KR20240023900A - Gripper capable of implementing various motion - Google Patents

Abstract

The present invention relates to a gripper that can be used in logistics facilities, manufacturing facilities, or medical facilities.
A gripper according to an embodiment of the present invention is a gripper including a base, a driving part disposed on the base, and a plurality of gripping parts connected to the driving part, wherein the gripping part includes an input link connected to the driving part, and a gripper for gripping an object. It includes a fingertip provided with the ground and a plurality of connection links connecting the input link and the fingertip, and the tip of the fingertip moves along a trajectory parallel to the ground until the grip part contacts the object.

Description

Gripper capable of implementing various motion}

The present invention relates to a gripper, and more specifically, to a gripper that can mechanically implement various motions depending on the position and shape of the object.

Grippers for piece picking can be broadly divided into grippers whose fingertips move in parallel based on the operation method and adaptive grippers whose fingertips' movement changes depending on the shape of the object.

A parallel gripper grips an object while its fingertips move parallel to a horizontal or vertical line, and can be used to perform precise transfer work in a factory where the size and shape of the object to be gripped is constant. However, these parallel grippers have the disadvantage that the size and shape of the object to be gripped are fixed, and the gripping range of the gripper is relatively small.

Additionally, the adaptive gripper can grip various objects by adapting or modifying the fingertips of the gripper to suit the shape and size of the object. However, in order to perform this adaptive motion, the fingertips of the adaptive gripper move in a curved end trajectory. This causes the fingertip to collide with the shelf or the ground rather than the object due to minor vision errors. In addition, the adaptive gripper has the disadvantage that the gripping force decreases depending on the movement of the finger tips, and as the gripping range increases, the size of the object that cannot be grasped during adaptive gripping becomes relatively larger due to the limitations of the structure.

The above-mentioned background technology is technical information that the inventor possessed for deriving the present invention or acquired in the process of deriving the present invention, and cannot necessarily be said to be known technology disclosed to the general public before filing the application for the present invention.

Japanese Registered Patent Publication JP 5284066 B2

The present invention is an invention to solve the above-mentioned problems, and provides a gripper that can grip an object more strongly while implementing the operations of both a parallel gripper and an adaptive gripper.

However, these problems are illustrative, and the problems to be solved by the present invention are not limited thereto.

A gripper according to an embodiment of the present invention is a gripper including a base, a driving part disposed on the base, and a plurality of gripping parts connected to the driving part, wherein the gripping part includes an input link connected to the driving part, and a gripper for gripping an object. It includes a fingertip provided with the ground and a plurality of connection links connecting the input link and the fingertip, and the tip of the fingertip moves along a trajectory parallel to the ground until the grip part contacts the object.

In the gripper according to an embodiment of the present invention, the fingertips of the gripper move toward the object until they contact the object, and when the gripper contacts the object, they move downward to lower the object.

In the gripper according to an embodiment of the present invention, when an object contacts one of the plurality of connection links, the gripper may rotate so that the finger tip contacts the object.

In the gripper according to an embodiment of the present invention, when the gripper contacts an object, the gripper moves the fingertips downward so that the object contacts the support surface of the base, and a plurality of connections connected to the base Any one of the links may become dislodged from the base.

In the gripper according to an embodiment of the present invention, the base includes a plurality of mounting surfaces, the gripping portion includes lifting blocks arranged to be capable of being raised and lowered on each of the mounting surfaces, and the plurality of connection links have one end A first connection link connected to the lifting block, a second connection link at one end connected to the input link and the other end connected to the other end of the first connection link, and one end connected to the first connection link and the second connection link. It may include a third connection link that is connected and the other end of which is connected to one side of the fingertip, and a fourth connection link that has one end connected to the lifting block and the other end of which is connected to the other side of the fingertip.

In the gripper according to an embodiment of the present invention, when the gripper is not in contact with the object, the lifting block is lowered when the fingertip moves toward the object so that the height of the tip of the fingertip is maintained constant. You can.

In the gripper according to an embodiment of the present invention, when the gripper does not contact the object, the first connection link and the third connection link may move while being fixed to each other.

In the gripper according to an embodiment of the present invention, the gripper includes a stopper disposed between the first connection link and the third connection link to maintain the minimum angle between the first connection link and the third connection link. More may be included.

In the gripper according to an embodiment of the present invention, when the object first contacts the fourth connection link without contacting the finger tip, the third connection link rotates to spread apart with respect to the first connection link and the finger The tip may contact the object.

In the gripper according to an embodiment of the present invention, the plurality of connection links further include a fifth connection link, one end of which is connected to one side of the fourth connection link, and the base is provided with a protrusion and the protrusion. It further includes a support part detachably supporting the other end of the fifth connection link, wherein when the finger tip contacts the object, the grip part receives a downward force, and the downward force of the grip part connects the support part and the fifth connection link. If the fastening force between the links becomes greater, the fifth connection link may separate from the support portion.

Other aspects, features and advantages other than those described above will become apparent from the detailed description, claims and drawings for carrying out the invention below.

The gripper according to an embodiment of the present invention can stably grip an object by implementing different operations depending on the shape and gripping position of the object.

The gripper according to an embodiment of the present invention can minimize the working radius while preventing the gripper from interfering with external environments other than the object during the gripping operation through parallel motion.

The gripper according to an embodiment of the present invention can support an object more stably through a motion of increasing gripping force.

Figure 1 shows a perspective view of a gripper according to an embodiment of the present invention.
Figure 2 shows a front view of a gripper according to an embodiment of the present invention.
Figure 3 shows a gripper according to an embodiment of the present invention.
Figure 4 shows a part of the grip portion according to an embodiment of the present invention.
Figures 5 and 6 show a state in which a gripper grips an object according to an embodiment of the present invention.
7 to 9 show parallel motion of the gripper according to an embodiment of the present invention.
10 to 12 show adaptive motion of a gripper according to an embodiment of the present invention.
Figures 13 and 14 show a motion to increase the gripping force of the gripper according to an embodiment of the present invention.

Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the description of the invention. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all transformations, equivalents, and substitutes included in the spirit and technical scope of the present invention. In describing the present invention, the same identification numbers are used for the same components even if they are shown in different embodiments.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. When describing with reference to the drawings, identical or corresponding components will be assigned the same reference numerals and redundant description thereof will be omitted. .

In the following embodiments, terms such as first and second are used not in a limiting sense but for the purpose of distinguishing one component from another component.

In the following examples, singular terms include plural terms unless the context clearly dictates otherwise.

In the following embodiments, terms such as include or have mean that the features or components described in the specification exist, and do not exclude in advance the possibility of adding one or more other features or components.

In the drawings, the sizes of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, so the present invention is not necessarily limited to what is shown.

In the following embodiments, the x-axis, y-axis, and z-axis are not limited to the three axes in the Cartesian coordinate system, but can be interpreted in a broad sense including these. For example, the x-axis, y-axis, and z-axis may be orthogonal to each other, but may also refer to different directions that are not orthogonal to each other.

In cases where an embodiment can be implemented differently, a specific process sequence may be performed differently from the described sequence. For example, two processes described in succession may be performed substantially at the same time, or may be performed in an order opposite to that in which they are described.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Figure 1 shows a perspective view of the gripper 10 according to an embodiment of the present invention, Figure 2 shows a front view of the gripper 10 according to an embodiment of the present invention, and Figure 3 shows an embodiment of the present invention. Figure 4 shows a part of the gripper 300 according to an embodiment of the present invention, and Figures 5 and 6 show the gripper 10 according to an embodiment of the present invention. Indicates the state of holding.

The gripper 10 according to an embodiment of the present invention can be placed in a logistics facility and used to sort and transport goods. For example, when the vision system confirms the location, shape, and size of the item and transmits this to the control system, the control system can operate the gripper 10 based on this. The gripper 10 can be independently placed in the sorting and transfer system or used as an end tool of a separate manipulation robot. Additionally, the gripper 10 may be placed in traditional manufacturing facilities as well as logistics facilities, or may be placed in collaborative robots, surgical robots, etc.

In FIGS. 1 to 6 and FIGS. 7 to 14 described later, the gripper 10 is arranged to face upward, but this is shown for convenience of explanation and does not limit the direction in which the gripper 10 faces. For example, the gripper 10 may be arranged downward or towards the side to grip an object placed on the ground. Additionally, the gripper 10 may be arranged upward or tilted at a predetermined angle in order to grip an object located on the ceiling. The orientation direction of the gripper 10 or the moving direction of the gripper 300 described below is only the direction shown in the drawings, and in reality, the gripper 10 and/or the gripper 300 move in various directions toward the object. It can be placed and moved.

Referring to FIGS. 1 to 4 , the gripper 10 according to an embodiment of the present invention may include a base 100, a driving unit 200, and a gripping unit 300.

The base 100 supports the gripper 10 to secure the gripper 10 to a robot or other equipment. For example, the driving unit 200 may be disposed on one side and the other side of the base 100, and the gripping unit 300 may also be mounted on the base 100 to correspond to each driving unit 200. For example, the base 100 protrudes upward from the center, and may have a shape in which a pair of drive units 200 and a pair of corresponding grip units 300 are mounted on both sides of the center.

In one embodiment, the base 100 may include a support surface 110 and a mounting surface 120.

As shown in FIGS. 1 and 2, the support surface 110 may be formed above the center of the base 100. The support surface 110 is a plane formed on the center of the base 100 and may be disposed between a pair of gripping parts 300. The support surface 110 may define a boundary so that the object does not move inside the gripper 10 when the gripper 10 grips the object. Additionally, the support surface 110 supports the object together with the pair of grippers 300, allowing the gripper 10 to support the object more stably.

The shape and size of the support surface 110 are not particularly limited, and it is sufficient to have a flat shape to stably support the object. The support surface 110 may be arranged so that at least a portion of the support surface 110 overlaps the gripper 300 in the width direction (for example, the X-axis direction in FIG. 1).

In one embodiment, the support surface 110 may have an area larger than the area of the surface on which the gripper 300 grips the object. More specifically, the dimensions of the support surface 110 in the width direction and/or the length direction (for example, the Y-axis direction in FIG. 1) may be larger than the dimensions of the gripping surface 321 of the finger tip 320. Through this, the support surface 110 together with the gripper 300 can stably support the object.

One or more mounting surfaces 120 are formed on the base 100 to support the driving unit 200 and the holding unit 300. For example, as shown in FIGS. 1 and 2, the mounting surface 120 may be disposed on one side and the other, respectively, with respect to the center of the base 100. The mounting surface 120 extends from the lower part of the base 100 to both sides, and a pair of driving units 200 can be inserted below the mounting surface 120. Additionally, a pair of gripping parts 300 may be respectively disposed on the mounting surface 120.

The base 100 may further include a protrusion 130. As shown in FIGS. 1 and 2, the protrusions 130 may be formed to protrude toward the grip portion 300 from the center of the base 100, more specifically, from both sides of the support surface 110. The protrusion 130 may be connected to the fifth connection link 335 of the gripper 300, which will be described later. The fifth connection link 335 is detachably connected to the protrusion 130 and may be fixed to the protrusion 130 or separated from the protrusion 130 according to the operation of the gripper 300.

In one embodiment, the protrusion 130 may include a support portion 140 (see FIGS. 7 to 14) on one side. For example, the support part 140 is a magnet that is disposed inside or outside the protrusion 130 and can support the fifth connection link 335 with magnetic force. When the gripper 300 receives a downward force as it contacts the object, the supporter 140 can support the fifth connection link 335 until a force greater than the magnetic force with the fifth connection link 335 is generated. there is. Afterwards, if a force greater than the magnetic force between the support part 140 and the fifth connection link 335 is generated downward, the fifth connection link 335 may be separated from the support part 140.

In another embodiment, the support portion 140 may support the fifth connection link 335 through an elastic member. More specifically, the support part 140 may be a static load spring. Even if the stroke increases after reaching the maximum load, a smoother link operation can be achieved by using a constant load spring with a constant load.

The driving unit 200 performs the gripping operation of the gripper 10. For example, when the vision system identifies an object, the control system transmits an operation signal to the driving unit 200. The driving unit 200 grasps the object by retracting or opening the gripping unit 300 based on a signal received from the control system.

In one embodiment, the driving unit 200 is a motor and may have a gear at one end. More specifically, the drive unit 200 may be provided with a gear at one end connected to the holding unit 300, and more specifically, at one end connected to the input link 310 of the holding unit 300. For example, when the drive unit 200 rotates through the gear, which is a worm gear, the input link 310, which also has a gear at the end so as to be connected to the gear, rotates and the gripper 300 can operate.

However, the type of the driving unit 200 is not limited to this, and it is sufficient as long as it can operate the input link 310. In another embodiment, the driving unit 200 may be a hydraulic cylinder or a pneumatic cylinder.

The gripper 300 directly contacts the object and grips it. In one embodiment, a pair of gripping parts 300 may be arranged to be symmetrical to each other about the base 100.

In one embodiment, the gripper 300 may include an input link 310, a fingertip 320, one or more connection links 330, and a lifting block 340.

The input link 310 receives power from the driving unit 200 and operates the gripping unit 300. For example, one end of the input link 310 is connected to one end of the drive unit 200 equipped with a gear, and may rotate as the drive unit 200 rotates. More specifically, one end of the input link 310 is engaged with a worm gear provided in the driving unit 200, and can rotate clockwise or counterclockwise as seen in FIG. 2. The other end of the input link 310 may be connected to a second connection link 332, which will be described later. As the input link 310 rotates, the connection link 330 including the second connection link 332 rotates and the fingertip 320 rotates, so that it can grip the object or be separated from the object.

In one embodiment, at least a portion of the input link 310 may be disposed between the first connection links 331. As shown in FIGS. 3 and 4, the input link 310 is disposed between the first connection links 331 in one direction (for example, the X-axis direction in FIG. 3), thereby making the gripper 10 compact. It can be implemented.

In one embodiment, the input link 310 may include a bent portion 310a. For example, as shown in FIG. 3, one end of the input link 310 may be connected to the driving unit 200 and the other end may be connected to the second connection link 332, and a bent portion 310a bent outward between one end and the other end. ) may include. Through this shape, it is possible to prevent the input link 310 from interfering with the stopper 350, which will be described later, when operating.

In one embodiment, the input link 310 may be connected to the base 100. More specifically, one end of the input link 310 connected to the driving unit 200 may be connected to the base 100. Accordingly, even if the gripper 300 rotates, the position of one end of the input link 310 connected to the drive unit 200 does not change, and through this, parallel motion of the gripper 10 can be implemented. This will be described later.

The finger tip 320 directly contacts the object and grips it. As shown in Figures 1 to 3, the finger tip 320 is disposed at the tip of the gripping part 300 and may include a gripping surface 321 on one side. The gripping surface 321 is a flat surface disposed on the inside of the finger tip 320 and, in one embodiment, may include an anti-slip pad and/or a plurality of protrusions to support the object.

The shape of the finger tip 320 is not particularly limited. For example, as shown in FIGS. 1 to 3, the finger tip 320 may have a gripping surface 321 extending perpendicular to the ground and a portion extending outward from the bottom thereof to have an overall “ㄴ” shape.

The fingertip 320 may be connected to one or more connection links 330. For example, the lower end of the finger tip 320 may be connected to the third connection link 333 and the fourth connection link 334, respectively. When the input link 310 rotates, the third connection link 333 and/or the fourth connection link 334 rotates and the fingertip 320 may also rotate in the same direction.

The connection link 330 is a link connecting the base 100, the input link 310, and the finger tip 320, and transmits the power transmitted from the drive unit 200 to the input link 310 to the finger tip 320. do. There may be a plurality of connection links 330.

In one embodiment, the connection link 330 includes a first connection link 331, a second connection link 332, a third connection link 333, a fourth connection link 334, and a fifth connection link 335. It can be included.

The first connection link 331 may be disposed on the outermost side of the plurality of connection links 330. 1 to 4, one end of the first connection link 331 is rotatably connected to the lifting block 340, which will be described later, and the other end is connected to the second connection link 332 and the third connection link 333. ) and can be rotatably connected. When the input link 310 rotates, the second connection link 332 rotates and the first connection link 331 connected thereto may also rotate in the same direction. In addition, one end of the first connection link 331 is connected to the lifting block 340, so that it can be raised and lowered in the height direction. For example, when the lifting block 340 descends or rises to implement the parallel motion of the gripper 10, the first connection link 331 connected thereto also descends or rises to implement the parallel motion of the finger tip 320. You can.

In one embodiment, the first connection link 331 may include a pair of bars 331a facing each other in the width direction and a connection portion 331b connecting them. The pair of bars 331a have a straight bar shape and may be arranged to be spaced apart from each other at a predetermined distance. As shown in FIG. 3, at least a portion of the input link 310 may be inserted into the gap between the pair of bars 331a. In particular, the gripper 10 can be miniaturized in one direction (for example, the Y-axis direction in FIG. 3) by operating the gripper 300 while the curved portion of the input link 310 is inserted into the corresponding gap.

The connection portion 331b is a block disposed between a pair of bars 331a and connects them, and may be disposed in the middle or further of the first connection link 331 in the longitudinal direction. A stopper 350, which will be described later, may extend from one side of the connecting portion 331b and extend toward the other end of the first connecting link 331, that is, the connecting portion with the third connecting link 333.

The second connection link 332 is directly connected to the input link 310 and transmits the movement of the input link 310 to the other connection link 330 and the fingertip 320. For example, one end of the second connection link 332 may be rotatably connected to the input link 310, and the other end may be rotatably connected to the first connection link 331 and the third connection link 333. Accordingly, when the input link 310 rotates, the second connection link 332 rotates, and the first connection link 331 and the third connection link 333 rotate, causing the finger tip 320 to rotate.

In one embodiment, the second connection link 332 may include a bent portion 332a. The bent portion 332a is formed between one end and the other end of the second connection link 332 and is bent in the opposite direction to the bent portion 310a of the input link 310. Through this shape, it is possible to prevent the second connection link 332 from interfering with the stopper 350 when it rotates.

The third connection link 333 may have one end rotatably connected to the first connection link 331 and the second connection link 332, and the other end may be rotatably connected to one side of the finger tip 320. For example, as shown in FIGS. 1 to 4, the third connection link 333 is inserted between a pair of bars 331a of the first connection link 331 and is connected to the first connection link 331. You can. When the input link 310 rotates, the third connection link 333 rotates and the fingertip 320 directly connected thereto may rotate.

The fourth connection link 334 may have one end rotatably connected to the lifting block 340 and the other end rotatably connected to the other side of the finger tip 320. The other end of the fourth connection link 334 may be spaced inward from the other end of the third connection link 333 and connected to the finger tip 320. In addition, like the first connection link 331, the fourth connection link 334 has one end connected to the lifting block 340, so that it can be raised and lowered together according to the lifting operation of the lifting block 340.

In one embodiment, the fourth connection link 334 may include a portion bent in the width direction of the gripper 10 (for example, the X-axis direction in FIG. 1). The bent portion is formed in a direction that spreads outward at a position corresponding to the input link 310 and the second connection link 332, so that when the gripper 300 is operated, the fourth connection link 334 is the input link ( 310) and the second connection link 332.

One end of the fifth connection link 335 may be rotatably connected to the fourth connection link 334, and the other end may be rotatably connected to the protrusion 130, more specifically, the support portion 140. The fifth connection link 335 rotates together with the rotation of the fourth connection link 334, and can selectively deviate from the support portion 140, especially when the grip portion 300 receives a downward force. . That is, when a force greater than the fastening force between the fifth connection link 335 and the support part 140 is generated in the grip part 300, the fifth connection link 335 is separated from the support part 140 and the grip part 300 moves downward. moves to , and through this, a motion of increasing gripping force can be implemented.

In one embodiment, the fifth connection link 335 may be connected between one end and the other end of the fourth connection link 334. 1 to 3, the fifth connection link 335 is disposed inside the fourth connection link 334, and is connected to the fourth connection at a position below the middle of the fourth connection link 334 in the longitudinal direction. It may be rotatably connected to the link 334.

The stopper 350 is disposed between the first connection link 331 and the third connection link 333 to limit the angle between the first connection link 331 and the third connection link 333. For example, as shown in FIG. 4, the stopper 350 may extend from the connection portion 331b toward the third connection link 333. One end of the stopper 350 may selectively contact the contact portion 333a formed on the inside of the third connection link 333. Accordingly, when the angle between the first connection link 331 and the third connection link 333 reaches a preset angle, the stopper 350 comes into contact with the contact portion 333a of the third connection link 333, and The angle between the first connection link 331 and the third connection link 333 can be prevented from being less than a preset angle.

The range of the minimum angle between the first connection link 331 and the third connection link 333 by the stopper 350 is 60 degrees to 160 degrees, preferably 90 degrees to 150 degrees, more preferably 100 degrees to 100 degrees. It could be 130 degrees.

The elastic member 360 is disposed between the first connection link 331 and the third connection link 333. For example, as shown in FIG. 4, one end of the elastic member 360 may be placed on the inner surface of the stopper 350, and the other end may be placed on the inner surface of the contact portion 333a of the third connection link 333. there is. Accordingly, when the input link 310 rotates in one direction and the first connection link 331 and the third connection link 333 rotate toward each other, the elastic member 360 is gradually compressed, and the stopper 350 When the first connection link 331 and the third connection link 333 reach the minimum angle, the elastic member 360 can be maximally compressed. Then, when the input link 310 rotates in the other direction so that the first connection link 331 and the third connection link 333 rotate away from each other, the restoring force of the elastic member 360 is added to the first connection link ( 331) and the third connection link 333 can be separated more quickly. Here, the elastic member 360 may include various types of springs such as coil springs, torsion springs, spiral springs, and leaf springs, and other elastic members.

The lifting block 340 is arranged to be able to be lifted up and down on the base 100 and may be connected to the connection link 330. For example, as shown in FIGS. 1 to 3, a pair of lifting blocks 340 are arranged to correspond to the mounting surface 120 of the base 100, and a support shaft 120a extending from the mounting surface 120 It can be supported by . Additionally, the lifting block 340 may be mounted on the driving unit 200. Additionally, a first connection link 331 and a fourth connection link 334 may be rotatably connected to one side and the other side of the lifting block 340, respectively.

When the gripper 300 operates and receives downward force, the lifting block 340 moves downward. Accordingly, the first connection link 331 and the fourth connection link 334 connected to the lifting block 340 also move downward, and the grip part 300 may move downward as a whole. Afterwards, when the gripping part 300 receives upward force, the lifting block 340 moves upward, and the gripping part 300 also moves upward. The lifting distance of the lifting block 340 may be the distance between the lifting block 340 and the mounting surface 120.

Next, referring to FIGS. 5 and 6 , a state in which the gripper 10 grips the object O according to an embodiment of the present invention will be described.

Figure 5 shows a state in which the gripper 10 grips a flat object O. When the driving unit 200 operates, the pair of gripping parts 300 move toward the object O, and at this time, the finger tips 320 move in a parallel motion while maintaining the gripping surface 321 perpendicular to the ground. It looks like Afterwards, a pair of gripping units 300 grip the contact surfaces of the object O from both sides, the driving unit 200 continues to operate, the input link 310 rotates, and the fifth connection link 335 is connected to the protrusion 130. ) and the gripping part 300 descends as a whole. At this time, since one end of the input link 310 is rotatably fixed to the base 100, the contact surface between one end of the input link 310 that receives the driving force from the driving unit 200, the object O, and the finger tip 320 The distance between them gradually decreases. Through this, it is possible to implement a motion to increase the gripping force that can increase the force for gripping the object (O) even when a certain torque is applied.

FIG. 6 shows a state in which the gripper 10 grips an object O that has a curved surface or an uneven shape. When the driving unit 200 operates, the pair of gripping parts 300 move toward the object O, and at this time, the finger tips 320 move in a parallel motion while maintaining the gripping surface 321 perpendicular to the ground. It looks like Afterwards, when the object O contacts one of the plurality of connection links 330, the connection link 330 may act as a constraint condition for the operation of the gripper 300. That is, the object O is placed between a pair of gripping parts 300, and the object O contacts the connecting link 330 of each holding part 300, so that the connecting link 330 is no longer connected. It does not rotate. For example, as shown in FIG. 6, when the object O contacts the fourth connection link 334, the fourth connection link 334 no longer rotates even if the drive unit 200 operates, and the first connection link 334 no longer rotates. By the operation of the link 331 to the third connection link 333, the finger tip 320 rotates inward and implements an adaptive motion surrounding the object O. Afterwards, if the driving unit 200 continues to operate, the gripping unit 300 can be lowered as a whole to implement a motion of increasing gripping force.

Next, the operation of the gripper 10 according to an embodiment of the present invention will be described based on FIGS. 7 to 14.

7 to 9 show the parallel motion of the gripper 10 according to an embodiment of the present invention, and FIGS. 10 to 12 show the adaptive motion of the gripper 10 according to an embodiment of the present invention. 13 to 14 show a motion to increase the gripping force of the gripper 10 according to an embodiment of the present invention. For convenience of explanation, only one of the gripping parts 300 provided in the gripper 10 is shown in FIGS. 7 to 14 , but the gripper 10 may be provided with a pair of gripping parts 300.

First, as shown in FIG. 7, in the initial state, the gripper 10 may be arranged so that the virtual surface P1 extending the gripping surface 321 of the finger tip 320 is perpendicular to the ground. In this state, when the vision system detects the object O, the control system transmits an operation signal to the gripper 10, and the drive unit 200 operates to grip the object O. When the driving unit 200 rotates, the input link 310, one end of which is connected to the driving unit 200, rotates (for example, counterclockwise in FIG. 8). In addition, the first connection link 331 and the second connection link 332 connected to the input link 310 may also rotate in the same manner, thereby allowing the gripping portion 300 to move overall to the left and/or rotate counterclockwise.

In one embodiment, the tip 321a of the finger tip 320 may move while maintaining a substantially constant height until the gripper 300 contacts the object O. More specifically, as shown in FIG. 8, one end of the first connection link 331 and the fourth connection link 334 is rotatably connected to the lifting block 340. Also, as described above, the space between the first connection link 331 and the third connection link 333 is not narrowed below the minimum angle by the stopper 350. According to this link structure, when the input link 310 rotates counterclockwise, the finger tip 320 rotates counterclockwise and the lifting block 340 moves downward. Accordingly, the tip 321a of the finger tip 320 does not draw a curved trajectory, but moves linearly to the left parallel to the ground while maintaining a constant height.

When the input link 310 rotates further and the fourth connection link 334 is located to the left of the fifth connection link 335 as shown in FIG. 9, the lifting block 340 rises again. Similarly, through the lowering operation of the lifting block 340, the tip 321a of the finger tip 320 can be maintained at a constant height parallel to the ground without rising or falling. This operation of the gripper 10 is called a parallel motion, and proceeds until the finger tip 320 contacts the object O.

Here, “substantially constant height” means not only a strictly physically constant height, but also the same including minute errors that occur due to vibration or tolerance that occurs during the operation of the gripper 10.

In one embodiment, during parallel motion, the angle between the first connection link 331 and the third connection link 333 may always be maintained at the minimum angle by the stopper 350.

In this way, the gripper 10 according to an embodiment of the present invention implements parallel motion before gripping the object O, thereby minimizing the range in which the gripper 300 moves (particularly, movement in the height direction). In addition, even if the gripper 300 protrudes further toward the tip than the actual position of the object O due to errors in the vision system, etc., the gripper 300 moves in parallel while maintaining a constant height, thereby ensuring that the object O is placed. It can prevent collisions with bases such as the ground or shelves.

Next, the adaptive motion of the gripper 10 will be described with reference to FIGS. 10 to 12.

As shown in Figure 10, in the initial state the gripper 10 is in the same position as the parallel motion shown in Figure 7. As the input link 310 continues to rotate, the gripper 300 rotates counterclockwise and one of the plurality of connection links 330 comes into contact with the object O. For example, as shown in FIG. 11, when the fourth connection link 334 contacts the object O, the fourth connection link 334 and the fifth connection link 335 connected thereto no longer rotate. Here, the opposite side of the object O is also in contact with the fourth connection link 334 of the other gripping part 300.

Afterwards, when the input link 310 rotates, the fourth connection link 334 and the fifth connection link 335 no longer rotate, and the first connection link 331 and the third connection link 333 move away from each other. It rotates. Accordingly, as shown in FIG. 12, the finger tip 320 rotates counterclockwise and the gripping surface 321 of the finger tip 320 comes into contact with another point of the object O. In this way, when the object O contacts the connection link 330 rather than the finger tip 320, the gripper 10 moves the finger tip 320 to the object O in order to stably grip the object O. Adaptive motion is implemented for stable gripping.

Next, the motion to increase the gripping force of the gripper 10 will be described with reference to FIGS. 13 to 15.

As shown in FIG. 13 , when the fingertip 320 contacts the object O, the gripper 300 does not rotate to move in the left or right direction and can be treated as one rigid body. That is, when the pair of gripping parts 300 contact the object O, the degrees of freedom of the plurality of connection links 330 are restricted, and the gripping parts 300 receive a downward force.

Accordingly, the triangle T2 formed by the fourth connection link 334 and the fifth connection link 335 receives a downward force with its inner angle fixed. As seen above, the fifth connection link 335 is detachably connected to the support portion 140 of the protrusion 130. Therefore, if the driving unit 200 continues to operate and the downward moving force exceeds the fastening force between the fifth connection link 335 and the support unit 140, the fifth connection link 335 moves to the support unit 140 as shown in FIG. 14. ) deviates from. Accordingly, as the lifting block 340 descends, the gripping part 300 also descends as a whole.

Here, since one end of the input link 310 is rotatably fixed to the base 100, one end of the input link 310 does not descend. Therefore, the distance between the point (or surface) where the object O contacts the gripping surface 321 and one end of the input link 310, that is, the distance of the force applied by the driving unit 200 to the object O gradually decreases. . When the torque of the driving unit 200 is constant, the distance to the application point gradually decreases, so the force with which the gripping unit 300 grips the object O gradually increases. Through this configuration, the gripper 10 can implement a motion that increases the gripping force.

In one embodiment, the gripper 300 may move the object O downward until one side of the object O contacts the support surface 110 of the base 100. When the object O contacts the support surface 110, the object O can be supported more stably by the pair of gripping parts 300 and the support surface 110.

13 and 14 show a case where the object O has a contact surface parallel to the gripping surface 321 of the finger tip 320, but the present invention is not limited to this. For example, even when the object O has a curved surface or an uneven shape, the gripper 10 can implement a motion to increase the gripping force. More specifically, as shown in FIG. 12, when the object O contacts the gripping surface 321 of the finger tip 320, the gripping part 300 is similarly treated as one rigid body, and the gripping part 300 is positioned below. You will receive strength from Afterwards, when the driving unit 200 continues to operate and the downward force of the grip unit 300 exceeds the fastening force of the fifth connection link 335 and the support unit 140, the fifth connection link 335 is separated from the support unit 140. break away Additionally, as the lifting block 340 descends, the gripping unit 300 and the object O also descend, thereby implementing a motion of increasing gripping force.

Through this configuration, the gripper 10 according to an embodiment of the present invention can stably grip the object O by implementing different operations depending on the shape and gripping position of the object O.

The gripper 10 according to an embodiment of the present invention can minimize the working radius while preventing the gripper 10 from interfering with external environments other than the object O during the gripping operation through parallel motion.

The gripper 10 according to an embodiment of the present invention can support the object O more stably through a motion of increasing gripping force.

Although the present invention has been described with reference to the embodiments shown in the drawings, these are merely examples. Those skilled in the art can fully understand that various modifications and equivalent other embodiments are possible from the embodiments. Therefore, the true technical protection scope of the present invention should be determined based on the attached claims.

The specific technical content described in the embodiment is an example and does not limit the technical scope of the embodiment. In order to describe the invention concisely and clearly, descriptions of conventional general techniques and configurations may be omitted. In addition, the connection of lines or the absence of connections between components shown in the drawings exemplify functional connections and/or physical or circuit connections, and in actual devices, various functional connections or physical connections may be replaced or added. It can be expressed as connections, or circuit connections. Additionally, if there is no specific mention such as “essential,” “important,” etc., it may not be a necessary component for the application of the present invention.

“The” or similar designators used in the description and claims may refer to both the singular and the plural, unless otherwise specified. In addition, when a range is described in an example, the invention includes the application of individual values within the range (unless there is a statement to the contrary), and each individual value constituting the range is described in the description of the invention. same. Additionally, unless the order of the steps constituting the method according to the embodiment is explicitly stated or there is no description to the contrary, the steps may be performed in an appropriate order. The embodiments are not necessarily limited by the order of description of the above steps. The use of any examples or illustrative terms (e.g., etc.) in the embodiments is merely to describe the embodiments in detail, and unless limited by the claims, the examples or illustrative terms do not limit the scope of the embodiments. That is not the case. Additionally, those skilled in the art will appreciate that various modifications, combinations and changes may be made according to design conditions and factors within the scope of the appended claims or their equivalents.

10: Gripper
100: base
200: driving unit
300: gripping part

Claims (10)

A gripper including a base, a driving part disposed on the base, and a plurality of gripping parts connected to the driving part,
The gripping unit includes an input link connected to the driving unit, a fingertip having a gripping surface for gripping an object, and a plurality of connection links connecting the input link and the fingertip,
A gripper in which the tip of the finger tip moves along a trajectory parallel to the ground until the gripping part contacts the object. According to paragraph 1,
The gripper moves the fingertips toward the object until the gripping part contacts the object, and moves downward when the gripping part contacts the object to lower the object. According to paragraph 1,
When the object contacts one of the plurality of connection links, the gripper rotates so that the fingertips contact the object. According to paragraph 1,
When the gripper contacts the object, the gripper moves the finger tip downward so that the object contacts the support surface of the base, and one of a plurality of connection links connected to the base is separated from the base. . According to paragraph 1,
The base includes a plurality of mounting surfaces,
The gripping unit includes lifting blocks arranged to be capable of being raised and lowered on the mounting surface, respectively,
The plurality of connection links include a first connection link having one end connected to the elevating block, a second connection link having one end connected to the input link and the other end connected to the other end of the first connection link, and one end connected to the first connection link. A link, a third connection link connected to the second connection link and the other end connected to one side of the fingertip, and a fourth connection link whose one end is connected to the lifting block and the other end is connected to the other side of the fingertip. , gripper. According to clause 5,
When the gripping part is not in contact with the object, the lifting block is lowered when the fingertip moves toward the object, so that the height of the tip of the fingertip is kept constant. According to clause 5,
When the gripper does not contact the object, the first connection link and the third connection link move while being fixed to each other. In clause 7,
The gripper further includes a stopper disposed between the first connection link and the third connection link to maintain a minimum angle between the first connection link and the third connection link. According to clause 5,
When an object first contacts the fourth connection link without contacting the fingertip, the third connection link rotates to spread apart with respect to the first connection link, and the fingertip contacts the object. According to clause 5,
The plurality of connection links further include a fifth connection link, one end of which is connected to one side of the fourth connection link,
The base further includes a protrusion and a support portion provided on the protrusion to detachably support the other end of the fifth connection link,
When the finger tip contacts the object, the grip part receives a downward force, and when the downward force of the grip part is greater than the fastening force between the support part and the fifth connection link, the fifth connection link separates from the support part, Gripper.

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