Pre-braking system

Abstract

The invention relates to the field of vehicle braking, and discloses a pre-braking system, during braking, a braking control unit can control a trailer air brake system and a main vehicle oil brake system to execute braking actions in sequence, a trailer is prevented from impacting a main vehicle during braking, and therefore the braking safety is effectively improved. In the parking process, the parking control unit can control the main vehicle oil brake system and the trailer air brake system to operate, parking linkage control over the main vehicle and the trailer is achieved, and the parking operation of a user is simplified. Besides, the gas drying unit is used for drying gas output by the gas supply unit, condensate water can be prevented from flowing in the system, failure of the brake function caused by premature damage of various components in the system is avoided, the service life of the components is prolonged, and therefore the driving safety coefficient is increased. Moreover, the air pressure monitoring unit monitors the air pressure output by the brake control unit to the trailer air brake system, so that whether the system leaks air or not can be monitored in real time, and fault judgment is facilitated.

Description

Technical Field

[0001] The present application belongs to the technical field of vehicle braking, and in particular relates to a pre-braking system. Background Art

[0002] Traditional vehicles (such as tractors) that use trailers to tow their main vehicles generally use air brake systems to achieve braking functions. When braking, the air brake valve is usually operated by a pull rod or a pull wire. This trailer braking method has poor compatibility and consistency with the main vehicle's oil brake system. When the vehicle speed is high, the trailer has a large inertia due to its heavy weight (especially when carrying cargo), and it is easy to fail to brake synchronously with the main vehicle and impact the main vehicle, resulting in the inability to ensure safety during braking. Summary of the invention

[0003] The purpose of this application is to provide a pre-braking system that can coordinate the operation of the main vehicle's oil brake system and the trailer's air brake system to avoid the trailer impacting the main vehicle during braking, thereby improving braking safety.

[0004] In order to achieve the above object, the present application provides a pre-braking system, which includes:

[0005] Air supply unit;

[0006] A brake control unit is connected to the air supply unit and is used to connect the trailer air brake system and the main vehicle oil brake system, and can control the trailer air brake system and the main vehicle oil brake system to perform braking actions in sequence;

[0007] A parking control unit, used to control the brake control unit to drive the trailer air brake system to perform braking action and control the main vehicle oil brake system to perform braking action;

[0008] a gas drying unit connected between the gas supply unit and the brake control unit and capable of drying the gas output by the gas supply unit; and

[0009] The air pressure monitoring unit is connected to the brake control unit and can monitor the air pressure output by the brake control unit to the trailer air brake system.

[0010] In some embodiments, the air supply unit includes an air source device, and the brake control unit includes:

[0011] A mixing control valve connected to the air source device and used to connect the main vehicle oil brake system and the trailer air brake system. The mixing control valve can be triggered when the main vehicle oil brake system supplies oil to drive the trailer air brake system to perform a braking action;

[0012] A pre-brake control valve is connected between the air source device and the mixing control valve in a normally closed state and can be opened when triggered. When the pre-brake control valve is opened, the gas of the air source device can be introduced into the mixing control valve to trigger the mixing control valve to drive the trailer air brake system to perform a braking action;

[0013] The brake operating mechanism is connected to the pre-brake control valve and is used to trigger the coordinated action of the pre-brake control valve and the mixed control valve when being operated, so that the trailer air brake system and the main vehicle oil brake system can perform braking actions in sequence.

[0014] In some embodiments, the mixing control valve includes a valve housing, a valve core mechanism disposed in a housing cavity of the valve housing, and a main air inlet end, a main air outlet end, an air inlet control end, an oil inlet control end, an air outlet energy supply end, and an air outlet control end disposed in a housing wall of the valve housing and respectively connected to the housing cavity;

[0015] The air outlet energy supply end and the air outlet control end are both used to connect to the trailer air brake system, the main air inlet end is connected to the air drying unit, the air inlet control end is connected to the air drying unit through the pre-brake control valve, and the oil inlet control end is used to connect to the main vehicle oil brake system. The air inlet control end and the oil inlet control end can be triggered when input pressure is applied to control the valve core mechanism to move from the first valve core position to the second valve core position;

[0016] In the first valve core position, the air outlet control end is connected to the main exhaust end, and the main air intake end is disconnected from the air outlet control end. In the second valve core position, the air outlet control end is disconnected from the main exhaust end, and the main air intake end is connected to both the air outlet energy supply end and the air outlet control end.

[0017] In some embodiments, the brake control unit further includes a pressure limiting valve, and the pre-brake control valve is connected to the air intake control end via the pressure limiting valve; and / or, the air supply unit further includes an air storage device, and the air source device is connected to the pre-brake control valve and the main air intake end via the air storage device.

[0018] In some embodiments, the gas drying unit includes a drying device, which includes a drying air inlet, a drying air outlet, a heater and a temperature sensor, the drying air inlet is connected to the air supply unit, the drying air outlet is connected to the brake control unit, the temperature sensor is used to monitor the internal temperature of the drying device, and the heater is configured to be turned on when the internal temperature is less than a preset critical temperature and turned off when the internal temperature is not less than the preset critical temperature.

[0019] In some embodiments, the gas drying unit includes a drying device and a regeneration gas storage device, the drying device includes a drying air inlet, a drying air outlet and a regeneration air outlet, the drying air inlet is connected to the air supply unit, the drying air outlet is connected to the brake control unit, and the regeneration gas storage device is connected to the regeneration air outlet and can blow gas back to the drying device.

[0020] In some embodiments, the gas drying unit includes a drying device and a silencer, the drying device includes a drying air inlet, a drying air outlet and a unloading valve, the unloading valve is connected between the drying air inlet and the drying air outlet, and the silencer is connected to the air outlet end of the unloading valve.

[0021] In some embodiments, the parking control unit comprises:

[0022] a parking control valve, which is used to be connected between the transmission hydraulic system and the mixing control valve in a normally closed state and can be opened to conduct the transmission hydraulic system and the mixing control valve when triggered;

[0023] The parking control mechanism is used to stop triggering the parking control valve when being manipulated to cut off the conduction between the transmission hydraulic system and the mixing control valve. The mixing control valve can be triggered when the parking control valve is switched from an open state to a closed state to control both the trailer air brake system and the main vehicle oil brake system to perform braking actions.

[0024] In some embodiments, the air pressure monitoring unit includes a first air pressure sensor for monitoring the air pressure of the air outlet power supply end and a second air pressure sensor for monitoring the air pressure of the air outlet control end.

[0025] In some embodiments, the mixing control valve also includes a throttling element arranged between the main air inlet end and the air outlet power supply end; when the valve core mechanism is in the second valve core position and the second air pressure sensor monitors that the air pressure at the air outlet control end is less than the preset control air pressure, the main air inlet end is connected to the air outlet power supply end through the throttling element; when the valve core mechanism is in the second valve core position and the second air pressure sensor monitors that the air pressure at the air outlet control end is not less than the preset control air pressure, the main air inlet end is directly connected to the air outlet power supply end.

[0026] By adopting the pre-braking system of the present application, when braking, the brake control unit can control the trailer air brake system and the main vehicle oil brake system to perform the braking action successively, so that the trailer with larger weight and inertia slows down before the main vehicle, avoiding the impact of the trailer on the main vehicle during braking, thereby effectively improving the braking safety. When parking, the parking control unit can control the operation of the main vehicle oil brake system and the trailer air brake system to achieve the parking linkage control of the main vehicle and the trailer, simplifying the user's parking operation. In addition, the gas drying unit is used to dry the gas output by the gas supply unit, which can prevent condensed water from flowing in the system, avoid premature damage to various components in the system and cause the brake function to fail, extend the service life of the components, and thus improve the driving safety factor. Furthermore, the present application can also monitor the gas pressure output by the brake control unit to the trailer air brake system through the air pressure monitoring unit, and monitor whether there is air leakage in the system in real time, which is convenient for fault judgment.

[0027] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without creative work. In the drawings:

[0029] Figure 1 A schematic diagram of a pre-braking system in a specific implementation manner of the present application;

[0030] Figure 2 for Figure 1 Schematic diagram of the mixing control valve in;

[0031] Figure 3 It is a structural schematic diagram of a mixing control valve in a specific implementation manner of the present application.

[0032] Description of Reference Numerals

[0033] 1 Air source device 2 Drying device

[0034] 3 Regeneration gas storage device 4 Silencer

[0035] 5 Air storage device 6 Foot brake

[0036] 7 Pre-brake control valve 8 Pressure limiting valve

[0037] 9 Mixing control valve 10 Handbrake lever

[0038] 11 Parking control valve 12 First air pressure sensor

[0039] 13 Second air pressure sensor

[0040] 91 Valve housing 92 Main air inlet

[0041] 93 Main exhaust port 94 Intake control port

[0042] 95 Oil inlet control terminal 96 Pressure relief control terminal

[0043] 97 Air supply end 98 Air control end

[0044] 99 first spring 910 second spring

[0045] 911 Third spring 912 Pressure relief drive piston

[0046] 913 core rod 914 oil inlet drive piston

[0047] 915 Intake drive piston 916 Differential piston

[0048] 917 Exhaust piston 918 Throttle element

[0049] 919 Exhaust clearance

[0050] 95a First oil inlet control terminal 95b Second oil inlet control terminal DETAILED DESCRIPTION

[0051] The specific implementation of the present application is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present application, and is not used to limit the present application.

[0052] Reference Figures 1 to 3 The first exemplary embodiment of the present application provides a pre-braking system, which includes an air supply unit and a brake control unit. The brake control unit is connected to the air supply unit, and the brake control unit is used to connect the trailer air brake system and the main vehicle oil brake system. The brake control unit can also control the trailer air brake system and the main vehicle oil brake system to perform braking actions in sequence.

[0053] Through the above settings, when braking, the brake control unit can control the trailer's air brake system and the main vehicle's oil brake system to perform braking actions in sequence, so that the trailer with heavier weight and inertia slows down before the main vehicle, avoiding the trailer from impacting the main vehicle during braking, thereby effectively improving braking safety.

[0054] In some embodiments, the air supply unit includes an air source device 1, for example, the air source device 1 can be an air compressor, which can deliver compressed air to the brake control unit. The brake control unit includes a pre-brake control valve 7, a mixing control valve 9 and a brake operating mechanism.

[0055] Specifically, the mixing control valve 9 is connected to the air source device 1, and the mixing control valve 9 is used to connect the main vehicle oil brake system and the trailer air brake system. The mixing control valve 9 can be triggered when the main vehicle oil brake system supplies oil to drive the trailer air brake system to perform braking action.

[0056] The pre-brake control valve 7 is connected between the air source device 1 and the mixing control valve 9 in a normally closed state, and the pre-brake control valve 7 can open when triggered. The pre-brake control valve 7 can introduce the gas of the air source device 1 into the mixing control valve 9 when opened, so as to trigger the mixing control valve 9 to drive the trailer air brake system to perform braking action.

[0057] The brake operating mechanism is connected to the pre-brake control valve 7, and the brake operating mechanism is used to first trigger the pre-brake control valve 7 when being operated, and cooperate with the mixed control valve 9 to control the trailer air brake system and the main vehicle oil brake system to perform braking actions in sequence.

[0058] By adopting the configuration of the embodiment, when braking is needed, the pre-brake control valve 7 can be triggered to open first by operating the brake operating mechanism, and the oil pump driving the main vehicle oil brake system will also run as the braking action proceeds. In this way, the pre-brake control valve 7 can introduce the gas of the air source device 1 into the mixing control valve 9, and the main vehicle oil brake system supplies oil to the mixing control valve 9. On this basis, the mixing control valve 9 can output the pre-brake control energy preferentially when the pre-brake control valve 7 is triggered first and a smaller air pressure is input, thereby driving the trailer air brake system to perform the braking action first. As the braking operation proceeds, the main vehicle oil brake system will also perform the braking action after the trailer air brake system brakes. Therefore, as the braking operation progresses, the trailer air brake system will be pre-executed relative to the main vehicle oil brake system, thereby avoiding the trailer from impacting the main vehicle during braking, effectively improving the braking safety.

[0059] From the perspective of the entire braking process, the main vehicle's oil brake system is linked to the trailer's air brake system through the mixing control valve 9. The oil pressure of the main vehicle's oil brake system is proportional to the braking pressure of the trailer's air brake system, and the progressive output of the braking pressure can be achieved, thereby achieving coordinated operation of the main vehicle's oil brake system and the trailer's air brake system, solving the problem of poor compatibility between the existing main vehicle's oil brake system and the trailer's air brake system.

[0060] Moreover, the present application adopts an integrated mixing control valve 9, which is beneficial to reduce the number of valves in the system, thereby reducing potential failure points and effectively reducing the risk of brake failure. At the same time, the integrated mixing control valve 9 also has the advantages of easy installation, labor saving and time saving.

[0061] In some embodiments, the mixing control valve 9 includes a valve housing 91, a valve core mechanism arranged in the shell cavity of the valve housing 91, and a main air inlet end 92, a main exhaust end 93, an air inlet control end 94, an oil inlet control end 95, an air outlet power supply end 97 and an air outlet control end 98 which are arranged on the shell wall of the valve housing 91 and are respectively connected to the shell cavity.

[0062] Among them, the air outlet power supply end 97 and the air outlet control end 98 are both used to connect to the trailer air brake system (usually the air outlet power supply end 97 is connected to the air inlet end of the relay valve of the trailer air brake system, and the air outlet control end 98 is connected to the control end of the relay valve), the main air inlet end 92 is connected to the air source device 1, the air inlet control end 94 is connected to the air source device 1 through the pre-brake control valve 7, and the oil inlet control end 95 is used to connect to the main vehicle oil brake system. Both the air inlet control end 94 and the oil inlet control end 95 can be triggered when input pressure is applied to control the valve core mechanism to move from the first valve core position to the second valve core position.

[0063] When the valve core mechanism is in the first valve core position, the outlet control end 98 is connected to the main exhaust end 93, and the main intake end 92 is disconnected from the outlet control end 98, so the outlet control end 98 cannot output gas to the trailer air brake system, and the trailer air brake system cannot be driven to operate. When the valve core mechanism is in the second valve core position, the outlet control end 98 is disconnected from the main exhaust end 93, and the main intake end 92 is connected to the outlet energy supply end 97 and the outlet control end 98, and the trailer air brake system is driven to operate.

[0064] In addition, the brake operating mechanism can move when operated by the user, thereby triggering the pre-brake control valve 7 to open and driving the oil pump of the main vehicle's oil brake system to operate, so that the air intake control end 94 and the oil intake control end 95 are triggered in sequence.

[0065] Through the arrangement in this embodiment, when braking is required, the pre-brake control valve 7 can be triggered to open and the oil pump of the main vehicle oil brake system can be driven to operate by operating the brake operating mechanism. Before the brake actuator of the main vehicle oil brake system obtains sufficient oil pressure to operate and the oil inlet control end 95 of the mixing control valve 9 obtains sufficient oil pressure from the main vehicle oil brake system to be triggered, the air inlet control end 94 of the mixing control valve 9 can be first triggered when a relatively small air pressure is input from the air source device 1 through the pre-brake control valve 7. Therefore, before the main vehicle oil brake system performs the braking action, the air inlet control end 94 first controls the valve core mechanism of the mixing control valve 9 to move from the first valve core position to the second valve core position so that the main air inlet end 92 of the mixing control valve 9 connected to the air source device 1 is connected to the air outlet energy supply end 97 and the air outlet control end 98. In this way, the air outlet energy supply end 97 can supply air to the trailer air brake system, and the air outlet control end 98 can control the operation of the trailer air brake system, thereby driving the trailer air brake system to perform the braking action before the main vehicle oil brake system. Next, when the oil inlet control end 95 of the mixing control valve 9 is triggered, the oil inlet control end 95 can control the valve core mechanism so that the main vehicle oil brake system is linked with the trailer air brake system through the mixing control valve 9, so that the oil pressure of the main vehicle oil brake system is proportional to the brake pressure of the trailer air brake system, and the progressive output of the brake pressure can be achieved.

[0066] In some embodiments, reference Figure 3 The oil inlet control end 95, the air inlet control end 94, the air outlet control end 98, the main air inlet end 92 and the main air outlet end 93 are sequentially arranged along the axial direction of the valve housing 91. The valve core mechanism includes a first spring 99, a second spring 910, an oil inlet drive piston 914, an air inlet drive piston 915, a differential piston 916 and an air outlet piston 917 provided with an air outlet passage.

[0067] Among them, the oil inlet drive piston 914, the air inlet drive piston 915, the differential piston 916 and the exhaust piston 917 are respectively aligned with the oil inlet control end 95, the air inlet control end 94, the air outlet control end 98 and the main air inlet end 92 along the radial direction of the valve housing 91. The first spring 99 and the second spring 910 are respectively used to drive the differential piston 916 and the exhaust piston 917 to reset. In addition, the air outlet energy supply end 97 is connected to the main air inlet end 92.

[0068] When the valve core mechanism is in the first valve core position, the first spring 99 and the second spring 910 are not subjected to force, and the differential piston 916 and the exhaust piston 917 are axially spaced (an exhaust gap 919 is formed at the interval). At this time, the exhaust channel of the exhaust piston 917 connects the air outlet control end 98 and the main exhaust end 93 (specifically, the air outlet control end 98, the exhaust gap 919, the exhaust channel of the exhaust piston 917 and the main exhaust end 93 are connected in sequence), and one end of the exhaust piston 917 toward the differential piston 916 abuts against the inner periphery of the valve housing 91 to cut off the connection between the main air inlet end 92 and the air outlet control end 98. Therefore, at this time, the air outlet control end 98 cannot output gas to the trailer air brake system, and the trailer air brake system cannot be driven to operate.

[0069] When the pre-brake control valve 7 is opened and the intake control end 94 is triggered, air pressure is formed at the intake control end 94 to push the intake drive piston 915 and the differential piston 916 to move toward the exhaust piston 917 (the first spring 99 is compressed during this process), until the differential piston 916 and the exhaust piston 917 are axially abutted, thereby cutting off the connection between the outlet control end 98 and the main exhaust end 93. Then, the air pressure at the air intake control end 94 continues to push the air intake drive piston 915, the differential piston 916 and the exhaust piston 917 toward the main exhaust end 93 (during this process, the first spring 99 and the second spring 910 are both compressed), so that the end of the exhaust piston 917 toward the differential piston 916 is out of contact with the inner periphery of the valve housing 91 to connect the main air intake end 92 and the air outlet control end 98 (that is, the valve core mechanism moves to the second valve core position). At this time, since the main air intake end 92 is connected to the air outlet energy supply end 97 and the air outlet control end 98, the trailer air brake system is driven to operate. At the same time, the brake actuator of the main vehicle oil brake system does not obtain sufficient oil pressure to operate, and the oil intake control end 95 does not obtain sufficient oil pressure from the main vehicle oil brake system to be triggered. Therefore, the brake actuator of the trailer air brake system will operate before the brake actuator of the main vehicle oil brake system.

[0070] When the air pressure at the air outlet control end 98 reaches equilibrium with the air intake control end 94, the first spring 99 and the second spring 910 in a compressed state can drive the intake drive piston 915, the differential piston 916 and the exhaust piston 917 to reset, thereby reopening the air outlet control end 98 and the main exhaust end 93, and re-cutting off the connection between the main intake end 92 and the air outlet control end 98.

[0071] But at the same time, the brake actuator of the main vehicle's oil brake system has obtained sufficient oil pressure to operate, and the oil inlet control end 95 has obtained sufficient oil pressure from the main vehicle's oil brake system and has been triggered. Therefore, the oil pressure at the oil inlet control end 95 can again push the intake drive piston 915 and the differential piston 916 to move toward the exhaust piston 917 (the first spring 99 is compressed during this process), until the differential piston 916 and the exhaust piston 917 are axially abutted, and the conduction between the outlet control end 98 and the main exhaust end 93 can be cut off again. Then, the oil pressure at the oil inlet control end 95 continues to push the intake drive piston 915, the differential piston 916 and the exhaust piston 917 to move toward the main exhaust end 93 (during this process, the first spring 99 and the second spring 910 are both compressed), so that the end of the exhaust piston 917 toward the differential piston 916 is out of contact with the inner periphery of the valve housing 91 to connect the main intake end 92 and the air outlet control end 98 again (that is, the valve core mechanism moves to the second valve core position). At this time, since the main intake end 92 is connected to the air outlet energy supply end 97 and the air outlet control end 98, the trailer air brake system continues to be driven and operated by the oil inlet control end 95. At this time, it is equivalent to the main vehicle oil brake system being linked with the trailer air brake system through the mixing control valve 9, and the oil pressure of the main vehicle oil brake system is used to continue to control the operation of the trailer air brake system. Not only that, the output oil pressure of the main vehicle oil brake system is proportional to the braking pressure of the trailer air brake system, so that the progressive output of the braking pressure can be achieved.

[0072] When the brake operating mechanism is reset, the pre-brake control valve 7 is closed and the oil pump of the main vehicle's oil brake system stops running, so that the air pressure at the intake control end 94 and the oil pressure at the oil intake control end 95 gradually decrease, and the valve core mechanism cannot continue to be maintained in the second valve core position. At this time, under the elastic force of the first spring 99 and the second spring 910, the valve core mechanism is reset to the first valve core position, and the exhaust channel of the exhaust piston 917 connects the air outlet control end 98 and the main exhaust end 93, and the main air intake end 92 and the air outlet control end 98 are cut off.

[0073] In some embodiments, the brake operating mechanism includes a foot brake plate 6 and a foot brake position sensor for detecting the position of the foot brake plate 6. The foot brake position sensor is electrically connected to the control end of the pre-brake control valve 7. The foot brake position sensor is usually arranged at the starting end of the pedal stroke of the foot brake plate 6 to first trigger the trailer air brake and then trigger the main vehicle oil brake. For example, the foot brake position sensor can use a travel switch. When the user steps on the foot brake plate 6, the foot brake plate 6 immediately triggers the travel switch. The travel switch sends a signal to the control end of the pre-brake control valve 7, thereby controlling the pre-brake control valve 7 to open. In addition, the pre-brake control valve 7 can use different types of control valves such as a normally closed two-position three-way solenoid valve.

[0074] In some embodiments, the pre-brake system also includes a pressure limiting valve 8. At this time, the pre-brake control valve 7 is connected to the intake control end 94 through the pressure limiting valve 8. By setting the pressure limiting valve 8, the air pressure range at the intake control end 94 can be limited.

[0075] In some embodiments, the pre-brake system also includes an air storage device 5. At this time, the air source device 1 is connected to the pre-brake control valve 7 and the main air intake end 92 through the air storage device 5. The air storage device 5 can ensure that sufficient gas is output to the pre-brake control valve 7 and the main air intake end 92, which is beneficial to improving the stability and reliability of the system.

[0076] In some embodiments, reference Figure 1 and Figure 3 , the brake operating mechanism includes a left brake operating mechanism and a right brake operating mechanism (such as a brake operating mechanism in a tractor), and the oil inlet control end 95 may include a first oil inlet control end 95a and a second oil inlet control end 95b for connecting the left oil brake system and the right oil brake system in the main vehicle oil brake system, respectively. Among them, the left brake operating mechanism can trigger the pre-brake control valve 7 to open when being operated and drive the left oil brake system to operate so that the air inlet control end 94 and the first oil inlet control end 95a are triggered in sequence, and the right brake operating mechanism can trigger the pre-brake control valve 7 to open when being operated and drive the right oil brake system to operate so that the air inlet control end 94 and the second oil inlet control end 95b are triggered in sequence. Therefore, no matter whether the user operates the left brake operating mechanism or the right brake operating mechanism, the linkage control of the main vehicle oil brake system and the trailer air brake system can be achieved.

[0077] In some embodiments, the pre-braking system further includes a parking control unit, which is used to control the brake control unit to drive the trailer air brake system to perform braking action, and the parking control unit is also used to control the main vehicle oil brake system to perform braking action.

[0078] Through the setting in this embodiment, when parking, the parking control unit can control both the main vehicle's oil brake system and the trailer's air brake system to perform braking actions, thereby realizing linkage parking control of the main vehicle and the trailer, thereby simplifying the user's parking operation.

[0079] In some embodiments, the parking control unit includes a parking control valve 11 and a parking operating mechanism. Specifically, the parking control valve 11 is used to be connected between the transmission hydraulic system and the mixing control valve 9 in a normally closed state, and the parking control valve 11 can be opened when triggered to conduct the transmission hydraulic system and the mixing control valve 9. For example, when the vehicle is started, when the parking operating mechanism is not operated, the parking control valve 11 will be triggered and remain in the open state, thereby conducting the transmission hydraulic system and the mixing control valve 9. The parking operating mechanism is used to stop triggering the parking control valve 11 when it is operated (for example, pulling the handbrake lever 10) to cut off the conduction between the transmission hydraulic system and the mixing control valve 9, and the mixing control valve 9 can be triggered when the parking control valve 11 is switched from the open state to the closed state to control the trailer air brake system and the main vehicle oil brake system to perform the braking action.

[0080] In some embodiments, the mixed control valve 9 also includes a pressure relief control end 96 disposed on the shell wall of the valve shell 91 and connected to the shell cavity, and the pressure relief control end 96 can be triggered during pressure relief to control the valve core mechanism to move from the first valve core position to the second valve core position. At this time, the parking control valve 11 is used to connect the gearbox hydraulic system and the pressure relief control end 96. In addition, the parking control mechanism is used to connect the main vehicle oil brake system, and is used to stop triggering the parking control valve 11 when being manipulated (for example, pulling the handbrake lever 10) to cut off the conduction between the gearbox hydraulic system and the mixed control valve 9, so that the pressure relief control end 96 is triggered by pressure relief. At this time, the valve core mechanism is controlled by the pressure relief control end 96 to move from the first valve core position to the second valve core position, driving the trailer air brake system to perform the braking action. At the same time, the parking control mechanism also drives the main vehicle oil brake system to perform the braking action, thereby realizing the parking linkage control of the main vehicle and the trailer.

[0081] In some embodiments, reference Figure 3 The pressure relief control end 96, the air outlet control end 98, the main air inlet end 92 and the main air outlet end 93 are sequentially arranged along the axial direction of the valve housing 91. The valve core mechanism includes a first spring 99, a second spring 910, a third spring 911, and a pressure relief drive piston 912, a core rod 913 (for example, the core rod 913 can movably pass through the oil inlet drive piston 914 and the air inlet drive piston 915 in sequence), a differential piston 916 and an exhaust piston 917 (provided with an exhaust passage) sequentially arranged along the axial direction of the valve housing 91.

[0082] The pressure relief driving piston 912, the differential piston 916 and the exhaust piston 917 are respectively aligned with the pressure relief control end 96, the outlet control end 98 and the main air inlet end 92 along the radial direction of the valve housing 91. The first spring 99, the second spring 910 and the third spring 911 are respectively used to drive the differential piston 916, the exhaust piston 917 and the pressure relief driving piston 912 to reset. The outlet energy supply end 97 is connected to the main air inlet end 92.

[0083] When the valve core mechanism is in the first valve core position, the first spring 99 and the second spring 910 are not stressed, and the parking control valve 11 is in an open state, so there is oil pressure at the pressure relief control end 96, and the pressure relief driving piston 912 compresses the third spring 911 under the oil pressure of the pressure relief control end 96. In addition, the differential piston 916 and the exhaust piston 917 are spaced axially (an exhaust gap 919 is formed at the interval), and the exhaust channel conducts the air outlet control end 98 and the main exhaust end 93 (specifically, the air outlet control end 98, the exhaust gap 919, the exhaust channel of the exhaust piston 917 and the main exhaust end 93 are connected in sequence), and the end of the exhaust piston 917 facing the differential piston 916 abuts against the inner periphery of the valve housing 91 to cut off the conduction between the main air inlet end 92 and the air outlet control end 98, so at this time, the air outlet control end 98 cannot output gas to the trailer air brake system, and the trailer air brake system cannot be driven to operate.

[0084] When the user operates the parking operating mechanism (for example, pulling the handbrake lever 10) and stops triggering the parking control valve 11, the parking control valve 11 switches from an open state to a closed state, and the transmission hydraulic system and the mixing control valve 9 are cut off from being connected, thereby releasing pressure at the pressure relief control end 96. The pressure relief drive piston 912 pushes the core rod 913 and the differential piston 916 toward the exhaust piston 917 under the elastic force of the third spring 911 in a compressed state (the first spring 99 is compressed during this process), until the differential piston 916 and the exhaust piston 917 are axially abutted, and the connection between the outlet control end 98 and the main exhaust end 93 can be cut off. Then, the third spring 911 continues to push the pressure relief drive piston 912, the core rod 913, the differential piston 916 and the exhaust piston 917 toward the main exhaust end 93 (during this process, the first spring 99 and the second spring 910 are both compressed), so that the end of the exhaust piston 917 toward the differential piston 916 is out of contact with the inner periphery of the valve housing 91 to connect the main air intake end 92 and the air outlet control end 98 (that is, the valve core mechanism moves to the second valve core position). At this time, since the main air intake end 92 is connected to the air outlet energy supply end 97 and the air outlet control end 98, the trailer air brake system is driven to operate. At the same time, the parking control mechanism drives the main vehicle oil brake system to operate, thereby realizing the parking linkage control of the main vehicle and the trailer.

[0085] When the parking operating mechanism is reset (for example, when the handbrake lever 10 is released), the parking control valve 11 is triggered again to switch from a closed state to an open state, so that the transmission hydraulic system supplies oil to the pressure relief control end 96 again, so that the pressure relief drive piston 912 compresses the third spring 911 under the oil pressure of the pressure relief control end 96, and the differential piston 916 and the exhaust piston 917 lose the thrust from the third spring 911, so that the differential piston 916 and the exhaust piston 917 will be reset under the elastic force of the first spring 99 and the second spring 910 in the compressed state, and at the same time drive the core rod 913 to reset, so that the valve core mechanism is reset to the first valve core position, and the exhaust channel of the exhaust piston 917 is re-connected to the air outlet control end 98 and the main exhaust end 93, and the main air intake end 92 and the air outlet control end 98 are cut off and connected again.

[0086] In some embodiments, the parking control valve 11 may be a normally closed two-position three-way solenoid valve or other different types of control valves.

[0087] In some embodiments, the pre-brake system further includes a gas drying unit, which is connected between the air supply unit and the brake control unit and is capable of drying the gas output by the air supply unit. For example, the gas drying unit can be connected to the main air intake end 92 and the pre-brake control valve 7, or connected to the main air intake end 92 and the pre-brake control valve 7 through the air storage device 5.

[0088] By using the gas drying unit to dry the gas output by the air supply unit, condensed water (for example, condensed water formed when the high-temperature gas discharged from the air compressor is cooled) can be prevented from flowing in the pre-brake system, thereby avoiding premature damage to various components in the pre-brake system that may cause the brake function to fail, extending the service life of the components and thus improving the driving safety factor.

[0089] In some embodiments, the gas drying unit includes a drying device 2, and the drying device 2 includes a drying air inlet, a drying air outlet, a heater, and a temperature sensor. The drying air inlet is connected to the air supply unit, the drying air outlet is connected to the brake control unit, the temperature sensor is used to monitor the internal temperature of the drying device 2, and the heater is configured to be turned on when the internal temperature is less than a preset critical temperature and turned off when the internal temperature is not less than the preset critical temperature.

[0090] Through the above arrangement, the heater can reheat the condensed water into water vapor, making it easier to absorb the desiccant in the drying device 2. By using the temperature sensor to determine the start and stop timing of the heater, the energy consumption of the heater can be saved and the cost can be reduced.

[0091] In some embodiments, the gas drying unit includes a drying device 2 and a regeneration gas storage device 3, and the drying device 2 includes a drying air inlet, a drying air outlet, and a regeneration air outlet. The drying air inlet is connected to the air supply unit, the drying air outlet is connected to the brake control unit, and the regeneration air storage device 3 is connected to the regeneration air outlet and can blow gas back to the drying device 2.

[0092] By back-blowing gas to the drying device 2 through the regenerated gas storage device 3, the moisture in the desiccant can be blown into the atmosphere, thereby maintaining the activity of the desiccant for a long time and ensuring that the drying device 2 can work effectively for a long time.

[0093] In some embodiments, the gas drying unit includes a drying device 2 and a muffler 4, wherein the drying device 2 includes a drying air inlet, a drying air outlet, and a relief valve, wherein the relief valve is connected between the drying air inlet and the drying air outlet, and the muffler 4 is connected to the air outlet end of the relief valve.

[0094] When the air pressure in the air circuit exceeds a preset maximum value, the unloading valve can release pressure to ensure that the air pressure in the air circuit is restored to below the preset maximum value. When the unloading valve continuously releases pressure, a large noise will be generated. Therefore, a silencer 4 is provided to reduce noise and improve human comfort and driving experience.

[0095] In some embodiments, the pre-brake system also includes an air pressure monitoring unit, which is connected to the brake control unit and can monitor the gas pressure output by the brake control unit to the trailer air brake system, and monitor whether there is air leakage in the system in real time, so as to facilitate fault diagnosis. For example, the air pressure monitoring unit can be connected to a display screen in the vehicle, so that the monitoring results of the air pressure monitoring unit can be displayed in real time on the display screen, so that the user can know in time whether the current pre-brake system can operate normally. In addition, the air pressure monitoring unit may include a first air pressure sensor 12 for monitoring the air pressure of the air supply end 97 and a second air pressure sensor 13 for monitoring the air pressure of the air control end 98, and even a third air pressure sensor may be further provided to monitor the gas pressure of the air storage device 5. Similarly, the third air pressure sensor may also be connected to the display screen in the vehicle.

[0096] In some embodiments, the mixing control valve 9 further includes a throttling element 918 disposed between the main air inlet end 92 and the air outlet power supply end 97. When the valve core mechanism is in the second valve core position and the second air pressure sensor 13 detects that the air pressure at the air outlet control end 98 is less than the preset control air pressure, the main air inlet end 92 is connected to the air outlet power supply end 97 through the throttling element 918. When the valve core mechanism is in the second valve core position and the second air pressure sensor 13 detects that the air pressure at the air outlet control end 98 is not less than the preset control air pressure, the main air inlet end 92 is directly connected to the air outlet power supply end 97.

[0097] The above-mentioned setting can be applied to the situation where the air outlet control end 98 leaks. Specifically, when the air outlet control end 98 leaks, if the user operates the brake operating mechanism (for example, stepping on the foot brake plate 6), the vehicle will determine that the current valve core mechanism is in the second valve core position and the second air pressure sensor 13 detects that the air pressure of the air outlet control end 98 is less than the preset control air pressure. At this time, the throttling element 918 automatically opens and connects the main air inlet end 92 and the air outlet energy supply end 97, so that the amount of gas flowing from the main air inlet end 92 to the air outlet energy supply end 97 is sharply reduced. At the same time, the gas in the air outlet energy supply end 97 is quickly discharged to the atmosphere through the leak point of the air outlet control end 98, thereby causing the air pressure in the air outlet energy supply end 97 (usually also equivalent to the air pressure at the air inlet of the brake valve in the trailer air brake system) to drop suddenly, for example, to 150kpa within 2 seconds. In this way, the emergency braking function in the vehicle can be triggered to avoid the situation of slipping, and ensure the safety during walking braking or slope parking. When the brakes are released or the vehicle is parked, the throttling element 918 can be automatically closed, so that the main air inlet end 92 is directly connected to the air outlet power supply end 97.

[0098] A second exemplary embodiment of the present application also provides a brake assembly, which includes a main vehicle oil brake system for being set on a main vehicle, a trailer air brake system for being set on a trailer towed by the main vehicle, and the above-mentioned pre-braking system connected between the main vehicle oil brake system and the trailer air brake system.

[0099] The third exemplary embodiment of the present application further provides a tractor, which includes a main vehicle, a trailer and the above-mentioned brake assembly.

[0100] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0101] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0102] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0103] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A pre-braking system, characterized in that: include: Air supply unit; A brake control unit is connected to the air supply unit and is used to connect the trailer air brake system and the main vehicle oil brake system, and can control the trailer air brake system and the main vehicle oil brake system to perform braking actions in sequence; A parking control unit, used to control the brake control unit to drive the trailer air brake system to perform braking action and control the main vehicle oil brake system to perform braking action; a gas drying unit connected between the gas supply unit and the brake control unit and capable of drying the gas output by the gas supply unit; and The air pressure monitoring unit is connected to the brake control unit and can monitor the air pressure output by the brake control unit to the trailer air brake system.

2. The pre-braking system according to claim 1, characterized in that: The air supply unit comprises an air source device (1), and the brake control unit comprises: A mixing control valve (9) is connected to the air source device (1) and is used to connect the main vehicle oil brake system and the trailer air brake system. The mixing control valve (9) can be triggered when the main vehicle oil brake system supplies oil to drive the trailer air brake system to perform a braking action; A pre-brake control valve (7) is connected between the air source device (1) and the mixing control valve (9) in a normally closed state and can be opened when triggered. When the pre-brake control valve (7) is opened, the gas of the air source device (1) can be introduced into the mixing control valve (9) to trigger the mixing control valve (9) to drive the trailer air brake system to perform a braking action; The brake operating mechanism is connected to the pre-brake control valve (7) and is used to trigger the pre-brake control valve (7) and the mixed control valve (9) to work together when being operated, so that the trailer air brake system and the main vehicle oil brake system can perform braking actions in sequence.

3. The pre-braking system according to claim 2, characterized in that: The mixing control valve (9) comprises a valve housing (91), a valve core mechanism arranged in a housing cavity of the valve housing (91), and a main air inlet end (92), a main air outlet end (93), an air inlet control end (94), an oil inlet control end (95), an air outlet energy supply end (97), and an air outlet control end (98) arranged on a housing wall of the valve housing (91) and respectively connected to the housing cavity; The air outlet energy supply end (97) and the air outlet control end (98) are both used to connect to the trailer air brake system, the main air inlet end (92) is connected to the air drying unit, the air inlet control end (94) is connected to the air drying unit via the pre-brake control valve (7), and the oil inlet control end (95) is used to connect to the main vehicle oil brake system, and the air inlet control end (94) and the oil inlet control end (95) can be triggered when input pressure is applied to control the valve core mechanism to move from a first valve core position to a second valve core position; When the first valve core is in the position, the outlet control end (98) is connected to the main exhaust end (93), and the main intake end (92) is disconnected from the outlet control end (98); when the second valve core is in the position, the outlet control end (98) is disconnected from the main exhaust end (93), and the main intake end (92) is connected to both the outlet energy supply end (97) and the outlet control end (98).

4. The pre-braking system according to claim 3, characterized in that: The brake control unit further comprises a pressure limiting valve (8), and the pre-brake control valve (7) is connected to the air intake control end (94) via the pressure limiting valve (8); and / or, the air supply unit further comprises an air storage device (5), and the air source device (1) is connected to the pre-brake control valve (7) and the main air intake end (92) via the air storage device (5).

5. The pre-braking system according to claim 1, characterized in that: The gas drying unit comprises a drying device (2), the drying device (2) comprises a drying air inlet, a drying air outlet, a heater and a temperature sensor, the drying air inlet is connected to the air supply unit, the drying air outlet is connected to the brake control unit, the temperature sensor is used to monitor the internal temperature of the drying device (2), and the heater is configured to be turned on when the internal temperature is less than a preset critical temperature and turned off when the internal temperature is not less than the preset critical temperature.

6. The pre-braking system according to claim 1, characterized in that: The gas drying unit comprises a drying device (2) and a regeneration gas storage device (3), the drying device (2) comprises a drying air inlet, a drying air outlet and a regeneration air outlet, the drying air inlet is connected to the air supply unit, the drying air outlet is connected to the brake control unit, and the regeneration gas storage device (3) is connected to the regeneration air outlet and is capable of blowing gas back to the drying device (2).

7. The pre-braking system according to claim 1, characterized in that: The gas drying unit comprises a drying device (2) and a silencer (4), the drying device (2) comprising a drying air inlet, a drying air outlet and a relief valve, the relief valve being connected between the drying air inlet and the drying air outlet, and the silencer (4) being connected to the air outlet end of the relief valve.

8. The pre-braking system according to claim 2, characterized in that: The parking control unit comprises: A parking control valve (11) is used to be connected between the transmission hydraulic system and the mixing control valve (9) in a normally closed state, and can be opened when triggered to conduct the transmission hydraulic system and the mixing control valve (9); The parking control mechanism is used to stop triggering the parking control valve (11) when being operated so as to cut off the conduction between the transmission hydraulic system and the mixing control valve (9), and the mixing control valve (9) can be triggered when the parking control valve (11) is switched from an open state to a closed state so as to control both the trailer air brake system and the main vehicle oil brake system to perform a braking action.

9. The pre-braking system according to claim 3, characterized in that: The air pressure monitoring unit comprises a first air pressure sensor (12) for monitoring the air pressure of the air outlet power supply end (97) and a second air pressure sensor (13) for monitoring the air pressure of the air outlet control end (98).

10. The pre-braking system according to claim 9, characterized in that: The mixing control valve (9) further comprises a throttling element (918) arranged between the main air inlet end (92) and the air outlet power supply end (97); when the valve core mechanism is in the second valve core position and the second air pressure sensor (13) detects that the air pressure at the air outlet control end (98) is less than the preset control air pressure, the main air inlet end (92) is connected to the air outlet power supply end (97) through the throttling element (918); when the valve core mechanism is in the second valve core position and the second air pressure sensor (13) detects that the air pressure at the air outlet control end (98) is not less than the preset control air pressure, the main air inlet end (92) is directly connected to the air outlet power supply end (97).

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