WO2021244375A1

WO2021244375A1 - Brake integrated valve block and double-circuit wet braking system applying same

Info

Publication number: WO2021244375A1
Application number: PCT/CN2021/096136
Authority: WO
Inventors: 毕胜; 吴猛; 刘敏; 薛振见
Original assignee: 安徽合力股份有限公司
Priority date: 2020-06-04
Filing date: 2021-05-26
Publication date: 2021-12-09
Also published as: CN111634277A; DE212021000255U1

Abstract

A brake integrated valve block (5) and a double-circuit wet braking system applying the valve block (5). The system comprises a first brake circuit and a second brake circuit; a three-position four-way solenoid valve (14) is comprised in the first brake circuit and the second brake circuit; the three-position four-way solenoid valve (14) is provided between a double-circuit hydraulic brake valve (11) and a first one-way valve (15) and a second one-way valve (16); one group of oil ports of the three-position four-way solenoid valve are respectively connected to a first oil outlet of the double-circuit hydraulic brake valve (11) and a first oil inlet of the first one-way valve (15), and the other group of oil ports are respectively connected to a second oil outlet of the double-circuit hydraulic brake valve (11) and a first oil inlet of the second one-way valve (16); the system further comprises an emergency brake circuit led out by an emergency energy accumulator (6), a two-position two-way proportional valve (21), the first one-way valve (15), the second one-way valve (16), the three-position four-way solenoid valve (14), and the double-circuit hydraulic brake valve (11).

Description

Brake integrated valve block and double-circuit wet brake system using the valve block

Technical field

The invention relates to the field of brake systems, in particular to a brake integrated valve block and a dual-circuit wet brake system using the valve block.

Background technique

At present, heavy-duty vehicles, such as heavy-duty forklifts, empty container stackers and full container hoists, use a single brake circuit as the wet brake system. As shown in Figure 1, the gear pump 04 is removed from the hydraulic The hydraulic oil is sucked from the oil tank 01 and supplied to the charging valve 05. The hydraulic oil enters the accumulator 07 through the charging valve 05, and enters the drive axle 012 to provide the hydraulic oil required for cooling of the brakes on both sides. The drive axle 012 is connected with a jam alarm switch 013, a brake light switch 011, and a hydraulic oil tank 01. The left pedal 010 and the right pedal 08 are connected through the shuttle valve 09, and the left pedal 010 and the right pedal 08 are also connected to energy storage.器07 and low voltage alarm switch 06. The disadvantages of the above scheme are as follows:

1. When the whole machine is fully loaded, the speed of the whole vehicle should not be too high, otherwise the safety during operation cannot be guaranteed; and when it is fully loaded, the brakes cannot be automatically identified and controlled, and the implementation is still subject to human judgment. The driver is still driving at full speed and cannot brake in time under full load conditions. Case;

2. Once the pipeline bursts in the single-circuit system, the emergency brake disc will lock up instantly, and the cargo may be thrown out, which is even more dangerous.

Summary of the invention

The object of the present invention is to provide a brake integrated valve block and a dual-circuit wet brake system using the valve block to solve the problems raised in the background art.

In order to achieve the above objectives, the present invention provides the following technical solutions:

A brake integrated valve block, comprising a valve housing, the valve housing is provided with a main valve, a two-position three-way control valve, a first two-position two-way control valve and a second two-position two-way control valve connected to form The double-circuit charging valve also includes an overflow valve and a back pressure check valve. The H1 port of the back pressure check valve is connected to the PA port of the valve housing and the H3 port of the overflow valve. The H2 oil port of the valve is connected to the P1 oil port of the valve housing, and the H4 oil port of the relief valve is connected to the T2 oil port of the valve housing.

As an improved solution of the present invention, the D1 port of the first two-position two-way control valve is connected to the D2 port of the second two-position control valve, and the D3 port of the first two-position two-way control valve is connected to the valve The A1 port of the housing is connected, the D4 port of the second two-position two-way control valve is connected to the A2 port of the valve housing; the E port of the two-position three-way control valve is connected with the G port and then connected to the first For the D2 port of the two-position two-way control valve, its F port is connected to the B3 port of the main valve one way, and the other is connected to the T1 port of the valve housing; the B1 port of the main valve is connected to the valve respectively The N port and P1 port of the housing, the B2 port is connected to the D1 port of the first two-position two-way control valve and the D2 port of the second two-position two-way control valve, and the B4 port is connected to the P1 of the valve housing Oil port.

As an improved solution of the present invention, the model of the double-circuit filling valve is ACV-L25F-00A.

A dual-circuit wet brake system using the above-mentioned brake integrated valve block, which includes a dual-circuit hydraulic brake valve, a first one-way valve, and a first wet brake, which is mainly drawn from the A1 oil port of the brake integrated valve block and connected to the dual-circuit hydraulic brake valve. The first brake circuit is connected to constitute the first brake circuit, the A1 oil port of the brake integrated valve block is also connected with a first accumulator; , The second one-way valve and the second wet brake are connected in sequence to form a second brake circuit, the A2 port of the brake integrated valve block is also connected with a second accumulator; the P1 of the brake integrated valve block The oil ports, T1 oil ports, and T2 oil ports are all connected to the hydraulic oil tank; it also includes a three-position four-way solenoid valve, which is arranged between the two-circuit hydraulic brake valve and the first one-way valve and the second one-way valve. Between the one-way valves, one set of oil ports are respectively connected to the first oil outlet of the dual-circuit hydraulic brake valve and the first oil inlet of the first one-way valve, and the other set of oil ports are respectively connected to the dual-circuit hydraulic brake The second oil outlet of the valve and the first oil inlet of the second one-way valve.

As an improved solution of the present invention, the PA port of the brake integrated valve block is connected to the emergency accumulator and the first port of the two-position two-way proportional valve; the second check valve of the first check valve and the second check valve of the second check valve The oil inlets are connected and jointly connected to the second oil port of the two-position two-way proportional valve. The T3 and T4 oil ports of the dual-circuit hydraulic brake valve are both connected to a hydraulic oil tank.

As an improved solution of the present invention, the PA port of the brake integrated valve block is also connected to an emergency accumulator; in the first brake circuit, the A1 port of the brake integrated valve block is also connected to the first low pressure alarm Switch, a first pressure sensor is connected between the two-circuit hydraulic brake valve and the three-position four-way solenoid valve; in the second brake circuit, the A2 port of the brake integrated valve block is also connected with a second low pressure An alarm switch, a second pressure sensor is connected between the two-circuit hydraulic brake valve and the three-position four-way solenoid valve.

As an improved solution of the present invention, it also includes an electrical controller, the electrical controller and the first low-pressure alarm switch, the second low-pressure alarm switch, the first pressure sensor, the second pressure sensor, three-position four-way solenoid valve and The two-position two-way proportional valve is electrically connected.

As an improved solution of the present invention, it also includes a cooling circuit derived from the N oil port of the brake integrated valve block, and the two cooling oil ports of the first wet brake are correspondingly connected to the two cooling oil ports of the second wet brake. The N oil port of the brake integrated valve block is connected to one of the cooling oil ports of the first wet brake, and one of the cooling oil ports of the second wet brake is connected to a hydraulic oil tank through a built-in oil return filter.

As an improved solution of the present invention, the model of the dual-circuit hydraulic brake valve is HBV3-L10F-00.

The present invention has the following beneficial effects:

1. When the vehicle is fully loaded, when the driver of the vehicle controls the brake, he can actively control the brake oil pressure, and try to avoid sudden braking while ensuring safe operation to effectively prevent the cargo from being thrown out;

2. With the first brake circuit and the second brake circuit, even if one of the brake circuits is damaged, the whole vehicle can be braked, and it is not prone to flicking.

3. When both circuits are damaged or fail, the emergency accumulator can be switched immediately to ensure a reliable, autonomous and stable braking.

Description of the drawings

Figure 1 is a schematic diagram of a prior art braking system;

Figure 2 is a schematic diagram of the present invention.

In the picture: 1-hydraulic oil tank; 2-suction filter; 3-gear pump; 4-motor; 5-brake integrated valve block; 51-main valve; 52-two-position three-way control valve; 53-second two -Position two-way control valve; 54-first two-position two-way control valve; 55-overflow valve; 56-back pressure check valve; 6-emergency accumulator; 7-first accumulator; 8-second Accumulator; 9-second low-pressure alarm switch; 10-first low-pressure alarm switch; 11-dual-circuit hydraulic brake valve; 12-second pressure sensor; 13-first pressure sensor; 14-three-position four-way solenoid Valve; 15-First one-way valve; 16-Second one-way valve; 17-Second wet brake; 18-Built-in oil return filter; 19-Electrical controller; 20-Oil tank breather cap; 21-Two positions Two-way proportional valve; 22-the first wet brake.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

Refer to Figure 2, a brake integrated valve block, including a valve housing. The valve housing is provided with a main valve 51, a two-position three-way control valve 52, a first two-position two-way control valve 54 and a second two-position two-way valve. The control valve 53 is connected to form a dual-circuit charging valve, and the model of the dual-circuit charging valve can be ACV-L25F-00A.

The brake integrated valve block also includes a relief valve 55 and a back pressure check valve 56. The H1 port of the back pressure check valve 56 is connected to the PA port of the valve housing and the H3 port of the relief valve 55. The back pressure is single The H2 port of the valve 56 is connected to the P1 port of the valve casing, and the H4 port of the relief valve 55 is connected to the T2 port of the valve casing.

Specifically, the D1 port of the first two-position two-way control valve 54 and the D2 port of the second two-position control valve 53 are connected by a three-way joint, and the D3 port of the first two-position two-way control valve 54 is connected to The A1 port of the valve housing is connected, and the D4 port of the second two-position two-way control valve 53 is connected to the A2 port of the valve housing.

The E port and G port of the two-position three-way control valve 52 are connected together to the D2 port of the second two-position two-way control valve 53, the F port is connected all the way to the B3 port of the main valve 51, and the other Connect the T1 port of the valve housing.

The B1 port of the main valve 51 is respectively connected to the N port and the P1 port of the valve housing, and the B2 port is connected to the D1 port of the first two-position two-way control valve 54 and the D2 port of the second two-position two-way control valve 53 The three-way joint at the oil port is specifically the point C shown in Figure 2, and its B4 port is connected to the P1 port of the valve housing.

A dual-circuit wet brake system, which applies the above-mentioned brake integrated valve block 5. The hydraulic oil tank 1 of the brake system is installed on one side of the frame of the whole vehicle. The oil tank breather cap 20 is installed on the hydraulic oil tank 1. The oil suction port of the gear pump 3 is directly connected to the oil suction filter 2 built in the hydraulic oil tank 1, and the motor 4 is connected with the gear pump 3 to drive the gear pump 3 to rotate, and the outlet of the gear pump 3 is connected to the P1 oil port of the valve housing.

The brake system includes a first brake circuit and a second brake circuit. The first brake circuit is: the A1 oil port of the brake integrated valve block 5 leads to the K6 port, and the K6 port is connected to the dual-circuit hydraulic brake valve 11. The first oil inlet (P3 oil port) and the first accumulator 7, the first oil outlet (A3 oil port) of the dual circuit brake valve 11 is connected to the J1 oil port on the three-position four-way solenoid valve 14, three positions The J2 oil port of the four-way solenoid valve 14 is connected to the first oil inlet (J5 oil port) of the first check valve 15, and the J5 oil port is connected to the K2 oil port of the first wet brake 22.

The second brake circuit is: the K5 port is led from the A2 port of the brake integrated valve block 5, and the K5 port is connected to the second oil inlet (P4 port) of the dual-circuit hydraulic brake valve 11 and the second accumulator 8 , The second oil outlet (A4 port) of the dual-circuit brake valve 11 is connected to the J2 port of the three-position four-way solenoid valve 14, and the J4 port of the three-position four-way solenoid valve 14 is connected to the second one-way valve 15. The first oil inlet (J8 oil port), the J8 oil port is connected to the K3 oil port of the second wet brake 17.

Preferably, the model of the dual-circuit hydraulic brake valve can be selected as HBV3-L10F-00.

In this system, the P1 oil ports, T1 oil ports, and T2 oil ports of the brake integrated valve block 5 and the T3 and T4 oil ports of the dual-circuit hydraulic brake valve 11 are all connected to the hydraulic oil tank 1.

Further, the system also includes an emergency brake circuit, wherein the second oil inlet (J6 oil port) of the first one-way valve 15 is connected to the second oil inlet (J7 oil port) of the second one-way valve 16 , And jointly connect the second port (P8 port) of the two-position two-way proportional valve 21, and the first port (P7 port) of the two-position two-way proportional valve 21 is connected to the PA port of the brake integrated valve block 5. And emergency accumulator 6. The emergency brake circuit includes the emergency accumulator 6, the two-position two-way proportional valve 21, the first one-way valve 15, the second one-way valve 16, the three-dimensional four-way solenoid valve 14, and the two-circuit hydraulic brake valve 11, The hydraulic oil tank 1 constitutes a circuit.

Further, in the first brake circuit, the A1 oil port of the brake integrated valve block 5 is also connected with a first low-pressure alarm switch 10, and a first low-pressure alarm switch 10 is connected between the dual-circuit hydraulic brake valve 11 and the three-position four-way solenoid valve 14. A pressure sensor 13; in the second brake circuit, the A2 port of the brake integrated valve block 5 is also connected to a second low-pressure alarm switch 9, and the dual-circuit hydraulic brake valve 11 is connected with the three-position four-way solenoid valve 14. There is a second pressure sensor 12.

Further, the system also includes an electrical controller 19, the electrical controller 19 is connected to the first low-pressure alarm switch 10, the second low-pressure alarm switch 9, the first pressure sensor 13, the second pressure sensor 12, and the three-position four-way solenoid valve 14. And the two-position two-way proportional valve 21 are electrically connected.

Further, the system also includes a cooling circuit derived from the N oil port of the brake integrated valve block 5, specifically: the two cooling oil ports of the first wet brake 22 correspond to the two cooling oil ports of the second wet brake 17 Connected, the N port of the brake integrated valve block 5 is connected to one of the cooling oil ports (K1 port) of the first wet brake 22, and one of the cooling oil ports (K4 port) of the second wet brake 17 is through the built-in return The oil filter 18 is connected to the hydraulic oil tank 1.

The following describes the implementation principle of this system.

1. When the vehicle is in normal working condition, the implementation principle of this system is:

When the whole machine is working, the gear pump 3 sucks the hydraulic oil from the hydraulic oil tank 1 through the suction filter 2 and supplies it to the P1 port on the brake integrated valve block 5. The high-pressure oil passes through the main valve inside the brake integrated valve block 5. The B1 port and B2 port of 51 respectively supply the first two-position two-way control valve 54 and the second two-position two-way control valve 53 from the B2 port. The high-pressure oil through the D1 port enters the first two-position two-way control valve 54 and then fills the first accumulator 7 through the D3 port and the A1 port. Similarly, the high-pressure oil passes through the D2 port and D4 port of the second two-position two-way control valve 53, and then fills the second accumulator 8 through the A2 port.

When the internal pressure of the first accumulator 7 and the second accumulator 8 reaches the set pressure, the internal pressure of the first accumulator 7 and the second accumulator 8 will pass through the A1, A2 oil on the brake integrated valve block 5. Port feedback to the D3 oil and D4 ports on the first two-position two-way control valve 54 and the second two-position control valve 53 to directly control the first two-position two-way control valve 54 and the second two-way two-way control The spool of valve 53 moves to the corresponding closed oil circuit. At this time, the first two-position two-way control valve 54 and the second two-position control valve 53 almost cut off the oil circuit, and the main valve 51 stops to the first two-position two-way The control valve 54 and the second two-position two-way control valve 53 provide high-pressure oil,

At this time, the two-position three-way control valve 52 starts to work, and the oil from the main valve 51 will enter the F port on the two-position three-way control valve 52 through the B3 port, and then return to the brake integrated valve block 5. T1 port.

The excess oil is supplied to the first wet brake 22 and the second wet brake 17 through the N port on the integrated brake integrated valve block 5 for internal cooling. Finally, this oil passes through the K4 port and then passes through the built-in oil return. The filter 18 returns the hydraulic oil tank 1.

The other way enters the back pressure check valve 56 and directly fills the emergency accumulator 6 with liquid. After the emergency accumulator 6 is full, the surplus possible oil directly overflows from the overflow valve 55 back to the brake integrated valve block 5. Upper T2 oil port, and then return to hydraulic oil tank 1.

At this time, the system has no demand for high-pressure oil, the accumulator pressure will be maintained within a certain pressure range, the system is approximately in a balanced state, and the high-pressure oil reaches the P3 and P4 ports on the dual-circuit hydraulic brake valve 11, waiting When the brake is stepped on, the output is required instantaneously. At this time, the driver steps on the brake pedal, the upper and lower spools on the dual-circuit hydraulic brake valve 11 start to work synchronously, and the A3 and A4 ports on the dual-circuit hydraulic brake valve 11 output at the same time The brake fluid with a certain pressure and a certain flow required for braking passes through the J1 and J2 ports on the three-position four-way solenoid valve 14 directly to the J3 and J4 ports on the three-position four-way solenoid valve 14, and finally reaches The K2 and k3 oil ports on the first wet brake 22 and the second wet brake 17 realize the braking of the whole machine.

This braking is controlled by the driver and is controlled by the driver. At this time, the second low-pressure alarm switch 9, the first low-pressure alarm switch 10, the second pressure sensor 12, and the first pressure sensor 13 maintain normal working conditions, and will not alarm or trigger the logical control sequence of the electrical controller 19 .

2. When the vehicle is in a fully loaded emergency braking state and the cargo is in front of the vehicle, the combined center of gravity of the whole machine and the cargo will move forward. The sudden braking will cause the cargo to slip off and other safety risks. For this, the implementation principle of this system is as follows:

When the driver steps on the dual-circuit hydraulic brake valve 11, it also outputs a certain pressure of oil through the A3 and A4 ports on the dual-circuit hydraulic brake valve 11, and then passes through the three-position four-way solenoid valve 14 as the first wet driver , The second wet brake 17 provides brake fluid, the electrical controller 19 collects load data and vehicle speed data, and judges the timing of activation of the middle throttle position of the spool of the three-position four-way solenoid valve 14. The high-pressure oil part of the four-way solenoid valve 14 is cut to the middle throttle position of the three-position four-way solenoid valve 14, so that the full-load emergency braking is divided into two pressure levels, and the braking time and braking force curve are optimized to make it more stable , So that the goods will not slip off due to inertia, and the braking distance after segmentation meets the standard requirements.

The electrical controller 19 compares the collected data with the preset program to calculate the time to be advanced corresponding to the best braking performance, so as to realize that the intelligent identification process of the system is knowable, controllable, adjustable, and optimizable, and finally The proportional opening of the three-position four-way solenoid valve 14 is optimized. The model of the electrical controller 19 can be Parker MC43.

3. When both the first brake circuit and the second brake circuit fail, the implementation principle of this system is:

When the whole vehicle cannot be braked, that is, when the dual-circuit hydraulic brake valve 11 is damaged or the pipeline between the dual-circuit brake valve 11 and the brake integrated valve block 5 is damaged, the second pressure sensor 12, the first pressure The sensor 13 will sense the abnormal pressure of the system, and transmit the abnormal pressure signals detected by the second pressure sensor 12 and the first pressure sensor 13 to the electrical controller 19. At this time, the electrical controller 19 provides the control signal of the two-position two-way proportional valve 21 to make The two-position two-way proportional valve 21 is instantly switched so that the high-pressure oil stored in the emergency accumulator 6 passes through the two-position two-way proportional valve 21 to the P9 port, and then enters through the first check valve 15 and the second check valve 16 The first wet brake 22 and the second wet brake 17 perform emergency braking.

At this time, the three-position four-way solenoid valve 14 is energized and works in a state where all oil ports are not connected; when the whole machine stops, the brake fluid pressure needs to be released. At this time, the three-position four-way solenoid valve 14 is energized and works in a state where the ports are connected, because the A3 and A4 ports on the dual-circuit hydraulic brake valve 11 are respectively connected to the T3 and T4 ports on the dual-circuit hydraulic brake valve 11 Therefore, the brake fluid directly flows back to the hydraulic oil tank 1 to complete the release of the brake. The above process can realize the autonomous braking of the system through the electrical controller 19, and the whole machine needs to be overhauled in time when it stops.

During the implementation of the system, the fuel tank breather cap 20 is used to complete the internal and external air exchange and pressure equalization of the hydraulic fuel tank 1. At the same time, in order to meet the demand, the J3 and J4 ports on the three-position four-way solenoid valve 14 and the first wet brake 22, the second Second, the connection of wet brake 17 must be all connected by steel pipes to prevent accidental pipeline blasting. At the same time, the compressibility of steel pipes is worse, which can better meet the precise control of brake oil pressure, and provide technical advantages for one-way and one-side smooth braking. , To ensure that the single-channel single-brake control machine will not run off or flick at the current speed, and realize the safety and reliability of the system.

Although this specification is described in accordance with the implementation manners, not each implementation manner only contains an independent technical solution. This narration in the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions of can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

In the description of the present invention, it should be noted that relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply these entities. Or there is any such actual relationship or sequence between operations. Moreover, the terms "including", "including" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device that includes a series of elements includes not only those elements, but also those that are not explicitly listed Other elements of, or also include elements inherent to this process, method, article or equipment. If there are no more restrictions, the element defined by the sentence "including a..." does not exclude the existence of other identical elements in the process, method, article, or equipment that includes the element.

In the description of the present invention, it should also be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", etc. are based on the orientation or positional relationship shown in the drawings, or The orientation or positional relationship usually placed when the product of the invention is used is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it cannot be understood as a limitation to the present invention.

In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "set" and "connection" should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection, or Integrally connected; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be a connection between two components. For those of ordinary skill in the art, the specific meaning of the above-mentioned terms in the present invention can be understood in specific situations.

Therefore, the foregoing descriptions are only preferred embodiments of this application, and are not used to limit the scope of implementation of this application; that is, all equivalent changes made in accordance with the scope of the claims of this application shall fall within the protection scope of the claims of this application. .

Claims

A brake integrated valve block, comprising a valve housing, the valve housing is provided with a main valve (51), a two-position three-way control valve (52), a first two-position two-way control valve (54) and a second The double-circuit filling valve formed by the connection of the two-position two-way control valve (53) is characterized in that it also includes an overflow valve (55) and a back pressure check valve (56), the back pressure check valve (56) The H1 port is connected to the PA port of the valve housing and the H3 port of the relief valve (55), the H2 port of the back pressure check valve (56) is connected to the P1 port of the valve housing, the relief valve The H4 port of (55) is connected to the T2 port of the valve housing.
The brake integrated valve block according to claim 1, wherein the D1 port of the first two-position two-way control valve (54) and the D2 port of the second two-position two-way control valve (53) Oil port connection, the D3 port of the first two-position two-way control valve (54) is connected to the A1 port of the valve housing, and the D4 port of the second two-position two-way control valve (53) is connected to the A2 port of the valve housing Connection; the E port and G port of the two-position three-way control valve (52) are connected together to the D2 port of the second two-position two-way control valve (53), and the F port is connected to the The B3 port of the main valve (51) is connected to the T1 port of the valve housing; the B1 port of the main valve (51) is connected to the N port and the P1 port of the valve housing respectively, and the B2 port is Connect the D1 port of the first two-position two-way control valve (54) to the D2 port of the second two-position control valve (53), and connect the B4 port to the P1 port of the valve housing.
The brake integrated valve block according to claim 1 or 2, wherein the model of the double-circuit charging valve is ACV-L25F-00A.
A dual-circuit wet brake system using the brake integrated valve block according to claim 2, comprising a dual-circuit hydraulic brake valve (11), The first check valve (15) and the first wet brake (22) are connected in sequence to form a first brake circuit, and the A1 oil port of the brake integrated valve block (5) is also connected with a first accumulator (7) );

And the second one, which is mainly drawn from the A2 port of the brake integrated valve block (5) and connected with the dual-circuit hydraulic brake valve (11), the second one-way valve (16), and the second wet brake (17) in sequence. Brake circuit; the A2 port of the brake integrated valve block (5) is also connected with a second accumulator (8); the P1 port, T1 port, and T2 of the brake integrated valve block (5) The oil ports are all connected to the hydraulic oil tank (1); it is characterized in that:

It also includes a three-position four-way solenoid valve (14). The three-position four-way solenoid valve (14) is arranged between the two-circuit hydraulic brake valve (11) and the first one-way valve (15) and the second one-way valve ( 16), one set of oil ports are respectively connected to the first oil outlet of the dual-circuit hydraulic brake valve (11) and the first oil inlet of the first one-way valve (15), and the other set of oil ports are respectively connected The second oil outlet of the dual-circuit hydraulic brake valve (11) and the first oil inlet of the second one-way valve (16).
The dual-circuit wet brake system according to claim 4, wherein the PA port of the brake integrated valve block (5) is connected to an emergency accumulator (6) and a two-position two-way proportional valve (21) The first oil port; the first one-way valve (15) is connected to the second oil inlet of the second one-way valve (16), and is jointly connected to the second oil port of the two-position two-way proportional valve (21) , The T3 and T4 oil ports of the dual-circuit hydraulic brake valve (11) are both connected to the hydraulic oil tank (1).
The dual-circuit wet brake system according to claim 5, characterized in that, in the first brake circuit, the A1 oil port of the brake integrated valve block (5) is also connected with a first low pressure alarm switch (10) A first pressure sensor (13) is connected between the dual-circuit hydraulic brake valve (11) and the three-position four-way solenoid valve (14);

In the second brake circuit, the A2 oil port of the brake integrated valve block (5) is also connected with a second low-pressure alarm switch (9), and the double-circuit hydraulic brake valve (11) is connected to the three-position four-way solenoid A second pressure sensor (12) is connected between the valves (14).
The dual-circuit wet braking system according to claim 6, further comprising an electrical controller (19), the electrical controller (19) and the first low-voltage alarm switch (10), the second low-voltage The alarm switch (9), the first pressure sensor (13), the second pressure sensor (12), the three-position four-way solenoid valve (14) and the two-position two-way proportional valve (21) are electrically connected.
The dual-circuit wet brake system according to claim 5, further comprising a cooling circuit drawn from the N oil port of the brake integrated valve block (5), and two of the first wet brake (22) Two cooling oil ports are correspondingly connected to the two cooling oil ports of the second wet brake (17), and the N oil port of the brake integrated valve block (5) is connected to one of the cooling oils of the first wet brake (22) One of the cooling oil ports of the second wet brake (17) is connected to the hydraulic oil tank (1) through a built-in oil return filter (18).
The double-circuit wet brake system according to any one of claims 4-8, wherein the model of the double-circuit hydraulic brake valve (11) is HBV3-L10F-00.