US Patent 7950414 Regulating check valve and fuel injecton valve having the same

A valve chamber is defined in a valve body of the regulating check valve. A first communicating hole and a second communicating hole communicate the valve chamber with a first flow passage and with a the second flow passage, respectively. A valve element is slidably installed in the valve chamber to seat on or lift away from a valve seat to close or open the first communicating hole. A pressure in the first flow passage urges the valve element away from the valve seat, and a pressure in the second flow passage urges the valve element toward the valve seat. The spring is interposed between the valve element and the valve body to urge the valve element away from the valve seat.