Enhanced anti-corrosion type copper horn mouth gasket for air conditioner connecting pipe

Abstract

The invention discloses a reinforced anti-corrosion type copper horn mouth gasket for an air conditioner connecting pipe, and relates to the technical field of metal pipe fitting connection, the reinforced anti-corrosion type copper horn mouth gasket comprises a copper horn mouth gasket body, the copper horn mouth gasket body is embedded in the conical interior of an aluminum pipe horn mouth, and the gasket is made of a copper material with the compressive strength higher than that of an aluminum pipe. Interference fit is formed with the inner wall of the aluminum pipe horn mouth; a metal-based anti-corrosion coating is applied to the surface of the outer diameter of the copper horn mouth gasket, a stable physical isolation layer is formed, an electrochemical corrosion path generated by a copper-aluminum contact interface is blocked, and the service life of the connecting pipe is fundamentally prolonged. The structure has the double functions of strength enhancement and corrosion prevention, the lining stamping nesting and coating coating process is mature, large-scale production is easy, and a high-reliability and low-cost aluminum connecting pipe solution is provided for an air conditioning system.

Description

Technical Field

[0001] This invention relates to the field of metal pipe connection technology, specifically to an enhanced corrosion-resistant copper flared gasket for air conditioning connection pipes. Background Technology

[0002] Air conditioning connecting pipes are key components in refrigeration systems, connecting indoor and outdoor units and responsible for refrigerant transport. Traditional copper connecting pipes are gradually being replaced by aluminum connecting pipes due to cost and environmental concerns.

[0003] The existing air conditioning connection pipes have the following technical problems:

[0004] Structural strength defects: Aluminum is relatively soft, and the flared mouth is prone to plastic deformation during installation and fastening, leading to sealing failure and refrigerant leakage;

[0005] Electrochemical corrosion risk: When aluminum pipes are connected to copper valves and copper nuts in the system, the significant potential difference (about 0.5V) between copper and aluminum can cause electrochemical corrosion in humid environments, accelerating the failure of the connection interface.

[0006] Existing improvement solutions, such as simply increasing the wall thickness of the aluminum tube, sacrifice the advantage of lightweight construction, while localized plating treatments struggle to simultaneously address the deformation of the flared end and the corrosion protection of the threaded contact surface. Therefore, a technical solution is designed to simultaneously improve the structural strength and electrochemical corrosion resistance of the aluminum flared end, ensuring the long-term sealing and reliability of the air conditioning system. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides an enhanced corrosion-resistant copper flared gasket for air conditioning connecting pipes, thus solving the technical problems mentioned in the background section.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solution: an enhanced corrosion-resistant copper flared gasket for air conditioning connecting pipes, comprising a copper flared gasket body;

[0009] The inner side of the aluminum tube flare is tightly nested with a copper flare gasket. The copper flare gasket is made of copper material with higher compressive strength than aluminum and forms an interference fit with the inner wall of the aluminum tube flare.

[0010] The outer diameter surface of the copper flared gasket body is covered with an anti-corrosion coating, which is a Dacromet coating or one of electroplated zinc, nickel, chromium, tin, or zinc-nickel alloy.

[0011] Preferably, the liner is made of stainless steel, copper alloy or high-strength engineering plastic.

[0012] Preferably, the thickness of the anti-corrosion coating is 20-50 μm, and it is dried and cured to form a dense isolation layer.

[0013] Preferably, the lining has a thickness of 0.4 to 1.5 mm and is pre-formed into a conical structure by a stamping and stretching process.

[0014] Preferably, the lining is coated with a Dacromet coating or an electroplated zinc, nickel, chromium, tin, or zinc-nickel alloy.

[0015] Beneficial effects

[0016] This invention provides a reinforced, corrosion-resistant copper flared gasket for air conditioning connecting pipes. By nesting a high-strength, corrosion-resistant copper flared gasket inside the flared end of the aluminum pipe, this invention significantly improves the interface's resistance to deformation, effectively preventing plastic deformation and refrigerant leakage risks caused by installation tightening or vibration. Simultaneously, a metal-based anti-corrosion coating (Dacromet / galvanized / tin-plated) is applied to the outer diameter surface of the flared gasket, forming a stable physical isolation layer that blocks the electrochemical corrosion path at the copper-aluminum interface, fundamentally extending the service life of the connecting pipe. This structure combines the dual functions of strength enhancement and corrosion protection, and the inner liner stamping and coating processes are mature and easy to mass-produce, providing a highly reliable and low-cost aluminum connecting pipe solution for air conditioning systems. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the reinforced corrosion-resistant copper flared gasket for air conditioning connecting pipes according to the present invention.

[0018] In the figure: 1. Anti-corrosion coating on the outer surface of the copper flared mouth gasket; 2. The body of the copper flared mouth gasket; 3. The aluminum tube flared mouth. 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] Please see Figure 1 This invention provides a technical solution: a reinforced and corrosion-resistant copper flared gasket body 2 for air conditioning connecting pipes.

[0021] The inner side of the aluminum tube flared mouth 3 is tightly nested with a copper flared mouth gasket 2. The copper flared mouth gasket 2 is made of a metal or non-metal wear-resistant material with a compressive strength higher than that of aluminum, and forms an interference fit with the inner wall of the flared mouth.

[0022] The outer diameter surface of the copper flared gasket 2 is covered with an anti-corrosion coating 1, which is one of Dacromet coating, zinc plating, or tin plating.

[0023] In this embodiment, the copper flared gasket 2 is further configured to be made of stainless steel, copper alloy, or high-strength engineering plastic.

[0024] In this embodiment, the anti-corrosion coating 1 is further configured to have a thickness of 20-50 μm and is dried and cured to form a dense isolation layer.

[0025] In this embodiment, the copper flared mouth gasket 2 is further configured to have a thickness of 0.4 to 1.5 mm and is pre-formed into a conical structure by a stamping and stretching process.

[0026] In this embodiment, the anti-corrosion coating 1 is further configured to be a Dacromet coating, or an electroplated zinc, nickel, chromium, tin, or zinc-nickel alloy.

[0027] Its detailed connection method is a well-known technology in this field. The following mainly introduces the working principle and process, and the specific work is as follows.

[0028] Example: Example 1: Copper-based gasket + Dacromet coating solution

[0029] Structural parameters

[0030] Aluminum tube flared mouth (3): outer diameter Φ16mm (suitable for household wall-mounted air conditioner aluminum connecting pipe), wall thickness 1.0mm.

[0031] Copper bell mouth gasket (2):

[0032] Material: T2 copper plate (compressive strength ≥200MPa, higher than aluminum's 80MPa);

[0033] Thickness: 0.8mm;

[0034] Prefabrication process: First, electroplat a zinc layer (15μm thick) on the surface of the copper material → stamp and stretch it into a conical sleeve → the inner lining outer conical surface and the inner conical surface of the flared mouth have an interference fit of 0.05mm.

[0035] Anti-corrosion coating (1):

[0036] Type: Dacromet coating (zinc aluminum chromate);

[0037] Coating area: outer diameter surface of the flared end (area in contact with the copper nut);

[0038] Thickness: 30μm±5μm;

[0039] Curing process: Dry at 200℃ for 20 minutes.

[0040] Strength Enhancement Verification

[0041] Test method: Axial crush test is performed on the flared openings before and after the nested gasket (GB / T1048-2019).

[0042] result:

[0043] Sample compressive strength (kN) improvement rate

[0044] Unlined aluminum flared mouthpiece 3.2 —

[0045] 6.5 103% with copper lining

[0046] Corrosion resistance verification

[0047] Test method: Salt spray test of copper-aluminum connectors (GB / T 10125-2021), 35℃ / 5% NaCl solution.

[0048] result:

[0049] Time of first rust appearance on the sample (h)

[0050] Uncoated aluminum flared mouth + copper nut 24

[0051] Dacromet coating sample >120

[0052] Example 2: Stainless steel lining + tin plating solution

[0053] Structural parameters

[0054] Gasket (2): SUS304 stainless steel (1.2mm thick), cold-pressed after laser cutting, with an interference of 0.08mm.

[0055] Anti-corrosion coating (1):

[0056] Type: Electroplated tin layer;

[0057] Thickness: 25μm;

[0058] Electroplating process: Alkaline tin plating solution (temperature 40℃), current density 2A / dm³ 2 .

[0059] Technical effect

[0060] Compressive strength: increased from 3.2kN to 7.1kN (↑122%);

[0061] Salt spray corrosion resistance: >100 hours with no substrate corrosion (only slight oxidation of the coating).

[0062] Explanation of the correspondence with the claims

[0063] Key points covered by the claims embodiments

[0064] Right 1: Inner lining with interference fit + outer diameter anti-corrosion coating

[0065] Item 2: Lining material (copper / stainless steel)

[0066] 3. Coating thickness (30μm / 25μm) and curing process

[0067] Weight 4: Lining thickness (0.8mm / 1.2mm) + stamping and stretching prefabrication

[0068] Claim 5: Copper material pre-galvanized → stamping → nesting (Core of Example 1)

[0069] Technical effect implementation principle

[0070] Strength enhancement mechanism:

[0071] The high-strength inner lining (copper / stainless steel) bears more than 60% of the bolt tightening stress and inhibits the plastic deformation of the aluminum body;

[0072] The interference fit generates radial compressive stress, which increases the overall stiffness.

[0073] Corrosion-resistant synergistic design:

[0074] Pre-plated inner lining (right 5): blocks direct copper-aluminum contact (electrochemical corrosion source);

[0075] Outer diameter coating: isolates Cl- / H2O from the environment (electrochemical corrosion source), and the double protection reduces the corrosion current density by more than 90%.

[0076] It should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

Claims

1. A reinforced corrosion-resistant copper flared gasket for air conditioning connecting pipes, comprising a copper flared gasket body (2), characterized in that: The aluminum tube flared mouth (3) is tightly nested with a copper flared mouth gasket (2). The inner gasket (2) is made of copper material with higher compressive strength than aluminum, and forms an interference fit with the inner wall of the flared mouth. The outer diameter surface of the copper flared gasket (2) is covered with an anti-corrosion coating (1), which is one of Dacromet coating, zinc plating or tin plating.

2. The reinforced corrosion-resistant copper flared gasket for air conditioning connecting pipes according to claim 1, characterized in that, The material of the pad body (2) is stainless steel, copper alloy or high-strength engineering plastic.

3. The reinforced corrosion-resistant copper flared gasket for air conditioning connecting pipes according to claim 1, characterized in that, The thickness of the anti-corrosion coating (1) of the gasket is 20-50 μm, and it is dried and cured to form a dense isolation layer.

4. The reinforced corrosion-resistant copper flared gasket for air conditioning connecting pipes according to claim 1, characterized in that, The thickness of the pad body (2) is 0.4 to 1.5 mm, and it is pre-formed into a conical structure by stamping and stretching process.

5. The reinforced corrosion-resistant copper flared gasket for air conditioning connecting pipes according to claim 1, characterized in that, The anti-corrosion coating (1) of the gasket is made by coating the surface with Dacromet or electroplating with zinc, nickel, chromium, tin, zinc-nickel alloy, etc.

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