US2863437A

US2863437A - Fuel injection devices for multicylinder engines

Info

Publication number: US2863437A
Application number: US635219A
Authority: US
Inventors: Bessiere Pierre Etienne
Original assignee: Individual
Current assignee: Individual
Priority date: 1956-01-31
Filing date: 1957-01-22
Publication date: 1958-12-09
Anticipated expiration: 1975-12-09

Description

Dec. 9, 1958 P. E. BESSIERE 2,853,437

4FUEIE INJECTION DEVICES FOR MULTICYLINDER ENGINES Filed Jan. 22, 1957 FUEL IJECTIN DEVICES FR MULTI- CYLINDER ENGNES Pierre Etienne Bessiere, Paris, France Appiication .lanuary 22, 1957, Serial No. 635,219

Claims priority, application France January 31, 1956 Claims. (Cl. 12S-139) The present invention relates to multi-cylinder engine fuel injection devices in which a single .fuel pump cylinder is connected, thro-ugh a plurality of respective individual conduits, with a plurality of injectors each of which includes a spindle arranged to open the injection orice thereof under the effect o-f the pressure of the fuel to be injected acting thereon against the action of a closing spring.

The object of the present invention is to provide a fuel injection device of this kind which is better adapted to meet the requirements of practice than those known at the present time.

For this purpose, in the device according to my invention each of the above mentioned conduits is controlled by a valve which, during the periods of time for which no injection is to take place through the corresponding injector, is held in closing position by an electrowmagnet and which is opened by the pressure of the fuel delivered from the pump when the electro-magnet is brought out of action by control means acting upon the electric feed circuit thereof.

4Preferred embodiments of my invention will be hereinafter described with reference to the accompanying drawings, given merely by way of example and in which:

Fig. l is an elevational view, partly in section, of an embodiment of a fuel injection device according to my invention, for use with a four cylinder engine.

Figs. 2 and 3 illustrate electro-mechanical means for contro-lling the electro-magnetic locking means of this device.

The device according to my invention may be used with advantage in connection with an internal combustion engine including at least two cylinders the cycles of which have a phase difference between them, said cylinders being fed with fuel from a single fuel feed pump cylinder. My device is for use with diesel engines, spark plug ignition engines, four-stroke engines and two-stroke engines.

On the appended drawings, my invention is supposed to be applied to a four cylinder four-stroke diesel engine fed from a single cylinder injection pump.

This pump includes a frame 1 in which is journalled the pump driving shaft 2. A cam 3 fixed on said shaft acts through a push-piece 4 upon the pump piston S, which reciprocates in the pump cylinder 6. This cylinder is provided withrfuel inlet ports 7 through which fuel enters cylinder 6 when piston 5 is in its lowermost position, as shown by Fig. 1. Furthermore pump cylinder 6 is provided with a discharge valve 8 past which fuel is forced into .delivery conduit 9 by piston 5 after said piston, during its upward movement, has closed inlet po-rts 7. Delivery conduit 9 opens into a chamber 10 from which branch olf four' individual conduits 11a, 11b, 11C, 11d, each of which leads to an injector 12 mounted on one of the four cylinders of the engine.

Since the engine that is considered is a `four-stroke engine, fuel injections into the engine cylinders follow ICC one another at intervals corresponding to a rotation of 180 of the engine shaft. -If the shaft 2 of the pump 1 is driven at a speed equal to one half of that of the engine shaft, the successive positions of shaft 2 for which the pump is delivering fuel are at to one another. Therefore cam 3 includes four sectors so as to achieve four delivery strokes of pump cylinder 5 on every revolution of shaft 2.

`Of course, on every fuel delivery by pump 1, only one of the four injectors 12 connected with this pump is to Work, the three other injectors being then nonoperative.

Several distributing devices for this purpose have already been suggested. But, as a rule, these known devices are complicated and expensive and their operation is not fully reliable.

These drawbacks are eliminated with the device according to my invention. In this device, the communication between the conduit 13 which, in each injector 12, leads to the injector spindle (not visible on the drawing) and the corresponding individual feed conduit 11a (or 11b, or 11C, or 11d) is controlled `by a valve 14 held in closing position by electro-magnetic locking means as long as the injector 12 `is not to operate. Valve 1@ is mounted in such manner that the fuel pressure in the feed conduit (for instance 11a) tends to open it so that fuel can pass freely into `conduit 13 as soon as the electromagnetic locking means .are brought out of action.

Valve 14 and its electro-magnetic locking means may Vbe mounted in a lateral projection 15, made of a magnetic material, of the body of injector 12.

Advantageously, as shown by the drawing, the electro-magnetic locking means include a coil 16 housed in a circular groove'provided in part 15 so that the combination of said coil 16 with the magnetic walls which surround it constitutes a circular electro-magnet running around a cylindrical recess in which is slidably mounted a plunger 14. A disc-shaped armature 17, made of a magnetic material is rigid with said plunger 14. Advantageously, the disc constituted by armature 17 is provided with holes 17a extending throughout it so as to reduce its aerodynamic resistance to movement. A return spring 18 urges said armature 17 toward coil 16 during the suction stroke of the fuel pump piston.

Plunger 14, slidable in cylindrical recess 19, which is in communication with conduit 11a, controls the opening of a passage branching olf from said recess 19 and forming the end of conduit 13 which leads to the injector spindle. This arrangement makes it possible to avoid any air gap in the electromagnetic locking means without risk of the fuel-tightness of the valve being impaired by normal Wear and tear.

As long as a current of sufficient intensity is flowing through coil 16, the fuel pressure transmitted through conduit 11a which is acting upon the end of plunger 14 is insufficient to overcome the locking action exerted by electro-magnet 16 upon armature 17, Plunger 14 cuts off the communication between recess 19 and conduit 13. On the contrary, When the current flowing; through coil 16 is reduced or cut off, the fuel under pressure in cylinder 19 lifts plunger 14 and flows to the injector spindle which is opened by the fuel pressure, so that fuel is injected into the engine cylinder by the injector.

An electric control member, for instance in the form of a rotary switch 20 (Fig. 2) controls the operation of the electromagnetic locking means, each of said means in succession being temporarily brought out of action for the period during which injection is to take place into the corresponding engine cylinder.

This control member may cut off, vduring a suitable time period, the energizing current which `is normally flowing through the coilsof the locking :means (these coils being designated on Fig. 2 by the reference numerals 16a, 1Gb, 16e, 16d);

In the embodiment illustrated by Fig. 2, arotating switch controls the operation of valves 14. This switch comprises a rotating cylinder 20 of a conductor material carrying four rings on which are slidably applied brushes 41a, 41h, 41e, 41d inserted in the respective individual circuits of

coils

16a, 16h, 16C and 16d. These circuits are connected in shunt fashion with one of the terminals of a current source 22 the other terminal of which is connected through a brush 23 with the body 20 of the switch. Each of the above mentioned rings includes two portions, respectively 21a and 21a, 2lb and 21'11, 21C and 21c, 21d and 21d. Portions 21a, 21'b, 21c and Zlfd are off-set with respect to one another on the rotary switch body 20 so as to obtain the desired time oifsetting between their actions on

therrespective coils

16a, 16b, 16e and 16d. Switch body 2t) is for instance fixed on shaft 2 by key 36.

If, as above supposed,

coils

16a, 16h, 16's and 16d f are arranged so that, when a sufficient current flows therethrough, they keep the respective valves locked in closed position, sections 21a, 2lb, 21C and 21d are made of a conductor material so as to close the circuits of said coils. As for sections 21a, 21'b, 21'c and 21d, they are insulating or little conductive (then forming resistances) so as to cut ott or to lower the current flowing through said coils. It may also be supposed that armatures 17 are normally magnetized to be yieldingly applied on piece 15 and that

windings

16a, 16h, 16e and 16d are demagnetizing windings. In this case, portions 21a, 2lb, 21e and 21d of the rings are made of insulating or little Conductive material and portions 21'a, 21b, 21c and 21d of conductive material.

The operation of the above described fuel injection device is as follows if it is supposed that

coils

16a, 16h, 16e, 16d are magnetizing windings, that portions 21a, 2lb, 21C, 21d are conductors and that portions 21'a, 21b, 21c, 21d are insulators:

During one complete revolution of shaft 2, which corresponds to two revolutions of the engine shaft, four successive delivery strokes of injection pump 1-8 take place. During each of these delivery strokes the valve 14 of one of the four injectors 12 successively is released so that, every time, injection takes place in a different engine cylinder. As soon as the fuel pressure on the end of plunger 14 ceases to exist (which is due either to the end of the delivery stroke or to the opening of an outlet port in the delivery circuit) return spring 18 closes the corresponding valve 14. At the same time the armature 17 of the electromagnetic locking means is returned on to the corresponding electro-magnet 16, where it remains applied due to the fact that the energizing current is once more flowing through the correspondin coil. t

Adjustment of the amount of fuel fed to every engine cylinder on every operation of the injector thereof may be obtained through any suitable means, for instance by the use of a valve controlling a leak or bleed orifice provided in the fuel feed pipe leading to the injector.

According to a particularly advantageous embodiment illustrated by the drawings, such a valve, shown at 24 is provided in the delivery circuit of the pump upstream of the point where conduit 8 branches off to form individual conduits 11a, 11b, 11C, 11d leading to the respective injectors. In the embodiment illustrated by the drawing, this valve is therefore mounted in the wall of chamber 10.

Valve 24 is kept applied upon its seat by an electromagnet including a winding 25 housed in a recess of a support of magnetic material 26, so as to constitute two concentric

annular terminals

27 and 28 which cooperate with an armature 29 urged in the downward direction both by the pulling action of electro-magnet' 25-26 and by the resilient action of a return spring 30.

4 As long as an energizing current of a given intensity is flowing through winding 25, valve 24 closes the leak orifice 31 provided in the wall of chamber 10 (Fig. l). As soort as the current flowing through winding 25 is reduced or cut off, valve 24 opens and causes fuel to ow out through said orifice 31 and a second orifice 32 located downstream of valve 24, which immediatelyI stops injection due to the sudden drop of pressure through

conduits

9, 10, 11, so that valve 14 can close.

The fuel flowing out through orifice 32 is returned to the fuel tank or to the suction conduit of pump 1-8 through a passage which is not shown.

The energizing current of winding 25 may be controlled through any suitable means. However, advantageously, I make use of a rotating switch (Fig. 3) constituted by a stationary brush 33 in contact with a cylin der rotated by the engine. This cylinder has its surface 34 constituted by a conductive material capable of cooperating with brush 33 so as to close the circuit of winding 25. In this conducting surface 34 are provided as many insulating strips 3S as there are separate fuel injections for one revolution of the rotating cylinder. In the case shown by the drawing, where said cylinder is driven by shaft 2, which also drives cam 3, the number of these strips is four. Each strip 35 has parallel edges oblique with respect to the generatrices of the cylinder. These insulating strips are disposed, with respect to the insulating areas 21a, 2lb, 21C and 21d of switch 2t) (Fig. 2) in such manner that current is cut off in winding 25 generally after it is cut off in each of the coils 16a, 1Gb, 16C and 16d of the injectors and after the beginning of the delivery stroke of the pump. T he exact time at which the energizing current is cut off in winding 25,v

and consequently the amount of fuel injected by each of the injectors may be modified by relative longitudinal displacement of the cylinder and of brush 3 with respect to each other, for instance by sliding displacement of the cylinder on shaft 2 with respect to brush 33 (as shown in dotted lines on Fig. 3). The cylinder is driven by shaft 2 by means of feather key 37. It can be made to slide along shaft 2 by means of forked lever 38.

In a general manner, while I have, in the above description, disclosed what I deem to be practical and ecient embodiments of my invention, it should be well understood that I do not wish to be limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the preent invention as comprehended within the scope of the accompanying claims.

What I claim is:

l. For use in connection with an internal combustion engine having at least two cylinders the working cycles of which have a phase dierence between them, a fuel injection device which comprises, in combination, a recip-y rocating action fuel feed pump including a single4 cylinder, an injector mounted on each of said engine cylinders respectively, individual conduits extending each between the output of said pump and one of said injectors respectively, a valve in each of said conduits upstream of the injector located at the end of said conduit, said valve being arranged to cut oif, when it is closed, the ow of fuel through said last mentioned conduit, said valve being arranged to be urged toward opening position by the pressure of fuel in said last mentioned conduit upstream of said valve, an electro-magnet mounted to cooperate with each of said valves to hold it normally in closed position, electric means for normally holding said electromagnets operative for said purpose and means operatively connected with said pump for making each of said electro-magnets in its turn inoperative for a period of time during one delivery stroke of said pump.

2. A device according to claim l in which each of said valves includes a body provided with a cylindrical recess communicating at one end with that of said individual conduits which is controlled by said valve and a plunger slidable in said recess and rigid with the armature of the corresponding electro-magnet, the fuel passage of that of said injectors which is fed through said last mentioned conduit opening into the cylindrical Wall of said recess, said passage being closed by said plunger when said electro-magnet is energized.

3. A device according to claim 2 in which said valve body is integral with the body of the corresponding injector.

4. A device according to claim l further including a valve for the outlet of fuel from the output of said pump to stop fuel injection, said last mentioned valve being located at the output of said pump, upstream of the point Where said individual conduits branch off therefrom, and

electro-magnetic means for controlling the opening of said outlet valve.

5. A device according to claim 4 including a chamber in direct communication with the output of said pump, said individual conduits branching oil` from said chamber, said chamber being provided with an outlet orifice and said outlet valve being mounted in the wall of said chamber to control said orifice.

References Cited in the file of this patent UNITED STATES PATENTS 2,356,134 voit Aug. 22, 1944