CN106626433A - Automobile battery box made of multi-axial hybrid fiber composite material and manufacturing method of automobile battery box - Google Patents

Abstract

The invention belongs to the technical field of auto parts, and relates to a multi-axial hybrid fiber composite car battery box, which is made of multi-axial hybrid warp-knitted fabric prepared by carbon fiber and glass fiber through a multi-axial warp knitting process as a reinforcing material , a composite material based on epoxy resin; the multiaxial hybrid warp knitted fabric includes eight layers of parallel yarn layups arranged in sequence, and the layup angles of the layups are 0°, 45°, 90° ° and ‑45° with two plies for each ply angle, with 0° and 90° plies being carbon fiber material and 45° and ‑45° being glass fiber material. Among them, the 0° and 90° plies are the main stress directions, and the 45° and -45° plies are the non-stress directions. Beneficial effects: compared with traditional steel or high-density plastic battery boxes, the weight of the prepared battery box can be reduced by 30%, and the cost can be reduced by 40% compared with pure carbon fiber battery boxes. Higher production efficiency than laminated structures.

Description

A kind of multi-axial hybrid fiber composite car battery box and its manufacturing method

technical field

The invention belongs to the technical field of automobile parts, and in particular relates to an automobile battery box made of multiaxial hybrid fiber composite material and a manufacturing method thereof.

Background technique

As an important direction of the current and future development of automobiles, automobile lightweight has attracted more and more attention from designers. One of the important ways of automobile lightweight is to use lightweight materials. Carbon fiber composite materials have excellent mechanical properties and low density, and are gradually replacing steel and widely used in the automotive industry. In terms of the application of automobile battery boxes, CN105014988 discloses a carbon fiber automobile battery box and a manufacturing method of a carbon fiber automobile battery box. Carbon fiber laminated structural composite materials are used to replace steel materials, and while meeting the rigidity and strength requirements, the battery box is reduced. the quality of. However, because carbon fiber is relatively expensive, if the battery box is all made of carbon fiber composite materials, the cost will be greatly increased. At the same time, the process of laminating structural fiber layers is cumbersome, the preparation time is long, and the production efficiency is low.

Contents of the invention

In order to solve the defect in the prior art that there is a cumbersome layering process of laminated structure fibers, the present invention provides a multi-axial hybrid fiber composite car battery box and a manufacturing method thereof.

In order to solve the above technical problems, the technical solution adopted in the present invention is: a multi-axial hybrid fiber composite car battery box, the material of which is a multi-axial warp knitting process prepared by carbon fiber and glass fiber. Hybrid warp-knitted fabric as reinforcement material, composite material with epoxy resin as base material;

The multi-axial hybrid warp knitted fabric comprises eight layers of parallel yarn layups arranged in sequence, and the layup angles of the layups are 0°, 45°, 90° and -45°, and each layup angle has Two layups, of which 0° and 90° layups are made of carbon fiber material, of which 45° and -45° are made of glass fiber material. Among them, the 0° and 90° plies are the main stress directions, and the 45° and -45° plies are the non-stress directions.

As preferably, the carbon fiber is T300-3k, the tensile modulus is 230Gpa, and the tensile strength is 3.53Gpa, the glass fiber is E glass fiber, the tensile modulus is 74GPa, and the tensile strength is 3.5Gpa, and the ring The oxygen resin is NPEL-128 epoxy resin.

Further, the volume ratio of the reinforcing material to the base material is 1:1.

The method for manufacturing the above-mentioned multi-axial hybrid fiber composite car battery box includes the following steps:

(1) Mold pretreatment: Wipe the surface of the mold with a release agent to facilitate demoulding;

(2) Fabric laying: Lay the multi-axial hybrid warp knitted fabric in the mold cavity evenly according to the laying angle, prevent it from wrinkling, and trim off the excess scrap;

(3) Mold closing: close the upper mold and the lower mold, and seal and fasten the periphery;

(4) Resin injection: Mix epoxy resin and curing agent evenly, then inject from the mold inlet to fully infiltrate the multi-axial hybrid warp knitted fabric;

(5) Curing: the mold is placed in a heating furnace for temperature-controlled curing;

(6) Demoulding: Separate the upper and lower molds, separate the battery box from the mold and check whether the product is defective;

(7) Post-processing: Clean the mold and injection equipment with a mold cleaner.

Specifically, step (1) wipe the surface of the mold with a release agent for more than 3 times, each time at intervals of 15-20 minutes, and wipe in one direction.

Preferably, the mass ratio of the epoxy resin and the curing agent in step (4) is 1:0.005-0.1, and the epoxy resin and the curing agent are mixed uniformly, and left to stand for 20-30 minutes.

Further, in step (4), the injection pressure of the epoxy resin and curing agent injected from the injection port of the mold is 0.1-0.2 MPa, and the injection is stopped until no air bubbles appear at the injection port.

Preferably, the temperature-controlled curing conditions described in step (5) are as follows: a temperature of 40-50° C., and a curing time of 1.5-2 hours.

Preferably, the mold cleaning agent described in step (7) is acetone.

Beneficial effects: 1. The multi-axial hybrid fiber composite car battery case provided by the present invention adopts 8-layer carbon fiber/glass fiber mixed multi-axial warp-knitted fabric as fiber reinforcement material, epoxy resin as matrix, and the prepared battery Compared with traditional steel or high-density plastic battery boxes, the box is 30% lighter in weight.

2. The multi-axial hybrid fiber composite car battery box provided by the present invention uses carbon fiber and glass fiber as reinforcing materials, and the cost can be reduced by 40% compared with the pure carbon fiber battery box.

3. The multi-axial hybrid fiber composite car battery box provided by the present invention adopts a multi-axial warp weaving process, and the weaving process can realize mechanized integral molding. Compared with the cumbersome layer-by-layer laying process of ordinary laminated structures, the production efficiency Higher; multi-axial warp knitted fabrics have more stable structural properties than laminated boards. Compared with ordinary laminated structure battery boxes, while ensuring excellent mechanical properties along the fiber reinforcement direction, delamination is not easy to occur, interlayer performance better.

4. The multi-axial hybrid fiber composite car battery box provided by the present invention can adjust the laying position, laying sequence, laying angle and laying thickness of the two kinds of reinforcing fibers arbitrarily according to the structural requirements of battery boxes of different models, and can be designed Strong.

Description of drawings

Figure 1 is a schematic diagram of the three-dimensional structure of the battery box;

Figure 2 is a schematic diagram of the reverse structure of the battery box; in Figures 1 and 2, 1.1 is the bottom plate, 2.1 is the longitudinal rib, and 2.2 is the transverse rib.

Fig. 3 is a schematic diagram of the structure of a multi-axial hybrid warp knitted fabric; 3.1 in Fig. 3 is a 90° weft inserted yarn, 3.2 is a 45° weft inserted yarn, 3.3 is a -45° weft inserted yarn, 3.4 is a binding yarn, and 3.5 is a warp interleaved yarn.

Fig. 4 is the layup structure schematic diagram of embodiment 1 multi-axial hybrid warp knitted fabric; Among Fig. 4, 4.1 is the carbon fiber 0 ° direction layup, 4.2 is the glass fiber 45° direction layup, 4.3 is the glass fiber -45° direction layup 4.4 is carbon fiber layup in 90° direction, 4.5 is carbon fiber layup in 90° direction, 4.6 is glass fiber layup in -45° direction, 4.7 is glass fiber layup in 45° direction, 4.8 is carbon fiber layup in 0° direction, 4.9 is binding yarn.

Fig. 5 is the layup structure schematic diagram of embodiment 2 multi-axial hybrid warp knitted fabric; 5.1 carbon fiber 0 ° layup in Fig. 5, 5.2 carbon fiber 90° direction layup, 5.3 glass fiber -45° direction layup, 5.4 glass fiber 45° direction layup, 5.5 glass fiber layup in 45° direction, 5.6 glass fiber layup in -45° direction, 5.7 carbon fiber layup in 90° direction, 5.8 carbon fiber layup in 0° direction, 5.9 is binding yarn.

Fig. 6 is the schematic diagram of embodiment 3 laminated structure fabric structure; 6.1 carbon fiber 0 ° direction lay-up in Fig. Carbon fiber laying in 45° direction, 6.6 carbon fiber laying in -45° direction, 6.7 carbon fiber laying in 90° direction, 6.8 carbon fiber laying in 0° direction.

Figure 7 is a schematic diagram of the RTM system structure; in Figure 7, 7.1 is the air compressor, 7.2 is the injection molding machine, 7.31 is the fixing bolt, 7.32 is the injection port, 7.33 is the upper mold, 7.34 is the glue outlet, 7.35 is the lower mold, 7.4 It is a multi-axial mixed fiber warp knitted fabric, and 7.5 is a resin receiving bucket.

detailed description

In order to make the purpose, technical solution and advantages of the present invention clearer, further detailed description will be given below in conjunction with examples.

Example 1

In the first aspect, this example provides a multi-axial hybrid fiber composite car battery box, the structure of which includes a bottom plate 1.1, longitudinal ribs 2.1 and transverse ribs 2.2 arranged at the bottom of the bottom plate 1.1 as shown in Figure 1 and Figure 2 . Using multi-axial warp knitting technology, carbon fiber and glass fiber are used as reinforcement materials to prepare multi-axial hybrid warp knitted fabric. Epoxy resin is injected into the mold through RTM molding process, and the fabric is soaked and solidified to form a composite car battery box.

In the composite car battery box provided by the example of the present invention, the hybrid reinforcing material adopts a multi-axial warp-knitted structure, and the structural form is shown in FIG. 3 . The multi-axial hybrid warp knitting structure includes 3.1, 90° weft inserted yarn, 3.2, 45° weft inserted yarn, 3.3, -45° weft inserted yarn, 3.4, binding yarn, 3.5, 0° warp inserted yarn.

Compared with ordinary single-fiber reinforced laminates, multi-axial hybrid warp-knitted fabrics have a more stable structure, better mechanical properties, and stronger designability. The specific performance is as follows:

(1) The fibers in the multi-axial hybrid warp knitted fabric are distributed straight, so that the performance in the main direction of the fabric fibers can be fully exerted;

(2) The multi-axial hybrid warp knitted fabric introduces bundled yarns. Compared with the laminated structure, its interlayer performance is better and the overall performance of the structure is better;

(3) Multi-axial hybrid warp knitted fabrics are mixed with glass fibers in carbon fibers. Compared with single-fiber fabrics, the resulting hybrid effect greatly improves fracture toughness, impact resistance, and bending fatigue performance.

Specifically, the standard layup angle is selected for the layup, and the layup material and order are [0 _C , 45 _G , -45 _G , 90 _C ] _S where C represents carbon fiber, G represents glass fiber (the same below), and the specific structure As shown in Figure 4: from top to bottom are the first layer of carbon fiber layer 4.1 in the direction of 0°, the second layer of glass fiber layer 4.2 in the direction of 45°, the third layer of glass fiber layer 4.3 in the direction of -45°, and the second layer of glass fiber layer 4.3 in the direction of -45°. Four layers of carbon fiber laying 4.4 in 90° direction, fifth layer of carbon fiber laying 4.5 in 90° direction, sixth layer of glass fiber laying in -45° direction 4.6, seventh layer of glass fiber laying in 45° direction 4.7, eighth layer of carbon fiber Lay layers 4.8 and 4.9 in the 0° direction are binding yarns.

The second aspect of this example provides a method for manufacturing a multi-axial hybrid fiber composite car battery box. The process principle is shown in Figure 7, including the following steps:

Step (1) Preparation

1.1) Multi-axial hybrid warp-knitted fabric: Using the multi-axial warp-knitting process, two reinforcing materials, carbon fiber and glass fiber, are woven into the required multi-axial hybrid warp-knitted fabric according to the design angle and lay-up sequence.

1.2) Preparation of the mold; carefully check whether the mold is damaged and whether there are sundries inside

1.3) RTM molding equipment; check RTM injection equipment 7.2, prepare curing agent, release agent, air compressor 7.1 and other related accessories.

Step (2) Mold pretreatment

Wipe the inner surface of the mold with the mold release agent 4 times, moisten the mold gently in one direction, do not wipe back and forth, and wipe every 15 minutes.

Step (3) Fabric laying

Lay the multi-axial hybrid warp knitted fabric 7.4 woven according to the design requirements evenly in the mold cavity without wrinkling, and trim off excess leftovers.

Step (4) Mold closing

The upper mold 7.33 and the lower mold 7.35 are closed, and the periphery is sealed and fastened by fixing bolts 7.31.

Step (5) Resin Injection

5.1) The epoxy resin and curing agent are mixed according to the ratio of 1:0.05, and the experimental environment temperature is 25°C to ensure that the resin has good fluidity and wettability during the injection process.

5.2) Stir the epoxy resin and curing agent evenly, let it stand for 25 minutes, and remove the air in the mixed resin glue.

5.3) Set the air compressor 7.1 to ensure that the injection pressure is 0.15MPa, and inject the resin into the mold from the injection port 7.32. During the injection process, resin and air bubbles can be observed at the injection port 7.34; Bubbles appear, the glue fully infiltrates the fabric, the glue injection is stopped, and the resin coming out of the glue outlet 7.34 is collected by the resin receiving barrel 7.5.

Step (6) curing

The mold is placed in a heating furnace for temperature-controlled curing, the curing temperature is controlled at 40° C., and the curing time is 2 hours.

Step (7) demoulding

After the mold is cooled, the upper and lower molds are separated, the battery box is separated from the mold, and the product is inspected for defects.

Step (8) post-processing

Clean the mold and RTM dispensing equipment with acetone.

Example 2

The shape, material and preparation method of the car battery box provided in this example are basically the same as in Example 1, the difference lies in the layup of multi-axial hybrid warp-knitted fabric, and the layup angle and material are [0 _C , 90 _C , -45 _G ,45 _G ] _S , specifically as shown in Figure 5: the first layer of carbon fiber layer 5.1 at 0°, the second layer of carbon fiber layer 5.2 at 90°, the third layer of glass fiber layer 5.3 at -45°, and the fourth layer Glass fiber 5.4 in 45° direction, fifth layer of glass fiber in 45° direction 5.5, sixth layer of glass fiber in -45° direction 5.6, seventh layer of carbon fiber in 90° direction 5.7, eighth layer of carbon fiber 0 ° direction lay-up layer 5.8,5.9 is binding yarn.

Example 3

This example is used as a comparison. The shape and preparation method of the car battery box provided are basically the same as those in Example 1. The difference lies in the selection of pure carbon fiber laminated structure fabrics. Going up, the layup angle is [0 _C , 90 _C , -45 _C , 45 _C ] _S , as shown in Figure 6: the first layer of carbon fiber is laid in the direction of 0° 6.1, the second layer of carbon fiber is laid in the direction of 90° 6.2 , the third layer of carbon fiber -45° direction laying 6.3, the fourth layer of carbon fiber laying 6.4 at 45° direction, the fifth layer of carbon fiber laying 6.5 at 45° direction, the sixth layer of carbon fiber -45° direction laying 6.6, the seventh layer 6.7 for carbon fiber laying in 90° direction, and 6.8 for eighth carbon fiber laying in 0° direction.

The weight and rigidity of the battery case provided by Example 1, Example 2 and Example 3 and pure metal were tested respectively. A battery mass of 128kg is applied at the center of gravity of the battery box provided in each example, and the z-direction displacement of the battery box is measured.

The test results are shown in Table 1:

Table 1 Test results of each example

Through the comparison of Table 1, it is found that the two embodiments of the multi-axial hybrid fiber composite car battery box provided by the embodiment of the present invention have relatively high rigidity, which can ensure the safety of the battery when the car is running normally. Compared with the metal battery box, the overall mass of the multi-axial hybrid fiber composite car battery box is reduced by 30% because of the low density of the fiber composite. Compared with the pure carbon fiber laminated composite battery box, the cost is reduced by 40% by adding lower-priced glass fibers; and the multi-axial warp knitting process is adopted, which is simple in layer laying, easy to realize mechanization, and higher in production efficiency . In summary, the multi-axial hybrid fiber composite car battery box proposed by the present invention has the characteristics of light weight, high strength, low cost, and high efficiency.

Claims (9)

1. a kind of polyaxial fiber hybrid composite car battery box, it is characterised in that：Its material is, with carbon fiber and glass The polyaxial knitted fabric that mixes that fiber Jing multi-shaft warp knitting techniques are prepared into for reinforcing material, answering with epoxy resin as base material Condensation material；

The polyaxial knitted fabric that mixes is including eight layers of parallel yarn laying being arranged in order, the laying angle of the laying For 0 °, 45 °, 90 ° and -45 °, each laying angle has two layings, wherein 0 ° and 90 ° of layings are carbon fibre material, wherein 45 ° and -45 ° is glass fiber material.

2. polyaxial fiber hybrid composite car battery box according to claim 1, it is characterised in that：Described carbon Fiber is T300-3k, and stretch modulus is 230Gpa, tensile strength 3.53Gpa, and the glass fibre is E glass fibres, stretching die Amount 74GPa, tensile strength 3.5Gpa, described epoxy resin is NPEL-128 epoxy resin.

3. polyaxial fiber hybrid composite car battery box according to claim 1 and 2, it is characterised in that：It is described Reinforcing material and base material volume ratio be 1：1.

4. the manufacture method of the polyaxial fiber hybrid composite car battery box according to any one of claims 1 to 3, It is characterized in that：Comprise the steps：

(1) mould pretreatment：Wiped with releasing agent in die surface, be easy to the demoulding；

(2) fabric lays：The polyaxial knitted fabric that mixes is laid in die cavity according to laying angle is smooth, its pleat is not allowed Wrinkle, and pare off unnecessary leftover pieces；

(3) matched moulds：Upper mould is closed up with lower mould, peripheral sealing fastening；

(4) resin injection：Epoxy resin and curing agent are well mixed, are then injected from mould glue-feeder, fully infiltrate multiaxis To mixing knitted fabric；

(5) solidify：Mould is placed in into heating furnace carries out temperature control solidification；

(6) demoulding：Upper and lower mould is separated, battery case is spun off from mould and is checked that product has zero defect；

(7) post-process：Mould and glue injection equipment are cleared up with clean mould agent.

5. the manufacture method of polyaxial fiber hybrid composite car battery box according to claim 4, its feature exists In：Step (1) is wiped more than 3 times in die surface with releasing agent, per minor tick 15-20min, and is wiped according to a direction.

6. the manufacture method of polyaxial fiber hybrid composite car battery box according to claim 4, its feature exists In：Epoxy resin and curing agent mass ratio described in step (4) is 1：0.005～0.1, epoxy resin and curing agent mixing is equal After even, 20-30min is stood.

7. the manufacture method of the polyaxial fiber hybrid composite car battery box according to claim 4 or 6, its feature It is：Injection pressure in step (4) from mould glue-feeder injection epoxy resin and curing agent is 0.1～0.2MPa, and injecting glue is extremely Gum outlet does not have bubble to occur, and stops injecting glue.

8. the manufacture method of polyaxial fiber hybrid composite car battery box according to claim 4, its feature exists In：Temperature control condition of cure described in step (5) is that 40～50 DEG C of temperature, hardening time is 1.5～2h.

9. the manufacture method of polyaxial fiber hybrid composite car battery box according to claim 4, its feature exists In：Clean mould agent described in step (7) is acetone.