Piston for a variable displacement automotive air conditioning compressor

Abstract

The utility model discloses a piston of automobile variable displacement air conditioning compressor, including piston cylinder, the inside of piston cylinder is provided with hollow chamber, the fixed honeycomb body in hollow chamber, fixed with a plurality of connecting rings between honeycomb body and piston cylinder, the outer ring of piston cylinder is provided with a plurality of mounting grooves, and a sealing mechanism is installed in each mounting groove, and the sealing mechanism includes: wear -resisting alloy ring, shape memory alloy expansion ring and elastic graphite ring, elastic graphite ring is directly installed in the mounting groove of piston cylinder outer ring, the outside of elastic graphite ring is fixed with shape memory alloy expansion ring, and the outside of shape memory alloy expansion ring is fixed with wear -resisting alloy ring. The utility model discloses through hollow chamber inside piston cylinder collocation aluminum alloy honeycomb body, connecting ring and the structural design of reinforcing rib, while significantly reducing the weight of piston, with the help of sandwich effect, the bending -resistant, torsional stiffness is improved, can avoid component relative deformation and scatter radial pressure.

Description

Technical Field

[0001] This utility model relates to the field of compressor piston technology, and in particular to the piston of an automotive variable displacement air conditioning compressor. Background Technology

[0002] The piston is a key component of a variable displacement compressor. Its main function is to drive the outer ring of the swashplate to reciprocate through the rotation of the main shaft. This reciprocating motion allows the refrigerant inside the compressor to be drawn in and compressed, facilitating the exchange of refrigerant. The drawn-in refrigerant is then compressed by the compressor, becoming a high-temperature, high-pressure medium before being discharged.

[0003] In practical applications of automotive variable displacement air conditioning compressors, pistons must withstand complex conditions such as high-frequency reciprocating motion, high-pressure impact, and temperature fluctuations over extended periods. Existing piston structures have significant shortcomings: Firstly, traditional solid pistons are heavy, resulting in high reciprocating inertial forces, which not only increase engine drive load but also exacerbate wear on transmission components. Conversely, purely hollow pistons lack sufficient bending and torsional stiffness, leading to relative component deformation and radial pressure concentration over long-term use, affecting compressor operational stability. Secondly, piston sealing mechanisms often employ single-material or simple combination structures, making it difficult to balance wear resistance and sealing performance. This results in either rapid wear due to insufficient wear layer strength or refrigerant leakage due to poor seal fit. Furthermore, they cannot adapt to dimensional fluctuations caused by temperature changes, further reducing cooling efficiency and piston lifespan. Therefore, in response to these shortcomings... There is an urgent need to develop a structural design that combines a hollow internal cavity with an aluminum alloy honeycomb structure, connecting rings, and reinforcing ribs. This design significantly reduces piston weight while enhancing bending and torsional stiffness through the sandwich effect, preventing relative deformation of components and dispersing radial pressure. The sealing mechanism within the outer ring mounting groove employs a combination of elastic graphite rings, shape memory alloy expansion rings, and wear-resistant alloy rings. The wear-resistant alloy rings directly contact the cylinder to resist friction and high-pressure impacts, while the elastic graphite rings fill tiny gaps to strengthen the seal. The shape memory alloy expansion rings can radially expand and contract with temperature, bidirectionally tightening the inner and outer rings to improve sealing reliability and effectively prevent refrigerant leakage. The overall design balances lightweight, high strength, and high sealing performance, making it suitable for pistons in automotive variable displacement air conditioning compressors operating under high-frequency reciprocating, high-pressure, and high-temperature conditions. This overcomes current shortcomings in practical applications and meets current needs. Utility Model Content

[0004] The purpose of this invention is to provide a piston for a variable displacement air conditioning compressor for automobiles, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The piston of an automotive variable displacement air conditioning compressor includes a piston cylinder, a piston seat, and a sealing mechanism. The piston seat is welded and fixed to the bottom of the piston cylinder. The piston cylinder has a hollow cavity inside, and a honeycomb structure is fixed inside the hollow cavity. Multiple connecting rings are fixed between the honeycomb structure and the piston cylinder. The outer ring of the piston cylinder has multiple mounting grooves, and a sealing mechanism is installed in each mounting groove. The sealing mechanism includes a wear-resistant alloy ring, a shape memory alloy expansion ring, and an elastic graphite ring. The elastic graphite ring is directly installed in the mounting groove of the outer ring of the piston cylinder. A shape memory alloy expansion ring is fixed to the outside of the elastic graphite ring, and a wear-resistant alloy ring is fixed to the outside of the shape memory alloy expansion ring.

[0006] Preferably, the outer surfaces of both the piston cylinder and the piston seat are coated with a layer of polytetrafluoroethylene.

[0007] Preferably, four reinforcing ribs are evenly distributed and fixed on the inner side of the honeycomb structure.

[0008] Preferably, the honeycomb structure is made of aluminum alloy.

[0009] The beneficial effects of this utility model are as follows: In use, the piston of this automotive variable displacement air conditioning compressor significantly reduces the weight of the piston cylinder through the hollow cavity design. Simultaneously, the closed interlayer cavity formed between the piston cylinder, honeycomb body, and connecting ring utilizes the "interlayer effect" to enhance bending and torsional stiffness. The supporting role of the connecting ring prevents relative deformation between the piston cylinder and the honeycomb body, dispersing radial pressure. The wear-resistant alloy ring directly contacts the inner wall of the compressor cylinder to form a seal, directly resisting frictional wear between the piston and the cylinder wall during high-frequency reciprocating motion, and also withstanding the high-pressure impact during refrigerant compression, preventing premature wear of the ring and subsequent seal failure. The elastic graphite ring, with its soft texture and good sealing properties, can fill any tiny gaps between the wear-resistant alloy ring and the cylinder, strengthening the overall sealing effect and preventing high-pressure refrigerant leakage. The shape memory alloy expansion ring in the middle can achieve radial expansion and contraction through temperature sensing. When the compressor load increases and the temperature rises, the shape memory alloy expansion ring expands radially, both pushing the wear-resistant alloy ring outwards to ensure a tighter fit with the cylinder wall and squeezing the elastic graphite ring inwards, improving the reliability of the seal. In summary, this utility model, through its structural design of a hollow cavity inside the piston cylinder combined with an aluminum alloy honeycomb structure, connecting ring, and reinforcing ribs, significantly reduces the weight of the piston while enhancing its bending and torsional stiffness through the sandwich effect. This prevents relative deformation of components and disperses radial pressure. The sealing mechanism within the outer ring mounting groove employs a combination of an elastic graphite ring, a shape memory alloy expansion ring, and a wear-resistant alloy ring. The wear-resistant alloy ring directly contacts the cylinder to resist friction and high-pressure impact, while the elastic graphite ring fills tiny gaps to strengthen the seal. The shape memory alloy expansion ring can radially expand and contract with temperature, bidirectionally tightening the inner and outer rings to improve sealing reliability and effectively prevent refrigerant leakage. Overall, it balances lightweight, high strength, and high sealing performance, making it suitable for the high-frequency reciprocating, high-pressure, and high-temperature operating conditions of compressors. Attached Figure Description

[0010] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0011] Figure 2 This is a schematic diagram of the disassembled state of this utility model.

[0012] Figure 3 This is an internal sectional view of the present invention.

[0013] Figure 4 This is a partial structural schematic diagram of the present invention.

[0014] Legend: 1. Piston cylinder; 101. Hollow cavity; 102. Honeycomb structure; 103. Connecting ring; 104. Reinforcing rib; 2. Piston seat; 3. Sealing mechanism; 301. Wear-resistant alloy ring; 302. Shape memory alloy expansion ring; 303. Elastic graphite ring. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0016] Example

[0017] See Figures 1-4 In this embodiment of the invention, the piston of the automotive variable displacement air conditioning compressor includes a piston cylinder 1, a piston seat 2, and a sealing mechanism 3. The piston seat 2 is welded and fixed to the bottom of the piston cylinder 1. The piston cylinder 1 has a hollow cavity 101 inside, which greatly reduces the weight of the piston cylinder 1. A honeycomb body 102 is fixed inside the hollow cavity 101. Multiple connecting rings 103 are fixed between the honeycomb body 102 and the piston cylinder 1, forming a closed interlayer cavity between the piston cylinder 1, the honeycomb body 102, and the connecting rings 103. The "layer effect" enhances bending and torsional stiffness, resulting in increased stiffness compared to a single-walled hollow piston. The supporting effect of the connecting ring 103 prevents relative deformation between the piston cylinder 1 and the honeycomb body 102, while also dispersing radial pressure. Four reinforcing ribs 104 are evenly distributed and fixed on the inner side of the honeycomb body 102, which enhances the strength of the honeycomb body 102. The outer ring of the piston cylinder 1 is provided with multiple mounting grooves, and a sealing mechanism 3 is installed in each mounting groove. The sealing mechanism 3 contacts the inner wall of the compressor cylinder to form a seal. The sealing mechanism 3 includes: a resistant... The compressor comprises a wear-resistant alloy ring 301, a shape memory alloy expansion ring 302, and an elastic graphite ring 303. The elastic graphite ring 303 is directly installed in the mounting groove of the outer ring of the piston cylinder 1. The shape memory alloy expansion ring 302 is fixed to the outside of the elastic graphite ring 303, and the wear-resistant alloy ring 301 is fixed to the outside of the shape memory alloy expansion ring 302. In use, the wear-resistant alloy ring 301 directly contacts the inner wall of the compressor cylinder to form a seal, which can directly resist the frictional wear between the piston and the cylinder wall during high-frequency reciprocating motion, and can also withstand the high-pressure impact when compressing refrigerant, avoiding wear on the ring body. Excessive wear leads to seal failure; however, the elastic graphite ring 303, with its soft texture and good sealing performance, can fill any tiny gaps that may exist between the wear-resistant alloy ring 301 and the cylinder, enhancing the overall sealing effect and preventing high-pressure refrigerant leakage. The shape memory alloy expansion ring 302 in the middle can achieve radial expansion and contraction through temperature sensing. When the compressor load increases and the temperature rises, the shape memory alloy expansion ring 302 expands radially, which can both push the wear-resistant alloy ring 301 outward to make it fit more tightly against the cylinder wall, and squeeze the elastic graphite ring 303 inward to improve the reliability of the seal.

[0018] The honeycomb 102 is made of aluminum alloy, which gives it good strength and relatively light weight.

[0019] Both the outer surfaces of the piston cylinder 1 and the piston seat 2 are coated with a layer of polytetrafluoroethylene (PTFE), which improves wear resistance and smoothness.

[0020] Working Principle: In operation, the piston of this automotive variable displacement air conditioning compressor significantly reduces the weight of the piston cylinder 1 through the hollow cavity 101. Simultaneously, a closed sandwich cavity is formed between the piston cylinder 1, the honeycomb body 102, and the connecting ring 103, utilizing the "sandwich effect" to enhance bending and torsional stiffness. The supporting role of the connecting ring 103 prevents relative deformation between the piston cylinder 1 and the honeycomb body 102, dispersing radial pressure. The wear-resistant alloy ring 301 directly contacts the inner wall of the compressor cylinder to form a seal, directly resisting frictional wear between the piston and the cylinder wall during high-frequency reciprocating motion, and also bearing the weight of the compressed refrigerant. The high-pressure impact prevents the ring from wearing out too quickly and causing seal failure. The elastic graphite ring 303 is soft and has good sealing properties, which can fill the possible tiny gaps between the wear-resistant alloy ring 301 and the cylinder, enhance the overall sealing effect, and prevent high-pressure refrigerant leakage. The shape memory alloy expansion ring 302 in the middle can achieve radial expansion and contraction through temperature sensing. When the compressor load increases and the temperature rises, the shape memory alloy expansion ring 302 expands radially, which can both push the wear-resistant alloy ring 301 outward to make it fit more tightly with the cylinder wall, and squeeze the elastic graphite ring 303 inward to improve the reliability of the seal.

[0021] Furthermore, it should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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 direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0022] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. The piston of a variable displacement automotive air conditioning compressor, characterized in that, The piston cylinder (1), piston seat (2), and sealing mechanism (3) are included. The piston seat (2) is welded and fixed to the bottom of the piston cylinder (1). The piston cylinder (1) has a hollow cavity (101) inside. A honeycomb body (102) is fixed inside the hollow cavity (101). Multiple connecting rings (103) are fixed between the honeycomb body (102) and the piston cylinder (1). The outer ring of the piston cylinder (1) has multiple mounting grooves. A sealing mechanism (3) is installed in each mounting groove. The sealing mechanism (3) includes: a wear-resistant alloy ring (301), a shape memory alloy expansion ring (302), and an elastic graphite ring (303). The elastic graphite ring (303) is directly installed in the mounting groove of the outer ring of the piston cylinder (1). A shape memory alloy expansion ring (302) is fixed to the outside of the elastic graphite ring (303). A wear-resistant alloy ring (301) is fixed to the outside of the shape memory alloy expansion ring (302).

2. The piston of the automotive variable displacement air conditioning compressor according to claim 1, characterized in that, The outer surfaces of both the piston cylinder (1) and the piston seat (2) are coated with a layer of polytetrafluoroethylene.

3. The piston of the automotive variable displacement air conditioning compressor according to claim 1, characterized in that, Four reinforcing ribs (104) are evenly distributed and fixed on the inner side of the honeycomb body (102).

4. The piston of the automotive variable displacement air conditioning compressor according to claim 1, characterized in that, The honeycomb (102) is made of aluminum alloy.

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