Method for determining the internal parting structure of the bumper injection molded part

Abstract

The present invention discloses a molding determination method for a parting structure within a bumper injection molded part. The main design concept of the present invention is that, based on the structural section of the bumper injection molded part, the spatial position ranges of large caps, pull blocks, push blocks, large inclined tops and other areas related to the bumper demolding are determined in combination with preset offset distances, tilt angles, safety margins and other parameters, and the various areas are interrelated and progressively arranged during the determination process, thereby facilitating rapid confirmation of the molding feasibility of the bumper injection molded part with an undercut structure, and facilitating the avoidance of molding risks, effectively improving processing efficiency and accuracy, providing reliable technical support for the early stages of product development, and facilitating the rationalization of product design.

Description

Technical Field

[0001] The invention relates to the field of automobile manufacturing, and in particular to a molding determination method for a parting structure inside a bumper injection molded part. Background Art

[0002] If the ejection angle requirements are met during the molding of the car body injection molding, there is no need to consider the feasibility of molding and the mold can be directly ejected. However, during the product design of injection molding parts, when considering the surrounding environment such as assembly and overlap, it is often necessary to add an undercut structure to the injection molding parts to achieve matching overlap with the surrounding environment. If there is an undercut structure in the ejection direction during molding of the injection molding parts, the structure at the undercut cannot be directly ejected and needs to be realized with the help of a special structure on the mold.

[0003] The undercut structure on the body injection molding can generally be divided into a bumper inner parting structure and a doghouse structure. The present invention focuses on the bumper inner parting structure: considering the matching overlap state with the surrounding parts, the bumper edge (such as the rear bumper tire side and the body side) generally needs to form an inner parting structure, and the parting line is completely hidden at the bumper edge (below the R angle), and is not visible from the outside. The bumper inner parting structure described here is an undercut structure that is forced to deform and eject from the mold during the molding of the bumper injection molding. Figure 1 Taking the partial schematic diagram of a rear bumper injection molded part as an example, assuming that during normal direct demolding, the edge parting line should be at the parting line a shown. In order to hide the parting line, the parting line at the edge of the rear bumper will be adjusted to the position of the parting line b shown. As shown in the figure, the flange has a large undercut structure, which is difficult to achieve during normal direct demolding.

[0004] The aforementioned injection molded parts that can be directly demolded can be directly measured in the software to confirm the feasibility of molding and demolding; while during the molding confirmation of injection molded parts, the feasibility of the position where there is an undercut structure cannot be directly confirmed by software measurement. However, there is no reasonable and easy-to-implement solution in the industry to determine the feasibility of molding the undercut structure of injection molded parts. Summary of the invention

[0005] In view of the above, the present invention aims to provide a molding determination method for a parting structure in a bumper injection molded part to solve the aforementioned technical problems.

[0006] The technical solution adopted by the present invention is as follows:

[0007] The present invention provides a molding determination method for a parting structure inside a bumper injection molded part, comprising:

[0008] Pre-construct the structural section of the bumper injection molded part;

[0009] Based on the structural section, the dividing point between the large inclined top and the large cover cap during mold forming is determined;

[0010] According to the demarcation point, a large cap area is formed;

[0011] Based on the structural section, determining a bumper pull block area;

[0012] Determining a bumper push block area based on the structural section and the pull block area;

[0013] Based on the structural section, the push block area and the large cover cap area, a large sloping roof area is determined.

[0014] In at least one possible implementation, the method of determining the dividing point between the large slanted top and the large cap during mold forming includes: from the edge of the bumper represented on the structural section, offset a first preset distance inward in a direction perpendicular to the demolding direction, and extending parallel to the demolding direction to the body of the bumper and intersecting at one point to obtain the dividing point.

[0015] In at least one possible implementation, forming the large cap area according to the demarcation point includes: taking the demarcation point as a reference, constructing a large cap boundary line along a direction perpendicular to the demoulding direction at a first preset angle.

[0016] In at least one possible implementation, determining the bumper pull block area includes:

[0017] From the edge of the bumper represented on the structural section, offset a second preset distance toward the inside of the bumper along a direction perpendicular to the demolding direction to obtain a first lower vertex of the first boundary of the pull block;

[0018] Using the outermost point at the edge of the bumper and the first lower vertex, construct a second boundary of the pull block;

[0019] Taking the first lower vertex as a reference, constructing a straight line which is at a second preset angle to the demoulding direction to obtain the first boundary of the pull block;

[0020] A parallel line is drawn at a preset interval below the boundary line of the large cap, and two ends of the parallel line intersect with the bumper and the first boundary of the pull block respectively to obtain the third boundary of the pull block.

[0021] In at least one possible implementation, determining the bumper push block area includes:

[0022] Taking the parting line of the edge of the bumper as a reference, a straight line parallel to the ejection direction is extended outward to obtain the first boundary of the push block;

[0023] Taking the first lower vertex as a reference, a straight line parallel to the first boundary of the push block is constructed to obtain the second boundary of the push block.

[0024] In at least one possible implementation, determining the large sloping roof area includes:

[0025] Taking the second boundary of the push block as a reference, offsetting the third preset distance inward of the bumper along a direction perpendicular to the demoulding direction, and determining the second lower vertex of the first boundary of the large inclined top;

[0026] Taking the second lower vertex as a reference, a straight line is drawn toward the large cap area along a third preset angle with the demoulding direction to obtain the first boundary of the large inclined top;

[0027] Based on the second lower vertex, a perpendicular line is drawn to the second boundary of the push block to obtain the second boundary of the large inclined top;

[0028] Taking the two end points of the second boundary of the large inclined roof as reference, fourth preset distances are offset in opposite directions respectively to obtain two boundary vertices of the inclined roof rod of the large inclined roof, wherein the third preset distance is associated with the fourth preset distances.

[0029] In at least one possible implementation manner, after the large cap area and the large sloping roof area are determined, a minimum material thickness between the large cap and the large sloping roof is set.

[0030] The main design concept of the present invention is to determine the spatial position range of the large cap, pull block, push block, large inclined top and other areas related to the bumper demolding based on the structural section of the bumper injection molded part and combined with preset offset distance, inclination angle, safety margin and other parameters, and each area is interrelated and progressively arranged during the determination process, so it is convenient to quickly confirm the molding feasibility of the bumper injection molded part with an undercut structure, and it is beneficial to avoid molding risks, which can effectively improve processing efficiency and accuracy, provide reliable technical support for the early stage of product development, and facilitate the rationalization of product design. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described below with reference to the accompanying drawings, in which:

[0032] Figure 1 It is a partial schematic diagram of the injection molded part of the rear bumper;

[0033] Figure 2 A flow chart of a method for determining the molding of a parting structure in a bumper injection molded part provided by an embodiment of the present invention;

[0034] Figure 3 A cross-sectional view of the design and verification of the internal parting structure of the bumper injection molded part provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0036] The present invention proposes an embodiment of a method for determining the molding of a parting structure in a bumper injection molded part. Specifically, Figure 2 and Figure 3 shown, including:

[0037] Step S1, pre-constructing a structural section of a bumper injection molded part;

[0038] Step S2, based on the structural section, determining the dividing point between the large inclined top and the large cover cap during mold forming;

[0039] It should be explained here that the so-called large beveled roof and large cap are customary names in the industry for specific parts of the bumper injection molded parts and specific molds used for molding (similar to the pull block and push block mentioned below). The two are complete names, and the word "big" cannot be viewed in isolation, that is, the "big" in the two names is only a name and not a standard. Specifically, the edge of the bumper can be characterized from the structural section, offset inwardly along the direction perpendicular to the demolding direction by a first preset distance (such as at least 3mm, preferably 3mm to 5mm, so as to leave a safety gap during the movement of the large cap), and extend parallel to the demolding direction to the body of the bumper and intersect at one point, that is, the dividing point. It needs to be supplemented here, Figure 3 The drawings are not drawn strictly to scale and are for illustrative purposes only.

[0040] Step S3, forming a large capping area according to the demarcation point;

[0041] Specifically, based on the dividing point, a boundary line of the large cap (and the large slanted top) is constructed along a direction perpendicular to the demolding direction at a first preset angle (such as at least 3°, to ensure that the large slanted top can move directly in the direction perpendicular to the demolding direction), and the large cap area is divided based on the large cap boundary line.

[0042] Step S4, determining the bumper pull block area based on the structural section;

[0043] In actual operation, the first lower vertex of the first boundary of the pull block can be obtained by offsetting the second preset distance (such as at least 20 mm, which is the minimum width of the bumper sealing surface) toward the inner side of the bumper in a direction perpendicular to the demolding direction from the edge of the bumper represented on the structural section; then, the second boundary of the pull block is constructed (a straight line formed by two points) using the outermost point at the edge of the bumper (the edge of the undercut structure) and the first lower vertex; then, based on the first lower vertex, a straight line is constructed at a second preset angle to the demolding direction (such as 12°, the maximum angle of movement of the pull block power rod) to obtain the first boundary of the pull block; then, a parallel line is drawn at a preset spacing below the boundary line of the large cap (such as at least 30 mm, which can ensure the strength of the large slanted roof, that is, it meets the minimum thickness requirement of the large slanted roof), and the two ends of the parallel line intersect with the bumper and the first boundary of the pull block respectively to obtain the third boundary of the pull block, and the pull block area can be determined by the first boundary of the pull block, the second boundary of the pull block and the third boundary of the pull rod.

[0044] It should be noted that in actual operation, when the first boundary of the pull block meets the set side length (such as at least 50mm, which can meet the pull block power rod diameter ≥30mm, and the safety margin on both sides of the pull block power rod ≥10mm), the structure is feasible.

[0045] Step S5, determining a bumper push block area based on the structural section and the pull block area;

[0046] In combination with the foregoing, taking the parting line of the bumper edge as a reference, a straight line parallel to the demoulding direction is extended outward to obtain the first boundary of the push block; then, taking the first lower vertex as a reference, a straight line parallel to the first boundary of the push block is constructed to obtain the second boundary of the push block, and the push block area can be obtained from the first boundary of the push block, the second boundary of the push block and the aforementioned second boundary of the pull block.

[0047] Step S6, determining a large inclined roof area based on the structural section, the push block area and the large cap area;

[0048] Specifically, taking the second boundary of the push block as a reference, a third preset distance (e.g., at least 70 mm, including the diameter of the large slanted top rod and the safety margins on both sides) is offset toward the inner side of the bumper in a direction perpendicular to the demolding direction to determine the second lower vertex of the first boundary of the large slanted top; then, taking the second lower vertex as a reference, a straight line is drawn toward the large cap area along a third preset angle (e.g., at least 12°, preferably 15°-20°, which is the inclination angle of the back of the large slanted top) with respect to the demolding direction to obtain the first boundary of the large slanted top; based on the second lower vertex, a perpendicular line is drawn toward the second boundary of the push block. The second boundary of the large inclined top is obtained; with the two end points of the second boundary of the large inclined top as the reference, the fourth preset distance (such as at least 10mm, as a safety margin) is offset in opposite directions to obtain the two boundary vertices of the inclined top rod of the large inclined top. It should be pointed out here that in order to ensure the stability of the movement of the large inclined top, the third preset distance and the fourth preset distance need to be designed in association to ensure that the diameter of the inclined top rod of the large inclined top (that is, the distance between the two boundary vertices) must meet the preset diameter (such as at least 50mm); in addition, it can be added that the inclination angle of the inclined top rod can be 10° to 12° relative to the demoulding direction. Combined with the above, the angle of the mating surface of the pull block and the large inclined top is consistent with the first preset angle.

[0049] On this basis, it can be further supplemented that the avoidance amount between the large slanted roof and the large cap can be set along the direction of the boundary line of the large cap, that is, the design gap between the large cap and the large slanted roof. The design gap can ensure that the large slanted roof has sufficient space for movement. The specific avoidance amount size can be determined based on the undercut amount of the bumper, specifically, such as: avoidance amount = undercut amount + safety margin + manufacturing tolerance.

[0050] Finally, it can be added that after determining the large cap area and the large slanted roof area, the minimum thickness of the large cap can be set, that is, the minimum material thickness between the large cap and the large slanted roof (the distance from the inner side of the large cap of the bumper to the extension line of the large cap boundary line can be taken). According to the established strength requirements, for example, the minimum material thickness value is at least 30mm.

[0051] To sum up, the main design concept of the present invention is to determine the spatial position range of the large cap, pull block, push block, large inclined top and other areas related to the bumper demolding based on the structural section of the bumper injection molded part and combined with preset offset distance, inclination angle, safety margin and other parameters, and each area is interrelated and progressively arranged during the determination process, so it is convenient to quickly confirm the molding feasibility of the bumper injection molded part with an undercut structure, and it is beneficial to avoid molding risks, which can effectively improve processing efficiency and accuracy, provide reliable technical support for the early stage of product development, and facilitate the rationalization of product design.

[0052] In the embodiments of the present invention, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. A and B may be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c may represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, c may be single or multiple.

[0053] The above describes in detail the structure, features and effects of the present invention based on the embodiments shown in the drawings, but the above is only a preferred embodiment of the present invention. It should be noted that the technical features involved in the above embodiments and their preferred methods can be reasonably combined and matched into a variety of equivalent schemes by those skilled in the art without departing from or changing the design ideas and technical effects of the present invention; therefore, the present invention is not limited to the scope of implementation shown in the drawings, and all changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the specification and drawings, should be within the protection scope of the present invention.

Claims

1. A method for determining the molding of the internal parting structure of a bumper injection molded part, characterized in that: include: Pre-construct the structural section of the bumper injection molded part; Based on the structural section, the dividing point between the large inclined top and the large cover cap during mold forming is determined; According to the demarcation point, a large cap area is formed, including: taking the demarcation point as a reference, constructing a large cap boundary line along a direction perpendicular to the demoulding direction at a first preset angle; Based on the structural section, the bumper block area is determined, including: from the edge of the bumper represented on the structural section, a second preset distance is offset toward the inside of the bumper along a direction perpendicular to the demolding direction to obtain a first lower vertex of the first boundary of the block; using the outermost point at the edge of the bumper and the first lower vertex to construct the second boundary of the block; using the first lower vertex as a reference, constructing a straight line at a second preset angle to the demolding direction to obtain the first boundary of the block; making a parallel line at a preset spacing below the boundary line of the large cap, and the two ends of the parallel line intersect the bumper and the first boundary of the block respectively to obtain the third boundary of the block; Based on the structural section and the pull block area, determining the bumper push block area includes: taking the parting line of the bumper edge as a reference, extending a straight line parallel to the demoulding direction outward to obtain a first push block boundary; taking the first lower vertex as a reference, constructing a straight line parallel to the first push block boundary to obtain a second push block boundary; Based on the structural section, the push block area and the large cap area, the large slanted roof area is determined, including: taking the second boundary of the push block as a reference, offsetting a third preset distance toward the inner side of the bumper along a direction perpendicular to the demolding direction to determine the second lower vertex of the first boundary of the large slanted roof; taking the second lower vertex as a reference, drawing a straight line toward the large cap area at a third preset angle to the demolding direction to obtain the first boundary of the large slanted roof; drawing a perpendicular line to the second boundary of the push block based on the second lower vertex to obtain the second boundary of the large slanted roof; taking the two end points of the second boundary of the large slanted roof as a reference, offsetting the fourth preset distances in opposite directions respectively to obtain two boundary vertices of the slanted roof rod of the large slanted roof, wherein the third preset distance is associated with the fourth preset distance.

2. The molding determination method for the internal parting structure of the bumper injection molded part according to claim 1, characterized in that: The method for determining the dividing point between the large slanted top and the large cap during mold forming includes: from the edge of the bumper represented on the structural section, offset a first preset distance inward along a direction perpendicular to the demolding direction, and extending parallel to the demolding direction to the body of the bumper and intersecting at a point to obtain the dividing point.

3. The method for determining the molding of the internal parting structure of the bumper injection molded part according to any one of claims 1 to 2, characterized in that: After determining the large cap area and the large sloping top area, set the minimum material thickness between the large cap and the large sloping top.

Images