JPH05301191A - Articulated robot hand - Google Patents

Abstract

PURPOSE:To realize a simplification of structure and a light weight by reducing the number of driving sources, by providing rotation bodies to joints of an articulated robot hand, and connecting the rotation bodies to a driving source through transmission means, while placing clutching mechanisms between the rotation bodies and finger rods. CONSTITUTION:Plural finger rods 71 to 75 are connected in series through plural joints 21 to 25 each other to a base board 1. To the joints 21 to 25, plural pulleys 61 are fitted rotatably to plural shafts 6 fixed to the basic ends of the finger rods 71 to 75. Furthermore, between the shafts 6 and the pulleys 61, clutch mechanisms 5 which are removed when the rotation driving loads of the shafts 6 exceed a specific torque are placed. While the pulleys 61 are connected to each other with belts 64, a driving motor 4 is connected to the pulley 61 of the first joint 21 closest to the base board 1. Consequently, all the finger rods 71 to 75 are rotated at the angle corresponding to the unevenness of the surface of a substance respectively by using only a single driving motor 4, so as to surely grasp the substance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot hand for gripping or pinching objects having various contours.

[0002]

2. Description of the Related Art As such a robot hand, a multi-joint robot hand in which a plurality of finger rods are connected in series via joints is known. For example, in order to reliably clamp an object (8) having irregular irregularities on the surface as shown in FIG. 3, the rotation angle of each joint is adjusted according to the contour of the object to be clamped,
As shown in FIG. 3 (c), it is necessary to bring each finger rod along the surface of the object.

For this reason, in the conventional articulated robot hand, for example, a drive source such as a control motor is provided for each joint, and a sensor for detecting contact with an object is provided on each finger rod. Each drive source was controlled based on the signal from the sensor.

[0004]

However, by providing a drive source for each joint as in the conventional case, not only the weight of the robot hand itself increases but also each drive source is independently controlled according to the contour of the object. However, there is a problem that the control mechanism and circuit configuration for doing so become complicated.

An object of the present invention is to provide an articulated robot hand which can be made lighter in weight and simple in construction.

[0006]

In the articulated robot hand according to the present invention, a plurality of finger rods are connected to a base in series through joints, and each joint has a finger rod on the tip side of the hand. At the base end of the, there is provided a rotating body which is rotatable about the rotation axis of the finger rod. Further, a clutch mechanism is interposed between the base end portion of the finger rod and the rotating body, which engages when the rotational driving load of the finger rod is less than a predetermined torque and disengages when the rotational driving load of the finger rod exceeds the predetermined torque. The rotating bodies of the joints are connected to each other by power transmission means, and the rotary drive source is connected to the rotating body of the joint closest to the base.

[0007]

The rotary torque of the rotary drive source is sequentially transmitted from the rotary body of the joint closest to the base to the rotary body of the joint at the most advanced hand. In the no-load state until the robot hand contacts the object, the clutch mechanism of each joint is in the engaged state,
When the rotating body of the joint (first joint) closest to the base is rotationally driven, the finger rods on the tip side of the joint rotate together (see FIG. 3A).

When a part of the robot hand, for example, the first finger rod connected to the first joint comes into contact with the object, the driving load on the rotating body of the first joint increases and the clutch mechanism of the joint disengages. Next, the rotation of the rotating body of the second joint causes the second
The finger rod is driven toward the surface of the object (see FIG. 3 (b)).

As a result, the second finger rod contacts the surface of the object,
The driving load on the rotating body of the second joint increases, the clutch mechanism of the joint is disengaged, and then the third finger rod is driven toward the object surface by the rotation of the rotating body of the third joint. Thereafter, similarly, the finger rods on the tip side are sequentially driven, and finally all the finger rods come into contact with the object surface (Fig. 3).
(See (c)).

[0010]

According to the articulated robot hand of the present invention, all the finger rods are rotated by a rotation angle corresponding to the unevenness of the object surface by providing only one rotary drive source on the base, and the object surface is rotated. It is possible to go along. Therefore, the weight can be significantly reduced as compared with the conventional device in which the power source is arranged in all the joints. Also, the rotation angle of each joint is automatically variably set according to the unevenness of the object by the clutch mechanism provided in each joint, so that complicated control based on multiple sensors as in the past is not required and the configuration is simplified. Be promoted.

[0011]

An embodiment of the present invention will be described in detail below with reference to the drawings. This embodiment is based on a base as shown in FIGS. 3 (a) (b) (c).
(1) Two robot hands (2) and (3) are projectingly provided on the upper side, and the object (8) is sandwiched from both sides by both robot hands.

Each of the robot hands (2) and (3) has first to fifth finger rods (71) with respect to the support finger rod (7) fixed to the base (1).
(72) (73) (74) (75) to the first to fifth joints (31) (32) (33) respectively
(34) and (35) are bendably connected.

FIG. 1 shows a concrete configuration example of the robot hands (2) and (3). A bearing is provided at the tip of the supporting finger rod (7).
The first finger rod (71) is rotatably supported via the (65), and the tip of the first finger rod (71) is further supported by the second finger rod (7) via the bearing (65).
2) is rotatably supported and has the same support and connection structure up to the most advanced 5th finger rod (75).

Each joint (21) (22) ... (25) has a pair of left and right pulley grooves (62) (63) with respect to the shaft (6) fixed to the proximal end of each finger rod. The pulley (61) is freely rotatably fitted, and the friction clutch mechanism (5) is interposed between the shaft (6) and the pulley (61).

A drive motor (4) is provided on the base (1),
A pulley (41) is attached to the motor shaft. The pulley (41) is connected to the pulley of the first joint (21) via the belt (64).
Concatenated with (61). Further, the pulley (61) is a belt (6
It is connected to the pulley (61) of the second joint (22) via 4), and a similar power transmission mechanism is provided up to the most advanced fifth joint (25). As a result, the power of the drive motor (4) is finally transmitted to the pulley (61) of the fifth joint (25).

Friction clutch mechanism provided in each joint (5)
Has a well-known configuration in which the friction surface engages to transmit power when the transmission torque is equal to or less than a predetermined value, and the friction surface slides to interrupt power transmission when the transmission torque exceeds a predetermined value.

FIG. 2 shows a concrete example of the clutch mechanism (5).
A cylindrical body (53) is rotatably supported by the shaft (6), and a first friction plate (51) that rotates integrally with the outer peripheral surface of the shaft (6) is provided inside the cylindrical body (53). ) And second friction plates (52) that mesh with the inner peripheral surface of the tubular body (53) and rotate integrally with each other are alternately arranged. The plurality of friction plates (51) (52) are pressure plates ( The corrugated leaf springs (55) are pressed against each other via 56).
A preload adjusting ring (54) is fitted on the shaft (6) to press the end of the corrugated leaf spring (55) toward the pressure plate (56).

The outer peripheral surface of the cylindrical body (53) is provided with the pair of pulley grooves.
A pulley (61) having (62) and (63) is integrally attached.

Therefore, when the rotation of the drive motor (4) is transmitted to the pulley (61), the cylindrical body (53) rotates integrally and the first friction plate (51) rotates. At this time, the shaft
If the rotational drive load of (6) is less than a predetermined value, the first friction plate
By the frictional engagement of the (51) and the second friction plate (52), the first friction plate
The rotation of (51) is transmitted to the shaft (6) via the second friction plate (52).

On the other hand, when the rotational driving load of the shaft (6) exceeds a predetermined value, a slip occurs between the first friction plate (51) and the second friction plate (52), and the shaft (6) does not rotate. .. The predetermined value (slip torque), which is the boundary of engagement and disengagement of the clutch mechanism (5), can be adjusted by the axially fixed position of the preload adjusting ring (54).

Both robot hands as shown in FIGS. 3 (a) (b) (c)
In the process of pinching the object (8) by (2) and (3), the rotational torque of the motor is sequentially transmitted from the first joint (21) to the fifth joint (25).

In the unloaded state until the robot hands (2) and (3) come into contact with the object (8) as shown in FIG. 3A, the clutch mechanism of each joint is in the engaged state and the first joint ( By the first finger rod (71) being driven to rotate inward about 21),
The second to fifth finger rods (72) (73) (74) (75) rotate integrally.

After that, when a part of the robot hand, for example, the first finger rod (71) comes into contact with the object (8) as shown in FIG. 3 (b), the rotational driving load on the first finger rod (71) is applied at that time. Increased,
The clutch mechanism of the first joint (31) slips and the rotation of the first finger rod (71) stops.

Next, the second finger rod (72) is rotationally driven inward by the rotation of the second joint (22), as a result, the second finger rod (72).
Comes into contact with the object (8).

Thereafter, similarly, the finger rods on the front end side are sequentially driven to rotate inward, and finally all the finger rods (71) (72) (73) (74) as shown in FIG. 3 (c). ) (75) bends according to the unevenness of the object (8), and these finger rods are pressed against the object (8) by a force according to the slip torque set in the clutch mechanism of each joint.

As a result, the object (8) is attached to both robot hands.
By (2) and (3), it is sandwiched in a stable state from both sides. The motor may be rotated in the reverse direction to release the pinching of the object (8).

According to the robot hand, it is possible to reliably support various objects having different weights and shapes by appropriately adjusting the slip torque of the clutch mechanism of each joint. In addition, by equipping each robot hand with a single motor at the base end, all the finger rods can be driven to rotate up to an angle according to the contour of the object. Absent.

Therefore, the robot hand can be made much smaller and lighter than the conventional device.

The above description of the embodiments is for explaining the present invention and should not be construed as limiting the invention described in the claims or reducing the scope. Further, the configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims.

For example, in place of the belt transmission mechanism shown in FIG. 1, it is a matter of course that various known rotation transmission mechanisms such as a gear mechanism can be adopted. It is also possible to drive the two robot hands (2) and (3) shown in FIG. 3 with a single common motor.

[Brief description of drawings]

FIG. 1 is a sectional view of an articulated robot hand according to the present invention.

FIG. 2 is a sectional view of a clutch mechanism.

FIG. 3 is a series of plan views illustrating an object pinching operation performed by a pair of robot hands.

[Explanation of symbols]

 (1) Base (2) Robot hand (21) Joint (4) Drive motor (5) Clutch mechanism (6) Shaft (61) Pulley (64) Belt (71) Finger bar

Claims (1)

[Claims] 1. A multi-joint robot hand in which a plurality of finger rods are connected to a base in series via joints, and each joint has a finger end at a base end portion of the finger rod on the hand tip side. A rotating body that can rotate freely around the rotation axis of the rod is deployed,
A clutch mechanism is interposed between the base end portion of the finger rod and the rotating body to engage when the rotational drive load of the finger rod is less than or equal to a predetermined torque, and disengage when the load exceeds the predetermined torque to rotate each joint. The bodies are connected to each other by power transmission means,
A multi-joint robot hand characterized in that a rotary drive source is connected to the rotary body of the joint closest to the base.