JPH04111791A - Robot hand - Google Patents

Abstract

PURPOSE:To grip an object being out of grip center with a single driving unit by constituting a closed loop from guides arranged respectively on finger parts of a hand, a fixing unit and a winding unit by means of a rope-like member so as to interlock those together. CONSTITUTION:Even if an object 11 gripped with finger parts 2 and 3 of a hand is not arranged at the grip center, by winding a rope-like member, which is arranged so as to interlock a fixing unit 4, guides 6 arranged respectively on the finger parts 2 and 3 of the hand and a winding unit 8 together, with the winding unit 8, the hand can be closed until it is brought into contact with the object tightly by generating grip force at the finger parts 2 and 3 of the hand. Furthermore, by means of springs 9 and 10, the object to be gripped 11 is moved to the normal position where those spring forces can be balanced. Since only a single driving source is sufficient for the winding unit 8, the object 11 being out of grip center can also be gripped by means of a nuiaxial hand so that the object 11 can be kept in the normal position after it has been gripped.

Description

[Detailed description of the invention] (b) Industrial application field The present invention relates to the configuration of a robot hand.

(B) Conventional technology Currently, the manipulator hand attached to a movable trolley has running errors and manipulator errors, so during handling, positioning is performed again and the manipulator is moved to the gripping center and gripped. (Refer to Japanese Patent Application Laid-open No. 104358/1983).

In addition, as a gripping method when the gripping center is shifted, there is a method of gripping while controlling the left and right sides of the hand by attaching motors to each side, but it is necessary to have two drive units and to return the grip to the center after gripping. Control is also required. (Refer to page 174 of the 2nd Academic Lecture Materials of the Robotics Society of Japan).

(c) Problems to be Solved by the Invention The present invention provides a robot hand that eliminates the above-mentioned drawbacks and achieves the intended purpose with a simple configuration.

(d) Means for Solving the Problems In the robot hand of the present invention, the guides provided on the fingers of the hand, the fixing part, and the winding part are arranged and interlocked so as to form a closed loop using a rope-like member. The loaf-shaped member is wound up in the winding part from the fixing part through the guides provided on each of the finger parts, thereby applying a gripping force to the node and applying a spring that acts in the direction of opening the finger part. The fingers of the hand are released to a predetermined position by releasing the tension of the rope-like member that is provided and wound up by the action of the spring, and the object is lifted after being gripped by the balance of the force of the spring. Return to the previous position.

(e) Effect With the above configuration, even if the object gripped by the fingers of the hand is not located at the grip center, the fixed part
By winding up a rope-like member arranged so as to interlock the guide provided on each finger of the hand and the winding part, a gripping force is generated at the finger of the hand by winding it up with the winding part, and the hand is targeted. Close until it touches the object.

In addition, the spring allows the force to be balanced in a fixed position.
\The object being held moves. Furthermore, since only one drive source is required for the winding section, it is possible to grip an object that is not at the center of the grip by gripping with the uniaxial grip and hold it at the rear grip position.

(F) Embodiment In the embodiment shown in FIGS. 1 to 3, an object that is not at the center of the grip is gripped by a uniaxial hand, and after being gripped, the object is lifted and returned to the center of the grip by a spring.

Figure 1 shows how to use the hand to grasp an object (
11). First, the finger parts (2) and (3) of the hand attached to the fixed base (1) are
1i (2) and (3) and the fixed base (1) are connected by a joint part/rope fixing part (4), and each can move freely. In addition, the rope-like member (5) starts from the joint part/rope fixing part (4) and the finger part (2) of the knot.
) and a guide (7) provided in the middle of the fingers (3) of the other hand. The springs (9) and (10) are coil springs that have a force that acts in the direction of opening the fingers (2) and (3) of the hand. Winding shaft (
8) is connected to a motor as a drive source.

In Figure 1, the winding amount of the rope-like member (5) by the winding shaft (8) is 0, and the fingers (2) (3'1) of the hand are opened to the maximum by the springs (9) and (10). The hand is balanced by springs (9) and (10), and the fingers (2) and (3) of the hand are equidistant from the gripping center.This figure shows an object (11 ) is a diagram with a hand inserted to grasp it.

FIG. 2 is a diagram showing a grip state of the object (11).

After inserting the hand, the rope-like member (5) is wound up by the rope winding shaft (8). At this time, the force for winding up the rope-like member (5) is applied to the guide (
6) The force is transmitted to (7) and becomes a force that closes the fingers (2) and (3) of the hand inward. At this time, the movement of the fingers (2) and (3) of the hand starts from the point shown in Fig. 1, and the left and right fingers begin to close almost simultaneously. Next, the fingers (3) of the hand touch the object (11) first and stop.

Therefore, as the rope-like member (5) continues to be wound up, the fingers (2) of the hand move until they touch the object (11), as shown in FIG. In this state, the rope-like member (5) is wound up and the rotation of the shaft (8) is stopped until the object (11) is completely gripped. The shape of the rope-like member (5) at this time constitutes a substantially triangular closed loop, and the length of the rope-like member does not change no matter where the object (11) is gripped.

Therefore, even if the rope-like member (5) is strongly tightened, the object (11)
) can be seen that no force is generated to move it from side to side.

FIG. 3 shows a state in which the object (11) is gripped and lifted, and a state in which the object (11) is landed at a fixed position after being moved.

By completely gripping the object (11) in the state shown in Figure 1 and then lifting it, the frictional force between the object (11) and the floor becomes O, and the force of the springs (9) and (10) balances both springs. It returns to the position where it was released (the preset gripping center) and becomes as shown in Fig. 3. Therefore, the position when the player lands at another location after moving is also the center of the hand.

FIG. 4 shows an embodiment in which the hand has four fingers.

In this case as well, the same operations as in FIGS. 1, 2, and 3 described in the first embodiment described above are performed. Hand fingers (2
)(3)(2')(3°) are arranged as shown in the figure, and the rope-shaped member (5) serves as the joint part and rope fixing part (4
) as the starting point, the middle guides (6) and (7) for the fingers of the hand (2) and (3), and the guides for the joint part (30) and (31).
, the middle guide (6') of the fingers (2') (3') of the hand
) (7') Wind it up by the motor (12) of the drive source via the guide (32) of the joint part. Similarly, when the grip moves back and lands on the fixed position, the springs (9) (10) (9°
) (10°) and land at a position centered on the balance position.

(g) Effects of the invention The effects of the present invention are as follows.

■ It is possible to grasp objects that are not at the center of the grip with just one drive unit.

■ After gripping an object that is not at the gripping center, it is returned to the gripping center by the force of the spring, so no control is required to return it to the gripping center.

■ Even if the number of finger parts of the hand is increased, only one driving part can be used.

■ By increasing the open state of the fingers of the hand, the control is simple and the hand can grip even when the control has a large error. When moving and landing at a different location, the control error is absorbed each time the robot lands in the grip center.

■ In the future, it is thought that more robots will be able to grasp and move objects, so this will have a large effect in terms of absorbing control errors.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIGS. 1 to 3 show a state in which a hand having a pair of fingers is inserted to grip an object, a state in which the hand is gripping an object, and a grip center. FIG. 4 is an explanatory diagram showing the returned state, and FIG. 4 is an explanatory diagram of a case where an object is grasped with a hand having two pairs of fingers in another embodiment of the present invention. FIG. FIG. 2 is an enlarged explanatory diagram of main parts. (1)... Fixed base, (2) (3)... Finger part, (4)
... Fixed part, (5) ... Rope-like member, (6) (7
)...Guide, (8)...Rope winding shaft, (9)
(10)...Stripes 1 long, (11)...Object.

Claims (1)

[Claims] 1) In a robot hand that grips an object from the left and right sides and lifts or lifts the object horizontally after gripping, a guide, a fixing part, and a winding part provided on each finger of the hand are connected by rope-like members. The rope-like member is arranged and interlocked to form a closed loop, and the rope-like member is wound up by the winding part from the fixing part to the finger part through guides provided on each finger part, thereby imparting a gripping force to the hand and the finger part. A spring that acts in the releasing direction is provided, and by releasing the tension of the wound rope-like member by the action of the spring, the fingers of the hand are released to a predetermined position, and the balance of the force of the spring allows the grip to be held. A robot hand that is characterized by the ability to return to a predetermined position after picking up an object.