Connecting structure of reducing aluminum tube and copper capillary tube

Abstract

The utility model discloses a connecting structure of a reducing aluminum tube and a copper capillary tube, which relates to the technical field of evaporators, and comprises a reducing aluminum tube, the inner diameter of the reducing aluminum tube is gradually reduced from one end along the axial center line direction, and the minimum inner diameter range is 2.1-2.4 mm. The end of the reducing aluminum tube with the minimum inner diameter is connected with the copper capillary tube in a matched mode, and the copper capillary tube is connected with the copper capillary tube in a matched mode. The copper capillary pipe comprises a welding pipe part connected with the end, with the minimum inner diameter, of the reducing aluminum pipe in a matched mode, one end of the welding pipe part is connected with a limiting pipe part, one end of the limiting pipe part is connected with a main body pipe part, and the welding pipe part, the limiting pipe part and the main body pipe part form a Z-shaped pipeline structure. The variable-diameter aluminum pipe with the inner diameter gradually reduced can be directly subjected to flame brazing with the copper capillary pipe of the Z-shaped pipeline structure, traditional copper-aluminum resistance welding can be replaced, the machining difficulty is reduced, the number of welding spots can be further reduced, the abnormal problem that airflow noise is large is solved, and the product quality is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of evaporators, in particular to a connection structure of a variable diameter aluminum tube and a copper capillary tube. Background Art

[0002] An aluminum tube is wrapped around the outside of the inner tank of the freezer evaporator for heat exchange. The inlet end of the aluminum tube installed in most existing freezer evaporators needs to be connected to a copper capillary. The connection between the traditional freezer aluminum tube and the copper capillary is generally achieved by setting a copper transition tube. One end of the copper transition tube is resistance welded to the aluminum tube, and the other end is flame brazed to the copper capillary. However, due to the large potential difference between copper and aluminum, and the internal environment of the evaporator is often a humid environment with alternating hot and cold, electrochemical corrosion is very likely to occur between the two. In order to prevent corrosion at the connection between the two, the surface is usually painted or covered with a waterproof heat shrink tube. However, these methods generally have poor processability and reliability, and are still prone to corrosion and leakage. When a copper capillary with an outer diameter of 1.8 mm and an inner diameter of 0.65 mm is directly connected to a copper transition tube with an outer diameter of 4.75 mm, it is easy to generate a large airflow noise, which will undoubtedly directly affect the quality of the freezer and reduce the product experience. Utility Model Content

[0003] The utility model aims to provide a connection structure of a variable diameter aluminum tube and a copper capillary tube to solve the technical problems mentioned in the above background technology.

[0004] The technical problem to be solved by the utility model can be achieved through the following technical solutions:

[0005] A connection structure of a variable diameter aluminum tube and a copper capillary tube, comprising a variable diameter aluminum tube, the inner diameter of which gradually decreases from one end along the axial centerline direction, and the minimum inner diameter ranges from 2.1 to 2.4 mm, and the copper capillary tube is connected to one end of the variable diameter aluminum tube with the minimum inner diameter;

[0006] The copper capillary includes a welding pipe portion matched with one end of the variable diameter aluminum tube with the smallest inner diameter, one end of the welding pipe portion is connected to a limiting pipe portion, one end of the limiting pipe portion is connected to a main pipe portion, and the welding pipe portion, the limiting pipe portion and the main pipe portion constitute a Z-shaped pipeline structure.

[0007] As a further solution of the utility model: the specifications of the copper capillary are an outer diameter of 1.8 mm and an inner diameter of 0.65 mm.

[0008] As a further solution of the utility model: the specifications of the copper capillary are an outer diameter of 2.0 mm and an inner diameter of 0.71 mm.

[0009] As a further solution of the utility model: the matching depth of the reduced diameter aluminum tube and the copper capillary tube is 20 to 35 mm, and the reduced diameter aluminum tube and the copper capillary tube are connected by flame brazing.

[0010] As a further solution of the utility model: the combustible gas used in the flame brazing is low-temperature natural gas.

[0011] As a further solution of the utility model: the combustible gas used in the flame brazing is acetylene.

[0012] As a further solution of the utility model: a welding sealing layer is distributed between the variable diameter aluminum tube and the copper capillary, and the material of the welding sealing layer is zinc-aluminum solder paste.

[0013] As a further solution of the utility model: a protective sleeve is provided at the joint of the reduced diameter aluminum tube and the copper capillary tube, and the material of the protective sleeve is butyl rubber.

[0014] Beneficial effects of the utility model:

[0015] 1. The utility model can directly flame braze the variable diameter aluminum tube with gradually decreasing inner diameter with the copper capillary of the Z-shaped pipeline structure, which can replace the traditional copper-aluminum resistance welding and reduce the processing difficulty, and can further reduce the number of welding points, reduce the abnormal problem of large airflow noise, and improve product quality.

[0016] 2. The utility model directly connects the reduced diameter aluminum tube with the copper capillary tube, which is safe and reliable, reduces the use of copper transition tubes, reduces material costs, and has high applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The utility model is further described below in conjunction with the accompanying drawings.

[0018] Figure 1 It is a three-dimensional schematic diagram of the whole device in the utility model;

[0019] Figure 2 It is a schematic diagram of the copper capillary structure in the utility model;

[0020] Figure 3 This utility model Figure 2 Enlarged schematic diagram at point A in the middle.

[0021] In the figure: 1. Reduced diameter aluminum tube; 2. Copper capillary; 21. Welded tube; 22. Limiting tube; 23. Main tube; 3. Welding sealing layer; 4. Protective cover. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] like Figure 1-3 As shown, a connection structure of a variable diameter aluminum tube and a copper capillary tube comprises a variable diameter aluminum tube 1, the inner diameter of the variable diameter aluminum tube 1 gradually decreases from one end along the axial centerline direction, and the minimum inner diameter range is 2.1 to 2.4 mm. The variable diameter aluminum tube 1 can be obtained by rotating and knocking aluminum tubes with the same diameter through a dedicated machine tool processing equipment so that the specifications of the aluminum tubes reach the specified inner and outer diameter sizes. The end of the variable diameter aluminum tube 1 with the smallest inner diameter is equipped with a copper capillary tube 2. The connection between the variable diameter aluminum tube 1 and the copper capillary tube 2 forms a complete pipeline passage, which can effectively achieve the purpose of cold and heat exchange;

[0024] The copper capillary 2 includes a welding tube portion 21 matched with the minimum inner diameter end of the variable diameter aluminum tube 1, one end of the welding tube portion 21 is connected to a limiting tube portion 22, one end of the limiting tube portion 22 is connected to a main tube portion 23, and the welding tube portion 21, the limiting tube portion 22 and the main tube portion 23 constitute a Z-shaped pipeline structure. Through the Z-shaped pipeline structure, the insertion depth of the welding tube portion 21 can be constrained when it is inserted into the minimum inner diameter end of the variable diameter aluminum tube 1, thereby avoiding the matching depth being too deep or too shallow.

[0025] In this embodiment, specifically, the copper capillary 2 has an outer diameter of 1.8 mm and an inner diameter of 0.65 mm.

[0026] In this embodiment, specifically, the copper capillary 2 has an outer diameter of 2.0 mm and an inner diameter of 0.71 mm.

[0027] In the present embodiment, specifically, the fitting depth between the reducer aluminum tube 1 and the copper capillary 2 is 20 to 35 mm, and the reducer aluminum tube 1 and the copper capillary 2 are connected by flame brazing. The fitting depth of 20 to 35 mm set between the reducer aluminum tube 1 and the copper capillary 2 can effectively avoid welding blockage at the fitting port of the copper capillary 2 during flame brazing, thereby ensuring the normal use of the device.

[0028] In this embodiment, specifically, the combustible gas used in flame brazing is low-temperature natural gas. Low-temperature natural gas generally refers to liquefied natural gas, which is a form of natural gas that is cooled to an extremely low temperature and becomes a liquid, and can be used for flame brazing.

[0029] In this embodiment, specifically, the combustible gas used in flame brazing is acetylene. Acetylene is an organic compound with a chemical formula of C2H2, commonly known as wind coal or calcium carbide gas. It is a colorless gas at room temperature and pressure, slightly soluble in water, soluble in ethanol, acetone, chloroform, benzene, and miscible in ether, and is used for flame brazing.

[0030] In this embodiment, specifically, a welding sealing layer 3 is distributed between the reduced diameter aluminum tube 1 and the copper capillary 2. The material of the welding sealing layer 3 is zinc-aluminum solder paste. When flame brazing is performed at the joint of the reduced diameter aluminum tube 1 and the copper capillary 2, the zinc-aluminum solder paste can be melted to form a connection between the aluminum tube 1 and the copper capillary 2, thereby ensuring the stability and sealing of the two when they are connected.

[0031] In the present embodiment, specifically, a protective sleeve 4 is provided at the joint of the variable diameter aluminum tube 1 and the copper capillary 2. The material of the protective sleeve 4 is butyl rubber. The protective sleeve 4 can protect the joint of the variable diameter aluminum tube 1 and the copper capillary 2, protect the welding point from copper-aluminum corrosion and reduce noise, and can effectively reduce the airflow noise.

[0032] The working principle of the utility model is as follows: when the device is in use, the staff can insert the welding pipe part 21 into the end of the smallest inner diameter of the variable diameter aluminum tube 1, and the Z-shaped pipeline structure composed of the welding pipe part 21, the limiting pipe part 22 and the main pipe part 23 can be used to constrain the insertion depth, and then the zinc-aluminum solder paste can be melted during flame brazing, so as to weld the aluminum tube 1 and the copper capillary 2.

[0033] The above is a detailed description of an embodiment of the utility model, but the content is only a preferred embodiment of the utility model and cannot be considered to limit the scope of implementation of the utility model. All equivalent changes and improvements made within the scope of application of the utility model should still fall within the scope of the patent coverage of the utility model.

Claims

1. A connection structure of a variable diameter aluminum tube and a copper capillary tube, characterized in that: It comprises a variable diameter aluminum tube (1), the inner diameter of the variable diameter aluminum tube (1) gradually decreases from one end along the axial centerline direction, and the minimum inner diameter ranges from 2.1 to 2.4 mm, and the end of the variable diameter aluminum tube (1) with the smallest inner diameter is connected to a copper capillary tube (2); The copper capillary tube (2) comprises a welding tube portion (21) matched with the smallest inner diameter end of the variable diameter aluminum tube (1); one end of the welding tube portion (21) is connected to a limiting tube portion (22); one end of the limiting tube portion (22) is connected to a main body tube portion (23); the welding tube portion (21), the limiting tube portion (22) and the main body tube portion (23) form a Z-shaped pipeline structure.

2. The connection structure of a variable diameter aluminum tube and a copper capillary tube according to claim 1, characterized in that: The copper capillary (2) has an outer diameter of 1.8 mm and an inner diameter of 0.65 mm.

3. The connection structure of a variable diameter aluminum tube and a copper capillary tube according to claim 1, characterized in that: The copper capillary (2) has an outer diameter of 2.0 mm and an inner diameter of 0.71 mm.

4. The connection structure of a variable diameter aluminum tube and a copper capillary tube according to claim 1, characterized in that: The matching depth between the reduced diameter aluminum tube (1) and the copper capillary tube (2) is 20 to 35 mm, and the reduced diameter aluminum tube (1) and the copper capillary tube (2) are connected by flame brazing.

5. The connection structure of a variable diameter aluminum tube and a copper capillary tube according to claim 4, characterized in that: The combustible gas used in the flame brazing is low-temperature natural gas.

6. The connection structure of a variable diameter aluminum tube and a copper capillary tube according to claim 4, characterized in that: The combustible gas used in the flame brazing is acetylene.

7. The connection structure of a variable diameter aluminum tube and a copper capillary tube according to claim 1, characterized in that: A welding seal layer (3) is distributed between the reduced diameter aluminum tube (1) and the copper capillary tube (2), and the material of the welding seal layer (3) is zinc-aluminum solder paste.

8. The connection structure of a variable diameter aluminum tube and a copper capillary tube according to claim 1, characterized in that: A protective sleeve (4) is provided at the joint between the reduced diameter aluminum tube (1) and the copper capillary tube (2), and the material of the protective sleeve (4) is butyl rubber.

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