JP7149119B2 - industrial robot - Google Patents

Description

The present invention relates to an industrial robot that transports objects such as semiconductor wafers.

The industrial robot described in Patent Document 1 is a robot that transports a semiconductor wafer, and includes a hand that holds the semiconductor wafer, an arm that moves the hand in a horizontal plane, an arm support that supports the arm, and an arm support. and an elevating mechanism for elevating the part. By moving the hand in the horizontal plane and lifting and lowering, the semiconductor wafer is transferred from the storage cassette to the heating furnace, and the heat-treated semiconductor wafer is transferred from the heating furnace to the storage cassette.

JP 2010-179419 A

A worker approaches the robot during teaching to store the trajectory of the arm in the robot or during maintenance of the industrial robot. For example, when a worker's foot is caught 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.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an industrial robot capable of detecting an obstacle present below the bottom surface of an arm support portion that is raised and lowered.

An industrial robot according to one aspect of the present invention is an industrial robot installed on a floor , comprising a hand holding an object to be conveyed, an arm for moving the hand in a horizontal plane, and supporting the arm, Further, an arm support portion arranged at a position closer to the floor surface than the hand and the arm, an elevating mechanism for lifting and lowering the arm support portion, and an obstacle existing below the bottom surface of the arm support portion are detected. a detection unit, the detection unit being arranged along the bottom surface of the arm support unit with a gap between the bottom surface and the arm support unit in an up-and-down direction relative to the arm support unit; and a sensor that detects displacement of the movable body in the vertical direction.

ADVANTAGE OF THE INVENTION According to this invention, the industrial robot which can detect the obstacle which exists under the bottom face of the arm support part raised/lowered can be provided.

1 is a plan view of an example of an industrial robot for describing an embodiment of the present invention, and is a plan view of a state in which an arm is retracted; FIG. FIG. 2 is a plan view of the industrial robot of FIG. 1, showing a state in which an arm is extended; 2 is a front view of the industrial robot of FIG. 1; FIG. FIG. 2 is a front view of a detector of the industrial robot of FIG. 1; FIG. 5 is a side view of the detector of FIG. 4;

(Overall configuration of industrial robot)
1 to 3 show an example of an industrial robot for describing embodiments of the present invention. An industrial robot 1 (hereinafter referred to as "robot 1") is a robot for transporting a semiconductor wafer 2 (hereinafter referred to as "wafer 2") which is an object to be transported. The robot 1, for example, simultaneously unloads a plurality of wafers 2 from a cassette (not shown) in which a plurality of wafers 2 are stacked and stored at a predetermined pitch. Then, the robot 1 loads the plurality of wafers 2 carried out from the cassette into a heating furnace (not shown) of the semiconductor manufacturing system in which the plurality of wafers 2 are stacked and stored at a predetermined pitch. Further, the robot 1 simultaneously unloads a plurality of wafers 2 from the heating furnace and loads the unloaded wafers 2 into the cassette.

The robot 1 includes a wafer loading mechanism 3 on which a plurality of wafers 2 are loaded, a first arm 4 that rotatably supports the base end side of the wafer loading mechanism 3, and storage of the wafers 2 in a cassette or a heating furnace. A sensing hand 5 for detecting a state, a second arm 6 rotatably supporting the proximal side of the sensing hand 5, and rotatable proximal sides of the first arm 4 and the second arm 6. a lift mechanism 8 that supports the arm support 7 so that it can move up and down;

The wafer mounting mechanism 3 has a plurality of transfer hands that are arranged so as to overlap vertically 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. good.

The sensing hand 5 is for detecting the housing state (inclination, protrusion, etc.) of the wafer 2 in the cassette or in the heating furnace before the wafer 2 is unloaded from the cassette or the like. The sensing hand 5 is vertically moved integrally with the arm support portion 7 , and the wafer 2 is placed on the sensing hand 5 according to the vertical movement of the sensing hand 5 . The wafer 2 placed on the sensing hand 5 may be transferred between the cassette and the heating furnace by the sensing hand 5 .

The first arm 4 and the second arm 6 have two joints and are configured to expand 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 expand and contract individually. The arm support section 7 has a first support section 9 that supports the first arm 4 and the second arm 6 and a second support section 10 that supports the first support section 9 . A turning 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 elevating mechanism 8 is configured using, for example, a linear motion guide including a feed screw shaft arranged to extend in the vertical direction and a strut supporting the feed screw shaft. A nut member is provided that threads onto the shaft. The feed screw shaft is rotated by the motor, and the second support portion 10 is vertically moved along the feed screw shaft according to the rotation of the feed screw shaft. Thereby, the arm support part 7 is raised and lowered.

(Structure of detector)
4 and 5 show the configuration of the detector 20. FIG. The detector 20 detects an obstacle present 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 has a movable body 21 that can move in the vertical direction Z with respect to the arm support 7, and a sensor 22 that detects displacement of the movable body 21 in the vertical direction.

The movable body 21 is formed in a substantially rectangular plate shape, is arranged along the bottom surface 11 of the arm support portion 7, and is arranged with a gap therebetween. One of two directions parallel to the bottom surface 11 of the arm supporting portion 7 and perpendicular to each other is defined as a first direction X and the other is defined as a second direction Y. The one end portion 23 is supported by the arm support portion 7 so as to be rotatable about a shaft 24 extending in the second direction Y. As shown in FIG. The rotation range of the movable body 21 is regulated by the suspending portion 25 . The hanging portion 25 is composed of a guide plate 27 formed with an engagement hole 26 extending in the elevation direction Z, and an engagement pin 28 that engages with the engagement hole 26. In this example, the guide plate 27 is It 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 acts on the movable body 21, the engagement pin 28 is in contact with the edge of the upper end side of the engagement hole 26, and the second end of the movable body 21 opposite to the first end 23 The movable body 21 is held in a state slightly inclined with respect to the bottom surface 11 of the arm support portion 7 so that the portion 29 is arranged below the first end portion 23 . When the movable body 21, which is lowered together with the arm support section 7, contacts an obstacle present below the bottom surface 11 of the arm support section 7, the movable body 21 closes the gap between the bottom surface 11 and the second end 29. It rotates around the shaft 24 so as to narrow it. As a result, the second end portion 29 side of the movable body 21 relative to the shaft 24 is displaced upward with respect to the arm support portion 7 .

The sensor 22 that detects the displacement of the movable body 21 in the vertical direction Z may be a non-contact sensor such as an optical sensor, but is preferably a contact sensor. used. A contact sensor is simpler than a non-contact sensor and can stably detect the displacement of the movable body 21 .

The sensor 22 is provided on one side surface 30 of the arm support portion 7 intersecting the second direction Y, and the movable body 21 extends along the side surface 30 in the elevation direction Z to the hinge lever 31 of the sensor 22 . A sensor engaging portion 32 is provided that reaches. When the movable body 21 in contact with the obstacle moves upward with respect to the arm support portion 7 , the sensor engaging portion 32 presses the hinge lever 31 . As a result, the sensor 22 is turned on, and the displacement of the movable body 21 in the vertical direction Z is detected by the sensor 22 . When the sensor 22 is turned on, a detection signal is output from the sensor 22 to a control section (not shown), and upon receiving the detection signal, the control section controls the lifting mechanism 8 to stop the arm support section 7 from descending. If necessary, the brake that stops the arm support 7 may be actuated, or the arm support 7 may be raised.

In this way, by detecting the displacement in the elevation direction Z of the plate-shaped movable body 21 arranged along the bottom surface 11 of the arm support section 7 , even with one sensor 22 , the bottom surface of the arm support section 7 can be detected. Obstacles placed below 11 can be detected in a wide range. Preferably, the movable body 21 covers the entire bottom surface 11 of the arm support portion 7 . As a result, obstacles placed below the bottom surface 11 can be detected more reliably.

Also, preferably, as shown in FIG. A displacement of an intermediate portion between the first end portion 23 and the second end portion 29 is detected. The amount of displacement of the movable body 21 varies depending on the position of each part of the movable body 21 in the first direction X, and the amount of displacement on the second end 29 side is relatively large. By detecting the displacement of the intermediate portion of the movable body 21, the displacement amount of the detection target portion of the movable body 21 can be adapted to the detectable range of the sensor 22 (the stroke of the hinge lever 31).

Alternatively, the sensor 22 may be provided on the bottom surface 11 of the arm support portion 7, and the hinge lever 31 may be directly pressed by the movable body 21. is limited by the interval between By providing the sensor 22 on the side surface 30 of the arm support portion 7 as in this example, the degree of freedom in designing the sensor 22 can be increased.

As described above, the industrial robot disclosed in this specification includes a hand that holds an object to be transferred, an arm that moves the hand in a horizontal plane, an arm support that supports the arm, and the arm An elevating mechanism for raising and lowering the support portion; and a plate-shaped movable body that is arranged with a gap between and movable with respect to the arm support in the vertical direction of the arm support, and a sensor that detects the displacement of the movable body in the vertical direction. , has By detecting the displacement of the plate-shaped movable body arranged along the bottom surface of the arm support, even with a single sensor, obstacles arranged below the bottom surface of the arm support can be detected in a wide range. .

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

Further, in the industrial robot disclosed in this specification, the sensor is a contact sensor. Contact sensors are simpler and more stable than non-contact sensors.

Further, the industrial robot disclosed in this specification has a first direction and a second direction that are parallel to the bottom surface of the arm support and are perpendicular to each other, and the first direction of the movable body is one of the first directions. One end is supported by the arm support so as to be rotatable around an axis extending in the second direction, and the sensor is mounted on the second end of the movable body opposite to the first end. to detect the displacement of the intermediate portion between According to this configuration, the amount of displacement of the detection target portion of the movable body can be adapted to the detectable range of the contact sensor.

Further, in the industrial robot disclosed in this specification, the sensor is provided on one side surface of the arm support section that intersects with the second direction, and the movable body moves from the intermediate portion to the arm. It has a sensor engagement portion extending to the sensor in the elevation direction along the side surface of the support portion. This configuration increases the degree of freedom in designing the sensor.

1 industrial robot 2 semiconductor wafer (transport object)
3 Wafer mounting mechanism 4 First arm 5 Sensing hand 6 Second arm 7 Arm supporting part 8 Elevating mechanism 9 First supporting part 10 Second supporting part 11 Bottom surface of arm supporting part 20 Detecting part 21 Movable body 22 Sensor 23 Movable body first end 24 shaft 25 hanging portion 26 engagement hole 27 guide plate 28 engagement pin 29 second end 30 of movable body side 31 of arm support portion hinge lever 32 sensor engaging portion X first direction Y 2 direction Z up/down direction

Claims (5)

An industrial robot installed on the floor,
a hand holding an object to be conveyed;
an arm that moves the hand in a horizontal plane;
an arm support that supports the arm and is arranged at a position closer to the floor surface than the hand and the arm ;
an elevating mechanism for elevating the arm support;
a detection unit that detects an obstacle present below the bottom surface of the arm support;
with
The detection unit is
a plate-shaped movable body disposed along the bottom surface of the arm support and spaced apart from the bottom surface and movable relative to the arm support in the vertical direction of the arm support;
a sensor that detects displacement in the vertical direction of the movable body;
industrial robot with The industrial robot according to claim 1,
The movable body is an industrial robot covering the entire bottom surface of the arm support. The industrial robot according to claim 1 or 2,
The industrial robot, wherein the sensor is a contact sensor. The industrial robot according to claim 3,
With the directions parallel to the bottom surface of the arm support portion and perpendicular to each other as a first direction and a second direction,
one first end of the movable body in the first direction is rotatably supported by the arm support portion about an axis extending in the second direction;
The sensor is an industrial robot that detects displacement of an intermediate portion between the first end and the opposite second end of the movable body. The industrial robot according to claim 4,
The sensor is provided on one side surface of the arm support that intersects with the second direction,
The movable body has a sensor engagement portion extending from the intermediate portion to the sensor along the side surface of the arm support portion in the elevation direction.

Images