![](https://www.audimanual.ru/img/100/2477.jpg)
Scheme of the main dosing system and econostat of the Pierburg 1B3 carburetor: 3 - throttle valve; 5 - main fuel jet; 11 - main air jet; 12 - atomizer; 13 - econostat fuel jet; 14 - econostat air jet; 15 - check valve; 16 - injection tube
Starting device
When starting a cold engine under the influence of a thermostatic bimetallic spring of an automatic starting device, the air damper blocks the air flow through the carburetor duct, throttle valve 3 (see diagram) under the action of a system of rods and cams 2, the drive opens slightly, providing an increase in the rotational speed of a cold engine at idle.
Under the action of vacuum in the diaphragm cavity of the starting device, an increased amount of fuel passes through the main fuel jet, which ensures the start of a cold engine.
After starting the engine vacuum. arising in the inlet pipeline of a running engine, actuates the pneumatic actuator 4, slightly opening the air damper. After warming up with the transition to the load mode through the system of rods and levers driven by the throttle valve, the air damper opens slightly, which causes a depletion of the combustible mixture and ensures uninterrupted engine operation.
Idle system and transition system
Fuel taken from the float chamber through the main fuel jet 5 (see diagram) enters the well of the emulsion tubes and is supplied to the idle fuel jet 6. At the outlet of the jet 6, the fuel is mixed with air entering through the idle air jet. The emulsion is supplied to the outlet 7 of the idle system under the throttle valve through a hole regulated by a quality needle screw 8 (composition) mixture, and through the hole closed when the ignition is turned off by the electromagnetic shut-off valve 9.
When the throttle valve 3 is smoothly opened, the combustible mixture enters the vertical channel of the transition system 10, which leads to a gradual increase in the engine crankshaft speed.
![](https://www.audimanual.ru/img/100/2478.jpg)
Scheme of operation of the idle system and the transition system of the Pierburg 1VZ carburetor: 3 - throttle valve; 5 - main fuel jet; 6 - idle fuel jet; 7 - spray opening of the idle system; 8 - quality adjusting screw (composition) mixtures; 9 - electromagnetic shut-off valve; 10 - slots of the transition system
![](https://www.audimanual.ru/img/100/2479.jpg)
Scheme of operation of the Pierburg 1VZ carburetor when starting a cold engine: 1 - air damper; 2 - system of rods and cams for slightly opening the throttle valve; 3 - throttle valve; 4 - air damper pneumatic actuator
Main dosing system
Fuel is fed through a needle valve into the float chamber. The float hinged on the axis regulates the opening of the needle valve opening to maintain a constant fuel level in the float chamber. There is a damping device between the needle valve and the float tongue.
From the float chamber fuel through the main fuel jet 5 (see diagram) enters the emulsion cabin, where it mixes with the air flowing through the jet 11. Then the fuel-air mixture fills the mixing chamber formed by the small and large diffusers 12.
The carburetor has an econostat, which further enriches the fuel-air mixture at full engine load at speeds close to maximum. From the float chamber, the fuel passes through the channel and through the jet 13 enters the fuel tube, in the upper part of which the eye is mixed with the air entering through the air jet 14. The resulting emulsion passes through the check valve 15 and is ejected through the injection tube 16 into the mixing chamber, further enriching combustible mixture, ensuring the operation of the engine at high speeds.
Accelerator pump
Under the action of the lever 17, the throttle valve opens, the spring 18 rotates the cam 19, which acts on the lever 20 of the accelerator pump drive. The lever presses on the piston 21, which pumps the fuel coming from the float chamber through the check ball valve 22 to the atomizer 23.
Cam drive spring 18 dampens the force of a sharp opening of the throttle, which increases the duration of fuel injection. The position of the cam drive spring on the throttle shaft is adjustable. The piston well has a sealing collar 24 and a return spring 25. The damper spring 26, located in the cavity of the piston itself, serves to regulate the movement of the piston depending on the amount of fuel passing through the atomizer.
![](https://www.audimanual.ru/img/100/2484.jpg)
Pierburg 1VZ carburetor accelerator pump diagram: 17 - throttle control lever; 18 - accelerator pump cam drive spring; 19 - accelerator pump cam; 20 - accelerator pump drive lever; 21 - piston rod of the accelerator pump; 22 - check ball valve; 23 - accelerator pump sprayer; 24 - sealing cuff; 25 - return spring; 26 - damper spring of the accelerator pump piston
Visitor comments