A recessed fitment return air duct assembly

Abstract

The present application relates to the technical field of refrigeration system pipe assembly, and discloses a groove fitting type return air pipe assembly for refrigerator and freezer. The assembly comprises a return air pipe and a capillary tube, the outer wall of the return air pipe is provided with a groove, and the local pipe body of the capillary tube is embedded in the groove to form an arc surface fitting structure; the outer wall of the capillary tube is provided with an insulating anticorrosive coating, and the outer sides of the pipe sections of the two groups of pipes are covered with fastening coating layers. The present application changes the traditional pipe line contact into arc surface contact, effectively improves the heat exchange efficiency, and reduces the pipe material cost; the groove positioning and the fastening coating layer are combined to fix, the pipe fitting is firm, and the pipe is not easy to loosen and dislocate during processing and use; the insulating anticorrosive coating is used to isolate copper and aluminum dissimilar metals, block the electrochemical corrosion reaction, and effectively protect the aluminum return air pipe; the present application has simple and reasonable structure, saves the traditional aluminum foil bottoming protection process, is convenient for automatic batch production, and effectively improves the overall consistency and use reliability of the product.

Description

Technical Field

[0001] This invention relates to the field of refrigeration system piping components, specifically to a grooved, fitted return pipe assembly for refrigerators and freezers. Background Technology

[0002] In the refrigeration systems of household refrigerators and freezers, the return pipe is a crucial conduit connecting the evaporator and compressor. To improve refrigeration efficiency, the return pipe is typically installed parallel to and tightly fitted with a capillary tube to enhance heat exchange efficiency, forming a return pipe assembly. Current return pipe assemblies are commonly fixed using methods such as aluminum foil wrapping, heat shrink tubing wrapping, soldering, or laser welding.

[0003] The existing structure has many defects: the return pipe and capillary tube are in linear contact, resulting in a small heat exchange area and low efficiency. The length of the pipe needs to be increased to meet the heat exchange requirements, which leads to increased material costs and refrigerant charge. The wrapping and fixing method is not tight, and separation is easy to occur during subsequent processing such as pipe bending and forming, which affects the heat exchange effect. The return pipe is mostly made of aluminum and the capillary tube is mostly made of copper. The potential difference between the two metals is present in direct contact, which can easily cause electrochemical reactions in humid environments, resulting in rapid corrosion of the aluminum pipe. Conventional anti-corrosion requires first applying aluminum foil to the aluminum pipe and then wrapping it completely. The process is cumbersome, relies on manual operation, has low automation, poor product consistency, and high production costs. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a grooved return pipe assembly with high heat exchange efficiency, firm fit, good corrosion resistance and simple processing.

[0005] The technical solution adopted by the present invention to solve its technical problem is: a groove-fitting return air pipe assembly, including a return air pipe and a capillary tube, wherein a groove is formed on the outer wall of the return air pipe, and a portion of the capillary tube is embedded in the groove and forms an arc-shaped fitting structure with the inner wall of the groove; the outer wall of the capillary tube is provided with an insulating and anti-corrosion coating, and the outer side of the arc-shaped fitting structure is covered with a fastening coating layer.

[0006] Preferably, the return gas pipe is made of aluminum and the capillary tube is made of copper.

[0007] Preferably, the return air pipe, made of aluminum tubing, is integrally extruded using a continuous extrusion process.

[0008] Preferably, the capillary tube body forming the arc-shaped bonding structure is the bonding section of the capillary.

[0009] Preferably, the overall length of the capillary is longer than, equal to or shorter than the overall length of the return air pipe, and the capillary extending beyond the return air pipe constitutes an extension section; otherwise, there is no extension section.

[0010] Preferably, the extension section is bent and wound to form a spiral ring structure, or is arranged in a straight structure.

[0011] Preferably, the groove is an arc-shaped, U-shaped, or Ω-shaped structure.

[0012] Preferably, the number of grooves provided on the outer wall of the return air pipe is one, two, or more.

[0013] Preferably, the insulating and anti-corrosion coating is any one of water-based insulating varnish, polyimide varnish, or epoxy resin insulating varnish.

[0014] Preferably, the fastening covering layer is an aluminum foil tape layer or a heat shrink tubing layer.

[0015] The advantages of this invention are: This invention utilizes a capillary tube embedded in a groove on the outer wall of a return gas pipe to form an arc-shaped contact structure, changing the contact from line to surface, significantly improving heat exchange efficiency, shortening the parallel length of pipelines, and reducing material costs. The capillary tube is positioned by the groove and then secured with a tight-fitting coating, ensuring a firm fit and preventing separation of the capillary tube and return gas pipe during processing, thus guaranteeing stable heat exchange. The insulating and anti-corrosion coating on the outer wall of the capillary tube effectively isolates dissimilar metals such as copper and aluminum, blocking electrochemical reactions and preventing aluminum pipe corrosion at its source. This invention features a novel overall structure, eliminating the need for the aluminum foil underlayment process found in existing technologies, simplifying processing, facilitating automated production, and significantly improving product consistency and quality. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention, in which longer pipe sections are omitted from the drawing using large S-shaped wavy lines; Figure 2 for Figure 1 Schematic diagram of section AA; Figure 3 for Figure 1 A schematic diagram of the left-side view structure; Figure 4 This is a schematic diagram of the cross-section of the return air pipe of the present invention.

[0018] In the diagram: 1. Return air pipe; 1-1. Groove; 2. Capillary tube; 2-1. Spiral annular structure; 3. Fastening coating layer. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail. This application discloses a groove-fitting return air pipe assembly, including a return air pipe 1 and a capillary tube 2. A groove 1-1 is formed on the outer wall of the return air pipe 1. A portion of the capillary tube 2 is embedded in the groove 1-1 and forms an arc-shaped fitting structure with the inner wall of the groove 1-1. An insulating and anti-corrosion coating is provided on the outer wall of the capillary tube 2, and a fastening covering layer 3 is wrapped around the outside of the arc-shaped fitting structure.

[0021] The capillary tube 2 with its arc-shaped fitting structure is the fitting section of the capillary tube 2. In actual assembly and use, the overall length of the capillary tube 2 can be flexibly set according to the system matching, installation space and pipeline layout requirements. It can be set to be longer than the overall length of the return pipe 1, equal to the length of the return pipe 1, or shorter than the overall length of the return pipe 1.

[0022] When the overall length of capillary tube 2 is greater than the overall length of return pipe 1, the portion of capillary tube 2 that extends beyond return pipe 1 naturally forms an extension section; in the case where the length of capillary tube 2 is the same as or shorter than that of return pipe 1, the extension section structure is not present.

[0023] As a preferred embodiment, the extension section can be bent and wound to form a spiral ring structure 2-1, which saves installation space, buffers pipeline operation vibration, reduces operating noise, and improves the pipeline's resistance to bending and fatigue. Alternatively, the extension section can also maintain a straight structure to meet the requirements of conventional pipeline straight-line connection installation.

[0024] In this embodiment, the return gas pipe 1 is made of aluminum tubing and is integrally formed by the industry-standard continuous extrusion process, resulting in a seamless structure with high structural integrity and high forming precision. The capillary tube 2 is made of copper tubing, which has excellent thermal conductivity and meets the high-efficiency heat exchange requirements of the refrigeration system. The groove 1-1 on the outer wall of the return gas pipe 1 can be set as an arc, U-shaped, or Ω-shaped structure. The number of grooves 1-1 can be set as one, two, or more depending on the heat exchange specifications, which can adapt to the fitting and assembly requirements of single or multiple capillary tubes and has a wide range of applications.

[0025] The insulating and anti-corrosion coating on the outer wall of capillary tube 2 can be any one of water-based insulating varnish, polyimide varnish, or epoxy resin insulating varnish, forming reliable insulation, anti-oxidation, and anti-corrosion protection for the capillary surface. Simultaneously, this coating effectively isolates copper and aluminum, two dissimilar metals, blocking electrochemical reactions caused by metal potential differences. This fundamentally solves the corrosion problem of traditional aluminum tube structures, eliminating the need for the traditional aluminum foil undercoating process, significantly simplifying the production process, facilitating automated mass production, and effectively improving product consistency and production efficiency.

[0026] The fastening layer 3 uses an aluminum foil tape layer or a heat shrink tubing layer, which makes the wrapping operation simple, provides a good pressing and fixing effect, and can maintain the double tube fit for a long time.

[0027] During actual assembly and processing, the capillary tube 2 is first pretreated by coating its outer wall with an insulating and anti-corrosion coating and curing it to complete the surface protection treatment.

[0028] Subsequently, the capillary tube 2 is precisely embedded into the groove 1-1 of the return pipe 1. This abandons the traditional linear contact between round tubes and replaces it with a large-area arc-shaped contact with the groove 1-1, which effectively increases the heat exchange contact area and significantly improves the heat exchange efficiency. While achieving the same heat exchange performance, the parallel fitting length of the pipeline can be shortened, reducing the amount of pipe material used. At the same time, the overall volume occupied by the pipeline is reduced, and the amount of refrigerant added is reduced, effectively saving production and usage costs.

[0029] After the pipes are aligned and fitted, a tight-fitting covering layer 3 is applied to the outside of the double-pipe fitting section. Combined with the positioning and limiting function of the groove 1-1, this ensures that the return pipe 1 and capillary tube 2 are tightly compressed and seamlessly integrated. This effectively prevents problems such as pipe misalignment, loosening, and separation during subsequent pipe bending and assembly. It also maintains a stable heat exchange state even after long-term use, preventing heat exchange efficiency degradation and significantly improving the overall assembly reliability and service life of the return pipe 1 assembly.

[0030] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any equivalent transformations, improvements, and combinations made to the structure of the present invention within the scope of the present invention's design concept should fall within the scope of protection of the present invention.

Claims

1. A grooved fitting type return air pipe assembly, comprising a return air pipe and a capillary tube, characterized in that, The outer wall of the return pipe is provided with a groove, and a portion of the capillary tube is embedded in the groove and forms an arc-shaped fitting structure with the inner wall of the groove; the outer wall of the capillary tube is provided with an insulating and anti-corrosion coating, and the outer side of the arc-shaped fitting structure is covered with a fastening coating layer.

2. The groove-fitting return air pipe assembly according to claim 1, characterized in that: The return gas pipe is made of aluminum, and the capillary tube is made of copper.

3. The groove-fitting return air pipe assembly according to claim 2, characterized in that: The return gas pipe, made of aluminum tubing, is integrally extruded using a continuous extrusion process.

4. The groove-fitting return air pipe assembly according to claim 1, characterized in that: The capillary tube body that forms the arc-shaped bonding structure is the bonding section of the capillary.

5. The groove-fitting return air pipe assembly according to claim 4, characterized in that: The overall length of the capillary is longer than, equal to or shorter than the overall length of the return air pipe. The capillary extending beyond the return air pipe constitutes an extension section. In other cases, there is no extension section.

6. The groove-fitting return air pipe assembly according to claim 5, characterized in that: The extension section is bent and wound to form a spiral ring structure, or is set in a straight structure.

7. The groove-fitting return air pipe assembly according to claim 1, characterized in that: The groove is an arc-shaped, U-shaped, or Ω-shaped structure.

8. The groove-fitting return air pipe assembly according to claim 1, characterized in that: The number of grooves provided on the outer wall of the return air pipe can be one, two, or more.

9. The groove-fitting return air pipe assembly according to claim 1, characterized in that: The insulating and anti-corrosion coating is any one of water-based insulating varnish, polyimide varnish, or epoxy resin insulating varnish.

10. A groove-fitting return air pipe assembly according to claim 1, characterized in that: The fastening covering layer is an aluminum foil tape layer or a heat shrink tubing layer.

Images