Piezo Injector Operation: Restrictor
The restrictor has a.2 mm orifice which increases the pressure in the fuel return of the fuel injectors. The operating pressure in the leakage oil circuit is about 10 bar.
INDEX EXPLANATION CHART
| Index | Explanation |
|---|---|
| 1 | Connection from injector leakage line |
| 2 | Filter |
| 3 | Restrictor (.2mm) |
| 4 | Filter |
| 5 | Connection to low pressure line |
The fuel flowing from the piezo-fuel injectors via the fuel return connection (1) initially passes through a filter (2), through restrictor (3) and then through a further filter (4) to connection (5) back into the fuel feed to the high pressure pump.
There is a filter (2 and 4) on either side of restrictor (3) as the restrictor has no specific direction of flow. The filters ensure that the actual restrictor (3) does not become clogged.