JPS59158361A - Controller for variable venturi carburetor - Google Patents

Abstract

PURPOSE:To supply mixture at the optimum air-to-fuel ratio during normal, accelerated and decelerated runs of an engine by making driving control of a Venturi valve according to engine speed and throttle opening. CONSTITUTION:The signals detected by an engine temperature detector 11, an engine speed detector 12, a detector 13 for opening of a throttle valve 4 and a detector 14 for the position of a Venturi valve 5 are sent to a central processor 16 via an interface 15 and then stored in a memory 17. The relation between the values detected by said detectors 11, 12 and 13 and the opening of the Venturi valve 5 which will provide the optimum air-to-fuel ratio for an engine according to its normal, starting, warming-up and other running conditions is stored in the memory 17 as maps. Said memory 17 sends the signal processed according to relating map to a driving motor 6 via the interface 15 and a motor driving part 18 to move the Venturi valve 5. The valve 5 may be thereby controlled so that the mixture may have the optimum air-to-fuel ratio throughout the operating range of the engine.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control system for a variable Hentschli carburetor.

In a conventional variable venturi type carburetor, the venturi valve is moved by the negative pressure generated in the venturi section, and controls the air-fuel ratio of the air-fuel mixture taken into the engine. However, since the air-fuel ratio is determined based only on the negative pressure of the venturi section, the air-fuel mixture does not match the optimum level required by the engine during engine operating conditions such as engine acceleration/deceleration and steady state. It does not necessarily correspond to the air-fuel ratio.

In view of the above-mentioned problems, an object of the present invention is to achieve the optimum air-fuel ratio required by the engine, especially during steady state and acceleration/deceleration of the engine, by controlling the venturi valve based on the engine speed and throttle opening. An object of the present invention is to provide a control device for a variable venturi type carburetor that can supply an air-fuel mixture.

To achieve the above object, the present invention enables a variable Henturi type carburetor to drive a venturi valve that changes the opening area of the venturi part by a drive part, and also includes a detection part that detects engine rotational speed and throttle opening. The detection signal of each detection section is processed by an electronic control section according to a predetermined relationship map, and the drive section is controlled by the output signal of the electronic control section.

The present invention will not be explained by referring to the drawings but by examples.

FIG. 1 shows an example of a tIJ modified Hentschli type carburetor used in the present invention, in which air is supplied from an air purifier (not shown) as indicated by the arrow, and after a mixture is formed in this carburetor 1, It is supplied to the engine side (not shown) as indicated by the arrow.

2nd part is the henna lily part where the flow path is constricted. On the lower side of the henna lily part 2 is a fuel tank that stores fuel at a constant level.
- A chamber 3 is provided, and a throttle valve 4 is provided downstream. A piston-shaped henna valve 5 is installed so as to be able to slide across the henna lily part 2, and a driving vehicle 6 of a J motor 6 is driven by a rack 5a carved on the side surface of the henna lily valve 5.
A is engaged. The drive motor 6 moves the henna lily valve 5 downward by -F under control to be described later, thereby changing the opening area of the henna lily portion 2. In addition, a needle valve 7 is fixed to the lower end of the henna lily valve 5, and by moving the needle valve 7 downwards,
Controls the opening degree of the fuel injection port 8.

FIGS. 2 and 3 show the vaporizer 1 together with an electronic control section 10 that is a control mechanism.

In the figure, 11 is an engine temperature detection section, 12 is an engine rotation speed detection section, which is provided in the engine (not shown), and 13 is an opening detection section of the throttle valve 4;
Reference numeral 4 denotes a detection unit for detecting the position of the henna lily valve 5 (that is, the opening degree of the henna lily valve 5), both of which are provided in the vaporizer 1.

The engine temperature detection section 11 may be installed to be embedded in the cylinder head or cylinder body, or may be installed to measure the temperature of lubricating oil or the temperature of cooling water in the case of a water-cooled engine.

The detection signals of each of the detectors 11, 12, 13, and 14 are input to the central processing unit 16 via the interface 15, and these signals are processed according to the relationship map described later stored in the memory device 17. Then, the processed signal is sent to the ink face 15. It is output to the drive motor 6 via the motor drive section 12.

The drive motor 6 is operated by the henna lily valve 5 so as to obtain an air-fuel mixture with an optimum air-fuel ratio for the engine in its operating state.
move.

- The above-mentioned description t, 1 device 17 is used when the engine is running normally.

The opening degree f (
N, S), g (T), h (T) and each of the above detectors 11
．． 12.13 detects the relationship between engine speed N, engine'/A'A degree], throttle opening S, etc., is stored as a relationship map as shown in Fig. 4.5.6. . The storage device 17 also stores programs for switching to the steady flow, starting flow, warm-up flow 1, and acceleration/deceleration flow depending on the operating state of the engine. In addition, 19 is a power supply, 20 is a main switch, 21 is a constant voltage circuit, 22 is an A/I converter that converts one analog signal into a digital signal, 23 is a runaway prevention circuit, and 24 is a It is a clock oscillator.

The main routine control by the electronic control section 10 is performed as shown in the flowchart shown in FIG.
, throttle opening S, and engine temperature T, the flow is switched to a starting subroutine, an acceleration/deceleration subroutine, a warm-up subroutine, a constant wealth subroutine, and the like. In each of the subroutines such as constant air, startup, warm-up, and acceleration/deceleration that have been switched in this way, the venturi valve opening degree xt is calculated as shown in the flow shown in Figure 8, and this is compared with the current position xp. Rotate the drive motor 6 until the difference becomes 0.
, the opening degree of the venturi valve 5 is controlled to be the above calculated value xt.

Therefore, the air-fuel mixture is controlled to have the optimum air-fuel ratio over the entire range of engine operating conditions.

As described above, during operation at constant speed and acceleration/deceleration, the optimum air-fuel ratio for the operating condition can be obtained by adjusting the engine rotational speed N and throttle opening S.

In addition, the engine temperature '■' has an effect at the time of starting and warming up, and the optimum air-fuel ratio can be obtained based on this engine temperature T. Especially in the starting subroutine, the engine? Quality'F
is used as a control signal, and the lower α11.1 of the venturi valve 5 is lowered to the position where it touches the fuel injection port 8 as shown by the chain line] 2i: If the jet area is increased and the fuel comes out more easily, It becomes possible to omit the choke mechanism and the like provided in conventional devices.

FIG. 9 shows another embodiment of the present invention, in which the applied carburetor 1° is configured to drive the bench valve 5 via a diaphragm 25 with negative and positive signals.

In the device of this embodiment, a solenoid valve 27 is connected to a pump 26 which is a negative pressure source via a surge pump 31, a solenoid valve 28 is connected to the atmosphere, and a solenoid valve 29 is connected to a venturi section 2. , are connected to the diaphragm chamber 30, respectively.

Each of these solenoid valves 27, 28, 29 is driven by the electronic control section 10. The electronic control unit 10 closes the solenoid valve 27, 28
When the solenoid valve 27 is opened, the valve 5 is lowered, and when the solenoid valve 27 is opened and the valve 28 is closed, the valve 5 is raised. Therefore, if the opening and closing of the solenoid valves 27 and 28 are controlled according to the relationship map shown in Fig. 4.5.6 in the same way as in the above embodiment, the air-fuel mixture can be adjusted to the optimum level in each engine operating state. It is possible to control the air-fuel ratio.

The circuit of the solenoid valve 29 is the same as that of the solenoid valve 27. ．． This is a safety mechanism that maintains the function of the carburetor 1 even when the operation by the carburetor 28 becomes impossible. Instead of being connected to the vacuum pump 26, the negative pressure source for the solenoid valve 27 may be connected to the intake passage, as shown by the chain line in the figure.

In the latter embodiment, since an existing diaphragm-driven carburetor can be used, there is an advantage that the present invention can be applied without major modification of the carburetor.

In each of the embodiments described above, the venturi valve 5 does not necessarily have to be piston-shaped, but may be plate-shaped. Further, although the drive motor 6 in the first embodiment drives the venturi valve 5 up and down by rotation, it may instead be driven directly by a solenoid linearly.

''In a variable Hentschuri type carburetor, the present invention enables a driving section to drive a venturi valve that changes the opening area of the venturi section, and a detection section that detects engine rotational speed and throttle opening. The detection signal of each detection section is processed by the electronic control section according to a predetermined relationship map, and the drive section is controlled by the output signal of the electronic control section.
Based on the throttle opening degree, it is possible to obtain a mixture with an optimal air-fuel ratio required by the engine during steady and acceleration/deceleration operation of the engine.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a carburetor to which the present invention is applied, FIG. 2 is a schematic diagram illustrating the same carburetor and a control device according to the present invention, and FIG. 3 is a more specific control circuit diagram. , Figure 4 is a relationship map diagram during steady operation of the engine, Figure 5 is a relationship map diagram when the engine is started, Figure 6 is a relationship map diagram when the engine is warmed up, and Figure 7 is a control flow according to the present invention. 8 is a chart of the control flow of the subroutine, and FIG. 9 is a schematic diagram showing another embodiment of the present invention. 1.1″... Carburetor, 2... Venturi section, 4...
Throttle valve, 5... Venturi valve, 6... Drive motor, 10... Electronic control unit, 11... (engine temperature) detection unit, 12... (engine speed) detection unit, 13... (throttle) (opening degree) detection section, 14...
(Venturi valve position) detection unit, 25...Diaphragm, 26...Pump, 30...Diaphragm chamber. Agent: Patent Attorney Makoto Ogawa − Patent Attorney: Ken Noguchi Teru: Patent Attorney: Kazuhiko Saishita Engine Temperature No. 5 14 (T) Fig. 7

Claims (1)

[Claims] In the variable Hentschuri type carburetor, the venturi valve that changes the opening area of the venturi part can be driven by the drive part, and a detection part is provided to detect the engine rotation speed and the throttle opening, and the detection signal of each detection part is A control device for a variable venturi carburetor, which performs processing in an electronic control section according to a predetermined relationship map, and controls the drive section using an output signal from the electronic control section.