1, SkyActiv
SkyActiv (English: SKYACTIV Technology) presented in October 2010 as Japan’s Mazda Motor Corp., plans to 2015’s of gasoline and diesel vehicles for the main technical elements optimization engine, automatic transmission and a manual transmission, chassis, body structure.
2, Engine
petrol
SKYACTIV-G type engine
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launched in Japan in 2011 of 30 June facelift third generation Demio, “13-SKYACTIV” class models equipped with the use of SkyActiv 1.3L SKYACTIV-G engine type. The engine tool having the following characteristics:
In the production of gasoline engines, the compression ratio for the first time to reach 14.0: 1.
High compression burning significantly enhancing the efficiency of the engine, fuel consumption and torque than in the past more than 15 percentage lift.
to increase low-speed torque domain.
Theoretically the compression ratio increased from 10.0 to 15.0, the combustion efficiency can be increased to about 9 percentage, but a high compression ratio of the compression stroke, the temperature near the upper dead point increases, causing engine knock and decrease in output power . Therefore this technique to reduce the residual gases by means of the combustion chamber, to achieve a high compression ratio, the main technologies:
4-2-1 exhaust system path length: four-cylinder in-line engine, for example, if an exhaust path is too short, since the exhaust pressure wave of high pressure cylinder 3 is discharged exhaust valves actually enters the exhaust stroke has been completed, is about to start the intake stroke of the first cylinders. In this way, the exhausted gas again into the combustion chamber, the high temperature residual gas increased. However, extension of the exhaust path 4-2-1 exhaust system, so that the high pressure wave takes more time to reach the other cylinders, to reduce the chance of residual exhaust gas.However, lengthening the path of the exhaust gas temperature drop starting, catalyst contact time delay. Therefore Mazda seek to ensure stable combustion in the premise, the ignition delay time to maintain the exhaust gas temperature.
Porous ejecting apparatus: 1.3L SKYACTIV-G type engine unit 6 a hole injection systems, and enhance the air flow, the injection pressure strengthened in order to improve combustion.
concave piston crown: a piston head designed as a recess hole, the fuel injector is formed near the spark plug in the stack gas mixture to help stabilize combustion. Furthermore, this problem can be solved recesses piston crown flame contact cooling loss initial combustion occurs. Diesel engine
SKYACTIV-D Engine type
High compression top dead center of a diesel engine compression ratio is very high temperature and pressure, so the post fuel injection, then appropriate pre-mixed gas ignition has not yet formed. Formation of local nonuniform combustion and generates nitrogen oxides (oxides of nitrogen, referred to as NOx), and the combustion is insufficient to produce carbon monoxide oxidation portion (carbon monoxide, referred to as CO) and particulate matter (particulate matter, referred to as PM).
SkyActiv diesel engine compression ratio will be reduced to 14.0: 1, but also reduce its temperature and pressure. Since the ignition timing is extended, air is mixed with fuel that contributes to the uniform combustion, it is possible to reduce carbon monoxide, hydrocarbons, nitrogen oxides, and other solid particulate matter caused by air pollution. Furthermore, since dead center in the combustion chamber jet, combustion, so the work efficiency is generally higher than the high compression ratio of a diesel engine. Relatively speaking, the lower the compression ratio and the thickness may be reduced into an aluminum cylinder, can mechanically weight. The diameter of the crankshaft main journal shortened from 60mm to 52mm, not only to reduce the 25 percent by weight, mechanical resistance also decreases.
However, since other automakers in the past did not dare to lower the compression ratio diesel engines, mainly focused on:
low compression ratio of the compressed air temperature is relatively low, it is difficult to start the engine.
warm-up operation after the launch is not stable enough, vulnerable to fire half the state.
Accordingly, SKYACTIV-D diesel engine taking the following techniques to avoid preSaid disadvantages:
The variable valve lift mechanism (Variable Valve Lift, referred VVL): Although this has not been announced Mazda VVL device specific data parameters, but the vent valve mechanism is disposed in the suction stroke the exhaust valve is opened a little, so that the exhaust gas in the exhaust pipe back into the cylinder in order to improve the countercurrent intake temperature, while promoting the rise in temperature during compression, to improve the ignition stability.
Porous pressure injection apparatus: new porous fuel injection device containing multiple injection mode, the injection time can accurately control the amount of discharge and increase the concentration of the mixed fuel and air. The mechanism to do before the primary combustion spray, main injection, after injection, 3 times each, a total of 9 times injection; in conjunction with ceramic igniter plug, to ensure the normal start in a low compression ratio in the environment.
Further, SKYACTIV-D apparatus of the type more twin turbo system, not intended to enhance the torque, but is for cleaning exhaust gas and reducing fuel consumption. These two turbines of different sizes with different engine operating speeds, respectively pressurized. Thus only ensures high torque, high power output of the low-speed range of the high speed range, while also reducing NOx CO and particulate matter emissions.
3, the award-winning record
2010: December 3rd 1.3L SKYACTIV-G engine type obtained 32nd 2011 Car of the Year Japan Special Award.
2011: November 18 1.3L SKYACTIV-G engine type to get 21th 2012 RJC Technology of the Year Award Car of the Year; December 7 the same type of combustion engine, the 2012 Japan Society for Technology Award .
2012: February 22 1.3L SKYACTIV-G engine type awarded by the General Foundation of the Association for the Promotion of mechanical 9th new machinery revitalization Award.
4, chassis
SKYACTIV-CHASSIS chassis
is referred to as its “SKYACTIV-CHASSIS” lightweight chassis structure, and existing under reduced compared to a chassis 14 percent by weight. Suspension mining redesigned front MacPherson, rear multi-link configuration structure in order to achieve the medium-speed domain agile, high-speed region stable state. Four suspension coil springs not only through change, also retuned the steering system.
5, the body structure
“SKYACTIV-BODY” with lightweight body as a target, to improve structural rigidity 30 percent, while the percentage of weight loss 8. Each seeks to complete a high-tensile steel, to avoid bending or welding; together with the difference in material selection for engagement to achieve integrity and sturdiness of the overall body structure.