CN113771069A

CN113771069A - Soft gripping device with adjustable gripping range and controllable rigidity and manufacturing method

Info

Publication number: CN113771069A
Application number: CN202110940771.9A
Authority: CN
Inventors: 盖龄杰; 宗小峰
Original assignee: China University of Geosciences
Current assignee: China University of Geosciences
Priority date: 2021-08-17
Filing date: 2021-08-17
Publication date: 2021-12-10
Anticipated expiration: 2041-08-17
Also published as: CN113771069B

Abstract

The invention provides a soft gripping device with adjustable gripping range and controllable rigidity, which is used for connecting two soft fingers and comprises: the soft main body cavity is provided with a plurality of chambers at intervals along the length direction at one side, the sectional area of each chamber is gradually reduced from the bottom to the top, and the distance between any two adjacent chambers is controlled by the air pressure in the main body cavity; and the variable rigidity layer is arranged on the other side of the main body cavity and comprises an accommodating cavity and a porosity variable material arranged in the accommodating cavity, and the rigidity of the variable rigidity layer is controlled by the negative pressure in the accommodating cavity. The invention has the beneficial effects that: the problem of poor rigid-flexible coupling of a soft finger and a rigid support is solved, and the coupling is good and the flexibility is high; automatically adjusting the grabbing range; the variable-porosity materials are mutually stacked and extruded by sucking the variable-rigidity layer under negative pressure, so that the rigidity of the soft support structure is controllable, and the bearing capacity of the gripping device is enhanced.

Description

Soft gripping device with adjustable gripping range and controllable rigidity and manufacturing method

Technical Field

The invention relates to the technical field of soft robots, in particular to a soft grasping device with an adjustable grasping range and controllable rigidity and a manufacturing method thereof.

Background

The soft robot is a new hot spot of the current robot technology, and compared with the traditional rigid robot, the soft robot is mostly made of flexible materials such as silicon rubber and the like, and has the advantages of large degree of freedom, soft deformation and better environmental adaptability. The soft gripper is an execution component for interaction between the soft robot and a target object, can replace human beings to complete gripping, sorting and other works in various complex environments, and is widely concerned by scientific research institutions and students all over the world.

Generally, soft hand grips consist of gripping means and soft finger structures. However, most of the current research is focused on soft finger structures, and the research on grasping devices is less. Through the research of the literature, the Chinese patent application with the application number of CN201810632541.4 discloses a soft gripper with a self-adaptive gripping diameter, and the device can self-adaptively adjust the gripping diameter by installing mechanical structures such as a spring, a sliding block and the like on a bracket, thereby avoiding the installation of fastening structures such as bolts and the like and having better detachability. In addition, the Chinese patent application 202010629657.X discloses a pneumatic soft manipulator, a negative pressure structure and a pneumatic push rod are mounted on a bracket of the device, fingers can be driven to translate inwards or outwards by negative pressure suction, and objects with different sizes can be grabbed to a certain extent.

However, in the case of the above two patents, the support portions of the currently available soft-body gripping devices are rigid, namely: the existing soft body grasping device does not achieve true full softening. The existing gripping devices based on rigid-flexible coupling have the following drawbacks: on one hand, the rigid support structure has freedom degree constraint, most of the rigid support structure can only do translational motion on a plane, and the grabbing range of the soft fingers is greatly limited; on the other hand, when applied to soft objects such as fruit and vegetable picking, the rigid support structure may damage the soft objects such as fruits and vegetables. Thirdly, the rigid support is combined with the soft gripper, so that the defect of poor rigid-flexible coupling exists, and the all-soft gripping device can effectively solve/avoid the problems. However, the soft support combined with the soft finger is made of soft materials such as silica gel, which leads to the inevitable defect of hard bearing of the soft support structure.

Disclosure of Invention

In view of the above, in order to overcome the above-mentioned drawbacks of the soft gripping device, embodiments of the present invention provide a soft gripping device with adjustable gripping range and controllable stiffness and a manufacturing method thereof.

The embodiment of the invention provides a soft gripping device with adjustable gripping range and controllable rigidity, which is used for connecting two soft fingers and comprises:

the soft main body cavity is provided with a plurality of chambers at intervals along the length direction at one side, the sectional area of each chamber is gradually reduced from the bottom to the top, and the distance between any two adjacent chambers is controlled by the air pressure in the main body cavity;

and the variable rigidity layer is arranged on the other side of the main body cavity and comprises an accommodating cavity and a porosity variable material arranged in the accommodating cavity, and the rigidity of the variable rigidity layer is controlled by the negative pressure in the accommodating cavity.

Further, the cross-sectional shape of the chamber is an isosceles triangle or an isosceles trapezoid.

Further, the porosity variable material is a non-stretchable flexible sheet arranged in a stacked manner or a non-stretchable flexible strip arranged in a stacked manner.

Further, the porosity variable material is particles filled in the accommodating cavity.

Furthermore, an air path communicated with the outside is arranged in the main body cavity and is respectively communicated with the cavities.

Furthermore, fingerstalls are arranged at two ends of the cavity of the main body and are used for being connected with the soft fingers.

Further, all the cavities are uniformly distributed along the length direction of the main body cavity.

The technical scheme of the soft gripping device with adjustable gripping range and controllable rigidity provided by the embodiment of the invention has the following beneficial effects:

the gripping device is designed by adopting soft materials, the problem that the rigid-flexible coupling of soft fingers and a rigid support in the traditional gripping device is poor can be effectively solved, the coupling is good, the softness is high, and soft objects such as fruits, vegetables and cakes are not easy to damage in the gripping process;

the grabbing range is adjusted in a pneumatic mode, so that the soft finger fixing device not only has the function of fixing soft fingers, but also has the function of automatically adjusting the grabbing range, not only can grab objects larger than the conventional size of the device, but also can grab objects smaller than the conventional size of the device, has more degrees of freedom, and can automatically adjust the grabbing range;

the variable rigidity layer is designed, and the variable porosity materials are mutually stacked and extruded by sucking the variable rigidity layer under negative pressure, so that the rigidity of the soft support structure is controllable, and the bearing capacity of the gripping device is enhanced.

The embodiment of the invention also provides a manufacturing method of the soft gripping device with adjustable gripping range and controllable rigidity, which comprises the following steps:

s1, forming a main body cavity by injection molding of silica gel through a first mold, wherein the first mold comprises a lower mold and an upper mold, a plurality of mold cavities arranged at intervals are arranged in an inner cavity of the lower mold, a plurality of insert blocks are arranged on the upper mold, the cross sections of the insert blocks are gradually increased from bottom to top, the upper mold is covered with the lower mold, and each insert block is inserted into one mold cavity;

s2, manufacturing an accommodating cavity by injection molding of silica gel through a second mold, arranging a porosity variable material in the accommodating cavity, and then bonding the accommodating cavity to one side of the main cavity, which is far away from all the cavities.

Further, the plug block is a wedge-shaped block.

The technical scheme of the manufacturing method of the soft gripping device with adjustable gripping range and controllable rigidity provided by the embodiment of the invention has the beneficial effects that: the main body cavity is manufactured by a silica gel injection molding method, and then the variable rigidity layer is manufactured, so that the soft grasping device with adjustable grasping range and controllable rigidity is manufactured, and the grasping device adopts a full-soft structure, so that the degree of freedom is high, the softness is high, and the coupling is good; the grabbing range can be automatically adjusted, and soft objects such as fruits, vegetables and cakes are not easy to damage in the grabbing process; the rigidity is controllable, and the bearing capacity of the gripping device is enhanced.

Drawings

FIG. 1 is a perspective view of a soft gripping device with adjustable gripping range and controllable rigidity according to the present invention;

FIG. 2 is a cross-sectional view of a soft gripping device with adjustable gripping range and controllable stiffness according to the present invention;

FIG. 3 is a perspective view of the body cavity 1 of FIG. 1;

FIG. 4 is a top view of the body cavity 1 of FIG. 3;

FIG. 5 is a schematic sectional view taken along line A-A in FIG. 4;

FIG. 6 is a schematic view of a soft finger;

FIG. 7 is a schematic view of the gripping device and two soft fingers in a first state (chamber and atmospheric pressure in the soft fingers);

FIG. 8 is a schematic view of the gripping device and two soft fingers in a second state (body cavity inspiration);

FIG. 9 is a schematic view of the gripping device and two soft fingers in a third state (with the body cavity inflated);

FIG. 10 is a schematic view of a fifth state of the gripping device and two soft fingers (body cavity inflated, soft finger inhaling);

FIG. 11 is a schematic view of a first mold;

fig. 12 is a schematic view of a second mold.

In the figure: 1-main body cavity, 101-cavity, 102-finger sleeve, 103-air inlet, 104-air channel, 2-variable rigidity layer, 201-accommodating cavity, 202-porosity variable material, 3-soft finger, 301-plug connector, 4-first mould, 401-lower mould, 401 a-model cavity, 401 b-finger sleeve cavity, 402-upper mould, 402 a-plug block, 5-second mould, 501-main mould, 502-mould cover and 502 a-plug board.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be further described with reference to the accompanying drawings.

Referring to fig. 7, the embodiment of the present invention provides a soft gripping device with adjustable gripping range and controllable rigidity, which is used for connecting two soft fingers 3, and comprises a main body cavity 1 and a variable rigidity layer 2.

Referring to fig. 1 and 2, the main body cavity 1 is approximately cylindrical and is formed by injection molding of a soft material, which may be a silicone rubber having a model of Econflex00-10 manufactured by Smooth-on company, usa, and the silicone rubber has a high tensile strength and a low shore stiffness, and is suitable for manufacturing a soft grip.

Referring to fig. 3, 4 and 5, a plurality of chambers 101 are disposed at intervals along a length direction on one side of the main body cavity 1, a sectional area of each chamber 101 is gradually reduced from a bottom to a top, and a reasonable distance should be maintained between two adjacent chambers 101. The chambers 101 have substantially the same shape and size and are uniformly distributed along the length direction of the main body cavity 1. The number of the chambers 101 may be determined according to the length of the body cavity 1, and is generally set to three or more.

The shape of the chamber 101 can be selected in many ways, but it should be ensured that the cross-sectional area of the bottom is larger and the cross-sectional area of the top is smaller, so as to form a variable cross-sectional shape, so that the inside of each chamber 101 is relatively separated when the inside of the main body cavity 1 is positively pressurized, and the inside of each chamber 101 is relatively close when the inside of the main body cavity 1 is negatively pressurized, that is, the distance between any two adjacent chambers 101 is controlled by the air pressure in the main body cavity 1. Meanwhile, the change of the distance between two adjacent chambers 101 can enable the body cavity 1 to achieve two opposite bending states as a whole. Preferably, the cross-sectional shape of the chamber 101 is an isosceles triangle or an isosceles trapezoid.

In addition, an air path 104 communicated with the outside is arranged inside the main body cavity 1, the air path 104 is arranged at the bottom of the main body cavity 1, and the air path 104 is sequentially connected with the bottom of each chamber 101 so as to communicate each chamber 101. The main body cavity 1 is further provided with an air inlet 103 communicated with the outside, and the inside of the main body cavity 1 can be inflated through the air inlet 103. In this embodiment, the gas inlet 103 is disposed on one of the chambers 101.

The two ends of the main body cavity 1 are used for connecting the two soft fingers 3, in this embodiment, the two ends of the main body cavity 1 are both provided with finger sleeves 102, the end of each soft finger 3 is provided with a plug 301, and the plug 301 of the two soft fingers 3 are respectively plugged with the two finger sleeves 102.

Referring to fig. 1 and 2, the variable stiffness layer 2 is disposed on the other side of the main body cavity 1, i.e. on the side opposite to each of the chambers 101. The variable stiffness layer 2 includes a receiving cavity 201 and a porosity variable material 202 disposed inside the receiving cavity 201. The accommodating cavity 201 is further provided with an air pipe, and the air pipe is used for sucking air into the accommodating cavity 201 to enable the inside of the accommodating cavity 201 to be at negative pressure, so that the compactness of the porosity variable material 202 is changed, and the rigidity of the variable rigidity layer 2 is controlled by the negative pressure in the accommodating cavity 201.

There are many options for the variable porosity material 202, and first the variable porosity material 202 may be a non-stretchable flexible sheet in a stacked arrangement or a non-stretchable flexible strip in a stacked arrangement. Wherein the non-retractable flexible sheet includes and is not limited to paper sheet, plastic sheet, etc., and the non-retractable flexible strip includes and is not limited to paper strip, plastic strip, etc. The non-telescopic flexible sheets and the non-telescopic flexible strips are mutually stacked and pressed, the negative pressure degree is different, the rigidity is different, and therefore the rigidity is adjusted.

The porosity variable material 202 may also be particles filled in the accommodating cavity. The particles comprise and are not limited to particles such as rice grains and coffee beans, gaps among the particles are small under the action of negative pressure, the degree of the negative pressure is different, the compaction degree among the particles is different, the rigidity is different, and the rigidity can be adjusted.

The working principle of the soft gripping device with adjustable gripping range and controllable rigidity in cooperation with the two soft fingers is as follows: the main body cavity 1 is inflated or sucked, so that positive pressure or negative pressure is kept in each chamber 101, the distance between two adjacent chambers 101 is changed, and the gripping device is further enabled to achieve a bending state in two directions. When the gripping device is bent, negative pressure is absorbed in the accommodating cavity 201, the degree of compaction of the variable porosity material 202 is changed, and the rigidity of the variable rigidity layer 2, namely the rigidity of the whole gripping device, is adjusted.

Referring to fig. 7-10, fig. 7 is a schematic view of the soft finger 3 being uninflated and inhaling and the main body cavity 1 being uninflated and inhaling in a natural state. Figure 8 is a schematic illustration of the soft finger 3 uninflated and inhaling, and the body chamber 1 inhaling. Figure 9 is a schematic view of the soft finger 3 uninflated and inhaled and the body cavity 1 inflated. Fig. 10 is a schematic view of the soft finger 3 inhaling and the main body cavity 1 inflating. It is obvious that the distance (range) between the two soft fingers 3 varies with the curvature and the bending direction of the gripping device in the natural state, the inflated state and the air suction state. Therefore, the gripping range of the soft fingers 3 can be adjusted, and the soft fingers can grip large-size objects and small-size objects.

In addition, in order to realize the processing and manufacturing of the soft gripping device with adjustable gripping range and controllable rigidity, the embodiment of the invention also provides a manufacturing method of the soft gripping device with adjustable gripping range and controllable rigidity, which comprises the following steps:

referring to fig. 11, in S1, a main body cavity 1 is formed by injection molding of silica gel through a first mold 4, where the first mold 4 includes a lower mold 401 and an upper mold 402, two ends of an inner cavity of the lower mold 401 are respectively provided with a finger stall cavity 401b, and a plurality of mold cavities 401a are disposed between the two finger stall cavities 401b and spaced from each other, the upper mold 402 is provided with a plurality of inserts 402a, cross-sectional areas of the inserts 402a gradually increase from bottom to top, the upper mold 402 and the lower mold 401 cover each other, and each insert 402a is inserted into one of the mold cavities 401 a. The insert 402a is inserted into the mold cavity 401a to form the cavity 101 by injection molding, and the insert 402a is a variable cross-section block, preferably a wedge-shaped block. In order to facilitate demoulding, an arched handle is arranged at the back of the upper mould 402, and vaseline lubricant is uniformly coated on the inner wall of the first mould 4 when the mould is used. The bottom of the main cavity 1 is opened.

S2, manufacturing the accommodating cavity 201, disposing the porosity variable material 202 inside the accommodating cavity 201, and then bonding the accommodating cavity 201 to the main cavity 1 on the side away from all the chambers 101. The accommodating cavity 201 is made of silica gel through injection molding of the second mold 5.

Referring to fig. 12, specifically, the second mold 5 includes a main mold 501 and a mold cover 502, wherein the main mold 501 is a rectangular groove body, the lower part of the mold cover 502 is provided with an inserting plate 502a, the mold cover 502 covers the notch of the main mold 501, and the inserting plate 502a is inserted into the main mold 501, so as to form a rectangular groove through injection molding, and then arrange the porosity variable material 202 in the rectangular groove, and seal the notch to form the variable rigidity layer 2, and finally, the variable rigidity layer 2 is adhered to the bottom of the main cavity 1, and the bottom of the main cavity 1 is sealed, so that the inside of the main cavity 1 forms a sealed cavity.

In this document, the terms front, back, upper and lower are used to define the components in the drawings and the positions of the components relative to each other, and are used for clarity and convenience of the technical solution. It is to be understood that the use of the directional terms should not be taken to limit the scope of the claims.

The features of the embodiments and embodiments described herein above may be combined with each other without conflict.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. The utility model provides a snatch adjustable, controllable software of controllable rigidity and grab device for connect two software fingers, its characterized in that includes:

2. The soft gripping device with adjustable gripping range and controllable rigidity as claimed in claim 1, wherein: the cross section of the chamber is in the shape of an isosceles triangle or an isosceles trapezoid.

3. The soft gripping device with adjustable gripping range and controllable rigidity as claimed in claim 1, wherein: the porosity variable material is a non-telescopic flexible sheet arranged in a stacked mode or a non-telescopic flexible strip arranged in a stacked mode.

4. The soft gripping device with adjustable gripping range and controllable rigidity as claimed in claim 1, wherein: the porosity variable material is particles filled in the accommodating cavity.

5. The soft gripping device with adjustable gripping range and controllable rigidity as claimed in claim 1, wherein: the main body cavity is internally provided with an air path communicated with the outside, and the air path is respectively communicated with the cavities.

6. The soft gripping device with adjustable gripping range and controllable rigidity as claimed in claim 1, wherein: fingerstalls are arranged at two ends of the main body cavity and are used for being connected with the soft fingers.

7. The soft gripping device with adjustable gripping range and controllable rigidity as claimed in claim 1, wherein: all the cavities are uniformly distributed along the length direction of the main body cavity.

8. The method for manufacturing the soft gripping device with the adjustable gripping range and the controllable rigidity as claimed in claim 1, which comprises the following steps:

9. The method for manufacturing the soft gripping device with adjustable gripping range and controllable rigidity according to claim 8, wherein the method comprises the following steps: the plug-in block is a wedge-shaped block.