JP2000008991A - Fuel injection valve and internal combustion engine, and fuel swirl element and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To implement sufficient atomization and to make fuel be a wide-angle solid spray, by comprising swirl mechanism for forming a swirl flow of fuel around a valve seat and a valve element, and an auxiliary fuel supply means for supplying the fuel to a center portion of the fuel spray injected from a fuel injection port. SOLUTION: A fuel swirl element (a swirler) 2 comprises; four eccentric base swirl grooves 10 on bottom faces of the swirler 2; for eccentric upstream swirl grooves 11 above the bottom faces of the swirler 2; and a fuel swirl chamber 12 for bypassing the base swirl grooves 10 and upstream swirl grooves 11. When a valve element lifts according to a injection signal, fuel is made to flow into the swirl grooves 10, 11 through a fuel passage 14 disposed between the swirler 2 and an injector body. The fuel in the fuel swirl chamber 12 is started to swirl caused by a flow of the upstream swirl grooves 11. Since swirl flows of the fuel formed in the base swirl groove 10 are not weaken to be injected, a current in a swirl direction and a current in a perpendicular direction become almost the same velocity, as time passes off. Accordingly, an injection angle in a first stage is made to be narrower and an injection angle in a last stage is made to be wider so that flow rate distribution is provided near a center of spray, resulting in uniform fuel distribution in the spray.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection valve, an internal combustion engine, a fuel swirl element, and a method for manufacturing a fuel swirl element.

[0002]

2. Description of the Related Art It is well known that a fuel injection valve for supplying fuel to a combustion chamber by port injection, which imparts a swirling force to fuel to promote atomization, as disclosed in, for example, Japanese Patent Application Laid-Open No. 7-174008. . This is a configuration in which the groove has two steps, in which a flow having a swirling force is wrapped with a flow having no swirling force to narrow the spray angle. The spray injected from such a swirl atomization type fuel injection valve basically shows a hollow conical shape because the fuel is concentrated on the outer periphery of the spray by the swirling force (FIG. 28A).

In a gasoline engine of the direct fuel injection type, injecting fuel directly into the combustion chamber, the spray shape is an important key that affects the engine performance. The spray of the conventional swirl atomization type fuel injection valve has a hollow conical shape as described above, so that a fuel has a thick portion and a thin portion, and the concentration distribution in the spray becomes non-uniform.

As a method of making the spray distribution uniform, there is known a method of providing a vertical groove in a fuel swirling element and injecting sprays having different swirling forces as disclosed in Japanese Patent Application Laid-Open No. 9-303235. However, in this method, since the swirling flow is weakened by the non-swirl flow in the flute, it is not possible to obtain a spray having a wide spray angle.

[0005]

When a spray having a non-uniform concentration distribution in the spray as described above is applied to a direct injection engine, a fuel concentration portion collides with and adheres to a piston or the like, and the fuel is discharged before ignition. It cannot be completely converted, and hydrocarbon (HC) and soot are generated. Further, in the lean portion, the transmission of the flame is slowed down, so that the combustion speed is slowed down, causing unstable combustion. Furthermore, when the fuel is concentrated at a certain position, the piston is cooled by the heat of vaporization of the fuel, and the cooling loss increases.

[0006] In the case of a solid spray type fuel injection valve for port injection, in order to suppress the amount of adhesion to the inner wall surface of the intake manifold, and to transport fuel to the intake port at the entrance of the combustion chamber far from the fuel injection valve, The spray angle was small and a spray having a penetrating power was formed. Such a spray is shown in FIG.
As shown in FIG. 8 (b), fuel is concentrated in the center,
C. There is a limit to the reduction of soot and the improvement of combustion stability, and the problem that the efficiency of the engine deteriorates due to an increase in cooling loss is inevitable. No consideration is given to atomization of fuel spray.

Further, even if the spray distribution is uniform, there is a problem that a spray having a wide spray angle cannot be obtained.

Accordingly, an object of the present invention is to realize a solid spray having a wide spray angle while sufficiently atomizing the spray injected from the fuel injection valve into the combustion chamber. That is, an object of the present invention is to provide a swirl mechanism upstream of a valve seat to achieve a wide-angle solid spray while achieving sufficient atomization.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an in-cylinder in which fuel is injected directly from a fuel injection port downstream of a valve seat into a combustion chamber of an internal combustion engine in accordance with an operation of a valve body which comes into contact with or separates from a valve seat. An injection type fuel injection valve, wherein a swirl mechanism for forming a swirling flow of fuel around the valve seat and the valve body, and an auxiliary for supplying fuel to a center portion of fuel spray injected from the fuel injection port This is achieved by employing a fuel injection valve having fuel supply means.

In addition, an injection nozzle body having a valve seat and a fuel injection port provided through the valve seat downstream of the valve seat, a movable element having a valve portion that comes into contact with and separates from the valve seat, A stator that is stored and fixed and forms a fuel storage chamber around the valve seat and the valve portion; a radial passage that supplies fuel having a turning force to the fuel storage chamber; and a fuel that is introduced into the radial passage. Achieved by employing a fuel injection valve having a fuel introduction passage which opens to the fuel storage chamber at a position where the radial passage is axially separated from a contact surface between the stator and the nozzle. Is done.

A valve element reciprocating in the axial direction, the valve element having a valve portion formed at the tip thereof, and a fuel swirl element inserted through the valve element, and seals fuel in cooperation with the valve element. A seal portion, a fuel swirl chamber formed to the bottom surface of the element to apply a swirling force to the fuel downstream of the seal portion, and a fuel swirl chamber formed downstream of the seal portion to supply fuel to the swirl chamber This is achieved by employing a fuel injection valve having an upstream swirl groove and a fuel swirl element that forms a fuel passage for supplying fuel to the swirl groove.

A valve element reciprocating in the axial direction and having a valve portion formed at the tip thereof, and a fuel swirl element passing through the valve element, sealing fuel in cooperation with the valve element. A fuel having a seal portion and a bottom turning groove formed so as to increase in height from the center side of the element toward the outside, and forming a fuel passage for supplying fuel to the turning groove; This is achieved by employing a fuel injection valve having a swirl element.

Also, a valve body reciprocating in the axial direction and having a valve portion formed at the tip thereof, a valve seat for controlling the amount of fuel injected in cooperation with the valve portion, and an upstream of the valve seat This is achieved by employing a fuel injection valve having two fuel swirl flow forming means installed in the fuel injection valve.

Also, a valve element reciprocating in the axial direction and having a valve portion formed at the tip thereof, and a fuel swirl element inserted through the valve element, cooperating with the valve element to seal fuel. A seal portion, a fuel swirl chamber formed to the bottom surface of the element to apply a swirling force to the fuel downstream of the seal portion, and a fuel swirl chamber formed downstream of the seal portion to supply fuel to the swirl chamber A fuel injection valve having an upstream swirl groove, a fuel swirl element for generating a fuel passage for supplying fuel to the swirl groove, and a combustion chamber formed by using a deep-drain piston; This is achieved by employing a direct injection internal combustion engine that injects fuel directly from the injection valve into the combustion chamber.

Also, a valve element reciprocating in the axial direction and having a valve portion formed at the tip thereof, and a fuel swirl element inserted through the valve element, cooperating with the valve element to seal fuel. A seal portion, a fuel swirl chamber formed to the bottom surface of the element to apply a swirling force to the fuel downstream of the seal portion, and a fuel swirl chamber formed downstream of the seal portion to supply fuel to the swirl chamber A fuel injection valve having an upstream swirl groove, a fuel swirl element for producing a fuel passage for supplying fuel to the swirl groove, and a combustion chamber formed by using a flat piston; This is achieved by employing a direct injection internal combustion engine that injects fuel directly from the valve into the combustion chamber.

Further, in the fuel swirl element used for the fuel injection valve, a hole for inserting a valve element of the fuel injection valve is provided,
A seal portion formed integrally with the hole to seal fuel in cooperation with the valve element; and a fuel swirl formed to a bottom surface of the element to apply a swirling force to the fuel downstream of the seal portion. A fuel swirling element having a chamber and an upstream swirl groove formed downstream of the seal portion for supplying fuel to the swirl chamber, and forming a fuel passage for supplying fuel to the swirl groove. Is achieved by doing

Also, in the fuel swirl element used for the fuel injection valve, a hole for inserting a valve element of the fuel injection valve is provided,
A seal portion formed integrally with the hole to seal fuel in cooperation with the valve element, and a bottom turn formed to increase in height from the center side to the outside of the element And a fuel swirl element having a groove and forming a fuel passage for supplying fuel to the swirl groove.

[0018]

1 is a longitudinal sectional view of a fuel injection valve, and FIGS. 2 and 3 are a bottom view and a sectional view of a fuel swirling element.
The fuel injection valve (injector) 1 includes a nozzle 5 for injecting fuel at the tip, a valve seat 7, a fuel swirling element (swirler) 2, a valve body 3 and an electromagnetic coil for driving the valve body 4, and a spring 6 for pressing down the valve body 3. , And a stopper 8. The swirler 2 has four bottom turning grooves 10 eccentric from the center on the bottom surface, and four upstream turning grooves 11 similarly eccentric are provided above the bottom surface of the swirler. Bottom turning groove 10 and upstream turning groove 11
The fuel swirl chamber 12 is provided so as to bypass the valve body 3, and the seal portion 13 is configured to contact and seal the valve body 3.
Actually, a gap of several μm is formed. The gap 14 between the swirler 2 and the injector 1 main body becomes a fuel passage for supplying fuel to the swirl groove. The bottom turning groove 10 and the upstream turning groove 11 may be coaxial. Further, as shown in FIG. 3, a structure having only the upstream turning groove 11 without the bottom turning groove 10 may be used.

The operation of the injector will be described. Normally, the valve element 3 is pressed against a valve seat 7 by a spring 6 to seal fuel flowing from above. But,
When an injection signal is input from the outside, the coil 4 operates to form a magnetic circuit between the valve body 3 and a part of the injector 1 main body and the coil 4, and the valve body 3 is pulled up by overcoming the force of the spring 6. . The valve body 3 collides with the stopper 8 and stops.
While the injection signal is being input, the coil continues to operate, so that the valve element 3 stops on the stopper 8 while hitting the stopper 8. However, when the injection signal disappears, the magnetic circuit disappears, and the force of the spring 6 is reduced. As a result, the valve element 3 returns to the valve seat 7.

The flow of the fuel will be described. The fuel flows into the injector 1 from above at a constant pressure, and reaches the swirler 2 through the fuel passage in the center of the injection valve and the fuel passage in the valve body. When the valve 3 rises according to the injection signal, the fuel starts to flow. The fuel flows into the swirl groove through the fuel passage 14 between the swirler 2 and the injector 1 body.

The flow inside the fuel swirl chamber will be described with reference to the simulation results shown in FIGS.

FIG. 4 shows the fuel flow velocity vector of the fuel swirl chamber 12 0.2 ms after the start of the injection. The fuel that has flowed into the upstream swirl groove 11 reaches the fuel swirl chamber 12 and starts to flow downstream while giving a swirl force to the fuel filled in the fuel swirl chamber 12 due to the eccentricity of the groove. The fuel that has flowed into the bottom swirl groove 10 reaches the lower end of the fuel swirl chamber 12, and the fuel moves from the gap between the valve seat 7 and the valve body 3 to the nozzle 5 with the swirling force due to the eccentricity of the groove. Fuel is injected from the nozzle 5.

FIG. 5 shows the flow velocity on the line passing through the central axis of the nozzle 5 at the same time as FIG. 21 is the vertical direction 210,
22 represents the flow velocity in the radial direction 220 and 23 represents the flow velocity in the turning direction 230. Immediately after the start of injection, the component in the turning direction is smaller than the component in the vertical direction. This is because the fuel that has flowed in from the bottom swirl groove 10 merges with the fuel that does not have a speed component in the swirl direction that is filled in the fuel swirl chamber 12, so that the swirling force is weakened. When the turning speed component is small, the spray angle of the spray to be sprayed tends to be small.

FIG. 6 shows a fuel flow velocity vector in the fuel swirl chamber 12 at 0.5 ms after the start of the injection and after the fuel swirl chamber has reached a steady flow. Since the flow from the upstream swirl groove 11 completely swirls the fuel in the fuel swirl chamber 12, the fuel flowing from the bottom swirl groove 10 is directly injected with a strong swirling force.

FIG. 7 shows the fuel flow rate at the nozzle outlet at the same time as FIG. As in FIG. 5, 21 is the vertical direction,
Reference numeral 22 denotes the radial direction, and reference numeral 23 denotes the turning velocity. After a lapse of time from the start of the injection, the flow velocity in the turning direction and the flow velocity in the vertical direction become substantially the same. This is because the fuel in the fuel swirl chamber 12 starts to swirl due to the flow from the upstream swirl groove 11, so that the swirl flow formed by the bottom swirl groove 10 is injected without being weakened. A spray having a wide spray angle is formed due to a strong turning force.

FIG. 8 shows the spatial distribution of the injected fuel calculated from the nozzle outlet flow velocity of the conventional injector by simulation and arranged by the spray angle. The series of the graph shows the cumulative flow rate of the fuel until the display time when the flow rate 1 ms after the start of the injection is set to 100%. The spray angle at which the fuel is distributed is constant irrespective of the elapsed time from the start of the injection, and the spray becomes a hollow conical spray having no flow rate distribution at the center. Further, the flow distribution at the center after 0.2 ms occurs because the fuel accumulated at the nozzle tip is injected with a small swirling force.

FIG. 9 shows the spatial distribution of the spray by the simulation using FIG. The display is the same as in FIG. The reason why there is fuel in the center is that the fuel accumulated at the nozzle tip is injected with a weak swirling force as in the case of the hollow spray. The spray angle increases as time elapses from the start of injection. Thus, by forming a spray having a narrow spray angle in the early stage and a wide spray angle in the latter period, a solid spray having a flow rate distribution near the center and a uniform fuel distribution in the spray can be formed.

FIG. 10 schematically shows the relationship between the time after the start of injection and the spray angle, and the shape of the spray. 0.2 ms from the start of injection
It was created based on a series of photographs taken each time. Immediately after the start of the spraying, the spray angle is narrow, and the spray angle is widened with time. However, a bell-shaped spray is formed at the spray tip since the narrow spray angle component remains.

FIG. 11 schematically shows the fuel distribution when the spray is received at a position 50 mm downstream of the injector. The area of the mountain represents the total flow. The hollow spray has two peaks and the fuel has a small distribution in the center, whereas the solidified solid spray has a flow rate distribution as a whole and has no significant peak.

FIGS. 12 to 14 show a method of controlling the degree of solidity of spraying.

As shown in FIG. 12, the distance of the upstream swirl groove 11 from the swirler bottom surface is a, the diameter of the fuel swirl chamber 12 is b, the representative value (for example, cross-sectional area) of the bottom swirl groove 10 is c, Is assumed to be d. The spray angle of the spray increases with the time from the start of the injection, and the slower the spread speed, the more the fuel is distributed in the center and the degree of solidity tends to increase.

When the size of a is reduced, the swirl of the upstream swirl groove 11 reaches the bottom surface of the fuel swirl chamber earlier, so that the spray angle spreads faster and the solidity is low. Conversely, if the dimension of “a” is increased, it takes time for the fuel in the upstream swirl groove 11 to reach the fuel swirl chamber bottom surface, and the spray angle increases slowly, so that a more solid spray can be formed.

When the diameter b of the fuel swirl chamber is small, the fuel in the upstream swirl groove 11 reaches the bottom surface of the fuel swirl chamber quickly and the spray easily spreads as shown in FIG. 13, but the spray angle is gradually widened by increasing b. It is possible to increase the degree of solidity.

FIG. 14 shows the bottom turning groove 10 and the upstream turning groove 11.
In the case where the ratio of the representative values is changed, and when c / d is large (when there is no flow from the upstream swirl groove 11 in consideration of an extreme case), the spray angle is almost the same as the conventional spray from the initial stage of spraying But when c / d is reduced, the upstream turning groove 1
The influence of the flow from 1 increases, and it takes time for this flow to reach the bottom of the fuel swirl chamber, so that it takes time to increase the spray angle. Therefore, the degree of solidity can be increased (FIG. 3 can be considered as the case where c / d = 0).

When the volume of the fuel swirl chamber from the upstream swirl groove 11 to the bottom surface of the fuel swirl chamber is increased, the fuel swirl chamber becomes solid, and when the fuel swirl chamber is reduced, the fuel swirl chamber becomes hollow. Further, the spray injected when the flow from the upstream swirl groove 11 reaches the bottom surface of the fuel swirl chamber has the final spray angle.

FIG. 15 shows an example of a swirler manufacturing method. FIG.
-It is difficult to machine the upstream turning groove 11 with the structure of Fig. 3. At the position where the upstream turning groove 11 is to be provided, the swirler is divided into two members, a member 30 and a member 31, and the members 30 or 31 are separated.
Cut a groove in It is necessary to match the positions of the fuel passages of the member 30 and the member 31 at the time of assembly, but processing becomes easy. When the swirler is manufactured in this manner, it can be said that the swirler 2 has two fuel swirl flow forming means.
Further, since one member has two swirl grooves as in the swirler 2 of FIG. 2, it can be said that the swirler has two fuel swirl flow forming means. In FIG.
If the bottom turning groove 10 is not cut in the member 30, the one shown in FIG. 3 is obtained.

A method of sealing fuel will be described with reference to FIG. In the conventional product, there is no fuel swirl chamber 12 so that the seal is provided between the rod portion of the valve body and the inner wall of the swirler. However, since the fuel swirl chamber 12 is provided in the seal portion, the valve body 3 and the inner wall of the swirler are sealed. A structure for sealing between some of the seal portions 13 is adopted. The gap between the seal portion 13 and the valve body 3 is about several μm. The size of each part is height x diameter of the swirler 2 body.
6 × 8 mm, the axial length of the seal portion 弁 1 mm, the relationship between the diameter D of the plunger of the valve body 3 and the diameter d of the ball of the valve body 3 is D ≧
d. The valve body 3 has a valve portion (a ball in this example) at its tip. Therefore, after the valve body 3 is manufactured, it can be passed through the swirler 2. The stroke of the valve element 3 is several tens μ
m, the scale is such that the positional relationship between the valve body 3 and the swirler 2 hardly changes in the drawing.

Although a ball valve type is shown in the figure, a needle type valve body as shown in FIG. 21 or a valve body in which a ball and a plunger are integrally formed are also conceivable.

Another embodiment will be described.

FIG. 17 is a view in which the number of machining steps is reduced by using two upper and lower turning grooves in FIG. Since the fuel flowing from the upstream swirl groove 41 is uniformly mixed before reaching the fuel swirl chamber bottom surface, the effect of reducing the number is small. The same applies to the case where three turning grooves are provided, and the same applies to a combination of two or four turning grooves.

FIG. 18 includes a straight groove 42 which is not eccentric with respect to the center axis on the bottom surface of the swirler, and an eccentric upstream turning groove 43 which is located above the straight groove 42. Immediately after the start of the injection, the fuel flowing from the straight groove 42 is crushed and atomized at the central portion and injected at the center. In the latter half of the injection, the fuel swirled from the upstream swirl groove 43 sprays a spray having a wide spray angle. Thus, a solid spray can be obtained in the initial stage by narrow-angle spraying by collision atomization, and in a later stage by wide-angle spraying by swirling atomization.

FIG. 19 shows a bottom swivel groove 44 with a small eccentric amount on the swirler bottom surface and an upstream swivel groove 4 with a large eccentric amount on the upper part.
5 is provided. In the early stage of the injection, the narrow-angle spray flowing from the bottom swirl groove 44, and in the later stage of the injection, the flow from the upstream swirl groove 45 and the flow from the bottom swirl groove 44 merge to form a wide-angle spray, thereby realizing a solid state.

If the straight groove 42 in FIG. 18 is regarded as a special bottom turning groove with zero eccentricity, it can be said that the swirler in FIG. 18 also has two turning grooves, and the swirler up to FIG.
In the special case of FIG. 19, it can be said that each has two swirl grooves (two fuel swirl flow forming means).

FIG. 20 is composed of four vertical grooves 46 extending from the upper surface to the lower surface of the swirler, and eccentric horizontal grooves (upstream turning grooves) 47. Initially, fuel having no swirling force flows from the vertical groove 46, but the spray angle gradually becomes wider and solidified by the effect of the horizontal groove 47. In this configuration, if the position of the lateral groove 47 is too high and the height of the fuel swirl chamber 12 is large, it is not preferable because the flow in the fuel swirl chamber obstructs the flow of the vertical groove 46. In addition, it is not preferable that the lateral groove 47 is on the bottom surface of the swirler because the flow from the vertical groove 46 and the flow from the lateral groove 47 are jetted simultaneously.

The conventional swirl-type bottom swirl groove alone may cause a fuel concentration portion (spray streak) in which the injected fuel may not be sufficiently mixed. In addition, fuel can be injected in a sufficiently mixed state, and a fuel concentration portion (spray of spray) does not occur.

FIG. 21 shows a swirler together with a swirler for controlling the spray angle by a swirling flow forming means having a spiral groove formed in a valve body. The swirler 2 has a bottom surface turning groove 10 and the valve body 3 has a spiral groove 60. When the valve body 3 rises, first, fuel is injected from the spiral groove 60, and then the flows from the bottom surface turning groove 10 merge. The space between the valve element and the swirler must be sealed. As shown in the drawing, the turning force of the fuel injected from the bottom turning groove 10 is K, and the turning force of the fuel injected from the spiral groove 60 is L. By controlling the turning forces of K and L, a solid spray can be formed. In the case of K> L (FIG. 22), the spray angle is narrow immediately after the start of the injection, and the spray angle increases with the influence of the strong swirling force of K over time, forming a solid spray. Conversely, K <
In the case of L (FIG. 23), immediately after the start of the injection, a spray with a wide spray angle can be obtained with a strong swirling force of L, but the swirling force gradually weakens and the spray angle narrows because a weak swirling force of K influences halfway. . In this case, a solid spray is formed by bringing a wide-angle spray at an early stage and a narrow-angle spray at a later stage, which is the reverse of the previous embodiment.

Similarly, a configuration in which a spiral groove is cut in the ball valve is also conceivable (FIG. 24).

Even in the case of using a spiral groove as shown in FIGS. 21 to 24, the spray is made solid by using two fuel swirling flow forming means on the upstream side of the valve seat 7 as in FIG. .

FIG. 25 shows a structure in which a diagonal groove 50 eccentric from the center is provided on the bottom surface of the swirler, and the cross section of the diagonal groove 50 becomes smaller as approaching the center. FIG. 26 is an enlarged view of the inclined groove 50. The flow rate of the fuel flowing out is large on the g side (outside) because the exit area is small, and the flow velocity is slow on the h side (inside) because the exit area is large. The outer side is solidified by generating a swirling flow of a stronger swirl and the inner side of a weaker swirl.
As shown in FIG. 27, a solid spray is always injected from the start to the end of the injection. The spray angle of this spray is independent of time.

As described above, the fuel spray can be solidified (the fuel concentration distribution in the spray can be made uniform) as shown in FIG.

The piston cavity shape of the direct injection engine includes flat, shallow dish, deep dish and the like. For flat pistons, sprays that are susceptible to air flow are suitable. This is for suppressing the amount of fuel adhering to the combustion chamber wall and the piston head. For example, atomized spray having a short penetration is suitable. The conventional hollow spray has been continuously sprayed to an extremely narrow annular fixed portion. However, the solid spray according to the present invention does not continuously spray into a very narrow fixed portion, so that the spray is not pushed later and the penetration is shortened. A hollow spray that is widely dispersed in the atmosphere and compacted under pressure is suitable for a shallow dish piston. Since the deep dish piston has a deep cavity and a long distance to the plug, it is considered that a solid spray that is uniformly dispersed in the atmosphere and has a penetrating force under pressure is suitable. Further, in the case of the conventional hollow spray, the spray in the direction of the ignition plug is difficult to blow up, so that stratified stable combustion cannot be realized. For this reason, in the deep-dish piston, a flow rate distribution also exists near the center of spraying, and it is considered that solid spraying that is easy to blow up in the direction of the spark plug is suitable.

Therefore, it is conceivable to use the above-described solid spray for a flat piston, a deep dish piston, or the like. When this solid spray is applied to an in-cylinder injection engine using a flat piston, the spray can be uniformly distributed in the combustion chamber as shown in FIG. 29, and is applied to the piston like a hollow spray or conventional solid spray. There is no concentrated distribution of fuel. Since the fuel does not concentrate on the piston, the cooling loss can be reduced. Further, since the spray is uniformly distributed in the combustion chamber, the fuel vaporization time can be shortened. When applied to a deep-drain piston, the spray easily falls into the cavity, that is, the amount of fuel that protrudes from the cavity is small, and the spray can be concentrated near the ignition plug, which has the effect of reducing HC.

[0053]

According to the present invention, the spray angle can be widened and the spray can be atomized and solidified, so that the atomized spray having a uniform concentration can be injected into the entire combustion chamber. . This contributes to obtaining stable combustion, enhances thermal efficiency, and contributes to suppression of HC and soot generation.

[Brief description of the drawings]

FIG. 1 is a sectional view of a fuel injection valve.

FIG. 2 shows a fuel swirling element (1).

FIG. 3 shows a fuel swirling element (2).

FIG. 4 shows the state inside a fuel swirl chamber immediately after the start of injection (calculation result).

FIG. 5 shows the flow velocity at the nozzle outlet immediately after the start of injection (calculation result).

FIG. 6 shows a state inside a fuel swirl chamber in a steady state (calculation result).

FIG. 7 is a flow rate at a nozzle outlet in a steady state (calculated result).

FIG. 8 shows a relationship between a spray flow rate and a spray angle (calculation result 1).

FIG. 9 shows a relationship between a spray flow rate and a spray angle (calculation result 2).

FIG. 10 shows the relationship between spray angle and time (1).

FIG. 11 shows fuel distribution.

FIG. 12 is a control result (1) of the degree of solidity.

FIG. 13 is a control result (2) of a solid degree.

FIG. 14 is a control result (3) of the degree of solidity.

FIG. 15 shows an example of a method for manufacturing a fuel swirling element.

FIG. 16 shows a fuel sealing method.

FIG. 17 shows a fuel swirling element (3).

FIG. 18 shows a fuel swirling element (4).

FIG. 19 shows a fuel swirling element (5).

FIG. 20 shows a fuel swirling element (6).

FIG. 21 is a fuel swirl flow forming means (1).

FIG. 22 shows a relationship between time and spray angle (2).

FIG. 23 shows a relationship between time and spray angle (3).

FIG. 24 shows a fuel swirl flow forming means (2).

FIG. 25 shows a fuel swirling element (7).

FIG. 26 is an enlarged view of a diagonal groove.

FIG. 27 shows the relationship between the flow rate of spray and the spray angle (3).

FIG. 28: Comparison of spray shapes.

FIG. 29 shows an example of application to a flat piston.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fuel injection valve, 2 ... Fuel turning element, 3 ... Valve element, 4 ... Electromagnetic coil, 5 ... Nozzle, 6 ... Spring, 7 ... Valve seat, 8 ... Stopper, 10 ... Bottom turning groove, 11 ... Upstream turning groove , 12: fuel swirl chamber, 13: seal portion, 14: fuel passage.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takuya Shiraishi 7-1-1, Omikacho, Hitachi City, Ibaraki Prefecture Inside the Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Minoru Osuka 7-1 Omikamachi, Hitachi City, Ibaraki Prefecture No. 1 F-term in Hitachi, Ltd. Hitachi Research Laboratory (reference) 3G066 AA02 AB02 AD12 BA03 BA17 BA24 BA26 BA55 CC06U CC14 CC18 CC20 CC42 CC43 CC48 CC66 CD30 CE22

Claims (12)

[Claims] An in-cylinder injection type fuel injection valve for directly injecting fuel from a fuel injection port downstream of a valve seat into a combustion chamber of an internal combustion engine in accordance with an operation of a valve body which comes into contact with or separates from a valve seat. And a swirl mechanism that forms a swirling flow of fuel around the valve seat and the valve element; and an auxiliary fuel supply unit that supplies fuel to a center portion of fuel spray injected from the fuel injection port. valve. 2. An injection nozzle body having a valve seat and a fuel injection port penetrating downstream of the valve seat, a movable element having a valve portion that comes into contact with and separates from the valve seat, A stator that is stored and fixed and forms a fuel storage chamber around the valve seat and the valve portion; a radial passage that supplies fuel having a turning force to the fuel storage chamber; and a fuel that is introduced into the radial passage. A fuel injection valve having a fuel introduction passage, wherein the radial passage is open to the fuel storage chamber at a position axially away from a contact surface between the stator and the nozzle. 3. A valve element which reciprocates in the axial direction and has a valve portion formed at the tip thereof, and a fuel swirl element which penetrates the valve element, and seals fuel in cooperation with the valve element. A seal portion, a fuel swirl chamber formed to the bottom surface of the element to apply a swirling force to the fuel downstream of the seal portion, and a fuel swirl chamber formed downstream of the seal portion to supply fuel to the swirl chamber A fuel swirl element having an upstream swirl groove and a fuel swirl element for forming a fuel passage for supplying fuel to the swirl groove. 4. The fuel injection valve according to claim 3, wherein a bottom turning groove is provided in the element, and the fuel passage also supplies fuel to the bottom turning groove. 5. A valve element which reciprocates in the axial direction and has a valve portion formed at the tip thereof, and a fuel swirl element which penetrates the valve element, and seals fuel in cooperation with the valve element. A fuel having a seal portion and a bottom turning groove formed so as to increase in height from the center side of the element toward the outside, and forming a fuel passage for supplying fuel to the turning groove; A fuel injection valve having a swirl element. 6. A valve body which reciprocates in the axial direction and has a valve at its tip, a valve seat for controlling the amount of fuel injected in cooperation with the valve, and an upstream of the valve seat. A fuel injection valve having two fuel swirling flow forming means installed in the fuel injection valve. 7. A valve element which reciprocates in the axial direction and has a valve portion formed at the tip thereof, and a fuel swirling element which penetrates the valve element, and seals fuel in cooperation with the valve element. A seal part,
A fuel swirl chamber formed up to the bottom surface of the element to apply a swirling force to fuel downstream of the seal portion, and an upstream swirl groove formed downstream of the seal portion to supply fuel to the swirl chamber. A fuel injection valve having a fuel swirling element for generating a fuel passage for supplying fuel to the swirl groove, and a combustion chamber formed by using a deep-drain piston. An in-cylinder internal combustion engine that injects fuel directly into the combustion chamber. 8. A valve element which reciprocates in the axial direction and has a valve portion formed at the tip thereof, and a fuel swirling element which penetrates the valve element, and seals fuel in cooperation with the valve element. A seal part,
A fuel swirl chamber formed up to the bottom surface of the element to apply a swirling force to fuel downstream of the seal portion, and an upstream swirl groove formed downstream of the seal portion to supply fuel to the swirl chamber. A fuel injection valve provided with a fuel swirl element for generating a fuel passage for supplying fuel to the swirl groove, and a combustion chamber formed by using a flat piston. A direct injection internal combustion engine that injects fuel directly into the chamber. 9. A fuel injection valve according to claim 3, further comprising: a combustion chamber formed by using a deep-drain piston or a flat piston, wherein fuel is directly supplied from the fuel injection valve to the combustion chamber. A direct injection internal combustion engine that injects. 10. A fuel swirl element used for a fuel injection valve, wherein a hole through which a valve element of the fuel injection valve is inserted is formed integrally with the hole, and a fuel seal is formed in cooperation with the valve element. A fuel swirl chamber formed up to the bottom surface of the element for applying a swirling force to the fuel downstream of the seal part, and formed downstream of the seal part to supply fuel to the swirl chamber And a fuel swirl element that has a set upstream swirl groove and generates a fuel passage for supplying fuel to the swirl groove. 11. A fuel swirl element used for a fuel injection valve, wherein a hole through which a valve element of the fuel injection valve is inserted is formed integrally with the hole, and a fuel seal is formed in cooperation with the valve element. And a bottom swirl groove formed so as to increase the height from the center side of the element toward the outside, and generate a fuel passage for supplying fuel to the swirl groove. Fuel swirl element. 12. The method of manufacturing a fuel swirl element according to claim 10, wherein the fuel swirl element is divided at a position where the upstream swirl groove is to be provided, and the upstream swirl groove is machined. Method.