US2541419A - Gas metering apparatus for gas engines - Google Patents

Description

Feb. 13, 1951 HOLLOWAY 2,541,419

GAS METERING APPARATUS FOR GAS ENGINES Filed Oct. 20, 1949 2 Sheets-Sheet l INVENTOR.

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jlt'arneq 2 Sheets-Sheet 2 M QB' LWeA INVENTOR. Q06 H. Hv6mw B Feb. 13, 1951 J. H. HOLLOWAY GAS METERING APPARATUS FOR GAS ENGINES Filed 007k. 20, 1949 Patented Feb. 13, 1951 UNITED STATES PATENT OFFICE GAS METERING APPARATUS FOR- GAS ENGINES Application October 20, 1949, Serial No. 122,559

4 Claims.

The invention relates to gas engines and more particularly to high compression gas engines.

In high compression gas engines'in which no air throttling controls are used and a full cylinder of air at atmospheric pressure is taken in at each cycle, only the gas is metered or regulated to meet the demand, and the object of this invention is to provide a new and improved gas metering apparatus for such a gas engine.

A further object of the invention is .to provide a gas metering or regulating apparatus embodying a zero pressure gas regulator, the outlet from I the quantitive relation of the gas delivered in response to the load demand must be held to reasonably close limits. The regulating system herein shown has been found to satisfy these requirements.

Gaseous fuel from a suitable source of pressure supply is conducted through a supply pipe 1 I provided with a shut-01f cock 8, and strainer 9 which is controlled by a governor operated metering valve and also the inlet to which isv controlled by a governor operated pressure regulator valve. It has been found that by regulating the pressure at the entrance of the zero regulator, the response of the regulator is greatly enhanced, which is a decided advantage in securing close regulation of engine speed by the governor..

The invention further consists in the several features hereinafter set forth and more particularly defined by claims at the conclusion hereof.

In the drawings:

Fig. 1 is an elevation view through a regulating apparatus embodying the invention, parts bein broken away and parts being shown in section;

Fig. 2 is a plan view of the apparatus, part of the air inlet being shown in section;

, Fig. 3 is a detailed vertical sectional view taken on the line 3-3 of Fig. 2

Fig. 4 is a detailed horizontal sectional view taken on the line 44 of Fig. 3.

Referring to the drawings, the numeral 5 desi nates generally a high compression gas engine which may be of the gase Diesel type, that is, an engine in which the compression pressures are high enough to cause auto-i nition of a pilot oil charge at the end of the compression stroke, the compression ratios, for example, being from 14:1 to :1 and 6 is the manifold for this engine. The present invention is a gas metering apparatus for an engine of the above type where no air throttling is used when operating under high compression and regardless of whether a pilot oil ignition charge or some other form of ignition is used and is an apparatus by which the load on the engine is regulated entirely by the volume of gas per cycle.

In order to get satisfactory speed regulation for an engine of the type described, the time delay of the various valves and regulators must be reduced to the absolute minimum because the gas charge must be drawn in and compressed before nition can, take place causing a time delay, and

to a reduced pressure regulator ll] of known construction where its pressure is reduced from supply pressure in the mains to a pressure of six to seven inches of water and is-then conducted by a pipe II to a so-called zero pressure governor l2 and then to the inlet manifold 6 of the engine.

One form of governor or regulator I2 is shown in Fig. l as including a housing I4 having a partition 15 between its inlet and outlet provided with an opening l6 controlled by a valve I! which is anchored at its upper end to a flexible diaphragm l8 that divides the upper part of the housing into chambers l9 and 20, the valve and diaphragm being biased to a closed position by a spring 2| enclosed within the housing. The chamber 20 has an air inlet 22. The chamber I9 is in restricted communication through a passage 23 with the outlet side of the housing. The valve I1 is opened and closed through differences in pressure occurring in the chambers I9 and 20. A small diaphragm Ila separates the inlet of the housing from the chamber IS. The device above described while called a zero pressure governor or regulator does not reduce the gas pressure exactly to zero, but it can reduce it to a valve close to zero, for example, to a pressure about one-eighth inch of water.

According to the present invention, a throttling pressure valve in the form of a butterfly valve 24 is mounted in the piping II at the entrance end of the zero pressure regulator, and this valve is controlled by the governor of the engine. Also,

a gas metering valve 25 is mounted at the exit end of the zero pressure regulator and is governor controlled. As herein shown, the valve 25 is a rotary piston valve mounted in a housing 26 connected to the zero pressure governor or regulator l2 by a pipe 27 and connected with the engine by a pipe or tube 28 which projects into the inlet passage 29 for the manifold 6, so that the gas described operates by means of a vacuum at theengine end of the system and a predetermined pressure setup at the other end of the system from the gas supply line. As the load is applied to the engine, its speed is reduced and the vacuum also decreases which normally would result in less gas being furnished to the engine, but this action is offset in the present structure by increasing the pressure at the other end of the system by further opening the valve 24. By regulating the pressure at the entrance end of the zero regulator l2, the response of this regulator is greatly enhanced which is a decided advantage in securing close regulation by the governor. If the valve 24 is omitted and constant pressure imposed on the regulator l2, it over-compensates, allowing the pressure beyond said regulator to increase too high and become too low when it opens and closes giving rise to governor hunting, that is to say, either too much gas is admitted temporarily to the engine at which time it overspeeds, and not enough at the next instant, so that the speed drops below the required speed. With the inclusion of the valve 24 in the system operated by the governor conjointly with the metering valve 25, as said valve 25 is opened, the valve 24 is opened to increase the gas pressure at the entrance to the regulator with the result that hunting is prevented and the system responds to the demands of various loads with great rapidity.

A typical example of the systems operation is as follows: Assume stable operation with a given load, speed and flow characteristics through the system. The load demand is increased, the governor opens the metering valve 25 and the pressure regulator valve 24. At the same time the engine slows down and the vacuum or suction on the system is decreased. However, the suction of the 'zero regulator is increased becausethe main metering valve 25 has opened, thereby allowing more gas to flow through the zero regu la'tor. Due to decrease in engine vacuum with decrease in speed, the performance would be poorer were it not for the fact that the opening of the valve '24 by the governor has caused an increased gas pressure at the inlet side of the zero gas regulator which compensates for the decease in vacuum at the exit of the regulator. In short the deficiency of vacuum on the zero regu- 4 lator due to slowing down the engine is corrected by the opening of the pressure control valve 24, thereby increasing the gas pressure on the inlet side of the zero regulator.

I desire it to be understood that this invention is not to be limited to any particular form or arrangement of parts except "so far as such limitations are included in the claims.

What I claim as my invention is:

'1. In gas control apparatus for a high compression internal combustion engine of the type described, the combination with a source of gas under pressure, of a zero pressure regulator con- I nected with said sou-roe and with said engine, an

engine governor operated gas metering valve between "said regulator and said engine, and an engine governor operated pressure control means for said regulator adapted to compensate for reduction in vacuum at the outlet side of said regulator as the speed of the engine is reduced on an increase in load on the engine.

2. .In gas control apparatus for a high compression internal combustion engine of the type described, the combination with a source of gas under pressure, of a zero pressure regulator connected with said source and with said engine, an engine governor operated gas metering valve between said regulator and said engine, and an engine governor operatedpressure control valve at the entrance end of said regulator, said valves opening conjointly so that as the volume of gas admitted by said metering valve increases the gas pressure at the inlet to said regulator increases.

3. In gas control apparatus for a high compression engine of the type described, the combination with a source of gas under pressure, of a zero pressure regulator connected with said source and with said engine, 'a gas metering valve between said regulator and said engine, a pressure control valve at the entrance end of said regulator, means operatively connecting said valves togetherior simultaneously opening said valves, and an engine governor operated member for operating said valves.

4. In gas control apparatus for a high compression engine of the type described, the combination with a source of gas under pressure, of a zero pressure regulator connected with said source and with said engine, arotary ga'sm'etering valve between said regulator and said engine, a rotary pressure control "valve at the entrance end of said regulator, a link operatively connecting said valves together for their simultaneous movement to an open position, and an engine governor operated memberv for operating said valves.

JOHN H. HOLLOWAY.

No references cited.

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