An injection mold, an injection molding method, and a long pin connector

Abstract

This invention discloses an injection mold, an injection molding method, and a long pin connector. The injection mold includes upper and lower molds, two core pins (one and two) extending coaxially into the mold cavity, and a side core that seals and connects the two core pins axially. The injection molding method involves mold closing, core pin installation, side core insertion for sealing, and injection molding. The connector housing includes terminal holes one and two corresponding to the core pins and a communicating terminal slot, with the terminals inserted into the channel formed by these three components. This solution achieves three-point positioning of the terminals ("both ends + middle") without extending the core pins, balancing core pin strength and positioning effect, while the side core prevents overflow and improves housing precision. This significantly improves product yield and signal transmission reliability.

Description

Technical Field

[0001] This invention relates to connector manufacturing technology, and more specifically to an injection mold for a long pin connector, an injection molding method based on the mold, and a long pin connector manufactured using the method. Background Technology

[0002] Long pin connectors are widely used in automotive electronics, industrial control, and other fields due to their long signal transmission distance and high connection stability requirements. Their core performance depends on the assembly precision of the terminals within the plastic housing, especially the degree of misalignment in the functional areas of the terminals, which must be strictly controlled; otherwise, problems such as insertion / removal jamming and signal transmission distortion may occur.

[0003] To reduce terminal misalignment, sufficient fixing and limiting area must be provided for the terminals during the molding of the plastic shell. In traditional technology ( Figure 1 , Figure 2 The plastic shell of the long PIN connector is formed by injection molding. Two sets of coaxial core pins are set inside the mold to form the mounting holes at both ends of the terminal. The fixed distance of the core pins directly determines the limiting effect of the terminal—the longer the fixed distance, the more sufficient the terminal head and tail are limited, and the lower the risk of misalignment. However, limited by the structural strength of the mold core (i.e., the core pin), if the fixed distance of the core pins is simply extended, the core pins are prone to bending and breaking under injection pressure, leading to mold damage or failure of the plastic shell molding; if the fixed distance of the core pins is shortened, the limiting area of ​​the terminal is insufficient, and it is impossible to effectively restrain the terminal misalignment, making it difficult to meet the product precision requirements.

[0004] Therefore, designing an injection mold and corresponding molding scheme that can both ensure the strength of the mold core pin and provide sufficient limiting area for the terminal has become a key technical challenge in solving the terminal misalignment problem of long PIN connectors. Summary of the Invention

[0005] To overcome the aforementioned deficiencies of the prior art, the primary objective of this invention is to provide an injection mold that optimizes the mating structure between the core pin assembly and the side core, balancing the strength of the mold core with the terminal positioning requirements. The second objective of this invention is to provide an injection molding method based on the aforementioned injection mold, which is simple to operate and achieves high molding accuracy. The third objective of this invention is to provide a long pin connector with high-precision shell molding, stable terminal positioning, and effectively prevents terminal misalignment.

[0006] To achieve the above objectives, the technical solution provided by the present invention is as follows.

[0007] To achieve the above and other related objectives, the technical solution provided by the present invention is: an injection mold, comprising:

[0008] Injection mold, wherein the injection mold has a mold cavity;

[0009] The core needle assembly includes a first core needle and a second core needle, which extend into the mold cavity and are coaxially spaced apart.

[0010] A side core extends into the mold cavity and is at least partially axially sealed between the first core pin and the second core pin.

[0011] The preferred technical solution is as follows: the injection mold includes an upper mold and a lower mold, the upper mold has an upper cavity on its bottom side, and the lower mold has a lower cavity on its top side. The upper cavity and the lower cavity are correspondingly arranged and constitute the mold cavity.

[0012] The preferred technical solution is as follows: the upper mold is provided with a window 1 for the core needle 1 to extend into the mold cavity, and the lower mold is provided with a window 2 for the core needle 2 to extend into the mold cavity; the bottom edge of the upper mold is provided with a notch 1, and the top edge of the lower mold is provided with a notch 2, and the notch 1 and the notch 2 are correspondingly provided and constitute a window 3 for the side core to extend into the mold cavity.

[0013] The preferred technical solution is that the upper mold or the lower mold is provided with an injection port.

[0014] An injection molding method, based on the above-mentioned injection mold, includes the following steps:

[0015] Step 1: Prepare the injection mold, which has a cavity designed based on the shape of the plastic shell;

[0016] Step 2: Insert the first core pin and the second core pin into the mold cavity, and keep the first core pin and the second core pin coaxially spaced apart;

[0017] Step 3: Insert the side core into the mold cavity, ensuring that the side core is at least partially axially sealed between the first core pin and the second core pin;

[0018] Step 4: Inject molten plastic into the mold cavity, and remove the finished product after it cools and solidifies.

[0019] A preferred technical solution is as follows: In step one, the injection mold includes an upper mold and a lower mold. The upper mold has an upper cavity on its bottom side and a window 1 communicating with the upper cavity on its top side. The bottom edge of the upper mold has a notch 1 communicating with the upper cavity. The lower mold has a lower cavity on its top side and a window 2 communicating with the lower cavity on its bottom side. The top edge of the lower mold has a notch 2 communicating with the lower cavity. The upper mold and the lower mold are joined together, and the upper cavity and the lower cavity constitute the mold cavity.

[0020] The preferred technical solution is as follows: In step two, the first core needle is inserted into the mold cavity through the first window, and the second core needle is inserted into the mold cavity through the second window, with the first core needle and the second core needle being coaxially spaced apart.

[0021] The preferred technical solution is as follows: In step three, the side core is inserted into the mold cavity through the window three formed by the notch one and the notch two, and the side core is at least partially axially sealed between the core pin one and the core pin two.

[0022] The preferred technical solution is as follows: In step four, molten plastic is injected into the mold cavity through the injection port, and the finished product is removed after cooling and molding.

[0023] A long pin connector includes a plastic shell and terminals. The plastic shell is manufactured using the injection molding method described above. Terminal hole one and terminal hole two are formed in the plastic shell, and terminal hole one and terminal hole two are coaxially spaced apart. A terminal groove is formed on the plastic shell, and the terminal groove axially connects terminal hole one and terminal hole two. The terminals are inserted into terminal hole one, terminal groove, and terminal hole two. Terminal hole one is correspondingly matched with pin one, terminal hole two is correspondingly matched with pin two, and the terminal groove is correspondingly matched with the portion of the side core connecting between pin one and pin two.

[0024] Due to the application of the above technical solution, the beneficial effects of this invention are as follows:

[0025] This invention resolves the contradiction between core pin strength and terminal positioning: By setting independent side cores to connect core pin one and core pin two, an axially continuous positioning channel (terminal hole one + terminal slot + terminal hole two) can be formed without extending the length of the core pin itself. This ensures the structural strength of the core pin (avoiding bending and breakage caused by excessive core pin length) and provides a three-point positioning structure of "both ends + middle" for the terminal. The contact area between the terminal and the plastic shell is significantly increased, and the terminal misalignment is greatly reduced, solving the core problem of "insufficient terminal positioning due to core pin strength limitation" in traditional technology.

[0026] Improved molding precision of plastic shell: The sealed connection structure between the side core and core pin one and core pin two effectively blocks the overflow channel of molten plastic in the gap between the core pins, avoiding the generation of burrs and overflow inside the plastic shell. The smoothness and dimensional accuracy of the inner wall of the plastic shell are significantly improved, providing a guarantee for the precise assembly of the terminals.

[0027] Simple structure and high production efficiency: The upper mold, lower mold, core pin assembly and side core of the injection mold are all modularly designed, making assembly and disassembly convenient; the injection molding method steps are clear, no complex process adjustments are required, and mass production can be achieved quickly, reducing production costs.

[0028] Stable connector performance: The terminals of the long PIN connector are securely assembled through a three-point limiting structure. There is no offset or loosening of the terminals during insertion and removal, which significantly improves the stability and reliability of signal transmission and increases the product qualification rate by more than 30%. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the long pin connector structure involved in the background art.

[0030] Figure 2 This is a schematic diagram of the cross-section of a long PIN connector involved in the background art.

[0031] Figure 3 This is a schematic diagram of the cross-section of the mold involved in the present invention.

[0032] Figure 4 This is a schematic diagram of the long PIN connector structure involved in the present invention.

[0033] Figure 5 This is a schematic cross-sectional view of the long PIN connector involved in the present invention.

[0034] Figure 6 This is a flowchart illustrating the injection molding method involved in the present invention. Detailed Implementation

[0035] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0036] Please see Figures 1-6 It should be noted that in the description of this invention, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. These terms are used only for the convenience of describing the invention and for simplifying the description, 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 invention. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. The terms "horizontal," "vertical," and "suspended," etc., do not indicate that the component must be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0037] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal communication 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.

[0038] Example:

[0039] like Figure 3 As shown, in this embodiment of the injection mold, the upper cavity on the bottom side of the upper mold 1 and the lower cavity on the top side of the lower mold 2 are closed to form a mold cavity 3. The shape of the mold cavity 3 is consistent with the plastic shell 11 of the long PIN connector. Core pin 1 4 is inserted into the upper half of the mold cavity 3 through window 1 7 of the upper mold 1, and core pin 2 5 is inserted into the lower half of the mold cavity 3 through window 2 8 of the lower mold 2. Core pin 1 4 and core pin 2 5 are coaxial and spaced apart by a distance of 5-10mm. Side core 6 is inserted into the mold cavity 3 through window 3 9. Its upper end is sealed to the lower end face of core pin 1 4, and its lower end is sealed to the upper end face of core pin 2 5. The outer diameter of side core 6 is consistent with the outer diameter of core pin 1 4 and core pin 2 5, ensuring that the inner diameter of the terminal groove 15 after molding matches the inner diameter of terminal hole 1 13 and terminal hole 2 14.

[0040] During injection molding, molten plastic is injected into the mold cavity 3 through the injection port 10 of the upper mold 1. After cooling and solidification, a plastic shell 11 with terminal hole 13, terminal hole 14 and terminal groove 15 is formed. Figure 4 , Figure 5 After the terminal 12 is inserted into the combined channel, the upper section of the terminal 12 is interference-fitted with the inner wall of the terminal hole 13, the middle section is interference-fitted with the inner wall of the terminal slot 15, and the lower section is interference-fitted with the inner wall of the terminal hole 14, thereby achieving three-point limiting and effectively preventing the terminal 12 from deflecting.

[0041] In this embodiment, core pin 4, core pin 5, and side core 6 are all made of SKD11 mold steel, which has high strength and good wear resistance; the molten plastic is made of PA66 + 30% glass fiber material, which has good mechanical strength and insulation properties. Testing shows that the long pin connector made using this method has a terminal misalignment of ≤0.02mm, far superior to the 0.08mm standard of traditional technology. Furthermore, the mold can withstand 50,000 continuous production cycles without core pin bending or breakage, and the plastic shell overflow defect rate is reduced to below 0.5%.

[0042] like Figure 6 As shown, this application also relates to an injection molding method, comprising the following steps:

[0043] Step 1: Prepare the injection mold. The injection mold has a cavity 3 designed based on the shape of the plastic shell 11.

[0044] Step 2: Insert core pin 1 4 and core pin 2 5 into mold cavity 3, and keep core pin 1 4 and core pin 2 5 coaxially spaced;

[0045] Step 3: Insert the side core 6 into the mold cavity 3, ensuring that the side core 6 is at least partially axially sealed between the core pin 1 4 and the core pin 2 5;

[0046] Step 4: Inject molten plastic into mold cavity 3, and remove the finished product after it cools and solidifies.

[0047] Therefore, the present invention has the following advantages:

[0048] This invention resolves the contradiction between core pin strength and terminal positioning: By setting independent side cores to connect core pin one and core pin two, an axially continuous positioning channel (terminal hole one + terminal slot + terminal hole two) can be formed without extending the length of the core pin itself. This ensures the structural strength of the core pin (avoiding bending and breakage caused by excessive core pin length) and provides a three-point positioning structure of "both ends + middle" for the terminal. The contact area between the terminal and the plastic shell is significantly increased, and the terminal misalignment is greatly reduced, solving the core problem of "insufficient terminal positioning due to core pin strength limitation" in traditional technology.

[0049] Improved molding precision of plastic shell: The sealed connection structure between the side core and core pin one and core pin two effectively blocks the overflow channel of molten plastic in the gap between the core pins, avoiding the generation of burrs and overflow inside the plastic shell. The smoothness and dimensional accuracy of the inner wall of the plastic shell are significantly improved, providing a guarantee for the precise assembly of the terminals.

[0050] Simple structure and high production efficiency: The upper mold, lower mold, core pin assembly and side core of the injection mold are all modularly designed, making assembly and disassembly convenient; the injection molding method steps are clear, no complex process adjustments are required, and mass production can be achieved quickly, reducing production costs.

[0051] Stable connector performance: The terminals of the long PIN connector are securely assembled through a three-point limiting structure. There is no offset or loosening of the terminals during insertion and removal, which significantly improves the stability and reliability of signal transmission and increases the product qualification rate by more than 30%.

[0052] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. An injection mold for a long pin connector, characterized in that, include: Injection mold, wherein the injection mold has a mold cavity; The core needle assembly includes a first core needle and a second core needle, which extend into the mold cavity and are coaxially spaced apart. A side core, which extends into the mold cavity and is at least partially axially sealed between the first core pin and the second core pin; The injection mold includes an upper mold and a lower mold. The upper mold has an upper cavity on its bottom side and a lower mold has a lower cavity on its top side. The upper cavity and the lower cavity are correspondingly arranged and constitute the mold cavity. The upper mold is provided with a window 1 for the core needle 1 to extend into the mold cavity, and the lower mold is provided with a window 2 for the core needle 2 to extend into the mold cavity; the bottom edge of the upper mold is provided with a notch 1, and the top edge of the lower mold is provided with a notch 2. The notch 1 and the notch 2 are correspondingly provided and form a window 3 for the side core to extend into the mold cavity.

2. The injection mold according to claim 1, characterized in that: The upper mold or the lower mold is provided with an injection port.

3. An injection molding method for long pin connectors, characterized in that: Based on the injection mold according to any one of claims 1-2, the process includes the following steps: Step 1: Prepare the injection mold, which has a cavity designed based on the shape of the plastic shell; Step 2: Insert the first core pin and the second core pin into the mold cavity, and keep the first core pin and the second core pin coaxially spaced apart; Step 3: Insert the side core into the mold cavity, ensuring that the side core is at least partially axially sealed between the first core pin and the second core pin; Step 4: Inject molten plastic into the mold cavity, and remove the finished product after it cools and solidifies.

4. The injection molding method according to claim 3, characterized in that: In step one, the injection mold includes an upper mold and a lower mold. The upper mold has an upper cavity on its bottom side and a window connecting to the upper cavity on its top side. The bottom edge of the upper mold has a notch connecting to the upper cavity. The lower mold has a lower cavity on its top side and a window connecting to the lower cavity on its bottom side. The top edge of the lower mold has a notch connecting to the lower cavity. The upper mold and the lower mold are joined together, and the upper cavity and the lower cavity constitute the mold cavity.

5. The injection molding method according to claim 4, characterized in that: In step two, the first core needle is inserted into the mold cavity through the first window, and the second core needle is inserted into the mold cavity through the second window, with the first core needle and the second core needle being coaxially spaced apart.

6. The injection molding method according to claim 4, characterized in that: In step three, the side core is inserted into the mold cavity through the window three formed by the notch one and the notch two, and the side core is at least partially axially sealed between the core pin one and the core pin two.

7. The injection molding method according to claim 4, characterized in that: In step four, molten plastic is injected into the mold cavity through the injection port, and the finished product is removed after cooling and solidification.

8. A long pin connector, characterized in that: The device includes a plastic shell and terminals. The plastic shell is manufactured using the injection molding method according to any one of claims 3-7. Terminal hole one and terminal hole two are formed in the plastic shell. Terminal hole one and terminal hole two are coaxially spaced apart. Terminal groove is formed on the plastic shell. Terminal groove connects terminal hole one and terminal hole two along the axial direction. Terminals are inserted into terminal hole one, terminal groove and terminal hole two. Terminal hole one is correspondingly matched with core pin one, terminal hole two is correspondingly matched with core pin two, and the portion of terminal groove connected to the side core between core pin one and core pin two is correspondingly matched.

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