Honda reloads in the introduction of the eighth generation Accord models, there is a 3.5LVCM engine equipped with models. The 3.5LVCM engine uses the V6 set, and has three, three, three, three operating mode. Simply put, this 3.5L engine, both as a V6 engine work, but also at the same time according to the engine conditions need, "turned" for the inline 3-cylinder engine or V-4-cylinder engine.
    With these three different modes of operation, the VCM system can carefully adjust the working displacement of the engine to keep pace with the requirements of the dynamic environment and greatly improve the fuel economy. But also to meet the same engine when necessary, the highest performance requirements. Often, these two points are almost impossible to coexist with conventional engines.
    When the engine starts, accelerates, or hits the mountain, the engine will start all six cylinders to run, primarily to meet the heating of the various parts of the cylinder at the beginning of the engine start, or to meet the demand for power output. At this point, the engine can meet the maximum power or maximum torque of the power needs.
    If the vehicle is in the low-speed cruise speed or low engine load requirements (idle state), VCM system will control the VTEC system to close the engine side of the three cylinders into the exhaust and oil to complete from the V6 engine To the alignment of the 3-cylinder engine operating mode switch. At this point, this 3.5L engine, the actual working displacement of only 1.75L.
    In the medium acceleration, high-speed cruise and gentle slope driving, the engine will use four cylinders to run. At this point, the VCM system will only keep the engine in each row of three cylinders closest to the far end of the two cylinders of the normal working state, relative to the center of the cylinder will be closed.
    Through this kind of engine in different working conditions to change the flexible control of the work displacement, this generation Accord equipped with 3.5LVCM engine relative to the previous generation Accord equipped with the 3.0L engine, fuel economy even reduced by 7% The However, the above description is only the work effect, the following, I will VCM system to do a more profound explanation of the working principle.
    1, VCM system is how the VTEC system on the engine cylinder on and off operation?
  First of all, in the VCM system on the engine before the cylinder operation, the throttle opening, speed, engine speed, automatic gearbox and other related environmental factors to calculate the data in order to determine whether the current work environment should be Enable the corresponding 3-cylinder or 4-cylinder work plan. In addition, the system will additionally determine whether the engine oil pressure supports the VCM system to switch the operating mode and whether the temperature of the catalytic converter will remain within the proper range after the engine has under variable displacement operation. In this step, VCM system has for environmental factors, power demand and environmental protection of these three aspects of the conditions in the moment to complete the decision to change the cylinder work.
    If the VCM system to determine the engine cylinder, then the VTEC system will be ordered to adjust the ignition timing, wire-controlled throttle opening to facilitate the cylinder to open and close a smooth transition. Then VCM through the VTEC system to the electronic control device issued instructions, so that with the cylinder head of the rocker shaft bracket plays a dual role of the slide valve to selectively guide the oil cylinder to a specific cylinder rocker sync piston, The connection and disconnection of the control, so as to achieve the intake and exhaust valve operation and stop the control. At the same time, the fuel control module will automatically resume, cut off the fuel supply of these specific cylinders.
    Simply put, the VCM system is like a leveraging system, when the VCM system work, it is like pumping away the lever below the "fulcrum", so that the lever will not do "seesaw" action , That is, the car engine valve is no longer work, so as to achieve the purpose of closing the cylinder. Of course, want to let the engine a cylinder to work again, then only need to "fulcrum" to re-installed on it.
    2, if the individual cylinder in a particular situation does not work, will cause the engine wear uneven?
    No, the engine will stop working with a small number of cylinders, only the inlet, the exhaust valve and the fuel supply system will stop working. But the engine piston is still in normal operation. Throughout the work process, the engine parts of the cylinder wear parts are the same. As for the rocker wear and cylinder parts at different temperatures, the degree of wear is very small can be ignored.
    At the same time, the author needs to add a detail: in which the engine is in the 3-cylinder or 4-cylinder under any of the working conditions, the non-working cylinder spark plug will continue to ignite to ensure that the spark plug temperature will be put into work when the cylinder can be achieved Work requirements, and to prevent the residual oil and gas mixture within the cylinder caused by spark plug oil pollution, resulting in decreased ignition efficiency.
    3, in the other car brands, whether there is a similar engine variable displacement technology?
 Left: The 5.7LHEMI engine used on the Dodge model, but it is worth noting that the engine uses a bottom camshaft design. Right: HEMI engine control unilateral cylinder open and close the valve.
    The general 5.3LV8 engine is equipped with a common DOD, variable displacement system, the system works by relying on a specially designed valve stem to complete, depending on the presence of hydraulic pressure to control the closure of the valve stem.
    In the United States GM Group, Chrysler Group and the German Mercedes-Benz company also has a similar and Honda Corporation variable displacement technology, but how to achieve the effect of variable displacement, the company's technical principles are still different. In the above three companies, only the US GM Group HEMI technology used (variable displacement technology) and Honda VCM technology used by the largest degree of similarity.
    However, Honda and all other competitors, the difference is that the Honda VCM system focused on the medium displacement of the V6 engine; but its competitors are variable displacement technology is applied to the larger displacement of the V8 , And even V12 engine, and only 4/8 (V8), 8/12 (V12) and other two variable displacement options. From the civil and promotional point of view, Honda's VCM technology is more practical.
    4, VCM system work effect
    Sensitivity: When the engine is in non-6-cylinder operation, there will be an "ECO" light on the dashboard to indicate the driver: The current engine is in a 3-cylinder or 4-cylinder "lazy" way of working. When the driver to step down the throttle, want to get a larger power output, "ECO" light will be extinguished immediately, while the engine power will continue to push back from behind. If the driver releases the accelerator pedal for 1-3 seconds, the "ECO" light will turn on. It can be said, VCM system is a very practical technology, not a "show" flower shelf.
    Smoothness: According to the author personally test drive 3.5L models of experience, no matter how the VCM engine in the 3,4,6 cylinder between the working state of the switch, I can not feel the cylinder opening and closing between the pause or tremor The It can be said, VCM system for Honda is still quite a mature technology.