JPS6116076Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a robot arm that is used in an industrial robot and moves while receiving driving force from a motor or the like.

Generally, in an articulated robot arm, the frame body is formed to have a U-shaped cross section, and a cover plate is attached to the U-shaped opening to form a box shape. Further, a rotating shaft is welded to one side of the frame body and is pivotally supported by another arm, a machine stand, etc., and is moved to a predetermined position by rotation of this rotating shaft.

Motors, drive shafts, gears, etc. for driving other arms, hands, etc. are assembled inside such robot arms, and after these are assembled and adjusted, they are closed with a cover plate. However, the frame body and cover plate are thin plates, so when rotating,
The torsional rigidity around the longitudinal axis is relatively low when subjected to a reaction force generated during operation of the internal motor.

As a countermeasure to this problem, if the frame body and cover plate are made of thick material, the overall weight will increase, which will hinder the quick movement of the arm. Further, since it is necessary to repair parts such as a motor assembled into the frame body, it is impossible to attach a reinforcing material that permanently closes the opening of the frame body.

In consideration of the above facts, the present invention aims to provide a robot arm that is easy to assemble and repair parts within the frame body, and has high torsional rigidity.

In the robot arm according to the present invention, a frame-shaped reinforcing plate having a through hole for insertion of a motor, etc. is fixed around the opening of the frame body to improve torsional rigidity around the longitudinal axis of the arm.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, in this embodiment, a frame body 10 is made of a thin plate material such as aluminum and bent to have a U-shaped cross section, and the inner surface is used as a space for accommodating a motor and the like.

This frame body 10 has side plates 1 at both ends in the longitudinal direction.
2 and 14 are fixed to make the frame body into a box shape with one side open. Here, the side plate 14 is partially open to prevent the motor shaft from interfering with it and to maintain strength.

Further, the outer diameter of the frame body 10 gradually increases from one end where the side plate 12 is attached to the other end where the side plate 14 is attached.
The frame body 10 is located near the end where is attached.
A rotating shaft 16 is fixed in a direction perpendicular to the. This rotating shaft 16 is designed to be pivotally supported by another arm, a machine stand, etc. (not shown), and the frame body 10 is designed to rotate together with this rotating shaft 16 in response to a driving force from a motor or the like.

A side plate 1 is provided at the longitudinally intermediate portion of the frame body 10.
An intermediate plate 18 parallel to 2 and 14 is the frame main body 10.
is fixed to the inner periphery of the rotary shaft 16 and the rotating shaft 16. A motor (not shown) or the like can be attached to this intermediate plate 18, and can drive a wrist device attached to the side plate 12 via a drive shaft, gears, etc.

A reinforcing plate 2 is provided around the opening of the frame body 10.
0 and 22 are fixed.

By making the reinforcing plates 20 and 22 approximately the same thickness as the frame body 10, workability can be improved and welding distortion can be reduced without impairing welding performance when welding to the frame body 10.

The reinforcing plates 20 and 22 have a rectangular outer shape, and each has a rectangular insertion through hole 24 bored in its center. Therefore, the reinforcing plates 20, 22 are in the form of a frame in which through holes are formed except for the periphery.

The reinforcing plate 20 is located inside the frame body 10, on the side plate 1.
2 and to the inside of the intermediate plate 18. Further, the reinforcing plate 22 is located inside the frame body 10,
It is fixed to the other side of the intermediate plate 18 and to the inside of the side plate 14.

As shown in FIG. 2, these reinforcing plates are fixed to the frame body 10 at a position slightly moved from the opening end 10A toward the bottom surface 10B. This secures the welded portion 26 when the reinforcing plates 20, 22 are welded to the frame body.

A cover plate 28 is fixed to the tip 10A of the frame body 10, and this cover plate 28 is attached to the reinforcing plates 20, 22.
It is also possible to attach it closely to the In this case, screw holes for attachment screws may be drilled in the reinforcing plates 20 and 22.

In the robot arm of this embodiment configured as described above, the motor, drive shaft, gears, etc. can be assembled into the frame body 10 through the through holes 24 of the reinforcing plates 20 and 22, so that it is possible to assemble them. The work is significantly easier.

After the assembly is completed, the cover plate 28 is attached to the opening of the frame body 10, and the arm becomes ready for operation.

When the robot is in operation, the frame body 10 rotates together with the rotary shaft 16 and moves to a specified position, and the wrist attached to the side plate 12 and the hand supported by this wrist perform specified tasks using the driving force of the motor. During this operation, the frame main body 10 receives bending force and twisting force due to reaction force from the hand, etc.
Since the strength of the frame body is improved by the reinforcing plates 20 and 22, no major deformation occurs. Particularly, since a part of the reinforcing plates 20 and 22 are fixed to the intermediate plate 18, it is possible to sufficiently cope with the case where the central part of the frame body 10 has a structure that is susceptible to bending and torsional stress due to the load from the hand. can do.

When inspecting or repairing the arm, by removing the cover plate 28, a worker can easily inspect or repair the motor, drive shaft, etc. through the through hole 24.

In this embodiment, since the reinforcing plates 20 and 22 have the through holes 24, the weight increase of the entire arm can be suppressed to within 10%, and the opening area of the frame main body opening is reduced by about 33%. Workability will not be impaired by only using the On the other hand, the torsional rigidity of the arm is improved approximately five times, and the amount of deformation during movement is significantly reduced.

FIG. 3 shows an arm according to a second embodiment of the present invention.

In this embodiment as well, reinforcing plates 20 and 22 are fixed to the opening of the frame body 10.
A corner reinforcing plate 30 is fixed between each corner part 0B.

These corner reinforcing plates 30 are stretched across the opposing parts of the frame body 10 and the respective intersections of the side plates 12, 14 and the intermediate plate 18, thereby creating a gap between the frame body 10 and the side plates 12 or 14. Further, a triangular closed cross section is formed between the frame body 10 and the intermediate plate 18 to increase the strength of the corner portion.

These corner reinforcing plates 30 do not interfere with assembly into the frame main body 10, repair work, etc., and are designed to have further increased strength compared to the first embodiment. In addition, this corner reinforcing plate 30 is the reinforcing plate 2.
0,22 to the frame body 10,
The reinforcing plate 2 is used for positioning the reinforcing plates 20 and 22.
The distance between 0 and 22 and the bottom surface 10B of the frame body 10 can be uniform, which helps improve workability.

The means for fixing the reinforcing plates 20, 22 and the corner reinforcing plates 30 in each of the above embodiments is not limited to welding, but other means such as adhesion may also be used.

As explained above, in the robot arm according to the present invention, a frame-shaped reinforcing plate is fixed around the opening of the main body of the frame, which increases the torsional rigidity around the longitudinal axis while minimizing the weight increase of the arm and the opening area. It has an excellent effect that can improve the

[Brief explanation of the drawing]

Figure 1 shows the first part of the robot arm according to the present invention.
FIG. 2 is a sectional view taken along the line of FIG. 1, and FIG. 3 is a front view showing a second embodiment of the present invention. 10... Frame body, 12, 14... Side plate,
16... Rotating shaft, 18... Intermediate plate, 20, 22...
... Reinforcement plate, 24 ... Through hole for insertion, 30 ... Corner reinforcement plate.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A frame-shaped thin reinforcing plate having a through hole for insertion is fixed to an opening of a frame body having a substantially U-shaped cross section to increase torsional rigidity around the longitudinal axis. A robot arm featuring improved features. (2) A side plate and an intermediate plate are welded to the frame body at both longitudinal ends and an intermediate portion thereof, and the periphery of the thin reinforcing plate is fixed to the side surfaces of the frame body, the side plate, and the intermediate plate. The arm for a robot according to claim 1 of the above-mentioned utility model registration claim.