parts having the same functions as those in FIGS. 1 to 6 are denoted by the same reference numerals as those in FIGS.

In the embodiment shown in FIG. 7, the linear actuator 9 is disposed so as to be superimposed on the center of the base 1, and the base 1, each linear actuator 9 and each claw arm 5 are linked and connected via each pivot portion 8. The claw arm 5 opens and closes by the expansion and contraction of the linear actuator 9. Since the claw arm 5 moves along a locus centering on the pivot portion 8, a scroll shape is indicated as X in the figure. Open and close. Further, since the plurality of mounting holes 10 are provided, the chuck characteristics can be easily changed.

[0037]

According to a first aspect of the present invention, there is provided a hand mechanism used for equipment such as a robot or a crane for transferring or assembling a workpiece, wherein at least two gripping claws for gripping the workpiece and the gripping nail are driven. Since each of the gripping claws operates with an independent and variable stroke, various types of workpieces can be made to be gripping objects within the range of the stroke of the gripping claws and the weight of the hand, In addition, since it is not necessary to prepare a gripping hand for each work to be handled, no hand replacement time is required, and the cost of the hand can be reduced.

According to a second aspect of the present invention, in the first aspect of the present invention, there is provided a detecting means for detecting a three-dimensional or two-dimensional work position, and each of the gripping claws is operated based on a detection result of the detecting means. Therefore, accurate transfer and assembly can be performed based on the position recognized by the position detection sensor, and accordingly, the posture, shape, and dimensions of the work to be handled can be flexibly handled.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the driving means comprises at least one actuator and a differential mechanism for transmitting power from the actuator to each of the gripping claws. The power from the actuator is not transmitted to the claws that first contact the work as a gripping force, but is transmitted as the driving force of the other pawl, and is transmitted uniformly when the pair of claws come into contact. Thus, the gripping force can be continuously maintained while the work position is maintained, so that accurate transfer and assembly can be performed using the recognition data with high resistance to disturbance.

According to a fourth aspect of the present invention, in the third aspect of the present invention, a locking means is provided between each power transmission shaft from the differential mechanism to each of the gripping claws, and the locking action of the locking means causes the locking action. Since each gripping claw operates integrally, it is possible to switch between a centering function and a function following the hand.

According to a fifth aspect of the present invention, in the first or second aspect of the invention, the driving means comprises an air cylinder and a link mechanism for connecting the air cylinder and the gripping claws. Since the gripping claws perform a fulcrum opening / closing chucking operation via the link mechanism, the driving of each of the claws is performed via a link.
The position holding force can be increased by the frictional force between the fulcrum opening / closing claw and the work, and the characteristics can be easily changed by changing the link force point and the fulcrum. Even if there is, it is not necessary to manufacture a new hand, and the cost can be reduced.

According to a sixth aspect of the present invention, in the first or second aspect, the driving means comprises a rotary actuator, a pulley provided on an output shaft of the rotary actuator, the pulley, and each of the gripping claws. Since the gripping claws perform a chucking operation by driving the rotary actuator, the driving means can be integrated and arranged, so that the hand can be made compact. Further, the grip force and the stroke can be easily changed by changing the power point of the grip claw or the pulley.

According to a seventh aspect of the present invention, in the sixth aspect of the present invention, since an encoder for detecting the amount of movement of each of the gripping claws is provided on the rotary actuator, the amount of movement of each gripping claw and, consequently, The relative position of the work and the hand, the size of the work, and the like are obtained by calculation, whereby the robot can perform accurate transfer and assembly based on the data.

According to an eighth aspect of the present invention, in the first or the second aspect of the present invention, the driving means includes at least one actuator and a clutch disposed on an output shaft of the actuator and provided for each of the gripping claws. Since each of the gripping claws is operated by the at least one actuator, the number of actuators can be reduced, and a compact and low-cost gripping claw independent drive hand is possible.

According to a ninth aspect of the present invention, there is provided a hand mechanism used for equipment such as a robot or a crane for transferring or assembling a work, wherein at least three gripping claws which operate by drawing a scroll-like locus for gripping the work. And an actuator provided for each of the gripping claws to drive the gripping claws, so that the hand size can be reduced as compared to the gripping stroke. Strong position holding force,
It is unlikely that the workpiece will shift or fall during transfer.

[Brief description of the drawings]

FIG. 1 is a main part configuration diagram for explaining an embodiment of a hand mechanism according to the present invention.

FIG. 2 is a main part configuration diagram for explaining another embodiment of the hand mechanism according to the present invention.

FIG. 3 is a main part configuration diagram for explaining another embodiment of the hand mechanism according to the present invention.

FIG. 4 is a main part configuration diagram for explaining another embodiment of the hand mechanism according to the present invention.

FIG. 5 is a main part configuration diagram for explaining another embodiment of the hand mechanism according to the present invention.

FIG. 6 is a main part configuration diagram for explaining another embodiment of the hand mechanism according to the present invention.

FIG. 7 is a main part configuration diagram for explaining another embodiment of the hand mechanism according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base, 2 ... Bearing bracket, 3 ... Ball screw,
3a left ball screw, 3b right ball screw, 4 differential mechanism, 5 claw arm, 6 actuator, 7 locking mechanism, 8 pivot part, 9 linear actuator, 10
... Mounting holes, 11 ... Small end, 12 ... Wire, 13 ... Pulley, 14 ... Rotary actuator, 15 ... Rotary actuator base, 16 ... Encoder, 17 ... Clutch pulley, 18 ... Ball nut, X ... Operation direction of claw arm 5 , Y: operating direction of the linear actuator 9, Z: rotating direction of the pulley 13, Z '
... Rotating direction of clutch pulley.

Claims (9)

[Claims] 1. A hand mechanism used for a device such as a robot or a crane for transferring or assembling a work, comprising: at least two gripping claws for gripping the work; and driving means for driving the gripping claws. A hand mechanism wherein each of the gripping claws operates with an independent and variable stroke. 2. The hand according to claim 1, further comprising detection means for detecting a three-dimensional or two-dimensional work position, wherein each of the gripping claws is operated based on a detection result of the detection means. mechanism. 3. The hand mechanism according to claim 1, wherein the driving unit includes at least one actuator and a differential mechanism that transmits power from the actuator to each of the gripping claws. . 4. A lock means is provided between each power transmission shaft from the differential mechanism to each of the gripping claws, and each of the gripping claws is integrally operated by a locking action of the locking means. The hand mechanism according to claim 3, wherein 5. The driving means comprises an air cylinder and a link mechanism for connecting the air cylinder and the gripping claws, and the gripping claws are opened and closed via the link mechanism by driving the air cylinder. The hand mechanism according to claim 1 or 2, which performs a chucking operation. 6. The driving means comprises a rotary actuator, a pulley disposed on an output shaft of the rotary actuator, and a wire connecting the pulley and each of the gripping claws, and driven by the rotary actuator. The hand mechanism according to claim 1, wherein each of the grip claws performs a chucking operation. 7. The hand mechanism according to claim 6, wherein an encoder for detecting an amount of movement of each of the gripping claws is provided on the rotary actuator. 8. The driving means includes at least one actuator and a clutch disposed on an output shaft of the actuator and provided for each of the gripping claws. The hand mechanism according to claim 1, wherein the hand mechanism operates. 9. A hand mechanism used for equipment such as a robot or a crane for transferring or assembling a work, wherein at least three gripping claws which operate by drawing a scroll-like locus to grip the work, and each of the gripping claws. A hand mechanism comprising: an actuator provided for each claw to drive each gripping claw.