Brake valve

Abstract

The invention provides a brake valve, and belongs to the technical field of hydraulic pressure. The problem that an existing brake valve lags in response is solved. The brake valve comprises a valve body and a push rod, a first oil cavity and a second oil cavity are formed between one end of a main valve element and the valve body, the first oil cavity is communicated with a brake oil way, a first one-way assembly capable of enabling the second oil cavity to be communicated with the brake oil way is arranged in the valve body, and a pressure relief cavity communicated with the second oil cavity and an oil return oil way is formed in the main valve element. A pressure relief valve element capable of blocking communication between the second oil cavity and the oil return way is arranged in the pressure relief cavity in a sliding mode, and the pressure relief cavity is provided with an opening communicated with the first oil cavity. A mounting hole communicated with the oil inlet path and the oil return path is further formed in the main valve element, an auxiliary valve element for blocking communication of the oil inlet path and the oil return path is arranged in the mounting hole in a sliding mode, a pressure cavity is formed between one end of the auxiliary valve element and the main valve element, the end of the auxiliary valve element is connected with the push rod, and the pressure cavity is communicated with the oil return path through the auxiliary valve element. The brake valve has the advantages that the response timeliness and the brake effect are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic pressure and relates to a brake valve. Background Art

[0002] The function of the brake valve is to control the hydraulic braking of the vehicle. It includes a valve body with an inner cavity. A piston assembly is slidably connected in the valve body. The brake pedal is connected to one end of the piston assembly through a push rod. There is an oil chamber for storing brake fluid between the piston assembly and the valve body. The valve body has a brake oil port for outputting the brake fluid. When the driver steps on the brake pedal, the piston assembly is driven to move, the volume of the oil chamber is reduced, and the brake fluid is compressed, causing the brake fluid to generate pressure. The pressurized brake fluid flows to the brake through the brake oil port.

[0003] Engineering vehicles are heavy and need to be loaded with goods when traveling in construction sites, mines or other rugged areas. The load may change frequently, which means that the braking of engineering vehicles requires greater braking pressure. The braking pressure is determined by the entire braking system, including brake valves, brake fluid, brake lines, brake pads, brake discs / drums, etc. If we start with the brake valve, combined with the large brake fluid flow required for the braking of engineering vehicles, the output flow of the brake valve needs to be increased. If the oil chamber volume is reduced to increase the brake fluid pressure, the output flow of the brake valve will be reduced, which cannot meet the large flow braking needs of engineering vehicles. Therefore, those skilled in the art will select a large-capacity brake valve, which has a larger oil chamber and increases the force applied to the piston assembly, such as using oil pressure to assist the movement of the piston assembly, such as a full hydraulic brake valve CN201620817367.7 disclosed in Chinese patent literature; or change the existing brake fluid pressurization method, where the brake fluid is pressurized by a hydraulic pump, and the brake fluid output by the hydraulic pump is guided to the brake through the movement of the piston assembly of the brake valve, such as a hydraulic brake valve CN200920119050.6 disclosed in Chinese patent literature.

[0004] Moreover, the movement of the piston assembly in the initial stage is driven by the force manually applied to the brake pedal, and the direction of the force is easily deflected when acting on the piston assembly through the push rod, thereby affecting the movement stability of the piston assembly. In order to improve the movement stability of the piston assembly, technical personnel in this field can easily think of setting a spring assembly between the push rod and the piston assembly, so that the force transmitted by the push rod acts on the piston assembly with the help of the spring assembly. For example, Chinese patent literature discloses a hydraulic brake valve CN202221738475.7 for engineering machinery vehicles. Summary of the invention

[0005] The purpose of the present invention is to address the above-mentioned problems existing in the prior art and to propose a brake valve, the technical problem to be solved is how to improve the timeliness of response while ensuring the braking effect.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A brake valve comprises a valve body and a push rod, the valve body having an oil inlet circuit, an oil return circuit and a brake oil circuit, the valve body being slidably connected with a main valve core, characterized in that a first oil chamber is formed between one end of the main valve core and the valve body, the first oil chamber is connected with the brake oil circuit, the main valve core also has a mounting hole connected with both the oil inlet circuit and the oil return circuit, an auxiliary valve core is slidably arranged in the mounting hole to block the connection between the oil inlet circuit and the oil return circuit, a pressure chamber is formed between one end of the auxiliary valve core and the main valve core, and the end is connected to the push rod, the pressure chamber is connected with the oil return circuit through the auxiliary valve core, and when the push rod drives the auxiliary valve core to move, the pressure chamber is connected with the oil inlet circuit through the auxiliary valve core.

[0008] When the vehicle brakes, the driver steps on the brake pedal, and the push rod drives the auxiliary valve core to move relative to the main valve core, triggering the brake valve to work. The specific working process is as follows: the auxiliary valve core first cuts off the connection between the pressure chamber and the return oil circuit, and connects the pressure chamber with the oil inlet circuit, so that the hydraulic oil in the oil inlet circuit enters the pressure chamber and acts on one end of the main valve core, that is, the main valve core is driven to move with the help of oil pressure. At this time, the main valve core drives the pressure relief valve core to move synchronously, compressing the first oil chamber, so that the first oil chamber delivers brake fluid to the brake through the brake oil circuit. It can be seen that the present application cancels the structure of driving the main valve core to move by artificially applying a force, but instead uses the brake fluid entering the valve body to act on one end of the main valve core to drive the main valve core to move, thereby improving the response speed of the brake valve after the driver steps on the brake pedal and ensuring the oil pressure output by the brake valve. Furthermore, the present application is based on the structure of the main valve core controlling the on-off of the oil circuit, and introduces the brake fluid into the interior of the main valve core, that is, the mounting hole, and slides an auxiliary valve core in the mounting hole, so that the pressure chamber formed at one end of the main valve core controls the flow of brake fluid into or out of the pressure chamber by driving the auxiliary valve core to move, thereby realizing the movement control of the main valve core.

[0009] A second oil chamber is also formed between the main valve core and the valve body, the second oil chamber and the first oil chamber are both located at one end of the main valve core, a first one-way component is provided in the valve body, which can make the second oil chamber conduct to the brake oil circuit, the main valve core also has a pressure relief chamber connected to both the second oil chamber and the return oil circuit, a pressure relief valve core is slidably arranged in the pressure relief chamber, which can block the connection between the second oil chamber and the return oil circuit, the pressure relief chamber has an opening connected to the first oil chamber, when the oil pressure in the first oil chamber increases and pushes the pressure relief valve core to slide, the second oil chamber is connected to the return oil circuit. When braking, the main valve core moves to compress the second oil chamber first, so that the brake fluid in the second oil chamber generates pressure, and the first oil chamber is connected to the brake oil circuit. At this time, the pressure in the brake oil circuit is less than that of the second oil chamber, and the first one-way component is opened under the action of the oil pressure in the second oil chamber, and the oil in the second oil chamber supplies oil to the brake through the brake oil circuit. As the brake fluid in the second oil chamber flows to the brake through the brake oil circuit, the brake builds pressure, and the pressure relief valve core in the initial state blocks the connection between the second oil chamber and the return oil circuit. When the oil pressure in the brake oil circuit exceeds the oil pressure in the second oil chamber, the first one-way component is closed. Because the first oil chamber is connected to the brake oil circuit, the opening of the pressure relief chamber is connected to the first oil chamber, so that the oil pressure in the first oil chamber flows into the opening of the pressure relief chamber and acts on the pressure relief valve core. At this time, the pressure relief valve core moves relative to the main valve core under the action of the oil pressure in the first oil chamber, so that the second oil chamber and the return oil circuit are connected. The brake fluid in the second oil chamber flows through the pressure relief chamber to the oil return circuit, that is, the second oil chamber is unloaded, and the brake fluid pressure in the first oil chamber is further increased, so that the oil pressure flowing to the brake through the brake oil circuit is increased, thereby increasing the braking pressure and the output flow rate. Furthermore, the present application does not simply increase the volume of the oil chamber for accommodating the brake fluid in the brake valve, but sets two oil chambers, and the pressure of the brake fluid is amplified in stages through the synergistic effect of the two oil chambers, and the brake fluid is output through the brake oil circuit in two stages. In the first stage, the second oil chamber can quickly build up pressure and output brake fluid under the push of the main valve core, so that the brake pad is close to the brake disc to ensure the braking response speed of the brake valve. In the second stage, the first oil chamber outputs brake fluid with greater pressure under the push of the main valve core, thereby improving the response timeliness and the braking effect.

[0010] In the above-mentioned brake valve, the return oil circuit is located between the brake oil circuit and the oil inlet circuit, and the return oil circuit has a first return oil hole and a second return oil hole arranged at intervals along the axial direction of the main valve core, the main valve core has a second compression part that is columnar and slides against the wall of the second oil chamber, a first annular connecting groove is opened on the second compression part, the second oil chamber is connected with the first return oil hole through the first connecting groove, the main valve core is provided with a first return spring located in the second oil chamber, the first return spring elastically acts on the second compression part, and the second oil chamber can be connected with the second return oil hole. During braking, when the second oil chamber is depressurized, the brake fluid flowing out of the second oil chamber flows through the first connecting groove to the oil return circuit, so that part of the oil can be stored in the first connecting groove. When braking is completed, the main valve core moves back under the elastic force of the first return spring, and the first connecting groove can quickly replenish oil for the second oil chamber to avoid the second oil chamber from being emptied, thereby ensuring the movement stability of the main valve core. When the main valve core moves back to the initial position, the second oil chamber is connected to the second oil return hole, and the oil required for the next braking can be replenished for the second oil chamber through the oil return circuit, thereby ensuring a large flow output of the second oil chamber.

[0011] In the above-mentioned brake valve, the main valve core is provided with an assembly hole extending from one end to the other end, and the brake valve also includes a second stopper, which is threadedly connected to the assembly hole and separates the assembly hole to form the above-mentioned mounting hole and pressure relief chamber. This structure converts the oil circuit connection structure provided on the valve body in the prior art into one provided in the assembly hole of the main valve core, so that the cross-sectional area of ​​the main valve core can be set larger under the premise that the volume of the valve body remains unchanged, further increasing the area ratio of the first oil chamber to the main valve core, and improving the braking force output by the first oil chamber. The assembly hole separates the mounting hole and the pressure relief chamber through the second stopper, so that the setting of the oil circuit is based on the main valve core.

[0012] In the above brake valve, the second limiter also has a head abutting against the bottom of the mounting hole and a rod threadedly connected to the pressure relief chamber, the rod is stepped, the head and the rod are an integrated structure, and a first sealing ring is provided between the rod and the cavity wall of the pressure relief chamber, the head abuts against the first sealing ring, and a third return spring is provided on the head sleeve, one end of the third return spring abuts against the bottom of the mounting hole, and the other end of the third return spring abuts against the end of the auxiliary valve core. The head abuts against the bottom of the mounting hole, so that the penetration depth of the rod in the connecting section is determined, the first sealing ring improves the sealing between the connecting section and the mounting hole, the head limits the position of the third return spring, avoids the position deviation of the third return spring, and makes the elastic force of the third return member stably act on the end of the auxiliary valve core, improving the position stability of the auxiliary valve core.

[0013] In the above-mentioned brake valve, a second annular connecting groove is opened on the second compression part, and the second connecting groove is connected to the oil inlet circuit. The mounting hole includes a flared section and a straight hole section in the shape of a circular hole. The auxiliary valve core is columnar and is slidably connected to the straight hole section. The wall surface of the straight hole section is provided with an inflow hole and an outflow hole arranged along the axial direction of the main valve core. The outflow hole is connected to the first connecting groove, and the inflow hole is connected to the second connecting groove. The brake valve also includes a valve sleeve slidably connected to the valve body, and the pressure chamber is located between the wall surface of the flared section and the auxiliary valve core. One end of the valve sleeve is fixedly connected to the push rod, and the other end of the valve sleeve is connected to the auxiliary valve core. The second connecting channel provides assistance for the inflow and outflow of brake fluid, thereby increasing the speed at which the brake fluid enters or flows out of the pressure chamber; the inflow hole and the outflow hole are arranged at intervals along the axial direction of the connecting section, so that the inflow hole and the outflow hole are located on the moving path of the auxiliary valve core, and the valve sleeve is extended into the expansion section to shorten the setting length of the auxiliary valve core and improve the movement stability of the auxiliary valve core. The expansion section provides space for the setting of the pressure chamber, and this structure increases the effective area of ​​one end of the main valve core.

[0014] In the above brake valve, the aperture of the flared section gradually decreases from the end face of the main valve core toward the straight hole section, and a second limit retaining ring is fixedly connected to the wall surface of the small end of the flared section, the valve sleeve extends into the flared section, and the valve sleeve can abut against the first limit retaining ring, and the auxiliary valve core abuts against the second limit retaining ring under the elastic force of the third reset spring. The limit retaining ring has a limiting effect on the initial position of the auxiliary valve core on the one hand, and on the other hand limits the maximum movement stroke of the valve sleeve moving toward the main valve core installation hole to avoid interference between the main valve core and the valve sleeve.

[0015] In the above brake valve, one end of the auxiliary valve core extends out of the second limit retaining ring and is clamped with the valve sleeve, and the auxiliary valve core has a through hole extending from one end to the other end, and the pressure chamber is connected with the inflow hole or the outflow hole through the through hole. The valve sleeve and the auxiliary valve core are linked by the clamping structure, and the brake fluid enters the pressure chamber or flows out of the pressure chamber through the inside of the auxiliary valve core, which avoids the impact of the brake fluid on the auxiliary valve core during the flow process to the greatest extent, and increases the contact area between the auxiliary valve core and the mounting hole.

[0016] In the above-mentioned brake valve, the inner wall of the valve body has a contraction portion that protrudes inward and is annular, the first oil chamber is located on the radial inner side of the contraction portion, and the second oil chamber is located on the axial outer side of the contraction portion. The main valve core also has a first compression portion that is columnar and slides against the wall of the first oil chamber. The cross-sectional area of ​​the second compression portion is 4-8 times the cross-sectional area of ​​the first compression portion, and the first one-way component is arranged in the contraction portion. This structure makes the volume of the second oil chamber larger than that of the first oil chamber. The brake fluid contained in the second oil chamber is sufficient to make the brake disc and the brake pad fit together. When the main valve core moves, the second compression part compresses the second oil chamber, and the second oil chamber first supplies oil to the brake. As the brake pressure increases, the second oil chamber is unloaded. According to the principles of fluid mechanics, the oil pressure P=the force F acting on the main valve core divided by the piston effective area A. Since the cross-sectional area of ​​the second compression part is 4-8 times that of the first compression part, the piston effective area is reduced, so that the output oil pressure of the first oil chamber increases. When the brake disc on the brake fits with the brake pad, the brake fluid is output from the first oil chamber to supply oil to the brake. In this way, both large displacement and high pressure can be guaranteed. The first one-way component is arranged in the contraction part to prevent the first one-way component from occupying the space of the oil chamber.

[0017] In the above-mentioned brake valve, the opening of the pressure relief chamber is located on the end face of the main valve core, and a first limit retaining ring is positioned at the opening of the pressure relief chamber. The pressure relief chamber includes a sliding section and a connecting section in the shape of a circular hole. The aperture of the connecting section is larger than the aperture of the sliding section. One end of the connecting section is connected to the sliding section, and the other end of the connecting section has a thread. The rod is threadedly connected to the connecting section. The rod is sleeved with a second return spring which elastically acts on one end of the pressure relief valve core and makes the other end of the pressure relief valve core abut against the first limit retaining ring. The pressure relief valve core has an oil passage. When the pressure relief valve core abuts against the end face of the rod, the second oil chamber is connected to the return oil passage through the pressure relief chamber. The opening of the pressure relief chamber is set on the end face of the main valve core to reduce the resistance of the oil in the first oil chamber to enter the pressure relief chamber. The aperture of the connecting section is larger than the aperture of the sliding section. The first limit ring prevents the pressure relief valve core from escaping from the opening of the pressure relief chamber. The rod of the second limit member is penetrated in the connecting section. On the one hand, the rod provides support and guidance for the second return spring. On the other hand, the rod clarifies the maximum movement stroke of the pressure relief valve core relative to the main valve core under the action of hydraulic pressure, thereby ensuring the connection stability between the second oil chamber and the return oil circuit. If there is a processing error, the depth of the rod extending into the connecting section can be adjusted by rotating the second limit member, and the movement stroke of the pressure relief valve core can be fine-tuned to ensure the connection stability and reduce the processing accuracy of the main valve core and the assembly accuracy of various components.

[0018] Compared with the prior art, the brake valve provided by the present invention has the following advantages:

[0019] 1. When the auxiliary valve core is in the initial state, the auxiliary valve core blocks the inflow hole, and the pressure chamber is connected to the oil return line; when the auxiliary valve core blocks the outflow hole, the pressure chamber is connected to the oil inlet line, and the brake fluid entering the pressure chamber acts on one end of the main valve core, so that the main valve core moves under the pressure of the oil, that is, the brake fluid provides assistance for the movement of the main valve core.

[0020] 2. The present application adopts a dual-chamber design, that is, two oil chambers for containing brake fluid are arranged between the valve body and the main valve core. The two oil chambers respectively match the pressures required for the brake at different stages, and the volume of one of the oil chambers is larger than the other. When the main valve core moves, the brake fluid is first transported to the brake by the larger oil chamber to achieve the abutment of the brake pad and the brake disc in the brake, and the main valve core continues to move. Under the premise that the force driving the main valve core to move remains unchanged, the area ratio of the smaller oil chamber to the main valve core increases, so that the oil pressure output by the smaller oil chamber increases to meet the pressure required for the brake pad to clamp the brake disc, thereby increasing the braking pressure while increasing the output flow.

[0021] 3. On the basis of the double-chamber structure, the larger oil chamber is depressurized during the braking process to reduce the movement resistance of the main valve core, so that the force driving the movement of the main valve core acts completely on the small oil chamber, further increasing the oil pressure that can be output by the small oil chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a cross-sectional view of the brake valve in its initial state.

[0023] Figure 2 yes Figure 1 A partial enlarged view of point A in the middle.

[0024] Figure 3 yes Figure 1 A partial enlarged view of .

[0025] Figure 4 yes Figure 3 A partial enlarged view of point B in the middle.

[0026] Figure 5 This is a cross-sectional view of the brake valve in braking state. Figure 1 .

[0027] Figure 6 yes Figure 5 A partial enlarged view of point C in the middle.

[0028] Figure 7 yes Figure 5 A partial enlarged view of .

[0029] Figure 8 This is a cross-sectional view of the brake valve in braking state. Figure 2 .

[0030] Fig. 9 yes Figure 8 A partial enlarged view of .

[0031] Fig.10 yes Fig. 9 A partial enlarged view of point D in the middle.

[0032] In the figure, 1, valve body; 11, oil inlet circuit; 12, oil return circuit; 121, first oil return hole; 122, second oil return hole; 13, brake oil circuit; 14, mounting hole; 141, expansion section; 142, straight hole section; 143, outflow hole; 144, inflow hole; 145, second limit retaining ring; 15, pressure chamber; 16, pressure relief chamber; 161, opening; 162, sliding section; 163, connecting section; 17, contraction section; 171, step hole; 172, step surface; 2, push rod; 3, main valve core; 31, first compression section; 32, second compression section; 321, first connecting groove; 322, second connecting groove; 33, assembly hole; 34, inlet Oil hole; 35, oil outlet hole; 4, first oil chamber; 5, auxiliary valve core; 51, through hole; 6, second oil chamber; 61, first return spring; 7, first one-way component; 71, steel ball; 72, first limit piece; 8, pressure relief valve core; 81, oil passage; 82, first connecting hole; 83, second connecting hole; 9, second limit piece; 91, rod; 92, head; 93, first sealing ring; 10, first limit retaining ring; 101, second return spring; 102, third return spring; 103, valve sleeve; 104, second sealing ring; 105, second single component; Br, brake port; T, oil return port; P, oil inlet; PA, accumulator interface. DETAILED DESCRIPTION

[0033] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0034] like Figure 1-Figure 4As shown, the brake valve includes a valve body 1 and a push rod 2, the valve body 1 has an oil inlet circuit 11, an oil return circuit 12 and a brake circuit 13, the oil inlet circuit 11 has an oil inlet port P and an accumulator interface PA located on the outer wall of the valve body 1, the oil return circuit 12 has an oil return port T located on the outer wall of the valve body 1, the brake circuit 13 has a brake port Br located on the outer wall of the valve body 1, a main valve core 3 is slidably connected in the valve body 1, a first oil chamber 4 and a second oil chamber 6 connected to the brake circuit 13 are provided between one end of the main valve core 3 and the valve body 1, and the other end of the main valve core 3 faces the push rod 2, and a mounting hole 14 connected to both the oil inlet circuit 11 and the oil return circuit 12 is opened at one end of the main valve core 3 facing the push rod 2, an auxiliary valve core 5 blocking the connection between the oil inlet circuit 11 and the oil return circuit 12 is slidably connected in the mounting hole 14, and the auxiliary valve One end of the core 5 is connected to the push rod 2, and a pressure chamber 15 is formed between the end and the main valve core 3. The pressure chamber 15 is connected to the return oil circuit 12 through the auxiliary valve core 5. When the push rod 2 drives the auxiliary valve core 5 to move, the pressure chamber 15 is connected to the oil inlet circuit 11 through the auxiliary valve core 5. The valve body 1 is provided with a first one-way component 7 that can enable the second oil chamber 6 to conduct to the brake oil circuit 13. The other end of the main valve core 3 has a pressure relief chamber 16 that is connected to both the second oil chamber 6 and the return oil circuit 12. A pressure relief valve core 8 that blocks the connection between the oil inlet circuit 11 and the return oil circuit 12 is slidably connected in the pressure relief chamber 16. The pressure relief chamber 16 has an opening 161 that is connected to the first oil chamber 4. When the oil pressure in the first oil chamber 4 increases and pushes the pressure relief valve core 8 to slide, the pressure relief valve core 8 slides to connect the second oil chamber 6 with the return oil circuit 12.

[0035] like Figure 3 As shown, the inner wall of the valve body 1 has a contraction portion 17 that protrudes inward and is annular, the first oil chamber 4 is located on the radial inner side of the contraction portion 17, and the second oil chamber 6 is located on the axial outer side of the contraction portion 17. The main valve core 3 has a first compression portion 31 that slides against the cavity wall of the first oil chamber 4 in a columnar shape and a second compression portion 32 that slides against the cavity wall of the second oil chamber 6. The cross-sectional area of ​​the second compression portion 32 is 4-8 times the cross-sectional area of ​​the first compression portion 31; a step hole 171 is provided on the contraction portion 17, the large end of the step hole 171 is connected to the brake oil circuit 13, and the small end of the step hole 171 is connected to the second oil chamber 6, the first one-way component 7 includes a steel ball 71 located in the step hole 171, and a first limiter 72 that penetrates into the step hole 171 is fixedly connected to the valve body 1, and the steel ball 71 can roll between the first limiter 72 and the step surface 172 of the step hole 171.

[0036] like Figure 1-Figure 3As shown, the return oil circuit 12 is located between the brake oil circuit 13 and the oil inlet circuit 11, and the return oil circuit 12 has a first return oil hole 121 and a second return oil hole 122 located on the inner wall of the valve body 1 and spaced apart along the axial direction of the main valve core 3. A first annular connecting groove 321 is opened on the second compression portion 32, and the second oil chamber 6 is connected with the first return oil hole 121 through the first connecting groove 321. A first return spring 61 is provided in the second oil chamber 6, and the first return spring 61 elastically acts on the second compression portion 32. When the main valve core 3 is in the initial state, the second oil chamber 6 is connected with the second return oil hole 122, and a second single component 105 is provided on the main valve core 3 to connect the first connecting groove 321 to the second oil chamber 6.

[0037] like Figure 1 As shown, the main valve core 3 is provided with an assembly hole 33 extending from one end to the other end, and the brake valve also includes a second limit member 9, which is threadedly connected to the assembly hole 33 and separates the assembly hole 33 to form the above-mentioned mounting hole 14 and the pressure relief chamber 16. The opening 161 of the pressure relief chamber 16 is located on the end surface of the main valve core 3, and a first limit retaining ring 10 is positioned at the opening 161 of the pressure relief chamber 16. The pressure relief chamber 16 includes a sliding section 162 and a connecting section 163 in the shape of a circular hole. The aperture of the connecting section 163 is larger than the aperture of the sliding section 162. One end of the connecting section 163 is connected to the sliding section 162, and the other end of the connecting section 163 has a thread. The second limit member 9 has a rod portion 91 that passes through the connecting section 163 and is connected to the mounting hole 14. The head 92 abuts against the bottom of the hole 14, and the head 92 and the rod 91 are an integrated structure. The rod 91 is stepped and threadedly connected to the connecting section 163. The rod 91 is sleeved with a first sealing ring 93 whose outer ring abuts against the connecting section 163. The head 92 abuts against the first sealing ring 93, and the head 92 is sleeved with a third return spring 102. One end of the third return spring 102 abuts against the bottom of the mounting hole 14, and the other end of the third return spring 102 is connected to the auxiliary valve. The end of the core 5 abuts against the pressure relief valve core 8; the rod portion 91 is sleeved with a second return spring 101 that elastically acts on one end of the pressure relief valve core 8 and makes the other end of the pressure relief valve core 8 abut against the first limit retaining ring 10. The main valve core 3 is provided with an oil inlet hole 34 connecting the second oil chamber 6 and the sliding section 162, and an oil outlet hole 35 connecting the first connecting groove 321 and the connecting section 163. The pressure relief valve core 8 is columnar and is slidably connected to the sliding section 162. The pressure relief valve core 8 has an oil passage 81, and the oil passage 8 The pressure relief valve core 8 has a first communicating hole 82 and a second communicating hole 83 on the outer wall of the pressure relief valve core 8. The first communicating hole 82 can communicate with the oil inlet hole 34. The second communicating hole 83 is located in the communicating section 163. When the pressure relief valve core 8 abuts against the end surface of the rod portion 91, the first communicating hole 82 communicates with the oil inlet hole 34. The pressure relief spring is sleeved with a second sealing ring 104 abutting against the wall surface of the sliding section 162. The second sealing ring 104 prevents the oil in the first oil chamber 4 from entering the second oil chamber 6.

[0038] like Figure 5-Figure 6 As shown, a second connecting groove 322 in an annular shape is provided on the second compression part 32, and the second connecting groove 322 is connected to the oil inlet oil path 11. The mounting hole 14 includes a flared section 141 and a straight hole section 142 in the shape of a circular hole. The auxiliary valve core 5 is columnar and is slidably connected to the straight hole section 142. An inflow hole 144 and an outflow hole 143 are provided on the wall surface of the straight hole section 142, which are arranged at intervals along the axial direction of the main valve core 3. The outflow hole 143 is connected to the first connecting groove 321, and the inflow hole 144 is connected to the second connecting groove 322. The aperture of the flared section 141 is greater than that of the main valve core 3. The end face of the expansion section 141 gradually narrows toward the straight hole section 142, the pressure chamber 15 is located between the wall surface of the expansion section 141 and the auxiliary valve core 5, and a second limit retaining ring 145 is fixedly connected to the wall surface of the small end of the expansion section 141. The auxiliary valve core 5 abuts against the second limit retaining ring 145 under the elastic force of the third return spring 102. The brake valve also includes a valve sleeve 103 slidably connected to the valve body 1, one end of the valve sleeve 103 is fixedly connected to the push rod 2, and the other end of the valve sleeve 103 extends into the expansion section 141 and is connected to the auxiliary valve core 5, and the valve sleeve 103 can abut against the first limit retaining ring 10.

[0039] like Figure 1-Figure 4 As shown, when the main valve core 3 is in the initial state, the second oil chamber 6 is connected to the oil return port T through the second oil return hole 122, the pressure relief valve core 8 blocks the orifice of the oil inlet hole 34, and cuts off the connection between the second oil chamber 6 and the oil return oil path 12, the auxiliary valve core 5 blocks the inflow hole 144, and cuts off the connection between the pressure chamber 15 and the oil inlet oil path 11. At this time, the pressure chamber 15 is connected to the oil return oil path 12, as shown in FIG. Figure 5 As shown in Figure 1, when the driver presses the brake pedal, Figure 6 As shown, the push rod 2 overcomes the elastic force of the third return spring 102 through the valve sleeve 103, drives the auxiliary valve core 5 to move leftward, and the auxiliary valve core 5 blocks the orifice of the outflow hole 143, cuts off the connection between the pressure chamber 15 and the return oil circuit 12, connects the pressure chamber 15 and the oil inlet circuit 11, and the brake fluid enters the pressure chamber 15 and acts on one end of the main valve core 3, as shown in FIG. Figure 7 As shown, the main valve core 3 overcomes the elastic force of the first return spring 61 and moves leftward, cutting off the communication between the second oil return hole 122 and the oil return port T. The main valve core 3 continues to move leftward, compressing the brake fluid in the second oil chamber 6, so that the second oil chamber 6 starts to build pressure. When the oil pressure in the second oil chamber 6 is greater than the pressure in the brake oil circuit 13, since the first oil chamber 4 is connected with the brake oil circuit 13, the pressure in the first oil chamber 4 is also lower than that in the second oil chamber 6. The steel ball 71 abuts against the first limiter 72 under the pressure of the second oil chamber 6, and the brake fluid in the second oil chamber 6 flows into the brake oil circuit 13 through the step hole 171, and the pressurized brake fluid is output to the brake through the brake port Br. The pressure of the brake gradually increases with the inflow of the brake fluid, and the oil pressure in the brake oil circuit 13 is basically equivalent to that of the brake, as shown in FIG. Figure 8-Figure 9As shown, when the oil pressure of the brake oil circuit 13 is greater than that of the second oil chamber 6, the steel ball 71 abuts against the step surface 172 under the pressure of the brake oil circuit 13, disconnecting the second oil chamber 6 from the brake oil circuit 13. At this time, the oil pressure of the first oil chamber 4 is also greater than that of the second oil chamber 6. Fig.10 As shown, the brake fluid in the first oil chamber 4 will enter the opening 161 of the pressure relief chamber 16 and act on one end of the pressure relief valve core 8, so that the pressure relief valve core 8 overcomes the elastic force of the second return spring 101 and moves rightward relative to the main valve core 3. When the pressure relief valve core 8 abuts against the end face of the rod portion 91 of the second limiter 9, the first connecting hole 82 is completely connected with the oil inlet hole 34, so that the brake fluid in the second oil chamber 6 flows out from the second connecting hole 83 and then flows to the return oil circuit 12 through the oil outlet hole 35, so that the second oil chamber 6 is depressurized. The leftward movement of the main valve core 3 will compress the first oil chamber 4, and the force applied to the main valve core 3 will act on the first oil chamber 4. Because the cross-sectional area of ​​the second compression portion 32 is 4-8 times the cross-sectional area of ​​the first compression portion 31, the compression of the first oil chamber 4 will output an oil pressure greater than that of the second oil chamber 6 to assist in the final stage of braking. The brake pad clamps the brake disc, thereby completing vehicle braking. After braking is completed, the driver releases the brake pedal, and the auxiliary valve core 5 is reset under the elastic force of the third return spring 102, disconnecting the connection between the pressure chamber 15 and the oil inlet oil circuit 11, connecting the pressure chamber 15 and the oil return oil circuit 12, so that the pressure chamber 15 is unloaded, and the main valve core 3 moves right under the elastic force of the first return spring 61, and the brake oil returns to the brake valve through the brake port Br, and the returned brake fluid fills the first oil chamber 4. At this time, the second single component 105 is opened, so that the oil in the oil return oil circuit 12 enters the second oil chamber 6 through the oil replenishing oil circuit to prevent the second oil chamber 6 from being sucked empty, and the pressure relief valve core 8 moves left under the elastic force of the second return spring 101, and the pressure relief valve core 8 again abuts against the limit retaining ring, so that the pressure relief valve core 8 cuts off the connection between the second oil chamber 6 and the oil return oil circuit 12, and when the brake valve returns to its initial state, the second single component 105 is closed, and the second oil chamber 6 is connected to the second oil return hole 122 again. At this time, the oil return port T can be used as an oil replenishing port for the second oil chamber 6 , that is, the brake fluid can be replenished into the second oil chamber 6 through the oil return port T.

[0040] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0041] Although this article uses more valve body 1, oil inlet oil circuit 11, oil return oil circuit 12, first oil return hole 121, second oil return hole 122, brake oil circuit 13, mounting hole 14, expansion section 141, straight hole section 142, outflow hole 143, inflow hole 144, second limit retaining ring 145, pressure chamber 15, pressure relief chamber 16, opening 161, sliding section 162, connecting section 163, contraction section 17, step hole 171, step surface 172, push rod 2, main valve core 3, first compression section 31, second compression section 32, first connecting groove 321, second connecting groove 322, assembly hole 33, oil inlet hole 34, oil outlet hole 35, first oil chamber 4, auxiliary valve core 5, through hole 51, second oil chamber 6, first return spring 61, first one-way component 7, steel ball 71, first stopper 72, pressure relief valve core 8, oil passage 81, first connecting hole 82, second connecting hole 83, second stopper 9, rod 91, head 92, first sealing ring 93, first stopper ring 10, second return spring 101, third return spring 102, valve sleeve 103, second sealing ring 104, second single component 105, brake port Br, oil return port T, oil inlet port P, accumulator interface PA and other terms, but the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional restrictions is contrary to the spirit of the present invention.

Claims

1. A brake valve, comprising a valve body (1) and a push rod (2), wherein the valve body (1) has an oil inlet circuit (11), an oil return circuit (12) and a brake circuit (13), and a main valve core (3) is slidably connected to the valve body (1), characterized in that: A first oil chamber (4) is formed between one end of the main valve core (3) and the valve body (1), and the first oil chamber (4) is connected to the brake oil circuit (13). The main valve core (3) has a mounting hole (14) connected to both the oil inlet circuit (11) and the oil return circuit (12). An auxiliary valve core (5) is slidably arranged in the mounting hole (14) to block the connection between the oil inlet circuit (11) and the oil return circuit (12). A pressure chamber (15) is formed between one end of the auxiliary valve core (5) and the main valve core (3), and the end is connected to the push rod (2). The pressure chamber (15) is connected to the oil return circuit (12) through the auxiliary valve core (5). When the push rod (2) drives the auxiliary valve core (5) to move, the pressure chamber (15) is connected to the oil inlet circuit (11) through the auxiliary valve core (5).

2. The brake valve according to claim 1, characterized in that: A second oil chamber (6) is also formed between the main valve core (3) and the valve body (1). The second oil chamber (6) and the first oil chamber (4) are both located at one end of the main valve core (3). A first one-way component (7) is provided in the valve body (1) for enabling the second oil chamber (6) to be connected to the brake oil circuit (13). The main valve core (3) also has a pressure relief chamber (16) in communication with both the second oil chamber (6) and the oil return circuit (12). A pressure relief valve core (8) is slidably provided in the pressure relief chamber (16) for blocking the connection between the second oil chamber (6) and the oil return circuit (12). The pressure relief chamber (16) has an opening (161) in communication with the first oil chamber (4). When the oil pressure in the first oil chamber (4) increases and pushes the pressure relief valve core (8) to slide, the second oil chamber (6) is connected to the oil return circuit (12).

3. The brake valve according to claim 2, characterized in that: The oil return circuit (12) is located between the brake oil circuit (13) and the oil inlet circuit (11), and the oil return circuit (12) has a first oil return hole (121) and a second oil return hole (122) arranged at intervals along the axial direction of the main valve core (3). The main valve core (3) has a second compression portion (32) in a columnar shape and sliding against the cavity wall of the second oil chamber (6). A first annular communication groove (321) is provided on the second compression portion (32), and the second oil chamber (6) is communicated with the first oil return hole (121) through the first communication groove (321). A first return spring (61) located in the second oil chamber (6) is sleeved on the main valve core (3), and the first return spring (61) elastically acts on the second compression portion (32), so that the second oil chamber (6) can be communicated with the second oil return hole (122).

4. The brake valve according to claim 3, characterized in that: The main valve core (3) is provided with an assembly hole (33) extending from one end to the other end. The brake valve further comprises a second stopper (9), wherein the second stopper (9) is threadedly connected in the assembly hole (33) and separates the assembly hole (33) into the above-mentioned mounting hole (14) and the pressure relief chamber (16).

5. The brake valve according to claim 4, characterized in that: The second limiting member (9) further comprises a head portion (92) abutting against the bottom of the mounting hole (14) and a rod portion (91) screwed to the pressure relief chamber (16); the rod portion (91) is stepped; the head portion (92) and the rod portion (91) are an integrated structure; a first sealing ring (93) is provided between the rod portion (91) and the cavity wall of the pressure relief chamber (16); the head portion (92) abuts against the first sealing ring (93); a third return spring (102) is provided on the outer sleeve of the head portion (92); one end of the third return spring (102) abuts against the bottom of the mounting hole (14); and the other end of the third return spring (102) abuts against the end of the auxiliary valve core (5).

6. The brake valve according to claim 5, characterized in that The second compression portion (32) is also provided with a second communicating groove (322) in the shape of an annulus, the second communicating groove (322) being communicated with the oil inlet passage (11), the mounting hole (14) comprising a flared section (141) and a straight hole section (142) in the shape of a circular hole, the auxiliary valve core (5) being columnar and slidably connected to the straight hole section (142), the wall surface of the straight hole section (142) being provided with outflow holes (143) and flow holes (144) arranged at intervals along the axial direction of the main valve core (3) The inlet hole (144) and the outlet hole (143) are connected to the first connecting groove (321), the inlet hole (144) is connected to the second connecting groove (322), the brake valve also includes a valve sleeve (103) slidably connected to the valve body (1), the pressure chamber (15) is located between the wall surface of the expansion section (141) and the auxiliary valve core (5), one end of the valve sleeve (103) is fixedly connected to the push rod (2), and the other end of the valve sleeve (103) is connected to the auxiliary valve core (5).

7. The brake valve according to claim 6, characterized in that The aperture of the expanded section (141) gradually decreases from the end face of the main valve core (3) toward the straight hole section (142), and a second limit retaining ring (145) is fixedly connected to the wall surface of the small end of the expanded section (141). The valve sleeve (103) extends into the expanded section (141), and the valve sleeve (103) can abut against the first limit retaining ring (10), and the auxiliary valve core (5) abuts against the second limit retaining ring (145) under the elastic force of the third return spring (102).

8. The brake valve according to claim 7, characterized in that One end of the auxiliary valve core (5) extends out of the second limit retaining ring (145) and is clamped with the valve sleeve (103), and the auxiliary valve core (5) has a through hole (51) extending from one end to the other end, and the pressure chamber (15) is connected to the inflow hole (144) or the outflow hole (143) through the through hole (51).

9. The brake valve according to any one of claims 3 to 8, characterized in that: The inner wall of the valve body (1) has an inwardly protruding annular contraction portion (17), the first oil chamber (4) is located radially inside the contraction portion (17), the second oil chamber (6) is located axially outside the contraction portion (17), the main valve core (3) also has a first compression portion (31) which is columnar and slides against the wall of the first oil chamber (4), and the cross-sectional area of ​​the second compression portion (32) is 4 to 8 times the cross-sectional area of ​​the first compression portion (31).

10. The brake valve according to any one of claims 5 to 8, characterized in that: The opening (161) of the pressure relief chamber (16) is located on the end surface of the main valve core (3); a first limit retaining ring (10) is positioned at the opening (161) of the pressure relief chamber (16); the pressure relief chamber (16) comprises a sliding section (162) and a connecting section (163) in the shape of a circular hole; the hole diameter of the connecting section (163) is larger than the hole diameter of the sliding section (162); one end of the connecting section (163) is connected to the sliding section (162), and the other end of the connecting section (163) has a The rod (91) is threadedly connected to the connecting section (163). A second return spring (101) is sleeved on the rod (91) and elastically acts on one end of the pressure relief valve core (8) to make the other end of the pressure relief valve core (8) abut against the first limit retaining ring (10). The pressure relief valve core (8) has an oil passage (81). When the pressure relief valve core (8) abuts against the end surface of the rod (91), the second oil chamber (6) is connected to the oil return passage (12) through the pressure relief chamber (16).

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