Throttle valve installation maintenance

The installation  maintenance of the throttle valve should pay attention to the following matters: the valve often needs to be operated, so it should be installed in a position that is easy  convenient to operate. When installing, pay attention to the direction of the medium  the direction of the arrow marked on the valve body.

(1) The source of the throttle body sediment is more complicated, but it can be classified into the following categories:

1. Mechanical impurities in the oil  colloid, asphalt, carbon slag  other dirt precipitated by oxidation accumulate in the throttling gap.

2. Since the oil is aged  squeezed to generate charged polar molecules,  there is a potential difference on the metal surface of the throttling gap, the polar molecules are adsorbed to the surface of the gap to form a firm boundary adsorption layer,  the thickness of the adsorption layer Generally, it is 5~8 microns, which affects the size of the throttling gap. When the above accumulation  adsorbate grow to a certain thickness, they will be washed away by the liquid flow,  then reattached to the valve port. This cycle is repeated, forming a pulsation of the flow.

3. When the pressure difference of the valve port is large, due to the high temperature of the valve port, the degree of extrusion of the liquid is enhanced,  the metal surface is also more susceptible to friction to form a potential difference, so it is easy to cause blockage when the pressure difference is large.

4. PCV exhaust gas source: the combustible gas mixture in the combustion chamber enters the crankcase through the piston gap  is mixed with the oil vapor. To avoid dilution  contamination of the oil, the mixture is drawn into the intake tract by a positive crankcase ventilation system (PCV) for secondary combustion. After this part of the exhaust gas enters the intake port, it will condense to form a liquid phase due to the decrease in temperature,  the "unstable components" in it will be oxidized  condensed at high temperature, forming grease  adhesion on the surface of the throttle valve.

5. In-depth lubricating oil for turbocharged compressors: For turbocharged engines, the exhaust gas drive method is generally adopted at present, that is, the high-pressure exhaust gas generated by the exhaust port is used to drive the turbine,  the compressor blades in the intake port are driven by the coaxial shaft. , forming a supercharged intake air flow. However, under long-term  harsh working conditions, the coaxial bearing is prone to the penetration  volatilization of lubricating oil,  the inflation efficiency is doubled when adding it,  it is more likely to form heavy oil pollution  aggravate the adhesion of the throttle body deposits.

6. Fuel vapor discharged  the carbon canister: In the fuel vapor adsorbed by the engine carbon canister, as long as it is easy to form throttle valve deposits, cyclopentadiene can be oxidized  condensed to form a colloidal oil scale under continuous high temperature.

(2) Maintenance  cleaning of the throttle valve When the throttle valve (ie butterfly valve) is blocked by sediment, the throttle valve opening value is disordered, the engine cannot control its opening stably  accurately,  the opening value is too low It will cause difficulty in starting, unstable idling  abnormal flameout; when the engine accelerates  decelerates, the throttle valve cannot respond in time, which will cause acceleration delay  sudden acceleration.

The working principle  function of the throttle valve are introduced here,  I hope it will be helpful for everyone to understand the throttle valve. Most of the opening  closing parts of the throttle valve are conical streamline, through which the flow  pressure can be adjusted by changing the cross-sectional area of the passage. The throttle valve is used to reduce the medium pressure in the case of high pressure.