Air suspension system air supply unit and air supply method thereof

Abstract

The present invention discloses an air supply unit for an air suspension system and an air supply method thereof, comprising a forward charging unit, a reverse exhaust unit and a controller; the forward charging unit comprises an electric air pump, an air storage tank, a first one-way valve and a first switch solenoid valve; the air outlet interface of the electric air pump, the first one-way valve and the air storage tank are connected in sequence, and the air storage tank is charged by the electric air pump; the first switch solenoid valve is connected between the automobile air spring assembly and the pipeline between the first one-way valve and the air storage tank, and the automobile air spring assembly is supplemented with air through the air storage tank; the reverse exhaust unit comprises a second switch solenoid valve, a third switch solenoid valve, a fourth switch solenoid valve and a conversion cylinder. The conversion cylinder is provided with a low-pressure interface and a high-pressure interface, and the second switch solenoid valve is connected between the automobile air spring assembly and the high-pressure interface. The present invention increases the energy recovery and utilization function of the air suspension system, while reducing the failure rate and energy consumption of the air pump.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile air suspension, and in particular relates to an air supply unit of an air suspension system and an air supply method thereof. Background Art

[0002] The suspension system refers to the entire support system composed of springs and shock absorbers between the car body and the tires. The function of the suspension system is to support the car body and improve the riding experience. Different types of suspension systems will give drivers different driving experiences. Among the many suspension systems, the air suspension system has developed rapidly in recent years and has attracted great attention from consumers. It is also one of the key research objects of automobile chassis manufacturers.

[0003] The air suspension system is different from the traditional spring suspension system. It uses air springs to support the vehicle body and adjusts the air pressure and vehicle height by electrical or mechanical means to achieve better suspension comfort, stability and speed change performance. The application number is CN201910058168.0, an air suspension system, a working method of the air suspension system and a car. The axle of the car is connected to the frame through the air suspension system. The air suspension system includes a first air spring and a second air spring arranged in parallel with each other. The first air spring and the second air spring are both connected between the frame and the axle. The air suspension system also includes a height fixing device. The two ends of the height fixing device are respectively connected to the frame and the axle. The extension direction of the height fixing device is parallel to the extension direction of the first air spring. The height fixing device can be extended and retracted along the extension direction of the first air spring, that is, the air suspension system can achieve height and stiffness decoupling adjustment.

[0004] The air pump in the above air suspension system is responsible for inputting high-pressure gas into the air tank, and the air tank is responsible for inputting high-pressure gas into the air spring. When the height of the vehicle body needs to be increased, that is, the length of the air spring needs to be extended, the air tank is responsible for outputting high-pressure gas to the air spring; when the height of the vehicle body needs to be lowered, that is, the length of the air spring needs to be shortened, the air spring discharges its internal high-pressure gas directly into the surrounding atmosphere, and when the length of the air spring needs to be extended again, the air tank needs to output high-pressure gas to the air spring again. As long as the gas in the air tank is discharged, the air pump needs to input high-pressure gas into the air tank. However, this air suspension system has the following shortcomings:

[0005] 1. The high-pressure gas in the air spring is directly discharged without being recycled, resulting in energy waste.

[0006] 2. After the high-pressure gas of the air spring is discharged, the air pump needs to add a corresponding amount of compressed air to the air tank. Since the air suspension system needs to be adjusted at any time according to road conditions during driving, the air spring may be discharged frequently, which will cause the air pump to work for a long time and increase the failure rate of the air pump.

[0007] 3. The air pump of some cars is driven by electricity, such as new energy vehicles. The air pump is one of the more powerful components in the air suspension system. The air pump works for a long time and consumes a lot of electricity, which affects the car's endurance. Summary of the invention

[0008] In view of the deficiencies of the prior art, the energy recovery and utilization function of the air suspension system is increased, while the failure rate and energy consumption of the air pump are reduced. The present invention provides an air supply unit for an air suspension system, including a forward inflation unit, a reverse exhaust unit and a controller; the forward inflation unit includes an electric air pump, an air tank, a first one-way valve and a first switch solenoid valve; the air outlet interface of the electric air pump, the first one-way valve and the air tank are connected in sequence, and the air tank is inflated by the electric air pump; the first switch solenoid valve is connected to the automobile air spring assembly and the pipeline between the first one-way valve and the air tank, and the automobile air spring assembly is replenished with air through the air tank; the reverse exhaust unit includes a second switch solenoid valve, a third switch solenoid valve, a fourth switch solenoid valve and a conversion cylinder; the conversion cylinder is provided with a low-pressure interface and a high-pressure interface, and the second switch solenoid valve A pipeline connected between the automobile air spring assembly and the high-pressure interface, and between the second switch solenoid valve and the high-pressure interface, and a pipeline between the first one-way valve and the air tank, is provided with a second one-way valve for preventing gas from flowing back from the air tank to the high-pressure interface; the third switch solenoid valve is connected between the automobile air spring assembly and the low-pressure interface, and the pipeline between the third switch solenoid valve and the low-pressure interface is connected to the exhaust source through the fourth switch solenoid valve, and the pipeline between the third switch solenoid valve and the low-pressure interface is connected to the pipeline between the electric air pump and the first one-way valve; the controller is electrically connected to the electric air pump, the first switch solenoid valve, the second switch solenoid valve, the third switch solenoid valve and the fourth switch solenoid valve, respectively.

[0009] Compared with the prior art, the advantages of the present invention include:

[0010] 1. During the shortening process of the automobile air spring assembly, the compressed air discharged is not discharged directly, but the compressed air is pressurized and pressed into the air tank by switching back and forth of the conversion cylinder, so as to make full use of the energy in the discharged compressed air and realize energy recovery.

[0011] 2. The pressurization process of the conversion cylinder is actually the on-off combination of the first switch solenoid valve, the second switch solenoid valve, the third switch solenoid valve and the fourth switch solenoid valve controlled by the controller, and the controller, the first switch solenoid valve, the second switch solenoid valve, the third switch solenoid valve and the fourth switch solenoid valve themselves have low power consumption. The air pressure discharged from the automobile air spring assembly can be increased only by converting the cylinder, the on-off sequence of the solenoid valve and reasonable pipeline layout, that is, the energy recovery of the air suspension system is achieved with low energy consumption, and the energy consumption of the automobile itself is extremely low, and the original endurance of the automobile is not affected.

[0012] 3. Compared with the existing air suspension system, the reverse exhaust unit in the present invention can reversely compress the compressed air that needs to be discharged into the air tank, which can reduce the consumption rate of compressed air in the air tank and correspondingly reduce the working time of the electric air pump, which is beneficial to extend the service life of the electric air pump and reduce the failure rate.

[0013] 4. The electric air pump works for a shorter time and consumes less electricity. For new energy pure electric vehicles, the consumption of the battery is correspondingly reduced, and the impact on the cruising range is smaller.

[0014] Preferably, a drying tank is provided in the pipeline between the electric air pump and the first one-way valve, and the air inlet interface of the drying tank is connected to the pipeline between the fourth switch solenoid valve and the electric air pump, and the air outlet interface of the drying tank is connected to the pipeline between the third switch solenoid valve and the low-pressure interface. The air outlet interface and the back-blowing interface of the drying tank are connected to the pipeline between the third switch solenoid valve and the low-pressure interface through a two-position three-way solenoid valve, which is used to switch the filtering state and the back-blowing state of the drying tank. The compressed air output by the electric air pump contains moisture, and the moisture in the wet compressed air is adsorbed and intercepted in the drying tank after passing through the drying tank. A part of the compressed air released by the automobile air spring assembly is compressed into the air storage tank for recycling, and another part of the compressed air enters from the back-blowing interface of the drying tank to blow out the moisture adsorbed in the drying tank, and finally passes through the fourth switch solenoid valve and is discharged from the exhaust source to the atmosphere. Even if this part of the compressed air is discharged externally, it is not directly discharged to the atmosphere, but the energy of this part of the compressed air is fully utilized to recoil the drying tank to achieve drainage, so as to ensure that the drying tank is in a normal filtering state for a long time.

[0015] Preferably, a pneumatic relief valve is provided in the pipeline between the drying tank and the electric air pump. If the outlet pressure of the electric air pump increases abnormally and exceeds the safety pressure of the pneumatic relief valve due to other reasons such as the drying tank, the solenoid valve, and the pipeline, the pneumatic relief valve will automatically open to prevent the electric air pump, pipeline, etc. from being damaged by excessive pressure.

[0016] Preferably, the conversion cylinder comprises a cylinder body, a low-pressure end cover, a high-pressure end cover and a piston body; the low-pressure end cover and the high-pressure end cover are respectively sealed and connected to the two ends of the cylinder body, the piston body is slidably sealed in the piston cavity of the cylinder body, and the push rod of the piston body extends from the high-pressure end cover; the piston body slides in the piston cavity, thereby making the piston cavity between the piston body and the low-pressure end cover become a low-pressure piston cavity, and making the piston cavity between the piston body and the high-pressure end cover become a high-pressure piston cavity; the low-pressure interface and the high-pressure interface are respectively connected to the low-pressure piston cavity and the high-pressure piston cavity in a one-to-one correspondence. The area of ​​the piston body corresponding to the low-pressure piston cavity is greater than the area of ​​the piston body corresponding to the high-pressure piston cavity, and there is an area difference between the two, resulting in different pressures in the two cavities. When compressed air enters from the low-pressure piston cavity, it pushes the piston body to move to the side of the high-pressure end cover, thereby forming compressed air with a higher pressure than the air pressure of the gas storage tank in the high-pressure piston cavity, which is sufficient to press the compressed air in the high-pressure piston cavity into the gas storage tank to achieve energy recovery.

[0017] The present invention also provides an air supply method for an air supply unit of an air suspension system, which includes two steps of forward inflation and reverse exhaust. The forward inflation is similar to the existing inflation direction, and both are through, the electric air pump is started, the drying tank is switched to the filtering state through the two-position three-way solenoid valve, and then the compressed air is respectively pressed into the air storage tank and the low-pressure piston cavity after passing through the drying tank, until the current air pressure in the air storage tank reaches the set air pressure, and the electric air pump is turned off. The first switch solenoid valve is opened, and the compressed air in the air storage tank is added to the automobile air spring assembly until the air pressure of the automobile air spring assembly reaches the preset value, and the first switch solenoid valve is closed.

[0018] Compared with the exhaust method of the existing air suspension system, the existing air suspension system directly exhausts the compressed air, while the reverse exhaust of the present invention is to open both the second switch solenoid valve and the fourth switch solenoid valve, and the drying tank is switched to the backflush state through the two-position three-way solenoid valve. The compressed air of the automobile air spring assembly enters the high-pressure piston chamber and pushes the piston body to the low-pressure end cover, thereby allowing the compressed air in the low-pressure piston chamber to enter from the backflush interface of the drying tank, and finally discharged through the fourth switch solenoid valve, and the fourth switch solenoid valve is closed. The function of this step is to push the piston to one side of the low-pressure end cover, and at the same time, the compressed air in the low-pressure piston chamber passes through the backflush interface to reverse the moisture in the drying tank and then discharges it to the atmosphere, preparing for subsequent pressurization. Then, the second switch solenoid valve is closed, the third switch solenoid valve is opened, the compressed air of the automobile air spring assembly enters the low-pressure piston chamber and pushes the piston body to the high-pressure end cover, thereby pressing the compressed air in the high-pressure piston chamber into the air storage tank, and the third switch solenoid valve is closed. Since the air pressure in the air tank is higher than the air pressure of the automobile air spring assembly, the pressure-increasing effect is obtained by utilizing the piston area difference of the conversion cylinder, and the air pressure in the high-pressure piston chamber is increased to be greater than the air pressure in the air tank, and the compressed air in the high-pressure piston chamber is smoothly pressed into the air tank to achieve energy recovery. Finally, the above steps are repeated until all the compressed air that needs to be discharged from the automobile air spring assembly is pressed into the air tank and discharged from the fourth switch solenoid valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 This is a connection diagram of Embodiment 1;

[0021] Figure 2 It is a structural schematic diagram of the conversion cylinder in the first embodiment;

[0022] Figure 3 for Figure 2 Schematic diagram of the splitting;

[0023] Figure 4 for Figure 2 A cross-sectional view of

[0024] Figure 5 The connection diagram of the second embodiment Figure 1 ;

[0025] Figure 6 The connection diagram of the second embodiment Figure 2 .

[0026] Figure numerals: 1. controller; 2. electric air pump; 3. air storage tank; 4. first one-way valve; 5. second one-way valve; 6. first switch solenoid valve; 7. second switch solenoid valve; 8. third switch solenoid valve; 9. fourth switch solenoid valve; 10. fifth switch solenoid valve; 11. two-position three-way solenoid valve; 12. drying tank; 13. conversion cylinder; 14. automobile air spring assembly; 15. exhaust source; 16. cylinder body; 17. low-pressure end cover; 18. high-pressure end cover; 19. piston body; 20. low-pressure interface; 21. high-pressure interface. DETAILED DESCRIPTION

[0027] In view of the deficiencies in the prior art, the inventor of this case has proposed the technical solution of the present invention after long-term research and extensive practice. The following will further explain the technical solution, its implementation process and principle, etc. in conjunction with the drawings in the embodiments of this application and specific implementation cases.

[0028] It should be noted that the embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, the present invention covers any substitution, modification, equivalent method and scheme made on the spirit, principle and scope of the present invention defined by the claims. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In the description of the present application, "first", "second", "third" and similar words do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, "one" or "an" and other similar words do not indicate a quantity limitation, but indicate the existence of at least one. "Include" or "comprise" and other similar words mean that the elements or objects appearing before "include" or "comprises" include the elements or objects listed after "include" or "comprises" and their equivalents, and do not exclude other elements or objects. "Connect" or "connected" and other similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0030] Embodiment 1:

[0031] Embodiment 1 provides an air suspension system air supply unit, which can be used for the air suspension system of existing internal combustion engine vehicles, the air suspension system of new energy vehicles, including pure electric new energy vehicles, hybrid new energy vehicles, and other vehicles with air suspension systems, which are not limited in this embodiment.

[0032] The air supply unit in this embodiment is as follows:

[0033] like Figure 1 As shown, the air supply unit includes a forward inflation unit, a reverse exhaust unit and a controller 1, wherein the controller 1 adopts a programmable on-board control unit. The on-board control unit is generally integrated on the vehicle's ECU, and its specific model is not limited. The ECU technology is mature and stable to meet the functions of the forward inflation unit and the reverse exhaust unit.

[0034] The forward inflation unit in this embodiment includes an electric air pump 2, an air tank 3, a first one-way valve 4 and a first switch solenoid valve 6. The air outlet interface of the electric air pump 2, the first one-way valve 4 and the air tank 3 are connected in sequence, and the air tank 3 is inflated through the electric air pump 2. A pneumatic overflow valve is provided at the air outlet interface of the electric air pump 2, and the pneumatic overflow valve is provided with a safety air pressure value. Once the real-time air pressure of the air outlet interface of the electric air pump 2 is higher than the safety air pressure value, the pneumatic overflow valve automatically opens to avoid excessive pressure from damaging the electric air pump 2, pipelines, etc. The first switch solenoid valve 6 is connected between the automobile air spring assembly 14 and the pipeline between the first one-way valve 4 and the air tank 3, and the automobile air spring assembly 14 is replenished with air through the air tank 3.

[0035] The reverse exhaust unit in this embodiment is as follows:

[0036] The reverse exhaust unit includes a second switch solenoid valve 7, a third switch solenoid valve 8, a fourth switch solenoid valve 9 and a conversion cylinder 13. The conversion cylinder 13 is provided with a low-pressure interface 20 and a high-pressure interface 21, the second switch solenoid valve 7 is connected between the automobile air spring assembly 14 and the high-pressure interface 21, and the pipeline between the second switch solenoid valve 7 and the high-pressure interface 21 and the pipeline between the first check valve 4 and the gas tank 3 are provided with a second check valve 5 for preventing gas from flowing back from the gas tank 3 to the high-pressure interface 21. The conduction direction of the first check valve 4 is toward the direction where the gas tank 3 is located, and the conduction direction of the second check valve 5 is toward the direction where the high-pressure interface 21 is located. The third switch solenoid valve 8 is connected between the automobile air spring assembly 14 and the low-pressure interface 20, and the pipeline between the third switch solenoid valve 8 and the low-pressure interface 20 is connected to the exhaust source 15 through the fourth switch solenoid valve 9, and the pipeline between the third switch solenoid valve 8 and the low-pressure interface 20 is connected to the pipeline between the electric air pump 2 and the first check valve 4.

[0037] The specific structure of the conversion cylinder 13 in this embodiment is as follows:

[0038] like Figures 2 to 4As shown, the conversion cylinder 13 includes a cylinder body 16, a low-pressure end cover 17, a high-pressure end cover 18 and a piston body 19; the low-pressure end cover 17 and the high-pressure end cover 18 are respectively sealed and connected to the two ends of the cylinder body 16, the piston body 19 is slidably sealed in the piston cavity of the cylinder body 16, and the push rod of the piston body 19 extends from the high-pressure end cover 18; the piston body 19 slides in the piston cavity, thereby making the piston cavity between the piston body 19 and the low-pressure end cover 17 become a low-pressure piston cavity, and making the piston cavity between the piston body 19 and the high-pressure end cover 18 become a high-pressure piston cavity; the low-pressure interface 20 and the high-pressure interface 21 are respectively connected to the low-pressure piston cavity and the high-pressure piston cavity in a one-to-one correspondence. The area of ​​the piston body 19 corresponding to the low-pressure piston cavity is larger than the area of ​​the piston body 19 corresponding to the high-pressure piston cavity, and there is an area difference between the two, resulting in different pressures in the two cavities. When compressed air enters from the low-pressure piston chamber, it pushes the piston body 19 to move toward the high-pressure end cover 18, thereby forming compressed air with a higher pressure than that of the air storage tank 3 in the high-pressure piston chamber.

[0039] The controller 1 in this embodiment is electrically connected to the electric air pump 2, the first switch solenoid valve 6, the second switch solenoid valve 7, the third switch solenoid valve 8 and the fourth switch solenoid valve 9 respectively. The storage module of the controller 1 stores the automatic operation program of the forward charging unit and the reverse exhaust unit. The automatic operation program of the forward charging unit is: start the electric air pump 2, pressurize the air tank 3 to the set pressure, and then control the on and off of the first switch solenoid valve 6 to replenish air to the air suspension system at any time. The automatic operation program of the reverse exhaust unit is to use the on and off of the second switch solenoid valve 7, the third switch solenoid valve 8 and the fourth switch solenoid valve 9, and the pressure ratio of the conversion cylinder 13 to press the compressed air discharged from the air suspension system into the air tank 3 for reuse, which can reduce the compressed air consumption rate of the air tank 3, and correspondingly reduce the working time of the electric air pump 2, which is conducive to extending the service life of the electric air pump 2 and reducing the failure rate. In addition, the working time of the electric air pump 2 is shorter and the electric energy consumed is less. For new energy pure electric vehicles, the consumption of the battery is correspondingly reduced, and the impact on the endurance time is smaller.

[0040] Embodiment 2:

[0041] Embodiment 2 provides another air suspension system air supply unit. Embodiment 2 has the same reference numerals as Embodiment 1. Embodiment 2 differs from Embodiment 1 in that: a water filter and a reverse discharge pipeline are added on the basis of Embodiment 1, as follows:

[0042] like Figure 5As shown, a drying tank 12 is provided in the pipeline between the electric air pump 2 and the first one-way valve 4, and the air inlet interface of the drying tank 12 is connected to the pipeline between the fourth switch solenoid valve 9 and the electric air pump 2, and the air outlet interface of the drying tank 12 is connected to the pipeline between the third switch solenoid valve 8 and the low-pressure interface 20. The air outlet interface and the back-blowing interface of the drying tank 12 are connected to the pipeline between the third switch solenoid valve 8 and the low-pressure interface 20 through a two-position three-way solenoid valve 11, which is used to switch the filtering state and the back-blowing state of the drying tank 12. The two-position three-way solenoid valve 11 here is electrically connected to the controller 1. The pneumatic overflow valve is arranged in the pipeline between the drying tank 12 and the electric air pump 2. If the outlet pressure of the electric air pump 2 increases abnormally and exceeds the safety air pressure of the pneumatic overflow valve due to other reasons of the drying tank 12, the solenoid valve, and the pipeline, the pneumatic overflow valve will automatically open.

[0043] The compressed air output by the electric air pump 2 in this embodiment contains moisture. The moisture in the wet compressed air is absorbed and intercepted in the drying tank 12 after passing through the drying tank 12. A part of the compressed air released by the automobile air spring assembly 14 is pressed into the air storage tank 3 for recycling, and another part of the compressed air enters from the back-blowing interface of the drying tank 12 to blow out the moisture absorbed in the drying tank 12, and finally passes through the fourth switch solenoid valve 9 and is discharged to the atmosphere from the exhaust source 15. Even if this part of the compressed air is discharged, it is not directly discharged to the atmosphere, but the energy of this part of the compressed air is fully utilized to recoil the drying tank 12 to achieve drainage, ensuring that the drying tank 12 is in a normal filtering state for a long time.

[0044] In addition, if Figure 6 As shown, most automobile air spring assemblies 14 are provided with four groups, that is, each wheel corresponds to a group of automobile air spring assemblies 14, and the four groups of automobile air spring assemblies 14 are respectively connected to the first switch solenoid valve 6, and a fifth switch solenoid valve 10 can also be provided at each automobile air spring assembly 14, and the four fifth switch solenoid valves 10 are respectively connected to the first switch solenoid valve 6. That is, the first switch solenoid valve 6 serves as the total on-off solenoid valve of the four automobile air spring assemblies 14, and the four fifth switch solenoid valves 10 serve as the branch on-off solenoid valves. The advantage of such a setting is that when a single automobile air spring assembly 14 is repaired, the fifth switch solenoid valve 10 corresponding to the automobile air spring assembly 14 can be closed to avoid affecting the remaining three automobile air spring assemblies 14.

[0045] Embodiment three:

[0046] Embodiment 3 provides an air supply method for an air supply unit of an air suspension system. Embodiment 3 has the same reference numerals as Embodiment 2, and the air supply method of Embodiment 3 is based on the air supply unit of the air suspension system of Embodiment 2.

[0047] The air supply method of the third embodiment includes forward inflation and reverse exhaust, and the forward inflation steps are as follows:

[0048] The electric air pump 2 is started, and the drying tank 12 is switched to the filtering state through the two-position three-way solenoid valve 11. The filtering state means that the air inlet and air outlet interfaces of the drying tank 12 are connected to the pipeline, so that the compressed air is respectively pressed into the air storage tank 3 and the low-pressure piston chamber after passing through the drying tank 12, until the current air pressure in the air storage tank 3 reaches the set air pressure, and then the electric air pump 2 is turned off. The first switch solenoid valve 6 is opened, and if a fifth switch solenoid valve 10 is provided, the fifth switch solenoid valve 10 is opened at the same time. The compressed air in the air storage tank 3 is replenished into the automobile air spring assembly 14 until the air pressure of the automobile air spring assembly 14 reaches the preset value, and the first switch solenoid valve 6 is closed, and if a fifth switch solenoid valve 10 is provided, the fifth switch solenoid valve 10 is closed at the same time.

[0049] After forward inflation, during the reverse inflation process, the fifth switch solenoid valve 10 needs to be in an open state, and the steps of reverse inflation are as follows:

[0050] The second switch solenoid valve 7 and the fourth switch solenoid valve 9 are both open, and the drying tank 12 is switched to the back-blowing state through the two-position three-way solenoid valve 11. In the back-blowing state, the back-blowing interface and the air outlet interface of the drying tank 12 are connected to the pipeline. However, if the air pressure of the air storage tank 3 is lower than that of the automobile air spring assembly 14, the second switch solenoid valve 7 is opened, and the fourth switch solenoid valve 9 is kept closed first. When the compressed air in the automobile air spring assembly 14 is first pressed into the air storage tank 3 and reaches equal air pressure, the fourth switch solenoid valve 9 is opened. This special situation may be that the air storage tank 3 is used for other pneumatic parts and the air is not replenished in time, causing the air storage tank 3 to be short of air. Then the compressed air of the automobile air spring assembly 14 enters the high-pressure piston chamber and pushes the piston body 19 to the low-pressure end cover 17, so that the compressed air in the low-pressure piston chamber enters from the back-blowing interface of the drying tank 12, and finally is discharged through the fourth switch solenoid valve 9, and the fourth switch solenoid valve 9 is closed. The function of this step is to push the piston to one side of the low-pressure end cover 17, and at the same time, the compressed air in the low-pressure piston chamber is discharged to the atmosphere through the recoil interface to discharge the moisture in the drying tank 12, so as to prepare for the subsequent pressurization. Then, the second switch solenoid valve 7 is closed, the third switch solenoid valve 8 is opened, the compressed air of the automobile air spring assembly 14 enters the low-pressure piston chamber and pushes the piston body 19 to the high-pressure end cover 18, and then the compressed air in the high-pressure piston chamber is pressed into the air storage tank 3, and the third switch solenoid valve 8 is closed. Since the air pressure in the air storage tank 3 is higher than the air pressure of the automobile air spring assembly 14, the area difference of the piston body 19 of the conversion cylinder 13 is used to obtain the pressurization effect, and the air pressure of the high-pressure piston chamber is increased to a level greater than the air pressure of the air storage tank 3, and the compressed air in the high-pressure piston chamber is smoothly pressed into the air storage tank 3 to achieve energy recovery. Finally, the above steps are repeated until all the compressed air that needs to be discharged from the automobile air spring assembly 14 is pressed into the air storage tank 3 and discharged from the fourth switch solenoid valve 9.

[0051] The air supply method of this embodiment utilizes the back and forth switching of the conversion cylinder 13, and pressurizes part of the compressed air discharged from the automobile air spring assembly 14 and presses it into the air storage tank 3 for reuse. The energy consumption in the pressurization process is only the on-off combination of the first switch solenoid valve 6, the second switch solenoid valve 7, the third switch solenoid valve 8, the fourth switch solenoid valve 9 and the two-position three-way solenoid valve 11 controlled by the controller 1, which has low power, the electric air pump 2 does not work, and the energy consumption is low, thereby making full use of the energy in the compressed air discharged from the outside to achieve energy recovery.

[0052] In the description of this application, unless otherwise clearly specified and limited, the technical or scientific terms used should have the usual meanings understood by persons with general skills in the field to which this application belongs. Terms such as "install", "connect", and "connect" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, a conflicting connection, or an integrated connection. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0053] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly. It cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, some simple deductions or substitutions can be made without departing from the concept of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. An air supply method for an air supply unit of an air suspension system, characterized in that: The air supply unit of the air suspension system comprises a forward inflation unit, a reverse exhaust unit and a controller (1); The forward inflation unit comprises an electric air pump (2), an air storage tank (3), a first one-way valve (4) and a first switch solenoid valve (6); the air outlet interface of the electric air pump (2), the first one-way valve (4) and the air storage tank (3) are connected in sequence, and the air storage tank (3) is inflated through the electric air pump (2); the first switch solenoid valve (6) is connected between the automobile air spring assembly (14) and the pipeline between the first one-way valve (4) and the air storage tank (3), and the automobile air spring assembly (14) is replenished with air through the air storage tank (3); The reverse exhaust unit comprises a second switch solenoid valve (7), a third switch solenoid valve (8), a fourth switch solenoid valve (9) and a conversion cylinder (13); the conversion cylinder (13) is provided with a low-pressure interface (20) and a high-pressure interface (21); the second switch solenoid valve (7) is connected between the automobile air spring assembly (14) and the high-pressure interface (21); and a second check valve (5) for preventing gas from flowing back from the gas storage tank (3) to the high-pressure interface (21) is provided between the pipeline between the second switch solenoid valve (7) and the high-pressure interface (21) and the pipeline between the first check valve (4) and the gas storage tank (3); The third switch solenoid valve (8) is connected between the automobile air spring assembly (14) and the low-pressure interface (20), and the pipeline between the third switch solenoid valve (8) and the low-pressure interface (20) is connected to the exhaust source (15) through the fourth switch solenoid valve (9), and the pipeline between the third switch solenoid valve (8) and the low-pressure interface (20) is connected to the pipeline between the electric air pump (2) and the first one-way valve (4); The controller (1) is electrically connected to the electric air pump (2), the first switch solenoid valve (6), the second switch solenoid valve (7), the third switch solenoid valve (8) and the fourth switch solenoid valve (9) respectively; A drying tank (12) is provided in the pipeline between the electric air pump (2) and the first one-way valve (4); an air inlet interface of the drying tank (12) is connected to the pipeline between the fourth switch solenoid valve (9) and the electric air pump (2); and an air outlet interface of the drying tank (12) is connected to the pipeline between the third switch solenoid valve (8) and the low-pressure interface (20); The air outlet interface and the back-blowing interface of the drying tank (12) are connected to the pipeline between the third switch solenoid valve (8) and the low-pressure interface (20) through a two-position three-way solenoid valve (11), and are used to switch the filtering state and the back-blowing state of the drying tank (12); The conversion cylinder (13) comprises a cylinder body (16), a low-pressure end cover (17), a high-pressure end cover (18) and a piston body (19); the low-pressure end cover (17) and the high-pressure end cover (18) are respectively sealed and connected to the two ends of the cylinder body (16); the piston body (19) is slidably sealed in the piston cavity of the cylinder body (16), and the push rod of the piston body (19) extends from the high-pressure end cover (18); the piston body (19) slides in the piston cavity, thereby making the piston cavity between the piston body (19) and the low-pressure end cover (17) become a low-pressure piston cavity, and making the piston cavity between the piston body (19) and the high-pressure end cover (18) become a high-pressure piston cavity; the low-pressure interface (20) and the high-pressure interface (21) are respectively connected to the low-pressure piston cavity and the high-pressure piston cavity in a one-to-one correspondence; Here are the steps: S1, the controller (1) operates the forward charging unit, the electric air pump (2) is started, the drying tank (12) is switched to the filtering state through the two-position three-way solenoid valve (11), and the compressed air is then passed through the drying tank (12) and pressed into the air storage tank (3) and the low-pressure piston chamber respectively, until the current air pressure in the air storage tank (3) reaches the set air pressure, and the electric air pump (2) is turned off; S101, the first switch solenoid valve (6) is opened, and the compressed air in the air storage tank (3) is replenished into the automobile air spring assembly (14) until the air pressure of the automobile air spring assembly (14) reaches a preset value, and the first switch solenoid valve (6) is closed; S2, the controller (1) operates the reverse exhaust unit, the second switch solenoid valve (7) and the fourth switch solenoid valve (9) are both opened, the drying tank (12) is switched to the back-blowing state through the two-position three-way solenoid valve (11), the compressed air of the automobile air spring assembly (14) enters the high-pressure piston chamber and pushes the piston body (19) to the low-pressure end cover (17), thereby allowing the compressed air in the low-pressure piston chamber to enter from the back-blowing interface of the drying tank (12), and finally discharged through the fourth switch solenoid valve (9), and the fourth switch solenoid valve (9) is closed; S201, the second switch solenoid valve (7) is closed, the third switch solenoid valve (8) is opened, the compressed air of the automobile air spring assembly (14) enters the low-pressure piston chamber and pushes the piston body (19) to the high-pressure end cover (18), and then the compressed air in the high-pressure piston chamber is pressed into the air storage tank (3), and the third switch solenoid valve (8) is closed; S301, repeat S2 and S201 until all the compressed air to be discharged from the automobile air spring assembly (14) is compressed into the air storage tank (3) and discharged from the fourth switch solenoid valve (9).

2. The air supply method of the air supply unit of the air suspension system according to claim 1, characterized in that: The pipeline between the drying tank (12) and the electric air pump (2) is provided with a pneumatic overflow valve.

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