Electric appliance box composite outer cover

Abstract

This utility model relates to a composite outer cover for an electrical box. The outer cover includes a steel outer shell and a plastic inner liner. The steel outer shell includes an inwardly recessed cavity and a flange extending outward along the opening of the cavity. The plastic inner liner is laminated within the cavity of the steel outer shell and connected to the flange. The composite outer cover for an electrical box provided by this utility model is composed of a steel outer shell and a plastic inner liner, possessing both the excellent structural strength, weather resistance, and fire resistance of the steel outer shell, and the insulating properties of the plastic inner liner, which reduces the likelihood of short circuits in electrical components, thus meeting new industry electrical standards.

Description

Technical Field

[0001] This utility model relates to electrical equipment components, and in particular to a composite outer cover for an electrical box. Background Technology

[0002] Electrical equipment often has a rectangular electrical box, which houses circuit boards, electrical components, cables, etc. After these electrical components are installed, the electrical box cover is placed on top of the electrical box and secured to the box with four screws to protect the internal electrical components.

[0003] Traditional electrical appliance box covers are made of either plastic or metal. The main problems with injection-molded plastic electrical appliance box covers are their weak structural strength and insufficient flame retardancy or fire resistance. Furthermore, for electrical equipment installed outdoors, plastic electrical appliance box covers lack sufficient resistance to ultraviolet radiation and aging. Metal electrical appliance box covers are made from color-coated steel sheets with galvanized or aluminized zinc plating as the base material, offering good structural strength, corrosion resistance, aging resistance, and fire resistance. However, they pose a risk of short circuits to internal electrical components and do not meet relevant industry electrical standards. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a composite outer cover for an electrical box made of metal and plastic, which addresses the above-mentioned shortcomings.

[0005] This utility model is achieved through the following technical solution:

[0006] An electrical box composite cover includes a steel outer shell and a plastic inner liner. The steel outer shell includes an inwardly recessed cavity and a flange extending outward along the opening of the cavity. The plastic inner liner is composited within the cavity of the steel outer shell and connected to the flange.

[0007] Furthermore, in the aforementioned composite outer cover for an electrical box, the flange is provided with a plurality of mounting and fixing holes evenly distributed.

[0008] Furthermore, in the aforementioned composite outer cover for an electrical box, a plurality of connecting holes are evenly provided on the flange for connection with the plastic liner.

[0009] Furthermore, in the aforementioned composite outer cover for an electrical box, the connecting hole is a flared shape extending outward from the flange surface.

[0010] Furthermore, in the aforementioned composite outer cover for an electrical box, the connecting hole includes a neck and a tapered top, one end of the neck is vertically connected to the flange surface, and the small end of the tapered top is connected to the other end of the neck.

[0011] Furthermore, in the aforementioned composite outer cover for an electrical box, the height of the connecting hole does not exceed 4 / 5 of the thickness of the plastic liner.

[0012] Furthermore, in the aforementioned composite outer cover for an electrical box, the plastic liner has the same outline shape as the steel outer shell and is completely fitted to the inner side of the steel outer shell.

[0013] Furthermore, in the aforementioned composite outer cover for an electrical box, the steel outer shell with an outwardly curved flange is placed in the cavity of an injection mold, and polycarbonate material is directly injection molded onto the cavity and the flange of the steel outer shell to form the plastic liner. The plastic liner is then connected to the connecting hole. The outwardly curved flange of the steel outer shell is straightened by the cooled and contracted polycarbonate material to form the composite outer cover.

[0014] Furthermore, in the aforementioned composite outer cover for an electrical box, the steel outer shell has a rectangular structure, and each of the four corners of the flange has a mounting hole, while several connection holes are evenly distributed on the four sides of the flange.

[0015] Furthermore, in the aforementioned composite outer cover for an electrical box, the steel outer shell is made of color steel sheet stamped with galvanized sheet or aluminized zinc sheet as the base material.

[0016] The advantages and effects of this utility model are:

[0017] 1. The composite outer cover of the electrical box provided by this utility model is composed of a steel outer shell and a plastic inner liner. It has the excellent structural strength, weather resistance and fire resistance of the steel outer shell, and the insulation and short circuit prevention of electrical components of the plastic inner liner, so as to meet the new industry electrical standards.

[0018] 2. The composite outer cover of the electrical box provided by this utility model has a plastic liner directly injection molded inside the steel shell. The process is simple and efficient. The steel shell and the plastic liner are firmly connected together through the connecting holes, which is firm and reliable and eliminates the risk of glue cracking and detachment.

[0019] 3. The flange of the steel outer shell of the composite cover of the electrical box provided by this utility model is pre-set to bend in the opposite direction, which solves the problem that the plastic liner is subjected to internal stress due to shrinkage and obstruction by the connecting hole of the steel outer shell during the injection molding solidification process, causing the steel outer shell to bend. This results in a straight flange, which is conducive to sealing and fixing with the electrical box. Attached Figure Description

[0020] Figure 1 A front view of the composite outer cover provided by this utility model is shown;

[0021] Figure 2 A reverse side view of the composite outer cover provided by this utility model is shown;

[0022] Figure 3 This diagram illustrates the separation of the steel outer shell and the plastic inner liner of the composite cover provided by this utility model.

[0023] Figure 4 A schematic diagram of the steel outer shell of the composite cover provided by this utility model is shown;

[0024] Figure 5 A side view of the steel outer shell of the composite cover provided by this utility model is shown;

[0025] Figure 6 A cross-sectional view of the outer shell of the composite cover provided by this utility model is shown;

[0026] Figure 7 This diagram illustrates the connection between the steel outer shell and the plastic inner liner of the composite cover provided by this utility model.

[0027] Explanation of reference numerals in the attached drawings: 1-Steel outer shell, 2-Plastic inner liner, 3-Cavity, 4-Flange, 5-Mounting and fixing hole, 6-Connection hole, 6a-Neck of hole, 6b-Top of tapered hole. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of the embodiments of this utility model will be described in more detail below with reference to the accompanying drawings. The described embodiments are only some, not all, of the embodiments of this utility model. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model. The embodiments of this utility model will be described in detail below with reference to the accompanying drawings:

[0029] In the description of this utility model, it should be understood that, unless otherwise stated, "a plurality of" means two or more; the terms "center," "longitudinal," "lateral," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and 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, and therefore should not be construed as a limitation on the scope of protection of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "joined" should be interpreted broadly, for example, as fixed connections, detachable connections, or integral connections; they can be direct connections or indirect connections through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0030] like Figures 1 to 3 As shown, the composite outer cover of the electrical box includes a steel outer shell 1 and a plastic inner liner 2 embedded within the steel outer shell 1. The steel outer shell 1 includes an inwardly recessed cavity 3 and a flange 4 extending outward along the opening of the cavity 3. The extending plane of the flange 4 is perpendicular to the depth direction of the cavity 3. Here, "inward" and "outward" are two opposite directions; the recessed direction of the cavity 3 is inward relative to the steel outer shell 1, and the opposite direction is outward relative to the steel outer shell 1. Specifically, the steel outer shell 1 is stamped from a color steel plate with galvanized or aluminized zinc plate as the base material, and can be integrally formed. Preferably, the thickness of the steel outer shell 1 is 0.8 mm, and the external dimensions of the steel outer shell 1 are 250 mm x 130 mm, wherein the depth of the cavity 3 is 30 mm and the width of the flange 4 is 15 mm.

[0031] The plastic liner 2 is laminated within the cavity 3 of the steel outer shell 1 and connected to the flange 4. Specifically, the plastic liner 2 has the same outline shape as the steel outer shell 1 and is completely fitted to the inner surface of the steel outer shell 1. Here, the inner surface of the steel outer shell 1 is the surface formed by the cavity and flange on one side of the cavity portion of the cavity 3, and its opposite side surface is the outer surface of the steel outer shell 1. The plastic liner 2 is made of polycarbonate (PC), has a flame retardant rating of UL94 V-0, and contains a UV stabilizer; its thickness is preferably 1.5 mm.

[0032] like Figure 4As shown, the flange 4 is evenly provided with a plurality of mounting holes 5 and a plurality of connecting holes 6. The mounting holes 5 are used to fix the composite outer cover of the electrical box to the electrical box with screws, and the connecting holes 6 are used to connect the steel outer shell 1 to the plastic inner liner 2. In one embodiment, the steel outer shell 1 has a rectangular structure, and a mounting hole 5 is provided at each of the four corners of the flange 4, and a plurality of connecting holes 6 are evenly distributed on the four sides of the flange 4. Preferably, the diameter of the mounting hole 5 is 6 mm; the height of the connecting hole 6 is 1.2 mm.

[0033] like Figure 5 , 6 As shown, the connecting hole 6 is a trumpet shape extending outward from the surface of the flange 4. Specifically, the connecting hole includes a neck 6a and a tapered top 6b connected to the neck 6a. The neck 6a is a cylindrical structure and is perpendicularly connected to the flange 4. The tapered top 6b is a tapered structure. One end of the neck 6a is perpendicularly connected to the surface of the flange 4, the smaller end of the tapered top 6b is connected to the other end of the neck 6a, and the larger end of the tapered top 6b extends outward.

[0034] like Figure 7 As shown, the plastic liner 2 is produced using injection molding. A pre-designed steel outer shell with an outwardly curved flange is placed inside the injection mold cavity. Polycarbonate material is then directly injection molded onto the cavity and flange of the steel outer shell to form the plastic liner. Simultaneously, the polycarbonate material wraps around the connecting hole. After cooling, the plastic liner connects to the connecting hole, thus connecting the steel outer shell and the plastic liner together. During the cooling process, the outwardly curved flange of the pre-designed steel outer shell is straightened by the cooling and shrinking polycarbonate material, forming the steel outer shell 1, thus obtaining the composite outer cover. The height of the connecting hole 6 does not exceed 4 / 5 of the thickness of the plastic liner 2. During the injection molding production of the plastic liner 2, the mounting fixing hole 5 also serves to position the steel outer shell when it is placed inside the injection mold cavity.

[0035] In one embodiment, the steel outer shell 1 has a rectangular structure, including two long-side flanges and two short-side flanges. Specifically, before manufacturing the plastic liner 2, the long-side flanges of the pre-designed steel outer shell have an outward curvature. During the cooling process of the injection molding of the plastic liner 2, the shrinkage of the polycarbonate material is restricted by the connecting holes on the steel outer shell, resulting in significant internal stress, causing the two long-side flanges of the steel outer shell to bend inward. Therefore, the two long-side flanges of the steel outer shell are pre-deformed with a reverse arc shape to counteract the bending deformation caused by internal stress during the injection molding process, thereby obtaining straight long-side flanges. The reverse pre-deformation on the two long-side flanges is a smooth arc shape with a chord height of 2.5 mm.

[0036] The above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit the scope of implementation of this utility model. Any equivalent changes and modifications made within the protection scope of this utility model should be considered to fall within the protection scope of this utility model.

Claims

1. A composite outer cover for an electrical appliance box, characterized in that, The composite cover includes a steel outer shell and a plastic inner liner. The steel outer shell includes an inwardly recessed cavity and a flange extending outward along the opening of the cavity. The plastic inner liner is composited within the cavity of the steel outer shell and connected to the flange.

2. The composite outer cover for an electrical box according to claim 1, characterized in that, The flange is provided with several mounting and fixing holes evenly spaced.

3. The composite outer cover for an electrical box according to claim 1 or 2, characterized in that, The flange is provided with several evenly spaced connection holes for connecting with the plastic liner.

4. The composite outer cover for an electrical box according to claim 3, characterized in that, The connection hole is flared outward from the flange surface.

5. The composite outer cover for an electrical box according to claim 4, characterized in that, The connecting hole includes a neck and a tapered top. One end of the neck is vertically connected to the flange surface, and the small end of the tapered top is connected to the other end of the neck.

6. The composite outer cover for an electrical box according to claim 3, characterized in that, The height of the connecting hole does not exceed 4 / 5 of the thickness of the plastic liner.

7. A composite outer cover for an electrical box according to claim 1 or 2, characterized in that, The plastic liner has the same outline shape as the steel outer shell and fits completely against the inner side of the steel outer shell.

8. The composite outer cover for an electrical box according to claim 3, characterized in that, The steel housing with an outwardly curved flange is placed in the cavity of an injection mold. Polycarbonate material is directly injection molded onto the cavity and the flange of the steel housing to form the plastic liner. The plastic liner is then connected to the connecting hole. The outwardly curved flange of the steel housing is straightened by the cooled and contracted polycarbonate material to form the composite cover.

9. The composite outer cover for an electrical box according to claim 1, characterized in that, The steel outer shell has a rectangular structure, and each of the four corners of the flange has a mounting hole, while several connection holes are evenly distributed on the four sides of the flange.

10. The composite outer cover for an electrical box according to claim 1, characterized in that, The steel outer shell is made of color steel plate stamped with galvanized sheet or aluminum-zinc plate as the base material.

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