2010 Mazda 3 i-stop

The Mazda booth at the 2009 Geneva Motor Show is greener than ever. One way to achieved Mazda is developing the single technology that idle the engine shuts off when stopped in traffic jams and similar situations, as a way of reducing fuel consumption.

The Mazda 3 will be powered by the MZR 2.0L DISI engine idle with green technology window - Mazda i the single system. Developed exclusively by Mazda, is the only idle stop system that restarts the engine using the remaining energy in the piston (with the help of a fast starter) by direct injection of fuel into the cylinder and cause to force the piston down. The benefit of the combination of a DISI engine with i-STOP (originally called SISS: Smart Stop inactivity) is that the system restarts the engine about two times faster, and quieter, than conventional idle stop systems.

The combination of these two patented technologies for Mazda and other aerodynamic modifications to help the new Mazda 3 reach approximately 14 percent lower fuel consumption (combined) than the previous Mazda 3.

When the driver stops the vehicle (red light, traffic jam) the engine stops automatically and is set to be ready for an early resumption. As soon as the driver presses the clutch, the engine is started automatically restart procedure. This is a completely neutral for the driver.


Mazda 3 i-stop green technology

When stopped at a stoplight or in a traffic jam, turn off the engine at idle can reduce fuel consumption by about 5 percent under city driving mode tests. However, the problem with the idle stop systems is that they are based solely on the use of an electric motor to restart the engine. As such, they require a long period of time to achieve combustion in the engine when it restarts. In the real world driving, this means a delay between the moment the accelerator pedal is pressed down and the car begins to move, as well as vibration and noise.

The i-stop for the new Mazda 3 takes the DISI direct-injection engine of the potential for improving fuel economy, restarting the engine quickly and quietly by direct injection of fuel into the cylinder and cause the the piston and rod set up. The motor is controlled with precision to make this happen:

Special motor requirements

To use the energy of combustion of the initial stages of restarting the engine and start the engine quickly, the following three conditions must be met while the engine is stopped. (1) The engine must be able to inject the fuel directly into the combustion chamber and ignite, (2) a sufficient amount of clean air must exist in the combustion chamber of the cylinder when the fuel is lit, and (3) control system the computer must be able to determine which cylinder fires immediately after starting the engine. The i-stop, so you must use a direct injection engine that can provide fuel to the combustion chamber under high pressure, and can easily ignite the fuel. Mazda MZR 2.0 DISI liters of gasoline engine is ideal for this.

Piston position control

The pistons are stopped at the appropriate position when the engine is stopped, an appropriate amount of air is maintained within the combustion chamber and the combustion chamber is evacuated due to reduce the amount of unburned gasoline. To this end, the position of the piston is controlled by applying current to the motor generator, while the engine is off. In this way, operates as an electric motor, while using the signal from the crank angle sensor that monitors the position of the control piston to stop the feedback in the appointment of the piston within its expansion stroke.

Special check valve and balancing of the crankshaft

To find the combustion chamber, the new Mazda 3 i-pause the system opens the throttle valve slightly during the shutdown process. (The valve is normally closed to shut off the engine.) Regulate the crank angle sensor can only be determined by the forward rotation, which leaves them unable to control or reverse rotation to determine the correct position of the piston. Mazda i stop using a crank angle sensor that is capable of controlling the rotation of the crankshaft in both directions, allowing you to accurately determine the correct position of the piston. To maintain the proper balance crankshaft when the engine is stopped, is slightly rotated in the opposite direction.

Faster restart + fuel

These measures make it possible to inject fuel properly when you restart the engine and the control of ignition advance, which allows the combustion energy to be used while the engine is stopped and to restart the engine in 0.35 seconds, about half the time required for conventional idle stop systems. While the new Mazda stop-i system employs combustion energy to restart the engine is assisted by the starter motor only for the first turns of the crankshaft. This achieves the optimum balance between maximizing the fuel savings and minimize the amount of time required to restart the engine. As a result, I will stop to reduce fuel consumption beyond what is possible through the combustion of energy by itself to restart the engine.

Driver support system of communication

On the new Mazda 3 is fed by the 2.0 DISI MZR engine, the i-stop driver supports allowing visual confirmation of operation in relation to the driving style. There is a i-on / off switch on the dashboard, the driver and the group contains a light that shows "i-stop" when the system turns off the engine in front of traffic lights, for example. When disabled, an amber light indicates that the i-stop is not in the system.

Ensure reliable operation

The new Mazda 3 i-stop system (only available with the MZR DISI 2.0-liter gasoline) is equipped with an auxiliary battery that powers the system if the main battery is not loaded properly or some similar problem occurs . This added measure of control ensures that the driver can use the natural system without giving a second thought. In addition, the system will not shut down the engine if the car is stopped on a road with a very steep grade (more than 14 percent incline).