CN115674806A - Composite impact-resistant fork and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of handling robot forks, and discloses a composite impact-resistant fork and a preparation method thereof. A surface impact-resistant layer, an intermediate interface layer, and a bottom rigid layer are sequentially arranged from one side to the other side, wherein the The surface impact-resistant layer is a composite structure of carbon fiber two-dimensional weaving structure and thermoplastic resin matrix; the middle interface layer is a composite structure of aramid honeycomb structure and thermoplastic resin matrix; the bottom rigid layer includes a main body and several buffer sheets, and the main body is high A composite structure of a three-dimensional braided structure of strong carbon fibers and a thermosetting resin matrix, and several buffer sheets are evenly pre-embedded on the side of the main body close to the middle interface layer. The cargo fork of this structure has good impact resistance, rigidity, shock resistance and cushioning performance.

Description

Composite impact-resistant fork and preparation method thereof

technical field

The invention belongs to the technical field of handling robot forks, and in particular relates to a composite impact-resistant fork and a preparation method thereof.

Background technique

The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

With the continuous development of science and technology, many tasks are gradually changed from manual processing to robotics, which greatly saves manpower and improves work efficiency. The handling robot has high-speed and stable control technology. Through trajectory optimization, improving the rigidity of the fork and joint servo performance, the stability of handling is realized. The handling robot can realize the complete automatic handling and transfer of goods, and its working performance directly affects the production efficiency, so it has positive significance for the improvement and optimization of the fork in the handling robot.

Compared with ordinary forks, carbon fiber composite forks have the advantages of light weight, strong corrosion resistance, and high fatigue strength. The composite material has a hierarchical structure. Under these forces, the hierarchical structure of the carbon fiber composite material is easy to delaminate, and the overall fork is prone to deformation or even bending, which affects the overall service life of the fork.

Contents of the invention

Aiming at the deficiencies in the prior art, the object of the present invention is to provide a composite impact-resistant fork and a preparation method thereof.

In order to achieve the above object, the present invention is achieved through the following technical solutions:

In the first aspect, the present invention provides a composite impact-resistant fork, in which a surface impact-resistant layer, an intermediate interface layer and a bottom rigid layer are sequentially arranged from one side to the other, wherein,

The surface impact-resistant layer is a composite structure of carbon fiber two-dimensional weaving structure and thermoplastic resin matrix;

The middle interface layer adopts the composite structure of aramid fiber honeycomb structure and thermoplastic resin matrix;

The bottom rigid layer includes a main body and several buffer sheets. The main body is a composite structure of a high-strength carbon fiber three-dimensional braided structure and a thermosetting resin matrix. Side, so that the buffer sheet is directly bonded to the middle interface layer;

The thickness of the buffer sheet is greater than or equal to 1 mm, and the thickness of the bottom rigid layer is at least twice the thickness of the buffer sheet.

In a second aspect, the present invention provides a method for preparing the composite impact-resistant fork, comprising the following steps:

Aramid honeycombs milled to shape and filled with thermoplastic resin;

Lay thermoplastic films on the upper and lower surfaces of the aramid honeycomb filled with thermoplastic resin;

Then lay a carbon fiber two-dimensional woven structure prepreg and a carbon fiber three-dimensional woven structure prepreg on the upper and lower surfaces of the aramid honeycomb, and evenly embed a buffer sheet in the side of the carbon fiber three-dimensional woven structure prepreg close to the aramid honeycomb;

After the laying is completed, it is hot-pressed and solidified to form the finished product.

The beneficial effects obtained by one or more embodiments of the present invention are as follows:

The surface impact-resistant layer is a composite structure of carbon fiber two-dimensional weaving structure and thermoplastic resin matrix. The carbon fiber two-dimensional weaving structure strengthens the resin matrix isotropically, and there will be no weak reinforcement direction. At the same time, the reinforcing structure is a two-dimensional weaving structure. There is a strong interaction force between carbon fibers, so that it will not split under strong impact, and has strong impact resistance.

The middle interface layer adopts a composite structure of aramid fiber honeycomb and thermoplastic resin. This structure has strong shear resistance and can effectively improve the shear resistance of the fork, especially the bending strength of the fork. At the same time, this structure can significantly reduce the weight of the fork and enhance the specific strength of the fork.

The main body of the bottom rigid layer is a composite structure of high-strength carbon fiber three-dimensional braided structure and thermosetting resin matrix. This structure has strong rigidity. As the most basic support at the bottom, it can effectively reduce the deformation of the fork during forklifting. Provide strong support for the surface impact-resistant layer and the middle interface layer to effectively improve the performance of the composite fork.

The buffer sheet is evenly embedded on the side of the bottom rigid layer close to the middle interface layer. The buffer sheet is used for energy absorption, which can better buffer the impact force exerted on the fork and reduce the instantaneous impact on the bottom rigid layer. , to improve the stress of the bottom rigid layer and avoid the bottom rigid layer from breaking under a large impact force. At the same time, the buffer sheet also has shock-absorbing properties, making the forklift more stable.

The thickness of the buffer sheet is greater than or equal to 1mm to ensure an effective buffering effect, and the thickness of the bottom rigid layer is limited so that the bottom rigid layer removes the thickness of the embedded buffer sheet, and there is still enough thickness for the impact-resistant layer on the surface of the fork and the intermediate interface layer for effective support.

If the buffer sheet is pre-embedded inside the bottom rigid layer, when the buffer sheet and the middle interface layer are bonded through a part of the bottom rigid layer, the part of the bottom rigid layer first needs to transmit the force to the buffer sheet through deformation, so that the buffer sheet can However, the deformed bottom rigid layer will drive other parts to deform one after another, resulting in the weakened effect of the buffer sheet. Therefore, the buffer sheet is set to be bonded and fixed directly with the middle interface layer. When the goods are placed on the fork body, the force is directly transmitted to the buffer sheet through the surface impact-resistant layer and the middle interface layer, so that the buffer sheet can play a corresponding role. To reduce the deformation of the bottom rigid layer.

During the hot pressing process, a small amount of resin in the prepreg cloth on both sides of the aramid honeycomb enters the aramid honeycomb and is combined with the aramid honeycomb to form a whole, so that the surface impact-resistant layer, the middle interface layer and the bottom rigid layer form a whole to avoid The fork is delaminated during use, which can further improve the rigidity and impact resistance of the fork. At the same time, the composite material has good corrosion resistance.

Description of drawings

The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention, and the schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention.

Fig. 1 is a schematic diagram of the overall structure of the composite impact-resistant plate structure of the embodiment of the present invention;

Fig. 2 is a plan view of the bottom rigid layer of the composite impact-resistant plate structure of the embodiment of the present invention.

Among them, 1. Surface impact-resistant layer; 2. Intermediate interface layer; 3. Bottom rigid layer; 4. Buffer sheet.

Detailed ways

It should be noted that the following detailed description is exemplary and intended to provide further explanation of the present invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

In the first aspect, the present invention provides a composite impact-resistant fork, in which a surface impact-resistant layer, an intermediate interface layer and a bottom rigid layer are sequentially arranged from one side to the other, wherein,

The surface impact-resistant layer is a composite structure of carbon fiber two-dimensional weaving structure and thermoplastic resin matrix;

The middle interface layer adopts the composite structure of aramid fiber honeycomb structure and thermoplastic resin matrix;

The bottom rigid layer includes a main body and several buffer sheets. The main body is a composite structure of a high-strength carbon fiber three-dimensional braided structure and a thermosetting resin matrix. Side, so that the buffer sheet is directly bonded to the middle interface layer;

The thickness of the buffer sheet is greater than or equal to 1 mm, and the thickness of the bottom rigid layer is at least twice the thickness of the buffer sheet.

Carbon fiber is a special fiber with high strength and high modulus. It has excellent mechanical properties such as high strength and high modulus, and has the advantages of light weight, stable chemical composition, and good high temperature resistance. Compared with ordinary steel forks, carbon fiber composite forks have the advantages of light weight, high strength-to-mass ratio, strong corrosion resistance, and high fatigue strength. The aramid honeycomb core mainly bears the shear stress in the sandwich structure, which makes the sandwich structure have high bending stiffness.

The plate adopts a multi-layer structure, which effectively improves the rigidity, impact resistance and friction resistance of the fork.

In some embodiments, the buffer sheet is a chopped carbon fiber reinforced silicone rubber composite material.

The embedded buffer sheet in the rigid layer is composed of silicone rubber doped with chopped carbon fiber, which not only has good high strength and high specific stiffness, but also has excellent shock absorption and anti-vibration buffering effect.

Preferably, the mass percentage of silicone rubber in the buffer sheet is 30-50%, and the length of the chopped carbon fiber is 2-5mm.

In some embodiments, the two-dimensional planar weave structure of the surface impact-resistant layer is selected from plain weave, twill weave or satin weave structure, and the resin content is 30%-60%.

Preferably, the carbon fibers of the surface impact-resistant layer are high-strength carbon fibers selected from T300, T700, T800 or T1000.

Preferably, the thermoplastic resin of the surface impact-resistant layer is selected from polyethylene, polypropylene, polyvinyl chloride or polystyrene.

Preferably, the thickness of the surface impact-resistant layer is 2-4mm.

In some embodiments, the thickness of the intermediate interface layer is 3-5 mm.

Preferably, the resin content of the intermediate interface layer is 30%-60%.

The manufacture of aramid honeycomb generally adopts the method of stretching and expansion. The production process is mainly divided into nine processes: gluing, lamination, pressing, cutting, stretching, shaping, dipping, curing, and sheet cutting. The thermoplastic resin can be selected from any type of thermoplastic resin used in the surface impact-resistant layer, and is not limited to the above-mentioned types.

In some embodiments, the bottom rigid layer has a thickness of 3-5 mm, and the buffer sheet has a thickness of 1-2 mm.

Preferably, the thickness difference between the bottom rigid layer and the buffer sheet is at least 2 mm. To ensure the rigidity of the bottom rigid layer on the side where the buffer sheet is not embedded, so as to provide sufficient support.

Preferably, the resin content of the bottom rigid layer is 30-60%.

Preferably, the three-dimensional braided structure of the bottom rigid layer is a three-dimensional four-way, three-dimensional five-way, three-dimensional six-way or three-dimensional seven-way braided structure;

The thermosetting resin is selected from epoxy resin, phenolic resin, unsaturated polyester resin or urea-formaldehyde resin.

In a second aspect, the present invention provides a method for preparing the composite impact-resistant fork, comprising the following steps:

Aramid honeycombs milled to shape and filled with thermoplastic resin;

Lay thermoplastic films on the upper and lower surfaces filled with aramid honeycomb;

Then lay a carbon fiber two-dimensional woven structure prepreg and a carbon fiber three-dimensional woven structure prepreg on the upper and lower surfaces of the aramid honeycomb, and evenly embed a buffer sheet in the side of the carbon fiber three-dimensional woven structure prepreg close to the aramid honeycomb;

After the laying is completed, it is hot-pressed and solidified to form the finished product.

In some embodiments, the material of the thermoplastic film is polyetherimide (PEI), polyetherketone (PEK), polysulfone (PSF) or polyethersulfone (PES).

In some embodiments, the preparation method of the carbon fiber two-dimensional woven structure prepreg is as follows: the thermoplastic film and the carbon fiber cloth are stacked on a preheated press, and hot pressed to obtain the product;

The hot-pressing temperature is 120-150°C, the pressure is 0.5-2MPa, and the hot-pressing time is 20-60 minutes. After the hot-pressing is completed, stop heating and keep for 40-60 minutes.

Preferably, ultrafine thermoplastic bonding powder is sprayed between adjacent carbon fiber cloths.

Further preferably, the ultrafine thermoplastic bonding powder is selected from polyamide powder, polyethylene powder or polyurethane powder. The particle size of the powder can be flexibly selected within the range of 200-2000 mesh.

In some embodiments, the temperature of thermocompression curing molding is 110-130° C., and the molding pressure is 0.1-0.5 MPa.

The compression molding is to place the laminated sheet made of prepreg cloth into a specific metal mold, and then heat and press to solidify and form. The compression molding process is to first cut the carbon fiber sheet according to the size of the product, clean the mold with a specific structure, apply a release agent, place the carbon fiber sheet, and perform mold closing. When screwing the screw, apply lubricating oil to ensure smooth mold opening. . Place the completed carbon fiber product mold on the preheated hot press, and decompress 3 to 4 times with an interval of 10 to 20 seconds. The temperature of the press is set at 130-180°C, the pressure is 2-10 MPa, the pressing time is 30-90 minutes, and then the heating is stopped for 30-60 minutes. After the mold is cooled, demoulding is carried out.

The present invention will be further described below in conjunction with embodiment.

Example 1

As shown in Figure 1, the surface impact-resistant layer 1 is made of T700 high-strength carbon fiber for two-dimensional twill weaving and composited with polyethylene resin, with a thickness of 3mm and a resin content of 40%. Polyamide powder with a particle size of 1000 mesh is used for hot-press forming, and polyetherimide film is selected as the thermoplastic film. For hot pressing and compression molding, set the temperature of the press to 150°C and the pressure to 6 MPa. Before pressurization, depressurize three times with a time interval of 10s, pressurize for 40min, and then stop heating for 35min.

The middle interface layer 2 is a honeycomb structure, which is composed of an aramid honeycomb structure and a polypropylene resin matrix, with a resin content of 60% and a thickness of 5 mm.

The bottom rigid layer 3 is made of T1000 high-strength carbon fiber, adopts a three-dimensional seven-way weaving structure and is impregnated with epoxy resin, and the buffer sheet 4 is composed of silicone rubber doped with chopped carbon fiber. The silicone rubber content is 30%, and the length of the chopped carbon fiber is 2mm. The thickness of the buffer sheet is 2mm, and the buffer sheet is evenly distributed in the bottom rigid layer in a matrix. The bottom rigid layer has a thickness of 5mm and a resin content of 40%.

The above three laminated parts are cured and molded in an autoclave at a curing temperature of 120° C. and a molding pressure of 0.3 MPa. The structural board has an overall resin matrix content of 45% and a thickness of 13mm.

Example 2

The surface impact-resistant layer is made of T800 high-strength carbon fiber for two-dimensional plain weave and polypropylene resin, with a thickness of 2mm and a resin content of 50%. Polyethylene powder with a particle size of 1000 mesh is used for hot-press forming, and polysulfone film is selected as the thermoplastic film. For hot pressing and compression molding, the temperature of the press is set at 180°C and the pressure is 7 MPa. Before pressurization, depressurization is performed three times with a time interval of 10s. The pressurization time is 80min, and then the heating is stopped for 40min.

The middle honeycomb layer is composed of aramid honeycomb structure and polyethylene resin matrix, the resin content is 50%, and the thickness is 4mm.

The rigid layer at the bottom adopts T300 high-strength carbon fiber, adopts three-dimensional four-way weaving structure and phenolic resin impregnation composite, the buffer sheet is composed of silicone rubber doped with chopped carbon fiber, the silicone rubber content is 50%, the length of chopped carbon fiber is 4mm, and the buffer sheet The thickness is 2mm, and the buffer sheets are evenly distributed in the bottom rigid layer in a matrix. The bottom rigid layer has a thickness of 4mm and a resin content of 50%.

The above three laminated parts are cured and molded in an autoclave at a curing temperature of 120° C. and a molding pressure of 0.3 MPa. The overall resin matrix content of the structural plate is 50%, and the thickness is 10mm.

Example 3

The surface impact-resistant layer is made of T700 high-strength carbon fiber for two-dimensional satin weaving and polyvinyl chloride resin, with a thickness of 3mm and a resin content of 60%. Polyamide powder with a particle size of 800 mesh is used for hot-press forming, and polyetherimide film is selected as the thermoplastic film. For hot pressing and compression molding, set the temperature of the press to 150°C and the pressure to 6 MPa. Before pressurization, depressurize three times with a time interval of 10s, pressurize for 90min, and then stop heating for 35min.

The middle interface layer is a honeycomb structure, which is composed of an aramid honeycomb structure and a polyvinyl chloride resin matrix, with a resin content of 60% and a thickness of 5mm.

The bottom rigid layer adopts T1000 high-strength carbon fiber, adopts three-dimensional five-way weaving structure and is impregnated with urea-formaldehyde resin. The buffer sheet is composed of silicone rubber doped with chopped carbon fiber. The silicone rubber content is 40%. The thickness is 1mm, and the buffer sheets are evenly distributed in the bottom rigid layer in a matrix. The bottom rigid layer has a thickness of 4mm and a resin content of 55%.

The above three laminated parts are cured and molded in an autoclave at a curing temperature of 120° C. and a molding pressure of 0.3 MPa. The structural board has an overall resin matrix content of 58% and a thickness of 12 mm.

Example 4

The surface impact-resistant layer is made of T300 high-strength carbon fiber for two-dimensional twill weaving and polyethylene resin, with a thickness of 3mm and a resin content of 50%. Polyamide powder with a particle size of 500 mesh is used for hot-press forming, and polyetherimide film is selected as the thermoplastic film. For hot pressing and compression molding, the temperature of the press is set at 130°C and the pressure is 5 MPa. Before pressurization, depressurization is performed three times with a time interval of 10s, and the pressurization time is 50 minutes, and then the heating is stopped for 60 minutes.

The middle interface layer is a honeycomb structure, which is composed of an aramid honeycomb structure and a polypropylene resin matrix, with a resin content of 30% and a thickness of 4mm. The bottom rigid layer adopts T1000 high-strength carbon fiber, adopts three-dimensional six-way weaving structure and epoxy resin impregnation composite, the buffer sheet is composed of silicone rubber doped with chopped carbon fiber, the silicone rubber content is 30%, the length of chopped carbon fiber is 2mm, the buffer sheet The thickness is 2mm, and the buffer sheets are evenly distributed in the bottom rigid layer in a matrix. The bottom rigid layer has a thickness of 4mm and a resin content of 40%.

The above three laminated parts are cured and molded in an autoclave at a curing temperature of 120° C. and a molding pressure of 0.3 MPa. The structural board has an overall resin matrix content of 40% and a thickness of 11 mm.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A composite impact-resistant fork, characterized in that: a surface impact-resistant layer, an intermediate interface layer and a bottom rigid layer are arranged successively from one side to the other side, wherein, The surface impact-resistant layer is a composite structure of carbon fiber two-dimensional weaving structure and thermoplastic resin matrix; The middle interface layer adopts the composite structure of aramid fiber honeycomb structure and thermoplastic resin matrix; The bottom rigid layer includes a main body and several buffer sheets. The main body is a composite structure of a high-strength carbon fiber three-dimensional braided structure and a thermosetting resin matrix. Side, so that the buffer sheet is directly bonded to the middle interface layer; The thickness of the buffer sheet is greater than or equal to 1 mm, and the thickness of the bottom rigid layer is at least twice the thickness of the buffer sheet. 2. The composite impact-resistant fork according to claim 1, characterized in that: the buffer sheet is a chopped carbon fiber reinforced silicone rubber composite material; the mass percentage of the silicone rubber in the buffer sheet is 30-50%, and the chopped carbon fiber The length is 2-5mm. 3. The composite impact-resistant fork according to claim 1, characterized in that: the two-dimensional planar weave structure of the surface impact-resistant layer is selected from plain weave, twill or satin weave structure; the carbon fiber of the surface impact-resistant layer is high-strength carbon fiber, Choose from T300, T700, T800 or T1000. 4. The composite impact-resistant fork according to claim 1, characterized in that: the thickness of the surface impact-resistant layer is 2-4mm; the thickness of the middle interface layer is 3-5mm; the thickness of the bottom rigid layer is 3-5mm, The thickness of the buffer sheet is 1-2mm. 5. The composite impact-resistant fork according to claim 1, characterized in that: the thickness difference between the bottom rigid layer and the buffer sheet is at least 2mm. 6. The composite impact-resistant fork according to claim 1, characterized in that: the resin content of the surface impact-resistant layer is 30%-60%, the resin content of the middle interface layer is 30%-60%, and the resin content of the bottom rigid layer The resin content is 30%-60%. 7. The preparation method of the composite impact-resistant fork according to any one of claims 1-6, characterized in that: comprising the following steps: Aramid honeycombs milled to shape and filled with thermoplastic resin; Lay thermoplastic films on the upper and lower surfaces of the aramid honeycomb filled with thermoplastic resin; Then lay a carbon fiber two-dimensional woven structure prepreg and a carbon fiber three-dimensional woven structure prepreg on the upper and lower surfaces of the aramid honeycomb, and evenly embed a buffer sheet in the side of the carbon fiber three-dimensional woven structure prepreg close to the aramid honeycomb; After the laying is completed, it is hot-pressed and solidified to form the finished product. 8 . The method for preparing a composite impact-resistant fork according to claim 7 , wherein the material of the thermoplastic film is polyetherimide, polyetherketone, polysulfone or polyethersulfone. 9. The preparation method of the composite impact-resistant fork according to claim 7, characterized in that: the preparation method of the carbon fiber two-dimensional weaving structure prepreg is: placing the thermoplastic film and the carbon fiber cloth laminated on the preheated On the press, hot pressing, that is; The hot-pressing temperature is 120-150°C, the pressure is 0.5-2MPa, the hot-pressing time is 20-60 minutes, and after the hot-pressing is completed, stop heating and keep for 40-60 minutes. 10. The preparation method of the composite impact-resistant fork according to claim 7, characterized in that: ultrafine thermoplastic bonding powder is sprayed between adjacent carbon fiber cloths; the ultrafine thermoplastic bonding powder is selected from polyamide powder, polyethylene powder or polyurethane powder.

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