Hydraulic control system and control method for a skid steer loader

Abstract

The application relates to a wire control loader hydraulic control system and a control method, and belongs to the technical field of engineering machinery hydraulic pressure. The system comprises a communication-connected electric control unit and a remote control unit, the remote control unit is used for man-machine interaction and sending control instructions to the electric control unit, the electric control unit is connected with an electric control handle and outputs control signals to the electric control handle, the electric control handle is connected with an electro-hydraulic proportional electromagnetic valve, the electro-hydraulic proportional electromagnetic valve is connected with a multi-way reversing valve, and the multi-way reversing valve controls a working oil cylinder. The remote control unit used for man-machine interaction remotely sends control instructions to the electric control unit, drives the steering oil cylinder and the working oil cylinder, and completes walking steering operation and loading and unloading operation, so that remote control of the hydraulic system can be realized, manual operation is not needed, and execution is more convenient and safer.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic technology for engineering machinery, specifically a hydraulic control system and control method for a wire-controlled loader. Background Technology

[0002] Construction machinery operates in diverse environments. For example, some work environments for loaders are harsh, posing safety hazards to drivers' health and lives. Furthermore, with societal development, fewer and fewer people are willing to engage in such work. Given this situation, a new technology is needed to fundamentally solve the driver safety problem. Remote-controlled (wire-controlled) loaders have emerged to address this need. Traditional loader hydraulic systems use a hydraulically controlled pilot handle to drive a multi-way directional valve, which in turn drives the working cylinders for loading and unloading operations. Traditional loader steering systems are also purely hydraulically driven steering gears, driven by a steering wheel, which in turn drives a flow amplification valve or directly drives the cylinders for steering. Thus, whether loading or steering, operators must manually operate the handle or steering wheel to drive the multi-way valve or flow amplification valve to complete the operation. Summary of the Invention

[0003] The purpose of this invention is to solve the problem that the hydraulic control of loaders requires manual operation, which is inconvenient.

[0004] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0005] This invention relates to a hydraulic control system for a wire-controlled loader, belonging to the field of hydraulic technology for construction machinery. It includes an electronic control unit (ECU) and a remote control unit connected via communication. The remote control unit is used for human-machine interaction and sends control commands to the ECU. The ECU is connected to an electronic control handle and outputs control signals to the handle. The handle is connected to an electro-hydraulic proportional solenoid valve, which is connected to a multi-way directional valve. The multi-way directional valve controls the working cylinder. Control commands are remotely sent from the remote control unit to the ECU to drive the steering cylinder and the working cylinder.

[0006] Preferably, the working cylinder includes a tipping cylinder and a working cylinder.

[0007] Preferably, the electric control handle is connected to an electro-hydraulic steering gear, which is connected to a steering cylinder and controls the steering cylinder to perform steering operations.

[0008] Preferably, the A2 port of the electro-hydraulic proportional solenoid valve is also connected to an unloading valve, which is connected to the K port of the multi-way directional valve.

[0009] Preferably, the electro-hydraulic steering gear is connected to a flow amplification valve, which is connected to the dynamic steering cylinder.

[0010] A hydraulic control method for a drive-by-wire loader, wherein the method is executed according to the aforementioned control system, and the method comprises:

[0011] The remote control unit sends control commands to the electronic control unit, which then outputs control signals to the electronic control handle. The electronic control handle controls the electro-hydraulic proportional solenoid valve to output corresponding pilot pressure according to the control signals. The pilot pressure controls the directional valve core of the multi-way directional valve, thereby controlling the movement of the working cylinder.

[0012] Preferably, the method further includes the electronic control unit outputting a control signal to the electro-hydraulic steering gear, the electro-hydraulic steering gear outputting steering hydraulic oil pressure according to the received signal, which is then supplied to the flow amplification valve, and the flow amplification valve outputting high-pressure oil into the steering cylinder and driving the steering cylinder to perform steering action.

[0013] Preferably, the method further includes an electro-hydraulic proportional solenoid valve driving the unloading valve to open, thereby unloading the pressure at port K of the multi-way directional valve, and connecting the large and small chambers of the boom cylinder to allow the boom to fall freely.

[0014] Preferably, during the steering operation, the proportional solenoid valve in the electro-hydraulic steering gear outputs corresponding hydraulic pressure according to the electrical signal sent by the electronic control unit. This pressure drives the proportional directional valve of the steering gear, which in turn drives the steering gear to rotate, outputting a small flow of hydraulic oil. The output flow rate is proportional to the speed of the remote-controlled steering wheel according to a pre-set ratio.

[0015] Preferably, during the loading and unloading operation, the electro-hydraulic proportional solenoid valve outputs corresponding hydraulic pressure according to the signal from the remote control handle. This pressure drives the valve core of the multi-way directional valve to open and switch. The opening section of the valve core of the proportional valve is proportional to the operating range of the handle.

[0016] Compared with the prior art, the technical solution provided by this invention has the following advantages:

[0017] This invention discloses a hydraulic control system and method for a drive-by-wire loader, comprising an electronic control unit (ECU) and a remote control unit connected via communication. The remote control unit is used for human-machine interaction and sends control commands to the ECU. The ECU is connected to an electronic control handle and outputs control signals to the handle. The handle is connected to an electro-hydraulic proportional solenoid valve, which is connected to a multi-way directional valve. The multi-way directional valve controls a working cylinder. By remotely sending control commands from the remote control unit to the ECU to drive the steering cylinder and the working cylinder, the system can perform walking, steering, loading, and unloading operations. This allows for remote control of the hydraulic system, eliminating the need for manual operation and making it more convenient and safer. Attached Figure Description

[0018] Figure 1This is a schematic diagram of the overall structure of a hydraulic control system for a loader according to the present invention.

[0019] Explanation of the labels in the diagram:

[0020] 1. Electrical control unit; 2. Electrical control handle; 3. Electro-hydraulic proportional solenoid valve; 4. Pilot oil supply valve; 5. Unloading valve; 6. Flow amplification valve; 7. Steering cylinder; 8. Electro-hydraulic steering gear; 9. Multi-way directional valve; 10. Boom cylinder; 11. Bucket cylinder; 12. Hydraulic oil tank; 13. Hydraulic pump. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0022] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0023] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0024] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0025] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] Example 1

[0028] See attached document Figure 1 This embodiment of a wire-controlled loader hydraulic control system includes an electronic control unit (ECU) and a remote control unit connected by communication. The remote control unit is used for human-machine interaction and sends control commands to the ECU. The ECU is connected to an electronic control handle 2 and outputs control signals to the handle 2. The handle 2 is connected to an electro-hydraulic proportional solenoid valve 3, which is connected to a multi-way directional valve 9. The multi-way directional valve 9 controls working cylinders (10, 11). By remotely sending control commands from the remote control unit to the ECU to drive the steering cylinder and working cylinder, the system can complete walking, steering, loading, and unloading operations. This allows for remote control of the hydraulic system without manual operation, making it more convenient and safer.

[0029] Specifically, the working cylinders include a tipping cylinder 10 and a boom cylinder 11. The electric control handle 2 is connected to an electro-hydraulic steering device 8, which is connected to a steering cylinder 7 and controls the steering cylinder 7 to perform steering operations.

[0030] Specifically, the a2 port of the electro-hydraulic proportional solenoid valve 3 is also connected to an unloading valve 5, which is connected to the K port of the multi-way directional valve 9. The electro-hydraulic proportional solenoid valve 3 drives the unloading valve 5 to open, thereby relieving the pressure at the K port of the multi-way directional valve 9, and connecting the large and small chambers of the boom cylinder 10, allowing the boom to fall freely.

[0031] Specifically, the electro-hydraulic steering gear 8 is connected to a flow amplification valve 6, which is connected to the steering cylinder 7. The electronic control unit outputs a control signal to the electro-hydraulic steering gear 8, which outputs steering hydraulic oil pressure according to the received signal, and sends it to the flow amplification valve 6. The flow amplification valve 6 outputs high-pressure oil into the steering cylinder 7 and drives the steering cylinder 7 to perform steering actions.

[0032] This embodiment also includes a hydraulic pump 12 and a hydraulic oil tank 13. The hydraulic oil tank 13 is used to store hydraulic oil, and the hydraulic pump 12 supplies hydraulic oil to the system. The P port of the electro-hydraulic proportional solenoid valve 3 is connected to the pilot supply valve 4, and the T port of the pilot supply valve 4 is connected to the hydraulic oil tank 12.

[0033] Example 2

[0034] A hydraulic control method for a drive-by-wire loader, wherein the method is executed using the control system described in Example 1, and the method is as follows:

[0035] The remote control unit sends control commands to the electronic control unit 1, which outputs control signals to the electronic control handle 2. The electronic control handle 2 controls the electro-hydraulic proportional solenoid valve 3 to output corresponding pilot pressure according to the control signals. The pilot pressure controls the directional valve core of the multi-way directional valve 9 to control the action of the working cylinder.

[0036] The method further includes the electronic control unit outputting a control signal to the electro-hydraulic steering gear 8, the electro-hydraulic steering gear 8 outputting steering hydraulic oil pressure according to the received signal, which is supplied to the flow amplification valve 6, and the flow amplification valve 6 outputting high-pressure oil into the steering cylinder 7 and driving the steering cylinder 7 to perform steering action.

[0037] The method also includes the electro-hydraulic proportional solenoid valve 3 driving the unloading valve 5 to open, thereby unloading the pressure at the K port of the multi-way directional valve 9, and connecting the large and small chambers of the boom cylinder 10 to allow the boom to fall freely.

[0038] During the steering operation, the proportional solenoid valve in the electro-hydraulic steering gear 8 outputs corresponding hydraulic pressure according to the electrical signal sent by the electronic control unit. This pressure drives the proportional directional valve of the steering gear, which drives the steering gear to rotate and outputs a small flow of hydraulic oil (flow rate 0-60L / min, pressure 0-17MPa). The output flow rate is proportional to the speed of the remote control steering wheel.

[0039] During loading and unloading operations, based on signals from the remote control handle, the electro-hydraulic proportional solenoid valve outputs corresponding hydraulic pressure. This pressure drives the spool of the multi-way directional valve to open and reverse. The opening section of the proportional valve spool is proportional to the operating range of the handle. The output pressure of the electro-hydraulic proportional solenoid valve is a low-pressure value, ranging from 0 to 2.8 MPa. This pressure corresponds to the preload of the preload spring of the multi-way valve spool, ensuring that the opening degree of the multi-way valve spool is proportional to the operating range of the control handle. When the power of the hydraulic system is below the rated value, the flow rate of the multi-way valve is proportional to the opening degree of the spool. When the power of the hydraulic system reaches the rated value, the flow rate of the multi-way valve adopts a constant power control law, meaning the product of the flow rate and pressure is a set value.

[0040] During the steering operation, the proportional solenoid valve in the electro-hydraulic steering gear 8 outputs corresponding hydraulic pressure according to the electrical signal sent by the electronic control unit. This pressure drives the proportional reversing valve of the steering gear, which drives the steering gear to rotate and outputs a small flow of hydraulic oil. The output flow rate is proportional to the speed of the remote control steering wheel.

[0041] During loading and unloading operations, the electro-hydraulic proportional solenoid valve outputs corresponding hydraulic pressure according to the signal from the remote control handle. This pressure drives the spool of the multi-way directional valve to open and switch. The opening section of the spool of the proportional valve is proportional to the operating range of the handle.

[0042] The above-described embodiments are merely illustrative of certain implementations of the present invention, and are described in a relatively specific and detailed manner. However, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements are all within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A hydraulic control method for a drive-by-wire loader, characterized in that: The method is implemented using the following control system, which includes an electronic control unit and a remote control unit connected by communication. The remote control unit is used for human-machine interaction and sends control commands to the electronic control unit (1). The electronic control unit (1) is connected to an electronic control handle (2) and outputs control signals to the electronic control handle (2). The electronic control handle (2) is connected to an electro-hydraulic proportional solenoid valve (3). The electro-hydraulic proportional solenoid valve (3) is connected to a multi-way directional valve (9). The multi-way directional valve (9) controls the working cylinders (10, 11). The electronic control handle (2) is connected to an electro-hydraulic control steering gear (8). The electro-hydraulic control steering gear (8) is connected to a steering cylinder (7) and controls the steering cylinder (7) to perform steering operations. The electro-hydraulic control steering gear (8) is connected to a flow amplification valve (6). The flow amplification valve (6) is connected to the steering cylinder (7). The method is as follows: The remote control unit sends control commands to the electronic control unit, and the electronic control unit outputs control signals to the electronic control handle (2). The electronic control handle (2) controls the electro-hydraulic proportional solenoid valve (3) to output corresponding pilot pressure according to the control signal. The pilot pressure controls the directional valve core of the multi-way directional valve (9) to control the action of the working cylinder. When the power of the hydraulic system does not reach the rated value, the flow rate of the multi-way directional valve (9) is directly proportional to the opening degree of the valve core. When the power of the hydraulic system reaches the rated value, the flow rate of the multi-way directional valve (9) adopts the constant power control law, that is, the product of the flow rate and the pressure is a set value. The method also includes the output of the control signal of the electronic control unit to the electro-hydraulic control steering gear (8). The electro-hydraulic control steering gear (8) outputs the steering hydraulic oil pressure according to the received signal and gives it to the flow amplification valve (6). The flow amplification valve (6) outputs high pressure oil into the steering cylinder (7) and drives the steering cylinder (7) to perform steering action. During the steering operation, the proportional solenoid valve in the electro-hydraulic steering gear (8) outputs the corresponding hydraulic pressure according to the electrical signal sent by the electronic control unit. This pressure drives the proportional reversing valve of the steering gear, and the proportional reversing valve drives the steering gear to rotate, outputting a small flow of hydraulic oil. The output flow rate is proportional to the speed of the remote control steering wheel.

2. The hydraulic control method for a drive-by-wire loader according to claim 1, characterized in that: The method also includes an electro-hydraulic proportional solenoid valve (3) driving the unloading valve (5) to open, so that the pressure at the K port of the multi-way directional valve (9) is unloaded, and the large and small chambers of the boom cylinder (10) are connected, so that the boom falls freely.

3. The hydraulic control method for a wire-controlled loader according to claim 1, characterized in that: The method further includes: During loading and unloading operations, the electro-hydraulic proportional solenoid valve outputs corresponding hydraulic pressure according to the signal from the remote control handle. This pressure drives the valve core of the multi-way directional valve to open and switch. The opening section of the valve core of the proportional valve is proportional to the operating range of the handle.

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