Intelligent water meters have been developed for nearly 8 years now. Eight years in the market put into use the smart meter some quality, technical problems. These problems eventually focus on the actuator. Developers on the actuator more or less done basic functions of the experiment, to verify the function in the actual use of the reliability. Why does the proven actuator present an unexpected problem in the user's formal use? I think there is a design structure, test methods, comprehensive test environment. Here's my personal opinion on the issue of actuator integration. First, the design structure 1. The basic principles of actuator work Currently on the market the types of actuators include: solenoid pilot valve, motor pilot valve, motor ball valve, plane stack valve. Electromagnetic pilot valve works: When the solenoid valve is opened, the pressure relief valve on the pressure relief valve, the pressure inside the pipeline will push the valve seal open, the smart meter to work; solenoid valve is closed, the pressure relief chamber is closed Hole, at this time in the valve seal on the cavity of the water pressure rose rapidly until the valve seal is pressed against the valve port, closed the outlet. Motor pilot valve is the use of deceleration mechanism, in order to solve the problem of moving parts of the seal, the use of the principle of magnetic drive lever actuation pressure relief hole opening and closing, so as to achieve the valve seal on and off. It is similar to the electromagnetic pilot valve principle, but the time and reaction speed is slower than the electromagnetic pilot valve. The problem is the same with the solenoid pilot valve. Motor ball valve principle of work: the speed reduction mechanism will slow down the motor, the torque will be increased to promote the ball valve to rotate, to open and close the function. For the valve manufacturing process itself is relatively high, the degree of rotation of the ball valve to have a very standard parameter that the rotary valve must be controlled within the scope of a set of process parameters. In addition, the seal of the driving rod is also a key point. The O-ring is basically used for sealing. Therefore, if the rubber ring is too tight, it will increase the torque. If it is too loose, it will lead to tightness and leakage. Stacking valve works: Slowdown by the slowdown in the motor speed, the torque will be increased to promote the plane stack valve rotation, to open and close the function. Sealed by the pressure on the film to ensure. Plane stack valve on the flatness and smoothness of the valve surface requirements are quite high, but also for the material requirements also have high requirements. In order to solve these problems, the use of ceramic substrate under the laminated valve stack, the use of other high-strength wear-resistant material on the film, completely according to the principle of chemical mechanical seal manufacturing and processing, not only ensure a reasonable contact surface, and Guaranteed minimum friction coefficient. 2. Structural Analysis Electromagnetic pilot valve and the motor pilot valve in the actual use of tap water pipe, there has been due to a long time leading to the plugging of water quality problems, the pressure stem stem caused by adsorption of iron particles caused by stem stuck and so on, through The use of the market and the feedback of information, developers have learned that this structure of the actuator is not suitable for our current water quality use. As a result, developers turn to the ball valve and the plane stack valve. Now use the ball valve a little more. Following a comprehensive analysis of the structure of the ball valve, the plane stack valve: Motor ball valve: In the structure of the ball valve to improve the level of technology, the ball valve torque control will not leak in a certain torque parameter range. This process requirements include two requirements, first, the degree of tightness between the ball valve and the seal clamping ring, it is necessary to maintain a certain pressure will not close when closed leaks; but also under the external force used to rotate Torque in a parameter range. The value of this parameter should be: F> f1 + f2 + f3 Where: F - torque output by the motor-driven reduction gear mechanism; f1 - torque of the ball rotation; f2 - torque of the rubber seal of the rotating rod; f3 - Pipeline dynamic pressure on the ball valve force; the current market, motor ball valve switching time from: 8 seconds to 14 seconds there are several, of which about 8 seconds the structure of the motor ball valve and 14 seconds of the motor ball valve has been tested. The test environment is 1.0MPa, the power supply is the battery direct supply. The test is a new battery. Test results: 8 seconds motor ball valve in 0.6MPa dynamic environment is very difficult to close the valve, and sometimes do not even close; 14 seconds motor valve 1.0MPa dynamic environment more normal off valve, there is no turn-off error. According to the results of the two tests, we can see that torque is very important to the ball valve. We assume that the motor is the same parameter, then if the 8-second time is 1, then the 14-second time is 1.75. Therefore, the key motor ball valve speed reduction mechanism is the size of the problem, but in front of several technological problems is also very important. Plane stack valve: a mechanical seal on the basis of the development of a valve. The characteristics of the valve is horizontal, the flow is up and down, so when the valve is closed, the water pressure on the valve is a great role, the higher the pressure the better sealing performance. Valve is working for the plane rotation movement, the friction coefficient to be overcome between the valve, and the impact of water pressure on it as large as the ball valve. But to overcome the friction under the hydraulic pressure on the stack. Friction between laminations through the actual test, a few fu did not increase the amount of force. The test is carried out on the same water meter and according to the following methods: (1) The ammeter is connected in series with the switch circuit, the valve is opened and the valve is closed; (2) The IC card water meter is installed in the pump pipe of 105m head, Pressure gauge and tee to install the valve to regulate the pressure of the pipeline water supply; ⑶ open the pump to adjust the pressure at about 1.0MPa, the valve to run the switch test; ⑷ by adjusting the pressure of the valve will be gradually adjusted to 1.5MPa. Test is carried out in a dynamic environment, exactly the same with the actual use of industrial and mining, the required current at 1.0MPa pressure is: off the valve 50mA, when it is about to turn off, the current suddenly rose to 110mA; open the valve current: open When the valve is started, the current is about 110mA. When the valve is opened, the current drops rapidly to 50mA. When the water pressure is 1.5MPa, the required current is: the valve starts to turn off 55mA, when it is about to turn off, the current suddenly rises to about 120mA; when the valve is open, the current is about 120mA when the valve is started, when the valve opens, The current drops rapidly to 55mA. From the experimental results, it can be seen that the influence of water pressure on the laminated valve is very small, and the change of the current in the reaction is 5 mA to 10 mA. Pressure increased from 1.0MPa to 1.5MPa increased by 50%; current rose from 50mA to 55mA and from 110mA rose to about 120mA, an increase of about 10%, therefore, in laminated valve hydraulic valve opening force The impact is relatively small, the relationship is 1: 5. Of course this must be based on the specific material and coefficient of friction. Plane stack valve deceleration mechanism switching time of 8 seconds and 14 seconds. Two kinds of time the valve was tested, the test environment is 1.0MPa, the power supply is the battery supply. The test is a new battery. Test results: 8 seconds plane stack valve in 1.0MPa dynamic environment switch is normal; 14 seconds plane stack valve in 1.5MPa dynamic environment switch is normal. 3. Summary From the results of the experiment and the theoretical calculation, we already know that the structure of the plane stack valve is more suitable for the actuators used in smart meters. In mountainous cities, the water supply pressure is higher than that in ordinary plain cities. At present, the water pressure of tall buildings in urban areas is also higher than that of common floors. Without well-validated valves, Function Intelligent water meter is a modern high-tech products, representing the level of automation instrumentation development, as a developer, smart meter development to meet the requirements of users on the first place, the product should be able to cover all the use of the environment. Second, the valve drive structure In the plane stack valve structure, the current structure for the valve drive is: 1. Upright pole plus double nitrile rubber O-ring to prevent water leakage; 2. Up and down with a strong magnetic drive, To prevent water leakage. The two methods in terms of structure, the seal should be magnetic drive method is more reasonable, and the current sealing effect is still very good. However, the quality of tap water delivered to our customers by our country's water division is not pure water, there are many impurities in the water, and also contain considerable iron-containing substances in the impurities. Due to the water quality, in less than 6 years, the ferrous materials in the water will be attracted by the strong magnetic force of the driven gear, tightly wrapped by the gear, and finally the friction coefficient of the ferromagnetic gear rotating in the water Increase, there will even be rotation hysteresis. This situation has occurred in the motor pilot valve on many occasions. So, the products which still use the motor pilot valve are basically gone. O-ring seal upright, sealed with pressure liquid is impossible, especially for IC card water meter that is more difficult to use, first, the use of the motor itself, small power, torque is small, O-ring over Tight will quickly increase the Mocha coefficient, the switch valve current increases; Second, O-ring too loose will result in sealing effect, prone to leakage. If you want to be processed into not loose, then the process requirements increase, resulting in increased manufacturing costs. Even if the processing technology is mature, O-ring long-term under the pressure of water will produce deformation, water pressure in general, will be about two years, O-ring seal leak. At present, the IC card water meter product quality, has become better and better, plagued quality problems are often after installation, the use of a year or two, there is no valve or leak and other issues. If it is a magnetically actuated valve, it will open the valve for a longer period of time due to an increase in the Mocha factor. How to solve the problem, I think: in the IC card water meter, O-ring and magnetic drive structure is not intended to be used in pressurized pipe network, the seal of the water should be used mechanical seal structure for long Time to seal, so as to ensure that in 6 years of use to ensure that no leakage, while ensuring the valve function is achieved. Currently appeared in the course of user quality problems found in the process, mainly leaking, the valve can not be completely closed, the valve loses its function. The crux of these quality problems is due to the sealing structure used in the valve drive. If the valve-driven sealing structure is improved, the problem of water leakage and the technical problem of losing the valve performance can be completely solved. Mechanical seal is a dynamic seal, commonly used in the chemical industry. The sealing reliability is very good. The introduction of mechanical seals in the IC card water meter industry is an important measure to improve the IC card water meter technology. It is also the best way to solve the problem of IC card water meter leakage and loss of executive function within a certain period of time. Third, the test method Smart meter is installed in the home thousands of households measuring instruments, with automatic measurement, control arrears and other functions, usually do not need people to care and maintenance, relying solely on the IC card in the data and information transmission , The implementation of modern management. As a factory product, with each function is to enter the reliable test equipment inspection and certification is qualified to the factory. General test and test equipment, because the measurement equipment manufacturing license forensics from time to time, but the valve dynamic test equipment due to forensics without specific requirements, so the general factory will not be prepared, thus resulting in the valve There is no dynamic test equipment manufacturers will go to research and development and manufacturing, resulting in no valve dynamic test, making the IC card water meter valve without leaving the factory for dynamic testing at home users to install. Caused the current valve leakage, can not shut the valve and other quality and technical problems. If you want to make a good product, all the testing methods can not be missing. Valve dynamic test, is a simulation test in the normal state of use. This state should be able to cover all the water environment. Check Valve dynamic implementation of the function there is a very important point is the voltage test, what kind of voltage is the most suitable? Each intelligent water meter has the same function, that is, when the battery voltage is lower than the set value, the single chip instructs the valve to close the function and the battery voltage at this time is the lowest voltage in the smart water meter, that is, The last valve closing action is in the lowest battery voltage environment. This can set the test, test conditions: 1. Water pressure: 1.0Mpa; 2. Voltage: smart meter set 80% of the limit voltage regulated power supply; or simulate the battery minimum voltage conditions as a test, test the power supply . As a measuring appliance manufacturing license assessment department should be intelligent water meter forensics equipment to increase valve dynamic detection of special equipment, so as to ensure that the factory product quality to meet the requirements.