JPH0311384Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a fuel supply device for an internal combustion engine such as an electronically controlled fuel injection device.

In recent years, in order to maintain the air-fuel ratio at an appropriate value for any operating condition of the engine, fuel is first controlled according to the amount of depression of the accelerator pedal, and then the amount of air is supplied accordingly. Fuel supply devices for internal combustion engines, such as electronically controlled fuel injection devices, that perform various necessary operations are being developed, but it is difficult to use this type of fuel supply device with a throttle valve for each cylinder. When applied to a multi-cylinder engine, there is a problem in that it is necessary to solve the problem of an increase in throttle operation force due to an increase in the force required to drive the entire throttle valve.

In view of the above problems, the present invention provides a throttle system in which a plurality of throttle valves are fixed to a single throttle shaft, and the throttle shaft is driven by a motor that rotates according to the amount of depression of the accelerator pedal. The present invention aims to provide a fuel supply system for an internal combustion engine that realizes reduction of operating force and application of this type of fuel supply system to a multi-cylinder engine. 1st
1 and 2 show an electronically controlled fuel injection system, in which 1 is an intake cylinder, 2 is an injector whose fuel injection amount is determined according to the amount of depression of an accelerator pedal (not shown), and 5 is a main body of a carburetor. An accelerator arm 6 is connected to an accelerator pedal (not shown) and can rotate in response to the operation of the accelerator pedal. Reference numeral 6 detects the rotation angle of the accelerator arm 5 to determine the amount of depression of the accelerator pedal, that is, the injector 2. This is a potentiometer for detecting the amount of fuel ejected from. 7 is an intake passage whose upstream side is connected to the upstream side of the intake cylinder 1 and whose downstream side is branched and connected to each cylinder; 8 is a throttle shaft that passes through the non-branched portion of the intake passage 7; 9 is an upstream side of the injector 2; Throttle shaft 8 on the side
10 is a low speed throttle valve driving motor such as a servo motor or a stepping motor connected to the externally projecting end of the throttle shaft 8 via a pulley and a belt. 11
12 is a secondary intake manifold whose upstream side is connected to the intake cylinder 1 and whose downstream side is branched and connected to each cylinder; 12 is the secondary intake manifold 1
One secondary throttle shaft 13 passes through each branch of the secondary intake manifold 11, and is fixed to the secondary throttle shaft 12 within each branch of the secondary intake manifold 11. A medium-high speed throttle valve is provided upstream of the connection part with the intake manifold 11, and 14 is a servo motor or stepping motor, etc. connected to the mid-exposed part of the secondary throttle shaft 12 via a pulley and a belt. This is a motor for driving a throttle valve for medium and high speeds. Reference numeral 15 indicates the drive motors 10 and 14 in response to information such as the amount of fuel injected from the injector 2 detected by the potentiometer 6 and the engine speed detected by a rotation sensor (not shown). This is an electronic control circuit that controls the opening degrees of the throttle valves 9 and 13 and the amount of fuel jetted from the injector 2 by rotating them.

Since the fuel supply system for an internal combustion engine according to the present invention is constructed as described above, when the accelerator pedal (not shown) is depressed during engine operation, the accelerator arm 5 is rotated as shown in FIG. 1, and fuel is supplied from the injector 2. The amount increases. At the same time, an increase in the fuel flow rate is detected by the potentiometer 6, so the electronic control circuit 15 first rotates the drive motor 10 at a low speed according to this information and information on the engine rotation speed from a rotation sensor (not shown). When the fuel flow rate further increases and the rotational speed of the engine increases, the driving motor 14 is rotated to increase the opening degree of the medium/high speed throttle valve 13. On the other hand, when the accelerator pedal is released, the amount of fuel supplied from the injector 2 decreases, contrary to the above, so the electronic control circuit 15 first decreases the opening degree of the medium-high speed throttle valve 13, and then decreases the opening degree of the low-speed throttle valve 9. The opening degree will be decreased. Therefore, since the air supply amount is increased or decreased in accordance with the increase or decrease in the fuel supply amount, the appropriate air-fuel mixture is always supplied to each cylinder. The fuel supply system of the present invention operates as described above. A plurality of throttle valves 13 are fixed to one throttle shaft 12, and the throttle shaft 12 is rotated according to the amount of depression of the accelerator pedal. Since it is driven by the motor 14, the throttle operating force is reduced, and it is fully compatible with multi-cylinder engines.

FIG. 3 shows a second embodiment, in which all the medium and high speed throttle valves 13 are divided into several groups each, and each group is fixed to one secondary throttle shaft 12. , each secondary throttle shaft 1
2 are respectively driven by respective medium/high speed throttle valve drive motors 14. FIG. 4 shows a third embodiment, in which an injector 16 is disposed in each branch of the intake passage 7, and this case has the advantage of being easy to mount.

Incidentally, in the third embodiment, as in the first and second embodiments, a plurality of medium and high speed throttle valves 13 are fixed to one secondary throttle shaft 12, and the secondary throttle valve 13 is fixed to one secondary throttle shaft 12. Needless to say, the torque shaft 12 is driven by a drive motor 14 which is rotated in response to a signal of the degree of depression of the accelerator pedal.

As described above, the fuel supply system for an internal combustion engine according to the present invention reduces the throttle operating force and is fully suitable for multi-cylinder engines. Furthermore, fuel lag is prevented, and the engine intake air-fuel mixture can be made uniform from low speed to high speed.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view of an embodiment of the fuel supply system for an internal combustion engine according to the present invention, Fig. 2 is a schematic horizontal sectional view of the throttle valve section for medium and high speeds of the above embodiment, and Fig. 3 is a second embodiment. FIG. 4 is a schematic horizontal sectional view of the middle and high speed throttle valve section of the example, and FIG. 4 is a vertical sectional view of the third embodiment. 1... Intake cylinder, 2, 16... Injector,
5... Accelerator arm, 6... Potentiometer, 7... Intake passage, 8... Throttle shaft, 9... Low speed throttle valve, 10... Low speed throttle valve drive motor, 11... Secondary Side intake manifold, 12...Secondary side throttle shaft, 13
... Throttle valve for medium and high speeds, 14... Motor for driving the throttle valve for medium and high speeds, 15... Electronic control circuit.

Claims (1)

[Claims for Utility Model Registration] (1) In a fuel supply system for an internal combustion engine applied to a multi-cylinder engine, a single intake cylinder and a plurality of secondary passages in a plurality of cylinders branched from the intake cylinder are provided with In the unbranched part of the intake passage that connects the downstream side of the intermediate and high speed throttle valve, there is a low speed throttle valve, and a fuel valve downstream of the low speed throttle valve that determines the amount of fuel to be injected according to the amount of accelerator pedal depression. In addition, a potentiometer for detecting the amount of accelerator depression, motors for driving the low-speed throttle valve and medium-high speed throttle valve, and the fuel injection valve and two motors are controlled. The opening degree of the two types of throttle valves is separately controlled by the signal from the potentiometer via the electronic control circuit and the motor, thereby ensuring uniformity of the engine intake air-fuel mixture from low speed to high speed. 1. A fuel supply device for an internal combustion engine, characterized in that the fuel supply device is configured to achieve the following: (2) The fuel supply device for an internal combustion engine according to claim (1), wherein the medium-high speed throttle valve driving motor is comprised of a plurality of motors. (3) Scope of claim (1) for registration of a utility model, in which the fuel injection valve is provided at each branch part of the intake passage, or
The fuel supply device for an internal combustion engine according to (2).