JPH0428905B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection valve, and more particularly, the invention relates to a fuel injection valve, which is installed in an internal combustion engine having a piston having a cavity and a valve recess on the top surface. This invention relates to a fuel injection valve that injects fuel along a surface.

In order to increase the combustion efficiency of an internal combustion engine, it is necessary to use a certain amount of air supplied to the combustion chamber as effectively as possible. For this reason, swirls are given to the intake air, and various combustion chamber shapes are devised.

With this objective in mind, the present invention aims to realize a fuel injection valve that can generate fuel spray that conforms to the shape of a given combustion chamber.

Normally, the nozzle diameter of a fuel injector is determined according to the distance of the cavity, so naturally the spray will not have enough power to reach the valve recess, which extends to an area further away from the outer periphery of the cavity. air is not used effectively. For this reason, it may be possible to inject fuel so that it reaches the valve recess in particular, and a prior art related to this is shown in ``Combustion chamber of direct injection internal combustion engine'' in Utility Model Application Publication No. 144219/1983. ing. According to the prior art, for a fuel injection valve for an internal combustion engine equipped with a piston having a cavity and a valve recess on the top surface, the angle formed by the axis of the nozzle in the injection direction with respect to the axis of the injection valve is determined by The valve recess oriented nozzle is made larger than the valve recess oriented nozzle, and to put it simply, the valve recess oriented fuel is blown at a larger angle. According to this prior art, the reach distance of the fuel spray in the direction of the valve recess is certainly increased, and the problem of insufficient reaching power is solved. However, in order to achieve homogenization of combustion in order to increase combustion efficiency in a combustion chamber having such a shape, it is not possible to achieve this by simply adjusting the travel distance of the fuel. That is, the space volume due to the valve recess does not exist in exchange for the space volume due to the cavity, but is added to the space volume of the cavity. Therefore, the homogenization of combustion in this case should be solved by adjusting the fuel range and, rather than by adjusting the range, by adjusting the fuel supply amount.

The prior art described above cannot be a solution to the problem of homogenizing combustion.

The present invention has been made to solve the above-mentioned problems of the conventional art. On the other hand, for fuel injection valves that inject fuel along a conical surface at a constant angle, the purpose is to achieve homogenization of combustion within the combustion chamber in order to increase combustion efficiency.

The present invention provides a means for making the amount of fuel injected for a phase directed toward a valve recess larger than the amount of fuel injected for a phase directed toward an intermediate portion sandwiched between a pair of adjacent valve recesses, such as the above-described method. The diameter of the nozzles belonging to the former phase is made larger than the diameter of the nozzles belonging to the latter phase, or the arrangement density of the nozzles of the former phase is made greater than that of the latter phase, or the nozzle arrangement of the former phase is made upper and lower. It is characterized by having a two-stage structure, such as making the diameter of the nozzle in the upper stage larger than that in the lower stage.

Embodiments of the present invention will be described based on the drawings. 1st
In the figures and FIG. 2, a piston 1 has a cavity 2 and a valve recess 5 for valves 3, 4, etc. formed on its top surface. 6 is a fuel injection valve, and 7 represents atomized fuel injected from a nozzle provided at the tip 8 of the valve. All of the nozzles 9 belong to the phase that points toward the valve recess 5.
10 are a pair of adjacent valve recesses 5, 5.
This is a nozzle that belongs to the phase that points toward the middle part between the two. As can be seen, the nozzle 9 has a larger diameter than the nozzle 10, thereby increasing the amount of fuel for the phase directed toward the valve recess 5 (indicated by arrow P in FIG. 2).

FIG. 3 shows a different embodiment. As in the above embodiment, if the nozzle diameter in the direction of arrow P is made larger than the nozzle diameter in the phase of the cavity section (indicated by arrow Q in Figure 2), a difference will occur in the particle size of the spray particles, which will have an adverse effect on the combustion state. It may cause In such a case, this embodiment is extremely suitable. That is, in this embodiment, the amount of injected fuel is increased toward the phase in a specific direction by providing a difference in the arrangement density of the number of injection holes without providing a difference in the injection hole diameter. In FIG. 3, the nozzle 10 belonging to the phase pointing toward the four valve recesses 5, 5, .
The arrangement density of the nozzles 10, 10, . . . is made larger than the arrangement density of the nozzles 10, 10, . This is intended to achieve the same effect as the example in FIG. 2 regarding the total amount of fuel injected for each phase.

Figures 4 and 5 show a further different embodiment, and in this example, the injection direction of all the nozzles with respect to the piston center axis remains along a conical surface at a constant angle, and the phase direction is directed toward the valve recess. This is an example in which the nozzle arrangement in the part belonging to the above is arranged in two stages, upper and lower, and the diameter of the upper nozzle is larger than the diameter of the lower nozzle. In this case, in principle, the upper nozzle 11
It can be assumed that the fuel injected from the nozzle 11 is for the valve recess and the lower nozzle 12 is for the cavity, but the fuel injected from the nozzle 11 is for the valve recess and the cavity. It may also be set as a total value. When the nozzle arrangement is arranged in two stages, upper and lower, as in this example, it is possible to comprehensively address both the requirements regarding the reach distance of the injected spray and the requirements regarding the amount of supply depending on the phase of the injected fuel. It has the advantage of being extremely simple to process.

Since the fuel injection valve according to the present invention is configured as described above, it is possible to achieve homogenization of combustion in the combustion chamber of an internal combustion engine with a relatively simple configuration, and increase combustion efficiency. It is extremely effective in achieving this goal.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a peripheral device including the device of the present invention;
2 and 3 are explanatory diagrams of different embodiments of the device of the present invention, FIG. 4 is an enlarged view of essential parts of still another embodiment of the device of the present invention, and FIG. 5 is a sectional view thereof. . 1... Piston, 2... Cavity, 3, 4...
...Valve, 5...Valve recess, 6...Fuel injection valve,
7...Atomized fuel, 8...Tip, 9,10,
11,12...Fountain.

Claims (1)

[Scope of Claims] 1. In a fuel injection valve that is installed in an internal combustion engine and is equipped with a piston that has a cavity and a valve recess on its top surface, and that injects fuel along a conical surface at a constant angle with respect to the central axis of the piston, the valve recess is A fuel injection system characterized by comprising means for making the amount of fuel injected for a phase directed toward a larger amount than the amount of fuel injected for a phase directed toward an intermediate portion sandwiched between a pair of adjacent valve recesses. valve. 2. A patent in which, among a plurality of nozzles provided in a fuel injection valve, the diameter of the nozzle in the phase that points toward the valve recess is larger than the diameter of the nozzle that belongs to the phase that points toward the intermediate portion between a pair of adjacent valve recesses. A fuel injection valve according to claim 1. 3. Claim 1, wherein the arrangement density of the number of nozzles belonging to the phase oriented toward the valve recess is greater than the arrangement density of the number of nozzles belonging to the phase oriented toward the intermediate portion sandwiched between a pair of adjacent valve recesses. fuel injection valve. 4. The fuel injection valve according to claim 1, wherein the nozzle ports in the portion belonging to the phase oriented toward the valve recess are arranged in two stages, upper and lower, and the diameter of the upper stage nozzle is larger than the diameter of the lower stage nozzle.