JPH09290389A - Articulated unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make fine adjusting capable till obtaining a prescribed attitude also make an articulation instantaneously fixable, by charging a clearance of a fitting surface of a ball and a socket with an electroviscous fluid changing viscosity by applied voltage, and applying voltage to this viscous fluid to limit movement of the articulation. SOLUTION: In an articulated unit 1, a fitting surface of a ball 2 and a socket 3 is formed by a conductor, a clearance of the fitting surface is charged with an electroviscous fluid 4, voltage is applied to this viscous fluid 4. This viscous fluid 4 is constituted by electric insulating oil, polarizable organic fine particle, etc. A cylinder 8 is inserted to shaft core of the ball 2, in its tip end, a storage chamber 9 of the viscous fluid 4 is provided, a clearance of the ball 2 and the socket 3 is connected by a charge hole 10. Pressing of a piston 11 corrects capacity change of the viscous fluid 4. The ball 2 is rotated 90 to 120 degree, when a direction and angle of the articulated unit 1 are obtained in a desired attitude, high voltage is applied, the viscous fluid is instantaneously solidified, its attitude is fixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial joint unit used for medical care devices, industrial robots, and the like.

[0002]

An artificial joint unit used in a medical care device, an industrial robot or the like can freely change its direction and angle, and if necessary, its posture in a predetermined direction and angle. Is required to hold. Thus, the joint unit is required to simultaneously satisfy two contradictory elements, a movable element that freely changes its direction and angle, and a fixed element that holds its posture. There was no flexible joint unit that could satisfy all of the following factors.

When a voltage is applied to an electrorheological fluid, its viscosity increases over a wide range depending on the magnitude of the applied voltage, and solidifies at a certain voltage value or more. In the present invention, paying attention to the characteristics of the electrorheological fluid, the joint unit is filled with the electrorheological fluid, and a voltage is applied as necessary. As a result, the frictional resistance of the movable portion is increased to limit the movement of the joint, or the joint is instantaneously fixed to maintain the posture. The present invention has been made for the purpose of simultaneously utilizing the characteristics of the electrorheological fluid to simultaneously satisfy two contradictory elements of a movable element and a fixed element of the joint unit.

[0004]

In order to achieve the above object, the present invention is configured as follows.

That is, according to the first aspect of the invention, the joint fitting surface of the joint joint is formed of a conductor, the gap between the fitting surfaces is filled with an electrorheological fluid, and a voltage is applied to the electrorheological fluid. It is a joint unit provided with means. In addition, claim 2
The invention according to claim 1 is the joint unit according to claim 1, wherein the joint joint comprises a socket and a ball fitted therein.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a sectional view of a joint unit embodying the present invention. In the joint unit 1, a fitting surface of the ball 2 and the socket 3 is formed of a conductor, a gap between the fitting surfaces is filled with an electrorheological fluid 4, and a voltage feeding device (not shown) is applied to the electrorheological fluid 4. ) Is provided.

The gap between the ball 2 and the socket 3 is sealed with a double O-ring 5 to prevent the electrorheological fluid 4 from leaking. The O-ring 5 is fitted into the fitting groove 6 formed on the surface of the ball 2 by about 50% so that the O-ring 5 does not come off when the ball 2 rotates in the socket 3.
Instead of the O-ring 5, a magnetic fluid may be used as a sealing material. That is, as shown in FIG. 2, the ring-shaped magnet M1 is fitted into the fitting groove 6 formed on the surface of the ball 2, and the magnetic fluid M2 is accumulated around it. The sealing material for the magnetic fluid M2 may be used together with the O-ring 5.

A spacer 7 is projected on the surface of the ball 2 so that the fitting surfaces of the ball 2 and the socket 3 are not pressed against each other. The height of the spacer 7 is substantially the same as the gap between the mating surfaces of the ball 2 and the socket 3, and the ball 2 rotating in the socket 3
The height should not interfere with the movement of. By the action of the spacer 7, even if an external force of attraction / pressing acts between the ball 2 and the socket 3, the gap between the fitting surfaces of the ball 2 and the socket 3 can be kept constant.

A cylinder 8 is inserted into the axis of the ball 2, and a storage chamber 9 for the electrorheological fluid 4 is provided at the tip of the cylinder 8. And
A filling hole 10 connects the storage chamber 9 and the gap between the fitting surfaces of the ball 2 and the socket 3. The bottom of the storage chamber 9 is pressed by a piston 11 with an O-ring, and the piston 11 moves the cylinder 8
The spring adjustment screw 12 that is screwed onto the inner circumference of the
Energize with. The piston 11 can correct the volume change of the electrorheological fluid 4 due to temperature or minute leak. Further, by changing the position of the spring adjusting screw 12, it is possible to adjust the internal pressure of the electrorheological fluid 4 filling the gap between the fitting surfaces of the ball 2 and the socket 3.

The shape of the joint unit 1 may be not only a spherical body that rotates sphere but also a cylindrical body that rotates in a plane. The rotation angle of the ball 2 is limited by the size of the diameter of the opening of the socket 3, but it is possible to rotate about 90 to 120 degrees (solid angle) due to the structure. The shape of the ball 2 may be hemispherical for weight reduction, or voids may be provided in the ball 2 to the extent that strength is not impaired.

The socket 3 is made of light metal such as titanium or high-density polyethylene, and is structurally assembled by joining two divided members, and has a diameter of 1c depending on the purpose.
It can also be on the order of m to several tens of cm. The ball 2 is made of a material that takes mechanical strength into consideration, such as aluminum, titanium, or high density polyethylene.

The electrorheological fluid 4 is selected and used according to the purpose, such as a dispersion type electrorheological fluid composed of electrically insulating oil and polarizable organic fine particles, or a liquid crystal type electrorheological fluid using cholesteric liquid crystal.

The applied voltage of the electrorheological fluid 4 is practically 1.00 for the current electrorheological fluid 4 when the gap between the fitting surfaces of the ball 2 and the socket 3 is set to about 500 μm.
An applied voltage of around 0 V is required.

The joint unit 1 embodying the present invention is constructed as described above, and when it is used in a medical care device or the like, a caregiver or a cared person himself / herself changes the direction and angle of the joint unit 1 by a manual electric switch. , Voice electrical switch,
Alternatively, a voltage is applied to the electrorheological fluid 4 filled in the gap between the mating surfaces of the ball 2 and the socket 3 using a foot switch or the like.

When the direction and angle of the joint unit 1 reach a desired posture, a high voltage is applied to solidify the electrorheological fluid 4, and the joint is instantaneously fixed to maintain that posture. Alternatively, when fine adjustment is required until the desired posture is achieved, the applied voltage is adjusted to increase the frictional resistance of the movable part, and the adjustment is repeated until the optimal posture is achieved while limiting the movement of the joint.

The ball joint 14 and the socket joint 15 are formed in a convex shape and a concave shape so that they can be connected. The convex ball joint 14 and the concave socket joint 15 connect a plurality of joint units 1 to form a multi-joint unit 16 as shown in FIG. 3 or other units or the fixed wall 1.
Connect to 7.

When this joint unit 1 is used as a single joint unit 1, it functions as a simple joint.
When a plurality of joint units 1 are connected to form the multi-joint unit 16, it plays an important role corresponding to a human arm in the medical care device. That is, when holding the cared person, the articulated unit 16 is fixed in an appropriate posture, and effectively supports complicated exercises such as standing up of the cared person and assistance in walking.

[0018]

The joint unit of the present invention utilizes the characteristics of the electrorheological fluid whose viscosity changes according to the applied voltage, and fills the gap between the mating surfaces of the ball and the socket with the electrorheological fluid. A voltage is applied to this electrorheological fluid to limit the movement of the joint. Therefore, according to the present invention, it is possible to finely adjust the joint to a desired posture, and when the desired posture is achieved, the joint can be instantaneously fixed and the posture can be maintained. This joint unit or a multi-joint unit that connects joint units should make full use of its structural and functional characteristics not only in medical care devices but also in the application fields of medical machines and industrial robots. You can Further, the joint unit of the present invention can be used in a liquid such as water if it is electrically shielded.

[Brief description of drawings]

FIG. 1 is a sectional view of a joint unit embodying the present invention.

FIG. 2 is an example of a joint unit using a magnetic fluid as a sealing material.

FIG. 3 is an example of a multi-joint unit in which joint units are connected.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 joint unit 2 ball 3 socket 4 electrorheological fluid 5 O ring 6 fitting groove 7 spacer 8 cylinder 9 storage chamber 10 filling hole 11 piston 12 spring adjusting screw 13 spring 14 ball joint 15 socket joint 16 multi-joint unit 17 fixed wall

Claims (2)

[Claims] 1. A joint fitting surface of a joint joint is made of a conductor,
A joint unit comprising a power supply means for filling a gap between the fitting surfaces with an electrorheological fluid and applying a voltage to the electrorheological fluid. 2. The joint unit according to claim 1, wherein the joint joint is composed of a socket and a ball fitted therein.