CN113061320A

CN113061320A - Sandwich composite material plate for robot structure and protection and preparation method

Info

Publication number: CN113061320A
Application number: CN202110305513.3A
Authority: CN
Inventors: 赵立军; 金子旭; 蒲子涵; 牛锦鹏; 刘鑫
Original assignee: Harbin Institute of Technology
Current assignee: Harbin Institute of Technology
Priority date: 2021-03-25
Filing date: 2021-03-25
Publication date: 2021-07-02
Anticipated expiration: 2041-03-25
Also published as: CN113061320B

Abstract

The invention relates to a sandwich composite material plate for robot structure and protection and a preparation method thereof, and aims to solve the problems that the existing carbon fiber composite material is relatively high in cost, poor in energy absorption effect, easy to damage the internal structure after being impacted and difficult to apply and popularize in the fields of light load and low cost. And the carbon fiber layer is pressed on the middle wood layer through an epoxy adhesive, and bubbles are removed through pressing, so that the process of the raw material plate is completed. The invention greatly improves the mechanical property and the dimensional stability of the wooden board under the condition of not changing the average density to a large extent, so that the wooden board has better tensile, compression and hardness levels and more uniform vibration propagation. The invention is suitable for the protective plate structure of the mobile robot.

Description

Sandwich composite material plate for robot structure and protection and preparation method

Technical Field

The invention relates to a sandwich composite material plate, in particular to a sandwich composite material plate for robot structure and protection and a preparation method thereof, and belongs to the technical field of robot protective materials.

Background

The mobile robot needs to travel in long voyage in competition competitions, earthquake relief and dangerous search and rescue scenes, the situations of collision, smashing, extrusion and the like are easily caused by environment uncertainty, and the material with light weight, high toughness and high strength can effectively protect the robot from being deformed or physically damaged, improve the survival rate of the robot and enable the robot to operate flexibly.

At present, the structure and the protection of the mobile robot mostly adopt resin-based carbon fiber composite materials, and the mobile robot has the characteristics of high strength, high modulus, high temperature resistance, fatigue resistance, corrosion resistance, water resistance, creep resistance and the like. Because the carbon fiber has high elastic modulus, the composite material part is allowed to be used in an ultimate stress state, and the defect that the glass fiber resin composite material is only allowed to be used under the condition of less than 60 percent of ultimate stress is overcome. The composite material has the obvious advantages of impact resistance, fatigue resistance, antifriction and wear resistance, self-lubrication, corrosion resistance, heat resistance and the like, so that the composite material is widely applied to robot structures. However, the carbon fiber composite material has relatively high cost and poor energy absorption effect, is easy to damage the internal structure after receiving impact, and has difficulty in application and popularization in some light-load low-cost fields.

Based on the above, publication No. CN208469204U, published japanese patent No. 20190205 discloses a carbon fiber sandwich composite sound insulation board, which is filled with a foam material and is used for sound insulation and vibration absorption.

Disclosure of Invention

The invention provides a sandwich composite material plate for robot structure and protection and a preparation method thereof, aiming at solving the problems that the existing carbon fiber composite material is relatively high in cost, poor in energy absorption effect, easy to damage the internal structure after being impacted and difficult to apply and popularize in some light-load and low-cost fields.

The technical scheme adopted by the invention for solving the problems is as follows:

a light high-strength sandwich composite material plate for a robot structure and protection comprises at least two carbon fiber layers and at least one wood layer, wherein the wood layer is located between the two carbon fiber layers.

A preparation method of the sandwich composite material plate for robot structure and protection comprises the following steps:

step one, preparing raw materials: the method comprises the following steps of preparing related tools including an electronic scale, a pressing plate counterweight, a rolling brush, a hobbing cutter and a roller, wherein the related tools include a double-base epoxy resin, carbon fiber cloth, a basswood layer plate and a vacuum bag film, and cutting carbon fibers into a proper shape by the hobbing cutter arranged on the vacuum bag film;

step two, blending the double-base epoxy resin: fully mixing epoxy resin and a curing agent, and standing the mixture aside for 1 minute to defoam;

thirdly, laying the cut carbon fiber cloth on a basswood laminate, pouring the mixed epoxy resin on each part of the carbon fiber cloth in a small quantity and multiple times manner, and rolling the carbon fiber cloth to be uniform by using a rolling brush until the epoxy resin permeates into the basswood laminate;

fourthly, laying the cut vacuum bag film on the surface, and rolling by using a roller to fully soak and uniformly distribute the epoxy resin;

step five, turning over the basswood layer, paving carbon fiber cloth on the other surface, re-preparing epoxy resin, and repeating the steps of the step three and the step four;

placing the plate processed in the step five on a plane, laying a vacuum film on the plane, completely covering the whole plate by the vacuum film, and reserving a margin of about 2cm at the edge; then, placing a pressing plate on the plate to enable the pressing plate to completely press the plate, and placing a balance weight on the plate;

and seventhly, storing the sample plate in a constant temperature environment, taking out the sample plate when the curing time is 450-510 minutes at the ambient temperature of 25 ℃, and removing the vacuum bag film to obtain a plate finished product.

The invention has the beneficial effects that:

1. through the compounding of the carbon fiber layer and the wood layer, the mechanical property of the sandwich panel is greatly improved, and compared with the elasticity modulus of the wood layer, the elasticity modulus can be improved by about 80-240%, and the surface hardness is improved by about 60-120%.

2. And (4) low density. The density of the material can reach 0.6 to 1g/cm³(by changing the amount of epoxy resin and wood species of the wood layer), the method is more suitable for light structures.

3. Dimensional stability. By coating the carbon fibers and the epoxy resin, the influence of external humidity on wood is avoided, the approximate size is kept constant, and the cracking risk is basically eliminated.

4. The cost is low. The method has the advantages of less carbon fiber material, simple process, convenient secondary processing and low manufacturing cost.

5. The surface hardness is high, and can be adjusted between 80A-90D shore by matching with different resin-based reinforcing materials;

6. the whole toughness is good, and the normal deformation can reach 180%.

Drawings

FIG. 1 is a schematic structural view of a three-layer sandwich panel of the present invention;

FIG. 2 is a schematic structural view of a five-layer sandwich panel of the present invention;

FIG. 3 is a schematic view of the pan-tilt mechanism of the present invention applied to a mobile service robot;

FIG. 4 is a schematic view of a chassis configuration of the present invention as applied to a robotic competition;

Detailed Description

The first embodiment is as follows: referring to fig. 1 to 2, the present embodiment is described, and the lightweight high-strength sandwich composite material plate for robot structure and protection according to the present embodiment includes at least two carbon fiber layers 1 and at least one wood layer 2, and the wood layer 2 is located between the two carbon fiber layers 1.

The invention greatly improves the mechanical property and the dimensional stability of the wooden board under the condition of not changing the average density to a large extent, so that the wooden board has better tensile, compression and hardness levels and more uniform vibration propagation. The material is suitable for protecting a mobile robot in a scene of originally using a wood material, and is a novel low-cost light material between a carbon fiber material and wood.

The traditional wood material has obvious anisotropy, good mechanical property in the grain direction and poor mechanical property in the orthogonal direction of the grain, for example, the elastic modulus of the spruce along the grain is 11.55GPa, while the elastic modulus of the transverse grain is only 0.26 GPa. The traditional wood has very obvious moisture absorption, is very sensitive to environmental humidity, has obvious dry shrinkage and wet expansion characteristics, has obvious difference between radial and chord dry shrinkage rates, and is easy to cause cracking of materials. The coating to the wooden layer of carbon fiber material and epoxy is passed through in this design, has realized timber and external environment's isolation, has avoided the influence of external humidity to timber performance, has improved dimensional stability, has increased substantially simultaneously composite board's mechanical properties such as young's modulus.

The carbon fiber material has quite high specific strength, the internal structure is that a plurality of layers of carbon fiber cloth are arranged in different directions and are pressed and bonded by using an adhesive, the density of the carbon fiber material is about 1.76-1.8 g/cm3, the modulus of the carbon fiber material can reach 230GPa, and the carbon fiber material is a typical low-density high-strength material. However, the design density can reach 0.6-1 g/cm3 (by changing the amount of epoxy resin and the type of wood), and the design is more suitable for light structures. However, due to the structural limitation of the carbon fiber cloth, the thickness of the single-layer carbon fiber cloth is limited (about 0.2mm), and the carbon fiber layers of the sandwich plate can only be stacked through multiple layers of carbon cloth if the thickness of the carbon fiber layers is increased. In addition, the carbon fiber layer and the wood layer are bonded through the epoxy-based adhesive, the wood layer is not too thick and the surface is not too compact, the permeation effect of the epoxy-based adhesive is not ideal due to the too thick and compact surface, the bonding effect of the carbon fiber layer and the wood layer is poor, and the interlayer tearing and the like are possibly caused. Generally, the ratio of the thickness of the carbon fiber layer to the thickness of the wood layer is preferably 10-20, and the mechanical properties are partially adversely affected by too thin or too thick carbon fiber layer. In the same way, certain requirements are provided for the wood type of the wood layer, and tests show that the effect of the basswood veneer is ideal.

Because the middle part is filled for the wood layer, the wood layer can be preferentially broken when being impacted by an overlarge normal direction, the energy is absorbed, and then the energy is blocked to be transmitted to the inside of the structure, the principle of the energy absorption structure is similar to that of an energy absorption box and the like arranged by an automobile for protecting a driver, and therefore the internal structure is effectively guaranteed not to be damaged by impact. Meanwhile, the carbon fiber layer coated on the outer layer can maintain the basic form of the board after the wood layer is broken, bear a certain load, ensure the realization of the basic function to the minimum degree and avoid secondary damage caused by direct fracture.

The second embodiment is as follows: the present embodiment will be described with reference to fig. 1 to 2, and the wood layer 2 and the carbon fiber layer 1 according to the present embodiment are bonded by an epoxy-based adhesive.

Other components and connections are the same as those in the first embodiment.

The third concrete implementation mode: the present embodiment will be described with reference to fig. 2, in which the carbon fiber layer 1 is formed by arranging a plurality of carbon fiber cloths in different directions and pressing and bonding the carbon fiber cloths with an adhesive.

Other components are connected in the same manner as in the first or second embodiment.

The fourth concrete implementation mode: referring to fig. 2, the present embodiment is described, and the sandwich composite material plate for robot structure and protection in the present embodiment is a five-layer sandwich material plate composed of three carbon fiber layers 1 and two wood layers 2.

Other components and connection relationships are the same as those in the first, second or third embodiment.

The fifth concrete implementation mode: the present embodiment is described with reference to fig. 1 to 2, and the sandwich composite material plate for robot structure and protection according to the present embodiment is a seven-layer sandwich material plate composed of four carbon fiber layers 1 and three wood layers 2. When a large load needs to be borne, the effect can be realized by increasing the number of layers, for example, changing 3 layers of plates into 5 layers of sandwich material plates, 7 layers of sandwich material plates and the like.

Other components and connections are the same as those of the first, second, third or fourth embodiments.

The sixth specific implementation mode: the present embodiment is described with reference to fig. 1 to 2, and the thickness ratio of the carbon fiber layer 1 to the wood layer 2 in the present embodiment is 10 to 20.

Other components and connection relationships are the same as those in the first, second, third, fourth or fifth embodiment.

The seventh embodiment: in the present embodiment, the wood layer 2 is a basswood veneer according to the present embodiment, which is described with reference to fig. 3. Other components and connection relationships are the same as those in the first, second, third, fourth, fifth or sixth embodiment.

The specific implementation mode is eight: the present embodiment is described with reference to fig. 1 to 2, and the preparation method of the present embodiment includes the following steps:

Other components and connection relations are the same as those of the first, second, third, fourth, fifth, sixth or seventh embodiment.

The specific implementation method nine: the present embodiment is described with reference to fig. 1 to fig. 2, and the viscosity of the dual-base epoxy resin after mixing is 600-800mpas at an ambient temperature of 25 ℃.

Other components and connection relationships are the same as those of the first, second, third, fourth, fifth, sixth, seventh or eighth embodiment.

The detailed implementation mode is ten: referring to fig. 1 to 2, the present embodiment is described, wherein the weight ratio of the epoxy resin to the curing agent in the second step of the present embodiment is 10: 3.

other components and connection relations are the same as those of the first, second, third, fourth, fifth, sixth, seventh, eighth or ninth embodiment.

The concrete implementation mode eleven: referring to FIGS. 1-2, the weight of the counterweight is selected according to the actual area of the plate, and the reference value of the counterweight is 200kg/m 2.

Other components and connection relationships are the same as those of the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth or tenth embodiment.

The specific implementation mode twelve: referring to fig. 3, the mobile robot inevitably receives impact during high-speed movement, and damages the knot structure. If according to traditional design for reducing weight, use materials such as carbon fiber more, however if impact load is slightly bigger, because the cost is higher, and difficult absorbed energy, easily will strike and transmit inner structure, and then cause inner structure's damage. The invention is very suitable for application, and under the condition of slightly basic design, the carbon fiber composite material plate (with the thickness of 3mm & lt 3 & gt K) is replaced by the sandwich composite material plate (5 layers), so that the structural strength of about 80 percent can be maintained, meanwhile, the weight of about 10 percent and the cost of about 50 percent can be reduced, and the work of the whole mechanism is more efficient and reliable. Simultaneously because the middle part fills for the wooden layer, the wooden layer can be preferentially broken when receiving too big normal direction impact, with energy absorption, and then blocks the energy and to the inside transmission of structure to effectively guarantee that inner structure does not receive the destruction of assaulting. Meanwhile, the carbon fiber layer coated on the outer layer can maintain the basic form of the board after the wood layer is broken, bear a certain load, ensure the realization of the basic function to the minimum degree and avoid secondary damage caused by direct fracture.

If the pan-tilt mechanism of the mobile service robot, the supporting plate and the outer protecting plate can use the plate, the weight and the cost of the whole machine can be effectively reduced. Simultaneously because the characteristic of inside wooden layer, this type panel still has certain shock-absorbing capacity, can effectively reduce noise and vibration like the periodic vibration production that the friction pulley transmitter constitutes to can reduce the product noise through reasonable design, and then strengthen the use experience and the stability of robot.

The lower diagram is a pan-tilt structure commonly found in Robomaster robot races, which functions as a mechanism for launching and scoring projectiles (17mm TPU balls) in a parallel arrangement through 2 friction wheels fixed to the lower plate. The upper cover plate (i.e. reference numeral 3 in the attached figure 3) of the mechanism is usually made of carbon fiber composite material, so that the cost is high and the mass is large. According to the force analysis, the lower friction wheel, namely the lower mounting plate, is a main force structure, and the upper cover plate is stressed less, so that the composite material plate can be used for replacement, the mass can be effectively reduced, and the response speed of the holder system is further improved.

The specific implementation mode is thirteen: the present embodiment is described with reference to fig. 4, and is a chassis structure applied to Robomaster robot competition, where 2 structures for storing shots (one kind of objects in the competition) on the chassis are located at the center of the chassis and at one side of the chassis (i.e. reference numerals 4 and 5 in fig. 4 in the specification), and the structure mainly receives shots dropped from above, and needs to have a certain impact resistance, and needs to have a low moisture absorption due to a high humidity of ambient air, and at the same time, has a low density, thereby facilitating a lightweight design. The composite plate in the application is very suitable for the working condition, and the working performance of a similar system can be effectively improved.

The specific implementation mode is fourteen: the composite material plate can also be applied to a sound box equipment shell. Acoustic equipment has related requirements on acoustic performance of a shell material, so solid wood plates are adopted mostly, but the solid wood plates can cause local expansion and deformation of the plates due to damp after being used for a long time, and performance of the whole equipment is further influenced. In contrast, the fiber layer outside the wood layer is acted, so that water vapor cannot penetrate through the fiber layer soaked by the epoxy resin, the anticorrosion effect on the wood layer is achieved, and the service life of the middle wood layer is prolonged. Meanwhile, due to the traction effect of the outer layer fibers, the mechanical property of the whole plate is more uniform, local deformation and expansion are not easy to occur, and the service performance of the whole equipment can be improved.

Benefit from the intensity promotion that the fibrous layer brought, sandwich panel thickness of this structure can be thinner, makes it also can regard as the attraction material in the room to a certain extent, relies on the low rigidity characteristic that the thinner panel brought to convert the air vibration into the mechanical oscillation at panel middle part, and then absorbs the energy, realizes attracting the effect. Although the effect cannot be compared with that of a special attraction material, the characteristics of low cost, low weight and difficult damage of the invention also indicate that the invention has corresponding value. Through preliminary simulation and analysis, the type of plate with the thickness of 2mm is paved in a square room with about 20 planes, the noise of 10db can be reduced under the noise with the background of 80db, and the maintenance is simple and convenient.

The concrete implementation mode is fifteen: the composite board can also be used as a ribbed plate of toys such as aeromodelling and the like. At present, composite materials such as carbon fiber and glass fiber are mostly adopted for supporting plates of key components in middle-end and high-end aeromodelling, but the parts have no higher stress requirements under the same scene, and the carbon fiber or glass fiber can be replaced by the supporting plate, so that the cost is reduced while the general strength is ensured, and the weight of the aeromodelling is reduced to a certain extent. Meanwhile, due to the characteristics of the sandwich board, when danger occurs, the inner wood layer can be damaged preferentially, but due to the constraint of the outer fiber layer, fragments generated by the inner wood layer cannot fly out, so that the personal safety of a user and other people is prevented from being harmed, and the safety is ensured. The effect is similar to that of the safety glass of an automobile, and because toys such as a model airplane and the like have higher speed and kinetic energy and are extremely easy to cause harm to users or other people, the safety guarantee from the aspect of materials is very important.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. The utility model provides a press from both sides core combined material board for robot structure and protection which characterized in that: the light high-strength sandwich composite material plate for the robot structure and protection comprises at least two carbon fiber layers (1) and at least one wood layer (2), wherein the wood layer (2) is located between the two carbon fiber layers (1).

2. The light-weight high-strength sandwich composite material plate for robot structure and protection according to claim 1, characterized in that: the wood layer (2) and the carbon fiber layer (1) are bonded by an epoxy-based adhesive.

3. The sandwich composite material plate for robot structure and protection according to claim 2, characterized in that: the carbon fiber layer (1) is formed by arranging a plurality of layers of carbon fiber cloth in different directions and pressing and bonding the carbon fiber cloth by an adhesive.

4. The sandwich composite material plate for robot structure and protection according to claim 3, wherein: the sandwich composite material plate for the robot structure and protection is a five-layer sandwich material plate consisting of three carbon fiber layers (1) and two wood layers (2).

5. The sandwich composite material plate for robot structure and protection according to claim 1, characterized in that: the sandwich composite material plate for the robot structure and protection is a seven-layer sandwich material plate consisting of four carbon fiber layers (1) and three wood layers (2).

6. The sandwich composite material plate for robot structure and protection according to claim 1, characterized in that: the thickness ratio of the carbon fiber layer (1) to the wood layer (2) is 10-20.

7. The sandwich composite material plate for robot structure and protection according to claim 1, characterized in that: the wood layer (2) is a basswood layer plate.

8. A preparation method of a sandwich composite material plate for robot structure and protection is characterized by comprising the following steps: the preparation method comprises the following steps:

9. A preparation method of a sandwich composite material plate for robot structure and protection is characterized by comprising the following steps: when the ambient temperature of the double-base epoxy resin in the step one is 25 ℃, the mixed viscosity is 600-800 mpas.

10. A preparation method of a sandwich composite material plate for robot structure and protection is characterized by comprising the following steps: the weight ratio of the epoxy resin to the curing agent in the second step is 10: 3.

11. a preparation method of a sandwich composite material plate for robot structure and protection is characterized by comprising the following steps: the weight of the counterweight is selected according to the actual area of the plate, and the reference value of the counterweight is 200kg/m ^ 2.