JPS603340Y2 - Fuel injection engine intake system - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an intake device for a fuel injection type engine.

Generally, a fuel injection engine uses an injection pump instead of a carburetor to inject fuel into an intake passage, and the injection amount is automatically adjusted depending on the intake air amount.

Therefore, it has been attracting attention in recent years as a vehicle for popular use because it can control the fuel more suited to the engine load than a carburetor, improve fuel efficiency, and reduce air pollution.

However, in this fuel-injected engine, the throttle valve opening is small and the intake air velocity is low at light loads, so the injected fuel is not sufficiently atomized and mixed with air.
There was a problem in that it was not possible to sufficiently improve fuel efficiency and reduce unburned components.

To solve the above problems, conventionally, an injection nozzle is provided in the intake passage downstream of the throttle valve, and an air passage is provided whose one end is open to the atmosphere and the other end is opened to the intake passage near the injection nozzle. A method has been proposed in which the atomization of fuel injected from an injection nozzle is promoted by flow (see Japanese Utility Model Application No. 51-87126).

However, even with this proposed structure, fuel atomization was not sufficient, especially under light loads.

In view of this, the present invention provides a first throttle valve on the upstream side of the intake passage and a second throttle valve on the downstream side thereof, and provides the first throttle valve upstream of the second throttle valve and the second throttle valve on the downstream side thereof.
An injection nozzle and an air bleed for injecting air against the fuel from the injection nozzle are provided downstream of the throttle valve, so that the fuel is injected from the injection nozzle toward the second throttle valve, and the air bleed effect causes mist. This product provides an intake device for a fuel injection engine that further promotes atomization of the atomized fuel through the throttling effect of a second throttle valve, which promotes atomization of fuel and mixing with air mainly during light loads. The purpose is to

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below with reference to the drawings.

Reference numeral 1 denotes an intake passage of a fuel injection type engine, with a first throttle valve 2 on its upstream side and a second throttle valve 3 on its downstream side.
is rotatably supported.

Reference numeral 4 denotes a support member provided downstream of the first throttle valve 2 and upstream of the second throttle valve 3, and provided with an air bleed 6 that communicates the injection nozzle 5 and the atmosphere with the intake passage 1. There is.

The air bleed 6 uses the negative pressure in the intake passage 1 to eject air to the fuel injected from the injection lower part of the injection nozzle 5, thereby atomizing the fuel.

Further, the injection nozzle 5 is located at a corner of the intake passage 1 so as to inject fuel toward the second throttle valve 3.

Note that 8 is a fuel oil pipe connected to a fuel injection pump (not shown), 9 and 10 are sealing materials, and 11 is an engine body.

Therefore, with respect to the fuel injected from the injection nozzle 5, air is first injected from the air bleed 6 due to the pressure difference between the negative pressure in the intake passage 1 and the atmospheric pressure, and the air atomizes the fuel. The atomized fuel is then mixed with the intake air from the first throttle valve 2 and is supplied to the combustion chamber 11 through the second throttle valve.

During light loads, the first and second throttle valves 2.3
Since the degree of opening of Atomization of fuel is promoted at the throttle valve 3.

That is, the fuel is atomized by collision with the second throttle valve 3, and the fuel is atomized by utilizing the air flow velocity around the second throttle valve 3.

Note that under high load, the opening force of the first and second throttle valves 2 and 3 increases, and while the throttling effect of the second throttle valve 3 becomes smaller, the negative pressure in the intake passage 1 and the atmospheric pressure decrease. The pressure difference becomes smaller and the so-called air bleed effect becomes smaller, but at this point, the flow velocity of the intake air in the intake passage is high, so the fuel injected into the intake passage 1 is sufficiently absorbed by the intake air flowing through the intake passage 1. Atomized.

As described above, the present invention provides an air bleed for injecting air to the fuel from the injection nozzle, and positions the injection nozzle downstream of the first throttle valve and upstream of the second throttle valve. By injecting fuel from the injection nozzle toward the throttle valve, when the load is light, the atomized fuel is transferred to the second tank due to the air bleed effect.
Because the atomization is further atomized by the throttling effect of the throttle valve,
It has an excellent effect in that sufficient atomization is performed even under light loads as well as under high loads.

[Brief explanation of the drawing]

The drawing is a sectional view illustrating an embodiment of the present invention. 1... Intake passage, 2... First throttle valve, 3... Second throttle valve, 4...
・Support member, 5...Injection nozzle, 6...
・Air bleed, 7... Injection port, 8...
・Fuel oil pipe, 9, 10... Seal material, 1
1...Engine body.

Claims (1)

[Scope of utility model registration request] The intake passage is provided with a first throttle valve on the upstream side and a second throttle valve on the downstream side, and an injection nozzle and fuel from the injection nozzle are provided upstream of the second throttle valve and downstream of the first throttle valve. 1. An intake device for a fuel-injected engine, characterized in that an air bleed is provided to inject air to the injector, and fuel is injected from the injection nozzle toward a second throttle valve.