JPH10264068A - Robot hand - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a robot hand capable of preventing displacement during transfer and locating works of complicated and various kinds of shapes at exact locations and angles in the next process by using the robot hand for a high level carrier robot provided with a shape recognizing device, etc., and performing a shape aligning fixing for the robot hand to works (objects to be clamped) by a pin. SOLUTION: A work is fixed by fixing elevating and lowering of a pin 26 as necessary and using a supporting hook 28 supporting the work from the lower direction as necessary such as when the work is heavy by a robot hand provided with an attracting part 23 such as an electromagnet attracting the work and a shape aligning part 25 provided with 6 or more pins 26 lowering by the gravity for performing a shape aligning to the work.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a robot hand, and more particularly to a robot hand capable of transporting and holding a work (an object to be grasped) at an accurate position and angle while ensuring grip.

[0002]

2. Description of the Related Art Robots have been widely used in many industrial fields, and the penetration thereof has been remarkable even in transfer operations at production sites. Particularly recently, in order to perform more precise work, an advanced robot system that has an image processing device that processes video information of a work captured via a shape recognition device and a robot controller that controls a robot based on this image processing data Is used. For example, Japanese Patent Application Laid-Open
In 134731, a work image captured by an image input camera is processed by a recognition device to obtain a line segment image from a contour line, a specific portion of a simple shape in the image is recognized, and the image is compared with an image of a model that has been input in advance. There has been proposed a device that calculates an appropriate picking angle and position of a robot arm, controls a robot hand, and picks up the robot hand. As described above, the robot control technology based on the electronic technology enables advanced work.

On the other hand, there are two types of robot hands that carry mechanical parts, a clamp type imitating a part beyond a human wrist, that is, a hand and a finger, and a suction type using magnetism or air suction. The clamp type is used, and the latter is used for less precise work. In the case of precision work such as transport that requires accurate positioning of complex workpieces such as tandem press products and transfer press products in the next process, the dedicated clamp-type robot hand that can easily grip the workpiece is used as described above. It is used for advanced robot systems, and it also performs pre-teaching operations called teaching prior to work.

[0004]

However, this method is extremely efficient for continuous work of one kind, but in the case of work of many kinds, a special robot hand corresponding to the work is prepared each time. It is extremely inefficient and difficult to use. For this reason, attempts have been made to use a suction type robot hand instead of the above-mentioned dedicated clamp type to handle a wide variety of products. The position and angle were misaligned, making it unsuitable for work that required precise positioning in the next step.

SUMMARY OF THE INVENTION It is an object of the present invention to hold a workpiece having a complicated shape of various types at a correct position and angle in the next process by preventing the workpiece from being displaced during transport and preventing the workpiece from being displaced during transport. It is to provide a robot hand suitable for work.

[0006]

According to the present invention, in order to achieve the above object, the shape information of a work taken in through a shape recognition device is processed by a shape recognition processing device, and the robot is controlled by a robot control device. The advanced robot system to be controlled is provided with the robot hand of the present invention, that is, the suction unit for sucking the work, and the profile fixing unit for fixing along the shape of the work with six or more pins descending by its own weight. This is achieved by using a robot hand characterized by the following.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Since the robot hand of the present invention has the above-described configuration, six or more pins descending by its own weight provided on the side-by-side fixing portion of the robot hand are formed into a work shape. The work piece is sucked upward by the suction unit, and if necessary, before or after suction, the vertical movement of the pin is fixed with a fixed plate to fix the work. By supporting the robot, it is possible to prevent a deviation between the robot hand and the workpiece during the high-speed transfer from the gripping to the stationary operation, and the precisely calculated operation of the robot is accurately realized.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an overall view showing an example of a robot transfer operation using the robot hand of the present invention. FIGS. 2 to 4 respectively show a gripping unit and a supporting unit showing each stage during the picking operation. FIG. 5 is a front view, FIG. 5 is a cross-sectional view taken along the line AA of FIG.
FIG. 6 is a plan view of a fixing plate for fixing the vertical movement of a pin below the holding plate, and FIG. 7 is a cross-sectional view taken along the line BB of FIG. 5 before the operation of the robot.

In FIG. 1, the scanning type sensor 4
The shape information obtained by scanning the work 5 on the work table 6 before transport is sent to a shape recognition processing device 9 provided with a monitor and input device 8, and compared with work shape data input in advance. The processing data and / or command data is sent to a robot control device 11 having a monitor and input device 10, and the command data operates the robot 1 to suction the work 23 of the present invention (see FIG. 2). And a gripping portion 3 having a contour fixing portion 25 (see FIG. 2) for fixing the workpiece along the shape of the workpiece with six or more pins descending by its own weight. Then, the work 5 is accurately placed on the work table 7 in the next process.
If necessary, such as when the weight of the work is large, the work is fixed from below by the support 2 provided with the support hook 28 (see FIG. 2) from immediately after the pickup to before the stationary.

The pick-up operation will be described in more detail. FIG. 2 shows a state before a workpiece is gripped, FIG. 3 shows a state during a gripping operation, and FIG. As described above, the robot hand is constituted by the holding part 3 for suspending the work and the movable supporting part 2 for supporting the work from below during the transfer, and is in the state of FIG. The electromagnet 23 as the attraction part of the part 3 is in the upper release position, the pins 26 that drop by their own weight are all in the position that they have dropped by their own weight, and the support hooks 28 of the support part 2 are also in the upper stationary position.
In the initial stage of the pickup, the gripping part 3 is lowered onto the work 5, and the state shown in FIG. 3, that is, the pins 26 in the profile fixing part 25 are pushed up to the respective positions of the work by the work 5, and the whole pin is Is fixed along the shape. Next, the electromagnet 23 is moved to the optimum plane instructed by the shape recognition processing device by operating the suction transmission rod 24 by driving the suction operation box 21, and the work 5 is appropriately energized and sucked (the state shown in FIG. 4) and picked up. . Further, when the weight is large, the support hook 28 rotates as shown in FIG. 4 to support the workpiece 5 from below by operating the support transmission rod 27 by driving the support operation box 22 of the support unit 2. Next, the process is moved to the next step, and the landing / stationary work at the final stage of the transfer is performed in the reverse order of the pick-up work.

Next, the operation of the profile fixing portion 25 will be described in detail. FIG. 5 is a sectional view taken along the line AA of the profile fixing portion 25 (the pin 26 is omitted for convenience of explanation), and FIG. 7 is a sectional view taken along the line AA of FIG. In the casing 31, a hold plate 33 is provided, and six or more holes 35 (eight in this example) are opened. A pin 26 having a smaller diameter than the hole passes through each hole 35. Below the hold plate 33, there is a fixing plate 34 for fixing the vertical movement of the pin as shown in FIG. 6, and the same number of connecting slots as the hold plate 33 are provided in this. The connection long hole is the same as the hole 36 slightly larger than the hole 36 of the hold plate 33 whose center is located at the position matched with the hold plate 33 and the center of the hole 36 which is shifted clockwise by a small angle θ. Is connected at a center-to-center distance smaller than the small hole radius. For example, when the workpiece is not picked up, as shown in FIG.
In a state where the pin 26 is combined with the pin 26 so that the pin 26 can be lowered by its own weight, and in a state where the pin 26 is picked up and the lifting of the pin 26 is fixed, as shown in FIG. The pin 26 is rotated by a small angle θ
Is fixed. The fixed plate 34 is driven by a fixed plate driving device 32 shown in FIG. Also, the hold plate 33
In addition, a circular hole is provided at the center of the lifting / lowering fixing plate 34, in which the electromagnet 23 sucks the work at an appropriate position and posture in accordance with a command from the robot controller.

Next, each part of the robot hand will be described. Hold plate It does not necessarily have to be a single flat plate, and the material does not matter.
It suffices to provide six or more pins that descend with their own weight, and the pins can function as contours to the work when picking up the work. If the number of the weight-falling pins is less than 6, the solid work conformity aimed at by the present invention cannot be realized, and if the number is too large, a problem occurs in maintenance. Therefore, the range from 6 to several tens is appropriate. FIG. 9 shows an example of a rectangular holding plate, and FIG. 10 shows an example of a rectangular holding plate having corners (both have 44 holes). FIG. 9 shows an example in which holes are arranged in a grid pattern, and FIG. 10 shows an example in which holes are radially arranged. However, the present invention is not limited to this. The same number of holes as the ceiling plate and the same arrangement as the ceiling plate are required, and it may be composed of multiple pieces like the hold plate, and the holes function as pins that drop by their own weight when released. It suffices if the lifting and lowering of the weight drop pin can be fixedly stopped. The material is not limited, but a metal flat plate is preferable in terms of robustness. In addition, the material that is elastically deformed at the contact portion with the pin has excellent stopping and fixing ability. If the work is a blanking material produced by a blanking press, for example, and is a relatively thin flat plate, the fixing plate can be omitted. Any length, thickness, or material can be used as long as the work can exhibit the conformability of the work due to its own weight drop. In addition, it is not always necessary to arrange the same pins, and in many cases, when transporting a relatively similar work, it is more stable to change the thickness, the length, and the like in consideration of the strength according to the part of the work. Suction unit The electromagnet is optimal when the work is made of a magnetic material such as iron, cobalt or nickel, but when a non-magnetic material such as plastic is used, vacuum (air suction) can be used.
In the case of a relatively thin flat plate made of the blanking material or the like, it can be fixedly installed at the center of the profile fixing portion. Supporting part (supporting unit) Any material, mechanism, and shape can be used as long as it can withstand the work weight by being pressed against the contoured part from below. Also, the work
In the case of a lightweight, simple, non-solid three-dimensional shape like the blanking material, the support portion can be omitted.

Hereinafter, the present invention will be described with reference to examples.

[0015]

Example 1 A cone having a height of 100 mm and a bottom circle diameter of 150 mm was cut 30 mm below the vertex on a perpendicular line from the vertex.
The iron work having an elliptical crest cut by a plane having an elevation angle of 30 degrees is subjected to a high-speed transfer test to the next process by the robot and the robot hand described in FIGS. Hour 1 m / sec). The robot has a maximum transfer distance of 3 m. The robot hand uses the contoured portion shown in FIGS.
0mm, inner diameter 70mm, thickness 10mm, hole diameter 7.1m
m, eight at regular intervals on a circle with a diameter of 130 mm), a fixing plate made of nylon (holes with a diameter of 10 mm and 7.1 mm, and the same size as the other holding plate 33), a stainless steel pin 26 (length of 7 mm in diameter) 70mm, head diameter 12mm
2 mm thick), an electromagnet attracting portion 23 (a cylindrical head having a diameter of 25 mm) and an iron supporting hook 2 acting on the center of the work bottom.
Equipped with eight. The work is placed on a table 1m high,
In the next step, a 0.5 m-high table 2 m apart was used. A circle and a top ellipse were drawn on the next step table in the same position as the bottom of the work, and the deviation between the position and the angle was measured. As a result of a total of 10 transport tests, the positional deviation was good within 1.5 mm and the angular deviation was good within 1.2 degrees.

[0016]

Embodiment 2 The work was the same as that of the embodiment 1 except that the work was the same type as that of the embodiment 1 and a steel disc having a diameter of 30 mm and a thickness of 1 mm was adhered to the center of the ellipse at the top, made of nylon, and the support hook 28 was inoperative. As a result of performing a test under the same conditions as in Example 1,
Exactly the same results as in Example 1 were obtained in ten tests.

[0017]

[Embodiment 3] A workpiece was made with a long diameter of 200 mm and a short diameter of 100 m.
The test was performed under exactly the same conditions as in Example 1 except that an elliptical blank made of iron having a thickness of 1 mm and a thickness of 1 mm was used, and the fixing plate 34 and the support hooks 28 were not operated. Example 1 after 10 tests
And similar results were obtained.

[0018]

[Comparative Example 1] As a result of removing all pins 26 in Examples 1, 2 and 3 and performing a test 10 times each, in any of the tests, the positional deviation was within 1.5 mm and the angle deviation was within 1.2 degrees. It never fit.

[0019]

According to the present invention, it is possible to prevent a deviation between a robot hand and a workpiece even in a transfer operation requiring high-speed and precise stationary exceeding 1 m / sec, and to accurately calculate a robot's movement. Can be implemented.

[Brief description of the drawings]

FIG. 1 is an overall view of a robot system using a robot hand according to the present invention.

FIG. 2 is a front view of the robot hand according to the present invention before gripping a workpiece.

FIG. 3 is a front view of the robot hand according to the present invention during a gripping operation.

FIG. 4 is a front view of the robot hand according to the present invention during gripping and transporting.

FIG. 5 is a sectional view taken along the line AA (of the profile fixing portion 25) of FIG. 2;

FIG. 6 is a plan view of a fixing plate of the robot hand according to the present invention.

FIG. 7 is a sectional view taken along the line BB of FIG. 5;

FIG. 8 is a cross-sectional view illustrating a state in which the robot hand of the present invention is fixed with a pin.

FIG. 9 is a plan view showing another example of the hold plate used for the robot hand of the present invention.

FIG. 10 is a plan view showing another example of the hold plate used for the robot hand of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Robot 2 Support part of robot hand 3 Grasping part of robot hand 4 Scanning sensor 5 Work (object to be grasped) 6 Work table on which object to be conveyed 7 Work table for next process 8 Monitor and input device of shape recognition processing device 9 Shape recognition processing device 10 Monitor and input device of robot control device 11 Robot control device 21 Suction operation box 22 Support operation box 23 Electromagnet (suction unit) 24 Suction transmission rod 25 Shaped fixing unit 26 Pin 27 Support transmission rod 28 Support hook 31 Casing 32 Fixing plate driving device 33 Hold plate 34 Fixing plate 35 Pin hole (Hole of holding plate) 36 Pin hole (Large circle of fixing plate connecting long hole) 37 Pin hole (Small circle of fixing plate connecting long hole)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Soji Ishii 77 Ijirino, Okayama Pref. Person Kenji Nishijima 61 Ijino, Soja City, Okayama Prefecture Nanyo Industry Co., Ltd.

Claims (3)

[Claims] 1. A robot hand comprising: a suction unit for adsorbing a work; and a profile fixing unit for fixing the work along the shape of the work with six or more pins descending by its own weight. 2. The robot hand according to claim 1, further comprising a device for stopping and raising and lowering the pin. 3. The robot hand according to claim 1, further comprising a movable support for supporting the work from below.