JPS58160537A - Mixer of liquefied gas internal-combustion engine - Google Patents

Abstract

PURPOSE:To enable uniform mixture to be supplied throughout various load conditions by using the captioned mixer in an liquefied gas internal combustion engine of an automobil or the like. CONSTITUTION:An annularly grooved mixture ejection hole 12 is formed between fitting faces of a mixer 3 and an intake pipe 11, namely, is put beneath a bore wall face 7. Mixture which is supplied from the hole and then metered by an air adjusting screw 9 is supplied in an engine 10 from the entire inner periphery of the bore wall face 7. Under this condition, the mixture metered by a throttle valve 6 flows on the bore wall face because of a small opening of the throttle valve. Under a partial load, since the mixture which is metered by the air adjusting screw 9 is also supplied on the bore wall face, the mixture ratio of the confluent mixtures flowing into one current may therefore become uniform so that CO% contained in exhaust gas in made uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquefied gas internal combustion engine fuel supply system, and particularly to a modification of a mixer of a fuel supply system suitable for a liquefied gas internal combustion engine for automobiles. Higas includes LPG, LNG, etc.

FIG. 1 shows the structure of a conventional liquefied gas supply device for internal combustion engines. A cylinder 1 that stores liquefied gas, a paper riser 2 that vaporizes and depressurizes the liquid phase liquefied gas supplied from the cylinder 1, a main jet 4 that measures this liquefied gas (there are 4 when variable jets are used), and a venturi 5. Mix it with the inhaled air at a constant rate, and squeeze this mixture into the aiki valve at valve 6.
It consists of a mixer 3 that meters the amount of water and supplies it to an internal combustion engine (hereinafter also referred to as engine). Here, the electric mixer 3 of the liquefied gas internal combustion engine differs from that of the gasoline internal combustion engine in that carbon and tar (oil contained in the liquefied gas) generated during blowback adhering to the throttle valve 6 and the bore wall 7 downstream of the throttle valve There is almost no cleaning effect for impurities such as This is due to the difference in physical properties between vaporized liquefied gas and liquid gasoline, with liquid gasoline having a better cleaning effect. Due to this rounding, the opening degree of the throttle valve 6 is very small (throttle valve 6
For example, when the gap between the valve and the wall of the throttle valve is very small i),
The amount of air-fuel mixture at idle becomes inaccurate due to the adhesion of carbon cool, resulting in a drop in engine speed at idle and engine stalling. For this reason, “pentieri”
A bypass 8 is provided between the throttle valve 5 and the throttle valve 6 downstream of the throttle valve 6, and an air adjustment screw 9 is provided in the middle thereof. Then, the air-fuel mixture is metered by the air adjust screw 9 without going through the throttle valve 6. During idling, the throttle valve 6 is fully closed or close to fully closed, and the amount of air-fuel mixture during idling is determined by the air adjustment screw 9.

The mixer 3 with such a conventional structure has a gap between the air adjustment screw 9 and the seat, which is more than four times that of the throttle valve 6, and which is less affected by reductions in idle speed due to carbon and tar adhesion. Consider the case where the engine is installed in the engine 10 as shown in Figure @2. The engine 10 is 4
In a cylinder engine, from the left in Figure 2, 1.2,...
・It will be a 4-cylinder engine. During idling, the air-fuel mixture is measured only by the air adjustment screw 9, so fuel is not distributed to each cylinder of the engine 10. As a result, as shown in Figure 3, the CO(16) contained in the exhaust gas also shows approximately the same value for the 1st to 4th cylinders. However, when the mixer 3 is under a partial load such as when the vehicle is traveling at a speed of 40 b/h, the throttle valve 6 of the mixer 3 opens as shown in FIG. 4, and the mixture is measured by the throttle valve 6 and the air adjustment screw 9. At this time, the inlet of the air-fuel mixture flowing into the bypass 8 is located below the pentieri-5.
Since the air and fuel are not mixed completely uniformly after I, the mixture ratio of the mixture measured by the throttle valve 6 and the mixture measured by the air adjustment screw 9 is not necessarily equal.

Furthermore, since the air-fuel mixture metered by the air adjustment screw 9 is ejected from one location on the bore wall surface 7, it is difficult to uniformly supply it to each cylinder. Fuel distribution changes. For example, the air-fuel mixture measured by the air adjustment screw 9 is
If the mixture ratio is thinner than the mixture measured by the needle, install the mixer 3 to the engine 10 as shown in Fig. Since Qi is difficult to be supplied, Figure 3 (B
As shown by the solid line, the CO (*) contained in the exhaust gas of 2.3 cylinders becomes more concentrated than that of 1.4 cylinders. As a result, 1~
Even if the average mixture ratio of the four cylinders is the economical mixture ratio or the theoretical mixture ratio, the mixture ratio of each cylinder is not necessarily the economical mixture ratio or the stoichiometric mixture ratio, which is unfavorable in terms of fuel efficiency and exhaust gas burnout.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquefied gas mixer for an internal combustion engine that can supply a uniform mixture ratio of air-fuel mixture to the internal combustion engine under all load conditions.

The present invention is a mixer for a liquefied gas internal combustion engine, characterized in that the air-fuel mixture supplied by the bypass is supplied from a nozzle provided on the entire bore wall downstream of the throttle valve.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.

As shown in the figure, an annular groove-shaped mixture jet port 12 is provided on the intake pipe 11 and the mounting surface of the mixer 3 under the bore wall surface 7 as shown in the figure. It is supplied to the engine 10 from the whole. As a result, when the engine is idling, the fuel distribution among the cylinders is good as in the conventional case, so that a uniform air-fuel mixture can be supplied to each cylinder. When the throttle valve opening is less than 201', the air-fuel mixture metered by the throttle valve 6 flows on the bore wall surface because the throttle valve opening is small under a partial load such as a vehicle speed of 40 fa/h. Since the air-fuel mixture metered by the air adjustment screw 9 is supplied onto the main bore surface, the mixture ratio of air-fuel mixture and air-flow mixture is uniform, and the mixture is contained in the exhaust gas as shown by the dotted line in Figure 3B. C0
00 is uniform. In addition, the bypass 8 measured by the air adjustment screw 9 should be
The air-fuel mixture flowing through the bypass valve 6 is measured by the throttle valve 6, and the air-fuel mixture flowing through the bypass 8 is measured by the throttle valve 6. Since the eyelid opening is small, the influence on fuel distribution to each cylinder is small. Small and can be ignored.

As a result, according to the present invention, under all load conditions,
We offer a mixer that can supply a uniform mixture ratio to each cylinder. FIG. 6 shows a view from the mounting surface of the intake pipe 11 of the mixer unit in the practical row of FIG. 5.

Since the groove of this shape is aged by forming υ by casting the groove, it also has the effect of making machining easier than the conventional groove.

FIG. 7 shows another embodiment of the invention. This is a case where the air-fuel mixture measured by the air adjustment screw 9 and flowing through the bypass is supplied from the air-fuel mixture outlet 12'' consisting of a plurality of holes formed in the bore wall surface 7. In the above embodiment, the air-fuel mixture outlet 12 is provided on the entire circumference. .12' is provided, but it does not necessarily have to be provided on the entire circumference, and may be provided at an appropriate location on the circumference.

@Figure 8 shows x He-+ 13 K m Fie 1! This is another embodiment in which the same air-fuel mixture jet port 12 as in the embodiment is provided.

This embodiment is an example in which the conventional Ixer 3 is modified to a minimum.

FIG. 9 is one row applied to a two-membrane actuated mixer.

[Brief explanation of drawings]

Figures 1 and 4 are cross-sectional views showing the structure of a conventional mixer;
Figure 2 shows the state in which the conventional mixer is installed on the engine, Figure 3 (AJ), Figure 3 ((f)) shows the exhaust gas from each cylinder of the engine when the conventional mixer and the mixer of the present invention are used. A diagram showing CO (Ls) contained in gas, FIGS. 5 and 6 are detailed explanatory diagrams of the present invention, and FIGS. 7 to 9 are explanatory diagrams of other embodiments of the present invention. 1... Cylinder, 2... Vaporizer, 3... Mixer, 4... Main jet, 5... Venturi, 6... Throttle valve, 7... Bore wall surface, 8... Bypass, 9...Air adjustment screw, 1o...Engine, 11...Intake pipe, 12...Fuel injection port (main injection fPJ), 12'...Fuel Figure 1 Figure 2 30 (A) Daido Chrysanthemum (β) / 2 3 4 Qi'? I, v. 〒 4 Figure 5 W6 Figure 7 Figure θ

Claims (1)

[Claims] 1. In a mixer for a liquefied gas internal combustion engine, which is equipped with a venturi, a throttle valve, and a pipe that supplies the mixture from between the venturi and the throttle valve to the downstream of the throttle valve, the mixture jet of the bypass is connected to the bore downstream of the throttle valve. A Z medium for a liquefied gas internal combustion engine, characterized by being provided dispersedly on the circumference.