Loader hydraulic braking system and loader

Abstract

The utility model discloses a hydraulic braking system of a loading machine and the loading machine. The hydraulic braking system comprises a whole vehicle controller, a braking execution part, a shuttle valve, a braking valve, an electric proportional valve and an energy accumulator, when a first brake signal is input into the vehicle control unit, pressure oil in the energy accumulator enters the shuttle valve through the brake valve and then enters the brake execution part; and when a second brake signal is input into the vehicle control unit, the pressure oil in the energy accumulator enters the shuttle valve through the electric proportional valve and then enters the brake execution part. According to the hydraulic braking system, due to the fact that the braking valve and the electric proportional valve are arranged in parallel, the hydraulic braking system can achieve external control, braking can be achieved without stepping on a braking pedal, and braking operation modes are diversified.

Description

Technical Field

[0001] The utility model relates to the technical field of loader braking, in particular to a hydraulic braking system for a loader and a loader. Background Art

[0002] The commonly used braking system of existing loaders is mainly hydraulic braking, which mainly consists of a brake pump, a brake valve, a filling valve, an accumulator, a filter, and a brake caliper. Its working principle is that the oil source of the brake pump enters the filling valve after being filtered by the filter, and the filling valve fills the accumulator with liquid to keep the pressure of the accumulator within a certain range. When the brake pedal connected to the brake valve is depressed, the oil fluid enters the brake valve from the accumulator, and the brake valve outputs the oil source to the brake caliper to achieve the braking of the whole machine. However, the existing hydraulic braking system of loaders cannot achieve external holes. During braking, it is necessary to depress the brake pedal to achieve braking, which limits its working scenarios. Summary of the Utility Model

[0003] In order to overcome at least one of the above-mentioned defects of the existing technology, one of the purposes of the present utility model is to provide a hydraulic braking system for a loader. By arranging a brake valve and an electro-hydraulic proportional valve in parallel, the hydraulic braking system can achieve external control, and it is no longer necessary to depress the brake pedal to achieve braking, making the braking operation methods diversified.

[0004] In order to overcome at least one of the above-mentioned defects of the existing technology, one of the purposes of the present utility model is to provide a loader. The aforesaid hydraulic braking system for a loader is applied to this loader, so that the loader has various braking operation methods and improves the usage scenarios of the loader.

[0005] The technical solution adopted by the present utility model to solve its problems is as follows:

[0006] A hydraulic braking system for a loader includes a vehicle controller, a brake actuator, a pressure sensor, a shuttle valve, a brake valve, an electro-hydraulic proportional valve, and an accumulator;

[0007] The oil inlet of the brake valve is connected to the oil port of the accumulator, and the oil outlet of the brake valve is connected to the first oil inlet of the shuttle valve;

[0008] The oil inlet of the electro-hydraulic proportional valve is connected to the oil port of the accumulator, and the oil outlet of the electro-hydraulic proportional valve is connected to the second oil inlet of the shuttle valve;

[0009] The oil outlet of the shuttle valve is connected to the brake actuator;

[0010] When a first braking signal is input to the vehicle controller, the pressurized oil in the accumulator enters the shuttle valve through the brake valve, and then enters the brake actuator;

[0011] When a second braking signal is input to the vehicle controller, the pressure oil in the accumulator enters the shuttle valve through the electro-hydraulic proportional valve and then enters the braking actuator;

[0012] When a first braking signal and a second braking signal are simultaneously input to the vehicle controller, the pressure oil discharged from the oil port of the accumulator respectively passes through the braking valve and the electro-hydraulic proportional valve, then both enter the shuttle valve, and then enter the braking actuator.

[0013] Further: The braking actuator includes a front axle and a rear axle, and a shuttle valve is respectively connected to each of the front axle and the rear axle;

[0014] Two electro-hydraulic proportional valves are provided, one of the electro-hydraulic proportional valves is connected to the second oil inlet of one of the shuttle valves, and the other electro-hydraulic proportional valve is connected to the second oil inlet of the other shuttle valve.

[0015] Further: Two accumulators are provided, one of the accumulators is connected to one of the electro-hydraulic proportional valves, and the other accumulator is connected to the other electro-hydraulic proportional valve.

[0016] Further: One braking valve is provided, and the braking valve has a first liquid inlet, a second liquid inlet, a first liquid outlet and a second liquid outlet;

[0017] The first liquid inlet is connected to the oil port of one of the accumulators, and the second liquid inlet is connected to the oil port of the other accumulator;

[0018] The first liquid outlet is connected to the first oil inlet of one of the shuttle valves, and the second liquid outlet is connected to the first oil inlet of the other shuttle valve.

[0019] Further: The pressure sensor is arranged at the oil outlet position of the shuttle valve, acquires the braking system pressure, and transmits the braking system pressure value signal to the vehicle controller, and the vehicle controller controls whether the accumulator is filled with oil according to the braking system pressure value signal.

[0020] Further: Two pressure sensors are provided, one of the pressure sensors is arranged at the oil outlet position of one of the shuttle valves, and the other pressure sensor is arranged at the oil outlet position of the other shuttle valve.

[0021] Further: It further includes an oil tank, a brake pump, a filter and a flushing valve;

[0022] The inlet of the brake pump is connected and communicated with the oil tank. The outlet of the brake pump is connected to the inlet of the filter. The outlet of the filter is connected to the inlet of the oil filling valve. The oil filling valve has a first outlet and a second outlet. The first outlet is connected to the oil port of one of the accumulators, and the second outlet is connected to the oil port of the other accumulator.

[0023] Further: The oil filling valve further has a third outlet, and the third outlet is connected and communicated with the oil tank.

[0024] Further: The first braking signal is the braking signal sent by stepping on the brake pedal to the brake valve.

[0025] The second braking signal is the braking signal input by the vehicle controller to the electro-hydraulic proportional valve.

[0026] A wheel loader includes the aforementioned wheel loader hydraulic braking system.

[0027] In summary, the wheel loader hydraulic braking system provided by the present invention has the following technical effects: By adding an electro-hydraulic proportional valve, and the electro-hydraulic proportional valve is arranged in parallel with the brake valve. When the second braking signal is input to the vehicle controller, the pressurized oil in the accumulator enters the shuttle valve through the electro-hydraulic proportional valve and then enters the braking execution part to realize the braking operation, making the braking operation of the hydraulic braking system diversified, capable of realizing braking through external control, and increasing the braking application scenarios of the wheel loader.

[0028] In summary, the wheel loader provided by the present invention has the following technical effects: The aforementioned wheel loader hydraulic braking system is applied to this wheel loader, making the wheel loader have multiple braking operation methods and improving the usage scenarios of the wheel loader. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the braking principle of a wheel loader hydraulic braking system of the present invention.

[0030] Among them, the meanings of the reference numerals are as follows:

[0031] 1. Brake pump; 2. Filter; 3. Oil filling valve; 4. Accumulator; 5. Brake valve; 6. Electro-hydraulic proportional valve; 7. Shuttle valve; 8. Pressure sensor; 9. Braking execution part. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] For better understanding and implementation, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0033] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present utility model belongs. The terms used in the description of the present utility model herein are only for the purpose of describing specific embodiments and are not intended to limit the present utility model.

[0035] Refer to Figure 1 , the present utility model discloses a hydraulic braking system for a loader.

[0036] A hydraulic braking system for a loader includes a vehicle controller, a braking actuator 9, a pressure sensor 8, a shuttle valve 7, a braking valve 5, an electro-hydraulic proportional valve 6, and an accumulator 4.

[0037] The oil inlet of the braking valve 5 is connected to the oil port of the accumulator 4, and the oil outlet of the braking valve 5 is connected to the first oil inlet of the shuttle valve 7.

[0038] The oil inlet of the electro-hydraulic proportional valve 6 is connected to the oil port of the accumulator 4, and the oil outlet of the electro-hydraulic proportional valve 6 is connected to the second oil inlet of the shuttle valve 7.

[0039] The oil outlet of the shuttle valve 7 is connected to the braking actuator 9.

[0040] When a first braking signal is input to the vehicle controller, the pressurized oil in the accumulator 4 passes through the braking valve 5 into the shuttle valve 7, and then into the braking actuator 9.

[0041] When a second braking signal is input to the vehicle controller, the pressurized oil in the accumulator 4 passes through the electro-hydraulic proportional valve 6 into the shuttle valve 7, and then into the braking actuator 9.

[0042] When a first braking signal and a second braking signal are simultaneously input to the vehicle controller, the pressurized oil discharged from the oil port of the accumulator 4 passes through the braking valve 5 and the electro-hydraulic proportional valve 6 respectively, then both enter the shuttle valve 7, and then into the braking actuator 9.

[0043] Based on the above solution, a hydraulic braking system that outputs braking pressure in parallel by using an electro-hydraulic proportional valve 6 and a braking valve 5 is adopted to achieve braking of the loader. During the braking process, it can be manually controlled by stepping on the brake pedal, and it can also be a hydraulic braking system for a loader that realizes external control by sending a braking signal to the vehicle controller.

[0044] Based on the above solution, by adding an electro-hydraulic proportional valve 6, and arranging the electro-hydraulic proportional valve in parallel with the brake valve 5, and when the second braking signal is input to the vehicle controller, the pressure oil in the accumulator 4 enters the shuttle valve 7 through the electro-hydraulic proportional valve 6, and then enters the brake actuator 9, realizing the braking operation, making the braking operation of the braking system diversified, and being able to achieve braking through external control, increasing the braking application scenarios of the loader.

[0045] Based on the above solution, there are the following three braking methods for a loader hydraulic braking system.

[0046] First, when the first braking signal is input to the vehicle controller, the pressure oil in the accumulator 4 enters the shuttle valve 7 through the brake valve 5, and then enters the brake actuator 9. The specific process is as follows: when braking is required, step on the brake pedal, the brake valve 5 opens, and the pressure oil enters the shuttle valve 7 from the accumulator 4 through the brake valve 5 and the first oil inlet of the shuttle valve 7, and is output from the oil outlet of the shuttle valve 7 to the brake actuator 9 to realize the braking of the whole vehicle.

[0047] Second, when the second braking signal is input to the vehicle controller, the pressure oil in the accumulator 4 enters the shuttle valve 7 through the electro-hydraulic proportional valve 6, and then enters the brake actuator 9. The specific process is as follows: input the braking signal to the vehicle controller through external control, the vehicle controller inputs current to the electro-hydraulic proportional valve 6, the electro-hydraulic proportional valve 6 opens, the pressure oil in the accumulator 4 enters the electro-hydraulic proportional valve 6 through the oil port of the accumulator 4, then enters the shuttle valve 7 from the electro-hydraulic proportional valve 6, and is output from the port of the shuttle valve 7 to the brake actuator 9 to realize the braking of the whole vehicle.

[0048] Third, when the first braking signal and the second braking signal are simultaneously input to the vehicle controller, the pressure oil discharged from the oil port of the accumulator 4 passes through the brake valve 5 and the electro-hydraulic proportional valve 6 respectively, and then both enter the shuttle valve 7, and then enter the brake actuator 9. That is, during the braking process, while stepping on the brake pedal, the braking signal is transmitted to the vehicle controller, so that the brake valve 5 and the electro-hydraulic proportional valve 6 are started and work simultaneously, and the brake valve 5 and the electro-hydraulic proportional valve 6 both transport hydraulic oil to the shuttle valve 7 to realize the braking operation.

[0049] In this technical solution, the brake actuator 9 includes a front axle and a rear axle, and a shuttle valve 7 is respectively connected to the front axle and the rear axle.

[0050] Two electro-hydraulic proportional valves 6 are provided, one of the electro-hydraulic proportional valves 6 is connected to the second oil inlet of one of the shuttle valves 7, and the other electro-hydraulic proportional valve 6 is connected to the second oil inlet of the other shuttle valve 7.

[0051] By setting two shuttle valves 7 and two electro-hydraulic proportional valves 6, during braking, the pressure of the hydraulic oil transported to the total brake actuator 9 is ensured to ensure reliable braking.

[0052] In this technical solution, two accumulators 4 are provided. One accumulator 4 is connected to an electro-hydraulic proportional valve 6, and the other accumulator 4 is connected to another electro-hydraulic proportional valve 6.

[0053] By providing two accumulators 4, hydraulic oil is respectively supplied to the electro-hydraulic proportional valves 6, which improves the braking reaction speed and shortens the braking reaction time.

[0054] In this technical solution, one brake valve 5 is provided. The brake valve 5 has a first liquid inlet, a second liquid inlet, a first liquid outlet, and a second liquid outlet.

[0055] The first liquid inlet is connected to the oil port of one of the accumulators 4, and the second liquid inlet is connected to the oil port of the other accumulator 4.

[0056] The first liquid outlet is connected to the first oil inlet of one of the shuttle valves 7, and the second liquid outlet is connected to the first oil inlet of the other shuttle valve 7.

[0057] The brake valve 5 adopts a two-position four-way valve, which is convenient for installation and has a low failure rate.

[0058] In this technical solution, the pressure sensor 8 is arranged at the oil outlet position of the shuttle valve 7 to obtain the braking system pressure and transmit the braking system pressure value signal to the vehicle controller. The vehicle controller controls whether the accumulator 4 is filled with oil according to the braking system pressure value signal. Two pressure sensors 8 are respectively arranged at the oil outlet positions of the two shuttle valves 7 to monitor the braking system pressure in real time, ensure the normal oil pressure in the accumulator 4, and be ready for braking at any time.

[0059] In this technical solution, two pressure sensors 8 are provided. One pressure sensor 8 is arranged at the oil outlet position of one of the shuttle valves 7, and the other pressure sensor 8 is arranged at the oil outlet position of the other shuttle valve 7.

[0060] In this technical solution, the hydraulic braking system of the loader further includes an oil tank, a brake pump 1, a filter 2, and a charging valve;

[0061] The inlet of the brake pump 1 is connected and communicated with the oil tank. The outlet of the brake pump 1 is connected to the inlet of the filter 2. The outlet of the filter 2 is connected to the inlet of the charging valve. The charging valve has a first outlet and a second outlet. The first outlet is connected to the oil port of one of the accumulators 4, and the second outlet is connected to the oil port of the other accumulator 4.

[0062] During operation, the hydraulic oil is input into the filter 2 through the brake pump 1. The oil passes through the filter 2 and then enters the charging valve 3. When the system pressure is lower than the set pressure, the charging valve 3 supplies liquid and oil to the two accumulators 4 respectively through the first outlet and the second outlet. When the pressure sensor 8 senses that the braking system pressure reaches the set pressure value, the charging valve 3 stops supplying liquid, and the hydraulic oil returns from the charging valve 3 to the hydraulic oil tank.

[0063] The oil filling valve further has a third outlet, which is connected to and communicates with the oil tank. When the pressure sensor 8 senses that the pressure of the braking system reaches the set pressure value, the oil filling valve 3 stops filling the liquid, and the hydraulic oil returns to the hydraulic oil tank from the third outlet of the oil filling valve 3.

[0064] In this technical solution, the first braking signal is the braking signal sent by stepping on the brake pedal to the brake valve 5.

[0065] The second braking signal is the braking signal input by the vehicle controller to the electro-hydraulic proportional valve 6. By starting the electro-hydraulic proportional valve 6 through the second braking signal, external control of the braking system can be realized, such as being applicable in the fields of braking control or driverless driving. That is, in the braking system of this solution, the electro-hydraulic proportional valve 6 and the brake valve 5 are controlled in parallel, which can realize external remote control of the vehicle braking or realize driverless braking by setting a program.

[0066] In this solution, a loader is also proposed. The loader applies the aforementioned hydraulic braking system of the loader, which solves the problem that the loader cannot brake the whole vehicle through external control. The electro-hydraulic proportional valve 6 and the brake valve 5 are used to control the vehicle braking in parallel, which is more intelligent and has a wider application range.

[0067] The technical means disclosed in the solution of the present utility model are not limited to the technical means disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present utility model, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present utility model.

Claims

1. A hydraulic braking system for a loader, characterized in that: It includes a vehicle controller, a brake actuator, a pressure sensor, a shuttle valve, a brake valve, an electro-hydraulic proportional valve, and an accumulator; The inlet port of the brake valve is connected to the oil port of the accumulator, and the outlet port of the brake valve is connected to the first inlet port of the shuttle valve; The inlet port of the electro-hydraulic proportional valve is connected to the oil port of the accumulator, and the outlet port of the electro-hydraulic proportional valve is connected to the second inlet port of the shuttle valve; The outlet port of the shuttle valve is connected to the brake actuator; When a first brake signal is input to the vehicle controller, the pressurized oil in the accumulator enters the shuttle valve through the brake valve and then enters the brake actuator; When a second brake signal is input to the vehicle controller, the pressurized oil in the accumulator enters the shuttle valve through the electro-hydraulic proportional valve and then enters the brake actuator; When a first brake signal and a second brake signal are simultaneously input to the vehicle controller, the pressurized oil discharged from the oil port of the accumulator passes through the brake valve and the electro-hydraulic proportional valve respectively, then both enter the shuttle valve, and then enter the brake actuator.

2. The hydraulic braking system of a loader according to claim 1, wherein: The brake actuator includes a front axle and a rear axle, and a shuttle valve is respectively connected to each of the front axle and the rear axle; There are two electro-hydraulic proportional valves. One of the electro-hydraulic proportional valves is connected to the second inlet port of one of the shuttle valves, and the other electro-hydraulic proportional valve is connected to the second inlet port of the other shuttle valve.

3. The loader hydraulic braking system according to claim 2, wherein: There are two accumulators. One of the accumulators is connected to one of the electro-hydraulic proportional valves, and the other accumulator is connected to the other electro-hydraulic proportional valve.

4. The hydraulic braking system of a loader according to claim 3, wherein: There is one brake valve, and the brake valve has a first liquid inlet, a second liquid inlet, a first liquid outlet, and a second liquid outlet; The first liquid inlet is connected to the oil port of one of the accumulators, and the second liquid inlet is connected to the oil port of the other accumulator; The first liquid outlet is connected to the first inlet port of one of the shuttle valves, and the second liquid outlet is connected to the first inlet port of the other shuttle valve.

5. The hydraulic braking system of a loader according to any one of claims 1 to 4, characterized in that: The pressure sensor is arranged at the outlet port of the shuttle valve, acquires the brake system pressure, and transmits the brake system pressure value signal to the vehicle controller. The vehicle controller controls whether the accumulator is filled with oil according to the brake system pressure value signal.

6. The loader hydraulic braking system according to claim 5, wherein: There are two pressure sensors. One of the pressure sensors is arranged at the outlet port of one of the shuttle valves, and the other pressure sensor is arranged at the outlet port of the other shuttle valve.

7. The hydraulic braking system of a loader according to claim 3, wherein: It further includes an oil tank, a brake pump, a filter, and a flushing valve; The inlet port of the brake pump is connected and communicated with the oil tank. The outlet port of the brake pump is connected to the inlet of the filter. The outlet of the filter is connected to the inlet of the flushing valve. The flushing valve has a first outlet and a second outlet. The first outlet is connected to the oil port of one of the accumulators, and the second outlet is connected to the oil port of the other accumulator.

8. The hydraulic braking system of a loader according to claim 7, wherein: The flushing valve further has a third outlet, and the third outlet is connected and communicated with the oil tank.

9. The hydraulic braking system of a loader according to claim 1, wherein: The first brake signal is the brake signal transmitted from the brake pedal to the brake valve when the brake pedal is depressed; The second braking signal is a braking signal input by the vehicle controller to the electro-hydraulic proportional valve.

10. A loader, characterized in that, It includes the loader hydraulic braking system according to any one of claims 1 to 9.

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