ZF To Offer Efficient Dynamics Start Stop with Autos

Start Stop transmission as part of BMW's Efficient Dynamics has so far only been available with manual boxes. Now ZF have come up with an auto solution...

ZF unites mechanism and asynchronous operation Asynchronous operation systems help with the Spritsparen, by switching off and when starting automatically again starting the combustion engine in the stop without effort of the driver. At present BMW in the program has most models with this technology. So far however only cars with four-cylinder and transmissions come into the benefit of the automatic time-out, because automatic transmissions are not startingstopable without further measures. The problem: If the combustion engine stands, the oil pump in the automatic transmission is not propelled, the transmission is pressure-free. Thus the necessary oil pressure is missing, in order to activate the logic elements in the transmission - clutches and brakes -. Start in this condition is impossible, since the force river is interrupted to the drive wheels from the engine. With the starting of the engine also the oil pump works immediately again, but while the starter already catapults the verb racer after approximately 350 milliseconds on its idling speed, the full oil pressure is located in the transmission - and thus the starting readiness - only after one more than twice as regards time interval. No customer accepts. Because before the pressure of approximately six bar can construct itself, the logic elements must be filled first with a certain oil volume. A way from the dilemma would be to propel the oil pump independently of the engine by electric motor. Requires however a high expenditure for noise isolation, since in the stop no engine noise masks the noise of the pump. In addition the necessary river loads the battery. For the new eight-course mechanism 8HP a system developed suppliers and transmission manufacturer ZF now, which the pressure build-up accelerated and so that the starting readiness of the automatic transmission guarantees in the same time, which the combustion engine needs for starting. With models with asynchronous operation system is attached these hydraulic memory components so called HIS to the oil circulation of the transmission. The cylindrical construction unit is crosswise behind the hydraulic control because of the transmission lower surface and stresses so no additional building area in the vehicle structure. His works according to the principle of a spring accumulator and needs in the stop phases of the combustion engine only little electricity. With this comparatively simple system the pressure build-up in the transmission is accelerated clearly; one can drive off without delay, as soon as the combustion engine runs. The asynchronous operation function is to lower consumption in the European Union cycle around further five per cent. Author: Hermann Josef Stappen

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Edited by thepits

Andrew Rolland wrote: Don't like the electronic handbrakes either.  Give me a proper lever to pull!  Ug! Proper man bit of kit, not a plastic switch.

what did J Clarkson say? "How can you get four-wheel-drive with a little electrical switch? You need a proper lever that goes CLUNK, like in a Land-Rover.

Never has a truer word been spoke.

thepits wrote: Andrew Rolland wrote: Don't like the electronic handbrakes either.  Give me a proper lever to pull!  Ug! Proper man bit of kit, not a plastic switch. what did J Clarkson say? "How can you get four-wheel-drive with a little electrical switch? You need a proper lever that goes CLUNK, like in a Land-Rover.   Never has a truer word been spoke.

I like the way he used landrover as an example.

A company synonymous with mechanical failures. That clunk is the gear box falling out

I've got money that says the electircal switch is far more reliable than anything landrover have ever made

I try my best