JPH04303494A - Fabric holding hand - Google Patents

Abstract

PURPOSE:To provide a general-purpose fabric holding hand capable of stably holding a necessary fabric with a simple means by visually recognizing the fabric, and mechanically holding the vicinity of the end edge of the fabric. CONSTITUTION:When laminated fabrics 4 are pressed by a pressing finger 2 and proper pressure is detected by a pressure sensor 9, the proper pressing force of the pressing finger 2 to the fabrics 4 is obtained. When the pressing finger 2 is pressed to the fabrics 4 with the proper pressing force, the position between the first and second fabrics 4 from the upper face of the laminated fabrics 4 can be approximately known. The tip section 3a of a gripping finger 3 can be moved to the position almost near the insertion position, the position between the first and second fabrics 4 is correctly detected by a visual sensor, the position of the tip section 3a of the gripping finger 3 is finely adjusted, thus the tip section 3a can be correctly moved between the desired laminated fabrics 4.

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 automating the handling of cloth in a sewing process.

0002

[Prior Art] Sewing equipment has made great progress in recent years, but handling of fabric during the sewing process, such as preparatory work such as folding and overlapping the fabric necessary for sewing work, and arranging the sewn items, has become more difficult. Automation cannot be said to have been fully put into practical use. This is due to the fact that the object to be handled is cloth, which is a flexible and easily deformable material.

[0003] Normally, during sewing work, a plurality of pieces of cloth are cut at a time in advance according to a pattern. For subsequent work, it is important to reliably separate one piece of fabric from the stack, and at this time, do not lift the next fabric together,
It is necessary to prevent wrinkles from forming and disturbing the laminated state. Although it goes without saying that the handling of cloth in the sewing process is not limited to such separation of cut cloth, this type of work is basic.

Fabric separation means that have already been introduced as devices for handling such fabrics include a picking method in which the cloth is picked up from above with an artificial finger, a needle pricking method in which it is separated by hooking it with a needle, and a vacuum suction method. , an air utilization method that uses air flow adsorption or an air film, an adhesive method that uses adhesive tape, a pleat method that separates by mechanically applying pleats, and a roller method that separates the material by winding it up with a roller. be.

[0005] However, many of these methods are specialized for the work to be performed and the type of fabric to which they are applied.
For example, there may be difficulty in grasping a cloth of arbitrary shape, repositioning it accurately, and placing it in an arbitrary designated position, or the cloth itself may have friction, air permeability, or susceptibility to folds. Because they make effective use of characteristics such as thickness, they are generally not highly versatile, as they cannot be applied to fabrics that have different characteristics.

[0006]

[Problems to be Solved by the Invention] The technical problem of the present invention is to visually recognize the cloth without using the characteristics of the cloth itself, and to mechanically detect the vicinity of the cut edge of the cloth. To provide a hand for gripping cloth, which has versatility for the work to be performed and the type of cloth to be applied by being grippable, and can stably grip the required cloth by a simple means.

[0007]

[Means for Solving the Problems] In order to solve the above problems, the cloth gripping hand of the present invention includes a presser finger and a picking finger, the presser finger has a cloth pinching surface at the tip, and the picking finger has a cloth pinching surface at its tip. , has a sharp tip inserted under the cloth to be gripped, and a portion of the tip slightly closer to the proximal end facing the presser finger is used to sandwich the cloth between the cloth pinching surface of the presser finger. The present invention is characterized in that the presser finger or the picking finger is provided with a visual sensor for detecting the insertion position of the picking finger at the edge of the cloth.

[0008] The above-mentioned visual sensor has a structure that includes a light guide that passes through the inside of the picking finger and reaches the sharp tip of the picking finger, and detects the insertion position of the picking finger at the edge of the cloth through the light guide, or It is possible to adopt a configuration in which a light reflecting surface is provided near the cloth clamping surface, and the insertion position of the pinching finger is detected by the light reflected from this reflective surface. A pressure sensor can be provided to detect the pressing force.

[0009]

[Operation] When separating the laminated cloth one by one using the above-mentioned hand, each finger is driven to press the laminated cloth with the presser finger, and then the tip of the picking finger is moved to the first sheet from the top of the laminated cloth. Insert it between the second cloth, grip the edge of the cloth between the cloth-pinching surfaces of the presser finger and the pick finger, and move it to the desired position.

[0010] When operating this hand, by feeding back the output of the visual sensor and pressure sensor to the drive mechanism of each finger, the tip of the picking finger can be accurately transferred between the laminated fabrics, and one piece of fabric can be secured. It can be held by In other words, when the appropriate pressure is detected by the pressure sensor, the presser finger can obtain an appropriate pressing force against the cloth, and in this state, the visual sensor can accurately press between the first and second sheets of cloth. By detecting this and finely adjusting the position of the tip of the picking finger, the tip can be accurately moved between the desired laminated fabrics and the desired fabric can be reliably gripped.

[0011] In this way, by visually recognizing the cloth and making it possible for the hand to mechanically grasp the edge of the cloth without using the characteristics of the cloth itself, the work to be performed by the hand can be achieved. and the versatility of applicable fabric types.
Moreover, it becomes possible to stably hold the necessary cloth by a simple means.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the structure of a first embodiment of a cloth gripping hand according to the present invention, and FIGS. 2A to 2C show its operation mode. This cloth gripping hand includes a hand body 1, a presser finger 2 and a picking finger 3 for gripping cloth, and is used by being attached to a robot arm or the like.

[0013] The presser finger 2 has a cloth pinching surface at the tip 2a, and the pinch finger 3 has a sharp tip 3a that is inserted under the cloth 4 to be gripped. A portion 3b facing the presser finger 2, which is slightly closer to the proximal end from the distal end thereof, is used as a cloth pinching surface for pinching the cloth 4 with the cloth pinching surface of the presser finger 2.

[0014] The above-mentioned pinch finger 3 is equipped with a light guide 5 that passes through the inside thereof and reaches a sharp tip 3a. This light guide 5 serves as an 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 holder, and can be formed by an optical fiber bundle. On the base end side of this light guide 5, a light source 6 such as a laser is installed opposite to the end face of the light guide for illumination, and an image of the laminated end face of the cloth obtained by passing it through the light guide 5 for detection is provided. A detection device 7 for detection is provided oppositely. This detection device 7 can be configured with a CCD or the like.

Further, a pressure sensor 9 is provided at the tip of the presser finger 2 to detect the pressing force against the cloth 4. This pressure sensor 9 is constructed by sealing a fluid such as grease in a cavity 10 formed of an elastic material such as silicone rubber, and disposing a pressure detection 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, which has a width necessary for gripping the cloth.
It becomes possible to control the attitude of the tip 3a of the cloth 4 so that it follows the laminated surface of the cloth 4. Further, on the back side of the picking finger 3 in the figure, a strain gauge 12 is provided to detect whether or not a piece of cloth has been reliably separated.

The cloth gripping hand having the above structure has its hand main body 1 attached to a robot arm, and the laminated cloth 4
When separating the cloth 4 one by one, each finger is driven by an appropriate drive mechanism provided in the hand main body 1 in the manner shown in A to C in FIG. 2. That is, first, when inserting the tip portion 3a, press down near the edge of the laminated fabric 4 with the presser finger 2 so that the fabric 4 does not easily fold in half (A in FIG. 2), and then press the tip of the pick finger 3. Insert the section 3a from the top surface between the first and second sheets (B in Fig. 2), and as the tip section 3a is inserted, keep the presser finger 2 in contact with the cloth 4 and rotate it without slipping. Finally, the end of the cloth 4 is held between the cloth scissoring surface of the tip 2a of the presser finger 2 and the cloth scissors surface slightly closer to the proximal end of the tip 3a of the picking finger 3 (C in Fig. 2). ) and move it to the required position. Such finger movements are suitable for separating a single piece of cloth without disturbing the layered cloth surfaces.

When operating the hand, the outputs of the visual sensor and pressure sensor 9 are fed back to the driving mechanism of each finger, so that the tip of the picking finger 3 is accurately transferred between the laminated cloths, and one piece of cloth is removed. The cloth 4 can be held securely. That is, when pressing the laminated cloth 4 with the presser finger 2, when an appropriate pressure is detected by the pressure sensor 9, an appropriate pressing force of the presser finger 2 against the cloth is obtained;
In addition, when the presser foot 2 is pressed against the cloth with an appropriate pressing force, the position between the first and second sheets from the top of the laminated cloth can be roughly known based on previously known data. Therefore, it is possible to move the tip 3a of the picking finger 3 to a position almost close to the insertion position, and in this state, the position between the first and second cloth can be accurately detected by the visual sensor. By finely adjusting the position of the tip 3a of the picking finger 3, the tip 3a can be accurately moved between the desired laminated fabrics. According to such an operation, at the same time as separating the laminated cloth 4, the cloth 4 is not folded in half;
By grasping the edge of the cloth, it becomes possible to easily move 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 the width necessary for gripping the cloth, the posture of the picking finger 3 can be controlled. Based on the outputs of both sensors, the tip of the picking finger 3 can be controlled to follow the laminated surface of the cloth 4.

Whether or not a piece of cloth has been reliably separated can be determined by checking the strain gauge 12 (Fig.
), and by detecting the amount of strain in the fingers when gripping the cloth 4 with the strain gauge 12, accurate judgment can be made. That is, since the amount of strain increase in the fingers when gripping cloth is approximately proportional to the thickness of the gripped cloth, it can be determined whether the cloth has been properly gripped by detecting this amount of strain. Therefore, if it is determined that zero or two or more cloths have been gripped, the cloth separation operation can be performed again to prevent the wrong number of cloths from being gripped.

The above-mentioned 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 that is slightly closer to the proximal end and facing the presser finger 22 is made into a cloth pinching surface that pinches the cloth between it and the presser finger 22. A detection device 27 comprising a CCD is provided with a light reflecting surface, and illuminates the edge of the laminated fabric with light projected from a light source 26 provided on the presser finger 22 and reflected by the light reflecting surface, and detects the edge of the fabric. is provided on the thumb finger 23.

In this case, as shown in FIG.
3 as a curved mirror that functions as a magnifying mirror, or as shown in FIG. By enlarging the edge of the cloth using a lens system, it is possible to accurately observe the position where the tip end 23a of the picking finger 23 is inserted.

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

FIG. 7 shows a third embodiment of the cloth gripping hand, in which a presser finger 32 is fixedly provided on the hand body 31, and a support portion 34 of the presser finger 32 constituted by a roller is attached to the hand body 31. It is slidably attached to the main body 31. In this embodiment as well, although not shown, a visual sensor is provided as in the first embodiment, and furthermore, the roller-shaped presser finger 32 may be provided with an appropriate pressure sensor.

[0025] At present, most of the work of stacking multiple pieces of cloth and setting them on sewing equipment is done manually, but by operating the hand in the reverse order of the cloth separation operation described above, it is possible to While placing the gripped cloth in a dimensional position, the cloth can be placed without shifting its position. This is because the presser foot holds the cloth until the last moment when it is released. Such cloth handling is suitable for positioning the cloth for the next operation.

[0026]

[Effects of the Invention] According to the cloth grasping hand of the present invention described in detail above, it is possible to visually grasp the cloth without using the characteristics of the cloth itself such as friction, air permeability, and ease of forming folds. By recognizing the fabric and being able to mechanically grasp the edges of the fabric,
It has versatility for the work to be performed and the type of fabric to be applied, and can stably grip the necessary fabric with a simple means.

[Brief explanation of the drawing]

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

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

FIG. 3 is a perspective view of a main part showing a modification 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 in the case where the light reflecting surface of the pinch finger is used as a magnifying glass in the second embodiment.

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

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

[Explanation of symbols]

Claims (4)

[Claims] Claim 1: A presser finger having a cloth-pinching surface at its tip, and a sharp tip inserted under the cloth to be gripped, and facing the presser finger slightly closer to the proximal end of the tip. a pinching finger whose portion is a cloth-pinching surface for pinching the cloth between the presser finger and the cloth-pinching surface of the presser finger; A cloth gripping hand characterized by being equipped with a visual sensor. 2. A light guide that passes through the inside of the picking finger and reaches the sharp tip thereof, and a visual sensor that detects the insertion position of the picking finger at the edge of the cloth through the light guide. 1. The cloth gripping hand according to 1. 3. The device according to claim 1, further comprising: a light reflecting surface provided near the cloth pinching surface of the picking finger; and a visual sensor for detecting the insertion position of the picking finger using light reflected from the reflecting surface. hand for gripping cloth. 4. The cloth gripping hand according to claim 1, wherein a pressure sensor is provided at the tip of the presser finger to detect the pressing force against the cloth.