Thermoplastic composite compression molding fixture and molding method

Abstract

The application belongs to the technical field of composite material forming, and discloses a thermoplastic composite material stamping forming clamp and a forming method. The thermoplastic composite material stamping forming clamp comprises a fixed frame, a sliding frame, an elastic member and an isolation film. The fixed frame comprises a sliding rod extending along a first direction. The sliding frame extends along a second direction and is slidingly connected to the sliding rod and can move along the first direction. One end of the elastic member is connected to the fixed frame, and the other end is connected to the sliding frame. The elastic member is in a stretched state to always provide a pulling force along the first direction to the sliding frame. One end of the isolation film along the first direction is fixed to the sliding frame, and the other end is connected to the fixed frame. The isolation film is attached with a thermoplastic plate. The thermoplastic composite material stamping forming clamp is suitable for batch production of thermoplastic composite material stamping structures, and is beneficial to guarantee the yield, improve the production continuity and material utilization rate, and reduce the manufacturing cost.

Description

Technical Field

[0001] This invention relates to the field of composite material molding technology, and in particular to a thermoplastic composite material stamping jig and molding method. Background Technology

[0002] Stamping is a crucial manufacturing process for thermoplastic composites used in aerospace, automotive, and other fields. A key technical aspect of this process is clamping the raw material, i.e., the thermoplastic sheet, in a specific design before stamping. This clamping is present throughout the entire stamping process, including positioning the thermoplastic sheet before heating, heating and melting it in the heating equipment, transferring it above and positioning it with the forming fixture, closing the mold and cooling it within the forming fixture to form the target structure, and demolding. Therefore, the clamping method has a continuous impact on the quality control, time cycle, and economic costs of structural manufacturing. Currently, there are two main clamping methods for thermoplastic composite stamping: spring suspension and pneumatic clamping. The spring suspension method basically uses hook springs to connect the thermoplastic sheet, cut from the unfolded contour of the structure, to the clamp. The pneumatic clamping method basically uses two opposing pneumatic control ends of the clamp to grip a high-temperature resistant insulating film, and positions the thermoplastic sheet on it.

[0003] The spring suspension method has the following drawbacks: 1) It requires tooling with good roughness and gloss to meet the surface quality requirements of the structural components. This standard tooling is expensive and has a long manufacturing cycle. 2) Under spring suspension conditions, the suitable heating temperature range for thermoplastic sheets is significantly narrower than that under the condition of membrane support. The highly softened state of the sheet is more conducive to subsequent molding, but it comes with a higher risk of spring pull-out, which can easily lead to scrap. In addition, it is necessary to conduct a large number of experiments to explore the size and distribution of the ear pieces of the thermoplastic sheet and to screen out springs with suitable stiffness and length. This experimental cycle is long and involves many variables, making it difficult to form a clear control law, which is not conducive to industrial production. 3) The protection range of the ear pieces by the heat insulation material is often difficult to determine. If the heat insulation range is too small, the suspension area is prone to heat accumulation until pull-out. If the range is too large, the suspension area will not melt sufficiently, which can easily cause wrinkles due to restricted interlayer slippage during the molding of the structural components. 4) When the sheet metal is heavy, such as when the structural components are long or thick, a large number of springs are needed to prevent the sheet metal from drooping excessively in the heating furnace and to prevent excessive shaking when the sheet metal is transferred at high speed to the forming fixture. Both of these situations can easily cause positioning deviations between the sheet metal and the forming fixture, resulting in deviations in the limiting angle of the structural components. 5) The material allowance required for spring suspension is much greater than that for the isolation membrane support method. The width of a single-sided lug is often 15mm to 50mm, and a total allowance of 30mm to 100mm is required on both sides. However, the length of thermoplastic stamping parts is generally in the range of 102mm to 103mm, resulting in low material utilization. 6) According to experimental experience, the spring suspension and removal operations in the two stages of preheating clamping preparation and post-forming demolding take nearly ten minutes. In particular, the demolding removal may require the use of tools due to the large tension. 7) Because the spring diameter is larger than the thickness of the tooling cavity, it is impossible to extend into the cavity to match shorter structures. Different tooling is required for parts of different lengths, increasing tooling costs. A shorter final part can also be obtained by initially fabricating a longer structure and removing more excess material, but this method significantly reduces material utilization and is not economically viable for mass production.

[0004] Pneumatic clamping has the following drawbacks: 1) Pneumatic clamps are generally designed by the stamping equipment manufacturer during equipment planning as part of the transfer equipment, rather than being added independently later. The cost of these pneumatic clamps is relatively high, generally exceeding that of forming tooling. 2) For stamping equipment containing pneumatic clamps, a dedicated air source also needs to be added during the infrastructure planning, resulting in continuous usage and maintenance costs during the production phase.

[0005] Therefore, there is an urgent need to provide a new type of thermoplastic composite material stamping fixture and forming method to solve the above-mentioned technical problems in the prior art. Summary of the Invention

[0006] One objective of this invention is to provide a thermoplastic composite material stamping fixture, which is suitable for the mass production of thermoplastic composite material stamping structures, and helps to ensure yield, improve production continuity and material utilization, and reduce manufacturing costs.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] The thermoplastic composite material stamping fixture includes a fixed frame, a sliding frame, an elastic element, and a release liner. The fixed frame includes a sliding rod extending along a first direction. The sliding frame extends along a second direction and is slidably connected to the sliding rod and capable of moving along the first direction. The first direction is perpendicular to the second direction. One end of the elastic element is connected to the fixed frame, and the other end is connected to the sliding frame. The elastic element is in a stretched state so that it always provides a tensile force along the first direction to the sliding frame. One end of the release liner is fixed to the sliding frame along the first direction, and the other end is connected to the fixed frame. The release liner is covered with a thermoplastic sheet.

[0009] Optionally, two sliding frames are provided, and the two sliding frames are slidably connected to the two ends of the sliding rod along the first direction, and the two sliding frames are fixed to the two ends of the isolation membrane along the first direction.

[0010] Optionally, there are two sliding rods spaced apart along the second direction, and the two ends of the sliding frame along the second direction are slidably connected to the two sliding rods respectively.

[0011] Optionally, the aforementioned fixed frame further includes two fixed brackets, which are respectively disposed at both ends of the sliding rod along the first direction, and the two fixed brackets are respectively fixed at both ends of the sliding rod along the second direction.

[0012] Optionally, multiple elastic elements are distributed at intervals along the second direction, with one end of each elastic element connected to the fixed frame and the other end connected to the sliding frame.

[0013] Optionally, the aforementioned mounting bracket is provided with positioning holes, which can be connected to the transfer equipment.

[0014] Optionally, either of the two sliding rods is provided with a transfer handle, which can be clamped by a transfer device.

[0015] Optionally, the sliding rod is provided with a positioning groove, which can be engaged with a positioning protrusion on the worktable of the stamping equipment.

[0016] Optionally, the thermoplastic sheet is attached to the release film with adhesive tape.

[0017] Another object of the present invention is to provide a method for stamping thermoplastic composite materials, which uses a thermoplastic composite material stamping fixture as described in any of the above embodiments, and includes the following steps: S1, fixing the release film to the sliding frame, and then slidingly connecting the sliding frame to the sliding rod; S2, connecting both ends of the elastic member to the sliding frame and the fixed frame respectively, so that the release film is in a stretched state, and then attaching the thermoplastic sheet to the release film; S3, placing the thermoplastic composite material stamping fixture carrying the thermoplastic sheet on the worktable of the stamping equipment, and starting the stamping equipment to stamp the thermoplastic sheet.

[0018] Beneficial effects:

[0019] The thermoplastic composite stamping fixture of this invention uses a release liner to support the thermoplastic sheet to be stamped. The release liner is fixed to a sliding frame, which is fixed to a fixed frame by an elastic element. The sliding frame is also slidably connected to a sliding rod of the fixed frame. The tensile force provided by the elastic element ensures that the release liner is always stretched. During the stamping process of the thermoplastic sheet, the release liner is stretched and taut by the elastic element, eliminating the need for external equipment to control the tension. This supports the flow of the thermoplastic sheet during the heating, rapid transfer, and forming stages of the stamping process, ensuring that the thermoplastic sheet is effectively supported and positioned by the release liner at each stage, preventing slippage and deformation. It also provides the necessary tension to keep the release liner taut, preventing ripples or wrinkles, while allowing the release liner to deform inwards with the thermoplastic sheet without plastic deformation or breakage. This improves the reusability of the thermoplastic composite stamping fixture. This thermoplastic composite stamping fixture is suitable for the mass production of thermoplastic composite stamped structures, helping to ensure yield, improve production continuity and material utilization, and reduce manufacturing costs. Attached Figure Description

[0020] Figure 1 This is a top view of the thermoplastic composite material stamping die provided in a specific embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram illustrating the process of placing a thermoplastic composite material stamping die into a stamping equipment according to a specific embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the thermoplastic sheet forming process on a thermoplastic composite material stamping die provided in a specific embodiment of the present invention.

[0023] In the picture:

[0024] 10. Stamping equipment; 11. Positioning protrusion; 100. Fixing frame; 110. Sliding rod; 111. Positioning groove; 112. Transfer handle; 120. Fixing bracket; 121. Positioning hole; 200. Sliding frame; 300. Elastic element; 400. Separating membrane; 401. Thermoplastic sheet; 402. Adhesive tape. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0026] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0029] The first direction described in this embodiment is: Figure 1 and Figure 3 The X direction shown is the length direction of the release liner 400 and the direction in which the thermoplastic sheet 401 deforms after compression; the second direction is... Figure 1The Y direction shown is the width direction of the separator 400, and the X direction is perpendicular to the Y direction.

[0030] Please refer to Figure 1 The thermoplastic composite material stamping fixture includes a fixed frame 100, a sliding frame 200, an elastic element 300, and a release membrane 400. The fixed frame 100 includes a sliding rod 110 extending along a first direction; the sliding frame 200 extends along a second direction, is slidably connected to the sliding rod 110, and is capable of moving along the first direction; the first direction is perpendicular to the second direction; one end of the elastic element 300 is connected to the fixed frame 100, and the other end is connected to the sliding frame 200. The elastic element 300 is in a stretched state so that it always provides a tensile force along the first direction to the sliding frame 200; one end of the release membrane 400 along the first direction is fixed to the sliding frame 200, and the other end is connected to the fixed frame 100. A thermoplastic sheet 401 is attached to the release membrane 400.

[0031] In this embodiment, the thermoplastic composite material stamping fixture uses a release diaphragm 400 to support the thermoplastic sheet 401 to be stamped. The release diaphragm 400 is fixed to a sliding frame 200, which is fixed to a fixed frame 100 by an elastic element 300. The sliding frame 200 is also slidably connected to a sliding rod 110 of the fixed frame 100. The tensile force provided by the elastic element 300 ensures that the release diaphragm 400 is always under tension. During the stamping process of the thermoplastic sheet 401, the release diaphragm 400 is held in place by the elastic element 300. The 00-tensioning mechanism eliminates the need for external equipment to control the tension, supporting the flow of the thermoplastic sheet 401 during the heating, rapid transfer, and forming stages of the stamping process. It ensures that the thermoplastic sheet 401 is effectively supported and positioned by the release liner 400 at every stage, preventing slippage and deformation. It provides the necessary tension to keep the release liner 400 taut without ripples or wrinkles, while allowing the release liner 400 to retract with the deformation of the thermoplastic sheet 401 without plastic deformation or breakage, thus improving the reusability of this thermoplastic composite stamping fixture. This thermoplastic composite stamping fixture is suitable for the mass production of thermoplastic composite stamped structures, helping to ensure yield, improve production continuity and material utilization, and reduce manufacturing costs.

[0032] In this embodiment, the thermoplastic sheet 401 is attached to the release liner 400 using adhesive tape 402. It should be noted that the adhesive tape 402 effectively secures the release liner 400 to the release liner 400 and facilitates removal, thus improving production efficiency in the batch molding process. Both the adhesive tape 402 and the release liner 400 are made of high-temperature resistant materials, which will not be described in detail here.

[0033] Furthermore, two sliding frames 200 are provided, each slidably connected to both ends of the sliding rod 110 along the first direction, and each fixed to both ends of the release diaphragm 400 along the first direction. The two sliding frames 200 allow the release diaphragm 400 to be stretched and tensioned simultaneously at both ends along the first direction, resulting in more uniform tension and better tension. This allows the release diaphragm 400 to deform and retract with the thermoplastic sheet 401 without plastic deformation or breakage, further improving the reusability of the thermoplastic composite material stamping fixture.

[0034] Optionally, two sliding rods 110 are spaced apart along the second direction, and the two ends of the sliding frame 200 along the second direction are slidably connected to the two sliding rods 110 respectively. The arrangement of the two sliding rods 110 allows the sliding frame 200 to be guided and limited by the two sliding rods 110 during the sliding process, making the force on the isolation membrane 400 more uniform and further improving the tensioning effect.

[0035] Furthermore, the aforementioned fixed frame 100 also includes two fixing brackets 120, which are correspondingly disposed at both ends of the sliding rod 110 along the first direction. The fixing brackets 120 also fix two sliding rods 110 to both ends along the second direction. The fixing brackets 120 provide fixation and support for the sliding rods 110, ensuring the mechanical strength of the fixed frame 100 and preventing deformation during the stretching of the isolation membrane 400.

[0036] Specifically, multiple elastic elements 300 are spaced apart along the second direction. One end of each elastic element 300 is connected to the fixed frame 120, and the other end is connected to the sliding frame 200. The multiple elastic elements 300 not only provide greater tensile force but also distribute the tensile force evenly along the second direction, ensuring that the separator 400 does not wrinkle or deform.

[0037] In this embodiment, both the fixed frame 120 and the sliding frame 200 are provided with a plurality of fixing holes. Those skilled in the art can arbitrarily select the corresponding fixing holes to suspend the elastic element 300, which will not be described in detail here.

[0038] Please continue to refer to this. Figure 1 and Figure 2 The aforementioned mounting bracket 120 is provided with positioning holes 121, which can be connected to the transfer equipment. Positioning holes 121 can be connected to the rail-type transfer equipment to improve stability and accuracy during the transfer process.

[0039] Optionally, either of the two sliding rods 110 is provided with a transfer handle 112, which can be gripped by a transfer device. The transfer device here is a multi-axis robot, which can grip the transfer handle 112 to securely transfer the thermoplastic composite stamping fixture and improve production quality.

[0040] Furthermore, the aforementioned sliding rod 110 is provided with a positioning groove 111, which can engage with the positioning protrusion 11 on the worktable of the stamping equipment 10. Thus, the thermoplastic composite material stamping fixture can be accurately aligned with the stamping equipment 10, and the positioning accuracy is improved through the engagement of the positioning groove 111 and the positioning protrusion 11.

[0041] like Figure 2 and Figure 3 As shown, this embodiment also provides a method for stamping thermoplastic composite materials. This method uses a thermoplastic composite material stamping fixture as described in any of the above schemes, and includes the following steps: S1, fixing the release liner 400 to the sliding frame 200, and then sliding the sliding frame 200 to the sliding rod 110; S2, connecting the two ends of the elastic member 300 to the sliding frame 200 and the fixed frame 100 respectively, so that the release liner 400 is in a stretched state, and then attaching the thermoplastic sheet 401 to the release liner 400; S3, placing the thermoplastic composite material stamping fixture carrying the thermoplastic sheet 401 on the worktable of the stamping equipment 10, and starting the stamping equipment 10 so that the thermoplastic sheet 401 is stamped.

[0042] This thermoplastic composite stamping method uses a thermoplastic composite stamping fixture as described in any of the above embodiments, thereby achieving the beneficial effects of the thermoplastic composite stamping fixture described in any of the above embodiments. Specifically, during the stamping process of the thermoplastic sheet 401, the release liner 400 is stretched and tightened by the elastic element 300 without the need for external equipment to control the tension. This supports the flow of the thermoplastic sheet 401 in the heating, rapid transfer, and forming stages of the stamping process, and ensures that the thermoplastic sheet 401 can be effectively supported and positioned by the release liner 400 at each stage, preventing slippage and deformation. It also provides the necessary tension to keep the release liner 400 taut and prevent ripples or wrinkles. At the same time, it allows the release liner 400 to deform and retract with the thermoplastic sheet 401 without plastic deformation or breakage, thus improving the reusability of the thermoplastic composite stamping fixture.

[0043] After the stamping equipment 10 closes the mold for a certain period of time and completes the stamping process, the thermoplastic sheet 401 and the release film 400 are demolded. During the demolding process, it is necessary to avoid damaging the release film 400 as much as possible, so as to maintain the cyclical use of the original thermoplastic composite material stamping fixture.

[0044] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A thermoplastic composite material stamping fixture, characterized in that, include: A fixed frame (100) includes a sliding rod (110) extending along a first direction. A sliding frame (200) extends along a second direction, is slidably connected to the sliding rod (110) and is capable of moving along a first direction; the first direction is perpendicular to the second direction. An elastic element (300) is connected at one end to the fixed frame (100) and at the other end to the sliding frame (200). The elastic element (300) is in a stretched state so that the elastic element (300) always provides a tensile force to the sliding frame (200) in the first direction. An isolation film (400) is fixed at one end to the sliding frame (200) along the first direction and at the other end to the fixed frame (100). A thermoplastic sheet (401) is attached to the isolation film (400). Two sliding frames (200) are provided, and the two sliding frames (200) are slidably connected to the two ends of the sliding rod (110) along the first direction, and the two sliding frames (200) are fixed to the two ends of the isolation membrane (400) along the first direction.

2. The thermoplastic composite material stamping fixture according to claim 1, characterized in that, Two sliding rods (110) are spaced apart along the second direction, and the sliding frame (200) is slidably connected to the two sliding rods (110) one by one at both ends along the second direction.

3. The thermoplastic composite material stamping fixture according to claim 2, characterized in that, The fixed frame (100) further includes two fixed brackets (120), which are respectively disposed at both ends of the sliding rod (110) along the first direction, and the two fixed brackets (120) are respectively fixed at both ends of the sliding rod (110) along the second direction.

4. The thermoplastic composite material stamping fixture according to claim 3, characterized in that, The elastic elements (300) are distributed at intervals along the second direction. One end of each elastic element (300) is connected to the fixed frame (120), and the other end is connected to the sliding frame (200).

5. The thermoplastic composite material stamping fixture according to claim 3, characterized in that, The mounting bracket (120) is provided with a positioning hole (121), which can be connected with the transfer device.

6. The thermoplastic composite material stamping fixture according to claim 2, characterized in that, Either of the two sliding rods (110) is provided with a transfer handle (112) which can be clamped by a transfer device.

7. The thermoplastic composite material stamping fixture according to claim 2, characterized in that, The sliding rod (110) is provided with a positioning groove (111), which can be connected with the positioning protrusion (11) on the worktable of the stamping equipment (10).

8. The thermoplastic composite material stamping fixture according to any one of claims 1-7, characterized in that, The thermoplastic sheet (401) is attached to the release film (400) by tape (402).

9. A method for stamping thermoplastic composite materials, characterized in that, Using the thermoplastic composite material stamping fixture as described in any one of claims 1-8, the steps include: S1. Fix the isolation membrane (400) to the sliding frame (200), and then slide the sliding frame (200) to the sliding rod (110). S2. Connect the two ends of the elastic element (300) to the sliding frame (200) and the fixed frame (100) respectively, so that the isolation film (400) is in a stretched state, and then attach the thermoplastic sheet (401) to the isolation film (400). S3. Place the thermoplastic composite material stamping fixture carrying the thermoplastic sheet (401) on the worktable of the stamping equipment (10), and start the stamping equipment (10) so that the thermoplastic sheet (401) is stamped.

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