Full-hydraulic two-way hydraulic control brake valve

Abstract

The invention discloses a full-hydraulic two-way hydraulic control brake valve which comprises a valve body and a brake pedal. A valve cavity is formed in the valve body, and a first valve element and a second valve element are arranged in the valve cavity in a sleeved mode. Reset spring sets are arranged in valve cavities in the two ends of a core body formed by the first valve element and the second valve element, and under the action of the reset spring sets, the first valve element and the second valve element are located at the first position, so that the first brake oil port is communicated with the first oil return port, and the second brake oil port is communicated with the second oil return port. When the brake pedal is in a treading state, the first valve element and the second valve element move to a second position, so that the first brake oil port is communicated with the oil inlet, and the second brake oil port is communicated with the second oil inlet; the valve cavity further communicates with a hydraulic control port, the hydraulic control port communicates with high-pressure hydraulic oil, and the hydraulic control port can work independently of the brake pedal, overcome the acting force of the reset spring set and drive the first valve element and the second valve element to move from the first position to the second position. The device is reasonable in structure, good in use safety and capable of being remotely controlled.

Description

Technical Field

[0001] The invention relates to the technical field of brake valves, in particular to a full hydraulic dual-circuit hydraulically controlled brake valve. Background Art

[0002] At present, with the upgrading and transformation of the braking system and the improvement of the manufacturing level, the use of hydraulic power brake system has become the development direction of wheeled engineering machinery braking system in the future. Among them, the hydraulic power brake valve is an important component of the hydraulic brake system. In the prior art, the hydraulic power brake valve includes a single-circuit hydraulic power brake valve and a dual-circuit hydraulic power brake valve, among which the dual-circuit hydraulic power brake valve is safer to use. As shown in the patent application number CN202122223745.2 entitled a series dual-circuit brake valve, when one brake circuit fails, the other brake circuit can still work normally. However, in production practice, whether it is a single-circuit hydraulic brake valve or a dual-circuit hydraulic brake valve, a brake pedal is usually used to control the on and off of the brake circuit. When the brake pedal fails or the operator cannot operate normally, the safety risk of using it in a harsh environment is high. Summary of the invention

[0003] The present invention discloses a fully hydraulic dual-circuit hydraulically controlled brake valve, which solves the technical problem of high risk of use when the pedal of a single-circuit or dual-circuit hydraulic brake valve in the prior art cannot function normally, and has the technical effects of reasonable structure, good safety in use and remote control. The technical solution adopted is as follows: A full hydraulic dual-circuit hydraulically controlled brake valve, comprising a valve body and a brake pedal; A valve cavity is formed in the valve body, a first valve core and a second valve core are sleeved in the valve cavity, and the valve cavity is connected with a first oil inlet, a second oil inlet, a first brake oil port, a second brake oil port, a first oil return port and a second oil return port respectively; A return spring group is provided in the valve cavity at both ends of the core body formed by the first valve core and the second valve core. Under the action of the return spring group, the first valve core and the second valve core are in the first position, so that the first brake oil port is connected to the first oil return port, and the second brake oil port is connected to the second oil return port; when the brake pedal is in a stepped state, the first valve core and the second valve core are displaced from the first position to the second position, so that the first brake oil port is connected to the oil inlet, and the second brake oil port is connected to the second oil inlet; The valve chamber is also connected to a hydraulic control port, which is connected to high-pressure hydraulic oil, and the hydraulic control port can work independently of the brake pedal to overcome the force of the return spring group and drive the first valve core and the second valve core to move from the first position to the second position.

[0004] On the basis of the above technical solution, it also includes a hydraulically controlled valve core, which is arranged close to the brake pedal and is arranged at one end of the core body formed by the first valve core and the second valve core. A third annular cavity is formed between the hydraulically controlled valve core and one end of the core body, and the third annular cavity is connected to the hydraulic control port.

[0005] On the basis of the above technical solution, it also includes a bushing, which is fixed in the valve cavity, and the bushing is sleeved on the outside of the hydraulic control valve core and connected to the hydraulic control valve core through a first sealing ring. When the first valve core and the second valve core are in the first position, the hydraulic control valve core abuts against the bushing upward to limit the displacement of the hydraulic control valve core; and the high-pressure oil entering the hydraulic control port is designed to be insufficient to push the bushing to displace in the valve cavity, but sufficient to overcome the sliding resistance of the core body formed by the first valve core and the second valve core in the valve cavity, so as to displace the core body in the valve cavity.

[0006] Based on the above technical solution, the oil pressure value entering the third annular cavity through the hydraulic control port is close to the brake pressure value output by the brake valve, and a solenoid valve is provided on the high-pressure pipeline connected to the hydraulic control port.

[0007] On the basis of the above technical solution, the third annular cavity is further connected to the pipe with an exhaust port, and an exhaust valve is provided at the exhaust port.

[0008] Based on the above technical solution, the valve body includes an upper valve body and a lower valve body, and the upper valve body and the lower valve body together enclose a valve cavity, the hydraulic control port, the first oil inlet, the first brake oil port and the first oil return port are arranged on the upper valve body and close to the brake pedal, and the second oil inlet, the second brake oil port and the second oil return port are arranged on the lower valve body.

[0009] On the basis of the above technical solution, a first annular cavity is formed on the first valve core, the first annular cavity is connected to the first brake oil port, and when the first valve core and the second valve core are displaced from the first position to the second position, the first annular cavity is switched from being connected to the first oil return port to being connected to the first oil inlet port; a second annular cavity is formed on the second valve core, the second annular cavity is connected to the second brake oil port, and when the first valve core and the second valve core are displaced from the first position to the second position, the second annular cavity is switched from being connected to the second oil port to being connected to the second oil inlet port.

[0010] On the basis of the above technical solution, a buffer cavity is formed between the abutment point between the first valve core and the second valve core and the inner wall surface of the valve cavity, a first feedback oil passage is provided in the first valve core, one end of the first feedback oil passage is connected with the first annular concave cavity, and the second end of the first feedback oil passage is connected with the buffer cavity; a second feedback oil passage is provided in the second valve core, one end of the second feedback oil passage is connected with the second annular concave cavity connecting pipe, and the second end of the second feedback oil passage is connected with the valve cavity away from the first valve core.

[0011] On the basis of the above technical scheme, it also includes a copper sleeve, a pressure cap, a boot sleeve and a pressure cap return spring, the copper sleeve is fixedly connected to the upper valve body downward, the pressure cap is arranged in the copper sleeve and is slidably connected to the inner wall of the copper sleeve up and down, the boot sleeve is an axially compressible annular component, the boot sleeve is arranged outside the copper sleeve and is fixedly connected to the upper valve body downward, the upper end of the boot sleeve is clamped on the length section of the pressure cap extending outside the copper sleeve, the pressure cap return spring is arranged in the pressure cap, and the two ends of the pressure cap return spring are respectively abutted against the upper valve body and the pressure cap, when the brake pedal is in a stepped state, the pressure cap displacement drives the first valve core and the second valve core to move through the return spring group, and when the brake pedal is released, the pressure cap is reset to the initial position under the action of the pressure cap return spring.

[0012] On the basis of the above technical solution, the return spring group includes a first spring arranged close to the first valve core and a second spring arranged close to the second valve core. The first spring is provided with a first spring seat inside. The first spring seat pushes the first valve core and the second valve core to move downward through a limiting ball. The two ends of the first spring are respectively abutted against the first spring seat and the inner wall surface of the pressure cap; the end of the lower valve body away from the upper valve body is connected to a plug, and the two ends of the second spring are respectively abutted against the countersunk hole on the plug and the second valve core.

[0013] Beneficial Effects The present invention has a reasonable structure, adopts a dual-circuit hydraulic brake system, and also includes a hydraulic control port, which can work independently of the brake pedal to drive the first valve core and the second valve core to move to complete the braking process. In this way, when the brake pedal fails, the staff cannot operate the brake pedal or other situations, the hydraulic control port can be remotely controlled to achieve the braking effect. It is safer to use and can be remotely controlled, providing conditions for applying the brake valve for braking in harsh environments.

[0014] In the present invention, the third annular cavity is connected to the hydraulic control port, and the third annular cavity is also connected to the exhaust valve. The exhaust valve and the solenoid valve cooperate to realize the charging and discharging of high-pressure oil therein, and then can replace the brake pedal, drive the first valve core and the second valve core to move, and complete the braking operation. The third annular cavity is an annular structure, and the high-pressure oil filled therein can act evenly on the first valve core, which is conducive to the smooth displacement of the first valve core and the second valve core. In addition, the hydraulic control valve core and the first valve core are enclosed to form a third annular concave cavity, and a first sealing ring is provided between the hydraulic control valve core and the valve cavity. In this way, on the one hand, sliding resistance is provided between the hydraulic control valve core and the valve cavity, and on the other hand, the high-pressure oil entering through the hydraulic control port can be prevented from leaking into the pressure cap, and the stability of use is good.

[0015] In addition, the high-pressure oil entering through the hydraulic control port is designed to be insufficient to overcome the sliding resistance between the hydraulic control valve core and the valve cavity, but sufficient to overcome the sliding resistance of the core body formed by the first valve core and the second valve core in the valve cavity, so that the core body can be displaced in the valve cavity. This is beneficial to accurately control the sliding action of the first valve core and the second valve core, and is beneficial to improving safety of use.

[0016] In the present invention, a valve cavity is formed in the valve body, in which the first valve core, the second valve core and the hydraulic control valve core are placed, and the valve sleeve is omitted, which is conducive to reducing costs and simplifying processes. In addition, the valve body includes an upper valve body and a lower valve body, which is convenient for valve cavity processing and is conducive to improving the processing accuracy of the valve cavity, thereby improving the working performance of the brake valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only one embodiment of the present invention, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0018] Figure 1 : A schematic diagram of the three-dimensional structure of the present invention; Figure 2 : The working principle diagram of the present invention; Figure 3 : A structural schematic diagram of the left view of the present invention after removing the brake pedal; Figure 4 : Figure 3 Schematic diagram of the cross-sectional structure along the AA direction; Figure 5 : Figure 4 Schematic diagram of the cross-sectional structure along the BB direction; DETAILED DESCRIPTION The following description and accompanying drawings fully illustrate the specific embodiments of this article so that those skilled in the art can practice them. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The scope of the embodiments of this article includes the entire scope of the claims, as well as all available equivalents of the claims. Herein, the terms "first", "second", etc. are only used to distinguish one element from another, without requiring or implying any actual relationship or order between these elements. In fact, the first element can also be called the second element, and vice versa. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the structure, device or equipment including a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also include elements inherent to such structure, device or equipment. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the structure, device or equipment including the elements. Each embodiment is described in a progressive manner herein, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other.

[0019] The terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. in this document indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing this document and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of this document, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, it can also be the internal communication of two elements, it can be a direct connection, or it can be an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0020] As used herein, the term "plurality" means two or more than two, unless otherwise specified.

[0021] In this document, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B.

[0022] In this article, the term "and / or" is a description of the association relationship between objects, indicating that three relationships may exist. For example, A and / or B means: A or B, or, A and B.

[0023] like Figures 1 to 5A full hydraulic dual-circuit hydraulically controlled brake valve is shown, comprising a valve body 3 and a brake pedal 100; like Figure 3 As shown, the valve body 3 includes an upper valve body 31 and a lower valve body 32, wherein the upper valve body 31 is arranged near the brake pedal 100, the upper valve body 31 and the lower valve body 32 are fixedly connected, the upper valve body 31 is provided with a through hole, and the lower valve body 32 is provided with a through hole, which is convenient for processing, and the upper valve body 31 and the lower valve body 32 are jointly enclosed to form a valve cavity, and the first valve core 1 and the second valve core 2 are sleeved in the valve cavity, and the valve cavity is respectively connected with the first oil inlet P1, the second oil inlet P2, the first brake oil port A1, the second brake oil port A2, the first oil return port T1 and the second oil return port T2; wherein, the first oil inlet P1, the first brake oil port A1 and the first oil return port T1 are arranged on the upper valve body 31, and the second oil inlet P2, the second brake oil port A2 and the second oil return port T2 are arranged on the lower valve body 32.

[0024] like Figures 3-5 As shown, the valve cavity at the upper valve body 31 is also connected to a hydraulic control port PP, which is connected to high-pressure hydraulic oil, and a solenoid valve is provided on the high-pressure pipeline connected to the hydraulic control port PP, which is electrically connected to the remote control device to facilitate the on-off control of the hydraulic control port PP.

[0025] A copper sleeve 10, a pressure cap 11, a boot sleeve 12 and a pressure cap reset spring 13 are also provided at one end of the upper valve body 31 away from the lower valve body 32. The copper sleeve 10 is fixedly connected to the upper valve body 31 downwardly, the pressure cap 11 is sleeved in the copper sleeve 10 and is slidably connected to the inner wall of the copper sleeve 10 up and down. The boot sleeve 12 is an axially compressible annular component, the boot sleeve 12 is sleeved outside the copper sleeve 10 and fixedly connected to the upper valve body 31 downwardly, the upper end of the boot sleeve 12 is clamped on the length section of the pressure cap 11 extending outside the copper sleeve 10, the pressure cap reset spring 13 is sleeved in the pressure cap 11, and the two ends of the pressure cap reset spring 13 are respectively abutted against the upper valve body 31 and the pressure cap 11, so that the pressure cap 11 can be kept in the initial position under the action of the pressure cap reset spring 13.

[0026] like Figure 1 As shown, the brake pedal 100 is hinged outside the upper valve body 31, and the brake pedal 100 includes a roller shaft that is rollingly connected to the top surface of the pressure cap 11 downward. When the brake pedal 100 is in a stepped state, the roller shaft presses the pressure cap 11 downward, and the pressure cap 11 is displaced relative to the copper sleeve 10, and the first valve core 1 and the second valve core 2 are driven to displace through the return spring group. When the brake pedal 100 is released, the pressure cap 11 is reset to the initial position under the action of the pressure cap return spring 13.

[0027] The end of the lower valve body 32 away from the upper valve body 31 is connected to a plug 16, so that a closed valve cavity can be formed. like Figure 4 and 5As shown, a return spring group is provided in the valve cavity at both ends of the core body formed by the first valve core 1 and the second valve core 2, and the return spring group includes a first spring 30 arranged close to the first valve core 1 and a second spring 40 arranged close to the second valve core 2. A first spring seat 14 is provided inside the first spring 30, and the first spring 30 seat pushes the first valve core 1 and the second valve core 2 to move downward through the limiting ball 15, and the two ends of the first spring 30 are respectively abutted against the first spring seat 14 and the inner wall surface of the pressure cap 11; the two ends of the second spring 40 are respectively abutted against the countersunk hole on the plug 16 and the second valve core 2.

[0028] In the present application, when the brake pedal 100 is released, under the action of the return spring group, the first valve core 1 and the second valve core 2 are in the first position. When the brake pedal 100 is in the stepped state, the first valve core 1 and the second valve core 2 are moved from the first position to the second position, thereby realizing dual-circuit braking.

[0029] Specifically, a first annular cavity 101 is formed on the first valve core 1, and the first annular cavity 101 is always connected to the first brake oil port A1; a second annular cavity 201 is formed on the second valve core 2, and the second annular cavity 201 is always connected to the second brake oil port A2; A buffer cavity is formed between the abutment between the first valve core 1 and the second valve core 2 and the inner wall of the valve cavity. A first feedback oil passage 102 is provided in the first valve core 1, one end of the first feedback oil passage 102 is connected to the first annular concave cavity 101, and the second end of the first feedback oil passage 101 is connected to the buffer cavity; a second feedback oil passage 202 is provided in the second valve core 2, one end of the second feedback oil passage 202 is connected to the second annular concave cavity 201, and the second end of the second feedback oil passage 202 is connected to the valve cavity away from the first valve core 1, so as to reduce the sliding resistance of the first valve core 1 and the second valve core 2 in the valve cavity.

[0030] When the first valve core 1 and the second valve core 2 are in the first position, the first brake oil port A1 is connected with the first oil return port T1, and the second brake oil port A2 is connected with the second oil return port T2; when the first valve core 1 and the second valve core 2 are displaced from the first position to the second position, the first annular cavity 101 is switched from being connected with the first oil return port T1 to being connected with the first oil inlet port P1; the second annular cavity 201 is switched from being connected with the second oil return port T2 to being connected with the second oil inlet port P2, that is, at this time, the first brake oil port A1 is connected with the first oil inlet port P1, and the second brake oil port A2 is connected with the second oil inlet port P2, thus forming a dual-circuit brake oil circuit; in this process, as the degree of depression of the brake pedal 100 is adjusted, the brake pressure is output to the brake in proportion, the operator feels comfortable, and the vehicle / equipment can be decelerated or stopped.

[0031] The hydraulic control port PP can work independently of the brake pedal 100, overcome the force of the return spring group, and drive the first valve core 1 and the second valve core 2 to move from the first position to the second position, so as to achieve a braking effect through the hydraulic control port PP when the brake pedal 100 cannot be controlled or the brake valve needs to be remotely controlled.

[0032] like Figure 4 and 5 As shown, it also includes a hydraulic control valve core 6, which is arranged near the brake pedal 100 and is arranged at one end of the core body formed by the first valve core 1 and the second valve core 2. The hydraulic control valve core 6 is upwardly connected to the spherical pair of the first spring seat 14 through the limiting ball 15, and a third annular cavity 7 is formed between the hydraulic control valve core 6 and one end of the first valve core 1. The third annular cavity 7 is connected to the hydraulic control port PP. The third annular cavity 7 is also connected to the exhaust port 9. The exhaust port 9 is provided with an exhaust valve. The exhaust valve and the solenoid valve cooperate to complete the charging and discharging process of the high-pressure oil in the first annular cavity 7.

[0033] like Figure 4 and 5 As shown, it also includes a bushing 16, which is fixed in the valve cavity, specifically, it also includes a limit retaining ring, the outer edge of the limit retaining ring is embedded in the valve cavity, the bushing 16 abuts against the shaft shoulder in the valve cavity downward, and the bushing 16 abuts against the limit retaining ring upward, so that the bushing 16 can be fixed in the valve cavity, and in addition, the outer wall of the bushing 16 is provided with an annular groove, and an O-ring is embedded in the annular groove; The bushing 16 is sleeved outside the hydraulic control valve core 6, and the inner wall surface of the bushing 16 is embedded with a first sealing ring. The bushing 16 is connected to the hydraulic control valve core 6 through the first sealing ring. In this embodiment, the first sealing ring is a lip seal to prevent the high-pressure oil in the first annular cavity 7 from leaking outward. When the first valve core 1 and the second valve core 1 are in the first position, the hydraulic control valve core 6 abuts against the inner top surface of the bushing 16 to limit the displacement of the hydraulic control valve core 6. The setting of the bushing 16 can, on the one hand, limit the upward displacement of the hydraulic control valve core 6, and on the other hand, when the first valve core 1 and the second valve core 2 are pushed from the first position to the second position by the brake pedal 100, the brake valve core 6 can be smoothly displaced downward to ensure appropriate pedaling force and facilitate operation.

[0034] In addition, the high-pressure oil entering the hydraulic control port PP is designed to be insufficient to push the bushing 16 to move in the valve cavity, but sufficient to overcome the sliding resistance of the core body formed by the first valve core 1 and the second valve core 2 in the valve cavity to enable the core body to move in the valve cavity.

[0035] In this embodiment, the oil pressure value entering the third annular cavity 7 through the hydraulic control port PP is close to the brake pressure value output by the brake valve, and the oil pressure of the high-pressure oil entering through the hydraulic control port PP is equal to the oil pressure of the high-pressure oil entering through the first oil inlet P1, and is greater than the oil pressure of the high-pressure oil entering through the second oil inlet P2 by 3~6bar, preferably 5bar.

[0036] The present invention is described above by way of examples, but the present invention is not limited to the above specific embodiments, and any changes or modifications made based on the present invention belong to the scope of protection claimed by the present invention.

Claims

1. A fully hydraulic dual-circuit hydraulically controlled brake valve, comprising a valve body (3) and a brake pedal (100); The valve body (3) has a valve cavity formed therein, a first valve core (1) and a second valve core (2) are sleeved in the valve cavity, and the valve cavity is respectively connected to a first oil inlet (P1), a second oil inlet (P2), a first brake oil port (A1), a second brake oil port (A2), a first oil return port (T1) and a second oil return port (T2); A return spring group is provided in the valve cavity at both ends of the core body formed by the first valve core (1) and the second valve core (2). Under the action of the return spring group, the first valve core (1) and the second valve core (2) are in a first position, so that the first brake oil port (A1) is connected to the first oil return port (T1), and the second brake oil port (A2) is connected to the second oil return port (T2); when the brake pedal (100) is in a stepped state, the first valve core (1) and the second valve core (2) are moved from the first position to the second position, so that the first brake oil port (A1) is connected to the first oil inlet (P1), and the second brake oil port (A2) is connected to the second oil inlet (P2); It is characterized in that The valve cavity is also connected to a hydraulic control port (PP), the hydraulic control port (PP) is connected to high-pressure hydraulic oil, and the hydraulic control port (PP) can work independently of the brake pedal (100), overcome the action force of the return spring group, and drive the first valve core (1) and the second valve core (2) to move from the first position to the second position.

2. The fully hydraulic dual-circuit hydraulically controlled brake valve according to claim 1, characterized in that: The invention also comprises a hydraulically controlled valve core (6), the hydraulically controlled valve core (6) being arranged close to the brake pedal (100) and being arranged at one end of a core body formed by the first valve core (1) and the second valve core (2), a third annular concave cavity (7) being formed between the hydraulically controlled valve core (6) and the one end of the core body, and the third annular concave cavity (7) being in communication with a hydraulically controlled port (PP).

3. The fully hydraulic dual-circuit hydraulically controlled brake valve according to claim 2, characterized in that: The invention also comprises a bushing (16), wherein the bushing (16) is fixedly arranged in the valve cavity, the bushing (16) is sleeved outside the hydraulic control valve core (6) and is connected to the hydraulic control valve core (6) via a first sealing ring; when the first valve core (1) and the second valve core (2) are in the first position, the hydraulic control valve core (6) abuts against the bushing (16) upwards to limit the displacement of the hydraulic control valve core (6); and the high-pressure oil entering the hydraulic control port (PP) is designed to be insufficient to push the bushing (16) to move in the valve cavity, but sufficient to overcome the sliding resistance of the core body formed by the first valve core (1) and the second valve core (2) in the valve cavity, so as to enable the core body to move in the valve cavity.

4. The fully hydraulic dual-circuit hydraulically controlled brake valve according to claim 3, characterized in that: The oil pressure value entering the third annular cavity (7) through the hydraulic control port (PP) is close to the brake pressure value output by the brake valve, and a solenoid valve is provided on the high-pressure pipeline connected to the hydraulic control port (PP).

5. The fully hydraulic dual-circuit hydraulically controlled brake valve according to claim 2, characterized in that: The third annular concave cavity (7) is also connected to a pipe having an exhaust port (9), and an exhaust valve is provided at the exhaust port (9).

6. The fully hydraulic dual-circuit hydraulically controlled brake valve according to any one of claims 1 to 5, characterized in that: The valve body (3) comprises an upper valve body (31) and a lower valve body (32), wherein the upper valve body (31) and the lower valve body (32) together enclose a valve cavity, wherein the hydraulic control port (PP), the first oil inlet port (P1), the first brake oil port (A1) and the first oil return port (T1) are arranged on the upper valve body (31) and close to the brake pedal (100), and the second oil inlet port (P2), the second brake oil port (A2) and the second oil return port (T2) are arranged on the lower valve body (32).

7. The fully hydraulic dual-circuit hydraulically controlled brake valve according to claim 6, characterized in that: A first annular concave cavity (101) is formed on the first valve core (1), the first annular concave cavity (101) is connected to the first brake oil port (A1), and when the first valve core (1) and the second valve core (2) are displaced from the first position to the second position, the first annular concave cavity (101) switches from being connected to the first oil return port (T1) to being connected to the first oil inlet port (P1); a second annular concave cavity (201) is formed on the second valve core (2), the second annular concave cavity (201) is connected to the second brake oil port (A2), and when the first valve core (1) and the second valve core (2) are displaced from the first position to the second position, the second annular concave cavity (201) switches from being connected to the second oil return port (T2) to being connected to the second oil inlet port (P2).

8. The fully hydraulic dual-circuit hydraulically controlled brake valve according to claim 7, characterized in that: A buffer cavity is formed between the abutment point between the first valve core (1) and the second valve core (2) and the inner wall surface of the valve cavity; a first feedback oil passage (102) is provided in the first valve core (1); one end of the first feedback oil passage (102) is communicated with the first annular concave cavity (101), and a second end of the first feedback oil passage (102) is communicated with the buffer cavity; a second feedback oil passage (202) is provided in the second valve core (2); one end of the second feedback oil passage (202) is communicated with the second annular concave cavity (201), and a second end of the second feedback oil passage (202) is communicated with the valve cavity away from the first valve core (1).

9. The fully hydraulic dual-circuit hydraulically controlled brake valve according to claim 7 or 8, characterized in that: The valve body (10) further comprises a copper sleeve (10), a pressure cap (11), a boot sleeve (12) and a pressure cap return spring (13); the copper sleeve (10) is fixedly connected downwardly to the upper valve body (31); the pressure cap (11) is sleeved in the copper sleeve (10) and is slidably connected to the inner wall of the copper sleeve (10) in an upward and downward manner; the boot sleeve (12) is an axially compressible annular component; the boot sleeve (12) is sleeved outside the copper sleeve (10) and is fixedly connected downwardly to the upper valve body (31); the upper end of the boot sleeve (12) is clamped on the pressure cap (11) and extends into the copper sleeve. On the length section outside the pressure cap (10), the pressure cap return spring (13) is sleeved in the pressure cap (11), and the two ends of the pressure cap return spring (13) are respectively in contact with the upper valve body (31) and the pressure cap (11). When the brake pedal (100) is in a stepped-on state, the pressure cap (11) is displaced through the return spring group to drive the first valve core (1) and the second valve core (2) to displace. When the brake pedal (100) is released, the pressure cap (11) is reset to the initial position under the action of the pressure cap return spring (13).

10. The fully hydraulic dual-circuit hydraulically controlled brake valve according to claim 9, characterized in that: The return spring assembly comprises a first spring (30) arranged near the first valve core (1) and a second spring (40) arranged near the second valve core (2); a first spring seat (14) is sleeved inside the first spring (30); the first spring seat (14) pushes the first valve core (1) and the second valve core (2) to move downward via a limiting ball (15); two ends of the first spring (30) respectively abut against the first spring seat (14) and the inner wall surface of the pressure cap (11); the end of the lower valve body (32) away from the upper valve body (31) is connected to a plug (16); two ends of the second spring (40) respectively abut against the countersunk hole on the plug (16) and the second valve core (2).

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