High-strength carbon fiber composite torsion shaft and preparation method thereof

Abstract

The invention belongs to the field of machine manufacturing, and discloses a high-strength carbon fiber composite torsion shaft which comprises a steel body and a carbon fiber coating layer. Spline shafts at the two ends of the steel body are consistent with a conventional torsion shaft structure, the diameter of a middle rod body is smaller than that of the conventional torsion shaft structure, the carbon fiber coating layer is arranged on the middle rod body of the steel body, and the diameter of the coated middle rod body is consistent with that of the conventional torsion shaft. The outer diameter of the metal round rod is designed to be of a carbon fiber structure, and carbon fibers are tightly combined with the torsion shaft structure through a specific winding mode and a curing process; the mechanical property and durability of the torsion shaft are remarkably improved, the weight of the torsion shaft is reduced, and light weight and high maneuverability of products and a whole vehicle are achieved.

Description

Technical Field

[0001] The invention belongs to the field of mechanical manufacturing, and in particular relates to a high-strength carbon fiber composite torsion shaft and a preparation method thereof. Background Art

[0002] The vehicle torsion shaft is used to support the vehicle body and reduce the impact of the ground on the vehicle body during movement. It is an elastic element of the suspension device. It is a steel round rod with splines at both ends and an axle in the middle, which is used to connect and fix to the two ends of the vehicle.

[0003] like Figure 1 As shown, the traditional torsion shaft is made of steel, which has problems such as heavy weight and easy fatigue. With the development of new lightweight materials and their manufacturing processes, carbon fiber has gradually become an ideal choice to replace traditional metal materials due to its high strength, low density and excellent fatigue resistance. In particular, the combined application of carbon fiber and metal materials has become the most reasonable and feasible solution. Summary of the invention

[0004] The technical problem to be solved by the present invention is that the traditional torsion shaft is made of steel, which has the problems of heavy weight and easy fatigue.

[0005] In order to solve the above technical problems, the specific technical solutions of the present invention are as follows:

[0006] A high-strength carbon fiber composite torsion shaft, comprising a steel body and a carbon fiber coating layer; the spline shafts at both ends of the steel body are consistent with the conventional torsion shaft structure, the diameter of the middle rod body is smaller than that of the conventional torsion shaft structure, and the carbon fiber coating layer is arranged on the middle rod body of the steel body, and the diameter of the middle rod body after coating is consistent with that of the conventional torsion shaft.

[0007] The thickness of the carbon fiber coating layer is 20%-40% of the diameter of the composite torsion shaft rod.

[0008] The present invention also provides a method for preparing a high-strength carbon fiber composite torsion shaft, comprising the following steps:

[0009] Step 1. Preparation

[0010] Step 1.1: Use 95% industrial alcohol to wipe the torque shaft to remove surface oil stains and other debris:

[0011] Step 1.2, take out the carbon fiber raw materials stored below -10°C, and use a CNC cutting machine to cut out unidirectional carbon fiber pre-impregnated resin materials for paving;

[0012] Step 2: Paving work

[0013] Step 2.1, prepare a single layer of carbon fiber cloth, and perform multi-layer winding of the carbon fiber and the axis of the torsion shaft at an angle of ±45°;

[0014] Step 2.2: The number of ply layers is calculated based on the single-layer thickness and total thickness requirements to fully utilize the tensile strength of the carbon fiber and disperse the stress generated by the torsion shaft during the torsion process;

[0015] Step 3: Autoclave forming

[0016] Step 3.1, vacuuming: Use nylon demoulding cloth, breathable felt, and high-temperature resistant plastic to cover the laid carbon fiber layer by layer, and then use rubber strips to seal the plastic along the edge. Use rubber strips to tie the wide parts of the plastic cloth to ensure that the plastic above the carbon fiber is flattened. Install a vacuum valve at the diagonal of the carbon fiber flat plate, and connect the air pipe for vacuuming to test vacuum the carbon fiber laying layer;

[0017] Step 3.2, check the sealing of plastic bonding. If the sealing is OK, push the carbon fiber parts into the autoclave via a trailer and close the autoclave door;

[0018] Step 3.3, hot pressing: first heat the autoclave to 60°C, keep it warm for 30 minutes, then heat it to 95°C, keep it warm for 30 minutes, pressurize it to 0.6MPa after the heat preservation, heat it to 120°C simultaneously, keep it warm and pressurize it for 90 minutes, finally cool it down to 60°C and reduce the pressure to 0MPa, and the heating and cooling rates are both 5°C / min;

[0019] Step 3.4: Take out the structural parts formed in the autoclave and demould them.

[0020] Among them, the selected carbon fiber strength is above T300.

[0021] The invention has the following advantages: the torsion shaft is based on metal material, the spline parts at both ends are made of metal material, and are connected to the middle metal round rod part as a whole, and the diameter of the metal round rod is smaller than the designed size, and the outer diameter of the metal round rod is designed to be a carbon fiber carbon fiber structure, and the carbon fiber carbon fiber is closely combined with the torsion shaft structure through a specific winding method and curing process. Through this invention, the mechanical properties and durability of the torsion shaft are significantly improved, the weight of the torsion shaft is reduced, and the lightweight and high mobility of the product and the whole vehicle are achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of a traditional torsion shaft;

[0023] Figure 2 It is a schematic diagram of the structure of the carbon fiber composite material torsion shaft of the present invention. DETAILED DESCRIPTION

[0024] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings.

[0025] like Figure 2 As shown, according to the structural characteristics of the torsion shaft, the present embodiment first prepares a steel torsion shaft, and the preparation process is consistent with the original process. The difference is that the middle rod body of the torsion shaft is smaller than the designed outer dimensions, and its specific dimensions are determined according to specific parameters such as the strength and torsion angle of the torsion shaft. The carbon fiber is generally within 20%-40% of the rod body diameter, that is, d = (0.6-0.8) D, where d is the diameter of the steel rod body, and D is the diameter of the entire composite torsion shaft rod body. The design structure is shown in the schematic diagram Figure 2 , including a steel body and a carbon fiber coating layer; the spline shafts at both ends of the steel body are consistent with the conventional torsion shaft structure, the diameter of the middle rod body is smaller than the conventional torsion shaft structure, and the carbon fiber coating layer is arranged on the middle rod body of the steel body, and the diameter of the middle rod body after coating is consistent with the conventional torsion shaft.

[0026] The manufacturing method of the torsion shaft of this embodiment is as follows:

[0027] 1. Preparation

[0028] (1) Use 95% industrial alcohol to wipe the torque shaft to remove surface oil stains and other debris:

[0029] (2) Take out the carbon fiber raw materials stored below -10°C and use a CNC cutting machine to cut out unidirectional carbon fiber pre-impregnated resin materials for paving. The carbon fiber should be selected with a strength of more than T300.

[0030] 2. Paving work

[0031] (1) Prepare a single-layer carbon fiber cloth, and wind the carbon fiber and the axis of the torsion shaft part in multiple layers at an angle of ±45°;

[0032] (2) The number of plies is calculated based on the single-layer thickness and total thickness requirements to fully utilize the tensile strength of the carbon fiber and disperse the stress generated by the torsion shaft during the torsion process.

[0033] 3. Hot press forming work

[0034] (1) Vacuuming: Cover the laid carbon fiber layer by layer with nylon release cloth, breathable felt, and high-temperature resistant plastic, and then seal the plastic along the edge with rubber strips. Tie the plastic strips at the wide part of the plastic cloth to ensure that the plastic above the carbon fiber is flattened. Install a vacuum valve at the diagonal of the carbon fiber flat plate, connect the air pipe for vacuuming, and test vacuuming the carbon fiber laying layer;

[0035] (2) Check the sealing of plastic bonding. If the sealing is OK, push the carbon fiber parts into the autoclave via a trailer and close the autoclave door;

[0036] (3) Hot pressing: first heat the autoclave to 60°C, keep it warm for 30 min, then heat it to 95°C, keep it warm for 30 min, pressurize it to 0.6 MPa after the heat preservation, then heat it to 120°C, keep it warm and pressurize it for 90 min, and finally cool it down to 60°C and reduce the pressure to 0 MPa, with the heating and cooling rates both being 5°C / min;

[0037] (4) Take out the structural parts formed by the autoclave and demould them.

[0038] The torsion shaft of this embodiment is based on metal material, and the spline parts at both ends are made of metal material, which is connected to the middle metal round rod part as a whole. The diameter of the metal round rod is smaller than the designed size, and the outer diameter of the metal round rod is designed to be a carbon fiber carbon fiber structure. Through a specific winding method and curing process, the carbon fiber carbon fiber is closely combined with the torsion shaft structure. Through this invention, the mechanical properties and durability of the torsion shaft are significantly improved, the weight of the torsion shaft is reduced, and the lightweight and high mobility of the product and the whole vehicle are achieved.

[0039] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, it is apparent to those skilled in the art that several modifications and improvements may be made without departing from the principles of the present invention, and these modifications and improvements should also be considered to fall within the scope of protection of the present invention.

Claims

1. A high-strength carbon fiber composite torsion shaft, characterized in that: It includes a steel body and a carbon fiber coating; the spline shafts at both ends of the steel body are consistent with the conventional torsion shaft structure, the diameter of the middle rod body is smaller than the conventional torsion shaft structure, and the carbon fiber coating is arranged on the middle rod body of the steel body, and the diameter of the middle rod body after coating is consistent with the conventional torsion shaft.

2. The high-strength carbon fiber composite torsion shaft according to claim 1, characterized in that: The thickness of the carbon fiber coating layer is 20%-40% of the diameter of the composite torsion shaft rod.

3. A method for preparing a high-strength carbon fiber composite torsion shaft, characterized in that: The steps include: Step 1. Preparation Step 1.1: Use 95% industrial alcohol to wipe the torque shaft to remove surface oil stains and other debris: Step 1.2, take out the carbon fiber raw materials stored below -10°C, and use a CNC cutting machine to cut out unidirectional carbon fiber pre-impregnated resin materials for paving; Step 2: Paving work Step 2.1, prepare a single layer of carbon fiber cloth, and perform multi-layer winding of the carbon fiber and the axis of the torsion shaft at an angle of ±45°; Step 2.2: The number of ply layers is calculated based on the single-layer thickness and total thickness requirements to fully utilize the tensile strength of the carbon fiber and disperse the stress generated by the torsion shaft during the torsion process; Step 3: Autoclave forming Step 3.1, vacuuming: Use nylon demoulding cloth, breathable felt, and high-temperature resistant plastic to cover the laid carbon fiber layer by layer, and then use rubber strips to seal the plastic along the edge. Use rubber strips to tie the wide parts of the plastic cloth to ensure that the plastic above the carbon fiber is flattened. Install a vacuum valve at the diagonal of the carbon fiber flat plate, and connect the air pipe for vacuuming to test vacuum the carbon fiber laying layer; Step 3.2, check the sealing of plastic bonding. If the sealing is OK, push the carbon fiber parts into the autoclave via a trailer and close the autoclave door; Step 3.3, hot pressing: first heat the autoclave to 60°C, keep it warm for 30 minutes, then heat it to 95°C, keep it warm for 30 minutes, pressurize it to 0.6MPa after the heat preservation, heat it to 120°C simultaneously, keep it warm and pressurize it for 90 minutes, finally cool it down to 60°C and reduce the pressure to 0MPa, and the heating and cooling rates are both 5°C / min; Step 3.4: Take out the structural parts formed in the autoclave and demould them.

4. The method for preparing a high-strength carbon fiber composite torsion shaft according to claim 3, characterized in that: The strength of the selected carbon fiber is above T300.

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