JPH0852684A - Robot arm - Google Patents

Abstract

PURPOSE:To provide a robot arm simplifying a structure and reducing a cost to attain spreading an applicable range. CONSTITUTION:A robot arm comprises a base end arm part 11, first/second arm parts 13, 15 telescopically connected along the lengthwise direction relating to the base end arm part 11, arm extending/contracting sheave mechanisms 17, 19 having a wire 32 linked around to each arm part 11, 13, 15, drive motor 16 driving the arm extending/contracting sheave mechanisms 17, 19 and arm positioning mechanisms 19, 20 fixing each arm 11, 13, 15 in the respective extending/contracting positions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a general industrial machine, and more particularly to a robot arm used in an extreme atmosphere such as a high vacuum.

[0002]

2. Description of the Related Art Generally, a robot arm used in an extreme atmosphere such as a high vacuum is driven to expand and contract by a piston cylinder. FIG. 5 schematically shows a conventional telescopic drive type robot arm using a piston cylinder.

As shown in FIG. 5, a piston 102 is movably fitted inside a cylindrical cylinder case 101, and a robot arm (not shown) is attached to the piston 102 via a piston rod 103. There is. Further, the cylinder case 101 has two cylinder chambers 104 and 105 formed by the piston 102.
Then, the supply port 10 of each cylinder chamber 104, 105
Fluid supply paths 110 and 111 having supply valves 108 and 109 are connected to 6 and 107, respectively, and the fluid supply paths 110 and 111 are connected to a fluid pump 112.
In addition, the exhaust port 11 of each cylinder chamber 104, 105
Fluid supply paths 117 and 118 having discharge valves 115 and 116 are connected to 3 and 114, respectively, and the fluid discharge paths 117 and 118 are connected to a fluid tank 119.

Therefore, when the fluid pump 112 is driven and the fluid is supplied from the supply port 107 into the cylinder chamber 105 with the supply valve 109 and the discharge valve 115 opened, the cylinder chamber 105 is opened. The inside is pressurized and the piston 102 is pushed upward, and the robot arm extends via the piston rod 103. At this time, the fluid in the cylinder chamber 104 is discharged from the discharge port 113 to the fluid tank 119 through the fluid discharge passage 117. On the other hand, with the supply valve 108 and the discharge valve 116 opened, the fluid pump 112 is driven to move the fluid to the fluid supply path 1.
When it is supplied from the supply port 106 into the cylinder chamber 104 through 10, the inside of the cylinder chamber 104 is pressurized and the piston 102 is pushed downward, and the robot arm is contracted via the piston rod 103. At this time, the fluid in the cylinder chamber 105 flows from the discharge port 114 to the fluid discharge passage 1
It is discharged through 18 to the fluid tank 119.

[0005]

However, in the above-described conventional robot arm, the piston cylinder is driven by pressurizing the fluid to expand and contract the robot arm. When such a conventional robot arm is used under a high vacuum, a high degree of cleanliness is required, and thus a high sealing property is required to contain a fluid. It is difficult to satisfy this high sealing property, which causes a problem that the mechanism is upsized and the cost is increased.

The present invention solves such a problem, and an object of the present invention is to provide a robot arm having a simplified structure and a reduced cost to expand its application range.

[0007]

A robot arm according to the present invention for achieving the above object comprises a base end arm portion and a plurality of base end arm portions which are extendably and contractably connected to each other along a longitudinal direction. Arm portion, a pulley mechanism for arm extension and a pulley mechanism for arm reduction having wires hung around each arm, and a pulley mechanism for arm extension and a pulley mechanism for arm reduction provided on the base end arm portion. And a arm positioning mechanism for fixing the respective arms at their respective expansion / contraction positions.

[0008]

When the pulley unit for arm extension is driven by the drive unit, the wire is pulled and the plurality of arm units extend along the longitudinal direction with respect to the base end arm unit. The position is retained. on the other hand,
When the arm retracting pulley mechanism is driven by the drive unit, the wire is pulled, and the plurality of arm units are contracted along the longitudinal direction with respect to the proximal end arm unit, and the arm positioning mechanism holds the position in the contracted position of each arm. It

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing a robot arm according to an embodiment of the present invention, FIG. 2 is a plan view showing an arm extension pulley mechanism of the robot arm, and FIG. 3 is a plane showing an arm contraction pulley mechanism of the robot arm. FIG. 4 shows a schematic view of the robot arm positioning mechanism.

As shown in FIGS. 1 to 3, in the robot arm of this embodiment, the base end arm portion 11 has a box-like shape, and a concave portion 12 which opens in one side in the longitudinal direction is formed inside. The first arm portion 13 has a box shape like the base end arm portion 11, and the outer peripheral portion is the recess 1 of the base end arm portion 11.
It is slidably fitted in the housing 2 and has a concave portion 14 which is open to one side in the longitudinal direction. The second arm portion 15 has a rod-like shape, and the outer peripheral portion of the second arm portion 15 has a concave portion 14 of the first arm portion 13.
It is slidably fitted to. In this way, the base arm part 1
The 1st and 1st arm part 13 and the 2nd arm part 15 are each expandably connected along a longitudinal direction. A stopper (not shown) is provided between the arm portions 11, 13 and 15 to regulate the amount of extension of each stopper.

With respect to the base end arm portion 11, the first arm portion 13 and the second arm portion 15 drive the arm extension pulley mechanism 17 and the arm contraction pulley mechanism 18 by a drive motor 16 as a drive portion, respectively. The arms 13 and 15 can be fixed at appropriate expansion / contraction positions by the arm positioning mechanisms 19 and 20.

That is, the base end arm portion 11 has a support shaft 21 drivingly connected to a drive motor 16 at one end thereof and a drive pulley 2 attached to the support shaft 21.
2 is fixed, and pulleys 23, 24 are pivotally attached to one side of the base end arm portion 11 at predetermined intervals. The first arm portion 13 is provided on one side thereof with a predetermined gap, and the pulley 2
5,26 are pivotally attached. A pulley 27 is pivotally attached to the base end of the second arm portion 15. A pulley 28 is pivotally attached to the proximal end of the base end arm portion 11 so as to face the pulley 23, and a pulley 30 is pivotally attached adjacent to the pulley 28. The first arm 13 has a pulley 25 at its base end.
A pulley 29 is pivotally attached so as to face with. Second arm section 1
The pulley 5 has a pulley 31 coaxially attached to the pulley 27. The middle portion of one wire 32 is wound around the drive pulley 22, and one end of the wire 32 is fixed to the tip portion of the first arm portion 13 via the pulleys 23, 24, 25, 26, 27.
Is locked to. The other end of the wire 32 wound around the drive pulley 22 is locked to a fixing pin 34 fixed to the base end of the first arm portion 13 via pulleys 28, 29, 30, 31.

Therefore, the drive motor 16 and the drive pulley 2
2. The pulleys 23, 24, 25, 26, 27 and the wires 32 wound around the pulleys 17 constitute the arm extension pulley mechanism 17, and the drive motor 16 and the drive pulley 22 and the pulleys 28,
A wire 32 around 29, 30, and 31 constitutes a pulley mechanism 18 for arm reduction.

The arm positioning mechanisms 19 and 20 are
As shown in FIG. 4A, it is provided on both sides of the base end arm portion 11 and the first arm portion 13. The arm positioning mechanisms 19 and 20 have substantially the same structure, and the base end is locked to the base end arm portion 11 or the first arm portion 13 and the tip end is pressed against the first arm portion 13 or the second arm portion 15. The locking member 35 and the mounting bolt 36 that holds the locking member 35. Then, as shown in FIG. 4B, the locking member 35 is attached to the leaf spring 36 by the heat insulating material 3.
The shape memory alloy 39 is fixed to the first arm 13 or the second arm 15 with the shape memory alloy 39 fixed to the first arm 13 or the second arm 15. There is.

Therefore, the first arm portion 13 is provided with respect to the base end arm portion 11 or the second arm portion is provided with respect to the first arm portion 13.
The arm portion 15 expands and contracts, and the arm positioning mechanism 19, 20
When frictional heat is generated in the pressure contact portion of the locking member 35 in
The shape memory alloy 39 exceeds the transformation point and deforms the entire locking member 35 to reduce the frictional resistance. Then, when the expansion and contraction of the arm portions 13 and 15 stop,
Frictional heat is not generated in the press contact portion of the locking member 35, and the shape memory alloy 39 returns to the original state of the locking member 35 to increase the friction resistance. By adjusting the tightening force of the mounting bolt 36, the pressure contact force of the locking member 35 with respect to the first arm portion 13 or the second arm portion 15 is changed, and the first arm portion with respect to the base end arm portion 11 is changed. 13 and the movement start order of the second arm unit 15 are set.

Thus, as shown in FIG. 1, the drive motor 1
When 6 is driven to rotate the drive pulley 22 in the direction A in the figure, the wire 32 is pulled in the same direction via the pulleys 23, 24, 25, 26 and 27. Then, the base arm part 1
The first arm portion 13 extends with respect to 1, and the second arm portion 15 extends with respect to the first arm portion 13. At this time, from the drive pulley 22, each pulley 28, 29, 30, 31
The wire 32 is paid out through the wire 32, and the number of pulleys and the attachment position are set so that the pulling amount and the paying amount of the wire 32 are equal on the expansion side and the contraction side of the wire 32. Then, at the extended position of each arm 13, 15, it is held at a predetermined stop position by each locking member 35 of the arm positioning mechanism 19, 20.

On the other hand, when the drive motor 16 is driven from the extended position of the arms 13 and 15 to rotate the drive pulley 22 in the direction B in the figure, the pulleys 28, 29, 30 and 31 are moved in the same direction. The wire 32 is pulled. Then, the first arm portion 13 contracts with respect to the base end arm portion 11, and
The second arm portion 15 contracts with respect to the first arm portion 13. At this time, from the drive pulley 22, each pulley 23, 24,
The wire 32 will be paid out via 25, 26, and 27. Then, when the arms 13 and 15 are in the contracted position, they are held at predetermined stop positions by the locking members 35 of the arm positioning mechanisms 19 and 20.

In the above embodiment, the robot arm is composed of the base end arm portion 11, the first arm portion 13 and the second arm portion 15, but the number of arms is not limited to the embodiment. .

[0020]

As described above in detail with reference to the embodiments, according to the robot arm of the present invention, a plurality of arm portions are telescopically connected to the base end arm portion along the longitudinal direction, Since a pulley mechanism for arm extension and a pulley mechanism for arm reduction which have a wire wound around each arm and are driven by a drive unit, and an arm positioning mechanism for fixing each arm at each expansion and contraction position are provided. It can be simplified and excellent in manufacturability and maintainability, and a large reduction in cost can be achieved. As a result, it can be used in an extreme atmosphere such as a high vacuum and its application range can be expanded.

[Brief description of drawings]

FIG. 1 is a perspective view showing a robot arm according to an embodiment of the present invention.

FIG. 2 is a plan view showing an arm extension pulley mechanism of a robot arm.

FIG. 3 is a plan view showing an arm reducing pulley mechanism of a robot arm.

FIG. 4 is a schematic view showing a positioning mechanism of a robot arm.

FIG. 5 is a schematic diagram of a telescopic drive type robot arm using a conventional piston cylinder.

[Explanation of symbols]

 11 Base End Arm 13 First Arm 15 Second Arm 16 Drive Motor 17 Arm Extension Pulley Mechanism 18 Arm Reduction Pulley Mechanism 19, 20 Arm Positioning Mechanism 35 Locking Member

Claims (1)

[Claims] 1. An arm extension for use, comprising: a base end arm portion; a plurality of arm portions connected to the base end arm portion so as to be extendable and contractible along a longitudinal direction; and a wire wound around each arm. A pulley mechanism and a pulley mechanism for arm reduction, a drive unit provided in the base end arm portion for driving the pulley mechanism for arm extension and the pulley mechanism for arm reduction, and an arm for fixing each arm at each expansion / contraction position. A robot arm having a positioning mechanism.