JPH0717485U - Industrial robot - Google Patents

Abstract

(57) [Abstract] [Purpose] An industrial robot that reduces the amount of fall of the lifting member as much as possible when the rotation transmission member of the rotary drive system for lifting the lifting member of the industrial robot is damaged. To provide. [Structure] A rotatable rotary shaft 2 is erected on a base 1, and a ball screw screwed on the rotary shaft and a ball nut supported by a lifting member 8 of an industrial robot are screwed together. Output shaft 301 and rotary shaft 2 of rotary drive machine 3
In an industrial robot having a rotation transmission mechanism composed of a rotation member fixed to each of the rotation members and a rotation transmission member connected between the rotation members, the rotation transmission mechanisms 7A and 7B are at least separated from each other in the axial direction. Two pairs of sensors are provided, which are provided with sensors 12A and 12B for detecting the cut state of each rotation transmission member, and a control means for stopping the rotary drive when any one of the sensors is activated. There is.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an industrial robot having a lifting member. More specifically, in an industrial robot, it is expected that an elevating member will drop in the direction of gravity due to an accident in the drive system, damaging the industrial robot itself and the equipment around the robot. Therefore, the present invention relates to an improvement of the industrial robot for preventing a fall accident of the lifting member.

[0002]

[Prior art]

 In an industrial robot having an elevating member, for example, the transfer robot shown in FIG. 4, a robot arm 801 which is appropriately expanded and contracted is attached to the elevating member 8 of the transfer robot RE, and the robot arm 801 has a free end portion. The attached robot hand 802 is operated so as to be freely displaced with respect to the transport destination WS.

Conventionally, in FIGS. 5 and 6, a rotatable shaft 20 which is rotatable with respect to a base 1 is erected, and a ball screw 201 screwed to the rotatable shaft 20 and an elevating member 8 of an industrial robot RE. Rotating members 4 and 5 which are fixed to the output shaft 301 and the rotating shaft 20 of the rotary drive machine 3 while being screwed with a supported ball nut, and a rotation transmitting member connected between the rotating members 4 and 5. A rotation transmission mechanism 7 composed of 6 and 6 is provided, and the elevating member 8 of the industrial robot is appropriately moved up and down by the rotation driving device 3. Since the rotation transmission member 6 such as the belt has the weakest mechanical strength in the rotation drive system, a sensor 12 for detecting a belt breakage is provided. The electromagnetic brake 21 directly connected to is operated to prevent the lifting member 8 from falling.

[0004]

[Problems to be solved by the device]

 By the way, according to the above-mentioned conventional technique, a time delay of about 100 to 300 ms occurs from the operation of the belt breakage detection sensor to the operation of the electromagnetic brake 21, and the brake slip is also added. It was supposed to stop at the position where it fell below the position at the time of occurrence. In this case, for example, when the tip of the robot is inserted in a work position with a small gap in the vertical direction, the tip of the robot collides with the device at the destination before the electromagnetic brake 21 operates and breaks the object to be conveyed. I was losing.

The present invention has been made in view of the above problems, and an object of the present invention is to raise and lower an elevating member of a rotary drive system for elevating the elevating member of an industrial robot when the rotation transmitting member is damaged. It is an object of the present invention to provide an industrial robot in which the amount of fall is minimized.

[0006]

[Means for solving the problem]

 According to the present invention, a rotatable rotary shaft is erected on a base, and a ball screw screwed on the rotary shaft and a ball nut supported by a lifting member of an industrial robot are screwed together and rotated. The invention is applied to an industrial robot provided with a rotation transmission mechanism including a rotation member fixed to the output shaft of a drive machine and the rotation shaft, and a rotation transmission member connected between the rotation members. The feature is that at least two pairs of the rotation transmitting mechanism are arranged axially separated from each other, and a sensor for detecting a disconnection state of each rotation transmitting member is provided and an operation of any one of the sensors is performed. At the same time, a control means for stopping the rotary drive machine is provided.

[0007]

【Example】

 Hereinafter, the present invention will be described in detail with reference to illustrated embodiments. In FIG. 1 to FIG. 3, reference numeral 2 is a rotary shaft rotatably erected on a base 1 of an industrial robot RE, and 3 is a rotary drive attached to the base 1, for example, the rotary drive 3 The output rotary shaft 301 and the rotary shaft 2 are arranged in parallel. 4A is a rotary member fixed to the output rotary shaft 301, 5A is a rotary member fixed to the rotary shaft 2 facing the rotary member 4A, and 6A is a rotation transmitting member connected between the rotary members 4A and 5A. The rotation members 4A, 5A and the rotation transmission member 6A constitute a first rotation transmission mechanism 7A. Reference numeral 7B is a second rotation transmission mechanism configured similarly to the first rotation transmission mechanism 7A, and is constituted by rotation members 4B and 5B and a rotation transmission member 6B. The first and second rotation transmission mechanisms 7A and 7B are arranged apart from each other in the axial direction of the output rotary shaft 301.

Reference numeral 8 denotes an elevating member of the industrial robot. The elevating member 8 is supported by the guide rails 9A and 9B and is movably supported in the Z direction. A so-called ball nut 11 is supported on the elevating member 8, and the ball nut 11 and a ball screw 201 screwed on the rotary shaft 2 are screwed together. 12A and 12B are sensors for detecting the cut state of the rotation transmission members 6A and 6B, respectively.

The elevating member 8 of the industrial robot supports, for example, a robot arm 801 and a robot hand 802 which are appropriately operated. Further, although not shown, a control means for stopping the rotary drive machine 3 is provided when either of the sensors 12A and 12B operates. The base 1 to the sensor 12 constitute an industrial robot RE.

In the above structure, when the rotary drive machine 3 is driven, the rotary shaft 2 is rotated via the rotation transmission mechanisms 7A and 7B. Therefore, the elevating member 8 is appropriately moved up and down in the Z ₁ direction or the Z ₂ direction via the ball screw 201 and the ball nut 11 that are screwed together.

By the way, when one of the rotation transmitting members 6A and 6B is disconnected during the operation of the industrial robot RE, the corresponding sensor 12A or 12B is actuated and the rotary drive 3 is immediately stopped. In this case, since the remaining uncut rotation transmitting member 6A or 6B is connected between the rotating members 4 and 5, the rotary shaft 2 is maintained in a non-rotatable state when the rotary drive 3 is stopped. Therefore, the elevating member 8 is positioned in the Z direction when the rotary drive 3 is stopped, and the falling amount of the elevating member 8 can be substantially zero.

For example, when the rotation transmitting member 6A is cut, an alarm signal, an indicator, etc. are actuated by the output signal of the sensor 12A, the rotation transmitting member 6A cut after knowing this state is regarded as a new one. Replace. In this way, once the rotation transmission member 6A is replaced, the new rotation transmission member 6A has a longer life than the rotation transmission member 6B that is permanently attached, so from the next time onward, it is certain that Will be disconnected. Of course, three or more pairs of rotation transmission mechanisms 7 can be provided.

Further, as the rotation transmitting members 6A and 6B, belts, chains, wires and the like can be appropriately selected. Further, the present invention can be applied to various robots having elevating members of, for example, an orthogonal type and a cylindrical coordinate type.

For example, in a wafer transfer robot used in a semiconductor manufacturing process, wafers stored in a cassette in multiple stages at narrow intervals are sequentially loaded and unloaded one by one. With the industrial robot according to the present invention, If so, the drop amount of the elevating member 8 is substantially zero when the rotation transmitting member 6 is cut as described above. Therefore, even if the above-mentioned accident occurs in a state where the tip of the robot is inserted into the narrow space of the cassette, there is no risk of damaging the wafer. Of course, since the added value per wafer is hundreds of thousands of yen or more, the economic effect of preventing wafer damage is extremely large.

Further, the industrial robot according to the present invention can be arbitrarily applied to welding, assembling, and the like. Of course, when one of the rotation transmitting members 6A and 6B is cut as described above, the falling amount of the elevating member 8 of the industrial robot is substantially zero, so that the tip of the robot comes into contact with another device. There is no such thing.

[0016]

[Effect of device]

 As is clear from the above description, in the industrial robot according to the present invention, in particular, the rotation transmission mechanism arranged between the output rotary shaft of the rotary drive and the rotary shaft is arranged in the axial direction of the output rotary shaft. Since at least two pairs are provided apart from each other and a sensor for detecting the cut state of each rotation transmission member is provided and the rotation driving machine is stopped when any one of the sensors is activated, one of the rotation transmission members is provided. When the robot is cut, the amount of fall of the raising and lowering member of the industrial robot is substantially zero, and it is possible to avoid contact between the tip of the robot and other equipment. Therefore, it is possible to prevent damage to the tip of the robot or other devices.

[Brief description of drawings]

FIG. 1 is a front sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is an explanatory view of a usage state of the industrial robot which is a target of the present invention.

FIG. 5 is a front sectional view showing a conventional example.

6 is a sectional view taken along line VI-VI in FIG.

[Explanation of symbols]

 RE Industrial Robot 1 Base 2 Rotation Shaft 201 Ball Screw 3 Rotational Drive 301 Output Shaft 4A, 4B Rotation Member 5A, 5B Rotation Member 6A, 6B Rotation Transmission Member 7A, 7B Rotation Transmission Mechanism 8 Lifting Member 11 Ball Nut 12A, 12B Sensor

Claims (1)

[Scope of utility model registration request] 1. A rotary shaft which is rotatable with respect to a base is erected, and a ball screw screwed on the rotary shaft and a ball nut supported by a lifting member of an industrial robot are screwed together and rotated. An industrial robot provided with a rotation transmission mechanism including a rotation member fixed to an output shaft of a drive machine and the rotation shaft, and a rotation transmission member connected between the rotation members. Are arranged at least two pairs apart from each other in the axial direction, and are provided with a sensor for detecting the cut state of each of the rotation transmission members, and a control means for stopping the rotary drive machine when any one of the sensors operates. An industrial robot that is installed.