JP4876796B2 - Industrial robot hand device - Google Patents

Description

  The present invention relates to a hand device for an industrial robot capable of gripping many workpieces including different shapes and dimensional differences.

Many hand devices of industrial robot systems that perform work on conventional production lines are used for handling workpieces. Automation systems using industrial robots are used in a wide variety of fields, such as putting materials into production lines, attaching and detaching workpieces to processing machines, and packing boxes. At the tip of the handling robot, a hand device called a robot hand or a hand device that grips a workpiece is usually mounted. Such hand devices are often driven by air cylinders.
Japanese Patent No. 3245095 US2004 / 0103740A1

  However, when the same robot system handles a large number of workpieces including different shapes and dimensional differences, the same hand device often cannot be gripped. Therefore, a method is available in which multiple hand devices with specifications suitable for the shape and dimensions of the workpiece are prepared, these are attached to the robot via an auto tool changer, and the hand device mounted on the robot is replaced when the production type is changed. There is. However, in order to replace the hand device attached via the auto tool changer, it takes time for the replacement operation, and in the case of a production line that frequently changes the production type, there is a problem that the production efficiency decreases. there were. Furthermore, in order to cope with workpieces of various shapes and dimensions, it is necessary to prepare a large number of hand devices corresponding to this, and in addition, it is necessary to prepare an auto tool changer, resulting in high equipment costs. There was a demerit. Further, as described in, for example, Patent Document 1 or Patent Document 2, as a method of gripping a large number of workpieces including different shapes and dimensional differences with the same hand device, a plurality of motors including a plurality of fingers (fingers) are provided. A hand device that drives each finger is known.

  However, according to the inventions described in Patent Document 1 or Patent Document 2, the hand device is composed of a plurality of fingers (finger). One hand is provided for each finger in order to open and close each finger. However, there is a disadvantage that the cost is increased. In addition, when the workpiece is gripped, the force exerted by the fingers on the workpiece is not balanced, and the workpiece cannot be gripped stably. To overcome this, a complicated control method is required. There was a drawback of being esoteric. Furthermore, when making a hand device of a small size, it is necessary to use a gear of a small size for the drive transmission of the joint part that opens and closes the finger, so a large torque cannot be transmitted and a large gripping force is realized. There was a drawback that it was difficult to do.

  An object of the present invention is to prepare a plurality of hand devices having specifications suitable for the shape and dimensions of a workpiece, which solve the conventional problems, and mount these on a robot via an auto tool changer when a production type is changed. Instead of responding by replacing the device, each finger is a hand device that drives multiple fingers (fingers) that can hold multiple workpieces with different shapes and dimensions with the same hand device. Each motor does not require one motor each time, it is easy to balance the force exerted by multiple fingers on the workpiece, and a large gripping force can be realized even with an inexpensive and small-sized hand device. The object is to provide a hand device for an industrial robot.

Therefore, the present invention includes a frame, a ball screw or a trapezoidal screw that is rotatably supported by the frame in the vertical direction, and a first servomotor that is fixed to the frame and that rotationally drives the ball screw or the trapezoidal screw. A first L-shaped finger supported on the frame for rotation about a horizontal axis and having a hook-shaped portion extending at the one end;
A pair of brackets fixed to the frame so as to be pivotable about an axis parallel to the ball screw or the trapezoidal screw, and one end of each bracket is rotatably supported around a horizontal axis and the 1 A second L-shaped finger having an extended hook at the end;
A rotary shaft fixed to each bracket, a pair of gears fixed to the rotary shaft and meshed with each other, and an output shaft fixed to any one of the pair of gears and the output shaft A second servo motor coupled with
A cam follower, a roller, or a pin that is rotatably supported around the second horizontal axis parallel to the horizontal axis at the end of each of the extended hook-shaped portions of the first and second L-shaped fingers;
A block fixed to a nut of the ball screw or trapezoidal screw and having a groove and a pair of deep circumferential grooves rotatably supporting the cam follower, roller or pin;
At least one end thereof is fixed to the frame 1, and the other end is composed of a linear motion bearing or a linear motion guide that guides the block in the axial direction of the ball screw or trapezoidal screw,
Each horizontal axis or each second horizontal axis is located on the same plane or on its own plane, and the other end of each finger is opened and closed by operating the first servo motor. The above-described problems of the present invention have been solved by the industrial robot hand device.

  In the present invention, since a single hand can be used as a parallel hand or a three-claw hand, a large number of workpieces having different shapes or dimensional differences can be gripped, and the same workpiece can be used in various directions. From the above, various clamping methods can be selected. Furthermore, the hand device of the present invention has three fingers of the first and second L-shaped fingers, and when the three fingers open and close, in order to perform a centripetal operation, the same hand device, A hand device that drives multiple fingers that can hold multiple workpieces within the maximum gripping dimension of two fingers, and does not require one motor for each finger, and opens and closes multiple fingers. Since the operation is driven by one motor, the cost can be reduced, and each horizontal axis and each second horizontal axis are located on the same plane or on the same plane of each other, and at least two fingers are provided. When opening and closing, the centripetal clamp operation is performed accurately and the gripping force of each finger is balanced, so there is no need to adjust the operation position, operation speed, and output of the multiple motors. Industrial robot hand device that is easy to control and can transmit a large torque by ball screw or trapezoidal screw without using a reduction mechanism such as gears at the joint, and can make a hand with large gripping force Became to provide.

An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic side block diagram showing a part of a hand device for an industrial robot according to an embodiment of the present invention, FIG. 2 is a schematic bottom view of FIG. 1, FIG. 3 is a schematic perspective view of FIG. FIG. 5 is a bottom view showing a state in which the pair of L-shaped fingers in FIG. 1 are swung by two second servo motors until they are turned in the same direction around an axis parallel to a ball screw or a trapezoidal screw. FIG. 6 is a schematic side block diagram in which a pair of L-shaped fingers in FIG. 1 are closed and indicated by a dotted line, and FIG. 6 is a schematic diagram showing a robot equipped with the industrial robot hand device of FIG. It is a side block diagram.

As shown in FIG. 6, the frame 1 of the hand device is fixed to the tip of the arm 21 of the articulated robot 9 fixed to the floor. As shown in FIG. 1, in an industrial robot hand device according to an embodiment of the present invention, a ball screw 2 (which may be a trapezoidal screw) rotatably supported in a vertical direction on a frame 1 of the hand device is rotatable. It is fixed. A first servomotor 3 that rotationally drives the ball screw 2 is fixed to the frame 1. Pulleys 10 and 11 are fixed to the shaft end of the ball screw 2 and the shaft end of the servo motor 3, respectively, and a timing belt 12 is hung between the pulleys 10 and 11. Further, the hand device includes a first L-shaped finger 4 supported on the frame 1 so that one end 26 is rotatable around the horizontal axis 8 and having an extended hook-shaped portion 17 on the one end 26, and a ball screw on the frame 1. A pair of brackets 15, 15 fixed so as to be pivotable around an axis parallel to 2, and one end 26 to each bracket 15, 15 is rotatably supported around the horizontal axis 8 and to one end 26. A second L-shaped finger 16, 16 having an extended hook 17;
As shown in FIG. 3, the rotating shafts 29 and 29 fixed to the brackets 15 and 15 respectively, the pair of gears 27 and 27 fixed to the rotating shafts 29 and 29 and meshed with each other, and the pair of gears 27 , 27, a second servo motor 28 whose output shaft is connected to one of the rotation shafts,
A cam follower 5 (roller) rotatably supported around a second horizontal axis 19 parallel to the horizontal axis 8 at each of the extended hook-shaped end portions 17 of the first and second L-shaped fingers 4, 16, 16. A block 6 having a groove 71 fixed to the nut 20 of the ball screw 2 and rotatably supporting the cam follower 5 and a pair of deep peripheral grooves 72, 72;
The frame 1 is fixed at least at one end, and the other end is composed of a linear guide (which may be a linear motion bearing) comprising a shaft 13 and a ball bush 14 for guiding the block in the axial direction of the ball screw or trapezoidal screw,
Each horizontal axis 8 or each second horizontal axis 19 is located on the same plane or on the same plane of itself, and the other end of each of the fingers 4, 16, 16 by operating the first servo motor 3. Opened and closed. In FIG. 2, each first horizontal axis 8 or each second horizontal axis 19 is orthogonal to the axial direction of the ball screw 2 and forms 120 degrees with each other. The three fingers 4, 16, 16 are bent in a C shape on the inside, but may be bent in a straight line or other shapes. A reduction gear (not shown) is interposed between the first and second servo motors 3 and 28 and their respective output shafts when necessary.

Here, when the first servo motor 3 is operated, the ball screw 2 rotates via the pulleys 10 and 11 and the timing belt 12, and the block 6 fixed to the ball screw nut 20 slides. Since the cam follower 5 is caught in the grooves 71, 72, 72 of the block 6, the fingers 4, 16, 16 swing and open / close. By operating the first servo motor 3 at a pre-recorded position, the fingers 4, 16, 16 can be opened and closed at any position, and a clamping operation can be performed according to the size of the target workpiece. . In addition, after clamping the workpiece with the fingers 4, 16, and 16, a current (stall current) is supplied so that the first servo motor 3 operates in the direction in which the fingers 4, 16, and 16 are operated. Then clamp the workpiece. Adjust the clamping force by adjusting the current.
When the second servo motor 28 is actuated, the second fingers 16 and 16 are pivoted symmetrically so that they are guided by a pair of deep circumferential grooves 72 and 72 and open around an axis parallel to the ball screw 2. To do. For example, as shown by the dotted line in FIG. 4, when the second fingers 16, 16 are in the same orientation, the second fingers 16, 16 are opposite to the first finger 4, and the hand device is 4 and the second fingers 16 and 16 form a parallel hand, which is suitable as a parallel hand for gripping a square workpiece or for clamping and handling a cylindrical workpiece from the side. In addition, as shown in FIG. 2, when the second fingers 16, 16 are at an angle of 120 degrees, the three fingers 4, 16, 16 are at a relative position of 120 degrees with respect to each other. In the form of a three-claw hand, which is used as a so-called three-claw hand and grips a cylindrical workpiece, it can be clamped from the axial direction.

  The industrial robot hand device according to the embodiment of the present invention can be used as a parallel hand or a three-claw hand with a single hand, and therefore can hold a large number of workpieces including different shapes and dimensions. In addition, various clamping methods can be selected for the same workpiece from various directions. Furthermore, the hand device of the present invention has three fingers of the first and second L-shaped fingers, and when the three fingers open and close, in order to perform a centripetal operation, the same hand device, A hand device that drives multiple fingers that can grip multiple workpieces within the maximum gripping dimension of two fingers, and does not require one motor for each finger, and opens and closes multiple fingers. Since the operation is driven by one motor, the cost can be reduced, and each horizontal axis and each second horizontal axis are located on the same plane or on the same plane of each other, and at least two fingers are provided. When opening and closing, the centripetal clamp operation is performed accurately and the gripping force of each finger is balanced, so there is no need to adjust the operation position, operation speed, and output of the multiple motors. Industrial robot hand device that is easy to control and can transmit a large torque by ball screw or trapezoidal screw without using a reduction mechanism such as gears at the joint, and can make a hand with large gripping force Became to provide.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side block diagram showing a part of an industrial robot hand device according to an embodiment of the present invention. The schematic bottom view of FIG. The schematic perspective view of FIG. FIG. 2 is a bottom view showing a state in which a pair of L-shaped fingers of FIG. 1 are turned by two second servo motors until they are turned in the same direction around an axis parallel to a ball screw or a trapezoidal screw. FIG. 2 is a schematic side block diagram in which a part of a pair of L-shaped fingers of FIG. It is a schematic side block diagram which shows the robot carrying the industrial robot hand apparatus of FIG.

Explanation of symbols

1: frame of hand device, 2: ball screw, 3: first servo motor 4: first finger, 5: cam follower, 6: block, 8: horizontal axis
13: Linear guide, 15, 15: 1 pair of brackets, 16, 16: Second finger
17: extension hook, 19: second horizontal shaft, 20: ball screw nut, 26: 1 end
27: 1 pair of gears, 28: second servo motor, 29: rotating shaft, 71: groove, 72: deep circumferential groove

Claims (2)

A frame, a ball screw or a trapezoidal screw that is rotatably supported by the frame in a vertical direction, a first servo motor that is fixed to the frame and rotationally drives the ball screw or the trapezoidal screw, and one end of the frame A first L-shaped finger supported rotatably around a horizontal axis and having an extended hook at the one end;
A pair of brackets fixed to the frame so as to be pivotable about an axis parallel to the ball screw or the trapezoidal screw, and one end of each bracket is rotatably supported around a horizontal axis and the 1 A second L-shaped finger having an extended hook at the end;
One rotating shaft fixed to each bracket, a pair of gears fixed to the rotating shaft and meshed with each other, and one of the pair of gears fixed to the frame. A second servo motor connected to the output shaft;
A cam follower, a roller, or a pin that is rotatably supported around the second horizontal axis parallel to the horizontal axis at the end of each of the extended hook-shaped portions of the first and second L-shaped fingers;
A block fixed to a nut of the ball screw or trapezoidal screw and having a groove and a pair of deep circumferential grooves rotatably supporting the cam follower, roller or pin;
At least one end thereof is fixed to the frame 1, and the other end is composed of a linear motion bearing or a linear motion guide that guides the block in the axial direction of the ball screw or trapezoidal screw,
Each horizontal axis or each second horizontal axis is located on the same plane or on its own plane, and the other end of each finger is opened and closed by operating the first servo motor. Industrial robot hand device characterized by that. And articulated robot that is secured to the floor, articulated robot, characterized in that it comprises a hand device of the industrial robot mounted claims 1 Symbol placement on the arm tip of the robot.

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