1. Variable Cylinder art
Variable Cylinder techniques are generally applicable to multi-cylinder large displacement models, such as V6, V8, V12 engine, because the daily running, power is not required in most cases output, so large displacement multi-cylinder becomes a waste, so the variable cylinder technology came into being, it can not require high power output, control the closing part of the cylinders to reduce fuel consumption.
VCM
VCM is called the Variable Cylinder Management, Honda R & D is a variable cylinder management technology, which can be closed by a cylinder of an individual, 3.5L V6 engine Shidao 3,4,6 varied between cylinders, so that the displacement of the engine can vary between 1.75-3.5L, thus saving fuel. In any case
vehicle start, acceleration or hill climbing and other high power output required of the engine will put all six cylinders to work. Only one cylinder group run in cruise and low engine load conditions, the system, i.e. three cylinders. At moderate acceleration, cruising speed, and with a gentle slope, the engine will be operated with four cylinders.
by means of three operating modes, the system can be carefully determined the VCM operation capacity of the engine, driving it at any time consistent with the requirements. Since the system will automatically close the intake and exhaust valves of the cylinder inoperative, can be avoided with the intake and exhaust suction associated losses and further improve the fuel economy. VCM system integrated to achieve the highest performance and maximum fuel economy – these two characteristics usually can not coexist on a conventional engine.
VCM VTEC system closed by intake and exhaust valves, the specific cylinder to stop the work, at the same time, by the powertrain control module of the cylinders fuel supply cut. In the three-cylinder operation mode, the rear cylinder group is stopped. In the four-cylinder operation mode, the front left and middle cylinders work cylinder group,Right rear cylinder and the intermediate cylinder group work.
Non-cylinder spark plug firing will continue, to minimize temperature loss of the spark plug, to prevent incomplete combustion spark plug of the cylinder oil back to work. The electronic control system, with a dedicated integrated spool valve, the spool and the rocker shaft holder in the cylinder head as a dual function. The instruction means issuing the electronic control systems, the spool valve will be selectively directed particular hydraulic cylinder the rocker arm. Then the hydraulic piston pushes synchronization, to achieve connection and disconnection of the rocker arm.
VCM system of throttle opening, vehicle speed, engine speed, automatic transmission gear selection and other factors are monitored to determine the appropriate program to enable the cylinders for various operating conditions. Moreover, the system also determines whether the engine oil pressure for switching the operation mode of the VCM, and whether the temperature of the catalytic converter will remain in an appropriate range. In order to make the transition of the cylinder can be enabled or disabled when smoothly, the system will adjust the ignition timing, the opening degree of the throttle wire, and accordingly enable or torque converter lockup released. Finally, the cylinder 3, the transition between 4 and six-cylinder mode of operation, the driver will perceive the complete state of less than
MDS
MDS is Chrysler HEMI engine tailored multi-stage variable displacement control system, called the MDS-multi-displacement system.
called the MDS, is substantially the same as the other variable displacement technology, rely closing respective cylinder to achieve the purpose of energy saving. Because OHV HEMI engine is used in the structure of the mountain covered with cam camshaft, not as design more complex secondary rocker arm and connected to the hydraulic control mechanism like the Honda VCM engine, we can only think of a way in the original structure.
HEMI engine valve by the camshaft – tappet – tappet – rocker arms series of operations of these driven mechanism, any link can be realized if it is possible to break off valve idea, but due to engine operating conditions demand, requiring the valve opening and closing control are fast enough, so as to ensure smooth and fast response, to ensure the V8 engine originally should have fun.
Finally ENGINEERINGEngineers decided fuss contact with the cam tappet above, they are designed as tappet HEMI engine a unique structure of the slider, the slider is connected with the valve push rod, a pin may be positioned below the slider of the card, the card the slider pin may be integrated with the tappet push valve push rod or the slider activity, is unable to push the valve tappet putt. Engineers for the bayonet in the engine oil designed a unique method, relying on oil lubrication system provides hydraulic push detent (solenoid valve control), bayonet itself with return spring, when the hydraulic pressure will automatically disappear back bit. During normal engine operation, the jammed slide card pin making it impossible to move freely up and down, push rod driver directly tappet valve rocker arm, when the engine needs to close the cylinder, the detent release, the slider will be able to slide vertically , occurs when the slider moves the tappet column stiffness relative movement, the push rod is no longer pushed, so that the valve was closed, while the ECU stops fuel injection to the cylinder, will reach the ldquo; Close cylinder rdquo; effect, realized ldquo; variable displacement rdquo ;.
In support of MDS technology, this 5.7L HEMI engine through the ECU to the engine load condition is determined, it is possible to run four-cylinder or eight-cylinder, four cylinder engine symmetric off, and the remaining 4 the cylinders constitute a ldquo; V4rdquo; engine, the engine can still maintain good ride.
equipped with MDS system HEMI engine was first in 2005 and served, was mounted on the Chrysler 300C, Jeep Grand Cherokee and Dodge Charger and other vehicles, and pickup trucks and large displacement cars under its own brand also fielded the engine. However, SRT-8 high-performance models under the Chrysler brand used 6.1L HEMI V8 engine did not use MDS technology.