An injection molding die and injection molding method for automobile parts

Abstract

This invention relates to the field of injection molding technology and discloses an injection molding mold and injection method for automotive parts. The mold includes two side frames a and two side frames b forming a rectangular structure. Side frames a and b are interlocked, and several cooling components are arranged inside. The front and rear sides of the cooling components are interference-fitted with side frame a, and the left and right sides are interference-fitted with side frame b or adjacent cooling components. The cooling components have internal cooling water channels communicating with the outside. Each cooling component consists of a heat-conducting plate, a cooling groove, a guide plate, and a cover plate. The guide plate divides the cooling groove into S-shaped flow channels, and the cover plate has connecting pipes. Each heat-conducting plate can be made of a material with different thermal conductivity according to cooling requirements, and combined with refrigerants of different temperatures in the corresponding flow channels, to achieve differentiated cooling in different zones. This invention achieves rapid assembly and tight fit through interference fit, improving heat transfer efficiency. Simultaneously, through differentiated thermal conductivity configuration, it effectively improves the cooling quality and molding accuracy of the injection molded parts.

Description

Technical Field

[0001] This invention relates to the field of injection molding, and in particular to an injection molding die and injection method for automotive parts. Background Technology

[0002] In the injection molding process of automotive parts, the mold's cooling system has a decisive impact on product quality and production efficiency. Traditional injection molds typically use methods such as drilling holes inside the mold core to form cooling channels or installing separate cooling plates on the outside of the mold cavity. However, these existing structures have the following shortcomings: Firstly, the assembly relationship between the cooling channels or cooling plates and the mold side frame is mostly clearance fit or bolt fixation, requiring the alignment of multiple components during installation, making the assembly process cumbersome. Moreover, after long-term use, loosening is easily caused by thermal expansion and contraction, leading to displacement of the cooling components and affecting the uniformity of cooling. Secondly, the positioning of the cooling components within the mold lacks reliable limiting structures, making it difficult to guarantee the tightness of the fit between the cooling components and between the cooling components and the side frame, easily forming air gaps and reducing heat transfer efficiency. Furthermore, when molds require differentiated cooling for areas with different wall thicknesses or different heat dissipation requirements, traditional integrated cooling structures struggle to flexibly adjust the cooling intensity of each area, often resorting to a uniform cooling medium temperature. This results in insufficient cooling of thick-walled areas and overcooling of thin-walled areas, leading to quality problems such as product warping and excessive internal stress, thus affecting the finished product's pass rate. Therefore, this invention proposes an injection molding mold and injection method for automotive parts to solve the aforementioned problems. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides an injection molding die and injection method for automotive parts.

[0004] The present invention provides an injection mold and injection method for automotive parts, which adopts the following technical solution:

[0005] An injection molding mold and injection method for automotive parts include two side frames a and two side frames b forming a rectangular structure. The two side frames a are mirror images of each other, and the two side frames b are mirror images of each other. The side frames a and side frames b are interlocked with each other.

[0006] Several cooling components are installed inside the space enclosed by side frame a and side frame b. The front and rear sides of the cooling components are interference-fitted with side frame a, and the left and right sides of the cooling components are interference-fitted with side frame b or adjacent cooling components. Cooling water connected to the outside is installed inside the cooling components.

[0007] Preferably, the cooling assembly includes a heat-conducting plate at the top, a cooling tank welded below the heat-conducting plate, a flow guide plate welded inside the cooling tank, the flow guide plate dividing the interior of the cooling tank into continuous S-shaped flow channels, an interference-fit cover plate fixedly connected to the bottom of the cooling tank, and a connecting pipe fixedly connected to both ends of the internal flow channels on the cover plate.

[0008] Preferably, a coolant with a lower temperature is installed in the flow channel of the heat-conducting plate with a large thermal conductivity.

[0009] The heat-conducting plate has a small thermal conductivity coefficient, and the refrigerant with a higher temperature is set in the flow channel.

[0010] Preferably, support strips a are vertically welded to the bottom of opposite sides of the two side frames a, and a retaining strip extending into the rectangular frame is fixedly connected below the support strip a. The front and rear sides of the cooling groove are provided with retaining grooves that fit with the retaining strips. The front and rear side walls of the heat-conducting plate abut against the inner wall of the side frame a.

[0011] Preferably, the bottom ends of the two side frames b are vertically welded with support bars b, and the two ends of the support bars b are also fixedly connected with protrusions extending into the rectangular frame. The two ends of the clips are provided with grooves that are interference-fitted with the protrusions.

[0012] Preferably, the slot, strip, groove, and protrusion are all wedge-shaped.

[0013] Preferably, the two ends of the side frame a are fixedly connected to an extension segment a, and a conduit is fixedly connected to the extension segment a. A tie rod is provided between two oppositely arranged conduits, and both ends of the tie rod are threaded with nuts for locking in opposite directions.

[0014] Preferably, the two ends of the side frame b are fixedly connected to an extension segment b, and a through hole is provided on the extension segment b.

[0015] Preferably, both ends of the side frame a are provided with sliding grooves along the front-back direction to their inner sides, and the longitudinal section of the sliding groove is T-shaped, with the opening width being smaller than the inner width. A slider is slidably embedded in the sliding groove, and a bolt extending outward from the end of the side frame a is threaded onto the slider. The bolt passes through the through hole of the outer extension section b, and the bolt and the slider cooperate to lock the side frame a and the side frame b.

[0016] Preferably, the bottom of the side frame a is also welded with a base for fixed connection with the external structure.

[0017] In summary, the present invention has at least one of the following beneficial technical effects:

[0018] The interference fit structure between the side frame and the cooling components enables rapid positioning and stable installation of the cooling components. No additional fasteners are needed to ensure a tight fit between the components, effectively eliminating air gaps and significantly improving heat transfer efficiency. Simultaneously, multiple cooling components are independent and can be modularly assembled using the side frame's clips and slots, making installation simple and quick, and disassembly and maintenance very convenient. More importantly, the heat-conducting plates of each cooling component can be made of materials with different thermal conductivity coefficients according to actual needs, and can be used with refrigerants at different temperatures within the corresponding flow channels. This allows for differentiated control of cooling requirements in different parts of the injection molded part, ensuring sufficient cooling of thick-walled areas while preventing overcooling deformation in thin-walled areas. This significantly improves the dimensional stability and surface quality of the injection molded products, reduces scrap rates, and lowers production costs. Attached Figure Description

[0019] Figure 1 This is an isometric structural schematic diagram of an embodiment of the invention.

[0020] Figure 2 This is a bottom-view isometric structural schematic diagram of an embodiment of the invention.

[0021] Figure 3 This is an exploded view of an embodiment of the invention.

[0022] Figure 4 This is a longitudinal sectional view of an embodiment of the invention.

[0023] Figure 5 This is a diagram of the frame connection structure of an embodiment of the invention.

[0024] Figure 6 This is a side frame structure diagram of an embodiment of the invention.

[0025] Figure 7 This is a structural diagram of a fastener according to an embodiment of the invention.

[0026] Figure 8 This is a structural diagram of the cooling assembly according to an embodiment of the invention.

[0027] Explanation of reference numerals in the attached drawings: 1. Side frame a; 11. Outer extension a; 12. Slide groove; 13. Support bar a; 131. Groove; 14. Locking strip; 15. Conduit; 2. Side frame b; 21. Outer extension b; 22. Through hole; 23. Support bar b; 24. Protrusion; 3. Tie rod; 4. Bolt; 41. Slider; 5. Base; 6. Cooling assembly; 61. Cover plate; 62. Connecting pipe; 63. Cooling tank; 64. Heat-conducting plate; 65. Locking groove; 66. Guide plate. Detailed Implementation

[0028] The following is in conjunction with the appendix Figure 1 - Appendix Figure 8 The present invention will be described in further detail below.

[0029] Example 1: Refer to Figure 1 - Figure 8 An injection molding mold and injection method for automotive parts include two side frames a1 and two side frames b2 forming a rectangular structure. The two side frames a1 are mirror images of the left and right sides of the rectangular structure, and the two side frames b2 are mirror images of the front and rear sides of the rectangular structure. The side frames a1 and b2 are interlocked to form a rectangular frame structure. A plurality of cooling components 6 are arranged inside the space enclosed by the side frames a1 and b2, arranged along the front-rear direction within the rectangular frame. The front and rear sides of the cooling components 6 are tightly fixed to the inner wall of the side frame a1 via an interference fit, and the left and right sides of the cooling components 6 are also tightly fixed to the inner wall of the side frame b2 or the side wall of adjacent cooling components 6 via an interference fit. The cooling components 6 have internal cooling water channels connected to the outside, through which cooling water circulates to achieve rapid cooling of the injection molded part.

[0030] The specific structure of side frame a

[0031] like Figures 1 to 3 As shown, two side frames a1 are located on the left and right sides of the rectangular frame, respectively. Extending sections a11 are fixedly connected to both ends of the side frames a1, and conduits 15 are fixedly connected to the extending sections a11. A pull rod 3 is positioned between the two opposing conduits 15, and both ends of the pull rod 3 are threaded with nuts for locking in opposite directions. Tightening the nuts can pull the two side frames a1 together. Both ends of the side frames a1 have grooves 12 extending inwards along the front-back direction. The longitudinal section of the grooves 12 is T-shaped, and its opening width is smaller than its internal width. A base 5 is welded to the bottom of the side frames a1 for fixed connection with the external structure, facilitating the fixed installation of the entire mold on the injection molding machine's worktable.

[0032] Support bars a13 are vertically welded to the bottom of opposite sides of both side frames a1, and the support bars a13 extend along the length of the side frames a1. A retaining strip 14 extending into the rectangular frame is fixedly connected below the support bars a13, and the retaining strip 14 is used to form an interference fit with the retaining groove 65 on the cooling assembly 6.

[0033] The specific structure of side frame b

[0034] like Figure 1 , Figure 3As shown, two side frames b2 are located on the front and rear sides of the rectangular frame, respectively. Both ends of the side frames b2 extend outwards and are fixedly connected to an extension section b21, with a through hole 22 through the extension section b21. A slider 41 is slidably fitted into the groove 12 of the side frame a1, and a bolt 4 extending outwards from the end of the side frame a1 is threaded onto the slider 41. The bolt 4 passes through the through hole 22 of the extension section b21, and the bolt 4 and the slider 41 cooperate to lock and fix the side frame a1 and side frame b2. Specifically, the slider 41 can slide and adjust its position in the front-rear direction within the groove 12. After the bolt 4 passes through the through hole 22, it is screwed into the threaded hole of the slider 41. Tightening the bolt 4 will press and fix the extension section b21 of the side frame b2 to the end of the side frame a1.

[0035] Support strips b23 are vertically welded to the bottom ends of opposite sides of both side frames b2, extending along the length of side frame b2. Both ends of the support strips b23 are fixedly connected to protrusions 24 extending inwards into the rectangular frame. Both ends of the retaining strip 14 have grooves 131 that interlock with the protrusions 24. After side frames a1 and b2 are assembled, the protrusions 24 are embedded in the grooves 131 to form an interference fit, ensuring a more secure locking of side frames a1 and b2 at corners.

[0036] Specific structure of cooling components

[0037] like Figures 4 to 8 As shown, the cooling assembly 6 includes a heat-conducting plate 64 at the top, and a cooling groove 63 welded below the heat-conducting plate 64. A guide plate 66 is welded inside the cooling groove 63, dividing the interior of the cooling groove 63 into continuous S-shaped flow channels. A cover plate 61 is fixedly connected to the bottom of the cooling groove 63, and the cover plate 61 and the cooling groove 63 are sealed together by an interference fit. Connecting pipes 62, which communicate with both ends of the internal flow channels, are also fixedly connected to the cover plate 61. One connecting pipe 62 serves as a cooling water inlet, and the other connecting pipe 62 serves as a cooling water outlet, both of which are connected to an external cooling water source.

[0038] The cooling tank 63 has locking slots 65 on both its front and rear sides, which are designed to fit into the locking strips 14 with an interference fit. During installation, the locking strips 14 are inserted into the locking slots 65 to form an interference fit, fixing the cooling assembly 6 between the two side frames a1 in the front-to-back direction. The front and rear side walls of the heat-conducting plate 64 abut against the inner wall of the side frame a1, ensuring a tight fit between the heat-conducting plate 64 and the side frame a1.

[0039] The slot 65, the strip 14, the groove 131, and the protrusion 24 are all wedge-shaped. The wedge-shaped design ensures that when the strip 14 is inserted into the slot 65 and the protrusion 24 is inserted into the groove 131, the fit becomes tighter and tighter as the insertion depth increases, thus achieving a reliable interference fit fixation.

[0040] Arrangement and working principle of cooling components

[0041] The cooling components 6 are arranged along the left-right direction inside the rectangular frame. During installation, first, the two side frames a1 are placed opposite each other. Then, several cooling components 6 are arranged sequentially between the two side frames a1, aligning the slots 65 on the front and rear sides of the cooling components 6 with the retaining strips 14 on the side frames a1 and pressing them in to achieve an interference fit. Next, the two side frames b2 are installed on the front and rear sides respectively, so that the protrusions 24 on the side frames b2 are embedded into the grooves 131 at both ends of the retaining strips 14, forming an interference fit. Finally, the two side frames a1 are locked relative to each other using the pull rod 3 and the nut, and the side frames a1 and b2 are locked and fixed using the bolts 4 and the slider 41, completing the assembly of the entire mold.

[0042] During injection molding, molten plastic is injected into the cavity formed by side frames a1, b2, and the cooling assembly 6. Cooling water enters the S-shaped flow channel inside the cooling tank 63 through the inlet of the connecting pipe 62, meanders along the S-shaped path formed by the guide plate 66, and flows out from the connecting pipe 62 at the other end. As the cooling water flows in the S-shaped flow channel, it absorbs the heat from the injection molded part inside the cavity through the wall of the cooling tank 63 and the heat-conducting plate 64, allowing the injection molded part to cool and solidify rapidly. The heat-conducting plate 64 is in direct contact with or close to the injection molded part, serving to transfer heat from the injection molded part to the cooling tank 63.

[0043] Selection of thermal conductivity of heat conduction plate

[0044] It is important to note that the thermal conductivity of each heat-conducting plate 64 can be selected differently based on actual usage requirements. For areas requiring rapid cooling (such as areas with thicker walls and slower heat dissipation), a material with higher thermal conductivity is selected for the heat-conducting plate 64, while a cooler at a lower temperature is introduced into the corresponding S-shaped flow channel to achieve efficient and rapid cooling. For areas requiring slow cooling (such as areas with thinner walls and prone to internal stress), a material with lower thermal conductivity is selected for the heat-conducting plate 64, while a cooler at a relatively higher temperature is introduced into the corresponding S-shaped flow channel to avoid product warping or excessive internal stress caused by excessively rapid cooling. This differentiated thermal conductivity configuration allows the mold to precisely control the temperature for the cooling needs of different parts, thereby effectively improving the molding quality of the injection molded product and reducing product deformation and dimensional deviations while ensuring cooling efficiency. Preferred embodiment

[0045] In a preferred embodiment, six cooling components 6 are provided within the mold. The two cooling components 6 located in the middle correspond to the thicker areas of the injection molded part. Their heat-conducting plates 64 are made of pure copper with a thermal conductivity of 380 W / (m·K), and low-temperature cooling water at a temperature of 5°C to 10°C flows through their corresponding S-shaped flow channels. The four cooling components 6 located on either side correspond to the thinner areas of the injection molded part. Their heat-conducting plates 64 are made of aluminum alloy with a thermal conductivity of 200 W / (m·K), and room-temperature water at a temperature of 20°C to 25°C flows through their corresponding S-shaped flow channels. This differentiated cooling configuration allows all parts of the injection molded part to cool and solidify simultaneously, effectively avoiding product warping and deformation caused by uneven cooling.

[0046] Assembly method

[0047] The assembly method of this mold is as follows: First, place the two side frames a1 opposite each other on the worktable. Then, arrange several cooling components 6 sequentially between the two side frames a1, aligning the slots 65 of the cooling components 6 with the retaining strips 14 of the side frames a1 and pressing them into place to achieve an interference fit. Next, install the two side frames b2 from the front and rear directions respectively, so that the protrusions 24 on the side frames b2 are embedded in the grooves 131 at both ends of the retaining strips 14. Then, install the slider 41 into the sliding groove 12 of the side frame a1, and screw the bolt 4 through the through hole 22 on the outer extension section b21 of the side frame b2 into the threaded hole of the slider 41 and pre-tighten it. Then, pass the pull rod 3 through the guide tubes 15 arranged opposite each other on the two side frames a1, and screw nuts on both ends of the pull rod 3 and pre-tighten them. Finally, tighten each bolt 4 and nut in sequence to achieve an interference fit between the side frames a1 and b2, and between the cooling components 6 and each side frame. After assembly, connect the connecting pipe 62 to the external cooling water source, and it is ready for use.

[0048] It should be noted that, in this document, terms such as “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0049] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An injection molding die for automotive parts, characterized in that: It includes two side frames a (1) and two side frames b (2) that form a rectangular structure. The two side frames a (1) are mirror images of each other and the two side frames b (2) are mirror images of each other. The side frames a (1) and b (2) are interlocked with each other. Several cooling components (6) are arranged inside the space enclosed by side frame a (1) and side frame b (2). The front and rear sides of the cooling components (6) are interference-fitted with side frame a (1), and the left and right sides of the cooling components (6) are interference-fitted with side frame b (2) or adjacent cooling components (6). Cooling water connected to the outside is arranged inside the cooling components (6).

2. The injection molding die for automotive parts according to claim 1, characterized in that: The cooling assembly (6) includes a heat-conducting plate (64) at the top, a cooling tank (63) welded below the heat-conducting plate (64), a flow guide plate (66) welded inside the cooling tank (63), the flow guide plate (66) divides the interior of the cooling tank (63) into a continuous S-shaped flow channel, and an interference fit cover plate (61) is fixedly connected to the bottom of the cooling tank (63), and a connecting pipe (62) connected to both ends of the internal flow channel is also fixedly connected to the cover plate (61).

3. The injection mold for automotive parts according to claim 2, characterized in that: The heat-conducting plate (64) has a large thermal conductivity and a correspondingly lower temperature refrigerant in the flow channel; The heat-conducting plate (64) has a small flow channel with a corresponding refrigerant at a higher temperature.

4. The injection mold for automotive parts according to claim 1, characterized in that: Support strips a (13) are vertically welded to the bottom of opposite sides of the two side frames a (1), and a clip (14) extending into the rectangular frame is fixedly connected below the support strip a (13). The cooling groove (63) is provided with a slot (65) that fits into the clip (14) with interference fit. The front and rear side walls of the heat-conducting plate (64) abut against the inner wall of the side frame a (1).

5. The injection molding die for automotive parts according to claim 4, characterized in that: The two side frames b (2) are vertically welded with support bars b (23) at their opposite bottom ends. The two ends of the support bars b (23) are also fixedly connected with protrusions (24) extending into the rectangular frame. The two ends of the clip (14) are provided with grooves (131) that are interference-fitted with the protrusions (24).

6. The injection mold for automotive parts according to claim 5, characterized in that: The slot (65), the strip (14), the groove (131), and the protrusion (24) are all wedge-shaped structures.

7. The injection mold for automotive parts according to claim 1, characterized in that: The two ends of the side frame a (1) are fixedly connected to an extension section a (11), and a conduit (15) is fixedly connected to the extension section a (11). A pull rod (3) is provided between the two conduits (15) arranged opposite to each other. Both ends of the pull rod (3) are threaded with nuts for locking in opposite directions.

8. The injection molding method for an injection mold for automotive parts according to claim 7, characterized in that: The two ends of the side frame b (2) are fixedly connected to the outer extension section b (21), and the outer extension section b (21) is provided with a through hole (22).

9. The injection molding method for an injection mold for automotive parts according to claim 8, characterized in that: Both ends of the side frame a (1) are provided with sliding grooves (12) in the front-back direction. The longitudinal section of the sliding groove (12) is T-shaped, and its opening width is smaller than its internal width. A slider (41) is slidably embedded in the sliding groove (12). A bolt (4) extending to the outer side of the end of the side frame a (1) is threaded onto the slider (41). The bolt (4) is set through the through hole (22) of the outer extension section b (21). The bolt (4) and the slider (41) cooperate to lock the side frame a (1) and the side frame b (2).

10. The injection molding method for an injection mold for automotive parts according to claim 1, characterized in that: The bottom of the side frame a (1) is also welded with a base (5) for fixed connection with the external structure.

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