JPH0596479A - Rectangular coordinate type robot - Google Patents

Abstract

PURPOSE:To prevent a tool and a camera for work, mounted to the second mover of an X-axis table, from being damaged, even when a position deviation of the first mover is provided, and from generating collision against a Y-axis table, in a rectangular coordinate type robot of long stroke. CONSTITUTION:In the second unit comprising a slide block provided on an end part of an X-axis table 3 and a rotary block, by providing a detecting sensor 31 which stops driving by detecting a displacement when the displacement between the slide block fixed to the X-axis table 3 and the rotary block, slidable with the slide block and further rotatably engaged with the first movers 4, 5 of Y-axis tables 1, 2, exceeds a fixed value, damage can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a long stroke Cartesian coordinate robot.

[0002]

2. Description of the Related Art In recent years, robots used for mounting electronic parts are required to have high speed, high accuracy, and long stroke.

Conventionally, as a robot for performing various operations on a work such as a substrate with high positional accuracy, as shown in FIGS. 9 and 10, a Y-axis table 18 and a Y-axis table 18 are provided.
An X-axis table 19 which is supported in a cantilever manner on the axis table 18 and can be positioned at an arbitrary position in the Y direction, and a work head portion 20 which can be positioned at an arbitrary position in the X direction by the X-axis table 19. And this working head portion 20
It is known that a camera 25 as a work position recognizing means and a working tool 26 as a working means are provided at a predetermined distance D in the X direction.

In the above structure, the work head portion 20 is moved to the work 1 by the Y-axis table 18 and the X-axis table 19.
By moving to the work position of 0, the work 10
Move the camera 25 to the working position of
The work position is recognized with high accuracy, and the work head unit 20 is moved by the Y-axis table 18 or the X-axis table 19 based on the recognized work position and the distance D between the work tool 26 to perform the work. The work was conducted by guiding the tool 26 to the work position.

However, according to the configuration of the robot, X
Since the axis table 19 is supported by the Y-axis table 18 in a cantilever manner, if the stroke of the X-axis table 19 is increased corresponding to the workpiece 10 such as a substrate, vibration is likely to occur and high-speed operation is possible. There is a problem in that it takes time to position the work head portion 20 when stopping. In addition, the fastening bolts between the Y-axis table 18 and the X-axis table 19 are likely to be loosened. Further, there is a problem that the positioning accuracy of the work head portion 20 is significantly reduced due to yawing and rolling of the Y-axis table 18.

Therefore, the following Cartesian coordinate type robot has been proposed for the purpose of solving the above problems (see Japanese Patent Application No. 2-17241).

As shown in FIGS. 11 and 12, the Cartesian coordinate type robot has a pair of Y-axis tables 1 and 2 arranged in parallel with each other, and is guided along each of the tables 1 and 2 to provide an engaging shaft. The first moving bodies 4 and 5 positioned by the bodies 11 and 12 are provided, the X-axis table 3 orthogonal to both Y-axis tables 1 and 2 is arranged, and guided and moved along the X-axis table 3. The second moving body 21 is provided, and one end of the X-axis table 3 and the first moving body 4 provided on one Y-axis table (Y-axis table 1 in this embodiment) side are connected to the Y-axis table 1 and the X-axis. The first unit rotatably engaged around the axis of the engaging shaft body 11 orthogonal to the table 3, the other end of the X-axis table 3 and the other Y-axis table (in the present embodiment, the Y-axis table 2). ) Side first
The movable body 5 and the movable body 5 are rotatable about the axis of the engaging shaft body 12 orthogonal to the Y-axis table 2 and the X-axis table 3, and X
The second moving body 21 is provided with a camera 25 as a work position recognizing means and a working tool 26 as a working means. .. Reference numeral 27 in the figure denotes a work member mounting plate for mounting the camera 25 and the work tool 26.

In the above structure, both ends of the X-axis table 3 are supported and moved on the first moving bodies 4 and 5 of the pair of Y-axis tables 1 and 2, so that even when the X-axis table 3 becomes long. , The X-axis table 3 itself is stable, and its high speed movement and stop can be performed quickly.
Since the pair of axis tables 1 and 2 is provided, the occurrence of yawing and rolling of the Y axis tables 1 and 2 can be suppressed to a minimum, and therefore the position recognition means can be used for the camera 25.
And the working tool 26, which is a working means, can be guided to a predetermined position with high accuracy.

Further, one end of the X-axis table 3 and one of the first moving bodies (4 or 5) are rotatably engaged with each other, and the other end of the X-axis table 3 and the other of the first first body (4 or 5) are rotatably engaged. Since the movable bodies (4 or 5) are rotatably and slidably engaged with each other, the parallelism between the pair of Y-axis tables 1 and 2 or the pair of first movable bodies 4 should be avoided. Even if there is an error in the moving speeds of 5 and 5, these errors are easily absorbed.

[0010]

However, when an error occurs in the moving speeds of the first moving bodies 4 and 5 of the pair of Y-axis tables 1 and 2, the deviation between the pair of first moving bodies 4 and 5 becomes large. When the second moving body 21 of the axis table 3 is located at the end of its operation area, the camera 2 attached to the second moving body 21
5 and the working tool 26 collide with the Y-axis table 1 or 2 and are damaged.

The present invention solves the above-mentioned problems of the prior art. The working tool and camera attached to the second moving body of the X-axis table are not damaged by the deviation of the first moving body, and Y It is an object to provide a Cartesian coordinate type robot that does not collide with an axis table.

[0012]

In order to achieve this object, a Cartesian coordinate type robot of the present invention rotates around a Y-axis table provided at an end of an X-axis table and an axis orthogonal to the X-axis table. In the second unit that is supported so as to be slidable in the axial direction of the X-axis table, X
A sensor that is slidable with respect to the slide block fixed to the shaft table and that detects when the displacement of the rotary block that is rotatably engaged with the first moving body of the Y-axis table exceeds a certain value; When the axial displacement of the X-axis table increases, the X-axis table collides with the rotation block,
It is provided with a block for restricting displacement of the shaft table in the axial direction.

Also, the screw shaft body for positioning the moving body of the pair of Y-axis tables is provided with an elastic belt capable of transmitting the rotational force of both screw shaft bodies.

[0014]

With this configuration, when a displacement of the moving body of the Y-axis table occurs, the displacement of the slide block causes X-axis displacement.
The displacement of the shaft table in the axial direction is detected by the sensor, and when the displacement exceeds a certain amount, the power supply to the screw shaft body for positioning the moving body of the pair of Y-axis tables is stopped. Further, since the rotation belt of the screw shaft body for positioning the moving body of the pair of Y-axis tables is used for synchronization, it is possible to prevent the positional deviation from occurring between the pair of Y-axis tables.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

1 to 7 showing an embodiment of the present invention, the same parts as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted.

(Embodiment 1) As shown in FIGS. 1 to 6, a screw shaft body (for example, a ball screw is used as the first moving bodies 4 and 5 arranged inside each Y-axis table 1 and 2). 6 and 7 and electric motors 8 and 9 for rotating the screw shaft bodies 6 and 7, and further, the first moving bodies 4 and 5 are arranged on the screw shaft bodies 6 and 6 via nut bodies (not shown). It is screwed to 7. At one end of the X-axis table 3, the bearing 13 and the first
The first unit composed of the connecting member 14 rotatably engaged with the engaging shaft body 11 of the moving body 4 via the bearing 13
At the other end of the X-axis table 3, a slide block 15 fixed to the table 3 and a slide block 1 are provided.
5, slidable with the engaging bearing 12 of the first moving body 5.
The rotation block 17 rotatably engaged with the bearing 16 via the bearing 16, the sensor 31 for detecting the displacement of the slide block 15 and the rotation block 17, and the second unit composed of the detected object 32 of the sensor 31 are provided. Has been. The X-axis table 3 engaged with the first moving bodies 4 and 5 via the first and second units includes the two electric motors 8 of the Y-axis tables 1 and 2.
By driving 9 in synchronization, the Y-axis table 1,
It can be moved to any position along 2. Further, the X-axis table 3 and one Y-axis table 1 are rotatably engaged with each other, the X-axis table 3 and the other Y-axis table 2 are rotatably engaged with each other, and the X-axis table 3 is also provided.
Will be slidably engaged along the axis of the.

The X-axis table 3 is also provided with a second moving body 21 which is guided and moved along the axial direction thereof, like the Y-axis tables 1 and 2. That is, the second moving body 21 is a screw shaft body (for example, a ball screw is used) 2 which is also arranged inside the X-axis table 3.
2 and an electric motor 23 for rotating the screw shaft body 22 are arranged, and the second moving body 21 is screwed to the screw shaft body 22 via a nut body 24. Working member mounting plate 27 to which camera 25 and working tool 26 are mounted
Are arranged on the side surface of the second moving body 21 and movably in the axial direction of the X-axis table 3. That is, similarly to the above, the moving mechanism of the working member mounting plate 27 also has a screw shaft body (for example, a ball screw is used) 29 screwed into the nut body 28 mounted on the back surface of the working member mounting plate 27.
And the electric motor 30 for rotating the screw shaft body 29 is the second
It is provided on the moving body 21 side. 41 and 42 in the figure
Is a cable unit for transmitting power and control signals. In addition, precision motors are used as the electric motors and the ball screw as the screw shaft body.

The operation of the Cartesian coordinate type robot configured as described above will be described below. When performing work on a work such as a substrate, first, both electric motors 8 and 9 are driven to move the X-axis table 3 to the Y-axis table via the first moving bodies 4 and 5 on the Y-axis tables 1 and 2. 1 and 2, while driving the electric motor 23, the X-axis table 3
The upper second moving body 21 is moved onto the work. And
Further, the working member mounting plate 27 is moved along the X-axis table 3 via the electric motor 30 provided on the side of the second moving body 21, the position of the work is recognized by the camera 25, and the camera 25 and In consideration of the distance D from the working tool 26, the working tool 26 is guided to an accurate position for the work.

In this way, since both ends of the X-axis table 3 are supported on the first moving bodies 4 and 5 of the pair of Y-axis tables 1 and 2, even when the X-axis table 3 becomes long,
The X-axis table 3 itself is stable, and high-speed movement and stop thereof can be performed quickly, and since the Y-axis tables 1 and 2 are provided in pairs, the Y-axis tables 1 and 2 are provided.
It is possible to minimize the occurrence of yawing and rolling, so that the camera 25 and the working tool 26 can be guided to a predetermined position with high accuracy.

One end of the X-axis table 3 and one first moving body 4 are rotatably engaged, and the other end of the X-axis table 3 and the other first moving body 5 rotate. They are engaged and supported so as to be movable and slidable relative to each other, that is, relatively movable.

First moving bodies 4, 5 of both Y-axis tables 1, 2.
If an error occurs in the moving speed of the first moving body 4 and the positional deviation occurs in the first moving body 4 and 5, if the deviation becomes large, the second moving body 2
The position recognition camera 25 provided on the work member mounting plate 27 on the first and the electric motor 30 collide with the Y-axis table 2.
Here, without stopping the power supply to both the electric motors 8 and 9 of the Y-axis tables 1 and 2, the deviation of the first moving bodies 4 and 5 is caused by the interference between the block 33 provided on the X-axis and the rotating block 17. If restricted, assuming that the length of the X-axis table 3 in the axial direction is L and the deviation of the first moving body is 1, a force that is L / l times the axial power of the Y-axis table is the X-axis table 3 axis. It occurs in the mind.
If L = 1000 mm and l = 50 mm, the block 33 provided on the X-axis table has 100 blocks of Y-axis axial direction power.
0/50 = 20 times the force is applied and it breaks.

In the first embodiment of the present invention, the rotation block 17 is provided with the sensor 31, and the slide block 15 is provided with the detection object 32 of the sensor 31. First moving body 4,
When the slide block 15 is displaced in the axial direction of the X-axis table 3 from the rotation block 17 due to the deviation of the movement amount of 5, the detected body 32 moves beyond the detection range of the sensor 31, so that the sensor 31 moves the detected body 32. Immediately after no longer being detected, the power supply to both electric motors 8 and 9 of the Y-axis tables 1 and 2 is stopped. X-axis table 3 after stopping the power supply
Since only the inertial force is generated in the axial direction of the block 33, the block 33 and the rotary block 17 are not damaged even if they collide.

The block 33 is replaced with the slide block 1.
The same effect can be obtained even if it is provided on a plane that is parallel to the X-axis table 3 of 5 and includes the rotation block 17. Therefore, the work camera 25 and the work tool 26 attached to the second moving body 21 via the work member attachment plate 27 are
Before colliding with the shaft tables 1 and 2, the positional deviation of the first moving bodies 4 and 5 is restricted by the interference between the block 33 and the rotating block 17.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 7 and 8, the difference from the first embodiment is that the pulleys 34, 35 attached to the screw shaft bodies 6, 7 are mutually suspended by a belt 36 suspended by a tensioner 37. Counter 3 for detecting the number of rotations of the screw shaft bodies 6 and 7 and the structure capable of transmitting power
The point is that the comparator circuit 40 for detecting the difference between the rotational speeds of 8 and 39 is provided.

The operation of the Cartesian coordinate type robot configured as described above will be described below. First moving body 4,
When a position deviation occurs between the five shafts, the comparison circuit 40 detects the rotation speed deviations of the screw shaft bodies 6 and 7 via the counters 38 and 39. At this time, the belt 36 receives tension due to the rotational deviation of the pulleys 34 and 35, but the belt 36 absorbs the rotational deviation of the pulley due to elastic deformation, and the tension is stored as elastic energy in the belt 36. If the power supply to the electric motors 8 and 9 of the Y-axis tables 1 and 2 is stopped immediately after the comparison circuit 40 detects the rotation deviation of the screw shafts 6 and 7, the screw shafts 6 and 7 rotate only by the inertial force. Exercise, but belt 3
Since the power is transmitted to each other by 6, the first moving bodies 4 and 5 move in synchronization with each other. Therefore, the work camera 25 and the work tool 26 attached to the second moving body 21 via the work member attachment plate 27 are set to Y.
It does not collide with the axis tables 1 and 2.

[0028]

As is apparent from the above description of the embodiments, the present invention is capable of rotating about the Y-axis table provided at the end of the X-axis table and the axis orthogonal to the X-axis table.
In a second unit slidably engaged in the axial direction of the X-axis table, a slide block fixed to the X-axis table, and a first movable body of the Y-axis table slidable with the slide block. Is provided with a detection sensor for detecting that the displacement of the rotary block rotatably engaged with the rotary block exceeds a certain value, and the X-axis table collides with the rotary block when its axial displacement increases,
A structure provided with a block for restricting the axial displacement of the X-axis table, and an elastic belt capable of transmitting the rotational force of both screw shafts to the screw shaft that positions the moving body of the pair of Y-axis tables. With the above configuration, the work tool and the camera attached to the second moving body of the X-axis table are the first
It is possible to realize an excellent Cartesian coordinate type robot that is not damaged by the deviation of the moving body and does not collide with the Y-axis table.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a Cartesian coordinate type robot according to a first embodiment of the present invention.

FIG. 2 is a schematic plan view of the Cartesian coordinate type robot.

FIG. 3 is a perspective view of an essential part of an engaging portion between a Y-axis table and an X-axis table of the Cartesian coordinate robot.

FIG. 4 is a sectional view taken along the line II of FIG.

FIG. 5 is a plan view of a main part of the first moving body of the Cartesian coordinate robot according to the first embodiment of the present invention in a normal state.

FIG. 6 is a plan view of an essential part of the same Cartesian coordinate robot in a state in which a position deviation has occurred between the first moving bodies.

FIG. 7 is a schematic plan view showing the concept of a Cartesian coordinate type robot according to a second embodiment of the present invention.

FIG. 8 is a plan view of a main part of the Cartesian coordinate type robot.

FIG. 9 is a schematic perspective view of a conventional Cartesian coordinate robot.

FIG. 10 is a schematic plan view of the same Cartesian coordinate type robot.

FIG. 11 is a plan view of an essential part of a first moving body of the same rectangular coordinate type robot in a normal state.

FIG. 12 is a plan view of a main part of the same Cartesian coordinate robot in a state where a positional deviation has occurred between the first moving bodies.

[Explanation of symbols]

 1, 2 Y-axis table 3 X-axis table 4, 5 First moving body 14 Connecting member 15 Slide block 21 Second moving body 25 Camera 26 Working tool 31 Sensor 32 Detected body 33 block

Claims (2)

[Claims] 1. A pair of Y-axis tables are arranged in parallel with each other, and a first moving body which is guided and moved by a screw shaft body is provided along each of these tables, and is orthogonal to the both Y-axis tables. An X-axis table is arranged, a second moving body is provided which is guided and moved along the Y-axis table, and the first moving body is provided at one end of the X-axis table and the one Y-axis table side. A first unit that rotatably engages with the Y-axis table and an X-axis table about an axis orthogonal to the Y-axis table, the other end of the X-axis table, and the other Y-axis table side. A rotation block that is rotatable around an axis that is orthogonal to the Y-axis table and the X-axis table, and a slide block that is slidably supported in an axial direction of the X-axis table. A robot comprising a second unit including a second unit, and a work position recognizing unit and a working unit disposed on the second moving body, wherein the rotary block and the slide block are provided in the rotary block of the second unit. A sensor for detecting the displacement of the first moving body and stopping the power supply to the first moving body, and a sliding direction of the Y-axis table sandwiching the rotary block on a plane parallel to the Y-axis table and including the rotary block. A Cartesian coordinate type robot provided with an object to be detected provided on the opposite shaft end of the second table or on the rotating block. 2. A counter for counting the positions of a pair of first moving bodies, a comparison circuit for detecting the positional deviation between them and stopping the power supply to the first moving body, and a pair of Y-axis table screw shafts. The Cartesian coordinate robot according to claim 1, further comprising an elastic belt for transmitting power between the bodies.