JPH0361669A - Turbulent flow generating device - Google Patents

Abstract

PURPOSE:To accelerate fuel atomization by pivotally supporting the basic edge onto the upstream side of a fuel adhesion part on the inner wall surface of a suction port and installing a flapper which holds the turning angle larger as the output becomes smaller and setting the turning edge of the flapper at the min. turning angle position so as to be opposed to the fuel adhesion part. CONSTITUTION:A controller 22 executes the main routine of the engine control and executes a variety of subroutines at the same time. In the fuel injection routine, the injection timing is calculated on the basis of the engine revolution speed information and carries out fuel injection in an intake passage 10. When the opening degree control routine is reached, the operation state information is taken out, and the frapper opening degree theta is calculated, and opening degree correction is carried out on the basis of the map. The output electric current corresponding to the flapper opening degree theta is outputted into a flapper driving device 23, and the opening degree of a flapper 30 is kept. Therefore, the flapper can be kept at an optimum gap (t) according to a variety of operation states, and an eddy current in the vertical direction is allowed to flow down on a fuel adhesion part (a), and fuel atomization can be accelerated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a turbulence generating device capable of promoting atomization of fuel within an intake port of an internal combustion engine. The present invention relates to a turbulence generating device for an internal combustion engine equipped with a fuel system.

(Prior Art) Conventionally, in the fuel supply system of an internal combustion engine, a so-called multi-point injection (MPI system) in which a fuel injection valve is provided for each intake port is known.

In this case, each fuel injection valve is controlled to vary its injection timing and valve opening time in accordance with a control signal from the control means, thereby obtaining the optimum air-fuel ratio depending on the engine operating state. .

By the way, as shown in FIG. 9, this type of fuel injection valve l
When the fuel injection valve 1 performs an injection operation at a predetermined timing, for example, during the exhaust stroke of each cylinder, the fuel from the fuel injection valve 1 adheres to the inner wall surface of the intake port 2. The fuel in the fuel adhesion part a on the inner wall surface is accelerated to vaporize by the intake air flow A generated with the opening operation of the intake valve 3, flows to the combustion chamber 4 side, and is further influenced by swirl etc. in the same chamber. (Problem to be solved by the invention) However, the flow velocity distribution in the cross-sectional direction of the intake air flow in the intake boat 2 is almost layered. This problem is particularly acute in the case of alcohol fuel, which has a flow-like shape and generates very little turbulence, and does not sufficiently promote atomization of the fuel.

For this reason, it is desirable to generate turbulence in the airflow in the intake port 2 in order to promote the vaporization of the fuel in the fuel adhesion part a. A valve 5 (shown in Figure 1O) is provided;
The valve is operated by throttling during partial loads when the airflow velocity is particularly likely to decrease, thereby increasing the intake velocity and promoting atomization of the fuel adhering to the inner wall surface of the boat.

However, in this case, the vortices generated by passing on both sides of the butterfly valve 5 collide with each other at the downstream position of the butterfly valve, reducing their kinetic energy and disappearing early, which promotes atomization of the fuel. It is not supposed to be done with sufficient certainty.

Furthermore, in the case of a two-valve intake engine, one side of the two intake boats is closed during partial load to increase the flow velocity on the open boat side.

However, even in this case, although it is useful for generating swirl in the combustion chamber 4, it is not possible to generate turbulence in the flow in the intake port 2, and it is necessary to sufficiently promote the atomization of the fuel adhering to the inner wall. It is not.

An object of the present invention is to provide a turbulence generating device that can reliably promote atomization of fuel adhering to the inner wall surface of an intake boat.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides a fuel injection valve that is disposed opposite to an intake port of an internal combustion engine and injects fuel, and a fuel injection valve that is disposed opposite to an intake port of an internal combustion engine and injects fuel, and a fuel injection valve that injects fuel from the fuel injection valve. a flapper whose base end is pivotally supported upstream of the fuel adhering portion on the inner wall surface of the intake port, and whose rotating end is formed to increase or decrease its rotation angle in a direction that narrows the cross section of the intake port; and output information generation means for generating output information of the internal combustion engine, and flapper control means for operating the flapper so that the rotation angle of the flapper is held larger as the output of the internal combustion engine is smaller, The invention is characterized in that the rotation end of the flapper at the minimum rotation angle position is configured to face the fuel adhering portion.

(Function) When the rotating end of the flapper is held at the required rotating angle position to narrow the cross section of the intake port, the intake air passes through the rotating end of the flapper, increasing the flow velocity, and A vortex flow that wraps vertically toward the fuel adhering portion is generated, and this vortex flow promotes atomization of the fuel in the fuel adhering portion.

(Embodiment) The turbulence generating device shown in FIG. 1 is installed in an engine 12 that uses alcohol fuel and has a fuel injection valve 11 disposed opposite to the intake passage IO.

This engine 12 is a four-cylinder multi-point injection type, and the downstream part of the intake port I3 is branched, and two intake valves 16 are operated simultaneously to send intake air into the combustion chamber 14.
It is meant to be inhaled internally.

The cylinder head 15 has a body 18 for supporting the flapper.
An intake manifold 17 in which a manifold 171 and a surge tank 172 are integrated is connected through the intake manifold 17 .

Furthermore, an air cleaner (not shown) is connected to the other end of the manifold 17 via an intake pipe 34.

A fuel injection valve 11 is attached to each earthen wall at a position facing each cylinder of the body 18, and a flapper 20 is attached to the lower wall. The fuel injection valve 11 receives alcohol fuel at a constant pressure from the fuel supply system 21, and receives a driving current from a controller 22, which will be described later, to open the valve and perform injection.The injection trajectory of this valve is as shown in Fig. 2. Then, the fuel is injected in two parts into the branch parts of a pair of intake ports for each cylinder, thereby forming two fuel adhering parts a on the lower wall surfaces of each branch part.

The fuel supply system 21 includes a fuel pipe 24, an alcohol concentration sensor 25 that outputs information on the alcohol concentration in the fuel contained therein, and a fuel tank 2G from which the fuel pipe 24 extends.

The flapper 20 has the shape of a thick-walled valve body that operates in a tilting manner.

When it is in the closed position (the position shown by the two-dot chain line in FIG. 1) HO, its upper surface is formed to be substantially continuous with the other bottom surface of the intake passage 10, and its base end 201 is connected to the flapper drive device 23.
The rotating end 202 is arranged opposite to the fuel adhering portion a. Then, the full opening value M at which the flapper 20 maximizes its rotation angle (the position shown by the solid line in FIG. 1)
When held at Hl, the gap t between the rotation end 202 and the upper wall surface of the intake passage is sufficiently narrowed. This gap t can increase the flow velocity of the intake air passing through the gap t, and can generate a large number of vortices that are drawn vertically (in the vertical direction) into the airflow flowing down toward the fuel adhering portion a at the rear position of the flapper 20.

The flapper drive device 23 includes a motor driven by the drive current of the controller 22 and a speed reducer that reduces the rotation speed output by the motor and transmits the rotation to the flapper 20.

Reference numeral 27 in FIG. 1 indicates a throttle valve, and reference numeral 27 indicates a throttle valve.
8 indicates a throttle opening correction valve. Here, the throttle valve 27 is configured to rotate in response to an operating force corresponding to the amount of depression of an accelerator pedal (not shown), so that intake air flows into the intake passage 10 in an amount corresponding to the opening degree thereof.

Here, the flow resistance of the intake passage 10 increases due to the squeezing operation of the flapper, but this reduces the amount of intake air passing through the throttle valve 27, resulting in a difference in the amount of intake air compared to when the flapper is in the closed position HO. Out. In order to correct this, a throttle opening correction valve 28 is used here. This throttle opening correction valve 28 is connected to the controller 22, and is opened from the closed state by the opening current generated by the controller. Here, the controller 22 adjusts the valve opening based on the load information based on the map shown in FIG. Calculate,
Throttle opening correction valve 28 adjusts the drive current according to the opening.
is configured to output to .

Here, the throttle opening correction valve 28 is set to close when the load increases, that is, when the throttle valve opens.

The controller 22 is a well-known electronic control device, and has a rotation sensor 29 at its input terminal that outputs engine rotation speed information.
, a load sensor 19 that outputs information on the amount of depression of the accelerator pedal (not shown). Intake temperature sensor 30 that outputs intake temperature information. Intake pressure sensor 31 that outputs intake pressure information. Signals are input from a water temperature sensor 32 that outputs water temperature information, a position sensor 33 that outputs information on the closed position of the flapper 20, an alcohol concentration sensor 25, and the like. From the output end of the controller, a fuel injection valve 11. Each output circuit is configured so that an output is issued to the flapper opening device 23 and the throttle opening correction valve 28, respectively.

The control circuit of the controller 22 performs a well-known fuel injection control process and also performs an opening control process as shown in the seventh @.

Below, the operation of the turbulence generator shown in Fig. 1 will be explained in Figs. 4(a) and 4(a).
This will be explained together with the explanatory diagram of fuel injection timing in b) and the opening control routine in FIG.

The controller 22 executes a main routine for engine control, and at the same time executes various subroutines in response to various interrupt conditions.

In the fuel injection routine, engine speed information.

The injection time ft corresponding to the injection amount is calculated based on load information, intake temperature information, intake pressure information, water temperature information, etc. according to the amount of depression of the accelerator pedal. Then, the injection timing for each cylinder is calculated according to the output of each crank sensor (not shown),
Every time the same timing is reached, the fuel injection valve 11 is driven to inject fuel into the intake passage 1o.

In this case, when one engine is in a stable driving state, a sequential control pattern is adopted, and at that time, fuel is injected into each cylinder during the exhaust stroke once every two revolutions (shown as Fl in Fig. 4), and the engine is started at a low temperature. At times, a cold start pattern is adopted, in which case fuel is injected into the gold cylinder twice per revolution (shown as F2 in Figure 4).

When the opening control loop is reached, the engine speed information, load information, intake temperature information, intake pressure information, water temperature information, etc., which are operating state information, are first taken in, and the flapper opening degree θ is calculated. In this case, FIGS. 5(a), (b), (c)
), (d) based on each map.

The correction amounts θ1 to θ4 for each flapper opening are calculated according to the engine speed N, load P, water temperature Tw, and alcohol concentration α, and the flapper opening θ is determined based on these.

In step a3, the throttle opening correction amount is calculated based on the load information with reference to the opening calculation map (see FIG. 6).

In step a4, an output current corresponding to the flapper opening degree θ is outputted to the flapper driving device 23 to maintain the flapper 20 at the calculated opening degree, and the throttle opening correction valve 28 is used to correct the flow rate reduction caused by the flapper 20. Outputs the thigh dynamic current to and returns to the main routine.

In this way, the turbulence generating device shown in Fig. 1 calculates the flapper opening degree θ according to the operating state of the engine, and can hold the flapper at the optimum gap t according to each operating state, and allows each fuel adhesion part a to A sufficient amount of vertical vortex flow can be achieved. In particular, the vortex flowing down toward the fuel adhesion part a does not generate vortices from the opposite side (in this case, the lower side), so the vortex energy is generated by canceling each other out from oppositely wound vortices like in a butterfly valve. It is possible to prevent premature disappearance of the fuel and promote sufficient atomization of the fuel.

As a result, the vaporization of the fuel in the fuel adhesion part a can be sufficiently promoted, combustion can be stabilized at low loads, startability is improved, the amount of fuel injection can be reduced compared to before, fuel efficiency can be improved, and exhaust gas has been improved. be done. In particular, it is easy to improve the startability of alcohol fuel, which has poor vaporizability.

In the above description, the throttle valve 27 is operated in conjunction with the accelerator pedal, and the flapper 20 is operated by squeezing the controller 22. However, instead of this, the throttle valve 27 is operated in conjunction with the accelerator pedal. This function may also be used by the flapper 20a. Note that many of the same members as in the turbulence generating device shown in Fig. 1 are used here.
Identical members are given the same reference numerals and redundant explanations will be omitted. In this case, the controller 22a takes in information on the amount of depression of the accelerator pedal from the load sensor 19, determines the basic flapper opening degree according to this amount of depression, and calculates the basic flapper opening degree according to this amount of depression. is further corrected using engine speed information, load information, intake temperature information, intake pressure information, water temperature information, etc. to calculate the optimal flapper opening degree. Then, an output current that secures the flapper opening may be outputted to the flapper drive device 23a, and the flapper 20a may be controlled to be maintained at the opening.In this case, the intake air amount is also adjusted by the flapper 20a. At the same time, this can supply a vortex toward the fuel adhering portion a, promoting atomization of the fuel, and achieving the same effects as the turbulent flow generating device shown in FIG. 1. In particular, the throttle valve can be eliminated and the device can be simplified.

In the above, the engine is an alcohol engine, and is a four-cylinder multi-point injection type with two intake valves, but the present invention can be applied to a gasoline engine instead.

Furthermore, the present invention can also be applied to a multi-point injection type engine with one intake valve and two intake valves.

It is possible to obtain the same effects as the two-valve type.

(Effects of the Invention) As described above, the present invention can generate a vertical vortex flow in the intake air flow that passes through the rotating end of the flapper and flows toward the fuel adhering portion. In particular, since the vortices are drawn in in one direction, there is no generation of vortices that cancel each other out and cause energy loss, and this vortex sufficiently promotes atomization of the fuel at the fuel adhesion area, resulting in combustion at low loads. It is possible to stabilize the engine, improve startability, reduce the amount of fuel injection compared to conventional systems, improve fuel efficiency, and improve exhaust gas emissions.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of a turbulence generating device as an embodiment of the present invention, FIG. 2 is a schematic perspective view of main components of the same device, and FIG. 3 is a vertical sectional view of a part of the body of the same device. Figures 4(a) and (b) are illustrations of the crank angle position and stroke of the engine to which the same device is installed, and Figures 5(a), (b), (
c) and (d) are characteristic diagrams of the flapper opening calculation map used in the control performed by the controller of the above device, and Fig. 6 is the opening calculation of the throttle opening correction valve 28 used in the control performed by the controller of the same device. MAP characteristic diagram, FIG. 7 is a flowchart of a control program for opening calculation processing used in control performed by the controller of the above device, and FIG. 8 is an overall configuration diagram of a turbulence generating device as another embodiment of the present invention. , FIG. 9, and FIG. 10 are sectional views of essential parts of different conventional devices. 10... Intake path, 11... Fuel injection valve, 12...
Engine, 13... Intake port, 20... Flapper, 22... Controller, 23... Flapper drive device, a... Fuel adhesion part, 201... Base end of flapper, 202... The rotating end of the flapper. Figure U, Figure W, Figure 1, ＼

Claims (1)

[Claims] A fuel injection valve is arranged opposite to an intake port of an internal combustion engine and injects fuel; a flapper configured to be supported and whose rotating end increases or decreases its rotational angle in a direction that narrows the cross section of the intake port; an output information generating means for generating output information of the internal combustion engine; and an output of the internal combustion engine. and a flapper driving means for operating the flapper so that the rotation angle of the flapper is held larger as A turbulence generator configured in