US2860780A - Fuel injection valve - Google Patents

Description

Nov. 18, 1958 K. zn-:scHE E TAL 2,360,780

FUEL INJECTION VALVE Original Filed Dec. 6. 1954 Patented Nov. 18, 1958 United States Patent Otitice 4 FUEL INJECTION VALVE Kurt YZiesche, Koln-Holweide, and Bernhard Sonntag,

Koln-Buchforst, Germany, assignors to Klockner-Humboldt-Deutz Aktiengesellschaft, Koln, Germany Original application December 6, 1954, Serial No. 473,397, now Patent No. 2,812,979, dated November 12, 1957. Divided and this application May 22, 1957, Serial No. 660,913 j Claims priority, application Germany December 12, 1953 Claims. (Cl. 299-107.6)

The present invention relates to fuel injection valves and, more particularly, is directed to a fuel injection valve having a closing body `suspended in a pendulum-like manner for use in connection with internal combustion engines. This application is a divisional application of our co-pending application Ser. No. 473,397 tiled December 6, 195,4, now Patent No. 2,812,979.

It is an object of this invention to-provide an improved fuel injection valve of the above mentioned type which will assure that the fuel will equally well be atomized when starting the internal combustion engine and driving the same at low speed as well as at high speed.

It is still another object of this invention to provide a fuel injection valve which will impart a riing movement upon.the fuel after the latter has passed the closing body of the valve to thereby produce a widely atomized fuel jet. j

Still another object of this invention consists in providing a fuel injection valve of the type set forth in the preceding paragraphs, in which the stroke of the closing body is limited without interrupting the flow of fuel to the injection opening.

` Still another object of this invention consists in the provision of a fuel injection valve of the above mentioned type which has improved self-centering characteristics with regard to the openings through which the fuel passes in atomize'd condition.

These and other objects and advantages of the invention will appear more clearly from the following speciiication in connection with the accompanying drawings, in which:

Fig. 1 illustrates a longitudinal section through the valve casing with a valve according to the present invention, said valve being provided withcone-shaped `strokelimiting means.

Fig. 2 is a longitudinalsection similar to that of Fig. `1 of a valve according to the invention having a strokelimiting surface substantially perpendicular to the longitudinal axis of the valve. 1

Fig. 3 is a section taken along the line III-III of Fig. 2.

General arrangement The primary feature of the fuel injection valve according to the present invention consists in that that side of the suspended closing body which is adjacent the co-mbustion chamber of the cylinder or cylinder head controlled thereby, is provided with a stud-like extension which widens in a cone-shaped manner towards said com-4 bustion chamber, and is arranged in a bore having a diameter slightly larger than the largest diameter of said extension and directly leading into said combustion chamber. The arrangement is such that during the injection operation, at least at larger opening strokes of said valve, the portion of largest diameter of said extension moves out of said bore.

Since with fuel injection valves having a closing member will in its opening position center itself within the fuel passing around said closing member, provided the p Oint of suspension in closing position of said elo-sing member is located vertically over the center of the area confined by the sealing circle along which the closing member rests on the valve seat, also the stud carried according to the invention by the closing member will center itself within the narrow bore surrounding said stud. When the closing body lcarries out short strokes only, the stud will release only small annular spaces, whereas with increasing strokes, larger annular passages will be released dueA to the `cone-shaped design of the said stud. This means that during the startingo-peration of the internal combustion engine and at low speed thereof, the fuel will during the injection operation be atomized in as good condition as will be the case at high speeds of the said engine.

According to a further development of the fuel injection valve according to the invention, the `closing body of the valve may be so designed that it will taper toward the combustion chamber in a cone-like manner while-the thus formed cone-shaped surface is provided with riding grooves in a manner known per se. In this way a riing movement will be imparted upon the fuel While it passes through said grooves as a result of which a wide atomized fuel jet will pass through the annular clearance released by the said stud. When the riflng grooves on the closing body extend in radial direction a pointed slender jet will be obtained.

According to a still further development of the present invention, the stroke of the closing body may be limited by a cone-shaped surface of the casing which extends parallel to the above-mentioned cone-shaped grooved surface of the closing body.

In order to hinder the centering of the valve as little as possible, it is advantageous to limit the stroke of the closing body by means of an annular surface of the casing, which surface is substantially perpendicular to the longitudinal axis of the valve. The shape of the fuel jet can then furthermore be influenced by providing the circumference of the closing body with straight or riing grooves which lead into the annular surface of the closing body, which ysurface cooperates with thel stroke-limiting surface in the casing. The said grooves are at their mouth of such a depth that the fuel ow to the injection opening will not be interrupted when the closing body engages the valve seat. u t

Preferably the closing body is so designed 4that it tapers in a cone-shaped manner from the cross section engaged by said grooves towards the combustion'chamber, and is preferably surrounded in spaced relationshipf=within the range of said cone-shaped surface bya parallel casing surface. 't l f As stated above, with the new valve `referred to in the preceding paragraphs, the closing body aswell as the stud carried thereby center themselves in the".y two bores pertaining thereto. However, the valveca'singwhich comprises the valve seat and the nozzle plate comprising the cylindrical bore surro-unding the stud have to be manufactured as separate parts and have to be centered with regard to each other. If the nozzle plate is not precisely centered with regard to the valve casing, it is certain inaccuracy in the centering between valve casing and nozzle plate cannot be avoided during the normal manufacturing process. Such inaccuracy may, if desired, be prevented by a careful and therefore time consuming and expensive special machining operation. However, according to the present invention, the above mentioned drawback can be avoided when care is taken that the nozzle needle can swing freely in a pendulum fashion in-its spring collar which is arranged at that side of the needle which is remote from the combustion chamber.

Structural arrangement Referring now to the drawings in detail and Fig. 1

thereof in particular, the fuel injection valve shown therein comprises a valve member generally designated 1a with a closing body 1, a stem 2 and a stem head or shoulder 2a. As will be seen from Fig. 1, the `closing body 1 is suspended in a pendulum-like manner on a spring collar or cap 3 byl means of stem 2, stem head or shoulder 2a, and rolling means 3a. The rolling means 3a preferably consistsy of a spring ring of substantially circular cross `section and supports the head 2a while being movable in the cone-shaped portion 3b of the spring cap 3. The cone-shaped portion 3b leads into a cylindrical bore 3c which has a considerably greater inner diameter than the outer diameter of the stem 2 so that the stem 2 can freely swing within the bore 3c. The spring cap 3 is supported by a spring 5 arranged in a bore 4a of the valvecasing 4. This spring is so designed that it normally holds the yclosing body 1 in its closing position shown in Fig. 1, in which the hernispherical surface portion 1b of the body 1 engages the valve seat 4b which latter forms a part. of the coneshaped or frustrated cone-shaped chamber 21. The chamber 21 merges with a similar but inversely arranged conical chamber 22.

The closing body 1 carries an extension 6 in form of a stud which has a portion 6a widening in a coneshaped manner toward the combustion chamber. The cone-shaped portion 6a-is surrounded by a cylindrical bore 7, the diameter of which is slightly greater than the maximum diameter of the cone-shaped portion 6a. The portion 6a is so arranged within the bore 7 that it will leave the latter at least at larger strokes of the closing body 1. Due to its cone-shaped design, the portion 6a will, depending upon the valve stroke, leave a more or less greater clearance between the inner surface of the bore 7 and the extension 6. More specifically, with short strokes of the valve, small clearances, and larger strokes, larger clearances between the extension 6 and the inner surface of the bore 7 will be obtained. In this Way it is assured that also during the starting operation of the internal combustion engine and at low speed thereof, the fuel will enter the combustion chamber in a well atomized condition. With the valve shown in Fig. l, the fuel enters the combustion chamber in a wide atomized condition because the closing body 1 tapers in a cone-shaped manner toward the extension 6, and the cone-shaped surface 1c of the closing body 1 is provided with spiral or rifiing grooves 8. The coneshaped surface 9 of the plate 9a limits the stroke of the injection valve.

Referring now to the modification shown in Fig. 2, the valve illustrated therein has its closing body 11 provided with a collar which at the end of the opening movement of the valve abuts an annular surface or shoulder 12 in the valve casing 13, said surface 12 being substantially perpendicular to the longitudinal axis of the valve stem 20. The circumference of the closing body is provided with radial grooves 14 which are so deep that when the closing body rests upon the surface 12,

the fuel after passing around the semi-spherical closingA body can still enter a cone-shaped clearance 15 confined by a cone-shaped extension 16 and the adjacent portion of the casing 13. This clearance finally merges with the guiding bore 17 for the stud 18. 'I'he fact that the abutment surface 12 is perpendicular to the longitudinal axis of the valve stem has the advantage that when the valve abuts or rests on the surface 12, it will not be pressed toward the' side, a danger which when employing cone-shaped valve l'seats exists due to certain minor inaccuracies which cannot be avoided during the production of the valve. j i

It is, of course, to be understood thatv the present invention is, by no meansflimited to the particular construction shown in the drawings, but also comprises any modifications within the scope of the appendedA claims.

What we claim is:

1. In combination in a fuel injection valve: a casing having fuel passage means therethrough including a substantially vertical first bore and a frusto-conical shaped chamber arranged below said bore insubstantially axial alignment therewith and provided with a frusto-conical valve seat for conveying fuel therethrough to a combustion chamber, said passage means also including an injection bore communicating with said frustoconical vshaped chamber and in substantially axial alignment therewith while being arranged belowsaid valve seat, a valve member including a stem extending into said first bore and having its upper end provided with a shoulder and having its lower end provided with a closing body located within said frusta-conical shaped chamber, said closing body having a hemispherical surface for engagement with said valve seat, supportingrnieans adjacent said shoulder, spring means resting in said first bore while having its upper end in engagement with said supporting means so as continuously to urge Vthe same upwardly, said supporting means comprising a spring collar having an axial bore therethrough comprising a lower cylindrical portion of a diameter considerably greater than the diameter of the adjacent stem portion of said valve member and havingan adjacent upper frusto-conical portion tapering toward said cylindrical portion and being spaced from said shoulder, rolling means arranged in said frustoconical portion and in engagement with said shoulder to thereby suspend said valve member so as to allow tilting movement thereof in any direction, and an extension member rigidly connected to the bottom portion of said closing body, said extension member having a frusto-conical control surface section widening in a direction away from said stem and extending into said injection bore, the largest diameter of said control surface section within said injection bore when said valve member engages said valve seat being slightly less than the diameter of said injection bore so as to leave a clearance therebetween for the fuel to be injected and to allow tilting movement of said extension member within said injection bore when said valve member tilts about said supporting means, said frusto-conical control surface section being operable gradually to increase the space between the latter and said injection bore in response to the downward movement of said valve member against the thrust of said spring means.

2. A fuel injection valve according to claim lI in which said rolling means consists of a spring ring of substantially circular cross section.

3. In combination in a fuel injection valve: a casing having fuel passage means therethrough including a substantially vertical first bore and a frusto-conical shaped chamber arranged below said bore in substantially axial alignment therewith and provided with a frusto-conical valve seat for conveying fuel therethrough to a combustion chamber, said passage means also including an injection bore communicating with said truste-conical shaped chamber and in substantially axial alignment therewith while being arranged below said valve seat, a valve member including a stem extending into said first bore and having its upper end provided with a shoulder and having its lower end provided with a closing body located within said frusto-eonicalshaped chamber, said closing body having a rst surface section of substantially semispherical shape for sealing engagement with said valve seat and having a second surface section of frusto-conical shape adjacent to said first surface section and tapering in a direction away from the latter, said second surface section being provided with riing grooves, supporting means adjacent said shoulder, spring means resting in said lrst bore while having its upper end in engagement with said supporting means so as continuously to urge th: same upwardly, said supporting means comprising a spring collar having an axial bore therethrough comprising a lower cylindrical portion of a diameter considerably greater than the diameter of the adjacent stem portion of 'said valve member and having an adjacent upper frusto-conical portion tapering toward said cylindrical portion and being spaced from said shoulder, rolling means arranged in said frusto-conical portion and in engagement with said shoulder to thereby suspend said valve member so as to allow tilting movement thereof in any direction, and an extension member rigidly connected to the bottom portion of said closing body, said extension member having a frustoconical control surface section widening in a direction away from said stem and extending into said injection bore, the largest diam eter of said control surface section within said injection bore when said valve member engages said valve seat being slightly less than the diameter of said injection bore so as to leave a clearance therebetween for the fuel to be injected and to allow tilting movement of said extension member within said injection bore when said valve member tilts about said supporting means, said frusto-conical control surface section being operable gradually to increase the space between the latter and said injection bore in response to the downward movement of said valve member against the thrust of said spring means.

4. In combination in a fuel injection valve: a casing having fuel passage means therethrough including a substantially vertical first bore and a frusto-conical shaped chamber arranged below said bore in substantially axial alignment therewith and provided with a truste-conical valve seat for conveying fuel therethrough to a combustion chamber, said passage means also including an injection bore communicating with said frusto-conical shaped chamber and in substantially axial alignment -therewith while being arranged below said valve seat, a

valve member including a stem extending into said first bore and having its upper end provided with a shoulder and having its lower end provided with a closing body located within said frusto-conical shaped chamber, said closing body having a hemispherical surface for engagement with said valve seat and being provided with a collar, said frusto-conical shaped chamber being pro vided with a shoulder at that end thereof which is remote from said rst bore for engagement with said collal to thereby limit the maximum downward stroke of said valve member, supporting means arranged adjacent said first mentioned shoulder, spring means resting in said rst bore while having its upper end in engagement with said supporting means so as continuously to urge the same upwardly, said suporting means comprising a spring collar having an axial bore therethrough comprising a lower cylindrical portion of a diameter considerably greater than the diameter of the adjacent stem portion of said valve member and having an adjacent upper frusto-conical portion tapering toward said cylindrical portion and being spaced from said rst mentioned shoulder, rolling means arranged in said frusto-conical portion and in engagement with said tirst mentioned shoulder to thereby suspend said valve member so as to allow tilting movement thereof in any direction, and an extension member rigidly connected to the bottom portion of said closing body, said extension member having a frustoconical control surface section widening in a direction away from said stem and extending into said injection bore, the largest diameter of said control surface section within said injection bore when said valve member engages said valve seat being slightly less than the diameter of said injection bore so as to leave a clearance there between for the fuel to be injected and to allow tilting movement of said extension member within said injection bore when said valve member tilts about said supporting means, said frusto-conical control surface section being operable gradually to increase the space between the latter and said injection bore in response to the downward movement of said valve member against the thrust of said spring means.

5. A fuel injection valve according to claim 4, in which the bottom portion of said collar is provided with radial grooves.

References Cited in the tile of this patent UNITED STATES PATENTS 2,172,556 Edwards Sept. 12, 1939 2,407,915 Ball Sept. 17, 1946 2,410,946 Johnson Nov. 12, 1946 2,719,055 Lauck Sept. 27, 1955 2,812,979 Ziesche et al. Nov. l2, 1957 FOREIGN PATENTS 866,597 France May 26, 1941 726,727 Germany s- Oct. 19, 1942

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