CN112829338B

CN112829338B - Composite material forming method

Info

Publication number: CN112829338B
Application number: CN202011637268.8A
Authority: CN
Inventors: 黄永勇; 郑张宜; 邹一飞; 沈亚东; 何衍生
Original assignee: Hubei Sanjiang Aerospace Group Hongyang Electromechanical Co Ltd
Current assignee: Hubei Sanjiang Aerospace Group Hongyang Electromechanical Co Ltd
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2023-03-24
Anticipated expiration: 2040-12-31
Also published as: CN112829338A

Abstract

The invention discloses a composite material forming method, relates to the technical field of composite material forming, and solves the technical problem that machines are not suitable due to the fact that composite material products are large in size in the prior art. The vacuum bag and the mold core are enclosed to form a closed molding cavity, the vacuum bag and the mold cavity wall are enclosed to form a closed pressurizing cavity, prepreg laying is carried out in the molding cavity, the female mold is provided with a charging and discharging valve which is communicated with the pressurizing cavity, the male mold is provided with a heat exchange tube and a vacuum tube, the heat exchange tube is communicated with a heat conduction oil pipeline of a mold temperature controller, and one end of the vacuum tube is communicated with the molding cavity. The mould temperature control device utilizes the existing mould temperature controller, vacuum pump and pressurized air source, has the characteristics of simple structure, convenient manufacture, low cost and strong applicability, and is especially used for molding composite material products with large sizes.

Description

Composite material forming method

Technical Field

The invention relates to the technical field of composite material forming, in particular to a composite material forming method.

Background

The molding of the composite material structure requires that a mold is solidified into a certain shape so as to meet the requirement of the overall dimension. If the composite structure is thick, a long operation time is required. The normal temperature curing resin system can not meet the requirement of the process working life due to short curing time, and the adopted resin system needs to be heated and cured. For products with low mechanical property requirements, the products can be formed by adopting processes such as resin vacuum infusion (RTM) and the like. However, the composite material product with thicker thickness and higher mechanical property requirement is formed by adopting the RTM process, and the internal defects such as glue shortage or looseness easily occur;

another way of forming composite material is to heat, compact and cure the composite material by autoclave. The autoclave has a large and complex overall structure and high manufacturing cost. Particularly, when the composite material product is thick, has high mechanical property requirement and has a size larger than that of the existing autoclave, if a new large autoclave is designed and purchased again, the production cost is greatly improved, the time is delayed, and the normal and smooth production is delayed.

Disclosure of Invention

The application provides a combined material forming die, has solved the uncomfortable technical problem of machine that combined material product shaping arouses because the size is great among the prior art.

The application provides a combined material forming die, terrace die and die including reciprocal anchorage, the terrace die is equipped with the core, the die is equipped with the die cavity, the die cavity forms the die cavity wall in the die, the die cavity internal fixation is equipped with the vacuum bag, the vacuum bag encloses with the core and closes to form confined shaping cavity, the vacuum bag encloses with the die cavity wall and forms confined pressurization cavity, carry out the preimpregnation material in the shaping cavity and spread the layer, the die is equipped with the air filling and discharging valve, air filling and discharging valve one end and pressurization cavity intercommunication, the other end is connected with the air supply, be equipped with hot exchange pipe and evacuation pipe in the terrace die, hot exchange pipe and the heat conduction oil pipeline intercommunication of mould temperature machine, evacuation pipe runs through the terrace die setting, evacuation pipe one end and shaping cavity intercommunication, the other end is connected with the vacuum pump.

Preferably, the mold core is provided with a molding surface and temperature measuring holes, the temperature measuring holes and the molding surface are arranged at intervals, the prepreg is laid on the molding surface, and the mold temperature machine is provided with temperature measuring couples which are arranged in the temperature measuring holes.

Preferably, the heat exchange tubes are uniformly arranged in the male die in a wavy shape, and are arranged at intervals with the temperature measuring holes.

Preferably, the mold core is provided with a molding surface and a demolding mechanism, the male mold is provided with a demolding hole, the demolding hole penetrates through the male mold and forms an opening in the molding surface, the demolding mechanism comprises a sealing screw, the sealing screw is matched with a sealing pad, and the sealing screw penetrates through the sealing pad and is installed in the demolding hole in a threaded manner;

the demoulding mechanism is also provided with an ejection screw which is used for ejecting the formed product out of the forming surface after the sealing screw is disassembled and the ejection screw penetrates through the demoulding hole.

Preferably, the demolding hole comprises a first channel and at least one second channel, one end of each second channel is communicated with the corresponding first channel, the corresponding first channel forms an opening in the molding surface, the corresponding first channel and the corresponding second channel jointly penetrate through the corresponding male die, a sealing ring is embedded in the corresponding first channel, and a sealing screw is installed in the corresponding second channel in a threaded mode.

Preferably, a sealing rope is embedded in the contact surface of the male die and the female die.

Preferably, the male die is screwed with the female die.

Preferably, the female die is provided with a safety valve and a pressure gauge, the safety valve and the pressure gauge are both arranged through the female die, an inlet of the safety valve is communicated with the pressurizing chamber, and a measuring head of the pressure gauge extends into the pressurizing chamber;

the vacuum tube is also connected with a vacuum meter.

Preferably, the vacuum bag is secured to the male mould.

A composite material forming method comprises the steps of vacuumizing a forming cavity through a vacuum pump and inflating a pressurizing cavity through an air source to realize pressurizing and curing of the composite material forming die;

and the single vacuumizing step and the single pressurizing and curing step are carried out before and after to form a cycle, and the single laying product forming comprises at least one cycle.

The beneficial effect of this application is as follows: the invention uses the male die and the female die to match with the existing die temperature machine, the vacuum pump and the air source, when in molding, the composite material is layered in the molding cavity by prepreg, the composite material is heated by the matching of the die temperature machine and the heat exchange tube, which is beneficial to the accurate control of heating, the vacuum pump is matched with the vacuum pump to carry out vacuum pumping treatment in the molding cavity, the air source is matched with the air charging and discharging valve to charge and discharge the pressurizing cavity, and the pressurized curing process of the composite material is adjusted, thereby realizing the molding process of the composite material.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention.

Fig. 1 is a schematic structural diagram of a composite material molding die provided in the present application, which is cross-sectional in a length direction;

fig. 2 is a schematic structural diagram of a transverse width direction of a composite material forming die provided by the present application;

FIG. 3 is a further detailed schematic view of FIG. 1;

FIG. 4 is a further detailed schematic view of FIG. 2;

FIG. 5 is a schematic structural view of a male die provided with a temperature measuring hole;

FIG. 6 isbase:Sub>A schematic cross-sectional view taken at A-A of FIG. 5;

FIG. 7 is a schematic structural view of a male die provided with a heat exchange tube according to the present application;

FIG. 8 is a schematic cross-sectional view taken at B-B of FIG. 9;

FIG. 9 is a schematic cross-sectional view taken at C-C of FIG. 8;

FIG. 10 is an enlarged view of a portion of FIG. 9 at D;

fig. 11 is a schematic structural view of fig. 10 with the gasket and the sealing screw omitted.

The attached drawings are marked as follows: 100-male die, 110-forming chamber, 111-laminating product, 112-forming surface, 120-heat exchange tube, 130-vacuumizing tube, 131-vacuum meter, 140-temperature measuring hole, 150-demoulding hole, 151-first channel, 151 a-sealing ring, 152-second channel, 152 a-sealing screw, 152 b-sealing gasket, 160-sealing rope, 200-female die, 210-vacuum bag, 220-pressurizing chamber, 230-air charging and discharging valve, 240-safety valve and 250-pressure meter.

Detailed Description

The embodiment of the application provides a combined material forming die, and solves the technical problem that machines are not suitable due to the fact that the size of a combined material product is large in the prior art.

In order to solve the technical problems, the general idea of the embodiment of the application is as follows:

a composite material forming die comprises a male die 100 and a female die 200 which are fixed with each other, wherein the male die 100 is provided with a core, the female die 200 is provided with a cavity, the cavity is arranged on the wall of a forming cavity of the female die 200, a vacuum bag 210 is fixedly arranged in the cavity, the vacuum bag 210 and the core enclose to form a closed forming cavity 110, the vacuum bag 210 and the cavity wall enclose to form a closed pressurizing cavity 220, prepreg laying is carried out in the forming cavity 110, the female die 200 is provided with an air charging and discharging valve 230, one end of the air charging and discharging valve 230 is communicated with the pressurizing cavity 220, the other end of the air charging and discharging valve is connected with an air source, a heat exchange tube 120 and a vacuum tube 130 are arranged in the male die 100, the heat exchange tube 120 is communicated with a heat conduction oil pipeline of a die temperature controller, the vacuum tube 130 penetrates through the male die 100, one end of the vacuum tube 130 is communicated with the forming cavity 110, and the other end of the vacuum pump is connected with the vacuum pump.

In order to better understand the technical scheme, the technical scheme is described in detail in the following with reference to the attached drawings of the specification and specific embodiments.

Referring to fig. 1 and 2, it is shown in brief that the composite material forming mold includes a male mold 100 and a female mold 200, the male mold 100 is provided with a mold core, the female mold 200 is provided with a mold cavity, a cavity wall is formed in the female mold 200 by the mold cavity, the male mold 100 and the female mold 200 are fixed in a butt joint manner, and the mold core is matched with the mold cavity.

In the composite material forming, especially when the composite material product aimed at by the technical scheme of the embodiment is thick, long and has high standard requirements on mechanical properties, the requirements of heating, pressurizing and vacuum degree are involved. Referring to fig. 3 and 4, the composite material forming mold including the male mold 100 and the female mold 200 is provided with corresponding heat exchange tubes 120, air inflation/deflation valves 230 and vacuum evacuation tubes 130, and the composite material is formed by cooperating with the existing mold temperature controller, pressurized air source and vacuum pump equipment which are common in factories.

First, the implementation of pressurization and evacuation in the mold is explained, referring to fig. 3 and 4, a vacuum bag 210 is disposed between the core and the cavity, the vacuum bag 210 divides the space enclosed by the core and the cavity wall into a pressurization chamber 220 and a molding chamber 110, wherein the vacuum bag 210 and the core enclose to form the closed molding chamber 110, and the vacuum bag 210 and the cavity wall enclose to form the closed pressurization chamber 220. The vacuum bag 210 may be selectively secured to the cavity wall of the female mold 200 or may be selectively secured to the male mold 100. The composite material is placed in the molding chamber 110 by vacuuming the molding chamber 110 and by inflating the pressurizing chamber 220, pressure is applied to the composite material.

Wherein, the air valve 230 sets up in the recess, and air valve 230 one end and pressurization cavity 220 intercommunication fill, and the other end passes through the nipple, relevant pipeline connection pressurization air supply. The inflation process of the pressurization chamber 220 by the pressurization gas source through the pipeline, the nozzle and the inflation and deflation valve 230 also includes the deflation process of detaching the corresponding pipeline and opening the inflation and deflation valve 230 to discharge the high-pressure gas in the pressurization chamber 220 from the nozzle. The pressurized air source can adopt a commonly used nitrogen cylinder, and is simple to discharge.

The heat exchange tube 120 is disposed on the male mold 100, and performs a heating process on the composite material at the molding surface 112 of the male mold 100. As shown in fig. 7, the heat exchange tube 120 is preferably uniformly arranged in the male mold 100 in a wave-shaped manner with a large arrangement area, thereby improving heat exchange efficiency. The joints at the two ends of the heat exchange tube 120 extend out of the male die 100 and are communicated with a heat conducting oil pipeline of the die temperature controller, the heating condition of the male die 100 is controlled by a heating system, a temperature measuring and controlling system of the die temperature controller, the heating effect is good, the controllability is strong, and the requirement of the curing and heating temperature of a product is met.

The evacuation tube 130 is disposed through the male mold 100, an opening at one end of the evacuation tube 130 is communicated with the molding chamber 110, a evacuation port is formed at the other end of the evacuation tube 130 on the outer wall of the male mold 100, and the evacuation port is connected to a vacuum pump and a vacuum pressure gauge 250 through corresponding pipelines and valves, as shown in fig. 4, so as to meet the vacuum degree requirement when the product is cured.

The male die 100 and the female die 200 are fixedly connected, and the male die can be firmly connected through a plurality of screws, and can also be connected in other connection modes such as riveting and the like.

Preferably, in the process of using the mold temperature measuring machine, the temperature measurement of the temperature measurement couple is involved, referring to fig. 5 and 6, the male mold 100 is provided with the temperature measurement hole 140, the temperature measurement hole 140 is transversely arranged on the male mold 100, and the temperature measurement hole 140 is arranged at a distance from the molding surface 112, the distance is larger, so as not to affect the work of the molding surface 112. The temperature measurement couple of the mold temperature controller is arranged in the male mold 100 to detect the temperature of the male mold 100 in the heating process, thereby being beneficial to subsequent temperature adjustment. Preferably, the temperature measuring holes 140 and the heat exchanging pipes 120 are arranged on the same plane, and it is understood that the temperature measuring holes 140 and the heat exchanging pipes 120 are arranged at intervals.

Moreover, if very precise temperature control is not required for molding some composite materials, the heating condition of the composite material on the male die 100 can be indirectly controlled by controlling the output condition of the die temperature controller.

In the scheme of the composite material forming die, particularly aiming at the fact that a product to be formed is thick, long and high in mechanical property requirement, a new mode of repeated vacuum pumping and pressurization cycle alternate operation is adopted, and the performance of the thick product after processing is facilitated; in addition, the prepreg is spread on the molding surface 112 in the matching die in the new operation mode, so that the requirement of high mechanical property of composite material molding can be met, and the molding of a composite material product with a large length can be realized by setting the lengths of the male die 100 and the female die 200 in a related manner, so that the disadvantages of high cost, long preparation time and the like caused by redesigning and manufacturing a new autoclave when the required product length is large in the prior art are overcome.

Referring to fig. 3, the composite material forming mold is preferably further provided with a safety valve 240 and a pressure gauge 250 for regulating and protecting the pressure in the pressurizing chamber 220 in the working state, wherein the safety valve 240 and the pressure gauge 250 are both disposed on the female mold 200. The inlet of the safety valve 240 communicates with the pressurizing chamber 220, and the measuring head of the pressure gauge 250 is disposed to extend into the pressurizing chamber 220. Wherein the relief pressure of the relief valve 240 is greater than the curing service pressure setting.

In the solution of the present embodiment, it is necessary to ensure good sealing performance of the pressurization chamber 220 and the molding chamber 110 in the working state. As shown in fig. 4 and 6, the male die 100 is fixedly connected with the female die 200, and has contact surfaces that are in contact with each other, and a sealing rope 160 is embedded at the contact surfaces to realize sealing at the contact surfaces. The sealing string 160 is preferably embedded in the lower punch 100 for easy installation. The sealing rope 160 may also be in the form of other conventional sealing strips, which need to be resistant to a certain high temperature, such as silicone rubber rope.

In the above technical solution, due to the heavy weight of the male die 100 and the female die 200, the male die 100 and the female die 200 are connected to each other by using a hoisting manner by selecting a lifting ring structure provided on the female die 200 and the male die 100. The female die 200 is preferably provided with lifting rings at the center of the length, the male die 100 is preferably provided with lifting rings at the two ends of the length, and the lifting rings can be checked by ANSYS analysis after the lifting rings are arranged.

Referring to fig. 8 to 11, the present embodiment further provides a demolding mechanism, which is beneficial to demolding a product after molding and sealing during molding. Specifically, the demolding mechanism includes a sealing screw 152a and an ejector screw, the male mold 100 is provided with a demolding hole 150, the sealing screw 152a is threadedly mounted in the demolding hole 150 in the molding process to ensure good sealing performance, the sealing screw 152a is taken down after molding, and the ejector screw is matched with the demolding hole 150 to perform demolding treatment on the product on the molding surface 112.

The demolding holes 150 form openings in the molding surface 112, so that ejection force can be directly applied to products on the molding surface 112 during demolding, and the demolding holes 150 penetrate through the male mold 100. Referring to fig. 10, the sealing screw 152a is engaged with the sealing pad 152b and then installed in the demolding hole 150, and the hole wall of the demolding hole 150 is partially threaded.

Referring to fig. 9, 10 and 11, the demolding hole 150 includes a first channel 151 and at least one second channel 152, one end of each second channel 152 is communicated with the first channel 151, the first channel 151 forms an opening on the molding surface 112, the first channel 151 and the second channel 152 are arranged to jointly penetrate through the male mold 100, a sealing ring 151a is embedded in the first channel 151, and a sealing screw 152a is threadedly mounted on the second channel 152. As shown in fig. 9, the demolding hole 150 is provided with a first channel 151 and two second ducts 152, each second duct 152 is threadedly mounted with a sealing screw 152a, and during the demolding process, a plurality of ejection screws cooperate to transmit the ejection force from the sealing ring 151a to the product on the molding surface 112, so as to realize the demolding. The sealing performance of the demoulding hole 150 is further enhanced through the arrangement of the sealing ring 151a in the first channel 151, a product can be protected during demoulding, and the pressure intensity borne by the product is reduced.

The embodiment also provides a composite material forming method, which adopts the composite material forming die, and is particularly suitable for forming products made of composite materials which are relatively thick, long and have high requirements on mechanical properties.

Wherein, preferably adopt the mode of many times evacuation and the solidification alternate action of pressurization, satisfy the requirement that mechanical properties is high when the product is thicker.

Specifically, the vacuum pumping process is performed on the forming chamber 110 by a vacuum pump, and the pressurization chamber 220 is inflated by a gas source to perform the pressurization curing process. The single vacuumizing step and the single pressurizing and curing step are performed in a cycle before and after, and the forming of the single layering product 111 comprises at least one cycle. The number of cycles in a single cycle is preset.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. The composite material forming method is characterized by comprising a composite material forming die, wherein the composite material forming die comprises a male die and a female die which are fixed with each other, the male die is provided with a core, the female die is provided with a cavity, the cavity is arranged on the cavity wall of the female die, a vacuum bag is fixedly arranged in the cavity, the vacuum bag and the core are enclosed to form a closed forming cavity, the vacuum bag and the cavity wall are enclosed to form a closed pressurizing cavity, and prepreg laying is carried out in the forming cavity; the female die is provided with a charging and discharging valve, one end of the charging and discharging valve is communicated with the pressurizing cavity, and the other end of the charging and discharging valve is connected with an air source; a heat exchange pipe is arranged in the male die and is communicated with a heat conduction oil pipeline of the die temperature controller; the male die is also provided with a vacuumizing tube, the vacuumizing tube penetrates through the male die, one end of the vacuumizing tube is communicated with the forming cavity, and the other end of the vacuumizing tube is connected with a vacuum pump; the composite material forming method comprises the steps of vacuumizing the forming cavity through the vacuum pump, inflating the pressurizing cavity through the air source to realize pressurizing and curing, forming a cycle before and after the single vacuumizing step and the single pressurizing and curing step, and forming a single layer product, wherein the forming of the single layer product comprises at least two cycles.

2. The method for molding a composite material according to claim 1, wherein the core is provided with a molding surface and a temperature measurement hole, the temperature measurement hole is provided at a distance from the molding surface, the prepreg is laid on the molding surface, and the mold temperature measuring machine is provided with a temperature measurement pair, and the temperature measurement pair is mounted in the temperature measurement hole.

3. The composite molding method according to claim 2, wherein said heat exchange tubes are uniformly installed inside said male mold in a wave shape, and said heat exchange tubes are spaced apart from said temperature measurement holes.

4. The composite material molding method according to claim 1, wherein the core is provided with a molding surface and a demolding mechanism, the punch is provided with a demolding hole, the demolding hole is arranged through the punch and forms an opening on the molding surface, the demolding mechanism comprises a sealing screw, the sealing screw is matched with a sealing pad, and the sealing screw is threaded in the demolding hole after penetrating through the sealing pad;

the demoulding mechanism is also provided with an ejection screw which is used for ejecting a formed product out of the forming surface after the sealing screw is detached and the formed product penetrates through the demoulding hole.

5. The method for molding a composite material according to claim 4, wherein the demolding hole comprises a first channel and at least one second channel, one end of each second channel is communicated with the first channel, the first channel forms the opening on the molding surface, the first channel and the second channel are arranged through the male die together, a sealing ring is embedded in the first channel, and the sealing screw is mounted on the second channel in a threaded manner.

6. The method for molding a composite material according to claim 1, wherein a sealing rope is embedded at the contact surface of the male mold and the female mold.

7. The method of forming a composite material according to claim 1, wherein the male mold is screwed to the female mold.

8. The composite material molding method according to claim 1, wherein the female mold is provided with a safety valve and a pressure gauge, the safety valve and the pressure gauge are both arranged through the female mold, an inlet of the safety valve is communicated with the pressurizing chamber, and a measuring head of the pressure gauge is arranged to extend into the pressurizing chamber;

one end of the vacuum tube is also connected with a vacuum meter.

9. The composite molding method of claim 1 wherein said vacuum bag is secured to said male mold.