JPH0653198B2 - Cloth gripping hand - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cloth gripping hand used for automation of cloth handling in a sewing process.

[0002]

2. Description of the Related Art In recent years, sewing machines have made great progress. However, in the handling of cloth in the sewing process such as preparation work such as bending and overlapping of cloths necessary for sewing work and sorting work after sewing, Automation is not fully implemented. This is because the object to be handled is cloth, which is a flexible and easily deformable material.

[0003] Usually, in sewing work, a plurality of cloths are cut in advance at one time according to the template. For subsequent work, it is important to make sure one piece is separated from the piled cloth, and at this time, lift the next cloth together,
It is necessary to avoid wrinkling and disturbing the laminated state. Needless to say, the handling of the cloth in the sewing process is not limited to such separation of the cut cloth, but this kind of work is the basis.

As a device used for handling such a cloth, the cloth separating means which has already been introduced includes a pick-up method in which an artificial finger picks up from above, a needle stick method in which a cloth is hooked and separated, and vacuum suction. , Adsorption by air flow, air utilization method using air film, adhesive method using adhesive tape, pleating method that mechanically folds and separates, roller method that separates by winding with a roller, etc. is there.

However, many of these means are dedicated to the work to be performed and the type of cloth to be applied,
For example, it may be difficult to grip a cloth of any shape and reposition it correctly and put it in any specified position, or the cloth itself may have friction, breathability, and creases. It is customary that it does not have high versatility, since it cannot be applied to fabrics having different characteristics because it effectively uses characteristics such as sag.

[0006]

SUMMARY OF THE INVENTION The technical problem of the present invention is to visually recognize a cloth without utilizing the characteristics of the cloth itself and to mechanically detect the vicinity of the cut edge of the cloth. Another object of the present invention is to obtain a cloth gripping hand which has versatility for the work to be performed and the type of cloth to be applied by making the cloth grippable, and is capable of stably gripping necessary cloth by a simple means.

[0007]

A cloth gripping hand according to the present invention for solving the above-mentioned problems is provided with a pressing finger and a picking finger, and the pressing finger has a cloth sandwiching surface at a tip end thereof, and the picking finger is , For sandwiching the cloth with the cloth sandwiching surface of the presser finger, which has a sharp tip part to be inserted under the cloth to be grasped, and the portion facing the presser finger slightly closer to the base end from the tip part And a visual sensor for detecting the insertion position of the picking finger at the cloth end is provided on the pressing finger or the picking finger.

As the visual sensor, there is provided a light guide body that penetrates the inside of the picking finger and reaches its sharp tip, and detects the insertion position of the picking finger at the cloth edge through the light guide body, or the picking finger. It is possible to adopt a configuration in which a light reflecting surface is provided in the vicinity of the cloth sandwiching surface, and the insertion position of the picking finger is detected by the light reflected by this reflecting surface. A pressure sensor for detecting the pressing force can be provided.

[0009]

When the laminated cloth is separated one by one with the above hand, each finger is driven to press the laminated cloth with the pressing finger, and then the tip of the picking finger is set to the first sheet from the upper surface of the laminated cloth. It is inserted between the second sheets, and the end portion of the cloth is gripped by gripping between the cloth holding surfaces of the pressing finger and the picking finger and moved to a desired position.

During the operation of this hand, the output of the visual sensor and the pressure sensor is fed back to the driving mechanism side of each finger, so that the tip of the picking finger can be accurately moved between the laminated cloths, and one cloth can be surely secured. Can be held. That is, when the pressure sensor detects an appropriate pressure, the pressing finger obtains an appropriate pressing force against the cloth, and in that state, the visual sensor accurately detects the distance between the first and second cloths. By detecting and finely adjusting the position of the tip portion of the picking finger, the tip portion can be accurately transferred between desired laminated cloths, and a required cloth can be reliably gripped.

[0011] As described above, a work to be performed on the hand by visually recognizing the cloth and mechanically grasping the cloth end by the hand without utilizing the characteristics of the cloth itself. And versatility for the applied fabric type,
Moreover, the required cloth can be stably gripped by a simple means.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the construction of a first embodiment of a cloth gripping hand according to the present invention, and A to C of FIG. 2 show the modes of its operation. This cloth gripping hand is provided with a holding finger 2 and a gripping finger 3 for gripping cloth on a hand body 1, and is used by being attached to a robot arm or the like.

The pressing finger 2 has a cloth sandwiching surface at the tip portion 2a, and the picking finger 3 has a sharp tip portion 3a to be inserted under the cloth 4 to be grasped. A portion 3b, which is slightly closer to the base end from the tip portion and faces the pressing finger 2, is a cloth sandwiching surface for sandwiching the cloth 4 with the cloth sandwiching surface of the pressing finger 2.

The pinching finger 3 is provided with a light guide 5 which reaches the sharp tip 3a through the inside thereof. This light guide 5 proves the edge of the laminated cloth 4 and
It constitutes a part of a visual sensor for detecting the insertion position of the picking finger 3 at the end of the, and can be formed by an optical fiber bundle. On the base end side of the light guide 5, a light source 6 such as a laser is installed on the end face of the light guide for illumination, and an image of the laminated end face of the cloth obtained through the light guide 5 for detection is displayed. A detection device 7 for detection is provided oppositely. The detection device 7 can be composed of a CCD or the like.

A pressure sensor 9 for detecting the pressing force against the cloth 4 is provided at the tip of the pressing finger 2. The pressure sensor 9 is configured by enclosing a fluid such as grease in a cavity 10 formed of an elastic body such as silicon rubber, and disposing a pressure detecting element 11 in the fluid.

As can be seen from FIG. 3, the above-mentioned visual sensor can be provided at both ends of the picking finger 3 having a width necessary for gripping the cloth, whereby the picking finger 3 will be described later.
It is possible to control the posture of the tip end portion 3a of the cloth so as to follow the laminated surface of the cloth 4. In addition, a strain gauge 12 is provided on the back surface of the picking finger 3 in the figure to detect whether or not one piece of cloth is reliably separated.

In the cloth gripping hand having the above-mentioned structure, the hand body 1 is attached to the robot arm and the cloth 4 is laminated.
When separating the cloth 4, each finger is driven in a manner as shown in FIGS. 2A to 2C by an appropriate drive mechanism provided in the hand main body 1.
That is, first, when the tip portion 3a is inserted, the cloth 4 is pressed near the cloth end of the laminated cloth 4 so that the cloth 4 is not easily folded in half (A in FIG. 2), and then the tip of the picking finger 3 is pressed. Insert the portion 3a between the first and second sheets from the top surface (B in FIG. 2), and further rotate the presser finger 2 on the cloth 4 without slipping as the tip portion 3a is inserted, Finally, the end of the cloth 4 is sandwiched between the cloth scissor surface of the tip 2a of the presser finger 2 and the cloth scissor surface slightly closer to the base end from the tip 3a of the picking finger 3 and gripped (C in FIG. 2). ), To move to the required position. Such finger movements are suitable for separating a piece of cloth without disturbing the laminated cloth surfaces.

In the operation of the hand, the output of the visual sensor and the pressure sensor 9 is fed back to the driving mechanism side of each finger so that the tip of the picking finger 3 is accurately moved between the laminated cloths. The cloth 4 can be surely gripped. That is, in the case of pressing the laminated cloth 4 with the pressing finger 2, when the pressure sensor 9 detects an appropriate pressure, an appropriate pressing force of the pressing finger 2 against the cloth is obtained,
Further, when the presser finger 2 is pressed against the cloth with an appropriate pressing force, the position between the first and second sheets from the upper surface of the laminated cloth can be roughly known based on previously known data. Since it is possible to move the tip 3a of the picking finger 3 to a position almost close to the insertion position, in this state, the position between the first and second sheets of cloth can be accurately detected by the visual sensor. Then, by finely adjusting the position of the tip end portion 3a of the picking finger 3, the tip end portion 3a can be accurately transferred between desired laminated cloths. According to such an operation, at the same time when the stacked cloths 4 are separated, the cloths 4 are not folded in two,
By grasping the cloth edge, it becomes possible to easily shift to the next arbitrary work operation.

As shown in FIG. 3, when visual sensors are provided at both ends of the picking finger 3 having a width necessary for gripping the cloth, the posture of the picking finger 3 can be controlled. It is possible to control the tip portion of the picking finger 3 so as to follow the laminated surface of the cloth 4 based on the outputs of both sensors.

Whether or not a piece of cloth has been separated reliably is determined by providing a strain gauge 12 (FIG. 3) on the thin and easily deformable finger 3 to determine the amount of strain on the finger when the cloth 4 is gripped. It is possible to make an accurate determination by detecting with the strain gauge 12. That is, since the amount of increase in strain of the finger when gripping the cloth and the thickness of the cloth that is gripped are substantially proportional to each other, it is possible to determine whether or not the cloth is accurately gripped by detecting the amount of distortion. Therefore, when it is determined that 0 or more than 2 pieces of cloth have been gripped, it is possible to prevent the wrong number of cloths from being gripped by performing the cloth separating operation again.

The visual sensor can be constructed as in the second embodiment shown in FIG. In the visual sensor shown in the figure, a portion 23b of the picking finger 23, which is slightly closer to the base end and faces the holding finger 22, is a cloth holding surface for holding the cloth between the holding finger 22 and the vicinity thereof. A light-reflecting surface is provided, and the light source 26 provided on the pressing finger 22 projects the light to reflect the light reflected on the light-reflecting surface to illuminate the laminated cloth edge, and a detection device 27 including a CCD for detecting the cloth edge Is provided on the picking finger 23.

In this case, as shown in FIG.
The light reflecting surface of 3 is a curved mirror that functions as a magnifying glass, or as shown in FIG. 6, a magnifying lens system 28 is arranged in front of the detection device 27 in the pressing finger 22, and these curved mirrors are The lens system can be used to enlarge the cloth edge so that the position where the tip portion 23a of the thumb finger 23 is inserted can be accurately observed.

The visual sensor for detecting the insertion position of the picking finger at the cloth edge is, as described above, provided on either the pressing finger or the picking finger, or the light source or the detection position forming a part of the sensor. It can also be provided on the hand body side, and the configuration of the visual sensor itself is not limited to the above-described one, and various configurations can be adopted.

FIG. 7 shows a third embodiment of the hand for gripping the cloth, in which the holding finger 32 is fixedly provided on the hand main body 31, and the supporting portion 34 of the holding finger 32 constituted by a roller is used for the hand. It is slidably attached to the main body 31. Although not shown, a visual sensor is provided in this embodiment as in the first embodiment, and an appropriate pressure sensor can be provided on the roller-shaped pressing finger 32.

Most of the work such as stacking a plurality of cloths and setting them on a sewing machine is currently performed manually. However, by operating the hand in the reverse order of the above-described cloth separating operation, a predetermined 3 It is possible to place the cloth held in the three-dimensional position without causing displacement of the cloth. This is because the presser finger keeps pressing until the last moment of releasing the cloth. Such cloth handling is suitable for positioning the cloth for the next operation.

[0026]

According to the cloth gripping hand of the present invention described in detail above, it is possible to visually check the cloth itself without utilizing the characteristics of the cloth itself, such as friction, breathability and creases. Recognizing the cloth and making it possible to mechanically grip near the edge of the cloth,
The versatility of the work to be performed and the type of applied fabric can be provided, and the required fabric can be stably gripped by a simple means.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a first embodiment of a cloth gripping hand according to the present invention.

FIG. 2A to FIG. 2C are operation explanatory diagrams showing the cloth gripping operation in the order of operation.

FIG. 3 is a perspective view of an essential part showing a modified example of the first embodiment.

FIG. 4 is a perspective view of essential parts of a second embodiment.

FIG. 5 is a side view of a main part when the light reflecting surface of the picking finger is a magnifying glass in the second embodiment.

FIG. 6 is a side view of a main portion when a magnifying lens system is arranged in front of a detection device for a presser finger in the second embodiment.

FIG. 7 is a side view of a cloth gripping hand according to a third embodiment of the present invention.

[Explanation of symbols]

1 hand body, 9 pressure sensor, 2 presser finger, 22 presser finger, 2a tip part, 23 picking finger, 3 picking finger, 23a tip part, 3a
Tip part, 23b part, 3b
Part, 31 hand body, 4 cloth,
32 presser finger, 5 light guide,
33 picking fingers,

Claims (4)

[Claims] 1. A pressing finger having a cloth sandwiching surface at its tip, and a sharp tip inserted under the cloth to be grasped, and opposed to the pressing finger slightly closer to the base end from the tip. A part is provided with a picking finger which is a cloth holding surface for holding the cloth between the holding finger and the cloth holding surface, and the pressing finger or the holding finger detects the insertion position of the picking finger at the cloth end. A hand for cloth gripping, which is provided with the visual sensor of. 2. A light sensor which passes through the inside of the picking finger and reaches a sharp tip portion thereof, and a visual sensor for detecting the insertion position of the picking finger at the cloth end is provided through the light guiding body. The cloth gripping hand according to 1. 3. The light reflecting surface is provided in the vicinity of the cloth sandwiching surface of the picking finger, and a visual sensor for detecting the insertion position of the picking finger by the light reflected by the reflecting surface is provided. Hand for holding cloth. 4. The cloth gripping hand according to claim 1, wherein a pressure sensor for detecting a pressing force against the cloth is provided at the tip of the pressing finger.