JP3686090B2 - Engine fuel supply system - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an engine fuel supply apparatus having a fuel injection valve in an intake passage.
[0002]
[Prior art]
In the intake port fuel injection device (fuel supply device) that has been widely used in the past, the pp. 177-181 of the 8th internal combustion engine joint symposium lecture collection ('90 -1-24, 25, Tokyo) As disclosed in “Study on mixture formation in gasoline engine”, the fuel injected from the fuel injection valve collides with and adheres to the local part of the opposing cylinder wall, gradually evaporates, and is transported by the swirl in the cylinder It was a thing.
[0003]
Further, as disclosed in Japanese Utility Model Laid-Open Nos. 61-80365, 1-76560, 2-141678, and 2-141679, a throttle is formed around the injection hole of the fuel injection valve. Using the auxiliary air passage that bypasses the valve, the air from the upstream of the throttle valve is blown to atomize the fuel,
As disclosed in JP-A-61-16261 and JP-A-61-226563, the fuel injected from the fuel injection valve collides with the intake passage wall near the intake port, and from the upstream side of the throttle valve to the intake port wall. A swirl passage to blow out the air of
As disclosed in Japanese Patent Application Laid-Open No. 59-231133, there is known a pipe provided with a pipe for guiding the air upstream of the throttle valve near the intake valve of the engine.
[0004]
[Problems to be solved by the invention]
As described above, various fuel supply devices have been proposed in the past, but most of the fuel collides with the intake passage wall surface and the intake valve, or is carried by the air flow that bends at the intake valve, and the combustion chamber of the cylinder. Although it collides with the wall surface, according to such a system, the suction passage wall surface, the intake valve, and a part of the cylinder surface adhering to the cylinder wall surface cannot easily evaporate and are liable to enter the combustion chamber. As a result, the fuel that is not vaporized is incompletely combusted and exhausted, resulting in an increase in the amount of unburned hydrocarbons, and the air-fuel mixture introduced into the combustion chamber becomes uneven, resulting in a dense gas layer at the bottom. This causes a decrease in combustion efficiency.
[0005]
Therefore, conventionally, fuel adhering to the intake passage wall surface, intake valve, etc. is vaporized by heat before the fuel injection timing of the injection valve before the intake stroke, but this alone is not sufficient for vaporizing liquid fuel. Especially when starting at low temperatures, it is not sufficient.
[0006]
In order to deal with such a problem, a method of making the shape of the piston complicated and making the mixture uniform by distorting the mixture by the squash effect has been described in the above paper. It becomes complicated, increases the surface area, and heat loss tends to increase.
[0007]
As another countermeasure, it is necessary to make the fuel of the injection valve finer to 10 microns or less. However, atomization of fuel by air flow, atomization by ultrasonic waves, etc. can only process a small amount of fuel, and it remains a problem of becoming a liquid film by adhering to the wall surface, intake valve, etc. It has not yet been effective.
[0008]
The present invention has been made in view of the above points, and an object of the present invention is to provide a fuel supply device that can solve the above-described problems, improve the formation of mixed air in the combustion chamber, and improve combustion efficiency and exhaust purification. .
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention basically proposes the following problem solving means.
[0010]
According to the present invention, in a fuel supply apparatus having a fuel injection valve in an intake passage of an engine, each cylinder of the engine has two intake valves, and a throttle valve downstream of the intake passage corresponds to the intake valve. A swirl control valve is provided in one of the branch passages, and at least the engine is closed during low load operation. When the swirl control valve is closed, a swirl is generated by the air flow from one branch passage in the cylinder. Yes,
The fuel injection valve is a two-way injection valve that is located upstream of a branch point of the branch passage and injects fuel in two directions corresponding to the branch passage;
And the intake air flowing into the intake passage during the low load operation bypasses the throttle valve and Two directions Injection port And the two-way injection port between the intake passage and the branch point A bypass passage that blows out in the vicinity is provided, and this blown air is divided into two directions injected from the fuel injection valve. After Fuel spray In the intake passage Unify and deflect into the branch passage without the swirl control valve Let Fuel spray after deflection is more than fuel spray before deflection One Position near the center of the combustion chamber on the intake valve head or near the center of the combustion chamber between the intake valve and seat Change the angle of travel It is set to reach intensively.
The bypass passage serves as a means for forming a high-speed air flow due to a difference in intake pipe pressure upstream and downstream of the throttle valve during low load operation. Such an embodiment of the invention is shown, for example, in FIGS.
[0022]
【Example】
Embodiments of the present invention will be described with reference to the drawings.
[0023]
1 to 4 show a first embodiment of the present invention. This embodiment claims 1's This is a specific example.
[0024]
The engine 1 is a normal gasoline engine. A fuel injection valve 3 is arranged near the intake valve 2 at a position downstream of the throttle valve 15 in the intake passage 22. As the fuel injection valve (hereinafter referred to as an injection valve) 3, for example, an electromagnetic injection valve is used. Fuel injection port 4 of the nozzle body 4 of the injection valve 2 a is It faces the center side of the combustion chamber 10 on the upper surface of the head of the intake valve 2.
[0025]
An air nozzle body 6 is provided around the nozzle body 4, and the fuel injection port 4 a's The nozzle holes 9a and 9b of the air nozzle body 6 are disposed on the periphery of the tip.
[0026]
The nozzle holes 9a and 9b serve as an air outlet of the passage 8 that bypasses the throttle valve 15 of the intake passage 22, and the inlet of the bypass passage 8 opens upstream of the throttle valve 15. mouth To do.
[0027]
There are two nozzle holes 9a, 9b, for example, and the shape, angle and position of the nozzles 9a, 9b are surrounded by the high-speed air flow in which the fuel injected from the injection valve 3 is blown from the air nozzles 9a, 9b. Of these, it is set so as to intensively reach a place away from the wall of the cylinder 10 (here, near the center of the combustion chamber close to the spark plug 11). The high-speed air flow is generated when the pressure difference between the upstream and downstream of the throttle valve becomes large, for example, in a low load operation.
[0028]
The jets from the air nozzles 9a and 9b collide obliquely to synthesize a jet (air stream) having an elliptical cross section, and the two jets 9a and 9b have different hole diameters. The injected fuel that deflects in the direction is also deflected in the direction of the broken line B. The nozzles 9a and 9b are designed so that the deflection direction B is closer to the center of the combustion chamber 10 in the annular portion (between the intake valve 2 and its seat) 5, that is, closer to the spark plug 11.
[0029]
In the present embodiment, fuel is ejected from the injection valve 3 before the intake stroke of the engine 1.
[0030]
In the partial load operation, the fuel injected from the nozzle 4 takes a trajectory in the B direction without being surrounded by the air jets from the nozzles 9a and 9b, and is diffused. Code C As shown in FIG. 2, the upper surface of the head of the intake valve 2 locally collides with a position near the spark plug 11. When the intake valve 2 is opened, as shown in FIG. 3, the high-speed air flow from the nozzles 9a and 9b (at this time, no fuel is injected from the nozzle 4) is positioned in the annular portion 5 near the center of the combustion chamber. The fuel adhering to the intake valve 2 is blown off and atomized, and vaporization is promoted by a so-called Venturi effect sucked at a negative pressure. The fuel enters the center of the combustion chamber 10 and is excellent in the vicinity of the spark plug 11. An air-fuel mixture is formed.
[0031]
According to this embodiment, the fuel can be prevented from adhering to the intake pipe wall, the cylinder wall and the piston surface without being diffused.
[0032]
Further, the air E passing through the intake valve 2 flows so as to wrap the fuel as indicated by E1 and E2 in FIG. 3, and the fuel is guided to the center of the combustion chamber along the flow of E1 to prevent reattachment to the cylinder wall surface. The
[0033]
Furthermore, as another effect of the present embodiment, minute turbulence can be created in the combustion chamber 10 by the air of the air nozzle 6, and the atomized fuel diffuses from the center of the combustion chamber in this small vortex, so that mixing is performed. Promotes uniform formation of Qi.
[0034]
Next, when the engine load increases, the pressure in the intake pipe 22 increases, the speed of the jet B at the nozzle holes 9a and 9b decreases, and the fuel is uniformly supplied to the annular portion 5 as shown by A in FIG. become. At this time, even if the air nozzle 6 does not form a high-speed air flow, the speeds of the air E1 and E2 passing through the intake valve 2 are increased, so that the fuel is re-atomized as D by the intake air.
[0035]
Next, a second embodiment will be described with reference to FIGS. Second embodiment Also Claim 1's This is a specific example.
[0036]
In this embodiment, each cylinder 10 of the engine 1 has two intake valves 2 and 21, and the nozzle body 4 of the fuel injection valve 3 has a plurality of injection ports 4a and 4b corresponding to the two intake valves. It is a supply device.
[0037]
A partition wall 22 'is provided at a position near the cylinder 10 in the intake passage 22 to form branch passages 22a and 22b corresponding to the intake valves 2 and 21, respectively. One of the branch passages 22a corresponds to the engine load. A swirl control valve (hereinafter abbreviated as SCV) 13 that is controlled to open and close is provided. The SCV 13 is open when the load is high and closed when the load is low.
[0038]
On the other hand, the fuel injection valve 3 is located in the middle of the branch passages 22a and 22b downstream of the throttle valve, and an air nozzle body 6 is disposed around the nozzle body 4 of the injection valve. The air nozzle body 6 has its nozzle holes 9 and 91 positioned around the tip of the fuel injection ports 4a and 4b, and is upstream of the throttle valve from the air passage 8 bypassing the throttle valve of the intake passage 22 by the nozzle holes 9 and 91. Inject air. The nozzles 9 and 91 are a high-speed air flow that deflects the fuel injected from the injection ports 4a and 4b of the fuel injection valve 3 during low load operation to the side 22b without the SCV 13 in the branch passage (the high-speed air flow is a low load). It is set to blow out when the pressure difference between the upstream and downstream of the throttle valve becomes large as during operation. For example, if the nozzles 9 and 91 are circular, and the diameter Φ1 of the nozzle 9 is different from the diameter Φ2 of the nozzle 91 (Φ1> Φ2), the air jets from the nozzles 9 and 91 collide with each other, as shown in FIG. An elliptical jet as shown by C is formed, and the diameters Φ1 and Φ2 are made different from each other as described above, so that a difference occurs in the force of the air jet, which is deflected as shown in FIG. The fuel injected from the injection valve nozzles 4a and 4b passing therethrough is also unified and affected by the deflection of the air jet.
[0039]
Therefore, if the deflection direction B is set closer to the center of the combustion chamber 10 in the annular portion between the intake valve 2 and the seat as shown in FIG. 5C, the fuel is injected from the injection ports 4a and 4b of the fuel injection valve 3. The concentrated fuel is deflected to the branch passage 22b without the SCV 13 by the high-speed air flow blown from the air nozzles 9 and 91 during low load operation, and concentrated on the corresponding C region of the intake valve 2 shown in FIG. Be guided to. Therefore, the fuel injected from the injection valve 3 collides with a position C near the spark plug 11 of the annular portion 5 of the intake valve 2 without being surrounded by the air flow and diffusing. When the intake valve 2 is opened, the fuel adhering to the C position is re-atomized by the air jet B and supplied to the vicinity of the spark plug 11 in the combustion chamber 10 in the same manner as described in the first embodiment.
[0040]
Further, in this embodiment, during low load operation, the SCV 13 is closed, so that an eddy current is generated in the cylinder 11 due to the air flow from one branch passage, and the swirl enters the center of the combustion chamber as a whole. Diffuse to form a good mixture.
[0041]
When the load increases and the high load operation is performed, the SCV 13 is opened. In this case, since the pressure difference between the upstream and downstream of the throttle valve is small, high-speed airflow from the nozzles 9 and 91 does not occur, and the injected fuel passes separately through the branch passages 22a and 22b. It collides with each intake valve 21, 22.
[0042]
In this case, since the air flow rate in the intake passage 22 is high, the fuel is atomized by the intake air passing through the intake valves 2 and 21.
[0043]
The structure of the injection valve 3 is shown in FIG. The nozzle body 4 of the injection valve 3 is provided with fuel injection ports 4a and 4b. The valve 31 is pulled up by the electromagnetic force of the electromagnetic coil. The injection valve 3 is attached to the intake pipe 22 via a seal 23. An air nozzle body 6 is attached to the tip of the nozzle body 4 and its nozzle holes 91 and 92 are provided. Air is introduced into the air nozzle 6 from the upstream side of the throttle valve via the bypass passage 8 provided in the intake pipe 22.
[0044]
According to this embodiment, the same effect as that of the first embodiment can be obtained even with an engine having two intake valves per cylinder.
[0045]
FIG. 7 shows a conventional fuel supply device for a two-intake / one-cylinder engine illustrated for comparison with the first and second embodiments. The fuel injected from the injection valve 1 is the intake valve 2. 21 enters the cylinder 10. At that time, fuel adheres to the F1 and F2 portions of the cylinder wall. FIG. 8 is a fuel supply device for an engine of 1 intake valve / 1 cylinder specification illustrated for comparison with the first and second embodiments. A branch passage is formed at a position near the cylinder in the intake passage. An SCV 13 'is provided in one of the branch passages. In this case, when the SCV 13 'is closed during partial load operation and fuel and intake air are introduced into the branch passage without the SCV 13', the fuel injected from the injection valve 3 passes through the intake valve 2, passes through the F3 portion of the cylinder 4. Adhere to.
[0046]
In these fuel supply devices in FIGS. 7 and 8, the wall-attached fuel evaporates by receiving heat from the wall, but does not move to the center of the cylinder by swirl, and in order to make the air-fuel mixture uniform, A strong skew is necessary. Even if a vertical swirl is generated, it is difficult for the fuel vapor to move to the center. Although the SCV 13 is also used in the second embodiment, in this case, the atomized fuel concentrates in the center of the combustion chamber and diffuses around the center from the center. Does not occur.
[0047]
That is, in order to solve the above problems, as in the first and second embodiments, before the intake stroke, a position closer to the center of the combustion chamber (position close to the spark plug) on the upper surface of the head of the intake valve 2 is used. This can be achieved by collecting the injected fuel and re-atomizing it by the venturi effect caused by the high-speed air flow from the air nozzle.
[0048]
FIG. 9A shows another conventional fuel supply apparatus for an engine.
[0049]
In this conventional example, the fuel injected from the injection valve 50 into the intake passage 51 is carried by an air flow that bends at the intake port of the intake passage 52. However, the air flow follows the slope on the upper surface of the head and flows laterally. Thus, the injected fuel riding on this air flow collides with the combustion chamber wall surface 53 to form a liquid film 54. As a result, the liquid film is incompletely burned and exhausted, causing an increase in the amount of unburned hydrocarbons. This problem occurs particularly in the partial load operating region.
[0050]
In order to prevent this, as shown in FIG. 9B, in addition to providing the fuel injection valve 50 downstream of the throttle valve in the intake passage 51, a high-speed air flow is generated near the intake valve 52 of the engine during low load operation. A means for forming, for example, an auxiliary air passage 57 is provided (a specific example of the means for forming a high-speed air flow will be described later). This is achieved by setting a blowing angle that is a vertical flow at the passing position.
[0051]
In this way, even during partial load operation, fuel can be put on the high-speed air flow 56 from the auxiliary intake passage 57 to form an air-fuel mixture in the center of the combustion chamber. Therefore, fuel adhesion is eliminated, combustion efficiency is improved, and the amount of unburned hydrocarbons in the exhaust gas is greatly reduced.
[0052]
FIG. 10 shows an example (third embodiment) for realizing the principle of FIG. 9B. This example is claimed 2 This is a specific example.
[0053]
In this embodiment, the fuel injection valve 60 is disposed downstream of the throttle valve 67 in the intake passage 69, and the passage downstream of the throttle valve 67 in the intake passage 69 is divided into a main air passage 66 and an auxiliary air passage 63 in the vertical direction. An auxiliary valve 64 is provided in the main air passage 66 serving as a lower passage. The auxiliary valve 64 is controlled so as to be closed during low-load operation using an actuator, or is linked to the throttle valve 67. The outlet of the auxiliary air passage (upper passage) 63 is set so as to blow out air toward a position near the center of the combustion chamber 68 in the periphery of the head of the intake valve 61. The injection valve 60 is configured such that injected fuel is injected toward the center of the combustion chamber in the head of the intake valve 61.
[0054]
67 bypasses the throttle valve 67 and introduces the air upstream of the throttle valve into the nozzle of the injection valve 60 to atomize the injected fuel, and the bypass 67 is not necessary for the following effects.
[0055]
In the above configuration, the auxiliary valve 64 is closed during partial load operation. As a result, the air flowing downstream of the throttle valve 67 is guided to the auxiliary air passage 63 with a narrowed opening area, so that the air flow rate increases and a high-speed air flow is formed.
[0056]
The fuel injected from the injection valve 60 collides with the combustion chamber center side on the intake valve 61. An air flow 62 from the auxiliary air passage 63 is supplied so that the injected fuel just hits the intake valve 61. When the auxiliary valve 64 is closed, most of the air taken into the engine flows through the auxiliary air passage 63. Thereby, a vertical air flow 65 is formed in the combustion chamber. Due to this vortex, the air-fuel mixture does not travel laterally, and the fuel rides on the airflow and is concentratedly supplied to the center side of the combustion chamber, so that adhesion to the wall surface can be prevented.
[0057]
Further, since the auxiliary valve 64 is closed, the air flow does not hit the fuel 66, the spraying direction is not bent, and it goes straight to the target position on the intake valve 61.
[0058]
During the fully open operation, the auxiliary valve 64 is opened, and air is sucked into the engine without intake resistance.
[0059]
FIG. 11 shows the principle of the embodiment of FIG. 10 applied to a two-intake valve / cylinder engine (fourth embodiment). In The
[0060]
The fuel injection valve 73 has a plurality of fuel injection ports corresponding to the two intake valves, and branch passages 76 a and 76 b corresponding to the intake valves 70 and 70 are formed in a position near the cylinder in the intake passage 76.
[0061]
The branch passages are divided into main flow passages 76a ′ (76b ′) and auxiliary air passages (longitudinal airflow forming means) 76a ″ (76b ″). Main style Road 76 a ′ and 76 b ′ are controlled to open and close by the auxiliary valve 71. Here, the fuel is atomized by the air flow supplied from the air passage 75 bypassing the throttle valve 74, but the injection valve without the bypass 75 may be used. The auxiliary valve 71 may be interlocked with the throttle valve 74 or may be driven by a negative pressure diaphragm so as to be operated by the negative pressure of the intake pipe 76 so as to open at a low load.
[0062]
FIG. 12 also shows an application example of FIG. 10 (fifth embodiment). In The
[0063]
Also in this embodiment, the engine is a two-intake valve / cylinder type, and branch passages 84a and 84b corresponding to the respective intake valves 80 are formed in the vicinity of the cylinder 85 in the intake passage 84, and only one of the branch passages 84b is formed. Fuel is injected from the fuel injection valve 81. FIG. 12B is a side view, in which the cylinder of the branch passage 84b is divided into two parts in the vertical direction, and the auxiliary valve that is controlled to open and close in accordance with the engine load state in the lower passage among the divided passages. 82 is provided, and the upper passage 83 is set so as to function as a longitudinal airflow forming means.
[0064]
In the present embodiment, a mixture of fuel and air is supplied from one intake valve, and only air is supplied from the other intake valve. In this way, the air-fuel mixture distribution in the combustion chamber 85 can be made deeper and thinner in a certain portion, and the entire combustion chamber can be burned with a thin air-fuel mixture to obtain a lean burn mode.
[0065]
When the auxiliary valve 82 is closed during partial load operation, air passes through the upper half passage 83 and flows into the center of the combustion chamber 85 of the intake valve 80 as a vertical flow, forming a vertical vortex. By this vortex, the air-fuel mixture is agitated and the air-fuel mixture distribution becomes uniform.
[0066]
FIG. 13 shows a sixth embodiment. You . In this embodiment, a part of the one intake valve / cylinder intake passage 107 downstream of the throttle valve 104 is divided into upper and lower passages, an auxiliary valve 103 is provided in the lower passage 107b, and the auxiliary valve 103 is closed. The upper passage 107b functions as a vertical airflow forming means similar to the fifth embodiment. Reference numeral 105 denotes a fuel atomization bypass that guides air to the tip of the injection valve 106.
[0067]
According to the present embodiment, when the auxiliary valve 103 is closed, the air flows into the upper half passage 107b of the intake pipe, whereby the vertical flow of air flows into the center of the combustion chamber of the intake valve 89, and the combustion chamber A vertical vortex is generated at the center, and the combustion chamber is well stirred to form a good mixture.
[0068]
FIG. 14 shows a seventh embodiment. This embodiment claims 3 This is a specific example.
[0069]
In this embodiment, the fuel injection valve 95 is arranged downstream of the throttle valve 91 in the intake passage 96, but the auxiliary valve is not provided, and the auxiliary air passage 90 is formed in a form bypassing the throttle valve 91. Air from the upstream side of the throttle valve (auxiliary air) introduced from the auxiliary air passage 90 is blown out near the intake valve 94, and a vertical air flow is directed toward a position closer to the center of the fuel chamber between the intake valve 94 and its seat. It is designed to form.
[0070]
For this reason, when the throttle valve 91 is not fully opened (partial load operation), air flows through the auxiliary air passage 90 and a high-speed air flow is ejected from the blowout hole 93. This air flow is injected so as to collide with the center of the combustion chamber of the intake valve 94. For this reason, a minute vortex is formed in the center of the combustion chamber. By this vortex, the air-fuel mixture is agitated and the air-fuel mixture distribution in the combustion chamber becomes uniform.
[0071]
In this embodiment, the auxiliary air passage 90 may be provided with a cut valve 95 that closes during idle operation. This is because the amount of required air is small during idle operation, and if auxiliary air is flowed, the number of revolutions increases and fuel efficiency deteriorates.
[0072]
In order to further improve the accuracy, a control valve (solenoid valve) 124 may be used in the auxiliary air passage 90 as shown in the eighth embodiment of FIG. Reference numeral 125 denotes a control unit for the electromagnetic valve 124.
[0073]
FIG. 16 shows an example of a time chart of the control operation of the solenoid valve 124. (A) shows the intake state of a certain cylinder. In this intake state, the electromagnetic valve 124 is opened and auxiliary air is supplied as shown in (b) to form a minute vortex in the combustion chamber. If the auxiliary air is supplied at a time other than the intake stroke, the fuel remaining near the intake valve blows up to the upstream side of the intake pipe. Therefore, this can be prevented by performing the electromagnetic valve control as described above.
[0074]
Also, during idle operation, the amount of intake air increases and the rotational speed increases.
[0075]
(C) shows the intake stroke of another cylinder. In response to this, the solenoid valve 124 is operated as in (d).
[0076]
FIG. 17 shows a modification of the eighth embodiment (the ninth embodiment). A distributor 126 is provided instead of the solenoid valve 124 of FIG. The distributor 126 supplies auxiliary air to the passages 127a, 127b, 127c, and 127d corresponding to the respective cylinders. The distributor 126 is configured so that air flows when each cylinder is in the intake stroke.
[0077]
The distributor 126 is a rotary type, and 128 is a drive source thereof, and may be driven by, for example, an engine crank, or a motor that rotates in synchronization with the rotation of the engine. Even with such a configuration, the same operation as in the eighth embodiment is possible.
[0078]
Further, the opening degree of the auxiliary air passage may be controlled by the idle rotation control unit using an electromagnetic valve capable of continuous control instead of the electromagnetic valve of the eighth embodiment.
[0079]
FIG. 18 shows a tenth embodiment of the present invention. 4 This is a specific example.
[0080]
In this embodiment, each cylinder of the engine has two intake valves 109a and 109b, and the throttle valve downstream of the intake passage 107 is branched into two corresponding to the intake valves, and the engine 107 is connected to one of the branch passages 107a. There is provided an auxiliary valve 108 that is controlled to open and close according to the load operation state. The auxiliary valve 108 is closed during the partial load operation and opened during the fully open load operation.
[0081]
As shown in FIG. 18A, when the auxiliary valve 108 is open, the fuel injection valve 110 uniformly injects fuel toward both the branch passages 107a and 107b, and when the auxiliary valve-less 108 is closed, As shown in FIG. 18B, the fuel is set to be deflected and injected into the passage 107b without the auxiliary valve.
[0082]
FIG. 19 shows the configuration of the tip of the injection valve in FIG. FIG. 19A shows a state in which fuel is supplied to one intake valve when the auxiliary valve is closed. 113 is a blow-off passage of a bypass passage that guides air from the upstream side of the throttle valve, for example, and deflects the fuel trajectory by applying a high-speed air flow ejected from this passage 113 to the fuel immediately after injection from the metering orifice 112. . This deflection angle is the passage 107a in FIG.
[0083]
FIG. 19B shows a state in which the air flow from the air passage 113 is stopped. The fuel gushes straight without bending. This is performed when the auxiliary valve 107 in FIG. 18 is opened.
[0084]
According to the present embodiment, when the auxiliary valve 107 is closed, the intake air is supplied only from one passage 107a, and a large vortex is formed in the combustion chamber to promote the agitation of air and fuel, so that the mixture formation is good. To. When the auxiliary valve 107 is closed, the injection fuel is prevented from adhering thereto.
[0085]
20 is a partial cross-sectional view of the eleventh embodiment and its top view, and FIG. 5 This is a specific example.
[0086]
In this embodiment, the engine is a two-intake valve / cylinder type, and the throttle valve 99 downstream of the intake passage 96 is branched into two corresponding to the intake valves 100a and 100b. The bypass passage 96a takes in auxiliary air from the upstream side of the throttle valve 99 of the intake passage 96 and blows it out downstream of the throttle valve. The air outlet 96a 'of the bypass passage 96a is opposed to one end face of the partition wall 97 of the branch passage at an upstream position near the branch passage. Further, a fuel injection valve 98 is arranged on the extension line of the partition wall 97 and the air outlet 96a 'and immediately upstream of the air outlet 96a'.
[0087]
The air flow supplied from the bypass passage 96 a is ejected so as to collide with the end face of the partition wall 97. In this way, a minute vortex is formed at the center of the combustion chamber. The fuel ejected from the injection valve 98 is dispersed in the combustion chamber while diffusing along this vortex, and the mixture distribution in the combustion chamber becomes uniform. In this case, it is better not to inject the fuel to the outside 101 of the intake valves 100a and 100b. (If the fuel is supplied to the outside, the fuel is scattered on the wall of the combustion chamber, and attached fuel is generated. This can be achieved with the spray direction of the injection valve 98.
[0088]
FIG. 22 (a) shows a twelfth embodiment, 6 This is a specific example.
[0089]
In this embodiment, a pipe 116 is connected to the injection port of the fuel injection valve 115, and the injected fuel is guided through the pipe 116 to a position near the center of the combustion chamber between the intake valve 117 of the engine and its seat. I made it. In this way, the injected fuel travels straight without flowing in the airflow in the intake pipe 118 and reaches the target position.
[0090]
Also in this embodiment, it is possible to prevent the injected fuel from adhering to the combustion chamber wall.
[0091]
FIG. 22 (b) shows a modification of the twelfth embodiment (13th embodiment). 7 This is a specific example. The fuel injection valve 122 is disposed downstream of the throttle valve 121, and the air upstream of the throttle valve introduced from the passage 120 bypassing the throttle valve 121 blows out from the vicinity of the injection port of the fuel injection valve 121. A pipe 119 directed to the intake valve of the engine is connected to the injection port of the fuel injection valve 122, and the angle of the pipe 119 is between the intake valve 117 of the engine and the seat together with the air blown from the bypass passage 120. It is set to lead to a position near the center of the combustion chamber.
[0092]
According to the present embodiment, in addition to the same effects as in the twelfth embodiment, even when fuel injection is performed during the intake stroke, the air flow blown through the bypass passage 120 and the pipe 119 causes a minute amount in the combustion chamber. The vortex 65 is formed, and the fuel injected from the injection valve 122 is atomized by the air flow to further improve the air-fuel mixture formation and improve the fuel control response by supplying the fuel during the intake stroke. be able to.
[0093]
FIG. 23 shows a modification of the thirteenth embodiment (fourteenth embodiment). The difference from the thirteenth embodiment is that the fuel injection stroke is set before the intake stroke.
[0094]
According to this embodiment, the injected fuel that has collided with the intake valve 117 via the pipe 119 is atomized by the intake valve 117 by the air flow blown through the pipe 119. Also in this case, the fuel opens the pipe 119 toward the center of the combustion chamber on the intake valve.
[0095]
FIG. 24 is an example showing a connection structure between the pipe 119 and the injection valve 122, and air from the bypass passage 120 is supplied to a chamber 123 provided at the lower portion of the injection valve 122. From here, it is supplied into the pipe 119 through the hole 124. Inside the pipe 119, the injected fuel is blown out from the pipe end portion 125 without colliding with the inner wall of the pipe so as to be enveloped in the air.
[0096]
FIG. 25 shows another example of the pipe 119. In the pipe 119 double-passage structure, the injected fuel is passed through the inner passage 119b and the air from the bypass passage 120 is passed through the outer passage 119a.
[0097]
The inner passage 119 b of the pipe 119 is at the same level as the pressure in the intake pipe 118 via the communication passage 127. Air blown from the outer passage 119a through the opening 119a 'collides with the fuel 126 and is atomized. When there is no communication path 127, the pipe interior 119b becomes negative pressure by the injected fuel, and the fuel spreads and adheres to the inner wall of the pipe. If the communication path 127 is provided, the pressure in the intake pipe 118 and the pressure in the pipe 119b become equal, so that it is possible to prevent the spread of fuel and thus the adhesion of fuel.
[0098]
FIG. 26 shows a fifteenth embodiment of the present invention, which is a modification of the twelfth to fourteenth embodiments. 8 This is a specific example.
[0099]
The present embodiment is applied to a two-intake valve / cylinder type engine. One of the branch passages 118a corresponding to the intake valve 117a is provided with an SCV 108 that is controlled to open and close in accordance with the load state of the engine. In the branch passage, it is introduced into the direction 118b without the SCV. The pipe 119 supplies fuel only to one intake valve 117b and supplies it to a position near the center of the combustion chamber of the intake valve 117b.
[0100]
In this way, the fuel is distributed at the center of the combustion chamber, and the ignitability of the spark plug 131 is improved. Further, when the intake port of the branch passage 118a is closed by the SCV 108, a swirl is formed in the combustion chamber, and the formation and combustion of the air-fuel mixture are promoted.
[0101]
FIG. 27 shows a modification of the fifteenth embodiment (the sixteenth embodiment). The pipe 119 is opened so that fuel is supplied to the center of the head of the intake valve 117b. Even in this case, the air-fuel mixture can be distributed in the center of the combustion chamber.
[0102]
FIG. 28 shows a modified example of the double-structure pipe 119. A wedge-shaped member 135 is provided at the end of the pipe 119, and the injected fuel is set to collide therewith. Further, the atomization of the fuel is attempted so that the air injected from the outer passage 119a hits the wedge-shaped member 135. FIG. 29 shows an embodiment (seventeenth embodiment) using the pipe 119 of FIG. The fuel is divided in two directions by the wedge member 135 and is distributed to the intake valves 117a and 117b.
[0103]
FIG. 30 shows another example of the double structure pipe 119. When the air passing through the outer passage 119a of the pipe 119 is blown out from the end portion 119a ′, the air blows out in the direction of the air outlet 119a ′ so as to collide with the intake valve 117 or the gap between the intake valve 117 and the seat 136. Decide. In this way, the fuel can directly flow into the combustion chamber, and the air ejected from the pipe 119 is not only used for atomization of the fuel, but also forms a minute turbulent flow 137 in the combustion chamber, and the fuel Promote mixing. Furthermore, combustion is promoted by this turbulent flow.
[0104]
【The invention's effect】
As described above, according to the present invention, since atomized fuel can be supplied to the combustion chamber while preventing fuel from adhering to the wall surface of the combustion chamber, the mixture formation in the combustion chamber is improved, and combustion efficiency and exhaust purification are improved. Can do.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a first embodiment of the present invention.
FIG. 2 is an explanatory diagram showing a fuel adhesion state of an intake valve after fuel injection according to the first embodiment.
FIG. 3 is an explanatory diagram showing the operation of the first embodiment.
FIG. 4 is an explanatory diagram showing the operation of the first embodiment.
FIG. 5 is an explanatory diagram showing a second embodiment of the present invention.
FIG. 6 is a sectional view showing a nozzle portion of an injection valve used in a second embodiment.
FIG. 7 is an explanatory diagram showing problems of the conventional example
FIG. 8 is an explanatory diagram showing problems of the conventional example
FIGS. 9A and 9B are explanatory views showing problems of the conventional example, and FIG. 9B is an explanatory view showing the principle of the present invention.
FIG. 10 is an explanatory diagram showing a third embodiment of the present invention.
FIG. 11 is an explanatory diagram showing a fourth embodiment of the present invention.
FIG. 12 is an explanatory view showing a fifth embodiment of the present invention.
FIG. 13 is an explanatory view showing a sixth embodiment of the present invention.
FIG. 14 is an explanatory diagram showing a seventh embodiment of the present invention.
FIG. 15 is an explanatory view showing an eighth embodiment of the present invention.
FIG. 16 is a time chart showing the operating state of the eighth embodiment.
FIG. 17 is an explanatory view showing a ninth embodiment of the present invention.
FIG. 18 is an explanatory view showing a tenth embodiment of the present invention.
FIG. 19 is an explanatory view showing a nozzle portion of an injection valve used in the tenth embodiment.
FIG. 20 is an explanatory view showing an eleventh embodiment of the present invention.
FIG. 21 is a view from another angle of the eleventh embodiment.
22A is an explanatory view showing a twelfth embodiment of the present invention, and FIG. 22B is an explanatory view showing the thirteenth embodiment.
FIG. 23 is an explanatory view showing a fourteenth embodiment of the present invention.
FIG. 24 is an explanatory view showing an example of an injection valve and a pipe used in the thirteenth and fourteenth embodiments.
FIG. 25 is an explanatory view showing another example of the pipe.
FIG. 26 is an explanatory view showing a fifteenth embodiment of the present invention.
FIG. 27 is an explanatory view showing a sixteenth embodiment of the present invention.
FIG. 28 is an explanatory view showing another example of the pipe.
FIG. 29 is an explanatory view showing a seventeenth embodiment of the present invention.
FIG. 30 is an explanatory view showing another example of the pipe.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Engine, 2, 21 ... Intake valve, 3 ... Injection valve, 4 ... Injection nozzle body, 4a ... Fuel injection port, 5 ... Between intake valve and seat (annular part), 6 ... Air nozzle body, 8 ... Bypass passage (High-speed air flow forming means), 9a, 9b ... air outlet, 9, 91 ... air outlet, 10 ... combustion chamber, 11 ... spark plug, 13 ... SCV, 15 ... throttle valve, 22 '... partition wall, 22a , 22b ... branch passage, 57 ... bypass passage (longitudinal airflow forming means), 119 ... pipe.

Claims (3)

In a fuel supply apparatus having a fuel injection valve in an intake passage of an engine, each cylinder of the engine has two intake valves, and a throttle valve downstream of the intake passage is branched into two corresponding to the intake valve. In addition, a swirl control valve is provided in one of the branch passages to close at least when the engine is operated at low load, and when the swirl control valve is closed, swirl is generated in the cylinder by the air flow from one branch passage,
The fuel injection valve is a two-way injection valve that is located upstream of a branch point of the branch passage and injects fuel in two directions corresponding to the branch passage;
And the low-load intake air flowing into the intake passage during operation, the vicinity of the two directions injection port between the said branch point of the intake passage and two directions injection port of the fuel injection valve by bypassing the throttle valve A bypass passage is provided to blow out the fuel, and the sprayed fuel sprayed from the fuel injection valve by the blown air is unified in the two directions to be unified in the intake passage and deflected to the branch passage without the swirl control valve. was intensive fuel spray after deflection by changing the advancing angle to the position of the combustion chamber closer to the center between the combustion chamber closer to the center position or the intake valve seat on the head of one of the intake valve than fuel spray before deflection The fuel supply device for an engine is set so as to reach The engine fuel supply device according to claim 1, wherein the unified injected fuel is set so as to collide with a portion of one intake valve close to the spark plug. 3. Two nozzle holes serving as air outlets of the bypass passage are formed, air jets blown from these nozzle holes are set to collide, and the diameters of the nozzle holes are set to be different. The fuel supply device for the engine described.

Images