Composite extrusion type cavity sound insulation block structure

Abstract

The utility model belongs to the technical field of injection molding products, and particularly relates to a composite extrusion type cavity sound insulation block structure which comprises a PA (Polyamide) framework, an EVA (Ethylene Vinyl Acetate) polystyrene foam layer and a PA plastic nail, the PA framework and the EVA polystyrene foam layer form an integrated structure through a composite extrusion process, and a PA plastic nail is arranged on the PA framework; the PA glue nail is used for being clamped in a single hole of the thermal expansion pipe, so that the sound insulation block is fixed to the end of the thermal expansion pipe. The integrated sound insulation block structure is formed through the PA and EVA composite extrusion technology, the single PA glue nail is used for being connected with the single hole of the heat expansion pipe in a clamped mode to achieve fixation, compared with a traditional double-hole injection molding structure, the heat expansion pipe machining procedure (double-hole machining is not needed) and the assembly process are obviously simplified, and the machining cost and the mold investment are reduced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to injection molding product technical field, concretely relates to a kind of composite extrusion type cavity sound insulation block structure. BACKGROUND

[0002] In the field of automobile manufacturing, the cavity sound insulation structure of the end of the heat expansion tube is an important part of the vehicle body noise reduction system. In the prior art, the PA (polyamide) and EVA (ethylene-vinyl acetate copolymer) sound insulation block arranged at the end of the heat expansion tube is usually made by injection molding process, which requires two mounting holes to be machined on the heat expansion tube, and the sound insulation block is fixed by clamping. This traditional scheme has the following technical defects:

[0003] Complex process: the heat expansion tube needs to be double-holed, which increases the machining process and precision requirements, and a complex mold structure is needed during the injection molding process, resulting in low production efficiency;

[0004] High cost: the complexity of double-hole machining and injection molding process not only increases equipment investment and processing time, but also increases material loss rate, which increases the overall production cost;

[0005] Installation is not convenient: the double-hole clamping structure requires high installation precision, and alignment deviation may occur during actual assembly, affecting the stability of the sound insulation block and the heat expansion tube.

[0006] To solve the above problems, although there are some improved schemes in the prior art, an optimized structure that considers process simplification and cost control has not been formed. Therefore, it is urgent to design a new sound insulation block structure that can reduce the machining process of the heat expansion tube, simplify the installation process and reduce the production cost. INVENTION CONTENTS

[0007] The utility model aims to provide a kind of composite extrusion type cavity sound insulation block structure to solve the problems in the background art.

[0008] To achieve the above-mentioned purpose, the utility model provides the following technical scheme: a kind of composite extrusion type cavity sound insulation block structure, including PA skeleton, EVA foamed adhesive layer and PA adhesive nail;The PA skeleton and EVA foamed adhesive layer form an integrated structure by composite extrusion process, and the PA skeleton is provided with PA adhesive nail;The PA adhesive nail is used for clamping in the single hole of the heat expansion tube, so that the sound insulation block is fixed to the end of the heat expansion tube.

[0009] Preferably, the PA skeleton is made of polyamide material by injection molding, and the EVA foamed adhesive layer is coated on the outer peripheral surface of the PA skeleton by extrusion process to form a PA-EVA composite structure.

[0010] Preferably, the PA adhesive nails are arranged at the end of the PA skeleton, and the number is one, which is matched with the single opening on the heat expansion tube.

[0011] Preferably, the PA adhesive nails are elastic structures, and the end is provided with a barb or a boss, which is in interference fit with the inner wall of the opening of the heat expansion tube.

[0012] Preferably, the cross section of the EVA foaming adhesive layer is arc-shaped or rectangular, and the thickness is 2-5mm, which is used for filling the gap and forming a sealed sound insulation layer.

[0013] Preferably, the PA skeleton is provided with a reinforcing rib, which is distributed along the length direction to enhance the structural strength.

[0014] The beneficial effects of the utility model are: the utility model forms an integrated sound insulation block structure through PA and EVA composite extrusion process, realizes fixation by using a single PA adhesive nail to clamp the single opening of the heat expansion tube, compared with the traditional double-hole injection molding structure, significantly simplifies the heat expansion tube processing procedure (no double-hole processing) and assembly process, reduces the mechanical processing cost and mold investment; the composite extrusion process improves the production efficiency, reduces the material loss at the same time, and reduces the overall cost; the elastic clamping structure of the PA adhesive nail ensures the installation precision and stability, the EVA foaming adhesive layer effectively fills the cavity to form a sealed sound insulation layer, synchronously ensures the sound insulation performance on the basis of simplifying the process, realizes the collaborative optimization of process, cost and performance. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a structural diagram of the utility model;

[0016] Figure 2 It is an exploded view of the utility model;

[0017] Figure 3 It is an application diagram of the utility model;

[0018] Figure 4 It is an application diagram of the utility model in another direction. DETAILED DESCRIPTION

[0019] In the description of the present disclosure, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the present disclosure.

[0020] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0022] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings and preferred embodiments.

[0023] like Figures 1-4 As shown, a composite extruded cavity sound insulation block structure includes a PA skeleton 1, an EVA foam layer 2, and PA adhesive nails 3. The PA skeleton and the EVA foam layer are integrated into a single structure through a composite extrusion process. PA adhesive nails are provided on the PA skeleton. The PA adhesive nails are used to snap into a single opening 41 of a thermal expansion tube 4, fixing the sound insulation block to the end of the thermal expansion tube. First, the PA skeleton is injection molded from polyamide (PA) material. A nail hole 11 is provided at the end of the skeleton for installing the PA adhesive nail 3, and a barbed boss 31 is provided at the end of the PA adhesive nail. The outer periphery of the PA skeleton is coated with an ethylene-vinyl acetate copolymer (EVA) foam layer through a composite extrusion process to form an arc-shaped cross-section structure with a thickness of 2-5mm. Reinforcing ribs are provided along the length of the skeleton to enhance rigidity. The semi-finished product after extrusion is trimmed at the edges by a punching process, so that the PA adhesive nails and the EVA foam layer form a precisely fitted integrated structure. A single hole 41 with a diameter matching the PA glue nail is made at the corresponding position of the thermal expansion tube. During installation, the PA glue nail is inserted into the hole, and the barbed boss forms an interference fit with the hole wall. At the same time, the EVA foam layer tightly abuts against the body sheet metal, filling the cavity between the thermal expansion tube and the sheet metal.

[0024] The structure realizes technical breakthrough through "single-hole clamping + composite extrusion": the PA glue nail utilizes the elastic barb structure to form mechanical locking with the single hole of the heat expansion tube, replaces the traditional double-hole clamping design, and reduces the heat expansion tube processing procedure; the composite extrusion process makes the PA skeleton and the EVA foaming glue layer form molecular-level combination, compared with the injection molding process, reduces the mold investment and material loss. After the sound insulation block is installed, the EVA foaming glue layer fills the cavity due to elastic deformation, blocks the air flow and noise propagation, and at the same time, the reinforcing rib structure of the PA skeleton ensures the overall anti-deformation ability. The single-hole fixing mode reduces the difficulty of installation alignment, the interference fit of the PA glue nail ensures the connection stability, the continuity of the composite extrusion process improves the efficiency, and finally realizes the synergistic effect of "process simplification - cost reduction - sound insulation performance optimization".

[0025] It should be noted that, for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should be considered within the scope of protection of the present application.

Claims

1. A composite extruded cavity sound insulation block structure, characterized in that: It includes a PA skeleton, an EVA foam layer, and PA adhesive nails; the PA skeleton and the EVA foam layer are integrated into a single structure through a composite extrusion process, and the PA skeleton is provided with PA adhesive nails; the PA adhesive nails are used to snap into a single opening in the thermal expansion tube, so that the sound insulation block is fixed to the end of the thermal expansion tube.

2. The composite extruded cavity sound insulation block structure according to claim 1, characterized in that: The PA skeleton is injection molded from polyamide material, and the EVA foam layer is coated onto the outer periphery of the PA skeleton through an extrusion process to form a PA-EVA composite structure.

3. The composite extruded cavity sound insulation block structure according to claim 1, characterized in that: The PA adhesive pin is located at the end of the PA frame, and there is only one of them, which is adapted to and snapped into a single opening on the thermal expansion tube.

4. The composite extruded cavity sound insulation block structure according to claim 1, characterized in that: The PA adhesive nail is an elastic structure with barbs or protrusions at its ends, forming an interference fit with the inner wall of the opening in the thermal expansion tube.

5. The composite extruded cavity sound insulation block structure according to claim 1, characterized in that: The cross-section of the EVA foam layer is arc-shaped or rectangular, and the thickness is 2-5mm. It is used to fill gaps and form a sealing and sound insulation layer.

6. The composite extruded cavity sound insulation block structure according to claim 1, characterized in that: The PA skeleton is provided with reinforcing ribs, which are distributed along the length direction to enhance the structural strength.

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