JPS6179587A - Parallel link 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] [Technical Field of the Invention] The present invention provides a method suitable for loading and unloading objects onto and from an automatic guided vehicle, for example. Regarding parallel link robots.

[Technical background of the invention and its problems]

Robots with multiple joints, such as articulated robots,
It is common practice to incorporate the motor and reducer inside the arm, but if the motor is housed inside the arm as in the case of Jin, space is used effectively, but the energy required to move the motor is unnecessarily consumed. As a result, the payload capacity will decrease accordingly. For this reason, conventionally, for example, as described in Japanese Patent Publication No. 56-22677.

For example, a hydraulic actuator such as a cylinder is attached to the lower end (first joint side) of the upper arm (first arm), and the lower arm (second arm) attached to the upper arm so that it can rotate freely The lower arm is connected to the actuator by an intermediate member and a lower arm support member to operate the lower arm. However, when transmitting power through the links in this way, it is necessary to increase the rigidity of the links in order to improve positioning accuracy, which increases the size and weight of the component parts, making the robot more compact, and increasing the weight of the components. It is not possible to reduce the weight of the vehicle, and there are various inconveniences when it is attached to an automatic guided vehicle and used for loading and unloading conveyed objects.

[Purpose of the invention]

The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a parallel link robot that is small, lightweight, and can be mounted on an automatic guided vehicle.

[Summary of the invention]

The present invention provides a rotatable input shaft of a reducer in which an input side rotation axis and an output side rotation axis are coaxially disposed on the other end of a first arm whose one end is rotatably supported on a base. A parallel link that directly rotates the input shaft of the reducer via a belt transmission mechanism, with one end of the second arm attached to the output side and a motor attached near one end of the first arm. It's a robot.

[Embodiments of the invention]

The details of the present invention will be explained below with reference to an embodiment shown in FIGS. 1 to U. This embodiment is mounted on an automatic guided vehicle for transporting wafers in the manufacture of semiconductor devices. Third
The figure shows the overall configuration, in which a robot (2) that loads and unloads wafers onto an automatic guided vehicle (1) is mounted. First, to explain the outline of the transport vehicle (1), the vehicle body (3) has a rectangular chassis (3a), and a pair of driving wheels (4), (4) are attached to the lower surface of the vehicle, diagonally apart from each other. and a pair of driven wheels (5) on the other diagonal.
, (5) is installed.

Both drive wheels (4) have the same configuration, and are attached to the chassis (3).
A casing (6) is fixed to a), and a wheel holder (8) is rotatably attached to this via a detail (7). This holds the wheel (9) rotatably and is also equipped with a travel motor (1G), which drives the wheel (9) at appropriate times.
A steering wheel (α) is installed inside, and a timing belt (not shown) rotates the details (power) and rotates the wheels (9).
) steering is performed. Note that these travel motors (irj
, the steering motor (17J) is controlled by a control device described later. Among the driven wheels (5), (5), one is a wheel holder (Is is a chassis ( 3a), and supports the vehicle body (3) elastically by a support spring aυ.The other driven wheel (5) is supported by a wheel holder against the vehicle body (3) K. (lω
is fixedly attached, and the wheels (14) are rotatably supported thereon. These wheels f9), (14)
On the vehicle body (3) supported by
8 is for traveling the transport vehicle (1) and driving the robot (2) (
It is used by switching alternately) and is a wireless device (L
Reference numeral 9 is for communicating with a higher-level control device, etc., and has a built-in control device or a microconbeater (not shown) to control the transport vehicle (1) and robot (2).

This conveyance vehicle (4) travels by receiving commands from a higher-level control device via the wireless device α-Y, or by a person directly giving commands from an instruction device. When driving, the guidance track sensor detects the route.

The control device +201 controls the steering motor 2 and the travel motor 4 so that the controller 201 travels along the track.

The above is a general description of the transport vehicle (1). Next, the robot (
Let's talk about 2). Robot (2) has vertical axis rotation part C!
It consists of a
A column (c) is fixedly erected above a.). This consists of a cylindrical member with a brim-shaped catch seat (2) formed at its upper end, and a motor (not shown), a reducer, and a pair of motors, whose rotational axis is a vertical axis in the vertical direction, is located halfway inside. Ball bearings (c), etc. are installed. Further, a rotary base plate is rotatably attached to the catch seat (3) via a bearing (c). This rotational pace (to) is the bearing (
A disk part holder supported by a ball bearing (a) extends downward in the center of this.

(to) and a vertical shaft part (7) supported vertically by (to), and this vertical shaft part (to) is connected to the above-mentioned motor (not shown) housed in the column (c) via a speed reducer. Additionally, the rotating base is driven by this motor.

Furthermore, a first limit sensor Gυ consisting of a photoelectric switch is provided on the catch Q4, a photoelectric conversion element (32a) is provided on the outside of the catch C4, and an actuating piece (32b) is provided on the outside of the disc portion 01. The actuating piece (32b) is attached to the photoelectric conversion element (32b) by one rotation of the base (c).
An electrical signal is emitted into the gap 32a) to restrict the rotation range of the rotation base.

Next, to explain about the horizontal axis rotation part (221, G11
) is a base made of a disc-shaped member, which is fixed to the disc-shaped part.

It rotates together with the rotating base Q mark. On this base 0υ, a pair of first joint supports (43, (43) are provided facing each other apart from each other. Between them, a first reducer (] -monic drive) (44 is connected to its input shaft) (High speed side”) G451
It is rotatably supported and installed vertically. The output side f41El of this first reduction gear (2) rotates concentrically with the input shaft (4).

One end υ of the first arm 6υ is attached to the output side 0Q, and the first arm 51 rotates together with the output side (46).

These first reducer (44, one end 51 of the first arm) and the first joint support (a, (43) form a first joint.

The input shaft (49 is the vJ1 joint axis. This input shaft (boo IJ 64) is attached to the 4th joint, and the first
The rotation of the first motor t5!5 attached to the joint support body (43) is transmitted via the timing belt (→), and the first arm (A) is connected to the horizontal input shaft (first joint shaft) 09.
Rotate around. The rotation of this first arm 6G is as follows.

the second limiter 67), that is, the first joint support G
The photoelectric conversion element (58&) attached to i3 and the actuating piece (58b) attached to one end 51) of the first arm ω
The υ turning range is regulated by a photoelectric switch consisting of.

Also, the rotation axis (45a) of the first joint shaft (input shaft) (9)
) and the vertical axis (to) of the rotation base (to) intersect at right angles.

As mentioned above, the first arm (to) has one end 61)
is a part of the first joint 53, and the other end is the second arm I3.
It is part of the second joint (goods) that connects with no. A motor mounting hole is formed near one end 6, into which a second motor for rotating the #c2 arm II is inserted and fixed. The other end of the first arm 60 is connected to the second joint support 1. It is a trowel, and the second reducer ff1)
The input shaft (high speed side) σa is rotatably supported. The second reducer συ is a harmonic drive, and one end 17!19 of the 21st-muri is attached to the 9th floor on the output side (low speed side), and the input shaft σ is the second joint shaft of the second joint. Therefore, the rotation of the second motor is controlled by a belt transmission mechanism consisting of a pulley decoy, a timing belt η and a pulley σ.
76a), the input shaft (7'; !J is rotated, and the second arm (G3 rotates around the It consists of a joint support gutter, [F]■, a second reducer σD, and one end (79) of the second arm 62. As mentioned above, the second arm 5li2/ has one end (c) connected to the The third joint riS3 is part of a two-joint phantom, and the other end is equipped with a connecting pin υ.
The hand support base is rotatably attached via a connecting pin (81) serving as a third joint shaft.

And the inner surface 0i4) of the 27th arm 63 is connected to the connecting pin [
It is provided offset outward by a distance t from the line connecting the second joint axis σ2 and the second joint axis σ2, and is formed to avoid mutual interference with the M1 arm mallet during turning. Further, a first articulated bar an and a second articulated bar are provided in parallel between the first arm 51 and the second arm, and each arm is connected to a first parallel link 03. A second parallel link is formed. That is, an L-shaped connecting member (G) is rotatably attached to the $22 input shaft (input shaft) σa, and one end of the first connecting rod a+) is attached to one side (E) of the L-shape. The other end is rotatably connected to a bracket fixed to the base @D. and the first articulated bar a1
) is equal to the distance between the axis (45 m) of the first joint shaft (45) and the axis (7211) of the second joint shaft ('73), and the height of the connection center of the bracket, is equal to the height of the axis (45a), and constitutes the first parallel link a.Also, the other side of the connecting member (g), the second arm I2, the other side and the hand support A second parallel link is similarly constituted by the second articulated rods and the hand support base, which are rotatably connected to each other.

With these configurations, even if the first arm aα and the second arm 6a rotate arbitrarily, one side (A) is always kept horizontal.

The other side (G) is kept vertical, and the surface (101) on which the hand support base is attached is always kept in a constant posture, in the vertical direction (vertical plane) in this embodiment. A hand rotating device (102) is attached to the surface (101). This contains a motor and reducer (not shown) inside.
A hand (103) is attached to the tip thereof, and the hand (103) rotates as the soter rotates. A finger (105) attached to the hand (103) is also a button that opens and closes as the motor (104) rotates. Further, a third limiter (106) is attached near the third joint axis υ of the hand support base. In other words, there are three photoelectric switches (108a) on the second arm side.
, (108b), (108C) are attached, and the corresponding actuating piece (109) is...
c) It is attached to the side. This results in the addition of the parallel link angles.

Next, the operation of this embodiment will be explained with reference to FIG. In this example, the robot is
One power supply device is used by switching when operating the robot, and includes a travel control CPU (121) and a robot control C'PU (122). Travel commands are sent via wireless etc. from the host controller to the travel control CPU (
121) When K is entered, the switching circuit (123) switches the power source to the running system. Next, the travel control circuit (124) is activated by a command from the travel control CPU (121), and each motor is driven by the travel drive circuit (125) and the steering circuit (126) to travel. When a predetermined stage, yK: is reached, travel is stopped, the travel control CPU (121) switches the stain source, and the switching circuit (131) connects the power to the robot system.

As a result, the robot is immediately returned to its origin, and the robot (2) is driven by the robot drive circuit (133) according to the program via the robot control circuit (132) in response to a command from the robot control CPU (122), and the robot (2) is A drop off will take place. Regarding the movement of each part of the robot (2), when the motor (not shown) in the column (c) is driven, the rotation pace (c) rotates, the base (4υ) rotates, and the horizontal axis rotation part a3 The whole unit rotates.Next, when the first motor (to) is driven, the pulley @ is rotated via the timing belt, and the input shaft (first joint shaft)
(4!19 rotates to the output side) due to deceleration rotation
Arm ■ rotates. Furthermore, when the second motor (64) is driven, the pulley IN is rotated, and the pulley mount is rotated via the tie belt ση, and the input shaft (second joint shaft) 67J
rotates, and the second arm pivots due to the output side σ3, which is decelerated by the second speed reducer σ.

In this way, the first arm 12 and the second arm 12 rotate, but the first parallel link (G) and the second parallel link e4
) is constructed, and one end of the first connecting rod Oυ is fixed to the bracket (Jun), so the connecting member (G) is always in a constant posture and each side (η, (the flame is maintained vertically and horizontally). The mounting surface (101) is always kept in the vertical direction, and the hand (103) is also always moved in the vertical direction.

Rotation pace el again! a) is the first limit sensor 01)
The rotation limit of the first joint is regulated by the second limit sensor 67), and the turning limit of the first joint is regulated by the second limit sensor 67).
81) has a turning limit regulated by a third limit sensor (108). Further, as in this embodiment, the center of the first joint 6 and the center of the rotational pace □□□ are made to coincide with each other, which has the effect of significantly simplifying the calculation of the operating program.

〔Effect of the invention〕

As detailed above, in the robot of the present invention, the second motor for rotating the second arm is attached to the vicinity of the first joint of the first arm, and the second motor is attached to the second joint.

Since the input shaft of the reducer that drives this is configured to be driven by the belt transmission body and the second motor, there is no need to provide a drive link to drive the second arm, and only a light belt transmission body is required. In addition, since the second motor is provided at one end of the first arm, unnecessary power consumption is suppressed when moving each arm, and the structure can be made small and lightweight, so there is no problem even if it is mounted on a transport vehicle. It also has the excellent effect of not causing any Furthermore, since the input shaft of the reducer is directly rotated by the belt transmission body, even if the belt tension or motor rotation changes slightly during transmission, the error in the movement of the second arm will be 1/( (reduction ratio), and produces an effect that does not cause any practical problems.

[Brief explanation of the drawing]

FIG. 1 is a front view of an embodiment of the present invention, FIG. 2 is a plan view, FIG. 3 is an overall configuration diagram of a robot mounted on an automatic guided vehicle, and FIG. 4 is a side view of the main parts. Figure 5 is the third
Figure 6 is an enlarged cross-sectional view of the main part (vertical axis rotation part) in the figure, Figure 6 is an enlarged cross-sectional view of the main part (second joint) in Figure 4, and Figure 7 is an enlarged cross-section of the main part (first joint) in Figure 4. 8 and 9 are schematic diagrams of the main part (third limit sensor), and FIG. 10 is a block diagram. G11): Base H (51: 1st arm. 6υ one end, (63: 2nd arm. 6!9: 2nd arm drive motor. (71): (2nd) reducer. ■: Input shaft (Second joint axis). σ3: Output side. (76a): Belt transmission mechanism, (103):
Hand. Agent Patent Attorney Noriyuki Chika (and 1 other person) Figure 2, Figure 3, Lo; 7, Figure 4, Figure 8, Figure 9, Figure 1O, 125

Claims (3)

[Claims] (1) A first arm whose one end is rotatably supported by a base, and an input shaft and output side axis are located on the same straight line, and the input shaft is rotatable at the other end of the first arm. a second arm having one end attached to the output side of the reducer and a hand attached to the other end;
A parallel link robot comprising: a second arm drive motor attached near one end of the first arm; and a belt transmission mechanism that directly transmits rotation of the motor to the input shaft. (2) The parallel link robot according to claim 1, wherein the reducer is a harmock drive. (3) The parallel link robot according to claim 1 or 2, wherein the belt of the belt transmission body is a timing belt.