Injection mold for automobile rearview mirror decorative cover

Abstract

The utility model relates to an injection mold for an automobile rearview mirror trim cover, which is characterized in that a forming surface for forming a thin-wall structure at an opening of the trim cover on a mold cavity and a mold core inclines towards the outer side of the trim cover, and the inclination amount and the inclination angle of the forming surface are determined according to the design size of the trim cover and the deformation amount of mold flow analysis or sample measurement, so that the trim cover can be demolded automatically; and a demolding mechanism is removed from the mold. Therefore, the mold disclosed by the utility model can be automatically demolded without a sliding block mechanism, so that the mold structure becomes simpler, meanwhile, a parting line left on the decorative cover at the joint between the sliding block mechanism and the mold cavity disappears, the work of removing the parting line is omitted, and the appearance of the decorative cover is smoother and more attractive.

Description

Technical Field

[0001] This utility model relates to the field of automotive rearview mirror technology, and in particular to an injection mold for an automotive rearview mirror decorative cover. Background Technology

[0002] Car rearview mirror covers conceal and protect other parts of the car rearview mirror, but because they are exposed to the outside, they also affect the car's external appearance.

[0003] Finished car rearview mirror decorative covers, such as Figure 1 As shown, both the left and lower openings are fastened to other parts, so the thin wall surface at the opening of the decorative cover will slope inwards towards the inside of the decorative cover. Figure 1 As shown by the arrow, it is also called a buckle. The parameters of the buckle are described by the buckle amount (the amount of deformation at the very end) and the buckle angle. The buckle structure creates a clamping force when the decorative cover is fastened to other parts, making the connection more secure.

[0004] Car rearview mirror covers are typically made of plastic or resin and are injection molded. An injection mold includes a molding section, gating system, guiding mechanism, ejection device, lateral parting and core-pulling mechanism, cooling and heating system, and venting system. The molding section determines the shape, structure, and dimensions of the molded material, and usually consists of a core and a cavity. The core forms the inner surface shape of the product, and the cavity forms the outer surface shape. Therefore, the structure and parameters of the mold's molding section depend on the product. Figure 2 As shown, in existing technologies, both the core and cavity surfaces of the mold have undercut structures. These undercut structures require the product to be ejected by a slider mechanism during demolding. This inevitably creates a connection line between the slider mechanism and the cavity, which also leaves a parting line (mold parting line) on the outer surface of the decorative cover. To improve the appearance of the injection molded part, the mold parting line is usually treated, but it cannot be completely free of marks like other surfaces, thus still affecting its aesthetics. Utility Model Content

[0005] In view of the shortcomings or deficiencies of the prior art, the technical problem to be solved by this utility model is to provide a decorative cover mold with a simpler structure, and the products made with this mold have a more beautiful appearance.

[0006] To solve the above-mentioned technical problems, the present invention has the following structure:

[0007] The injection mold for the car rearview mirror decorative cover includes a cavity and a core. The forming surface of the cavity and core, which forms the thin-walled structure at the opening of the decorative cover, is inclined to the outside of the decorative cover.

[0008] The present invention removes the demolding mechanism from the mold, allowing the decorative cover to be demolded automatically.

[0009] Furthermore, the tilt amount and tilt angle of the forming surface are determined based on the design dimensions of the decorative cover and the deformation amount obtained from mold flow analysis. Alternatively, the tilt amount and tilt angle of the forming surface are determined based on the design dimensions of the decorative cover and the deformation amount measured from the sample.

[0010] Compared with the prior art, the advantages of this utility model are:

[0011] This invention eliminates the undercut phenomenon in the mold cavity, allowing the product to be demolded automatically without a slider mechanism. The mold structure is thus simplified. At the same time, the parting line left on the decorative cover at the connection between the slider mechanism and the mold cavity also disappears, saving the work of removing the parting line. The surface of the decorative cover is smoother and more beautiful. Attached Figure Description

[0012] The following figures illustrate some specific embodiments of the present invention in an exemplary and non-limiting manner. The same reference numerals in the figures represent the same or similar parts or components.

[0013] Figure 1 3D rendering of a car rearview mirror decorative cover;

[0014] Figure 2 : A 3D view of an existing automotive rearview mirror decorative cover mold in its open state;

[0015] Figure 3 : A perspective view of the car rearview mirror decorative cover mold in the open state.

[0016] The symbols in the diagram represent the following meanings:

[0017] 1-Decorative cover, 2-Core, 3-Cavity, 4-Forming surface, 5-Slider mechanism. Detailed Implementation

[0018] The following will further explain the concept, specific structure and technical effects of this utility model in conjunction with the accompanying drawings, so as to fully understand the purpose, features and effects of this utility model.

[0019] It should be noted that in the description of this utility model, the terms "upper," "lower," "left," "right," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. "Inner" refers to the direction of the internal space enclosed by the thin wall of the decorative cover 1, and "outer" refers to the opposite direction. These are simplified descriptions made only for the convenience of describing this utility model, and do not mean that the indicated elements must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limitations on this utility model.

[0020] The inventors simulated and analyzed the molding process of the decorative cover 1, determined the product deformation direction and amount, and found that the decorative cover 1 deforms inward after demolding, and the deformation amount is relatively large. This indicates that the curved surface of the mold cavity does not need to have an undercut structure. Therefore, this utility model improves the molding part of the mold for the automotive rearview mirror decorative cover 1, so that the thin wall surface at the opening of the decorative cover 1 does not undercut inward. After removing the undercut structure, the product no longer needs the slider mechanism 5 to demold itself, so the slider mechanism is also eliminated from the mold. Figure 3 Therefore, the mold structure of the decorative cover of this utility model is simplified, and the parting line left on the decorative cover 1 at the connection between the slider mechanism 5 and the cavity is also eliminated, making the surface of the decorative cover 1 smoother and more beautiful.

[0021] The injection mold for the automotive rearview mirror decorative cover includes a cavity 3 and a core 2. The forming surface 4 on the cavity 3 and core 2, which forms the thin-walled structure at the opening of the decorative cover 1, is inclined outwards. The amount and angle of inclination are determined based on the design dimensions of the decorative cover 1 and the deformation amount analyzed by mold flow analysis or by sample measurement.

[0022] Examples illustrating the advantages of this embodiment, such as Figure 1 As shown, the inward undercut at the opening of the decorative cover 1 is 1.25mm, and the undercut angle is 2.3°. According to mold flow analysis, the inward deformation at the opening of the decorative cover 1 after demolding is 2.1mm, which is greater than the undercut of the finished product. This means that even if the surfaces forming the opening of the decorative cover 1 on the mold core 2 and cavity 3 are inclined outwards towards the decorative cover 1, as long as the appropriate inclination amount and angle are selected, the inward deformation of 2.1mm after demolding will still achieve the inward undercut designed for the product. The opening size near the root of the mold core 2 is larger than the top, so the decorative cover 1 can be demolded automatically without a demolding mechanism (e.g., Figure 3 As shown in the figure, based on this, the demolding mechanism is removed from the mold of this utility model, and the mold structure is simpler.

[0023] The demolding mechanism, such as the slider mechanism 5, pushes the product to assist in demolding when the decorative cover cannot be demolded on its own.

[0024] Different rearview mirror decorative covers have different shapes and thicknesses, resulting in different liquid flow patterns during injection molding. Therefore, a new mold flow analysis must be performed for each type of decorative cover. The dimensions of cavity 3 and core 2 forming surface 4 are then determined based on the deformation determined by the mold flow analysis. Alternatively, the tilt amount and tilt angle can be initially determined based on the mold flow analysis results, a sample can be made, and the actual deformation of the sample can be measured. The tilt amount and tilt angle of forming surface 4 can then be determined based on the actual deformation.

[0025] This invention simulates and analyzes the flow of injection molding materials, discovering the deformation direction and amount of the decorative cover. Based on this, the shape and size of the mold core and cavity are improved, eliminating the undercut phenomenon in the mold cavity. This allows the product to be demolded automatically without a slider mechanism, thus simplifying the mold structure. At the same time, the parting line left on the decorative cover at the connection between the slider mechanism and the mold cavity also disappears, saving the work of removing the parting line. The surface of the decorative cover is smoother and more beautiful.

[0026] The above embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications, or equivalent substitutions of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention and should be covered within the scope of the claims of the present invention.

Claims

1. An injection mold for a car rearview mirror decorative cover, the molding part comprising a cavity (3) and a core (2), characterized in that, The forming surfaces (4) on the cavity (3) and the core (2) that form the thin-walled structure at the opening of the decorative cover are inclined to the outside of the decorative cover.

2. The injection mold for the automotive rearview mirror decorative cover according to claim 1, characterized in that, Remove the demolding mechanism, and the decorative cover can be demolded automatically.

3. The injection mold for the automotive rearview mirror decorative cover according to claim 2, characterized in that, The tilt amount and tilt angle of the forming surface (4) are determined based on the design dimensions of the decorative cover and the deformation amount of the mold flow analysis.

4. The injection mold for the automotive rearview mirror decorative cover according to claim 2, characterized in that, The tilt amount and tilt angle of the forming surface (4) are determined based on the design dimensions of the decorative cover and the amount of deformation measured on the sample.

Images