Cooling device for injector

A cooling device for a fluid injection valve provided in an exhaust pipe of an internal combustion engine and injecting fluid into the exhaust pipe comprising;

• a fluid-space forming unit extending in an axial direction of the fluid injection valve to a forward end of the fluid injection valve, the fluid-space forming unit having an inner wall member and an outer wall member and surrounding the forward end of the fluid injection valve, and the fluid-space forming unit forming a fluid space between the inner wall member and the outer wall member in order that cooling water flows through the fluid space;
• at least two partitioning walls provided in the fluid space at such positions which are separated from each other in a circumferential direction of the fluid injection valve, each of the partitioning walls extending in an axial direction of the fluid injection valve so as to divide the fluid space into multiple fluid flow areas arranged in the circumferential direction of the fluid injection valve;
• wherein each of the partitioning walls forms a fluid communication portion in a forward-end space of the fluid space and the forward-end space surrounds the forward end of the fluid injection valve, so that the forward-end space is entirely communicated through the fluid communication portions in its circumferential direction,
• wherein the multiple fluid flow areas include an inlet-side fluid space and an outlet-side fluid space, which are separated from each other in the circumferential direction by the partitioning walls,
• wherein an inlet port is provided in the fluid-space forming unit at a position, which is different from a portion of the fluid space communicated to the forward-end space, so that the inlet port is communicated to the inlet-side fluid space except for the forward-end space, and
• wherein an outlet port is provided in the fluid-space forming unit at a position, which is different from the portion of the fluid space communicated to the forward-end space, so that the outlet port is communicated to the outlet-side fluid space except for the forward-end space.

A cooling device for a fluid injection valve of an internal combustion engine comprising;

• an outside housing member having a recessed portion;
• an inside housing member formed in a cylindrical shape and inserted into the recessed portion in such a way that an outer peripheral surface of the inside housing member is opposed to an inner peripheral surface of the outside housing member in a radial direction of the outside housing member via a radial space, wherein the inside housing member accommodates therein the fluid injection valve so as to surround a circumference of a forward end portion of the fluid injection valve which injects fluid into an exhaust pipe of the internal combustion engine;
• a fluid space of annular shape formed in the recessed portion between the outside housing member and the inside housing member, wherein cooling water is supplied into the fluid space in order to cool down the forward end portion of the fluid injection valve;
• an inlet port formed in the outside housing member and communicated to the fluid space;
• an outlet port formed in the outside housing member and communicated to the fluid space;
• multiple partitioning walls, each of which is provided in the fluid space and extends not only in a radial direction of the fluid space from its inside peripheral surface to its outside peripheral surface but also in an axial direction of the fluid space, wherein the partitioning walls are arranged in a circumferential direction of the fluid space at intervals so that the fluid space is divided into multiple fluid flow areas neighboring to each other in the circumferential direction;
• and
• a fluid communication portion formed in at least one of the partitioning walls for communicating neighboring fluid flow areas to each other in the circumferential direction of the fluid space, so that the cooling water flows in the fluid space in the circumferential direction from one of the fluid flow area to the neighboring fluid flow area through the fluid communication portion.