JPH0451315B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an articulated arm.

Some robots and automatic machines are used to transport painting guns, welding torches, and inspection monitoring equipment into confined spaces during painting work, welding work, and maintenance inspection work within nuclear power plants. There is something that controls the arms of. These can provide a sufficient degree of freedom in the movement of the arm, but in some cases an arm that can move freely like an elephant's trunk is required.

As arms capable of such free movement, multi-joint gear type, multi-joint wire type, link type arms, etc. have already been proposed, but since these use motors, hydraulic pressure, or pneumatic pressure as the drive source, However, the disadvantage is that the entire device becomes heavy.

The present invention has been made to solve the above-mentioned drawbacks, and its purpose is to provide a lightweight multi-jointed arm.

In order to achieve the above object, the present invention divides a multi-jointed arm into a plurality of nodes along its entire length, and arranges a plurality of coiled shape memory alloys between each node, and
A bias spring is provided symmetrically to each shape memory alloy with respect to the center of the arm, and a cable is further provided to heat each shape memory alloy.

An embodiment of the present invention will be described below based on the accompanying drawings.

FIG. 1 is an overall side view of a multi-joint arm according to the present invention, FIG. 2 is a cutaway side view of the same multi-joint arm, and FIG.
The figures are a cross-sectional view taken along the line A--A in FIG. 2, FIG. 4 is an enlarged view of the joints, and FIG. 5 is an overall side view of the multi-joint arm showing the operating state.

As shown in FIG. 1, a monitoring device 2 is attached to the tip of the multi-joint arm 1.
The entire area is covered with a bellows 3 as shown in FIG. The interior of this multi-joint arm 1 is divided into a plurality of parts by a plurality of joints 4 arranged in the axial direction, and each joint 4 is connected by a shaft 5 having a universal joint at both ends. ing. Also, between each node 4 is a multi-jointed arm 1.
Bias spring 6 and shape memory alloys 7a, 7b, 7c, 7d (however,
7d is not shown. ) is provided.
A cable 8 for heating these is connected to the shape memory alloys 7a, 7b, 7c, and 7d.

Note that the bias spring 6 and the shape memory alloy 7a,
7b, 7c, and 7d are attached symmetrically with respect to the center of each node 4, and the arrangement of the bias spring 6 and the shape memory alloys 7a, 7b, 7c, and 7d is alternately exchanged for each node 4. It's summery.

When the multi-joint arm 1 is bent to the right, for example, as shown in FIG. The multi-joint arm 1 can be bent in a predetermined direction.

If the shape memory alloy 7c is bent in the opposite direction, the multi-joint arm 1 is bent in the left direction in FIG. 4 by heating the shape memory alloy 7c to return it to its contracted direction.

As described above, the multi-joint arm 1 can be freely bent three-dimensionally, and FIG. 5 shows the state when the multi-joint arm 1 is freely bent.

As is clear from the above description, according to the present invention, a lightweight shape memory alloy, a bias spring, and a heating cable are used as the actuator for bending the multi-joint arm, so the weight of the entire device can be reduced. In addition, the joints are configured along the entire length of the multi-joint arm, and the mounting position of the shape memory alloy is changed for each joint, increasing the degree of freedom of movement of the multi-joint arm and allowing it to move in multiple directions. This allows for flexible bending.

[Brief explanation of the drawing]

Fig. 1 is an overall side view of a multi-joint arm according to an embodiment of the present invention, Fig. 2 is a cutaway side view of the multi-joint arm, Fig. 3 is a sectional view taken along the line A-A in Fig. 2, and Fig. 4 5 is an enlarged view of the joints, and FIG. 5 is an overall side view of the multi-joint arm showing the operating state. In the drawing, 1 is a multi-jointed arm, 2 is a monitoring device, and 3 is a multi-joint arm.
is a bellows, 4 is a node, 5 is a shaft, 6 is a bias spring, 7a, 7b, 7c, 7d are shape memory alloys, 8
is a heating cable.

Claims (1)

[Claims] 1 The arm is divided into multiple nodes along the entire length, multiple coiled shape memory alloys are arranged between each node, bias springs are installed symmetrically with each shape memory alloy with respect to the center of the arm, and each An articulated arm characterized by being constructed by wiring a cable that heats a shape memory alloy.