Power plants – Fluid motor means driven by waste heat or by exhaust energy... – With supercharging means for engine
Patent
1998-06-18
2000-07-11
Kamen, Noah P.
Power plants
Fluid motor means driven by waste heat or by exhaust energy...
With supercharging means for engine
251 635, F02B 3712
Patent
active
060855258
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to a valve device, comprising a housing with an inlet and an outlet to be connected to an exhaust conduit in an internal combustion engine, an exhaust passage disposed between the inlet and outlet, a valve body which can be set in various positions to vary the throughflow area of the exhaust passage, and operating means for setting the valve body.
It is known that it is possible by merely increasing the exhaust counterpressure in the exhaust conduit of an internal combustion engine, with the aid of a valve device of the above mentioned type, to achieve an increase in the engine braking effect of the vehicle. A further increase in the engine braking effect can be achieved if communication is established in a known manner between the exhaust system and the engine cylinders during the latter portion of the intake stroke, so that gas from the exhaust system can flow into the cylinders. This results in a pressure increase in the cylinder, and an inner charging pressure which increases the compression work after cutting off the communication between the cylinders and the exhaust system.
A known type of valve device for varying the exhaust counterpressure is an exhaust pressure regulator comprising a damper in the exhaust conduit. Great demands are placed on the design of damper valves which must be able to function with high reliability and lone life in the exhaust conduit environment. They must be able to withstand high mechanical and thermal stresses. In the open position, they must not provide any flow impediment or create turbulence in the exhaust conduit, and they must not stick so that they do not reach their defined positions, something which often happens after a relatively short operating period due to deposits of soot.
SUMMARY OF THE INVENTION
The purpose of the present invention is in general to achieve a valve device of the type described above which can withstand higher thermal and mechanical stresses than a damper valve and which has a simple design and high reliability. The particular purpose is to achieve a valve device which makes it possible in a turbocharged engine to utilize the turbo unit in a better manner than previously in order to vary the braking power of the engine.
This is achieved according to the present invention by virtue of the fact that the housing has a cylinder communicating with the exhaust passage, the cylinder housing having radial play and a valve body in the form of a piston displaceable into the passage under the effect of a pressure medium. The piston has at its distal and proximal end surfaces, valve discs where the proximal disc in an extended position of the piston abut against a proximal seat formed in the cylinder, and the distal disc in a retracted position of the piston abut against a distal seat formed in the cylinder.
In such a valve device, the piston is the only moving part. The piston does not require any return springs or particular operating means, since it functions in itself as both the valve body in a valve housing, and as the operating piston in an operating cylinder.
It has been shown that a valve device according to the present invention, in contrast to a damper valve, can function as a throttle valve in the extremely aggressive environment prevailing in engine exhaust pipes. In a turbocharged engine it can be arranged as a throttle valve upstream of the turbine portion of the turbocompressor unit, which provides a number of advantages.
By placing a valve device closer to the exhaust outlet of the cylinders, the volume of the exhaust conduits is reduced between the exhaust valves and the valve device in the exhaust conduit, which means that the pistons need not force out as much gas as previously to create a certain level of counterpressure. High counterpressure can therefore be obtained more rapidly.
In a turbocharged engine with the exhaust pressure regulator downstream of the turbine, the pressure drop required over the turbine to enable the turbine to drive the compressor, is not obtai
AB Volvo
Kamen Noah P.
LandOfFree
Valve for varying the exhaust counterpressure in an internal com does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Valve for varying the exhaust counterpressure in an internal com, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Valve for varying the exhaust counterpressure in an internal com will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-530338