CN110666838B

CN110666838B - Industrial robot

Info

Publication number: CN110666838B
Application number: CN201910584124.1A
Authority: CN
Inventors: 风间俊道
Original assignee: Nidec Sankyo Corp
Current assignee: Nidec Sankyo Corp
Priority date: 2018-07-03
Filing date: 2019-07-01
Publication date: 2022-12-16
Anticipated expiration: 2039-07-01
Also published as: JP7149119B2; CN110666838A; JP2020009820A

Abstract

The invention provides an industrial robot which can detect an obstacle existing below the bottom surface of a lifting arm support part. An industrial robot (1) is provided with: the hand (3, 5) for holding a conveyed object (2), the arms (4, 6) for moving the hands (3, 5) in a horizontal plane, an arm support part (7) for supporting the arms (4, 6), a lifting mechanism (8) for lifting the arm support part (7), and a detection part (20) for detecting an obstacle existing below a bottom surface (11) of the arm support part (7), wherein the detection part (20) has a movable body (21) and a sensor (22), wherein the movable body (21) is plate-shaped, is arranged along the bottom surface (11) of the arm support part (7) and is separated from the bottom surface (11), can move in a lifting direction (Z) relative to the arm support part (7), and the sensor (22) detects the displacement of the movable body (21) in the lifting direction (Z).

Description

Industrial robot

Technical Field

The present invention relates to an industrial robot for transporting a transport object such as a semiconductor wafer.

Background

The industrial robot described in patent document 1 is a robot for transporting a semiconductor wafer, and includes a hand for holding the semiconductor wafer, an arm for moving the hand in a horizontal plane, an arm support for supporting the arm, and a lifting mechanism for lifting the arm support. The semiconductor wafers are transferred from the storage cassette to the heating furnace by the movement and the lifting and lowering of the hand in the horizontal plane, and the semiconductor wafers subjected to the heat treatment are transferred from the heating furnace to the storage cassette.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2010-179419

Disclosure of Invention

Technical problem to be solved by the invention

When teaching the trajectory of the robot storage arm or when maintaining the industrial robot, the operator approaches the robot. For example, when the foot of the operator is sandwiched between the bottom surface of the arm support and the floor on which the industrial robot is installed, it is desirable to stop the industrial robot quickly.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an industrial robot capable of detecting an obstacle existing below the bottom surface of a raised and lowered arm support.

Technical scheme for solving technical problem

One aspect of the present invention provides an industrial robot including: a hand that holds a conveyance target; an arm that moves the hand in a horizontal plane; an arm support portion that supports the arm; a lifting mechanism that lifts and lowers the arm support portion; and a detection unit that detects an obstacle present below a bottom surface of the arm support unit; the detection unit includes: a movable body having a plate shape, the movable body being disposed along the bottom surface of the arm support portion with a gap therebetween, and being movable in a lifting direction of the arm support portion with respect to the arm support portion; and a sensor that detects displacement of the movable body in the lifting direction.

(effect of the invention)

According to the present invention, it is possible to provide an industrial robot capable of detecting an obstacle existing below the bottom surface of a raised and lowered arm support.

Drawings

Fig. 1 is a plan view of an example of an industrial robot for explaining an embodiment of the present invention, and is a plan view of a state where an arm is retracted.

Fig. 2 is a plan view of the industrial robot of fig. 1, in which an arm is extended.

Fig. 3 is a front view of the industrial robot of fig. 1.

Fig. 4 is a front view of a detection portion of the industrial robot of fig. 1.

Fig. 5 is a side view of the detection unit of fig. 4.

(description of reference numerals)

1. Industrial robot

2. Semiconductor wafer (object to be carried)

3. Wafer loading mechanism

4. First arm

5. Hand for sensing

6. Second arm

7. Arm support

8. Lifting mechanism

9. First support part

10. Second support part

11. Bottom surface of arm support

20. Detection part

21. Movable body

22. Sensor with a sensor element

23. First end of movable body

24. Shaft

25. Suspension part

26. Clamping hole

27. Guide plate

28. Engaging pin

29. Second end of the movable body

30. Side surface of the arm support

31. Hinge rod

32. Sensor fastening part

X first direction

Y second direction

Direction of Z lifting

Detailed Description

(Overall Structure of Industrial robot)

Fig. 1 to 3 show an example of an industrial robot for explaining an embodiment of the present invention. An industrial robot 1 (hereinafter referred to as "robot 1") is a robot for conveying a semiconductor wafer 2 (hereinafter referred to as "wafer 2") as a conveyance target. The robot 1 simultaneously carries out a plurality of wafers 2 from a cassette (not shown) in which the plurality of wafers 2 are stacked and stored at a predetermined pitch, for example. The robot 1 carries the plurality of wafers 2 carried out of the cassette into a heating furnace (not shown) of a semiconductor manufacturing system in which the plurality of wafers 2 are stacked and stored at a predetermined pitch. The robot 1 simultaneously carries out a plurality of wafers 2 from the heating furnace and carries the carried-out wafers 2 into the cassette.

The robot 1 includes: a wafer loading mechanism 3 for loading a plurality of wafers 2, a first arm 4 for rotatably supporting the base end side of the wafer loading mechanism 3, a sensing hand 5 for detecting the storage state of the wafers 2 in the cassette or in the heating furnace, a second arm 6 for rotatably supporting the base end side of the sensing hand 5, an arm support 7 for rotatably supporting the base end sides of the first arm 4 and the second arm 6, a lifting mechanism 8 for lifting and lowering the arm support 7, and a detection unit 20 for detecting an obstacle existing below the bottom surface 11 of the arm support 7.

The wafer loading mechanism 3 has a plurality of carrying hands arranged to be overlapped in the vertical direction at a predetermined pitch. The pitch of the wafers 2 stored in the cassette may be different from the pitch of the wafers 2 stored in the heating furnace, and the wafer loading mechanism 3 may be configured to be capable of changing the pitch of the plurality of carrying hands.

The sensor hand 5 is used to detect the storage state (inclination, protrusion, etc.) of the wafer 2 in the cassette or the heating furnace before the wafer 2 is carried out of the cassette or the like. The sensing hand 5 moves up and down integrally with the arm support 7, and the wafer 2 is placed on the sensing hand 5 in accordance with the up and down movement of the sensing hand 5. The wafer 2 placed on the sensing hand 5 may be transported between the cassette and the heating furnace by the sensing hand 5.

The first arm 4 and the second arm 6 are configured to have two joint portions and to extend and contract as a whole. The base end side of the first arm 4 and the base end side of the second arm 6 are supported by an arm support portion 7 and individually extend and contract. The arm support 7 includes a first support 9 that supports the first arm 4 and the second arm 6, and a second support 10 that supports the first support 9. A rotation mechanism for rotating the first support portion 9 is housed inside the second support portion 10, and the first support portion 9 is rotatably supported by the second support portion 10.

The lifting mechanism 8 is configured using, for example, a linear guide including a feed screw shaft extending in the vertical direction and a support portion supporting the feed screw shaft, and the second support portion 10 is provided with a nut member screwed to the feed screw shaft. The second support part 10 moves up and down along the feed screw shaft in accordance with the rotation of the feed screw shaft by rotating the feed screw shaft by the motor. Thereby, the arm support 7 is lifted and lowered.

(Structure of detection part)

Fig. 4 and 5 show the structure of the detection unit 20. The detection unit 20 detects an obstacle existing below the bottom surface 11 of the arm support 7 when the arm support 7 is lowered by the lifting mechanism 8. The detection unit 20 includes a movable body 21 movable in the ascending/descending direction Z with respect to the arm support unit 7, and a sensor 22 for detecting a displacement in the ascending/descending direction of the movable body 21.

The movable body 21 is formed in a substantially rectangular plate shape, is disposed along the bottom surface 11 of the arm support portion 7, and is disposed at a distance from the bottom surface 11. One of two directions parallel to and perpendicular to the bottom surface 11 of the arm support portion 7 is defined as a first direction X, and the other is defined as a second direction Y, and a first end portion 23 of one of both end portions of the movable body 21 in the first direction X is supported by the arm support portion 7 so as to be rotatable about a shaft 24 extending in the second direction Y. Further, the rotation range of the movable body 21 is limited by the suspension portion 25. The suspending portion 25 is composed of a guide plate 27 formed with an engaging hole 26 extending in the vertical direction Z and an engaging pin 28 engaging with the engaging hole 26, and in this example, the guide plate 27 is provided on the movable body 21 and the engaging pin 28 is provided on the arm support portion 7.

In a state where no external force is applied to the movable body 21, the engagement pin 28 abuts against the edge of the upper end side of the engagement hole 26, and the movable body 21 is held in a slightly inclined state with respect to the bottom surface 11 of the arm support portion 7 so that the second end portion 29 of the movable body 21 on the opposite side to the first end portion 23 is disposed below the first end portion 23. When the movable body 21 that descends integrally with the arm support portion 7 comes into contact with an obstacle existing below the bottom surface 11 of the arm support portion 7, the movable body 21 rotates about the shaft 24 so as to reduce the interval between the bottom surface 11 and the second end portion 29. Thereby, the movable body 21 is displaced upward relative to the arm support portion 7 on the side closer to the second end 29 than the shaft 24.

The sensor 22 for detecting the displacement of the movable body 21 in the lifting direction Z may be a non-contact sensor such as an optical sensor, but a contact sensor is preferable, and in this example, a hinge-lever type microswitch is used. The touch sensor is simpler than the non-touch sensor and can stably detect the displacement of the movable body 21.

The sensor 22 is provided on a side surface 30 of the arm support portion 7 intersecting the second direction Y, and the movable body 21 is provided with a sensor engaging portion 32 extending along the side surface 30 in the elevation direction Z and reaching the hinge rod 31 of the sensor 22. When the movable body 21 abutting on the obstacle moves upward with respect to the arm support portion 7, the sensor engagement portion 32 presses the hinge lever 31. Thereby, sensor 22 is turned on, and the displacement of movable body 21 in lifting direction Z is detected by sensor 22. When the sensor 22 is turned on, a detection signal is output from the sensor 22 to a control unit (not shown), and the control unit that receives the detection signal controls the lifting mechanism 8 to stop the arm support 7 from being lowered. If necessary, a brake for stopping the arm support portion 7 may be activated, or the arm support portion 7 may be raised.

By detecting the displacement in the lifting direction Z of the plate-like movable body 21 disposed along the bottom surface 11 of the arm support portion 7 in this manner, an obstacle disposed below the bottom surface 11 of the arm support portion 7 can be detected over a wide range even with one sensor 22. Preferably, the movable body 21 covers the entire bottom surface 11 of the arm support portion 7. This enables more reliable detection of an obstacle disposed below the bottom surface 11.

As shown in fig. 4, the sensor engagement portion 32 is preferably provided between the first end portion 23 and the second end portion 29 of the movable body 21, and the sensor 22 preferably detects a displacement of the movable body 21 at an intermediate portion between the first end portion 23 and the second end portion 29. The amount of displacement of the movable body 21 differs depending on the position of each portion of the movable body 21 in the first direction X, and the amount of displacement on the second end portion 29 side is relatively large. By detecting the displacement of the intermediate portion of movable body 21, the displacement amount of the detection target portion of movable body 21 can be made to fit the detectable range of sensor 22 (the stroke of hinge lever 31).

Further, sensor 22 may be provided on bottom surface 11 of arm support portion 7, and hinge lever 31 may be directly pressed by movable body 21, but in this case, the size of sensor 22 is limited by the distance between bottom surface 11 and movable body 21. As shown in this example, by providing the sensor 22 on the side surface 30 of the arm support portion 7, the degree of freedom in designing the sensor 22 can be improved.

As described above, the industrial robot disclosed in the present specification includes: the detection unit includes a plate-shaped movable body disposed along the bottom surface of the arm support portion with a space therebetween, and a sensor that detects displacement of the movable body in the lifting direction of the arm support portion with respect to the arm support portion. By detecting the displacement of the plate-like movable body disposed along the bottom surface of the arm support portion, an obstacle disposed below the bottom surface of the arm support portion can be detected over a wide range even with a single sensor.

In the industrial robot disclosed in the present specification, the movable body covers the entire bottom surface of the arm support portion. According to this configuration, the obstacle disposed below the bottom surface of the arm support portion can be detected more reliably.

In the industrial robot disclosed in the present specification, the sensor is a contact sensor. The touch sensor is simpler and can perform detection more stably than a non-touch sensor.

In the industrial robot disclosed in the present specification, directions parallel to the bottom surface of the arm support portion and perpendicular to each other are defined as a first direction and a second direction, a first end portion of the movable body on one side in the first direction is supported by the arm support portion and is rotatable about an axis extending in the second direction, and the sensor detects a displacement of the movable body at an intermediate portion between the first end portion and a second end portion on an opposite side. With this configuration, the displacement amount of the detection target portion of the movable body is adjusted to the detectable range of the touch sensor.

In the industrial robot disclosed in the present specification, the sensor is provided on one side surface of the arm support portion intersecting the second direction, and the movable body includes a sensor engagement portion extending from the intermediate portion to the sensor in the lifting direction along the side surface of the arm support portion. With this configuration, the degree of freedom in designing the sensor is improved.

Claims

1. An industrial robot comprising:

a hand that holds a conveyance object;

an arm that moves the hand in a horizontal plane;

an arm support that supports the arm;

a lifting mechanism that lifts and lowers the arm support portion; and

a detection unit that detects an obstacle present below a bottom surface of the arm support unit;

the detection unit includes:

a movable body having a plate shape, the movable body being disposed along the bottom surface of the arm support portion with a gap therebetween, and being movable in a lifting direction of the arm support portion with respect to the arm support portion; and

a sensor that detects displacement of the movable body in the ascending and descending direction,

the sensor is a touch sensor and the sensor is,

the first direction and the second direction are directions parallel to the bottom surface of the arm support part and perpendicular to each other,

a first end portion on one side in the first direction of the movable body is supported by the arm support portion and is rotatable about an axis extending in the second direction,

the sensor detects a displacement of an intermediate portion between the first end portion and a second end portion on an opposite side of the movable body,

the sensor is provided on one side surface of the arm support portion intersecting the second direction,

the movable body has a sensor engaging portion extending from the intermediate portion to the sensor along the side surface of the arm support portion in the lifting direction.

2. The industrial robot of claim 1,

the movable body covers the entire bottom surface of the arm support portion.