JP7637079B2 - Gripper - Google Patents

Description

The present invention relates to grippers used in industrial robots and the like, and in particular to grippers that grip work objects by opening and closing.

In recent years, industrial robots have been used for a variety of purposes, including transporting and assembling parts. Industrial robots that transport work objects, known as material handling, have also been put to practical use. When transporting work objects using an industrial robot, a gripper (sometimes called an end effector) is attached to the arm of the industrial robot, and the work object is manipulated by the gripper. Different grippers are used depending on the nature and shape of the work object, and there are grippers that use suction forces such as magnetic force or vacuum pulling, and grip the work object by opening and closing.

As an example of a gripper that grasps a work target by opening and closing, the one disclosed in Patent Document 1 is known. In the gripper of Patent Document 1, a leaf spring and cushioning material are opened and closed by an actuator. It is disclosed that this gripper can grasp and transport objects with fragile mechanical properties.

Japanese Patent Application Publication No. 7-276281

The gripper in Patent Document 1 uses cushioning material in the portion where the gripper grips the object to be gripped (the object of the transport operation), thereby mitigating the impact force during gripping.
Furthermore, when the gripper is used in an industrial robot or the like, the gripping operation is repeated and accurate gripping and transport are required each time.

An object of the present invention is to provide a gripper that can flexibly grip an object to be gripped and can reliably grip an object repeatedly.

As a result of extensive research, the inventors discovered that when the gripper becomes flexible, the reliability of repeated gripping is easily compromised. They also discovered that one of the reasons for this is that when gripping is repeated, the gripping member does not recover from deformation caused by gripping in time, and the gripping member enters the next gripping operation in a crushed state. The inventors also found that the phenomenon of delayed recovery is likely to occur when the gripping member has a hollow portion.
After much research, the inventor discovered that the above problem could be solved by providing an air passage that connects the hollow portions of the hollow protrusions or hollow ridges on the grip member, and thus completed the present invention.

The present invention is a gripper having a claw member that can be opened and closed to grip an object to be gripped, and a grip member attached to the claw member so as to come into contact with the object to be gripped when gripping the object, wherein the grip member includes a plate-shaped elastic member made of resin, the elastic member having a plurality of hollow protrusions each having a hollow portion and a flat plate-shaped base, the hollow protrusions being formed to protrude so as to be scattered on the base, the hollow protrusions having a hollow cylindrical side wall erected from the base and having a closed end on the opposite side to the base, an air communication passage being provided to connect the hollow portions of adjacent hollow protrusions, the communication passage being a tunnel-shaped passage provided between the side walls of adjacent hollow protrusions (first invention).

The present invention also provides a gripper having a claw member that can be opened and closed to grip an object to be gripped, and a grip member attached to the claw member so as to come into contact with the object to be gripped when gripping the object, wherein the grip member includes a plate-shaped elastic member made of resin, the elastic member having a plurality of hollow ridges having hollow portions and a flat plate-shaped base, the hollow ridges being formed to protrude in a line on the base, the hollow ridges having a pair of side walls erected from the base and having a closed end on the opposite side to the base, an air communication passage being provided to connect the hollow portions of adjacent hollow ridges, and the communication passage being a tunnel-shaped passage provided between the side walls of adjacent hollow ridges (a second invention).

The present invention also provides a gripper having claw members that can be opened and closed to grip an object to be gripped, and a grip member attached to the claw members so as to come into contact with the object to be gripped when gripping the object, wherein the grip member includes a plate-shaped elastic member made of resin, the elastic member having a plurality of hollow protrusions each having a hollow portion and a flat base, the hollow protrusions being formed to protrude so as to be scattered on the base, the hollow protrusions having a hollow cylindrical side wall erected from the base and having a closed end on the opposite side to the base, an air communication passage being provided to connect the hollow portions of adjacent hollow protrusions, a through hole being provided in the base at the portion where the hollow protrusions are provided, and a protrusion that protrudes on the opposite side to the hollow protrusions is provided on the base so as to separate the base and the claw members, and the communication passage is constituted by the spaced apart space and the through hole (a third invention).
The present invention also provides a gripper having a claw member that can be opened and closed to grip an object to be gripped, and a grip member attached to the claw member so as to come into contact with the object to be gripped when gripping the object, wherein the grip member includes a plate-shaped elastic member made of resin, the elastic member having a plurality of hollow ridges having hollow portions and a flat base, the hollow ridges are formed to protrude side by side on the base, the hollow ridges have a pair of side walls erected from the base, and an end opposite the base is closed, an air communication passage is provided to connect the hollow portions of adjacent hollow ridges, a through hole is provided in the base at the portion where the hollow ridges are provided, and a protrusion that protrudes opposite the hollow ridges is provided on the base so as to separate the base and the claw member, and the communication passage is formed by the separated space and the through hole (fourth invention).
The present invention also provides a gripper having claw members that can be opened and closed to grip an object to be gripped, and a grip member attached to the claw members so as to come into contact with the object to be gripped when gripping the object, wherein the grip member includes a plate-shaped elastic member made of resin, the elastic member having a plurality of hollow protrusions each having a hollow portion and a flat base, the hollow protrusions being formed to protrude so as to be scattered on the base, the hollow protrusions having a hollow cylindrical side wall erected from the base, and an end opposite the base being closed, an air communication passage is provided to connect the hollow portions of adjacent hollow protrusions, the base has a through hole in the portion where the hollow protrusions are provided, and a breathable sheet material is provided adjacent to the base, and the communication passage is constituted by the breathable sheet material and the through hole (a fifth invention).
The present invention also provides a gripper having claw members that can be opened and closed to grip an object to be gripped, and a grip member attached to the claw members so as to come into contact with the object to be gripped when gripping the object, wherein the grip member includes a plate-shaped elastic member made of resin, the elastic member having a plurality of hollow ridges having hollow portions and a flat plate-shaped base, the hollow ridges are formed to protrude side by side on the base, the hollow ridges have a pair of side walls erected from the base, and an end opposite the base is closed, an air communication passage is provided to connect the hollow portions of adjacent hollow ridges, a through hole is provided in the base at the portion where the hollow ridges are provided, and a breathable sheet material is provided adjacent to the base, and the communication passage is formed by the breathable sheet material and the through hole (a sixth invention).

According to the gripper of the present invention (the first to sixth inventions ), the hollow protrusions and hollow ridges having hollow portions can be flexibly deformed, so that the object to be gripped can be flexibly gripped. In addition, since an air passage is provided that connects the hollow portions of the hollow protrusions and hollow ridges, the hollow protrusions and hollow ridges that are crushed during gripping are prevented from sticking to the claw members like suction cups, so that repeated gripping can be performed reliably. Furthermore, according to the first or second invention , the holding force is also increased. Furthermore, according to the first to sixth inventions , such excellent grippers can be easily manufactured.

FIG. 1 is a schematic diagram of an industrial robot equipped with a gripper according to the present invention. 1A and 1B are diagrams illustrating a configuration of a gripper according to the present invention. 3 is a cross-sectional view showing the structure of a claw member and a grip member of the gripper according to the first embodiment of the present invention. FIG. FIG. 2 is a perspective view of an elastic member in the gripper according to the first embodiment of the present invention. 4 is a cross-sectional view showing a deformation state of a gripping member when an object to be gripped is gripped by the gripper of the first embodiment of the present invention. FIG. 10A and 10B are cross-sectional views showing deformations of the gripping member when an object to be gripped is gripped by the gripper of the reference example. 13A to 13C are diagrams showing other examples of the arrangement of hollow protrusions and communication passages. 13A to 13C are a front view, a cross-sectional view, and a rear view of an elastic member used in a gripper according to a second embodiment of the present invention. 13 is a cross-sectional view showing the structure of a claw member and a grip member of a gripper according to a third embodiment of the present invention. FIG. 13A to 13C are a front view, a cross-sectional view, and a perspective view of an elastic member used in a gripper according to a fourth embodiment of the present invention. 11A and 11B are diagrams illustrating deformation of a cushion member when an object to be gripped is gripped by a conventional gripper.

The following describes an embodiment of the invention, taking as an example a gripper attached to an industrial robot, with reference to the drawings. Note that the invention is not limited to the specific embodiment shown below, and can be implemented by modifying its form. For example, the gripper of the present invention can be used not only in industrial robots, but also in robots used in homes, hospitals, etc.

Figure 1 is a schematic diagram of an industrial robot equipped with a gripper 10 according to a first embodiment of the present invention. Gripper 10 is attached to the tip of arm A of the robot when in use. The specific type and form of the robot arm are not particularly limited. Arm A may be a multi-joint type or a parallel moving arm.

Figure 2 is a diagram showing the configuration of the gripper 10 of the present invention. The gripper of the present invention can grip a gripping object 99 (also described as a work object) by opening and closing the gripper, and an industrial robot equipped with the gripper of the present invention can grip and transport the gripping object.

The gripper 10 has a drive unit 19 and claw bases 18, 18. The drive unit 19 is provided with a power device (e.g., a motor, a pressure cylinder, etc.) and a mechanism (e.g., a reduction mechanism, a link, a cam, etc.) that causes the claw bases 18, 18 to open and close, thereby opening and closing the claw members 11, 11 and the grip members 12, 12, which will be described later. For example, in this embodiment, the drive unit 19 is configured to combine an electric motor and a ball screw so that the claw bases 18, 18 open and close in parallel. The specific configuration and mechanism of the drive unit 19 and the claw bases 18 are not particularly limited, and may open and close the claw members and grip members in parallel, or may open and close in a compass-like manner. In addition, the claw bases 18, 18 are not essential, and the drive unit 19 may directly open and close the claw members 11, 11, which will be described later. If the claw bases 18, 18 are provided, it is convenient because it is easy to replace the claw members 11 and the grip members 12 in the gripper 10.

The gripper 10 has claw members 11, 11 and grip members 12, 12. The claw member 11 is provided so as to be openable and closable so that the gripper 10 can grip the object to be gripped 99. In this embodiment, the claw member 11 is attached to the claw base 18 by a screw or the like, so as to be openable and closable. The grip member 12 is attached to the claw member 11, and opens and closes together with the claw member. In addition, the grip member 12 is provided so as to come into direct contact with the object to be gripped 99 when gripping the object to be gripped 99.

The direction in which the claw members 11 and the gripping members 12 move in association with the gripping operation of the gripper 10 will be referred to as the “gripping direction.” In Fig. 2, the gripping direction is the left-right direction in the figure.
In this embodiment, two claw members 11 and two grip members 12 are provided to form a pair. As a result, an object to be grasped placed between the grip members 12, 12 is grasped between the grip members 12, 12 as the gap between the claw members 11, 11 narrows. The number of claw members 11 and grip members 12 is not limited to two, and may be one, or three or more.

The configurations of the claw members 11 and the grip members 12 will be described in more detail below.
Fig. 3 is a cross-sectional view showing the structure of the claw member 11 and the gripping member 12 in the gripper 10 of the first embodiment. The upper left diagram of Fig. 3 is a cross-sectional view taken from a viewpoint corresponding to the claw member 11 and the gripping member 12 on the left side in Fig. 2. In the upper left diagram of Fig. 3 and the lower left diagram of Fig. 3 (X-X cross-sectional view), the gripping direction is the left-right direction of the diagram, and in the upper right diagram of Fig. 3 (Y-Y cross-sectional view), the gripping direction is the depth direction of the paper.

The claw member 11 is formed of a harder material than the grip member 12, such as metal or plastic, so that the opening and closing movement of the claw base 18 provided by the drive unit 19 is efficiently transmitted to the grip member 12. Although not essential, it is preferable that the claw member 11 is configured so that when gripping is performed by the gripper 10, the grip member 12 is sandwiched between the claw member 11 and the object to be gripped 99, and the claw member 11 pushes the object to be gripped 99 via the grip member 12.

The gripping members 12 are more flexible than the claw members 11, and when the gripper 10 grips the object 99, the gripping members 12 deform as the object 99 is gripped.
The gripping member 12 includes an elastic member 131. Preferably, but not necessarily, the gripping member 12 also includes a gripping layer 121. When the gripping layer 121 is provided, the gripping member 12 is configured in a structure in which the gripping layer 121 and the elastic member 131 are arranged in order from the side of the object to be gripped (99).

The elastic member 131 is formed from a resin so as to have flexibility that allows elastic deformation when gripping the gripping object 99. The resin constituting the elastic member 131 may be rubber, a thermoplastic elastomer, a thermoplastic resin, a thermosetting resin, or the like. Although not limited, typically, the resin constituting the elastic member 131 is rubber or elastomer, and it is preferable that the hardness of the resin is about 50 degrees to 85 degrees in Duro A hardness. Also, although not essential, it is preferable that the hardness of the resin constituting the elastic member 131 is higher than the hardness of the resin constituting the gripping layer 121, as in this embodiment.

The elastic member 131 is plate-shaped. The elastic member 131 has a flat base 132 and a plurality of hollow protrusions 133, 133 having hollow portions 133V. The hollow protrusions 133, 133 are formed to protrude from the base 132 so as to be scattered at predetermined intervals. In this embodiment, the hollow protrusions 133, 133 are scattered in an orthogonal lattice pattern. A perspective view of the elastic member 131 having a plurality of hollow protrusions 133, 133 standing on the base 132 is shown in Figure 4.
Although not required, in this embodiment, the elastic member 131 is attached to the claw member 11 so that the base 132 is positioned on the claw member 11 side and the tip side (one end) 131a of the protruding hollow protrusion 133 is positioned on the side of the object to be grasped (99).

The hollow protrusion 133 has a cylindrical side wall 134. The side wall 134 is arranged in a cylindrical shape so as to rise from the flat base 132 in the thickness direction of the base. The internal space of the cylindrical side wall 134 forms the hollow portion 133V of the hollow protrusion 133. The side wall 134 is typically arranged in a cylindrical shape. The side wall 134 may be in the shape of a square tube. The side wall 134 may be arranged in a tapered shape.

The hollow projection 133 has an end opposite the base 132 that is closed by a top 135. The top 135 is provided to close the tip of the side wall 134. In this embodiment, the top 135 is provided in a flat plate shape that is approximately parallel to the base 132. The top 135 may be provided in a hemispherical, dome-like, or conical shape. The top 135 may also have a protrusion or a recess.

In the elastic member 131, air communication passages 137, 137 are provided to connect the hollow portions 133V, 133V of adjacent hollow protrusions 133, 133. In this embodiment, the communication passage 137 is a tunnel-shaped passage provided between the side walls 134, 134 of adjacent hollow protrusions 133, 133. Although not essential, it is preferable that the communication passage 137 is provided in a straight line between the hollow protrusions 133, 133, as in this embodiment.

In this embodiment, the communication passage 137 is defined by a passage wall 138. The passage wall 138 has, for example, an inverted U-shaped cross section, and stands upright from the base 132. At the portion where the passage wall 138 and the hollow protrusion 133 are connected, a hole is provided in the side wall 134 of the hollow protrusion, and the hollow portion 133V of the hollow protrusion and the communication passage 137 are in communication. The cross-sectional shape of the passage wall 138 is not particularly limited, and may be an inverted V-shape, an arc shape, or a rectangle.

Also, preferably, the air communication passages 137, 137 are provided in a network shape so as to two-dimensionally connect the scattered hollow protrusions 133, 133.
Although communication passages 137, 137 may be provided so that all of the hollow protrusions are mutually connected, a plurality of hollow protrusions may be divided into several groups, and air communication passages 137, 137 may be provided so that hollow portions within the same group are connected. Also, there may be hollow protrusions without communication passages.

Although not essential, preferably, as in this embodiment, a tunnel-shaped communication passage 137 is provided to connect the hollow protrusion 133 provided on the peripheral portion of the elastic member to the peripheral edge E of the elastic member, and the communication passage 137 is open at the peripheral edge E of the elastic member 131.

Although not essential, in this embodiment, the elastic member 131 is configured by integrally molding the base 132 and the hollow protrusions 133 into a single continuous sheet. In other words, holes are formed in the base 132 at the portions where the hollow protrusions 133 are provided. The elastic member 131 in this form can be molded by injection molding, vacuum forming, press molding, or the like.

Although not required, as in this embodiment, the grip member 12 may have a gripping layer 121. The gripping layer 121 is a layer provided so as to come into contact with an object to be gripped. In addition, the outer surface of the gripping layer 121 will hereinafter be referred to as a gripping surface 12S.
The gripping layer 121 is a layer formed in a flat plate shape. Preferably, the gripping layer 121 is made of a resin having a durometer A hardness of 30 to 80 HDA according to JIS-K6253. When the gripping layer 121 is made of a resin, the resin constituting the gripping layer 121 may be a rubber such as silicone rubber, acrylonitrile butadiene rubber, or urethane rubber, or a thermosetting resin, or a thermoplastic elastomer such as an olefin-based thermoplastic elastomer or a styrene-based thermoplastic elastomer, or a thermoplastic resin such as a soft polyvinyl chloride resin or a polyvinyl acetate resin (EVA resin). These resins may contain various additives, fillers, and the like, as necessary.

The material constituting the gripping layer 121 is not limited to resin. Even if the material constituting the gripping layer 121 contains a somewhat hard material, if the thickness of the gripping layer 121 is made thin, for example 0.3 to 1 mm, the gripping layer 121 can be made flexibly deformable in the gripping direction. Examples of other materials or ingredients constituting the gripping layer include materials in which resin is applied to or impregnated into a cloth material (for example, artificial leather material or tarpaulin material), and laminated materials in which cloth (woven fabric or nonwoven fabric), paper, resin sheets, etc. are laminated. Of course, the gripping layer 121 may be composed of a single layer.

In addition, although not required, in this embodiment, the elastic member 131 is provided so that the tip 131a of the hollow protrusion abuts the gripping layer 121. Although not required, the elastic member 131 may be adhered to the gripping layer 121. Furthermore, the elastic member 131 may be adhered to, welded to, or integrally molded with the gripping layer 121.

By placing the elastic member 131 behind the gripping layer 121 while abutting against the gripping layer 121, the areas where the tips 131a of the hollow protrusions of the elastic member 131 come into contact with the gripping layer 121 and the areas where the elastic member 131 does not come into contact with the gripping layer 121 are distributed in an island-like pattern when viewed along the gripping direction. The gripping layer 121 can flexibly deform in the gripping direction, but at the areas where it comes into contact with the elastic member 131, the gripping layer 121 is supported by the elastic member 131, limiting deformation in the gripping direction. The combination of the elastic member and gripping layer that forms such an island-like structure contributes to increasing flexibility and holding power.

Although not essential, the grip member 12 is preferably configured to include an outer skin member 120, as in this embodiment. In this embodiment, the outer skin member 120 is a member having a hollow structure, a part of which is configured to become the gripping layer 121. It is preferable that the elastic member 131 is disposed inside the outer skin member 120 (the hollow portion of the hollow structure).

Furthermore, although not essential, preferably, as in this embodiment, the grip member 12 is provided with an air vent 124 through which air inside the outer cover member 120 escapes to the outside of the outer cover member when the gripping object 99 is gripped. The provision of the air vent 124 promotes flexible deformation of the grip member 12 when gripping the gripping object.
In this embodiment, one side of the outer cover member 120 formed in a hollow box shape is removed, and this portion serves as the ventilation hole 124. The specific shape of the ventilation hole may be other shapes.

Although not required, the outer cover member 120 of the grip member 12 in this embodiment may have the following configuration: The outer cover member 120 is integrally molded into a box-like hollow shape having a flat wall (hereinafter also referred to as a “gripping wall”) that serves as a gripping layer 121 and side walls 122 and 123.
Here, the side walls 122, 123 of the outer cover member refer to walls extending along the opening/closing direction (gripping direction) of the gripping operation, and the side walls 122, 123 extend in the opposite direction to the gripping object 99 with respect to the gripping wall (121). The side walls 122, 123 extending along the gripping direction are preferably provided in a flat or cylindrical shape.

The flat gripping layer 121 does not need to be a completely flat plate; even a gripping layer with a slightly curved or spherical surface that is slightly convex or concave is included in the flat gripping layer as long as it is generally flat.
Furthermore, the gripping surface 12S where the gripping layer 121 comes into contact with the gripped object 99 may be provided with a background pattern such as protrusions, holes, ridges, grooves, checkering, dot patterns, matte finish, wrinkles, or grains in order to adjust the frictional force or surface adhesion. When the gripping surface 12S side of the gripping layer 121 is made of resin, granular materials such as silica particles or rubber particles may be kneaded into the resin so that the granular materials are exposed on the gripping surface 12S. Alternatively, the gripping surface 12S may be provided with a surface layer made of a material different from the gripping wall, such as silicone rubber, EVA resin, nonwoven fabric, or resin film (polyimide film, PET film, etc.).

The integration (attachment) of the grip member 12 and the claw member 11 is not particularly limited. In this embodiment, the outer cover member 120 is provided with an attachment section 125 with a bag-shaped hole, and the claw member 11 is inserted into the hole of the attachment section 125 to integrate the grip member 12 and the claw member 11. If necessary to prevent falling off, the outer cover member 120 and the claw member 11 may be screwed together, or the two may be fixed together with an adhesive, a pressure-sensitive adhesive, or an adhesive tape. Alternatively, the elastic member 131 and the gripping layer 121 may be integrated with the claw member 11 in sequence using an adhesive or the like to form the grip member 12 and integrate it with the claw member 11.

A method for manufacturing the members constituting the gripper 10 will be described.
The driving unit 19, the claw base 18, the claw member 11, etc. can be manufactured in the same manner as the members of a conventionally known industrial robot. The gripping layer 121 (outer cover member 120) of the grip member 12 can be manufactured by injection molding, cast molding, or the like, of a rubber material or a thermoplastic elastomer material. The elastic member 131 of the grip member 12 can be manufactured by injection molding of a rubber material or a thermoplastic elastomer material, or by pressing a sheet material of a rubber material or a thermoplastic elastomer material. The obtained elastic member 131 is pushed into the inside of the outer cover member 120 to integrate them so that they do not come off each other, and the above-mentioned grip member 12 is obtained.

The effects of the gripper 10 of the first embodiment will be described.
According to the gripper 10, when gripping the gripping object 99, the hollow protrusions 133, 133 of the elastic member 131 are deformed in a crushing manner to grip the gripping object 99, so that the gripping object can be flexibly gripped. If the gripping object can be flexibly gripped, it becomes possible to grip gripping objects of various shapes in various postures, and the robustness of the gripping operation is improved.

Figure 5 shows the deformation state of the grip member when the gripper 10 of this embodiment grips the gripping object 99. In particular, in the gripper 10, the hollow protrusion 133 has a hollow cylindrical side wall 134 erected from the base 132, and the end opposite the base is closed. Furthermore, an air communication passage 137 is provided to connect the hollow portions 133V, 133V of the adjacent hollow protrusions. Therefore, when the hollow protrusion 133 is crushed in conjunction with gripping, the air in the hollow portion 133V of the hollow protrusion is not trapped but can flow to the adjacent hollow protrusion and even to the outside space. In Figure 5, such air flow is indicated by arrows. Therefore, the air is prevented from being trapped and hindering the deformation of the hollow protrusion 133, and the hollow protrusion 133 can be flexibly deformed.

In addition, an air communication passage 137 is provided to connect the hollow portions 133V of the hollow protrusions 133, so that when the grip is released, air is returned to the hollow portions 133V through the communication passage 137, preventing the hollow protrusions that are crushed during gripping from sticking to the claw members, etc., like suction cups, and ensuring repeated gripping.

Figure 6 shows a deformed form of the gripper of the reference example when gripping an object to be gripped 99. The gripper of the reference example differs from the gripper 10 of the first embodiment in that the elastic member 931 does not have a communication passage 137, but in other respects it has roughly the same configuration. With the gripper of the reference example, even if the grip is released from the gripping state of Figure 6, the crushed hollow protrusion 933 is difficult to restore. This is because air is difficult to return to the hollow portion 933V, and the crushed hollow protrusion 933 sticks to the claw member 11, outer skin member 120, etc. like a suction cup.

As in the reference example, if the crushed hollow protrusion 933 is difficult to restore, when gripping is repeated, the gripping member will not be able to restore in time after the grip is released, and the next gripping operation will begin with the gripping member in a crushed state, which can easily compromise the reliability of repeated gripping.

On the other hand, according to the gripper 10 of the first embodiment described above, since the communication passage 137 is provided, when the grip is released, air is supplied to the hollow portion 133V of the hollow protrusion 133 that was crushed through the communication passage 137, making it easier for the hollow protrusion to return to its original shape. Therefore, repeated gripping can be performed reliably.

As described above, with the gripper of the first embodiment, the object to be grasped can be grasped flexibly, and the hollow protrusions that are crushed during grasping are prevented from sticking to the claw members, etc., like suction cups, thereby ensuring repeated grasping.
In the above embodiment, an example was shown in which the gripping layer 121 is disposed between the elastic member 131 and the object to be gripped (99), but the above effect is also obtained in an embodiment in which there is no gripping layer.

In addition, although not essential, if the communication passage 137 is a tunnel-shaped passage extending between the side walls 134, 134 of adjacent hollow protrusions 133, 133, as in the gripper 10 of this embodiment, the holding force when gripping the object to be gripped 99 is also improved.

Here, the holding force when gripping the object to be gripped 99 refers to the magnitude of the force that can resist when attempting to move the object to be gripped in a direction perpendicular to the gripping direction (for example, the up and down direction in Figure 2). If the holding force is weak, the object to be gripped 99 will easily fall even if you try to lift it vertically upwards with the gripper in the position shown in Figures 1 and 2.

Figure 11 shows a gripper equipped with conventional cushioning materials (e.g., urethane sponge) 82, 82 at the tips of claw members 81, 81 as described in Patent Document 1. However, in this conventional technology, the holding force depends solely on the frictional force between the cushioning material 82 and the object to be gripped. Therefore, if the cushioning material 82 is soft, the cushioning material is likely to deform in a direction perpendicular to the gripping direction, reducing the holding force, and the object to be gripped 99 is likely to slip and easily fall off. In other words, with conventional cushioning materials known in the art, it was not possible to improve both the softness of the cushioning material and the holding force of the gripper.

In the gripper of the first embodiment described above, as shown in FIG. 5, when an object to be grasped is grasped, the object to be grasped 99 enters between the hollow protrusions 133, 133 spaced at a predetermined distance, i.e., into the sea part of the sea-island structure, and is grasped by the gripper 10. In this state, even if the object to be grasped tries to slip out in the vertical direction of FIG. 5, the hollow protrusions 133 catch on the object to be grasped, thereby increasing the holding force.

If the communication passage 137 is a tunnel-shaped passage provided between the side walls 134, 134 of adjacent hollow protrusions 133, 133, as in the gripper 10 of this embodiment, the passage wall 138 that defines the tunnel passage connects the side walls 134, 134 of the hollow protrusion, and the hollow protrusion 133 is supported in the vertical direction in FIG. 5, thereby increasing the rigidity of the hollow protrusion 133 (rigidity in the vertical direction in FIG. 5). As a result, even if a force acts in a direction that causes the gripped object to slip out from the gripping state in FIG. 5, the hollow protrusion is more reliably prevented from falling over and causing the gripped object to slip out. In other words, the holding force is further increased.

Furthermore, when the gripper 10 has a gripping layer 121, as in the first embodiment described above, the gripping layer 121 deforms to adhere closely to the surface of the object to be gripped 99, as shown in FIG. 5, so that a sufficiently large frictional force can be generated between the gripping layer 121 and the object to be gripped 99, thereby particularly enhancing the holding force.

From the viewpoint of further increasing the holding power, it is preferable that the gripping layer 121 is made of a resin having a duro A hardness of 30 to 80 HDA in accordance with JIS-K6253, the elastic member is made of a resin, and the hardness of the resin constituting the elastic member is higher than the hardness of the resin constituting the gripping layer and the hardness of the resin constituting the support. In this way, the grip member 12 becomes more flexible, and the portion in contact with the elastic member 131 firmly supports the gripping layer 121 from the back side, making it easier for the gripping layer 121 to hook onto the object to be gripped 99, thereby increasing the holding power.

Furthermore, if the communication passage 137 is a tunnel-shaped passage provided between the side walls 134, 134 of adjacent hollow protrusions 133, 133 as in this embodiment, the communication passages 137, 137 are already built into the elastic member 131, and the gripper configuration including the communication passage 137 is completed simply by attaching the elastic member 131 to the claw member 11, making it easier to manufacture an excellent gripper.

Furthermore, from the viewpoint of easily integrating the elastic member 131 with the gripping layer 121, it is preferable that, as in this embodiment, the grip member 12 is configured to include the outer skin member 120, the outer skin member 120 is configured to have a hollow structure so that a part of the outer skin member 120 becomes the gripping layer 121, and the elastic member 131 is disposed inside the outer skin member 120 (hollow portion).

The invention relating to the gripper 10 of the first embodiment described above is not limited to the above embodiment, and can be implemented with various modifications. Other embodiments of the invention are described below, but in the following description, the differences from the above embodiment will be mainly described, and similar parts will be given the same numbers and will not be described in detail. Furthermore, these embodiments can be implemented by combining parts with each other or by replacing parts.

The specific configuration of the elastic member 131 in the above embodiment can be changed. In the above description of the first embodiment, the form of the elastic member 131 in which the hollow protrusions 133, 133 are arranged on the intersections of an orthogonal lattice is exemplified, but the planar pattern in which these hollow protrusions 133, 133 are arranged as viewed along the gripping direction may be a planar pattern in which the hollow protrusions 133, 133 are located at each vertex of a virtual tile of triangles or hexagons. Figure 7 illustrates a planar pattern of the arrangement of the hollow protrusions 133, 133 and the communication passages 137, 137 as viewed along the gripping direction as a modified example of the elastic member. Figure 7 shows an example in which the cylindrical hollow protrusions 133, 133 are arranged in a planar pattern like a tile of equilateral triangles, and the communication passages 137, 137 are provided to connect the hollow protrusions in an equilateral triangular pattern. In this embodiment, some of the communication passages connect the hollow protrusions 133 and the periphery of the elastic member (the upper edge of the figure). Additionally, the hollow protrusions 133, 133 may be randomly scattered on the base.

8A and 8B are a front view, a sectional view, and a rear view of an elastic member 231 used in the gripper of the second embodiment. The elastic member 231 can configure the gripper in a similar manner to the elastic member 131 of the first embodiment.
8 is similar to the elastic member 131 of the first embodiment in that hollow protrusions 233, 233 having hollow portions in a predetermined planar pattern are formed to protrude from a flat base 232. In the elastic member 231 shown in FIG. 8, a through hole 234 is further provided in the base 232 at the portion where the hollow protrusion 233 is provided, and the hollow portion 233V of the hollow protrusion 233 communicates with the space on the rear side of the base 232.

Furthermore, the base 232 is provided with protrusions 235, 235 that protrude on the side opposite the hollow protrusion 233. The protrusions 235 are typically provided around the through hole 234 or between the hollow protrusions. Due to the presence of the protrusions 235, 235, when the elastic member 231 is attached to the claw member 11, the base 232 and the claw member 11 are not in close contact with each other but are spaced apart.

In the gripper of the second embodiment, the space S, i.e., the space S created by the separation of the claw member 11 and the base 232, and the through hole 234 form an air communication passage.

With this configuration, even when the elastic member 231 of this embodiment is used, the hollow portions 233V, 233V of the hollow protrusions 233, 233 are connected to each other, allowing air to flow between them. Therefore, by providing such an elastic member 231, the hollow protrusions become flexible and the elastic member has particularly good restoring properties, improving the reliability of the grip when gripping repeatedly.

The specific shape of the protrusions 235, 235 provided on the back side of the base 232 is not particularly limited, and may be dot-shaped, or may be an oval or string-shaped protrusion. From the viewpoint of improving the restoring ability of the elastic member, it is sufficient that these protrusions 235 are provided so as not to form a seal line that would impede the flow of air.

Furthermore, as in this embodiment, the base 232 has a through hole 234 in the portion where the hollow protrusion 233 is provided, and the base 232 has a protrusion 235 that protrudes on the opposite side of the hollow protrusion 233, so that the base 232 and the claw member 11 are spaced apart, and if the space S and the through hole 234 form the communication passage, then simply attaching the elastic member 231 to the claw member 11 completes the structure of the gripper including the communication passage, making it easier to manufacture an excellent gripper.

9 shows a cross-sectional view of the claw members and gripping members of the gripper of the third embodiment. The gripper of the third embodiment has the same configuration as the gripper of the first embodiment, except that the shape of the elastic member 331 is different and that a breathable sheet material 335 is provided.
The elastic member 331 of this embodiment has a flat base 332 and a plurality of hollow protrusions 333, 333 having hollow portions. The hollow protrusions 333, 333 are formed to protrude from the base 332 so as to be aligned at predetermined intervals. The base 332 has through holes 334, 334 in the portions where the hollow protrusions 333, 333 are provided.

The breathable sheet material 335 is provided adjacent to the base 332. The breathable sheet material 335 may be any material that allows air to pass through in the thickness direction and in the in-plane direction of the sheet, and examples of such materials include woven fabric, nonwoven fabric, cotton, and foamed resin sheets with an open-cell structure. In this embodiment, the through holes 334, 334 and the breathable sheet material 335 form an air communication passage. With this configuration, the hollow portions 333V, 333V of the hollow protrusions 333, 333 communicate with each other, allowing air to flow between them. Therefore, with such a gripper, the hollow protrusions become flexible and the elastic member has particularly good restoring properties, improving the reliability of gripping when gripping repeatedly.

Furthermore, as in this embodiment, if the base 332 has a through hole 334 in the portion where the hollow protrusion 333 is provided, and a breathable sheet material 335 is provided adjacent to the base 332, and a communication passage is formed by the breathable sheet material 335 and the through hole 334, then the gripper configuration including the communication passage can be completed simply by attaching the elastic member 331 and the breathable sheet material 335 to the claw member 11, making it easier to manufacture an excellent gripper.

Figure 10 shows a front view, a cross-sectional view, and a perspective view of an elastic member 431 used in a gripper of the fourth embodiment. This elastic member 431 can be used to configure a gripper in a similar form to the elastic member 131 of the first embodiment. The elastic member 431 shown in Figure 10 has a flat base 432 and multiple hollow ridges 433, 433 having a hollow portion. The hollow ridges 433, 433 are formed to protrude from the base 432 so as to be aligned at a predetermined interval. The hollow ridges 433 may be linear or may be broken lines. In this embodiment, they are curved, particularly arc-shaped. The interval between the hollow ridges 433, 433 may be constant, but may also vary, and the interval between each ridge may be different.

Although not required, the hollow ridge 433 has a hollow first ridge portion 434 extending from the base 432, a plate-shaped step portion 435 arranged in a stepped manner, and a second ridge portion 436 extending from the center side of the ridge of the step portion 435 in a direction away from the base 432.
In the hollow ridge 433, the inner width D3 of the cylindrical first ridge portion 434 is made larger than the outer width D4 of the second ridge portion 436, and when the object to be grasped is grasped, the hollow ridge 433 is compressed, and a part of the second ridge portion 436 fits inside the first ridge portion 434, forming a stepped hollow ridge.

By providing the elastic member 431 with hollow ridges 433, 433 of this configuration, the gripper of the fourth embodiment, like the first embodiment, particularly enhances the flexibility of the gripping member. Note that it is not essential that the hollow ridges are stepped, and it is sufficient that the hollow ridges 433 have a pair of side walls erected from the base 432 and that the end opposite the base 432 is closed. When the hollow ridges 433 are stepped, as in this embodiment, flexibility is particularly enhanced.

When the hollow protrusion is formed in an arc shape as in this embodiment, it is preferable to attach it to the gripper so that the arc is convex vertically downward during the gripping operation. In this way, the holding force is particularly high.

Also in this embodiment, communication passages 437, 437 are provided that communicate between the hollow portions 433V, 433V of the adjacent hollow ridges 433, 433. The communication passage 437 may be, for example, an inverted U-shaped passage wall 438 that connects the side walls of the adjacent hollow ridges 433, 433, similar to the communication passage in the elastic member in the first embodiment.
By providing the communication passage, the elastic member 431 becomes more flexible and the hollow ridges 433 have better restoring properties when the grip is released, improving the reliability of gripping when gripping repeatedly.

The elastic member 431 of this embodiment is preferably used in conjunction with the gripping layer 121. Also, the elastic member 431 of this embodiment is preferably attached to the claw member 11 so that the base 432 is located on the side of the claw member 11 and the hollow ridge 433 protrudes in the direction toward the object to be gripped.

In the explanation of the fourth embodiment, an example was shown in which the hollow ridges 433, 433 provided on the elastic member are formed in a stepped shape, but the hollow protrusions 133 (233) and the like in the elastic members of the first and second embodiments may also be formed in a stepped hollow protrusion configuration, thereby particularly enhancing the flexibility of the hollow protrusions.

In addition, an elastic member 431 having hollow ridges 433, 433 as in the fourth embodiment may be provided with a protrusion (235) as in the second embodiment (Figure 8), and the base 432 on which the hollow ridges 433 are provided may be separated from the claw member, and the space created may be utilized to form a communication passage.
In addition, an elastic member 431 having hollow ridges 433, 433 as in the fourth embodiment may be provided with a breathable sheet material (335) as in the third embodiment (Figure 9), and a communication passage may be formed by utilizing a portion of the breathable sheet material.
In these modified examples as well, the object to be grasped can be grasped flexibly and repeatedly and reliably.

Furthermore, the specific configuration of the communication passage is not limited to that exemplified in the above embodiment. For example, the elastic member 331 used in the third embodiment of FIG. 9 may be further provided with a groove, and the groove portion may serve as the communication passage. In this case, the groove is provided on the surface of the base 332 facing the claw member so as to connect the hollow portions 333V, 333V. Such a groove similarly connects the hollow portions of the elastic member, thereby achieving the same effect.

In addition, in the above embodiment, the communication passage is built into the elastic member, or is provided between the elastic member and the claw member, but the manner in which the communication passage is provided is not limited to these. For example, grooves, holes, or passages that will become part of the communication passage may be provided in the outer cover member or the claw member, and these grooves, holes, or passages may be used to communicate with the hollow parts of the elastic member.

In the above embodiment, the claw member is mainly a hard member, but the claw member is not particularly limited as long as the gripping force can be transmitted to the object to be gripped via a flexible grip member between the claw member and the object to be gripped. For example, the claw member may be a highly rigid member such as metal or hard plastic, but it may also be made of rubber or soft plastic. The claw member may also be hollow and gas or liquid may be poured inside to change the rigidity of the claw member. The claw member may also have a movable part and be configured to be capable of active deformation such as bending.

The shape and properties of the object to be grasped by the gripper are not particularly limited, so long as the object can be grasped. The gripper of the above embodiment is highly flexible, so it is possible to grasp objects of various shapes, such as rectangular parallelepipeds, cylinders, polygonal pyramids, polyhedrons, spheres, and ellipsoids, in a variety of positions.

Grippers are attached to the end of robot arms and can be used, for example, for transport tasks, making them highly useful in industry.

A robot arm 10 gripper 11 claw member 12 grip member 120 outer cover member 121 gripping layer 131 elastic member 132 base 133 hollow protrusion 133V hollow portion 134 side wall 137 communication passage 138 passage wall 99 object to be gripped

Claims (6)

A claw member that is provided so as to be able to open and close so as to grip an object to be gripped;
a gripping member attached to the jaw member so as to come into contact with the object to be gripped when gripping the object,
The grip member includes a plate-shaped elastic member made of resin,
The elastic member has a plurality of hollow protrusions each having a hollow portion and a flat base portion.
The hollow projections are formed so as to protrude from the base in a scattered manner,
The hollow protrusion has a hollow cylindrical side wall extending from a base portion,
The end opposite the base is closed,
An air communication passage is provided to connect the hollow portions of the adjacent hollow projections ,
The communication passage is a tunnel-shaped passage provided between the side walls of the hollow protrusions adjacent to each other.
Gripper. A claw member that is provided so as to be able to open and close so as to grip an object to be gripped;
a gripping member attached to the jaw member so as to come into contact with the object to be gripped when gripping the object,
The grip member includes a plate-shaped elastic member made of resin,
The elastic member has a plurality of hollow ridges having hollow portions and a flat base portion,
The hollow protrusions are formed in a line on the base,
The hollow ridge has a pair of side walls extending from a base portion,
The end opposite the base is closed,
An air passage is provided to connect the hollow portions of the adjacent hollow ridges ,
The communication passage is a tunnel-shaped passage provided between the side walls of the adjacent hollow ridges.
Gripper. A claw member that is provided so as to be able to open and close so as to grip an object to be gripped;
a gripping member attached to the jaw member so as to come into contact with the object to be gripped when gripping the object,
The grip member includes a plate-shaped elastic member made of resin,
The elastic member has a plurality of hollow protrusions each having a hollow portion and a flat base portion.
The hollow projections are formed so as to protrude from the base in a scattered manner,
The hollow protrusion has a hollow cylindrical side wall extending from a base portion,
The end opposite the base is closed,
An air communication passage is provided to connect the hollow portions of the adjacent hollow projections,
The base has a through hole in a portion where the hollow protrusion is provided,
The base portion is provided with a protrusion protruding on a side opposite to the hollow protrusion, so that the base portion and the claw member are spaced apart from each other.
The space and the through hole form the communication passage.
Gripper. A claw member that is provided so as to be able to open and close so as to grip an object to be gripped;
a gripping member attached to the jaw member so as to come into contact with the object to be gripped when gripping the object,
The grip member includes a plate-shaped elastic member made of resin,
The elastic member has a plurality of hollow ridges having hollow portions and a flat base portion,
The hollow protrusions are formed in a line on the base,
The hollow ridge has a pair of side walls extending from a base portion,
The end opposite the base is closed,
An air passage is provided to connect the hollow portions of the adjacent hollow ridges,
The base portion has a through hole in a portion where the hollow protrusion is provided,
The base portion is provided with a protrusion protruding on a side opposite to the hollow protrusion so that the base portion and the claw member are spaced apart from each other.
The space and the through hole form the communication passage.
Gripper. A claw member that is provided so as to be able to open and close so as to grip an object to be gripped;
a gripping member attached to the jaw member so as to come into contact with the object to be gripped when gripping the object,
The grip member includes a plate-shaped elastic member made of resin,
The elastic member has a plurality of hollow protrusions each having a hollow portion and a flat base portion.
The hollow projections are formed so as to protrude from the base in a scattered manner,
The hollow protrusion has a hollow cylindrical side wall extending from a base portion,
The end opposite the base is closed,
An air communication passage is provided to connect the hollow portions of the adjacent hollow projections,
The base has a through hole in a portion where the hollow protrusion is provided,
A breathable sheet material is provided adjacent the base;
The communication passage is formed by the breathable sheet material and the through holes.
Gripper. A claw member that is provided so as to be able to open and close so as to grip an object to be gripped;
a gripping member attached to the jaw member so as to come into contact with the object to be gripped when gripping the object,
The grip member includes a plate-shaped elastic member made of resin,
The elastic member has a plurality of hollow ridges having hollow portions and a flat base portion,
The hollow protrusions are formed in a line on the base,
The hollow ridge has a pair of side walls extending from a base portion,
The end opposite the base is closed,
An air passage is provided to connect the hollow portions of the adjacent hollow ridges,
The base portion has a through hole in a portion where the hollow protrusion is provided,
A breathable sheet material is provided adjacent the base;
The communication passage is formed by the breathable sheet material and the through holes.
Gripper.

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