Liquid filling valve, hydraulic braking system for running and hydraulic steering system for running

Abstract

The present application relates to hydraulic valve, disclose a kind of liquid-filled valve, including energy accumulator (1) and the working oil path connected with inlet (P) and working oil port (A), the working oil path is provided with check valve (2), the energy accumulator (1) is connected with the reverse oil port of check valve (2), further comprising hydraulic control reversing valve (3) and hydraulic bridge path, the hydraulic control reversing valve (3) includes the first oil port (B1) connected with the inlet (P), the second oil port (B2) connected with return oil port (T) and the third oil port (B3) connected with the hydraulic bridge path, the energy accumulator (1) and the hydraulic bridge path are respectively connected with the hydraulic control port of the hydraulic control reversing valve (3), to control the switching of the hydraulic control reversing valve (3).The present application also discloses a kind of running hydraulic brake system and running hydraulic steering system.The liquid-filled valve of the present application increases the width of energy accumulator working pressure interval, with wide-range pressure maintaining function.

Description

Technical Field

[0001] This invention relates to hydraulic valves, specifically to a filling valve, and also to a vehicle hydraulic braking system and a vehicle hydraulic steering system. Background Technology

[0002] Currently, the conventional principle of filling valves is as follows: Figure 1 As shown, in the initial state, the oil inlet P fills the accumulator 1 with liquid. When the pressure in the accumulator 1 reaches the pressure setting value of the sequence valve R, the sequence valve R opens, and the oil inlet P connects to the return port T. The oil inlet P is then unloaded. At this time, the accumulator 1 is in a high-pressure state under the holding action of the one-way valve 2. When the foot pedal is activated, the high-pressure oil in the accumulator 1 is input to the steering cylinder or brake through the foot pedal valve. At the same time, its internal pressure decreases. After the actuator has been activated multiple times, when the pressure in the accumulator 1 is less than a certain value, the sequence valve R closes, and the oil inlet P fills the accumulator 1 again until its internal pressure reaches the opening value of the sequence valve R, at which point the oil inlet P is unloaded. As the actuator connected to the working oil port A continues to work, the accumulator 1 is cyclically filled with liquid according to the above process.

[0003] Generally speaking, the closing pressure of the sequence valve R is about 85% of the fully open pressure. This causes the accumulator 1 to start filling when the internal pressure drops to 85% of the maximum pressure. However, the 15% pressure range is limited in the amount of oil that the accumulator 1 can hold. As a result, the sequence valve R opens and closes frequently, the oil pump works frequently, and the accumulator 1 is filled frequently as the actuator connected to the working port A works, which greatly reduces the service life of each component.

[0004] Therefore, a new filling valve needs to be designed. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a filling valve that increases the width of the working pressure range of the accumulator and has a wide-range pressure holding function.

[0006] Furthermore, the technical problem to be solved by the present invention is to provide a driving hydraulic braking system that can reduce the frequency of oil pump operation and accumulator charging, and extend the service life of each component.

[0007] Furthermore, the technical problem to be solved by the present invention is to provide a hydraulic steering system for vehicles that can reduce the frequency of operation of the oil source pump and the frequency of accumulator filling, thereby extending the service life of each component.

[0008] To achieve the above objectives, a first aspect of the present invention provides a filling valve, comprising an accumulator and a working oil circuit connecting an oil inlet and a working oil port. A one-way valve is provided on the working oil circuit, and the accumulator is connected to the reverse oil port of the one-way valve. The valve also includes a hydraulically controlled directional valve and a hydraulic bridge circuit. The hydraulically controlled directional valve includes a first oil port connected to the oil inlet, a second oil port connected to the return oil port, and a third oil port connected to the hydraulic bridge circuit. The accumulator and the hydraulic bridge circuit are respectively connected to the hydraulic control port of the hydraulically controlled directional valve to control the switching of the hydraulically controlled directional valve.

[0009] Preferably, the hydraulic control port of the hydraulic directional valve is one, the hydraulic bridge includes a wide-range holding valve and a throttle valve, the accumulator is connected to the hydraulic control port through the wide-range holding valve, and the hydraulic control port is also connected to a part of the oil line of the hydraulic bridge between the wide-range holding valve and the throttle valve, and the throttle valve is connected to the third oil port of the hydraulic directional valve.

[0010] Furthermore, when the pressure at the hydraulic control port of the hydraulic directional valve is less than the spring force in the spring control chamber of the hydraulic directional valve, the second oil port of the hydraulic directional valve is connected to its third oil port, and the hydraulic oil flowing in from the inlet is introduced into the accumulator through the check valve.

[0011] More preferably, the throttle valve is located inside the hydraulic directional valve, and when the second port of the hydraulic directional valve is connected to its third port, the hydraulic control port is connected to the return port through the throttle valve.

[0012] Preferably, the hydraulic control valve has two hydraulic control ports, the hydraulic bridge includes a wide-range holding valve and a throttle valve, the accumulator is connected to one of the hydraulic control ports, the other hydraulic control port is connected to a portion of the oil line of the hydraulic bridge between the wide-range holding valve and the throttle valve, the throttle valve is connected to the third oil port of the hydraulic control valve, and the wide-range holding valve is connected to the oil tank.

[0013] Furthermore, when the pressure at the hydraulic control port connected to the accumulator is less than the spring force of the spring control chamber of the hydraulic directional valve, the first oil port of the hydraulic directional valve is connected to its third oil port, and the hydraulic oil flowing in from the inlet is introduced into the accumulator through the check valve.

[0014] More preferably, the throttle valve is located inside the hydraulic directional valve. When the first port of the hydraulic directional valve is connected to its third port, the hydraulic control port connected to the hydraulic bridge is connected to the oil inlet through the throttle valve.

[0015] Preferably, the wide-range holding valve is an adjustable flow valve.

[0016] The second invention provides a vehicle hydraulic braking system, including the filling valve described in any one of the first aspects of the technical solution.

[0017] A third aspect of the present invention provides a hydraulic steering system for vehicles, including the filling valve described in any one of the technical solutions of the first aspect.

[0018] Through the above technical solution, the present invention has innovatively designed a hydraulic bridge circuit. By controlling the pressure of the hydraulic control port of the hydraulic control directional valve through the hydraulic bridge circuit, the working pressure range of the accumulator can be effectively expanded, thereby enabling the filling valve to have a wide-range pressure holding function.

[0019] Specifically, the hydraulic bridge circuit mainly consists of a wide-range holding valve and a throttle valve. By adjusting the flow area of ​​the wide-range holding valve and the throttle valve through parameter design, the wide range controls the high and low working pressures respectively, thereby realizing the wide-range pressure holding function.

[0020] Furthermore, applying the filling valve of the present invention to a vehicle hydraulic braking system or a vehicle hydraulic steering system can reduce the operating frequency of the accumulator and other components, and extend their service life.

[0021] Other features and more prominent advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0022] Figure 1 This is the hydraulic schematic diagram of an existing filling valve;

[0023] Figure 2 This is a hydraulic schematic diagram of a filling valve according to one embodiment of the present invention;

[0024] Figure 3 This is a hydraulic schematic diagram of a filling valve according to another embodiment of the present invention.

[0025] Explanation of reference numerals in the attached figures

[0026] 1. Accumulator 2. Check valve

[0027] P oil inlet A working oil inlet

[0028] T return oil port

[0029] 3. Hydraulic directional valve B1: First oil port of the hydraulic directional valve

[0030] B2 is the second port of the hydraulic directional valve; B3 is the third port of the hydraulic directional valve.

[0031] K1 hydraulic control port

[0032] 4. Wide-range holding valve 5. Throttling valve

[0033] R sequence valve Detailed Implementation

[0034] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0035] Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as “first,” “second,” or “third” may explicitly or implicitly include one or more of the stated features.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0037] First, it should be noted that those skilled in the art, after understanding the technical concept of the filling valve of this invention, can also make simple replacements to the oil circuit or valves to achieve the wide-range pressure holding function of the filling valve of this invention, which also falls within the protection scope of this invention. Related hydraulic components, such as directional valves, throttle valves, check valves, accumulators, etc., are well known to those skilled in the art and are also commonly used components in existing hydraulic systems. Therefore, these hydraulic components will only be briefly described below, and the focus will be on the original hydraulic connection relationship of the filling valve of this invention. The technical term "wide-range" is defined relative to the working pressure range of the accumulator 1 in a conventional filling valve, such as... Figure 1 As shown, the accumulator 1 of a conventional filling valve can only hold hydraulic oil within 15% of its working pressure range, which limits the amount of hydraulic oil it can hold. Therefore, in the various technical solutions of this invention, the technical term "wide range" mainly refers to giving the accumulator 1 of the filling valve of this invention a wider working pressure range.

[0038] like Figure 2 and Figure 3As shown, the filling valve of the basic embodiment of the present invention includes an accumulator 1 and a working oil circuit connecting the oil inlet P and the working oil port A. A one-way valve 2 is provided on the working oil circuit. The accumulator 1 is connected to the reverse oil port of the one-way valve 2. It also includes a hydraulically controlled directional valve 3 and a hydraulic bridge circuit. The hydraulically controlled directional valve 3 includes a first oil port B1 connected to the oil inlet P, a second oil port B2 connected to the return oil port T, and a third oil port B3 connected to the hydraulic bridge circuit. The accumulator 1 and the hydraulic bridge circuit are respectively connected to the hydraulic control port K1 of the hydraulically controlled directional valve 3 to control the switching of the hydraulically controlled directional valve 3.

[0039] The filling valve has three working states: filling, unloading, and pressure holding.

[0040] When in the filling state, the oil inlet P and the oil return port T are disconnected. Hydraulic oil flows from the oil inlet P into the accumulator 1 through the check valve 2. When the pressure at the filling and discharging ports of the accumulator 1 increases to a certain value, it works with the hydraulic bridge circuit to control the hydraulic directional valve 3 to switch directions, entering the unloading state, i.e., the oil inlet P and the oil return port T are connected. At the same time, the pressure of the accumulator 1 is maintained at a high pressure under the action of the check valve 2. As the actuator connected to the working port A works, the hydraulic oil inside the accumulator 1 decreases, i.e., the pressure at the filling and discharging ports of the accumulator 1 decreases. When it decreases to a certain value, it works with the hydraulic bridge circuit to control the hydraulic directional valve 3 to switch directions again, re-entering the filling state.

[0041] Among them, the pressure control of the hydraulic control port of the hydraulic control directional valve 3 through the hydraulic bridge circuit can increase the width of the working pressure range of the accumulator 1 compared with the conventional filling valve.

[0042] As can be seen from the above, compared with conventional filling valves, the filling valve of the present invention has an original design of hydraulic bridge circuit. The hydraulic bridge circuit can control the low-pressure filling and high-pressure unloading pressure of the filling valve. In conjunction with the hydraulic control directional valve 3, it can effectively expand the working pressure range of the accumulator 1, so that the filling valve of the present invention has a wide-range pressure holding function. When the filling valve of the present invention is applied to the hydraulic braking system or hydraulic steering system of a vehicle, the operating frequency of each component in the system, such as the operating frequency of the oil pump, can be reduced, thereby extending the service life of each component.

[0043] The following describes specific embodiments of the filling valve of the present invention.

[0044] In a preferred embodiment, refer to Figure 2As shown in the figure, the hydraulic bridge circuit consists of a wide-range holding valve 4 and a throttle valve 5. The hydraulic control valve 3 has a hydraulic control port K1. The charging and discharging port of the accumulator 1 is connected to the hydraulic control port K1. The wide-range holding valve 4 is arranged on the oil path between the charging and discharging port of the accumulator 1 and the hydraulic control port K1, and the hydraulic control port K1 is also connected to a part of the oil path of the hydraulic bridge circuit between the wide-range holding valve 4 and the throttle valve 5. The throttle valve 5 is connected to the third oil port B3 of the hydraulic control valve 3.

[0045] For the sake of easy understanding, the above preferred embodiment will be described in combination with the hydraulic principle.

[0046] Suppose the pressure of the hydraulic control port K1 of the hydraulic control valve 3 is P1, the pressure acting area is A1, the spring force of the spring control chamber of the hydraulic control valve 3 is Fs, and the working pressure of the charging and discharging port of the accumulator 1 is P2; during the filling process, the oil inlet P and the oil return port T are disconnected, the second oil port B2 of the hydraulic control valve 3 is communicated with its third oil port B3, and the hydraulic oil flows from the oil inlet P through the one-way valve 2 into the accumulator 1. As the pressure P1 of the hydraulic control port K1 continuously rises, when P1*A1 = Fs, the hydraulic control valve 3 changes its direction, and the second oil port B2 of the hydraulic control valve 3 is communicated with its first oil port B1 to unload the oil inlet P; during the filling process, when approaching the direction change of the hydraulic control valve 3, a small part of the hydraulic oil flows through the wide-range holding valve 4 and the throttle valve 5 to the oil return port T, and a pressure loss is formed during the flowing process, making the pressure P1 of the hydraulic control port K1 less than the working pressure P2 of the charging and discharging port of the accumulator 1, thereby increasing the high-pressure range of the accumulator 1; after the second oil port B2 and the third oil port B3 of the hydraulic control valve 3 are disconnected, the pressure P1 of the hydraulic control port K1 will rise to be consistent with the working pressure P2 of the charging and discharging port of the accumulator 1. Under the action of the one-way valve 2, the accumulator 1 maintains a high-pressure state; as the actuator structure connected to the working oil port A works, the hydraulic oil in the accumulator 1 decreases, and the pressure P1 of the hydraulic control port K1 and the working pressure P2 of the charging and discharging port of the accumulator 1 decrease simultaneously. When P1 < Fs / A1, the hydraulic control valve 3 changes its direction, and the second oil port B2 of the hydraulic control valve 3 is communicated with its third oil port B3 again, entering the filling state.

[0047] As can be seen from the above, the low-pressure filling pressure of the filling valve of the present invention is determined by the spring force Fs of the spring control chamber of the hydraulic control valve 3 and the pressure acting area A1 of the hydraulic control port K1, and the high-pressure unloading pressure is determined by the spring force Fs of the spring control chamber of the hydraulic control valve 3, the pressure acting area A1 of the hydraulic control port K1, and the wide-range holding valve 4 and the throttle valve 5; therefore, by designing the parameters of the spring force Fs of the spring control chamber of the hydraulic control valve 3, the parameters of the pressure acting area A1 of the hydraulic control port K1, and adjusting the flow area of the wide-range holding valve 4 and the throttle valve 5, the high and low working pressures can be controlled respectively, the high and low pressure ranges can be increased, and the user's usage requirements can be met.

[0048] It should be noted that, in the design, the throttle valve 5 can be located in the oil line between the hydraulic control port K1 and the third oil port B3 of the hydraulic directional valve 3; however, in order to make the structure of the filling valve of the present invention more compact, the throttle valve 5 can be located inside the hydraulic directional valve 3, i.e., as shown below. Figure 2 The diagram shows a working position of the hydraulic directional valve 3, in which one end of the throttle valve 5 is connected to the third port B3 of the hydraulic directional valve 3. When the second port B2 of the hydraulic directional valve 3 is connected to its third port B3, the other end of the throttle valve 5 can be connected to the return port T.

[0049] In another preferred embodiment, refer to Figure 3 As shown, the hydraulic directional valve 3 has two hydraulic control ports K1. One hydraulic control port K1 is connected to the accumulator 1, and the other hydraulic control port K1 is connected to the oil line between the wide-range holding valve 4 and the throttle valve 5. The wide-range holding valve 4 and the throttle valve 5 are combined to form a hydraulic bridge circuit. The wide-range holding valve 4 is connected to the oil tank, and the throttle valve 5 is connected to the third oil port B3 of the hydraulic directional valve 3.

[0050] To facilitate a further understanding of the preferred embodiments of the present invention, the preferred embodiments will be described below in conjunction with the hydraulic principle.

[0051] Let the pressure of the hydraulic control port K1 connected to the accumulator 1 be P1, the pressure acting area be A1, the pressure of the hydraulic control port K1 connected to the hydraulic bridge circuit be P3, the pressure acting area be A3, the spring force of the spring control chamber of the hydraulic control valve 3 be Fs, and the working pressure of the charging and discharging port of the accumulator 1 be P2. In this preferred embodiment, in each working state of the filling valve, the pressure P1 of the hydraulic control port K1 connected to the accumulator 1 is equal to the working pressure P2 of the charging and discharging port of the accumulator 1; during filling, the oil inlet P and the oil return port T are disconnected, the first oil port B1 of the hydraulic control valve 3 is connected to its third oil port B3, and only a very small flow rate flows back to the fuel tank through the wide-range holding valve 4 and the throttle valve 5. Most of the hydraulic oil flows from the oil inlet P into the accumulator 1 through the check valve 2. Before filling, P1*A1 < P3*A3 + Fs. As filling progresses, the pressure P1 of the hydraulic control port K1 connected to the accumulator 1 rises. When P1*A1 = P3*A3 + Fs, the hydraulic control valve 3 changes its direction, and the first oil port B1 of the hydraulic control valve 3 is connected to its second oil port B2 to unload the oil inlet P; at this time, P1 = (P3*A3 + Fs) / A1, which is the system unloading pressure. The first oil port B1 of the hydraulic control valve 3 is disconnected from its third oil port B3, and the pressure P3 of the hydraulic control port K1 connected to the hydraulic bridge circuit drops to zero, thereby increasing the high-pressure range of the accumulator 1; at the same time, under the action of the check valve 2, the accumulator 1 maintains a high-pressure state; as the actuator structure connected to the working oil port A works, the hydraulic oil in the accumulator 1 decreases, and the pressure P of the hydraulic control port K1 connected to the accumulator 1 drops. When P1 < Fs / A1, the hydraulic control valve 3 changes its direction, and the first oil port B1 of the hydraulic control valve 3 is connected to its third oil port B3 to enter the filling state.

[0052] As can be seen from the above, the low-pressure filling pressure of the filling valve of the present invention is determined by the spring force Fs of the spring control chamber of the hydraulic control valve 3 and the pressure acting area A1 of the hydraulic control port K1 connected to the accumulator 1. The high-pressure unloading pressure is determined by the spring force Fs of the spring control chamber of the hydraulic control valve 3, the pressure acting area A1 of the hydraulic control port K1 connected to the accumulator 1, the pressure P3 of the hydraulic control port K1 connected to the hydraulic bridge circuit, and the pressure acting area A3. The pressure P3 is controlled by the hydraulic bridge circuit composed of the wide-range holding valve 4 and the throttle valve 5; therefore, by designing the parameters of the spring force Fs of the spring control chamber of the hydraulic control valve 3, the pressure acting area A1 of the hydraulic control port K1 connected to the accumulator 1, and the pressure acting area A3 of the hydraulic control port K1 connected to the hydraulic bridge circuit, and adjusting the wide-range holding valve 4, the high and low working pressures can be controlled respectively, increasing the width of the working pressure range of the accumulator 1, enabling the filling valve to have a good wide-range pressure holding function, and meeting the user's usage requirements.

[0053] Similarly, in this preferred embodiment, the throttle valve 5 can be installed in the oil line between the hydraulic control port K1 and the third oil port B3 of the hydraulic directional valve 3; however, in order to make the structure of the filling valve of the present invention more compact, the throttle valve 5 can be installed inside the hydraulic directional valve 3, i.e. Figure 3 The diagram shows a working position of the hydraulic directional valve 3, in which one end of the throttle valve 5 is connected to the third port B3 of the hydraulic directional valve 3. When the first port B1 of the hydraulic directional valve 3 is connected to its third port B3, the other end of the throttle valve 5 can be connected to the inlet port P.

[0054] In a specific embodiment, the wide-range holding valve 4 can be an adjustable flow valve with an adjustable orifice, while the throttle valve 5 can be a fixed orifice.

[0055] Reference Figure 2 and Figure 3As shown, the preferred embodiment of the filling valve of the present invention includes an accumulator 1, a working oil circuit, a check valve 2, a hydraulically controlled directional valve 3, and a hydraulic bridge circuit. The working oil circuit connects the inlet port P and the working port A, and the check valve 2 is disposed on the working oil circuit. The working port A can be connected to the actuator. The accumulator 1 is also connected to the working oil circuit, and the charging / discharging port of the accumulator 1 is connected to the reverse port of the check valve 2. The forward port of the check valve 3 is connected to the inlet port P. The hydraulic bridge circuit consists of a wide-range holding valve 4 and a throttle valve 5, which controls the low-pressure filling and high-pressure unloading pressures of the filling valve. In a specific embodiment, there are two ways to set up the hydraulic bridge circuit. In one way, the hydraulically controlled directional valve 3 has a hydraulic control port K1, and the charging / discharging port of the accumulator 1 is connected to the hydraulic control port K1. A wide-range holding valve 4 is connected to port K1 and is installed in the oil line between the charging / discharging port of accumulator 1 and the hydraulic control port K1 of hydraulic directional valve 3. A throttle valve 5 is installed inside hydraulic directional valve 3, with one end connected to the third port B3. When the second port B2 of hydraulic directional valve 3 is connected to its third port B3, the other end of the throttle valve 5 is connected to the second port B2 of hydraulic directional valve 3, i.e., connected to the return port T. Furthermore, hydraulic control port K1 is also connected to the third port B3 of hydraulic directional valve 3. Thus, let the pressure at hydraulic control port K1 of hydraulic directional valve 3 be P1, the pressure action area be A1, and the spring force of the spring control chamber of hydraulic directional valve 3 be Fs. As hydraulic control port K1 continuously rises, when P1*A1=Fs… When s, the hydraulic directional valve 3 reverses, unloading the inlet P. Near the reversal point of the hydraulic directional valve 3, a small portion of the hydraulic oil flows through the wide-range holding valve 4 and the throttle valve 5 to the return port T. This flow creates pressure loss, causing the pressure P1 at the hydraulic control port K1 to be less than the working pressure P2 at the charging / discharging port of the accumulator 1, thus increasing the high-pressure range of the accumulator 1. Alternatively, the hydraulic directional valve 3 has two hydraulic control ports K1. The charging / discharging port of the accumulator 1 is connected to one of these ports, and the other is connected to the oil line between the wide-range holding valve 4 and the throttle valve 5. One end of the wide-range holding valve 4 is connected to the oil tank, and the other end is connected to the third port B3 of the hydraulic directional valve 3. The throttle valve 5 is located inside the hydraulic directional valve 3. One end of the throttle valve 5 is connected to the third port B3 of the hydraulic directional valve 3. When the first port B1 of the hydraulic directional valve 3 is connected to its third port B3, the other end of the throttle valve 5 is connected to the first port B1 of the hydraulic directional valve 3, that is, connected to the inlet port P. As the pressure P1 of the hydraulic control port K1 connected to the accumulator 1 rises, when P1*A1=P3*A3+Fs, the hydraulic directional valve 3 reverses, and the first port B1 of the hydraulic directional valve 3 is connected to its second port B2, unloading the inlet port P. Since the first port B1 of the hydraulic directional valve 3 is disconnected from its third port B3, the pressure P3 of the hydraulic control port K1 connected to the hydraulic bridge circuit drops to zero, thereby increasing the high pressure range of the accumulator 1. Among them, the wide-range holding valve 4 can be an adjustable flow valve.In other words, the filling valve of this invention effectively expands the working pressure range of the accumulator 1 by specifically adding a hydraulic bridge circuit composed of a wide-range holding valve 4 and a throttle valve 5, thereby achieving a wide-range pressure holding function.

[0056] The hydraulic braking system for vehicles of the present invention includes the filling valve as described in any of the above technical solutions, and therefore has at least all the beneficial effects brought about by the technical solutions of the above filling valve embodiments.

[0057] The hydraulic steering system of the present invention includes the filling valve as described in any of the above technical solutions, and therefore has at least all the beneficial effects brought about by the technical solutions of the above filling valve embodiments.

[0058] When the filling valve of the present invention is applied to a vehicle hydraulic braking system or a vehicle hydraulic steering system, the filling valve can be manufactured as an independent hydraulic valve for easy assembly. Moreover, since the filling valve of the present invention has a wide-range pressure holding function, it can reduce the operating frequency of other components in the vehicle hydraulic braking system or vehicle hydraulic steering system, such as the operating frequency of the oil pump, and extend its service life. Of course, the filling valve of the present invention can also be applied to other hydraulic control systems and equipment that require a wide-range pressure holding function.

[0059] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A filling valve, comprising an accumulator (1) and a working oil circuit connecting an oil inlet (P) and a working oil port (A), wherein a one-way valve (2) is provided on the working oil circuit, and the accumulator (1) is connected to the reverse oil port of the one-way valve (2), characterized in that, It also includes a hydraulically controlled directional valve (3) and a hydraulic bridge circuit. The hydraulically controlled directional valve (3) includes a first oil port (B1) connected to the oil inlet (P), a second oil port (B2) connected to the oil return port (T), and a third oil port (B3) connected to the hydraulic bridge circuit. The accumulator (1) and the hydraulic bridge circuit are respectively connected to the hydraulic control port (K1) of the hydraulically controlled directional valve (3) to control the switching of the hydraulically controlled directional valve (3). The hydraulic control port (K1) of the accumulator (1) is one. The hydraulic bridge circuit includes a wide-range holding valve (4) and a throttle valve (5). The accumulator (1) is connected to the hydraulic control port (K1) through the wide-range holding valve (4). The hydraulic control port (K1) is also connected to a part of the oil line of the hydraulic bridge circuit between the wide-range holding valve (4) and the throttle valve (5). The throttle valve (5) is connected to the third oil port (B3) of the hydraulic control directional valve (3).

2. The filling valve according to claim 1, characterized in that, When the pressure at the hydraulic control port (K1) of the hydraulic directional valve (3) is less than the spring force of the spring control chamber of the hydraulic directional valve (3), the second oil port (B2) of the hydraulic directional valve (3) is connected to its third oil port (B3), and the hydraulic oil flowing in from the oil inlet (P) is introduced into the accumulator (1) through the check valve (2).

3. The filling valve according to claim 2, characterized in that, The throttle valve (5) is located inside the hydraulic control directional valve (3). When the second oil port (B2) of the hydraulic control directional valve (3) is connected to its third oil port (B3), the hydraulic control port (K1) is connected to the return oil port (T) through the throttle valve (5).

4. A filling valve, comprising an accumulator (1) and a working oil circuit connecting an oil inlet (P) and a working oil port (A), wherein a one-way valve (2) is provided on the working oil circuit, and the accumulator (1) is connected to the reverse oil port of the one-way valve (2), characterized in that, It also includes a hydraulically controlled directional valve (3) and a hydraulic bridge circuit. The hydraulically controlled directional valve (3) includes a first oil port (B1) connected to the oil inlet (P), a second oil port (B2) connected to the oil return port (T), and a third oil port (B3) connected to the hydraulic bridge circuit. The accumulator (1) and the hydraulic bridge circuit are respectively connected to the hydraulic control port (K1) of the hydraulically controlled directional valve (3) to control the switching of the hydraulically controlled directional valve (3). The hydraulic control port (K1) of the hydraulically controlled directional valve (3) is... The number of control ports (K1) is two. The hydraulic bridge circuit includes a wide-range holding valve (4) and a throttle valve (5). The accumulator (1) is connected to one of the hydraulic control ports (K1). The other hydraulic control port (K1) is connected to a portion of the oil line of the hydraulic bridge circuit between the wide-range holding valve (4) and the throttle valve (5). The throttle valve (5) is connected to the third oil port (B3) of the hydraulic control directional valve (3). The wide-range holding valve (4) is connected to the oil tank.

5. The filling valve according to claim 4, characterized in that, When the pressure of the hydraulic control port (K1) connected to the accumulator (1) is less than the spring force of the spring control chamber of the hydraulic directional valve (3), the first oil port (B1) of the hydraulic directional valve (3) is connected to its third oil port (B3), and the hydraulic oil flowing in from the oil inlet (P) is introduced into the accumulator (1) through the check valve (2).

6. The filling valve according to claim 5, characterized in that, The throttle valve (5) is located inside the hydraulic control directional valve (3). When the first oil port (B1) of the hydraulic control directional valve (3) is connected to its third oil port (B3), the hydraulic control port (K1) connected to the hydraulic bridge is connected to the oil inlet (P) through the throttle valve (5).

7. The filling valve according to any one of claims 1 to 6, characterized in that, The wide-range holding valve (4) is an adjustable flow valve.

8. A hydraulic braking system for vehicles, characterized in that, Includes the filling valve according to any one of claims 1 to 7.

9. A hydraulic steering system for vehicles, characterized in that, Includes the filling valve according to any one of claims 1 to 7.

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