The animation shows the processes inside a four-stroke spark ignition engine from the point of view of the control system. A cross-section of a four-stroke spark ignition engine and the corresponding control diagram are shown.
Note on use
As with all animations, the windows can be zoomed in or out by clicking on them.
You can also zoom in or out on the contents of a window itself. To do this, click on one of the selection buttons under the “Views” heading:
After starting the application, you can view the animation in full-screen mode. To do this, click on “View” and then on “Full screen”:
To exit full screen mode, press the Esc key.
Description of the animation
The timing diagram shows the valve timing of an internal combustion engine as a function of the angle of the camshaft. The length of the respective phases depends directly on how the cams are aligned on the camshaft. The timing diagram is therefore sometimes also referred to as a camshaft diagram.
The ignition timing is shown in the timing diagram.
The air-fuel mixture is ignited even before the piston reaches top dead centre. This is the point at which the piston is at the top of the cylinder.
The ignition point shifts depending on the engine speed. In the animation, the engine speed can be changed interactively, as happens when the accelerator pedal is pressed.
The cross-section of the four-stroke petrol engine can be zoomed in. The valve overlap then also becomes visible. Valve overlap means that both valves are open at the same time when expelling.
Valve overlap offers several advantages:
- More efficient gas exchange: exhaust gases are expelled more efficiently. More fresh air enters the combustion chamber.
- Improved cooling: The engine is cooled better thanks to the improved air exchange.
The duration and position of valve overlap varies from engine to engine and depends on the design features and performance targets. Careful optimisation of valve overlap can influence engine performance, fuel consumption and emission levels.
Overview and download
| Title | Control of a four-stroke petrol engine |
| Target group | Teachers and lecturerse |
| Platforms | Microsoft® Windows® Apple® Macintosh® (version dependent) |
| Features | Full screen mode lossless zoom Large screens and projection screens supported |
| Licence | Freeware |
| Download | Contact us |
Contributors
C. Hein, S. Rikowski
Source information
- Technical drawing of the motor: based on Ulrich Rapp (http://www.ulrich-rapp.de/stoff/fahrzeug/motor/index.htm)
- Authoring tool (control elements supplied): Adobe Animate