Fiber composite constant-velocity joint retainer forming process and forming die

Abstract

A molding process and mold for fiber composite universal joint cages are disclosed. This invention primarily addresses the current lack of molds with a reasonable structure, easy demolding, and capable of meeting the molding requirements of fiber composite materials. The invention provides a molding process and mold for fiber composite universal joint cages. The mold structure is simple and easy to process and assemble; the molding process steps are concise and convenient to operate, facilitating consistent process control in mass production; it enables efficient compression molding of fiber composite universal joint cages, reduces mold manufacturing costs, shortens processing cycles, and improves product qualification rates, resulting in significant economic benefits.

Description

Technical Field

[0001] This invention relates to the field of automotive parts manufacturing, specifically to a fiber composite universal joint cage molding process and its molding die. Background Technology

[0002] Universal joints, as key components in automotive transmission systems, use their cages to constrain the position of rolling elements and ensure smooth power transmission. They typically feature complex spatial curved surface structures and multiple spherical windows, requiring high structural strength, wear resistance, and dimensional accuracy. Traditionally, universal joint cages are mostly manufactured using metal materials. However, with the increasing demand for lightweight and high-performance vehicles, fiber composite materials, due to their high specific strength, high specific stiffness, and good fatigue resistance, are increasingly being used in the manufacture of universal joint cages. However, fiber composite universal joint cages have complex structures, especially their spherical windows and multi-curved spatial structures of inner and outer contours. When using traditional molds for molding, problems arise such as difficulty in demolding, unreasonable cavity segmentation, and difficulty in ensuring molding accuracy. Furthermore, existing molds are mostly integral or simple parting structures, which are difficult to adapt to the complex geometry of the cage, easily leading to product defects or damage to the fiber structure. In addition, the molding process requires high precision in demolding, positioning, and cavity sealing of the cage fiber preform, resulting in complex structures and high costs. Therefore, there is an urgent need for a universal joint retainer mold and its molding process that is structurally reasonable, easy to demold, and low in cost, and can meet the molding requirements of fiber composite materials. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, the present invention provides a molding process and molding die for a fiber composite universal joint cage, which mainly solves the problem of the lack of a mold with a reasonable structure, easy demolding and able to meet the molding requirements of fiber composite materials.

[0004] The technical solution of the present invention is as follows: A molding die for a fiber composite universal joint retainer includes an upper die and a lower die, wherein the upper end face of the lower die is provided with a middle die, and further includes... A circular groove is located at the center of the intermediate mold; A core is disposed on the upper end face of the lower mold, with at least a portion of the core disposed within the circular groove, forming a cavity between the core and the middle mold. The slider is movably mounted on the middle mold, and one end extends into the cavity when the upper mold is closed.

[0005] The back of the slider is provided with a first inclined surface, and the upper mold is provided with a second inclined surface that cooperates with the first inclined surface.

[0006] The core includes a rod, and the outer circumferential wall of the rod is provided with an annular silicone layer, which is used for demolding and compensating for assembly gaps.

[0007] The intermediate mold is provided with a groove for sliding cooperation with the slider.

[0008] The thickness of the silicone layer is 1 mm to 3 mm.

[0009] The number of sliders 4 is 6 or 8.

[0010] A process for molding a fiber composite universal joint cage includes the following steps: Step 1: Preheat the mold for forming a fiber composite universal joint retainer as described above; Step 2: Laying the prepreg; Step 3: Mold closing and slide assembly; Step 4: Apply pressure and heat to cure; Step 5: Demold and remove the product.

[0011] Step one involves preheating the mold to 60°C using a press to ensure uniform mold temperature.

[0012] The second step involves selecting the appropriate number of prepreg layers based on the product design thickness, trimming it into a shape consistent with the product outline, and then manually laying it flat and accurately on the surface of the silicone layer inside the mold.

[0013] Step 3: Assemble the sliders sequentially to the side core-pulling position of the mold and lock them in place. Then drive the press to close the mold, so that the upper mold, lower mold and slider form a closed and precisely sized cavity.

[0014] Step four involves starting the press to apply a mold-closing pressure of 100 kg, while simultaneously heating the mold to 150°C and maintaining this temperature and pressure for 40 minutes.

[0015] Step five involves waiting for the heat preservation and pressure holding to end, then depressurizing the press and opening the mold. The side core-pulling sliders are then manually removed one by one to separate the product from the mold cavity. Finally, the product is manually peeled off the surface of the silicone layer.

[0016] The beneficial effects of this invention are as follows: This invention provides a molding process and molding die for a fiber composite universal joint retainer. The die structure is simple and easy to process and assemble; the molding process steps are concise and easy to operate, making it easy to achieve process consistency control in mass production; it can realize efficient compression molding of fiber composite universal joint retainers, reduce die manufacturing costs, shorten processing cycle, improve product qualification rate, and has good economic benefits. Attached Figure Description

[0017] Figure 1 This is an exploded view of one embodiment of the present invention.

[0018] Figure 2This is a schematic diagram of a structure according to an embodiment of the present invention.

[0019] Figure 3 This is a three-dimensional schematic diagram of the core according to an embodiment of the present invention.

[0020] Figure 4 This is a cross-sectional schematic diagram of an embodiment of the present invention. Detailed Implementation

[0021] The invention will be further described below with reference to the accompanying drawings, such as... Figure 1 As shown, this embodiment of the invention provides a molding die for a fiber composite universal joint retainer, including an upper die 1, a lower die 3, and a middle die 2 disposed on the upper end face of the lower die 3. A circular groove 21 is formed at the center of the middle die 2. A core 5 is disposed on the upper end face of the lower die, and at least a portion of the core 5 extends into the circular groove 21. A cavity 7 for accommodating fiber prepreg is formed between the core 5 and the middle die 2. A slider 4 is movably mounted on the middle die 2. When the upper die 1 is closed, one end of the slider 4 extends into the cavity 7 to form the window of the retainer. The cavity is used to form the overall outline of the retainer.

[0022] In this embodiment, both the upper mold 1 and the lower mold 3 are plate-shaped structures, and the middle mold 2 is fixedly disposed on the upper end face of the lower mold 3. A circular groove 21 is formed at the center of the middle mold 2, and its shape and size match the lower end of the core 5. The core 5 is fixedly installed on the upper end face of the lower mold, and the lower mold can be provided with mounting holes for installing the core. When the mold is closed, the upper mold 1 moves downward, and a cavity 7 is formed between the outer wall of the core 5 and the inner wall of the middle mold 2. The shape of the cavity 7 matches the outer contour of the universal joint retainer.

[0023] refer to Figure 4 The slider 4 has a first inclined surface on its back, and the upper mold 1 has a second inclined surface 11 that mates with the first inclined surface. When the mold is closed, the upper mold 1 moves downwards, and the second inclined surface 11 contacts the first inclined surface and slides relative to it, thereby pushing the slider 4 towards the center of the mold, causing one end of the slider 4 to extend into the cavity 7. When the upper mold 1 is fully closed, the slider 4 is pushed to a predetermined position. When the mold is opened, the upper mold 1 is lifted upwards, the second inclined surface 11 disengages from the first inclined surface, the slider 4 loses its pushing force and is in a relaxed state. The sliders 4 are then manually removed one by one, achieving separation of the product from the mold cavity.

[0024] In this embodiment, the number of sliders 4 is 6 or 8, and the specific number can be determined according to the number of windows and structural dimensions of the universal joint retainer.

[0025] refer to Figure 3The core 5 includes a rod body, and an annular silicone layer 6 is provided on the circumferential outer wall of the rod body. The silicone layer 6 is used to assist demolding after the product has cured and to compensate for the assembly gaps between the various parts of the mold. Specifically, the thickness of the silicone layer 6 is 1 mm to 3 mm. Under the action of mold closing pressure, the silicone layer 6 undergoes elastic deformation, which can effectively fill the tiny gaps between the core 5 and the middle mold 2 and the slider 4, improve the sealing performance of the mold, and prevent resin leakage.

[0026] refer to Figure 1 The middle mold 2 is provided with a groove 22 for sliding engagement with the slider 4. The groove 22 is arranged radially and serves to guide and limit the slider 4, ensuring that the slider 4 moves stably radially during mold closing and opening, and avoiding deviation or jamming.

[0027] This invention also provides a molding process for a fiber composite universal joint cage, which uses the above-mentioned molding die and includes the following steps: Step 1: Mold preheating: Preheat the mold to 60℃ using a press to ensure uniform mold temperature, which facilitates the subsequent resin to fully impregnate the fibers, ensures stable curing reaction, improves product quality, and shortens the molding cycle.

[0028] Step 2: Laying the Prepreg: Select the appropriate number of fiber prepreg layers based on the product design thickness, and trim them to match the product's outline. Then, manually lay them flat and accurately on the silicone layer surface within the mold, ensuring no wrinkles or misalignment. Multi-layer and multi-angle layup designs can be implemented according to the product's stress requirements.

[0029] Step 3: Mold closing and slider assembly: Assemble the sliders in sequence to the side core-pulling position of the mold and lock them. Then drive the press to close the mold, so that the upper mold 1, lower mold 3 and slider 4 form a closed and precisely sized cavity, ensuring that there are no gaps or misalignments after mold closing, and providing a stable molding space for the prepreg to flow and solidify evenly under pressure.

[0030] Step 4: Pressurization and Heating Curing: Start the press and apply 100 kg of mold closing pressure. At the same time, heat the mold to 150°C. Maintain the temperature and pressure at this level for 40 minutes to allow the resin in the prepreg to flow fully, impregnate the fibers, and undergo a complete cross-linking and curing reaction, ensuring that the product achieves the designed mechanical properties and dimensional stability.

[0031] Step 5: Demolding and product removal: After the heat preservation and pressure holding are completed, the press is depressurized and the mold is opened. The side core-pulling sliders are removed one by one to separate the product from the mold cavity. Then, the product is peeled off the silicone layer surface to obtain a molded part with no sticking and an intact surface.

[0032] After demolding and removing the product, a CNC machining step may also be included: positioning and clamping the demolded product, and performing CNC precision machining on the surface area that was in contact with the silicone layer during the molding process to remove any possible traces of flash, resin build-up, or surface unevenness, thereby improving the dimensional accuracy and surface finish of this part and meeting the final assembly and use requirements of the product.

[0033] The working process of this invention will be described below in conjunction with the mold structure and molding process: Initially, the upper mold 1 is in the raised position, and the slider 4 is in the relaxed state. First, the mold is preheated according to steps one and two, and fiber prepreg is laid on the surface of the silicone layer 6 of the core 5.

[0034] Then, following step three, each slider 4 is inserted into the groove 22 of the middle mold 2, and the press is driven to move the upper mold 1 downwards. During the descent of the upper mold 1, the second inclined surface 11 contacts and slides relative to the first inclined surface on the back of the slider 4, pushing the slider 4 radially towards the center of the mold along the groove 22. When the upper mold 1 is closed, one end of the slider 4 extends into the cavity 7, forming a closed and complete cavity together with the core 5 and the middle mold 2. Following step four, pressure is applied and heating is applied to cure the resin in the prepreg. After curing, following step five, the press is depressurized and the upper mold 1 is lifted upwards, the second inclined surface 11 separates from the first inclined surface, and the slider 4 loses its thrust. Subsequently, each slider 4 is manually removed from the mold in sequence to separate the product from the mold cavity, and finally the product is peeled off from the surface of the silicone layer 6. If necessary, the product is CNC precision-machined to obtain the final product.

[0035] The technical solution provided by this invention achieves compression molding of a fiber composite universal joint cage by setting a circular groove, a core, a slider, and a silicone layer. During mold closing, the upper mold drives the slider inward via an inclined plane, resulting in a simple structure and reliable operation. After mold opening, the sliders are manually removed sequentially, making demolding simple and controllable, avoiding damage to the product caused by forced demolding. The silicone layer facilitates demolding and compensates for assembly gaps, improving the mold's sealing performance and molding quality. Compared with existing technologies, this invention has advantages such as simple mold structure, low manufacturing cost, convenient operation, stable molding quality, and high product qualification rate, demonstrating good economic benefits and application value.

[0036] The embodiments described with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention. The embodiments should not be considered as limiting the invention, but any improvements made based on the spirit of the invention should be within the scope of protection of the invention.

Claims

1. A molding die for a fiber composite universal joint retainer, comprising an upper die (1) and a lower die (3), wherein the upper end face of the lower die is provided with a middle die (2), characterized in that: Also includes A circular groove (21) is located at the center of the intermediate mold; The core (5) is located on the upper end face of the lower mold, and at least part of the core is located in the circular groove, forming a cavity (7) between the core and the middle mold. The slider (4) is movably mounted on the middle mold, and one end extends into the cavity when the upper mold is closed.

2. The fiber composite universal joint retainer molding die according to claim 1, characterized in that: The back of the slider is provided with a first inclined surface, and the upper mold is provided with a second inclined surface (11) that cooperates with the first inclined surface.

3. The fiber composite universal joint retainer molding die according to claim 1, characterized in that: The core includes a rod body, and the outer circumferential wall of the rod body is provided with an annular silicone layer (6), which is used for demolding and compensating for assembly gaps.

4. The fiber composite universal joint retainer molding die according to claim 1, characterized in that: The intermediate mold is provided with a groove (22) for sliding cooperation with the slider.

5. A fiber composite universal joint retainer molding die according to claim 3, characterized in that: The thickness of the silicone layer (6) is 1 mm to 3 mm.

6. The fiber composite universal joint retainer molding die according to claim 1, characterized in that: The number of sliders (4) is 6 or 8.

7. A molding process for a fiber composite universal joint cage, characterized in that, Includes the following steps: Step 1: Preheat the fiber composite universal joint retainer molding die as described in any one of claims 1-6; Step 2: Laying the prepreg; Step 3: Mold closing and slide assembly; Step 4: Apply pressure and heat to cure; Step 5: Demold and remove the product.

8. The molding process for a fiber composite universal joint cage according to claim 7, characterized in that: Step one involves preheating the mold to 60°C using a press to ensure uniform mold temperature.

9. The molding process for a fiber composite universal joint cage according to claim 7, characterized in that: The second step involves selecting the appropriate number of prepreg layers based on the product design thickness, trimming it into a shape consistent with the product outline, and then manually laying it flat and accurately on the surface of the silicone layer inside the mold.

10. The molding process for a fiber composite universal joint cage according to claim 7, characterized in that: Step 3: Assemble the sliders sequentially to the side core-pulling position of the mold and lock them in place. Then drive the press to close the mold, so that the upper mold, lower mold and slider form a closed and precisely sized cavity.

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