Electro-hydraulic proportional core closing control system of loading machine

Abstract

The utility model relates to the technical field of hydraulic systems of loaders, and provides an electro-hydraulic proportional core closing control system of a loader, which comprises a hydraulic variable frequency motor, the output end of the hydraulic variable frequency motor is connected with a triple hydraulic pump, the input end of the triple hydraulic pump is communicated with an oil tank, and the output end of the triple hydraulic pump is connected with a steering unit, an action unit and a control unit; the steering unit comprises a pilot steering gear, a steering oil cylinder and a steering flow amplifying valve; the action unit comprises a three-way overflow speed regulating valve, an external control electromagnetic valve and a proportional core-closed multi-way valve; the three-way overflow speed regulating valve is connected with the steering flow amplifying valve; the control unit comprises a pilot handle, a pilot pressure selection valve, a pilot pressure sensor and a hydraulic motor controller, and the hydraulic motor controller is connected with the pilot pressure sensor, the external control electromagnetic valve and the hydraulic variable frequency motor. According to the hydraulic control system, the composite action and the micro-control action of the loading machine can be realized, hydraulic flow can be supplied as required, the energy loss is reduced, and the economical efficiency and the practicability of the loading machine in use are improved.

Description

Technical Field

[0001] This utility model relates to the technical field of hydraulic systems for loaders, and specifically to an electro-hydraulic proportional closed-core control system for loaders. Background Technology

[0002] Currently, the electrification of loaders is a green energy source that meets the needs of the times. The existing hydraulic systems of electric loaders generally retain the dual-pump combination of gear pumps used in diesel loaders, and use the speed adjustment of the motor to control the variable flow rate, which meets the basic working conditions of loaders and has a certain energy-saving effect.

[0003] However, the following drawbacks still exist: Currently, loaders generally use open circuits, and the extension and retraction of the working device cylinder is achieved through the switching action of the open-center multi-way valve in the middle position. The throttling loss is large and the economy is poor; moreover, it is not easy to meet the working requirements of the loader's compound action and micro-control action, and its practicality is poor.

[0004] Therefore, to address the above problems, a loader electro-hydraulic proportional closed-core control system is proposed. Utility Model Content

[0005] This invention addresses the shortcomings of existing technologies by developing an electro-hydraulic proportional closed-core control system for loaders. This system enables the loader to perform compound and micro-control actions, and can supply hydraulic flow on demand, reducing energy loss and improving economy and practicality.

[0006] To achieve the above objectives, this utility model employs the following technical solution:

[0007] A loader electro-hydraulic proportional closed-core control system includes a hydraulic variable frequency motor, the output end of which is connected to a triple hydraulic pump, the input end of which is connected to an oil tank, and the output end of which is connected to a steering unit, an actuation unit, and a control unit. The steering unit includes a pilot steering gear, a steering cylinder, and a steering flow amplification valve. The actuation unit includes a three-way relief speed control valve, an external control solenoid valve, and a proportional closed-core multi-way valve, with the three-way relief speed control valve connected to the steering flow amplification valve. The control unit includes a pilot handle, a pilot pressure selection valve, a pilot pressure sensor, and a hydraulic motor controller, with the hydraulic motor controller connected to the pilot pressure sensor, the external control solenoid valve, and the hydraulic variable frequency motor.

[0008] Preferably, the actuation unit also includes a bucket tilting cylinder and a boom cylinder, with the bucket tilting cylinder connected to a proportional closed-core multi-way valve and the boom cylinder connected to a proportional closed-core multi-way valve and a pilot pressure selection valve.

[0009] Preferably, the triple hydraulic pump includes a steering pump, a working pump, and a pilot pump. The steering pump is connected to the steering unit and is used to provide steering oil for the loader; the working pump is connected to the actuation unit and is used to provide actuation oil for the bucket cylinder and boom cylinder; the pilot pump is connected to the pilot pressure selection valve and is used to provide control oil for the pilot handle.

[0010] Preferably, the pilot steering gear is connected to the steering flow amplification valve and the pilot pump, and the steering flow amplification valve is connected to the steering pump and the steering cylinder to control the movement of the steering cylinder.

[0011] As a preferred embodiment, the three-way overflow speed control valve is connected to the working pump, the external control solenoid valve and the proportional closed-core multi-way valve, the external control solenoid valve is connected to the pilot pump and the pilot pressure selection valve, and the proportional closed-core multi-way valve is connected to the pilot pressure selection valve.

[0012] Preferably, the pilot pressure selection valve is connected to the pilot handle, and the pilot handle is connected to the pilot pressure sensor.

[0013] Preferably, it also includes a hydraulic oil cooler, a proportional closed-core multi-way valve, and a pilot handle.

[0014] As a preferred embodiment, the pilot steering gear, steering flow amplification valve, three-way relief speed control valve, external control solenoid valve, and hydraulic oil cooler are all connected back to the oil tank for oil return.

[0015] The effects provided in the utility model description are merely those of the embodiments, and not all the effects of the utility model. The above technical solution has the following advantages:

[0016] This invention utilizes a quantitative gear pump matched with a proportional closed-core multi-way valve to achieve compound actions while ensuring the gear pump's high cost-effectiveness. It fully leverages the frequency conversion performance of the hydraulic variable frequency motor to achieve on-demand flow supply. By using an externally controlled solenoid valve to reduce bypass overflow losses during idling, energy loss is minimized, thus meeting the requirements for energy saving, micro-control, and compound actions in loader operation. Furthermore, when using the same battery power, it can extend the loader's operating time and improve the loader's economic efficiency during operation. Attached Figure Description

[0017] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention.

[0018] Figure 1 This is a schematic diagram of the overall system connection according to an embodiment of the present utility model;

[0019] Figure 2 This is a schematic diagram of the connection of the steering unit in an embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the connection of the action unit in an embodiment of the present utility model;

[0021] Figure 4 This is a connection diagram of the control unit in an embodiment of the present utility model;

[0022] Figure 5 This is a schematic diagram showing the connection between the three-way overflow speed control valve and the external control solenoid valve in an embodiment of this utility model.

[0023] Figure 6 This is a schematic diagram of a proportional closed-core multi-way valve according to an embodiment of the present invention.

[0024] In the diagram, 1. Triple hydraulic pump; 2. Pilot steering gear; 3. Steering cylinder; 4. Steering flow amplification valve; 5. Three-way relief speed control valve; 6. External control solenoid valve; 7. Proportional closed-core multi-way valve; 8. Hydraulic oil cooler; 9. Bucket cylinder; 10. Boom cylinder; 11. Pilot handle; 12. Pilot pressure selection valve; 13. Hydraulic variable frequency motor; 14. Pilot pressure sensor; 15. Hydraulic motor controller; 101. Steering pump; 102. Working pump; 103. Pilot pump. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] like Figures 1-6 As shown, this utility model provides a technical solution:

[0027] A loader electro-hydraulic proportional closed-core control system includes a hydraulic variable frequency motor 13. The output end of the hydraulic variable frequency motor 13 is connected to a triple hydraulic pump 1 via a spline or coupling. The input end of the triple hydraulic pump 1 is connected to an oil tank containing hydraulic oil. The output end of the triple hydraulic pump 1 is connected to a steering unit, an actuation unit, and a control unit. The steering unit includes a pilot steering gear 2, a steering cylinder 3, and a steering flow amplification valve 4. The actuation unit includes a three-way relief speed control valve 5, an external control solenoid valve 6, and a proportional closed-core multi-way valve 7. The three-way relief speed control valve 5 is connected to the steering flow amplification valve 7. The flow amplification valve 4 includes a priority valve and a main valve core. The priority valve is connected to a three-way relief speed control valve 5, which is used to supply the excess flow through the flow amplification valve 4 to the actuating unit, thereby improving the efficiency of hydraulic oil use. The control unit includes a pilot handle 11, a pilot pressure selection valve 12, a pilot pressure sensor 14, and a hydraulic motor controller 15. The hydraulic motor controller 15 is connected to the pilot pressure sensor 14, an external control solenoid valve 6, and a hydraulic variable frequency motor 13, and is used to control the overall operation of the system.

[0028] In this embodiment, the actuation unit also includes a bucket-turning cylinder 9 and a boom cylinder 10. The internal connection of the proportional closed-core multi-way valve 7 is a conventional connection. The proportional closed-core multi-way valve 7 includes a bucket-turning valve core and a boom-turning valve core. The bucket-turning cylinder 9 is connected to the bucket-turning valve core of the proportional closed-core multi-way valve 7. The boom cylinder 10 is connected to the boom-turning valve core of the proportional closed-core multi-way valve 7 and the pilot pressure selection valve 12. Two boom cylinders 10 are provided, including a boom cylinder and a forearm cylinder. The boom cylinder and the forearm cylinder operate simultaneously to avoid excessive stroke and excessive oil pressure required when a single cylinder operates, thereby reducing oil pressure demand and improving economy.

[0029] In this embodiment, the triple hydraulic pump 1 includes a steering pump 101, a working pump 102, and a pilot pump 103. The steering pump 101 is connected to the steering unit and is used to provide steering oil for the loader. Specifically, the steering pump 101 is connected to the priority valve in the steering flow amplification valve 4. The working pump 102 is connected to the actuation unit and is used to provide actuation oil for the bucket cylinder 9 and the boom cylinder 10. Specifically, the working pump 102 is connected to the three-way overflow speed control valve 5. The pilot pump 103 is connected to the pilot pressure selection valve 12 and is used to provide control oil for the pilot handle 11. The pilot pump 103 is also connected to a safety valve, the other end of which is connected back to the oil tank to protect the pilot pump 103 and improve safety.

[0030] In this embodiment, the pilot steering unit 2 is connected to the steering flow amplification valve 4 and the pilot pump 103. The steering flow amplification valve 4 is connected to the steering pump 101 and the steering cylinder 3 and is used to control the movement of the steering cylinder 3. Two steering cylinders 3 are provided, and the two steering cylinders 3 can move simultaneously and in opposite directions to improve the steering efficiency of the loader.

[0031] In this embodiment, the three-way overflow speed control valve 5 is connected to the working pump 102, the external control solenoid valve 6 and the proportional closed-core multi-way valve 7. The external control solenoid valve 6 is connected to the pilot pump 103 and the pilot pressure selection valve 12. The proportional closed-core multi-way valve 7 is connected to the pilot pressure selection valve 12.

[0032] In this embodiment, the pilot pressure selection valve 12 is connected to the pilot handle 11, and the pilot handle 11 is connected to the pilot pressure sensor 14. Two pilot handles 11 are provided, and commonly used settings can be adopted to control different actions of the bucket cylinder 9 or the boom cylinder 10.

[0033] In this embodiment, a hydraulic oil cooler 8 is also included, which is connected to a proportional closed-core multi-way valve 7 and a pilot handle 11, for cooling the hydraulic oil and preventing the hydraulic oil temperature from being too high and affecting the control efficiency.

[0034] In this embodiment, the pilot steering gear 2, steering flow amplification valve 4, three-way overflow speed control valve 5, external control solenoid valve 6, and hydraulic oil cooler 8 are all connected back to the oil tank for oil return, so that the hydraulic system forms a loop and improves the system's economy. A return oil filter element is installed between the hydraulic oil cooler 8 and the oil tank to filter the hydraulic oil returning to the oil tank.

[0035] Working principle: The operator controls the pilot handle 11. Based on the angle of the pilot handle 11's movement, a corresponding pressure signal is output and transmitted via the pilot pressure sensor 14 to the hydraulic motor controller 15. The hydraulic motor controller 15 controls the output speed of the hydraulic variable frequency motor 13. When the output pressure is low, the valve core displacement of the proportional closed-core multi-way valve 7 is small, indicating a smaller required flow rate. The output speed of the hydraulic variable frequency motor 13 remains at idle. The triple hydraulic pump 1 outputs a small flow rate. Part of this flow enters the bucket cylinder 9 or the boom cylinder 10, resulting in a slower cylinder movement to meet micro-motion requirements. The excess flow returns to the oil tank via the three-way overflow speed control valve 5. When the output pressure is low... When the pressure is high, the valve core displacement of the proportional closed-core multi-way valve 7 is large, indicating that the required flow rate is also large. The output speed of the hydraulic variable frequency motor 13 changes proportionally according to the magnitude of the signal from the pilot pressure sensor 14. The triple hydraulic pump 1 outputs the corresponding flow rate into the bucket cylinder 9 or the boom cylinder 10 to achieve the flow rate requirement for the corresponding speed. At this time, there is no excess flow through the three-way relief speed control valve 5. When the pilot handle 11 is not in motion, the output pressure is zero. The hydraulic motor controller 15 outputs a signal to the external control solenoid valve 6 to make it work in the lower position. The output pressure of the pilot pump 103 acts on the three-way relief speed control valve 5 through the shuttle valve. The working pump 102 and the steering pump 101 are unloaded under low pressure to achieve energy saving.

[0036] Any aspects of this utility model that are not detailed herein are conventional technical means known to those skilled in the art.

[0037] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0038] Furthermore, the terms "first" and "second" 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "multiple" means two or more unless otherwise explicitly specified.

[0039] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

[0040] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A loader electro-hydraulic proportional closed-core control system, comprising a hydraulic variable frequency motor (13), characterized in that: The output end of the hydraulic variable frequency motor (13) is connected to the triple hydraulic pump (1), the input end of the triple hydraulic pump (1) is connected to the oil tank, and the output end of the triple hydraulic pump (1) is connected to the steering unit, the action unit and the control unit. The steering unit includes a pilot steering gear (2), a steering cylinder (3), and a steering flow amplification valve (4); The actuation unit includes a three-way overflow speed control valve (5), an external control solenoid valve (6), and a proportional closed-core multi-way valve (7). The three-way overflow speed control valve (5) is connected to the directional flow amplification valve (4). The control unit includes a pilot handle (11), a pilot pressure selection valve (12), a pilot pressure sensor (14), and a hydraulic motor controller (15). The hydraulic motor controller (15) is connected to the pilot pressure sensor (14), the external control solenoid valve (6), and the hydraulic variable frequency motor (13).

2. The loader electro-hydraulic proportional closed-core control system according to claim 1, characterized in that: The actuation unit also includes a bucket cylinder (9) and a boom cylinder (10). The bucket cylinder (9) is connected to a proportional closed-core multi-way valve (7), and the boom cylinder (10) is connected to the proportional closed-core multi-way valve (7) and a pilot pressure selection valve (12).

3. The loader electro-hydraulic proportional closed-core control system according to claim 2, characterized in that: The triple hydraulic pump (1) includes a steering pump (101), a working pump (102), and a pilot pump (103). The steering pump (101) is connected to the steering unit and is used to provide steering oil for the loader. The working pump (102) is connected to the actuation unit and is used to provide actuation oil for the bucket cylinder (9) and the boom cylinder (10). The pilot pump (103) is connected to the pilot pressure selection valve (12) and is used to provide control oil for the pilot handle (11).

4. The loader electro-hydraulic proportional closed-core control system according to claim 3, characterized in that: The pilot steering gear (2) is connected to the steering flow amplification valve (4) and the pilot pump (103). The steering flow amplification valve (4) is connected to the steering pump (101) and the steering cylinder (3) and is used to control the action of the steering cylinder (3).

5. The loader electro-hydraulic proportional closed-core control system according to claim 4, characterized in that: The three-way overflow speed control valve (5) is connected to the working pump (102), the external control solenoid valve (6) and the proportional closed-core multi-way valve (7). The external control solenoid valve (6) is connected to the pilot pump (103) and the pilot pressure selection valve (12). The proportional closed-core multi-way valve (7) is connected to the pilot pressure selection valve (12).

6. The loader electro-hydraulic proportional closed-core control system according to claim 5, characterized in that: The pilot pressure selection valve (12) is connected to the pilot handle (11), and the pilot handle (11) is connected to the pilot pressure sensor (14).

7. The loader electro-hydraulic proportional closed-core control system according to claim 6, characterized in that: It also includes a hydraulic oil cooler (8), a proportional closed-core multi-way valve (7), and a pilot handle (11).

8. The loader electro-hydraulic proportional closed-core control system according to claim 7, characterized in that: The pilot steering gear (2), steering flow amplification valve (4), three-way overflow speed control valve (5), external control solenoid valve (6) and hydraulic oil cooler (8) are all connected back to the oil tank for oil return.

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