Structure for preventing stress cracking of BOSS column

Abstract

The utility model is applicable to the technical field of injection molding and embedding, and provides a structure for preventing stress cracking of a BOSS column, a nut is placed on a heating table to be heated to 380 DEG C, after being heated, the nut is quickly embedded into a BOSS hole through a hot-pressing tool, the end face of the embedded nut is flush with the end face of the BOSS hole, and in the injection molding process, the BOSS column is embedded into the BOSS hole through the hot-pressing tool, so that the stress cracking of the BOSS column is prevented. The BOSS hole and the nut which are subjected to hot melting processing can meet the design and use requirements after various tests due to the facts that the constraint of different shrinkage rates of the insert nut does not exist and the internal stress of the plastic part is not enough to cause stress cracking of a product.

Description

Technical Field

[0001] The utility model belongs to the technical field of injection molding embedding, and in particular relates to a structure for preventing stress cracking of a BOSS column. Background Art

[0002] Among plastic parts, for products or tanks with airtightness requirements, the connection between the air pipe joint and the plastic part is generally fastened and connected in the form of flange nuts, bolts and sealing rings to ensure that the connection part can withstand a certain atmospheric pressure without leakage. For some products with structural restrictions, in some plastic products, it is necessary to embed nuts in the plastic products. The purpose of embedding nuts is to use nuts to prefabricate threaded interfaces for plastic products. Most of them are directly embedded in plastic parts to form an integrated structure. The air pipe joint is directly connected to the plastic part in the form of threads.

[0003] During the injection molding process of plastic parts connected with bolts, insert nuts are added. Due to the different shrinkage rates of metal nuts and plastic parts, local stress is generated during the molding process and cooling shrinkage process of the plastic parts. Under natural conditions, the stress release process produces local cracking around the nut, which is mainly concentrated at the position where the nut and the plastic part are combined. In the aerospace field, particular attention is paid to the structural strength of the product, and solving the stress cracking problem is a very important quality indicator. Therefore, the utility model proposes a structure for preventing BOSS column stress cracking to solve the above problem. Utility Model Content

[0004] The utility model provides a structure for preventing stress cracking of a BOSS column, aiming to solve the problems raised by the background technology.

[0005] The utility model is implemented as follows: a structure for preventing stress cracking of a BOSS column comprises a plastic part and a BOSS hole;

[0006] The plastic part is provided with a plurality of protruding BOSS holes, the outer wall of the BOSS hole is provided with a plurality of reinforcing ribs evenly distributed in a circular ring shape, a protective sleeve is provided outside the reinforcing rib, a nut is provided in the BOSS hole, and the nut and the BOSS hole are installed by hot-melt embedding.

[0007] Preferably, the BOSS hole has a diameter of 7.4 mm.

[0008] Preferably, the nut is a stainless steel nut of specification M5*L8.

[0009] Preferably, the nut is heated to 380° C. and then embedded into the BOSS hole by hot-melt embedding.

[0010] Preferably, the end face of the nut after embedding is flush with the end face of the BOSS hole.

[0011] Compared with the prior art, the beneficial effects of the utility model are:

[0012] The utility model discloses a structure for preventing stress cracking of a BOSS column, wherein a nut is placed on a heating table and heated to 380°C, and after the nut is heated, the nut is quickly embedded into the BOSS hole through a hot pressing tool, wherein the end face of the embedded nut is flush with the end face of the BOSS hole, and during the injection molding process, since there is no constraint of the corresponding different shrinkage rates of the insert nut, and the internal stress of the plastic part itself is not sufficient to cause stress cracking of the product, the BOSS hole and nut processed by hot melt can meet the design and use requirements after passing various tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a three-dimensional schematic diagram of the overall structure in the embodiment;

[0014] Figure 2 It is a front view of the overall structure in the embodiment;

[0015] Figure 3 for Figure 1 The enlarged schematic diagram at A in the middle;

[0016] Figure 4 It is a three-dimensional schematic diagram of the overall structure in the comparative example;

[0017] Figure 5 It is a front view of the overall structure in the comparative example;

[0018] Figure 6 for Figure 4 Enlarged schematic diagram of point B in the middle.

[0019] In the figure:

[0020] 1. Plastic parts; 2. BOSS hole; 3. Nut; 4. Reinforcement ribs; 5. Protective cover. DETAILED DESCRIPTION

[0021] The technical solution of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present utility model, rather than all of the embodiments.

[0022] The components of the embodiments of the present invention generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention.

[0023] Based on the embodiments of the present utility model, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present utility model.

[0024] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0025] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] Example:

[0027] See also Figures 1 to 3 The utility model provides a technical solution: a structure for preventing stress cracking of a BOSS column, comprising a plastic part 1 and a BOSS hole 2; a plurality of protruding BOSS holes 2 are provided on the plastic part 1, a plurality of reinforcing ribs 4 evenly distributed in a circular ring shape are provided on the outer wall of the BOSS hole 2, a protective cover 5 is provided on the outside of the reinforcing rib 4, a nut 3 is provided in the BOSS hole 2, and the nut 3 and the BOSS hole 2 are installed by hot melt embedding.

[0028] Furthermore, the diameter of the BOSS hole 2 is 7.4 mm.

[0029] Furthermore, the nut 3 is a stainless steel nut of specification M5*L8.

[0030] Furthermore, the nut 3 is heated to 380° C. and then embedded into the BOSS hole 2 by hot-melt embedding.

[0031] Furthermore, the end face of the embedded nut 3 is flush with the end face of the BOSS hole 2 .

[0032] In this embodiment, the BOSS hole 2, the reinforcing rib 4 and the protective cover 5 constitute a BOSS column structure, wherein the aperture of the BOSS hole 2 is 7.4 mm in diameter, and the nut 3 and the BOSS hole 2 are embedded in a hot-melt manner, and the nut 3 is placed on a heating table and heated to 380°C. After the nut 3 is heated, the nut 3 is quickly embedded in the BOSS hole 2 by a hot-pressing tool, wherein the end face of the embedded nut 3 is flush with the end face of the BOSS hole 2. During the injection molding process, since there is no constraint of the corresponding different shrinkage rates of the insert nut 3, and the internal stress of the plastic part 1 itself is not enough to cause stress cracking of the product, the BOSS hole 2 and the nut 3 processed by hot-melt can meet the design and use requirements after passing various tests;

[0033] The heating table is a loading table for devices that increase the temperature of objects, and the source is "Mechanical Engineering Terminology Volume 3"; hot melt embedding means that the nut 3 is embedded into the BOSS hole 2 through the embedding process after the nut 3 is heated; the reinforcing rib 4 and the protective sleeve 5 are used to protect and strengthen the BOSS hole 2, and the assembly method between the BOSS hole 2 and the nut 3 is interference fit;

[0034] The hot-melt embedded structure was subjected to a torque test, and the electric screwdriver was calibrated to 3.25-4N.m (the torque of the electric screwdriver has reached its limit). Each screw was tightened and loosened three times, and no thread slipping occurred.

[0035] The hot-melt embedded structure was subjected to a load-bearing test with a load of 28KG and a test time of 5 minutes. After the test, it was found that the BOSS column had no cracks, no holes, and no displacement of the screws.

[0036] Comparative Example:

[0037] A structure for preventing stress cracking of a BOSS column comprises a plastic part 1 and a BOSS hole 2; a plurality of protruding BOSS holes 2 are provided on the plastic part 1, a plurality of reinforcing ribs 4 evenly distributed in a circular ring shape are provided on the outer wall of the BOSS hole 2, a protective sleeve 5 is provided on the outside of the reinforcing rib 4, a nut 3 is provided in the BOSS hole 2, and the nut 3 and the BOSS hole 2 are installed by injection molding embedding.

[0038] Furthermore, the diameter of the BOSS hole 2 is 7.4 mm.

[0039] Furthermore, the nut 3 is a stainless steel nut of specification M5*L8.

[0040] Furthermore, the end face of the embedded nut 3 is flush with the end face of the BOSS hole 2 .

[0041] In this embodiment, the BOSS hole 2, the reinforcing rib 4 and the protective cover 5 constitute a BOSS column structure, wherein the aperture of the BOSS hole 2 is 7.4 mm in diameter, and the nut 3 and the BOSS hole 2 are installed by injection molding, and the nut 3 is embedded in the BOSS hole 2, wherein the end face of the embedded nut 3 is flush with the end face of the BOSS hole 2.

[0042] Comparison of Example and Comparative Example:

[0043] The embodiment mainly solves the design of the bonding process between the nut and the plastic part 1. The injection molding embedding method in the comparative example is changed to the hot melt embedding method in the embodiment. The nut 3 is placed on a heating table and heated to 380°C. After the nut 3 is heated, the nut 3 is quickly embedded into the BOSS hole 2 through a hot pressing tool, wherein the end face of the embedded nut 3 is flush with the end face of the BOSS hole 2. During the injection molding process, since there is no constraint of the corresponding different shrinkage rates of the insert nut 3, and the internal stress of the plastic part 1 itself is not enough to cause stress cracking in the product, the BOSS hole 2 and the nut 3 after hot melt processing can meet the design and use requirements after passing various tests.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A structure for preventing stress cracking of BOSS columns, characterized by: It includes a plastic part (1) and a BOSS hole (2); The plastic part (1) is provided with a plurality of protruding BOSS holes (2), the outer wall of the BOSS hole (2) is provided with a plurality of reinforcing ribs (4) evenly distributed in a circular ring shape, the outer part of the reinforcing rib (4) is provided with a protective sleeve (5), the BOSS hole (2) is provided with a nut (3), and the nut (3) and the BOSS hole (2) are installed by hot-melt embedding.

2. A structure for preventing BOSS column stress cracking according to claim 1, characterized in that: The diameter of the BOSS hole (2) is 7.4 mm.

3. A structure for preventing BOSS column stress cracking according to claim 1, characterized in that: The nut (3) is a stainless steel nut of specification M5*L8.

4. A structure for preventing BOSS column stress cracking according to claim 3, characterized in that: After being embedded, the end surface of the nut (3) is flush with the end surface of the BOSS hole (2).

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