JPS6343408Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a mixture supply system for an internal combustion engine.

A fuel-injected internal combustion engine has two main fuel injection valves that are installed separately for each cylinder and injects fuel into the main combustion chambers of these cylinders, and one that is common to all cylinders.
The electronic control device controls the opening of these injection valves according to the operating status of the engine to supply fuel to the engine. something is known.

However, since the fuel injection amount of the auxiliary fuel injection valve is smaller than that of the main fuel injection valve, it is difficult for the injected fuel to atomize. Therefore, as shown in FIG. 1, a throttle valve is installed in the side wall 2a of the throttle body 2 of the air-fuel mixture supply device 1, with one end opening into the chamber 4 on the upstream side of the throttle valve 3, and the other end being attached to the throttle body side wall 2a. An air passage 2b is formed which communicates with the emulsion tube 6 facing the injection nozzle 5a of the auxiliary fuel injection valve 5.
Air introduced from the upstream side of the throttle valve 3 is supplied to the emulsion tube 6 through the emulsion tube 6 to promote atomization of the fuel injected from the fuel injection valve 5.

Incidentally, in the electronically controlled engine, blow-by gas is refluxed depending on the operating state of the engine to control the release of harmful substances. However, when such blow-by gas reflux control is performed, substances such as oil, fuel, and carbon contained in the blow-by gas mix into the chamber 4 and enter the air passage 2b, causing damage to the inner wall surface or the emulsion. It adheres to the inside of the joint tube 6, narrowing the passage, and in some cases, blocking it.
As a result, the atomization of the fuel is extremely reduced, which may cause engine trouble.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to prevent foreign matter from entering the air passage for fuel atomization formed in the throttle body. In order to achieve this object, in the present invention, the air bleed inlet of the air passage provided in the throttle body forming the intake passage is opened at the upper end surface of the throttle body, and the air bleed inlet of the air passage provided in the throttle body forming the intake passage is opened at the upper end surface of the throttle body, and the air bleed inlet is opened on the upper end surface of the throttle body, and the air bleed inlet is opened on the upper end surface of the throttle body. An internal combustion engine in which air introduced from an intake passage and fuel injected from a fuel injection valve are introduced into an emulsion tube and mixed, and the mixture is supplied into an intake passage downstream of a throttle valve. In the air-fuel mixture supply device, a jet for regulating incoming air to a certain amount is press-fitted into the air bleed inlet so that its upper end surface protrudes from the upper end surface of the throttle body, and the jet is attached to the upper end surface of the throttle body to form an intake passage. A small chamber having an air inlet opening toward the downstream side of the intake passage is provided in the cover forming a chamber on the upstream side of the intake passage, and the jet is made to protrude into the small chamber, and the air inlet of the small chamber is positioned above the jet. This invention provides a mixture supply device for an internal combustion engine, characterized in that it is located downstream from an end face.

An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 2 shows a sectional view of a mixture supply device to which the present invention is applied, and the upper opening end (upper end surface) 11a of the throttle body 11 of the mixture supply device 10 is connected to the opening end 13a of a cover 13 forming a chamber 12. The lower open end 11b is connected to the head of the engine (not shown) via an intake manifold 15 shown by a two-dot chain line. Main intake passages 16, 17 and a sub-intake passage 18 are formed within the throttle body 11, and throttle valves 19-21 are disposed within each of these passages 16-18. A holder portion 11d is integrally formed approximately at the center of the side wall 11c of the throttle body 11 and protrudes outward, and an auxiliary fuel injection valve 22 is mounted on the holder portion 11d.

A tip 22a of the fuel injection valve 22 is connected to an emulsion tube 23 mounted on the side wall 11c and disposed diagonally downwardly across the sub-intake passage 18 in its diametrical direction. Throttle body 1
In the side wall 11c of 1, there is an air passage 11e in the vertical direction.
is bored, one side open end 11f communicates with a hole 23a bored in the side wall of the emulsion tube 23, and the other side open end (hereinafter referred to as air bleed inlet) 11g is the upper end surface ( The air bleed inlet 11g is open at the upper end surface of the throttle body 11, and a jet member 24 for regulating incoming air to a constant amount is press-fitted into the air bleed inlet 11g. The upper end surface 24a of the jet member 24 is connected to the side wall 11.
It protrudes above the upper end surface of c.

A small chamber (chamber) 14 is formed on the inner surface of the cover 13, facing the jet member 24 and larger than the jet member 24. It is defined by a wall surface 13b projecting to the opening end surface 13c in an L-shape, and is formed to open downward. The small chamber 14 is an intake passage 18
It has an air inlet section 14a that opens toward the downstream side. The upper end surface 24a of the jet member 24 is projected into the small chamber 14, and the small chamber 14
The air inlet portion 14a of the jet member 24 is located downstream of the upper end surface 24a of the jet member 24. Therefore, from the air inlet portion 14a into the small chamber 14, the arrow A
As shown in , a part of the intake air is introduced upward in the direction opposite to the flow of air from the chamber 12 toward the downstream side of the intake passages 16 to 18 in the throttle body 11 (in the direction shown by arrow B), and this introduced air is Intake air is configured to flow into the air passage 11e through the jet member 24.

Note that the jet member 24 is necessary for regulating the amount of air flowing into the air passage 11e to a constant amount. That is, when forming the air passage 11e in the side wall 11c of the throttle body 11 by post-processing, the air passage 11e has a relatively large diameter due to processing technology, resulting in a lean air-fuel ratio. Therefore, a jet member 24 having a predetermined diameter is provided in order to make the air-fuel ratio appropriate.

In this configuration, the intake passages 16 to 1 of the throttle body 11 are opened from the chamber 12 as shown by arrow A in accordance with the absolute pressure inside the intake manifold 15.
Air or a gas such as the above-mentioned blow-by gas flows into the intake manifold 15 through the intake passages 16 to 18. At the same time, as shown by arrow B, a part of the gas (intake air) within the chamber 12 flows into the small chamber 14 from the air inlet portion 14a of the small chamber 14 in an upward direction opposite to the flow of the air. At this time, foreign substances such as oil, fuel, and carbon mixed in the gas as described above fall in the direction of the sub-intake passage 18, and are prevented from entering the small chamber 14. Further, the upper end surface 2 of the jet member 24
4a protrudes into the small chamber 14, and the small chamber 14
Since the air inlet portion 14a is located downstream from the upper end surface 24a of the jet member 24, even if some of the foreign matter enters the small chamber 14, the foreign matter will not be able to enter the air passage 11e from the jet member 24. Intrusion is prevented. In this way, air that does not contain foreign matter flows into the emulsion tube 23 through the jet member 24 and the air passage 11e, and after being mixed with the fuel injected into the emulsion tube 23 from the fuel injection valve 22, the air flows through the hole 23b. is atomized and injected into the intake passage 18 from the intake manifold 1.
5 to an engine (not shown).

As explained above, according to the present invention, the air bleed inlet of the air passage provided in the throttle body forming the intake passage is opened at the upper end surface of the throttle body, and the intake air is passed through the air passage to the upstream side of the throttle valve. A mixture of internal combustion engines in which air introduced from a passage and fuel injected from a fuel injection valve are introduced into an emulsion tube and mixed, and this mixture is supplied into the intake passage downstream of the throttle valve. In the air supply device, a jet that regulates inflowing air to a certain amount is press-fitted into the air bleed inlet so that its upper end surface protrudes from the upper end surface of the throttle body, and is attached to the upper end surface of the throttle body and is connected to the intake passage. A small chamber having an air inlet opening toward the downstream side of the intake passage is provided in the cover forming the chamber on the upstream side, and the jet is made to protrude into the small chamber, and the air inlet of the small chamber is connected to the upper end surface of the jet. With the configuration located further downstream, it is possible to prevent foreign matter mixed in the intake passage from entering the air passage with a combination of the minimum necessary parts, and as a result, the air-fuel mixture can be maintained for a long period of time. It can be made good.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a conventional air-fuel mixture supply device for an internal combustion engine, and FIG. 2 is a longitudinal sectional view showing an embodiment of the air-fuel mixture supply device for an internal combustion engine according to the present invention. 10...Mixture supply device, 11...Throttle body, 11e...Air passage, 11g...Air bleed inlet, 12...Chamber, 13...Cover, 14...Small chamber, 14a...Air inlet section, 15
...Intake manifold, 22...Fuel injection valve, 2
3... Emulsion tube, 24... Jet member (jet), 24a... Upper end surface of jet.

Claims (1)

[Scope of utility model registration request] The air bleed inlet of the air passage provided in the throttle body that forms the intake passage is opened at the upper end surface of the throttle body, and the air introduced from the intake passage on the upstream side of the throttle valve through the air passage and the air from the fuel injection valve are In the air-fuel mixture supply device for an internal combustion engine, the mixture is introduced into an emulsion tube and mixed with the fuel to be injected, and the mixture is supplied into the intake passage downstream of the throttle valve. A jet for regulating incoming air to a certain amount is press-fitted so that its upper end surface protrudes from the upper end surface of the throttle body, and the intake air is attached to a cover that is attached to the upper end surface of the throttle body and forms a chamber on the upstream side of the intake passage. A small chamber having an air inlet opening toward the downstream side of the passage is provided, the jet projects into the small chamber, and the air inlet of the small chamber is located downstream of the upper end surface of the jet. Air-fuel mixture supply system for internal combustion engines.