Full-electronic-controlled load-sensitive system with bulldozing floating function and control method

Abstract

A fully electronically controlled load-sensitive system and control method with bulldozing floating function is disclosed. The system includes an electronically controlled pump, which is sequentially connected to a pressure sensor, a pressure reducing valve, and an electronically controlled load-sensitive valve. The electronically controlled load-sensitive valve is connected to a bulldozer blade cylinder via a two-position four-way solenoid valve, and the two-position four-way solenoid valve and the bulldozer blade cylinder have two connection methods. The system also includes a controller connected to an electric pilot handle, proportional solenoid valve I, proportional solenoid valve II, the electronically controlled pump, a directional valve, and the two-position four-way solenoid valve. This fully electronically controlled load-sensitive system and control method realizes the bulldozing floating function of an excavator within a fully electronically controlled load-sensitive system, further improving the performance of the fully electronically controlled excavator and enhancing its competitiveness. Through the two-position four-way solenoid valve, the system achieves the coexistence of a two-way hydraulic lock and the bulldozing floating function, autonomously selecting the pipeline route according to different working conditions to realize the functional application.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, specifically a fully electronically controlled load-sensitive system with bulldozing floating function. Background Technology

[0002] With societal development, fully electronic control systems are becoming increasingly widespread in excavators. In recent years, with advancements in hydraulic control technology, load-sensitive systems, especially fully electronic load-sensitive systems, have become the main development direction for mini excavators due to their outstanding performance.

[0003] A fully electric excavator control system typically consists of a controller, electric control lever, proportional solenoid valve, main valve, main pump, and engine. The process for each action in a fully electric excavator is as follows: the operator manipulates the electric control lever, generating an action signal based on the lever's travel. This signal is sent to the controller via the CAN bus. The controller calculates and outputs a target current to the proportional solenoid valve, thereby controlling the main pump's displacement and the main valve's spool opening to distribute hydraulic oil to each working device, thus enabling the action of each device and achieving precise control of its operating speed.

[0004] In existing mini excavator systems, the load-sensitive system provides load feedback to the main pump, which adjusts as needed. When there is no load feedback, the main valve unloading valve opens, allowing hydraulic oil to flow to the hydraulic tank. Existing technology can realize the bulldozer floating function of the hydraulically controlled load-sensitive system in excavators, but the fully electronically controlled load-sensitive system lacks load pressure feedback, making it impossible to provide feedback to the load-sensitive pump via a pilot pressure feedback pipeline. Furthermore, when the bulldozer blade is in a floating state, the large and small chambers of the bulldozer blade cylinder are identical to those in the hydraulic tank, making it impossible to use a two-way hydraulic lock and thus failing to maintain pressure and lock the cylinder position.

[0005] Floating bulldozer blade: A function in which the bulldozer blade is not controlled by a hydraulic cylinder and relies entirely on its own weight to achieve rapid bulldozing and leveling operations. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a fully electronically controlled load-sensing system with bulldozing floating function that has a simple structure and good performance.

[0007] This invention is achieved through the following technical solution: a fully electrically controlled load-sensitive system with bulldozing floating function, comprising an electrically controlled pump, wherein a pressure sensor, a pressure reducing valve, and an electrically controlled load-sensitive valve are sequentially connected to the oil outlet of the electrically controlled pump; the electrically controlled load-sensitive valve comprises an electro-proportional unloading valve and a reversing valve; the reversing valve is connected to the bulldozer blade cylinder via a two-position eight-way solenoid valve; the two-position eight-way solenoid valve and the bulldozer blade cylinder are provided with two connection methods: one is a direct connection via hydraulic lines, and the other is a two-way hydraulic lock on the hydraulic lines; the system also includes a controller, wherein the controller is connected to an electrically pilot handle, a proportional solenoid valve I, a proportional solenoid valve II, an electrically controlled pump, an electro-proportional unloading valve, and a two-position eight-way solenoid valve; the proportional solenoid valve I and the proportional solenoid valve II are respectively connected to the two control ends of the reversing valve.

[0008] Furthermore, the electronically controlled pump is a variable pump controlled by a controller.

[0009] The pressure sensor collects the system pressure input to the controller.

[0010] The output end of the pressure reducing valve is connected to proportional solenoid valve I and proportional solenoid valve II respectively.

[0011] The electro-proportional unloading valve is located at the input end of the directional valve, and the output end of the electro-proportional unloading valve is connected to the hydraulic oil tank.

[0012] The electro-proportional unloading valve is a two-position two-way solenoid directional valve.

[0013] The reversing valve is a four-position six-way hydraulically controlled reversing valve.

[0014] The electric pilot handle is equipped with a single-sided limit positioning device.

[0015] The control method for a fully electronically controlled load-sensitive system with bulldozing and floating function includes the following steps:

[0016] S1. When the electric pilot handle deflects to the predetermined angle, a signal is sent to the controller; S2. After receiving the signal from the electric pilot handle, the controller sends a control signal to the proportional solenoid valves at the corresponding control terminals of the two-position eight-way solenoid valve and the directional valve.

[0017] S3, the two-position eight-way solenoid valve is energized, avoiding connection between the two-way hydraulic lock and the bulldozer cylinder; the directional valve is in the working position where both chambers of the bulldozer cylinder are connected to the hydraulic oil tank under the action of the pilot hydraulic oil.

[0018] S4. When the excavator is detected to be idling, the controller reduces the electrical signal output to the proportional unloading valve and simultaneously reduces the electrical signal output to the electronically controlled pump, causing Q... 电控泵 >Q 电比例卸荷阀 .

[0019] The present invention has the following advantages: The present invention provides a fully electronically controlled load-sensitive system and control method with bulldozing floating function, which realizes the bulldozing floating function of the excavator on the fully electronically controlled load-sensitive system, further improving the performance of the fully electronically controlled excavator and enhancing its competitiveness; through a two-position eight-way solenoid valve, the two-way hydraulic lock and the bulldozing floating function coexist, and the pipeline route can be selected autonomously according to different working conditions to realize the functional application. Attached Figure Description

[0020] The accompanying drawings, as part of this invention, are provided to further illustrate the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation thereof. Clearly, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0021] In the attached diagram:

[0022] Figure 1 This is a hydraulic schematic diagram of the present invention;

[0023] Figure 2 This is the control principle diagram of the present invention.

[0024] In the diagram: 1. Electric pump, 2. Hydraulic tank, 3. Pressure sensor, 4. Pressure reducing valve, 5. Proportional solenoid valve I, 6. Electric load sensitive valve, 61. Electric proportional unloading valve, 62. Directional control valve, 7. Proportional solenoid valve II, 8. Two-position eight-way solenoid valve, 9. Two-way hydraulic lock, 10. Bulldozer blade cylinder, 11. Electric pilot handle, 12. Controller.

[0025] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0027] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0028] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] like Figure 1 The diagram illustrates a fully electrically controlled load-sensitive system with bulldozing floating function. It includes an electrically controlled pump 1, whose outlet is sequentially connected to a pressure sensor 3, a pressure reducing valve 4, and an electrically controlled load-sensitive valve 6. The electrically controlled load-sensitive valve 6 includes an electro-proportional unloading valve 61 and a directional control valve 62. The directional control valve 62 is connected to a bulldozer blade cylinder 10 via a two-position eight-way solenoid valve 8. Two connection methods exist between the two-position eight-way solenoid valve 8 and the bulldozer blade cylinder 10: one is a direct hydraulic line connection, and the other has a two-way hydraulic lock 9 on the hydraulic line. The system also includes a controller 12, which is connected to an electrically pilot handle 11, proportional solenoid valve I 5, proportional solenoid valve II 7, the electrically controlled pump 1, the electro-proportional unloading valve 61, and the two-position eight-way solenoid valve 8. The proportional solenoid valves I 5 and II 7 are respectively connected to the two control terminals of the directional control valve 62. The output terminal of the pressure reducing valve 4 is connected to both the proportional solenoid valves I 5 and II 7. The fully electrically controlled load-sensitive system with bulldozing floating function of the present invention includes a hydraulic control system and an electronic control system. The hydraulic control system includes an electronically controlled pump, a pressure reducing valve, a proportional solenoid valve I, a proportional solenoid valve II, an electronically controlled load-sensitive valve, a two-position eight-way solenoid valve, a two-way hydraulic lock, and a bulldozer blade cylinder. The electronically controlled load-sensitive valve includes an electro-proportional unloading valve and a directional valve. The directional valve is connected to the two-position eight-way solenoid valve. The two-position eight-way solenoid valve is connected to the bulldozer blade cylinder through two connection methods: one is a conventional hydraulic pipeline connection, and the other is equipped with a two-way hydraulic lock. Under the action of the two-way hydraulic lock, when the bulldozer handle is in the non-floating position, the control hydraulic oil can flow in one direction. Unaffected by external load interference, the two-position eight-way solenoid valve can receive signals from the controller. When the bulldozer handle is in the non-floating position, the solenoid valve is not energized, the valve core is in the right position, and the oil circuit passes through the bidirectional hydraulic lock. When the bulldozer handle is in the floating position, the control valve core is in the left position, and the oil circuit avoids the hydraulic lock. The electronic control system includes an electric pilot handle, a controller, and a pressure sensor. The electric pilot handle and the pressure sensor are connected to the input end of the controller. The output end of the controller is connected to the electric pump, proportional solenoid valve I, proportional solenoid valve II, electric proportional unloading valve, and two-position eight-way solenoid valve. The controller outputs an electrical signal to control the pump and valve actions, thereby realizing the control of the bulldozer blade cylinder action.

[0030] like Figure 1The diagram illustrates a fully electronically controlled load-sensitive system with bulldozing floating function. The electronically controlled pump 1 is a variable displacement pump controlled by a controller 12. The electronically controlled pump of this invention is a variable displacement pump; the fully electronically controlled pump changes its displacement by receiving signals from the controller to meet the requirements of the hydraulic system.

[0031] like Figure 1 The diagram illustrates a fully electrically controlled load-sensitive system with bulldozing and floating functionality. The pressure sensor 3 collects the system pressure input to the controller 12. The pressure sensor is connected to the controller's input terminal. When the set pressure is reached, the pressure sensor collects the pressure, and the controller will not change the current values ​​of the main pump and the main valve's electromagnetic unloading valve, thus maintaining this state.

[0032] like Figure 1 The diagram illustrates a fully electrically controlled load-sensitive system with bulldozing floating function. The electro-proportional unloading valve 61 is located at the input end of the directional control valve 62, and its output end is connected to the hydraulic oil tank 2. The electro-proportional unloading valve 61 is a two-position, two-way solenoid directional control valve. The unloading valve of this invention is a proportional solenoid valve, controllable by a controller. Located at the input end of the directional control valve, when unloading is required, the controller controls the unloading valve to switch directions, allowing the hydraulic oil output from the electrically controlled pump to flow through the unloading valve to the hydraulic oil tank, cutting off the oil entering the directional control valve. Simultaneously, by changing the input electrical quantity, the output flow rate of the unloading valve can be adjusted.

[0033] like Figure 1 The invention illustrates a fully electrically controlled load-sensitive system with bulldozing floating function, wherein the reversing valve 62 is a four-position six-way hydraulically controlled reversing valve. The four-position reversing valve in the electrically controlled load-sensitive valve of this invention is controlled by the pilot pressure output from a proportional solenoid valve to realize the reversing of the valve. The four working positions are: bulldozer blade cylinder piston rod extension, piston rod retraction, cylinder large and small chamber connection, and oil circuit cutoff.

[0034] like Figure 1 The invention illustrates a fully electrically controlled load-sensitive system with a bulldozing floating function, wherein the electric pilot handle 11 is equipped with a single-sided limit positioning device. The electric pilot bulldozing handle of this invention includes single-sided limit positioning, which enables limit position locking control and can output a handle signal to the controller based on the handle deflection angle, thereby controlling the bulldozing hydraulic system.

[0035] like Figure 2 The control method of a fully electronically controlled load-sensitive system with bulldozing floating function, as shown, includes the following steps:

[0036] S1. When the electric pilot handle 11 swings to a predetermined angle, it sends a signal to the controller 12; S2. After receiving the signal from the electric pilot handle 11, the controller 12 sends a control signal to the proportional solenoid valves at the corresponding control terminals of the two-position eight-way solenoid valve 8 and the directional valve 62.

[0037] S3. The two-position eight-way solenoid valve 8 is energized, avoiding the connection between the two-way hydraulic lock 9 and the bulldozer cylinder 10; the reversing valve 62 is in the working position where both chambers of the bulldozer cylinder 10 are connected to the hydraulic oil tank 2 under the action of the pilot hydraulic oil.

[0038] S4. When the excavator is detected to be idling, the controller 12 reduces the electrical signal output to the proportional unloading valve 61 and simultaneously reduces the electrical signal output to the electric pump 1, causing Q... 电控泵 >Q 电比例卸荷阀 .

[0039] In the system of the present invention, when the deflection angle of the electric pilot bulldozer handle is less than a predetermined value, the controller receives a signal from the electric pilot bulldozer handle and sends electrical signals to the proportional solenoid valve I and the proportional solenoid valve II respectively according to the direction of the electric pilot bulldozer handle, which pushes the reversing valve in the electronically controlled load sensitive valve to the left position and the right position respectively. At this time, the controller does not output a signal to the two-position eight-way solenoid valve, so that its valve core is in the right position, and the hydraulic oil is delivered to the bulldozer blade cylinder after passing through the bidirectional hydraulic lock, so that it rises and falls. When the electric pilot bulldozer handle deflection angle exceeds a predetermined value, the electric pilot bulldozer handle's one-way limit position locking control is activated, maintaining a stable handle position. The controller receives an electrical signal from the electric pilot bulldozer handle and pushes the directional valve to the right second position via the proportional solenoid valve, connecting the large and small chambers of the bulldozer blade cylinder and leading to the hydraulic oil tank. Simultaneously, the controller outputs a signal to the two-position eight-way solenoid valve, causing its valve core to be in the left position, preventing hydraulic oil from entering the bulldozer blade cylinder through the bidirectional hydraulic lock, thus achieving the bulldozer blade floating function. At the same time, when the excavator is idling, the controller simultaneously outputs signals to the fully electric pump and the electro-proportional unloading valve, increasing the flow rate of the fully electric pump and reducing the flow capacity of the electro-proportional unloading valve 61, thus enabling Q... 电控泵 >Q 电比例卸荷阀 Increase the hydraulic system pressure to the set value to maintain the pilot pressure, thereby keeping the directional valve in the right second position and maintaining the floating working state of the bulldozer blade.

[0040] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0041] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features found in other embodiments but not others, combinations of features from different embodiments are also within the scope of protection of this invention and form different embodiments. For example, in the embodiments described above, those skilled in the art can use them in combination based on known technical solutions and the technical problems to be solved by this application.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A control method for a fully electronically controlled load-sensitive system with bulldozing floating function, characterized in that: The system includes an electric pump (1), the oil outlet of which is connected in sequence to a pressure sensor (3), a pressure reducing valve (4) and an electric load sensitive valve (6). The electric load sensitive valve (6) includes an electric proportional unloading valve (61) and a reversing valve (62). The reversing valve (62) is connected to a bulldozer cylinder (10) via a two-position eight-way solenoid valve (8). There are two connection methods between the two-position eight-way solenoid valve (8) and the bulldozer cylinder (10): one is a direct connection via hydraulic lines, and the other is a two-way hydraulic lock (9) on the hydraulic lines. The system also includes a controller (12), which is connected to an electric pilot handle (11), a proportional solenoid valve I (5), a proportional solenoid valve II (7), the electric pump (1), the electric proportional unloading valve (61), and the two-position eight-way solenoid valve (8). The proportional solenoid valve I (5) and the proportional solenoid valve II (7) are respectively connected to the two control ends of the reversing valve (62). The electro-proportional unloading valve (61) is located at the input end of the directional valve (62), and the output end of the electro-proportional unloading valve (61) is connected to the hydraulic oil tank (2). The method includes the following steps: S1. When the electric pilot handle (11) swings to a predetermined angle, a signal is sent to the controller (12); S2. After receiving the signal from the electric pilot handle (11), the controller (12) sends a control signal to the proportional solenoid valves at the corresponding control terminals of the two-position eight-way solenoid valve (8) and the directional valve (62); S3. The two-position eight-way solenoid valve (8) is energized, avoiding the connection between the two-way hydraulic lock (9) and the bulldozer cylinder (10); the reversing valve (62) is in the working position where both chambers of the bulldozer cylinder (10) are connected to the hydraulic oil tank (2) under the action of the pilot hydraulic oil. S4, when detecting that the excavator is in idle working condition, the controller (12) reduces the electric signal output to the electric proportional unloading valve (61), and reduces the electric signal output to the electric control pump (1) at the same time, so that Q 电控泵 >Q 电比例卸荷阀 .

2. The control method for a fully electronically controlled load-sensitive system with bulldozing floating function as described in claim 1, characterized in that: The electronically controlled pump (1) is a variable pump controlled by the controller (12).

3. The control method for a fully electronically controlled load-sensitive system with bulldozing floating function as described in claim 1, characterized in that: The pressure sensor (3) collects the system pressure input to the controller (12).

4. The control method for a fully electronically controlled load-sensitive system with bulldozing floating function as described in claim 1, characterized in that: The output end of the pressure reducing valve (4) is connected to the proportional solenoid valve I (5) and the proportional solenoid valve II (7) respectively.

5. The control method for a fully electronically controlled load-sensitive system with bulldozing floating function as described in claim 1, characterized in that: The electro-proportional unloading valve (61) is a two-position two-way solenoid directional valve.

6. The control method for a fully electronically controlled load-sensitive system with bulldozing floating function as described in claim 1, characterized in that: The reversing valve (62) is a four-position six-way hydraulic reversing valve.

7. The control method for a fully electronically controlled load-sensitive system with bulldozing floating function as described in claim 1, characterized in that: The electric pilot handle (11) is equipped with a single-sided limit positioning device.

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