Grip device and manufacturing method thereof

Abstract

To provide a gripping device capable of carrying out work or fine work in a narrow space by increasing a strength and durability to a level to be able to resist inner pressure which can bend a gripping member even when thin, and a method for manufacturing the same.SOLUTION: A gripping device 1 capable of gripping an object comprises: a gripping member 2 made of a flexible material and provided with a ventilation path 23 in which a plurality of projections 21 having air chambers 22 therein are arranged adjacent to each other and which is communicated with each air chamber 22; and a skeleton member 3 sealed in at least parts of the air chambers 22 and the ventilation path 23. When gas is pressure-inserted into the ventilation path 23, the gas enters into a gap between the air chamber 22 or the inner wall surface of the air chamber 22 and the skeleton member 3, and the projections 21 expand to be bent.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a gripping device capable of gripping an object and a method for manufacturing the same. [Background technology]

[0002] Conventionally, gripping devices, such as robot hands, that are made of flexible materials and bend by air pressure have been known. For example, Japanese Patent Laid-Open Publication No. 61-203287 discloses a robot hand finger that has a tubular body made of flexible material, a bellows portion on one side wall, and a plate-like portion on the opposite side wall, and that bends by increasing the internal pressure (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 61-203287 Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional gripping devices, including the fingers for the robot hand described in Patent Document 1, are formed with a thick wall so that they will not burst or break even when air is injected with a pressure that is enough to bend the fingertips and grip them. For this reason, they are unsuitable for work in narrow spaces or for delicate work, and there are also problems with the difficulty of controlling the gripping force.

[0005] On the other hand, if the thickness is made thin, the strength and durability decrease, and there is a risk of rupture or breakage, so the internal pressure must be lowered. However, if the internal pressure is low, there are problems such as a decrease in gripping force and the tendency for the container to bend under its own weight, making it difficult to grip the object.

[0006] The present invention has been made to solve these problems, and aims to provide a gripping device and a manufacturing method thereof that has improved strength and durability to the extent that it can withstand internal pressure that can bend the gripping member even if it is thin, and that can be used to work in narrow spaces or perform detailed work. [Means for solving the problem]

[0007] The gripping device of the present invention is a gripping device capable of gripping an object, with improved strength and durability to the extent that it can withstand internal pressure that can bend the gripping member even if the gripping member is thin, in order to solve the problem of working in narrow spaces or performing delicate work, and has a gripping member made of a flexible material, with multiple protrusions each having an air chamber inside and arranged adjacent to each other, and an air passage communicating with each of the air chambers, and a skeletal member sealed in at least a portion of the air chambers and the air passage, and when gas is pressurized into the air passage, the gas flows into the gap between the air chamber or the inner wall surface of the air chamber and the skeletal member, causing the protrusions to expand and bend.

[0008] Furthermore, as one aspect of the present invention, in order to solve the problem of preventing the gripping member and the skeletal member from adhering to each other and ensuring that gas flows into the gap between them, the gripping member and the skeletal member may be formed from materials that do not adhere to each other.

[0009] Furthermore, as one aspect of the present invention, in order to solve the problem of preventing the gripping member and the skeletal member from adhering to each other and ensuring that gas flows into the gap between them, an anti-adhesion agent may be applied to the contact surfaces of the gripping member and the skeletal member to prevent them from adhering to each other.

[0010] Furthermore, as one aspect of the present invention, in order to solve the problem of further enhancing the effect of improving strength and durability provided by the skeletal member, the skeletal member may have a shape that fills all of the air chambers and the ventilation paths.

[0011] The method for manufacturing a gripping device according to the present invention solves the problem of manufacturing a gripping device that can be used in narrow spaces or for fine work by improving the strength and durability to a level that can withstand internal pressure that can bend a gripping member even if the gripping member is thin, and includes the following steps: a gripping member forming step of forming a gripping member that has a plurality of protrusions arranged adjacent to each other and each having air chambers inside, and that has air passages communicating with each of the air chambers, and is made of a flexible material, with one side of the gripping member being open; a skeletal member forming step of forming a skeletal member that can be sealed in at least a portion of the air chambers and the air passages; a skeletal member filling step of filling at least a portion of the air chambers and the air passages with a skeletal member; and a skeletal member sealing step of pouring the flexible material in liquid form into one side of the gripping member filled with the skeletal member, hardening it, and sealing the skeletal member.

[0012] Furthermore, as one aspect of the present invention, in order to solve the problem of preventing the gripping member and the skeletal member from adhering to each other and ensuring that gas flows into the gap between them, the gripping member and the skeletal member may be formed from materials that do not adhere to each other.

[0013] Furthermore, as one aspect of the present invention, in order to solve the problem of preventing the gripping member and the skeletal member from adhering to each other and ensuring that gas flows into the gap between them, an anti-adhesion agent application step may be included before the skeletal member filling step, in which an anti-adhesion agent is applied to the contact surfaces of the gripping member and the skeletal member to prevent them from adhering to each other. [Effects of the Invention]

[0014] According to the present invention, strength and durability are improved to the extent that the gripping member can withstand internal pressure that can bend the gripping member even if the wall thickness is thin, and work in narrow spaces or detailed work can be performed. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view showing an embodiment of a gripping device according to the present invention. [Figure 2]1A is a front view of a gripping member of the present embodiment, FIG. 1B is a side view seen from below the front view, and FIG. 1C is a central cross-sectional view of the front view. [Figure 3] 3A to 3D are diagrams showing (a) a gripping member forming step, (b) a skeletal member forming step, (c) a skeletal member filling step, and (d) a skeletal member encapsulating step in the manufacturing method of the gripping device of this embodiment. [Figure 4] In the gripping device of this embodiment, (a) a diagram showing the state in which an object is clamped by the gripping members, (b) a schematic diagram of a protrusion into which gas has been pressurized, and (c) a diagram showing the state in which the object is gripped by the gripping members. [Figure 5] FIG. 1 is a diagram showing a skeletal member used in Model B of Example 1. [Figure 6] FIG. 10 is a diagram showing a simulation result of the first embodiment. [Figure 7] 10A to 10C are diagrams showing the skeletal members used in (a) Model C, (b) Model D, and (c) Model E in Example 2. [Figure 8] FIG. 10 is a diagram showing a simulation result of model A in Example 2. [Figure 9] FIG. 10 is a diagram showing a simulation result of model B in Example 2. [Figure 10] FIG. 10 is a diagram showing a simulation result of model C in Example 2. [Figure 11] FIG. 10 is a diagram showing a simulation result of model D in Example 2. [Figure 12] FIG. 10 is a diagram showing a simulation result of Model E in Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of a gripping device and a manufacturing method thereof according to the present invention will be described with reference to the drawings.

[0017] The gripping device 1 of this embodiment is capable of gripping an object, and as shown in Fig. 1, mainly comprises a gripping member 2 that grips the object, a skeletal member 3 that forms the skeleton of the gripping member 2, and a device main body 4 that fixes the gripping member 2. Each component will be explained below. In the present invention, the concept of an object includes all objects that can be gripped, including soft objects such as food and fragile objects.

[0018] The gripping member 2 is used to grip an object and is made of a flexible, soft material. In this embodiment, the gripping member 2 has a tapered tip and is formed in a thin, generally flat plate shape, as shown in FIG. 2(a). Furthermore, on the outer surface of the gripping member 2, as shown in FIGS. 2(b) and 2(c), a plurality of protrusions 21 each having an air chamber 22 therein are arranged adjacent to each other, and the gripping member 2 is provided with air passages 23 communicating with each of the air chambers 22 and a gas pressure inlet 24 for pressurizing gas into the air passage 23. Furthermore, in this embodiment, the gripping member 2 has a deflection prevention portion 25 that prevents deflection when the gripping member 2 is turned sideways.

[0019] 2(a), in this embodiment, the plurality of protrusions 21 are formed in a substantially rectangular parallelepiped shape and are arranged in parallel with the longitudinal direction of the gripping member 2 so that the longitudinal directions of the protrusions 21 are perpendicular to each other. With this configuration, as will be described later, when gas is injected, the tip of the gripping member 2 bends toward the inner surface. However, the shape and arrangement of the protrusions 21 are not limited to the above configuration and can be changed as appropriate.

[0020] For example, if the protrusions 21 are arranged in parallel such that the longitudinal direction of each protrusion is parallel to the longitudinal direction of the gripping member 2, the side edges (the upper and lower end edges in FIG. 2(a)) of the gripping member 2 will bend toward the inner surface. In this way, the gripping member 2 can be bent in a desired direction depending on the orientation and arrangement of the adjacently arranged protrusions 21.

[0021] The flexible material constituting the gripping member 2 is not particularly limited as long as it is a flexible material having elasticity like rubber, including thermosetting elastomers such as silicone resin and thermoplastic elastomers such as thermoplastic polyurethane (TPU). However, it is preferable to embed a harder material such as polylactic acid (PLA) in the deflection prevention section 25.

[0022] The skeleton member 3 is sealed inside the gripping member 2 and functions as a skeleton of the gripping member 2. In this embodiment, the skeleton member 3 is formed from a flexible, soft material and has a shape that fills the entire air chamber 22 and the air passage 23. However, the skeleton member 3 is not limited to this configuration, and as will be described later in Example 2, the skeleton member 3 may have a shape that seals at least a portion of the air chamber 22 and the air passage 23. Furthermore, the skeleton member 3 is not limited to a soft material, and may be made of a metal material or the like. This makes it possible to adjust the degree of curvature of the gripping member 2.

[0023] In this embodiment, the gripping member 2 and the skeletal member 3 are formed of materials that do not adhere to each other. For example, if the gripping member 2 is made of silicone resin, the skeletal member 3 is made of thermoplastic polyurethane or the like. This prevents the gripping member 2 and the skeletal member 3 from adhering to each other, and a gap through which gas can flow can be formed between them. However, this configuration is not limited to this, and even if the materials are adhesive to each other, an anti-adhesion agent that prevents adhesion between the gripping member 2 and the skeletal member 3 may be applied to the contact surface between them. This anti-adhesion agent is selected appropriately depending on the materials of the gripping member 2 and the skeletal member 3, and examples include fluorine-based release agents and silicone-based release agents.

[0024] The device main body 4 is attached to a moving device (not shown) such as a robot arm, and fixes the gripping members 2. In this embodiment, as shown in FIG. 1, the base ends of the pair of gripping members 2 are fixed by a fixing plate 41 with the inner surfaces of the pair of gripping members 2 facing each other. In this embodiment, as shown in FIG. 1, the fixing plate 41 has screw holes 42 through which screws for fixing to the device main body 4 are passed, and a communication hole 43 that communicates with the gas pressure inlet 24 of the gripping member 2. In addition, as shown in FIG. 1, a mounting plate 44 for placing a gripped object on extends forward from the device main body 4 at an intermediate position between the gripping members 2.

[0025] In this embodiment, two gripping members 2 are provided as a pair, but the present invention is not limited to this configuration and the number of gripping members may be increased or decreased as appropriate depending on the object. For example, one gripping member 2 may be provided facing a flat plate-like member, and the object may be gripped by being pressed against the plate-like member by the gripping member 2. Alternatively, four gripping members 2 may be used to grip the object from four directions.

[0026] Next, a method for manufacturing the gripping device 1 of this embodiment will be described.

[0027] When manufacturing the gripping device 1 of this embodiment, first, the gripping member 2 is formed (gripping member forming step). Specifically, a liquid flexible material is poured into a mold that resembles the shape of the gripping member 2 and is hardened. As a result, as shown in FIG. 3(a), the gripping member 2 is formed with one side open, in which a plurality of protrusions 21 each having air chambers 22 therein are arranged adjacent to each other, and each having air passages 23 communicating with each of the air chambers 22.

[0028] In this embodiment, when the liquid flexible material is poured into the mold, as shown in Fig. 2(a), a pair of deflection prevention parts 25, 25 molded in advance from a hard resin are set in the mold on both sides of the air passage 23 on the base end side of the gripping member 2. In this way, the gripping member 2 is formed with the deflection prevention parts 25 embedded in it.

[0029] Next, a skeleton member 3 to be enclosed inside the gripping member 2 is formed (skeleton member forming step). In this embodiment, the skeleton member 3 is formed from a material that does not bond to the gripping member 2, and as shown in FIG. 3(b), has a shape that fills all of the air chamber 22 and the air passage 23. Note that, like the gripping member 2, the skeleton member 3 may be formed using a molding die, or may be shaped using a 3D printer or the like.

[0030] Next, the skeletal member 3 is filled into the air chambers 22 and the air passages 23 from the open side of the gripping member 2 (skeletal member filling step). In this embodiment, the skeletal member 3 is filled by fitting a previously formed skeletal member 3 into the interior of the gripping member 2. As a result, as shown in FIG. 3(c), the skeletal member 3 is filled in a state of being in close contact with the inner wall surfaces of the air chambers 22 and the air passages 23 of the gripping member 2. Note that the gripping member 2 formed in the gripping member forming step may be used as a mold, and a liquid flexible material that is the raw material of the skeletal member 3 may be poured into the mold and hardened, thereby filling the gripping member 2 with the skeletal member 3. In this case, the skeletal member forming step and the skeletal member filling step are performed simultaneously.

[0031] Finally, the skeleton member 3 filled inside the gripping member 2 is sealed (skeleton member sealing step). Specifically, as shown in Fig. 3(d), a liquid flexible material is poured onto one side of the gripping member 2 filled with the skeleton member 3 and hardened, thereby sealing the skeleton member 3. At this time, the liquid flexible material poured to seal the skeleton member 3 hardens in a state where it does not adhere to the skeleton member 3 but only adheres to the gripping member 2.

[0032] For this reason, the structure is configured so that gas can flow into the gap between the inner wall surface of the air chamber 22 and the skeletal member 3, and into the gap between the inner wall surface of the ventilation path 23 and the skeletal member 3. In addition, the liquid flexible material poured into one side hardens to become one with the gripping member 2, making it less likely to peel off than when it is bonded with an adhesive or the like. Furthermore, as will be described later in Example 1, by incorporating the skeletal member 3 into the air chamber 22 and the ventilation path 23, strength and durability are improved, making it possible to inject air with an internal pressure that is sufficient to bend the gripping member even if the wall thickness is thin.

[0033] Next, a description will be given of the operation of the gripping device 1 of this embodiment. In the following description, the gripping device 1 is used by being attached to a moving device (not shown) such as a robot arm.

[0034] First, when using the gripping device 1 of this embodiment, as shown in Fig. 4(a), the gripping device 1 is moved and positioned so that the pair of gripping members 2, 2 sandwich the object. At this time, each gripping member 2 is formed in a thin, approximately flat plate shape, making it easy to insert into narrow spaces or crowded areas and suitable for delicate work. This makes it possible, for example, to grip different types of cut cakes and pack them densely into small boxes.

[0035] In this embodiment, the framework member 3 and the deflection prevention section 25 enclosed inside the gripping member 2 prevent the gripping member 2 from deflecting due to its own weight. This makes it possible to use the gripping member 2 in various orientations depending on the shape of the object and the type of work being performed.

[0036] Next, when gas is injected into the air passage 23 through the gas pressure inlet 24 connected to a gas supply tube (not shown), the gas flows into the gap between the inner wall surface of the air chamber 22 and the skeletal member 3, as shown in Fig. 4(b), causing each protrusion 21 to expand. As a result, due to interference between adjacent protrusions 21 and differences in the expansion rate between the outer and inner surfaces, the gripping member 2 bends inward and grips the object.

[0037] In this embodiment, the framework member 3 sealed inside the gripping member 2 improves the strength and durability of the gripping member 2 to the extent that it can withstand internal pressure that can bend the gripping member 2, even if it is thin. Therefore, the gripping member 2 will not break even when a higher-pressure gas is injected than before, and the gripping member 2 becomes hard all the way to its tip, improving the gripping force. Therefore, even heavy or minute objects can be easily gripped.

[0038] The gripping device 1 and the manufacturing method thereof according to the present embodiment described above provide the following advantages. 1. Even though the thickness is thin, the strength and durability are improved to the extent that the gripping member 2 can withstand the internal pressure that can bend it, making it possible to perform work in narrow spaces or delicate work. 2. The gripping member 2 and the framework member 3 can be prevented from adhering to each other, and gas can be reliably introduced into the gap between them. 3. The effect of improving the strength and durability provided by the skeletal member 3 can be further enhanced. 4. If the gripping member 2 has a thin wall thickness, the gripping force can be easily controlled precisely, and even soft foods can be packed tightly in boxes. 5. It can automate tasks such as grasping, aligning, and packing objects, reducing the number of workers required in food factories and other facilities that previously required many manual processes, thereby alleviating labor shortages and improving operating rates.

[0039] Next, specific examples of the gripping device 1 and the manufacturing method thereof according to the present invention will be described. Note that the technical scope of the present invention is not limited to the features shown in the following examples. [Example]

[0040] In this Example 1, a simulation was carried out to confirm the extent to which the strength and durability of the gripping member 2 are improved by the skeletal member 3.

[0041] The simulation conditions in this Example 1 are as follows. Simulation software: SolidWorks 2011 Simulation Loading conditions: A pressure of 0.04 MPa is applied to the inside of the gripping member 2.

[0042] The model of the gripping member 2 used in the simulation is as follows. A: Hollow gripping member 2 without skeletal member 3 enclosed B: A gripping member 2 enclosing a framework member 3 (FIG. 5) shaped to fill the entire air chamber 22 and the air passage 23.

[0043] Figure 6 shows the results of a simulation of the stress generated when pressurization was applied inside the gripping member 2 under the above conditions. As shown in Figure 6, in Model A, in which the skeletal member 3 was not enclosed, a large stress of up to approximately 0.05 MPa was generated in the air chamber 22 and the air vent path 23, and a strong load was applied. On the other hand, in Model B, in which the skeletal member 3 was enclosed, only about half the stress of Model A was generated in the air chamber 22 and the air vent path 23, and a strong load was not applied overall.

[0044] According to the above-described first embodiment, it has been shown that by enclosing the skeletal member 3 in the air chamber 22 and the air passage 23 of the gripping member 2, the strength and durability can be improved. [Example]

[0045] In this Example 2, a simulation was carried out to confirm how much the strength and durability of the gripping member 2 differ depending on the shape of the skeletal member 3.

[0046] The simulation conditions in the second embodiment are the same as those in the first embodiment. The model of the gripping member 2 used in the simulation is as follows. A: Hollow gripping member 2 without skeletal member 3 enclosed B: A gripping member 2 enclosing a framework member 3 (FIG. 5) shaped to fill the entire air chamber 22 and the air passage 23. C: A gripping member 2 in which a framework member 3 (FIG. 7(a)) having a shape that fills only the air passage 23 is enclosed. D: The gripping member 2 enclosing the skeletal member 3 (FIG. 7(b)) shaped to fill only the air passage 23 and the air chamber 22 in the Z direction of the air passage 23. E: The gripping member 2 enclosing the frame member 3 (FIG. 7(c)) shaped to fill only the air passage 23 and the air chamber 22 in the Y direction of the air passage 23.

[0047] Figures 8 to 12 show the results of a simulation of the amount of displacement when pressurization is applied inside the gripping member 2 under the above conditions. As shown in Figure 8, in model A, in which the skeletal member 3 is not enclosed, the amount of displacement in the air chamber 22 and the air passage 23 was the largest at about 0.7 to 1.0 mm, making it prone to breakage. On the other hand, as shown in Figure 9, in model B, in which the skeletal member 3 is enclosed throughout, the amount of displacement in the air chamber 22 and the air passage 23 was the smallest at about 0.0 to 0.6 mm, making it less prone to breakage.

[0048] As shown in Figures 10 to 12, in models C to E in which the skeletal member 3 was partially enclosed, the displacement in the air chamber 22 was approximately 0.5 to 1.0, but overall the displacement was reduced compared to model A, and although not as much as model B, they were less susceptible to breakage.

[0049] According to the above-described Example 2, it was shown that the strength and durability were improved by enclosing the skeletal member 3 in at least a part of the air chamber 22 and the ventilation path 23 of the gripping member 2. It was also shown that the effect of improving the strength and durability by the skeletal member 3 was further enhanced by enclosing the skeletal member 3 having a shape that fills the entire air chamber 22 and the ventilation path 23 of the gripping member 2.

[0050] The gripping device 1 and the manufacturing method thereof according to the present invention are not limited to the above-described embodiment, and can be modified as appropriate.

[0051] For example, in the above-described embodiment, the pair of grip members 2, 2 are used with the grip members facing horizontally, but the present invention is not limited to this configuration. The grip members 2 may also be used with the grip members facing downward, as in a crane game.

[0052] In addition, in the above-described embodiment, a thin, substantially flat gripping member 2 is used, but the present invention is not limited to this configuration. That is, even if a thick gripping member 2, like that of an existing robot hand, has a structure similar to that of the above-described embodiment, improvements in strength, durability, and gripping force can be expected. [Explanation of symbols]

[0053] 1 Gripping device 2. Gripping member 3. Frame members 4. Device body 21 Protrusion 22 Air chamber 23 Ventilation channel 24 Gas pressure inlet 25 Deflection prevention part 41 Fixed plate 42 screw holes 43 Communication hole 44 Loading plate

Claims

1. A gripping device capable of gripping an object, a gripping member formed of a flexible material in a substantially flat plate shape, the gripping member having a plurality of protrusions arranged adjacent to each other and each having an air chamber therein and an air passage communicating with each of the air chambers; a framework member enclosed in at least a portion of the air chamber and the air passage; and the skeletal member is sealed in a state of being in close contact with the inner wall surfaces of the air chamber and the air passage, When gas is injected into the air passage, the gas flows into the air chamber or into the gap between the inner wall surface of the air chamber and the skeletal member, causing the protrusion to expand and bend.

2. A gripping device capable of gripping an object, a gripping member made of a flexible material, the gripping member having a plurality of protrusions arranged adjacent to each other and each having an air chamber therein, and an air passage communicating with each of the air chambers; a framework member enclosed in at least a portion of the air chamber and the air passage; and the skeletal member has a shape that fills the entire air chamber and the air passage, When gas is injected into the air passage, the gas flows into the air chamber or into the gap between the inner wall surface of the air chamber and the skeletal member, causing the protrusion to expand and bend.

3. 3. The gripping device according to claim 1, wherein the gripping member and the skeletal member are formed of materials that do not adhere to each other.

4. 3. The gripping device according to claim 1, wherein an anti-adhesion agent is applied to contact surfaces of the gripping member and the framework member to prevent them from adhering to each other.

5. a gripping member forming step of forming a gripping member made of a flexible material with a plurality of protrusions each having an air chamber therein arranged adjacent to one another and with air passages communicating with each of the air chambers, the gripping member having one side open; a skeleton member forming step of forming a skeleton member capable of sealing at least a portion of the air chamber and the ventilation path; a skeleton member filling step of filling at least a portion of the air chamber and the ventilation channel with a skeleton member; a skeleton member encapsulating step of pouring the liquid flexible material into one side surface of the gripping member filled with the skeleton member and hardening the material to encapsulate the skeleton member; A method for manufacturing a gripping device, comprising:

6. The method for manufacturing a gripping device according to claim 5 , wherein the gripping member and the skeletal member are formed of materials that do not adhere to each other.

7. 6. The method for manufacturing a gripping device according to claim 5, further comprising, before the skeletal member filling step, applying an anti-adhesion agent to contact surfaces of the gripping member and the skeletal member to prevent them from adhering to each other.

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