Internal-combustion engines – Engine speed regulator – Responsive to deceleration mode
Patent
1995-02-15
1996-10-15
Argenbright, Tony M.
Internal-combustion engines
Engine speed regulator
Responsive to deceleration mode
F01L 1306
Patent
active
055643850
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL AREA
The present invention relates to a method for engine retardation with a multi-cylinder combustion engine, which for each cylinder with matching piston has at least one exhaust valve for control of the connection between a combustion chamber in the cylinder and an exhaust system, whereby the combustion cheer is connected to the exhaust system through opening of the exhaust valve at least when the piston in the cylinder is in the so called compression phase, said opening being achieved by a change of clearance in the valve mechanism of the combustion engine, thereby activating one or more extra cam ridges on the camshaft of the engine, which continuously activates the valve mechanism in dependence of the momentary position of the engine crankshaft through an actively adjustable, hydraulically operated clearance regulating device, which for active control of the engine retardation is adjusted between different positions by means of a hydraulic fluid pressure, whereby the angular camshaft position at which the exhaust valves are opened by the said extra cam ridge or ridges is dependent on the momentary clearance in the valve mechanism.
The present invention also concerns a device for realization of the method for engine retardation with a multi-cylinder combustion engine, which for each cylinder with matching piston has at least one exhaust valve for control of the connection between a combustion cheer in the cylinder and an exhaust system, whereby the combustion chamber is connected to the exhaust system through opening of the exhaust valve at least when the piston in the cylinder is in the so called compression phase, said opening being achieved by a change of clearance in the valve mechanism of the combustion engine, thereby activating one or more extra cam ridges on the camshaft of the engine, which continuously activates the valve mechanism in dependence of the momentary position of the engine crankshaft through an actively adjustable, hydraulically operated clearance regulating device, which for active control of the engine retardation is arranged to be adjusted by a hydraulic fluid pressure staying below a maximum value controlled by a pressure relief valve, whereby the camshaft angular position at which the exhaust valves are opened by the said extra cam ridge or ridges is dependent on the momentary clearance in the valve mechanism.
Especially for heavier vehicles, there are high demands on efficient engine retardation, which thereby reduces the wear on the wheel brakes and thus improves the operating economy.
STATE OF THE ART
By engine retardation with a four-stroke combustion engine a certain braking power is achieved due to the internal resistance of the engine, a.o. due to friction. This effect is however relatively small, and in modern engines it has been even further reduced. It is known to increase the engine retardation power through the installation of a restriction means, like a throttle in the exhaust system, e.g. in the form of a so called AT regulator. In this way, part of the work during the piston exhaust phase can be used to increase the braking power.
It is also known to increase the braking power by so called compression retardation. By opening some or all of the engine exhaust valves, a partial flow into the exhaust system of air being compressed during the compression phase is achieved, which means that part of the compression work obtained during the compression phase cannot be regained during the expansion phase, thus causing the braking power to increase. In one such known compression retarder the ordinary exhaust valves are used, whereby the camshaft has at least one extra cam ridge for achieving the extra opening of the exhaust valves. This extra ridge gives a relatively small lifting height and a controllable hydraulic element is arranged in the valve mechanism in order to activate the extra cam ridge only during engine retardation, see e.g. W091/08381.
In this known retarder the hydraulic element consists of a clearance regulating device. This device is bro
REFERENCES:
patent: 3367312 (1968-02-01), Jonsson
patent: 3786792 (1974-01-01), Pelizzoni et al.
patent: 4398510 (1983-08-01), Custer
AB Volvo
Argenbright Tony M.
LandOfFree
Method and device for motor-braking by means of a multi-cylinder does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and device for motor-braking by means of a multi-cylinder, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and device for motor-braking by means of a multi-cylinder will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1238234