JPS6036721A - Stratified-mixture supplied engine - Google Patents

Abstract

PURPOSE:To enable to raise the intake efficiency of an engine, by selecting either of stratified combustion or homogeneous combustion according to the engine load, and weakening the intensity of swirl at the time of homogeneous combustion as compared with that at the time of stratified combustion by a swirl control means. CONSTITUTION:At the time of low-load operation of an engine detected by a detecting means 17, a control unit 19 consisting of a microcomputer or the like controls the quantity of intake air to keep it constant by fully opening a throttle valve 14 and functions to cause stratified lean combustion by supplying stratifying fuel toward an igniting means 8 from an injection nozzle 9. When the engine load is raised to a prescribed value, the combustion mode is switched to homogenenus combustion by decreasing the quantity of stratifying fuel and starting supply of scattering fuel from an injection nozzle 12 to compensate the decreased quantity of fuel. Further, at the time of low-load operation of the engine, the control unit 19 functions to strengthen the swirl by closing a swirl control plate 16 by a swirl control means 18, and the swirl is weakened with lowering of the load. On the other hand, at the time of high-load operation when homogeneous combustion is employed, abnormal rise of the combustion speed is prevented by weakening the swirl and the intake efficiency is raised by reducing resistance to the intake-air flow.

Description

[Detailed description of the invention] (Industrial application field) BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stratified air charge engine.

(Prior art) Conventionally, for the purpose of improving the fuel efficiency and emission performance of an engine, the fuel necessary for ignition out of the fuel supplied to the combustion chamber according to the load has been unevenly distributed near the ignition device. A stratified air charge engine that can realize lean combustion as a whole by enriching the air-fuel ratio only in this part to perform stratified combustion with improved ignitability has been proposed, for example, in Japanese Patent Application Laid-Open No. 49-6280.
No. 7, JP-A-49-128109.

In the above-mentioned stratified air supply engine, the ignition fuel supplied around the ignition device is constant regardless of the load, and at the same time the ignition fuel 13+ is supplied, an amount of dispersed fuel corresponding to the zero load is supplied. At low loads, the proportion of fuel unevenly distributed around the ignition device is large, resulting in stratified combustion, while at high loads, the proportion of fuel distributed and supplied to J3 increases. I will do it.

Therefore, in stratified combustion where fuel is unevenly distributed around the ignition device, when shifting from C stratified combustion to uniform combustion as the load increases as shown in [-], the ignition device N ignites the In order to sufficiently mix the stratified fuel with air and propagate the flame throughout the combustion chamber to sufficiently burn the entire supplied fuel, it is necessary to generate a swirl in the intake air introduced into the combustion chamber. On the other hand, in the case of uniform combustion where fuel is distributed and supplied, the amount of intake air increases, and the swirl becomes stronger, and the generation of such a strong swirl actually causes an abnormal increase in the combustion rate. Combustion noise and knocking based on 1r1<b
In addition, the generation of swirl itself causes intake resistance, reducing intake efficiency and causing power loss.

([-1] of the invention) In view of the above-mentioned circumstances, the present invention provides a7 !lC1 TA11 or (' means 5) of fuel is dispersed and supplied throughout the combustion chamber to achieve good θI'Q scrap combustion and uniform combustion.
1, while ensuring reliable 41 layered combustion due to strong swirl and 1 formation at low t1 lX:+, while high
, 16: + It, ) The purpose of this invention is to provide an If/i-type intake engine in which the occurrence of (Puru noise I) and output loss are improved.

(Structure of the Invention) The stratified air supply of the present invention is equipped with a stratified air supply engine (, L, around a large device in the combustion chamber) - a fuel 11 supply for supplying fuel, and ignition from the fuel supply means at low load. l'ii ii
51.4) In the case of high load I), the fuel is dispersed throughout the meat, and the stone fire is distributed over the whole meat. 11 (In order to achieve uniform combustion by feeding and igniting the air, a swirl control means is provided to give a swirl to the intake air flowing into the combustion chamber and to control the strength of the swirl.) ], The uniform combustion 11,) is characterized by the fact that the C swirl is weaker than in stratified combustion.

(Effect of the invention) 33-11 ((1r=“■Cough odor (1.
, combustion 4. i,? Ignition device 81: When fuel is supplied unevenly to 7F to 471, reliable stratified combustion is achieved by the generation of 0-strong sparks, and fuel efficiency is achieved by lean AU combustion. , 1+3 in the high ti driving range
For fuel supply means. 1. Disperse the fuel and weaken the swirl to achieve uniform combustion, reducing intake resistance without producing smoke or combustion noise,
It is possible to improve intake efficiency and ensure good rr high output operation.

(Actual fJ1!1 example) 1. Referring to drawings IJJ and 1, the actual embodiment of the present invention will be explained in detail.

Example 1 In this example (as shown in FIGS. 1 to 5), the fuel IJξ
The fuel supply stage F is divided into a first fuel supply means for stratification and a second fuel supply means for dispersion.
This figure shows an example in which the fuel supply 1"9 is configured.

In Fig. 1, -4, -1 engine is located at d3, 1 is a combustion chamber formed on one side of the piston 2, 3 is an intake passage through which intake air is introduced into the combustion chamber 1, 4 is combustion chamber 1 to 1) 1
C shows the catalyst device installed in the ventilation 4, which discharges gas (11 gas passage, E) la, 19 J gas r, 611 exhaust valve, 7 i, l il+l.

The combustion chamber 1 is provided with an ignition device 8 using a spark plug, and a stratified fuel injection nozzle 9 for supplying fuel is provided around the ignition device 8. A fuel injection 0=1 pump 10 is connected to the fuel injection pump 9, thereby forming a first fuel injection means 11.

On the other hand, the intake passage 3 is provided with a second fuel supply f through a dispersion fuel injection nozzle 12 which distributes and supplies fuel into the combustion chamber 1.
A stage 13 is interposed. Furthermore, this dispersion fuel lI
7! A throttle valve 1/l is arranged downstream of the river nozzle 12,
This throttle valve 14 is equipped with an actuator 15 ()7 which performs the closing operation during that time.
A space (not shown) is provided to control the area of the intake passage 3.

Furthermore, as shown in FIG. 2, in the downstream portion of the intake passage 3, 1 (1) is applied to a freely rotatable swirl adjustment plate 1, and 16 (J) is applied to this swirl adjustment plate 1.
Is the opening/closing movement a'1? [The actuator 17 is connected so that the intake air introduced into the "C1 combustion chamber" is 71 in the circumferential direction.
Swirl control means 18 is configured to apply the swirl noll S and control the swirl strength. In other words, the swirl adjustment blows 1 to 16 are closed and the second In the state shown in the figure, IJ, the intake air is throttled by this swirl adjustment plate 16'C:f
, the flow velocity increases, and the intake air is introduced from the tangent to the combustion What is the force in the 11 turning direction? j is not generated, and no swirl is generated.

111: Fuel injection pump 1 of first fuel f'l supply NV11
0, 2nd fuel supply stage 1 stage 13 dispersion fuel injection 64 nostle 12, throttle valve 1/10') 7 Kuchiko J-ta 15, and swirl control tall "1" IJ 1 B's actuator 17. , controlled by the control [stage 11].

1-The closing spring 11 means 19 is a load detecting means 20 for detecting the zero load of the engine by, for example, an accelerator sensor.
Receives the negative front signal from the engine, the engine rotation signal from the engine rotation signal 21, etc. Even if the injection q1h1 is controlled downwardly (3. 1° upward t1 control means which controls the early opening operation of the comparison valve 14 and the opening degree of the throttle adjustment plate 1-16). According to No. 19 (fuel supply amount control corresponding to one load is performed by receiving the signal from the detection means 20 on the 11th t-j,
During regular operation in the low/medium load range below the nQ constant load, the second fuel supply means 13 stops supplying distributed fuel, and the first fuel supply means 11 is supplied with stratified fuel. Stratified combustion is carried out by supplying the stratified fuels 1 and 1, and the supply of stratified fuel is increased as the load increases, and when the set load is exceeded, the supply of stratified fuel is reduced. On the other hand, the distributed fuel by the second fuel supply means 13 starts to be supplied on the f1 load in the vicinity of the above set angle, and is used to compensate for the decrease in stratified fuel by the first fuel F1 supply means 11. , the total supply increases as the load increases.

7-11 (The fuel supply fr1 is increased to shift from stratified combustion to uniform combustion. At that time, the injection IJJ l'i2 for each injection, the injection number (511292 rotation speed) Correspondingly cover the settings.

J/', S4-,, The first fuel supply f stage 11 + h'+ corresponding to the f1 load of the engine, and the fuel supply hl control til+ to the second fuel stage supply means 13 are shown in Figure 13. Figure 33 shows the fluctuations in the fuel supply amount Q from 01 to 1 on November 9 and the fluctuations in the excess air ratio λ, and the throttle valve 14 is Basically, the intake air ω is constant in the fully open state, and ti A (7) Increase the fuel supply ♀Q with respect to I[i addition (]) (Reduce the air excess II!ll ratio λ, that is, increase the air-fuel ratio m <t,'r In the 1-fuel supply oak Q, which is provided to perform output control, in the area 1
of fuel is supplied to the first fuel supply means 1 'Ih' 6,
The fuel in the region (■) is supplied from the second fuel (1) from the first stage 13. The supply of stratified fuel by the first fuel 1'H1 supply means 11 is at the set load number at point A] (kl, It This setting C'i dh increases as the load increases.
When the point Δ is exceeded, the supply of fuel r1 from the first fuel supply means 11 is reduced, and when the load exceeds the point B = 8- (,1, stratified fuel 'PI l115 a
・Prevention of clogging and Iln with carbon of I nozzle 9
Continuing small injections on heat shield 11-V).

-h, the supply of the dispersed fuel 11 by the second fuel supply means 13 starts at the set load number at point A, and when the load increases, the first fuel supply means 11 starts supplying the stratified fuel 11. This is to compensate for the decrease in the supply of fuel, and to supply increased fuel in response to the overall increase in zero loads.

The set load at point A in Table 10 is set to 0 load state, where at point A, 1 IJ of excess air λ is below the shield-large limit excess air ratio λ that allows ignition even in a homogeneous mixture. ,Also,
The zero load at point B is then r:, I is a-31, the air excess ratio λ is j for stratified combustion, and the air utilization rate is i1 (the air excess ratio 2 is lowered and smoke begins to occur). The above J,
The load condition is set as follows.

Therefore, under the above A points, there is a stratified combustion region in which fuel is supplied unevenly around the ignition device 8 of one combustion chamber 1, and at points 8 and above, fuel is supplied in a distributed manner throughout the combustion chamber 1. In the uniform combustion region, the area between A and 13 is F? #): Transition region from the combustion Q'+ region to the uniform combustion region.

In addition, 1 of the dispersed combustion H by the rice 12 combustion 11j feeding stage f 13
1 (feeding start period 11.ff!1) of the stratified fuel r1 by the fuel supply means 11 Negative summon ■ state (・You can open the 11 salary and get 11.

Stratified combustion *3 (
Supply and second fuel supply - The switching λ of distributed fuel It supply by ru13 gradually decreases and increases as lx ii [! [Since] layered rP, i I--, it is switched in a Δn・A-like manner so that b J, i.

Next, FIG. 1 shows the injection timing of the stratified fuel (ll?J!
In the region where stratification is performed under the 8Q constant C'J 6:t I of the above A point, the injection ■S light is 11g l1ii-191S point. 69 constant (＼Re, 1
lrj EJ・j The fuel is polarized around the ignition device 8 to the right 9) r flif CW so (1-1. Cross the above point A to 3 points /) iii 1- row:) As it moves to territory 1 - (, sentry C1l 11.7 tllll
Woshin Nr C'+4 Lz l Samurai 111]
) Wow? '[A, first fuel supply means 11 to
1) reduce the combustion chamber 1
(So that it is dispersed throughout the body). I, :, J of idling Itγ, when the load is extremely low, the ignition timing is slightly advanced and the ignition timing is stable +'l.

Opening/closing control of throttle valve 1/1 by control means 19)
J, lit actually leave & throttle valve 14 open. s
bL, < is a reduction 'r'M ILT's J, Unagami low load poetry, or engine cooling, which reduces intake air bj by reducing 1α.

Further, the control 11 means 19 controls the snow blowing force (
211 Tsunawa I Swirl system 9 (1 means 18 stool adjustment gray 1 to 16 1α control is as shown by the solid line in Fig. 5), the swirl adjustment is performed at low Q load below the set load △ + 1 s. Plays 1 to 16 are closed to strengthen the swirl, and the point B becomes 1, so almost no swirl is generated.This swirl ratio is calculated by converting engine speed = 1 1-'17 into・There is a ratio C of the thrill rotation speed, strong swirl, and 4 more \.

/, 1, Ru ``ILT El visit A +,',t
f/, T' LJ, n Sen is low Y;
, r (set so that the fuel injection is weakly generated.This 41 is a low C).At some point, the amount of fuel injection Q=J is also small, and the amount of fuel injection Q'f is very low. Swirl is weak when C1 is loaded with low 0, and 1, U, and snorl (1), which is strong against C1, makes the stratification of the fuel unstable and may lower the ignitability. I have to.

, (, t, 2, -1 - Power distribution () The special 1 () shown by the solid line in the diagram is for the case where the swirl strength can be continuously controlled 11, and the swirl control J first stage I F3 is Swirl adjustment plays 1 to 16 are set to A and Δ) (3-Open and close).
The change in the swirl strength as shown by the chain line in the figure (゛ is the th;) of the control method of the control method j (ε) of the According to the engine, it is suitable for low and medium loads below setting f16:+△.
- In the J6 rich operation region, stratified combustion is performed with the generation of strong swirl.) C) Good ignition is obtained, and rare, J9 combustion is made possible to improve fuel efficiency. 12- In the stratified region, the intake air H1 is kept constant without closing the throttle valve 1/I, and the C output control 911 is performed by the fuel supply h1 from the first fuel supply r1 stage 11. As a result, the pumping loss associated with the throttling operation of the throttle valve 14 can be significantly reduced, and fuel efficiency is further improved.

In addition, in the high-angle pre-operation range exceeding the above-mentioned 11 load point A, the system shifts from stratified combustion to uniform combustion to increase the air utilization rate and perform high-output operation without smoke generation. , weakens the swirl to suppress the occurrence of combustion noise and huffing caused by a sudden increase in combustion speed, and also reduces intake resistance and improves the intake gas rate.
3. Good driving f1 performance in all areas and fuel efficiency due to reduction of pumping [1st]. &P1 can be improved.

J3, front h1 (the second fuel stone supply means 13 supplies dispersed fuel to the intake passage 3 using a carburetor) -C Chiyoi.

Further, in the above embodiment, the dispersing fuel 1'+l jet q' nozzle 12 of the second fuel supply stage 13 is interposed in the middle of the intake passage 3, but this second fuel supply means 13 dispersion fuel 131 sentry port/1 nozzle 12 to the first fuel supply hand ■Ω
Similarly to the stratified fuel injection nozzle 9 of No. 11, it may be arranged in the combustion chamber 1 in the same way as the stratified fuel injection nozzle 9;
The injection timing of the dispersed fuel directly supplied to the combustion chamber 1 by the fuel supply means 13 is earlier than the fuel injection timing by the first fuel supply means 11, and the injection is completed between the intake stroke and the early stage of the compression stroke. The fuel r1 supplied by the second fuel supply means 13 is uniformly dispersed in the combustion chamber 1 by mixing with the intake air, thereby achieving uniform combustion.

Embodiment 2 This embodiment is shown in FIG.

In the engine shown in FIGS. 6 and 7, 22 is a primary intake passage that opens to the primary intake boat 23 of the combustion chamber 1, and 24 is a secondary intake passage that also opens to the secondary intake boat 25. , 26 is an air passage connected to the 171 air port 27, 28 is a primary intake valve, 29 is a secondary intake valve, 30 is an exhaust valve, and 8 is an ignition device using a spark plug.

2. The downstream portion of the primary intake passage 22 is curved to introduce intake air from the tangential direction of the combustion chamber 1.
At the same time, the Tsuchiura side merges with the secondary intake passage 24, and the intake air is regulated by the operation of the throttle valve 14. In addition, a swirl-1 control valve 3 is provided in the secondary intake passage 24 marked -1-.
The swirl control valve 31 is connected to the same actuator (not shown) as in the previous example, and constitutes a swirl control means 18 for controlling the strength of the swirl.

In other words, when the swirl valve 31 is fully open, intake air is supplied only through the primary intake passage 22 to create a strong swirl, while the swirl valve 31 is fully open. During operation, intake air is also supplied from the secondary intake passage 24, and the 'primary intake passage 22
The swirl becomes weaker as the intake air passage through the air is reduced.

In addition, when the primary intake valve 28 is opened, the ignition device f'l 83Ii tJ in the combustion chamber 1 is injected into the primary intake passage 22 from the valve gap. A fuel supply means 3 is provided with a fuel nozzle 32 for injecting fuel.
3 is constituted.

Toi-i+! The fuel rice supply means 33, the throttle valve 14, and the swirl control valve 31 of the swirl control means 18 are controlled by the same control means (not shown) as in the previous example to control the C1 fuel FI.
The amount of fuel injected from the l-injection i11/I nozzle 32, the injection timing, the opening degree of the throttle valve 14, the opening degree of the swirl control valve 31, and the opening/closing timing are controlled.

The fuel supply means 333 controls the output by increasing the amount of fuel supplied according to the load, and controls the injection timing tJ1 by switching between stratified combustion and uniform combustion with J, -). ,ing.

′? I rope 1, fire 1' + I watch! The J-I I+, ) period is carried out as shown in FIG. 8, where S indicates the injection start timing and F indicates the injection trailing timing. FIG. 3 of Example 1 shows that the fuel 110 injection time in the stratified region below 1 (the setting corresponding to point A) is at the end of the intake stroke (when the primary intake passage 22 is closed). Immediately before the injection q・1 in the 0.￥ period, the fuel I'+1 is the primary intake valve 28
Fuel flows into the combustion chamber 1 through the valve opening gap and is supplied unevenly around the ignition device 8, and even when the piston 2 moves 1-4 in the compression stroke, the fuel is unevenly distributed in the upper part of the combustion chamber 1. This results in stratified combustion of 1j.

At that time, the amount of fuel injection is kept constant (each period, the injection starts early, and increases by one foot as the load increases).

In addition, when the set load at point A is exceeded, the injection angle is greatly advanced to make it faster, and when the load exceeds point 8, the injection path is kept constant and the injection start is advanced. The injection time is increased as the load increases, and by supplying fuel from the beginning of the intake stroke, the fuel that has flowed into the combustion chamber 1 is dispersed throughout the combustion chamber 1 by the flow of intake air, ensuring uniform combustion. It is something to do.

For switching between stratified combustion and uniform combustion, the swirl control means IE3 installed in the secondary intake passage 24 has a slurry 11/11 to 1-1-1-1-1-1-1-1-1 to 1-1-1-1-1 to 1-1-1-1-1-1 to 1-1-1 of the swirl control means IE3 interposed in the secondary intake passage 24, as shown in FIG. +, 11111 control i; 11 is performed, and 1, 4 i (specifically setting (i l=:IA6)) closes and produces a strong swirl, while the above-mentioned From the set point to the secondary intake passage 22, intake air is also supplied from the secondary intake passage 22, and the swirl of the intake air supplied by the primary intake passage 22 is weakly combed.
Combustion) Nakagame's 5' Shibata-1 In addition to suppressing the occurrence of combustion noise and knocking, the intake resistance is slightly reduced to zero. be.

The control of the opening degree of the throttle valve 1/I in this embodiment (-) is as follows:
This is done as shown in FIG. In this example, a3() is added to the stratified area.
Compared to the previous example, the stratification of the combustion gas
Therefore, the compensator valve '14 must be throttled to reduce the amount of intake air, as shown in the chain line in a conventional carburetor engine. 1. Compared to Shino (2), which performs output control with Aiki filling and lifting, the aperture depth of Zon is small, and it is 11 (reduction/n 1λ) of Bon [dengu [Jsu]. Seriously, T engine cold machine 11.? Ic kl U'l The throttle valve opening is set as shown in line C and J, and the one-pronged machine ('l is set).

Therefore, even if d3 is present in this example, the low angle charge +1. 'I performs lean combustion using stratified combustion associated with the formation of a strong swirl of 4F+. While aiming at the bamboo direction -1-, high [) load +
1. In '7, it is possible to perform high output operation without swirling, noise, or light loss of 11 output due to uniform combustion with weak swirl.

KA3, Snorl strong (＼ control is performed in accordance with 11 iii and l), and in addition to detecting the transition to uniform combustion, it is also possible to cover the swirl weakly in response to the shift to uniform combustion. f
'J, yes.

4. Brief explanation of the drawings: Figures 1 to 5 show a first embodiment of the present invention; Fig. 3 is a dimensional characteristic diagram showing the fuel Fl (I' supply speed control (all) as well as the excess air ratio for the first fuel injection, and Fig. 4 shows the dimensional characteristics of the fuel Fl A characteristic diagram showing the injection timing and ignition time of stratified fuel by the utilization supply means, Figure 5 is @
Figure 1 shows the swirl ratio with respect to load fluctuations.
1, shi, m Figure 6 is a bottom view of a stratified intake engine (with a partial cross section of the cylinder head shown in Figure C), Figure 7 is a sectional view taken along the vn-vn line in Figure 6, 9) 8
Fig. (part 1) Fig. 91, No. 91, E negative), 2 λ 1! Figure 1 shows the opening control of the throttle valve.

1... Combustion'! i<3...Intake passage F
(...Ignition Kl?'/ 9...Stratification fuel ladle 110Q・1 nozzle'10・
...Fuel 11Q IJI pump 11...
First fuel 1 supply means 12...Distribution fuel 11 injection nozzle 13--...-ff+2 Fuel)+l Il
l 48 r 1st stage 1 (5......s(knoll adjustment play 1~1 7...... la'ri -)] +
, i-ichiyo 1 B...Three reel collar 11
Means 19... Control 1 stage 20... [1
Load detection means 31... Swirl 1 to 11 - Rubber 132... Fuel injection nozzle 33...
・・・・Fuel supply means←K -0 Kouyucho Akira Kan K Igiri Gourd - 〇忽 Gotogo 1.1 Mad Mido Ward - 廝屓

Claims (1)

[Claims] (1) It is equipped with a fuel supply means for supplying fuel into the combustion chamber and an ignition device disposed inside the combustion chamber, and when the load is low, the fuel supply means supplies fuel unevenly around the ignition device and ignites it. This is a stratified air charge engine that performs stratified combustion, while at high loads it performs uniform combustion by dispersing °C fuel into the combustion chamber and igniting it. 1. A stratified air supply engine, characterized in that a swirl control means is provided for controlling the swirl strength, and the swirl is made weaker during the uniform combustion than during stratified combustion.