1 Technical Valvetronic electronic valve
Introduction:.
BMW’s six-cylinder unit is not only lighter than all competing products, but also provides excellent output and performance. This is due to the unique BMW Valvetronic fully variable valve control electronics largely, the system may be based on the accelerator pedal opening degree position of the valve and control the stepless adjustment time.
On a conventional engine, controlling the output power depends almost entirely on the intake air throttle valve ldquo; throttle rdquo; realized, in the process will inevitably lose some power. In contrast, Valvetronic electronic valve control technology enables the engine load changes and minimize cycle management needs to ensure a high level of fuel efficiency and better engine response speed. Other advantages include improved smooth engine operation and minimize exhaust emissions.
magnesium aluminum crankcase and with a second generation of the electric valve Valvetronic BMW BMW straight-six-cylinder unit via a more compact overall system to achieve a higher engine speed. Thus, by operation of the valve ensures faster acceleration, the driver’s operation of the accelerator pedal is depressed to get a faster response and a larger speed margin is formed at each gear.
In the gasoline engine, the BMW Valvetronic technology can be said to be the best variable valve technology today.
technical principles:
Application BMW Valvetronic engine technology is the world’s first no throttle (also He said the throttle, the English called throttle butterfly) engine.
ldquo; throttle rdquo; isIn the engine intake manifold looks like in a shape of a butterfly (throttle English called throttle butterfly, butterfly butterfly is mean) of a throttle valve.
What are the advantages throttle then lose it? This advantage is fuel-efficient. The test results are shown various Valvetronic engine 7 can save more than the percentage of fuel consumption the conventional engine. Why did not understand throttle the engine will be fuel-efficient, we must first understand how the traditional engine throttle is working. When you step on the gas fuel, the engine fueling may feel you, but the fact is not directly pressed the accelerator you increase the amount of oil injected into the engine cylinder, but to change the size of the intake throttle switch, thereby changing into the cylinder the amount of air, the car’s jet fuel supply system monitors the amount of air through much of the throttle before deciding how much fuel is injected into, and this is the way the engine throttle control. This design is hope that a different throttle opening, does not change the oil and gas mixing ratio in order to avoid stalling.
so why not fuel-efficient engine throttle is it? When you light throttle, the throttle is only slightly open, but pulled down while the piston operation, an attempt to close off the intake air from the intake pipe, a vacuum is created between the throttle valve case and the piston, the outside atmospheric pressure for movement of the piston is formed a lot of resistance, greatly energy consumption, the lower the engine speed, throttle shut more closely, the greater the energy losses. Therefore, by subtracting the engine throttle Valvetronic can save fuel consumption, particularly at low speed time. In conventional engines, air intake pipe through the throttle valve, and then through the inlet valve before entering the top of the cylinder of the engine cylinders. The inlet valve is controlled by a timing belt switching time, the camshaft, the intake valve opening depth remains fixed regardless of high and low speed.
Valvetronic engine and, by definition, Valve tronic is electronically controlled valve means. After dispense throttle, the engine intake air amount is controlled by an electronic control directly the inlet valve opening depth. In fact, the whole mechanism is quite complicated to explain, very professional, generally speaking, the traditional signal of the throttle when the engine is mechanically transmitted to control the intake pipe of the throttle. Valvetronic engine signal when the throttleIt is electronically transmitted to the engine intake and exhaust valve on top of the stepper motor. After receiving the signal will make appropriate rotation of the stepping motor, via a propeller shaft, the rocker arm piston crown, changing the depth of the tappet of the intake valve open, the more shallow throttle, the more the inlet valve to open shallow, the more the pedal to deep, the inlet valve to open deeper. Valvetronic engine throttle omitted, directly electronically controlled to adjust the intake air inlet valve, such a design other than the addition Another important advantage of fuel, the throttle response time is faster. After a conventional manner to the engine throttle control of the throttle valve, throttle, throttle opening, air flows have to wait to fill the intake manifold, will be poured into the cylinder. Valvetronic engine and controls the intake throttle valve opening directly depth, immediately a lot of air into the cylinder.
Valvetronic engine intake valve opening shallowest depth 0.25mm, 38.8 times the maximum difference reaches 9.7mm. And the reaction time from the shallowest to the deepest changed as long as the required 0.3 seconds. BMW’s Valvetronic engine is a new engine manufacturing plant in the United Kingdom, the entire Valvetronic system is pre-assembled modules can be directly installed on top of the engine cylinder. BMW claims that application of Valvetronic engine technology to enhance 14 percentage efficiency than conventional engines, but not exclusively, credit Valvetronic technology. BMW, where the percentage is from 7 Valvetronic technology, the percentage is from 3 to reduce friction losses, it is the percentage of the credit 6 4-speed automatic transmission. But because many pay more Valvetronic engine intake valve control mechanism, it can have mechanical contact and friction, but when it exceeds 6000 rpm, the engine efficiency and smoothness is not good. Valvetronic engine using a combination of software and hardware of the
instead of gearing type throttle configuration. Valvetronic electronic control word meaning substituted traditional mechanical control valve mechanism.
Valvetronic modified intake valve timing and lift, Valvetronic system with a traditional engine, as the cam shaft, and the eccentric shaft there is also a jack mechanism and the roller, step by a stepper motor driven, by receiving fromThrottle position signal, the stepping motor to change the offset of the eccentric cam, an intake valve actuator to change some of the mechanical transmission via indirectly.
Comparative fuel injection system with traditional valve means Valvetronic mechanism monitors the flow rate of air flow through the throttle valve to determine the amount of fuel combustion when the engine needs, that is when the more open the throttle valve play, the more air into the combustion chamber of it. When the lighter throttle, part throttle even close to close. When the piston is still in operation, part of the air into the intake manifold, when the throttle valve between the combustion chamber and the intake manifold vacuum occurring portions, the piston, the pump wastes energy and suction resistance, the engineers a phenomenon known as ldquo; pumping loss rdquo; (pumping loss), when idling, the throttle open only part, so there is more energy loss.
Improved helical gear changing motor rotation amount of the eccentric shaft, the rocker arm and driven by a conventional camshaft interconnection moving forward, and then transmitted to the pressure reduction valve rocker finally.
Valvetronic amount of air can be reduced lift of the valve, and into the combustion chamber, the pumping loss to a minimum.
compared to traditional lenticular engine, Valvetronic using an additional eccentric shafts, some of the stepping motor and the rocker arm is set to control the valve being opened or closed, if the weight of the rocker arm deeper intake door there will be a higher lift, Valvetronic is there a way to freely control the valve lift, the gas is to grow large valve lift, short intake valve lift is small.
Advantages:
In Valvetronic engine cooling water flowing through the cylinder head, the temperature can be reduced by about 60 percentage.
Water pump only half of the original size, to reduce the power loss of about 60 percentage.
direction of the power oil is heated quickly, reducing the pump power of pump used.
Water pump means and power pump on the same shaft, and between the heat exchanger and the cooling oil, the temperature is reduced by 30 percentage.