Hydraulic control dynamic containing cavity amplifying device and engineering vehicle brake cooling control system

Abstract

The invention discloses a hydraulic control dynamic cavity amplifying device and an engineering vehicle brake cooling control system, a brake system comprises a brake input device and a brake execution device, and the hydraulic control dynamic cavity amplifying device comprises a pedal detection device, a hydraulic control device and a hydraulic control device, the first valve body is provided with a first inner cavity, a first oil port communicated with a brake input device, a second oil port communicated with a brake execution device and a third oil port communicated with a pedal detection device; the first valve element is arranged in the first inner cavity in a penetrating mode and used for moving towards 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; an amplification cavity is formed in the side wall of the first valve element and used for being communicated with the first oil port and the second oil port at the first end position; the flow limiting device is arranged on an oil way between the first oil port and the amplification cavity and used for opening the first oil way when the pressure of the first oil port is smaller than that of the second oil port and closing the first oil way when the pressure is larger than that of the second oil port.

Description

Technical Field

[0001] The present invention relates to the technical field of brake systems, and in particular to a hydraulically controlled dynamic volume amplifying device. In addition, the present invention also relates to an engineering vehicle brake cooling control system comprising the hydraulically controlled dynamic volume amplifying device. Background Art

[0002] With the development of mining technology, mining depth is getting deeper and deeper, the degree of mechanization is getting higher and higher, and various types of engineering vehicles related to mining efficiency are becoming more and more valued. For non-road engineering vehicles, it is a basic requirement to meet the requirements of various types of operating mechanical arms and operating accessories, and the ability to adapt to heavy-loaded and harsh road conditions and drive safely has become a design focus. Therefore, the safe driving of engineering vehicles has become the core of the overall design, especially the braking performance directly determines the driving safety. At present, fully enclosed wet brakes are becoming more and more popular in engineering vehicles due to their technical advantages: on the one hand, they can provide a large braking torque while ensuring the compactness of the structure; on the other hand, the brakes work in a closed cavity, isolating the harsh working environment and having a long maintenance cycle. These advantages make fully enclosed wet brakes the preferred choice for engineering vehicles. There are many forms of fully enclosed wet brakes. Among them, the elastic part brake-hydraulic release type is used in relatively harsh environments such as mines, underground, and coal mines due to its fail-safe setting, and has strict requirements on braking performance. Such as wheel excavators, mining wheel dump trucks, underground loaders, and various non-road equipment such as rock drilling rigs and wet spraying rigs.

[0003] Although elastic brake-hydraulic release wet brakes are becoming more and more popular in engineering vehicles, cooling circuits are also matched to meet the heat dissipation requirements for strong cooling. However, in the actual vehicle installation and matching process, the existing brake cooling system matching elastic brake-hydraulic release wet brakes has at least the following problems:

[0004] 1. Insufficient adaptation to the main machine's working conditions. For example, when going down a long inclined shaft, it is necessary to maintain a uniform braking speed when going downhill, and the return braking is rarely used; for example, when the scraper equipment goes to the working surface without load and returns to the unloading point with full load, the braking force and braking frequency are different when empty or full load. Different equipment has different working conditions. The same equipment has multiple working conditions, with different braking frequencies and braking degrees, and thus different braking heat generation. The current brake cooling system has not been adapted and matched.

[0005] 2. Insufficient understanding of the brake structure itself, no in-depth analysis of the internal structure characteristics of the wet brake and no working condition guarantee in the system design;

[0006] refer to Figure 1The seal between the brake cavity and the external sealing steel sheet, and the brake cavity and the internal bearing sealing steel sheet area is actually sealed by the oil film formed between the steel sheets. The pressure that can be withstood does not exceed 2 bar, and the pressure resistance is extremely low. Therefore, on the one hand, the friction plate-pressure plate of the wet brake is in a closed cavity and is not affected by the outside world; on the other hand, the friction plate is immersed in the coolant, and high-intensity braking will cause huge heat, which needs to be dissipated in time to ensure braking performance. However, the friction plate cavity itself is not pressure-resistant and needs to be designed with pressure limit to ensure it. In the existing schemes, such as the underground scraper loader brake hydraulic system disclosed in Patent No.: CN201520303865, no diversion measures are set. When the wear is uneven, the resistance of each brake chamber is inconsistent, and the cooling flow will pass through the brake chamber with small resistance, which will lead to uneven heat dissipation; for example, the cooling hydraulic system of the underground scraper loader brake disclosed in Patent No.: CN201420600864 has diversion but does not consider the pressure resistance of the brake chamber, and the branch is not provided with overflow bypass protection; and the above schemes do not take the operating conditions into consideration, and adopt a constant flow rate for cooling. Generally, the cooling flow rate is set to ensure the maximum heat generation. Under light load conditions or low-frequency braking, excessive cooling will cause the cooling viscosity to increase. When the emergency brake is triggered, the drastic viscosity-temperature change will aggravate the wear; at the same time, large flow flushing increases the pressure of the brake chamber, which is easy to damage the seal.

[0007] On the other hand, reference Figure 2 , elastic brake-hydraulic release wet brake, because the friction plate and the pressure plate are completely immersed in the coolant, its friction mechanism is different from that of ordinary dry brakes. In general, because the friction pair of wet brakes is completely immersed in the coolant, the braking triggering process from light to heavy is oil film friction, oil film-friction plate friction, and friction plate friction. The friction force in the oil film friction stage is small, but there is no damage to the friction plate. However, this stage is a short stage in the whole process of braking force triggering, and it is not easy to achieve stable oil film friction output control; for the elastic brake-hydraulic release brake system, when the driver steps on the brake to trigger the brake, the pressure solution in the brake cylinder is released, thereby releasing the compressed elastic part, and then triggering the brake. The elastic part is a nonlinear element, and it is extremely difficult for the driver to find the brake feel, especially in conditions such as low-speed parking, slow speed sideways, and steep slope descent. The current brake control system does not provide a good solution. Summary of the invention

[0008] The present invention provides a hydraulically controlled dynamic volume amplifying device and an engineering vehicle brake cooling control system to solve the technical problems of poor brake response and poor brake feel of the engineering vehicle brake system in the prior art.

[0009] According to one aspect of the present invention, a hydraulically controlled dynamic volume amplifying device is provided, which is 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 to the braking system and drive the braking actuator to generate braking. The hydraulically controlled dynamic volume amplifying device includes:

[0010] A pedal detection device, used for outputting pressure when detecting that the brake pedal has an angle change based on a normal state;

[0011] a first valve body, used as a structural support, the first valve body having a first inner cavity, a first oil port connected to the first inner cavity and used to communicate with a brake input device, a second oil port connected to the first inner cavity and used to communicate with a brake actuator, and a third oil port connected to the first inner cavity and used to communicate with the pedal detection device, the first oil port and the second oil port are arranged near a first end of the first inner cavity, and the third oil port is arranged near a second end of the first inner cavity;

[0012] A first valve core is inserted into the first inner cavity and 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 a first limit position; a matching structure is provided on the side wall of the first valve core, and an amplification cavity is formed between the matching structure and the inner wall of the first inner cavity, and the amplification cavity 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 arranged on the first oil circuit between the first oil port and the amplification chamber, and is used to open the first oil circuit when the pressure of the first oil port is less than the pressure of the second oil port, and is also used to close the first oil circuit when the pressure of the first oil port is greater than the pressure of the second oil port.

[0014] As a further improvement of the above technical solution, the hydraulically controlled dynamic chamber amplification device also includes a reset piston, which is sleeved on the first valve core and located in the amplification chamber; the first valve core is used to connect the second end of the amplification chamber to the second oil port when moving to the first extreme position, thereby allowing the high-pressure oil to act on the second end of the reset piston to move toward the first end; the first valve core is also used to connect the first end of the amplification chamber to the second oil port when moving to the second extreme position, thereby keeping the reset piston moving toward the second end to press against the inner wall of the amplification chamber and block the oil path between the second oil port and the second end of the amplification chamber.

[0015] As a further improvement of the above technical solution, a first elastic reset member is arranged between the reset piston and the inner wall of the first end of the amplification chamber.

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

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

[0018] According to another aspect of the present invention, there is also provided a brake cooling control system for an engineering vehicle, which comprises the above-mentioned hydraulically controlled dynamic volume amplifying device.

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

[0020] The second valve body has a second inner cavity, an oil inlet, a control oil port and a plurality of oil outlets, and a diverter port connected to the oil inlet and the second inner cavity is opened in the second valve body, the number of the diverter ports matches the number of the oil outlets, and the distribution position of the diverter ports matches the distribution position of the oil outlets;

[0021] The second valve core is penetrated by the second inner cavity, and the second valve core is provided with a plurality of connecting structures matching the number of the oil outlets, and the connecting structures respectively include a first damping channel with a first flow specification and a second damping channel with a second flow specification, and 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 is used 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 of the above technical solution, the second valve body is provided with second oil return channels respectively connected to the oil outlets, and back pressure check valves are respectively provided on the second oil return channels corresponding to the positions of the oil outlets.

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

[0024] As a further improvement of the above technical solution, the engineering vehicle includes a front axle and a rear axle, the diversion device also includes a control device, and the control device is provided with a temperature detection unit for inputting control oil into the control oil port when it is detected that 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 the sole of his foot on the brake pedal without applying force and triggering the idle travel of the pedal, the pedal detection device detects the angle change of the brake pedal, so that the control oil is input to the third oil port, driving the first valve core to move toward the first end direction of the first inner cavity, and the first valve core moves to the first end to the first limit position to block the first oil port and the second oil port. At the same time, the amplification chamber connects the first oil port and the second oil port. The first oil port side still maintains the maximum input pressure, while the second oil port side is affected by the amplification of the amplification chamber, and the pressure decreases. The pressure on the first oil port side is greater than the pressure on the second oil port side. Under the action of the flow limiting device, the oil path between the first oil port and the amplification chamber is closed, the oil in the amplification chamber is sealed, and the pressure of the brake actuator is steadily reduced, forming a state that can trigger the brake friction pair to be in oil film friction, thereby obtaining an initial slow braking effect; when the driver applies force on the brake pedal, if the force is applied At a faster speed, the pressure on the first oil port side drops rapidly, making the pressure on the first oil port side less than the pressure on the second oil port side, the flow limiting device opens, and the high-pressure oil on the second oil port side flows out through the flow limiting device, achieving the same effect of releasing the hydraulic oil in the original brake system; the hydraulically controlled dynamic volume amplification device is used in conjunction with a brake pedal with an angle sensor to achieve a braking force in the oil film friction stage by lightly touching the empty stroke of the pedal, so that the driver can obtain a deceleration braking force by lightly touching the empty stroke of the brake pedal. The braking force can respond quickly and feedback stably without pedal attempts, providing the driver with a better sense of control, effectively improving the braking control performance, and effectively reducing the wear of the brake friction pad; when the brake volume amplification device takes effect, the reduced braking pressure can be connected with the pressure release by continuing to press the pedal deeply, thereby ensuring the continuity of braking, rapid response, and no impact on the original braking performance.

[0027] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

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

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

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

[0032] Figure 4 is a schematic diagram of a pedal angle pressure output curve in the prior art;

[0033] Figure 5 is a schematic diagram of a brake cooling control system for an engineering vehicle according to a preferred embodiment of the present invention;

[0034] Figure 6 It is a schematic diagram of the internal structure of the hydraulically controlled dynamic volume chamber amplification device of the preferred embodiment of the present invention;

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

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

[0037] Fig. 9 It is a schematic diagram of the cavity enlargement process of the brake control circuit of the preferred embodiment of the present invention;

[0038] Fig.10 It is a schematic diagram of the oil outflow process in the deep pedal amplification chamber of the brake control circuit of the preferred embodiment of the present invention;

[0039] Fig.11 is a schematic diagram of the internal structure of the diversion device of a preferred embodiment of the present invention;

[0040] Fig.12 Schematic diagram of a cooling control circuit according to 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 dynamic chamber amplification device; 25. First A valve body; 251, a first oil port; 252, a second oil port; 253, a third oil port; 254, a first oil return channel; 255, a third oil return channel; 26, a first valve core; 27, a reset piston; 28, a first elastic reset member; 29, a flow limiting device; 30, a second elastic reset member; 31, a brake cylinder; 32, a second valve body; 321, an oil inlet; 322, a diverter port; 323, an oil outlet; 324, a control oil port; 325, a third oil return channel; 33, a second valve core; 331, a first damping channel; 332, a second damping channel; 34, a third elastic reset member; 35, a control device. DETAILED DESCRIPTION

[0043] The embodiments of the present invention are 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 is a schematic diagram of a brake cooling control system for an engineering vehicle according to a preferred embodiment of the present invention; Figure 6 It is a schematic diagram of the internal structure of the hydraulically controlled dynamic volume chamber amplification device of the preferred embodiment of the present invention; Figure 7 is a schematic diagram of a brake control circuit in a preferred embodiment of the present invention; Figure 8 It is a schematic diagram of the action output pressure of the foot pedal detection device of the brake control circuit of the preferred embodiment of the present invention; Fig. 9 It is a schematic diagram of the cavity enlargement process of the brake control circuit of the preferred embodiment of the present invention; Fig.10 It is a schematic diagram of the oil outflow process in the deep pedal amplification chamber of the brake control circuit of the preferred embodiment of the present invention; Fig.11 is a schematic diagram of the internal structure of the diversion device of a preferred embodiment of the present invention; Fig.12 It is a schematic diagram of a cooling control circuit of a preferred embodiment of the present invention;.

[0045] like Figures 5 to 10 As shown, the hydraulically controlled dynamic volume amplifying device 24 of this embodiment is applied to a braking system, the braking system includes a braking input device 14 and a braking actuator, the braking input device 14 is used to input pressure to the braking system to drive the braking actuator to generate braking, and the hydraulically controlled dynamic volume amplifying device 24 includes:

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

[0047] The 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 connected to the first inner cavity and used to communicate with the brake input device 14, a second oil port 252 connected to the first inner cavity and used to communicate with the brake actuator, and a third oil port 253 connected to the first inner cavity and 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 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; a matching structure is provided on the side wall of the first valve core 26, and an amplification cavity is formed between the matching structure and the inner wall of the first inner cavity, and 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; wherein, when the first valve core 26 is at the second limit position, the first oil port 251 and the second oil port 252 are communicated through the inner cavity;

[0049] The flow limiting device 29 is arranged on the first oil circuit between the first oil port 251 and the amplification chamber, and is used to open the first oil circuit when the pressure of the first oil port 251 is less than the pressure of the second oil port 252, and is also used to close the first oil circuit 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 preferably includes a two-position three-way electromagnetic reversing valve, which is respectively connected to the pressure oil, the return oil circuit and the third oil port 253, and controls the third oil port 253 to communicate with the pressure oil or the return oil circuit according to the signal; the brake actuator preferably includes a brake cylinder 31, which is provided with a brake spring; the flow limiting device 29 is preferably a one-way valve;

[0051] It should be noted that the fully enclosed wet brake, due to the heat dissipation requirements of the closed cavity, is generally equipped with external circulation strong cooling. Figure 3, which is a typical brake cooling system matching spring brake-hydraulic release type wet brake in the prior art; including a main pump 1, a charging 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, and the connection relationship is shown in the figure; wherein the core components of the system are the brake input device 14 and the charging valve 4, the brake input device 14 includes a normally open inverse brake valve, and the system flow enters the cooler 18 using the bypass flow of the charging valve 4, and then enters the axle The brake chamber is strongly cooled, and the back pressure one-way valve 19 provides pressure limiting protection for the brake chamber. Other components are not elaborated too much, and are applied with reference to the existing technical structure and principle. The external circulation strong cooling design of this typical brake cooling system is to match the flow rate to meet the maximum heat dissipation demand, and overcool during non-frequent braking. Continuous large flow flushes the brake chamber, causing seal damage to the pressure-intolerant brake chamber, resulting in leakage. There is no diversion measure, or there is a diversion measure but no diversion pressure protection, which cannot fully guarantee the cooling effect of all brake chambers. When the inverse proportional 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 a nonlinear control, the initial micro-control (light braking) of the inverse proportional brake valve is almost difficult to control, which makes the foot brake engineering vehicle with the inverse proportional brake valve have a very poor driving feel.

[0052] The working principle of the liquid-controlled dynamic volume amplifying device 24 is as follows:

[0053] Under normal conditions, such as when the vehicle is traveling, the pressure oil flows through the brake input device 14 to the first oil port 251 of the hydraulic control dynamic chamber amplification device 24 and flows to the second oil port 252, acting on the brake actuator to compress the brake spring, and no braking is performed at this time;

[0054] When the driver places the sole of his foot on the brake pedal without applying force and triggering the idle travel of the pedal, the pedal detection device 23 detects the angle change of the brake pedal, so that the control oil is input to the third oil port 253, and the first valve core 26 is driven to move toward the first end direction of the first inner cavity. When the first valve core 26 moves to the first end to the first limit position, the first oil port 251 and the second oil port 252 are blocked, and at the same time, the amplification chamber connects the first oil port 251 and the second oil port 252. The first oil port 251 side still maintains the maximum input pressure, while the second oil port 252 side is affected by the amplification of the amplification chamber, and the pressure is reduced. The pressure on the first oil port 251 side is greater than the pressure on the second oil port 252 side. Under the action of the flow limiting device 29, the oil path between the first oil port 251 and the amplification chamber is closed, the oil in the amplification chamber is sealed, and the pressure of the brake actuator is steadily reduced, forming a state that can trigger the brake friction pair to be in oil film friction, and an initial deceleration braking effect is obtained; when the driver applies force to step on the brake When the pedal is moved, if the force is applied and the pedaling speed is fast, the pressure on the first oil port 251 side drops rapidly, making the pressure on the first oil port 251 side less than the pressure on the second oil port 252 side, and the flow limiting device 29 opens, and the high-pressure oil on the second oil port 252 side flows out through the flow limiting device 29, thereby achieving the effect of consistent release of the hydraulic oil of the original brake system; the hydraulically controlled dynamic volume amplification device 24 is used in conjunction with a brake pedal with an angle sensor to achieve a braking force in the oil film friction stage by lightly touching the empty stroke of the pedal, so that the driver can obtain a deceleration braking force by lightly touching the empty stroke of the brake pedal. The braking force can respond quickly and feedback stably without pedal trial, providing the driver with a better control feel, effectively improving the braking control performance, and effectively reducing the wear of the brake friction pad; when the brake volume amplification device takes effect, its reduced braking pressure can be connected with the pressure release by continuing to deeply step on the pedal, thereby 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, refer to Figure 4 The brake pedal generally has an idle travel of 4 to 6° in the initial triggering stage. Generally, when the driver puts his foot on the pedal without exerting force, the pedal angle changes within 6°. When the driver puts his foot on the pedal with the intention of braking, the hydraulically controlled dynamic volume amplifier receives a signal from the brake pedal, that is, the external control pressure triggers the switching of the first valve core 26 of the hydraulically controlled dynamic volume amplifier to increase the volume of the brake cavity. The specific enlarged volume of the cavity is based on the test setting, and the contact control of the amplified friction plate in the oil film friction stage is the design requirement to ensure that a controllable slow braking is provided.

[0056] In this embodiment, the hydraulically controlled dynamic chamber amplification device 24 also includes a reset piston 27, which is sleeved on the first valve core 26 and located in the amplification chamber; the first valve core 26 is used to connect the second end of the amplification chamber to the second oil port 252 when it moves to the first limit position, so that the high-pressure oil acts on the second end of the reset piston 27 to move it toward the first end; the first valve core 26 is also used to connect the first end of the amplification chamber to the second oil port 252 when it moves to the second limit position, so as to keep the reset piston 27 moving toward the second end and against the inner wall of the amplification chamber and block the oil path between the second oil port 252 and the second end of the amplification chamber. Specifically, an oil groove is set at a preset axial position on the inner chamber to connect to the first oil port 251 and the second oil port 252. When the first Before the valve core 26 moves to the first extreme position toward the first end, the side wall of the reset piston 27 blocks the oil groove. When the first valve core 26 moves to the first extreme position toward the first end, the second end position of the amplification chamber matches the oil groove position, and the pressure oil of the second oil port 252 can act on the second end of the reset piston 27 to move it toward the first end, thereby enlarging the braking cavity and reducing the pressure on the side of the second oil port 252 to obtain an initial slow braking effect; wherein, the first valve body 25 is provided with a first oil return 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 extreme position, that is, when the reset piston 27 is driven to move toward the first end, the hydraulic oil between its first end and the first end of the amplification chamber returns through the first oil return channel 254;

[0057] Preferably, the second end of the resurrection piston is provided with a force-bearing structure, which may be a chamfer arranged on the outer edge of the second end of the resurrection piston, so that the pressure oil in the oil groove acts on the resurrection piston to push it to move toward the first end; preferably, a first elastic resetting member 28 is provided between the reset piston 27 and the first end inner wall of the amplification chamber, which is preferably a spring. It can be understood that after the brake is canceled, the first oil port 251 restores the pressure to move the first valve core 26 to the second limit position, and the reset piston 27 is reset under the action of the first elastic resetting 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, so as to increase the effective area with the control oil and ensure the response speed; wherein, a ring groove structure similar to the matching structure is arranged near the second end of the first valve core 26 to form an oil cavity, and a third oil return channel 255325 is arranged on the first valve body 25. When the first valve core 26 moves toward the first end, the oil cavity and the third oil return channel 255325 are kept in communication for oil return; 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 embedded with sealing rings that cooperate with the inner wall of the inner cavity to ensure the sealing between the chambers.

[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 brake is released, 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 brake cooling control system for an engineering vehicle, which is applied with the hydraulically controlled dynamic volume amplifying device 24 of the above-mentioned preferred embodiment.

[0061] In this embodiment, the engineering vehicle brake cooling control system further includes a flow divider 21. Fig.11 and Fig.12 , the diversion device 21 comprises:

[0062] 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. A diverter port 322 connected to the oil inlet 321 and the second inner cavity is provided in the second valve body 32. The number of the diverter ports 322 matches the number of the oil outlets 323, and the distribution positions of the diverter ports 322 match the distribution positions of the oil outlets 323.

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

[0064] Wherein, it is preferred to set the apertures of the first damping channel 331 and the second damping channel 332 to different specifications to achieve the effect of having 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 preferred that the number of the oil outlets 323 is four, the connecting structure is four groups, the number of the diversion ports 322 is also four, and each oil outlet 323 is respectively 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;

[0066] It can be understood that, under normal conditions, each first damping channel 331 is connected to the corresponding diverter port 322 and the oil outlet 323 respectively. The control oil port 324 inputs pressure oil to activate the valve core to switch the first damping channel 331 to the second damping channel 332, so that each second damping channel 332 is connected to the corresponding diverter port 322 and the oil outlet 323, so as to achieve the purpose of changing the flow rate. Preferably, the flow rate of the first damping channel 331 is smaller than the flow rate of the second damping, and low-flow cooling is maintained during low-frequency braking. During high-frequency braking, the first damping channel 331 is switched to the second damping channel 332, and a larger cooling flow enters the brake chamber of the front and rear axles 16 for cooling. At the same time, both gears of damping can achieve equal flow diversion, which effectively guarantees the cooling requirements of high and low braking, reduces the large flow erosion of the brake cooling chamber, and improves the sealing life of the cooling chamber, effectively improving the handling performance and cooling effect of the braking system, and improving the service life of the brake.

[0067] Further, the shunt device 21 also includes a control device 35, and the control device 35 is provided with a temperature detection unit. The temperature detection unit can be specifically a temperature sensor 22. The control device 35 can be a two-position three-way solenoid valve, which is used to input control oil to the control oil port 324 when it is detected that the brake chamber temperature of the axle reaches a preset value or is within a preset range; specifically, when sensing high temperature, the control device 35 switches the oil circuit so that the pressure oil is connected to the control oil port 324 to act on the second valve core 33, automatically switches the high-flow rate shunt damping channel, and provides cooling flow in time at high temperature; at low temperature, it automatically closes and switches back to the first damping channel 331 to reduce the flow and reduce the pressure scouring of the cooling flow on the brake chamber, thereby increasing the service life of the steel sheet sealing film;

[0068] In this embodiment, the second valve body 32 is provided with a second oil return channel respectively connected to each oil outlet 323, and a back-pressure check valve 19 is respectively provided on the second oil return channel corresponding to each oil outlet 323. The back-pressure check valve 19 is separately arranged corresponding to each branch to ensure that each branch does not exceed the pressure limit of the friction plate cooling chamber. The device integrates diversion, switching, and back-pressure protection into one, realizes integrated control, has a simple and compact structure, occupies a small installation space, and is easy to disassemble and assemble.

[0069] In this embodiment, 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, and is preferably a spring. 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 diversion port 322 and the oil outlet 323 are connected by the first damping channel 331.

[0070] The vehicle brake 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 brake control and external circulation strong cooling, which effectively improves the brake control performance, ensures the cooling effect and increases the service life.

[0071] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "front", "rear", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0072] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A hydraulically controlled dynamic volume amplifying device, applied to a braking system, wherein the braking system comprises a braking input device (14) and a braking actuator, wherein the braking input device (14) is used to input pressure into the braking system and drive the braking actuator to operate to generate braking ... The liquid-controlled dynamic volume amplifying device comprises: A pedal detection device (23) is used to output pressure when detecting that the brake pedal has an angle change based on a normal state; A first valve body (25) is used as a structural support, the first valve body (25) having a first inner cavity, a first oil port (251) connected to the first inner cavity and used to communicate with a brake input device (14), a second oil port (252) connected to the first inner cavity and used to communicate with a brake actuator, and a third oil port (253) connected to the first inner cavity and used to communicate with the pedal detection device (23), the first oil port (251) and the second oil port (252) are arranged near a first end of the first inner cavity, and the third oil port (253) is arranged near a second end of the first inner cavity; a first valve core (26) inserted into the first inner cavity and used for blocking 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 a first limit position; a matching structure is provided on the side wall of the first valve core (26), and an amplification cavity is formed between the matching structure and the inner wall of the first inner cavity, and the amplification cavity is used for communicating 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 arranged on the first oil circuit between the first oil port (251) and the amplifying chamber, and is used to open the first oil circuit when the pressure of the first oil port (251) is less than the pressure of the second oil port (252), and is also used to close the first oil circuit when the pressure of the first oil port (251) is greater than the pressure of the second oil port (252).

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

3. The liquid-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 first end inner wall of the amplification chamber.

4. The liquid-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 chamber when the first valve core (26) moves to the first limit position.

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

6. A brake cooling control system for an engineering vehicle, characterized in that: The invention relates to a liquid-controlled dynamic cavity amplifying device according to any one of claims 1 to 5.

7. The engineering vehicle brake cooling control system according to claim 6, characterized in that: The engineering vehicle brake cooling control system further comprises a flow dividing device (21), wherein the flow dividing device (21) comprises: The second valve body (32) comprises a second inner cavity, an oil inlet (321), a control oil port (324) and a plurality of oil outlets (323); a diverter port (322) connected to the oil inlet (321) and the second inner cavity is provided in the second valve body (32); the number of the diverter ports (322) matches the number of the oil outlets (323); and the distribution positions of the diverter ports (322) match the distribution positions of the oil outlets (323); The second valve core (33) is inserted into the second inner cavity. The second valve core (33) is provided with a plurality of connecting structures matching the number of the oil outlets (323). The connecting structures respectively include a first damping channel (331) having a first flow specification and a second damping channel (332) having a second flow 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) in a normal state, 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 brake cooling control system according to claim 7, characterized in that: The second valve body (32) is provided with second oil return passages respectively connected to the oil outlets (323), and the second oil return passages are respectively provided with back pressure check valves (19) at positions corresponding to the oil outlets (323).

9. The engineering vehicle brake cooling control system according to claim 7, characterized in that: A third elastic return 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 brake cooling control system according to any one of claims 7 to 9, wherein the engineering vehicle comprises a front axle (15) and a rear axle (16), characterized in that: The flow dividing device (21) further comprises a control device (35), wherein the control device (35) is provided with a temperature detection unit for inputting control oil into the control oil port (324) when it is detected that the brake chamber temperature of the axle reaches a preset value or is within a preset range.

Images