Water injection system for internal combustion engines

Claim 1

In liquid injection apparatus for use with an internal combustion engine having an ignition system and an air intake manifold, the combination comprising a. a liquid pump and electrical drive therefor, the drive including an electrical motor, the pump having an outlet communicable with the engine air intake, b. and control means including an electrical make or break switch and a pulse rate frequency to analog converter to control electrical current flow to the drive via said switch in response to and as a function of electrical pulses produced by said ignition system, whereby the flow of liquid to the engine air intake will be a function of the pulse output of the ignition system, the switch directly connected in series with the motor, c. there being a switch actuator connected with the switch, the actuator operatively connected with the engine air intake manifold to close the switch enabling said current flow to the drive when air pressure in the manifold drops to predetermined level, whereby said flow of liquid to the engine air intake will then be established, the switch, when open, blocking current supply to the motor, d. the control means including a semiconductor connected to pass drive current to the pump drive, and an operational amplifier connected between the converter and semiconductor to supply said drive current as a function of the voltage output of the converter, e. and an RC feedback loop connected between the motor side of the switch and the operational amplifier to be responsive to closing of the switch to allow the control means to provide a temporary increase in power supplied to the drive followed by a reduction in power supplied to the drive, whereby the device may be quickly brought up to speed for providing a rapid delivery of liquid to said outlet.