Power plants – Fluid motor means driven by waste heat or by exhaust energy... – With supercharging means for engine
Patent
1996-08-15
1998-03-24
Koczo, Michael
Power plants
Fluid motor means driven by waste heat or by exhaust energy...
With supercharging means for engine
F02B 3712
Patent
active
057299803
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to pressure charging apparatus for internal combustion engines.
BACKGROUND AND SUMMARY OF THE INVENTION
The pressure charging apparatus may be a turbocharger or a supercharger in which, typically, in one known arrangement, engine boost level is controlled by a pneumatically controlled wastegate mechanism. The engine boost level is defined as the pressure level, relative to atmospheric, to which the turbocharger or supercharger compresses the air charge in the inlet manifold. The wastegate position, which controls the boost level is in turn controlled by a controlling pneumatic pressure which is regulated by a boost control solenoid valve. The boost control solenoid valve, which is fitted between the wastegate actuator mechanism and a pressure source (or reservoir), is actuated by an electrical control signal. This may be in the form of a voltage, frequency or duty cycle. The boost control solenoid valve is of a type where the full supply pressure is diverted to the wastegate actuator to open it fully (causing low engine boost) when a `low` signal is supplied to the solenoid. The full supply pressure is diverted to vent away and no pressure reaches the wastegate actuator (causing high engine boost), when a `high` signal is supplied to the solenoid. The solenoid operation is infinitely variable between these two extremes.
The signal to the boost control solenoid valve is usually supplied from an Electrical Control Unit (ECU), which may use engine speed, boost pressure and engine load amongst the incoming parameters. This enables the boost pressure to be controlled as desired via the action of the boost control solenoid valve. The ECU is pre-programmed to provide the desired boost levels dependent upon the incoming parameters. Additional safeguards may be incorporated into the inputs to the ECU, such that a low signal is sent to the boost control solenoid valve under conditions of engine stress (vibration or combustion detonation as examples) or for reason of vehicle safety inhibits (cruise control operation, vehicle braking and gearchange operation examples).
The existing arrangement is such that when a change is made to the electrical signal to the boost control solenoid valve, there is a delay before the wastegate actuator assumes the new position. This delay is dependent upon the control dynamics of the system such as the length of pipes and volume of the wastegate actuator and is generally engineered to be small. Under conditions of a changing signal to the boost control solenoid valve, there may also be a tracking error present that is to say the difference between the required and actual signal levels. This may occur under conditions of engine acceleration.
The existing arrangement does not permit the control dynamics to be altered in response either to the nature of the inputs to the ECU or to the state of the output from the ECU to the boost control solenoid valve.
According to the present invention there is provided pressure charging apparatus for internal combustion engines comprising means for supplying air under pressure to the engine inlet, a wastegate, a wastegate actuator for closing and opening the wastegate in order to alter the pressure in the engine inlet, characterised by a boost control for controlling the wastegate actuator, first valve means connected to the wastegate actuator and to the boost control, and control means operative to control the operation of second valve means in dependence, inter alia, upon a signal from a full throttle sensor and thereby the wastegate actuator.
In a preferred embodiment of the invention, the means for supplying air comprises an air compressor. The first valve means comprises a boost control solenoid valve operative in one position to vent to atmosphere. The second valve means is operative to connect the wastegate actuator (on the opposing side) to the means for supplying air or to atmosphere. The boost control is programmed to operate the boost control solenoid valve at a duty cycle which may be
REFERENCES:
patent: 3233403 (1966-02-01), MacInnes et al.
patent: 4449367 (1984-05-01), Moriguchi et al.
patent: 4467607 (1984-08-01), Rydquist et al.
patent: 4519210 (1985-05-01), Iwamoto et al.
patent: 4528816 (1985-07-01), Arnaud
patent: 4597264 (1986-07-01), Cipolla
patent: 4637210 (1987-01-01), Yamamoto
patent: 4697421 (1987-10-01), Otobe et al.
patent: 4763475 (1988-08-01), Toshio et al.
patent: 5155998 (1992-10-01), Monden
Koczo Michael
Rolls-Royce Motor Cars Limited
LandOfFree
Internal combustion engines does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Internal combustion engines, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Internal combustion engines will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2281021