Fabric Gripping Apparatus and Fabric Gripping System Employing The Same

Abstract

The gripper guide presses down on a part of the fabric to be gripped, supports the fabric pulled by the fingering motion to fold it, and supports one side of the folded fabric. The gripper finger module performs the fingering motion by reversing the bending direction of the gripper finger according to the magnitude of external air pressure, thereby pulling and pushing the top layer of the fabric pile toward the gripper guide in a contact state, and thus can fold and grip a predetermined part of the fabric in cooperation with the gripper guide. By periodically repeating this shape change of the gripper finger, the operation of gripping and releasing the fabric one sheet at a time can be repeated. At this time, the number of gripped fabric sheets is controlled to be one sheet based on the capacitance value of the capacitance sensor.

Description

Technology Field

[0001] The present invention relates to a fabric gripping technology for the automation field of a garment sewing factory, and more specifically, to a fabric gripping technology for picking up and transporting fabrics one by one from a fabric stack in which a number of soft fabrics are stacked. Background Technology

[0002] In clothing manufacturing, many processes, including the task of picking up fabric sheets one by one and aligning them to sewing machines, still rely on manual labor. This is because the development of hardware technology capable of performing the delicate work of handling clothing fabrics has not preceded it.

[0003] In the process of picking up individual sheets of fabric, it is important to control the process so that only one sheet is picked out from a stack of fabric and placed back down at a desired location. It is also important to minimize the possibility of the fabric being damaged or contaminated during this process.

[0004] As a large workforce is still required for this process, the indispensable use of labor has resulted in incomplete automation of the garment manufacturing process, hindering the organic design and optimization of the production system. Consequently, this imposes limitations on the automation and intelligence that encompass design, production, logistics, and distribution—the core of the future apparel industry. Furthermore, there are issues regarding the consumption of labor and personnel costs, leading to limitations on productivity and increased production costs.

[0005] To address these issues, a technology has been proposed that utilizes a vacuum pump to create a pressure difference, thereby gripping the fabric vertically. However, this vacuum-based gripping method is unsuitable for fabrics with porous surfaces, as air passes through them, making it impossible to create a pressure difference. Consequently, there is a problem where multiple sheets are gripped at once or none are gripped at all, depending on the material. As the garment manufacturing process becomes more automated and intelligent, requiring versatility across various fabrics, this technology is difficult to apply.

[0006] Meanwhile, a technology utilizing needles to pick up fabric has also been proposed. This technology employs a method of picking up fabric sheets one by one by directly controlling needles installed to move along a guide. A needle installed behind a flat, rigid contact surface is controlled to follow the guide, sequentially penetrating the contact surface and the fabric to insert it, and then the fabric is separated as the needle is retracted. Currently, this is being used in processes for picking up items such as shoe soles. However, the diameter of the easily controllable needles installed on the guide is excessively large for use on clothing fabrics, posing a problem that causes damage, such as creating noticeable holes in the fabric. Therefore, it is unsuitable for application in clothing manufacturing processes.

[0007] Therefore, there is a need for an efficient fabric clip that can be used on various types of fabric, uses a fine needle to prevent damage to the fabric, and picks up fabric sheets one by one. Prior art literature

[0008] Republic of Korea Patent Registration No. 10-1887214 (Needle pad and fabric gripper including the same) Republic of Korea Patent Registration No. 10-1988219 (Method and apparatus for gripping fabric) Republic of Korea Patent Registration No. 10-2561706 (Gripper system and grip control method of fabric robot) Republic of Korea Patent Registration No. 10-2661330 (Method and system for conveying fabric using vision-based gripping) The problem to be solved

[0009] One objective of the present invention is to provide a fabric gripping device capable of accurately and efficiently gripping fabric patterns one by one from laminated fabrics, cut pieces, and fabric pattern stacks without causing damage to the fabric.

[0010] In addition, another objective of the present invention is to provide a fabric gripping system capable of gripping one sheet at a time accurately and efficiently using the fabric gripping device.

[0011] The problems that the present invention aims to solve are not limited to the problems described above, and may be extended in various ways without departing from the spirit and scope of the present invention. means of solving the problem

[0012] A fabric gripping device according to embodiments for realizing one objective of the present invention comprises a gripper guide, a gripper finger module, and a fixed interface. The gripper guide is configured to support and fold the fabric being pulled by a fingering motion while pressing a part of the fabric to be gripped, and to support one side of the fabric in the folded state. The gripper finger module is configured to fold and grip a predetermined part of the fabric in cooperation with the gripper guide by performing the fingering motion, in which the direction of bending of the gripper finger is reversed according to the magnitude of external air pressure, thereby pulling and pushing the uppermost fabric of the fabric pile toward the gripper guide in a contact state. The fixed interface combines and fixes the upper part of the gripper guide and the upper part of the gripper finger module.

[0013] In exemplary embodiments, the gripper guide may include: a fabric pressing surface provided in a flat shape at the bottom and pressing the fabric vertically downward while in surface contact with the fabric to prevent the fabric from being pushed out in the horizontal direction; a fabric supporting surface formed in the shape of a vertical surface or a quasi-vertical surface by being folded at one corner of the fabric pressing surface and supporting one side of the fabric that is pulled toward itself by the gripping action, thereby supporting one side of the fabric that has climbed up and been folded; and a cushioning structure part having one end connected to the upper corner of the fabric supporting surface and the other end connected to the fixed interface, which elastically cushions the vertical and horizontal forces transmitted through the fabric pressing surface and the fabric supporting surface.

[0014] In exemplary embodiments, the cushioning structure may be an angled C-shaped portion comprising a lower plane extended in a first horizontal direction by being folded from the top of the fabric support surface, a vertical plane extended vertically upward by being folded from the end edge of the lower plane, and an upper plane extended in a second horizontal direction opposite to the first horizontal direction by being folded from the top edge of the vertical plane, or a C-shaped portion in which the lower end is connected to the top of the fabric support surface and the upper end is connected to the fixed interface.

[0015] In exemplary embodiments, the cushioning structure may further include a cushioning member disposed within a space enclosed by the lower plane, the vertical plane, and the upper plane of the cushioning structure to absorb shocks applied to the cushioning structure and dampen vibrations.

[0016] In exemplary embodiments, the pseudo-vertical surface of the fabric support surface may be a vertical inclined surface inclined at 5° to 20° with respect to the vertical direction.

[0017] In exemplary embodiments, the fabric gripping device may further include a pressure load sensor unit disposed between the fixed interface and the gripper guide and coupled to each, which detects a pressure load transmitted through the gripper guide due to a reaction when the gripper guide presses the fabric, converts it into a corresponding electrical signal, and outputs it.

[0018] In exemplary embodiments, the pressing load sensor unit may include a sensor connecting member fixed to the fixed interface; and a load cell sensor, one end of the body being a fixed end fixed to the sensor connecting member and the other end being a free end that can move freely by being coupled to the upper end of the gripper guide, and which detects strain caused by a pressing load transmitted through the upper end of the gripper guide and converts and outputs it as a corresponding electrical signal.

[0019] In exemplary embodiments, the gripper finger module may be configured such that when the air pressure inside the finger body of the gripper finger is negative pressure lower than normal pressure due to external air pressure, the finger body is gently bent in a first direction in which the fabric contact finger surface at the bottom of the finger body moves away from the gripper guide, and conversely, when the pressure is positive pressure higher than normal pressure, the finger body is gently bent in a second direction in which the fabric contact finger surface approaches the gripper guide.

[0020] In exemplary embodiments, the gripper finger module comprises: a finger body configured to be flexibly bent in the first direction or the second direction by means of the first side, wherein the first side is formed in a corrugated shape along the vertical direction by connecting a plurality of protrusions that provide a plurality of independent chambers communicating with the cavity, and wherein the first side is configured to be flexibly bent in the first direction or the second direction depending on whether the air pressure within the plurality of chambers is lower or higher than atmospheric pressure; a gripper finger including a fabric contact finger surface that extends in the form of an inclined surface from the bottom of the finger body and, during the shape deformation process in which the finger body bends from the first direction to the second direction, makes surface contact with the top fabric of the fabric pile to pull and push the top fabric toward the fabric support surface of the gripper guide, thereby gripping the fabric in a folded state in cooperation with the fabric support surface; and a gripper finger fixing block coupled to the fixed interface in a fixedly coupled state with the upper part of the finger body. It may include a gripper finger cover that covers the upper part of the finger body of the gripper finger and provides a passage through which air can enter and exit into a plurality of chambers inside the finger body, and is fixed to the gripper finger fixing block.

[0021] In exemplary embodiments, the gripper finger module may further include a capacitance sensor configured to detect the number of gripped fabrics by utilizing a capacitance of a size corresponding to the number of gripped fabrics between the conductive pad on the fabric contact finger surface and the fabric support surface, and having two electrodes facing the conductive pad and the fabric support surface.

[0022] In exemplary embodiments, the finger body may have a fine pattern (texture) formed on the surface facing the gripper guide to increase friction with the fabric and improve gripping stability, or a separate replaceable liner with such a fine pattern formed thereon may be attached.

[0023] Meanwhile, a fabric gripping system according to embodiments for realizing one objective of the present invention comprises the fabric gripping device mentioned above, a control unit, a pneumatic device, a pneumatic device driving unit, a conveying unit, and a sensing unit. The control unit controls the overall operation of the fabric gripping device. The pneumatic device can adjust the air pressure inside the finger body of the fabric gripping device to cause the fabric gripping device to grip or release the top layer of fabric from a pile of fabrics one by one. The pneumatic device driving unit can drive the pneumatic device to perform a gripping operation according to the control of the control unit. The conveying unit is equipped with a robot arm capable of three-dimensional movement on which the fabric gripping device is mounted, and can drive the movement of the robot arm according to the control of the control unit to convey the fabric gripping device gripping the top layer of fabric to a designated location. The sensing unit can detect whether the gripper guide of the fabric gripping device has descended and reached a fabric contact position using the output signal of the pressing load sensor unit of the fabric gripping device and notify the control unit, and can also detect whether a sheet of fabric has been gripped between the fabric support surface of the gripper guide and the fabric contact finger surface of the gripper finger using the output signal of the capacitance sensor of the fabric gripping device and notify the control unit. Effects of the invention

[0024] The fabric gripping device according to exemplary embodiments of the present invention enables successful automatic gripping without causing damage to the fabric pattern. In particular, the gripper finger and gripper guide according to the embodiment of the present invention have the advantage of being able to grip the fabric in a manner that does not cause damage to the fabric while having a high gripping force on the fabric.

[0025] A fabric gripping device according to exemplary embodiments of the present invention can reliably ensure that the number of gripped fabric patterns is accurately gripped one by one by further utilizing a capacitive sensor.

[0026] In addition, the fabric gripping device according to exemplary embodiments of the present invention can easily control the gripping and release operations of the fabric by controlling whether pneumatic pressure is input. Brief explanation of the drawing

[0027] FIG. 1 is a cross-sectional view of the combined state of a fabric gripping device according to an exemplary first embodiment of the present invention. Figure 2 is a modular exploded perspective view of the fabric gripping device illustrated in Figure 1. FIG. 3 is a cross-sectional view of the combined state of a fabric gripping device according to an exemplary second embodiment of the present invention. Figure 4 is a perspective view of the combined state of the fabric gripping device shown in Figure 3. FIG. 5 is a modular exploded view of the fabric gripping device illustrated in FIG. 3. FIG. 6 is a drawing for explaining a capacitive sensor applied to a gripper finger of a fabric gripping device according to embodiments of the present invention. FIG. 7 is a block diagram showing the configuration of a fabric gripping system that controls the operation of gripping a fabric using a fabric gripping device according to exemplary embodiments of the present invention. FIG. 8 illustrates the principle of operation for gripping a fabric by adjusting the air pressure of a gripping finger module in a fabric gripping device according to exemplary embodiments of the present invention. Specific details for implementing the invention

[0028] Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the attached drawings. Identical components in the drawings are given the same reference numerals, and redundant descriptions of identical components are omitted.

[0029] With respect to the embodiments of the present invention disclosed in the text, specific structural or functional descriptions are merely illustrative for the purpose of explaining the embodiments of the present invention. Embodiments of the present invention may be implemented in various forms and should not be interpreted as being limited to the embodiments described in the text. That is, the present invention may be subject to various modifications and may take various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to specific disclosed forms, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the present invention.

[0030] The terms used in this invention are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to indicate the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. Furthermore, terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another.

[0031] FIGS. 1 and 2 are a cross-sectional view of the combined state and a modular unit exploded perspective view of a fabric gripping device according to an exemplary first embodiment of the present invention.

[0032] Referring to FIGS. 1 and FIGS. 2, the fabric gripping device (10) may include a gripper guide (30), a gripper finger module (50), and a fixed interface (20).

[0033] The gripper guide (30) may have a structure that supports and folds the fabric being pulled by a fingering motion (described later) while pressing a part of the fabric to be gripped, and supports one side of the folded fabric. Specifically, the gripper guide (30) may include a fabric pressing surface (30-1), a fabric supporting surface (30-3), and a cushioning structure (30-5).

[0034] The fabric pressing surface (30-1) can be provided in the form of a flat plate at the bottom of the gripper guide (30). While the fabric gripping device (10) descends over the fabric pile (15) to grip the fabric and presses the fabric pile (15) vertically downward, and the gripping finger module (40) pulls the top fabric (15-1) for gripping, the fabric pressing surface (30-1) can serve to press and hold the top fabric (15-1) so that it does not slide horizontally while in direct surface contact with the top fabric (15-1).

[0035] The fabric support surface (30-3) can be formed in the shape of a vertical surface or a pseudo-vertical surface by being folded at one corner of the fabric pressing surface (30-1). The fabric support surface (30-3) supports one side of the top layer fabric (15-1) that is pulled toward it by the fingering action performed by the gripping finger module (40), thereby allowing the top layer fabric (15-1) to climb up and be folded. The fabric support surface (30-3) can support one side of the top layer fabric (15-1) that is folded in this way. It may be more advantageous to configure the fabric support surface (30-3) that performs this role as a plane that is slightly inclined with respect to the vertical direction rather than as a completely vertical surface. The fabric support surface (30-3) can be configured in the shape of a pseudo-vertical surface inclined by a predetermined angle (θ) with respect to the vertical direction. The predetermined angle (θ) is preferably about 5° to 20°. If the angle of inclination (θ) is less than 5°, the uppermost fabric (15-1) may not roll up and fold smoothly, and if it is greater than 20°, the contact area with the fabric contact finger surface (42) is very small, making it difficult to grip the fabric with sufficient force.

[0036] The cushioning structure (30-5) may have a structure in which one end is connected to the upper corner of the fabric support surface (30-3) and the other end is connected to the connecting part (20), thereby elastically cushioning the vertical and horizontal forces transmitted through the fabric pressing surface (30-1) and the fabric support surface (30-3). For example, the cushioning structure (30-5) may have an angled C-shape or a rounded C-shape. That is, the angled C-shape may be a structure including a lower plane (30-5b) that is folded from the upper end of the fabric support surface (30-3) and extends approximately horizontally, a vertical plane (30-5c) that is folded from the end corner of the lower plane (30-5b) and extends vertically upward, and an upper plane (30-5a) that is folded from the upper corner of the vertical plane (30-5c) and extends in a second horizontal direction opposite to the first horizontal direction. The round C-shape is a C-shaped structure, and its lower end can be connected to the upper end of the fabric support surface (30-3) and its upper end can be connected to the fixed interface (20).

[0037] For example, the gripper guide (30) may further include a finger module coupling surface (30-7) that is bent at the end of the upper plane (30-5a) of the cushioning structure (30-5) and extends vertically upward to face and is coupled with the gripper finger fixing block (52) of the gripper finger module (50), and a fixed interface coupling surface (30-9) that is bent at the end of the finger module coupling surface (30-7) and extends in a first horizontal direction to face and is coupled with the fixed interface (20).

[0038] The gripper guide (30) can be made of a metal material that is conductive and elastic. The fabric support surface (30-3) of the gripper guide (30) can function as one electrode of the capacitive sensor described later.

[0039] Next, the gripper finger module (50) may include a gripper finger (40), a gripper finger fixing block (52), and a gripper finger cover (54).

[0040] The gripping finger module (50) can be configured to fold and grip a predetermined part of the fabric in cooperation with the gripper guide (30) by performing a fingering operation in which the direction in which the gripper finger (40) bends is reversed according to the magnitude of the external air pressure, thereby pulling and pushing the uppermost fabric (15-1) of the fabric pile (15) toward the gripper guide (30) in a contact state.

[0041] The gripper finger module (50) can be configured such that when the air pressure inside the finger body (43) of the gripper finger (40) is negative pressure lower than normal pressure due to external air pressure, the finger body (43) is gently bent in a first direction away from the fabric contact finger surface (42) provided at the bottom of the finger body (43) and away from the fabric support surface (30-3) of the gripper guide (30), and conversely, when the pressure is positive pressure higher than normal pressure, the finger body (43) is gently bent in a second direction toward the fabric support surface (30-3) of the gripper guide (30).

[0042] In one embodiment, the gripper finger (40) may include a finger body (43) and a fabric contact finger surface (42). The finger body (43) is extended a predetermined length in the vertical direction to provide a cavity inside, and one side may be formed in a corrugated shape along the vertical direction by connecting a plurality of protrusions (44) that provide a plurality of independent chambers communicating with the cavity. One side of the corrugated shape allows the finger body (43) to easily bend flexibly in the first direction or the second direction depending on whether the air pressure in the plurality of chambers is lower or higher than the atmospheric pressure.

[0043] For example, the side opposite to the side where the protrusions (44) are formed on the finger body (43), that is, the surface facing the gripper guide (130), may be formed in the shape of an uneven surface (46) with a plurality of grooves. This uneven surface (46) can facilitate the flexible bending of the gripper finger (40) and at the same time strengthen the friction with the fabric. As another example, the finger body (43) may have a fine pattern (texture) formed on the surface facing the gripper guide (30) to increase friction with the fabric and improve gripping stability, or a separate replaceable liner (46) with such a fine pattern formed thereon may be attached.

[0044] The fabric contact finger surface (42) extends in the form of an inclined surface from the bottom of the finger body (43), and during the shape deformation process in which the finger body (43) bends in the first direction and then bends in the second direction, it can come into surface contact with the top fabric (15-1) of the fabric pile (15) and pull and push the top fabric (15-1) toward the fabric support surface (30-3) of the gripper guide (30). By doing so, the fabric contact finger surface (42) can cooperate with the fabric support surface (30-3) to grip the top fabric (15-1) in a folded state.

[0045] The gripping finger fixing block (52) can be connected to the fixing interface (20) via a fastening means (58), such as a bolt, while being fixedly connected to the upper part of the finger body (43). A sliding groove can be provided on the upper part of the gripping finger fixing block (52) to adjust the position of the fastening means (58). Additionally, the gripper finger cover (54) can cover the upper part of the finger body (43) and provide a passage through which air can enter and exit into a plurality of chambers inside the finger body (43). Furthermore, the gripper finger cover (54) can be fixed to the gripper finger fixing block (52). A tube plug (57) can be installed at the entrance of the passage of the gripper finger cover (54). The tube plug (57) can be inserted and fastened into the entrance of the passage of the gripper finger cover (54). The tube plug (57) is connected to a pneumatic fitting tube (56) that transmits external air, allowing air to enter and exit from / into the finger body (43).

[0046] Meanwhile, the fixed interface (20) can be fixed by joining the upper part of the gripper guide (30) and the upper part of the gripper finger module (50) together using fastening means such as bolts and nuts. The fixed interface (20) is also configured to include a standardized hole or fastening part for joining to an external robot arm (190) or a gripper moving means such as a related jig, so that it can be mounted at a precise location on such a robot arm (190). Through the fixed interface (20), the fabric gripping device (10) can move while suspended from the robot arm (190).

[0047] FIGS. 3 and FIGS. 4 are a cross-sectional view and a perspective view of the combined state of a fabric gripping device according to a second embodiment of the present invention, and FIG. 5 is an exploded perspective view.

[0048] The fabric gripping device (100) according to the second embodiment includes a gripper finger module (50) including a gripper finger (40) and a fixed interface (20), which has the same configuration as that of the fabric gripping device (10) according to the first embodiment, so a description thereof is omitted.

[0049] In addition to including a gripper guide (130), the fabric gripping device (100) according to the second embodiment may further include a pressing load sensor part (140). Additionally, the fabric gripping device (100) may further include a cushioning member (137).

[0050] The gripper guide (130) is identical to the gripper guide (30) of the first embodiment in that it includes a fabric pressing surface (130-1), a fabric supporting surface (130-3), and a cushioning structure (130-5). The roles of the fabric pressing surface (130-1), the fabric supporting surface (130-3), and the cushioning structure (130-5) are identical to those of the fabric pressing surface (30-1), the fabric supporting surface (30-3), and the cushioning structure (30-5) of the first embodiment. However, the gripper guide (130) is a structure in which the finger module coupling surface (30-7) and the fixed interface coupling surface (30-9) of the first embodiment are omitted.

[0051] For example, the gripper guide (130) is a structure formed by folding a single metal plate four times to have a cross-section similar to the letter 'L' when viewed from the side, and securing the necessary rigidity with minimal material. The fabric pressing surface (130-1) is preferably designed in the shape of a wide plate to have a large contact area with the fabric, suitable for stably pressing the entire fabric downward without localized pressure concentration.

[0052] The gripper guide (130) can be made of a material with high durability and corrosion resistance, such as stainless steel. Additionally, it is desirable to make it of a material with high rigidity and surface hardness that does not cause deformation or wear even with repeated fabric pressing motions. Furthermore, since the gripper guide (130) must be coupled with a capacitance measurement system to detect whether the gripped fabric is a single sheet, it needs to be made of a conductive metal material. Through this conductivity, it may also electrically detect whether the gripper guide (130) has come into contact with the fabric.

[0053] The gripper guide (130) repeatedly performs the action of pressing the fabric pile (15) downward using the fabric pressing surface (130-1) every time a gripping action is performed. Due to the nature of this action, a continuous repetitive load is applied to the gripper guide (130), so it is desirable to design it to have sufficient durability so that fatigue failure does not occur. To enhance the durability of the gripper guide (130), a cushioning member (137) may be placed to fill the space enclosed by the lower plane (130-5a), vertical plane (130-5b), and upper plane (130-5c) of the cushioning structure (130-5). The cushioning member (137) may be made of a material capable of absorbing shocks applied to the cushioning structure (130-5) and damping vibrations to suppress shape deformation or failure of the gripper guide (130). The cushioning member (137) may be made of, for example, a polyurethane material.

[0054] The fabric gripping device (100) according to the second embodiment may further include a pressure load sensor unit (140). The pressure load sensor unit (140) can detect a pressure load transmitted through the gripper guide (130) due to a reaction generated when the gripper guide (130) presses the fabric pile (15), convert it into a corresponding electrical signal, and output it.

[0055] The pressure load sensor unit (140) may be positioned between the fixed interface (20) and the gripper guide (130) and coupled to each of them. For example, the pressure load sensor unit (140) may include a pressure load sensor (145) and a sensor connecting member (138). The sensor connecting member (138) may be fixedly coupled to the fixed interface (20) through a fastening means (22), such as a bolt. The pressure load sensor (145) has a fixed end (142a) of its body fixed to the sensor connecting member (138), and a free end (142b) that can move freely, which is coupled directly to the top of the gripper guide (130) or indirectly through the connecting member (134) by fastening the bolt (135). And a strain sensor (144a, 144b) is installed between one end (142a) and the other end (142b) of the body of the pressure load sensor (145). A commercially available load cell sensor may also be used as the pressure load sensor (145).

[0056] When the gripper guide (130) presses the fabric pile (15), the load pushes the other end (142b), which is the free end of the pressing load sensor (145), upward through the cushioning structure (130-5), and accordingly, the strain sensors (144a, 144b) undergo deformation. The electrical signal converted in correspondence with the strain of the strain sensors (144a, 144b) can be transmitted to the sensing unit (200) through an output cable (146) protected by a cable cover (148). By analyzing the magnitude of the electrical signal, it can be determined whether the gripper guide (130) has come into contact with and started pressing the fabric pile (15). That is, by using the output signal of the pressing load sensor unit (140), it can be determined whether the gripper guide (130) has descended and reached a starting position where it can grip the fabric pile (15).

[0057] Meanwhile, FIG. 6 illustrates the configuration of a capacitive sensor applied to a gripper finger of a fabric gripping device (10, 100) according to the first and second embodiments.

[0058] Referring to FIG. 6, the fabric gripping device (10, 100) may further include a capacitance sensor (60). The capacitance sensor (60) may include a conductive pad (45) attached to the inclined surface of the fabric contact finger surface (42) and two electrodes facing the fabric support surface (30-3, 130-3) of the conductive gripper guide (30, 130). The capacitance sensor (60) has a capacitance of a size corresponding to the number of fabrics gripped between the conductive pad (45) of the fabric contact finger surface (42) and the fabric support surface (30-3, 130-3) of the gripper guide (30, 130). The conductive pad (45) may be constructed by attaching a conductive fabric with conductive silicone. The conductive pad (45) may be connected to a wire (45-1) fixed with an eyelet. Therefore, by measuring the capacitance of the capacitance sensor (60), the number of fabrics gripped between the fabric contact finger surface (42) and the gripper guide (30, 130) can be detected.

[0059] FIG. 7 shows the configuration of a fabric gripping system that controls the operation of gripping a fabric using a fabric gripping device according to exemplary embodiments of the present invention.

[0060] Referring to FIG. 7, the fabric gripping system (200) may include a control unit (180), a pneumatic unit (160), a pneumatic unit driving unit (170), a conveying unit (195) including a robot arm (190), and a sensing unit (175).

[0061] The control unit (180) can control the overall operation of the gripping system (200). The control unit (180) may include hardware capable of executing a computer-executable program, namely a processing unit and memory, and the control content of the control unit described below may be written as a computer program and embedded in the memory. The processing unit can control the overall operation described below by executing the computer program embedded in the memory. Examples of the processing unit may be implemented using one or more general-purpose or special-purpose computers, such as a central processing unit (CPU), processor, controller, arithmetic logic unit (ALU), digital signal processor, microcomputer, field programmable array (FPA), programmable logic unit (PLU), microprocessor, or any other device capable of executing and responding to instructions.

[0062] The pneumatic device (160) can adjust the air pressure inside the finger body (43) of the fabric gripping device (10, or 100) to allow the fabric gripping device (10, or 100) to grip or release the top layer of fabric from the fabric pile (15) one by one. The pneumatic device drive unit (170) can drive the pneumatic device (160) under the control of the control unit (180) to perform the operation of gripping the fabric or releasing the gripped fabric.

[0063] The transfer unit (195) is equipped with a robot arm (190) capable of three-dimensional movement and is equipped with a fabric gripping device, and can drive the movement of the robot arm (190) according to the control of the control unit (180). By driving such a robot arm (190), the fabric gripping device (10 or 100) gripping the top fabric (15-1) can be transferred to a designated position.

[0064] The sensing unit (175) can detect whether the gripper guide (30, or 130) of the fabric gripping device (10 or 100) has descended and reached a fabric contact position by using the output signal of the pressing load sensor unit (140) of the fabric gripping device (10 or 100), and notify the control unit (180). The sensing unit (175) can also detect whether a top layer of fabric (15-1) has been gripped between the fabric support surface (30-3, 130-3) of the gripper guide (30 or 130) and the fabric contact finger surface (42) of the gripper finger (40) by using the capacitive sensor (60), and notify the control unit (180).

[0065] FIG. 8 is a diagram illustrating the principle of operation for gripping a fabric by adjusting the air pressure within the finger body of a gripping finger module in a fabric gripping device according to exemplary embodiments of the present invention.

[0066] Referring to FIG. 8, in accordance with a gripping start command instructed by the control unit (180), the transfer unit (195) can drive the robot arm (190) to lower the fabric gripping device (10, 100) toward the fabric pile (15). While lowering, the sensing unit (175) can monitor the output signal of the pressing load sensor unit (140) and, upon detecting the moment when the intensity of the output signal exceeds a limit, output a signal to the control unit (180) to inform it of this fact. Upon receiving the signal, the control unit (180) can determine that the fabric pressing surface (30-1, 130-1) of the gripper guide (30, 130) has entered in contact with the fabric pile (15) and can instruct the transfer unit (195) not to lower the fabric gripping device (10, 100) any further.

[0067] In this state, the control unit (180) can instruct the pneumatic drive unit (170) to have the pneumatic unit (160) extract air from inside the finger body (43) of the gripper finger (40) which is in an atmospheric pressure state. Accordingly, the inside of the finger body (43) changes to a negative pressure state lower than atmospheric pressure, and the gripper finger (40) bends away from the gripper guide (30, 130), causing the fabric contact finger surface (42) to be slightly lifted upward (see (A) in FIG. 8).

[0068] In that state, the control unit (180) can instruct the pneumatic drive unit (170) to have the pneumatic unit (160) inject high-pressure air into the finger body (43) of the gripper finger (40). Accordingly, the inside of the finger body (43) can change from an atmospheric pressure state to a positive pressure state higher than atmospheric pressure. When the finger body (43) is in an atmospheric pressure state, the bent gripper finger (40) is restored to a linear state (see (B) in FIG. 8).

[0069] At this time, the fabric contact finger surface (42) comes into contact with the uppermost fabric (15-1). As the finger body (43) continues to change to a positive pressure state, the gripper finger (40) now bends in a direction that moves closer to the gripper guide (30, 130), and the fabric contact finger surface (42) is slightly lifted upward, gradually increasing the contact area with the gripper guide (30, 130). In this process, the fabric contact finger surface (42) can pull and push the uppermost fabric (15-1) in contact toward the gripper guide (30, 130). At this time, since the uppermost fabric (15-1) cannot move the part that is pressed by the fabric pressing surface (30-1, 130-1), the fabric portion between the gripper guide (30, 130) and the fabric contact finger surface (42) is folded and rolled up between the fabric support surface (30-3, 130-3) and the fabric contact finger surface (42) (see (C) in FIG. 8).

[0070] In this state, the capacitance sensor (60) has a capacitance size corresponding to the number of fabrics gripped in between. The sensing unit (175) can determine whether there is one fabric gripped by detecting the capacitance size appearing at the output terminal of the capacitance sensor (60) and notify the control unit (180). If it is determined that one top-level fabric (15-1) has been successfully gripped, the control unit (180) can instruct the transfer unit (195) to transfer the fabric gripping device (10, 100) to a designated location. By doing so, the gripped top-level fabric (15-1) can be transferred to a designated location.

[0071] When the pneumatic drive unit (170) causes the pneumatic device (160) to convert the air pressure inside the finger body (43) back to negative pressure according to the instructions of the control unit (180), the fabric gripping device (10, 100) releases the gripped top layer fabric (15-1).

[0072] By repeatedly performing this process, the fabrics in the fabric pile (15) can be gripped one by one and transported to a desired location. Industrial applicability

[0073] The present invention can be used to transport fabric patterns for sewing operations to make clothes. However, the application of the present invention is not limited to fabrics, and can be applied without limitation to any printable object, such as leather or sheets of various materials.

[0074] Although an inkjet printing-based automatic fabric serial number printing device has been described above with reference to preferred embodiments and the limited drawings of the present invention, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the invention as described in the claims below. Explanation of the symbols

[0075] 10, 100: Fabric gripping device 20: Fixed interface 30, 130: Gripper Guide 30-1, 130-1: Fabric Pressing Surface 30-3, 130-3: Fabric support surface 30-5, 130-5: Cushioning structure 40: Gripper finger 43: Finger body 45: Fabric contact finger surface 50: Gripper finger module 60: Capacitive sensor 137: Buffer member 140: Pressure load sensor unit 145: Pressure load sensor 200: Fabric Griping System

Claims

Claim 1 A fabric gripping device characterized by comprising: a gripper guide configured to support and fold a fabric pulled by a fingering motion while pressing a part of a fabric to be gripped, and to support one side of the fabric in a folded state; a gripper finger module configured to fold and grip a predetermined part of the fabric in cooperation with the gripper guide by performing the fingering motion, in which the direction of bending of the gripper finger is reversed according to the magnitude of external air pressure, thereby pulling and pushing the uppermost fabric of the fabric pile toward the gripper guide in a contact state; and a fixing interface that combines and fixes the upper part of the gripper guide and the upper part of the gripper finger module. Claim 2 A fabric gripping device according to claim 1, wherein the gripper guide comprises: a fabric pressing surface provided in a flat shape at the bottom and pressing the fabric vertically downward while in surface contact with the fabric to prevent the fabric from being pushed out in the horizontal direction; a fabric supporting surface formed in the shape of a vertical surface or a quasi-vertical surface by being folded at one corner of the fabric pressing surface and supporting one side of the fabric being pulled toward itself by the gripping operation, thereby supporting one side of the fabric that has climbed up and been folded; and a cushioning structure having one end connected to the upper corner of the fabric supporting surface and the other end connected to the fixed interface, which elastically cushions the vertical and horizontal forces transmitted through the fabric pressing surface and the fabric supporting surface. Claim 3 A fabric gripping device according to claim 2, wherein the cushioning structure comprises an angled C-shaped portion including a lower plane extended in a first horizontal direction by being folded from the top of the fabric support surface, a vertical plane extended vertically upward by being folded from the end edge of the lower plane, and an upper plane extended in a second horizontal direction opposite to the first horizontal direction by being folded from the top edge of the vertical plane, or a C-shaped portion in which the lower end is connected to the top of the fabric support surface and the upper end is connected to the fixed interface. Claim 4 A fabric gripping device according to paragraph 3, characterized in that the cushioning structure further includes a cushioning member disposed within a space enclosed by the lower plane, the vertical plane, and the upper plane of the cushioning structure, which absorbs shocks applied to the cushioning structure and dampens vibrations. Claim 5 A fabric gripping device according to claim 2, characterized in that the pseudo-vertical surface of the fabric support surface is a vertical inclined surface inclined at 5° to 20° with respect to the vertical direction. Claim 6 A fabric gripping device according to claim 1, further comprising a pressure load sensor unit disposed between the fixed interface and the gripper guide and coupled to each, which detects a pressure load transmitted through the gripper guide due to a reaction when the gripper guide presses the fabric, converts it into a corresponding electrical signal, and outputs it. Claim 7 A fabric gripping device according to claim 6, wherein the pressing load sensor part comprises: a sensor connecting member fixed to the fixed interface; and a load cell sensor, wherein one end of the body is a fixed end fixed to the sensor connecting member and the other end is a free end that is coupled to the upper end of the gripper guide and can move freely, and which detects strain generated by a pressing load transmitted through the upper end of the gripper guide and converts and outputs it as a corresponding electrical signal. Claim 8 A fabric gripping device according to claim 1, wherein the gripper finger module is configured such that when the air pressure inside the finger body of the gripper finger is a negative pressure lower than atmospheric pressure due to external air pressure, the finger body is gently bent in a first direction in which the fabric contact finger surface at the bottom of the finger body moves away from the gripper guide, and conversely, when the pressure is a positive pressure higher than atmospheric pressure, the finger body is gently bent in a second direction in which the fabric contact finger surface approaches the gripper guide. Claim 9 In paragraph 2, the gripper finger module comprises: a finger body configured such that it is extended a predetermined length in a vertical direction to provide a cavity inside, wherein a first side is formed in a corrugated shape along a vertical direction by connecting a plurality of protrusions that provide a plurality of independent chambers communicating with the cavity, and wherein the lower fabric contact finger surface can be flexibly bent in a first direction away from the gripper guide or in a second direction opposite to the first direction depending on whether the air pressure inside the plurality of chambers is lower or higher than atmospheric pressure due to the corrugated first side; and a fabric contact finger surface extending in the form of an inclined surface from the bottom of the finger body, and comprising a fabric contact finger surface that makes surface contact with the uppermost fabric of the fabric pile during the shape deformation process in which the finger body bends from the first direction to the second direction, thereby pulling and pushing the uppermost fabric toward the fabric support surface of the gripper guide to grip the uppermost fabric in a folded state in cooperation with the fabric support surface. A fabric gripping device characterized by comprising: a gripper finger fixing block coupled to the fixed interface in a fixedly coupled state with the upper part of the finger body; and a gripper finger cover fixed to the gripper finger fixing block, which covers the upper part of the finger body of the gripper finger and provides a passage through which air can enter and exit into a plurality of chambers inside the finger body. Claim 10 A fabric gripping device according to claim 9, characterized in that the second side opposite to the first side of the finger body is formed in the shape of an uneven surface having a plurality of horizontal grooves. Claim 11 A fabric gripping device according to claim 9, wherein the gripper finger module comprises two electrodes facing a conductive pad attached to the surface of the fabric contact finger surface and a conductive fabric support surface, and further comprises a capacitance sensor configured to detect the number of fabrics gripped by utilizing a capacitance of a size corresponding to the number of fabrics gripped between the conductive pad of the fabric contact finger surface and the fabric support surface. Claim 12 A fabric gripping device according to claim 9, characterized in that the finger body has a fine pattern (texture) formed on the surface facing the gripper guide to increase friction with the fabric and improve gripping stability, or has a separate replaceable liner with such a fine pattern attached. Claim 13 A fabric gripping device described in any one of claims 1 to 12; a control unit that controls the overall operation of the fabric gripping device; a pneumatic device that adjusts the air pressure inside the finger body of the fabric gripping device to cause the fabric gripping device to grip or release the top layer of fabric one by one from a pile of fabrics; a pneumatic device driving unit that drives the pneumatic device to perform a gripping operation according to the control of the control unit; and a transfer unit equipped with a robot arm capable of three-dimensional movement on which the fabric gripping device is mounted, and which drives the movement of the robot arm according to the control of the control unit to transfer the fabric gripping device gripping the top layer of fabric to a designated position. A fabric gripping system characterized by including a sensing unit that detects whether the gripper guide of the fabric gripping device has descended and reached a fabric contact position using the output signal of the pressing load sensor unit of the fabric gripping device and notifies the control unit, and also detects whether a single sheet of fabric has been gripped between the fabric support surface of the gripper guide and the fabric contact finger surface of the gripper finger using the output signal of the capacitance sensor of the fabric gripping device and notifies the control unit.

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