Injection device for reagent

An injection device for administering a reagent into an exhaust chamber of an internal combustion engine, the injection device comprising:

• a device inlet and a device outlet,
• a valve housing defining a valve seat,
• a valve member movable outwardly from the valve housing, away from the valve seat, to permit the reagent to be delivered into the exhaust chamber through the device outlet, whereby a force is applied to the valve member due to reagent delivered to the device inlet which serves to urge the valve member away from the valve seat,
• a bias device for applying a biasing force to the valve member which serves to urge the valve member against the valve seat so as to prevent delivery of the reagent through the device outlet into the exhaust chamber;
• and
• a stop member for limiting the extent of movement of the valve member outwardly from the valve housing,
• wherein the valve member includes a projection which is held securely within the stop member so that the valve member and the stop member move together as a single part.

An injection device for administering a reagent into an exhaust chamber of an internal combustion engine, the injection device comprising:

• a device inlet and a device outlet,
• a valve housing defining a valve seat,
• a valve member movable outwardly from the valve housing, away from the valve seat, to permit the reagent to be delivered into the exhaust chamber through the device outlet, whereby a force is applied to the valve member due to reagent delivered to the device inlet which serves to urge the valve member away from the valve seat,
• a bias device for applying a biasing force to the valve member which serves to urge the valve member against the valve seat so as to prevent delivery of the reagent through the device outlet into the exhaust chamber;
• a stop member for limiting the extent of movement of the valve member outwardly from the valve housing, and
• a sleeve within which the stop member is held securely so that the sleeve and the stop member move together as a single part.

An injection device for administering a reagent into an exhaust chamber of an internal combustion engine, the injection device comprising:

• a device inlet,
• a device outlet,
• a sub-assembly comprising (i) a valve housing defining a valve seat, (ii) a valve device movable outwardly from the valve housing, away from the valve seat, to permit the reagent to be delivered into the exhaust chamber through the device outlet, whereby a force is applied to the valve device due to reagent delivered to the device inlet which serves to urge the valve device away from the valve seat, and (iii) biasing device for applying a biasing force to the valve device which serves to urge the valve device against the valve seat so as to prevent delivery of the reagent through the device outlet into the exhaust chamber;
• a device housing separate from the valve housing and having a housing bore within which the valve housing is held securely so as to hold the sub-assembly securely within the device housing;
• and
• wherein the valve device comprises a sleeve and a valve member, the bias device is located between a surface of the valve housing and a surface of the sleeve, and the positioning of the sleeve relative to the valve member sets a minimum force required to move the valve device away from the valve seat.