Concept explainers
- Explain staged and continuously variable value timing systems.
The explanation of staged and continuously variable valve timing systems.
Explanation of Solution
Staged variable valve timing:
Staged valve timing consists of a central camshaft, where the lobes push against the wall to open when the camshaft is rotated. Crankshaft provides input to drive cam. Both the valves can be opened when there is a single cam. In the case of two cams, one can be used for intake and the second cam is for exhaust.
Valve timing ideal value point changes with a change in rpm. It is related to engine performance and fuel efficiency.
It involves three cams with different timing and lifts profile.
Stage one- low speed.
Stage two- medium speed.
Stage three- high speed.
Example − Honda VTEC system.
Continuously variable valve timing:
Continuously variable valve timing camshaft is fitted with a phaser. It is mounted in place of timing pulley, sprocket, or gear. The principle of phaser is based on a helical gear set or vanes enclosed in a housing. When the engine is running, it helps in changing time from cam-shaft to crankshaft.
It can be electronically or hydraulic controlled.
Example − Toyota’s VVT-i system.
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Chapter 12 Solutions
Tech Manual for Erjavec's Automotive Technology: A Systems Approach
- Access Pearson Course Home Scoresarrow_forwardAccess Pearson Mastering Engineering Back to my courses Course Home Course Home Scoresarrow_forwardAccess Pearson Mastering Engineering Back to my courses Course Home Course Home Scores ■Review Next >arrow_forwardA gear has a gear wheel with 16 teeth. The gear should be dimensioned for the highest and lowest gear ratio. Looking for output power, torque, speed?nin= 2000 rpmmin = 30Nmn=0,9a max= 450 mmModule 4Gear limitsz1 z213 13-1614 14-2615 15-4516 16-10117 17-131418 18-…..I have calculate but I can’t get the right answers…..√16 =459x60/56x57=1.1 lowest59x60/13x13=20,94 highestnut=2000/1.1= 1818rpmnut=2000/20.94=95.5 rpmMut=1.1x30=33 NmMut=20.94x30=628,2 Nm(Right answer)LowestZ=13, M=24,4Nm, n=2462 rpmHighestZ=92, M=172,5Nm, n=347,8 rpmP=5655W on botharrow_forwardPlease see attached pic.arrow_forwardPlease see attached pic.arrow_forwardarrow_back_iosSEE MORE QUESTIONSarrow_forward_ios
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