JP2023101838A - Gripper - Google Patents

Abstract

To provide a gripper capable of ensuring repeated gripping while flexibly gripping an article to be gripped.SOLUTION: A gripper 10 comprises: a claw member 11; and a grip member 12. The grip member 12 includes a platelike elastic member 131 made of a resin. The elastic member 131 has a plurality of hollow projections 133, 133 having hollow parts 133V, and a flat platelike base 132. The hollow projections 133 are projectively formed to be dispersed on the base. The hollow projections 133 have hollow cylindrical side walls 134 erected from the base, and are closed at the tail ends opposite to the base 132. An air connection passage 137 is provided so as to connect the hollow parts 133V and 133V of the hollow projections 133 and 133 adjacent to each other.SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD The present invention relates to a gripper used in an industrial robot or the like, and more particularly to a gripper that grips a work object by opening and closing operations.

In recent years, industrial robots have been used for various purposes such as transporting and assembling parts. Industrial robots for so-called material handling, which transport work objects, have also been put to practical use. When an industrial robot transports a work object, 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. There are grippers that use magnetic force, suction force such as vacuum suction, and grippers that grip the work object by opening and closing operations.

As a gripper that grips a work object by opening and closing operations, for example, the gripper disclosed in Patent Document 1 is known. In the gripper disclosed in Patent Document 1, a leaf spring and a cushion material are opened and closed by an actuator. The gripper is disclosed to be capable of gripping and transporting objects with weak mechanical properties.

JP-A-7-276281

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

SUMMARY OF THE INVENTION It is an object of the present invention to provide a gripper capable of flexibly gripping an object to be gripped and reliably gripping it repeatedly.

As a result of intensive studies, the inventors have found that if the gripper becomes flexible, the reliability of repeated gripping tends to be impaired. They found that one of the reasons for this is that when gripping is repeated, the deformation of the grip member due to gripping cannot be restored in time, and the next gripping operation is started while the grip member is in a collapsed state. In addition, the inventors have found that when the grip member has a hollow portion, the phenomenon of delay in restoration tends to occur.
As a result of intensive studies, the inventor found that the above problems can be solved by providing an air communication passage so as to connect the hollow portions of the hollow projections and hollow ridges provided on the grip member, and 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 that is attached to the claw member so as to come into contact with the gripped object when gripping the gripped object, wherein the grip member includes a plate-like elastic member made of resin, the elastic member has a plurality of hollow projections having hollow portions, and a flat plate-shaped base, and the hollow projections are formed so as to protrude from the base. , which has a hollow cylindrical side wall erected from a base, an end opposite to the base is closed, and an air communication passage is provided so as to connect the hollow portions of adjacent hollow projections (first invention).

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

In the first invention or the second invention, preferably, the communication passage is a tunnel-shaped passage provided between side walls of mutually adjacent hollow projections or hollow ridges (third invention). In the first invention or the second invention, preferably, the base is provided with a through hole in a portion where the hollow projection or the hollow ridge is provided, and the base is provided with a projection projecting in the opposite direction to the hollow projection or the hollow ridge so that the base and the claw member are spaced apart, and the separated space and the through hole constitute the communication passage (fourth invention). In the first invention or the second invention, preferably, the base is provided with a through hole in a portion provided with a hollow projection or a hollow ridge, and an air permeable sheet material is provided adjacent to the base, and the air permeable sheet material and the through hole constitute the communication passage (fifth invention).

According to the gripper of the present invention (the first and second inventions), the hollow protrusions and hollow ridges having the hollow portion can be flexibly deformed, so that the gripping object can be flexibly gripped. In addition, since an air communication passage is provided to connect the hollow parts of the hollow protrusions and hollow ridges, it is possible to prevent the hollow protrusions and hollow ridges crushed during gripping from sticking to the claw members like suction cups, so that repeated gripping can be reliably performed. Furthermore, according to the third invention, the holding force is also enhanced. Further, according to the third, fourth, and fifth inventions, it becomes easier to manufacture such excellent grippers.

1 is a schematic diagram of an industrial robot equipped with a gripper of the present invention; FIG. It is a figure which shows the structure of the gripper of this invention. FIG. 4 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. 4 is a perspective view of an elastic member in the gripper of the first embodiment of the invention; FIG. 4 is a cross-sectional view showing a modified form of a grip member when gripping an object to be gripped by the gripper of the first embodiment of the present invention; FIG. 10 is a cross-sectional view showing a deformed form of a grip member when gripping an object to be gripped by the gripper of the reference example; FIG. 10 is a diagram showing another example of arrangement of hollow projections and connecting passages; FIG. 8A is 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; FIG. 11 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. 10A is 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; FIG. 10 is a diagram showing deformation of a cushion member when gripping an object to be gripped by a conventional gripper;

Embodiments of the invention will be described below with reference to the drawings, taking a gripper attached to an industrial robot as an example. In addition, the invention is not limited to the individual embodiments shown below, and can be implemented by changing the form. For example, the gripper of the present invention can be used not only for industrial robots, but also for robots used in homes, hospitals, and the like.

FIG. 1 is a schematic diagram of an industrial robot equipped with a gripper 10 according to the first embodiment of the present invention. The gripper 10 is used by being attached to the tip of the arm A of the robot. The specific form and form of the arm of the robot are not particularly limited. The arm A may be a multi-joint type or a parallel movement type arm.

FIG. 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 target 99 (also referred to as a work target) by opening and closing operations, and an industrial robot equipped with the gripper of the present invention can grip and transport the gripped target.

The gripper 10 has a drive portion 19 and claw bases 18,18. Claw bases 18, 18 are opened and closed by a power device (e.g., motor, pressure cylinder, etc.) and mechanisms (e.g., deceleration mechanism, link, cam, etc.) provided in drive unit 19, and claw members 11, 11 and grip members 12, 12, which will be described later, are opened and closed. For example, in this embodiment, an electric motor and a ball screw are combined to configure the drive unit 19 so that the claw bases 18, 18 open and close in parallel. The specific configuration and mechanism of the driving portion 19 and the claw base portion 18 are not particularly limited, and the claw members and grip members may be opened and closed in parallel, or may be opened and closed like a compass. Further, the claw bases 18, 18 are not essential, and the claw members 11, 11, which will be described later, may be directly driven to open and close by the driving portion 19. FIG. With the claw bases 18, 18, the claw member 11 and the grip member 12 of the gripper 10 can be easily replaced, which is convenient.

The gripper 10 has claw members 11,11 and grip members 12,12. The claw member 11 is provided to be openable and closable so that the gripper 10 grips the gripping target 99 . In this embodiment, the claw member 11 is attached to the claw base portion 18 with a screw or the like so that it can be opened and closed. The grip member 12 is attached to the pawl member 11 and opens and closes together with the pawl member. Also, the grip member 12 is provided so as to come into direct contact with the grasped object 99 when grasping the grasped object 99 .

The direction in which the claw member 11 and the gripping member 12 move as the gripper 10 grips is hereinafter referred to as the "gripping direction". In FIG. 2, the gripping direction is the horizontal direction in the drawing.
Further, in this embodiment, two claw members 11 and two grip members 12 are provided so as to form a pair. As a result, the object to be gripped placed between the grip members 12, 12 is gripped 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 member 11 and the grip member 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 grip member 12 in the gripper 10 of the first embodiment. The upper left figure in FIG. 3 is a sectional view from a viewpoint corresponding to the claw member 11 and the grip member 12 on the left side in FIG. In the upper left diagram of FIG. 3 and the lower left diagram of FIG. 3 (XX sectional view), the gripping direction is the horizontal direction of the diagram, and in the upper right diagram of FIG.

The pawl member 11 is made of a material harder than the grip member 12, such as metal or plastic, so that the opening/closing motion of the pawl base portion 18 given by the driving portion 19 is well transmitted to the grip member 12. Although not essential, the claw member 11 is preferably configured such that the grip member 12 is sandwiched between the claw member 11 and the gripped object 99 when the gripper 10 grips the gripper 10, and the claw member 11 pushes the gripped object 99 via the grip member 12.

The grip member 12 is more flexible than the claw member 11 , and when the gripper 10 grips the gripping target 99 , the gripping target 99 is gripped while the grip member 12 is deformed.
The grip member 12 includes elastic members 131 . Preferably, but not necessarily, gripping member 12 also includes gripping layer 121 . When the gripping layer 121 is provided, the gripping member 12 is constructed in a structure in which the gripping layer 121 and the elastic member 131 are arranged in order from the gripped object (99) side.

The elastic member 131 is made of resin so as to be flexible enough to be elastically deformed when the gripping object 99 is gripped. The resin forming the elastic member 131 may be rubber, thermoplastic elastomer, thermoplastic resin, thermosetting resin, or the like. Although not limited, the resin constituting the elastic member 131 is typically rubber or elastomer, and its hardness is preferably about 50 to 85 degrees in terms of Duro A hardness. Also, although not essential, the hardness of the resin forming the elastic member 131 is preferably higher than the hardness of the resin forming the gripping layer 121 as in the present embodiment.

The elastic member 131 is plate-shaped. The elastic member 131 has a flat base portion 132 and a plurality of hollow protrusions 133, 133 having a hollow portion 133V. The hollow projections 133, 133 are protrudingly formed on the base 132 so as to be scattered at predetermined intervals. In this embodiment, the hollow protrusions 133, 133 are interspersed in an orthogonal grid pattern. FIG. 4 shows a perspective view of an elastic member 131 having a plurality of hollow projections 133, 133 erected on a base portion 132. As shown in FIG.
Although not essential, in the present embodiment, the elastic member 131 is attached to the claw member 11 so that the base portion 132 is positioned on the claw member 11 side, and the tip side (one end) 131a of the protruding hollow projection 133 is positioned on the grasped object (99) side.

The hollow projection 133 has a cylindrical side wall 134 . The side wall 134 is cylindrically erected from the flat base 132 in the thickness direction of the base. The inner space of the cylindrical side wall 134 serves as a hollow portion 133V of the hollow projection 133. As shown in FIG. Side wall 134 is typically provided in a cylindrical shape. Side wall 134 may be rectangular. Side wall 134 may be tapered.

Also, the hollow protrusion 133 is closed by a top portion 135 at the end opposite to the base portion 132 . A top portion 135 is provided to close the tip of the side wall 134 . In this embodiment, the top portion 135 is provided in a flat plate shape substantially parallel to the base portion 132 . The apex 135 may be provided in a hemispherical, dome, or conical shape. Also, the top portion 135 may be provided with projections or recesses.

In the elastic member 131, air communication passages 137, 137 are provided so as to communicate the hollow portions 133V, 133V of the hollow projections 133, 133 adjacent to each other. Although not essential, it is preferable that the communication passage 137 is provided linearly between the hollow projections 133, 133 as in this embodiment.

In this embodiment, the connecting passageway 137 is defined by passageway walls 138 . The passage wall 138 has, for example, an inverted U-shaped cross section and is erected from the base 132 . A hole is provided in the side wall 134 of the hollow projection at the portion where the passage wall 138 and the hollow projection 133 are connected, and the hollow portion 133V of the hollow projection communicates with the communication passage 137 . 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 rectangular shape.

Further, preferably, the air communication passages 137, 137 are provided in a network shape so as to two-dimensionally connect the scattered hollow projections 133, 133. As shown in FIG.
The communication passages 137, 137 may be provided so that all of the hollow projections communicate with each other, or the plurality of hollow projections may be divided into several groups, and the air communication passages 137, 137 may be provided so that the hollow portions communicate within the same group. Moreover, there may be a hollow projection that is not provided with a connecting passage.

Although not essential, preferably, as in the present embodiment, a tunnel-shaped connecting passage 137 is provided so as to connect the hollow projection 133 provided on the peripheral edge of the elastic member and the peripheral edge E of the elastic member, and the communicating passage 137 is released at the peripheral edge E of the elastic member 131.

Although not essential, in the present embodiment, the elastic member 131 is integrally molded into a single sheet in which the base portion 132 and the hollow projections 133 are continuous. That is, a hole is opened in the base portion 132 at the portion where the hollow projection 133 is provided. The elastic member 131 having such a shape can be molded by injection molding, vacuum molding, press molding, or the like.

Although not essential, the gripping member 12 may have a gripping layer 121 as in this embodiment. The gripping layer 121 is a layer provided so as to come into contact with a gripping target. Also, the outer surface of the gripping layer 121 is hereinafter 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 Duro A hardness of 30 to 80HDA conforming to JIS-K6253. When the gripping layer 121 is made of resin, the resin composing the gripping layer 121 may be rubber such as silicone rubber, acrylonitrile-butadiene rubber, or urethane rubber, or a thermosetting resin, may be a thermoplastic elastomer such as an olefin-based thermoplastic elastomer or a styrene-based thermoplastic elastomer, or may be a thermoplastic resin such as a soft vinyl chloride resin or a vinyl acetate resin (EVA resin). Various additives, fillers, and the like may be added to these resins, if necessary.

The material forming the gripping layer 121 is not limited to resin. Further, even if the material constituting the gripping layer 121 contains a slightly hard material, the gripping layer 121 can be flexibly deformed in the gripping direction if the thickness of the gripping layer 121 is thin, for example, 0.3 to 1 mm. Examples of other materials and materials that make up the gripping layer include materials obtained by coating or impregnating cloth with resin (for example, artificial leather materials and tarpaulin materials), and laminated materials obtained by laminating cloth (woven fabric or non-woven fabric), paper, resin sheets, or the like. Of course, the gripping layer 121 may be composed of a single layer.

Also, although not essential, in the present embodiment, the elastic member 131 is provided so that the tip 131 a of the hollow projection contacts the grip layer 121 . Although not required, the elastic member 131 may be adhered to the gripping layer 121 . Also, the elastic member 131 may be adhered, welded, or molded integrally with the gripping layer 121 .

By arranging the elastic member 131 behind the gripping layer 121 while being in contact with the gripping layer 121, the portion where the tip 131a of the hollow projection of the elastic member 131 contacts the gripping layer 121 and the portion where the elastic member 131 and the gripping layer 121 do not contact are distributed in a sea-island shape when viewed along the gripping direction. Although the gripping layer 121 can be flexibly deformed in the gripping direction, the gripping layer 121 is supported by the elastic member 131 at the portion that contacts the elastic member 131, and deformation in the gripping direction is restricted. The combination of the elastic member and the gripping layer to form such a sea-island structure contributes to enhancing flexibility and holding power.

Also, preferably, but not necessarily, as in this embodiment, the grip member 12 is configured to include a skin member 120 . In this embodiment, the outer skin member 120 is a member having a hollow structure, a part of which serves as the gripping layer 121 . It is preferable that the elastic member 131 is arranged inside the outer skin member 120 (the hollow portion of the hollow structure).

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

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

The flat plate-like gripping layer 121 does not have to be a perfect flat plate, and even a gripping layer with a slightly bulging or concave curved surface or a spherical gripping layer is included in the flat gripping layer as long as it is generally flat.
In addition, the gripping surface 12S of the gripping layer 121 in contact with the gripping object 99 may be provided with a background pattern such as projections, holes, ridges, grooves, checkering, dot patterns, satin finish, wrinkles, and embossing in order to adjust the frictional force and the adhesiveness of the surface. When the gripping surface 12S side of the gripping layer 121 is made of resin, granules such as silica grains or rubber grains may be kneaded into the resin so that the granules are exposed on the gripping surface 12S. Alternatively, the gripping surface 12S may be provided with a surface layer composed of a material different from that of the gripping wall, such as silicone rubber, EVA resin, nonwoven fabric, or resin film (polyimide film, PET film, etc.).

Integration (attachment) of the grip member 12 and the claw member 11 is not particularly limited. In this embodiment, the outer skin member 120 is provided with a mounting portion 125 having a bag-shaped hole, and the claw member 11 is inserted into the hole of the mounting portion 125 to integrate the grip member 12 and the claw member 11 . If necessary to prevent falling off, the outer skin member 120 and the claw member 11 may be screwed together, or they may be fixed with an adhesive, adhesive, or adhesive tape. Alternatively, the elastic member 131 and the gripping layer 121 may be sequentially integrated with the claw member 11 using an adhesive or the like to form the grip member 12 and be integrated with the claw member 11 .

A method of manufacturing the members and the like for configuring the gripper 10 will be described.
The driving portion 19, the claw base portion 18, the claw member 11, and the like can be manufactured in the same manner as conventionally known industrial robot members. The grip layer 121 (outer skin 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. Also, the elastic member 131 of the grip member 12 can be manufactured by injection molding a rubber material or a thermoplastic elastomer material, or by pressing a sheet material of a rubber material or a thermoplastic elastomer material. The grip member 12 is obtained by pressing the obtained elastic member 131 into the inside of the outer skin member 120 to integrate them so as not to come off from each other.

The effect of the gripper 10 of the said 1st Embodiment is demonstrated.
According to the gripper 10, when gripping the gripping object 99, the hollow projections 133, 133 of the elastic member 131 are deformed so as to be crushed to grip the gripping object 99, so that the gripping object can be gripped flexibly. If the gripping target can be flexibly gripped, gripping targets having various shapes can be gripped in various postures, and the robustness of the gripping operation can be enhanced.

FIG. 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 projection 133 has a hollow cylindrical side wall 134 erected from the base portion 132, the end opposite to the base portion is closed, and an air communication passage 137 is provided so as to connect the hollow portions 133V, 133V of the hollow projections adjacent to each other. , into adjacent hollow projections and even into the outer space. In FIG. 5, such air flows are indicated by arrows. Therefore, it is possible to prevent the deformation of the hollow projection 133 from being hindered due to entrapment of air, so that the hollow projection 133 can be flexibly deformed.

In addition, since the air communication passage 137 that connects the hollow portion 133V of the hollow projection 133 is provided, when the grip is released, air is returned to the hollow portion 133V through the communication passage 137, and the hollow projection crushed during gripping is suppressed from sticking to the claw member like a suction cup, and repeated gripping can be performed reliably.

FIG. 6 shows a modified form of the gripper of the reference example when gripping the gripping object 99 . The gripper of the reference example differs from the gripper 10 of the first embodiment in that the connecting passage 137 is not provided in the elastic member 931, but otherwise has substantially the same configuration. In the gripper of the reference example, even if the grip is released from the gripping state of FIG. 6, the crushed hollow projection 933 is difficult to restore. This is because it is difficult for air to return to the hollow portion 933V, and the crushed hollow protrusion 933 sticks to the pawl member 11, the outer skin member 120, and the like like a suction cup.

As in the reference example, if the collapsed hollow protrusion 933 is difficult to restore, the grip member cannot be restored in time after the grip is released when the grip is repeated, and the next gripping operation is started while the grip member is in a collapsed state, and the reliability of repeated gripping is likely to be impaired.

On the other hand, according to the gripper 10 of the first embodiment, since the communication passage 137 is provided, when the grip is released, air is supplied through the communication passage 137 to the hollow portion 133V of the hollow projection 133 that has been crushed, and the hollow projection easily returns to its original shape. Therefore, repeated gripping can be reliably performed.

As described above, according to the gripper of the first embodiment, it is possible to grip the object to be gripped flexibly while suppressing the hollow projections that are crushed during gripping from sticking to the claw members or the like like suction cups, so that repeated gripping can be reliably performed.
In the description of the above embodiment, an example in which the gripping layer 121 is arranged between the elastic member 131 and the gripping object (99) has been shown, but the above effect is obtained even in the embodiment without the gripping layer.

Also, although not essential, if the communication passage 137 is a tunnel-shaped passage extending between the side walls 134, 134 of the hollow projections 133, 133 adjacent to each other, as in the gripper 10 of the present embodiment, the holding force when grasping the grasped object 99 is also improved.

Here, the holding force when gripping the gripping object 99 is the magnitude of the force that can resist an attempt to move the gripping object in a direction orthogonal to the gripping direction (for example, the vertical direction in FIG. 2). If the holding force is small, even if an attempt is made to lift the grasped object 99 vertically upward in the posture of the gripper as shown in FIGS. 1 and 2, the grasped object is likely to fall.

FIG. 11 shows a gripper having conventional cushion materials (e.g., urethane sponge) 82, 82 at the tips of claw members 81, 81, as disclosed in Patent Document 1. In such a conventional technique, the holding force is solely dependent on the frictional force between the cushion material 82 and the gripped object. That is, in the conventionally known cushioning material, both the flexibility of the cushioning material and the holding force of the gripper could not be improved.

In the gripper of the first embodiment, as shown in FIG. 5, when an object to be gripped is gripped, the object to be gripped 99 enters between the hollow projections 133, 133 provided at a predetermined interval, i.e., into the sea portion of the sea-island structure, and the gripped object 99 is gripped by the gripper 10. In such a state, even if the object to be gripped is pulled out in the vertical direction in FIG. It can be caught on things and its holding power is enhanced.

If the connecting passage 137 is a tunnel-shaped passage provided between the side walls 134, 134 of the hollow projections 133, 133 adjacent to each other, as in the gripper 10 of the present embodiment, the passage wall 138 defining the tunnel passage connects the side walls 134, 134 of the hollow projections, and the hollow projection 133 is supported in the vertical direction in FIG. As a result, even if a force acts in the direction in which the gripped object is pulled out from the gripped state of FIG. 5, it is possible to more reliably prevent the hollow protrusion from falling sideways and the gripped object from being pulled out. That is, the holding force is further enhanced.

Furthermore, when the gripper layer 121 is provided like the gripper 10 of the first embodiment, the gripping layer 121 deforms so as to come into close contact with the surface of the gripped object 99, as shown in FIG.

From the viewpoint of further increasing the holding force, it is preferable that the gripping layer 121 is made of a resin having a Duro A hardness of 30 to 80HDA conforming to JIS-K6253, the elastic member is made of 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 resin constituting the support. This is because the grip member 12 becomes more flexible and the portion with which the elastic member 131 abuts firmly supports the gripping layer 121 from the back side, so that the gripping layer 121 can be more easily caught on the gripped object 99, and the holding force can be further enhanced.

In addition, if the connecting passage 137 is a tunnel-like passage provided between the side walls 134, 134 of the hollow protrusions 133, 133 adjacent to each other as in the present embodiment, the connecting passages 137, 137 are formed in advance in the elastic member 131, and the configuration of the gripper including the connecting passage 137 is completed only by attaching the elastic member 131 to the claw member 11, which makes it easy to manufacture an excellent gripper.

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

The invention relating to the gripper 10 of the first embodiment is not limited to the above embodiment, and can be implemented with various modifications. Other embodiments of the invention will be described below, but in the following description, differences from the above embodiment will be mainly described. Moreover, these embodiments can be implemented by combining some of them with each other or replacing some of them.

The specific configuration of the elastic member 131 in the above embodiment can be changed. In the description of the first embodiment, the hollow projections 133, 133 are arranged on the intersection points of the orthogonal grid as an example of the elastic member 131. However, the planar pattern in which these hollow projections 133, 133 are arranged when viewed along the gripping direction may be a planar pattern in which the hollow projections 133, 133 are located at each vertex when triangles or hexagons are virtually laid out. As a modified example of the elastic member, FIG. 7 illustrates a plane pattern of the arrangement of the hollow protrusions 133 and 133 and the connecting passages 137 and 137 when viewed along the gripping direction. FIG. 7 shows an example in which cylindrical hollow projections 133, 133 are arranged in a planar pattern of equilateral triangles, and connecting passages 137, 137 are provided so as to connect the hollow projections in an equilateral triangle pattern. Also in this embodiment, a part of the communication passage connects the hollow projection 133 and the peripheral edge of the elastic member (upper edge in the drawing). Alternatively, the hollow projections 133, 133 may be randomly scattered on the base.

FIG. 8 shows a front view, a cross-sectional view, and a rear view of the elastic member 231 used in the gripper of the second embodiment. This elastic member 231 can constitute a gripper in the same form as the elastic member 131 of the first embodiment.
An elastic member 231 shown in FIG. 8 is similar to the elastic member 131 of the first embodiment in that hollow protrusions 233, 233 having hollow portions are formed in a predetermined planar pattern from a flat base portion 232. As shown in FIG. In the elastic member 231 shown in FIG. 8, the base portion 232 is further provided with a through hole 234 in 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 back side of the base portion 232.

Furthermore, the base 232 is provided with projections 235 , 235 projecting in the opposite direction to the hollow projection 233 . The projections 235 are typically provided around the through holes 234, between hollow projections, and the like. Due to the presence of the projections 235 , 235 , when the elastic member 231 is attached to the claw member 11 , the base 232 and the claw member 11 do not come into close contact with each other and are separated from each other.

In the gripper of the second embodiment, the space S, that is, the space S generated by separating the pawl member 11 and the base 232 from each other and the through hole 234 constitute an air communication passage.

With such a configuration, even if the elastic member 231 of the present embodiment is used, the hollow portions 233V, 233V of the hollow projections 233, 233 are communicated with each other so that air can flow through each other. Therefore, if such an elastic member 231 is provided, the hollow projection becomes flexible, and the elastic member has particularly good restorability, thereby improving the certainty of gripping when repeatedly gripping.

The specific form of the projections 235, 235 provided on the back side of the base 232 is not particularly limited, and may be dot-shaped, oval-shaped, or string-shaped projections. From the viewpoint of improving the resilience of the elastic member, it is sufficient that the projections 235 are provided so as not to constitute a seal line that hinders the flow of air.

Further, as in the present embodiment, the base 232 is provided with a through hole 234 in a portion where the hollow projection 233 is provided, and the base 232 is provided with a projection 235 projecting in the opposite direction to the hollow projection 233 so that the base 232 and the claw member 11 are separated from each other. A superior gripper is easier to manufacture because the configuration of the gripper including the connecting passage is completed.

FIG. 9 shows a cross-sectional view of the claw member and the grip member 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 the breathable sheet material 335 is provided.
The elastic member 331 of this embodiment has a flat base 332 and a plurality of hollow projections 333, 333 having hollow portions. The hollow protrusions 333, 333 are formed to protrude from the base portion 332 so as to be arranged at a predetermined interval. The base portion 332 is provided with through holes 334, 334 in portions where the hollow projections 333, 333 are provided.

A breathable sheet material 335 is provided adjacent the base 332 . The air-permeable sheet material 335 may be any material as long as it allows air to pass through in the thickness direction and in-plane direction of the sheet. In this embodiment, the through holes 334 and 334 and the air-permeable sheet material 335 constitute an air communication passage. With such a configuration, the hollow portions 333V, 333V of the hollow projections 333, 333 are communicated with each other so that air can flow through each other. Therefore, according to such a gripper, the hollow projection becomes flexible, and the restoring property of the elastic member is particularly improved, thereby improving the reliability of gripping when repeatedly gripping.

Further, as in the present embodiment, the base portion 332 is provided with the through hole 334 at the portion where the hollow projection 333 is provided, the air permeable sheet material 335 is provided adjacent to the base portion 332, and if the communication passage is formed by the air permeable sheet material 335 and the through hole 334, the configuration of the gripper including the communication passage is completed only by attaching the elastic member 331 and the air permeable sheet material 335 to the claw member 11, and thus an excellent gripper can be manufactured. easier to do.

FIG. 10 shows a front view, cross-sectional view and perspective view of an elastic member 431 used in the gripper of the fourth embodiment. This elastic member 431 can constitute a gripper in the same form as the elastic member 131 of the first embodiment. The elastic member 431 shown in FIG. 10 has a flat base portion 432 and a plurality of hollow ridges 433, 433 having hollow portions. The hollow ridges 433, 433 are formed to protrude from the base portion 432 so as to be arranged at a predetermined interval. The hollow ridge 433 may be linear or polygonal. In this embodiment, it is curvilinear, in particular arcuate. Although the interval between the hollow ridges 433, 433 may be constant, it may vary, and the interval between the ridges may be different.

Although not essential, the hollow ridge 433 has a first hollow ridge 434 erected from the base 432, a stepped plate-like step 435, and a second ridge 436 erected from the center of the ridge 435 in a direction away from the base 432.
In the hollow ridge 433, the inner width D3 of the tubular first ridge 434 is larger than the outer width D4 of the second ridge 436, and the hollow ridge 433 is formed into a stepped hollow ridge so that the hollow ridge 433 is compressed and part of the second ridge 436 enters the inside of the first ridge 434 when gripping an object to be gripped.

By providing the elastic member 431 with the hollow ridges 433, 433 having such a configuration, the gripper of the fourth embodiment can also have enhanced flexibility, as in the first embodiment. It should be noted that it is not essential for the hollow ridges to have a stepped shape, and the hollow ridges 433 may have a pair of side walls erected from the base 432 and the end opposite to the base 432 may be closed. When the hollow ridges 433 are stepped as in this embodiment, the flexibility is particularly enhanced.

When the hollow ridges are arc-shaped as in the present embodiment, they are preferably attached to the gripper so that the arc is vertically downwardly convex during the gripping operation. In this way the holding force is particularly high.

Also in this embodiment, communication passages 437, 437 are provided for communicating the hollow portions 433V, 433V of the hollow ridges 433, 433 adjacent to each other. For example, the communication passage 437 may connect side walls of the adjacent hollow ridges 433, 433 with an inverted U-shaped passage wall 438, similar to the communication passage in the elastic member in the first embodiment.
The provision of the communication passage makes the elastic member 431 more flexible, and improves the resilience of the hollow ridges 433 when the grip is released, improving the reliability of gripping when repeatedly gripping.

Preferably, the elastic member 431 of this embodiment is also used together with the gripping layer 121 . Preferably, the elastic member 431 of this embodiment is also attached to the claw member 11 so that the base portion 432 is positioned on the claw member 11 side and the hollow ridge 433 protrudes in the direction toward the grasped object.

In the description of the fourth embodiment, an example in which the hollow ridges 433, 433 provided on the elastic member are stepped was shown, but the hollow projections 133 (233) and the like in the elastic members of the first embodiment and the second embodiment may also be configured as stepped hollow projections to particularly enhance the flexibility of the hollow projections.

Alternatively, the elastic member 431 having the hollow ridges 433, 433 as in the fourth embodiment may be provided with projections (235) as in the second embodiment (FIG. 8), and the base 432 provided with the hollow ridges 433 may be separated from the claw member, and the space thus separated may be used to form a communication passage.
Also, the elastic member 431 having the hollow ridges 433, 433 as in the fourth embodiment may be provided with the breathable sheet material (335) as in the third embodiment (FIG. 9), and the air-permeable sheet material portion may be used to construct the connecting passage.
In these modified examples as well, the object to be grasped can be grasped flexibly and repeatedly grasped reliably.

Also, the specific configuration of the communication passage is not limited to the one 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 be used as a communication passage. In this case, grooves are provided on the claw member side surface of the base portion 332 so as to communicate with the hollow portions 333V, 333V. Such a groove likewise allows the hollow portion of the elastic member to communicate with each other, thereby exhibiting the same effect.

In addition, in the description of the above embodiment, the connecting passage is built into the elastic member or the connecting passage is provided between the elastic member and the claw member, but the form in which the connecting passage is provided is not limited to these. For example, grooves, holes, or passages to be part of the communication passages may be provided in the skin member or claw member, and the hollow portions of the elastic member may be communicated using these grooves, holes, or passages.

In the description of the above embodiment, the claw member is mainly described as a hard member, but the claw member is not particularly limited as long as the grasping force is transmitted to the grasped object via the flexible grip member between the claw member and the grasped object when grasping. For example, the pawl member may be a highly rigid member made of metal or hard plastic, but the pawl member may be made of rubber or soft plastic. Alternatively, the pawl member may be made hollow, and the rigidity of the pawl member may be varied by filling gas or liquid therein. Moreover, the claw member may have a movable portion and be configured to be capable of active deformation such as bending.

The shape and properties of the object to be gripped by the gripper are not particularly limited as long as the gripping operation is possible. Since the grippers of the above embodiments are highly flexible, they are capable of gripping objects of various shapes, such as cuboids, cylinders, polygonal pyramids, polyhedrons, spheres, and ellipsoids, in various postures.

The gripper is attached to the tip of the robot arm and can be used for, for example, transportation work, and has a high industrial utility value.

A Robot arm 10 Gripper 11 Claw member 12 Grip member 120 Skin member 121 Grasping layer 131 Elastic member 132 Base 133 Hollow protrusion 133V Hollow part 134 Side wall 137 Communication passage 138 Passage wall 99 Object to be grasped

Claims (5)

a claw member that can be opened and closed so as to grip an object to be gripped;
a gripping member attached to the claw member so as to come into contact with the gripped object when gripping the gripped object, the gripper comprising:
The grip member includes a plate-shaped elastic member made of resin,
The elastic member has a plurality of hollow protrusions having hollow portions and a flat plate-like base,
The hollow protrusions are protrudingly formed so as to be scattered on the base,
The hollow projection has a hollow cylindrical side wall erected from a base, and
the end opposite the base is closed,
An air communication passage is provided so as to connect the hollow parts of the hollow projections adjacent to each other,
gripper. a claw member that can be opened and closed so as to grip an object to be gripped;
a gripping member attached to the claw member so as to come into contact with the gripped object when gripping the gripped object, the gripper comprising:
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 plate-like base,
The hollow ridges are formed to protrude side by side on the base,
The hollow ridge has a pair of side walls erected from a base, and
the end opposite the base is closed,
An air communication passage is provided so as to connect the hollow parts of the hollow ridges adjacent to each other,
gripper. The communication passage is a tunnel-shaped passage provided between side walls of adjacent hollow projections or hollow ridges.
A gripper according to claim 1 or claim 2. The base is provided with a through hole in a portion provided with a hollow projection or a hollow ridge,
The base is provided with a hollow projection or a projection protruding in the opposite direction to the hollow ridge so that the base and the claw member are spaced apart,
The space and the through hole constitute the communication passage,
A gripper according to claim 1 or claim 2. The base is provided with a through hole in a portion provided with a hollow projection or a hollow ridge,
A breathable sheet material is provided adjacent the base,
The communication passage is constituted by a breathable sheet material and a through hole,
A gripper according to claim 1 or claim 2.

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