US1613000A - Internal-combustion-engine fuel-injection device - Google Patents

Description

Jan. 4 1927.

W. P. WIDDOWSON INTERNAL COMBUSTION ENGINE FUEL INJECTION DEVICE Filed August 8, 192.

Patented Jan. 4, 1927.

UNITED STATES WALTER PERCY WIDDOWSO'N, OF LONDON, ENGLAND.

INTEBlNAL CloMBUsTloN-ENGINE FUEL-INJECTION DEVICE.

Application filed August 8, 1921, Serial No.

490,639, and in Great Britain May 5, 1920,

(GRANTED UNDER THE PROVISIONS OF THE ACT OF MARCH '3, 1921, 41- STAT. L, 1313.)

This invention relates to internal combustion engines of the type in-which liquid fuel is injected into the combustion chamber,

at or near the end of the compression stroke by means of a. fuel injection pump, and in which a fuel injection pump pumps the liquid fuelto a fuel injection valve. which is opened by the pressure of the liquid fuel,

or other suitable means, the amount of liquid fuel injected into the combustion chamber being regulated by a release or spill valve which is opened by control or governing mechanism at a variable or fixed point in the stroke of the fuel pump plunger, thereby spilling the fuel for the remainder of the stroke of the plunger.

Heretofore it has been proposed in a forced liquid fuel supplv to internal combustion engines, to provide two by-pass valves designed to be operated at different periods of the forcing stroke of the oil pump, the two valves being in some cases substituted bya single duplex valve.

' The present invention comprises an internal combustion engine liquid fuel injection device having a spring-loaded injection valve and a single-spill valve or by-pass in a passage communicating with the fuel reservolr. wherein the bv-pass is not brought into use until after sufficient fuel has been forced through the injection valve. and a' continuous pressure circuit established between the-pump and the spill valve.

The release or spill valve may be placed on the body of the fuel injection valve. or in any other convenient position. and is placed in communication with the fuel injection valve pump through the injection valve. Bv having the spill valve arranged to let the oil furnished by the remainder of the piston stroke to pass through the injection valve chamber, this chamberis continuously washed out and also slightly cooled The system may be provided with a liquid fuel strainer arranged between the fuel pump and the injection valve.

. An embodiment of the invention is illustrated by the accompanying drawing wherein a is the combustion chamber of an internal combustion engine. I) the fuel injection valve, 1 the body thereof, 0 the spill valve, d the liquid fuel plunger, and 18 the cam. 1

The fuel injection valve body 1 is screwed into an opening in the engine casting leading to the combustion chamber, and is provided with an inlet passage 2, and an outlet passage 3, leading respectively to and from a pressure chamber 4 wherein fluid pressure of the liq'uid fuel is exerted upon ashoulder 5 on the spindle of the valve 7). This spindle is loadedby aspring 6 in the known manner so thatthe valve 7) will not be raised from its seat until the pressure in the delivered liquid fuel rises above the amount necessary to overcome load of thespring 6.

The inlet passage 2, of the valve casing is connected by a delivery pipe 7 to the delivery valve 8 of the liquid fuel pump. and the outlet passage 3 is connected bv a return pipe 9 to the upper side of a spill valve 0. This spill valve is held on its seat in thevalve body 12 by aspring 10, and has a spindle extending through a stuffing box 11. This valve spindle is arranged in line or coaxial with avalve operating rod 13 pivoted to a lever 14 secured to a shaft 15 onwhich is secured the pump operatingrocking lever 16. One end of this lever is provided with a roller 17, adapted to bear on acam 18 secured on the cam shaft 19 of the engine; the other end of thelever 16 bears in a slot in the pump plunger (1 in such a manner that when the roller 17 is raised by thecam 18, the other end of thelever 16 will force the plunger d into its barrel against the action of areturn spring 20.Strainer 26 is set under plunger d to act on the oil before it passes to valve 8.

The underside of nected by apipe 21 to the underside of thesuction valve 22 of the fuel pump. Thepiston 26 supporting thespring 10 on the spindle of the valve 0 is perforated at 27 to admit fluid under pressure to both sides of the piston. Thesuction valve 22 is placed in communication with the liquid fuel reservoir by asuction pipe 25.

A control rpd 23 is adapted to move at right angles tot-he valve spindle 11 between the end thereof and the end of the valve operatmg ,rod 13, and has an-inclined member 2 1 attached thereto adapted to engage, on one side the end of the spindle 11 and on the other, the'end of thevalve rod 13, so that when theinclined member 24 moves to the right it will reduce the distance between it and the ends of the valve spindie -11 and the spill valve 0 is con- 7valve rod 13, and so. cause a variation in the time of engagement between the said spindle and rod according to the extent of longitudinal movement of the governing or control rod 23.

ltt will be readily understood from the above description that the fuelpump 0perates in the well known manner, so that on the down or delivery stroke of the plungerd upon the rotation of the cam shaft 19, liquid fuel is compressed in the pipes and passages, until the pressuretherein rises to that at which the injection valve 1) is designed to open. After the opening of thevalve 6 the continued movement of thecam 18 causes thevalve rod 13 to open the release or spill valve 0, and on the opening of this valve the fuel pressure is released thereby allowing the injection valve to close automatically, and for the remainder of the fuel pump stroke the fuel is discharged through the I passages 2 and 3 in the injection valve body and the pipe 9 and spill valve 0 andpipe 21 to thesuction pipe 25 of the fuel pump.

What I claim and desire to secure by Letters Patent is In an internal combustion engine liquid fuel injection device, in combination, an injection valve structure comprisin a valve chamber having an injection outlet and a valve controlling said outlet, said valve having a surface exposed to the pressure in said chamber to be opened thereby, a spring resisting opening movement of said valve, 21 fuel pump connected with said chamber to supply fuel thereto under pressure, a spill valve connected with said'injection valve chamber, operating means for said pump, and means operating in synchronism with said pump operating means -for opening said spill valve during the end of each pressure stroke of said pump whereby said valve chamber will be relieved of pressure and said injection valve allowed to close, said spill valve at other times being closed.

In witness whereof I aflix'my signature.

WALTER PERCY WIDDOWSON.

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