Appeal No. 2002-2039 Page 7
Application No. 09/258,712
Located within the upper housing 106 is a second intensifier piston 132 that has
an intensifier 134 which moves within the injector chamber 128. The intensifier 134
is captured by an insert 136 that is attached to the piston 132. Coupled to the piston
132 is a spring assembly 138. The area ratio of the piston 132 and the intensifier 134 is
such that the fuel within injector chamber 128 is pressurized to a value higher than the
fuel pressure within the intensifier chamber 116.
In operation, the intensifier 12 provides a pressurized fuel to the intensifier
chamber 114. The pressurized fuel lifts the intensifier piston 132 and compresses the
spring assembly 138. The fuel also flows from the intensifier 12 into the injector
chamber 128 via passage 126. When the piston 132 reaches a top dead center
position, a control valve 16 (see Figure 1) is opened to allow fuel to flow out of the
intensifier chamber 116. The flow of fuel reduces the pressure in the chamber 114 and
allows the spring assembly 138 to move the piston 132 back to the original position.
Movement of the piston 132 also moves the intensifier 134, which reduces the volume
of the injector chamber 128 and increases the pressure of the fuel therein. The highly
pressurized fuel lifts the needle valve 120 and is ejected through the nozzle openings
118. When the piston 132 reaches the fully stroked position, the control valve 16 is
closed and the pressure within the intensifier chamber 128 is increased by the
intensifier 12, wherein the process is repeated.
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Last modified: November 3, 2007