A mechanism integrating automotive plastic water-assisted molding die and punching.

Abstract

This utility model discloses an integrated molding and punching mechanism for automotive plastic water-assisted molding, relating to the field of pipe mold technology. It includes a lower mold, a core mold, and an upper mold. The core mold is located within the lower mold, and a first mold cavity is formed on the core mold. The upper mold is fixed to the lower mold, and a second mold cavity is formed on the upper mold. When the upper mold is fixed to the lower mold, the second mold cavity and the first mold cavity together form an injection molding chamber. Molten material is injected into the injection molding chamber, and high-pressure water is injected to penetrate the molten core, pushing the plastic tightly against the inner wall of the injection molding chamber. Finally, it cools and solidifies to form the desired pipe, thus forming a circular pipe. This utility model integrates punching holes and a built-in punching mechanism on the core mold, combining water-assisted molding and punching processes into a single mold. Compared to the traditional process that requires removing the pipe from the mold and transferring it to a separate punch press for secondary processing, this directly eliminates the need for repeated workpiece positioning and clamping, shortening the production cycle.

Description

Technical Field

[0001] This utility model relates to the field of pipe mold technology, and in particular to a mechanism that integrates automotive plastic water-assisted process molding mold and punching. Background Technology

[0002] In the automotive manufacturing industry, plastic circular pipes (such as cooling water pipes and air ducts) are widely used due to their advantages such as lightweight, corrosion resistance, and ease of molding. Water-assisted injection molding (water-assisted process), as a highly efficient technology, is particularly suitable for producing hollow or thin-walled complex pipe components. The core of this process lies in a specialized mold, which typically includes a lower mold / core assembly with a first mold cavity and an upper mold with a second mold cavity. After mold closing, the second mold cavity and the core assembly together form the injection chamber, into which molten plastic is injected. Subsequently, high-pressure water (or other media) is injected to penetrate the molten core, pushing the plastic tightly against the wall of the first mold cavity, and finally cooling and solidifying to form the desired pipe. The design of this type of mold directly affects the molding quality, dimensional accuracy, and production efficiency of the pipe.

[0003] However, existing water-assisted molding processes generally have significant limitations when producing circular pipes with side holes or end openings. After molding, the pipes typically need to be removed from the mold and transferred to a separate punching station or equipment for secondary hole drilling. This not only increases additional operating steps, equipment investment, and space occupation, but more importantly, it significantly extends the overall production cycle. Furthermore, the pipes are highly susceptible to deformation or damage during transfer and secondary clamping, affecting product yield. Secondly, traditional mechanical punching methods, when applied to plastic pipes that have just been demolded, are still at high temperatures, and whose structural strength has not fully developed, are prone to defects such as burrs, cracks, or inner wall collapse at the punched edges, making it difficult to meet the stringent requirements of the automotive industry for high sealing and high strength at pipe system connections. Therefore, there is an urgent need for a mold solution that integrates molding and high-precision punching functions to overcome the aforementioned efficiency and quality bottlenecks.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content

[0005] The purpose of this invention is to overcome the significant limitations of existing water-assisted molding processes when producing circular pipes with side holes or end openings. After molding, the pipes usually need to be removed from the mold and transferred to a separate punching station or equipment for secondary hole drilling. This not only increases additional operating steps, equipment investment, and space occupation, but more importantly, it significantly extends the overall production cycle. Furthermore, the pipes are prone to deformation or damage during transfer and secondary clamping, affecting the product qualification rate. Secondly, traditional mechanical punching methods, when applied to plastic pipes that have just been demolded, are still at high temperatures, and whose structural strength has not been fully established, are prone to defects such as burrs, cracks, or inner wall collapse at the punching edges, making it difficult to meet the stringent requirements of the automotive industry for high sealing and high strength at pipe system connections. This invention provides a mechanism that integrates automotive plastic water-assisted molding mold and punching. By integrating punching holes and a built-in punching mechanism on the mold core, the water-assisted molding and punching processes are completed in a single mold. Compared with the traditional process that requires removing the pipe from the mold and transferring it to a separate punch press for secondary processing, this directly eliminates the need for repeated workpiece positioning and clamping, shortens the production cycle, and avoids the risk of deformation of high-temperature soft pipes during transportation, thus improving the product qualification rate. At the same time, it reduces the investment in independent punching equipment and space occupation, resulting in a significant reduction in overall manufacturing costs.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] This utility model discloses a mechanism integrating a water-assisted molding die and a punching mechanism for automotive plastics, including a lower die, a core die, and an upper die. The core die is provided inside the lower die, and a first mold cavity is provided on the core die. The upper die is fixed on the lower die. Optionally, the upper die is fixed on the lower die by bolts. A second mold cavity is provided on the upper die. When the upper die is fixed on the lower die, the second mold cavity and the first mold cavity together form an injection molding chamber. Molten material is injected into the injection molding chamber, and high-pressure water is injected to penetrate the core of the melt, pushing the plastic to adhere tightly to the inner wall of the injection molding chamber. Finally, it cools and solidifies to form the desired pipe, thus forming a circular pipe.

[0008] A punching hole is provided on the mold core at a position opposite to the first mold cavity. A punching mechanism is provided in the punching hole. The punching mechanism is used to punch and open the circular pipe formed by the injection molding chamber.

[0009] In one embodiment of the present invention, the cross-section of the second mold cavity is an arc-shaped structure.

[0010] In one embodiment of the present invention, the punching mechanism includes a punching needle and a high-pressure oil cylinder fixed to the lower die by screws. The punching needle is located in the punching hole and is mounted on the high-pressure oil cylinder. An external oil nozzle is embedded in the outer wall of the lower die and is connected to the high-pressure oil cylinder through a connecting pipe.

[0011] In use, an external oil nozzle is connected to an external oil pump, which pumps hydraulic oil into the high-pressure oil cylinder. The punching needle extends to punch and cut holes in the circular pipe formed in the injection molding chamber.

[0012] In one embodiment of the present invention, a limiting ring is welded and fixed on the outer wall of the punching needle, and a return spring is sleeved on the punching needle below the limiting ring. The top end of the return spring is welded and fixed to the limiting ring, and the bottom end of the return spring is fixedly connected to the outer wall of the high-pressure oil cylinder. The return spring is provided so that when the punching is completed and the hydraulic oil is pumped out by the oil pump, the return force of the return spring will drive the punching needle to retract and return to the initial position.

[0013] In one embodiment of the present invention, the punching hole is a cylindrical structure that penetrates the mold core. The bottom end of the punching hole is provided with a first expansion section and a second expansion section, wherein the second expansion section is located above the first expansion section, the inner diameter of the first expansion section is adapted to the outer diameter of the high-pressure oil cylinder, and the inner diameter of the second expansion section is adapted to the outer diameter of the limiting ring.

[0014] In one embodiment of the present invention, a cylinder regulating valve is installed at the bottom of the high-pressure cylinder. The cylinder regulating valve is used to regulate the rate at which hydraulic oil is pumped into the high-pressure cylinder through the connecting pipe and to adjust the extension and retraction rate of the punching needle, thereby facilitating punching and opening holes for circular pipes of different materials and improving the stability of the punching and opening holes.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] This invention relates to an integrated mold and punching mechanism for automotive plastic water-assisted molding. By integrating punching holes and a built-in punching mechanism on the mold core, the water-assisted molding and punching processes are completed in a single mold. Compared with the traditional process that requires removing the pipe from the mold and transferring it to a separate punch press for secondary processing, this directly eliminates the need for repeated workpiece positioning and clamping, shortens the production cycle, and avoids the risk of deformation of high-temperature soft pipes during transportation, thus improving the product qualification rate. At the same time, it reduces the investment in independent punching equipment and space occupation, resulting in a significant reduction in overall manufacturing costs.

[0017] Furthermore, the high-pressure hydraulic cylinder drives the punching needle to punch the pipe in the early stage of cooling. At this time, the plastic is in a semi-molten state, and the punching plasticity is significantly better than the traditional cold punching process. With the injection of high-pressure water to penetrate the core of the melt for support, there are no burrs or micro-cracks on the punched edge, and the hole diameter accuracy is higher, which makes it easier to meet the high sealing connection requirements of automotive pipelines. Attached Figure Description

[0018] Figure 1 This is a cross-sectional schematic diagram according to an embodiment of the present invention;

[0019] Figure 2 According to one embodiment of the present invention Figure 1 Enlarged view of area A;

[0020] Figure 3 This is a schematic diagram of the assembly structure of the lower mold and the mold core according to an embodiment of the present invention;

[0021] Figure 4 According to one embodiment of the present invention Figure 3 Enlarged view of area B;

[0022] Figure 5 This is a schematic diagram of the disassembled structure of the lower mold and the mold core according to an embodiment of the present invention;

[0023] Figure 6 This is a schematic diagram of the punching mechanism according to an embodiment of the present invention.

[0024] Reference numerals in the attached drawings: 1. Punching needle; 2. Return spring; 21. Limiting ring; 3. High-pressure hydraulic cylinder; 4. Hydraulic cylinder regulating valve; 41. Connecting pipe; 5. External oil nozzle; 6. Mold core; 61. First mold cavity; 62. Punching hole; 7. Lower mold; 8. Upper mold; 81. Second mold cavity. Detailed Implementation

[0025] The following is in conjunction with the appendix Figure 1 - Appendix Figure 6 The specific embodiments of the present invention will be described in detail, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0026] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0027] The present invention relates to an integrated molding die and punching mechanism for automotive plastic water-assisted processing, which is not limited to the description in the following embodiments.

[0028] Example 1

[0029] A mechanism integrating a water-assisted molding die and punching for automotive plastics includes a lower die 7, a core 6, and an upper die 8. The core 6 is disposed inside the lower die 7, and a first mold cavity 61 is formed on the core 6. The upper die 8 is fixed on the lower die 7. Optionally, the upper die 8 is fixed to the lower die 7 by bolts. A second mold cavity 81 is provided on the upper die 8. When the upper die 8 is fixed on the lower die 7, the second mold cavity 81 and the first mold cavity 61 together constitute an injection molding chamber. Molten material is injected into the injection molding chamber, and high-pressure water is injected to penetrate the core of the melt, pushing the plastic to adhere tightly to the inner wall of the injection molding chamber. Finally, the plastic cools and solidifies to form the desired pipe, thus forming a circular pipe.

[0030] A punching hole 62 is provided on the mold core 6 at a position opposite to the first mold cavity 61. A punching mechanism is provided in the punching hole 62. The punching mechanism is used to punch and open the circular pipe formed by the injection molding cavity.

[0031] In this implementation, by integrating the punching hole 62 and the built-in punching mechanism on the mold core 6, the water-assisted forming and punching processes are integrated into a single mold. Compared with the traditional process that requires the pipe to be removed from the mold and transferred to an independent punch press for secondary processing, this directly eliminates the need for repeated workpiece positioning and clamping, shortens the production cycle, and avoids the risk of deformation of high-temperature soft pipes during transportation, thus improving the product qualification rate. At the same time, it reduces the investment in independent punching equipment and the space occupation, resulting in a significant reduction in overall manufacturing costs.

[0032] Example 2

[0033] This embodiment further discloses the specific structure of the punching mechanism based on the above embodiments;

[0034] The punching mechanism includes a punching needle 1 and a high-pressure oil cylinder 3 fixed to the lower die 7 by screws. The punching needle 1 is located in the punching hole 62 and is mounted on the high-pressure oil cylinder 3. An external oil nozzle 5 is embedded in the outer wall of the lower die 7 and is connected to the high-pressure oil cylinder 3 through a connecting pipe 41.

[0035] In use, the external oil nozzle 5 is connected to an external oil pump, which pumps hydraulic oil into the high-pressure oil cylinder 3. The punching needle 1 extends to punch and open the circular pipe formed in the injection molding chamber.

[0036] A limiting ring 21 is welded and fixed to the outer wall of the punching needle 1. A return spring 2 is sleeved on the punching needle 1 below the limiting ring 21. The top end of the return spring 2 is welded and fixed to the limiting ring 21, and the bottom end of the return spring 2 is fixedly connected to the outer wall of the high-pressure oil cylinder 3. It should be noted that the return spring 2 is designed so that when the punching is completed and the hydraulic oil is pumped out by the oil pump, the return force of the return spring 2 will drive the punching needle 1 to retract and return to its initial position.

[0037] The punching hole 62 is a cylindrical structure that penetrates the mold core 6. The bottom end of the punching hole 62 has a first expansion section and a second expansion section, with the second expansion section located above the first expansion section. The inner diameter of the first expansion section matches the outer diameter of the high-pressure cylinder 3, and the inner diameter of the second expansion section matches the outer diameter of the limiting ring 21. It should be noted that after the mold is assembled, the upper part of the high-pressure cylinder 3 is located within the first expansion section, and the limiting ring 21 is located within the second expansion section.

[0038] The bottom of the high-pressure cylinder 3 is equipped with a cylinder regulating valve 4. The cylinder regulating valve 4 is used to regulate the rate at which hydraulic oil is pumped into the high-pressure cylinder 3 through the connecting pipe 41, and to adjust the extension and retraction rate of the punching needle 1, thereby facilitating punching and opening holes for circular pipes of different materials and improving the stability of the punching and opening holes.

[0039] In this embodiment, the high-pressure cylinder 3 drives the punching needle 1 to punch in the early stage of pipe cooling. At this time, the plastic is in a semi-molten state, and the punching plasticity is significantly better than the traditional cold punching process. With the injection of high-pressure water to penetrate the core of the melt for support, there are no burrs or micro-cracks on the punching edge, and the hole diameter accuracy is higher, which is convenient to meet the high sealing connection requirements of automotive pipelines.

[0040] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A mechanism integrating a water-assisted molding die and a punching mechanism for automotive plastics, comprising a lower die (7), a core die (6), and an upper die (8), characterized in that, The lower mold (7) is provided with a mold core (6), and the mold core (6) is provided with a first mold cavity (61). The lower mold (7) is fixed with an upper mold (8), and the upper mold (8) is provided with a second mold cavity (81). When the upper mold (8) is fixed on the lower mold (7), the second mold cavity (81) and the first mold cavity (61) together constitute an injection molding chamber. By injecting molten material into the injection molding chamber, and by injecting high-pressure water to penetrate the core of the melt, the plastic is pushed to adhere tightly to the inner wall of the injection molding chamber. Finally, it is cooled and shaped to form the required pipe, thus forming a circular pipe. A punching hole (62) is provided on the mold core (6) at a position opposite to the first mold cavity (61). A punching mechanism is provided in the punching hole (62), which is used to punch and open the circular pipe formed by injection molding.

2. The mechanism integrating automotive plastic water-assisted molding die and punching according to claim 1, characterized in that: The cross-section of the second mold cavity (81) is an arc-shaped structure.

3. The mechanism of the automobile plastic water auxiliary process forming die and punching integration according to claim 2, characterized in that: The punching mechanism includes a punching needle (1) and a high-pressure oil cylinder (3) fixed to the lower die (7) by screws. The punching needle (1) is located in the punching hole (62) and is mounted on the high-pressure oil cylinder (3). An external oil nozzle (5) is embedded on the outer wall of the lower die (7). The external oil nozzle (5) is connected to the high-pressure oil cylinder (3) through a connecting pipe (41). When in use, the external oil nozzle (5) is connected to an external oil pump, and the hydraulic oil is pumped into the high-pressure oil cylinder (3) through the oil pump. The circular pipe formed by the injection molding chamber is punched open by the extension of the punching needle (1).

4. The mechanism of the automobile plastic water auxiliary process forming die and punching integration according to claim 3, characterized in that: A limiting ring (21) is welded and fixed on the outer wall of the punching needle (1). A return spring (2) is sleeved on the punching needle (1) below the limiting ring (21). The top end of the return spring (2) is welded and fixed to the limiting ring (21), and the bottom end of the return spring (2) is fixedly connected to the outer wall of the high-pressure oil cylinder (3).

5. The mechanism integrating automotive plastic water-assisted molding die and punching according to claim 4, characterized in that: The punching hole (62) is a cylindrical structure. The punching hole (62) penetrates the mold core (6). The bottom end of the punching hole (62) is provided with a first expansion section and a second expansion section. The second expansion section is located above the first expansion section. The inner diameter of the first expansion section is adapted to the outer diameter of the high-pressure oil cylinder (3). The inner diameter of the second expansion section is adapted to the outer diameter of the limiting ring (21).

6. The mechanism of the automobile plastic water auxiliary process forming die and punching integration according to claim 3, characterized in that: The bottom of the high-pressure cylinder (3) is equipped with a cylinder regulating valve (4), which is used to regulate the rate at which hydraulic oil is pumped into the high-pressure cylinder (3) through the connecting pipe (41).

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