Integrated brake fluid charging valve, hydraulic system and engineering machine

Abstract

An integrated brake fluid charging valve, a hydraulic system and an engineering machine. The integrated brake fluid charging valve comprises: a priority valve, a fluid charging pressure control valve, a first one-way valve, a second one-way valve, a proportional overflow valve and a pressure oil port, a first oil outlet, a second oil outlet, a third oil outlet and an oil return port. The pressure oil port is in fluid connection with the first oil outlet and the second oil outlet by means of the first one-way valve. The fluid charging pressure control valve is arranged between an oil inlet of the first one-way valve and the oil return port, and the priority valve and the proportional overflow valve are arranged in series between the pressure oil port and the oil return port. The second one-way valve is arranged between the priority valve and the third oil outlet. At least part of a hydraulic fluid input through the pressure oil port can be guided to the third oil outlet by means of the priority valve and the second one-way valve, and / or can be guided to the oil return port by means of the priority valve and the proportional overflow valve. The hydraulic system comprising the integrated brake fluid charging valve and the engineering machine are also provided. Integrating functions such as brake accumulator fluid charging, parking brake control and pilot oil supply into one valve block achieves an integrated design, thus reducing the difficulty and complexity of arrangement of hydraulic systems, and reducing system costs.

Description

Integrated brake filling valve, hydraulic system and construction machinery Technical Field

[0001] The present disclosure relates to the field of hydraulic technology, and more particularly to an integrated brake filling valve, a hydraulic system including the integrated brake filling valve, and an engineering machine including the hydraulic system. Background Art

[0002] Some types of construction machinery, such as loaders, utilize fully hydraulic brake systems, and their pilot systems require a pilot oil source. A common approach is to configure the brake system with a brake pump, while the pilot oil is supplied by another functional pump (the hydraulic oil output by the other functional pump is decompressed and then supplied to the pilot system), or to configure a separate pilot pump to maintain a constant pressure upstream of the pilot valve. This approach is particularly suitable for electrically driven loaders, as the motor offers excellent speed regulation. When used in conjunction with a metering pump, this creates a cost-effective and performance-optimized solution.

[0003] The disadvantage of using another functional pump, such as a metering pump, to provide pilot oil is that, even when there is no pilot action, the metering pump will still output flow and maintain a constant pressure in front of the pilot valve, which will result in continuous energy waste (in reality, neither the pilot system nor the brake system is always working, but only intermittently). In addition, configuring a separate pilot pump increases the cost and size of the pump.

[0004] The present disclosure is directed to solving at least one of the above-mentioned problems of the prior art as well as other problems.

[0005] Summary of the Invention

[0006] According to one aspect of the present disclosure, an integrated brake filling valve is provided, wherein the integrated brake filling valve includes a priority valve, a filling pressure control valve, a first one-way valve, a second one-way valve, a proportional relief valve, and a pressure oil port, a first oil outlet, a second oil outlet, a third oil outlet, and an oil return port, wherein:

[0007] The pressure oil port is fluidically connected to the first oil outlet and the second oil outlet via the first one-way valve;

[0008] The filling pressure control valve is arranged between the oil inlet of the first one-way valve and the oil return port;

[0009] The priority valve and the proportional relief valve are arranged in series between the pressure oil port and the return oil port;

[0010] The second one-way valve is arranged between the priority valve and the third oil outlet;

[0011] At least a portion of the hydraulic fluid input through the pressure oil port can be guided to the third oil outlet via the priority valve and the second one-way valve, and / or can be guided to the oil return port via the priority valve and the proportional relief valve.

[0012] Advantageously, the integrated brake filling valve further comprises a parking brake solenoid valve, which is arranged between the oil outlet of the first one-way valve and the second oil outlet.

[0013] Advantageously, the integrated brake charging valve further comprises a reverse shuttle valve, the first oil outlet comprises two brake accumulator oil ports, and the reverse shuttle valve is arranged between the oil outlet of the first one-way valve and the two brake accumulator oil ports.

[0014] Advantageously, the integrated brake filling valve further comprises a safety overflow valve arranged between the pressure oil port and the oil return port.

[0015] Advantageously, the oil return port comprises a first oil return port and a second oil return port, wherein the charging pressure control valve is fluidically connected to the first oil return port, and the proportional relief valve is fluidically connected to the second oil return port.

[0016] According to another aspect of the present disclosure, a hydraulic system is provided, comprising a hydraulic pump, a brake accumulator, a parking brake device, and a hydraulic oil tank, wherein the hydraulic system further comprises an integrated brake charging valve according to the present disclosure, wherein:

[0017] The pressure oil port of the integrated brake charging valve is fluidly connected to the output port of the hydraulic pump, the first oil outlet is fluidly connected to the brake accumulator, the second oil outlet is fluidly connected to the parking brake device, and the oil return port is fluidly connected to the hydraulic oil tank.

[0018] Advantageously, the third oil outlet of the integrated brake charging valve includes a pilot oil supply port and a pilot accumulator oil port, the pilot oil supply port is fluidically connected to the pilot valve of the hydraulic system, and the pilot accumulator oil port is fluidically connected to the pilot accumulator of the hydraulic system.

[0019] Advantageously, in a hydraulic system according to the present disclosure:

[0020] The hydraulic fluid provided by the hydraulic pump can be preferentially supplied to the first oil outlet and the second oil outlet via the pressure oil port of the integrated brake charging valve;

[0021] When the flow rate of the hydraulic fluid provided by the hydraulic pump is greater than the flow rate required by the brake accumulator and / or the parking brake device, at least a portion of the hydraulic fluid input through the pressure oil port can be directed to the third oil outlet via the priority valve and the second one-way valve, and / or can be directed to the return oil port via the priority valve and the proportional relief valve.

[0022] Advantageously, the proportional relief valve can be used to adjust the flow distribution of the hydraulic fluid between the second one-way valve and the proportional relief valve.

[0023] According to another aspect of the present disclosure, a construction machine including the hydraulic system is provided.

[0024] Key advantages of the integrated brake charge valve according to the present disclosure include:

[0025] (1) Integrate the functions of brake accumulator charging, parking brake control, and pilot oil supply into one valve block to achieve integrated design and reduce the difficulty and complexity of hydraulic system layout.

[0026] (2) Through functional integration, the brake and pilot share one pump, and through reasonable matching and control, a smaller displacement pump can be selected, reducing system costs.

[0027] (3) Through the reasonable control of the proportional relief valve, the pump can be kept in an unloading state except when the brake accumulator and the pilot accumulator are filled, thereby reducing the energy consumption and heat generation of the system.

[0028] (4) The electronically controlled proportional relief valve can avoid pressure fluctuations during the pilot accumulator filling process, making the subsequent pilot valve output stable.

[0029] (5) The independent oil return of the filling pressure control valve can prevent the influence of back pressure on the filling pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present disclosure will be described in more detail below with reference to the accompanying schematic drawings. The accompanying drawings and corresponding embodiments are for illustrative purposes only and are not intended to limit the present disclosure.

[0031] FIG1 schematically shows a hydraulic principle diagram of an integrated brake filling valve according to a preferred embodiment of the present disclosure.

[0032] List of reference numerals:

[0033] 1 Priority valve 2 Filling pressure control valve

[0034] 3 First one-way valve 4 Second one-way valve

[0035] 5 Proportional relief valve 6 First throttle hole

[0036] 7 Second throttle hole 8 Third throttle hole

[0037] 9 Parking brake solenoid valve 10 Reverse shuttle valve

[0038] 11 first spring 12 second spring

[0039] 13 Third spring 14 Fourth spring

[0040] 15 Fifth spring 16 Safety relief valve

[0041] 17 Filter 18 Pilot accumulator

[0042] 100 integrated brake filling valve DETAILED DESCRIPTION

[0043] Embodiments of the present disclosure are described below with reference to the accompanying drawings. In the following description, many specific details are set forth so that those skilled in the art can more fully understand and implement the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure may be implemented without some of these specific details. Furthermore, it should be understood that the present disclosure is not limited to the specific embodiments described. On the contrary, any combination of the features and elements described below may be considered to implement the present disclosure, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments, and advantages are for illustrative purposes only and should not be considered as elements or limitations of the claims unless expressly set forth in the claims.

[0044] FIG1 schematically shows a hydraulic principle diagram of an integrated brake filling valve 100 for construction machinery or other types of machinery according to a preferred embodiment of the present disclosure.

[0045] As shown in Figure 1, the integrated brake charge valve 100 includes a priority valve 1, a charge pressure control valve 2, a first check valve 3, a second check valve 4, a proportional relief valve 5, as well as a pressure oil port P, a first oil outlet port, a second oil outlet port PB, a third oil outlet port, and an oil return port. In the embodiment shown in Figure 1, two oil return ports are provided: a first oil return port T1 and a second oil return port T2.

[0046] The pressure oil port P or the oil inlet is fluidically connected to the oil inlet of the first one-way valve 3 via the first throttle hole 6 , and the oil outlet of the first one-way valve 3 is fluidically connected to the first oil outlet and the second oil outlet PB respectively.

[0047] The charging pressure control valve 2 is arranged between the oil inlet of the first check valve 3 and the first oil return port T1. The priority valve 1 and the proportional relief valve 5 are arranged in series between the pressure oil port P and the second oil return port T2.

[0048] Specifically, the oil inlet of priority valve 1 is fluidly connected to pressure oil port P, and its oil outlet is fluidly connected to the oil inlets of second check valve 4 and proportional relief valve 5, respectively. A first spring 11 is provided at the first end of the valve core of priority valve 1. The spring chamber accommodating first spring 11 is fluidly connected to the oil inlet of charge pressure control valve 2 via third throttle orifice 8. A control port is provided at the second end of the valve core of priority valve 1, which is fluidly connected to the oil inlet of priority valve 1.

[0049] The priority valve 1 has a first position where its oil inlet and oil outlet are fluidly disconnected, and a second position where its oil inlet and oil outlet are fluidly connected. A first spring 11 biases the valve core of the priority valve 1 toward the first position.

[0050] The oil inlet of the charging pressure control valve 2 is fluidically connected to the oil inlet of the first check valve 3 via a second throttle orifice 7, and the oil outlet is fluidically connected to the first oil return port T1. A second spring 12 is provided at the first end of the valve core of the charging pressure control valve 2, and a control port is provided at the second end to fluidically connect the oil inlet of the charging pressure control valve 2 and the oil outlet of the first check valve 3, respectively.

[0051] The charge pressure control valve 2 has a first position in which the oil inlet and the oil outlet are fluidly disconnected, and a second position in which the oil inlet and the oil outlet are fluidly connected. The second spring 12 biases the valve core of the charge pressure control valve 2 toward the first position.

[0052] The oil outlet of the second one-way valve 4 is fluidically connected to the third oil outlet.

[0053] The proportional relief valve 5 is an electrically controlled proportional relief valve. Its oil outlet is fluidically connected to the second oil return port T2. A third spring 13 is mounted on the first end of the valve core, while the second end of the valve core is equipped with an electromagnet and a control port fluidically connected to the oil inlet of the proportional relief valve 5.

[0054] The proportional relief valve 5 has a first position where its oil inlet and oil outlet are fluidly disconnected, and a second position where its oil inlet and oil outlet are fluidly connected. The third spring 13 biases the valve core of the proportional relief valve 5 toward the first position.

[0055] According to the present disclosure, at least a portion of the hydraulic fluid (hydraulic oil) input through the pressure oil port P can be directed to the third oil outlet via the priority valve 1 and the second one-way valve 4, and / or directed to the second oil return port T2 via the priority valve 1 and the proportional relief valve 5. Advantageously, by adjusting the position of the valve core of the proportional relief valve 5, the flow distribution of the hydraulic fluid between the second one-way valve 4 and the proportional relief valve 5 can be adjusted.

[0056] As shown in Figure 1, the integrated brake filling valve 100 also includes a parking brake solenoid valve 9, which is disposed between the oil outlet of the first check valve 3 and the second oil outlet PB. Specifically, the parking brake solenoid valve 9 is designed as a two-position, three-way valve, for example. Its first oil port is fluidically connected to the oil outlet of the first check valve 3, its second oil port is fluidically connected to the second oil outlet PB, and its third oil port is fluidically connected to the second oil return port T2. A fourth spring 14 is provided at the first end of the valve core of the parking brake solenoid valve 9, and an electromagnet is provided at the second end of the valve core.

[0057] The parking brake solenoid valve 9 has a first position and a second position. In the first position, the second oil port and the third oil port of the parking brake solenoid valve are in fluid communication, and the first oil port is blocked. In the second position, the first oil port and the second oil port of the parking brake solenoid valve 9 are in fluid communication, and the third oil port is blocked. A fourth spring 14 biases the valve spool of the parking brake solenoid valve 9 toward the first position.

[0058] In the embodiment shown in Figure 1, the integrated brake filling valve 100 also includes a reverse shuttle valve 10, the first oil outlet includes two brake accumulator oil ports A1 and A2, the oil inlet of the reverse shuttle valve 10 is fluidly connected to the oil outlet of the first one-way valve 3, and the two oil outlets of the reverse shuttle valve 10 are respectively fluidly connected to the two brake accumulator oil ports A1 and A2.

[0059] Advantageously, the integrated brake charging valve 100 also includes a safety relief valve 16, whose inlet is fluidically connected to the pressure port P and whose outlet is fluidically connected to the second oil return port T2. A control port is provided at the first end of the valve spool of the safety relief valve 16, which is fluidically connected to the valve inlet. A fifth spring 15 is provided at the second end of the valve spool to bias the safety relief valve 16 toward a position where the inlet and outlet are fluidically disconnected. The safety relief valve 16 is used to limit the maximum pressure at the pressure port P, protecting system components. Advantageously, the relief pressure of the safety relief valve 16 is adjustable.

[0060] As shown in FIG1 , the integrated brake filling valve 100 may further include a first pressure sensor interface Ps1 fluidically connected to the oil outlet of the first one-way valve 3 , for monitoring the pressure at the oil outlet of the first one-way valve 3 by means of a pressure sensor.

[0061] In the embodiment shown in Figure 1, the third oil outlet includes filter interfaces a1, a2, a second pressure sensor interface Ps2, and at least one auxiliary function oil port. The second pressure sensor interface Ps2 is used to monitor the pressure at the third oil outlet with the help of a pressure sensor. The at least one auxiliary function oil port includes, for example, the pilot oil supply port F and the pilot accumulator oil port Acc shown in Figure 1. The filter interface a1 can be fluidically connected to the filter 17, so that the hydraulic fluid flowing out through the filter interface a1 can be filtered through the filter 17 and then guided to the pilot oil supply port F and the pilot accumulator oil port Acc through the filter interface a2. The third oil outlet can also include other auxiliary function oil ports, such as an oil port that is directly fluidically connected to the oil outlet of the second one-way valve 4, and the oil port can be connected to other functional components of the hydraulic system (such as a fan).

[0062] Advantageously, the integrated brake charging valve 100 may further include a pressure measuring port M1 fluidically connected to the pressure oil port P so as to monitor the pressure of the hydraulic fluid input through the pressure oil port P.

[0063] Advantageously, the switching between the first position and the second position of the parking brake solenoid valve 9 and the proportional relief valve 5 is controlled by a controller. The controller may be a whole machine controller of the engineering machinery. In one embodiment, the controller is, for example, an electronic control module (ECM) of the engineering machinery.

[0064] Advantageously, the sizes of the second throttle hole 7 and the third throttle hole 8 are designed to be smaller than the size of the first throttle hole 6, so that when the priority valve 1 and the charging pressure control valve 2 are each in the second position, only a small portion of the hydraulic fluid reaches the first oil return port T1 via the charging pressure control valve 2.

[0065] It should be understood that the integrated brake charge valve 100 may include only a portion of the multiple components described above with reference to FIG. 1 . For example, in one embodiment, the integrated brake charge valve 100 may include only the priority valve 1 , the charge pressure control valve 2 , the first check valve 3 , the second check valve 4 , the proportional relief valve 5 , and associated oil ports. Furthermore, more components may be integrated into the integrated brake charge valve 100 .

[0066] Industrial Applicability

[0067] The integrated brake filling valve 100 according to the present disclosure is applicable to various engineering machines (such as excavators, loaders, bulldozers, etc.) or other machines with similar working conditions. The working principle of the hydraulic system including the integrated brake filling valve 100 is explained below using a loader as an example.

[0068] The loader's hydraulic system includes a hydraulic pump, a brake accumulator, a parking brake system, a hydraulic oil tank, and an integrated brake charging valve 100. The integrated brake charging valve 100 has its pressure oil port P fluidically connected to the hydraulic pump's output port, two brake accumulator oil ports A1 and A2 fluidically connected to the brake accumulator, a second oil outlet port PB fluidically connected to the parking brake system, and a first and second oil return ports T1 and T2 fluidically connected to the hydraulic oil tank. Furthermore, the brake accumulator oil ports A1 and A2 and the brake accumulator are also fluidically connected to the loader's service brake system.

[0069] Advantageously, the parking brake device is of a hydraulic release type, ie, the brake can be released when hydraulic fluid is delivered to the brake release chamber of the brake, and braking can be achieved when the hydraulic fluid in the brake release chamber of the brake is released.

[0070] In addition, the filter port a1 is fluidly connected to the filter 17 , the outlet of the filter 17 is fluidly connected to the filter port a2 , the pilot oil supply port F is fluidly connected to the pilot valve of the hydraulic system, and the pilot accumulator oil port Acc is fluidly connected to the pilot accumulator 18 of the hydraulic system.

[0071] Hydraulic fluid provided by the hydraulic pump is preferentially supplied to the first and second outlet ports PB via the pressure port P of the integrated brake charging valve 100 to charge the brake accumulator and / or to the parking brake device for releasing the parking brake. Integrated brake charging valve 100 ensures prioritized brake accumulator charging, a constant charging flow, and electronically controlled parking and releasing.

[0072] When the flow rate of hydraulic fluid provided by the hydraulic pump exceeds the flow rate required by the brake accumulator and / or parking brake device (e.g., when the brake accumulator is fully charged), priority valve 1 and charge pressure control valve 2 are each switched to a second position, where their respective inlets and outlets are fluidly connected. Due to the smaller size of second orifice 7, the majority of the hydraulic fluid from pressure port P flows through priority valve 1 and then through second check valve 4 to a third outlet, such as pilot supply port F and pilot accumulator port Acc, to supply the construction machine's pilot system, or to an auxiliary port fluidically connected to the construction machine's fan to supply the fan.

[0073] When the pressure sensor at the second pressure sensor port Ps2 detects that the pilot accumulator 18 is under pressure and needs to be charged, the controller controls the pressure upstream of the proportional relief valve 5 to allow hydraulic fluid to charge the pilot accumulator 18. The controller also controls the charging pressure and rate of the pilot accumulator 18 via the proportional relief valve 5. When the pressure in the pilot accumulator 18 reaches the set value, the controller unloads the pilot accumulator 18 via the proportional relief valve 5.

[0074] The main advantages of the integrated brake filling valve 100 are as follows:

[0075] (1) Integrate the functions of brake accumulator charging, parking brake control, and pilot oil supply into one valve block to achieve integrated design and reduce the difficulty and complexity of hydraulic system layout.

[0076] (2) Through functional integration, the brake and pilot share one pump, and through reasonable matching and control, a smaller displacement pump can be selected, reducing system costs.

[0077] (3) Through the reasonable control of the proportional relief valve, the pump can be in an unloading state except for the charging of the brake accumulator and the pilot accumulator, thereby reducing the energy consumption and heat generation of the system.

[0078] (4) The electronically controlled proportional relief valve can avoid pressure fluctuations during the pilot accumulator filling process, making the subsequent pilot valve output stable.

[0079] (5) The independent oil return of the filling pressure control valve can prevent the influence of back pressure on the filling pressure.

[0080] The integrated brake filling valve of the present disclosure has been described above with the aid of specific embodiments. It will be apparent to those skilled in the art that various changes and modifications may be made to the integrated brake filling valve of the present disclosure without departing from the design principles of the present disclosure. For example, an implementation of the present disclosure may not include some of the specific features described, and the present disclosure is not limited to the specific embodiments described, but rather any combination of the described features and elements may be envisioned. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed integrated brake filling valve. The description and examples are to be regarded as illustrative only, with the true scope being indicated by the appended claims and their equivalents.

Claims

1. An integrated brake filling valve, characterized in that: The integrated brake filling valve comprises a priority valve, a filling pressure control valve, a first one-way valve, a second one-way valve, a proportional relief valve, a pressure oil port, a first oil outlet, a second oil outlet, a third oil outlet and an oil return port, wherein: The pressure oil port is fluidically connected to the first oil outlet and the second oil outlet via a first one-way valve; The filling pressure control valve is arranged between the oil inlet of the first one-way valve and the oil return port; The priority valve and the proportional relief valve are arranged in series between the pressure oil port and the return oil port; The second one-way valve is arranged between the priority valve and the third oil outlet; At least a portion of the hydraulic fluid input through the pressure oil port can be guided to the third oil outlet via the priority valve and the second check valve, and / or can be guided to the return oil port via the priority valve and the proportional relief valve.

2. The integrated brake filling valve according to claim 1, characterized in that: The integrated brake filling valve further includes a parking brake solenoid valve, which is arranged between the oil outlet of the first one-way valve and the second oil outlet.

3. The integrated brake filling valve according to claim 2, characterized in that: The integrated brake filling valve further comprises a reverse shuttle valve, the first oil outlet comprises two brake accumulator oil ports, and the reverse shuttle valve is arranged between the oil outlet of the first one-way valve and the two brake accumulator oil ports.

4. The integrated brake filling valve according to claim 3, characterized in that: The integrated brake filling valve also includes a safety overflow valve arranged between the pressure oil port and the oil return port.

5. The integrated brake filling valve according to any one of claims 1 to 4, characterized in that: The oil return port comprises a first oil return port and a second oil return port, wherein the charging pressure control valve is fluidically connected to the first oil return port, and the proportional relief valve is fluidically connected to the second oil return port.

6. A hydraulic system comprising a hydraulic pump, a brake accumulator, a parking brake device and a hydraulic oil tank, characterized in that: The hydraulic system further comprises an integrated brake filling valve according to any one of claims 1 to 5, wherein: The pressure oil port of the integrated brake charging valve is fluidly connected to the output port of the hydraulic pump, the first oil outlet is fluidly connected to the brake accumulator, the second oil outlet is fluidly connected to the parking brake device, and the oil return port is fluidly connected to the hydraulic oil tank.

7. The hydraulic system according to claim 6, characterized in that: The third oil outlet of the integrated brake charging valve includes a pilot oil supply port and a pilot accumulator oil port. The pilot oil supply port is connected to the pilot valve fluid of the hydraulic system, and the pilot accumulator oil port is connected to the pilot accumulator fluid of the hydraulic system.

8. The hydraulic system according to claim 6 or 7, characterized in that: The hydraulic fluid provided by the hydraulic pump can be preferentially supplied to the first oil outlet and the second oil outlet via the pressure oil port of the integrated brake charging valve; When the flow rate of hydraulic fluid provided by the hydraulic pump is greater than the flow rate required by the brake accumulator and / or the parking brake device, at least a portion of the hydraulic fluid input through the pressure oil port can be directed to the third oil outlet via the priority valve and the second one-way valve, and / or can be directed to the return oil port via the priority valve and the proportional relief valve.

9. The hydraulic system according to claim 8, characterized in that: The proportional relief valve can be used to adjust the flow distribution of the hydraulic fluid between the second check valve and the proportional relief valve.

10. An engineering machine, characterized in that: The construction machine comprises a hydraulic system according to any one of claims 6 to 9.

Images