| 摘要 |
<p>A high pressure mixing head (1000) for mixing at least two reactive components for reaction injection molding or reinforced reaction injection molding processes, and a reactive component injection valve (2) for such high pressure mixing head. The mixing head comprises a mixing head body (999) having an elongated mixing chamber with a first metering plunger (2010) therein, said mixing chamber communicating with an elongated quieting chamber disposed substantially normal to said mixing chamber, said mixing chamber having at least one inlet port through which a reactive component is injected by a reactive component injection valve. The quieting chamber has a second clean-out plunger therein (3010). The first metering plunger has at least one axially extending by-pass channel (2080) which provides fluid communication between an inlet port (500) to said chamber and an outlet passage when said plunger is in its recirculation position, said channel thereby providing for recirculation of reactive component through said mixing head in a path external to said reactive component injection valve. The reactive component injection valve comprises a valve body (600); an injection nozzle (604,605) disposed in said body; a reactive component supply passage disposed in said body; a first reciprocating member (620) disposed within the supply passage and selectably positionable to open, partially open or close said nozzle, varying the flow of reactive component through said nozzle whereby the pour pressure of said component may be set; a reactive component recirculation passage disposed in said body; and a second reciprocating member (650) disposed within the recirculation passage selectably positionable to open, partially open or close said passage, thereby varying the flow of reactive component through said passage, whereby the recirculation pressure of said component may be set and recirculation is effected in a path internal to said reactive component injection valve.</p> |
