JPS6153550B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a reciprocating piston type fuel injection valve for an internal combustion engine, which has a valve body protruding into a combustion chamber of a cylinder, and has a valve needle therein that cooperates with a valve seat. and a plurality of nozzle holes distributed around the valve needle, and the fuel passing through the nozzle holes rhythmically lifts the valve needle from the valve seat and is ejected into the combustion chamber. Regarding fuel injection valves.

Fuel injection valves are generally designed to produce a good fuel jet at full engine load, thus ensuring good smokeless combustion within the combustion chamber of the cylinder. When carrying out this design, the nozzle holes with a relatively large diameter are arranged in one row, or the nozzle holes are arranged in two rows, in the latter case the diameter of the holes being selected to be correspondingly small. It is already known that when internal combustion engines are operated under partial load, optimal conditions for jet formation and combustion are not achieved.

An object of the present invention is to provide a fuel injection valve of the above-mentioned type, in which a jet flow is suitably formed even under partial load, and therefore fuel combustion can be suitably maintained. .

According to the invention, the purpose is to provide the fuel injection valve with:
A device separate from the valve needle is provided, by means of which the area of at least some of said nozzle holes is partially opened during partial loads of the engine, and the total area of all nozzle holes is opened during full loads. This is accomplished by doing what you want.

According to such a device, when the engine is under partial load, the opening area of at least some of the nozzle holes can be reduced, making it easier to form a jet flow and maintaining the combustion state of the fuel in a suitable state. be able to. At full engine load, the device operates to open the entire cross section of all nozzle holes.

Next, embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 1, the fuel injection valve has a valve body 1 consisting of an upper part 2 and a nozzle member 3, which parts are interconnected by a cap nut 4. The valve body 1 rests by means of a flange 5 on a cylinder head 6, which closes off a combustion chamber 8 of a cylinder of a reciprocating piston internal combustion engine from above. The valve body passes through the cylinder head 6 and into a plurality of nozzle holes 7 of the nozzle member 3.
An end portion having a diameter protrudes into the combustion chamber 8.

For supplying fuel, the valve body 1 has a conduit 10 which first extends radially through the flange 5 and then through the section 2, nozzle member 3 and substantially longitudinally of the valve body. The nozzle member 3 extends in the direction to reach the lower end area of the nozzle member 3. Said conduit 10
terminates in an annular chamber 11. An axially movable valve needle 12 is provided in the center of the valve body 1, the upper end of which is supported by a compression spring 14 via a spring washer 13. A spherical seat surface 15 is provided at the lower end of the valve needle 12, and the seat surface extends around the valve needle 12 and is slidable in the axial direction of the valve needle 12 to change the opening degree of the nozzle hole 7. Member 16
Co-operating with a corresponding spherical seat within the bush, said bush surrounds the needle 12 and the nozzle member 3 of the valve body 1.
The shaft is supported for axial movement within the shaft.

The valve member 16 has a plurality of holes 17 in the area of the annular chamber 11.
, the hole carries fuel from the annular chamber 11 to an annular chamber 19 between the valve member 16 and the section 18 of the valve needle 12.
to be transferred to This annular chamber 19 defines a seat surface 15 at its lower end. Valve member 16 has hole 17
It has a spherical seat surface 20 below the valve body 1.
co-operates with a corresponding seating surface provided on the nozzle member 3. The valve member 16 has an outer cylindrical shoulder 21 below the seating surfaces 20, 15, the lower end of which forms a front edge 22 which cooperates with the nozzle bore 7 and which The opening area of the nozzle hole 7 is changed as shown in FIGS. 2a and 2b in relation to the height of the nozzle.

The nozzle member 16 , which is prevented from twisting relative to the nozzle member 3 , rests at its upper end against a piston-like intermediate member 25 , which slides in a cylindrical bore in the part 2 of the valve body 1 . and its upper end rests against another bush 26. The piston-shaped intermediate member 25 and the another bush 2
6 surrounds the valve needle 12. The button 2
6 itself is supported via a spring washer 27 against a compression spring 28 , and the upper end of the spring 28 rests against a spring washer 29 , which presses against the spring washer 13 of the compression spring 14 within the valve body 1 . located below. The spring washer 29 is attached to the valve body 1 by means of a spacing sleeve 30 and a hollow screw 31 screwed onto the flange 5.
is fixed inside. The hollow screw 31 surrounds the upper end of the compression spring 14, which rests on a screw 32 screwed into the hollow screw.

A conduit 36 opens into the cylinder chamber receiving the piston-like intermediate member 25, which conduit 36 extends substantially longitudinally through the valve body 1 and whose upper end extends longitudinally into the flange 5. It's starting to lengthen. Said line 36 is connected to a pressure medium source (not shown), which is connected to the flange 5 via a valve. Upper impact surface 3 of the cylinder chamber
5 forms an abutment for the movement of the intermediate member 25, which is preferably designed to be adjustable, and mechanical or hydraulic means can be used for this adjustment.

The fuel injection valve operates in the following manner. At full load of the internal combustion engine, the supply of pressure medium through the line 36 is cut off, and the valve member 16 is connected to the compression spring 2.
I am only under the pressure of 8. The high-pressure fuel periodically introduced into the line 10 passes through the hole 17 into the annular chamber 19.
, at which point the valve needle 12 is first lifted against the pressure of the spring 14. The valve seat 15 is thus lifted from the corresponding seat in the valve member 16 and the fuel reaches the chamber in front of the nozzle bore 7. Since the only force acting on the upper end of the valve member 16 is the pressure of the spring 28, this bush will rise under the pressure of the fuel, its leading edge 22 will open all the nozzles 7, and the fuel will flow through the holes 7. and reaches the fuel chamber 8 of the cylinder unobstructed by the leading edge 22 (FIG. 2b). After the fuel pressure has decreased in this way, the valve member 16
The valve needle 12 then returns to the starting position shown in FIG.

When the internal combustion engine is operated under partial load, pressure medium is supplied through line 36 and valve member 16
In addition to the pressure of the spring 28, the pressure of the pressure medium on the piston-shaped intermediate member 25 acts on the valve member 16, and the valve member 16 is pushed down into its lower position.
The fuel supplied through the line 10 returns to the annular chamber 1
1 and passes through the hole 17 into the annular chamber 19, where the fuel causes the needle 12 to move upwards against the pressure of the spring 14 and can flow into the chamber in front of the nozzle hole 7. The fuel leaving this chamber then flows through the second holes 7 into the combustion chamber 8 of the cylinder, the opening area of all the holes 7 being reduced.
This is because the leading edge 22 of the valve member 16 partially covers every other nozzle hole 7, and the remaining nozzle holes are completely closed by the valve member 16 (second a). figure). That is, as shown in FIG. 2a, the front edge 22 of the valve member 16 is provided with a plurality of recesses around the periphery so as to open only a portion of the plurality of nozzle holes 7. The structure is such that a partial release of the area of the nozzle holes 7 occurs in only some of the plurality of nozzle holes 7 during a partial load.

In the embodiment shown in FIGS. 3a to 3c, the lower end of the valve member 16 cooperating with the nozzle hole 7 is serrated and has the same number of teeth 40 as there are nozzle holes. Each tooth 40 tapers downward from the valve member 16 and tapers from the outer circumference to the inner circumference of the bush to form a cutting edge.
The maximum width of each tooth 40 is approximately equal to the diameter of the nozzle hole, and the height of each tooth is slightly larger than the diameter of the nozzle hole. At part load, the valve member 16 assumes the position shown in FIG. 3a;
In this position, each nozzle hole 7 is preceded by a tooth 40 which allows the fuel to pass through a portion of the total area of the hole 7 and which cuts the jet of fuel through this hole 7 longitudinally. However, atmospheric oxygen can be conveniently brought close to the fuel portion within the combustion chamber 8. Complete combustion therefore takes place even under partial load. At full load, valve member 1
6 occupies the position shown in FIG. 3b, in which the fuel flows unimpeded by anything into the nozzle 7 through the serrations.

In the embodiment shown in FIGS. 4a and 4b, the front edge 22 of the valve member 16 has a radial notch 41, each notch being associated with a respective nozzle hole 7 and having a triangular cross-section. have. In this example, too, at partial load only a portion of the opening area of each nozzle hole 7 is opened (Fig. 4a), and the jet of fuel passing through the hole is divided into a plurality of small portions by the notch. As a result, combustion can be carried out efficiently. At full load, on the other hand, the fuel passes unhindered through the entire opening area of all nozzle holes (FIG. 4b). The same thing is the fifth
This also occurs in the case of the embodiments of FIG. are doing.

In the embodiment shown in FIGS. 6a and 6b, the leading edge 22 is formed as a flat edge on the circumference of the valve member 16, and the nozzle hole 7 is formed as a flat edge on the circumference of the valve member 16.
They are positioned so that they overlap in two rows inside. In the case of partial load, only the nozzle holes of the upper row are partially opened, and at the same time all the nozzle holes of the lower row are opened (FIG. 6a). At full load, all the nozzle holes in the lower row as well as all the nozzle holes in the upper row are open to allow fuel to pass through (FIG. 6b).

As mentioned above, since the impact surface 35 is adjustable,
In the embodiment shown in FIGS. 3a to 6a, the leading edge 22 occupies an intermediate position during fuel injection;
The function of the bush for changing the opening area of the nozzle hole can be achieved by a rod supported in the hollow needle.

[Brief explanation of the drawing]

FIG. 1 is an axial sectional view of a fuel injection valve according to the present invention; FIGS. 2a and 2b are partially exploded views of the nozzle hole area, respectively, which are enlarged views of FIG. 1;
3a and 3b are respectively sectional views in the nozzle hole area of a variant of the fuel injection valve according to the invention; FIG. 3c is a sectional view taken along the line - of FIG. 3a; FIGS. 4a and 4b The figures are cross-sectional views in the nozzle hole area of different variant embodiments; 5
Figures a, 5b and 6a, 6b each show cross-sections in the area of the nozzle bore of two variant embodiments. In the figure, 1 is a valve body, 2 is an upper part, 3 is a nozzle member, 6 is a cylinder head, 7 is a nozzle hole, and 8
1 is a combustion chamber, 10 is a pipe, 11 is an annular chamber, 12 is a valve needle, 16 is a valve member, 17 is a hole, 19 is an annular chamber, 2
2 is a front edge, 26 is a bush, 30 is a spacing sleeve, and 36 is a conduit.

Claims (1)

[Claims] 1 A fuel injection valve for a reciprocating internal combustion engine, comprising a valve body 1 including a nozzle member 3 projecting into a combustion chamber 8 of a cylinder, the nozzle member 3 having a valve inside thereof cooperating with a valve seat 15. It has a needle 12 and a plurality of nozzle holes 7 distributed around the needle 12, and when the valve needle 12 leaves the valve seat 15, fuel passes through the nozzle hole 7 and enters the combustion chamber 8. A valve member 1 is adapted to periodically flow out into the nozzle hole 7, extends around the valve needle 12, is slidable in the axial direction of the valve needle 12, and controls opening and closing of the nozzle hole 7.
6, and this valve member 16 is designed to open the entire area of all nozzle holes 7 when the engine is under full load. A fuel injection valve characterized in that it is configured in such a shape that only some of the nozzle holes 7 are sometimes partially opened.