Lift axle gas circuit control system and commercial vehicle

Abstract

The utility model relates to a lift axle gas circuit control system and a commercial vehicle. The lift axle gas circuit control system comprises a frame; the air bag assemblies are fixed to the two opposite sides of the frame, and each air bag assembly comprises an ascending air bag and a pressing air bag located on one side of the ascending air bag; the first air inflation pipeline is connected to the rising air bags of the air bag assemblies, the first air inflation pipeline is provided with a first electromagnetic valve, and the first electromagnetic valve controls the rising air bags to be inflated or deflated; and the second inflation pipeline is connected to the pressing air bags of the air bag assemblies, the second inflation pipeline is provided with a second electromagnetic valve, and the second electromagnetic valve controls inflation or deflation of the pressing air bags. The rising airbags of the two airbag assemblies are fixed to the two sides of the frame, so that the rising airbags can be prevented from occupying the space in the middle of the vehicle as much as possible, and the technical problem that in the related technology, the rising airbags are placed at the positions, close to the middle of the vehicle, of the frame and occupy the container containing space is solved.

Description

Technical Field

[0001] This application relates to the technical field of vehicle control, and particularly relates to a lifting axle air circuit control system and a commercial vehicle. Background Art

[0002] The lifting axle is used in commercial vehicles, which can reduce transportation time and costs, improve work efficiency and reduce operating risks. In related technologies, the lifting airbags of the lifting axle are usually placed on the vehicle frame and close to the middle of the vehicle frame. However, placing the lifting airbags in the middle of the vehicle will affect the placement of the cargo box of the commercial vehicle and occupy the placement space of the cargo box. Summary of the Invention

[0003] This application provides a lifting axle air circuit control system and a commercial vehicle, which can solve the technical problem in related technologies that the lifting airbags are placed on the vehicle frame close to the middle of the vehicle, affecting the placement of the cargo box of the commercial vehicle and occupying the placement space of the cargo box.

[0004] In a first aspect, an embodiment of this application provides a lifting axle air circuit control system, which includes: a vehicle frame; at least two groups of airbag assemblies, at least two groups of the airbag assemblies are fixed on opposite sides of the vehicle frame, and each group of the airbag assemblies includes a rising airbag and a pressing airbag located on one side of the rising airbag; a first air supply pipeline, the first air supply pipeline is connected to the rising airbag of each group of the airbag assemblies, and a first solenoid valve is provided on the first air supply pipeline, and the first solenoid valve controls the inflation or deflation of the rising airbag; a second air supply pipeline, the second air supply pipeline is connected to the pressing airbag of each group of the airbag assemblies, and a second solenoid valve is provided on the second air supply pipeline, and the second solenoid valve controls the inflation or deflation of the pressing airbag.

[0005] In combination with the first aspect, in an implementation manner, a quick release valve is further connected to the first air supply pipeline, and the quick release valve is connected between the first solenoid valve and the rising airbag.

[0006] In combination with the first aspect, in an implementation manner, the lifting axle air circuit control system further includes an air storage tank, the air storage tank is respectively communicated with the first air supply pipeline and the second air supply pipeline, so that the first air supply pipeline and the second air supply pipeline are in parallel; a first air pressure regulating valve is connected to the first air supply pipeline, and the first air pressure regulating valve is connected between the air storage tank and the first solenoid valve.

[0007] In combination with the first aspect, in an implementation manner, the first solenoid valve includes: a first air inlet, the first air inlet is connected to the first air pressure regulating valve; a first air outlet, the first air outlet is connected to the rising airbag, and the first air inlet is communicated with the first air outlet; and a first air release port, the first air release port is connected to the rising airbag.

[0008] In combination with the first aspect, in one embodiment, the second air charging pipeline is connected with a second pneumatic regulating valve, and the second pneumatic regulating valve is connected between the air storage cylinder and the second solenoid valve.

[0009] In combination with the first aspect, in one embodiment, the second solenoid valve includes: a second air inlet connected to the second pneumatic regulating valve; a second air outlet connected to the lower pressing airbag, and the second air inlet communicates with the second air outlet; and a second air release port connected to the lower pressing airbag.

[0010] In combination with the first aspect, in one embodiment, the rising airbag and the lower pressing airbag are arranged vertically.

[0011] In combination with the first aspect, in one embodiment, the lifting axle air circuit control system further includes: a control unit, and the control unit is respectively connected to the first solenoid valve and the second solenoid valve in a signal connection.

[0012] In combination with the first aspect, in one embodiment, the lifting axle air circuit control system further includes: a pneumatic pressure sensor, the pneumatic pressure sensor is connected to the control unit in a signal connection, and the control unit is configured to control the opening and / or closing of the first solenoid valve and the second solenoid valve according to the signal of the pneumatic pressure sensor.

[0013] In a second aspect, an embodiment of the present application provides a commercial vehicle, which includes the above-mentioned lifting axle air circuit control system.

[0014] The beneficial effects brought by the technical solution provided by the embodiment of the present application include:

[0015] By fixing the two groups of airbag assemblies on the opposite sides of the vehicle frame, and the rising airbags are also located on both sides of the vehicle frame, the rising airbags can avoid occupying the space in the middle of the vehicle as much as possible, and respectively using the first solenoid valve to control the inflation and deflation of the rising airbags and using the second solenoid valve to control the inflation or deflation of the lower pressing airbag, the height of the lifting axle can be controlled, solving the technical problem in the related art that the lifting airbags are placed at a position close to the middle of the vehicle frame, occupying the placement space of the cargo box. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings.

[0017] Figure 1Schematic connection diagram of the lift axle air circuit control system provided by the embodiment of the present application;

[0018] Figure 2 Schematic structural diagram of the airbag assembly connected to the vehicle frame in the embodiment of the present application.

[0019] In the figure:

[0020] 1. Vehicle frame;

[0021] 2. Rising airbag;

[0022] 3. Pressing airbag;

[0023] 41. First solenoid valve; 411. First air inlet; 412. First air outlet; 413. First air release port; 42. Quick release valve; 43. First air pressure regulating valve; 44. Three-way valve;

[0024] 51. Second solenoid valve; 511. Second air inlet; 512. Second air outlet; 513. Second air release port; 52. Second air pressure regulating valve; 53. Four-way valve;

[0025] 6. Air storage cylinder;

[0026] 7. Constant through air pipe group. Detailed implementation manners

[0027] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present application.

[0028] The embodiment of the present application provides a lift axle air circuit control system, which can solve the technical problem in the related art that the lift airbag is placed near the middle position of the vehicle frame, affecting the placement of the commercial vehicle cargo box and occupying the placement space of the cargo box.

[0029] See Figure 1As shown in the figure, it is a lift axle air circuit control system provided by an embodiment of the present application, which may include: a vehicle frame 1; at least two sets of airbag assemblies, and at least two sets of the airbag assemblies are fixed on opposite sides of the vehicle frame 1. It should be understood that the airbag assemblies can be fixed on the vehicle frame 1 through brackets. Each set of the airbag assemblies includes a rising airbag 2 and a pressing airbag 3 located on one side of the rising airbag 2. The rising airbag 2 and the pressing airbag 3 can cooperate to control the height of the lift axle. In the embodiment of the present application, there are two sets of airbag assemblies, and each set of airbag assemblies has a rising airbag 2 and a pressing airbag 3. In some other embodiments, the number of airbag assemblies can be four sets, six sets or more than six sets, as long as they are symmetrically arranged on both sides of the vehicle to achieve symmetry on both sides of the commercial vehicle; a first air supply pipeline, the first air supply pipeline is connected to the rising airbag 2 of each set of the airbag assemblies, and the first air supply pipeline is provided with a first solenoid valve 41, and the first solenoid valve 41 controls the inflation or deflation of the rising airbag 2; a second air supply pipeline, the second air supply pipeline is connected to the pressing airbag 3 of each set of the airbag assemblies, and the second air supply pipeline is provided with a second solenoid valve 51, and the second solenoid valve 51 controls the inflation or deflation of the pressing airbag 3.

[0030] In the embodiment of the present application, by fixing two sets of airbag assemblies on opposite sides of the vehicle frame 1, the airbag assemblies can minimize the space occupied in the middle cargo box of the commercial vehicle as much as possible, and the rising airbags 2 in the airbag assemblies are also located on both sides of the vehicle frame 1, so that while the rising airbags 2 can avoid occupying the space in the middle of the vehicle as much as possible, they can also achieve the effect of lifting the lift axle under the action of the first air supply pipeline. In addition, by using the first solenoid valve 41 to control the inflation and deflation of the rising airbag 2 and the second solenoid valve 51 to control the inflation or deflation of the pressing airbag 3 respectively, the height of the lift axle can be controlled. That is, by controlling the first solenoid valve 41 and the second solenoid valve 51, the rising airbag 2 and the pressing airbag 3 can be inflated or deflated respectively, solving the technical problem in the related art that the lifting airbag is placed near the middle position of the vehicle frame 1, occupying the space for placing the cargo box. It should be understood that in the embodiment of the present application, the first air supply pipeline is connected to the rising airbag 2 and the second air supply pipeline is connected to the pressing airbag 3, and they are both connected to the air port of the rising airbag 2 or the descending airbag, and the inflation and deflation of the rising airbag 2 and the descending airbag are realized through the air port.

[0031] In some alternative embodiments, a quick release valve 42 is further connected to the first inflation pipeline. The quick release valve 42 is connected between the first electromagnetic valve 41 and the lifting airbag 2. The quick release valve 42 enables the lifting airbag 2 to achieve a rapid and safe descent when deflation is required, reducing the deflation time of the lifting airbag 2. When the commercial vehicle needs to lower the lifting bridge, the airbag 3 is usually inflated downward. To ensure a certain stability during the process of lowering the lifting bridge and to more precisely limit the height adjustment ability of the lifting bridge, making the ascent and descent of the lifting bridge more flexible and accurate, the deflation of the lifting airbag 2 can be controlled synchronously. In the embodiments of the present application, due to the addition of the quick release valve 42, when the lifting airbag 2 deflates, the gas can directly be discharged from the quick release valve 42. At this time, only a small amount of gas may flow back into the first electromagnetic valve 41 for deflation, thereby increasing the deflation speed of the lifting airbag 2. Moreover, deflating the lifting airbag 2 synchronously during the inflation process of the downward pressure airbag 3 can make the operation process of the lifting bridge air circuit control system safer.

[0032] In some alternative embodiments, the lifting bridge air circuit control system further includes an air storage tank 6. The air storage tank 6 is respectively communicated with the first inflation pipeline and the second inflation pipeline. High-pressure gas can be stored in the air storage tank 6. Through the connection between the air storage tank 6 and the first inflation pipeline and the second inflation pipeline, the air storage tank 6 can supply high-pressure gas to the first inflation pipeline and the second inflation pipeline. The first inflation pipeline and the second inflation pipeline are in parallel, enabling the air storage tank 6 to transmit high-pressure gas to only one of the inflation pipelines within a certain period of time. In the embodiments of the present application, which inflation pipeline the air storage tank 6 transmits high-pressure gas to is controlled by the first electromagnetic valve 41 and the second electromagnetic valve 51 respectively. The first inflation pipeline is connected with a first pneumatic pressure regulating valve 43. The first pneumatic pressure regulating valve 43 is connected between the air storage tank 6 and the first electromagnetic valve 41. Setting the first pneumatic pressure regulating valve 43 between the air storage tank 6 and the first electromagnetic valve 41 can regulate the pressure of the high-pressure gas in the air storage tank 6 supplied to the first inflation pipeline to protect the transportation safety of the high-pressure gas in the first inflation pipeline.

[0033] In some alternative embodiments, the first solenoid valve 41 may include: a first air inlet 411 connected to the first pneumatic pressure regulating valve 43; a first air outlet 412 connected to the ascending airbag 2, and the first air inlet 411 is in communication with the first air outlet 412. In the embodiments of the present application, when the ascending airbag 2 needs to be inflated, both the first air inlet 411 and the first air outlet 412 are in an open state. High-pressure gas flows from the first pneumatic pressure regulating valve 43 to the first air inlet 411, then flows out from the first air outlet 412 to the quick release valve 42, and finally enters the ascending airbag 2; and a first air release port 413. When the ascending airbag 2 needs to be inflated, the first air release port 413 may be in a closed state. The first air release port 413 is connected to the ascending airbag 2. When it is necessary to deflate the ascending airbag 2, the first air inlet 411 and the first air outlet 412 are closed, and the first air release port 413 is opened. In the embodiments of the present application, a three-way valve 44 may also be connected between the first solenoid valve 41 and the quick release valve 42. The quick release valve 42 may also be a three-way valve. Two of the valves of the quick release valve 42 are respectively connected to the air ports on two ascending airbags 2, and the other is connected to the three-way valve 44 between the first solenoid valve 41 and the quick release valve 42. The first air outlet 412 and the first air release port 413 are respectively connected to the two valves of the three-way valve 44. Preferably, the first solenoid valve 41 may be a dual solenoid valve. By controlling the dual solenoid valve, the inflation and deflation of the ascending airbag 2 can be achieved, enabling the control system to control the height of the lift axle in a simpler control manner.

[0034] In some alternative embodiments, the second air charging pipeline is connected with a second pneumatic pressure regulating valve 52. The second pneumatic pressure regulating valve 52 is connected between the air storage cylinder 6 and the second solenoid valve 51. The second pneumatic pressure regulating valve 52 can control the air pressure in the second air charging pipeline and protect the second air charging pipeline. In the embodiments of the present application, the first pneumatic pressure regulating valve 43 and the second pneumatic pressure regulating valve 52 are connected in parallel. Between the first pneumatic pressure regulating valve 43 and the second pneumatic pressure regulating valve 52 and the air storage cylinder 6, a normally open air pipe group 7 may also be connected. Both the first pneumatic pressure regulating valve 43 and the second pneumatic pressure regulating valve 52 are connected to the normally open air pipe group 7. The normally open air pipe group 7 can enable the high-pressure gas in the air storage cylinder 6 to first flow into the normally open air pipe group 7, where air pressure balance can be established, maintaining the stable operation of the lift axle air circuit control system.

[0035] In some alternative embodiments, the second solenoid valve 51 may include: a second air inlet 511 connected to the second pneumatic pressure regulating valve 52; a second air outlet 512 connected to the lower pressing airbag 3, and the second air inlet 511 is in communication with the second air outlet 512; and a second air release port 513 connected to the lower pressing airbag 3. When it is necessary to supply air to the lower pressing airbag 3, the second air inlet 511 and the second air outlet 512 are in an open state, and high-pressure gas enters the second solenoid valve 51 from the second pneumatic pressure regulating valve 52 through the second air inlet 511 and then is input into the lower pressing airbag 3 through the second air outlet 512. At this time, the second air release port 513 is in a closed state; when it is necessary to release the air from the lower pressing airbag 3, the second air inlet 511 and the second air outlet 512 are in a closed state, and the second air release port 513 is in an open state, and the gas in the lower pressing airbag 3 enters the second solenoid valve 51 through the second air release port 513 to achieve exhaust. Preferably, the second solenoid valve 51 may also be a dual solenoid valve, and a four-way valve 53 may be connected between the dual solenoid valve and the lower pressing airbag 3. Two of the valves of the four-way valve 53 are respectively connected to the air ports of the two lower pressing airbags 3, and the other two valves are respectively connected to the second air outlet 512 and the second air release port 513.

[0036] Preferably, the lifting airbag 2 and the lower pressing airbag 3 are arranged vertically, and the air ports of the lifting airbag 2 and the lowering airbag may be arranged opposite to each other and spaced apart from each other to reduce the mutual influence. Refer to Figure 2 As shown, the lifting airbag 2 and the lower pressing airbag 3 may be respectively connected to the vehicle frame 1 through brackets. After the air ports of the lifting airbag 2 and the lowering airbag are arranged opposite to each other, it is convenient to connect with other structures of the commercial vehicle on the sides where the lifting airbag 2 and the lowering airbag face away from each other, so that when the lifting airbag 2 and the lowering airbag are fixed on the vehicle frame 1, their stability can be enhanced by connecting with other structures respectively. In some other embodiments, the lifting airbag 2 and the lowering airbag may also be arranged in an interleaved manner.

[0037] In some alternative embodiments, the lift axle air circuit control system may further include: a control unit, which is respectively signal-connected to the first solenoid valve 41 and the second solenoid valve 51. That is, through the control unit, the first solenoid valve 41 and the second solenoid valve 51 can be closed simultaneously, or the first solenoid valve 41 and the second solenoid valve 51 can be controlled to open. In the embodiments of the present application, when the height of the lift axle needs to be increased, that is, during the lifting process of the lift axle, the control unit controls the first air inlet 411 and the first air outlet 412 in the first solenoid valve 41 to open, and the first air release port 413 to close. At this time, it can be regarded that the air inlet passage in the first solenoid valve 41 is opened and the exhaust passage is closed. The high-pressure gas enters the three-way valve 44 and the quick release valve 42 through the first air outlet 412, and then enters the rising airbag 2. Synchronously, the second air release port 513 in the second solenoid valve 51 is controlled to open, and the second air inlet 511 and the second air outlet 512 are both closed, which is regarded as the exhaust passage of the second solenoid valve 51 being opened and the air inlet passage being closed. Then, the gas in the pressing airbag 3 enters the exhaust passage of the second solenoid valve 51 through the three-way valve 44 and the second air release port 513. There may be an exhaust port in the exhaust passage, and the gas in the pressing airbag 3 is discharged through the exhaust port; when the height of the lift axle needs to be decreased, that is, when the lift axle is pressed down, the second air inlet 511 and the second air outlet 512 in the second solenoid valve 51 are both opened, and the second air release port 513 is closed. The high-pressure gas in the air storage cylinder 6 enters the air inlet passage of the second solenoid valve 51 through the second air inlet 511, and then flows to the pressing airbag 3 from the second air outlet 512. Synchronously, the first air inlet 411 and the first air outlet 412 are both closed. After the pressure on the valve connecting the first air outlet 412 of the quick release valve 42 is reduced, this valve also closes, and the exhaust passage of the quick release valve 42 is opened. The gas in the rising airbag 2 is discharged from the exhaust passage of the quick release valve 42 to enable the lift axle to descend quickly.

[0038] In some alternative embodiments, the lifting bridge air circuit control system further includes: a pressure sensor, the signal of the pressure sensor is connected to the control unit, and the control unit is configured to control the opening and / or closing of the first solenoid valve 41 and the second solenoid valve 51 according to the signal of the pressure sensor. Preferably, a pressure sensor can be connected to the lifting air bags 2 fixed on both sides of the vehicle frame 1, and a pressure sensor can also be connected to the pressing air bags 3 fixed on both sides of the vehicle frame 1. Each pressure sensor can be connected to the control unit. During the lifting or pressing process of the lifting bridge, the pressure sensors corresponding to the lifting air bags 2 and the pressing air bags 3 can monitor the pressure in their corresponding air bags in real time. When the pressure in the corresponding air bag reaches the set pressure value, the pressure sensor sends a signal to the control unit, and the control unit then controls the closing of each port of the intake channels of the first solenoid valve 41 and the second solenoid valve 51, so that the air bag is in a pressure-stabilized state, and the lifting bridge always maintains the state at the time of pressure stabilization. When in pressure stabilization, the lifting bridge may have been lifted or may have been pressed down.

[0039] An embodiment of the present application also provides a commercial vehicle, which may include the lifting bridge air circuit control system as described above.

[0040] In the description of the present application, it should be noted that the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0041] It should be noted that in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

[0042] The above are only specific embodiments of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application will not be limited to these embodiments shown herein, but rather will conform to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A lifting bridge air circuit control system, characterized in that: It includes: Frame (1); At least two groups of airbag assemblies, at least two groups of the airbag assemblies are fixed on opposite sides of the frame (1), and each group of the airbag assemblies includes a rising airbag (2) and a downward pressure airbag (3) located on one side of the rising airbag (2); A first inflation pipeline, the first inflation pipeline being connected to the ascending airbag (2) of each group of the airbag assembly, the first inflation pipeline being provided with a first solenoid valve (41), the first solenoid valve (41) controlling the inflation or deflation of the ascending airbag (2); A second inflation pipeline, the second inflation pipeline is connected to the downward pressure airbag (3) of each group of the airbag assembly, the second inflation pipeline is provided with a second solenoid valve (51), and the second solenoid valve (51) controls the inflation or deflation of the downward pressure airbag (3).

2. The lifting bridge air circuit control system according to claim 1, characterized in that: The first inflation pipeline is also connected to a quick release valve (42), and the quick release valve (42) is connected between the first solenoid valve (41) and the ascending airbag (2).

3. The lifting bridge air circuit control system according to claim 1, characterized in that: The lifting bridge air circuit control system further comprises an air storage cylinder (6), wherein the air storage cylinder (6) is respectively connected to the first air charging pipeline and the second air charging pipeline, so that the first air charging pipeline and the second air charging pipeline are connected in parallel; The first inflation pipeline is connected to a first air pressure regulating valve (43), and the first air pressure regulating valve (43) is connected between the air storage cylinder (6) and the first solenoid valve (41).

4. The lifting bridge air circuit control system according to claim 3, characterized in that: The first solenoid valve (41) comprises: A first air inlet (411), the first air inlet (411) being connected to the first air pressure regulating valve (43); a first air outlet (412), the first air outlet (412) being connected to the ascending air bag (2), and the first air inlet (411) being in communication with the first air outlet (412); and a first air release port (413), wherein the first air release port (413) is connected to the lifting air bag (2).

5. The lifting bridge air circuit control system according to claim 3, characterized in that: The second inflation pipeline is connected to a second air pressure regulating valve (52), and the second air pressure regulating valve (52) is connected between the air storage cylinder (6) and the second solenoid valve (51).

6. The lifting bridge air circuit control system according to claim 5, characterized in that: The second solenoid valve (51) comprises: A second air inlet (511), the second air inlet (511) being connected to the second air pressure regulating valve (52); a second air outlet (512), the second air outlet (512) being connected to the downward pressure airbag (3), and the second air inlet (511) being in communication with the second air outlet (512); and a second air release port (513), wherein the second air release port (513) is connected to the downward pressure airbag (3).

7. The lifting bridge air circuit control system according to claim 1, characterized in that: The lifting airbag (2) and the downward pressure airbag (3) are arranged vertically.

8. The lifting bridge air circuit control system according to claim 1, characterized in that: The lifting bridge air circuit control system also includes: A control unit is respectively connected to the first solenoid valve (41) and the second solenoid valve (51) by signals.

9. The lifting bridge air circuit control system according to claim 8, characterized in that: The lifting bridge air circuit control system also includes: An air pressure sensor, wherein the air pressure sensor signal is connected to the control unit, and the control unit is used to control the first solenoid valve (41) and the second solenoid valve (51) to open and / or close according to the signal of the air pressure sensor.

10. A commercial vehicle, characterized in that: It comprises a lifting bridge air circuit control system as claimed in any one of claims 1 to 9.

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