CN201107196Y - Micro air pressure detection device - Google Patents

Abstract

The utility model discloses a micro-air pressure detection device, which can be used for detecting the ventilating pressure in some valves with micro ventilating air pressure on automobiles, such as carbon tank valves and fuel tank valves. It solves the problem of high price of existing instruments for detecting these components. The structure is: a micro air pressure detection device, including a ventilation pipeline, a control valve arranged on the ventilation pipeline, a detection station is provided on the ventilation pipeline, and it is characterized in that at least one is connected in parallel upstream of the detection station on the ventilation pipeline. U-shaped tube, liquid is injected into the U-shaped tube, and a reading device is arranged at the U-shaped tube. The tiny air pressure detection device can also be used for air tightness detection of radiators and other parts, and can also be used for gas flow detection, etc., and has a wide range of applications.

Description

Micro air pressure detection device

technical field

The utility model relates to an air pressure detection device, in particular to a small air pressure detection device used for detecting parts with small ventilation air pressure on automobiles.

technical background

Some parts on the car need to be tested before assembly to ensure that they can work normally and stably after being assembled on the car. When the carbon tank valve and fuel tank valve on the car are tested, the airflow of a certain pressure is generally passed through these parts, and the purpose of distinguishing whether the relevant parts are qualified is achieved by measuring the pressure of the airflow when it flows stably in these parts. But these components have a common feature, that is, the fluid pressure passing through them during work is relatively small. For example, the carbon tank requires the valve to open when the positive pressure reaches 2Kp, and requires the valve to open when the negative pressure reaches 1Kp. Therefore, when testing these components, it is necessary to simulate a gas source whose pressure is similar to the fluid pressure when they actually work. For the detection of airflow with such a small pressure, if mechanical instruments are used for detection, the price of precision instruments is relatively high, and the minimum division value of ordinary instruments will not be lower than 0.1Mp, which is not applicable at all.

Contents of the invention

In order to overcome the above-mentioned defects existing in the detection process of some valves with small ventilation pressures on automobiles, the technical problem to be solved by the utility model is to provide a small air pressure detection device, which has a simple structure and is easy to manufacture. The utility model has the advantages of convenience, low manufacturing cost, and the ability to conveniently detect tiny air pressures.

In order to solve the above technical problems, the technical solution of the utility model is: a micro air pressure detection device, including a ventilation pipeline, a control valve arranged on the ventilation pipeline, and a detection station on the ventilation pipeline, which is characterized in that, on the ventilation pipeline There is at least one U-shaped tube connected in parallel upstream of the detection station, liquid is injected into the U-shaped tube, and a reading device is arranged at the U-shaped tube. The detection station is used to connect with the parts to be tested, the detection station is provided with a branch connected with the ventilation pipeline, the airflow in the branch passes through the parts to be tested, when the airflow reaches a stable The actual pressure of the gas passing through the component under test can be read through the reading device at this time.

Preferably, the U-shaped tube is made of transparent material, and the reading device is a layer marked on the U-shaped tube. When the reading device is a reticle layer, the liquid injected into the U-shaped tube is generally colored. By reading the reticle that is flush with the liquid surface, the pressure of the gas passing through the component under test can be obtained more conveniently. . Of course, the reading device can also be electronic, such as injecting mercury into the U-shaped tube, and directly reading the air pressure of the gas passing through the measured component through the position sensor and the reader arranged in the U-shaped tube. However, this electronic reader has the disadvantage of high cost.

Preferably, the detection station is provided with a positive pressure branch and a secondary pressure branch, and the positive pressure branch and the secondary pressure branch communicate with the ventilation pipeline through the first two-position three-way valve. The established positive and secondary pressure branches facilitate the measurement of the carbon canister. Through the switching of the first two-position three-way valve, the positive and secondary pressure of the carbon canister can be measured conveniently without changing the carbon canister and the ventilation pipeline. connection between.

Preferably, there are two U-shaped tubes, and the two U-shaped tubes communicate with the ventilation pipeline through the second two-position three-way valve. The specifications of the two U-shaped tubes can be the same or different. U-shaped tubes of the same specification can measure two parts to be tested at one time; The heights are different, which makes it possible to measure the measured components in two air pressure ranges in one set of the micro air pressure detection device, which increases the applicable scope of the micro air pressure detection device.

Preferably, two flowmeters with different specifications are arranged upstream of the U-shaped pipe in the ventilation pipeline, and the flowmeters communicate with the U-shaped pipe through a third two-position three-way valve. The provided flowmeter can measure the flow rate of the air flow in the pipeline, so as to facilitate the control of the air flow in the ventilation pipeline, so that the flow rate of the air flow meets the working requirements. Two flowmeters with different specifications can adapt to the requirements of gas measurement at different flow rates, which requires a certain understanding of the characteristics of the parts before testing the relevant parts, and select the corresponding flowmeter to connect to the vent pipe according to the characteristics of the parts on the road.

Therefore, the beneficial effects of the utility model:

1. Because the U-shaped tube filled with liquid is used to detect the ventilation performance of some parts with small ventilation air pressure, there is no need to use expensive mechanical instruments for measurement, and this small air pressure detection device can be completely self-made, reducing investment in testing equipment.

2. In the micro-air pressure detection device, the height change of the liquid level in the U-shaped tube is used to sense the ventilation air pressure in the tested part. The accuracy it can achieve can fully meet the accuracy requirements of some related parts on the car, ensuring The working stability of these components.

3. When measuring the relevant parts, directly connect the parts to the detection station in the micro air pressure detection device, and directly obtain the ventilation air pressure of the parts, which is very convenient to operate.

Description of drawings

Accompanying drawing 1 is the work flow structural diagram of the utility model tiny air pressure detection device, and the direction indicated by the arrow in the figure is the airflow direction in the ventilation pipeline.

Detailed ways

See accompanying drawing 1, the main body structure of the tiny air pressure detection device of the present utility model is a ventilation pipeline 2, is provided with several control valves in this ventilation pipeline 2. The air flow is passed into the ventilation pipeline 2, and the air flow is generally compressed air. Before the air flow is passed into the ventilation pipeline 2, it also needs to go through impurity removal and dehumidification treatment.

A decompression valve 1 is arranged upstream of the ventilation pipeline 2, and the pressure of the air source after passing through the decompression valve 1 can meet the actual detection requirements of the tiny air pressure detection device. Downstream of the pressure reducing valve 1 on the ventilation pipeline 2, two flowmeters 3 connected in parallel are arranged, and the specifications of the two flowmeters 3 are different. A third two-position three-way valve 4 is provided downstream of the flowmeter 3 , and different flowmeters 3 can be connected in series in the ventilation pipeline 2 by operating the third two-position three-way valve 4 . Downstream of the third two-position three-way valve 4, a second two-position three-way valve 5 is provided in the ventilation pipeline 2, and the second two-position three-way valve 5 is connected with the U-shaped pipe 6 and the U-shaped pipe 7 respectively. , by operating the second two-position three-way valve 5, the U-shaped pipe 6 and the U-shaped pipe 7 can be connected in parallel to the ventilation line 2, respectively. On the ventilation pipeline 2, testing stations are respectively arranged downstream of the U-shaped tube 6 and the U-shaped tube 7, and these testing stations are used to connect with the parts to be tested.

Liquid is injected in the above-mentioned U-shaped tube 6 and U-shaped tube 7, and reading devices are respectively provided at their positions. U-shaped tubes are generally made of transparent materials such as glass or plastics, and the described reading devices can be marked Score layer on U-shaped tube. The specifications of the U-shaped tube 6 and the U-shaped tube 7 are different, that is, the heights between them are different. The U-shaped tube with a large height is used to detect the measured parts with high ventilation pressure, while the U-shaped tube with a low height It is the part under test to detect low ventilation air pressure.

Downstream of the U-shaped pipe 7 on the ventilation pipeline 2, a first two-position three-way valve 8 is connected in series, and the first two-position three-way valve 8 is connected with the positive pressure branch 9 and the auxiliary pressure branch 10 respectively. The joints on the pressure branch 9 and the auxiliary pressure branch 10 can be used to connect with the positive and auxiliary pressure ports on the carbon tank 11 respectively. By operating the first two-position three-way valve 8, the positive and negative pressure on the carbon tank 11 can be adjusted. pressure to detect.

Claims (6)

1. A tiny air pressure detection device, comprising a ventilation pipeline, a control valve located on the ventilation pipeline, with a detection station on the ventilation pipeline, characterized in that the ventilation pipeline (2) is connected in parallel upstream of the detection station There is at least one transparent U-shaped tube filled with liquid, and a reading device is arranged at the U-shaped tube. 2. The tiny air pressure detection device according to claim 1, characterized in that the reading device is a scribe layer marked on the U-shaped tube. 3. The tiny air pressure detection device according to claim 1, characterized in that, the detection station is provided with a positive pressure branch (9) and an auxiliary pressure branch (10), and the positive pressure branch (9) and The auxiliary pressure branch (10) communicates with the ventilation pipeline (2) through the first two-position three-way valve (8). 4. The tiny air pressure detection device according to claim 1, 2 or 3, characterized in that there are two U-shaped tubes, and the two U-shaped tubes are connected to the communication channel through the second two-position three-way valve (5). Gas pipeline (2) communicates. 5. The tiny air pressure detection device according to claim 1, 2 or 3, characterized in that two flowmeters (3) with different specifications are arranged upstream of the U-shaped pipe in the ventilation pipeline (2) , the flow meter (3) communicates with the U-shaped pipe through the third two-position three-way valve (4). 6. The tiny air pressure detection device according to claim 4, characterized in that two flowmeters (3) with different specifications are arranged upstream of the U-shaped pipe in the ventilation pipeline (2), and the flowmeters ( 3) communicate with the U-shaped pipe through the third two-position three-way valve (4).

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