Trailer brake hydraulic system and tractor trailer brake system

Abstract

The utility model provides a trailer braking hydraulic system and a tractor trailer braking system, the trailer braking hydraulic system comprises a trailer braking oil cylinder, an energy accumulator and a reversing valve, an inlet of the reversing valve is connected with a braking oil source pipeline, a first outlet of the reversing valve is connected with the trailer braking oil cylinder, and a second outlet of the reversing valve is connected with the energy accumulator; a switch oil way and a release oil way are arranged between the trailer brake oil cylinder and the energy accumulator, and when the switch oil way is opened, oil in the energy accumulator can enter the trailer brake oil cylinder through the switch oil way. A releasing pump is arranged on the releasing oil way and can be used for pumping oil in the trailer brake oil cylinder into the energy accumulator. According to the trailer braking system, oil is supplied to the energy accumulator and the trailer braking oil cylinder through the reversing valve, and vehicle-mounted braking of a trailer is achieved; by operating the reversing valve, the switch oil way and the release pump, quick switching between vehicle-mounted braking and independent braking of the trailer is achieved, operation is convenient, and the safety of the trailer is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of tractor trailers, in particular to a trailer brake hydraulic system and a tractor trailer brake system. Background Art

[0002] With the rapid development of tractors in the international market, their application areas are gradually expanding. When a tractor is coupled to a trailer, the trailer's brakes also require corresponding hydraulic actuation. Currently, trailer brakes are mostly configured separately. To prepare for driving, after starting the engine, the tractor's front brakes and the trailer's brakes must be released separately. To park, both the tractor's front brakes and the trailer's brakes must be applied simultaneously. This makes simultaneous operation difficult, resulting in poor timeliness and convenience. Some tractors route the vehicle's brake pressure oil to the trailer's brakes, allowing braking of the entire tractor to simultaneously apply the brakes to the trailer. However, without braking the entire tractor, the trailer cannot be braked independently, compromising trailer safety. Utility Model Content

[0003] The technical problem to be solved by the utility model is: how to realize the quick switching between the trailer's onboard braking and the independent braking.

[0004] The technical solution of the utility model to solve the above technical problems is as follows:

[0005] The utility model provides a trailer brake hydraulic system, comprising a trailer brake oil cylinder, an accumulator, and a reversing valve, wherein an inlet of the reversing valve is connected to a brake oil source pipeline, a first outlet of the reversing valve is connected to the trailer brake oil cylinder, and a second outlet of the reversing valve is connected to the accumulator; a switch oil circuit and a release oil circuit are provided between the trailer brake oil cylinder and the accumulator, and when the switch oil circuit is opened, the oil in the accumulator can enter the trailer brake oil cylinder through the switch oil circuit; a release pump is provided on the release oil circuit, and the release pump can be used to pump the oil in the trailer brake oil cylinder into the accumulator.

[0006] The beneficial effects of the utility model are:

[0007] The utility model supplies oil to the accumulator and the trailer brake cylinder through the reversing valve, thereby realizing the filling of the accumulator and the trailer's onboard braking; when the entire vehicle is not involved in braking, the reversing valve is actuated and the switch oil circuit is opened to switch to the independent braking of the trailer, and the oil pressure in the accumulator is used to drive the trailer brake cylinder, which is quick to operate; by closing the switch oil circuit and starting the release pump, the independent braking can be released and the pressure in the accumulator can be restored. At this time, the reversing valve is actuated to switch to the trailer's onboard braking; thereby, the rapid switching between the trailer's onboard braking and independent braking is realized, the operation is convenient, and the safety of the trailer is improved.

[0008] On the basis of the above technical solution, the present invention can also be improved as follows.

[0009] Furthermore, a one-way valve is provided on the release oil circuit, and the one-way valve allows oil to flow from the trailer brake cylinder to the accumulator in one direction.

[0010] When the individual brakes are released, the oil in the accumulator is prevented from leaking into the trailer brake cylinder, which provides good reliability.

[0011] Furthermore, at least two one-way valves are provided, and the release pump is a reciprocating pump with a single connecting pipe, and the connecting pipe of the release pump is connected to the oil circuit between the two one-way valves.

[0012] The oil inlet and outlet of the release pump are both connected through the same pipe, which has a simple structure and low cost. The release pump draws oil into the trailer brake cylinder through one of the one-way valves, and then discharges oil into the accumulator through the other one-way valve, which facilitates the rapid release of individual brakes and fully restores the pressure of the accumulator, thereby improving reliability.

[0013] Furthermore, the release pump is a manual pump.

[0014] Simple structure and low cost.

[0015] Furthermore, the reversing valve is further provided with a pump interface, and the pipe for releasing the pump is connected to the pump interface; the valve core of the reversing valve is provided with a station a and a station b, and both station a and station b are provided with an inlet valve channel, an outlet valve channel, a second outlet valve channel, a pump valve channel and a release valve channel, the inlet valve channel is used to connect to the inlet of the reversing valve, the outlet valve channel is used to connect to the first outlet of the reversing valve, the second outlet valve channel is used to connect to the second outlet of the reversing valve, and the pump valve channel is used to connect to the pump interface of the reversing valve;

[0016] One end of the release valve channel is connected to the inlet valve channel of the station where it is located, and the other end of the release valve channel is connected to the second outlet valve channel of the station where it is located. The release valve channel is provided with two one-way valves, and the pump valve channel is connected between the two one-way valves of the release valve channel of the corresponding station;

[0017] The inlet valve channel of station a is connected to an outlet valve channel, and the inlet valve channel of station b is disconnected from an outlet valve channel.

[0018] It is convenient to integrate the release oil circuit into the reversing valve, which is easy to switch and occupies a small volume. At the same time, the reversing valve action can also realize the switching between the vehicle braking state and the independent braking state, which greatly improves the convenience of operation.

[0019] Furthermore, the b station is also provided with a switch valve channel, one end of the switch valve channel is connected to the first outlet valve channel of the b station, and the other end is connected to the second outlet valve channel of the b station.

[0020] It is convenient to integrate the switch oil circuit into the reversing valve, which is easy to switch and occupies a small volume. At the same time, the reversing valve action can also realize the switching between the vehicle braking state and the independent braking state, which greatly improves the convenience of operation.

[0021] Furthermore, the reversing valve is a manual reversing valve.

[0022] Easy to control manually and operate.

[0023] Furthermore, there are two trailer brake cylinders, and the cylinder ends of the two trailer brake cylinders are both connected to the first outlet of the reversing valve.

[0024] It is convenient to drive the brakes on both sides of the trailer, and the braking is smooth.

[0025] Furthermore, a return spring is provided on the piston rod side of the trailer brake cylinder, one end of the return spring abuts against the cylinder end of the trailer brake cylinder, and the other end abuts against the piston of the trailer brake cylinder.

[0026] When the onboard brake is released, it is convenient to drive the trailer brake cylinder to automatically reset and return the oil to the brake oil source pipeline.

[0027] The utility model also provides a tractor trailer brake system, comprising a trailer brake, a brake pressure oil source of a tractor and the above-mentioned trailer brake hydraulic system, wherein the trailer brake cylinder is connected to the trailer brake, and the brake oil source pipeline is connected to the brake pressure oil source of the tractor.

[0028] The mounting structure of the trailer brake on the trailer and the mounting structure of the brake pressure oil source on the tractor are both prior art, which realizes the quick switching between trailer braking and independent braking, is easy to operate, and improves the safety of the trailer. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a structural diagram of the utility model in the liquid-filled state.

[0030] Figure 2 This is a structural diagram of the utility model in the vehicle-mounted braking state.

[0031] Figure 3 This is a structural diagram of the utility model in a single braking state.

[0032] Figure 4 This is a structural diagram of the utility model in a single brake release state.

[0033] In the accompanying drawings, the technical features represented by the reference numerals are as follows:

[0034] 1-trailer brake cylinder; 2-accumulator; 3-reversing valve; 31-inlet valve channel; 32-first outlet valve channel; 33-second outlet valve channel; 34-pump valve channel; 35-release valve channel; 36-switch valve channel; 4-release pump; 5-brake oil source pipeline; 6-check valve; 7-return spring. DETAILED DESCRIPTION

[0035] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0036] This utility model refers to Figure 1-4 .

[0037] The utility model provides a trailer brake hydraulic system, comprising a trailer brake cylinder 1, an accumulator 2, and a reversing valve 3. The inlet of the reversing valve 3 is connected to a brake oil source pipeline 5, a first outlet of the reversing valve 3 is connected to the trailer brake cylinder 1, and a second outlet of the reversing valve 3 is connected to the accumulator 2; a switch oil circuit and a release oil circuit are provided between the trailer brake cylinder 1 and the accumulator 2, when the switch oil circuit is opened, the oil in the accumulator 2 can enter the trailer brake cylinder 1 through the switch oil circuit; a release pump 4 is provided on the release oil circuit, and the release pump 4 can be used to pump the oil in the trailer brake cylinder 1 into the accumulator 2.

[0038] principle:

[0039] During installation, brake oil source line 5 is connected to the tractor's brake pressure oil source. When the brake pedal is pressed, the brake pressure oil source activates, braking the tractor and supplying brake pressure oil to brake oil source line 5. When the brake pedal is released, the oil in brake oil source line 5 flows back to the brake pressure oil source along with the oil in the tractor's brake cylinder. The tractor's brake pressure oil source is prior art, and its oil supply and return mechanisms are unrelated to the technical problem addressed by the present invention.

[0040] When the vehicle is started for the first time, there is no pressure oil in the trailer brake cylinder 1, accumulator 2 and each pipeline; after starting, when the brake pedal is stepped on, the tractor's brake pressure oil source supplies oil to the brake oil source pipeline 5.

[0041] In the liquid-filled state, oil flows out from the second outlet of the reversing valve 3 , and the pressure oil in the brake oil source pipeline 5 is directly replenished to the accumulator 2 until the accumulator 2 is fully charged.

[0042] In the vehicle-mounted braking state, oil flows out of the first outlet of reversing valve 3, and the pressurized oil in brake oil source pipeline 5 enters trailer brake cylinder 1, pushing trailer brake cylinder 1 to extend. When the tractor brakes are released, trailer brake cylinder 1 retracts under its own restoring force, and the oil inside returns to brake oil source pipeline 5 through reversing valve 3.

[0043] In the single brake state, the inlet of the reversing valve 3 is closed, the switching oil circuit is opened, and the oil in the accumulator 2 enters the trailer brake cylinder 1 through the switching oil circuit, pushing the trailer brake cylinder 1 to extend. In the single brake release state, the switching oil circuit is closed, and the release pump 4 is activated, pumping the oil in the trailer brake cylinder 1 into the accumulator 2, restoring the pressure in the accumulator 2 to facilitate the next single brake.

[0044] Note: The switch oil circuit can be connected separately to the trailer brake cylinder 1 and accumulator 2, and a valve can be installed on the switch oil circuit; the release oil circuit can also be connected separately to the trailer brake cylinder 1 and accumulator 2. In addition, the switch oil circuit and the release oil circuit can also be integrated into the reversing valve 3.

[0045] With the present invention, oil is supplied to the accumulator 2 and the trailer brake cylinder 1 through the reversing valve 3, thereby realizing the filling of the accumulator 2 and the trailer's onboard braking. When the entire vehicle is not involved in braking, the reversing valve 3 is actuated and the switch oil circuit is opened to switch to the independent braking of the trailer, and the oil pressure in the accumulator 2 is used to drive the trailer brake cylinder 1, which is quick to operate. By closing the switch oil circuit and starting the release pump 4, the independent braking can be released and the pressure in the accumulator 2 can be restored. At this time, the reversing valve 3 is actuated to switch to the trailer's onboard braking. Thus, the rapid switching between the trailer's onboard braking and independent braking is realized, the operation is convenient, and the safety of the trailer is improved.

[0046] Furthermore, a one-way valve 6 is provided on the release oil circuit, and the one-way valve 6 allows oil to flow from the trailer brake cylinder 1 to the accumulator 2 in one direction.

[0047] In the state of individual brake release, the oil in the accumulator 2 is prevented from leaking to the trailer brake cylinder 1, and the reliability is good.

[0048] Furthermore, at least two one-way valves 6 are provided, and the release pump 4 is a reciprocating pump with a single pipe, and the pipe of the release pump 4 is connected to the oil circuit between the two one-way valves 6 .

[0049] The oil inlet and outlet of the release pump 4 are both connected to the same pipe, which has a simple structure and low cost. The release pump 4 draws oil into the trailer brake cylinder 1 through one of the one-way valves 6, and then discharges oil to the accumulator 2 through the other one-way valve 6, which facilitates the rapid release of the individual brakes and fully restores the pressure of the accumulator 2, thereby improving reliability.

[0050] Furthermore, the release pump 4 is a manual pump.

[0051] Simple structure and low cost.

[0052] Furthermore, the reversing valve 3 is further provided with a pump interface, and the pipe for releasing the pump 4 is connected to the pump interface; the valve core of the reversing valve 3 is provided with a station a and a station b, and both the station a and the station b are provided with an inlet valve channel 31, an outlet valve channel 32, a second outlet valve channel 33, a pump valve channel 34 and a release valve channel 35, the inlet valve channel 31 is used to connect to the inlet of the reversing valve 3, the outlet valve channel 32 is used to connect to the first outlet of the reversing valve 3, the second outlet valve channel 33 is used to connect to the second outlet of the reversing valve 3, and the pump valve channel 34 is used to connect to the pump interface of the reversing valve 3;

[0053] One end of the release valve channel 35 is connected to the inlet valve channel 31 of the station where it is located, and the other end of the release valve channel 35 is connected to the second outlet valve channel 33 of the station where it is located. The release valve channel 35 is provided with two one-way valves 6, and the pump valve channel 34 is connected between the two one-way valves 6 of the release valve channel 35 of the corresponding station;

[0054] The inlet valve passage 31 and an outlet valve passage 32 of the a station are connected to each other, while the inlet valve passage 31 and an outlet valve passage 32 of the b station are disconnected.

[0055] Principle: The housing of the reversing valve 3 cooperates with the valve core. By moving the valve core, a specific position of the valve core is moved to the position of the interface (inlet, first outlet, second outlet and pump interface) of the housing, thereby making the specific position of the valve core work. The structure of the housing and the valve core cooperation belongs to the existing technology. When the a station is working, the inlet valve channel 31 of the a station is connected to the inlet of the reversing valve 3, the first outlet valve channel 32 is connected to the first outlet of the reversing valve 3, the second outlet valve channel 33 is connected to the second outlet of the reversing valve 3, and the pump valve channel 34 is connected to the pump interface of the reversing valve 3; all valve channels of the b station are closed. When the b station is working, the inlet valve channel 31 of the b station is connected to the inlet of the reversing valve 3, the first outlet valve channel 32 is connected to the first outlet of the reversing valve 3, the second outlet valve channel 33 is connected to the second outlet of the reversing valve 3, and the pump valve channel 34 is connected to the pump interface of the reversing valve 3; all valve channels of the a station are closed.

[0056] The first outlet valve channel 32, the second outlet valve channel 33, the pump valve channel 34, and the release valve channel 35 together form the release oil circuit. Figure 1 As shown in FIG, the flow path of the oil through the a station is: the inlet of the reversing valve 3 → the inlet valve channel 31 → the release valve channel 35 → the second outlet valve channel 33 → the second outlet → the accumulator 2. After the accumulator 2 is charged, it does not need to be operated and automatically enters the vehicle braking state. Figure 2 As shown, the flow path of the oil through the a station is: the inlet of the reversing valve 3 → the inlet valve channel 31 → the first outlet valve channel 32 → the first outlet → the trailer brake cylinder 1. In the single braking state, the b station works, such as Figure 3As shown, under the action of the one-way valve 6, the oil in the trailer brake cylinder 1 and the accumulator 2 is prevented from flowing back to the brake oil source pipeline 5, ensuring that the pressure of the accumulator 2 can drive the trailer brake cylinder 1 through the switch oil circuit. Figure 4 As shown, the flow path of the oil through the a station is: (release pump 4 to absorb oil) trailer brake cylinder 1 → first outlet → first outlet valve channel 32 → first outlet valve channel 32 → release valve channel 35 → pump valve channel 34 → pump interface → release pump 4; (release pump 4 to discharge oil) release pump 4 → pump interface → pump valve channel 34 → second outlet valve channel 33 → second outlet → accumulator 2.

[0057] It is convenient to integrate the release oil circuit into the reversing valve 3, which is convenient to switch and occupies a small volume. At the same time, by utilizing the action of the reversing valve 3, the switching between the vehicle braking state and the independent braking state can also be realized, which greatly improves the convenience of operation.

[0058] Furthermore, the b station is further provided with a switch valve channel 36 , one end of the switch valve channel 36 is connected to the first outlet valve channel 32 of the b station, and the other end is connected to the second outlet valve channel 33 of the b station.

[0059] Principle: The second valve channel 33, the switch valve channel 36, and the first valve channel 32 together form the switch oil circuit. In the single braking state, the b station works, such as Figure 3 As shown, the flow path of the oil through the b station is: accumulator 2 → second outlet → second outlet valve channel 33 → switch valve channel 36 → first outlet valve channel 32 → first outlet → trailer brake cylinder 1.

[0060] It is convenient to integrate the switch oil circuit into the reversing valve 3, which is convenient to switch and occupies a small volume. At the same time, by utilizing the action of the reversing valve 3, the switching between the vehicle braking state and the independent braking state can also be realized, which greatly improves the convenience of operation.

[0061] Furthermore, the reversing valve 3 is a manual reversing valve.

[0062] Easy to control manually and operate.

[0063] Furthermore, two trailer brake cylinders 1 are provided, and cylinder ends of the two trailer brake cylinders 1 are both connected to the first outlet of the reversing valve 3 .

[0064] It is convenient to drive the brakes on both sides of the trailer, and the braking is smooth.

[0065] Furthermore, a return spring 7 is provided on the piston rod side of the trailer brake cylinder 1 , one end of the return spring 7 abuts against the cylinder end of the trailer brake cylinder 1 , and the other end abuts against the piston of the trailer brake cylinder 1 .

[0066] When the vehicle brake is released, it is convenient to drive the trailer brake cylinder 1 to automatically reset and return the oil to the brake oil source pipeline 5.

[0067] The utility model also provides a tractor trailer brake system, comprising a trailer brake, a brake pressure oil source of a tractor, and the above-mentioned trailer brake hydraulic system, wherein the trailer brake cylinder 1 is connected to the trailer brake, and the brake oil source pipeline 5 is connected to the brake pressure oil source of the tractor.

[0068] The mounting structure of the trailer brake on the trailer and the mounting structure of the brake pressure oil source on the tractor are both prior art, which realizes the quick switching between trailer braking and independent braking, is easy to operate, and improves the safety of the trailer.

[0069] In the description of the present invention, it should be understood that if there are descriptive terms indicating orientation, direction or positional relationship, such as: "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., the orientation or positional relationship indicated in this specification is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of understanding the present invention and simplifying the description, and does not indicate or imply that the referred part, element or whole must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0070] In addition, if there are order description terms, such as "first", "second", etc., their use in this specification is to facilitate understanding or simplify the description. For example, in order to distinguish multiple technical features with the same type or function, but they have to be mentioned separately, this specification may use prefix or suffix order description terms to distinguish them. Therefore, it cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" can explicitly or implicitly include at least one of such features. In the description of this utility model, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0071] In the present invention, if terms describing the relative functional relationship of structures are used, such as "install", "connect", "connect", "fix", etc., they should be understood in a broad sense unless otherwise clearly specified and limited. For example, "install", "connect", "connect", etc. can be fixed connections, detachable connections, or integrated; can be mechanical connections or electrical connections; can be direct connections or indirect connections through an intermediate medium, can be internal connections between two elements or interactive relationships between two elements; "fix" can be fixed to form an integral body, or can be detachably fixed through fasteners; can be directly fixed or fixed through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above-mentioned descriptive terms in the present invention can be understood according to the specific circumstances, the context, the coherence of the preceding and following texts, etc.

[0072] In this utility model, if descriptive terms with ancillary or connecting meaning appear, for example, a first feature being "on" or "below" a second feature, these should not be interpreted as limiting unless otherwise expressly specified or limited. For example, "on" or "below" may refer to direct contact between the first and second features, or indirect contact between the first and second features through an intermediary. Those skilled in the art will understand the specific meanings of these descriptive terms in this utility model based on the specific circumstances, context, and coherence of the preceding and following texts.

[0073] Furthermore, when a first feature is “above,” “above,” or “above” a second feature, it may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. When a first feature is “below,” “below,” or “below” a second feature, it may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0074] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" 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 invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine the different embodiments, examples and features of different embodiments and examples described in this specification, unless there is any contradiction, and these combinations or combinations should all fall within the scope summarized by the present invention.

[0075] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are illustrative and cannot be understood as limiting the present invention. Changes, modifications, substitutions and variations of the above embodiments made by ordinary technicians in the field within the scope of information available from public channels and in combination with the technical inspiration given by the application documents are still within the scope of protection of the present application.

Claims

1. A trailer brake hydraulic system, characterized by: The invention comprises a trailer brake oil cylinder (1), an accumulator (2), and a reversing valve (3); the inlet of the reversing valve (3) is connected to a brake oil source pipeline (5); the first outlet of the reversing valve (3) is connected to the trailer brake oil cylinder (1); and the second outlet of the reversing valve (3) is connected to the accumulator (2); a switch oil circuit and a release oil circuit are provided between the trailer brake oil cylinder (1) and the accumulator (2); when the switch oil circuit is opened, the oil in the accumulator (2) can enter the trailer brake oil cylinder (1) through the switch oil circuit; and a release pump (4) is provided on the release oil circuit, and the release pump (4) can be used to pump the oil in the trailer brake oil cylinder (1) into the accumulator (2).

2. The trailer brake hydraulic system according to claim 1, characterized in that: A one-way valve (6) is provided on the release oil circuit, and the one-way valve (6) allows oil to flow from the trailer brake cylinder (1) to the accumulator (2) in one direction.

3. The trailer brake hydraulic system according to claim 2, characterized in that: At least two one-way valves (6) are provided, the release pump (4) is a reciprocating pump with a single pipe, and the pipe of the release pump (4) is connected to the oil circuit between the two one-way valves (6).

4. The trailer brake hydraulic system according to claim 3, characterized in that: The release pump (4) is a manual pump.

5. The trailer brake hydraulic system according to claim 3, characterized in that: The reversing valve (3) is also provided with a pump interface, and the pipe of the release pump (4) is connected to the pump interface; the valve core of the reversing valve (3) is provided with a station a and a station b, and the station a and the station b are both provided with an inlet valve channel (31), an outlet valve channel (32), two outlet valve channels (33), a pump valve channel (34) and a release valve channel (35); the inlet valve channel (31) is used to connect to the inlet of the reversing valve (3), the outlet valve channel (32) is used to connect to the first outlet of the reversing valve (3), the two outlet valve channels (33) are used to connect to the second outlet of the reversing valve (3), and the pump valve channel (34) is used to connect to the pump interface of the reversing valve (3); One end of the release valve channel (35) is connected to the inlet valve channel (31) of the station where the release valve channel (35) is located, and the other end of the release valve channel (35) is connected to the second outlet valve channel (33) of the station where the release valve channel (35) is located. Two one-way valves (6) are provided on the release valve channel (35), and the pump valve channel (34) is connected between the two one-way valves (6) of the release valve channel (35) of the corresponding station; The inlet valve channel (31) and an outlet valve channel (32) of the a station are connected to each other, and the inlet valve channel (31) and an outlet valve channel (32) of the b station are disconnected.

6. The trailer brake hydraulic system according to claim 5, characterized in that: The b station is further provided with a switch valve channel (36), one end of which is connected to a first outlet valve channel (32) of the b station, and the other end of which is connected to a second outlet valve channel (33) of the b station.

7. The trailer brake hydraulic system according to claim 5, characterized in that: The reversing valve (3) is a manual reversing valve.

8. The trailer brake hydraulic system according to claim 1, characterized in that: Two trailer brake oil cylinders (1) are provided, and the cylinder ends of the two trailer brake oil cylinders (1) are both connected to the first outlet of the reversing valve (3).

9. The trailer brake hydraulic system according to claim 8, characterized in that: A return spring (7) is provided on the piston rod side of the trailer brake oil cylinder (1), one end of the return spring (7) abuts against the cylinder end of the trailer brake oil cylinder (1), and the other end abuts against the piston of the trailer brake oil cylinder (1).

10. A tractor trailer braking system, characterized in that: The invention comprises a trailer brake, a brake pressure oil source of a tractor and a trailer brake hydraulic system according to any one of claims 1 to 9, wherein the trailer brake cylinder (1) is connected to the trailer brake, and the brake oil source pipeline (5) is connected to the brake pressure oil source of the tractor.

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