Exhaust structure and design method of vehicle-mounted lens barrel injection mold

Abstract

The application discloses a kind of exhaust structure and design method of vehicle-mounted lens barrel injection mold, the exhaust structure includes front mould, back mould, inner diameter needle, and the front mould is equipped with mould parting surface;Two kinds of exhaust grooves are designed at mould parting surface: one is the cavity exhaust groove of the type cavity that is symmetrically distributed and connected with injection chamber and the external environment of mould, and the other is the runner exhaust groove of the runner that is symmetrically distributed and connected with injection flow and the external environment of mould;For the inner diameter needle structure that lens barrel mould is unique, according to the diameter size of inner diameter needle, the symmetrically distributed inner diameter needle exhaust groove is designed.According to actual production experience, four empirical formula are proposed to design the size and number of cavity exhaust groove, runner exhaust groove and inner diameter needle exhaust groove.The exhaust structure of vehicle-mounted lens barrel injection mold is optimized, and based on product material and mold size, a new lens barrel injection mold exhaust design method is proposed, which realizes timely exhaust of gas during injection molding process and improves the injection molding quality of vehicle-mounted lens barrel product.

Description

Technical Field

[0001] This invention relates to the field of injection mold technology, and specifically to a venting structure and design method for an injection mold for an automotive mirror barrel. Background Technology

[0002] With the rapid development of artificial intelligence, Advanced Driver Assistance Systems (ADAS) for automobiles, aiming to achieve fully autonomous driving, are becoming increasingly widespread. As signal input sensors within ADAS, the performance and stability of in-vehicle cameras directly impact the overall performance and stability of the system. The lens barrel, as an optical structural component of the camera, plays a crucial role in establishing the geometric space during optical imaging; its dimensional stability directly affects imaging accuracy and quality. Furthermore, in-vehicle cameras need to operate continuously for extended periods, often in environments with significant vibration and extreme weather conditions, withstanding temperatures ranging from approximately -40°C to 80°C. They also need to acquire stable data during complex movements, requiring wide dynamic range, low to medium pixel count, and wide-angle capabilities. Therefore, high demands are placed on components such as the camera lens barrel.

[0003] During injection molding of automotive lenses, defects such as scorching and air bubbles may appear on localized surfaces near the parting line and inside the lens barrel. This is because, during the injection process, gases generated by the thermal decomposition of the plastic material in the mold cavity cannot be expelled from the mold in a timely manner. If the gases in the mold cavity cannot be expelled for an extended period, it will directly cause injection molding defects such as material shortage, scorching, air bubbles, and surface haze, and indirectly cause injection molding defects such as shrinkage marks and exposed fiberglass. Summary of the Invention

[0004] To address the problem of product defects caused by poor mold venting during the injection molding of automotive mirror barrels, the present invention aims to provide a venting structure and design method for automotive mirror barrel injection molds. By rationally opening the mold vents, gas can be discharged in a timely manner during the injection molding process, thereby enabling the precision injection molding of automotive mirror barrel products.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A venting structure for an injection mold of a vehicle mirror barrel includes a front mold, a rear mold, a first inner diameter pin, and a second inner diameter pin, wherein the front mold is provided with a mold parting surface;

[0007] The mold parting surface has symmetrically arranged mold cavities and mold runners connecting the mold cavities; the mold parting surface has a mold injection gate for connecting the mold runners; the mold parting surface has a third venting groove for connecting the mold cavities with the external environment; the mold parting surface has a fourth venting groove for connecting the mold runners with the external environment.

[0008] The first inner diameter needle is embedded in the front mold, and the second inner diameter needle is embedded in the rear mold; the first inner diameter needle and the second inner diameter needle are separated by a frustum.

[0009] Furthermore, the third exhaust groove is symmetrically arranged and divided into two chambers, each chamber including 6 exhaust grooves.

[0010] Furthermore, the fourth exhaust channel is symmetrically arranged and includes 30 exhaust channels.

[0011] Furthermore, the first inner diameter needle is provided with a first venting groove, and the second inner diameter needle is provided with a second venting groove.

[0012] Furthermore, the first exhaust groove is symmetrically arranged and includes 6 exhaust grooves; the second exhaust groove is symmetrically arranged and includes 12 exhaust grooves.

[0013] This invention also provides a design method for the venting structure of an injection mold for a vehicle-mounted mirror barrel, comprising the following steps:

[0014] Determine the material of the lens barrel, and obtain the overflow value C of the material by consulting the standard. The overflow value C of the material represents the gap value (i.e. the amount of burrs) that the material will overflow during the molding process of the plastic part.

[0015] Calculate the dimension S1 of the third venting groove at the mold parting surface. Since the product molding accuracy must be ensured at the mold cavity, the dimension of the third venting groove should be as small as possible while ensuring that the gas can be discharged smoothly. The empirical formula 1 for calculating the third venting groove is as follows:

[0016]

[0017] Calculate the size S2 of the fourth venting groove at the mold parting surface. Since the material in the runner is in a molten state and at a high temperature, it is easy to generate gas. Therefore, the size of the fourth venting groove is larger than that of the third venting groove. The empirical formula 2 for calculating the fourth venting groove is as follows:

[0018]

[0019] Design the venting structure at the inner diameter pin of the lens barrel, including calculation of venting size and number of vents;

[0020] The empirical formula 3 for the inner diameter needle venting dimension S3 is as follows:

[0021]

[0022] The number of vents n of the inner diameter needle is related to the diameter D of the inner diameter needle structure; the empirical formula 4 for calculating the number of vents n is as follows: (The diameter D of the inner diameter needle is determined based on the mold structure.)

[0023]

[0024] Compared with the prior art, the present invention has the following advantages: The present invention adopts a symmetrical venting groove structure, optimizes the venting system of the mold, and designs a corresponding venting structure for the unique inner diameter needle structure of the automotive mirror barrel. It also proposes a venting design method for the injection mold of automotive mirror barrel, so as to avoid the product molding quality being affected by the inability of gas in the injection chamber and inner diameter needle of the mold to be effectively discharged. Attached Figure Description

[0025] The accompanying drawings described below are merely exemplary. Those skilled in the art can derive other embodiments based on the provided drawings without any inventive effort.

[0026] Figure 1 This is a schematic diagram of the front mold structure of an injection mold for a vehicle-mounted mirror barrel according to the present invention;

[0027] Figure 2 This is a schematic diagram of the rear mold structure of an injection mold for a vehicle-mounted mirror barrel according to the present invention;

[0028] Figure 3 This is a schematic diagram of the parting surface structure of an injection mold for a vehicle-mounted mirror barrel according to the present invention;

[0029] Figure 4 This is a schematic diagram of the unique inner diameter needle structure of an injection mold for a vehicle-mounted mirror barrel according to the present invention;

[0030] Figure 5 This is a flowchart of a method for designing venting in an injection mold for a vehicle-mounted mirror barrel according to the present invention;

[0031] In the diagram: 1-front mold; 2-rear mold; 3-mold parting surface; 4-mold cavity; 5-mold runner; 6-mold injection gate; 7-third venting groove; 8-fourth venting groove; 9-first inner diameter pin; 10-second inner diameter pin; 11-first venting groove; 12-second venting groove. Detailed Implementation

[0032] The following specific embodiments illustrate the implementation of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] like Figures 1-4 As shown, a venting structure for an injection mold of a vehicle mirror barrel includes a front mold 1, a rear mold 2, a first inner diameter pin 9, and a second inner diameter pin 10. The front mold 1 is provided with a mold parting surface 3.

[0034] The mold parting surface 3 is provided with symmetrically arranged mold cavities 4 and mold runners 5 connecting the mold cavities 4; the mold parting surface 3 is provided with a mold injection gate 6, which is used to connect the mold runners 5; the mold parting surface 3 is provided with a third venting groove 7, which is used to connect the mold cavity 4 with the external environment, and the third venting groove 7 is symmetrically arranged, divided into two cavities, each cavity including 6 venting grooves; the mold parting surface 3 is provided with a fourth venting groove 8, which is used to connect the mold runners 5 with the external environment, and the fourth venting groove 8 is symmetrically arranged, including 30 venting grooves.

[0035] The first inner diameter needle 9 is embedded in the front mold 1, and the second inner diameter needle 10 is embedded in the rear mold 2; the first inner diameter needle 9 and the second inner diameter needle 10 are separated by a frustum.

[0036] The first inner diameter needle 9 is provided with a first exhaust groove 11, and the second inner diameter needle 10 is provided with a second exhaust groove 12; the first exhaust groove 11 is symmetrically arranged and includes 6 exhaust grooves; the second exhaust groove 12 is symmetrically arranged and includes 12 exhaust grooves.

[0037] like Figure 5 As shown, a design method for the venting structure of an injection mold for a vehicle-mounted mirror barrel includes the following steps:

[0038] Step 1: Determine the material of the lens barrel and obtain the overflow value C of the material by consulting the standard. The overflow value C of the material represents the gap value of the material overflowing during the molding process of the plastic part.

[0039] Step 2: Calculate the dimension S1 of the third venting groove 7 at the parting surface 3 of the mold. Since the product molding accuracy must be ensured at the mold cavity 4, the dimension of the third venting groove 7 should be as small as possible while ensuring that the gas can be discharged smoothly. The empirical formula 1 for calculating the third venting groove 7 is as follows:

[0040]

[0041] Step 3: Calculate the dimension S2 of the fourth venting groove 8 at the parting surface 3 of the mold. Since the material in the runner is in a molten state and the temperature is high, it is easy to generate gas. Therefore, the dimension of the fourth venting groove 8 is larger than that of the third venting groove 7. The empirical formula 2 for calculating the fourth venting groove 8 is as follows:

[0042]

[0043] Step 4: Design the venting structure at the inner diameter pin of the lens barrel, including calculating the venting size and the number of vents;

[0044] The empirical formula 3 for the inner diameter needle venting dimension S3 is as follows:

[0045]

[0046] The number of vents n of the inner diameter needle is related to the diameter D of the inner diameter needle structure; the empirical formula 4 for calculating the number of vents n is as follows: (The diameter D of the inner diameter needle is determined based on the mold structure.)

[0047]

[0048] The design method is illustrated in detail below through specific examples.

[0049] Example 1

[0050] 1. The lens barrel material was determined to be PPS1141L4, and its overflow value was determined to be 0.02mm by consulting the standard.

[0051] 2. Calculate the size S1 of the cavity venting groove at the parting surface. The size of the cavity venting groove at the parting surface is calculated using empirical formula 1:

[0052]

[0053] 3. Calculate the venting groove size S2 at the parting surface. Based on empirical formula 2, the venting groove size at the parting surface is calculated as follows:

[0054]

[0055] 4. Design the venting structure at the inner diameter pin structure unique to the lens barrel mold. Calculate the venting dimensions of the inner diameter pin according to empirical formula 3:

[0056]

[0057] Based on the mold structure, the inner diameter needle diameter D1 of the front mold is 7.2mm, and the inner diameter needle diameter of the rear mold is 8.4mm. Based on empirical formulas...

[0058] Equation 4 calculates the number of venting pins in the inner diameter of the front mold as follows:

[0059]

[0060] According to empirical formula 4, the number of air vents required for the inner diameter needle of the thick film 2 is:

[0061]

[0062] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A venting structure for an injection mold of a vehicle-mounted mirror barrel, characterized in that, It includes a front mold (1), a rear mold (2), a first inner diameter pin (9), and a second inner diameter pin (10), wherein the front mold (1) is provided with a mold parting surface (3); The mold parting surface (3) is provided with symmetrically arranged mold cavities (4) and mold runners (5) connecting the mold cavities (4); the mold parting surface (3) is provided with a mold injection gate (6), which is used to connect the mold runners (5); the mold parting surface (3) is provided with a third venting groove (7), which is used to connect the mold cavity (4) with the external environment; the mold parting surface (3) is provided with a fourth venting groove (8), which is used to connect the mold runners (5) with the external environment; The first inner diameter needle (9) is embedded in the front mold (1), and the second inner diameter needle (10) is embedded in the rear mold (2); the first inner diameter needle (9) and the second inner diameter needle (10) are separated by a frustum; the first inner diameter needle (9) is provided with a first venting groove (11), and the second inner diameter needle (10) is provided with a second venting groove (12). The venting structure includes: determining the material of the lens barrel, obtaining the overflow value C of the material by consulting the standard, where the unit of C is mm, and the overflow value C of the material represents the gap size of the material overflowing during the molding process of the plastic part; Calculate the dimensions of the third venting groove (7) at the parting surface (3) of the mold. , The corresponding unit is mm. Since the product molding accuracy must be ensured at the mold cavity (4), the size of the third venting groove (7) should be as small as possible while ensuring that the gas can be discharged smoothly. The empirical formula for calculating the third venting groove (7) is as follows: In empirical formula 1, C and All are dimensionless values; Calculate the dimensions of the fourth venting groove (8) at the parting surface (3) of the mold. , The corresponding unit is mm. Since the material in the flow channel is in a molten state and the temperature is high, it is easy to generate gas. Therefore, the size of the fourth venting groove (8) is larger than that of the third venting groove (7). The empirical formula 2 for calculating the fourth venting groove (8) is as follows: In empirical formula 2, C and All are dimensionless values; Design the venting structure at the inner diameter pin of the lens barrel, including calculation of venting size and number of vents; The inner diameter needle exhaust size The empirical formula 3 is as follows: ； The number of vents, n, of the inner diameter needle is related to the diameter D of the inner diameter needle structure, where D is the inner diameter needle diameter in mm. The empirical formula for calculating the number of vents, n, is as follows: (The inner diameter needle diameter D is determined based on the mold structure.) In empirical formula 4, D is a dimensionless value.

2. The venting structure of the injection mold for a vehicle-mounted mirror barrel according to claim 1, characterized in that, The third exhaust groove (7) is arranged symmetrically and is divided into two chambers, each chamber including 6 exhaust grooves.

3. The venting structure of the injection mold for a vehicle-mounted mirror barrel according to claim 1, characterized in that, The fourth exhaust groove (8) is arranged symmetrically and includes 30 exhaust grooves.

4. The venting structure of the injection mold for a vehicle-mounted mirror barrel according to claim 1, characterized in that, The first exhaust groove (11) is symmetrically arranged and includes 6 exhaust grooves; the second exhaust groove (12) is symmetrically arranged and includes 12 exhaust grooves.

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