Patent GB-300245-A (GB)
Title: Improvements in means for regulating the air and gas supply to engines
IPC: F02M21/00
Filed: 1928-11-09
Abstract: 300,245. Motorenfabrik Deutz Akt.- Ges. Nov. 9, 1927, [Convention date]. Regulating.-The control of the air and gas supplies to a gas engine by the usual centrifugal governor is supplemented by hydraulic controlling- mechanism which automatically adjusts the air or gas supply so as to maintain the gas consumption at a minimum. Fig. 1 shows the centrifugal governor G connected by a linkage e to the throttle valves c, d controlling respectively the gas and air supplies through pipes a and b, The air throttle valve d is further connected to a cylinder f which is slowly reciprocated to and fro over a piston g on the linkage e by hydraulic mechanism comprising a pump l, valves p, k, and a regulator t the function of which is to arrest the reciprocating movement of the cylinder f in the direction which adjusts the air throttle so as to increase gas consumption, and to allow the reciprocating movement in the opposite direction, so that the centre of oscillation of the air throttle takes up the position which is most favourable to minimum gas consumption. The pump l discharges oil through a pipe m to the valve p, which as it slowly rotates, say once a minute, alternately supplies oil through a recess q<1> and pipe r to the regulator t, and vents oil from the regulator t back through the pipe r, port q, and return pipes s, o. Oil supplied to the regulator passes by a pipe g<1> to the valve k, which is on the same shaft as the valve p, and alternately reverses the flow through pipes h and i to opposite ends of the cylinder f, causing this to reciprocate. The regulator t comprises a control valve z presed upwards by a spring 0<1> and connected to a diaphragm x, subjected on the upper side by a pipe v to the pressure in the gassupply pipe a, and on its lower side by a pipe w to the pressure at a Venturi section u in the gas pipe. The valve z is surrounded by a sleeve valve a<1>, the two valves being connected by a pin k<1> passing through ports b<1> in the valve z. With the parts in the position shown, oil is supplied by the valve p to the regulator t and passes through ports b<1>, c<1>, d<1> therein to the pipe g<1>, which is connected by the valve k to the pipe h, the pipe i being connected to the return pipes n<1>, o. As a consequence, the cylinder f and air throttle d are moved to the right, increasing the supply of air. If this occasions an increase in gas consumption, the diaphragm and valve z are moved downwards so as to close the ports c<1>, d<1> and cut off the supply of oil to the cylinder f, thereby arresting the reciprocation in that direction. The valve p then comes into the position for venting the regulator t of oil pressure, which releases the sleeve valve a<1> from an oil-pressed catch m<1>, and allows a piston h<1> to be forced downwards by a spring against the pin k<1>, thus pressing the valve a<1> downwards so as to open the ports c<1>, d<1> again. The valve p then supplies another impulse of oil to the regulator t, and this oil passes through the ports c<1> d<1> to the valve k, which has arrived into the position for reversing the flow to the cylinder f so as to cause a reciprocation to the left. As this movement is favourable to a reduction of gas consumption, the regulator t maintains the flow of oil through the ports c<1>, d<1>, the diaphragm x being unable to raise the valves z, a<1> as they are held by the catch m<1>. When, however, the valve p next vents the regulator, the catch m<1> is released and the diaphragm is able to adjust the valve according to the flow of gas. In a modification, the air and gas throttle valves are moved axially by the centrifugal governor as before, but are ascillated about this axis by the hydraulic mechanism, the air-supply ports being constructed so that this oscillating movement varies their area but not the area of the gas-supply ports.