Pneumatic control system and execution method therefor

Abstract

A pneumatic control system and an execution method therefor. The system comprises at least one charge valve, a switching valve and an exhaust valve. The charge valve is a two-position two-way solenoid valve, with an inlet port in communication with an air source device. The switching valve is a two-position three-way solenoid valve and comprises: an inlet port P in communication with an outlet port of the charge valve; an outlet port A in communication with an oil tank; and an exhaust port T in communication with the external environment. The switching valve is switchable between a PA position in which the inlet port P is in communication with the outlet port A, and an AT position in which the exhaust port T is in communication with the outlet port A. The exhaust valve is a two-position two-way solenoid valve, with an inlet port in communication with the oil tank and an outlet port in communication with the external environment. The pneumatic control system has a simple structure and is able to ensure a pneumatic flow rate, thereby achieving rapid pressurization / depressurization. The system does not require proportional control by means of a solenoid valve position sensor, thereby saving on costs and improving the durability of the system.

Description

Pneumatic control system and method of performing the same TECHNICAL FIELD

[0001] The present application relates to the control technical field, and in particular, to a pneumatic control system and method of performing the same. BACKGROUND

[0002] A hydraulic retarder is usually used in heavy vehicles as an auxiliary braking device. The hydraulic retarder is connected to the drive train or gearbox, and the braking power is adjusted by adjusting the oil pressure of the oil tank in the hydraulic retarder. The hydraulic retarder can be pneumatically controlled by increasing or decreasing the pressure level of the oil tank through the pneumatic flow provided by the pneumatic control system. An air compressor is usually installed on the heavy vehicle to provide an air source for the pneumatic control system. In addition, the flow direction of the pneumatic flow is usually controlled by a set of pneumatic valves.

[0003] The pneumatic valve can control the pressurized charging flow to the hydraulic retarder oil tank and the pressure release flow discharged from the oil tank to the external environment. In the related art, the hydraulic retarder uses a two-position two-way valve, or uses a large passive two-position three-way mechanical valve driven by a pilot valve.

[0004] The pneumatic control system using the two-position two-way valve needs at least two solenoid valves to change the pneumatic flow direction between pressurization and pressure release. This requires calibration of solenoid valve control software to prevent accidental pressurization and pressure release at the same time. In addition, the flow diameter of the two-position two-way valve is small, and cannot meet the requirements of rapid pressurization and rapid pressure release.

[0005] The pneumatic control system using the passive two-position three-way mechanical valve, combined with the use of a diaphragm type rapid exhaust valve, can provide a larger flow area and achieve the above-mentioned rapid pressurization and pressure release functions. However, the combination of the above-mentioned two-position three-way mechanical valve, diaphragm type rapid exhaust valve and pilot valve occupies a large installation space.

[0006] Therefore, there is a need for a pneumatic control system with simple structure and capable of ensuring pneumatic flow and achieving rapid pressurization / pressure release.

[0007] SUMMARY

[0008] In order to overcome the problems in the related art, the present application provides a pneumatic control system and method of performing the same.

[0009] According to a first aspect of some embodiments of the present application, a pneumatic control system is provided, comprising: at least one charging valve, a switching valve, and a venting valve. The charging valve is a two-position two-way electromagnetic valve, having an inlet port connected to an air source device. The switching valve is a two-position three-way electromagnetic valve, comprising: an inlet port P connected to an outlet port of the charging valve; an outlet port A connected to an oil tank; and a relief port T connected to an external environment; the switching valve is switchable between a PA position in which the inlet port P is connected to the outlet port A, and an AT position in which the relief port T is connected to the outlet port A. The venting valve is a two-position two-way electromagnetic valve, having an inlet port connected to the oil tank, and an outlet port connected to the external environment.

[0010] In some embodiments, the charging valve has a plurality, and the plurality of charging valves are connected in parallel between the air source device and the switching valve, and the charging rate is controlled by independently controlling the opening and closing of the plurality of charging valves.

[0011] In some embodiments, the pneumatic control system further comprises: a pressure sensor installed at a port of the oil tank to measure a current air pressure in the oil tank.

[0012] In some embodiments, the pneumatic control system further comprises: a control unit configured to calculate a target air pressure required by the oil tank; and the control unit is connected to and controls the charging valve, the switching valve, the venting valve, and the pressure sensor, so that the current air pressure reaches the target air pressure.

[0013] In some embodiments, the pneumatic control system further comprises: a mechanical relief valve having an inlet port connected to the oil tank, and an outlet port connected to the external environment; the mechanical relief valve is used for emergency pressure relief, keeping the current air pressure in the oil tank below a fixed threshold.

[0014] According to a second aspect of some embodiments of the present application, a method for executing a pneumatic control system is provided, the pneumatic control system being as described above, the method comprising:

[0015] When the current air pressure in the oil tank is less than a target air pressure required by the oil tank, charging pressurization is performed, comprising: switching at least one of the charging valves to a connected state, switching the switching valve to the PA position, and switching the venting valve to a disconnected state;

[0016] When the current air pressure in the oil tank is greater than the target air pressure required by the oil tank, venting depressurization is performed, comprising: switching all charging valves to a disconnected state, and switching the venting valve to a connected state;

[0017] When the current air pressure in the oil tank equals a target air pressure required by the oil tank, the maintaining air pressure is performed, including: switching all the air charging valves to a non-communicating state, switching the switching valve to the PA position, and switching the air exhausting valve to a non-communicating state.

[0018] In some embodiments, the air charging valves have a plurality, and the plurality of air charging valves are connected in parallel between the air source device and the switching valve; the performing air charging pressurization further includes: performing normal air charging pressurization by switching part of the plurality of air charging valves to a communicating state; or, performing rapid air charging pressurization by switching all the air charging valves to a communicating state.

[0019] In some embodiments, the performing air exhausting depressurization further includes: performing normal air exhausting depressurization by switching the switching valve to the PA position; or, performing rapid air exhausting depressurization by switching the switching valve to the AT position.

[0020] In some embodiments, the pneumatic control system further includes: a mechanical depressurization valve, whose inlet port is communicated with the oil tank, and whose outlet port is communicated with an external environment. The performing method further includes: when the current air pressure in the oil tank exceeds a fixed threshold, performing emergency air exhausting depressurization, including: switching all the air charging valves to a non-communicating state, switching the switching valve to the AT position, switching the air exhausting valve to a communicating state, and switching the mechanical depressurization valve to a communicating state.

[0021] In some embodiments, the pneumatic control system further includes: a pressure sensor installed at a port of the oil tank; and a control unit connected with the air charging valves, the switching valve, the air exhausting valve, and the pressure sensor; the performing method further includes:

[0022] measuring, by the pressure sensor, the current air pressure in the oil tank;

[0023] calculating, by the control unit, a target air pressure required by the oil tank;

[0024] controlling, by the control unit, the state switching of the air charging valves, the switching valve, the air exhausting valve, and the pressure sensor, so that the current air pressure reaches the target air pressure.

[0025] The pneumatic control system and the execution method thereof provided by the embodiment of the present application have simple system structure and can guarantee pneumatic flow and realize rapid pressurization and depressurization. By controlling the on-off actuation of each electromagnetic valve (air charging valve, switching valve, air exhaust valve), normal air charging pressurization, rapid air charging pressurization, pressure maintenance, normal air exhaust depressurization and rapid air exhaust depressurization and other application scenarios can be realized. Each electromagnetic valve is of the on-off type and does not need to be provided with an electromagnetic valve position sensor for proportional control, so that the position sensor can be saved, thereby saving cost and simplifying the control algorithm, and thus the stability and reliability of the system are improved.

[0026] In addition, the air charging pressurization function, the pressure maintenance function and the air exhaust depressurization function of the system are integrated in a two-position three-way switching valve, so that a pilot valve does not need to be provided.

[0027] In addition, the air charging valve can be a normally closed (NC) two-position two-way valve, and the air exhaust valve can be a normally open (NO) two-position two-way valve, so that the air charging valve and the air exhaust valve can share the same housing and electromagnetic magnet size, which can save manufacturing cost.

[0028] In addition, the pneumatic control system of the present application is further provided with a mechanical depressurization valve for emergency depressurization when the current air pressure is higher than a preset fixed threshold, thereby improving the safety of the system. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments of the present application will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0030] Fig. 1 shows a structural schematic diagram of the pneumatic control system according to the embodiment of the present application;

[0031] Fig. 2 shows a flow chart of the execution method of the pneumatic control system according to the embodiment of the present application;

[0032] Fig. 3 shows a structural schematic diagram of the pneumatic control system according to the embodiment of the present application when normal air charging pressurization is performed;

[0033] Fig. 4 shows a structural schematic diagram of the pneumatic control system according to the embodiment of the present application when rapid air charging pressurization is performed;

[0034] Fig. 5 shows a structural schematic diagram of the pneumatic control system according to the embodiment of the present application when normal air exhaust depressurization is performed;

[0035] Fig. 6 shows a structural schematic diagram of the pneumatic control system according to the embodiment of the present application when rapid air exhaust depressurization is performed;

[0036] Figure 7 shows a structural schematic diagram of the pneumatic control system according to an embodiment of the present application when maintaining air pressure; and

[0037] Figure 8 shows a structural schematic diagram of the pneumatic control system according to an embodiment of the present application when emergency pressure relief. DETAILED DESCRIPTION

[0038] The exemplary embodiments will be described in detail herein with reference to the attached drawings. The following description is made with reference to the accompanying drawings in which like reference numerals refer to like elements, and the term "exemplary" is used herein to mean "serving as an example, instance, or illustration." The following description is not intended to limit the scope of the present application, but rather is intended to be illustrative thereof. It is to be understood that the following description is merely exemplary of the principles of the present application, and that numerous and various modifications could be made by those skilled in the art without departing from the spirit of the application, and the scope of the application is only limited by the claims appended hereto.

[0039] It should be understood that "a plurality of" means two or more, and that other quantifiers can be similarly interpreted. The term "and / or" means that the associated objects can exist together or separately. The term "or" means that the associated objects can exist together or separately. The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0040] It should be understood that the terms "first," "second," and the like, used in the description and in the claims, are used to describe various structures and are not intended to mean a particular order or sequence. Rather, these terms are used to distinguish between structures that are similar to one another. It should be understood that the terms "first," "second," and the like, are not intended to mean that a particular element is necessarily the first or second element in a sequence or series.

[0041] It should be understood that the term "connected" includes both direct and indirect connections, unless otherwise noted.

[0042] It should be understood that the operations of the embodiments as described herein are not limited to the specific order of the steps described. The steps can be performed in other orders or concurrently, unless otherwise indicated or unless it is inherent from the description. Furthermore, it is possible that the steps can be performed at the same time or in a different order than as described herein.

[0043] Hydraulic retarder is an auxiliary braking device, which is usually used in heavy vehicles to provide auxiliary braking function when the operating duration is long and the brake disc or brake drum on the wheels cannot meet the braking requirements. The hydraulic retarder is connected to the transmission system or gearbox of the vehicle in parallel or in series. When the braking device is activated, the mechanical rotation of the transmission shaft is transmitted to the torque converter, and the rotational mechanical energy is converted into water heat energy. Then, the water heat energy is discharged to the environment through the heat exchanger. The rotation of the torque converter and the fluid movement of the oil are achieved through the torque converter itself. The braking power ratio depends on the fill rate of the torque converter, and the fill rate depends on the amount of oil in the torque converter. In order to maintain the fill rate, the oil pressure is balanced with the return spring force of the torque converter impeller. Therefore, the adjustment of the total braking power of the hydraulic torque converter is achieved by adjusting the oil pressure.

[0044] The present application adopts a pneumatic control system to control the oil pressure in the hydraulic retarder, thereby achieving the adjustment of the braking power. The pneumatic control system can be arranged between an air source device and an oil tank of the hydraulic torque converter. The air source device can be an air compressor installed on the vehicle. The pneumatic control system can pressurize by filling air provided by the air source device into the oil tank, and can also depressurize by releasing air in the oil tank to the external environment.

[0045] According to an embodiment of the present application, a pneumatic control system is provided. Figure 1 shows a structural schematic diagram of the pneumatic control system according to an embodiment of the present application.

[0046] As shown in Figure 1, the pneumatic control system comprises at least one air charging valve 2, a switching valve 3 and an air exhaust valve 4. The air charging valve 2 can be a two-position two-way electromagnetic valve, and its air inlet port is communicated with an air source device 1. The switching valve 3 can be a two-position three-way electromagnetic valve, which comprises an air inlet port P communicated with the air outlet port of the air charging valve 2, an air outlet port A communicated with the oil tank 8, and a depressurization port T communicated with the external environment. The switching valve 3 is switchable between the PA position where the air inlet port P and the air outlet port A are communicated, and the AT position where the depressurization port T and the air outlet port A are communicated. The air exhaust valve 4 can be a two-position two-way electromagnetic valve, and its air inlet port is communicated with the oil tank 8, and its air outlet port is communicated with the external environment.

[0047] Specifically, when the switching valve 3 is switched to the PA position, the air charging valve 2 and the oil tank 8 are in a communication state, and the oil tank 8 is not communicated with the external environment; when the switching valve 3 is switched to the AT position, the oil tank 8 and the external environment are in a communication state, and the air charging valve 2 is not communicated with the oil tank 8, at this time the air pressure in the oil tank 8 can be exhausted and depressurized through the depressurization port T of the switching valve 3.

[0048] Optionally, the inflation valve 2 can be a normally closed (NC) two-position two-way valve, i.e., when the inflation valve 2 is closed, the inflation valve 2 is in a non-communication state; at this time, air from the air source device 1 cannot enter the switching valve 3 via the inflation valve 2, and thus cannot enter the tank 8 for inflation; when the inflation valve 2 is activated, the inflation valve 2 is in a communication state; at this time, air from the air source device 1 can enter the switching valve 3 via the inflation valve 2.

[0049] Optionally, the exhaust valve 4 can be a normally open (NO) two-position two-way valve, i.e., when the exhaust valve 4 is closed, the exhaust valve 4 is in a communication state; at this time, air from the tank 8 can be released to the external environment via the exhaust valve 4 for exhaust pressure relief; when the exhaust valve 4 is activated, the exhaust valve 4 is in a non-communication state; at this time, air from the tank 8 cannot be released to the external environment via the exhaust valve 4 for exhaust pressure relief.

[0050] It can be understood that the inflation valve 2 and the exhaust valve 4 can share the same housing and electromagnetic magnet size, thus saving manufacturing costs.

[0051] In some optional embodiments, the inflation valve 2 has multiple, multiple inflation valves 2 are connected in parallel between the air source device 1 and the switching valve 3, and the inflation rate is controlled by independently controlling the opening and closing of the multiple inflation valves 2.

[0052] Specifically, in some embodiments, as shown in FIG. 1, the inflation valve 2 has two. The inflation valve 2 includes a first inflation valve 21 and a second inflation valve 22. The first inflation valve 21 and the second inflation valve 22 are connected in parallel between the air source device 1 and the switching valve 3, and the inflation rate is controlled by independently controlling the opening and closing of the multiple inflation valves 2.

[0053] When both the first and second air charging valves 21 and 22 are in the closed state, i.e. both the first and second air charging valves 21 and 22 are in the non-communication state, the air from the air source device 1 cannot enter the switching valve 3, so that the air charging can be stopped. When either of the first and second air charging valves 21 and 22 is in the closed state and the other is in the open state, i.e. either of the first and second air charging valves 21 and 22 is in the non-communication state and the other is in the communication state, the air from the air source device 1 can only enter the switching valve 3 through the air charging valve in the open state, so that the normal air charging and pressurization can be realized. When both the first and second air charging valves 21 and 22 are in the open state, i.e. both the first and second air charging valves 21 and 22 are in the communication state, the air from the air source device 1 can enter the switching valve 3 through all the air charging valves, so that the rapid air charging and pressurization can be realized.

[0054] Of course, the air charging valve 2 can also be provided with more (more than two) to make the system have more gear rates of air charging and pressurization, and to realize more rapid air charging and pressurization, which will not be described here.

[0055] In some optional embodiments, the pneumatic control system further comprises a pressure sensor 6 installed at the port of the oil tank 8 to measure the current air pressure Ps in the oil tank 8.

[0056] Further, the pneumatic control system further comprises a control unit 7 configured to calculate the target air pressure Pt required by the oil tank 8; and the control unit 7 is connected to and controls the air charging valve 2, the switching valve 3, the air exhaust valve 4 and the pressure sensor 6, so that the current air pressure Ps reaches the target air pressure Pt.

[0057] Specifically, the pressure sensor 6 can measure the current air pressure Ps in the oil tank 8; the control unit 7 can calculate the target air pressure Pt required by the oil tank 8 according to requirements, for example, according to the current braking requirement of the vehicle.

[0058] When the current air pressure Ps is less than the target air pressure Pt, the oil tank 8 needs to be air charged and pressurized, at which time the control unit 7 can control at least one of the air charging valves 2 to open, switch the switching valve 3 to the PA position, and control the air exhaust valve 4 to open, so that the air from the air source device 1 charges into the oil tank 8 for pressurization; until the current air pressure Ps is equal to the target air pressure Pt, the control unit 7 can control all the air charging valves 2 to be closed to maintain the pressure.

[0059] When the current air pressure Ps is greater than the target air pressure Pt, the oil tank 8 needs to be depressurized, at this time the control unit 7 can control all the air charging valves 2 to be closed, and control the air exhaust valve 4 to be closed (i.e. in the communicating state) to make the air in the oil tank 8 depressurized through the air exhaust valve 4; until the current air pressure Ps is equal to the target air pressure Pt, the control unit 7 can control the air exhaust valve 4 to be closed to maintain the pressure. When depressurizing, the control unit 7 can control the switching valve 3 to switch to the PA position to perform normal air exhaust depressurization; the control unit 7 can also control the switching valve 3 to switch to the AT position, so that the air in the oil tank 8 can not only be depressurized through the air exhaust valve 4, but also be depressurized through the depressurization port T of the switching valve 3, thereby realizing rapid air exhaust depressurization.

[0060] The state switching of the air charging valves 2, the switching valve 3, the air exhaust valve 4 and the pressure sensor 6 is controlled by the control unit 7 to make the current air pressure Ps reach the target air pressure Pt.

[0061] In some optional embodiments, the pneumatic control system further comprises a mechanical depressurization valve 5, the air inlet port of which is communicated with the oil tank 8, and the air outlet port of which is communicated with the external environment. The mechanical depressurization valve 5 is used for emergency depressurization when the current air pressure is higher than a preset fixed threshold (for example, higher than 3.5 bar), so as to keep the current air pressure Ps in the oil tank 8 below the fixed threshold, thereby improving the safety of the system.

[0062] Embodiments of the present application also provide an execution method of a pneumatic control system, wherein the pneumatic control system is the system as described above. Specifically, FIG. 2 shows a flow block diagram of the execution method of the pneumatic control system according to an embodiment of the present application; FIGS. 3 to 8 show structural schematic diagrams of the pneumatic control system according to an embodiment of the present application in working states. The execution method comprises:

[0063] When the current air pressure Ps in the oil tank 8 is less than the target air pressure Pt required by the oil tank 8, air charging pressurization is performed, including: switching at least one of the air charging valves 2 to the starting state (i.e. the communicating state), switching the switching valve 3 to the PA position, and switching the air exhaust valve 4 to the starting state (i.e. the non-communicating state);

[0064] When the current air pressure Ps in the oil tank 8 is greater than the target air pressure Pt required by the oil tank 8, air exhaust depressurization is performed, including: switching all the air charging valves 2 to the closed state (i.e. the non-communicating state), and switching the air exhaust valve 4 to the closed state (i.e. the communicating state);

[0065] When the current air pressure Ps in the oil tank 8 is equal to the target air pressure Pt required by the oil tank 8, the air pressure maintaining is performed, including: switching all the charging valves 2 to the closed state (i.e., the non-communicating state), switching the switching valve 3 to the PA position, and switching the exhaust valve 4 to the closed state (i.e., the communicating state).

[0066] In some optional embodiments, Fig. 3 shows a structural schematic diagram of the pneumatic control system according to an embodiment of the present application during normal charging pressurization; and Fig. 4 shows a structural schematic diagram of the pneumatic control system according to an embodiment of the present application during rapid charging pressurization.

[0067] As shown in Figs. 2 to 4, the charging valves 2 are provided in plurality, and the plurality of charging valves 2 are connected in parallel between the air source device 1 and the switching valve 3; and the charging pressurization is further performed by:

[0068] performing normal charging pressurization: switching part of the charging valves 2 in the plurality of charging valves 2 to the communicating state; or

[0069] performing rapid charging pressurization: switching all the charging valves 2 to the communicating state.

[0070] Specifically, when the current air pressure Ps is less than the target air pressure Pt, and the difference is small, for example, 0 < Pt-Ps < 0.1 bar, the normal charging pressurization can be performed. As shown in Fig. 3, the first charging valve 21 is in the communicating state, while the second charging valve 22 is in the non-communicating state (or vice versa, which is not described here again).

[0071] When the current air pressure Ps is less than the target air pressure Pt, and the difference is large, for example, 0.3 bar < Pt-Ps < 2.8 bar, the rapid charging pressurization can be performed. As shown in Fig. 3, the first charging valve 21 and the second charging valve 22 are both in the communicating state, and the two charging valves charge simultaneously to rapidly pressurize the current air pressure Ps to the target air pressure Pt.

[0072] In some optional embodiments, Fig. 5 shows a structural schematic diagram of the pneumatic control system according to an embodiment of the present application during normal exhaust depressurization; and Fig. 6 shows a structural schematic diagram of the pneumatic control system according to an embodiment of the present application during rapid exhaust depressurization.

[0073] As shown in Figs. 2, 5 and 6, the exhaust depressurization is further performed by:

[0074] performing normal exhaust depressurization: switching the switching valve 3 to the PA position; or

[0075] performing rapid exhaust depressurization: switching the switching valve 3 to the AT position.

[0076] Specifically, when the current pressure Ps is greater than the target pressure Pt, and the difference is small, for example, 0 < Ps-Pt < 1 bar, normal venting pressure relief can be performed. As shown in FIG. 5, the venting valve 4 is switched to the closed state (i.e., the communication state), and the switching valve 3 is switched to the PA position, at which time the air pressure in the tank 8 can only be released through the venting valve 4, and the pressure relief rate is small.

[0077] When the current pressure Ps is greater than the target pressure Pt, and the difference is large, for example, Ps-Pt > 1 bar, Pt < 0.3 bar, fast venting pressure relief can be performed. As shown in FIG. 6, the venting valve 4 is switched to the closed state (i.e., the communication state), and the switching valve 3 is switched to the AT position, at which time the air pressure in the tank 8 can be released not only through the venting valve 4 but also through the pressure relief port T of the switching valve 3, and the pressure relief rate is large.

[0078] After the charging pressure boosting or venting pressure relief step, when the current pressure Ps is equal to the target pressure Pt, pressure maintenance needs to be performed. FIG. 7 shows a structural schematic diagram of the pneumatic control system according to an embodiment of the present application when pressure maintenance is performed. As shown in FIGS. 2 and 7, the charging valves 2 are all in the closed state (non-communication state), the switching valve 3 is switched to the PA position, and the venting valve is in the activated state (non-communication state). At this time, the air in the tank 8 cannot be filled or released, and thus pressure maintenance is achieved.

[0079] In some optional embodiments, FIG. 8 shows a structural schematic diagram of the pneumatic control system according to an embodiment of the present application when emergency pressure relief is performed.

[0080] As shown in FIG. 8, the pneumatic control system further includes a mechanical pressure relief valve 5, an intake port of which is communicated with the tank 8, and an exhaust port of which is communicated with the external environment; and the execution method further includes: when the current pressure Ps in the tank 8 exceeds a fixed threshold (for example, higher than 3.5 bar), performing emergency venting pressure relief, which includes: switching all the charging valves 2 to the non-communication state, switching the switching valve 3 to the AT position, switching the venting valve 4 to the communication state, and switching the mechanical pressure relief valve 5 to the communication state. By performing the emergency venting pressure relief step, the current pressure Ps in the tank 8 is maintained below the fixed threshold, so as to improve the safety of the system.

[0081] In some optional embodiments, the pneumatic control system further includes: a pressure sensor 6 installed at a port of the tank 8; and a control unit 7 connected to the charging valves 2, the switching valve 3, the venting valve 4, and the pressure sensor 6; and the execution method further includes:

[0082] measuring the current pressure Ps in the tank 8 by the pressure sensor 6;

[0083] calculating, by the control unit 7, a target air pressure Pt required by the oil tank 8;

[0084] controlling, by the control unit 7, the state switching of the air charging valve 2, the switching valve 3, the air exhaust valve 4 and the pressure sensor 6, so that the current air pressure Ps reaches the target air pressure Pt.

[0085] The method steps of the control unit 7 controlling the state switching of the air charging valve 2, the switching valve 3, the air exhaust valve 4 and the pressure sensor 6 are as described above, and will not be repeated here.

[0086] The pneumatic control system and the execution method thereof provided by the embodiments of the present application have simple system structure and can guarantee pneumatic flow, realizing rapid pressurization and depressurization. By controlling the on-off actuation of each electromagnetic valve (air charging valve, switching valve, air exhaust valve), normal air charging pressurization, rapid air charging pressurization, pressure maintenance, normal air exhaust depressurization and rapid air exhaust depressurization and other application scenarios can be realized. Each electromagnetic valve is of on-off type, and does not need to be provided with an electromagnetic valve position sensor for proportional control, so that the position sensor can be saved, thereby saving cost and simplifying the control algorithm, thus improving the stability and reliability of the system.

[0087] Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses or adaptive changes of this application following in general the principles of the application and including such steps that are readily apparent to those skilled in the art and including those not specifically disclosed. The specification and examples are to be regarded as exemplary in nature and the true scope and spirit of the application is indicated by the following claims.

[0088] It should be understood that the application is not limited to the precise construction that has been described above and illustrated in the accompanying drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application. The scope of the application should be limited only by the appended claims.

Claims

1. A pneumatic control system, characterized in that, The method comprises: at least one inflation valve (2), which is a two-position two-way electromagnetic valve, whose intake port is communicated with an air source device (1); a switching valve (3), which is a two-position three-way electromagnetic valve, comprising: an intake port P, which is communicated with an outlet port of the inflation valve (2); an outlet port A, which is communicated with an oil tank (8); and a pressure relief port T, which is communicated with an external environment; the switching valve (3) is switchable between a PA position in which the intake port P is communicated with the outlet port A and an AT position in which the pressure relief port T is communicated with the outlet port A; and an exhaust valve (4), which is a two-position two-way electromagnetic valve, whose intake port is communicated with the oil tank (8) and whose outlet port is communicated with an external environment.

2. The pneumatic control system of claim 1, wherein, The inflation valve (2) has multiple, and multiple inflation valves (2) are connected in parallel between the air source device (1) and the switching valve (3), and the inflation rate is controlled by independently controlling the opening and closing of multiple inflation valves (2).

3. The pneumatic control system of claim 1, wherein, Further comprising: a pressure sensor (6) installed at a port of the oil tank (8) to measure the current air pressure (Ps) in the oil tank (8).

4. The pneumatic control system of claim 3, wherein, Further comprising: a control unit (7) configured to calculate a target air pressure (Pt) required by the oil tank (8); and the control unit (7) is connected to and controls the inflation valve (2), the switching valve (3), the exhaust valve (4) and the pressure sensor (6) to make the current air pressure (Ps) reach the target air pressure (Pt).

5. The pneumatic control system of claim 1, wherein, Further comprising: a mechanical pressure relief valve (5), whose intake port is communicated with the oil tank (8) and whose outlet port is communicated with an external environment; the mechanical pressure relief valve (5) is used for emergency pressure relief to keep the current air pressure (Ps) in the oil tank (8) below a fixed threshold.

6. A method of execution of a pneumatic control system according to claim 1, characterized in that The execution method comprises: when the current air pressure (Ps) in the oil tank (8) is less than the target air pressure (Pt) required by the oil tank (8), performing inflation pressurization, comprising: switching at least one of the inflation valves (2) to a communication state, switching the switching valve (3) to the PA position, and switching the exhaust valve (4) to a non-communication state; when the current air pressure (Ps) in the oil tank (8) is greater than the target air pressure (Pt) required by the oil tank (8), performing exhaust pressure relief, comprising: switching all inflation valves (2) to a non-communication state, and switching the exhaust valve (4) to a communication state; when the current air pressure (Ps) in the oil tank (8) is equal to the target air pressure (Pt) required by the oil tank (8), performing pressure maintenance, comprising: switching all inflation valves (2) to a non-communication state, switching the switching valve (3) to the PA position, and switching the exhaust valve (4) to a non-communication state.

7. The execution method of claim 6, wherein, The inflation valve (2) has multiple, and multiple inflation valves (2) are connected in parallel between the air source device (1) and the switching valve (3); The execution of inflation pressurization further comprises: performing normal inflation pressurization: switching part of the multiple inflation valves (2) to a communication state; or performing rapid inflation pressurization: switching all inflation valves (2) to a communication state.

8. The execution method of claim 6, wherein, The execution of exhaust pressure relief further comprises: performing normal exhaust pressure relief: switching the switching valve (3) to the PA position; or performing fast exhaust pressure relief: switching the switching valve (3) to the AT position.

9. The execution method of claim 6, wherein, The pneumatic control system further comprises a mechanical pressure relief valve (5) having an inlet port connected to the oil tank (8) and an outlet port connected to the external environment; The execution method further comprises: when the current air pressure (Ps) in the oil tank (8) exceeds a fixed threshold, performing emergency exhaust pressure relief, including: switching all the charging valves (2) to the non-communication state, switching the switching valve (3) to the AT position, switching the exhaust valve (4) to the communication state, and switching the mechanical pressure relief valve (5) to the communication state.

10. The execution method of claim 6, wherein, The pneumatic control system further comprises: a pressure sensor (6) installed at the port of the oil tank (8); and a control unit (7) connected to the charging valve (2), the switching valve (3), the exhaust valve (4) and the pressure sensor (6); The execution method further comprises: measuring the current air pressure (Ps) in the oil tank (8) by the pressure sensor (6); calculating the target air pressure (Pt) required by the oil tank (8) by the control unit (7); controlling the state switching of the charging valve (2), the switching valve (3), the exhaust valve (4) and the pressure sensor (6) by the control unit (7) to make the current air pressure (Ps) reach the target air pressure (Pt).

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