CN200969048Y - A gas mass flow controller - Google Patents

Abstract

The utility model discloses a through the sensor, control flow control valve and control gas mass flow's controller through electric quantity converting circuit. The valve comprises a hollow base body, a flow detector arranged inside the base body, a circuit board, a flow control valve, a hollow body tightly screwed with the base body, and a gas flow layer channel arranged in the body, wherein a double-spring-sheet adjusting mechanism with high fatigue resistance is arranged between a valve head and a valve body of the flow control valve, the valve head and the valve seat are in plane contact with a large contact area, the inlet pressure is large, and the gas leakage rate is reduced. Through the adjusting mechanism of the double spring pieces capable of being directly positioned, the anti-fatigue strength of the double spring pieces is improved, the stability of the flow control valve is improved, the inlet pressure is high, the air leakage rate is reduced, and the power consumption is reduced.

Description

A gas mass flow controller

technical field

The utility model relates to a device for directly measuring and controlling gas mass flow, more specifically, relates to a controller for controlling gas mass flow by controlling a flow control valve through a sensor and a power conversion circuit.

technical background

The main disadvantage of the existing gas mass flowmeter is that the position of the single spring piece in the valve body is unstable, easy to change, and the elastic force is unstable. As the inlet pressure increases, the gas leakage rate of the spring piece in the valve body increases accordingly. In addition, this gas mass flow rate The power consumption of the device is large, which is a waste of electric energy.

Utility model content

The purpose of this utility model is to overcome the above-mentioned defects in the prior art, provide an adjustment mechanism of double springs that can be directly positioned, improve the fatigue resistance of the double springs, improve the stability of the solenoid valve, and the inlet pressure Large gas mass flow controller with reduced leak rate and low power consumption.

In order to achieve the above object, the technical solution provided by the utility model is as follows: construct a gas mass flow controller, including a hollow substrate, a flow detector arranged inside the substrate, a circuit board, a flow control valve, and a The base body is a hollow body tightly screwed together, and a gas laminar flow channel is arranged in the body.

In the above gas mass flow controller, the flow detector includes a capillary thin-wound temperature sensor.

In the above gas mass flow controller, the circuit board includes measurement and control circuits.

In the above-mentioned gas mass flow controller, the valve head and the valve body of the flow control valve are provided with a double-spring adjustment mechanism with high fatigue resistance, and a plane with a large contact area is provided between the valve head and the valve seat. High inlet pressure reduces air leakage rate.

In the above gas mass flow controller, the coil winding of the flow control valve is four turns.

In the above gas mass flow controller, a tapered pin restrictor is arranged in the gas laminar flow channel.

In the above gas mass flow controller, the flow detector and the flow control valve can be used independently.

Working principle: The gas mass flow controller is made by using the flow fluid to transfer heat to change the heat conduction distribution effect of measuring the temperature distribution of the capillary wall. It uses the principle of capillary heat transfer temperature difference calorimetry to measure the mass flow of gas, which can not be affected by temperature and pressure. The flow signal measured by the sensor is amplified, and then compared with the set voltage, and the obtained difference signal is used to drive the flow control valve, so as to realize on-off control and continuous control, and complete the tight control of gas mass flow.

The beneficial effect of the gas mass flow controller described in the utility model is: through the adjustment mechanism of the double spring leaf that can be directly positioned, the anti-fatigue strength of the double spring leaf is improved, and the stability of the flow control valve is improved at the same time. Large gas mass flow controller with reduced leak rate and low power consumption.

The gas mass flow controller described in the utility model will be further described below in conjunction with the accompanying drawings and embodiments:

Description of drawings

Fig. 1 is the assembly diagram of the gas mass flow controller of the present utility model;

Fig. 2 is a schematic cross-sectional view of the flow control valve.

Detailed ways

The following are the best embodiments of the gas mass flow controller described in the utility model, which does not limit the scope of protection of the utility model.

Referring to Fig. 1 and Fig. 2, a gas mass flow controller includes a hollow base body 19, a flow detector 23 arranged inside the base body, a circuit board 18, a flow control valve 16, and a hollow body 1 tightly screwed to the base body 1. The gas flow laminar channel 2 arranged in the body.

The flow detector 23 includes a capillary thin-wound temperature sensor 24, a sensor housing 22, the sensor housing 22 is tightly connected to the top of the sensor fixing plate 29, the bottom of the sensor fixing plate 29 is tightly screwed with the body 1, and the capillary thin-wound temperature sensor The pipe body 27 of 24 is pierced through the bottom of the sensor fixing plate 29 and is closely connected with the distribution hole 21 of the main body 1 .

Circuit board 18 includes measurement and control circuitry.

Between the valve head 5 and the valve body 8 of the flow control valve 16, there is a double spring leaf adjustment mechanism 7 with high fatigue resistance. The double spring leaf adjustment mechanism 7 can play the role of direct positioning and guiding, which not only improves the flow control valve The stability of 16 has strengthened the concentricity of the valve core 12 and the valve stem 15, and the bottom plane A of the valve head 5 and the end plane B of the valve seat 4 are set as a plane contact with a larger contact area, and the inlet pressure is large. To reduce the air leakage rate, the coil winding 10 of the flow control valve 16 has four turns.

The continuously adjustable working principle of the flow control valve 16 is: the voltage signal from the measurement circuit is compared with the set value, and the difference is sent to the flow control valve 16 through the regulation of the integral adjustment circuit of the control circuit. Control signal, until the flow control Valve 16 makes the flow equal to the set point.

Use the capillary to directly measure the gas mass flow tail straight-through type, which is suitable for the measurement and control of small gas flow, because the output characteristic of the sensor is parabolic, that is, after the gas flow exceeds the linear break, the output signal decreases with the increase of the gas flow , in order to ensure that the gas flow in the capillary is within the range of the linear segment of the output signal, a tapered pin restrictor 31 is provided in the gas flow layer channel 2 inside the body 1 to form a split flow structure. The gas flow in the capillary is consistent with the main channel The gas flow in the meter is in a fixed ratio, and if you choose different split ratios, you will have different gas mass flow ranges, so the split flow structure can meet the measurement requirements of any gas volume.

Connecting nuts 34 are provided at the left and right ends of the body 1 to facilitate connection with the main channel.

Working principle: The gas mass flow controller is made by using the flow fluid to transfer heat to change the heat conduction distribution effect of measuring the temperature distribution of the capillary wall. It uses the principle of capillary heat transfer temperature difference calorimetry to measure the mass flow of gas, which can not be affected by temperature and pressure. Amplify the flow signal measured by the sensor, then compare it with the set voltage, and use the obtained difference signal to drive and control the flow control valve 16, so as to realize on-off control and continuous control, and complete the tight control of the gas mass flow. control.

Claims (5)

1, a kind of gas mass flow amount controller, the matrix that comprises a hollow, be arranged on a flow detector of matrix inside, one circuit board, a flowrate control valve, the body of a hollow that closely is spirally connected with matrix, be arranged on an intrinsic gas fluid layer passage, it is characterized in that, be provided with the high dual spring sheet governor motion of antifatigue between the valve head of described flowrate control valve and the valve body, be provided with the bigger plane of contact area between valve head and the valve seat.

2, a kind of gas mass flow amount controller according to claim 1 is characterized in that, described flow detector can be that kapillary is carefully around the formula temperature sensor.

3, a kind of gas mass flow amount controller according to claim 1 is characterized in that, described circuit board comprises to be measured and control circuit.

4, a kind of gas mass flow amount controller according to claim 1 is characterized in that, is provided with a tapered pin restrictor in the described gas fluid layer passage.

5, a kind of gas mass flow amount controller according to claim 1 is characterized in that, the coil winding of described flowrate control valve is four circles.

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