JPH0265981A - Industrial robot - Google Patents

Abstract

PURPOSE:To increase strength with a simple structure and to enlarge an operation range by using a pair of speed reducers on a driving mechanism, sliding to the side of an adjacent like the opposing links constituting a parallelogram by making it at the same side and making the rocking axis of a wrist at the same side as a 1st link. CONSTITUTION:In case of turning 1st driving mechanism and 2nd driving mechanism in a clockwise direction, a 1st output part and 2nd output part are rocked in a clockwise direction at high torque and low speed, and 1st link 11 and 2nd link 12 are rocked with a fulcrum 10C as the axis as well. A parallelogram link 18 is squeezed and becomes in a diamond shape, but now, there is no interference between adjacent links and it is squeezed until the insides of the links opposed in parallel are brought into contact, and the operation range is enlarged. Also, due to the line connecting the center of the whirling axis of a wrist 15, the fulcrum of each joint and the axial center of the whirling of a frame 10 being on a straight line, the moment load applied on the bearing of each joint is reduced, the life of bearing of each joint is extended and the strength of the whole body is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an industrial robot, and particularly to the configuration of an arm of a vertically articulated robot and its drive mechanism.

(Prior Art) FIG. 6(a) is a side view of a conventional vertically articulated robot using parallelogram links, and FIG. 6(b) is a front view showing a frame rotatably mounted on an installation base 6. 7 has the first link 1. Second link 2, third link 3, fourth link 4
are connected in a parallelogram shape by rotation joints 3a, -4a, and 4b. In an industrial robot with this configuration, the more the parallelogram links are collapsed, the wider the range of motion becomes. However, this is also limited by interference between links as shown in FIG. 7(a).

Therefore, there are some links in which the interference part of one link is cut out, as shown in the lower part of FIG. 7(b), or is recessed, as shown in the upper part. It is also possible to shift the swinging surfaces of adjacent links laterally as shown in Fig. 7(c), but the width of the drive mechanism (
If W) in Figure 6 becomes wider, it will hit peripheral equipment when turning, so it is necessary to install the ball screw and link inside the frame, or change the direction of the axially long output shaft of the motor with a hooked gear to sandwich the width W. There is.

(Problems to be Solved by the Invention) Preventing interference between links in this way not only complicates the shape of the links, but also reduces strength if the operating range is expanded.

Therefore, in horizontal articulated robots, there is an offset mechanism (FIG. 7(C)) for the link swing surface that has been used in recent years.

However, in the case of vertical multi-joints, this diagram, in which the width W of the mechanical part is wide, cannot be adopted.

Therefore, it is an object of the present invention to provide a vertically articulated industrial robot with parallelogram links that can increase strength and expand the range of motion with a simple configuration.

[Structure of the invention]

(Means and effects for solving problem 11) In the present invention, the proximal ends of a first link and a second link are attached to a drive mechanism on the upper part of a frame that rotates on a base, and the proximal end is attached to the distal end of the second link. One end of the fourth link is connected to the tip of the third link which is parallel to the first link to which In a vertically articulated industrial robot with a wrist at the other end of the four links, a pair of eccentric differential speed reducers is used as the drive mechanism, and opposing links of the links forming a parallelogram are It is a vertically articulated industrial robot that has a simple structure, high strength, and a wide range of motion by moving it to the same side as the adjacent link and setting the wrist swing axis on the first link side of the fourth link. .

(Example) Hereinafter, an example of the industrial robot of the present invention will be described with reference to the drawings.

In FIG. 1, on the base 6, there is a drive mechanism 9, the details of which will be described later in FIG.
A frame 10 to which a frame 10 is attached is rotatably attached to the base 6 approximately at the center thereof by a drive device (not shown) having a drive shaft.

The clevis portions 10a and 10b have a fulcrum 1
A first link 11 whose upper part swings back and forth about 0c is installed vertically, and a second link 12 whose left part also swings up and down is attached to the left side of the first link 11 as shown in FIG. 1(b). It is installed offset. Furthermore, the rear end of the second link 12 has an upper part that swings back and forth about the joint 8, and a weight 13 at the lower end.
A third link 13 to which a is attached is attached vertically in parallel with the first link 11, and on the upper end of this third link 13 and the upper left side of the first link 11, the third link 13 and the joint 17 are connected to the first link 13. A fourth link 14 connected to the link 11 by a joint 16 is attached horizontally, and the first link to the fourth link form a parallelogram link 18. At the tip of the fourth link 14, there is a The lower end of a crank 20 is fixed to a rotating shaft 15a on the left side of the wrist 15 which swings.

Further, the lower end of a triangular plate 32 is swingably attached to the left side of the joint 16, and a rod 33 is connected parallel to the first link 11 to the left side of the upper left end of the triangular plate 32 and to the left side of the clevis portion 10a. The right side of the upper right end of the triangular plate 32 and the crank 20
A rod 31 is connected in parallel to the fourth link 14 on the right side of the tip.

Next, in FIG. 2 showing the A-A cross section of FIG. 1, a flange 22c having a substantially concave cross section and a disk shape when viewed from the right is fixed to the right clevis portion 10b coaxially with the fulcrum 10c.
A bearing 11b is inserted into the outer periphery of the left end of this flange 22c, and a flange 23c having a bearing 11a inserted into the outer periphery of the right end is similarly fixed to the left clevis portion 10a.

Further, between the clevis parts 10a and 10b, there is provided a first output part I9, which has a roughly cylindrical cross-section and a cylindrical shape when viewed from the right, with bearings 11a and llb inserted into the inner periphery of the left and right ends, and this first output part The lower end of the first link 11 is fixed to the outer peripheral upper surface of the link 19 .

Further, a second output section 25 having a substantially concave cross section is attached to the center of the first output section 19 via a bearing 11c near the line of action of a force, which will be described later, between the clevis sections 10a and 10b. , a notch hole 19 is provided at the left outer edge of the second output section 25.
The base end of the second link 12 passing through is fixed, and the second link 12 has bearings 8a and 8b inserted into the tip of the shaft 8c protruding to the right end across the line of action of a force to be described later. The lower ends of the three links 13 are connected to form a joint 8.

Further, between the left side of the flange 22c and the right side of the inside of the first output section 19, an eccentric differential type reducer (for example, Teijin Seiki Co., Ltd. RV reducer,
A speed reducer (hereinafter referred to as a speed reducer) 22b is fixed, and the right side (input side) of this speed reducer 22b is attached to the right side of the flange 22c, and the output shaft of the servo motor 22a is inserted to form the first drive device 22. There is. Similarly, flange 23c
An output shaft of a servo motor 23a whose output side (that is, right side) is fixed to the second output part 25 and is attached to the left side of the flange 23c is input between the right side of the servo motor 23a and the inside of the left side of the second output part 25. A speed reducer inserted on the side is connected to constitute the second drive device 23.

Furthermore, in FIG. 3 showing the BB cross section of FIG. 1.

At the intermediate joint 16 of the fourth link 14, the fourth link 1
A line (hereinafter referred to as the line of action of force) L passing through the center G of the hand processing device mounting surface of the wrist 15 parallel to the fourth link 14 is placed between the base end and the tip of the shaft 16c protruding to the right side of the fourth link 14. Bearings 16a and 16b are installed on the upper left and right sides of the link 11,
Similarly, at the joint 17 at the rear end of the fourth link, the fourth link 14
The upper end of the third link 13 is connected to the upper end of the third link 13 via bearings 17a and 17b, which are attached to the proximal end and the distal end of a shaft 17c that protrudes to the right side, with the line of force acting therebetween.

As a result, the line of action of the force is shown in FIGS. 1 to 3 between the drive shaft (not shown) between the base 6 and the frame 10 and the drive machine
i! ! The bearings 11a and llb of the drive mechanism 9, the bearings 8a and 8b of the joint 8, the bearings 16a and 16b of the joint 16, and the bearings 17a and 17b of the joint 17 are They are installed across the line of action.

Next, the operation of the industrial robot configured as described above will be explained.

First, in FIG. 1(a), when the first drive unit a22 and the second drive mechanism 23 are turned clockwise, the first output part 19 and the second output part 15 swing clockwise at high torque and low speed. Then, the first link 11 and the second link 12 also move clockwise to the fulcrum 10c.
Swings around the axis. Then, the parallelogram link 18 becomes the fourth
As shown by the dashed line in the figure, it collapses into a diamond shape, but there is no interference between adjacent links, and the links collapse until the inner sides of the parallel opposing links come into contact, expanding the operating range.

Also, since the line connecting the center of the rotation axis of the wrist 15, the fulcrum of each joint, and the axis of rotation of the frame 10 is in a straight line,
The moment load applied to the bearings at each joint is reduced, the force life of the bearings at each joint is extended, and the overall strength of the robot is increased.

Furthermore, in FIG. 4, the angle of the crank 2o is always constant, so even if there is no swinging actuator on the front and rear of the wrist 15, the mounting surface of the hand effector at the tip of the wrist will always be in a constant direction (for example, , when facing downward, the fourth link 14
It always points downward regardless of the elevation angle. ), it is easy to teach, especially in bullet rigging work.

Furthermore, in FIG. 4, no matter what position the wrist 15 moves,
Since the distance ratio of the weight 13a to the fulcrum 10c is constant, for example, when transporting workpieces of the same weight, the base 6
It is possible to reduce the increase in moment applied to

Further, in FIGS. 1 and 2, the width W of the drive mechanism 9 is approximately the width of only the first drive device 22 and the second drive device 23, and can be made narrower, thereby reducing interference with peripheral equipment.

FIG. 5 shows another embodiment of the industrial robot of the present invention,
The attachment part of the second link to the second output part is thinned by 180 degrees, and a stopper 23d is placed in the center of the surface of the flange 23c (the right side in FIG. 5(b)) opposite to that surface.
is installed. As a result.

It is possible to easily set a movement limit for the vertical movement of the fourth link 15 (during the downward movement, surfaces A and 8 in FIG. 5(a) touch, and during upward movement, the surfaces 0 and 0 touch).
By changing the width and position of 3d, the operating limit can be set arbitrarily.

〔Effect of the invention〕

As described above, according to the present invention, the base ends of the first link and the second link are attached to the drive mechanism provided at the upper part of the frame attached to the base via the pivot shaft.

A third link whose base end is connected to the tip of the second link is provided parallel to the first link, and a fourth link whose base end is connected to the tip of the third link is provided in the middle part of the first link. In an industrial robot whose tips are connected to form a parallelogram from a first link to a fourth link, and a wrist is attached to the tip of the fourth link, a pair of reducers is used in the drive mechanism to form a parallelogram. The opposing links that make up the shape are on the same side and shifted to the side of the adjacent link, and the pivot axis of the wrist is on the same side as the first link, resulting in a vertical multi-joint with a simple structure, high strength, and a wide range of motion. industrial robots can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an embodiment of the vertically articulated industrial robot of the present invention, Fig. 1(a) is a side view, Fig. 1(b) is a front view, and Fig. 2 is the same as Fig. 1. 3 is a detailed view of the BB-B cross section of FIG. 1, FIG. 4 is an explanatory view showing the action of the industrial robot of the present invention, and FIG. 5 is a detailed view of the industrial robot of the present invention. FIG. 6 is a detailed view of the main parts showing another embodiment, and FIG. 6 is a diagram showing the configuration of a conventional vertically articulated industrial robot.
) is a side view, FIG. 6(b) is a front view, and FIG. 7 is an explanatory view showing the operation of a conventional vertically articulated industrial robot. 6...Base 9...Drive mechanism 10...Frame 11...First link 12...Second link 13...Third link 14...Fourth link 15...Wrist 18 ...Parallel links 22b, 23b...Eccentric differential type reducer (873
3) Representative patent attorney Yoshiaki Inomata (and 1 other person) (α) (b) Figure 1 Figure 2 O is the point of action of the A-AIX product suspension, and the B-BIJjT side of the A-A X-shaped figure (b) Figure Figure

Claims (1)

[Claims] A drive mechanism is provided at the top of the frame that rotates on the base, the base ends of the first link and the second link are attached to this drive mechanism, and a third link is provided at the tip of the second link in parallel with the first link. The base ends of the links are connected, the rear end is connected to the tip of the third link, and the fourth link is provided in parallel with the second link, the rear end being connected to the tip of the first link, and forming a parallelogram. In the vertical articulated robot comprising a link and having a wrist attached to the tip of the fourth link, a pair of eccentrics are attached to the clevis part of the upper part of the frame, and the output side is attached to the proximal ends of the first link and the second link. A core differential type speed reducer is provided, the first link and the third link, the second link and the fourth link are on the same side, and the adjacent links are shifted laterally, and the swing axis of the wrist is moved to the fourth link. An industrial robot, characterized in that the industrial robot is provided on a side surface of the first link.