JPS5871094A - Wrist mechanism for robot - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wrist mechanism for a robot, and particularly to a robot having a rotational drive source for controlling the posture of a tool with respect to a workpiece in the wrist portion, and a core wire, a hose, a cable, etc. attached to the tool. The present invention relates to a wrist mechanism for a robot suitable for.

In order to avoid interference between the rotary drive source installed at the wrist of the robot to control the attitude of the tool with respect to the workpiece, and the core wire, hose, cable, etc. attached to the tool, the rotary drive source is placed far above the rotary drive source. Passing cables etc. Therefore, the length of the cable, etc. becomes long, and there is a risk that the welding robot may have trouble supplying the core wire, or the entire cable, etc. may fall sideways.If a support member is provided to prevent this sideways fall, it is difficult to There is a problem where the cable etc. bends sharply at the support member.

It is an object of the present invention to eliminate the problems of the prior art and to control the attitude of the tool with respect to the workpiece.The purpose of the present invention is to eliminate the interference between the one-way drive source provided at the wrist of the robot and the core wire, hose, cable, etc. attached to the tool. To provide a p-bond wrist mechanism that avoids this and allows the cables and the like to be smoothly arranged with a short length.

A feature of the present invention is that a hollow first rotary shaft and a second rotary shaft inserted into the hollow first rotary shaft are respectively installed at the tip of the robot arm in a direction perpendicular to the mounting surface of the robot pace. A first rotating body and a second rotating body are connected to one end and the other end of the first rotating shaft so as to rotate together, and the first rotating body The first thing is. A third rotating shaft, which is a tool mounting shaft, is provided in a direction perpendicular to the second rotating shaft, and the third rotating shaft is drivingly connected to the second rotating shaft, and is attached to the outer surface of the second rotating body. A rotary drive source is installed at an eccentric position with respect to the second rotary shaft, the second rotary shaft is drivingly connected to the rotary drive source, and the core wire attached to the tool attached to the #E3 rotary shaft is attached. , hoses, cables, etc. are passed through the open space on the rotating shaft of Wg2 in the second rotating body and are supported so that they can rotate together with the second rotating body. The above objective was certainly achieved.

Hereinafter, the present invention will be explained based on the drawings.

1 and 2 show an embodiment of the present invention. As shown in FIG. 1, a rotating table 2 is attached to a fixed pace 1, and a yoke 3 is attached to the rotating table 2. A parallel linkage mechanism is attached through the parallel linkage.

The parallel link mechanism includes a first link mechanism, as shown in FIG.
A link 4, a second link 5, a third link 6, and a fourth link 7, which are robot arms, are combined into a parallelogram.

The yoke 3 includes a first. A second motor 8, 9 is provided, and the third motor. The connection part of the fourth link 6.7 has a third
A motor 10 is provided. By driving the first motor 8, the first link 4 is rotated in the direction of arrow a in FIG. 1, and the second link 5 is moved in the direction of arrow X, thereby driving the second motor 9. In particular, the fourth link 7 is rotated in the direction of the arrow Y, and the second link 5 is linked to move in the direction of the arrow Y through the interlocking of the third link 6. Further, by driving the motor 10 of the ag3, the sprocket 11 connected to the third motor 10, the chain 712 stretched within the third link 6, the second... The rotational force is applied in this order to the sprocket 13 provided at the joint between the third links 4 and 5, the chain 14 stretched inside the second link 5, and the sprocket 15 provided at the tip of the second link 5. is transmitted, and the first
The rotating shaft 24 of the rotating shaft 24 can be rotated. Furthermore, within the parallel link mechanism, the sprocket)
Parallel to the rows of chains 11 and 13 and the rows of chains 12 and 14, there is a tin plate for controlling the posture of the first and second i-axes 24 and 26 in a direction that is always perpendicular to the mounting surface 11 of the pace 1. A six-butt row and a chain row i are provided, but only the sprocket 20 thereof is illustrated in FIG.
Other sprocket rows and chain rows are omitted.

At the tip of the second link 5 as a robot arm,
As shown enlarged in FIG. 2, a sleeve 23 411 is attached, a hollow first rotating shaft 24 is supported on the sleeve 23 via a bearing 25, and a second rotating shaft 24 is supported on the rotating shaft 24 of the WXggl. A shaft 26 is inserted through these first. The second rotating shafts 24 and 26 are provided so that they can rotate independently. Note that the reference numeral 27 in FIG. 2 indicates a bearing of the second rotating shaft.

The first rotating shaft 24 is connected to the tin rocket 11°13.
A sprocket 15 drivingly connected to the rows of chains 12 and 14, a shaft 16 supported by a bearing 17, bevel gears 18 and 18', and a key 19 are rotated by rotational force transmitted in this order. It looks like this.

Said 1st. As mentioned above, the second rotating shafts 24 and 26 are connected to a sprocket 20 linked to a tin rocket row and a chain row for attitude control provided inside the parallel link mechanism, and supported by a bearing 22. The posture is always controlled in a direction perpendicular to the writing surface 1' of the pace 1 through the posture control disk 21 and the sleeve 23 integrally connected thereto.

A cylindrical first rotating body 28 is connected to one end of the first rotating shaft 24, and a gearbox-shaped second rotating body 36 is connected to the other end via a set screw 7. First of all, the first rotating body 28 and the second rotating body 36 are designed to be able to rotate together with the first rotating shaft 24.

A bearing box 29 is integrally connected to the first rotary body 28, and the first rotary body 28 is connected to the bearing box 29 through a bearing 31, as shown in FIG. Second rotating shaft 24, 2
A third rotating shaft 30 is supported in a direction perpendicular to 6.

A tool can be attached to the third rotating shaft 30, and #! In the embodiment shown in FIG. 1, a torch 33, which is a welding tool, is attached via a torch holder 32. In FIG. 1, reference numeral 34 indicates a core wire supplied through the torch, 35 a conduit cable connected to the torch and supplying the core wire, and 35' a clamper for the conduit cable.

On the other hand, as shown in FIG.
The fourth motor 38, which is a co-rotating drive source, is installed at an eccentric position with respect to the rotating shaft 26, and the fourth motor 38
The rotating shaft 39 and the second rotation @26 JP-A-58-71
094(3) is an interval! They are arranged parallel to each other. Therefore, the fourth motor 38 can rotate in accordance with the rotation of the second rotating shaft 26 as the second rotating body 36 rotates.

By driving the fourth motor 38, the second rotating shaft 26 is rotated through the rotating shaft 39 of the fourth motor 38 and the gears 40 and 40' housed in the second rotating body 36. drive connection for rotation.

Further, as shown in the second name, when the second rotating shaft 26 is driven, the third rotating shaft 36 is connected to the second rotating shaft 26 and is provided inside the first rotating body 28. a harmonic reduction gear 41 connected thereto, a flex spline 42 connected thereto, and a shaft 43 connected to the flex spline 42 and supported by the first rotating body 28 via a bearing 44.
, bevel gears 45, 45' attached to the shaft 43 and the third one-rotation shaft 3o and housed in the bearing box 29,
The torch 33 is driven and connected so as to be rotated multiple times by the rotational force sequentially transmitted to the key 46, and is configured to be able to control the attitude of the torch 33 with respect to a plurality of keys (not shown).

9 (i) A rotation angle detector 47 whose height is significantly lower than that of the fourth motor 38 is installed at the center of rotation on the second rotating body 36, and the cough rotation angle detector 47 The rotation angle of the third rotation shaft 300 is detected through the second rotation shaft 26, and the attitude of the torch 33 with respect to the workpiece can be detected.

The conduit attached to the torch 33, which is a tool, is passed through the space near the center of rotation on the second rotating body 36, which is opened by installing the fourth motor 38 at an eccentric position with respect to the first and second rotating shafts 26. A cable 35 is arranged, and this conduit cable 35 is connected to the clamper 3.
5', and is supported so as to rotate together with the second rotating body 28.

In the robot of the above embodiment, by driving the turning table 2, a parallel link mechanism consisting of links 4 to 7 of tX1 to 4, a second link 5 which is a robot arm,
The interlocking member attached to the distal end of the torch 33 and the torch 33, which is a tool, rotate together in the direction of arrow 0 shown in FIG.

10 L[ By driving the first motor 8 attached to the yoke 3, the first link 4 rotates in the direction of arrow a, and the second link 5, which is the robot arm, rotates in the direction of arrow X. move parallel to.

Furthermore, by driving the second motor 9 attached to the yoke 3, the fourth link 7 rotates in the direction of the arrow, and through the interlocking movement of the third link 6, the second motor 9, which is the robot arm, rotates. The link 5 moves in parallel in the direction of arrow Y.

The wrist mechanism of the above embodiment operates as follows.

That is, 3rd. When the third motor 10 provided at the connection part of the fourth link 6.7 is driven, the tin rocket 1
1 and 13 and the chain 12 t-14 are interlocked, the sprocket 15 provided at the tip of the second link 5 is rotated, and then the shaft 16 and bevel gears 18 and 18 are rotated.
', the first rotating shaft 24 is rotated through the key 19, and then the first rotating body 28 and the bearing box 29 are rotated 260 times on the second rotating shaft, and the tool mounting tool supported by the bearing box 29 is rotated. The torch 33, which is a tool, is moved through the rotating shaft 30 in Figs. 1 and 2.
The torch 33 is rotated in the direction of the arrow shown in the figure, and the attitude of the torch 33 relative to the workpiece is controlled.

Meanwhile, the first. The second rotation axes 24 and 26 include a sprocket row and a chain row provided in the parallel link mechanism, a sprocket 20 provided in the second link 5, an attitude control disk 21 attached thereto, and a sleeve 23. The posture of the pace 1 is controlled so that it is always perpendicular to the mounting surface 1' of the pace 1.

As the first rotating shaft 24 is rotated, the second rotating body 36 is rotated synchronously with the first rotating body 28, and as a result, the bearing box 2 connected to the first rotating body 28 is rotated.
The torch 33 attached to the third rotating shaft 30 provided at Since they rotate together, the second rotating body 36
Interference between the fourth motor 38, which is a rotational drive source, installed at the center of the rotation above, and the cable 35, which is placed through the vicinity of the center of rotation on the second rotating body 36. Since the conduit cable 3.5 is not bent by the fourth motor 38, the core wire 34 can be supplied smoothly.

Further, since the conduit cable 35 passes through the open space at the center of rotation on the second rotating body 36, the length of the conduit cable 35 can be shortened.

Next, when the fourth motor 38 is driven, the second rotating shaft 26 is rotated via the gears 40 and 40' housed in the second rotating body 36, and then the harmonic reducer 41 reduces the speed. followed by flex spline 42
, a shaft 43, and a bevel gear 45 housed in the bearing box 29.
, 45', the third rotating shaft 30 is rotated through drive transmission across the key 46, and the torch 33, which is a tool attached to the third rotating shaft 30, is rotated in the direction of the arrow shown in FIG. and the posture is controlled relative to the workpiece.

Furthermore, this embodiment has the following advantages.

13 'Cr ■ Since the fourth motor 38 is arranged on one end side of the first rotating shaft 24 and the monolithic speed reducer 41 is arranged on the other end side, the inside of the first rotating shaft 24 is As a result of being able to suppress the transmission torque of the second rotating shaft 26 inserted through the
The second rotating shaft 26 can be made thinner, the width of the second link 5, which is the robot arm, can be made narrower, and a smaller fourth motor 38 can be used, so that the overall size can be reduced.

■ The bevel gears 18 and 45 are mounted on the paired bevel gears 18 and 45', and the bevel gears 18 and 45 are
Since the weight of each member is applied to 5', backlash can be eliminated without using special means such as springs.

■ It has three independent rotating parts, allowing the tool to operate in three degrees of freedom.

Note that the present invention is applicable not only to the illustrated welding robot but also to any robot that has a rotational drive source in its wrist for controlling the attitude of the tool relative to the workpiece, and that has a core edge, hose, cable, etc. attached to the tool. .

The non-invention is based on the above-described nine-dimensional structure, and according to the present invention, the first rotating body to which the tool is attached and the second rotating body to which the rotational drive source is installed are connected to the first rotating body. The core wire and hose attached to the tool are rotated together through the rotating shaft of the second rotating body.

Supporting cables etc., the first. Since the structure is such that the second rotating body and the cable etc. can rotate together,
Interference between the rotary drive source and the cable etc. can be avoided, and therefore there is an effect of eliminating all troubles such as the cable etc. being bent by the rotary drive source.

Further, according to the present invention, since the cable etc. are arranged through the space above the second rotating body which is opened by installing the rotary drive source at an eccentric position, the length of the cable etc. can be shortened. It also has the effect of allowing smooth placement.

[Brief explanation of drawings]

FIG. 1 is a front view of an embodiment of the present invention, and FIG. 2 is an enlarged sectional view taken along line 1-1 in FIG.

Claims (1)

[Claims] A hollow first rotating shaft and a second rotating shaft inserted therein are provided at the tip of the robot arm so that they can rotate independently in a direction perpendicular to the mounting surface of the robot pace. , at one end and the other end of the first rotating shaft.
A rotating body and a second rotating body are connected so that they can rotate together, and the first rotating body has a first rotating body. A third rotation axis, which is a tool mounting axis, is provided in a direction perpendicular to the second rotation axis, and the third rotation axis is a tool mounting axis.
a rotational shaft is drivingly connected to a second rotational shaft, a rotational drive source is attached to the outer surface of the second rotational body at an eccentric position relative to the second rotational shaft, and a second rotational drive source is attached to the rotational drive source at an eccentric position relative to the second rotational shaft The shafts are drivingly connected, and the core wire, hose, and cables attached to the tool attached to the third rotating shaft are passed through the open space on the 1g2 rotating shaft in the second rotating body, and $2
A wrist mechanism for a robot, characterized in that the wrist mechanism is supported so as to be able to rotate together with a rotating body.