Hydraulic emergency braking system and engineering machinery comprising same

Abstract

The invention relates to a hydraulic emergency braking system comprising a hydraulic oil tank (1), a hydraulic pump (2), a brake charging valve (3), an energy accumulator (4), a foot brake valve (6) and a brake (10), the hydraulic pump being capable of extracting hydraulic oil from the hydraulic oil tank and charging the energy accumulator via the brake charging valve; when the foot brake valve is stepped down, hydraulic oil in the energy accumulator can be conveyed to the brake through the foot brake valve so as to generate braking force. The hydraulic emergency braking system further comprises an emergency braking valve set, and the emergency braking valve set is configured to enable hydraulic oil in the energy accumulator to be conveyed to the brake through the emergency braking valve set so as to generate braking force when the pressure in the energy accumulator is lower than a preset threshold value. The invention further relates to engineering machinery comprising the hydraulic emergency braking system.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, and more specifically to a hydraulic emergency braking system and an engineering machine including the hydraulic emergency braking system. Background Technology

[0002] With increasing regulations and higher safety requirements from users in various regions, emergency braking systems have been gradually added to construction machinery to protect the lives and property of users in the event of a braking system failure. Currently, most emergency braking systems rely on the forced wear of the parking brake and require manual operation of the emergency brake switch by the driver. However, the driver needs a certain reaction time from noticing the malfunction to operating the emergency brake switch, which increases the risk. Therefore, it is necessary to improve the response speed of emergency braking to reduce this risk.

[0003] The present invention aims to solve at least one of the above-mentioned problems of the prior art, as well as other problems. Summary of the Invention

[0004] According to one aspect of the present invention, a hydraulic emergency braking system is provided, comprising a hydraulic oil tank, a hydraulic pump, a brake filling valve, an accumulator, a foot brake valve, and a brake, wherein:

[0005] The hydraulic pump is capable of drawing hydraulic oil from the hydraulic oil tank and charging the accumulator via the brake charging valve.

[0006] When the foot brake valve is depressed, the hydraulic oil in the accumulator can be delivered to the brake through the foot brake valve to generate braking force.

[0007] in,

[0008] The hydraulic emergency braking system further includes an emergency braking valve assembly configured such that when the pressure in the accumulator is lower than a predetermined threshold, hydraulic oil in the accumulator can be delivered to the brake via the emergency braking valve assembly to generate braking force.

[0009] Advantageously, the emergency braking valve assembly includes a hydraulically controlled switching valve disposed in the emergency braking hydraulic circuit between the accumulator and the brake, wherein:

[0010] When the pressure in the accumulator is equal to or greater than the predetermined threshold, the hydraulic control switch valve is in the closed position that disconnects the emergency braking oil circuit fluid.

[0011] When the pressure in the accumulator is lower than the predetermined threshold, the hydraulic control valve is in the open position, allowing fluid connection to the emergency braking oil circuit.

[0012] Advantageously, the emergency brake valve assembly further includes a relief valve disposed in the emergency brake hydraulic circuit, the inlet of the relief valve being fluidly connected to the accumulator, and the outlet of the relief valve being fluidly connected to the hydraulic control port of the hydraulic control switch valve, wherein:

[0013] When the pressure in the accumulator is lower than the predetermined threshold, the overflow valve is in the closed position;

[0014] When the pressure in the accumulator is equal to or greater than the predetermined threshold, the relief valve is in the open position, and the hydraulic oil from the accumulator reaches the hydraulic control port of the hydraulic control switch valve through the relief valve, causing the hydraulic control switch valve to switch from the open position to the closed position.

[0015] Advantageously, the emergency brake valve assembly further includes a hydraulically controlled directional valve, the hydraulically controlled directional valve including a first port fluidly connected to the outlet of the foot brake valve, a second port fluidly connected to the outlet of the hydraulically controlled switching valve, and a third port fluidly connected to the brake, wherein:

[0016] When the pressure in the accumulator is equal to or greater than the predetermined threshold, the hydraulic control directional valve is in the first position, in which the first oil port and the third oil port are in fluid communication, and the second oil port is closed.

[0017] When the pressure in the accumulator is lower than the predetermined threshold, the hydraulic control directional valve is in the second position, in which the second port and the third port are in fluid communication, and the first port is closed.

[0018] Advantageously, the accumulator includes a first accumulator and a second accumulator, the foot brake valve includes a first brake valve and a second brake valve mechanically connected to each other, and the brake includes a first brake and a second brake, wherein:

[0019] The first accumulator is fluidly connected to the first brake via the first brake valve;

[0020] The second accumulator is fluidly connected to the second brake via the second brake valve;

[0021] The emergency braking valve assembly also includes a shuttle valve, the first inlet of which is fluidly connected to the first accumulator, the second inlet of which is fluidly connected to the second accumulator, and the outlet of which is fluidly connected to the inlet of the hydraulic control switch valve and the inlet of the overflow valve.

[0022] Advantageously, the first port of the hydraulic directional valve is fluidly connected to the outlet of the first brake valve or the second brake valve.

[0023] Advantageously, the P port of the brake filling valve is fluidly connected to the oil outlet of the hydraulic pump, and the A1 and A2 ports of the brake filling valve are fluidly connected to the first accumulator and the second accumulator, respectively.

[0024] Advantageously, the shuttle valve, overflow valve, hydraulic control switch valve, and hydraulic control directional valve are integrated into a single valve block.

[0025] According to another aspect of the invention, an engineering machine is proposed, which includes a hydraulic emergency braking system according to the invention.

[0026] Advantageously, the construction machinery is wheeled construction machinery.

[0027] The hydraulic emergency braking system according to the present invention is an automatic emergency braking system based on the service brake, designed by adding simple hydraulic components (i.e., emergency brake valve assembly) to a conventional hydraulic service brake system. It can actively identify sudden failures of the hydraulic service brake system without requiring driver intervention. After a failure in the service brake system, it immediately applies emergency braking using residual energy, protecting the lives and property of the driver, surrounding personnel, and facilities. The response time for emergency braking using this hydraulic emergency braking system is significantly shorter than the driver's reaction time after receiving an alarm signal, significantly improving the safety of construction machinery. Attached Figure Description

[0028] Preferred embodiments of the invention will now be described in more detail with reference to the illustrative accompanying drawings. The drawings and corresponding embodiments are for illustrative purposes only and are not intended to limit the invention. In the drawings:

[0029] Figure 1 A schematic diagram of the hydraulic emergency braking system according to a preferred embodiment of the present invention is shown.

[0030] List of reference numerals in the attached diagram:

[0031] 1. Hydraulic oil tank 2. Hydraulic pump

[0032] 3 Brake fluid filling valve 4 Accumulator

[0033] 5. Shuttle valve 6. Foot brake valve

[0034] 7. Relief valve 8. Hydraulic control switch valve

[0035] 9 Hydraulic directional valve 10 Brake

[0036] 11 First brake 12 Second brake

[0037] 31 Overflow valve 41 First accumulator

[0038] 42 Second accumulator 61 First brake valve

[0039] 62 Second brake valve 71 Spring

[0040] 72 Solenoid valve 100 Hydraulic emergency braking system Detailed Implementation

[0041] Embodiments of the present invention are described below with reference to the accompanying drawings. In the following description, numerous specific details are set forth to enable those skilled in the art to more fully understand and implement the invention. However, it will be apparent to those skilled in the art that implementations of the invention may not include some of these specific details. Furthermore, it should be understood that the invention is not limited to the specific embodiments described. Rather, the invention can be conceived to be practiced with any combination of the features and elements described below, regardless of whether they relate to different embodiments. Therefore, the aspects, features, embodiments, and advantages described below are for illustrative purposes only and should not be construed as elements or limitations of the claims unless expressly set forth in the claims.

[0042] Figure 1 The diagram schematically illustrates the hydraulic principle of a hydraulic emergency braking system 100 for construction machinery according to a preferred embodiment of the present invention. This hydraulic emergency braking system 100 is particularly suitable for wheeled construction machinery. However, it should be understood that the same inventive principles can be applied to other construction machinery or other types of machinery with similar operating conditions.

[0043] like Figure 1 As shown, the hydraulic emergency braking system 100 includes a hydraulic oil tank 1, a hydraulic pump 2, a brake filling valve 3, an accumulator 4, a foot brake valve 6, and a brake 10. The hydraulic pump 2 can draw hydraulic oil from the hydraulic oil tank 1 and fill the accumulator 4 via the brake filling valve 3.

[0044] exist Figure 1 In the embodiment shown, the accumulator 4 includes a first accumulator 41 and a second accumulator 42, the foot brake valve 6 includes a first brake valve 61 and a second brake valve 62 that are mechanically connected to each other, and the brake 10 includes a first brake 11 and a second brake 12. The first accumulator 41 is fluidly connected to the first brake 11 via the first brake valve 61, and the second accumulator 42 is fluidly connected to the second brake 12 via the second brake valve 62.

[0045] The first brake 11 is, for example, the front brake of an engineering machine, and the second brake 12 is, for example, the rear brake of an engineering machine.

[0046] It should be understood that a single brake or multiple brakes can be installed as needed. Accordingly, one or more accumulators and brake valves can be installed corresponding to the number of brakes.

[0047] like Figure 1As shown, the oil inlet of the hydraulic pump 2 is fluidly connected to the hydraulic oil tank 1, the oil outlet of the hydraulic pump 2 is fluidly connected to the P port of the brake filling valve 3, and the A1 and A2 ports of the brake filling valve 3 are fluidly connected to the first accumulator 41 and the second accumulator 42, respectively.

[0048] The brake filling valve 3 allows for priority filling of the accumulator with lower pressure. The relief valve 31 of the brake filling valve 3 limits the maximum filling pressure of the accumulator. Once the maximum filling pressure is reached, hydraulic oil from the hydraulic pump 2 returns to the hydraulic oil tank 1 via the relief valve 31. When the pressure in the accumulator drops to a predetermined filling pressure, the hydraulic pump 2 refills the accumulator.

[0049] When braking is required, the driver depresses the foot brake valve 6, so that the hydraulic oil in the first accumulator 41 can be delivered to the first brake 11 through the first brake valve 61 to generate braking force, and the hydraulic oil in the second accumulator 42 can be delivered to the second brake 12 through the second brake valve 62 to generate braking force.

[0050] According to the present invention, the hydraulic emergency braking system 100 further includes an emergency braking valve assembly configured such that when the pressure in the accumulator is lower than a predetermined threshold, hydraulic oil in the accumulator can be delivered to the brake via the emergency braking valve assembly to generate braking force.

[0051] exist Figure 1 In the embodiment shown, the emergency braking valve assembly includes a shuttle valve 5, an overflow valve 7, a hydraulic control switch valve 8, and a hydraulic control directional valve 9 disposed in the emergency braking oil circuit between the accumulator 4 and the brake 10.

[0052] The first inlet of shuttle valve 5 is fluidly connected to the first accumulator 41, the second inlet of shuttle valve 5 is fluidly connected to the second accumulator 42, and the outlet of shuttle valve 5 is fluidly connected to the inlet of hydraulic control valve 8 and the inlet of relief valve 7. Shuttle valve 5 is used to deliver hydraulic oil from the higher-pressure of the first accumulator 41 and the second accumulator 42 to the inlet of relief valve 7 and the inlet of hydraulic control valve 8.

[0053] The hydraulic control valve 8 is used to selectively connect and disconnect the emergency braking hydraulic circuit. Figure 1 In the illustrated embodiment, the hydraulic control valve 8 is designed as a two-position two-way valve, having an open position where its inlet and outlet are in fluid communication, and a closed position where its inlet and outlet are disconnected from each other. A spring is provided at one end of the valve core of the hydraulic control valve 8, biasing the valve core towards the open position. A hydraulic control port is provided at the other end of the valve core of the hydraulic control valve 8, which is in fluid connection to the outlet of the relief valve 7.

[0054] The relief valve 7 has an open position where its inlet and outlet are in fluid communication, and a closed position where its inlet and outlet are disconnected from fluid flow. At the first end of the valve core of the relief valve 7 ( Figure 1 A spring 71 is provided at the lower end (as shown in the diagram), and the spring 71 biases the valve core of the relief valve 7 toward the closed position. At the second end of the valve core of the relief valve 7 (… Figure 1 A hydraulic control port is provided at the upper end (as shown in the figure) for fluid connection with the oil inlet of the relief valve 7.

[0055] When the pressure at the inlet of the relief valve 7 is less than a predetermined threshold, the relief valve 7 is in the closed position, where fluid flow between its inlet and outlet is disconnected, under the action of the spring 71. When the pressure at the inlet of the relief valve 7 is equal to or greater than the predetermined threshold, the relief valve 7 switches to the open position, where fluid flow between its inlet and outlet is connected. At this time, hydraulic oil from the shuttle valve 5 can reach the hydraulic control port of the hydraulic control valve 8 via the relief valve 7, causing the hydraulic control valve 8 to switch from the open position to the closed position.

[0056] Advantageously, spring 71 is an adjustable spring, and its preload is adjustable. For example, the preload of spring 71 can be adjusted by means of a spring adjusting screw. This allows the pressure threshold that causes the relief valve 7 to switch from the closed position to the open position to be set according to actual needs.

[0057] Advantageously, a solenoid valve 72 is provided at the first end of the valve core of the relief valve 7. When the solenoid valve 72 is energized, the electromagnetic force it generates and the spring force of the spring 71 act simultaneously on the valve core of the relief valve 7. By applying different currents to the solenoid valve 72, the pressure threshold that causes the relief valve 7 to switch positions can be adjusted more conveniently.

[0058] Advantageously, the solenoid valve 72 can be associated with the emergency brake switch of the construction machinery. For example, in one embodiment, both the solenoid valve 72 and the emergency brake switch are signal-connected to a controller. When the driver presses the emergency brake switch, the controller applies current to the solenoid valve 72, causing the relief valve 7 to close, thereby triggering the emergency brake of the construction machinery. The controller can be the overall controller of the construction machinery. In one embodiment, the controller is, for example, the electronic control module (ECM) of the construction machinery. Advantageously, the emergency brake switch can be located in the driver's cab.

[0059] The hydraulic directional valve 9 is designed as a two-position three-way valve, comprising a first port fluidly connected to the outlet A2 of the second brake valve 62, a second port fluidly connected to the outlet of the hydraulic switch valve 8, and a third port fluidly connected to the second brake 12. The hydraulic directional valve 9 has two operating positions, in the first position ( Figure 1 (As shown in the upper position), the first oil port and the third oil port are in fluid communication, and the second oil port is closed; in the second position ( Figure 1(As shown in the lower part), the second oil port and the third oil port are in fluid communication, while the first oil port is closed.

[0060] The first end of the valve core of the hydraulic directional valve 9 is provided with a spring for biasing the valve core toward the first position. The hydraulic control port at the first end of the valve core of the hydraulic directional valve 9 is fluidly connected to the first oil port of the hydraulic directional valve 9. The hydraulic control port at the second end of the valve core of the hydraulic directional valve 9 is fluidly connected to the second oil port of the hydraulic directional valve 9.

[0061] When the hydraulic directional valve 9 is in the first position, hydraulic oil from the second brake valve 62 can be delivered to the second brake 12 via the hydraulic directional valve 9 to generate braking force.

[0062] When the hydraulic directional valve 9 is in the second position, hydraulic oil from the hydraulic switch valve 8 can be delivered to the second brake 12 via the hydraulic directional valve 9 to generate braking force.

[0063] It should be understood that the first port of the hydraulic directional valve 9 can also be fluidly connected to the outlet A1 of the first brake valve 61. Furthermore, in another embodiment (not shown), two hydraulic directional valves can be provided, respectively located between the first brake valve 61 and the first brake 11, and between the second brake valve 62 and the second brake 12.

[0064] According to the present invention, the pressure at which the overflow valve 7 is switched from the closed position to the open position (i.e., the predetermined threshold mentioned above) is set as the emergency braking trigger pressure.

[0065] Under normal circumstances, the braking system pressure of the construction machinery is greater than the emergency braking trigger pressure. At this time, the relief valve 7 is in the open position, and the hydraulic oil from the shuttle valve 5 reaches the hydraulic control port of the hydraulic control valve 8 via the relief valve 7, causing the hydraulic control valve 8 to switch from the open position to the closed position. The hydraulic directional valve 9 is in its first position under the action of a spring at the first end of its valve core. Figure 1 (as shown in the upper position). Therefore, the emergency brake valve assembly is not functioning at this time. When the driver depresses the foot brake valve 6, the hydraulic oil in the first accumulator 41 is delivered to the first brake 11 via the first brake valve 61 to generate braking force, and the hydraulic oil in the second accumulator 42 is delivered to the second brake 12 via the second brake valve 62 to generate braking force.

[0066] When a sudden malfunction occurs in a braking system component (such as accumulator leakage), causing the pressure in the accumulator to fall below the emergency braking trigger pressure, the relief valve 7 switches to the closed position, and the hydraulic control valve 8 switches to the open position under the action of a spring at one end of its valve core. Hydraulic oil from the higher-pressure accumulator (first accumulator 41 or second accumulator 42) is then transported via the shuttle valve 5 and the hydraulic control valve 8 to the second port of the hydraulic control directional valve 9, causing the hydraulic control directional valve 9 to switch to the second position. Figure 1 (As shown in the lower position). Therefore, hydraulic oil can be delivered to the second brake 12 via the hydraulically controlled directional valve 9, thereby generating braking force and automatically braking the construction machinery.

[0067] Advantageously, the hydraulic emergency braking system 100 also includes a pressure sensor for measuring the pressure in the accumulator 4. This pressure sensor is signal-connected to the controller and sends the measured pressure signal to the controller. When the pressure in the accumulator 4 is lower than the emergency braking trigger pressure, the controller can issue an alarm signal to remind the driver that the braking system has malfunctioned and that emergency braking should be performed.

[0068] Advantageously, the shuttle valve 5, relief valve 7, hydraulic control switch valve 8, and hydraulic control directional valve 9 can be integrated into a single valve block. This allows for easy integration of the emergency braking valve assembly into existing braking systems.

[0069] It should be understood that the emergency brake valve assembly can have other suitable structures, as long as they can achieve the functions described above. For example, the switching of the hydraulic control valve 8 between the open and closed positions can be achieved by means of a structure different from that of the relief valve 7. In addition, the hydraulic control directional valve 9 can also be designed as a two-position two-way valve arranged between the hydraulic control valve 8 and the second brake 12, which is not fluidly connected to the foot brake valve 6.

[0070] Industrial applicability

[0071] The working principle of the hydraulic emergency braking system 100 according to the present invention will be explained in detail below.

[0072] During the operation of the construction machinery, the hydraulic pump 2 draws hydraulic oil from the hydraulic oil tank 1 and fills the first accumulator 41 and the second accumulator 42 with liquid through the brake filling valve 3.

[0073] Under normal circumstances, the braking system pressure of the construction machinery is greater than the emergency braking trigger pressure. At this time, the relief valve 7 is in the open position, and the hydraulic oil from the shuttle valve 5 reaches the hydraulic control port of the hydraulic control valve 8 via the relief valve 7, causing the hydraulic control valve 8 to switch from the open position to the closed position. The hydraulic directional valve 9 is in its first position under the action of a spring at the first end of its valve core. Figure 1(As shown in the upper position). Therefore, the emergency brake valve assembly is not in operation at this time. When braking is required, the driver depresses the foot brake valve 6, and the hydraulic oil in the first accumulator 41 and the second accumulator 42 is delivered to the first brake 11 and the second brake 12 respectively via the foot brake valve 6 to generate braking force. When the driver wants to brake in an emergency, he can press the emergency brake switch, which applies a large current to the solenoid valve 72 through the controller, causing the overflow valve 7 to close, thereby triggering the emergency braking of the construction machinery.

[0074] When a sudden malfunction occurs in a braking system component (such as accumulator leakage), causing the pressure in the accumulator to fall below the emergency braking trigger pressure, the relief valve 7 switches to the closed position, and the hydraulic control valve 8 switches to the open position under the action of a spring at one end of its valve core. Hydraulic oil from the higher-pressure accumulator (first accumulator 41 or second accumulator 42) is then transported via the shuttle valve 5 and the hydraulic control valve 8 to the second port of the hydraulic control directional valve 9, causing the hydraulic control directional valve 9 to switch to the second position. Figure 1 As shown in the lower position, hydraulic oil is delivered to the second brake 12 via the hydraulically controlled directional valve 9, thereby generating braking force and automatically braking the construction machinery. In this process, the response time of emergency braking achieved by the hydraulic emergency braking system 100 is much shorter than the driver's reaction time after discovering the alarm signal, significantly improving the safety of the construction machinery.

[0075] The hydraulic emergency braking system 100 according to the present invention is an automatic emergency braking system based on the service brake, designed by adding simple hydraulic components (i.e., emergency brake valve assembly) to a conventional hydraulic service brake system. It can actively identify sudden failures of the hydraulic service brake system without requiring personal reaction from the driver. After the service brake system fails, it uses residual energy to immediately implement emergency braking, protecting the life and property safety of the driver and surrounding personnel and facilities.

[0076] The hydraulic emergency braking system of the present invention has been described above with reference to specific embodiments. It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments without departing from the scope or spirit of the invention. For example, implementations of the invention may not include some of the features described, and the invention is not limited to the described specific embodiments, but any combination of the described features and elements is contemplated. Other embodiments will become apparent to those skilled in the art in consideration of the specification and practice with the disclosed hydraulic emergency braking system. The specification and examples are to be considered exemplary only, and the true scope is indicated by the appended claims and their equivalents.

Claims

1. A hydraulic emergency braking system, comprising a hydraulic tank (1), a hydraulic pump (2), a brake filling valve (3), an accumulator (4), a foot brake valve (6), and a brake (10), wherein: The hydraulic pump is capable of drawing hydraulic oil from the hydraulic oil tank and charging the accumulator via the brake charging valve. When the foot brake valve is depressed, the hydraulic oil in the accumulator can be delivered to the brake through the foot brake valve to generate braking force. Its features are, The hydraulic emergency braking system further includes an emergency braking valve assembly configured such that when the pressure in the accumulator is lower than a predetermined threshold, hydraulic oil in the accumulator can be delivered to the brake via the emergency braking valve assembly to generate braking force.

2. The hydraulic emergency braking system according to claim 1, wherein, The emergency braking valve assembly includes a hydraulically controlled switching valve (8) disposed in the emergency braking oil circuit between the accumulator and the brake, wherein: When the pressure in the accumulator is equal to or greater than the predetermined threshold, the hydraulic control switch valve is in the closed position that disconnects the emergency braking oil circuit fluid. When the pressure in the accumulator is lower than the predetermined threshold, the hydraulic control valve is in the open position, allowing fluid connection to the emergency braking oil circuit.

3. The hydraulic emergency braking system according to claim 2, wherein, The emergency braking valve assembly also includes a relief valve (7) disposed in the emergency braking oil circuit. The inlet of the relief valve is fluidly connected to the accumulator, and the outlet of the relief valve is fluidly connected to the hydraulic control port of the hydraulic control switch valve, wherein: When the pressure in the accumulator is lower than the predetermined threshold, the overflow valve is in the closed position; When the pressure in the accumulator is equal to or greater than the predetermined threshold, the relief valve is in the open position, and the hydraulic oil from the accumulator reaches the hydraulic control port of the hydraulic control switch valve through the relief valve, causing the hydraulic control switch valve to switch from the open position to the closed position.

4. The hydraulic emergency braking system according to claim 3, wherein, The emergency brake valve assembly further includes a hydraulically controlled directional valve (9), which includes a first port fluidly connected to the outlet of the foot brake valve, a second port fluidly connected to the outlet of the hydraulically controlled switch valve, and a third port fluidly connected to the brake, wherein: When the pressure in the accumulator is equal to or greater than the predetermined threshold, the hydraulic control directional valve is in the first position, in which the first oil port and the third oil port are in fluid communication, and the second oil port is closed. When the pressure in the accumulator is lower than the predetermined threshold, the hydraulic control directional valve is in the second position, in which the second port and the third port are in fluid communication, and the first port is closed.

5. The hydraulic emergency braking system according to claim 4, wherein, The accumulator includes a first accumulator and a second accumulator; the foot brake valve includes a first brake valve and a second brake valve mechanically connected to each other; the brake includes a first brake and a second brake, wherein: The first accumulator is fluidly connected to the first brake via the first brake valve; The second accumulator is fluidly connected to the second brake via the second brake valve; The emergency braking valve assembly also includes a shuttle valve (5), the first oil inlet of the shuttle valve is fluidly connected to the first accumulator, the second oil inlet of the shuttle valve is fluidly connected to the second accumulator, and the oil outlet of the shuttle valve is fluidly connected to the oil inlet of the hydraulic control switch valve and the oil inlet of the overflow valve.

6. The hydraulic emergency braking system according to claim 5, wherein, The first port of the hydraulic directional valve is fluidly connected to the outlet of either the first or second brake valve.

7. The hydraulic emergency braking system according to claim 3, wherein, A spring is provided at the first end of the valve core of the relief valve, and a hydraulic control port fluidly connected to the oil inlet of the relief valve is provided at the second end of the valve core of the relief valve. The spring biases the valve core of the relief valve toward the closed position of the relief valve, wherein the preload of the spring is adjustable.

8. The hydraulic emergency braking system according to claim 7, wherein, A solenoid valve is provided at the first end of the valve core of the overflow valve. When the solenoid valve is energized, it can generate an electromagnetic force acting on the valve core of the overflow valve.

9. The hydraulic emergency braking system according to claim 5 or 6, wherein, The P port of the brake filling valve is fluidly connected to the oil outlet of the hydraulic pump, and the A1 and A2 ports of the brake filling valve are fluidly connected to the first accumulator and the second accumulator, respectively.

10. The hydraulic emergency braking system according to claim 5 or 6, wherein, The shuttle valve, overflow valve, hydraulic control switch valve, and hydraulic control directional valve are integrated into a single valve block.

11. An engineering machine, comprising a hydraulic emergency braking system according to any one of claims 1 to 10.

12. The engineering machinery according to claim 11, wherein, The construction machinery in question is wheeled construction machinery.

Images