Control system and method for improving performance of electromagnetic proportional valve

Abstract

The invention provides a control system and method for improving the performance of an electromagnetic proportional valve, and the system comprises a controller which is connected with the electromagnetic proportional valve and is used for outputting a trapezoidal wave current signal with a certain frequency to the electromagnetic proportional valve when being powered on, and controlling the opening and closing of the electromagnetic proportional valve, hydraulic oil in the valve body of the electromagnetic proportional valve is stirred along with movement of the valve element, and the problems that the movement speed of the valve element is abnormal and the output pressure is abnormal due to the fact that the content of impurities in the oil is uneven are solved. The controller is further used for outputting a trapezoidal wave current signal to the electromagnetic proportional valve and controlling the electromagnetic proportional valve to be opened and closed when the electromagnetic valve of the whole vehicle operation safety handle switch is opened, new oil enters the electromagnetic proportional valve through the oil inlet in the process that the valve element moves back and forth, and the oil alternately flows out of the outlet and the oil return opening. Impurities flow out through circulation, and the purpose of cleaning is achieved. According to the control system and method, the problem that the electromagnetic proportional valve is poor in consistency due to long-time use and oil pollution is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of engineering machinery control, and in particular relates to a control system and a method for improving the performance of an electromagnetic proportional valve. Background Art

[0002] With the application of fully electronic hydraulic systems in excavators, the number of electromagnetic proportional valves used in excavators is increasing, and the performance requirements for electromagnetic proportional valves are also increasing. Impurities mixed in during the processing and assembly process, mechanical friction during work, and the harsh working environment of the excavator will cause many impurities to enter the oil and cause pollution, and then mix into the electromagnetic proportional valve, reducing its performance and worsening its consistency. During operation, when the machine is turned on, the controllability of the whole machine is different from the normal operation for a period of time. This is because if the machine does not work for a long time, impurities will be precipitated inside the valve body of the electromagnetic proportional valve. Due to the gravity effect, the impurities are precipitated in different parts of the valve body, and the impurity content in the hydraulic oil is uneven. The valve core movement resistance brought by the hydraulic oil will also change with the change of impurity content. The movement speed of the valve core changes under such a medium, resulting in differences in output pressure, which in turn affects the controllability of the excavator. At present, there is no good way to solve this phenomenon of excavators. Generally, a new switch solenoid valve is used to solve it, which is costly, labor-intensive and time-consuming. Summary of the invention

[0003] The object of the present invention is to provide a control system and method for improving the performance of an electromagnetic proportional valve, so as to solve the problems of poor consistency of the electromagnetic proportional valve due to long service time and oil contamination.

[0004] To achieve the above object, the technical solution adopted by the present invention is as follows: In one aspect, the present invention provides a control system for improving the performance of an electromagnetic proportional valve, comprising: The controller is connected to the electromagnetic proportional valve and is used to output a trapezoidal wave current signal to the electromagnetic proportional valve when powered on, control the opening and closing of the electromagnetic proportional valve, and stir the hydraulic oil in the valve body of the electromagnetic proportional valve evenly; and when the electromagnetic valve of the vehicle operation safety handle switch is opened, output a trapezoidal wave current signal to the electromagnetic proportional valve, control the opening and closing of the electromagnetic proportional valve, and make the hydraulic oil flow out alternately from the outlet and the return oil port of the electromagnetic proportional valve to clean impurities; and, The monitor is connected to the controller and is used to issue control instructions, wherein the control instructions include: an instruction to control the electromagnetic proportional valve to perform active flushing, an instruction to start the engine, and an instruction to open the safety handle switch electromagnetic valve.

[0005] Preferably, the monitor is connected to the controller via a CAN line.

[0006] Preferably, the monitor is also used to: Indicates that active flushing was unsuccessful; And display the alarm prompt that the flushing is completed.

[0007] Preferably, the controller is further used to: Connected to the start switch, when powered on, the controller is powered, receives the start signal and completes the start control; Connected to the safety handle switch solenoid valve, used to detect the on / off state of the safety handle switch solenoid valve; Connected to the electromagnetic proportional valve, it is used to control the output pressure of the electromagnetic proportional valve by the output current.

[0008] In a second aspect, the present invention provides a control method for the control system for improving the performance of the electromagnetic proportional valve, comprising: The controller monitors whether the power-on signal of the whole machine is turned on. If it is turned on, proceed to the next step, otherwise end this control; The controller monitors whether the vehicle has any fault alarm related to the electromagnetic proportional valve. If not, proceed to the next step, otherwise, end this control; The controller monitors whether the safety handle switch solenoid valve is open. If it is not open, the next step is executed, otherwise the control is terminated; The controller continuously outputs a trapezoidal wave current signal of a certain frequency within a set time to control the opening and closing of the electromagnetic proportional valve. During this process, the valve core moves back and forth, causing the hydraulic oil in the valve body of the electromagnetic proportional valve to stir to prevent impurities from settling.

[0009] Preferably, the set time is 1-2s.

[0010] In a third aspect, the present invention further provides a control method for the control system for improving the performance of the electromagnetic proportional valve, comprising: The controller monitors whether the power-on signal of the whole machine is turned on. If it is turned on, proceed to the next step, otherwise end this control; The controller monitors whether the vehicle has any fault alarm related to the electromagnetic proportional valve. If not, proceed to the next step, otherwise, end this control; The monitor sends an active flushing command to the electromagnetic proportional valve and prompts the engine to start; Determine whether the engine has been started by the controller; After the start-up is completed, the monitor sends a command to open the safety handle switch solenoid valve. If it is opened, the pilot hydraulic pump is driven, and oil is supplied to all the electromagnetic proportional valves of the vehicle through the safety handle switch solenoid valve; the control executes the next step; otherwise, the control ends; The controller continuously outputs a trapezoidal wave current signal of a certain frequency to control the opening and closing of the electromagnetic proportional valve, and the valve core moves back and forth. During the whole process, new oil enters the electromagnetic proportional valve through the oil inlet, and the oil flows out alternately at the outlet A and the return oil port T, and impurities are cleaned through circulation.

[0011] Preferably, the method further comprises: If the safety handle switch solenoid valve is not opened for a certain period of time, the control will be terminated. At the same time, the monitor will show that the active flushing was unsuccessful.

[0012] Preferably, the method further comprises: After flushing is completed, the monitor will display an alarm prompt indicating that flushing is complete.

[0013] Preferably, the controller is used to determine whether the engine is started, including: The engine speed signal is received to determine whether the speed is greater than or equal to the lowest idle speed of the engine. If so, it is determined that the start is completed.

[0014] Preferably, the method further comprises: If the startup is not completed for a period of time, the control will be terminated. At the same time, the monitor will show that the active flushing was unsuccessful.

[0015] Preferably, the frequency of the trapezoidal wave current signal is higher than the response frequency of the valve core of the hydraulic main valve.

[0016] Preferably, the controller supports controlling multiple groups of electromagnetic proportional valves at the same time, and needs to ensure that two electromagnetic proportional valves controlling the same hydraulic main valve core simultaneously output trapezoidal wave current signals of the same frequency.

[0017] The beneficial effects of the present invention are: The present invention provides a control system for improving the performance of electromagnetic proportional valves. Each time the power is turned on and the safety handle switch electromagnetic valve is not opened, a trapezoidal wave current signal of a certain frequency is output through the controller to control the opening and closing of the electromagnetic proportional valve. In this process, the valve core moves back and forth, so that the hydraulic oil in the valve body is also agitated with the movement of the valve core, and the precipitated impurities are also stirred and evenly fill the entire valve body due to the agitation, thereby solving the problem of abnormal valve core movement speed and output pressure caused by uneven impurity content in the oil, resulting in abnormal action. The method completes the entire control process by itself at each power-on, and can be interrupted at any time without affecting the operation of the entire machine. It is fast and effective.

[0018] When the safety handle switch solenoid valve is opened and the vehicle operation time is long, the controller outputs a trapezoidal wave current signal to control the opening and closing of the solenoid proportional valve, and the valve core moves back and forth. During the whole process, new oil enters the solenoid proportional valve through the oil inlet P, and the oil flows out alternately at the outlet A and the return oil port T. After multiple cycles, impurities flow out, achieving the purpose of cleaning.

[0019] The two methods of the present invention can exist simultaneously without interfering with each other. The whole process lasts for a short time, is convenient and fast, does not generate costs and can effectively solve problems in the market. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A flow chart of a control method for improving the performance of an electromagnetic proportional valve provided by the present invention; Figure 2 A schematic diagram of a control system for improving the performance of an electromagnetic proportional valve provided by the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0022] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0023] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, elements, steps or components, but does not exclude the presence or addition of one or more other features, elements, steps or components.

[0024] It should be emphasized here that the step marks mentioned below are not intended to limit the order of the steps, but it should be understood that the steps can be executed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be executed simultaneously.

[0025] In a first aspect, the present invention provides a control system for improving the performance of an electromagnetic proportional valve. Figure 2 , including: monitor 1, controller 2, start switch 3, engine 4, power supply 5, pilot hydraulic pump 6, oil tank 7, safety handle switch solenoid valve 8, solenoid proportional valve 9, hydraulic main valve 10, and electrical wiring harness and hydraulic pipelines for connecting various components; The monitor 1 is used for human-computer interaction and is connected to the controller via a CAN line for communication.

[0026] The start switch 3 includes two functions: a vehicle power-on function, which connects the vehicle battery to the vehicle electrical system to realize power supply; and an engine motor start signal output function.

[0027] The power supply 5 is used to supply power to the start switch 3 .

[0028] The safety handle switch solenoid valve 8 is a switch type solenoid valve, which is installed on the oil supply line of the hydraulic pilot oil circuit of the whole vehicle and is used to control the opening and closing of the oil supply line of the pilot system.

[0029] The electromagnetic proportional valve 9 is connected to the hydraulic main valve 10. The electromagnetic proportional valve 9 controls the movement speed and range of the valve core of the hydraulic main valve 10 by outputting pressure to realize various actions of the excavator.

[0030] The hydraulic pilot pump 6 is connected to the oil tank 7 to provide an oil source for the pilot system.

[0031] The controller 2 is connected to the start switch 3. When powered on, the controller is powered, receives the start signal and completes the start control; The controller 2 is connected to the safety handle switch solenoid valve 8 and is used to detect the on / off state of the safety handle switch solenoid valve 8; The controller 2 is connected to the electromagnetic proportional valve 9, and controls the magnitude of the output pressure of the electromagnetic proportional valve 9 by the magnitude of the output current.

[0032] For safety reasons, excavators are equipped with a safety handle switch solenoid valve. When the safety handle switch solenoid valve is opened, the vehicle's pilot oil circuit can supply oil normally. When it is disconnected, the hydraulic pilot control oil circuit can be quickly cut off to ensure the safety of people and vehicles. In addition, if the safety handle switch solenoid valve is opened, the engine cannot be started.

[0033] Based on the above control system, the present invention provides two methods to improve the performance of the electromagnetic proportional valve, as follows: Method 1: When the excavator is started, the sequence of actions is to power on the whole machine, start the engine, and finally open the safety handle switch solenoid valve to enter the working state normally. There is a certain time difference when the user performs this series of actions.

[0034] For this control method, see Figure 1 , the specific logic is as follows: The controller monitors whether the power-on signal of the whole machine is turned on. If it is powered on, it will proceed to the next step, otherwise it will end this control; The controller monitors whether the vehicle has any fault alarm related to the electromagnetic proportional valve, such as open circuit, short circuit, etc. If not, proceed to the next step, otherwise end this control; The controller monitors whether the safety handle switch solenoid valve is open. If it is not open, it executes the next step, otherwise it ends this control; The controller continuously outputs a trapezoidal wave current signal of a certain frequency within 1-2s to control the opening and closing of the electromagnetic proportional valve 9. During this process, the valve core moves back and forth. At this time, the hydraulic oil in the valve body of the electromagnetic proportional valve 9 will also be agitated with the movement of the valve core, and the precipitated impurities will also be evenly filled in the entire valve body due to the agitation, thereby solving the problem of abnormal valve core movement speed and output pressure caused by uneven impurity content in the oil, resulting in abnormal operation.

[0035] This method allows the controller to complete the entire control process automatically each time the power is turned on, and can be interrupted at any time without affecting the operation of the entire machine. It is fast and effective.

[0036] Method 2: Active flushing function of electromagnetic proportional valve is suitable for situations where the vehicle operation time is long and method 1 cannot meet the needs. Users can select the active flushing function through the human-computer interaction interface.

[0037] For this control method, see Figure 1 , the specific logic is as follows: The controller monitors whether the power-on signal of the whole machine is turned on. If it is powered on, it will proceed to the next step, otherwise it will end this control; The controller monitors whether the vehicle has any fault alarm related to the electromagnetic proportional valve, such as open circuit, short circuit, etc. If not, proceed to the next step, otherwise end this control; The user selects the active flushing function of the electromagnetic proportional valve through the monitor, and the monitor gives relevant operation instructions. One is to give the electromagnetic proportional valve flushing alarm sound or display prompt, and the other is to prompt to start the engine; The controller determines whether the engine has been started. Only after the engine has been started can it drive the hydraulic pilot pump to work normally, thereby providing oil source to the electromagnetic proportional valve; After the start-up is completed, the monitor prompts to open the safety handle switch solenoid valve. If it is opened, the pilot hydraulic pump is driven, and oil is supplied to all electromagnetic proportional valves of the vehicle through the safety handle switch solenoid valve; the control executes the next step; otherwise, the control ends. It should be noted that if the safety handle switch solenoid valve is not opened for a period of time (about 3 minutes), the control ends, and the controller transmits a signal to the monitor, which shows that the active flushing is unsuccessful; The controller continuously outputs a trapezoidal wave current signal of a certain frequency to control the opening and closing of the electromagnetic proportional valve, and the valve core performs a reciprocating motion. During the whole process, new oil enters the electromagnetic proportional valve through the oil inlet P, and the oil flows out alternately at the outlet A and the oil return port T. After multiple cycles, impurities flow out, achieving the purpose of cleaning; After the flushing is completed, the controller sends a signal to the monitor, and the monitor displays an alarm prompt indicating that the flushing is completed.

[0038] In the present invention, the control is used to determine whether the engine is started, specifically as follows: By receiving the engine speed signal, it is determined whether the speed is greater than or equal to the lowest idle speed of the engine to determine whether the start is completed. If the start is completed, the next step is performed, otherwise the control is terminated; It should be noted that if the startup is not completed after a period of time (about 3 minutes), the control will be terminated, and the controller will transmit a signal to the monitor, which will show that the active flushing was unsuccessful.

[0039] It should be noted that the controller can control multiple groups of solenoid proportional valves at the same time, but it is necessary to ensure that the two solenoid proportional valves controlling the same hydraulic main valve core output trapezoidal wave current signals of the same frequency at the same time, so that the output pressure of the solenoid proportional valve remains the same, and the hydraulic main valve core is subjected to two forces of equal magnitude and opposite directions, and thus will be in a stationary state.

[0040] It should be further explained that when setting the trapezoidal wave frequency, it must be higher than the response frequency of the hydraulic main valve core to ensure that the entire machine does not move and ensure safety.

[0041] In the present invention, the two methods can exist simultaneously without interfering with each other, the whole process lasts for a short time, is convenient and fast, does not generate costs and can effectively solve problems in the market.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A control system for improving the performance of an electromagnetic proportional valve, characterized in that: include: The controller is connected to the electromagnetic proportional valve and is used to output a trapezoidal wave current signal to the electromagnetic proportional valve when powered on, control the opening and closing of the electromagnetic proportional valve, and stir the hydraulic oil in the valve body of the electromagnetic proportional valve evenly; and when the electromagnetic valve of the vehicle operation safety handle switch is opened, output a trapezoidal wave current signal to the electromagnetic proportional valve, control the opening and closing of the electromagnetic proportional valve, and make the hydraulic oil flow out alternately from the outlet and the return oil port of the electromagnetic proportional valve to clean impurities; and, The monitor is connected to the controller and is used to issue control instructions, wherein the control instructions include: an instruction to control the electromagnetic proportional valve to perform active flushing, an instruction to start the engine, and an instruction to open the safety handle switch electromagnetic valve.

2. A control system for improving the performance of an electromagnetic proportional valve according to claim 1, characterized in that: The monitor is connected to the controller via a CAN line.

3. A control system for improving the performance of an electromagnetic proportional valve according to claim 2, characterized in that: The monitor is also used to: Indicates that active flushing was unsuccessful; And display the alarm prompt that the flushing is completed.

4. A control system for improving the performance of an electromagnetic proportional valve according to claim 1, characterized in that: The controller is also used to: Connected to the start switch, when powered on, the controller is powered, receives the start signal and completes the start control; Connected to the safety handle switch solenoid valve, used to detect the on / off state of the safety handle switch solenoid valve; Connected to the electromagnetic proportional valve, it is used to control the output pressure of the electromagnetic proportional valve by the output current.

5. A control method for improving the performance of a control system of an electromagnetic proportional valve according to any one of claims 1 to 4, characterized in that: include: The controller monitors whether the power-on signal of the whole machine is turned on. If it is turned on, proceed to the next step, otherwise end this control; The controller monitors whether the vehicle has any fault alarm related to the electromagnetic proportional valve. If not, proceed to the next step, otherwise, end this control; The controller monitors whether the safety handle switch solenoid valve is open. If it is not open, the next step is executed, otherwise the control is terminated; The controller continuously outputs a trapezoidal wave current signal of a certain frequency within a set time to control the opening and closing of the electromagnetic proportional valve. During this process, the valve core moves back and forth, causing the hydraulic oil in the valve body of the electromagnetic proportional valve to stir to prevent impurities from settling.

6. A control method for improving the performance of a solenoid proportional valve control system according to claim 5, characterized in that: The setting time is 1-2s.

7. A control method for improving the performance of a control system of an electromagnetic proportional valve according to any one of claims 1 to 4, characterized in that: include: The controller monitors whether the power-on signal of the whole machine is turned on. If it is turned on, proceed to the next step, otherwise end this control; The controller monitors whether the vehicle has any fault alarm related to the electromagnetic proportional valve. If not, proceed to the next step, otherwise, end this control; The monitor sends an active flushing command to the electromagnetic proportional valve and prompts the engine to start; Determine whether the engine has been started by the controller; After the start-up is completed, the monitor sends a command to open the safety handle switch solenoid valve. If it is opened, the pilot hydraulic pump is driven, and oil is supplied to all the electromagnetic proportional valves of the vehicle through the safety handle switch solenoid valve; the control executes the next step; otherwise, the control ends; The controller continuously outputs a trapezoidal wave current signal of a certain frequency to control the opening and closing of the electromagnetic proportional valve, and the valve core moves back and forth. During the whole process, new oil enters the electromagnetic proportional valve through the oil inlet, and the oil flows out alternately at the outlet A and the return oil port T, and impurities are cleaned through circulation.

8. The control method of a control system for improving the performance of an electromagnetic proportional valve according to claim 7, characterized in that: The method further comprises: If the safety handle switch solenoid valve is not opened for a certain period of time, the control will be terminated. At the same time, the monitor will show that the active flushing was unsuccessful.

9. The control method of a control system for improving the performance of an electromagnetic proportional valve according to claim 7, characterized in that: The method further comprises: After flushing is completed, the monitor will display an alarm prompt indicating that flushing is complete.

10. The control method of a control system for improving the performance of an electromagnetic proportional valve according to claim 7, characterized in that: The step of determining whether the engine is started by the controller includes: The engine speed signal is received to determine whether the speed is greater than or equal to the lowest idle speed of the engine. If so, it is determined that the start is completed.

11. A control method for improving the performance of a solenoid proportional valve control system according to claim 10, characterized in that: The method further comprises: If the startup is not completed for a period of time, the control will be terminated. At the same time, the monitor will show that the active flushing was unsuccessful.

12. A control method for improving the performance of a solenoid proportional valve control system according to claim 5 or 7, characterized in that: The frequency of the trapezoidal wave current signal is higher than the response frequency of the hydraulic main valve core.

13. A control method for a control system for improving the performance of an electromagnetic proportional valve according to claim 5 or 7, characterized in that: The controller supports controlling multiple groups of electromagnetic proportional valves at the same time, and needs to ensure that two electromagnetic proportional valves controlling the same hydraulic main valve core simultaneously output trapezoidal wave current signals of the same frequency.

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