A Real-time Flow Detection Method for a Switch Valve Control System

Abstract

The present invention discloses a real-time flow detection method for a switch valve control system. An acceleration vibration sensor respectively collects the vibration curves of each high-speed switch valve, and the collected signals can be converted into the acceleration motion curves of the valve core. The computer can convert the acceleration vibration curves of each high-speed switch valve into valve core displacement curves through a processor. In the case of knowing the structure of the high-speed switch valve, the valve core displacement curve can be converted into the opening area (A) curve of the high-speed switch valve. According to the measured values of the pressure sensors at the main oil inlet and the main oil return port of the switch valve control system, the pressure difference (ΔP) across the high-speed switch valve can be obtained. With k being the proportionality coefficient, the flow rate of each high-speed switch valve in the switch valve control system can be obtained, and then the total flow rate of the switch valve control system can be obtained according to the combination form of each high-speed switch valve in the switch valve control system. The present invention does not need to change the internal structure of the switch valve control system, and solves the problem of measuring the flow rate of each branch inside the switch valve control system in the field of digital hydraulics.

Description

Technical Field

[0001] The present invention relates to the field of digital valve flow detection, and particularly to a real-time flow detection method for a switching valve control system. Background Art

[0002] A digital valve specifically refers to a switching valve controlled by a digital signal and a valve island element integrated by switches. Due to the restrictive relationship among the spool quality, hydrodynamic force, and frequency response, individual high-speed switching valves are all faced with the limitation of small flow rate, and there are still certain limitations in applications where large flow rates are required.

[0003] To solve the application problem in the case of large flow rate, research institutions at home and abroad have proposed a switching valve control system structure that uses multiple high-speed switching valves in parallel to control the flow rate, and realizes the control of the flow rate by controlling the logical combination of the opening and closing of the high-speed switching valves.

[0004] At present, there are mainly two ways to detect the flow rate of the switching valve control system. One is to install a flow sensor at the main oil return port of the switching valve control system. The disadvantage of this method is that it is impossible to judge the flow rate of each branch high-speed switching valve. The other way is to install a flow sensor on each high-speed switching valve branch respectively. The disadvantage of this method is that the number of flow sensors used is too large, the cost is high, and it is also very difficult to install sensors inside the switching valve control system. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art. The present invention proposes an innovative method for detecting the flow rate of a digital valve control system using an acceleration vibration sensor. This method only needs to axially connect the acceleration vibration sensor to each high-speed switching valve, and then the flow rate of each branch high-speed switching valve can be measured without changing the internal structure of the switching valve control system.

[0006] The present invention first provides a real-time flow detection method for a switching valve control system, which includes the following steps:

[0007] 1) Install acceleration vibration sensors in the axial directions of each high-speed switching valve in the switching valve control system. The acceleration vibration sensors obtain the vibration signals during the working process of their corresponding high-speed switching valves. The signals are conditioned and amplified by a signal conditioner and then received by a processor. Install pressure sensors at the main oil inlet and main oil return ports of the switching valve control system respectively, and the signals of the pressure sensors are transmitted to the processor for reception;

[0008] 2) The processor converts the collected signals into the acceleration vibration curves of the spools in the high-speed switching valves.

[0009] 3) The processor converts the acceleration vibration curves of each high-speed switching valve into the spool displacement curves of each high-speed switching valve.

[0010] 4) Given the known structure of the high-speed switching valve, the processor converts the spool displacement curve into the opening area (A) curve of the high-speed switching valve. Based on the measured values of the pressure sensors at the main inlet and main return ports of the switching valve control system, the pressure difference (ΔP) across the high-speed switching valve is obtained. Let k be the proportionality coefficient. According to the formula Q = k·ΔP·A, the flow rate of each high-speed switching valve in the switching valve control system can be obtained.

[0011] 5) Obtain the total flow rate of the switching valve control system based on the combination form of each high-speed switching valve within the switching valve control system.

[0012] Preferably, the acceleration vibration sensor is installed on the valve body of the high-speed switching valve and is located in the axial direction of each spool of the high-speed switching valve.

[0013] Preferably, in step 2), the signal obtained by the acceleration vibration sensor is the acceleration vibration sensor, that is, the acceleration motion curve of the valve body of the high-speed switching valve. The signal obtained by the acceleration vibration sensor is the acceleration vibration sensor, that is, the acceleration motion curve of the valve body of the high-speed switching valve.

[0014] Given that the mass of the spool is m, the mass of the valve body is M, and the acceleration of the valve body is a1, the acceleration of the spool can be obtained as Therefore, based on the acceleration vibration curves of the valve body measured by each sensor, the acceleration vibration curves of the motion of each spool are obtained.

[0015] Preferably, in step 3),

[0016] Since the acceleration of the spool of the high-speed switching valve has been obtained, the displacement of the spool can be obtained by using double integration. Assuming the initial condition is 0, the spool velocity v = ∫adt, the displacement s = ∫vdt, and the displacement s = ∫(∫adt)dt. Therefore, the acceleration curves of the motion of each spool can be converted into the displacement curves of each spool.

[0017] Preferably, in step 5), the total flow rate of the switching valve control system is obtained based on the combination form of each high-speed switching valve within the switching valve control system; the total flow rate of the switching valve control system is the sum of the flow rates of each parallel branch within the switching valve control system.

[0018] In the present invention, the structures and strokes of the various high-speed switching valves in the switching valve control system may be the same or different. The control strategies of the various high-speed switching valves in the switching valve control system may be the same or different. The various high-speed switching valves in the switching valve control system are independently controlled. That is to say, the flow rate detection method of the present invention does not limit the selection and control strategy of the high-speed switching valves in the switching valve control system, and the present invention can be used in any case. The combination form of the various high-speed switching valves in the switching valve control system (i.e., the setting form of the fluid flow path in the switching valve control system) does not affect the method of the present invention. As long as the flow rates of the various high-speed switching valves are obtained, those skilled in the art can calculate the flow rate of the entire switching valve control system according to the setting form of the fluid flow path in the switching valve control system.

[0019] The present invention only needs to arrange acceleration vibration sensors to connect them to the various high-speed switching valves of the switching valve control system, and the flow rates corresponding to the various high-speed switching valves inside the switching valve control system can be measured without changing the internal structure of the switching valve control system, solving the problem of measuring the flow rates of each branch inside the switching valve control system in the digital hydraulic field. Brief Description of the Drawings

[0020] Figure 1 Schematic diagram of the hardware implementation of the flow rate detection method of the present invention;

[0021] Figure 2 Schematic diagram of the flow chart of the flow rate detection method of the present invention;

[0022] Figure 3 Schematic diagram of the interaction force between the valve core and the valve body. Detailed Embodiments

[0023] The following further elaborates and explains the present invention in conjunction with specific embodiments. The technical features of the various embodiments of the present invention can be combined correspondingly without conflict.

[0024] As Figure 1 shown, in order to implement the flow rate detection method of the present invention, this embodiment first provides a set of flow rate detection systems. The switching valve control system of this embodiment takes 12 high-speed switching valves as an example. It should be noted that the flow rate detection method of the present invention can be applied to any number of high-speed switching valves, and the high-speed switching valves can be arbitrarily selected; the high-speed switching valves can be in any combination form in the switching valve control system.

[0025] Figure 1Among them, component 1 is a 24V power supply for supplying power to the controller. 3-1, 3-2, and 3-3 are three identical controllers. Each controller has four output control ports to respectively control the movement of 12 high-speed switching valves. 4-1 to 4-12 are 12 identical acceleration vibration sensors, which are axially connected to the 12 high-speed switching valves respectively and are used to detect the vibration in the movement direction of the high-speed switching valves. 5-1 to 5-12 are 12 identical high-speed switching valves. 6 is a valve block, and its outer surface has a main oil inlet and a main oil return port. 7 is a pressure sensor at the main oil inlet, and a pressure sensor is also installed at the main oil return port on the other side of the valve block. 8 is a signal conditioner, which processes and amplifies the vibration signals collected by each acceleration vibration sensor. 9 is a 19V power supply for supplying power to the signal conditioner. 10 is a computer host, which can receive the vibration signals processed by the signal conditioner. 11 is a computer monitor.

[0026] The working process of measuring the flow rate of the switching valve control system by the acceleration vibration sensor in the present invention is as follows: During the working process of the switching valve control system, each acceleration vibration sensor respectively collects the vibration curves of the corresponding high-speed switching valves. Because this sensor is an acceleration vibration sensor, the collected signals can be converted into the acceleration motion curves of the valve cores in the high-speed switching valves. The computer can convert the acceleration vibration curves of each high-speed switching valve into the valve core displacement curves of each high-speed switching valve through the processor. Under the condition of knowing the structure of the high-speed switching valve, the valve core displacement curve can be converted into the opening area (A) curve of the high-speed switching valve. According to the measured values of the pressure sensors at the main oil inlet and the main oil return port of the switching valve control system, the pressure difference (ΔP) at both ends of the high-speed switching valve can be obtained. k is a proportionality coefficient. According to the formula Q = k·ΔP·A, the flow rate of each high-speed switching valve in the switching valve control system can be obtained. Then, the total flow rate of the switching valve control system can be obtained according to the combination form of each high-speed switching valve in the switching valve control system. For example, when all high-speed switching valves in the switching valve control system are connected in parallel, the sum of the flow rates of each high-speed switching valve in the switching valve control system is the total flow rate of the switching valve control system. The specific flow chart is shown as Figure 2 shown, Figure 2 which is the case where all high-speed switching valves in the switching valve control system are connected in parallel.

[0027] The following introduces the method of converting the vibration signals collected by each sensor into the acceleration curves of the movement of each valve core:

[0028] Since the sensor used in this invention is an acceleration vibration sensor, that is, the vibration signal detected by the sensor is the acceleration motion curve of the object connected thereto, namely the acceleration motion curve of the high-speed on-off valve body. Since the frictional force on the outer surface of the valve body is very small when the valve body vibrates in the on-off valve control system, it is negligible. Therefore, the spool and the valve body are respectively subjected to three pairs of interaction forces, namely the dynamic frictional force between the spool and the valve body, the spring force between the spool and the valve body, and the electromagnetic force between the spool and the valve body. The schematic diagram of the interaction force between the spool and the valve body is as shown in Figure 3 Figure 2.1, where 12 is the connection between the acceleration vibration sensor and the valve body, and the acceleration vibration curve measured by the sensor is the acceleration motion curve of the valve body. 13 is the valve body, and 14 is the spool. Taking the opening motion of the high-speed on-off valve as an example, the closing stage is the same. The upward movement of the spool is the opening motion of the high-speed on-off valve. The spool is subjected to three forces: F1 is the electromagnetic attraction force of the coil on the spool in the valve body, F2 is the force of the spring in the valve body on the spool, and F3 is the frictional force of the valve body on the movement of the spool. Ignoring the frictional force on the outer surface of the valve body, the valve body is subjected to three forces which are the reaction forces of the three forces on the spool respectively: F1' is the attraction force of the spool on the valve body, F2' is the reaction force of the valve body subjected to the spring, and F3' is the frictional force of the spool on the valve body. Given that the mass of the spool is m, the mass of the valve body is M, and the acceleration of the valve body is a1, the acceleration of the spool can be obtained as Therefore, this invention can obtain the acceleration curve of the movement of each spool according to the acceleration vibration curves measured by each sensor.

[0029] The following introduces the method of converting the acceleration curve of the movement of each spool into the displacement curve of each spool:

[0030] Acceleration is the rate of change of the velocity of an object, and velocity is the rate of change of the position of the same object. That is, velocity is the derivative of position, and acceleration is the derivative of velocity. There are the following formulas: Integration is the opposite of differentiation. If the acceleration of the high-speed on-off valve spool is known, the position of the object can be obtained by using double integration. Assuming the initial condition is 0, there are the following formulas: v = ∫adt, s = ∫vdt, s = ∫(∫adt)dt. Therefore, this invention can convert the acceleration curve of the movement of each spool into the displacement curve of each spool.

[0031] The calculation formula for the valve flow rate according to the opening area of the high-speed on-off valve is as follows:

[0032] Q = k·ΔP·A

[0033] Among them: A is the opening area corresponding to each high-speed on-off valve, ΔP is the pressure difference measured by the pressure sensors at the oil inlet and outlet of the on-off valve control system, k is the proportionality coefficient, and Q is the flow rate corresponding to each high-speed on-off valve in the on-off valve control system.

[0034] Finally, the total flow rate of the switching valve control system is obtained according to the combination form of each high-speed switching valve in the switching valve control system; the total flow rate of the switching valve control system is the sum of the flow rates of each parallel branch. Each parallel branch is obtained by combining several high-speed switching valves, and the flow rate of a certain high-speed switching valve connected in series on this branch can be selected as the flow rate of this parallel branch according to the specific combination form of the high-speed switching valves on this branch.

[0035] The method of the present invention can measure the flow rates corresponding to each high-speed switching valve inside the switching valve control system without changing the internal structure of the switching valve control system, and solves the problem of measuring the flow rates of each branch inside the switching valve control system in the field of digital hydraulics.

[0036] The above-described embodiments merely represent several implementation manners of the present invention, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the appended claims.

Claims

1. A real-time flow detection method for a switch valve control system, characterized in that Including the following steps: 1) Accelerometer vibration sensors are respectively installed in the axial direction of each high-speed switching valve in the switching valve control system. The accelerometer vibration sensors obtain the vibration signals during the operation of their corresponding high-speed switching valves. The signals are conditioned and amplified by a signal conditioner and then received by a processor. Pressure sensors are respectively installed at the main oil inlet and the main oil return port of the switching valve control system. The signals of the pressure sensors are transmitted to and received by the processor. 2) The processor converts the collected signals into the acceleration vibration curves of the spools in the high-speed switching valves. The signals obtained by the accelerometer vibration sensors are the acceleration motion curves of the valve bodies of the high-speed switching valves. Given that the mass of the valve core is m, the mass of the valve body is M, and the acceleration of the valve body is a1, the acceleration of the valve core can be obtained as Therefore, according to the acceleration vibration curves of the valve body measured by each sensor, the acceleration vibration curves of the movement of each valve core are obtained; 3) The processor converts the acceleration vibration curves of each high-speed switching valve into the spool displacement curves of each high-speed switching valve. 4) Given the structure of the high-speed switching valves, the processor converts the spool displacement curves into the opening area A curves of the high-speed switching valves. According to the measured values of the pressure sensors at the main oil inlet and the main oil return port of the switching valve control system, the pressure difference ΔP across the high-speed switching valves is obtained. k is a proportionality coefficient. According to the formula Q = k·ΔP·A, the flow rate Q of each high-speed switching valve in the switching valve control system can be obtained. 5) The total flow rate of the switching valve control system is obtained according to the combination form of each high-speed switching valve in the switching valve control system.

2. The real-time flow detection method of a switching valve control system according to claim 1, characterized in that, The accelerometer vibration sensors are installed on the valve bodies of the high-speed switching valves and are located in the axial direction of the spools of each high-speed switching valve.

3. The real-time flow detection method of a switch valve control system according to claim 1, wherein, In step 3) above, Since the acceleration of the spool of the high-speed switching valve has been obtained, the displacement of the spool can be obtained by double integration. Assuming the initial condition is 0, the spool velocity v = ∫adt, the displacement s = ∫vdt, and the displacement s = ∫(∫adt)dt. Therefore, the acceleration curves of the motion of each spool can be converted into the displacement curves of each spool.

4. The real-time flow detection method of a switch valve control system according to claim 1, characterized in that In step 5) above, the total flow rate of the switching valve control system is obtained according to the combination form of each high-speed switching valve in the switching valve control system. The total flow rate of the switching valve control system is the sum of the flow rates of each parallel branch in the switching valve control system.

5. The real-time flow detection method of a switching valve control system according to claim 1, characterized in that, The structures and strokes of each high-speed switching valve in the switching valve control system can be the same or different.

6. The real-time flow rate detection method of a switching valve control system according to claim 1, characterized in that, The control strategies of each high-speed switching valve in the switching valve control system can be the same or different.

7. The real-time flow detection method of a switching valve control system according to claim 1, characterized in that Each high-speed switching valve in the switching valve control system is independently controlled.

Images