JPS6137800Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an intake throttle valve device for an internal combustion engine in which a fuel injection device is installed in the intake system.

In a conventional intake throttle valve device of this type, for example, as shown in FIG. The throttle valve 4 was opened and closed using an accelerator pedal (not shown). Also, the fuel injection amount can be determined using the air flow meter 1.
The intake air amount per stroke is calculated based on the output signal of the engine and the output signal of a rotation sensor (not shown), that is, the intake air flow rate and the engine rotation speed, and the fuel supply amount for this air amount is calculated by the controller 5. The opening degree of the fuel injection valve 2 was adjusted.
In addition, in the figure, 6 is a battery, 7 is a thermo time switch, 8 is a water temperature sensor, 9 is a start switch,
10 is a fuel tank, 11 is a fuel pump, 12 is a fuel filter, 13 is a pressure regulator, 1
4 is a cold start injector, 15 is a correction air valve, 16 is a distributor, 17 is an exhaust passage, and 18 is an O ₂ sensor. (Magazine “Automotive Engineering of SAE” published in January 1981)
(pp. 66-74) However, in such a conventional intake throttle valve device, the opening degree of the throttle valve 4 can be variably adjusted at will according to the driver's will. Since a space with a considerable volume called a collector is provided, in order to suddenly change from a low load state to a high load state as when accelerating, the accelerator pedal is suddenly depressed and the opening of the throttle valve 4 is suddenly expanded. In this case, the air calculated by the air flow meter 1 is filled into the collector section and then supplied to the engine. Therefore, even though there is a time delay between the intake air amount detected by the air flow meter 1 and the actual intake air flow rate, the fuel injection amount is determined based on the output of the air flow meter 1. Therefore, during acceleration, etc., the electrical signal from the air flow meter 1 injects fuel faster than the measured air that passes through the air flow meter 1 passes through the intake passage and reaches the position of the fuel injection valve 2. Since the fuel is transmitted to the valve, the amount of fuel is increased before the amount of intake air is increased, resulting in a richer air-fuel ratio of the intake air-fuel mixture, which has a negative effect on fuel efficiency.

The present invention has been made in view of the above, and a second throttle valve is provided downstream of a first throttle valve whose opening is adjusted by an operating means such as an accelerator pedal, as in the past, and this second throttle valve is connected to a second throttle valve. By providing a delay means that opens the throttle valve later than the first throttle valve, it is possible to reduce the difference between the flow rate detected by the intake air flow rate detection means and the actual intake air flow rate, thereby preventing fluctuations in the air-fuel ratio during transient operation. Therefore, the purpose is to improve the maneuverability and fuel ratio of the engine.

The present invention will be described in detail below based on an illustrated embodiment.

FIG. 2 shows an embodiment of the present invention, in which an air flow meter 24 for detecting the flow rate of engine intake air is provided in the intake passage 23 leading from the air cleaner 21 to the intake port of the internal combustion engine 22. A fuel injection valve 25 is attached to the intake port. However, in the present invention, the fuel injection valve may be installed in another part of the intake passage or in the combustion chamber.

Further, a first throttle valve 26 is provided between the air flow meter 24 and the fuel injection valve 25 and is linked to an accelerator pedal (not shown), and a second throttle valve 27 is provided downstream of this throttle valve 26. The control lever 28 of the first throttle valve 26 and the second throttle valve 2
By interlocking the control lever 29 of No. 7 through the delay means 30, the second control lever 29 is activated only when the valve is opened.
The throttle valve 27 operates at a slower speed than the first throttle valve 26.

The delay means 30 is composed of, for example, a hydraulic shock absorber as shown in FIG.
The first plunger 31 linked to the control lever 28 of No. 6 and the second plunger 32 linked to the control lever 29 of the second throttle valve 27 are slidably inserted and held in the same cylinder 33 facing each other. A chamber 34 is formed. Then, a plunger 37 that forms a variable volume chamber 36 that communicates with this cylinder 34 via an oil passage 35 is tensioned by a spring 38 to urge the volume chamber 36 to contract, and then the cylinder chamber 34 is connected to the variable volume chamber 36. A check valve 39 that closes when oil flows into the cylinder chamber 34 is provided in a part of the oil passage 35.
The oil passage 35 and the variable volume chamber 36 are kept filled with hydraulic oil. 40 is an adjustment screw for the spring 38; 41 is a return spring that biases the second plunger 32 toward the first plunger 31; 42;
is a link rod that links the control lever 28 of the first throttle valve 26 to an accelerator pedal (not shown).

In the above configuration, when an accelerator pedal (not shown) is pressed to accelerate the engine 22,
Since the link rod 42 moves in the direction of the arrow in FIG. 3 and rotates the control lever 28 counterclockwise, the opening degree of the first throttle valve 26 increases.

When the control lever 28 of the first throttle valve 26 is rotated counterclockwise, the first plunger 3
1 moves to the right in the figure, the pressure in the cylinder chamber 34 increases. Therefore, the second plunger 32 moves to the right against the return spring 41 and rotates the control lever 29 counterclockwise, so that the second throttle valve 27 also opens, but the pressure in the cylinder chamber 34 increases. Then, the pressure in the variable volume chamber 36 also increases via the oil passage 35, so the plunger 37 forming the chamber 36 moves to the left in the figure against the spring 38. Then, since the volume of the variable volume chamber 36 increases, hydraulic oil flows into the variable volume chamber 36 from the cylinder chamber 34 through the oil passage 35 by this increased amount. Further, when the first plunger 31 stops and the pressure rise in the cylinder chamber 34 stops, the pressure rise in the variable volume chamber 36 stops. Then, the plunger 37 is moved by the spring 38 by the amount that it has moved earlier.
is pushed back and the hydraulic oil is returned to the cylinder chamber 34 to return the volume of the variable volume chamber 36 to its original state, so that the second plunger 32 is eventually moved by approximately the same amount as the movement amount of the first plunger 31. The openings of the first throttle valve 26 and the second throttle valve 27 match.

Also, during deceleration, the first plunger 31 moves to the left in the figure, and along with this, the second plunger 32 moves to the left.
move in the same direction, the first throttle valve 26 and the second throttle valve 26 move in the same direction.
At the same time, the opening degree with the throttle valve 27 becomes smaller. Note that at this time, since the volume of the variable volume chamber 36 is maintained at zero or the minimum value, the hydraulic oil is not moved.

That is, during acceleration operation, as the opening degree of the first throttle valve 26 increases, the opening degree of the second throttle valve 27 increases, but the opening degree of the second throttle valve 27 increases due to the delaying action of the delay means 30. Since the valve speed is suppressed, only the air filling the space between the two throttle valves 26 and 27 is measured in increase at the beginning of acceleration, and then after the second throttle valve 27 is opened, the air filling the collector section is measured in increase. will be done.

Therefore, in the past, as shown in Figure 4A, the measured flow rate of the air flow meter shown by the solid line deviates greatly from the actual engine air intake flow rate shown by the dashed line, so that the air-fuel ratio of the intake mixture during acceleration is However, in this invention, the flow rate measured by the air flow meter is increased in two stages as shown by the solid line in Figure 4B, and based on this, the air flow meter is rapidly expanded, resulting in overshoot. By preventing this, the difference between the measured value and the actual value becomes smaller, and the degree of enrichment of the air-fuel ratio becomes smaller.
Incidentally, FIG. 4C shows the fuel injection timing, and the time axis is the same as FIGS. 4A and B, and the opening characteristics of the first throttle valve 26 and the second throttle valve 27 described above are When diagrammed, it becomes as shown in Figure 5,
Of course, the opening speed of the second throttle valve 27 varies depending on the set pressure of the spring 38 by the adjusting screw 40.

Further, in the embodiment, the delay means is constituted by a hydraulic shock absorber, but at least the valve opening speed of the second throttle valve is made slower than the valve opening speed of the first throttle valve, or the valve opening timing is delayed. The specific structure is arbitrary as long as it works.

As explained above, according to the present invention, the first throttle valve and the second throttle valve are interposed in series in the intake passage, and the second throttle valve disposed on the downstream side is connected to the first throttle valve located on the upstream side. Filling the intake passage downstream of the throttle valve with air by opening the valve with a delay
Since the calculation is performed in stages, the error between the measured intake air flow rate and the actual intake air flow rate can be reduced even during sudden acceleration, and the accuracy of calculating the fuel injection amount can be improved. Therefore, the air-fuel ratio of the air-fuel mixture taken into the engine can be maintained at an appropriate value not only during steady operation but also during transient operation such as sudden acceleration, and the drivability and fuel efficiency of the engine can be improved.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional example, Fig. 2 is a block diagram of an embodiment of the present invention, Fig. 3 is an enlarged sectional view of the main part of Fig. 2, and Fig. 4 A, B, and C are intake air A characteristic diagram of flow rate and fuel injection timing, and FIG. 5 is an opening/closing characteristic diagram of the first throttle valve and the second throttle valve. 22... Internal combustion engine, 23... Intake passage, 24...
...Air flow meter, 25...Fuel injection valve, 26
...First throttle valve, 27...Second throttle valve, 30...
Delay means, 42... link rod.

Claims (1)

[Scope of utility model registration request] In an internal combustion engine comprising means for detecting an intake air flow rate and a fuel injection device for injecting and supplying an amount of fuel calculated using the intake air flow rate detected by the means, the intake air amount detection means is provided in an intake passage. and a first throttle valve and a second throttle valve are interposed in order from the upstream side of the intake air flow, the first throttle valve is interlocked with operating means by the driver, and the second throttle valve is operated later than the first throttle valve. An intake throttle valve device for an internal combustion engine, which is provided with a delay means for opening the valve.