VAPORIZER FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide a vaporizer capable of stably carrying out an operation of an engine without temporarily shielding feed of a gas fuel and diluting a concentration of air-fuel mixture at the time of snap action of a throttle valve. SOLUTION: The vaporizer V reduces a pressure to a predetermined primary pressure at a primary pressure reduction chamber and adjusts the pressure to a secondary pressure in the approximately atmospheric pressure state at a secondary pressure reduction chamber 36. A slow lock valve 28 for opening/closing a primary fuel deliver passage 27 is disposed at the delivery passage 27 opened from the primary pressure reduction chamber 22 and a slow lock pressure receiving chamber 30 divided by a slow lock diaphragm 29 for imparting an opening/closing operation force to the slow lock valve 28 and a suction passage 40 are communicated by a negative pressure introduction. A pressure control valve P is disposed at the introduction passage. The pressure control valve P is divided to an upstream chamber PA and a downstream chamber PB and is communicated by a by-path passage 3 bypassing a valve hole 2 and a valve hole 2. A check valve 6 is disposed facing to the valve hole and opens the valve hole 2 when the negative pressure of the suction passage 40 acting on the upstream chamber PA is a constant value or higher and it closes the valve hole when the negative pressure is a constant value or lower. A control orifice 7 is disposed at the by-path passage 3 and the upstream chamber PA and the downstream chamber PB are always communicated by the control orifice 7.