JPH1058372A - Industrial robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow an easy assembly work and make a robot compact, regarding an industrial robot having a second robot arm connected to the end of a first robot arm via a joint, and a wrist fitted to the second robot arm so as to be capable of freely turning around an axial line on a plane orthogonal the axial line of the joint. SOLUTION: A second robot arm 7 is formed to have a movable bracket 6b projected upward behind from one W-axial lateral side of the back of a flat disc part 7a along a plane orthogonal with the turning axial line of a wrist 8. Furthermore, a fixed bracket 6a is projected from the end of a first robot arm 5 so as to be dislocated toward the other W-axial lateral side of the back of the disc part 7a, and the movable bracket 6b is connected to the fixed bracket 6a in a cantilever form via the drive reducing gear Rw of the second robot arm 7. Also, a drive motor Mv for the wrist 8 is mounted on one W-axial lateral side of the back of the disc part 7a, so as to be positioned below the movable bracket 6b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a first robot arm which can swing vertically and a second robot arm which is attached to the tip of the first robot arm via a joint so as to swing vertically. And a wrist rotatably mounted on a second robot arm around an axis on a plane orthogonal to the axis of the joint.

[0002]

2. Description of the Related Art Conventionally, in an industrial robot of this kind, a joint portion at the tip of a first robot arm is configured to have a double-sided support structure that supports a second robot arm on both axial sides of the joint portion. However, this has the disadvantage that the structure of the joint becomes complicated and assembly becomes troublesome, and the axial dimension of the joint becomes large, making it difficult to miniaturize the robot.

As disclosed in Japanese Patent Application Laid-Open No. 57-27685, the joint at the tip of the first robot arm is
The second robot arm is configured to have a cantilever structure in which the first robot arm is cantilevered in the axial direction of the joint via a drive reducer for the second robot arm, and the second robot arm is connected to the joint. There is also known one that is attached from one side in the axial direction to facilitate assembly.

[0004]

In the conventional art provided with a cantilevered joint, the second robot arm is attached to the first robot arm offset to one axial side of the joint. However, the offset increases the axial dimension of the joint, and a torsional load acts on the first robot arm via the second robot arm, thereby adversely affecting the positioning accuracy of the robot.

SUMMARY OF THE INVENTION In view of the above, the present invention provides an industrial robot having a joint portion having a cantilever structure to facilitate assembly and to reduce the size and improve the positioning accuracy of the robot. The challenge is to do.

[0006]

Means for Solving the Problems In order to solve the above problems,
In the present invention, the first robot arm swingable in the vertical direction, the second robot arm attached to the tip of the first robot arm via the joint part so as to be swingable in the vertical direction, An industrial robot comprising: a wrist rotatably mounted on an axis on a plane orthogonal to an axis of a joint, wherein the joint is a first robot arm and a first robot arm is a first robot arm.
In a cantilever structure in which the robot arm is supported in a cantilever manner in the axial direction of the joint via a drive speed reducer for the second robot arm, the second robot arm is configured such that the axial direction of the joint is a lateral direction. Is constructed by projecting a movable bracket extending rearward and upward on one lateral side of the back surface of a flat plate-shaped portion along a plane perpendicular to the rotation axis of the wrist, The joint portion is configured by projecting a fixed bracket at the tip end so as to be deviated to the other side in the lateral direction, a movable bracket facing the fixed bracket, and a drive reducer for the second robot arm between the two brackets. A wrist drive motor is mounted on one side of the back of the board-shaped portion of the second robot arm below the movable bracket, and a wrist drive connected to the drive motor is provided on the front of the board-shaped portion. For deceleration It is attached to the wrist through.

According to the present invention, the axial dimension of the joint can be kept within the lateral width of the first robot arm.
Since the drive motor of the wrist can be arranged under the movable bracket so as to overlap the joints with good space efficiency, the length of the second robot arm can be shortened, and the robot can be downsized.

[0008] The board-like portion of the second robot arm is also a first robot arm.
Since the arrangement can be made so as to fit within the lateral width of the robot arm, the torsional load acting on the first robot arm via the second robot arm can be reduced, and the positioning accuracy of the robot can be improved.

When the wrist drive motor is mounted as described above, the drive motor is disposed offset with respect to the rotation axis of the wrist. As a result, the wrist and the wrist of the second robot arm are displaced. A hollow part penetrating along the rotation axis of the wrist is formed with the drive reducer, and a wiring member for a member provided on the wrist is inserted into the hollow part, so that the wiring can be neatly arranged. it can.

It is preferable that a rib is provided on the outer surface of the movable bracket so as to surround a connecting portion of the second robot arm to the drive reduction gear, thereby reinforcing the movable bracket. In this case, the rib is surrounded by the rib. By using the divided space as a wiring space for a wiring member for a drive motor on a wrist or a wiring member for a member provided on a wrist, wiring can be neatly arranged.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 3, reference numeral 1 denotes a bed which is elongated in the front-rear direction, and is driven by a drive motor Mx along a guide rail 1a on the bed 1 via a ball screw mechanism (not shown). A movable table 2 is provided, which is movable in the X-axis direction, which is the front-rear direction, and a robot body 3 that is rotatable around a vertical Z-axis is mounted on the movable table 2. A first joint 4 is provided at the upper end of the robot body 3, and a first robot arm 5 extending forward is attached to the joint 4 so as to be vertically swingable about a horizontal Y axis.
A second joint 6 is provided at the tip of the first robot arm 5,
A second robot arm 7 is attached to the joint 6 so as to be vertically swingable about a W axis parallel to the Y axis, and a wrist 8 is attached to a tip of the second robot arm 7 on a surface orthogonal to the W axis. It is mounted so that it can rotate around the V axis. The wrist 8 is provided with a tool mounting plate 8a rotatable around a U-axis orthogonal to the V-axis via a drive motor (not shown) and a speed reducer built therein, and thus X, Z, An industrial robot having six degrees of freedom of Y, W, V, and U is configured.

A shelf 2a is attached to the movable table 2. A cable support 9 is erected on one side of the rear end of the shelf 2a, and a wiring member is provided between the bed 1 and the cable support 9. , A distributor 11 is attached to the back side of the robot body 3, and a flexible cable tube 12 is disposed between the shelf 2 a and the distributor 11.
The wiring member is connected to the distributor 11 from the cable receiving stand 9 through the cable tube 12, and power is supplied from the distributor 11 to the drive motor Mz for the robot body 3 and the drive motor My for the first robot arm 5. A drive motor Mw for the second robot arm 7, a drive motor Mv for the wrist 8, and a drive motor built in the wrist 8 via a wiring member introduced into the first robot arm 5 through the inside of the robot body 3. Power is supplied to In FIG. 1, reference numeral 1b denotes a rail cover attached to the bed 1.

As shown in FIG. 4, the robot main body 3 has a base 3a on which a drive motor Mz is erected, and a cover bolted to the base 3a so as to cover a position where the drive motor Mz is disposed from above. And a base 3a.
Robot body 3 connected to the drive motor Mz
Is mounted, and the robot body 3 is placed on the movable table 2 via the speed reducer Rz. As shown in FIGS. 5A and 5B, the reduction gear Rz
1, a shaft R3 pivotally supported in the case R1 via a pair of bearings R2, and a pair of planetary gears R5 and R5 engaged with pins R4 mounted at equal intervals on the inner peripheral surface of the case R1. Three crankshafts R6 pivotally supported at three places in the circumferential direction of the shaft R3 to revolve a pair of planetary gears R5 and R5 with a phase difference of 180 °, and spur gears at the end of each crankshaft R6. It comprises a cyclo reducer having an input gear R8 meshing with R7. And the reduction gear Rz
The case R1 and the shaft R3 are respectively bolted to the base 3a and the movable table 2, and the output shaft of the drive motor Mz is connected to the input gear R8.
As a result, the robot main body 3 is turned around the Z axis via the speed reducer Rz.

The first joint 4 moves the first robot arm 5 to the robot main body 3 in the axial direction (Y-axis direction) of the first joint 4 via the drive reduction gear Ry of the first robot arm 5. It has a cantilever structure with a cantilever structure. In this case, the first robot arm 5 is connected to the robot body 3
However, if the robot is mounted offset to the side in the Y-axis direction, it is difficult to reduce the size of the robot, and an eccentric load acts on the robot main body 1 via the first robot arm 5 to reduce the positioning accuracy of the robot. Adverse effects.

Therefore, in this embodiment, the robot body 3
To the upper end of the cover portion 3b to one side in the Y-axis direction.
A fixed bracket 4a for the joint 4 is protruded, and a movable bracket 4b for the first joint 4 opposed to the fixed bracket 4a is formed on the other end of the tail end of the first robot arm 5 in the Y-axis direction. The first joint 4 is formed by disposing a drive reduction gear Ry of the first robot arm 5 between the brackets 4a and 4b. Thus, the dimension of the first joint 4 in the axial direction (Y-axis direction) is set within the width of the robot body 3 in the Y-axis direction, so that the size of the robot can be reduced. Since it is contained within the axial width, the unbalanced load acting on the robot body 3 is reduced,
The positioning accuracy of the robot can be improved. Further, in the present embodiment, the first joint 4 is provided directly above the position where the drive motor Mz of the robot main body 3 is disposed, so that the Y-axis is not offset from the Z-axis in the front-rear direction.
The size of the robot body 3 in the front-rear direction is shortened to further reduce the size of the robot.

The drive reduction gear Ry of the first robot arm 5
Is composed of a cyclo reduction gear similar to that shown in FIGS. 5A and 5B, and the case R1 and the shaft R3 of the reduction gear Ry are bolted to the fixed bracket 4a and the movable bracket 4b, respectively. Then, the output shaft of the drive motor My for the first robot arm 5 attached to the outer surface of the fixed bracket 4a is connected to the input gear R8 of the reduction gear Ry.
The first robot arm 5 is vertically swung by the drive motor My via the speed reducer Ry.

As shown in FIG. 6, a rib 4c is provided on the outer surface of the movable bracket 4b of the first joint 4 so as to surround a connecting portion to the speed reducer Ry.
By this, the movable bracket 4b is reinforced, and the mounting strength of the first robot arm 5 to the first joint 4 is ensured. A lid plate 4d that covers a space surrounded by the rib 4c is attached to an outer end surface of the rib 4c. Then, a flexible cable tube 13 is disposed in the space,
The lower end of the tube 13 faces the transparent window 3c opened on the side surface of the cover 3b of the robot body 3, and the upper end of the tube 13 faces the transparent window 4e opened above the movable bracket 4b. Drive motor Mw and wrist 8
A wiring member for supplying power to the driving motor Mv for use and a driving motor built in the wrist 8 is introduced from the distributor 11 into the first robot arm 5 through the inside of the robot body 3 and the cable tube 13. In this way, the space surrounded by the ribs 4c can be used as a space for arranging the wiring member, so that the wiring can be neatly arranged. In the drawing, reference numeral 14 denotes a cable holding piece provided in the first robot arm 5 for holding a wiring member.

As shown in FIGS. 7 to 9, the second joint 6 at the tip of the first robot arm 5 is used to move the second robot arm 7 to the first robot arm 5.
In the axial direction (W) of the second joint 6 via the drive reduction gear Rw of
It has a cantilever structure that cantileverly supports in the axial direction). In this case, if the second robot arm 7 is attached to the first robot arm 5 so as to be offset laterally in the W-axis direction, it is difficult to reduce the size of the robot, and the first robot arm 5 is attached to the second robot arm 5. 7, a torsional load acts, which adversely affects the positioning accuracy of the robot.

Therefore, in the present embodiment, the second robot arm 7 includes a flat plate-like portion 7a along a plane perpendicular to the rotation axis (V-axis) of the wrist 8, and a back surface of the plate-like portion 7a. A movable bracket 6b for the second joint 6 extending upward and rearward, protruding from one side in the W-axis direction, and being biased toward the other side in the W-axis direction toward the tip of the first robot arm 5. The movable bracket 6b is opposed to the fixed bracket 6a for the projecting second joint 6, and the second bracket 6a
The drive reduction gear Rw of the robot arm 7 is arranged.
Thus, the dimension of the second joint 6 in the axial direction (W-axis direction) is
Since the robot can be downsized by being accommodated within the width of the robot arm 5 in the W-axis direction, and the board-shaped portion 8a of the second robot arm 7 can also be accommodated within the width of the first robot arm 5 in the W-axis direction. The second robot arm 7 is attached to the robot arm 5
, The torsional load acting on the robot can be reduced, and the positioning accuracy of the robot can be improved. Further, in the present embodiment, FIG.
As shown in the figure, the drive speed reducer R of the first robot arm 5
y and the drive speed reducer Rv of the second robot arm 7 are arranged so as to intersect the same center plane a including the Z axis which is the turning axis of the robot main body 3, and the first and second joints The central portions of the shafts 4 and 6 in the axial direction are located on the center plane a. Therefore, the first robot arm 5 and the second robot arm 7
Since the entire arm consisting of the arm extends along the center plane a, the offset load acting on the robot body 3 can be reduced as much as possible, and the positioning accuracy of the robot can be further improved, and there is no offset. Teaching becomes easy.

The drive reduction gear Rw of the second robot arm 7
Is composed of a cyclo reduction gear similar to that shown in FIGS. 5A and 5B, and bolts the case R1 and the shaft R3 of the reduction gear Rw to the fixed bracket 6a and the movable bracket 6b, respectively. doing. Then, a drive motor Mw for the second robot arm 7 is horizontally provided at an intermediate portion of the first robot arm 5, and a driven pulley 15b connected via a belt 15 to a drive pulley 15a on an output shaft of the motor Mw. The shaft is connected to the input gear R8 of the speed reducer Rw, and the drive motor Mw drives the second gear through the speed reducer Rw.
The robot arm 7 is configured to swing up and down. In the figure, reference numeral 16 denotes a belt cover attached to the first robot arm 5.

A drive motor Mv for the wrist 8 is mounted on one side in the W-axis direction on the back surface of the disk-shaped portion 7a of the second robot arm 7 below the movable bracket 6b. The wrist 8 is attached to the front surface of the shaped part 7a via a drive reduction gear Rv of the wrist 8 connected to the drive motor Mv. According to this, the drive motor Mv for the wrist 8 can be arranged in a space-efficient manner so as to overlap the second joint 6, so that the length of the second robot arm 7 can be shortened and the robot can be downsized. It is advantageous above.

Also, on the outer surface of the movable bracket 6b,
A rib 6c is protruded so as to surround a connecting portion to the speed reducer Rw, and the movable bracket 6b is provided by the rib 6c.
To ensure the mounting strength of the second robot arm 7 to the first robot arm 5. Further, a cable cover 17 is attached to one side surface of the first robot arm 5 so as to extend forward from the arrangement portion of the drive motor Mw toward the movable bracket 6b, and a flexible cable tube 18 is provided in a space surrounded by the rib 6c. And the tube 18
One end of the tube 18 faces the inner surface of the distal end of the cable cover 17, and the other end of the tube 18 faces the outside of the space through the transparent window 6d formed in the rearwardly facing peripheral portion of the rib 6c. A wiring member for supplying power to the motor Mv and a drive motor built in the wrist 8 is connected to the cable tube 18 through the cable cover 17 from within the first robot arm 5.
To pass through. In this way, the space surrounded by the rib 6c can be used as a space for arranging the wiring member, so that the wiring can be neatly arranged.

The drive reduction gear Rv of the wrist 8 is shown in FIG.
The input gear R8 of the cyclo reducer shown in (B) is omitted, and the case R of the reducer Rv is formed.
1 and the shaft R3 are bolted to the disk-shaped portion 7a and the wrist 8 of the second robot arm 7, respectively. Here, the axis of the speed reducer Rv, that is, the V axis, which is the rotation axis of the wrist 8, is located on the center plane a including the Z axis, which is the rotation axis of the robot body 3, but the drive motor Mv for the wrist 8 is It is offset with respect to the V axis. Therefore, the drive motor Mv
A gear 19a meshing with a gear on the output shaft of the
The spur gear R7 is provided with a hollow shaft 19 to which a gear 19b meshes, and the drive motor Mv causes the wrist 8 to rotate around the V axis via the hollow shaft 19 and the speed reducer Rv. According to this configuration, the second robot arm 7
A hollow portion penetrating along the V-axis is formed in the disc-shaped portion 7a and the speed reducer Rv. Then, a pipe 20 is attached to the hollow portion, and the tube 1 is attached to the pipe 20.
A flexible cable tube 21 inserted through a wiring member for a drive motor built in the wrist 8 and derived from the wrist 8 is inserted so that the wiring of the wrist 8 can be neatly arranged.

A base 3 constituting the robot body 3
A fulcrum portion 22 that allows the cover portion 3b to be tilted forward is provided between the cover portion 3a and the cover portion 3b. Support part 22
May be constituted by a hinge for pivotally connecting the cover portion 3b to the base portion 3a so as to be able to tilt forward, but in the present embodiment, a protrusion 22a protruding from the lower end of the front surface of the cover portion 3b, 3a
And a receiver 22b protruding from the front surface of the cover 22b so as to face the lower side of the projection 22a, so that the cover 3b can be lifted by a crane or the like.

Further, the first robot arm 5 is extended rearward of the first joint 4, and a hook 23 made of a projection is provided on one side surface of the extension 5a. Then, at the time of maintenance, as shown in FIG. 10A, the first manually-operated winch 24 is swung while the first robot arm 5 is swung to the upper end position.
Is hooked on the hook portion 23, and a rope 24a such as a chain or a wire rope derived from the winch 24 is hooked on a hook portion 25 provided on one side of the end of the bed 1. In this state, the cover portion 3b is The bolt fixed to the base 3a is removed, and the manually wound winch 24 is operated in the direction in which the cable 24a is extended. According to this, the cover portion 3b is supported by the fulcrum portion 22 by the weight of the robot arms 5, 7 and the wrist 8, and tilts forward as shown in FIG.
The drive motor Mz covered with is exposed. Thus, even a robot arranged in a complicated place where a crane or the like cannot be arranged upward can perform the maintenance by exposing the drive motor Mz only by hand, and the maintainability is improved.

The hooks 23, 25 may be formed by holes, and the hooks 25 for the ropes 24a may be provided on the movable table 2 or the base 3a of the robot body 3.

[Brief description of the drawings]

FIG. 1 is a plan view of an example of the robot of the present invention.

FIG. 2 is a side view of the robot viewed from the direction of arrow II in FIG. 1;

FIG. 3 is a side view of the robot viewed from the direction of arrow III in FIG. 1;

FIG. 4 is a sectional view taken along the line IV-IV of FIG. 2;

5A is a longitudinal sectional view of a speed reducer, and FIG. 5B is a transverse sectional view of a speed reducer.

FIG. 6 is a right side view with a part of FIG. 4 cut away;

FIG. 7 is a sectional view taken along line VII-VII of FIG. 2;

8 is a sectional view taken along line VIII-VIII in FIG. 7;

9 is a sectional view taken along line IX-IX of FIG.

FIGS. 10A and 10B are views showing a tilting operation of the robot body during maintenance.

[Explanation of symbols]

Reference Signs List 5 first robot arm 6 joint 6a fixed bracket 6b movable bracket 6c rib 7 second robot arm 7a disk-shaped part 8 wrist Rw drive reducer for second robot arm Mv drive motor for wrist Rv drive reducer for wrist

Claims (3)

[Claims] A first robot arm which can swing vertically and a second robot arm which is attached to the tip of the first robot arm via a joint so as to be vertically swingable, and
An industrial robot comprising: a robot arm; and a wrist rotatably mounted on an axis on a plane orthogonal to the axis of the joint, wherein the joint is configured to move the second robot arm relative to the first robot arm. In a cantilever structure in which the joint portion is supported in a cantilever manner in the axial direction of the joint portion via a drive speed reducer for the second robot arm, the second robot arm is provided with A movable bracket is formed by projecting a movable bracket extending upward and rearward on one lateral side of the back surface of a flat board-like portion along a plane perpendicular to the rotation axis, and a horizontal bracket is provided on the distal end of the first robot arm. The joint portion is formed by projecting a fixed bracket so as to be deviated to the other side in the direction, disposing a movable bracket on the fixed bracket, and disposing a drive reducer for the second robot arm between the two brackets, B A wrist drive motor is mounted on one side in the lateral direction on the back side of the plate-shaped portion of the cut arm, and a drive motor for the wrist is attached to the front side of the plate-shaped portion via a drive reducer for the wrist connected to the drive motor. An industrial robot characterized by attaching a wrist. 2. A hollow portion which penetrates the board-shaped portion of the second robot arm and the drive speed reducer for the wrist along a rotation axis of the wrist and through which a wiring member for a member provided on the wrist is inserted. The industrial robot according to claim 1, wherein: 3. A rib is projected from an outer surface of the movable bracket so as to surround a connecting portion of the second robot arm to the drive reduction gear, and a space surrounded by the rib is provided by a wiring member for a drive motor on a wrist. The industrial robot according to claim 1, wherein the industrial robot is used in a space for arranging a wiring member for a member provided on a wrist.