Patent ID: 9482358
Filing Date: 2016-11-01
CPC Classification: F16K,H01F

Claim Text:
1. A solenoid valve comprising: a valve body defining a first port and a second port isolated from the first port; a bobbin mounted to the valve body, the bobbin comprising: a tube portion; a connection portion formed at one end of the tube portion; a mounting portion extending from the connection portion in a direction away from the tube portion and mounted to the valve body; and a hole axially extending through the tube portion, connection portion and mounting portion; a winding wound on the tube portion of the bobbin; a stator installed in one end of the hole in the bobbin remote from the mounting portion, the stator defining a third port therein; a plunger installed in the hole of the bobbin, the plunger having an outer circumferential surface and defining a void therein, the void being spaced from the outer circumferential surface; first and second plugs mounted at respective axial ends of the plunger; a flux return device fixed to the stator and the bobbin and configured for cooperating with the plunger and the stator to provide a path for magnetic flux generated by the winding; and a spring attached to the plunger and arranged to urge the plunger towards the valve body, wherein the plunger is slidably disposed within the hole in the bobbin and movable between a normal position, where the plunger is adjacent the valve body and the first plug closes the first port and the second port communicates with the third port via a passage, and an energized position where the plunger is adjacent the stator and the second plug closes the third port and the second port communicates with the first port via the hole in the bobbin; wherein, when energized, the winding moves the plunger against the urgings of the spring to the energized position; wherein the passage between the second port and the third port passes through the void of the plunger; and wherein the plunger comprises a body portion within which the void is formed, the body portion comprises a middle section and a air of end sections extending from respective ends of the middle section, a channel being formed between an inner surface of the bobbin and an outer surface of each of the end sections of the body portion, an opening being formed at a joint between the middle section and each of the end sections for communicating the void with a corresponding channel, the passage passing through the channels and the openings.