JPH05197B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an arm mechanism, and relates to a nuclear fuel reprocessing plant,
The present invention relates to an arm mechanism that can be used for manipulators used in various fusion reactors and other general manipulators.

[Technical background of the invention and its problems]

Generally, in a reprocessing plant or each fusion reactor, periodic inspections and maintenance of various types of equipment are performed by remote control using robots, unmanned vehicles, etc. equipped with manipulators. This is to prevent workers from being exposed to radiation.

On the other hand, robots and the like must enter and exit the reprocessing plant through a limited-sized loading/unloading entrance during periodic inspections and the like. Therefore, a manipulator attached to a robot or the like is formed so that it can contract and become small enough to pass through a carry-out port, and can extend and move within a wide working space.

However, conventional manipulators have a large number of arm mechanisms of a fixed length that are connected to each other using joints so that they can be bent freely, and there is a limit to how compact the manipulator can be, and the range of motion of each arm mechanism is limited. It was limited to the range of the sum of lengths.

[Purpose of the invention]

The present invention has been made in view of these points, and an object of the present invention is to provide an arm mechanism that can extend and contract the length of the arm itself and can be connected to other members so as to be relatively movable in three dimensions. shall be.

[Summary of the invention]

The arm mechanism of the present invention has three sets of double screw type telescoping machines erected in parallel on a proximal base at equal intervals on the circumference, and a spherical shaft at the tip of each of these telescoping machines. The present invention is characterized in that the joints are respectively attached, each of these spherical shaft joints is attached to the tip base so as to be slidable radially from the center thereof, and each extendable machine is provided with a telescopic drive mechanism for extending and contracting the telescopic machine.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 6.

1 and 2 show the entire arm mechanism of the present invention, and reference numeral 1 in the figures indicates a circular proximal base. On this proximal base 1, three sets of double-screw type telescoping rods 2 are fixed in an upright state parallel to each other at positions equally dividing the circumferential direction. Each telescopic rod 2 is formed by a fixed cylinder 3 fixed to the proximal base 1, a first screw rod 4, and a second screw rod 5. A spherical shaft joint 6 is connected to the tip of each second screw rod 5.
A circular tip base 7 is attached via. A telescopic drive mechanism 8 is provided at the upper end of each telescopic rod 2 to extend and retract the respective screw rods 4 and 5.

The first screw rod 4 is formed into a hollow cylindrical shape, and has a male threaded portion 4a on its surface and a female threaded portion 4b on its inner surface. The male threaded portion 4a and female threaded portion 4b are threaded in opposite directions. A male screw portion 5a is provided on the surface of the second screw rod 5, and is screwed into the female screw portion 4b of the first screw rod 4. Further, on the inner surface of the fixed tube 3, a female threaded portion 3a is formed to be screwed into the male threaded portion 4a of the first screw rod 4. Furthermore, a single keyway 4c is carved in the outer circumference of the first screw rod 4 in the axial direction. In this keyway 4c,
A key 9a driven into the output shaft gear 9 is engaged. As shown in FIG. 3, the output shaft gear 9 is rotatably housed in the fixed tube 3 so that the first screw rod 4 can be rotated by a key 9a. The output shaft gear 9 meshes with the input shaft gear 10. The input shaft gear 10 is rotated forward and backward by a motor 11. The motor 11 includes a reduction gear 11a and an encoder 11b. This motor 11
is fixed to the fixed cylinder 3. Next, the configuration of the spherical joint 6 fixed to the tip of the second screw rod 5 will be described. A ball seat 6a of the spherical joint 6 is fixed to the tip of the second screw rod 5, and a pin 12 is attached to the ball 6b.
passes through the pin 12 so that the ball 6b can slide on the pin 12 in the axial direction. Both ends of the pin 12 are supported by pin receivers 13, 13.
is fixed to the tip base 7. In this way, the spherical joint 6 can freely slide in the axial direction of the pin 12. The arrangement of these three sets of pins 12 is shown in FIG. As shown in the figure, the pins 12 are radially arranged at equal positions in the circumferential direction within the surface of the circular tip base 7. Next, the arrangement of the limit switches 14a and 14b for detecting the operating limits of expansion and contraction will be explained. A shark dog 4d is fixed to the rear end of the first screw rod 4 for operating the limit switches 14a and 14b. Limit switch 14
a and 14b are fixed to the fixed tube 3 at two locations apart. This distance corresponds to the maximum movable extension/contraction distance of the first screw rod 4. An opening 3 is provided in the mounting portion of the fixed cylinder 3 for the limit switches 14a, 14b.
b, 3b, and the operation of the dog 4d can be seen. As a result, the limit switches 14a, 1
The position of the dog 4b is adjusted so that the switch is operated when the dog 4d reaches each limit switch.

The arm mechanism thus formed is used, for example, as one arm member of a manipulator, and the other members of the bases 1 and 7 may be connected using appropriate connecting means. It goes without saying that by using the distal end base 7 of the arm mechanism as the distal end base 1 of the arm mechanism ahead thereof, the arm mechanism of the present invention can be continuously used to construct a manipulator that is extendable and retractable with multiple degrees of freedom.

Next, the operation of this embodiment will be explained.

First, as shown in FIGS. 1 and 5, when the distal end base 7 is made parallel to the proximal end base 1 to extend the arm to its full length, the motors 11 of each telescopic drive mechanism 8 are rotated in the same direction. As a result, each input shaft gear 1
0 causes each output shaft gear 9 to rotate at a constant speed, and each first screw rod 4 rotates at a constant speed together with the output shaft gear 9 via the key 9a. The female screw portion 3a of the fixing tube 3, into which the male screw portion 4a of the first screw rod 4 is screwed, has a fixed relationship with the motor 11, so the first screw rod 4 extends upward at the bit of the male screw portion 4a while rotating. Go.

On the other hand, each of the second screw rods 5 screwed into the inside of the first screw rod 4 has a spherical shaft joint 6 at the tip of the pin 1.
2 to the tip base 7, and is in a non-rotatable state by a pin 12. Therefore, when the first screw rod 4 rotates, the female screw portion 4 of the first screw rod 4
b is threadedly engaged with the male threaded portion 5a of the second screw rod 5,
In addition, since the female screw portion 4b of the first screw rod 4 and the male screw portion 4a of the first screw rod 4 have a reverse thread relationship, the second screw rod 5 also extends upward from the fixed tube 3 at the same time as the second screw rod 5. 1 extends upward relative to the screw rod 4. In this way, each second screw rod 5 extends upward at a constant speed, so that the distal base 7 is always kept parallel to the proximal base 1.

On the other hand, when each motor 11 is rotated at a constant speed in the opposite direction, each first screw rod 4 is screwed into each fixed seat 3 at a constant speed, and each second screw rod 5 is screwed into each first screw rod 4 at a constant speed. Therefore, the tip base 7 can be housed while always remaining parallel.

When the motors 11 are rotated at non-uniform speeds, the amount of extension of each telescoping rod 2 becomes non-uniform, and the distal base 7 becomes inclined with respect to the proximal base 1. The direction of the tip base 7 is uniquely determined by the length of each telescoping rod 2, and by changing the length of each telescoping rod 2, it can be tilted in any direction. If the length of each telescopic rod 2 is uneven in this way, the sixth
As shown in the figure, the spherical joint 6 moves the pin 12 on its axis and settles in a stable position. Tip base 7
Spherical joint 6 at each pin 12 when tilted
The position is uniquely determined from the inclination angle and direction of the tip base 7. In this way, the three motors 11 can move the tip base 7 three-dimensionally. In addition, the telescopic rod 2 can extend and contract from the shortest state to the longest state, and its operating range is extremely wide, making it useful as an arm member such as a manipulator. Furthermore, since the square spherical shaft joints 3 provided at the tips of the three sets of double screw type telescoping rods 2 are attached to the tip base 7 so as to be slidable radially from the center,
Even if there is a difference in the expansion and contraction of the three sets of telescopic rods 2, twisting of the base end base 1 and the distal end base 7 can be prevented.

[Effects of the Invention] As explained above, the arm mechanism of the present invention can extend and contract the length of the arm itself, can be connected to other members so as to be relatively movable in three dimensions, and is extremely compact. will be stored in. Therefore, it is suitable for carrying in and out through narrow entrances and exits, and since it is extended long, its operating range is wide, and it is effective when used in manipulators etc. that need to avoid obstacles. Furthermore, each spherical shaft joint provided at the tip of the three sets of double-threaded telescoping rods is attached to the tip base so that they can slide radially from the center, so even if there are differences in the expansion and contraction of the three sets of telescoping rods, , the inclination angle and direction of the tip base are uniquely determined, and
Twisting of the distal base and the proximal base can be prevented.

[Brief explanation of the drawing]

The drawing shows one embodiment of the arm mechanism of the present invention, and shows the first embodiment of the arm mechanism of the present invention.
The figure is a partially cutaway side view, FIG. 2 is a sectional view taken along the - line in FIG. 1, FIG. 3 is an enlarged sectional view taken along the - line in FIG. 5 is a partially cutaway side view showing the action of the arm mechanism in FIG. 1, and FIG. 6 is a side view showing the action near the pin 12 in FIG. 1. 1... Base end base, 2... Telescopic rod, 3... Spherical shaft joint, 7... Tip base, 8... Telescopic drive mechanism.

Claims (1)

[Claims] 1. On the proximal base, three sets of double screw type telescoping machines are set up in parallel at equal intervals on the circumference, and a spherical shaft joint is attached to the tip of each of these telescoping machines. Each spherical shaft joint is attached to the tip base,
Installed so that it can slide radially from its center,
An arm mechanism characterized in that each telescoping machine is provided with a telescoping drive mechanism that extends and retracts the telescoping machine.