| 摘要 |
<p>An arrangement for monitoring injection of fuel in an internal combustion engine, especially a compression ignition engine, in which fuel is injected into the or each cylinder via a fuel injector, comprises a polymeric piezoelectric pressure sensor (17), preferably in the form of a coaxial cable that is immersed in fuel that is in or in communication with a fuel injector (1) to sense pressure changes in the fuel. The sensor may be located in the high pressure line or in the low pressure return fuel line. In one specific embodiment, a coaxial cable pressure sensor is located in the excess fuel drain pipe (16) of a fuel injector (1). The arrangement has the advantage that it is mechanically very simple, thereby reducing expense of manufacture and maintenance, and yet is able to detect the beginning of fuel injection accurately due to good acoustic impedance matching of the pressure sensor and the fuel.</p> |
