S
SkyPup
Guest
As you all know, the diesel engine does not have any restricition in the intake tract such as a throttle valve common to all gasoline engine to regulate air (air is unregulated in diesel engines). So how do you keep the rpms from rocketing skyhigh with the cylinder head and the pistons following close behind? It took many years to keep those items working in harmony through the use of a mechanical governor in the fuel pump to limit fuel supply under torque, now controlled digitally by the ECU.
"Governor stories"
"It's a mistake to believe that the diesel engine is a crude machine that can only withstand crude handling" 1) Precision engineering and workmanship, as well as a high degree of intuitive feeling, are an absolute prerequisite if efficient functioning of the diesel engine is to be guaranteed and maintained.
At first, the form of diesel-engine control to which the above statement applies was carried out by the engine manufacturers themselves. But, in order to save the power takeoff which was required at the engine, they came up with the demand for an in-line pump with attached speed control (governor).
It was at the end of the "Twenties" (1920’s) that Bosch took up this latest challenge. Following amazing feats of mechanical engineering, a flyweight-controlled minimum-maximum-speed governor went into series production. A slightly modified version of this governor came on the market a little later in the form of a variable-speed governor which was needed in particular for tractor and boat engines.
This form of flyweight governor appeared to be unsuitable for small high-reving automotive diesel engines though, and the concept of a pneumatic governor was born: "The control rack is connected with a leather diaphragm. The vacuum in the manifold, which is dependent upon engine speed, changes the diaphragm setting and with it the delivery quantity which thus becomes a function of throttle-valve setting.”
In the post-war years from 1946 to 1948 (variable-fulcrum governor) and as from 1995 (governor with external tensioning springs), a variety of
considerably improve flyweight (mechanical) governor versions came onto the market (for instance, with integrated vibration dampers.
Supplementary devices for the adaptation of the full-load quantity to the desired engine torque curve (torque control) were fitted, as were devices for automatically setting the extra fuel needed for starting.
Today though, electronics plays a decisive role in the sector of diesel governing through BOSCH digital ECU control of the fuel pump pulses and width and injector duration and volumes.
The electronic speed-control systems (Electronic Diesel Control or EDC) make the optimal operation of the diesel engine a matter of course, greatly superceding the age of the mechanical governor.
1)Auer, Georg.
"Der Widerspenstigen Zähmung".
Diesel Report. Robert Bosch Gmbl-l.
Stuttgart 1977.8.
2)Schildberger, Friedrich. Bosch and the diesel engine.
Stuttgart, 1950.
------------------
99 JETTA TDI HERR WETTERAUER TORQUEMEISTER
98 KAFER WETT SPEKTAKULARE TURBOKOMPRESSOR
97 KTM 620 ADVENTURE RALLY PARIS-DAKAR SUPER THUMPER
[This message has been edited by SkyPup (edited July 22, 1999).]
"Governor stories"
"It's a mistake to believe that the diesel engine is a crude machine that can only withstand crude handling" 1) Precision engineering and workmanship, as well as a high degree of intuitive feeling, are an absolute prerequisite if efficient functioning of the diesel engine is to be guaranteed and maintained.
At first, the form of diesel-engine control to which the above statement applies was carried out by the engine manufacturers themselves. But, in order to save the power takeoff which was required at the engine, they came up with the demand for an in-line pump with attached speed control (governor).
It was at the end of the "Twenties" (1920’s) that Bosch took up this latest challenge. Following amazing feats of mechanical engineering, a flyweight-controlled minimum-maximum-speed governor went into series production. A slightly modified version of this governor came on the market a little later in the form of a variable-speed governor which was needed in particular for tractor and boat engines.
This form of flyweight governor appeared to be unsuitable for small high-reving automotive diesel engines though, and the concept of a pneumatic governor was born: "The control rack is connected with a leather diaphragm. The vacuum in the manifold, which is dependent upon engine speed, changes the diaphragm setting and with it the delivery quantity which thus becomes a function of throttle-valve setting.”
In the post-war years from 1946 to 1948 (variable-fulcrum governor) and as from 1995 (governor with external tensioning springs), a variety of
considerably improve flyweight (mechanical) governor versions came onto the market (for instance, with integrated vibration dampers.
Supplementary devices for the adaptation of the full-load quantity to the desired engine torque curve (torque control) were fitted, as were devices for automatically setting the extra fuel needed for starting.
Today though, electronics plays a decisive role in the sector of diesel governing through BOSCH digital ECU control of the fuel pump pulses and width and injector duration and volumes.
The electronic speed-control systems (Electronic Diesel Control or EDC) make the optimal operation of the diesel engine a matter of course, greatly superceding the age of the mechanical governor.
1)Auer, Georg.
"Der Widerspenstigen Zähmung".
Diesel Report. Robert Bosch Gmbl-l.
Stuttgart 1977.8.
2)Schildberger, Friedrich. Bosch and the diesel engine.
Stuttgart, 1950.
------------------
99 JETTA TDI HERR WETTERAUER TORQUEMEISTER
98 KAFER WETT SPEKTAKULARE TURBOKOMPRESSOR
97 KTM 620 ADVENTURE RALLY PARIS-DAKAR SUPER THUMPER
[This message has been edited by SkyPup (edited July 22, 1999).]