A method for manufacturing a compressor piston

Abstract

This invention provides a method for manufacturing a compressor piston. The compressor piston includes a hinge groove, the hinge groove includes a hinge hole and a mounting opening communicating with the hinge hole. The hinge hole is used to connect a transmission component to achieve eccentric rotation of the compressor piston and crankshaft, thereby compressing air. The manufacturing method includes: machining a piston body; the piston body is a cylindrical structure; making a cutting motion from the outer wall of the piston body, performing at least one wire cut along the inner wall of the mounting opening and the hinge hole to simultaneously obtain the hinge hole and the mounting opening, such that the diameter of the hinge hole ranges from 2.8 to 4 mm; precision grinding the hinge hole and the mounting opening; and surface treating the piston body to obtain the compressor piston. This invention solves the problems of current methods for machining the hinge groove of compressor pistons using drilling, which is difficult to achieve high precision, has high wall-breaking difficulty, and low processing efficiency.

Description

Technical Field

[0001] This invention relates to the field of compressor piston technology, and more specifically, to a method for manufacturing a compressor piston. Background Technology

[0002] A rotary compressor utilizes a cylindrical piston eccentrically mounted on a crankshaft, which undergoes planetary rolling motion within a cylindrical cylinder. This periodically changes the volume of the crescent-shaped space between the cylinder and the piston, thus completing the intake, compression, and exhaust processes. Rotary compressors are widely used in small and medium-sized refrigeration equipment such as household air conditioners and refrigerators due to their high efficiency, compact structure, small size, and light weight.

[0003] The outer wall of the hinged piston of the rotary compressor is provided with an axially penetrating groove. The vane has a head end and a tail end. The shape of the head end matches the groove and can be oscillatingly fitted into the groove so that the vane and the hinged piston form a hinge.

[0004] Currently, the processing of articulated grooves typically involves multiple steps, including machining and drilling, followed by wall breaking on the piston side to transform the through hole into a groove. However, ensuring the positional accuracy of the drilling and the perpendicularity of the groove is difficult, and the wall breaking process is also challenging. Maintaining the perpendicularity of the groove opening can lead to misaligned dimensions of the articulated piston, making it difficult to meet high-speed rotation requirements. This results in vibration and excessive noise during compressor operation, reducing its lifespan. Furthermore, drilling is an inefficient method for machining articulated grooves. Summary of the Invention

[0005] The problem solved by this invention is that the hinge groove of the compressor piston is difficult to machine with high precision by drilling, the wall breaking process is difficult and the processing efficiency is low.

[0006] To address the aforementioned problems, this invention provides a method for manufacturing a compressor piston. The compressor piston includes a hinge groove, the hinge groove includes a hinge hole and a mounting opening communicating with the hinge hole. The hinge hole is used to connect a transmission component to achieve eccentric rotation of the compressor piston and crankshaft, thereby compressing air. The manufacturing method is characterized by comprising: machining a piston body; the piston body having a cylindrical structure; making a cutting pass from the outer wall of the piston body, performing at least one wire cut along the inner wall of the mounting opening and the hinge hole to simultaneously obtain the hinge hole and the mounting opening, such that the diameter of the hinge hole ranges from 2.8 to 4 mm; precision grinding the hinge hole and the mounting opening; and performing surface treatment on the piston body to obtain the compressor piston.

[0007] The technical effects achieved by adopting this technical solution are as follows: the use of wire cutting to process the articulation groove can ensure that the cylindrical surface of the articulation groove has a high degree of perpendicularity to the end face; the wire cutting of the articulation groove along the specified path can effectively improve the cylindricity of the cylindrical surface of the articulation groove and the parallelism with respect to the axis. Therefore, after the sliding vane is installed, the articulation groove can rotate more smoothly, reduce vibration and noise, and improve the life of the compressor.

[0008] The cutting process involves entering through the outer wall of the piston body and exiting through the outer wall after wire cutting. Therefore, when machining the hinge groove, the mounting opening of the hinge groove is formed simultaneously, eliminating the need for subsequent wall-breaking processes and preventing piston failure due to non-perpendicularity or shape of the mounting opening. Wire cutting also makes it easier to ensure the symmetry of both sides of the mounting opening.

[0009] Using wire cutting technology allows for the simultaneous machining of the hinge grooves of at least two piston bodies, thereby significantly improving machining efficiency and ensuring the consistency of the hinge grooves of at least two piston bodies.

[0010] The hinge hole and mounting opening can be formed simultaneously using wire cutting, improving the processing efficiency of the hinge groove. Furthermore, the mounting opening requires a specific opening angle; using a predetermined processing path for wire cutting facilitates the rapid forming of the mounting opening to the predetermined size, reducing the need for separate milling or grinding processes, thus further improving the processing efficiency of the mounting opening.

[0011] Furthermore, the step of cutting from the outer wall of the piston body and making at least one wire cut along the inner wall of the mounting opening and the hinge hole to simultaneously obtain the hinge hole and the mounting opening specifically includes: stacking and fixing at least two piston bodies axially, cutting from the outer wall of the piston body, and simultaneously making at least one wire cut on all the piston bodies to obtain the initial hinge groove of the piston body.

[0012] The technical effects achieved by adopting this technical solution are as follows: After at least two piston bodies are stacked and fixed along the axial direction, the wire cutting process can simultaneously contact and process at least two piston bodies, and simultaneously process at least two hinge slots with installation openings according to the specified path. In contrast, the drilling process requires drilling sequentially even when stacked. Therefore, the wire cutting process can effectively improve the processing efficiency of the initial hinge slots when cutting the stacked piston bodies.

[0013] After the wire EDM machine is calibrated, at least two initial hinge slots processed by the metal wire can have the same perpendicularity, parallelism, and cylindricity. Therefore, the size requirements of at least two initial hinge slots are guaranteed, as well as the consistency of size and shape, which facilitates matching and installation with the slider.

[0014] Furthermore, the step of stacking and fixing at least two piston bodies axially specifically includes: fitting the central holes of at least two piston bodies onto a positioning post; the positioning post matching the central holes.

[0015] The technical effects achieved by adopting this technical solution are as follows: the positioning pin realizes the center positioning of at least two piston bodies, improves coaxiality, aligns the sides of at least two piston bodies, and facilitates the formation of consistent hinge grooves.

[0016] Furthermore, the hinge groove includes: a hinge hole and a mounting opening communicating with the hinge hole, a transition portion between the hinge hole and the mounting opening, the width of the transition portion being smaller than the diameter of the hinge hole, and the width of the transition portion being smaller than the outer width of the mounting opening; the fine grinding of the hinge hole and the mounting opening specifically includes: fine grinding the transition portion to form at least one rounded corner with a radius less than or equal to 0.2 mm; and honing the hinge hole using a honing rod.

[0017] The technical effects achieved by adopting this technical solution are as follows: the transition part is used to prevent the hinge shaft at the end of the slider from disengaging from the hinge hole. After the slider is installed axially from one side of the hinge groove, the hinge shaft can rotate stably in the hinge hole. The outer width of the mounting opening is greater than that of the hinge position, so that the slider has a certain swing space, and the two sides of the mounting opening can limit the slider and limit its swing angle.

[0018] Using a honing rod of appropriate size to finely grind the hinge hole inside the hole further improves the roundness, cylindricity, and smoothness of the hinge hole, and improves the uniformity of the fit clearance between the hinge shaft and the hinge hole.

[0019] Furthermore, the step of cutting from the outer wall of the piston body and performing at least one wire cut along the inner wall of the mounting opening and the hinge hole specifically includes: performing at least one wire cut roughing and multiple wire cut finishing on the piston body; after the wire cut roughing, the machining allowance of the wire cut finishing is 0.03mm to 0.06mm.

[0020] The technical effects achieved by adopting this solution are as follows: The larger cutting amount used in wire EDM roughing allows for efficient material removal, enabling the initial articulated groove to quickly approach the required inner diameter. Multiple wire EDM finishes gradually improve accuracy. Wire EDM roughing leaves sufficient cutting allowance for wire EDM finishes, improving accuracy while preventing damage to the electrode wire.

[0021] Furthermore, the roughing current of the wire EDM roughing process is greater than the roughing current of the wire EDM finishing process; and / or, the tool speed of the wire EDM roughing process is less than the tool speed of the wire EDM finishing process.

[0022] The technical effects achieved by adopting this technical solution are as follows: roughing uses a larger current and a smaller tool speed, which can achieve a larger cutting force and ensure stable feed during the wire EDM roughing process; while multiple wire EDM finishing uses a smaller cutting amount to improve cutting accuracy, and when the cutting force is sufficient, a larger tool speed can be used to improve the efficiency of finishing.

[0023] Furthermore, the surface treatment of the piston body to obtain the compressor piston specifically includes: deburring, cleaning, and rust prevention treatment of the piston body to obtain the compressor piston.

[0024] The technical effects achieved by adopting this technical solution are as follows: removing burrs from the piston body can effectively reduce its surface roughness and avoid damage or excessive noise caused by friction between the piston and the inner wall of the compressor cylinder during piston rotation; cleaning the removed burrs and debris further prevents friction between the piston and cylinder or blockage in each air chamber; and rust prevention treatment further improves surface quality and piston service life.

[0025] Furthermore, the processing of the piston body specifically includes: obtaining a blank by cutting a tube, casting, or cold heading; and processing the blank to obtain the piston body.

[0026] The technical effects achieved by adopting this technical solution are as follows: The blank of the piston body can be prepared from different materials; for example, using high-carbon chromium bearing steel can achieve higher hardness, wear resistance and fatigue strength. At this time, a large number of blanks can be quickly obtained by cutting high-carbon chromium bearing steel tubes. The blanks are cylindrical and have initial inner holes, which facilitates the machining of dimensions to obtain the piston body; while casting can directly obtain blanks with dimensions close to those of the piston body, and fewer subsequent wire cutting and fine grinding processes are required, thus resulting in higher processing efficiency; the coil is a ring structure, and after cold heading the coil, a cylindrical structure with holes can be directly formed. Directly machining the inner and outer dimensions of this cylindrical structure also facilitates faster production of the piston body.

[0027] Furthermore, the process of processing the blank to obtain the piston body specifically includes: turning the blank to obtain a semi-finished product; heat-treating the semi-finished product; and grinding the end face, outer wall, and inner wall of the semi-finished product to obtain the piston body.

[0028] The technical effects achieved by adopting this solution are as follows: Turning the blank yields a semi-finished product with dimensions close to the piston body, reducing the amount of grinding required for subsequent finishing. It also improves the coaxiality of the inner and outer walls before grinding, facilitating accurate machining of the outer wall after the semi-finished product is fitted and fixed on the locating pin, reducing circular runout errors. Heat treatment after turning eliminates residual machining stress in the semi-finished product, significantly improving hardness, strength, and wear resistance. Grinding the end faces of the semi-finished product improves the accuracy of the end faces, outer wall, and inner wall, reducing noise generated by friction during piston movement and enhancing the corrosion resistance of the piston surface.

[0029] Furthermore, the grinding of the end face, outer wall, and inner wall of the semi-finished product to obtain the piston body specifically includes: rough grinding and fine grinding of the end face, outer wall, and inner wall of the semi-finished product using a grinding wheel; and honing the inner wall of the semi-finished product using a honing rod to obtain the piston body.

[0030] The technical effects achieved by adopting this solution are as follows: Rough grinding of the end faces, outer walls, and inner walls of the semi-finished product allows for rapid dimensional approximation and improves grinding efficiency. Fine grinding of the end faces, outer walls, and inner walls further enhances the precision and surface quality of the semi-finished product. Through the combination of rough and fine grinding, the transmission between the piston body end face and the upper and lower covers, between the piston body outer wall and the cylinder inner wall, and between the piston inner wall and the outer wall of the crankshaft eccentric drive shaft becomes smoother and the operation more stable. Further honing of the inner wall of the semi-finished product facilitates assembly with the crankshaft eccentric drive shaft, reduces friction, and extends the service life of the eccentric drive shaft.

[0031] In summary, the above-mentioned technical solutions of this application can have one or more of the following advantages or beneficial effects: i) Using wire cutting to process the hinge groove can ensure that the cylindrical surface of the hinge groove has a high degree of perpendicularity to the end face; ii) Wire cutting along a specified path to process the hinge groove can effectively improve the cylindricity of the cylindrical surface of the hinge groove and the parallelism with respect to the axis, so that the hinge groove can rotate more smoothly after the sliding vane is installed, reducing vibration and noise and improving the compressor life; iii) When processing the hinge groove, the installation opening of the hinge groove is also formed simultaneously, eliminating the need for subsequent wall breaking processes and avoiding piston failure due to non-compliance of the perpendicularity or shape of the installation opening; iv) Using wire cutting facilitates the simultaneous processing of the hinge grooves of at least two piston bodies, thereby multiplying the processing efficiency and ensuring the consistency of the hinge grooves of at least two piston bodies; v) The positioning column realizes the center positioning of at least two piston bodies, improves coaxiality, aligns the sides of at least two piston bodies, and facilitates the processing to form consistent hinge grooves. Attached Figure Description

[0032] Figure 1 A flowchart illustrating a method for manufacturing a compressor piston provided by the present invention;

[0033] Figure 2 A flowchart illustrating the manufacturing process of a compressor piston;

[0034] Figure 3 This is a schematic diagram of the compressor piston.

[0035] Figure 4 for Figure 3 A magnified view of a portion of region I;

[0036] Figure 5 for Figure 4 A magnified view of a portion of region II;

[0037] Figure 6 This is a cross-sectional view of the compressor piston.

[0038] Explanation of reference numerals in the attached figures:

[0039] 100 - Compressor piston; 110 - Outer wall; 120 - Inner wall; 130 - End face; 140 - Hinge groove; 141 - Hinge hole; 142 - Mounting opening; 143 - Transition section. Detailed Implementation

[0040] The purpose of this invention is to provide a method for manufacturing a compressor piston, which achieves higher verticality of the articulation groove, improves processing efficiency, eliminates the need for a wall-breaking process, and facilitates the processing and installation of the opening.

[0041] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0042] See Figures 1-6 This invention provides a method for manufacturing a compressor piston 100. The compressor piston 100 includes a hinge groove, the hinge groove includes a hinge hole and a mounting opening communicating with the hinge hole. The hinge hole is used to connect a transmission component to achieve eccentric rotation of the compressor piston 100 and the crankshaft, thereby achieving air compression. The manufacturing method is characterized by: machining a piston body; the piston body is a cylindrical structure; making a cut from the outer wall of the piston body, performing at least one wire cut along the inner wall of the mounting opening 142 and the hinge hole 141, simultaneously obtaining the mounting opening 142 and the hinge hole 141, such that the diameter of the hinge hole 141 ranges from 2.8 to 4 mm; precision grinding the hinge hole 141 and the mounting opening 142; and surface treating the piston body to obtain the compressor piston 100.

[0043] In this embodiment, the hinge groove 140 is machined using wire cutting technology, which ensures that the cylindrical surface of the hinge groove 140 has a high degree of perpendicularity to the end face 130. The hinge groove 140 is machined by wire cutting along a specified path, which can effectively improve the cylindricity of the cylindrical surface of the hinge groove 140 and the parallelism with respect to the axis. Therefore, after the sliding vane is installed, the hinge groove 140 can rotate more smoothly, reducing vibration and noise and improving the life of the compressor.

[0044] The wire cutter enters from the outer wall 110 of the piston body and exits from the outer wall 110 after wire cutting. Therefore, when machining the hinge groove 140, the mounting opening 142 of the hinge groove 140 is also formed simultaneously, eliminating the need for subsequent wall-breaking processes and preventing piston failure due to non-compliance with the perpendicularity or shape of the mounting opening 142. Using wire cutting also makes it easier to ensure the symmetry of both sides of the mounting opening 142.

[0045] The use of wire cutting technology facilitates the simultaneous machining of the hinge grooves 140 of at least two piston bodies, thereby significantly improving machining efficiency and ensuring the consistency of the hinge grooves 140 of at least two piston bodies.

[0046] The hinge hole 141 and the mounting opening 142 can be formed simultaneously by wire cutting, improving the machining efficiency of the hinge groove 140. Furthermore, since the mounting opening 142 requires a specific opening angle, wire cutting using a predetermined machining path facilitates the rapid forming of the mounting opening 142 to the predetermined size, ensuring that the symmetry of the mounting opening 142 is ≤0.03. This reduces the need for separate milling or grinding of the mounting opening 142, further improving its machining efficiency.

[0047] In one specific embodiment, the process involves making a cut from the outer wall of the piston body and performing at least one wire cut along the inner wall of the mounting opening and the hinge hole to obtain the hinge hole and the mounting opening. Specifically, this includes stacking and fixing at least two piston bodies axially, making a cut from the outer wall 110 of the piston body, and performing at least one wire cut on all piston bodies simultaneously to obtain the initial hinge groove of the piston body.

[0048] It should be noted that after at least two piston bodies are stacked and fixed along the axial direction, the wire cutting process can simultaneously contact and process at least two piston bodies, simultaneously processing at least two hinge slots 140 with mounting openings 142 according to a specified path. In contrast, even with stacking, drilling processes require sequential drilling; therefore, wire cutting of the stacked piston bodies effectively improves the processing efficiency of the initial hinge slots. Preferably, 2-4 piston bodies are stacked along the axial direction and wire cutting is performed simultaneously.

[0049] After the wire EDM machine is calibrated, at least two initial hinge slots processed by the metal wire can have the same perpendicularity, parallelism, and cylindricity. Therefore, the size requirements of at least two initial hinge slots are guaranteed, as well as the consistency of size and shape, which facilitates matching and installation with the slider.

[0050] In one specific embodiment, at least two piston bodies are stacked and fixed axially, specifically including: fitting the central holes of at least two piston bodies onto a positioning post; the positioning post matches the central holes.

[0051] It should be noted that the positioning pin achieves the center positioning of at least two piston bodies, improves coaxiality, aligns the sides of at least two piston bodies, and facilitates the machining of a consistent hinge groove 140.

[0052] Furthermore, the end of the positioning post is threaded. After at least two piston bodies are stacked axially, a nut is installed at the end of the positioning post to tighten the piston body and prevent the piston body from loosening during wire cutting.

[0053] In one specific embodiment, the hinge groove 140 includes: a hinge hole 141 and a mounting opening 142 communicating with the hinge hole 141, a transition portion 143 between the hinge hole 141 and the mounting opening 142, the width of the transition portion 143 being smaller than the diameter of the hinge hole 141, and the width of the transition portion 143 being smaller than the outer width of the mounting opening 142; fine grinding of the hinge hole 141 and the mounting opening 142 specifically includes: fine grinding the transition portion 143 to form at least one rounded corner with a radius less than or equal to 0.2 mm; and honing the hinge hole 141 using a honing rod.

[0054] It should be noted that the transition part 143 is used to prevent the hinge shaft at the end of the slider from disengaging from the hinge hole 141. After the slider is installed axially from one side of the hinge groove 140, the hinge shaft can rotate stably within the hinge hole 141. The outer width of the mounting opening 142 is greater than that of the hinge position, so that the slider has a certain swing space, and the two sides of the mounting opening 142 can limit the slider and limit its swing angle.

[0055] In one specific embodiment, the transition portion 143 is a single rounded corner structure, or the transition portion 143 is arranged radially along the piston body and has rounded corners at both ends. Preferably, the radial length of the transition portion 143 is 0.1 to 0.3 mm, for example, 0.15 mm, to avoid the portion between the hinge hole 141 and the mounting opening 142 being too sharp and prone to breakage. The radius of the rounded corners at both ends of the transition portion 143 is, for example, 0.1 mm, to prevent wear between the inner side of the transition portion 143 and the hinge shaft, which could lead to damage to the hinge shaft or deformation of the transition portion. It also prevents the sliding connecting rod connected to the hinge shaft from colliding and wearing or scratching the outer side of the transition portion 143, which could lead to deformation and failure of the sliding plate.

[0056] Accordingly, at least one wire cut is performed along the inner wall 120 of the mounting opening 142 and the hinge hole 141, specifically including: inclined feed along one side of the mounting opening 142, wire cut one side of the transition portion 143, wire cut the inner wall 120 of the hinge hole 141, wire cut the other side of the transition portion 143, and inclined feed out along the other side of the mounting opening 142.

[0057] It should be noted that using a honing rod of appropriate size to finely grind the hinge hole 141 inside the hole further improves the roundness, cylindricity, and surface finish of the hinge hole 141, and enhances the uniformity of the fit clearance between the hinge shaft and the hinge hole 141. Specifically, further honing can make the roundness of the hinge hole 141 ≤ 0.005, the cylindricity ≤ 0.008, and the straightness of the axis ≤ 0.008.

[0058] Preferably, the final diameter of the hinge hole 141 is, for example, 3mm, 3.1mm, 3.125mm, 3.25mm, 3.5mm, etc., and is not limited here. Using this diameter range for the hinge hole 141 can ensure that the hinge shaft and slide plate that are hinged to it have sufficient strength, and achieve the effects of reducing thickness, saving internal space of the compressor cylinder, and saving materials.

[0059] In one specific embodiment, the fine grinding of the hinge hole 141 and the mounting opening 142 further includes: fine grinding the mounting opening 142. Specifically, the outer end of the mounting opening 142 is finely ground to form at least one rounded corner with a radius less than or equal to 0.2 mm, for example, 0.1 mm, to prevent the outer end of the mounting opening 142 from wearing or breaking against the inner wall 120 of the compressor cylinder.

[0060] In one specific embodiment, the step of making at least one wire cut along the inner wall 120 of the mounting opening 142 and the hinge hole 141 from the outer wall 110 of the piston body specifically includes: performing at least one wire cut roughing and multiple wire cut finishing operations on the piston body; after the wire cut roughing, the machining allowance for the wire cut finishing is 0.03 mm to 0.06 mm. For example, after the wire cut roughing, the machining allowance for the wire cut finishing is 0.04 mm, 0.045 mm, or 0.05 mm.

[0061] It should be noted that the larger cutting amount used in wire EDM roughing allows for efficient material removal, enabling the initial articulated groove 140 to quickly approach the actual required inner diameter. Multiple wire EDM finishes gradually improve accuracy. Wire EDM roughing leaves sufficient cutting allowance for wire EDM finishes, improving accuracy while preventing damage to the electrode wire.

[0062] Preferably, after each wire EDM roughing and finishing process, a grinding and finishing process can be added to ensure the flatness of the machined surface during subsequent wire EDM, thereby improving accuracy.

[0063] It should be noted that during the wire EDM roughing and wire EDM finishing processes, the wire EDM machining path is parallel to the inner wall 120 of the current hinge groove 140, meaning that the cutting amount of wire EDM is equal everywhere.

[0064] For example, the target angle of the mounting opening 142 is 100° to 110°, such as 104°, 105°, or 106°. After wire EDM finishing and after wire EDM roughing, the mounting opening 142 maintains this target angle to ensure smooth cutting and facilitate improved accuracy.

[0065] For example, the target width outside the mounting opening 142 is 4mm to 5mm, such as 4.5mm.

[0066] For example, the target width of the transition section 143 is, for example, 2mm to 3.5mm, such as 2.8mm.

[0067] Accordingly, at least one wire cut is performed along the inner wall 120 of the mounting opening 142 and the hinge hole 141, specifically including: after wire cutting rough machining, the width of the transition portion 143 is 1.88mm to 3.44mm, for example 2.71mm, the width of the outer side of the mounting opening 142 is 3.88mm to 4.94mm, for example 4.41mm, and the diameter of the hinge hole 141 is 2.68mm to 3.91mm, for example 3.035mm.

[0068] In one specific embodiment, the piston body is subjected to at least one wire EDM roughing and multiple wire EDM finishing operations; the roughing current of the wire EDM roughing is greater than the roughing current of the wire EDM finishing; and / or, the tool speed of the wire EDM roughing is less than the tool speed of the wire EDM finishing.

[0069] It should be noted that roughing uses a larger current and a smaller tool speed to achieve a greater cutting force, ensuring stable feed during the wire EDM roughing process; while multiple wire EDM finishing uses a smaller cutting amount to improve cutting accuracy, and when the cutting force is sufficient, a larger tool speed can be used to improve finishing efficiency.

[0070] Preferably, the wire EDM roughing process is performed once, and the wire EDM finishing process is performed 3-4 times.

[0071] Preferably, the roughing current is 3-6A, and the finishing current is 1-3A. The roughing speed is 160-180 square millimeters per minute, and the finishing speed is 350-500 square millimeters per minute.

[0072] In an optional embodiment, the hinge hole 141 can also be multiple shaft holes of different diameters, arranged coaxially in sequence, to match a hinge shaft that also has multiple shaft segments of different diameters, thereby achieving the limiting of the hinge shaft and the hinge hole 141. For example, the hinge hole 141 can be a combination of shaft holes with larger diameters at both ends and a shaft hole with a smaller diameter in the middle, or a combination of shaft holes with smaller diameters at both ends and a shaft hole with a larger diameter in the middle; no limitation is made here.

[0073] Correspondingly, the large diameter shaft hole portion can be obtained through additional milling or turning processes, and is machined along one side of the mounting opening; or it can be obtained by stacking and connecting multiple piston bodies after individual wire cutting, that is, after machining the corresponding diameter hinge hole 141 of multiple piston bodies individually, the multiple piston bodies are further assembled by setting an axial positioning structure or adding an external fixture on the piston body itself, so as to align and combine multiple shaft holes of different diameters, and the hinge shaft can be pre-installed before the multiple piston bodies are stacked.

[0074] In one specific embodiment, the piston body is surface treated to obtain the compressor piston 100, specifically including: deburring, cleaning, and rust prevention treatment of the piston body to obtain the compressor piston 100.

[0075] It should be noted that deburring the piston body can effectively reduce its surface roughness and prevent friction between the piston and the inner wall 120 of the compressor cylinder during piston rotation, which could lead to damage or excessive noise. Cleaning the removed burrs and debris further prevents friction between the piston and cylinder or blockage in the various air chambers. Rust prevention treatment further improves surface quality and piston lifespan.

[0076] Preferably, the piston body is deburred by brushing or magnetic polishing; the piston body is cleaned by ultrasonic cleaning; and the piston body is rust-proofed by immersion in water-based rust-preventive oil, which is not limited here.

[0077] By deburring, the fillets between the hinge hole 141 and the transition portion 143, between the transition portion 143 and the mounting opening 142, and between the mounting opening 142 and the outer wall 110 can reach R0.1 or less, thereby protecting the sliding vanes from wear after the compressor piston 100 is assembled with the vanes.

[0078] In one specific embodiment, the processing of the piston body includes: obtaining a blank by cutting a tube, casting, or cold heading; and processing the blank to obtain the piston body.

[0079] It should be noted that the blank for the coiled piston body can be prepared from different materials. For example, using high-carbon chromium bearing steel can achieve higher hardness, wear resistance, and fatigue strength. In this case, a large number of blanks can be quickly obtained by cutting high-carbon chromium bearing steel tubing. The blanks are cylindrical and have an initial inner hole, which facilitates the machining of dimensions to obtain the piston body. Casting, such as cast iron casting, can directly produce blanks with dimensions close to those of the piston body. The subsequent wire cutting and precision grinding processes are fewer, resulting in higher processing efficiency. Coiling is a ring structure. After cold heading, a cylindrical structure with holes can be directly formed. Directly machining the inner and outer dimensions of this cylindrical structure also facilitates faster production of the piston body.

[0080] Preferably, the blank of the piston body is made of GCr15 material, which can be obtained by cutting tubing; the blank of the piston body can also be made of 40Cr, 20Cr, or 20CrMnTi material, which can be obtained by cold heading.

[0081] In one specific embodiment, the piston body is obtained by processing the blank, specifically including: turning the blank to obtain a semi-finished product; heat treating the semi-finished product; and grinding the end face 130, outer wall 110, and inner wall 120 of the semi-finished product to obtain the piston body.

[0082] It should be noted that turning the blank yields a semi-finished product with dimensions close to the piston body, reducing the amount of grinding required for subsequent finishing. It also improves the coaxiality of the inner wall 120 and outer wall 110 before grinding, facilitating accurate machining of the outer wall 110 after the semi-finished product is fitted and fixed on the locating pin, reducing circular runout errors. Heat treatment after turning eliminates residual machining stress in the semi-finished product, significantly improving its toughness, hardness, strength, and wear resistance. Grinding the end face 130 of the semi-finished product improves the accuracy of the end face 130, outer wall 110, and inner wall 120, reducing noise generated by friction during piston movement and enhancing the corrosion resistance of the piston surface.

[0083] Preferably, the semi-finished product is subjected to heat treatment, specifically including cryogenic treatment. For example, the semi-finished product is placed in cryogenic liquid nitrogen, which effectively improves toughness while ensuring strength and hardness, preventing breakage during subsequent grinding and wire cutting, and also protecting the grinding wheel and the wire used for wire cutting.

[0084] In one specific embodiment, the end face 130, outer wall 110, and inner wall 120 of the semi-finished product are ground to obtain the piston body. Specifically, this includes: rough grinding and fine grinding of the end face 130, outer wall 110, and inner wall 120 of the semi-finished product using a grinding wheel; and honing of the inner wall 120 of the semi-finished product using a honing rod to obtain the piston body.

[0085] It should be noted that rough grinding of the end face 130, outer wall 110, and inner wall 120 of the semi-finished product is performed to quickly approximate the dimensions and improve grinding efficiency. Fine grinding of these same areas further enhances the precision and surface quality of the semi-finished product. Through the combination of rough and fine grinding, the transmission between the piston body end face 130 and the cylinder head, between the piston body outer wall 110 and the cylinder inner wall 120, and between the piston inner wall 120 and the crankshaft eccentric drive shaft outer wall 110 becomes smoother and the operation more stable. Further honing of the inner wall 120 of the semi-finished product facilitates the assembly of the inner wall 120 with the crankshaft eccentric drive shaft, reduces friction, and extends the service life of the eccentric drive shaft.

[0086] Preferably, the end face 130, outer wall 110, and inner wall 120 of the semi-finished product are rough and fine ground using a grinding wheel. Specifically, this includes rough grinding in the order of end face 130, outer wall 110, and inner wall 120, followed by fine grinding in the same order. Prioritizing the machining of end face 130 reduces burrs on the outer wall 110 and inner wall 120, facilitating burr removal and the wire cutting process on the outer wall 110.

[0087] Furthermore, before fine grinding the inner wall 120, the manufacturing method also includes: machining the chamfer between the inner wall 120 and the end face 130. Among them, fine grinding the inner wall 120 after chamfering can remove the burrs on the side of the chamfer facing the inner wall 120, thereby improving the flatness of the inner wall 120.

[0088] Furthermore, after honing the inner wall 120 of the semi-finished product to obtain the piston body using a honing rod, the manufacturing method also includes deburring. Specifically, burrs are removed from the inner wall 120, outer wall 110, and end face 130 of the piston body to avoid damage to the wire cut metal wire.

[0089] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A method for manufacturing a compressor piston, the compressor piston including a hinge groove, the hinge groove including a hinge hole and a mounting opening communicating with the hinge hole, the hinge hole being used to connect a transmission component to achieve eccentric rotation of the compressor piston and crankshaft, thereby achieving air compression, characterized in that, The manufacturing method includes: Machining the piston body; the piston body is a cylindrical structure; The piston body is fed into the outer wall and at least one wire cut is made along the inner wall of the mounting opening and the hinge hole to obtain the hinge hole and the mounting opening, such that the diameter of the hinge hole is in the range of 2.8 to 4 mm. The hinge hole and the mounting opening are precision ground; The piston body is surface treated to obtain a compressor piston; The hinge groove further includes a transition portion located between the hinge hole and the mounting opening, wherein the width of the transition portion is smaller than the diameter of the hinge hole and the width of the transition portion is smaller than the outer width of the mounting opening; The fine grinding of the hinge hole and the mounting opening specifically includes: fine grinding the transition portion to form at least one rounded corner with a radius less than or equal to 0.2 mm; and honing the hinge hole using a honing rod. The step of inserting a cutting tool into the outer wall of the piston body and performing at least one wire cut along the inner wall of the mounting opening and the hinge hole specifically includes: The piston body is subjected to at least one wire EDM roughing and multiple wire EDM finishing; after the wire EDM roughing, the machining allowance of the wire EDM finishing is 0.03mm to 0.06mm.

2. The manufacturing method according to claim 1, characterized in that, The process of inserting a cutting tool into the outer wall of the piston body and performing at least one wire cut along the inner wall of the mounting opening and the hinge hole to simultaneously obtain the hinge hole and the mounting opening specifically includes: At least two piston bodies are stacked and fixed axially. A wire cut is made from the outer wall of the piston body, and all piston bodies are simultaneously cut at least once to obtain the initial hinge groove of the piston body.

3. The manufacturing method according to claim 2, characterized in that, The step of stacking and fixing at least two piston bodies axially specifically includes: At least two of the piston bodies have their center holes fitted onto a positioning post; the positioning post matches the center holes.

4. The manufacturing method according to claim 1, characterized in that, The roughing current of the wire EDM roughing process is greater than the roughing current of the wire EDM finish process; and / or, the tool speed of the wire EDM roughing process is less than the tool speed of the wire EDM finish process.

5. The manufacturing method according to claim 1, characterized in that, The process of surface treating the piston body to obtain the compressor piston specifically includes: The piston body is deburred, cleaned, and rust-proofed to obtain the compressor piston.

6. The manufacturing method according to claim 1, characterized in that, The processed piston body specifically includes: A blank is obtained by cutting pipes, casting, or cold heading. The piston body is obtained by processing the blank.

7. The manufacturing method according to claim 6, characterized in that, The process of machining the blank to obtain the piston body specifically includes: The blank is turned to obtain a semi-finished product; The semi-finished product is subjected to heat treatment; The end face, outer wall, and inner wall of the semi-finished product are ground to obtain the piston body.

8. The manufacturing method according to claim 7, characterized in that, The grinding of the end face, outer wall, and inner wall of the semi-finished product to obtain the piston body specifically includes: The end face, outer wall, and inner wall of the semi-finished product are rough and fine ground using a grinding wheel. The piston body is obtained by honing the inner wall of the semi-finished product with a honing rod.

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