Patent Application
20080178592
The present invention relates to an engine intake air system.
Air used in the combustion process of an internal combustion engine must be clean. For this purpose, off-road vehicles require intake air to pass through a pre-cleaner and a filter. Such a pre-cleaner typically includes vortex tubes that separate debris from the air. This debris must be collected and removed on a continuous basis. The process of removing the debris is referred to as aspiration and has typically been done using suction from the cooling system fan or with an exhaust venturi. A simple, low cost alternative system for aspirating the precleaner is desired.
Accordingly, an object of this invention is to provide a simple and low cost system for improving aspiration of an engine air pre-cleaner.
A further object of the invention is to provide such a system which does not require any moving parts.
A further object of the invention is to provide such a system wherein the rate of aspiration is proportional to the speed and load of the engine.
These and other objects are achieved by the present invention, wherein an engine intake air system has a turbo-compressor with a turbine and a compressor, a pre-cleaner and a filter. The pre-cleaner has a dirty air outlet. Intake air flows to the compressor through the pre-cleaner and the filter. A compressed air line communicates compressed air from the compressor to a charge air cooler. The air amplifier has an inlet, a throat, nozzles in the throat and connected to the port, and an outlet. A first line communicates the inlet to the pre-cleaner dirty air outlet, and a second line communicates the port to the compressed air line. The nozzles inject compressed air into the throat and create a suction which is communicated to the pre-cleaner via the first line. This system eliminates all moving parts from the aspiration system, and the rate of aspiration is proportional to the speed and load of the engine.
Referring to
As best seen in
The air amplifier 30 is a conventional commercially available device, and has an inlet 40, a narrower throat 42, the inlet port 25, a plurality of nozzles 44 in the throat 42, and an outlet 46. The inlet 40 is connected to the pre-cleaner dirty air outlet 22 by line 28. The nozzles 44 are communicated with inlet port 25 and compressed air line 32 by an annular chamber 48 and a plurality of passages 50. The nozzles 44 inject compressed air into the throat 42 and create a suction which is communicated to the pre-cleaner outlet 22 via line 28. This suction aids in the extraction of dirty air from the pre-cleaner 18.
The nozzles 44 inject small amounts of compressed air into the throat 42 at velocities approaching the speed of sound. This creates a vacuum in the throat converging section, thereby amplifying the flow of air from the pre-cleaner outlet 22 and through the air amplifier 30. Thus, the air amplifier 30 will aspirate the pre-cleaner 18. By using a small amount of compressed air (after the turbo compressor 16), the air amplifier may be closely coupled to the air filter 20. This system eliminates all moving parts from the aspiration system, and the rate of aspiration is proportional to the speed and load of the engine, which is beneficial for the operation of the pre-cleaner 18. This system also results in a compact and low cost assembly of components with efficient routing of lines.
While the present invention has been described in conjunction with a specific embodiment, it is understood that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, this invention is intended to embrace all such alternatives, modifications and variations which fall within the spirit and scope of the appended claims.
