A thermoforming tool and thermoforming method for a thin-walled structural component and a composite material

Abstract

The present application relates to a kind of thin-walled structural member and composite hot forming tool and hot forming method, specifically relates to the field of hot forming, the thin-walled structural member and composite hot forming tool of the present application includes: nested cooperation female die and sub-mold;Between the female die and the workpiece to be formed, hot transformation material is configured;The hot transformation material includes: as temperature rises, it is transformed from flexible material to rigid material.The hot forming tool provided by the present application avoids the hard contact between the workpiece to be formed and the female die during the hot forming process by means of specific hot transformation material, which plays a certain buffering and supporting role, thereby ensuring that the thin-walled structural member does not appear large deformation and damage defects during the hot forming process, and ensuring that the product after hot forming can still be reasonably used.

Description

A thermoforming tooling and thermoforming method for thin-walled structural components and composite materials Technical Field

[0001] This invention relates to the field of thermoforming, specifically to a thermoforming fixture and method for thin-walled structural parts and composite materials, and more particularly to a thermoforming fixture and method for irregularly shaped thin-walled structural parts and composite materials. Background Technology

[0002] With the development of aerospace technology, the requirements for lightweight, thermal stability, and mechanical performance of related components in aircraft are becoming increasingly stringent. Currently, high-performance materials such as resin and carbon fiber are often used to replace some metal parts to ensure the performance of related components, thereby achieving the goal of lightweighting. For example, the heat insulation layer of the engine head is formed.

[0003] For example, CN112497587A discloses a method for molding the insulation layer of a fiber-wound engine head. The bottom layer is molded separately and then integrally molded. The bottom layer is placed in the molding mold, and then adhesive is brushed onto the bottom layer in the area above the crack arrest point, i.e., the bonding area with the cover layer, and dried. The insulation layer film is applied to the area of ​​the bottom layer with adhesive according to the thickness and shape of the cover layer. Before applying the film, the surface of the insulation layer film is brushed with adhesive and dried. After the cover layer insulation layer film is applied, the whole mold is closed, and then the molding mold is placed on a flat vulcanizing machine for vulcanization.

[0004] However, current irregular thin-walled structural components need to withstand large axial and radial loads during the thermoforming process of integral composite materials, which leads to large deformation and damage of irregular thin-walled structural components during the molding process, making the products unusable. Summary of the Invention

[0005] In view of the problems existing in the prior art, the purpose of the present invention is to provide a thermoforming tooling for thin-walled structural parts and composite materials, so as to solve the problem that irregular thin-walled structural parts need to withstand large axial and radial loads during the thermoforming process of integrally thermoforming with composite materials, which leads to large deformation and damage of irregular thin-walled structural parts during the forming process.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a thermoforming tooling for thin-walled structural components and composite materials, the thermoforming tooling for thin-walled structural components and composite materials comprising:

[0008] Nested mating of parent and child molds;

[0009] A heat-transfer material is disposed between the master mold and the workpiece to be formed;

[0010] The thermally transforming material includes materials that transform from flexible to rigid as the temperature increases.

[0011] The thermoforming fixture provided by this invention avoids hard contact between the workpiece to be formed and the master mold during the thermoforming process by using a specific heat-transformation material, which plays a certain role in buffering and supporting, thereby ensuring that thin-walled structural parts do not suffer from large deformation and damage during the thermoforming process, and ensuring that the thermoformed products can still be used reasonably.

[0012] As a preferred embodiment of the present invention, the female mold and the female mold are connected by a connector.

[0013] As a preferred embodiment of the present invention, the master mold includes an upper mold and a lower mold.

[0014] As a preferred technical solution of the present invention, the upper mold and the lower mold are configured with a positioning and mating structure and connected by a guide positioning shaft.

[0015] As a preferred technical solution of the present invention, the conversion temperature of the thermal transformation material from a flexible material to a rigid material is 80-120℃.

[0016] As a preferred technical solution of the present invention, the material of the master mold includes high-strength steel or mold steel.

[0017] As a preferred technical solution of the present invention, the material of the sub-mold includes high-strength steel or mold steel.

[0018] As a preferred technical solution of the present invention, the material of the thermal conversion material includes foamed material or rubber material.

[0019] As a preferred embodiment of the present invention, the thickness of the thermal conversion material is ≤1mm.

[0020] Secondly, the present invention provides a thermoforming method for thin-walled structural parts and composite materials, the thermoforming method comprising: assembling the workpiece to be formed with thermoforming tooling and then performing thermoforming.

[0021] A heat-transfer material is provided between the workpiece to be formed and the master mold of the thermoforming tooling;

[0022] The thermally transforming material includes materials that transform from flexible to rigid as the temperature increases.

[0023] Compared with existing technical solutions, the present invention has the following beneficial effects:

[0024] The thermoforming fixture for thin-walled structural parts and composite materials provided by the present invention, by configuring a specific heat-transformation material in the thermoforming fixture, enables the thin-walled structural parts to match the pressure of the hot pressing process as the temperature changes during the thermoforming process, thereby avoiding the deformation of the thin-walled structural parts during the forming process. The radial deformation of the thin-walled structural parts after thermoforming is <0.5mm. Attached Figure Description

[0025] Figure 1 is a schematic diagram of the thermoforming tooling for thin-walled structural parts and composite materials provided in an embodiment of the present invention.

[0026] In the diagram: 110 - upper mold, 120 - lower mold, 130 - guide positioning shaft, 200 - sub-mold, 300 - heat transfer material, 400 - thin-walled structural component.

[0027] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims. Detailed Implementation

[0028] To better illustrate the present invention and facilitate understanding of its technical solutions, typical but non-limiting embodiments of the present invention are as follows:

[0029] This embodiment provides a thermoforming fixture for thin-walled structural components and composite materials, as shown in Figure 1. The thermoforming fixture for thin-walled structural components and composite materials includes:

[0030] Nested mating of mother mold and child mold 200;

[0031] A heat-transformation material 300 is disposed between the master mold and the workpiece to be formed;

[0032] The thermal transformation material 300 includes materials that transform from flexible to rigid as the temperature increases.

[0033] In this invention, the thin-walled structural component 400 refers to a component with a wall thickness of <2.5mm.

[0034] In this invention, composite materials refer to composite materials commonly used in the art to be bonded to metals, such as phenolic prepreg and rubber-based composite materials.

[0035] In this invention, thermoforming refers to the diffusion bonding of the thin-walled structural component 400 with the composite material.

[0036] In this invention, the workpiece to be formed is placed between the master mold and the sub-mold 200 during the thermoforming process, and then a heat transfer material 300 is placed between the master mold and the workpiece to be formed.

[0037] In this invention, the master mold refers to the mold that contacts the outer wall of the product to be molded, or is responsible for forming the outer contour of the product, or the outer frame or cavity of the mold.

[0038] In this invention, sub-mold 200 refers to a mold that contacts the inner wall of the product to be molded, or is responsible for shaping the internal shape of the product, or is the inner cavity or core of a mold.

[0039] In this invention, the shapes of the specific sub-mold 200 and the mother mold can be reasonably designed according to the requirements of the molded product.

[0040] The female mold and the female mold 200 are connected by a connector.

[0041] In this invention, the connection between the mother mold and the child mold 200 is achieved by using connectors such as bolts and pins for positioning and fixing, so as to ensure an efficient and stable connection between the mother mold and the child mold 200.

[0042] The master mold includes an upper mold 110 and a lower mold 120.

[0043] The upper mold 110 and the lower mold 120 are equipped with a positioning and mating structure and are connected by a guide positioning shaft 130.

[0044] In this invention, the positioning and fitting structure used refers to the structure that can position and connect the upper mold 110 and the lower mold 120 to avoid misalignment and unreasonable assembly. For example, a concave-convex fitting structure can be used to achieve positioning and fitting, or positioning and fitting can be achieved by means of positioning parts or other components. For example, the positioning parts have different fitting structures with the upper mold 110 and the lower mold 120, and positioning and fitting can be achieved through specific fitting structures.

[0045] The thermal transformation temperature of the thermal transformation material 300 from a flexible material to a rigid material is 80-120℃, for example, it can be 80℃, 82℃, 84℃, 86℃, 88℃, 90℃, 92℃, 94℃, 96℃, 98℃, 100℃, 102℃, 104℃, 106℃, 108℃, 110℃, 112℃, 114℃, 116℃, 118℃ or 120℃, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0046] The material of the master mold includes high-strength steel or mold steel.

[0047] The material of the sub-mold 200 includes high-strength steel or mold steel.

[0048] For example, the high-strength steel used includes steels commonly used in the art as raw materials for molds, such as 30CrMnSiA and D406.

[0049] For example, the mold steel used includes steels such as 40Cr, 42Cr, and 42CrMo used as raw materials for molds.

[0050] The thermal conversion material 300 is made of either foamed material or rubber material.

[0051] For example, the thermal conversion material 300 used may be selected as a commercially available polymethacrylimide foam material, or a polymethacrylimide foam material prepared in accordance with the prior art that conforms to the definition of the present invention.

[0052] For example, the heat transfer material 300 used may be selected as commercially available nitrile rubber, chloroprene rubber, or modified nitrile rubber or modified chloroprene rubber prepared according to the prior art that conforms to the definition of the present invention.

[0053] The thickness of the thermal conversion material 300 is ≤1mm, for example, it can be 1mm, 0.9mm, 0.8mm, 0.7mm, 0.6mm, 0.5mm, 0.4mm, 0.3mm, 0.2mm or 0.1mm, etc., but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0054] In this invention, the thermoforming tooling and the thin-walled structural component 400 can be positioned and connected by bolts, pins, etc., so as to ensure that the cavity between the two is evenly distributed, thereby ensuring that the heat transfer material 300 is evenly distributed between the two.

[0055] Furthermore, this embodiment provides a thermoforming method for thin-walled structural parts and composite materials, which can be implemented based on the aforementioned thermoforming tooling, specifically including: assembling the workpiece to be formed with the thermoforming tooling and then performing thermoforming;

[0056] A heat transfer material 300 is provided between the workpiece to be formed and the master mold of the thermoforming tooling;

[0057] The thermal transformation material 300 includes materials that transform from flexible to rigid as the temperature increases.

[0058] In this invention, the pressure, temperature and other parameters that need to be controlled during the thermoforming process are designed according to the conventional requirements in the field and the requirements of the workpiece to be formed, and are not necessarily related to the tooling structure of this invention.

[0059] Furthermore, to illustrate the excellent forming effect achievable by the thermoforming tooling for thin-walled structural parts and composite materials provided by the present invention, the following practical example is used for explanation:

[0060] Example 1

[0061] This embodiment provides a thermoforming fixture for thin-walled structural parts and composite materials, including:

[0062] Nested mating of parent and child molds;

[0063] A heat-transformation material is disposed between the master mold and the workpiece to be formed (wall thickness is 2mm);

[0064] The thermal transformation material includes materials that transform from flexible to rigid as the temperature increases;

[0065] The mother mold and the daughter mold are connected by connectors;

[0066] The master mold includes an upper mold and a lower mold;

[0067] The upper and lower molds are equipped with a positioning and mating structure and are connected by a guide positioning shaft;

[0068] The thermal transformation temperature of the material from a flexible material to a rigid material is 90°C; the thickness of the thermal transformation material is 0.5 mm; the material of the thermal transformation material is polymethacrylamide foam.

[0069] The material of the master mold is 30CrMnSiA; the material of the slave mold is 30CrMnSiA.

[0070] Example 2

[0071] This embodiment provides a thermoforming fixture for thin-walled structural parts and composite materials, including:

[0072] Nested mating of parent and child molds;

[0073] A heat-transformation material is disposed between the master mold and the workpiece to be formed (wall thickness is 1mm);

[0074] The thermal transformation material includes materials that transform from flexible to rigid as the temperature increases;

[0075] The mother mold and the daughter mold are connected by connectors;

[0076] The master mold includes an upper mold and a lower mold;

[0077] The upper and lower molds are equipped with a positioning and mating structure and are connected by a guide positioning shaft;

[0078] The thermal conversion temperature of the material from a flexible material to a rigid material is 120°C; the thickness of the thermal conversion material is 0.11 mm; the material of the thermal conversion material is nitrile rubber.

[0079] The material of the master mold is 42CrMo; the material of the slave mold is 42CrMo.

[0080] Application Example 1

[0081] This embodiment provides a thermoforming method for thin-walled structural components and composite materials, using the thermoforming tooling for thin-walled structural components and composite materials provided in Embodiment 1, as detailed below:

[0082] The workpiece to be formed is assembled with the thermoforming fixture and then thermoformed.

[0083] Application Example 2

[0084] This embodiment provides a thermoforming method for thin-walled structural components and composite materials, using the thermoforming tooling for thin-walled structural components and composite materials provided in Embodiment 2, as detailed below:

[0085] The workpiece to be formed is assembled with the thermoforming fixture and then thermoformed.

[0086] Furthermore, the effects achievable by the thermoforming tooling for thin-walled structural parts and composite materials provided by the present invention are illustrated by the following comparative examples:

[0087] Comparison Example 1

[0088] The only difference from Example 1 is that no thermally transition material is placed between the master mold and the workpiece to be formed.

[0089] Comparison Example 2

[0090] The only difference from Example 1 is that a PVC layer is provided between the master mold and the workpiece to be formed.

[0091] Compare Example 3

[0092] The only difference from Example 1 is that a polyurethane layer is provided between the master mold and the workpiece to be formed.

[0093] Compare Example 4

[0094] The only difference from Example 2 is that no thermally transition material is placed between the master mold and the workpiece to be formed.

[0095] Compare Example 5

[0096] The only difference from Example 2 is that a PVC layer is provided between the master mold and the workpiece to be formed.

[0097] Comparison Example 6

[0098] The only difference from Example 2 is that a polyurethane layer is provided between the master mold and the workpiece to be formed.

[0099] The deformation of the thin-walled structural parts obtained by the above molding was detected and analyzed, and the results are shown in Table 1 below.

[0100] Table 1

[0101] Radial deformation of thin-walled structural components: Application example 1: 0.1mm; Application example 2: 0.3mm; Comparison example 1: 1.5mm; Comparison example 2: 0.8mm; Comparison example 3: 0.9mm; Comparison example 4: 1.4mm; Comparison example 5: 0.9mm; Comparison example 6: 1.1mm. surface

[0102] As shown in Table 1, the thermoforming fixture provided by the present invention avoids hard contact between the workpiece to be formed and the master mold during the thermoforming process by using a specific heat transfer material, which plays a certain role in buffering and supporting, thereby ensuring that the thin-walled structural parts do not suffer from large deformation and damage during the thermoforming process, and ensuring that the thermoformed products can still be used reasonably.

[0103] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0104] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0105] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A thermoforming tooling for thin-walled structural components and composite materials, characterized in that, The thermoforming fixture for the thin-walled structural component and composite material includes: a nested master mold and a slave mold; a thermally transforming material is disposed between the master mold and the workpiece to be formed; the thermally transforming material includes: a material that transforms from a flexible material to a rigid material as the temperature rises; the transformation temperature of the thermally transforming material from a flexible material to a rigid material is 80-120℃.

2. The thermoforming tooling for thin-walled structural components and composite materials as described in claim 1, characterized in that, The master mold and the slave mold are connected by connectors.

3. The thermoforming tooling for thin-walled structural parts and composite materials as described in claim 1, characterized in that, The master mold includes an upper mold and a lower mold.

4. The thermoforming tooling for thin-walled structural parts and composite materials as described in claim 3, characterized in that, The upper and lower molds are equipped with a positioning and mating structure and are connected by a guide positioning shaft.

5. The thermoforming tooling for thin-walled structural parts and composite materials as described in claim 1, characterized in that, The material of the master mold includes high-strength steel or mold steel.

6. The thermoforming tooling for thin-walled structural parts and composite materials as described in claim 1, characterized in that, The material of the sub-mold includes high-strength steel or mold steel.

7. The thermoforming tooling for thin-walled structural parts and composite materials as described in claim 1, characterized in that, The material of the thermal conversion material includes foamed material or rubber material.

8. The thermoforming tooling for thin-walled structural parts and composite materials as described in claim 1, characterized in that, The thickness of the thermal conversion material is ≤1mm.

9. A thermoforming method for thin-walled structural components and composite materials, characterized in that, The thermoforming method includes: assembling the workpiece to be formed with a thermoforming fixture and then performing thermoforming; a heat-transformation material is provided between the workpiece to be formed and the master mold of the thermoforming fixture; the heat-transformation material includes: a material that changes from a flexible material to a rigid material as the temperature rises.

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