Hydraulic control brake chamber amplification device and engineering vehicle brake cooling control system

Abstract

The application discloses a hydraulic control brake chamber amplification device and an engineering vehicle brake cooling control system. The brake system comprises a brake input device and a brake execution device. The hydraulic control brake chamber amplification device comprises a pedal detection device, a first valve body, a first valve core and a flow limiting device. The pedal detection device is used for outputting pressure when detecting the change of the brake pedal angle. The first valve body has a first inner cavity, a first oil port communicated with the brake input device, a second oil port communicated with the brake execution device and a third oil port communicated with the pedal detection device. The first valve core is arranged in the first inner cavity and is used for moving to the first end of the first inner cavity to block the first oil port and the second oil port when the pedal detection device outputs pressure to the third oil port. The side wall of the first valve core forms an amplification cavity, which is used for being communicated with the first oil port and the second oil port at the first end position respectively. The flow limiting device is arranged in the oil path between the first oil port and the amplification cavity and is used for opening the first oil path when the pressure of the first oil port is less than the pressure of the second oil port and closing the first oil path when the pressure of the first oil port is greater than the pressure of the second oil port.

Description

Technical Field

[0001] This invention relates to the field of braking system technology, and in particular, to a hydraulically controlled brake cavity amplification device. Furthermore, this invention also relates to a braking cooling control system for engineering vehicles that includes the aforementioned hydraulically controlled brake cavity amplification device. Background Technology

[0002] With the development of mining technology, mining depths are increasing, and the degree of mechanization is rising. Consequently, various engineering vehicles, which are crucial to mining efficiency, are receiving increasing attention. For off-road engineering vehicles, meeting the requirements for attaching various robotic arms and attachments is a basic requirement, while adaptability to heavy-duty and harsh road conditions and safe operation have become key design priorities. Therefore, safe operation of engineering vehicles is the core of the overall design, especially since braking performance directly determines driving safety. Currently, fully enclosed wet brakes are becoming increasingly popular in engineering vehicles due to their technological advantages: on the one hand, they provide a large braking torque while maintaining a compact structure; on the other hand, the brake operates in a closed cavity, isolating it from harsh working environments and allowing for long maintenance cycles. These advantages make fully enclosed wet brakes the preferred choice for engineering vehicles. There are various types of fully enclosed wet brakes. Among them, the elastic element brake-hydraulic release type is used in relatively harsh environments such as mines, underground mines, and coal mines, where there are strict requirements for braking performance. These types of wet brakes are used in wheeled excavators, mining wheel dump trucks, underground loaders, and various off-highway equipment such as rock drilling rigs and wet spraying rigs.

[0003] While elastic-component brake-hydraulic-release wet brakes are becoming increasingly common in engineering vehicles, and are equipped with cooling circuits for intensive cooling to meet heat dissipation requirements, existing brake cooling systems for these brakes have at least the following problems during actual vehicle installation and matching:

[0004] 1. Insufficient adaptation to the operating conditions of the main unit. For example, in long inclined shafts, constant speed braking is required when going downhill, and return braking is used less frequently; similarly, for shovels and loaders, the braking force and braking frequency are different when going to the working face unloaded and returning to the unloading point fully loaded. Different equipment operates under different conditions, and the same equipment has multiple operating conditions, resulting in different braking frequencies and braking degrees, and consequently, different braking heat generation. The current braking and cooling system has not been adapted to match these conditions.

[0005] 2. Insufficient understanding of the structural form of the brake itself, and lack of in-depth analysis of the internal structural characteristics of wet brakes and ensuring their working conditions in the system design;

[0006] refer to Figure 1The sealing between the brake chamber and the external sealing steel plates, as well as between the brake chamber and the internal bearing sealing steel plate area, is actually achieved by an oil film formed between the steel plates. This film can only withstand pressures up to 2 bar, exhibiting extremely low pressure resistance. Therefore, in wet brakes, on the one hand, the friction pads and pressure plates are located in a sealed chamber, unaffected by external interference; on the other hand, the friction pads are immersed in coolant, and high-intensity braking leads to significant heat generation, requiring timely heat dissipation to ensure braking performance. However, since the friction pad chamber itself is not pressure-resistant, it needs to be designed with pressure limiting to ensure proper functioning. In existing solutions, such as the underground shovel and loader braking hydraulic system disclosed in patent number CN201520303865, no flow diversion measures are set. When wear is uneven, the resistance of each brake chamber is inconsistent, and the cooling flow will pass through the brake chamber with lower resistance, resulting in uneven heat dissipation. Another example is the cooling hydraulic system of an underground shovel and loader brake disclosed in patent number CN201420600864. Although there is flow diversion, the pressure resistance of the brake chamber is not considered, and the branch circuit is not equipped with overflow bypass protection. Moreover, none of the above solutions consider the operating conditions and use constant flow for cooling. Generally, the cooling flow rate is set to ensure maximum heat generation. Under light load conditions or low-frequency braking, excessive cooling will lead to an increase in cooling viscosity. When emergency braking is triggered, the drastic viscosity-temperature change will aggravate wear. At the same time, the large flow rate scouring increases the pressure of the brake chamber and is prone to damage to the seal.

[0007] On the other hand, reference Figure 2 In a wet brake system with elastic element braking and hydraulic release, the friction mechanism differs from that of a conventional dry brake because the friction pads and pressure plates are completely immersed in coolant. In a wet brake, the braking process from light to heavy involves oil film friction, oil film-friction pad friction, and finally, friction pad friction. While the oil film friction stage has relatively low frictional force and causes no damage to the friction pads, it is a short phase in the entire braking force activation process, making it difficult to achieve stable oil film friction output control. In an elastic element braking-hydraulic release system, when the driver presses the brake pedal, the pressurized fluid in the brake cylinder is released, thereby releasing the compressed elastic element and triggering braking. The elastic element is a non-linear component, making it extremely difficult for the driver to find the brake pedal feel, especially in situations such as low-speed parking, slow approaching the curb, and steep hill descent. Current braking control systems do not provide a satisfactory solution for these situations. Summary of the Invention

[0008] This invention provides a hydraulically controlled dynamic cavity amplification device and a braking cooling control system for engineering vehicles to solve the technical problems of poor braking response and poor brake pedal feel in the prior art of engineering vehicle braking systems.

[0009] According to one aspect of the present invention, a hydraulically controlled actuated cavity amplification device is provided, applied to a braking system. The braking system includes a braking input device and a braking actuator. The braking input device is used to input pressure into the braking system to drive the braking actuator to actuate and generate braking. The hydraulically controlled actuated cavity amplification device includes:

[0010] A pedal detection device is used to output pressure when a change in angle of the brake pedal based on its normal state is detected.

[0011] A first valve body serves as a structural support. The first valve body has a first inner cavity, a first oil port communicating with the first inner cavity and for communicating with a brake input device, a second oil port communicating with the first inner cavity and for communicating with a brake actuator, and a third oil port communicating with the first inner cavity and for communicating with the pedal detection device. The first oil port and the second oil port are arranged near the first end of the first inner cavity, and the third oil port is arranged near the second end of the first inner cavity.

[0012] A first valve core, inserted into the first inner cavity, is used to block the first oil port and the second oil port when the pedal detection device outputs pressure to the third oil port and moves to the first end of the first inner cavity to the first limit position; the side wall of the first valve core is provided with a mating structure, and the mating structure and the inner wall of the first inner cavity form an amplification cavity, which is used to communicate with the first oil port and the second oil port respectively when the first valve core moves to the first limit position;

[0013] A flow limiting device is disposed on a first oil line between the first oil port and the amplification cavity, used to open the first oil line when the pressure at the first oil port is less than the pressure at the second oil port, and also used to close the first oil line when the pressure at the first oil port is greater than the pressure at the second oil port.

[0014] As a further improvement to the above technical solution, the hydraulically controlled amplified cavity further includes a reset piston, which is sleeved on the first valve core and located inside the amplification cavity; the first valve core is used to connect the second end of the amplification cavity to the second oil port when it moves to the first extreme position, thereby causing high-pressure oil to act on the second end of the reset piston and move it towards the first end; the first valve core is also used to connect the first end of the amplification cavity to the second oil port when it moves to the second extreme position, thereby keeping the reset piston moving towards the second end and pressing against the inner wall of the amplification cavity and blocking the oil passage between the second oil port and the second end of the amplification cavity.

[0015] As a further improvement to the above technical solution, a first elastic reset element is provided between the reset piston and the inner wall of the first end of the amplification cavity.

[0016] As a further improvement to the above technical solution, the first valve body is provided with a first oil return channel, which is used to connect to the first end of the amplification cavity when the first valve core moves to the first limit position.

[0017] As a further improvement to the above technical solution, a second elastic reset member is provided between the second end of the first valve core and the inner cavity.

[0018] According to another aspect of the present invention, a braking cooling control system for engineering vehicles is also provided, which includes the aforementioned hydraulic control braking cavity amplification device.

[0019] As a further improvement to the above technical solution, the engineering vehicle brake cooling control system further includes a flow diversion device, which includes:

[0020] The second valve body has a second inner cavity, an oil inlet, a control oil inlet, and multiple oil outlets. A diversion port is provided in the second valve body, which connects the oil inlet and the second inner cavity. The number of diversion ports matches the number of oil outlets, and the distribution position of the diversion ports matches the distribution position of the oil outlets.

[0021] The second valve core is disposed in the second inner cavity. The second valve core is provided with multiple sets of communication structures matching the number of oil outlets. The communication structures respectively include a first damping channel with a first flow rate specification and a second damping channel with a second flow rate specification. The second valve core is used to connect the first damping channel to the corresponding diversion port and the oil outlet under normal conditions, and to connect the second damping channel to the corresponding diversion port and the oil outlet when the control oil port has pressure input to switch the state.

[0022] As a further improvement to the above technical solution, the second valve body is provided with a second oil return channel that is connected to each of the oil outlets, and a back pressure check valve is provided on the second oil return channel corresponding to each of the oil outlets.

[0023] As a further improvement to the above technical solution, a third elastic reset member is provided between the second end of the second valve core and the inner wall of the second inner cavity.

[0024] As a further improvement to the above technical solution, the engineering vehicle includes a front axle and a rear axle, and the diversion device also includes a control device. The control device is equipped with a temperature detection unit, which is used to input control oil into the control oil port when the brake chamber temperature of the axle reaches a preset value or is within a preset range.

[0025] The present invention has the following beneficial effects:

[0026] When the driver places their foot on the brake pedal without applying force and triggers the pedal's free travel, the pedal detection device detects the change in brake pedal angle, causing control fluid to flow into the third port. This drives the first valve core to move towards the first end of the first inner cavity. When the first valve core moves to its first limit position, it blocks the first and second ports. Simultaneously, the amplification chamber connects the first and second ports. The first port side maintains its maximum input pressure, while the pressure on the second port side decreases due to the amplification effect of the amplification chamber. Since the pressure on the first port side is greater than that on the second port side, the oil passage between the first port and the amplification chamber is closed under the action of the flow limiting device. The fluid in the amplification chamber is sealed, and the pressure of the brake actuator decreases stably, creating a state that can trigger the brake friction pair to be in oil film friction, achieving the initial slow braking effect. When the driver applies force to press the brake pedal, if the force is applied... The pressure at the first port drops rapidly, making it lower than that at the second port. This activates the flow-limiting device, allowing the high-pressure oil at the second port to flow out, achieving a consistent release of hydraulic oil with the original braking system. This hydraulically controlled amplified valve chamber, used in conjunction with an angle-sensing brake pedal, generates braking force during the initial free travel of the pedal. This allows the driver to receive a slow braking force with just a light touch of the pedal, providing rapid response and stable feedback without requiring pedal input. This enhances the driver's control, effectively improving braking performance and reducing wear on the brake pads. When this amplified valve chamber is activated, the reduced braking pressure connects with the pressure released by further pedal depressing, ensuring continuous braking with rapid response and without affecting the original braking performance.

[0027] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0028] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0029] Figure 1 This is a schematic diagram of the internal structure of a wet brake in the prior art;

[0030] Figure 2 This is a schematic diagram of the braking stage of a spring-brake-hydraulic-release wet brake in the prior art;

[0031] Figure 3 This is a schematic diagram of a brake cooling system in the prior art;

[0032] Figure 4 This is a schematic diagram of the pedal angle pressure output curve in existing technology;

[0033] Figure 5 This is a schematic diagram of the engineering vehicle braking and cooling control system according to a preferred embodiment of the present invention;

[0034] Figure 6 This is a schematic diagram of the internal structure of the hydraulically controlled dynamic cavity amplification device according to a preferred embodiment of the present invention;

[0035] Figure 7 This is a schematic diagram of the braking control circuit of a preferred embodiment of the present invention;

[0036] Figure 8 This is a schematic diagram of the output pressure of the foot pedal detection device in the brake control circuit of the preferred embodiment of the present invention.

[0037] Figure 9 This is a schematic diagram of the cavity enlargement process of the braking control circuit in a preferred embodiment of the present invention;

[0038] Figure 10 This is a schematic diagram of the process of oil flowing out of the amplified cavity when the brake control circuit is deeply depressed according to a preferred embodiment of the present invention;

[0039] Figure 11 This is a schematic diagram of the internal structure of the diversion device according to a preferred embodiment of the present invention;

[0040] Figure 12 This is a schematic diagram of the cooling control circuit of a preferred embodiment of the present invention.

[0041] Legend:

[0042] 1. Main pump; 2. First pressure gauge; 3. Filter; 4. Filling valve; 5. Second pressure gauge; 6. First low-pressure alarm switch; 7. First accumulator; 8. Second accumulator; 9. Second low-pressure alarm switch; 10. First check valve; 11. Third accumulator; 12. Parking solenoid valve; 13. Parking pressure switch; 14. Brake input device; 15. Front axle; 16. Rear axle; 17. Cooling safety valve; 18. Cooler; 19. Back pressure check valve; 20. Hydraulic oil tank; 21. Diverter; 22. Temperature sensor; 23. Pedal detection device; 24. Hydraulic control valve chamber amplification device; 25. ... 1. Valve body; 251. First oil port; 252. Second oil port; 253. Third oil port; 254. First return oil passage; 255. Third return oil passage; 26. First valve core; 27. Reset piston; 28. First elastic reset element; 29. ​​Flow limiting device; 30. Second elastic reset element; 31. Brake cylinder; 32. Second valve body; 321. Oil inlet; 322. Flow divider; 323. Oil outlet; 324. Control oil port; 325. Third return oil passage; 33. Second valve core; 331. First damping passage; 332. Second damping passage; 34. Third elastic reset element; 35. Control device. Detailed Implementation

[0043] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0044] Figure 5 This is a schematic diagram of the engineering vehicle braking and cooling control system according to a preferred embodiment of the present invention; Figure 6 This is a schematic diagram of the internal structure of the hydraulically controlled dynamic cavity amplification device according to a preferred embodiment of the present invention; Figure 7 This is a schematic diagram of the braking control circuit of a preferred embodiment of the present invention; Figure 8 This is a schematic diagram of the output pressure of the foot pedal detection device in the brake control circuit of the preferred embodiment of the present invention. Figure 9 This is a schematic diagram of the cavity enlargement process of the braking control circuit in a preferred embodiment of the present invention; Figure 10 This is a schematic diagram of the process of oil flowing out of the amplified cavity when the brake control circuit is deeply depressed according to a preferred embodiment of the present invention; Figure 11 This is a schematic diagram of the internal structure of the diversion device according to a preferred embodiment of the present invention; Figure 12 This is a schematic diagram of the cooling control circuit of a preferred embodiment of the present invention.

[0045] like Figures 5 to 10 As shown, the hydraulically controlled brake cavity amplification device 24 of this embodiment is applied to a braking system. The braking system includes a brake input device 14 and a brake actuator. The brake input device 14 is used to input pressure into the braking system to drive the brake actuator to generate braking. The hydraulically controlled brake cavity amplification device 24 includes:

[0046] Pedal detection device 23 is used to output pressure when it detects that the brake pedal of brake input device 14 has undergone an angle change based on the normal state;

[0047] The first valve body 25 serves as a structural support. The first valve body 25 has a first inner cavity, a first oil port 251 that communicates with the first inner cavity and is used to communicate with the brake input device 14, a second oil port 252 that communicates with the first inner cavity and is used to communicate with the brake actuator, and a third oil port 253 that communicates with the first inner cavity and is used to communicate with the pedal detection device 23. The first oil port 251 and the second oil port 252 are arranged near the first end of the first inner cavity, and the third oil port 253 is arranged near the second end of the first inner cavity.

[0048] The first valve core 26 is disposed within the first inner cavity and is used to block the first oil port 251 and the second oil port 252 when it moves to the first limit position at the first end of the first inner cavity when the pedal detection device 23 outputs pressure to the third oil port 253. The side wall of the first valve core 26 is provided with a mating structure, which forms an amplification cavity with the inner wall of the first inner cavity. The amplification cavity is used to communicate with the first oil port 251 and the second oil port 252 respectively when the first valve core 26 moves to the first limit position. When the first valve core 26 is located at the second limit position, the first oil port 251 and the second oil port 252 are connected through the inner cavity.

[0049] The flow limiting device 29 is installed on the first oil line between the first oil port 251 and the amplification chamber. It is used to open the first oil line when the pressure of the first oil port 251 is less than the pressure of the second oil port 252, and also to close the first oil line when the pressure of the first oil port 251 is greater than the pressure of the second oil port 252.

[0050] The pedal detection device 23 is preferably a two-position three-way solenoid directional valve, which is connected to the pressure oil, the return oil circuit and the third oil port 253 respectively, and controls the third oil port 253 to connect to the pressure oil or the return oil circuit according to the signal; the brake actuator is preferably a brake cylinder 31 with a brake spring inside; the flow limiting device 29 is preferably a one-way valve.

[0051] It should be noted that fully enclosed wet brakes, due to the heat dissipation requirements of their sealed chambers, are generally equipped with external circulation forced cooling. (See reference...) Figure 3This is a typical brake cooling system for a spring-brake-hydraulic release type wet brake in the prior art; it includes a main pump 1, a filling valve 4, a parking solenoid valve 12, a parking pressure switch 13, a brake input device 14, a front axle 15, a rear axle 16, a cooling safety valve 17, a cooler 18, and a hydraulic oil tank 20; preferably, it also includes a first pressure gauge 2, a filter 3, a second pressure gauge 5, a first low-pressure alarm switch 6, a first accumulator 7, a second accumulator 8, a second low-pressure alarm switch 9, a first check valve 10, a back pressure check valve 19, and a third accumulator 11, with the connection relationship shown in the figure; wherein, the core components of the system are the brake input device 14 and the filling valve 4, the brake input device 14 includes a normally open inverse ratio brake valve, and the system flow utilizes the bypass flow of the filling valve 4 to enter the cooler 18, and then enters the axle. The brake chamber is subjected to forced cooling, and the back pressure check valve 19 provides pressure limiting protection for the brake chamber. Other components will not be elaborated on in detail, but will be referred to in the existing technical structure and principle application. The external circulation forced cooling design of this typical brake cooling system matches the flow rate to meet the maximum heat dissipation requirements, resulting in excessive cooling during infrequent braking. Continuous high-flow-rate flushing of the brake chamber can damage the seals of pressure-sensitive brake chambers, causing leakage. Furthermore, there is no flow diversion measure, or if there is a flow diversion measure, there is no pressure protection for the diversion circuit, which cannot fully guarantee the cooling effect of all brake chambers. When the inverse foot brake valve is actuated, the pressure fluid in the brake chamber is released, and the spring applies pressure to the brake friction pair, thereby achieving braking. Since the spring release is non-linearly controlled, the initial micro-control (slight braking) of the inverse brake valve is almost impossible to control, resulting in a very poor driving experience for engineering vehicles with inverse foot brake valves.

[0052] The working principle of this liquid-controlled dynamic cavity amplification device 24:

[0053] Under normal conditions, such as during vehicle operation, pressurized oil flows through the brake input device 14 to the first oil port 251 of the hydraulic control valve chamber amplification device 24 and then to the second oil port 252, acting on the brake actuator to compress the brake spring. At this time, no braking is performed.

[0054] When the driver places their foot on the brake pedal without applying force and triggers the pedal's free travel, the pedal detection device 23 detects the change in brake pedal angle, causing control oil to flow into the third port 253. This drives the first valve core 26 to move towards the first end of the first inner cavity. When the first valve core 26 moves to its first limit position, it blocks the first port 251 and the second port 252. Simultaneously, the amplification chamber connects the first port 251 and the second port 252. The first port 251 side maintains the maximum input pressure, while the pressure on the second port 252 side decreases due to the amplification effect of the amplification chamber. Since the pressure on the first port 251 side is greater than the pressure on the second port 252 side, the oil passage between the first port 251 and the amplification chamber is closed under the action of the flow limiting device 29. The oil in the amplification chamber is sealed, and the pressure of the brake actuator decreases steadily, forming a state that can trigger the brake friction pair to be in oil film friction, thus achieving the initial slow braking effect. When the driver applies force to press the brake pedal... When the pedal is pressed, if the force is applied quickly, the pressure on the first port 251 side drops rapidly, making the pressure on the first port 251 side less than the pressure on the second port 252 side. The flow limiting device 29 opens, and the high-pressure oil on the second port 252 side flows out through the flow limiting device 29, achieving the effect of consistent hydraulic oil release in the original braking system. This hydraulic control dynamic cavity amplification device 24, in conjunction with the brake pedal with angle sensing, enables the generation of braking force during the oil film friction stage when the pedal is lightly touched during its free travel. This allows the driver to obtain a slow braking force with just a light touch of the brake pedal during its free travel. This braking force can respond quickly and provide stable feedback without the need for pedal testing, providing the driver with better control and effectively improving braking control performance. At the same time, it effectively reduces the wear of the brake friction pads. When this brake cavity amplification device is activated, the reduced braking pressure can be connected with the pressure released by further pressing the pedal, thus ensuring the continuity of braking, rapid response, and no impact on the original braking performance.

[0055] Among them, the normally open inverse ratio brake valve is equipped with an angle sensor, for reference. Figure 4 During the initial triggering phase, the brake pedal typically has a free travel of 4–6°. When the driver places their foot on the pedal without applying pressure, the change in pedal angle is usually within 6°. When the driver places their foot on the pedal with the intention to brake, the hydraulic control volume amplifier receives a signal from the brake pedal, i.e., the external control pressure triggers the switching of the first valve core 26 of the hydraulic control volume amplifier device, increasing the brake cavity volume. The specific amplified cavity volume is based on test settings, with the design requirement being that the contact control of the amplified friction pads is in the oil film friction stage, ensuring a controllable and slow braking.

[0056] In this embodiment, the hydraulically controlled amplified cavity amplification device 24 further includes a reset piston 27, which is sleeved on the first valve core 26 and located inside the amplification cavity. The first valve core 26 is used to connect the second end of the amplification cavity to the second oil port 252 when it moves to the first extreme position, thereby causing high-pressure oil to act on the second end of the reset piston 27 and move it towards the first end. The first valve core 26 is also used to connect the first end of the amplification cavity to the second oil port 252 when it moves to the second extreme position, thereby keeping the reset piston 27 moving towards the second end and pressing against the inner wall of the amplification cavity and blocking the oil passage between the second oil port 252 and the second end of the amplification cavity. Specifically, an oil groove is provided at a preset axial position on the inner cavity, connecting to the first oil port 251 and the second oil port 252. When the first extreme position is reached, the oil groove is connected to the first oil port 251 and the second oil port 252. Before the valve core 26 moves to the first limit position, the side wall of the reset piston 27 blocks the oil groove. When the first valve core 26 moves to the first limit position, the position of the second end of the amplification chamber matches the position of the oil groove. The pressure oil of the second oil port 252 can act on the second end of the reset piston 27 to make it move towards the first end, thereby amplifying the braking cavity and reducing the pressure on the side of the second oil port 252, thus obtaining the initial slow braking effect. The first valve body 25 is provided with a first return oil channel 254, which is used to connect to the first end of the amplification chamber when the first valve core 26 moves to the first limit position. That is, when the reset piston 27 is driven to move towards the first end, the hydraulic oil between its first end and the first end of the amplification chamber returns through the first return oil channel 254.

[0057] Preferably, the second end of the reviving piston is provided with a force-bearing structure, which can be a chamfer on the outer edge of the second end of the reviving piston so that the pressure oil in the oil groove acts on the reviving piston to push it to move towards the first end; preferably, a first elastic reset member 28, preferably a spring, is provided between the reset piston 27 and the inner wall of the first end of the amplification chamber. It can be understood that after the brake is released, the pressure of the first oil port 251 returns, causing the first valve core 26 to move to the second limit position, and the reset piston 27 is reset under the action of the first elastic reset member 28.

[0058] It should be noted that the diameter of the inner cavity at the second end of the first valve body 25 is larger, and the diameter of the second end of the first valve core 26 is also larger, in order to increase the contact area with the control oil and ensure the response speed. Among them, the first valve core 26 near the second end is provided with an annular groove structure similar to the mating structure to form an oil cavity. The first valve body 25 is provided with a third oil return channel 255325. When the first valve core 26 moves towards the first end, the oil cavity and the third oil return channel 255325 remain connected to return oil. The first valve core 26 and the outer wall of the first end, the outer wall of the second end, and the outer wall between the amplification cavity and the oil cavity are respectively fitted with sealing rings that fit with the inner wall of the inner cavity to ensure the sealing between each chamber.

[0059] In this embodiment, a second elastic reset member 30 is provided between the second end of the first valve core 26 and the inner cavity. After the braking is canceled, the first valve core 26 is reset under the action of the pressure oil and the second elastic reset member 30.

[0060] On the other hand, this embodiment also provides a braking cooling control system for engineering vehicles, which uses the hydraulic control valve cavity amplification device 24 of the above preferred embodiment.

[0061] In this embodiment, the engineering vehicle brake cooling control system also includes a flow diversion device 21, as shown in the reference. Figure 11 and Figure 12 The diversion device 21 includes:

[0062] The second valve body 32 has a second inner cavity, an oil inlet 321, a control oil port 324, and multiple oil outlets 323. A diversion port 322 is provided in the second valve body 32 to connect the oil inlet 321 and the second inner cavity. The number of diversion ports 322 matches the number of oil outlets 323, and the distribution position of the diversion ports 322 matches the distribution position of the oil outlets 323.

[0063] The second valve core 33 is disposed in the second inner cavity. The second valve core 33 is provided with multiple sets of communication structures matching the number of oil outlets 323. The communication structures include a first damping channel 331 with a first flow rate specification and a second damping channel 332 with a second flow rate specification. The second valve core 33 is used to connect the first damping channel 331 to the corresponding diversion port 322 and oil outlet 323 under normal conditions, and to connect the second damping channel 332 to the corresponding diversion port 322 and oil outlet 323 when the control oil port 324 has pressure input to switch the state.

[0064] Preferably, the orifice diameters of the first damping channel 331 and the second damping channel 332 are set to different specifications to achieve different flow rates;

[0065] It should be understood that the engineering vehicle includes a front axle 15 and a rear axle 16. Based on this, it is preferable to have four oil outlets 323, four sets of connecting structures, and four branch outlets 322. Each oil outlet 323 is connected to the brake chamber at the first end of the front axle 15, the brake chamber at the second end of the front axle 15, the brake chamber at the first end of the rear axle 16, and the brake chamber at the second end of the rear axle 16, respectively.

[0066] Under normal conditions, each first damping channel 331 is connected to its corresponding diverter port 322 and oil outlet 323. By controlling the input of pressure oil through the oil port 324 to actuate the valve core, the first damping channel 331 is switched to the second damping channel 332, which in turn connects to its corresponding diverter port 322 and oil outlet 323, thereby changing the flow rate. Preferably, the flow rate of the first damping channel 331 is less than that of the second damping channel. During low-frequency braking, low-flow cooling is maintained, while during high-frequency braking, the first damping channel 331 is switched to the second damping channel 332, allowing a larger cooling flow rate to enter the braking chambers of the front and rear axles 16 for cooling. At the same time, both damping levels can achieve equal flow rate diversion, effectively ensuring the cooling requirements of high and low braking, reducing the large-flow scouring of the brake cooling chamber, improving the sealing life of the cooling chamber, effectively improving the control performance and cooling effect of the braking system, and extending the service life of the brake.

[0067] Furthermore, the diversion device 21 also includes a control device 35, which is equipped with a temperature detection unit, specifically a temperature sensor 22. The control device 35 can be a two-position three-way solenoid valve, used to input control oil into the control port 324 when the brake chamber temperature of the axle is detected to reach a preset value or be within a preset range. Specifically, when a high temperature is sensed, the control device 35 switches the oil circuit to connect the pressure oil to the control port 324 to act on the second valve core 33, automatically switching the high-flow-rate diversion damping channel to provide timely cooling flow at high temperatures; at low temperatures, it automatically closes and switches back to the first damping channel 331 to reduce the flow rate and reduce the pressure erosion of the brake chamber by the cooling flow, thereby improving the service life of the steel sheet sealing diaphragm.

[0068] In this embodiment, the second valve body 32 is provided with a second oil return channel that is connected to each oil outlet 323. A back pressure check valve 19 is provided on the second oil return channel corresponding to each oil outlet 323. Each branch is set separately to ensure that each branch does not exceed the pressure limit of the friction plate cooling chamber. This device integrates diversion, switching and back pressure protection into one unit, realizing integrated control. The structure is simple and compact, occupies little space, and is easy to install and disassemble.

[0069] In this embodiment, a third elastic reset member 34, preferably a spring, is provided between the second end of the second valve core 33 and the inner wall of the second inner cavity. After the control device 35 stops outputting control oil to the second valve core 33, the second valve core 33 is reset under the action of the third elastic reset member 34, and the first damping channel 331 connects the diversion port 322 and the oil outlet 323.

[0070] The vehicle braking cooling control system of this project fully considers the structural characteristics and braking performance of the fully enclosed wet brake, and improves the performance from the aspects of braking control and external circulation strong cooling, which effectively improves braking and handling performance, ensures cooling effect and extends service life.

[0071] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0072] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0073] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A hydraulically controlled actuated cavity amplification device, applied to a braking system, the braking system including a braking input device (14) and a braking actuator, the braking input device (14) being used to input pressure into the braking system to drive the braking actuator to actuate and generate braking, characterized in that, The fluid-controlled dynamic cavity amplification device includes: The pedal detection device (23) is used to output pressure when it detects that the brake pedal has undergone an angle change based on the normal state; A first valve body (25) is used as a structural support. The first valve body (25) has a first inner cavity, a first oil port (251) communicating with the first inner cavity and communicating with the brake input device (14), a second oil port (252) communicating with the first inner cavity and communicating with the brake actuator, and a third oil port (253) communicating with the first inner cavity and communicating with the pedal detection device (23). The first oil port (251) and the second oil port (252) are arranged near the first end of the first inner cavity, and the third oil port (253) is arranged near the second end of the first inner cavity. A first valve core (26) is inserted into the first inner cavity and is used to block the first oil port (251) and the second oil port (252) when the pedal detection device (23) outputs pressure to the third oil port (253) and moves to the first end of the first inner cavity to the first limit position; the side wall of the first valve core (26) is provided with a mating structure, and the mating structure and the inner wall of the first inner cavity form an amplification cavity, which is used to communicate with the first oil port (251) and the second oil port (252) respectively when the first valve core (26) moves to the first limit position; A flow limiting device (29) is provided on the first oil line between the first oil port (251) and the amplification cavity. It is used to open the first oil line when the pressure of the first oil port (251) is less than the pressure of the second oil port (252), and to close the first oil line when the pressure of the first oil port (251) is greater than the pressure of the second oil port (252).

2. The hydraulically controlled dynamic cavity amplification device according to claim 1, characterized in that, The hydraulically controlled amplified cavity further includes a reset piston (27), which is sleeved on the first valve core (26) and located inside the amplification cavity. The first valve core (26) is used to connect the second end of the amplification cavity to the second oil port (252) when it moves to the first limit position, thereby causing high-pressure oil to act on the second end of the reset piston (27) and move it towards the first end. The first valve core (26) is also used to connect the first end of the amplification cavity to the second oil port (252) when it moves to the second limit position, thereby keeping the reset piston (27) moving towards the second end and pressing against the inner wall of the amplification cavity and blocking the oil passage between the second oil port (252) and the second end of the amplification cavity.

3. The hydraulically controlled dynamic cavity amplification device according to claim 2, characterized in that, A first elastic reset member (28) is provided between the reset piston (27) and the inner wall of the first end of the amplification cavity.

4. The hydraulically controlled dynamic cavity amplification device according to claim 1, characterized in that, The first valve body (25) is provided with a first oil return channel (254) for connecting to the first end of the amplification cavity when the first valve core (26) moves to the first limit position.

5. The hydraulically controlled dynamic cavity amplification device according to claim 1, characterized in that, A second elastic reset member (30) is provided between the second end of the first valve core (26) and the inner cavity.

6. A braking cooling control system for engineering vehicles, characterized in that, The application includes the hydraulically controlled dynamic cavity amplification device according to any one of claims 1-5.

7. The engineering vehicle braking cooling control system according to claim 6, characterized in that, The engineering vehicle brake cooling control system further includes a flow divider (21), which includes: The second valve body (32) has a second inner cavity, an oil inlet (321), a control oil port (324), and a plurality of oil outlets (323). The second valve body (32) has a diversion port (322) that connects the oil inlet (321) and the second inner cavity. The number of diversion ports (322) matches the number of oil outlets (323), and the distribution position of the diversion ports (322) matches the distribution position of the oil outlets (323). The second valve core (33) is disposed in the second inner cavity. The second valve core (33) is provided with multiple sets of communication structures matching the number of oil outlets (323). The communication structures respectively include a first damping channel (331) with a first flow rate specification and a second damping channel (332) with a second flow rate specification. The second valve core (33) is used to connect the first damping channel (331) to the corresponding diverter port (322) and the oil outlet (323) under normal conditions, and to connect the second damping channel (332) to the corresponding diverter port (322) and the oil outlet (323) when the control oil port (324) has a pressure input to switch the state.

8. The engineering vehicle braking cooling control system according to claim 7, characterized in that, The second valve body (32) is provided with a second return oil channel that is connected to each of the oil outlets (323). A back pressure check valve (19) is provided on the second return oil channel corresponding to each of the oil outlets (323).

9. The engineering vehicle braking cooling control system according to claim 7, characterized in that, A third elastic reset member (34) is provided between the second end of the second valve core (33) and the inner wall of the second inner cavity.

10. The engineering vehicle braking cooling control system according to any one of claims 7-9, wherein the engineering vehicle comprises a front axle (15) and a rear axle (16), characterized in that, The diversion device (21) also includes a control device (35), which is equipped with a temperature detection unit for inputting control oil into the control oil port (324) when the brake chamber temperature of the axle is detected to reach a preset value or be within a preset range.

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