Injector for reductant delivery unit having fluid volume reduction assembly

A fluid injector, including a fluid inlet, a fluid outlet and a fluid path from the fluid inlet to the fluid outlet; a tube having an end at the fluid inlet; a filter disposed in the tube proximal tothe fluid inlet; and a volume reduction member disposed in the tube downstream of the filter, contacting an inner surface of the tube and including a through-bore defining at least a portion of the fluid path, the bore having a smaller diameter than an inner diameter of the tube and the volume reduction member occupying a volume in the tube such that the volume reduction member reduces an amount of space for fluid in the fluid injector. A cap member, in which the filter is disposed, engages with the volume reduction member such that the filter, the volume reduction member and the cap form a single assembly member. 流体喷射器包括：流体入口、流体出口、从流体入口到流体出口的流体路径；管，其具有在流体入口处的端部；过滤器，所述过滤器设置在所述管中靠近流体入口；和体积减小构件，其设置在管中在过滤器的下游，接触管的内表面，且包括限定流体路径的至少部分的通孔，孔具有比管的内径更小的直径，且体积减小构件占据管中的体积，从而体积减小构件减小流体喷射器的流体空间量。过滤器设置在其中的帽构件与体积减小构件接合，使得过滤器、体积减小