Walking hydraulic system and engineering vehicle thereof

Abstract

The invention provides a walking hydraulic system and an engineering vehicle thereof, and belongs to the technical field of engineering machinery. A pressure control valve of the walking hydraulic system is switched between a first opening state and a second opening state according to the braking stroke of a vehicle, in the first opening state, pressure oil in the first energy accumulator passes through the pressure control valve and then outputs high-pressure control oil to flow into a control cavity of the hydraulic control reversing valve, and in the second opening state, the pressure oil in the second energy accumulator passes through the pressure control valve and then outputs high-pressure control oil to flow into a control cavity of the hydraulic control reversing valve. After pressure oil in the first energy accumulator passes through the pressure control valve, low-pressure control oil is output and flows into a control cavity of the hydraulic control reversing valve; the hydraulic control reversing valve is used for being in a partial opening state under pushing of low-pressure control oil and being in an opening state under pushing of high-pressure control oil so as to adjust the flow of hydraulic oil of the hydraulic walking assembly flowing to the first energy accumulator through the hydraulic control reversing valve, and therefore energy recovery can adapt to and be matched with the braking stroke of a vehicle. The energy recovery effect is good and the braking performance of the vehicle is not influenced.

Description

Technical Field

[0001] The present application relates to the technical field of engineering machinery, and in particular to a walking hydraulic system and an engineering vehicle thereof. Background Art

[0002] Since excavators, loaders and other vehicles frequently slow down and brake when working and consume a lot of energy during the work process, by recovering and reusing the braking energy, exhaust emissions and fuel consumption can be reduced, achieving the goal of energy conservation and emission reduction.

[0003] In the related technology, an energy recovery system for engineering machinery is provided, wherein the engineering machinery includes a hydraulic pump and a hydraulic motor, the hydraulic pump is used to drive the hydraulic motor, the hydraulic pump and the hydraulic motor form a closed loop and together constitute a part of a closed system, and the energy recovery system includes an accumulator, wherein when the engineering machinery brakes, the energy recovery system can store part of the hydraulic fluid on the high-pressure side of the closed system in the accumulator to realize the recovery of braking energy.

[0004] However, in some application scenarios, when the above method is used to recover braking energy, the recovery effect is poor and will affect the braking effect of the vehicle. Summary of the invention

[0005] The present application provides a walking hydraulic system and an engineering vehicle thereof, which are used to solve the problem that the braking energy recovery method in the related art has poor recovery effect and affects the braking effect of the vehicle.

[0006] On the one hand, the present application provides a travel hydraulic system, including a hydraulic travel component, an energy storage component and a control device; the energy storage component includes at least one first accumulator, and the control device includes a pressure control valve and a hydraulically controlled reversing valve; the first accumulator is connected to the hydraulic travel component through the hydraulically controlled reversing valve, the pressure control valve is connected to the first accumulator, and the hydraulically controlled reversing valve is connected to the pressure control valve; the pressure control valve is used to switch between a first opening state and a second opening state according to the braking stroke of the vehicle, wherein, in the first opening state, the pressure oil stored in the first accumulator outputs low-pressure control oil through the pressure control valve to flow into the control chamber of the hydraulically controlled reversing valve, and in the second opening state, the pressure oil stored in the first accumulator outputs high-pressure control oil through the pressure control valve to flow into the control chamber of the hydraulically controlled reversing valve; the hydraulically controlled reversing valve is used to be in a partially open state under the push of the low-pressure control oil, and to be in a fully open state under the push of the high-pressure control oil, so as to adjust the flow rate of the hydraulic oil of the hydraulic travel component to the first accumulator through the hydraulically controlled reversing valve.

[0007] In one possible implementation, the walking hydraulic system provided by the present application, the energy storage component also includes at least one second accumulator, the control device also includes a control component and an electromagnetic reversing valve, the control component is communicated with the engine of the hydraulic walking component, the control component is used to detect the engine speed, and the second accumulator is connected to the hydraulic walking component through the electromagnetic reversing valve; the control component is configured to control the electromagnetic reversing valve to open when the engine changes from a first speed to a second speed, so as to connect the hydraulic walking component and the second accumulator, so that the hydraulic oil of the hydraulic walking component flows to the second accumulator via the electromagnetic reversing valve; wherein the first speed is greater than the second speed.

[0008] In one possible implementation, the travel hydraulic system provided by the present application also includes a brake member, which is connected to the outlet of the pressure control valve, and the outlet of at least one of the first accumulator and the second accumulator is connected to the inlet of the pressure control valve; the pressure control valve is also used to, in a first opening state, allow the pressure oil in the first accumulator and / or the pressure oil in the second accumulator to output low-pressure control oil through the pressure control valve to flow into the brake member; in a second opening state, allow the pressure oil in the first accumulator and / or the pressure oil in the second accumulator to output high-pressure control oil through the pressure control valve to flow into the brake member; the brake member is used to apply a first braking force to the brake disc of the hydraulic travel component under the push of the high-pressure control oil, and to apply a second braking force to the brake disc of the hydraulic travel component under the push of the low-pressure control oil; wherein the first braking force is greater than the second braking force.

[0009] In one possible implementation, the walking hydraulic system provided by the present application, the control device also includes an electric proportional reversing valve and a selection valve, the electric proportional reversing valve is electrically connected to the control component; the outlets of the first accumulator and the second accumulator are both connected to the inlet of the electric proportional reversing valve, and the outlet of the electric proportional reversing valve is connected to the high-pressure side of the hydraulic walking component through the selection valve, and the control component is configured to, when the engine changes from the third speed to the fourth speed, control the electric proportional reversing valve to open to connect the first accumulator and the high-pressure side of the hydraulic walking component, so that the hydraulic oil of the first accumulator flows to the high-pressure side of the hydraulic walking component via the electric proportional reversing valve, and connect the second accumulator and the high-pressure side of the hydraulic walking component, so that the hydraulic oil of the second accumulator flows to the high-pressure side of the hydraulic walking component via the electric proportional reversing valve; wherein, the third speed is less than the fourth speed.

[0010] In one possible implementation, the walking hydraulic system provided in the present application, the control component is also configured to, when it is detected that the difference between the fourth speed and the third speed is greater than a preset value, send a first instruction to the electric proportional reversing valve to increase the valve core opening of the electric proportional reversing valve; and, when it is detected that the difference between the fourth speed and the third speed is less than or equal to the preset value, send a second instruction to the electric proportional reversing valve to decrease the valve core opening of the electric proportional reversing valve.

[0011] In one possible implementation, the travel hydraulic system provided by the present application, the selection valve includes a first sub-outlet, a second sub-outlet and an inlet, the inlet is connected to the outlet of the electric proportional reversing valve, the first sub-outlet is connected to the first side of the hydraulic travel component, and the second sub-outlet is connected to the second side of the hydraulic travel component; the selection valve is configured to connect the inlet and the first sub-outlet when the pressure on the first side is greater than the pressure on the second side; or, to connect the inlet and the second sub-outlet when the pressure on the second side is greater than the pressure on the first side.

[0012] In a possible implementation, the walking hydraulic system provided in the present application also includes a first one-way valve and a second one-way valve, the first one-way valve is located between the hydraulically controlled reversing valve and the first accumulator, and the outlet of the hydraulically controlled reversing valve is connected to the inlet of the first accumulator through the first one-way valve; the second one-way valve is located between the electromagnetic reversing valve and the second accumulator, and the outlet of the electromagnetic reversing valve is connected to the inlet of the second accumulator through the second one-way valve.

[0013] In a possible implementation, the walking hydraulic system provided in the present application further includes a third one-way valve and a fourth one-way valve, and the outlet of the first accumulator and the outlet of the second accumulator are both connected to the inlet of the pressure control valve; the outlet of the first accumulator is connected to the inlet of the pressure control valve through the third one-way valve, and the outlet of the second accumulator is connected to the inlet of the pressure control valve through the fourth one-way valve.

[0014] In one possible implementation, the walking hydraulic system provided by the present application also includes a pressure cut-off valve assembly, the pressure cut-off valve assembly includes a first pressure cut-off valve and a second pressure cut-off valve; the first pressure cut-off valve is located between the first one-way valve and the first accumulator, the outlet of the first one-way valve is connected to the inlet of the first pressure cut-off valve, and the outlet of the first pressure cut-off valve is connected to the inlet of the first accumulator; the second pressure cut-off valve is located between the second one-way valve and the second accumulator, the outlet of the second one-way valve is connected to the inlet of the second pressure cut-off valve, and the outlet of the second pressure cut-off valve is connected to the inlet of the second accumulator.

[0015] On the other hand, the present application provides an engineering vehicle, comprising a vehicle body and a travel hydraulic system such as any one of the above-mentioned ones arranged on the vehicle body.

[0016] The application provides a travel hydraulic system and an engineering vehicle thereof. The travel hydraulic system is provided with a hydraulically controlled reversing valve and at least one first accumulator. The first accumulator is connected to the hydraulic travel component through the hydraulically controlled reversing valve to establish an energy recovery path during vehicle braking; a pressure control valve is provided to connect the pressure control valve to the first accumulator, and the hydraulically controlled reversing valve to the pressure control valve. In this way, the pressure control valve switches between a first opening state and a second opening state according to the braking stroke of the vehicle, so as to provide different reversing control pressures for the hydraulically controlled reversing valve through the pressure oil in the first accumulator, thereby realizing proportional adjustment of the valve core position of the hydraulically controlled reversing valve.

[0017] Among them, in the first opening state, corresponding to the slow and light braking stroke of the vehicle, the pressure oil stored in the first accumulator outputs low-pressure control oil through the pressure control valve to flow into the control chamber of the hydraulic control reversing valve, so that the hydraulic control reversing valve is in a partially open state under the push of the low-pressure control oil, thereby avoiding the first accumulator recovering a large flow of hydraulic oil from the hydraulic travel component through the hydraulic control reversing valve, resulting in a reduction in the effective flow of the hydraulic travel component, causing emergency braking of the vehicle; in the second opening state, corresponding to the emergency braking stroke of the vehicle, the pressure oil stored in the first accumulator outputs high-pressure control oil through the pressure control valve to flow into the control chamber of the hydraulic control reversing valve, so that the hydraulic control reversing valve is in a fully open state under the push of the high-pressure control oil, thereby avoiding the first accumulator recovering a small amount of hydraulic oil from the hydraulic travel component through the hydraulic control reversing valve, resulting in energy waste; in the walking hydraulic system provided by the present application, the energy recovery of the hydraulic travel component by the first accumulator through the hydraulic control reversing valve can adapt to the braking stroke of the matching vehicle, and the energy recovery effect is good and while recovering energy, it will not affect the braking effect of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0019] Figure 1 The structure of the walking hydraulic system provided in the embodiment of the present application is shown in FIG. Figure 1 ;

[0020] Figure 2 The structure of the walking hydraulic system provided in the embodiment of the present application is shown in FIG. Figure 2 ;

[0021] Figure 3 The structure of the walking hydraulic system provided in the embodiment of the present application is shown in FIG. Figure 3 ;

[0022] Figure 4 The structure of the walking hydraulic system provided in the embodiment of the present application is shown in FIG. Figure 4 .

[0023] Description of reference numerals:

[0024] 100-Energy storage component;

[0025] 110 - a first accumulator; 120 - a second accumulator;

[0026] 200-control device;

[0027] 210-pressure control valve; 220-hydraulic control reversing valve; 230-control part; 240-electromagnetic reversing valve; 250-electric proportional reversing valve; 260-selection valve; 270-hydraulic oil tank;

[0028] 300-brake parts;

[0029] 400-first one-way valve; 500-second one-way valve; 600-third one-way valve; 700-fourth one-way valve;

[0030] 800-pressure cut-off valve assembly;

[0031] 810-first pressure cut-off valve; 820-second pressure cut-off valve;

[0032] 900-Hydraulic travel assembly;

[0033] 910-hydraulic motor; 920-hydraulic pump; 930-engine; 940-shuttle valve. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme in the embodiment of the present application will be described in more detail below in conjunction with the drawings in the preferred embodiments of the present application. In the drawings, the same or similar reference numerals throughout represent the same or similar parts or parts with the same or similar functions. The described embodiments are part of the embodiments of the present application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application. The embodiments of the present application are described in detail below in conjunction with the drawings.

[0035] In the description of this application, 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, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0036] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application 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 should not be understood as a limitation on the present application.

[0037] The terms "first", "second", "third", "fourth", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein.

[0038] In addition, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus that includes a series of steps or elements is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such process, method, product, or apparatus.

[0039] As mentioned in the background technology, in the related technology, an energy recovery system for construction machinery is provided, wherein the construction machinery includes a hydraulic pump and a hydraulic motor, the hydraulic pump is used to drive the hydraulic motor, the hydraulic pump and the hydraulic motor form a closed loop and together constitute a part of a closed system, and the energy recovery system includes an accumulator, wherein, when the construction machinery brakes, the energy recovery system can store part of the hydraulic fluid on the high-pressure side of the closed system in the accumulator to realize the recovery of braking energy.

[0040] However, in some application scenarios, for example, when the vehicle is performing slow and light braking, if the flow rate of the hydraulic fluid on the high-pressure side of the closed system stored in the accumulator is large, the effective flow rate of the closed system will suddenly decrease, resulting in an emergency braking situation; when the vehicle is performing emergency braking, if the flow rate of the hydraulic fluid on the high-pressure side of the closed system stored in the accumulator is small, a large amount of hydraulic fluid in the closed system will be lost through overflow, and a large amount of high-pressure hydraulic energy will be lost; and the braking system loses a large amount of vehicle kinetic energy through friction of the brake pads, and also causes excessive wear to the brake pads, resulting in a huge waste of energy. Therefore, when the above method is used to recover braking energy, the recovery effect is poor and will affect the braking effect of the vehicle.

[0041] In view of this, the present application provides a walking hydraulic system and an engineering vehicle thereof. The walking hydraulic system is provided with a hydraulically controlled reversing valve and at least one first accumulator. The first accumulator is connected to the hydraulic walking component through the hydraulically controlled reversing valve to establish an energy recovery path during vehicle braking; a pressure control valve is provided to connect the pressure control valve to the first accumulator, and the hydraulically controlled reversing valve to the pressure control valve. In this way, the pressure control valve switches between a first opening state and a second opening state according to the braking stroke of the vehicle, so as to provide different reversing control pressures for the hydraulically controlled reversing valve through the pressure oil in the first accumulator, thereby realizing proportional adjustment of the valve core position of the hydraulically controlled reversing valve.

[0042] Among them, in the first opening state, corresponding to the slow and light braking stroke of the vehicle, the pressure oil stored in the first accumulator outputs low-pressure control oil through the pressure control valve to flow into the control chamber of the hydraulic control reversing valve, so that the hydraulic control reversing valve is in a partially open state under the push of the low-pressure control oil, thereby avoiding the first accumulator recovering a large flow of hydraulic oil from the hydraulic travel component through the hydraulic control reversing valve, resulting in a reduction in the effective flow of the hydraulic travel component, causing emergency braking of the vehicle; in the second opening state, corresponding to the emergency braking stroke of the vehicle, the pressure oil stored in the first accumulator outputs high-pressure control oil through the pressure control valve to flow into the control chamber of the hydraulic control reversing valve, so that the hydraulic control reversing valve is in a fully open state under the push of the high-pressure control oil, thereby avoiding the first accumulator recovering a small amount of hydraulic oil from the hydraulic travel component through the hydraulic control reversing valve, resulting in energy waste; in the walking hydraulic system provided by the present application, the energy recovery of the hydraulic travel component by the first accumulator through the hydraulic control reversing valve can adapt to the braking stroke of the matching vehicle, and the energy recovery effect is good and while recovering energy, it will not affect the braking effect of the vehicle.

[0043] Hereinafter, the present application will be described in detail with reference to the accompanying drawings and specific embodiments.

[0044] See also Figure 1 and Figure 4 The walking hydraulic system provided in the embodiment of the present application includes a hydraulic walking component 900, an energy storage component 100 and a control device 200; the energy storage component 100 includes at least one first accumulator 110, and the control device 200 includes a pressure control valve 210 and a hydraulically controlled reversing valve 220; the first accumulator 110 is connected to the hydraulic walking component 900 through the hydraulically controlled reversing valve 220, the pressure control valve 210 is connected to the first accumulator 110, and the hydraulically controlled reversing valve 220 is connected to the pressure control valve 210.

[0045] The pressure control valve 210 is used to switch between a first opening state and a second opening state according to the braking stroke of the vehicle, wherein, in the first opening state, the pressure oil stored in the first accumulator 110 outputs low-pressure control oil through the pressure control valve 210 to flow into the control chamber of the hydraulically controlled reversing valve 220, and in the second opening state, the pressure oil stored in the first accumulator 110 outputs high-pressure control oil through the pressure control valve 210 to flow into the control chamber of the hydraulically controlled reversing valve 220; the hydraulically controlled reversing valve 220 is used to be in a partially open state under the push of the low-pressure control oil, and to be in a fully open state under the push of the high-pressure control oil, so as to adjust the flow rate of the hydraulic oil of the hydraulic travel component 900 to the first accumulator 110 through the hydraulically controlled reversing valve 220.

[0046] It should be noted that the vehicle in the embodiment of the present application may be an engineering machine, such as a snow thrower, an excavator, a loader, etc. The hydraulic travel assembly 900 may include a hydraulic motor 910, which is used to drive the travel transmission system of the vehicle to achieve the travel of the vehicle.

[0047] It can be understood that when the travel hydraulic system of the embodiment of the present application recovers the braking energy of the vehicle, the hydraulic oil of the hydraulic travel component 900 flows to the first accumulator 110 via the hydraulically controlled reversing valve 220, which refers to the hydraulic oil on the high-pressure side of the hydraulic travel component 900.

[0048] Specifically, the first accumulator 110 is used to store the hydraulic oil on the high-pressure side of the hydraulic travel assembly 900 during braking; the pressure control valve 210 is used to switch between the first opening state and the second opening state according to the braking stroke of the vehicle, providing different braking pressures for the hydraulically controlled reversing valve 220.

[0049] It should be noted that, in a specific implementation, the pressure control valve 210 is continuously proportionally controlled, that is, when the vehicle is in a slow braking stroke, according to the change in the slow braking stroke of the vehicle, the valve core position of the pressure control valve 210 is correspondingly adjusted in the proportional process, and the state in which the valve core position does not exceed the critical position is the first opening state, that is, the first opening state can correspond to multiple positions of the valve core that change continuously, so as to output different control oil pressures, that is, the low-pressure control oil proportionally adjusts the valve core position of the hydraulically controlled reversing valve 220, so that the hydraulically controlled reversing valve 220 is in a partially open state as a whole.

[0050] Furthermore, when the vehicle is in an emergency braking stroke, according to the change in the emergency braking stroke of the vehicle, the valve core position of the pressure control valve 210 is correspondingly adjusted in the proportional adjustment process, and the state in which the valve core position exceeds the critical position is the second opening state, that is, the second opening state can also correspond to multiple positions of the valve core continuously changing to output different control oil pressures, that is, the high-pressure control oil proportionally adjusts the valve core position of the hydraulically controlled reversing valve 220, so that the hydraulically controlled reversing valve 220 is in a fully open state as a whole.

[0051] It is understandable that the critical position can be set according to the actual scenario, and the embodiments of the present application are not limited thereto.

[0052] The hydraulically controlled reversing valve 220 is used to disconnect the high-pressure oil circuit on the high-pressure side of the hydraulic travel component 900 from the oil circuit connected to the first accumulator 110 when the vehicle is not braking, so as to prevent the hydraulic oil on the high-pressure side from entering the first accumulator 110 for filling when the hydraulic travel component 900 is working normally, thereby affecting the working efficiency of the hydraulic travel component 900; and, when the vehicle is braking, the brake pressure provided by the pressure control valve 210 opens the valve core, so that the pressure oil of the hydraulic travel component 900 enters the first accumulator 110 for storage through the hydraulically controlled reversing valve 220.

[0053] Among them, the valve core opening of the hydraulically controlled reversing valve 220 is related to the braking pressure ratio. When the vehicle is in the first braking stroke, that is, the driver operates the brake pedal of the vehicle to be less than or equal to the preset distance and performs slow and stable braking, the pressure control valve 210 will be in the first opening state, so that the pressure oil stored in the first accumulator 110 outputs low-pressure control oil to the control chamber of the hydraulically controlled reversing valve 220 after passing through the pressure control valve 210, providing a smaller reversing control pressure for the hydraulically controlled reversing valve 220, so that the hydraulically controlled reversing valve 220 is in a partially open state. In this way, the hydraulic oil of the small flow of the hydraulic travel component 900 is stored in the first accumulator 110 through the hydraulically controlled reversing valve 220, which can avoid a sudden reduction in the effective flow of the hydraulic travel component 900 due to a large amount of hydraulic oil entering the first accumulator 110, causing the vehicle to have an emergency braking situation, posing a safety hazard to the driver.

[0054] When the vehicle is in the second braking stroke, that is, the moving distance of the driver's brake pedal is greater than the preset distance and emergency rapid braking is performed, the pressure control valve 210 will be in the second opening state, so that the pressure oil stored in the first accumulator 110 outputs high-pressure control oil to the control chamber of the hydraulically controlled reversing valve 220 after passing through the pressure control valve 210, providing a larger reversing control pressure for the hydraulically controlled reversing valve 220, so that the hydraulically controlled reversing valve 220 is in a fully open state. In this way, the hydraulic oil of the large-flow hydraulic travel component 900 is stored in the first accumulator 110, reducing the pressure loss of the hydraulic oil passing through the hydraulically controlled reversing valve 220, so that the hydraulic oil of the hydraulic travel component 900 can enter the first accumulator 110 more efficiently and quickly for filling and energy storage.

[0055] It should be noted that the preset distance can be set and adjusted according to actual conditions, and this embodiment of the present application will not be elaborated on this.

[0056] In specific implementation, the pressure control valve 210 of the embodiment of the present application can be manually controlled, or can be hydraulically controlled, electromagnetically controlled, or electro-hydraulic controlled, so that the pressure control valve 210 can provide different switching control pressures for the hydraulically controlled reversing valve 220 according to the braking stroke of the vehicle.

[0057] Illustratively, the pressure control valve 210 includes a valve body, and the valve body includes a valve seat and a valve core disposed on the valve seat.

[0058] When the pressure control valve 210 is manually controlled, the valve core can be connected to the vehicle's brake pedal through a linkage mechanism, wherein the linkage mechanism includes a connecting rod and a push rod connected to the connecting rod, the connecting rod is used to connect to the vehicle's brake pedal, and the push rod is connected to the valve core. In this way, when the driver steps on the brake pedal, the brake pedal will be displaced and the displacement will be transmitted to the valve core through the linkage mechanism, so that the valve core adjusts its position according to the size of the brake pedal displacement, thereby realizing the switching of different opening states.

[0059] When the pressure control valve 210 is controlled by hydraulic control, the pressure control valve 210 may also include a spring and a hydraulic control chamber for adjusting the position of the valve core, and the spring is used to set the initial position of the valve core; the hydraulic control chamber can be connected to the external control pressure oil through the hydraulic control oil port, so that when the driver steps on the brake pedal, the brake pedal is displaced, and different pressure oils are output according to the size of the brake pedal displacement and transmitted to the hydraulic control chamber of the pressure control valve 210, thereby adjusting the position of the valve core of the pressure control valve 210.

[0060] When the pressure control valve 210 is controlled by electromagnetic means, the pressure control valve 210 may also include a spring and an electromagnetic coil for generating a magnetic field to attract or repel the valve core. The electromagnetic coil may be connected to the brake pedal of the vehicle through the control device 200, wherein the control device 200 includes a controller and a stroke sensor connected to the controller for communication. The controller is electrically connected to the electromagnetic coil. The stroke sensor is used to detect the stroke of the brake pedal and output an electrical signal proportional to the stroke to the controller, so that the controller adjusts the current of the electromagnetic coil according to the displacement of the brake pedal, thereby changing the position of the valve core according to the strength of the magnetic field generated by the electromagnetic coil.

[0061] When the pressure control valve 210 is controlled by electromagnetic means, the hydraulic control method and the electromagnetic method mentioned above are combined, and the electromagnetic coil acts on the hydraulic control piston or diaphragm, so that the hydraulic control piston or diaphragm adjusts its position according to the magnetic field generated by the electromagnetic coil, thereby adjusting the position of the valve core.

[0062] The number of the first accumulators 110 in the embodiment of the present application can be set to one, and the vehicle braking energy can be recovered through one first accumulator 110. Of course, the number of the first accumulators 110 can also be set to at least two. The energy storage space can be increased by having more than two first accumulators 110 to meet the storage of a large flow of hydraulic oil flowing into the hydraulic travel component 900 when braking.

[0063] The embodiment of the present application does not limit the specific number of the hydraulically controlled reversing valve 220. For example, the first accumulator 110 is configured as follows: Figure 1 The two shown in FIG. 2 , wherein the hydraulically controlled reversing valve 220 can be set to Figure 1 As shown, the two first accumulators 110 are connected to the hydraulic travel assembly 900 through a hydraulically controlled reversing valve 220; of course, the hydraulically controlled reversing valve 220 can also be set to correspond one-to-one with the first accumulator 110, so that the first accumulator 110 is connected to the hydraulic travel assembly 900 through the corresponding hydraulically controlled reversing valve 220.

[0064] In summary, in the walking hydraulic system of the embodiment of the present application, the pressure control valve 210 switches between the first opening state and the second opening state according to the braking stroke of the vehicle, so as to provide different switching control pressures for the hydraulically controlled reversing valve 220 through the pressure oil in the first accumulator 110, thereby realizing proportional adjustment of the valve core position of the hydraulically controlled reversing valve 220, wherein, in the first opening state, corresponding to the slow and light braking stroke of the vehicle, the pressure oil stored in the first accumulator 110 outputs low-pressure control oil through the pressure control valve 210 to flow into the control chamber of the hydraulically controlled reversing valve 220, so that the hydraulically controlled reversing valve 220 is in a partially open state under the push of the low-pressure oil, thereby avoiding the first accumulator 110 recovering a large flow of hydraulic oil from the hydraulic walking component 900 through the hydraulically controlled reversing valve 220, resulting in a reduction in the effective flow of the hydraulic walking component 900, causing the vehicle to experience emergency braking.

[0065] In the second opening state, corresponding to the emergency braking stroke of the vehicle, the pressure oil stored in the first accumulator 110 outputs high-pressure control oil through the pressure control valve 210 to flow into the control chamber of the hydraulically controlled reversing valve 220, so that the hydraulically controlled reversing valve 220 is in a fully open state under the push of the high-pressure oil, thereby avoiding the small amount of hydraulic oil flow recovered by the first accumulator 110 to the hydraulic travel component 900 through the hydraulically controlled reversing valve 220, resulting in energy waste; with such a design, the energy recovery of the hydraulic travel component 900 by the first accumulator 110 through the hydraulically controlled reversing valve 220 can adapt to the braking stroke of the vehicle, and the energy recovery effect is good and will not affect the braking effect of the vehicle while recovering energy.

[0066] See also Figure 2 and Figure 4 In some embodiments, the energy storage assembly 100 further includes at least one second accumulator 120, and the control device 200 further includes a control component 230 and an electromagnetic reversing valve 240. The control component 230 is communicatively connected to the engine 930 of the hydraulic travel assembly 900, and the control component 230 is used to detect the rotation speed of the engine 930. The second accumulator 120 is connected to the hydraulic travel assembly 900 through the electromagnetic reversing valve 240; the control component 230 is configured to control the electromagnetic reversing valve 240 to open when the engine 930 changes from a first rotation speed to a second rotation speed, so as to connect the hydraulic travel assembly 900 and the second accumulator 120, so that the hydraulic oil of the hydraulic travel assembly 900 flows to the second accumulator 120 via the electromagnetic reversing valve 240; wherein the first rotation speed is greater than the second rotation speed.

[0067] Here, when the engine 930 changes from the first speed to the second speed, wherein the first speed is greater than the second speed, that is, the vehicle is in a decelerating running condition, the embodiment of the present application can reduce the energy loss during vehicle operation by setting a second accumulator 120 to recover the excess energy released when the vehicle decelerates, and the energy recovery of the hydraulic travel component 900 is more comprehensive.

[0068] Specifically, the control component 230 is used to output a control current to the electromagnetic reversing valve 240 according to the detected speed information of the engine 930 , so as to control the switch of the electromagnetic reversing valve 240 .

[0069] Illustratively, when the vehicle decelerates, the control component 230 sends a signal to control the valve core of the electromagnetic reversing valve 240 to open, thereby conducting the hydraulic oil of the hydraulic travel component 900 to the second accumulator 120 for storing energy; further, it can be understood that when the vehicle accelerates or moves at a constant speed, the controller will disconnect the control signal to the electromagnetic reversing valve 240, and the valve core of the electromagnetic reversing valve 240 will reset under the action of the spring force, so that its oil inlet and oil outlet are closed, thereby disconnecting the oil circuit between the hydraulic travel component 900 and the second accumulator 120, thereby preventing the hydraulic oil of the hydraulic travel component 900 from entering the second accumulator 120 for filling, affecting the working efficiency of the hydraulic travel component 900.

[0070] The embodiment of the present application does not limit the specific number of the second accumulator 120 and the electromagnetic reversing valve 240. For example, the second accumulator 120 can be set to one or more than two. When the second accumulator 120 is set to more than two, the electromagnetic reversing valve 240 can be set to one or one-to-one correspondence with the second accumulator 120.

[0071] In order to effectively utilize the energy recovered by the first accumulator 110 and the second accumulator 120, refer to Figure 3 and Figure 4 In some embodiments, the travel hydraulic system further includes a brake component 300, which is connected to the outlet of the pressure control valve 210, and the outlet of at least one of the first accumulator 110 and the second accumulator 120 is connected to the inlet of the pressure control valve 210; the pressure control valve 210 is also used to allow the pressure oil in the first accumulator 110 and / or the pressure oil in the second accumulator 120 to output high-pressure control oil to flow into the brake component 300 after passing through the pressure control valve 210 when in a first opening state.

[0072] In the second opening state, the pressure oil in the first accumulator 110 and / or the pressure oil in the second accumulator 120 outputs low-pressure control oil through the pressure control valve 210 and flows into the brake member 300; the brake member 300 is used to apply a first braking force to the brake disc of the hydraulic travel component 900 under the push of the high-pressure control oil, and to apply a second braking force to the brake disc of the hydraulic travel component 900 under the push of the low-pressure control oil; wherein the first braking force is greater than the second braking force.

[0073] With such arrangement, when the vehicle brakes, the hydraulic oil of the hydraulic travel assembly 900 stored and recovered by at least one of the first accumulator 110 and the second accumulator 120 is used as a brake oil source, and can be further acted on the brake component 300 through the pressure control valve 210 and used as a brake oil source, thereby utilizing the brake component 300 to brake the vehicle. Thus, components such as a pump source and a filling valve used for braking of the vehicle itself can be omitted, which is beneficial to reducing costs and making the vehicle lighter.

[0074] Specifically, the brake component 300 is used to apply braking force to the brake disc of the hydraulic travel assembly 900 after receiving the pressure oil, so as to achieve deceleration braking of the vehicle. In specific implementation, the brake component 300 applies different braking forces according to the pressure of the hydraulic oil, so as to ensure that the brake disc can be provided with appropriate braking force under different braking strokes, thereby improving the braking performance and safety under different driving conditions.

[0075] It should be noted that in the specific implementation, Figure 1 and Figure 4 As shown, the pressure control valve 210 is also configured with a hydraulic oil tank 270 , so that after the brake pedal is released, the pressure oil in the brake member 300 enters the hydraulic oil tank 270 through the oil return port of the pressure control valve 210 for storage.

[0076] For example, the brake member 300 may include a brake cylinder and a brake caliper, the brake caliper is connected to the piston of the brake cylinder, the brake disc of the vehicle is installed on the wheel axle of the vehicle, and the brake disc is used to cooperate with the brake caliper to generate friction, thereby achieving the braking of the vehicle. In this way, when the low-pressure oil flows into the brake cylinder through the pressure control valve 210 and pushes the piston to move accordingly, the piston pushes the brake caliper according to the pressure of the low-pressure oil, and applies a smaller braking force to the brake disc, that is, the second braking force suitable for the slow braking condition of the vehicle; when the high-pressure oil flows into the brake cylinder through the pressure control valve 210 and pushes the piston to move accordingly, the piston pushes the brake caliper according to the pressure of the high-pressure oil, and applies a larger braking force to the brake disc, that is, the first braking force suitable for the emergency braking condition.

[0077] It should be noted that the embodiment of the present application can brake the vehicle by recovering the stored braking energy through the first accumulator 110, or by recovering the stored deceleration energy through the second accumulator 120, or it can be a combination of the above two, which is not limited by the embodiment of the present application.

[0078] See also Figure 4In some examples, the control device 200 further includes an electric proportional reversing valve 250 and a selection valve 260, the electric proportional reversing valve 250 being electrically connected to the control component 230; the outlets of the first accumulator 110 and the second accumulator 120 are both connected to the inlet of the electric proportional reversing valve 250, and the outlet of the electric proportional reversing valve 250 is connected to the high-pressure side of the hydraulic travel component 900 through the selection valve 260, and the control component 230 is configured to control the electric proportional reversing valve 250 to open when the engine 930 changes from the third speed to the fourth speed, so as to connect the first accumulator 110 and the high-pressure side of the hydraulic travel component 900, so that the hydraulic oil of the first accumulator 110 flows to the high-pressure side of the hydraulic travel component 900 via the electric proportional reversing valve 250, and connect the second accumulator 120 and the high-pressure side of the hydraulic travel component 900, so that the hydraulic oil of the second accumulator 120 flows to the high-pressure side of the hydraulic travel component 900 via the electric proportional reversing valve 250; wherein the third speed is less than the fourth speed.

[0079] Specifically, the electric proportional reversing valve 250 is used to release the hydraulic oil stored in the first accumulator 110 and the second accumulator 120 to flow into the high-pressure side of the hydraulic travel assembly 900 when the engine 930 changes from the third speed to the fourth speed, so as to assist the vehicle in traveling. In specific implementation, the third speed being lower than the fourth speed may correspond to at least one of the vehicle's starting, accelerating, and uphill conditions.

[0080] Such an arrangement can reduce the load of the engine 930 of the hydraulic travel assembly 900, reduce the power consumption of the engine 930 and the fuel consumption of the vehicle.

[0081] By setting the selection valve 260, when the high-pressure side and the low-pressure side of the vehicle's hydraulic travel component 900 are interchanged under different working conditions, the selection valve 260 can ensure that the hydraulic oil flowing out through the electric proportional reversing valve 250 can correctly flow into the high-pressure side of the hydraulic travel component 900, thereby providing power for the vehicle's starting, acceleration, climbing and other working conditions.

[0082] like Figure 4 As shown, specifically, the selection valve 260 includes a first sub-outlet 4, a second sub-outlet 5 and an inlet 6, the inlet 6 is connected to the outlet of the electric proportional reversing valve 250, the first sub-outlet 4 is connected to the first side A of the hydraulic travel component 900, and the second sub-outlet 5 is connected to the second side B of the hydraulic travel component 900; the selection valve 260 is configured to connect the inlet 6 and the first sub-outlet 4 when the pressure on the first side A is greater than the pressure on the second side B; or, when the pressure on the second side B is greater than the pressure on the first side A, connect the inlet 6 and the second sub-outlet 5.

[0083] That is to say, when the first side A is the high-pressure side, the inlet 6 and the first sub-outlet 4 are connected through the action of the selection valve 260; when the second side B is the high-pressure side, the inlet 6 and the second sub-outlet are connected through the action of the selection valve 260; in this way, the hydraulic oil flowing out through the electric proportional reversing valve 250 can flow correctly into the high-pressure side of the hydraulic travel assembly 900 after passing through the selection valve 260, thereby driving the hydraulic motor 910 to accelerate the rotation.

[0084] The embodiment of the present application does not limit the specific type of the selection valve 260. For example, the selection valve 260 is set as a pressure-sensitive reversing valve, which may include a valve body, a valve core and a pressure-balancing piston located in the valve body. The first sub-outlet 4, the second sub-outlet 5 and the inlet 6 are arranged on the valve body. The pressure-balancing piston is used to detect the pressure difference between the first side A and the second side B, and drives the valve core to move according to the pressure difference. For example, when the pressure on the first side A rises and is greater than the pressure on the second side B, the pressure-balancing piston drives the valve core to move toward the first sub-outlet 4, so as to achieve the connection between the inlet 6 and the first sub-outlet 4.

[0085] Furthermore, the control component 230 is also configured to, when it is detected that the difference between the fourth speed and the third speed is greater than a preset value, send a first instruction to the electric proportional reversing valve 250 to increase the valve core opening of the electric proportional reversing valve 250; and, when it is detected that the difference between the fourth speed and the third speed is less than or equal to a preset value, send a second instruction to the electric proportional reversing valve 250 to decrease the valve core opening of the electric proportional reversing valve 250.

[0086] Specifically, the control component 230 sends a corresponding proportional signal to the electric proportional reversing valve 250 according to the speed of increase of the engine 930 speed, so that the electric proportional reversing valve 250 can also control the hydraulic oil stored in the first accumulator 110 and the second accumulator 120 to release and flow into the high-pressure side of the hydraulic travel component 900 with different valve openings under starting, acceleration and uphill conditions. In this way, it can quickly respond to changes in the speed of the engine 930, improve the response speed of the entire system, and optimize the performance of the vehicle under starting, acceleration and uphill conditions.

[0087] Exemplarily, when the vehicle goes uphill and starts, the engine 930 changes from the third speed to the fourth speed, and the difference between the fourth speed and the third speed is greater than the preset value, that is, the engine 930 shows a faster increase in speed, and the control component 230 sends a first instruction, that is, a large current signal, to the electric proportional reversing valve 250, so that the valve core opening of the electric proportional reversing valve 250 is larger, so that the hydraulic oil stored in the first accumulator 110 and the second accumulator 120 can be quickly released and replenished to the high-pressure side of the hydraulic travel component 900, driving the hydraulic motor 910 of the hydraulic travel component 900 to rotate, so that the hydraulic motor 910 can quickly complete the starting and climbing.

[0088] When the vehicle accelerates, the difference between the fourth speed and the third speed of the engine 930 is less than or equal to the preset value, that is, the engine 930 shows a slow increase in speed, and the control component 230 sends a second instruction, that is, a small current signal, to the electric proportional reversing valve 250, so that the valve core opening of the electric proportional reversing valve 250 is smaller. In this way, the hydraulic oil stored in the first accumulator 110 and the second accumulator 120 can be slowly released and replenished to the high-pressure side of the hydraulic travel component 900, driving the hydraulic motor 910 of the hydraulic travel component 900 to rotate, so that the hydraulic motor 910 can slowly complete the acceleration.

[0089] It is understandable that the preset value can be set according to actual conditions, and this will not be further described in the embodiments of the present application.

[0090] See 2 to Figure 4 In some examples, the walking hydraulic system also includes a first one-way valve 400 and a second one-way valve 500. The first one-way valve 400 is located between the hydraulically controlled reversing valve 220 and the first accumulator 110, and the outlet of the hydraulically controlled reversing valve 220 is connected to the inlet of the first accumulator 110 through the first one-way valve 400; the second one-way valve 500 is located between the electromagnetic reversing valve 240 and the second accumulator 120, and the outlet of the electromagnetic reversing valve 240 is connected to the inlet of the second accumulator 120 through the second one-way valve 500.

[0091] Through the above arrangement, when the oil pressure stored in the first accumulator 110 and the second accumulator 120 is higher than the hydraulic travel assembly 900, the first one-way valve 400 and the second one-way valve 500 can ensure that the hydraulic oil stored in the first accumulator 110 and the second accumulator 120 will not flow back to the hydraulic travel assembly 900, thereby avoiding affecting the braking and deceleration of the vehicle.

[0092] See 2 to Figure 4 In some embodiments, the walking hydraulic system further includes a third one-way valve 600 and a fourth one-way valve 700, and the outlet of the first accumulator 110 and the outlet of the second accumulator 120 are both connected to the inlet of the pressure control valve 210; the outlet of the first accumulator 110 is connected to the inlet of the pressure control valve 210 through the third one-way valve 600, and the outlet of the second accumulator 120 is connected to the inlet of the pressure control valve 210 through the fourth one-way valve 700.

[0093] In this way, the third one-way valve 600 and the fourth one-way valve 700 are provided to isolate the oil circuits of the first accumulator 110 and the second accumulator 120 . When the oil circuit of one of the first accumulator 110 and the second accumulator 120 is damaged due to an accident, the operation of the oil circuit of the other one is not affected.

[0094] Illustratively, by providing the fourth one-way valve 700, when the vehicle brakes, it can ensure that the hydraulic oil of the hydraulic travel component 900 can be stored in the first accumulator 110, thereby preventing the hydraulic oil from further entering the second accumulator 120 through the first accumulator 110, thereby causing the pressure in the second accumulator 120 to be too high and unable to store and recover the energy released by the hydraulic travel component 900 when the vehicle decelerates, resulting in energy waste.

[0095] By providing the third one-way valve 600, when the vehicle is braked only by the second accumulator 120, it is possible to prevent the second accumulator 120 from being connected to the first accumulator 110, thereby preventing the hydraulic oil in the second accumulator 120 from flowing into the first accumulator 110, causing the pressure of the second accumulator 120 to be low and unable to meet the pressure requirement during vehicle braking, thereby affecting the braking performance of the vehicle.

[0096] Continue to refer to 2 to Figure 4 In some examples, the walking hydraulic system also includes a pressure cut-off valve assembly 800, which includes a first pressure cut-off valve 810 and a second pressure cut-off valve 820; the first pressure cut-off valve 810 is located between the first one-way valve 400 and the first accumulator 110, and the outlet of the first one-way valve 400 is connected to the inlet of the first pressure cut-off valve 810, and the outlet of the first pressure cut-off valve 810 is connected to the inlet of the first accumulator 110; the second pressure cut-off valve 820 is located between the second one-way valve 500 and the second accumulator 120, and the outlet of the second one-way valve 500 is connected to the inlet of the second pressure cut-off valve 820, and the outlet of the second pressure cut-off valve 820 is connected to the inlet of the second accumulator 120.

[0097] Specifically, by setting the first pressure cut-off valve 810, when the braking energy is recovered, when the filling pressure in the first accumulator 110 reaches the threshold pressure set by the first pressure cut-off valve 810, the valve core of the first pressure cut-off valve 810 is closed to stop the filling, thereby preventing the hydraulic oil of the hydraulic travel assembly 900 from continuing to fill the first accumulator 110 and causing damage to the accumulator, thereby ensuring the safety and reliability of the first accumulator 110.

[0098] By setting the second pressure cut-off valve 820, when the deceleration energy is recovered, when the filling pressure in the second accumulator 120 reaches the threshold pressure set by the second pressure cut-off valve 820, the valve core of the second pressure cut-off valve 820 is closed to stop filling, thereby preventing the hydraulic oil of the hydraulic travel assembly 900 from continuing to fill the second accumulator 120 and causing damage to the second accumulator 120, thereby ensuring the safety and reliability of the second accumulator 120.

[0099] An embodiment of the present application also provides an engineering vehicle, comprising a vehicle body and a travel hydraulic system as described in any of the above embodiments, which is arranged on the vehicle body.

[0100] Among them, the overall structure and working principle of the walking hydraulic system are the same as those in the aforementioned embodiment and will not be repeated here.

[0101] In specific implementation, the hydraulic travel assembly 900 includes: Figure 1 The engine 930, hydraulic pump 920, hydraulic motor 910 and shuttle valve 940 are shown. The engine 930 drives the hydraulic pump 920 to output high-pressure oil, thereby driving the hydraulic motor 910 to rotate; the outlet of the hydraulic motor 910 is connected to the inlet of the hydraulically controlled reversing valve 220 of the control device 200 through the shuttle valve 940.

[0102] Specifically, the engine 930 is used to provide power input for the hydraulic travel component 900; the hydraulic pump 920 is used to provide a pressure oil source for the hydraulic travel component 900. When implemented specifically, Figure 4 As shown, the hydraulic pump 920 is equipped with a hydraulic oil tank 270 , and the hydraulic oil tank 270 is used to store and provide the hydraulic oil required by the hydraulic travel assembly 900 .

[0103] The hydraulic motor 910 is used to drive the vehicle's travel transmission system when rotating, thereby realizing the vehicle's travel; the shuttle valve 940 is used to select the high-pressure side of the hydraulic travel component 900 to be connected to the inlet of the hydraulic control reversing valve 220, so that the hydraulic oil of the hydraulic travel component 900 enters the first accumulator 110 for storage; for example, Figure 4 As shown, when the first side A of the hydraulic travel component 900 is the high-pressure side, the inlet 1 and the outlet 3 of the shuttle valve 940 are connected, and when the second side B of the hydraulic travel component 900 is the high-pressure side, the inlet 2 and the outlet 3 of the shuttle valve 940 are connected.

[0104] The engineering vehicle of the embodiment of the present application can achieve a better energy recovery effect for the vehicle by providing a travel hydraulic system, and while recovering energy, it will not affect the braking effect of the vehicle.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A walking hydraulic system, characterized in that: It comprises a hydraulic travel component (900), an energy storage component (100) and a control device (200); The energy storage assembly (100) comprises at least one first accumulator (110), and the control device (200) comprises a pressure control valve (210) and a hydraulically controlled reversing valve (220); the first accumulator (110) is connected to the hydraulic travel assembly (900) via the hydraulically controlled reversing valve (220), the pressure control valve (210) is connected to the first accumulator (110), and the hydraulically controlled reversing valve (220) is connected to the pressure control valve (210); The pressure control valve (210) is used to switch between a first opening state and a second opening state according to a braking stroke of the vehicle, wherein in the first opening state, the pressure oil stored in the first accumulator (110) outputs low-pressure control oil through the pressure control valve (210) to flow into the control chamber of the hydraulically controlled reversing valve (220), and in the second opening state, the pressure oil stored in the first accumulator (110) outputs high-pressure control oil through the pressure control valve (210) to flow into the control chamber of the hydraulically controlled reversing valve (220); The hydraulically controlled reversing valve (220) is used to be in a partially open state under the push of the low-pressure control oil, and to be in a fully open state under the push of the high-pressure control oil, so as to adjust the flow rate of the hydraulic oil of the hydraulic travel component (900) flowing to the first accumulator (110) via the hydraulically controlled reversing valve (220).

2. The walking hydraulic system according to claim 1, characterized in that: The energy storage assembly (100) further comprises at least one second accumulator (120); the control device (200) further comprises a control component (230) and an electromagnetic reversing valve (240); the control component (230) is communicatively connected to an engine (930) of the hydraulic travel assembly (900); the control component (230) is used to detect the rotation speed of the engine (930); and the second accumulator (120) is connected to the hydraulic travel assembly (900) via the electromagnetic reversing valve (240); The control component (230) is configured to control the electromagnetic reversing valve (240) to open when the engine (930) changes from a first speed to a second speed, so as to connect the hydraulic travel component (900) and the second accumulator (120), so that the hydraulic oil of the hydraulic travel component (900) flows into the second accumulator (120) via the electromagnetic reversing valve (240); wherein the first speed is greater than the second speed.

3. The walking hydraulic system according to claim 2, characterized in that: It also includes a brake member (300), the brake member (300) is connected to the outlet of the pressure control valve (210), and the outlet of at least one of the first accumulator (110) and the second accumulator (120) is connected to the inlet of the pressure control valve (210); The pressure control valve (210) is further used to, in the first opening state, allow the pressure oil in the first accumulator (110) and / or the pressure oil in the second accumulator (120) to output low-pressure control oil to flow into the brake component (300) through the pressure control valve (210); and in the second opening state, allow the pressure oil in the first accumulator (110) and / or the pressure oil in the second accumulator (120) to output high-pressure control oil to flow into the brake component (300) through the pressure control valve (210); The brake component (300) is used to apply a first braking force to the brake disc of the hydraulic travel component (900) under the push of the high-pressure control oil, and to apply a second braking force to the brake disc of the hydraulic travel component (900) under the push of the low-pressure control oil; wherein the first braking force is greater than the second braking force.

4. The walking hydraulic system according to claim 2, characterized in that: The control device (200) further comprises an electric proportional reversing valve (250) and a selection valve (260), wherein the electric proportional reversing valve (250) is electrically connected to the control element (230); The outlets of the first accumulator (110) and the second accumulator (120) are both connected to the inlet of the electric proportional reversing valve (250), and the outlet of the electric proportional reversing valve (250) is connected to the high-pressure side of the hydraulic travel assembly (900) via the selection valve (260); The control component (230) is configured to control the electric proportional reversing valve (250) to open when the engine (930) changes from the third speed to the fourth speed, so as to connect the first accumulator (110) and the high-pressure side of the hydraulic travel component (900), so that the hydraulic oil of the first accumulator (110) flows to the high-pressure side of the hydraulic travel component (900) via the electric proportional reversing valve (250), and to connect the second accumulator (120) and the high-pressure side of the hydraulic travel component (900), so that the hydraulic oil of the second accumulator (120) flows to the high-pressure side of the hydraulic travel component (900) via the electric proportional reversing valve (250); wherein the third speed is less than the fourth speed.

5. The walking hydraulic system according to claim 4, characterized in that: The control component (230) is further configured to, when detecting that the difference between the fourth speed and the third speed is greater than a preset value, send a first instruction to the electric proportional reversing valve (250) to increase the valve core opening of the electric proportional reversing valve (250); Furthermore, when it is detected that the difference between the fourth speed and the third speed is less than or equal to a preset value, a second instruction is sent to the electric proportional reversing valve (250) to reduce the valve core opening of the electric proportional reversing valve (250).

6. The walking hydraulic system according to claim 4, characterized in that: The selection valve (260) comprises a first sub-outlet, a second sub-outlet and an inlet, the inlet being connected to the outlet of the electric proportional reversing valve (250), the first sub-outlet being in communication with the first side of the hydraulic travel assembly (900), and the second sub-outlet being in communication with the second side of the hydraulic travel assembly (900); The selector valve (260) is configured to connect the inlet and the first sub-outlet when the pressure on the first side is greater than the pressure on the second side; or to connect the inlet and the second sub-outlet when the pressure on the second side is greater than the pressure on the first side.

7. The walking hydraulic system according to any one of claims 2 to 6, characterized in that: It also comprises a first one-way valve (400) and a second one-way valve (500), wherein the first one-way valve (400) is located between the hydraulically controlled reversing valve (220) and the first accumulator (110), and the outlet of the hydraulically controlled reversing valve (220) is connected to the inlet of the first accumulator (110) through the first one-way valve (400); The second one-way valve (500) is located between the electromagnetic reversing valve (240) and the second accumulator (120), and the outlet of the electromagnetic reversing valve (240) is connected to the inlet of the second accumulator (120) through the second one-way valve (500).

8. The walking hydraulic system according to any one of claims 3 to 6, characterized in that: It also includes a third one-way valve (600) and a fourth one-way valve (700), and the outlet of the first accumulator (110) and the outlet of the second accumulator (120) are both connected to the inlet of the pressure control valve (210); The outlet of the first accumulator (110) is connected to the inlet of the pressure control valve (210) through the third one-way valve (600), and the outlet of the second accumulator (120) is connected to the inlet of the pressure control valve (210) through the fourth one-way valve (700).

9. The walking hydraulic system according to claim 7, characterized in that: Also included is a pressure cut-off valve assembly (800), wherein the pressure cut-off valve assembly (800) includes a first pressure cut-off valve (810) and a second pressure cut-off valve (820); The first pressure cut-off valve (810) is located between the first one-way valve (400) and the first accumulator (110), the outlet of the first one-way valve (400) is connected to the inlet of the first pressure cut-off valve (810), and the outlet of the first pressure cut-off valve (810) is connected to the inlet of the first accumulator (110); The second pressure cut-off valve (820) is located between the second one-way valve (500) and the second accumulator (120); the outlet of the second one-way valve (500) is connected to the inlet of the second pressure cut-off valve (820); and the outlet of the second pressure cut-off valve (820) is connected to the inlet of the second accumulator (120).

10. An engineering vehicle, characterized in that: The vehicle comprises a vehicle body and a travel hydraulic system as claimed in any one of claims 1 to 9 arranged on the vehicle body.

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