JPH0411028Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial field of application) This invention relates to a support structure for a robot arm.

(Prior Art) A robot having a structure in which multiple arms rotate, that is, an articulated robot is disclosed in, for example, Japanese Patent Application Laid-Open No. 1986-
This type of robot needs to detect the amount of rotational displacement of the arm, so it is necessary to detect the amount of rotational displacement of the arm. A rotation detector such as a meter is used. In other words, the detector body of the rotation detector is fixed on the stationary side, and the rotating shaft of the detector is connected to the rotating shaft that rotates together with the arm via a coupling ring, etc., in order to detect the amount of rotational displacement of the arm. That's what I do.

(Problems to be Solved by the Invention) The conventional device described above has the following drawbacks. This is because the above-mentioned structure in which the rotating shaft of the detector is connected to the rotating shaft of the arm requires a large amount of space for mounting the detector. This means that the structure becomes complicated because it is necessary to use

This invention was made to solve the above-mentioned conventional drawbacks, and its purpose was to make the structure compact and simple while still detecting the rotational displacement of the arm in the same way as before. An object of the present invention is to provide a support structure for a robot arm.

(Means for Solving the Problems) Therefore, in the robot arm support structure of this invention, there is provided a detector main body 17a, and a rotating member rotatably supported by the detector main body 17a with its tip protruding from the detector main body 17a. The detector main body 17a of the rotation detector 17 having the shaft 19 is attached to the support member 1.
3 and 14, and a through hole 18 is provided in the support members 13 and 14 so that the tip of the rotary shaft 19 passes through the through hole 18 to the other side of the support members 13 and 14. A rotary bearing 20 is arranged in the through hole 18, and this bearing 2
0 rotatably supports the rotary shaft 19,
an arm 15 rotationally driven by a drive source 23;
16 is fixed to the distal end side of the rotating shaft 19, and the rotating shaft 19 also holds the arm 1.
5 and 16 are supported.

(Function) As described above, the rotation shaft 1 of the rotation detector 17
Since the arms 15 and 16 are directly fixed to and supported by the arm 9, the structure is compact and simple. In this case, even if a force from the arms 15 and 16 is applied to the tip side of the rotating shaft 19, the middle part of the rotating shaft 19 is supported by the supporting members 13 and 14 by the rotating bearing 20. This prevents the force from the arms 15 and 16 from being directly transmitted to the detector main body 17a, thereby preventing the detection accuracy from deteriorating.

(Example) Next, a specific example of the robot arm support structure of this invention will be described in detail with reference to the drawings.

Figures 2 to 4 show the overall structure of the robot, and as shown in the figures, this robot is relatively small, like a miniature robot for research.
A substantially cylindrical base 1 and a U-shaped frame 2 supported by the base 1 so as to be rotatable around a vertical axis.
and a link mechanism 3 movably supported by the frame 2. The base 1 has a top wall 4
A support shaft 5 extending vertically through the top wall 4 is rotatably supported via bearings 6, 6. A large-diameter gear 7 is fixed to the upper end of this support shaft 5, and the frame 2 is fixed to the upper end thereof, and a rotary shaft 9 of a potentiometer 8 is fixed to the lower end of this support shaft 5. It is connected. On the other hand, as shown in FIG. 2, a DC servo motor 10 is further attached to the back surface of the top wall 4, and the upper end of its output shaft 11 passes through the top wall 4 and is guided upward. A pinion 12 is attached to the lead-out end. The pinion 12 is engaged with the large-diameter gear 7, so that the motor 10 can rotate the support shaft 5 and the frame 2.

Further, the frame 2 includes a pair of frame parts extending parallel to each other in the vertical direction as shown in FIG. 3, that is, first and second frame parts 1 serving as supporting members.
3 and 14, a first arm 15 is rotatably supported on the first frame portion 13, and a second arm 16 is rotatably supported on the second frame portion 14. This support structure will be explained based on FIG. 1. First, in the first frame portion 13, a main body 17a of a potentiometer 17 as a rotation detector is attached to the outer surface of the upper portion thereof. A through hole 18 is formed in the first frame portion 13 at the mounting position of the potentiometer 17, and a rotary shaft 19 of the potentiometer 17 is formed in the first frame portion 13.
The distal end side is led out into the inside of the first frame portion 13 through the through hole 18 . As shown in the figure, a rotation bearing 20 is interposed between the inner circumferential surface of the through hole 18 and the outer circumferential surface of the rotary shaft 19.
is rotatably supported via a rotary bearing 20. A large-diameter gear 22 is attached to the tip side of the rotating shaft 19 via a collar 21, and one end of the first arm 15 is attached to a set screw (not shown) or the like further to the tip side. It is twisted and fixed. Note that the large diameter gear 22 and the first arm 15 are
It is fixed with a countersunk screw (not shown) or the like.
On the other hand, a DC servo motor 23 is attached to the outer surface near the lower end of the first frame part 13, and its output shaft 24 passes through a through hole 25 provided in the first frame part 13. led out to the inner side,
A pinion 26 is fixed to this lead-out end.
This pinion 26 is meshed with the large diameter gear 22, and the motor 23 drives the pinion 26.
6, the large diameter gear 22 is driven, thereby rotating the first arm 15 and rotationally driving the rotary shaft 19 of the potentiometer 17. Further, the support structure and drive mechanism of the second arm 16 relative to the second frame portion 14 are the same as those described above, so the same parts are denoted by the same reference numerals and the explanation thereof will be omitted. Note that the rotation axes of the first arm 15 and the second arm 16, that is, the rotation shafts 19, 19 of the potentiometers 17, 17 are arranged substantially on the same axis. A first link member 27 is rotatably supported at the tip of the first arm 15, and a second link member 28 is rotatably supported at the second arm 16.
The link member 27 and the second link member 28 are rotatably connected, and the first arm 15 and the second arm 1
6. The first link member 27 and the second link member 28 constitute a parallelogram link mechanism 3. Note that at the tip of the second link member 28,
Although not shown, a hand or the like is attached.

Next, the operating state of the robot will be explained. First, by driving the motor 10, the entire frame 2 and link mechanism 3 are rotated around the vertical axis, and the amount of rotational displacement at this time is detected by the potentiometer 8. The first arm 15 is also rotated by driving the motor 23 on the first frame portion 13 side, but in this case, the second link member 28 is rotated around the fulcrum A shown in FIG. Therefore, the amount of rotational displacement at this time is detected by the potentiometer 17 on the first frame portion 13 side. On the other hand, by driving the motor 23 on the second frame 14 side, the second arm 16
is rotated, thereby causing the second link member 28 to rotate significantly, and the amount of rotational displacement in this case is detected by the potentiometer 17 on the second frame portion 14 side.

In the robot having the above structure, the rotary shaft 19 of the potentiometers 17, 17,
Since the first and second arms 15, 16 are directly supported by the arms 19, the arms 15, 16
There is no need to separately provide a supporting shaft, so the structure is compact and simple. In this case, even if a force from the link mechanism 3 side acts on the rotary shafts 19, 19 of the potentiometers 17, 17, the intermediate portions of the rotary shafts 19, 19 are supported by the rotary bearings 20, 20. Therefore, the above-mentioned force can be prevented from being directly transmitted to the internal mechanism of the potentiometers 17, 17, and therefore the detection accuracy will not be reduced.

FIG. 5 shows a modified example of the robot, in which the portion above the frame 2 is replaced by a rail 29.
It was designed to run on top of the vehicle. In the figure, 30 is a sliding part provided on the frame 2 side, 31 is a running motor, 32 is a sprocket driven by the motor 31, 33 is a drive chain, and 34
1 and 2 respectively indicate potentiometers for detecting the traveling position. The structure of other parts is the same as that of the first embodiment, so the same parts are denoted by the same reference numerals and the explanation thereof will be omitted.

(Effect of the invention) In the robot arm support structure of this invention, the arm is supported on the rotating shaft of the rotation detector as described above, and the middle part of the rotating shaft is supported by a rotating bearing. Therefore, it is possible to make the support structure of the arm compact and simple, and it is also possible to prevent the detection accuracy from decreasing due to the force acting from the arm side.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of an embodiment of the robot arm support structure of this invention, FIG. 2 is a partially cutaway side view thereof, and FIG. 3 is a sectional view taken along the line - in FIG. 2. FIG. 4 is an overall perspective view thereof, and FIG. 5 is an overall perspective view of a modified example. 13...first frame part, 14...second frame part, 15...first arm, 16...second arm, 17...potentiometer, 17a...potentiometer body, 18...through hole , 19... Rotating shaft, 20... Rotating bearing, 23... Servo motor.

Claims (1)

[Scope of utility model registration request] The detector body 17a of the rotation detector 17 has a detector body 17a and a rotating shaft 19 rotatably supported by the detector body 17a with its tip protruding from the detector body 17a. This support member 13,
14 is provided with a through hole 18, and the tip of the rotating shaft 19 is inserted through the through hole 18 into the supporting member 13,
A rotary bearing 20 is arranged in the through hole 18 to rotatably support the rotary shaft 19, and the drive source 23
A support structure for a robot arm, characterized in that arms 15, 16, which are rotatably driven by a robot, are fixed to the distal end side of the rotary shaft 19, and the arms 15, 16 are also supported by the rotary shaft 19.