CN108274774A - The molding preparation process of the co-curing of metal and composite flywheel - Google Patents

Abstract

A preparation process for the co-curing molding of a metal and composite material flywheel, by dividing the metal and composite material co-curing flywheel into five areas and performing unidirectional prepreg layup in the corresponding areas of the molding mold according to their respective layup methods and Wrap the annular prefabricated body, buckle with the metal rim after the layup is completed, and solidify and form to obtain a metal and composite material flywheel. The invention can meet the requirements of the flywheel on the error of the moment of inertia, the quality of dynamic balance and the stability of high-speed rotation.

Description

Preparation process of co-solidification molding of metal and composite material flywheel

technical field

The invention relates to a technique in the field of composite material processing, in particular to a preparation process for co-solidification molding of a metal and composite material flywheel.

Background technique

In recent years, foreign research on satellite flywheels has mainly focused on the integration of flywheel energy storage and attitude control functions, and a variety of energy storage and attitude control integrated flywheels have been successfully developed; using composite materials with characteristics of greater tensile strength, The CFRP material is made into the wheel rim by winding method, which greatly increases the limit speed of the wheel body and greatly improves the energy storage density of the flywheel; at the same time, due to the integration of energy storage and attitude control, it saves a lot of star space and mass.

The composite material in the flywheel of the existing composite material and metal composite structure acts as a wheel spoke to reduce weight, and the outer metal wheel rim is machine-installed and replaceable. However, due to the screw connection between the stainless steel rim and the carbon fiber composite spoke, the connection reliability is poor and the dynamic balance is insufficient, especially after the high and low temperature cycle test, the dynamic balance deviates greatly.

The improved structure of the existing aluminum alloy wheel hub+carbon fiber composite material spoke+stainless steel rim adopts a metal-composite all-inclusive configuration. Although the rim and the spokes are connected in a heat-fitting-adhesive hybrid connection mode, there are no connecting screws. However, the bonding quality of the metal-composite material is poor, the structure and surface quality visible to the naked eye are not high, and the dynamic balance has drifted to a certain extent after the high and low temperature test.

Contents of the invention

Aiming at the above-mentioned deficiencies in the prior art, the present invention proposes a co-curing and molding preparation process of metal and composite material flywheels, which can meet the requirements of flywheels for moment of inertia error, dynamic balance quality and high-speed rotation stability.

The present invention is achieved through the following technical solutions:

In the present invention, the metal and composite material co-cured flywheel is divided into five areas, and the unidirectional prepreg is laid up in the corresponding areas of the molding mold according to the respective layup methods, and the annular prefabricated body is wrapped. After the layup is completed, it is combined with the metal wheel The metal and composite material flywheel is obtained by fastening the flange and curing and forming.

The forming mold refers to the metal-composite material co-curing flywheel forming mold scheme, which specifically adopts the structural form of a silicone soft mold auxiliary + metal combined mold, wherein the metal mold includes: an upper lobe forming mold as a female mold, and a male mold as a The lower flap forming mold.

The forming die is preferably made of No. 45 steel.

The five regions mentioned refer to: the foam region of the flywheel spoke, the hub region of the flywheel, the lower skin region of the flywheel spoke, the upper skin region of the flywheel spoke and the rim region of the flywheel.

The flywheel spoke foam area, the flywheel hub area, the flywheel spoke lower skin area and the flywheel rim area adopt their respective layup methods for unidirectional prepreg layup, and cross layup is required between different areas to ensure Connection stiffness and strength.

The upper skin area of the spokes of the flywheel is wrapped with a prefabricated unidirectional prepreg. When it is laid close to the foam, the layer close to the foam is laid at ±45°, and then the foam is filled into the foam area of the flywheel spokes, and then The unidirectional prepreg is applied to the skin area on the spokes of the flywheel, and the layup continues to the rim area of the flywheel.

The silicone rubber mold is prepared by selecting R10301 silicone rubber according to the digital model requirements of the designed flywheel.

The silicone rubber mold is prepared in the following way: firstly, after mixing the silica gel and the curing agent component, curing at room temperature for 24 hours; Keep warm for 6 hours. The Shore hardness of the finished silicone rubber mold is required to be 30-40, and the coefficient of linear expansion is 2.5-2.8×10 ^-4 /K.

The wheel hub prefabricated body is prepared in the following manner: pre-preparing the annular prefabricated body at the wheel hub with a layer thickness of 20mm, after the paving is completed, it is coated with glue and pre-compacted, and then the surface of the prefabricated body is cleaned and trimmed. And measure the thickness, and repair the area with large local thickness deviation.

The curing molding refers to: apply a pressure of 0.2 MPa through a pressure tank, keep the temperature at 160° C., and keep the temperature for 4 hours.

The composite material is M40JB/602 hot-melt prepreg.

The invention relates to a metal and composite material flywheel prepared by the above method, which is integrally formed by co-curing the metal and the composite material, which can avoid the dynamic balance drift of the flywheel, has high precision of the forming surface, and the main index flywheel dynamic unbalance quality < 1gcm ² ; moment of inertia of the wheel body 0.078±0.0015kg·m ² ; chatter and failure will not occur within the range of ±1500r/min.

technical effect

Compared with the prior art, the present invention adopts the combined mold design scheme, and utilizes the inner cavity soft mold to assist pressurization, thereby improving the forming accuracy of the relevant profiles of the flywheel composite material and avoiding subsequent machining steps for the flywheel composite material part; in addition The flywheel adopts integral co-curing and integral molding, and the inner cavity soft mold is used to assist pressurization. The composite material and metal are integrally formed at high temperature, which can ensure the performance of the bonding surface and avoid the dynamic balance drift of the flywheel. Simultaneously, the invention can completely solidify the composite material, ensure that there is no volatile matter under the vacuum condition, and meet the requirement of adapting to the space working environment.

Description of drawings

Fig. 1 is the structure schematic diagram of metal-composite co-cured flywheel of the present invention;

In the picture: 101 composite material spokes, 102 metal hubs, 103 metal rims;

Fig. 2A and Fig. 2B are the schematic diagrams of composite material layup of the present invention;

In the picture: 201 flywheel spoke foam area, 202 flywheel hub area, 203 flywheel spoke lower skin area, 204 flywheel spoke upper skin area, 205 flywheel rim area;

Fig. 3A is the layering method of the spokes, Fig. 3B is the layering method of the contact between the skin and the spokes, and Fig. 3C is a schematic diagram of the layering method at the contact surface of the spokes and the rim.

Detailed ways

This embodiment includes the following steps:

Step 1) The raw material is M40JB/602 hot-melt prepreg with a single layer thickness of 0.1mm. According to the design of the layup, the blanking and layout are carried out, and the layout requires accurate dimensions to ensure a high utilization rate of the prepreg.

Step 2) The silicone rubber is R10301 silicone rubber. In the preparation process of the silicone rubber soft film, first mix the silicone rubber components A and B, and then cure at room temperature for 24 hours; after curing, put the silicone rubber mold blank in an oven for heat treatment at 150°C and keep it warm for 6 hours. The Shore hardness of the completed silicone rubber mold is required to be 30-40, and the coefficient of linear expansion is 2.5-2.8×10-4/K.

Step 3) Pre-preparing the annular prefabricated body at the hub, with a layer thickness of 20mm. After the laying is completed, it is coated with glue and pre-compacted. Then, the surface of the prefabricated body is cleaned, trimmed, and the thickness is measured, and the area with a large local thickness deviation is repaired. After completion, the prefabricated body is placed for use.

Step 4) As shown in Figures 3A to 3C, first, on the forming male mold, the flywheel spoke foam area 201, the flywheel hub area 202, the flywheel spoke lower skin area 203, and the flywheel rim area 205 are individually layered according to their respective laying methods. When laying layers to the prepreg, different areas need to be cross-laminated to ensure the stiffness and strength of the connection. The hub area needs to wrap the prefabricated body with unidirectional prepreg; when laying close to the foam, the layer close to the foam should be ± 45° layup and then foam fill in the flywheel spoke foam area 201 of the mold. Afterwards, the upper skin area 204 of the flywheel spoke is covered with unidirectional prepreg, and the layup continues to the flywheel rim area 205 .

Step 5) Buckle the machined metal rim on the lower lobe forming mold to ensure that the contact surface between the metal rim and the composite material inside the rim has a certain pressure so that the metal and the composite material are in full contact and air bubbles are discharged. Then, buckle the female mold to complete the mold tooling.

Step 6) Place the co-cured flywheel as a whole in a pressure tank, apply a pressure of 0.2MPa, keep the temperature at 160°C, and keep it warm for 4 hours.

Step 7) After the product is demoulded, polish the edge flash of the product, measure the basic size of the product, and send it for flaw detection.

The experimental parameters, technical indicators and functional effects of the product prepared by the above method in this embodiment are: flywheel dynamic unbalanced mass<1gcm2; wheel body moment of inertia 0.078±0.0015kg· ^m2 ; Flutter and failure occurs. The first-order natural frequency of the wheel body is not less than 180Hz. The metal and the composite material are integrally co-cured and integrally formed, which can avoid the dynamic balance drift of the flywheel, and the precision of the forming surface is high.

The above specific implementation can be partially adjusted in different ways by those skilled in the art without departing from the principle and purpose of the present invention. The scope of protection of the present invention is subject to the claims and is not limited by the above specific implementation. Each implementation within the scope is bound by the invention.

Claims (10)

1. a kind of molding preparation process of the co-curing of metal and composite flywheel, which is characterized in that by by metal and again Condensation material co-curing flywheel is divided into five regions and in molding die corresponding region respectively according to corresponding ply sequence It carries out unidirectional pre-immersion material laying and wraps up annular precast body, fastened with metal rim after the completion of laying and cured molding obtains Metal and composite flywheel；

Five regions refer to：Skin areas, flywheel under flywheel spoke foam regions, flywheel hub region, flywheel spoke Skin areas and flywheel rim region on spoke.

2. according to the method described in claim 1, it is characterized in that, the flywheel spoke foam regions, flywheel hub region, fly Skin areas and flywheel rim region carry out unidirectional pre-immersion material laying using corresponding ply sequence under wheel spoke, not same district It carries out intersecting laying between domain to ensure coupling stiffness and intensity, specifically includes：

1. spoke ply sequence：

2. covering and spoke contact position ply sequence：

3. spoke and ply sequence at wheel rim contact surface：

3. according to the method described in claim 1, it is characterized in that, on the flywheel spoke skin areas using precast body it is unidirectional Prepreg wraps up, and when pawnshop is to close to foam, close to the layer use ± 45 ° laying of foam, foam is then inserted flywheel In spoke foam regions, unidirectional pre-immersion material then is carried out to skin areas on flywheel spoke again and is coated with, laying extends to flywheel In rim area.

4. according to the method described in claim 1, it is characterized in that, the molding die refers to metal-composite material co-curing Flywheel molding die scheme, the specific structure type for using silica gel flexible-mould assisted+metal assembled mould, metal die packet therein Contain：Epivalve molding die as former, the hypovalve molding die as formpiston.

5. method according to claim 1 or 4, characterized in that the molding die is made of No. 45 steel.

6. according to the method described in claim 1, it is characterized in that, the silicon rubber mould, according to design flywheel digital-to-analogue select R10301 silicon rubber is prepared.

7. according to the method described in claim 1, it is characterized in that, the wheel hub precast body is prepared in the following manner： Previously prepared wheel hub annular precast body, overlay thickness 20mm, coats after the completion of paved and inhales glue and pre-compacted, then to precast body Surface cleared up, deburring, and measures thickness, and the region larger to local thickness deviation is repaired to obtain.

8. according to the method described in claim 1, it is characterized in that, the curing molding refers to：Applied by pressurized tank 0.2MPa pressure, temperature are maintained at 160 DEG C, keep the temperature 4 hours.

9. according to the method described in claim 1, it is characterized in that, the composite material be M40JB/602 hot melt prepregs.

10. a kind of metal and composite flywheel being prepared by any of the above-described claim the method, feature exist In, be metal with composite material it is that whole co-curing is integrally formed, flywheel unbalance dynamic quality<1gcm²；Wheeling thereof inertia 0.078±0.0015kg·m²；Within the scope of ± 1500r/min flutter and failure do not occur for rotating speed.