A method for designing an air suction hole of an air piston compressor of a gas supplementing automobile suspension system

Abstract

The present application belongs to the technical field of compressor, disclose a kind of air hole design method of air-supplying automobile suspension system air piston compressor, comprising the following steps: height design of air hole;Air hole diameter design, air hole number design and air hole center line section shape design.The height design step of the air hole, the height design of air hole meets the requirement of minimum power consumption per air-supplying amount.The present application aims at the air-supplying demand of the compressor of automobile suspension system, designs a kind of high-efficiency air-supplying piston compressor for automobile suspension system;Compared with ordinary piston compressor, the air-supplying crankshaft screw integrated design compressor designed by the present application, through the optimization design of air hole, the compression efficiency is higher, and more energy-saving.Gas can be compressed to the required pressure in a shorter time, and the response speed of air suspension system is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of compressors, and particularly relates to a design method of an air suction hole of a gas-supplementing air suspension system air piston compressor. BACKGROUND

[0002] The most direct function of air suspension is that the height of the vehicle body is adjustable. When a vehicle is running at high speed, more than 60% of the power is consumed to resist wind resistance. When the speed exceeds 200km / h, the energy consumption to resist wind resistance accounts for more than 85%. The vehicle equipped with air suspension can adjust the clearance between the chassis and the ground to reduce wind resistance and thus reduce energy consumption. Compared with the metal parts of the traditional suspension system, the air suspension system can effectively reduce the weight and thus improve the cruising range of the new energy vehicle.

[0003] The air compressor is the core of the air supply unit, and high-pressure compressed air is generated by a single-stage reciprocating piston compressor. The piston compressor with integrated design of connecting rod and piston meets the design requirements of high integration and light weight. However, the integrated design of the connecting rod and the piston causes the piston to swing left and right in the vertical axial direction in addition to the axial movement in the suction and compression processes of the traditional piston compressor. The piston compressor of the air suspension system plays a key role in providing comfort, stability and adjustability. Compared with ordinary compressors, the gas-supplementing compressor has the advantages of high efficiency and can compress gas to the required pressure in a short time to meet the requirements of the suspension system for response speed, and has a broad application prospect in the field of automotive air suspension systems.

[0004] However, the research on the air compressor of the automotive suspension system is still relatively scarce, and the related research on the piston compressor with integrated design of the integrated swing type connecting rod and piston is even less. How to optimize the design of the piston compressor with integrated design of the integrated swing type connecting rod and piston to ensure the response sensitivity and stability of the automotive suspension system is a technical problem that needs to be solved. SUMMARY

[0005] The purpose of the present application is to provide a design method of an air suction hole of a gas-supplementing air suspension system air piston compressor, which optimizes the height, diameter, number and cross-sectional area of the air suction hole of the integrated swing type gas-supplementing piston air compressor to ensure the response sensitivity and stability of the automotive suspension system.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0007] A design method of an air suction hole of a gas-supplementing air suspension system air piston compressor, comprising the following steps:

[0008] Design of the height of the air supplementing hole;

[0009] The diameter of the air supplement hole, the number of the air supplement hole and the cross-sectional shape of the air supplement hole.

[0010] The height of the air supplement hole is designed to satisfy the power consumption per unit air supplement amount in the height design step of the air supplement hole. The minimum requirement.

[0011] The height of the air supplement hole is designed to satisfy the power consumption per unit air supplement amount in the height design step of the air supplement hole.

[0012]

[0013] The height of the air supplement hole is designed to satisfy the power consumption per unit air supplement amount in the height design step of the air supplement hole.

[0014] The state parameters P1, T1 and V1 of the gas in the suction state point are known quantities; the state parameters P4 and T4 of the gas when the air supplement starts after the compression Δt are unknown, and V4 is obtained according to the compressor speed N and the compression time Δt; when the pressure of the gas in the compression cavity reaches P3 and the air supplement is stopped with the stop valve closed, the piston top just reaches the uppermost part of the air supplement hole;

[0015] The state parameters P3 of the gas at the end of the gas supplementing are known, T3 is unknown, and V3 is obtained from the height h1 of the piston movement; the state parameters P3 and T3' of the gas supplemented into the compressor cavity are known; during the gas supplementing compression process, the original gas in the compression cavity, the gas supplemented into the compressor and the mixed gas after the gas supplementing are regarded as an adiabatic mixing process during the gas supplementing compression process, the mass and energy conservation laws are satisfied, the suction gas amount before the gas supplementing is known, and the gas supplementing amount m0 is unknown; after the gas supplementing is completed, the mixed gas is compressed to the exhaust point, and the state parameters P2, T2 and V2 of the gas at the exhaust state are known; the unknown parameters of the entire gas supplementing compression process are four: T3, P4, T4 and m0; the actual gas compression process from the state point 1 to the state point 4 satisfies the Van der Waals actual gas state equation; the adiabatic process from the state point 3 to the state point 4 satisfies the mass and energy conservation equations; the compression process from the state point 3 to the state point 2 satisfies the Van der Waals actual gas state equation; the gas state parameters at each state point and the gas supplementing amount m0 of the gas supplementing compression process are obtained by simultaneous solution; and the total power consumption of the entire gas supplementing compression process is calculated as follows:

[0016]

[0017] In the formula, V is the compression volume.

[0018] Further improvement of the present application is that the volume V4 of the state point 4 is solved as follows: at the end of the gas suction, the pressure of the gas is P1, the volume is V1, the temperature is T1, and the rotation speed of the compressor is N, then the rotation angular velocity of the crankshaft is ω, namely:

[0019]

[0020] The stop valve is opened at Δt moment after the compression process is started to supplement the gas to the compressor, the angle of the crankshaft rotation at the beginning of the gas supplementing is α, namely:

[0021]

[0022] The deflection angle of the piston surface is θ, namely:

[0023]

[0024] In the formula, l is the length of the piston rod, and r is the eccentric distance of the crankshaft;

[0025] The volume of the gas at the beginning of the gas supplementing is the volume of the compression cylinder, namely:

[0026]

[0027] In the formula, h and d are respectively the height and width of the compressor cylinder;

[0028] The actual state equation of the compression process from the state point 1 to the state point 4 is:

[0029]

[0030]

[0031] In the formula: P is the gas pressure; V is the gas volume; n is the gas mole number; R is the gas constant; T is the gas Kelvin temperature; a is the intermolecular attraction parameter; b is the molecular volume parameter;

[0032] At the end of the air supplement, the volume V3 of the state point 3 is solved as follows: the gas pressure in the compression cavity is P3, at this time, the piston top just reaches the uppermost of the air supplement hole, and the deflection angle of the piston at the end of the air supplement is calculated as follows:

[0033]

[0034]

[0035] The mass and energy conservation are met before and after the air supplement, the suction mass m s , the air supplement mass m0 and the total mass of the mixed gas after the air supplement m d The following equations are met:

[0036] m d = m s + m0 (14)

[0037] W + m s h4 + m0h0 = m d h3 (15)

[0038] Wherein, h0 is known, h4 is a function of P4 and T4, and is obtained according to the air property parameter table; h3 is a function of P3 and T3, wherein P3 is known, and T3 is to be solved;

[0039] After the air supplement is finished, the process from the state point 3 to the exhaust state point 2 meets the actual gas state equation, that is:

[0040]

[0041]

[0042] Equations (10), (11), (14), (15), (16) and (17) are solved respectively to obtain T3, P4, T4 and m0.

[0043] Further improvement of the application is that the diameter of the air supplement hole and the number of the air supplement hole are designed to meet the two requirements of the maximum air supplement amount in the same time and the minimum residual air amount in the air supplement pipeline after the air supplement at the same time.

[0044] The further improvement of the present application is that in the steps of designing the diameter of the air supplement hole and the number of the air supplement hole, the diameter and the number of the air supplement hole meet the two requirements of the maximum air supplement amount in the same time and the minimum residual air amount of the air supplement pipeline after air supplement at the same time; and the specific steps include the following steps.

[0045] The first step is to discretize the air supplement pipeline, determine the air density according to the temperature and pressure of the air at the air supplement starting point, and then determine the flow cross-sectional area of the gas in the pipeline according to the pipeline diameter;

[0046] The second step is to give an initial flow rate, calculate the flow resistance loss of the first initial microelement segment according to the Darcy-Weisbach formula, and iteratively solve the resistance loss and flow rate of the flow process;

[0047] The third step is to calculate the air flow and air supplement amount m0 according to the law of conservation of mass;

[0048] The fourth step is that the diffusion process of the residual air after air supplement to the inside of the suction cavity and the compression process of the suction process piston to the residual air both meet the Van der Waals real gas state equation, the initial pressure and temperature of the residual air are P3 and T3, the pressure and temperature after diffusion to the inside of the suction cavity are P5 and T5, the pressure P6 and temperature T6 after compression to the end of the suction process are determined by the Van der Waals real gas state equation, and the suction process power consumption of the compressor is calculated as follows:

[0049]

[0050] The total power consumption per unit air supplement amount is calculated as follows:

[0051]

[0052] The fifth step is to determine the diameter and number of the air supplement hole according to the total power consumption per unit air supplement amount. The minimum.

[0053] The further improvement of the present application is that in the step of designing the center line cross-sectional shape of the air supplement hole, the center line cross-sectional shape of the air supplement hole is an inclined circle.

[0054] The further improvement of the present application is that the air piston compressor includes a compressor shell, a crank, a connecting rod and a piston; the compressor shell is made of metal material; the connecting rod and the piston are an integrated connecting rod piston; a compressor cylinder is arranged in the compressor shell, and the piston is arranged in the compressor cylinder; a piston ring is mounted on the outer wall of the piston; and the connecting rod is connected to the crank.

[0055] The further improvement of the present application is that a plurality of air supplement holes are arranged on the compressor shell.

[0056] Compared with the prior art, the present application has the following beneficial effects:

[0057] The application provides a method for designing a gas supplementing air hole of an air piston compressor of an air suspension system of a vehicle, comprising the following steps: height design of the gas supplementing hole; diameter design of the gas supplementing hole, quantity design of the gas supplementing hole and design of a center line section shape of the gas supplementing hole. In the height design step of the gas supplementing hole, the height design of the gas supplementing hole satisfies the power consumption per unit gas supplementing amount The minimum requirement. The integrated design of the compressor valve piece is subjected to the vertical force acting on the valve piece surface and the lateral force caused by the swing movement of the piston rod during the compression and air suction process cycle; the application aims at the gas supplementing demand of the compressor of the air suspension system of the vehicle, and designs a high-efficiency gas supplementing piston compressor for the air suspension system of the vehicle; compared with the ordinary piston compressor, the gas supplementing crankshaft screw integrated design compressor designed in the application has higher compression efficiency and is more energy-saving. The gas can be compressed to the required pressure in a shorter time, and the response speed of the air suspension system is improved. BRIEF DESCRIPTION OF DRAWINGS

[0058] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application, and are incorporated in and constitute a part of this application. The embodiments of the application illustrated in the drawings, and their description, are presented to explain the application and not to limit or define the application. In the drawings:

[0059] Fig. 1 A structure schematic diagram of a gas supplementing air piston compressor of an air suspension system of a vehicle designed by the application.

[0060] Fig. 2 A working flow schematic diagram of a gas supplementing air piston compressor of an air suspension system of a vehicle designed by the application.

[0061] Fig. 3 A p-v flow schematic diagram of an air suction compression process of a gas supplementing air piston compressor of an air suspension system of a vehicle designed by the application. DETAILED DESCRIPTION

[0062] The application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other without conflict.

[0063] The following detailed description is exemplary and is intended to provide further detailed description of the application. Unless otherwise specified, all technical terms used in the application have the same meanings as those generally understood by the general technical personnel in the field to which the application belongs. The terms used in the application are only for the purpose of describing the specific embodiments and are not intended to limit the exemplary embodiments according to the application.

[0064] Embodiment 1

[0065] The air suspension system mainly comprises: air supply system (compressor 10, air tank 11, distribution valve), air spring, various sensors, etc. The compressor 10 inhales air from the atmosphere, compresses the air and discharges it into the air tank 11, and then adjusts the stiffness of the air spring and the height of the vehicle body by charging and discharging the air bag 12 through the distribution valve. Then, the remaining air is supplemented into the compression chamber of the compressor through the pipeline. The compressor is a rotary piston air compressor, and the crank connecting rod 3 is designed in one body, so that the piston is in a swing motion during the air suction and compression process. The swing angle θ of the piston swing motion is determined by the piston rod length l and the crank shaft eccentricity r.

[0066] Referring to Figs. 1 to 3 As shown in the figure, the present application provides a design method of air piston compressor for air-supplemented automobile suspension system, comprising the following steps: height design of air supplement hole 1, diameter design of air supplement hole 1, quantity design of air supplement hole 1, and correlation design of air supplement hole 1 center line section shape and piston swing inclination angle θ.

[0067] The height design of the air supplement hole 1 is constrained by the air supplement amount m0 and the cycle work W. The height design of the air supplement hole 1 needs to meet the minimum requirement of the work consumption per unit air supplement amount Each cycle period is divided into three processes: air suction, compression (air supplement), and air exhaust. Taking the air suction starting point as 0 time, the air suction end and the compression start as t0 time, the air suction pressure as P1, the stop valve 13 being opened to supplement air to the compressor at Δt time after the compression process starts, the pressure in the compression chamber being P4 at the beginning of air supplement, the air supplement pressure being P3, the compressor still being in the compression process during the air supplement process, the pressure of the gas in the compression chamber reaching P3, the air supplement being stopped, the stop valve being closed, and then the compressor continuously compressing the air with the pressure of P3 after air supplement to the air exhaust pressure P2, and then entering the air exhaust process to end a whole cycle.

[0068] The variables in the design calculation process are analyzed. First, the state parameters P1, T1 and V1 of the gas at the air suction state point are known quantities. The state parameters P4 and T4 of the gas at the beginning of air supplement after compression Δt are unknown, and V4 can be obtained according to the compressor speed N and the compression time Δt. When the pressure of the gas in the compression chamber reaches P3 and the stop valve is closed to stop air supplement, it is required that the piston top just reaches the uppermost part of the air supplement hole, i.e. from t0 time to the end of air supplement, the height h1 of the piston top rising, the thickness d1 of the piston sealing ring 4, the height h2 of the center of the air supplement hole 1 from the lower surface of the cylinder, and the diameter d2 of the air supplement hole meet the following conditions:

[0069]

[0070] At the end of the gas supplement, the state parameters P3 of the gas are known, T3 is unknown, and V3 can be obtained from the height h1 of the piston movement. The state parameters P3 and T3' of the gas supplemented into the compressor cavity are known. During the gas supplement compression process, the original gas in the compression cavity, the gas supplemented into the compressor, and the mixed gas after the gas supplement are considered as an adiabatic mixing process during the gas supplement compression process, satisfying the mass and energy conservation laws. The suction gas volume before the gas supplement is known, and the gas supplement volume m0 is unknown. After the gas supplement, the mixed gas is compressed to the exhaust point, and the state parameters P2, T2 and V2 of the gas at the exhaust state are known. As described above, there are four unknown parameters in the entire gas supplement compression process: T3, P4, T4 and m0. The gas supplement compression process satisfies: the actual gas compression process from state point 1 to state point 4, satisfying the Van der Waals actual gas state equation; the adiabatic process from state point 4 to state point 3, satisfying the mass and energy conservation equations; and the compression process from state point 3 to state point 2, satisfying the Van der Waals actual gas state equation. By simultaneous solution, the gas state parameters at each state point and the gas supplement volume m0 of the gas supplement compression process can be obtained. The total power consumption of the entire gas supplement compression process is calculated as follows:

[0071]

[0072] The power consumption per unit gas supplement is calculated as follows:

[0073]

[0074] Referring to the p-v flow chart of the compressor, the specific calculation steps are as follows: Fig. 3

[0075] First, the solving steps of V4 are as follows: at the end of the suction, the pressure of the gas is P1, the volume is V1, the temperature is T1, and the rotation speed of the compressor is N, then the angular velocity of the crankshaft is ω, that is:

[0076]

[0077] The stop valve is opened at time Δt after the start of the compression process to supplement the compressor, then the angle of the crankshaft rotation at the beginning of the gas supplement is α, that is:

[0078]

[0079] Then the deflection angle of the piston surface is θ, that is:

[0080]

[0081] The volume of the gas at the beginning of the gas supplement is the volume of the compression cylinder, that is:

[0082]

[0083] In the formula, h and d are the height and width of the compressor cylinder, respectively.​

[0084] The actual state equation of the compression process from state point 1 to state point 4 is:

[0085]

[0086]

[0087] wherein P is the gas pressure; V is the gas volume; n is the gas mole number; R is the gas constant, for air, 8.314 J / (mol·K) can be used as the general gas constant; T is the gas Kelvin temperature; a is the intermolecular attraction parameter; and b is the molecular volume parameter.

[0088] At the end of the air charge, the solving step of V3 is as follows: the gas pressure in the compression cavity is P3, at this time the piston top just reaches the uppermost of the air charge orifice, so the deflection angle of the piston at the end of the air charge is calculated as follows:

[0089]

[0090]

[0091] The mass and energy conservation are satisfied before and after the air charge, that is, the air intake mass m s , the air charge mass m0, and the total mass of the mixed gas after the air charge m d satisfy the following equations:

[0092] m d = m s + m0 (14)

[0093] W + m s h4 + m0h0 = m d h3 (15)

[0094] wherein h0 is known, h4 is a function of P4 and T4, and can be obtained according to the air property parameter table. Similarly, h3 is a function of P3 and T3, wherein P3 is known, and T3 is to be solved.

[0095] After the end of the air charge, the process from state point 3 to the exhaust state point 2 satisfies the actual gas state equation, that is:

[0096]

[0097]

[0098] In summary, the basic unknown independent variables are four: T3, P4, T4 and m0, which can be solved by simultaneously solving equations (10), (11), (14), (15), (16) and (17), to obtain T3, P4, T4 and m0.

[0099] The air supplement amount m0 of the air supplement compression process is related to the pressure difference between the state point 3 and the state point 4, and is also affected by the diameter design and the number design of the air supplement hole 1. Therefore, the diameter and the number of the air supplement hole 1 need to meet the two requirements of the maximum air supplement amount in the same time and the minimum residual air amount in the air supplement pipeline after air supplement, and the diameter and the number of the air supplement hole mainly affect the air supplement amount by affecting the flow resistance loss.

[0100] The specific determination steps of the diameter and the number of the air supplement hole 1 are as follows:

[0101] First step: Discretize the air supplement pipeline, determine the air density according to the temperature and the pressure of the air at the air supplement starting point, and then determine the gas flow cross-sectional area in the pipeline according to the pipeline diameter.

[0102] Second step: Given the initial flow rate, calculate the flow resistance loss of the first initial microelement segment according to the Darcy-Weisbach formula. Iteratively solve the resistance loss and the flow rate of the flow process.

[0103] Third step: Calculate the air flow rate and the air supplement amount m0 according to the law of conservation of mass.

[0104] Fourth step: The residual air amount after air supplement mainly affects the power consumption of the compressor in the suction process. The diffusion process of the residual air into the suction cavity and the compression process of the residual air by the piston in the suction process both satisfy the Van der Waals real gas state equation. The initial pressure and the temperature of the residual air are P3 and T3, the pressure and the temperature after diffusion into the suction cavity are P5 and T5, and the pressure P6 and the temperature T6 after compression to the end of the suction process can be determined by the Van der Waals real gas state equation. The power consumption of the suction process of the compressor is calculated as follows:

[0105]

[0106] Then, the total power consumption per unit air supplement amount is calculated as follows:

[0107]

[0108] Fifth step: According to The minimum, determine the diameter and the number of the air supplement hole 1.

[0109] The centerline cross-sectional shape of the air supplement hole 1 should be parallel to the upper surface 2 of the piston when the piston runs to a height h1, so as to reduce the influence of air supplement on the compression process, that is, the centerline cross-sectional shape of the air supplement hole 1 is an inclined circle.

[0110] It is apparent that the application can be carried out by other embodiments that do not depart from the spirit or essential characteristics thereof. Consequently, the above disclosure is considered as illustrative only and not restrictive on the application. As various changes could be made in the above compositions without departing from the scope of the application, it is intended that all changes fall within the scope of the application as claimed in the appended claims.

Claims

1. A method for designing the intake port of an air piston compressor in a fuel-injected automotive suspension system, characterized in that, Includes the following steps: Design of the height of the air inlet; Design of the diameter of the air inlet, the number of air inlet openings, and the cross-sectional shape of the centerline of the air inlet; In the step of designing the height of the air inlet, the height design of the air inlet must meet the power consumption per unit air inlet volume. Minimum requirement; In the design step of the air inlet height, from the end of intake and the start of compression at time t0 to the end of air inlet, the piston top rise height h1, the piston sealing ring thickness d1, the height h2 of the air inlet center from the lower surface of the cylinder, and the air inlet diameter d2 must satisfy the following conditions: In the design of the diameter and number of air inlet holes, the diameter and number of air inlet holes must simultaneously meet two requirements: maximizing the air supply volume within the same time period and minimizing the residual air volume in the air supply pipeline after air supply. Specifically, this includes the following steps: Step 1: Discretize the air supply pipeline and determine the air density based on the air temperature and pressure at the air supply starting point; then determine the cross-sectional area of ​​the gas flow in the pipeline based on the pipeline diameter. Step 2: Given an initial flow velocity, calculate the flow resistance loss of the first initial infinitesimal segment using the Darcy-Weisbach formula; iterate the solution for the flow resistance loss and flow velocity during the flow process. Step 3: Calculate the air flow rate and replenishment volume m0 according to the law of conservation of mass; Step 4: The diffusion process of the residual gas into the intake chamber after replenishment and the compression process of the residual gas by the piston during the intake process both satisfy the van der Waals equation of state for a real gas. The initial pressure and temperature of the residual gas are P3 and T3, respectively. The pressure and temperature after diffusion into the intake chamber are P5 and T5, respectively. The pressure P1 and temperature T6 after compression to the end of the intake process are determined by the van der Waals equation of state for a real gas. The power consumption of the compressor during the intake process is calculated as follows: The total power consumption per unit of replenished gas volume is calculated as follows: Step 5: Based on the total power consumption per unit of replenished gas volume Minimum, determine the diameter and number of air inlet holes.

2. The method for designing the intake port of an air piston compressor for a supplementary air suspension system according to claim 1, characterized in that, In the height design step of the air replenishment port, the starting point of air intake is taken as time 0, the end of air intake and the start of compression is taken as time t0, the intake pressure is P1, and the shut-off valve is opened at time Δt after the compression process starts to replenish the compressor with air. When the air replenishment starts, the pressure in the compression chamber is P4, and the pressure of the replenished gas is P3. During the air replenishment process, the compressor is still in the compression process. When the pressure of the gas in the compression chamber reaches P3, the air replenishment stops, the shut-off valve is closed, and then the compressor continues to compress the air with the replenished pressure of P3 to the exhaust pressure P2, and then enters the exhaust process to end a whole cycle. The state parameters P1, T1, and V1 of the gas at the intake state point are all known quantities; when gas replenishment begins after compression Δt, the state parameters P4 and T4 of the gas are unknown, and V4 is obtained based on the compressor speed N and compression duration Δt; when the pressure of the gas in the compression chamber reaches P3 and the shut-off valve closes to stop gas replenishment, the top of the piston just reaches the top of the gas replenishment port. At the end of the gas replenishment process, the gas state parameters P3 and T3 are known, and V3 is obtained from the piston's height h1. The state parameters P3 and T3′ of the gas replenished into the compressor cavity are known. During the gas replenishment compression process, the original gas in the compression cavity, the gas replenished into the compressor, and the gas mixture after replenishment are considered as an adiabatic mixing process, satisfying the laws of conservation of mass and energy. The intake volume before replenishment is known, and the replenishment volume m0 is unknown. After the gas replenishment is completed, the mixed gas is compressed to the exhaust point, and the state parameter P2 of the exhaust gas is unknown. T2 and V2 are both known quantities; there are four unknown parameters in the entire gas-fuel compression process: T3, P4, T4, and m0; the actual gas compression process from intake state point 1 to state point 4 satisfies the van der Waals equation of state for a real gas; the adiabatic process from state point 4 to state point 3 satisfies the mass and energy conservation equations; the compression process from state point 3 to state point 2 satisfies the van der Waals equation of state for a real gas; solving these equations simultaneously yields the gas state parameters and the gas-fuel quantity m0 at each state point in the gas-fuel compression process; the total power consumption of the entire gas-fuel compression process is calculated as follows: In the formula, V is the compression volume.

3. The method for designing the intake port of an air piston compressor for a supplemental air suspension system according to claim 2, characterized in that, The steps to solve for the volume V4 at state point 4 are as follows: At the end of intake, the gas pressure is P1, the volume is V1, the temperature is T1, and the compressor speed is N. Then the crankshaft's angular velocity is ω, that is: After the compression process starts, at time Δt, the shut-off valve is opened to supply gas to the compressor. The crankshaft rotation angle at the start of gas supply is α, that is: The deflection angle of the piston surface is θ, that is: Where l is the piston rod length and r is the crankshaft eccentricity; When the air supply begins, the gas volume is equal to the volume of the compression cylinder, that is: In the formula: h and d are the height and width of the compressor cylinder, respectively; The actual state equation for the compression process from state point 1 to state point 4 is: Where: P is the gas pressure; V is the gas volume; n is the number of gas moles; R is the gas constant; T is the Kelvin temperature of the gas; a is the intermolecular attraction parameter; b is the molecular volume parameter; When the gas replenishment is complete, the steps to calculate the volume V3 at state point 3 are as follows: The gas pressure inside the compression chamber is P3. At this time, the top of the piston just reaches the top of the gas replenishment port. The piston deflection angle at the end of the gas replenishment is calculated as follows: Before and after nitro air replenishment, mass and energy are conserved, and the inspiratory mass m s The mass of the replenished gas m0 and the total mass of the mixed gas after replenishment m d Satisfy the following equation: m d =m s +m0 (14) W+m s h4+m0h0=m d h3 (15) Where h0 is the enthalpy of the supplementary gas, which is a known quantity; h4 is a function of P4 and T4, obtained from the table of physical properties of air; h3 is a function of P3 and T3, where P3 is known and T3 is to be solved. After the gas replenishment is completed, the process from state point 3 to exhaust state point 2 satisfies the actual gas state equation, that is: Solve the equations (10), (11), (14), (15), (16) and (17) simultaneously to obtain T3, P4, T4 and m0.

4. The method for designing the intake port of an air piston compressor for a supplementary air suspension system according to claim 1, characterized in that, In the design of the diameter and number of air inlets, the diameter and number of air inlets must simultaneously meet the two requirements of maximizing the air supply volume within the same time period and minimizing the residual air volume in the air supply pipeline after air supply.

5. The method for designing the intake port of an air piston compressor for a supplemental air suspension system according to claim 1, characterized in that, In the design steps of the cross-sectional shape of the centerline of the air inlet, the cross-sectional shape of the centerline of the air inlet is an inclined circle.

6. The method for designing the intake port of an air piston compressor for a supplemental air suspension system according to claim 1, characterized in that, An air piston compressor includes a compressor housing, a crank, a connecting rod, and a piston; the compressor housing is made of metal; the connecting rod and piston are an integral connecting rod piston; a compressor cylinder is provided inside the compressor housing, and the piston is located in the compressor cylinder; piston rings are installed on the outer wall of the piston; the connecting rod is connected to the crank.

7. The method for designing the intake port of an air piston compressor for a supplemental air suspension system according to claim 6, characterized in that, The compressor housing has multiple air inlet holes.

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