JPS60195344A - Speed controller for multicylinder internal-combustion engine - Google Patents

Abstract

PURPOSE:To perform smooth speed control as well as to prevent any drawbacks due to the exhaust of unburned gas caused by a ignition cut and unsuitableness in an air-fuel ratio at the initial stage of fuel feed reopening caused by a fuel cut and so on from occurring, by making the specified cylinder alone stop its fuel injection by a signal of more than the setting speed. CONSTITUTION:A controlling part 54 calculates fundamental injection time on the basis of input signals out of each of sensor groups 56-64. A signal for a running velocity V is inputted into a control circuit 68 from a car speed sensor 66. When the velocity V is less than a first setting velocity V0, stop control will not take place. When the velocity V grows larger than the first setting speed V0 and less than a second setting speed (V0+DELTAV0>V>V0), each fuel injection of injection valves 46 and 48 is stopped at a first control circuit 70. Thus, a fuel injection valve is divided into two groups and one group alone is in stopped so that any shock due to a sudden output drop does not happen. In addition, a large quantity of unburned gas like in case of an ignition cut system is no case exhausted there and, what is more, unsuitableness in an air-fuel ratio at the initial stage of fuel feed reopening like in case of a fuel cut system is also nothing at all.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention has a simple structure, can perform speed control clearly without causing a sudden drop in output, and can emit unburned gas. The present invention relates to a speed control device for a multi-cylinder internal combustion engine that does not cause such inconvenience.

[Technical Background of the Invention] In recent years, fuel injection mechanisms that inject and atomize fuel and supply it to each cylinder, and superchargers that force-feed intake air have become widespread, dramatically improving the performance of internal combustion engines. However, with this improvement in engine performance, the speed performance of vehicles has also improved, leading to excessive speeding. Therefore, a speed control device has been proposed that prevents the vehicle speed from increasing beyond the set speed by cutting off the ignition or cutting the supplied fuel when the vehicle speed reaches the set speed.

[Problems with the Background Art] However, these conventional speed control devices cut off the ignition power and fuel for all cylinders of a multi-cylinder internal combustion engine all at once, so they are not susceptible to shocks caused by sudden drops in output. This caused a loss in drivability and ride feel.

Furthermore, in the case of the ignition cut method, a large amount of unburned gas is emitted during speed control, so it has been difficult to apply it to vehicles with catalyst-based exhaust gas countermeasures. Furthermore, in the case of a fuel cut method for an internal combustion engine with a fuel injection mechanism, the air-fuel ratio of the mixture does not return to the required value immediately when fuel supply is restarted, and a transition time is required, which has the disadvantage of increasing the catalyst temperature. Was.

[Purpose of the Invention] The present invention solves these problems, enables clean speed control without causing a shock due to a sudden drop in output during speed control, and impairs drivability and ride feeling, and improves speed control by cutting off the ignition. This eliminates inconveniences such as unburned gas emissions and mismatched air-fuel ratios at the initial stage of fuel supply resumption due to fuel cut.
Moreover, it is an object of the present invention to realize a speed control device for a multi-cylinder internal combustion engine with a simple structure.

[Structure of the Invention] In order to achieve this object, the present invention provides a fuel injection mechanism that injects and supplies a required amount of fuel to each cylinder depending on the engine operating state of a multi-cylinder internal combustion engine. It is characterized by being provided with a control circuit that inputs a signal and controls fuel injection in a predetermined cylinder to be stopped when the signal exceeds a set speed.

[Embodiments of the Invention] Next, embodiments of the present invention will be described in detail based on the drawings. FIG. 1 shows an embodiment of the invention. In the figure, 2 is an internal combustion engine with multiple cylinders, 4 is an air supply passage,
6 is an exhaust passage, and 8 is an exhaust turbine type supercharger. The supercharger 8 uses exhaust gas to rotate a turbine 10 provided in the middle of the exhaust passage 6, transmits this rotation to the compressor 12 provided in the middle of the air supply passage 4, and compresses the supply air taken in from the air cleaner 14. . A throttle valve 16 is provided in the air supply passage 4 on the downstream side of the compressor 12, and communicates with a surge tank 18. A first branch air supply passage 20 to a fourth branch air supply passage 26 branched from the surge tank 18 communicate with the air supply side of each cylinder 28 to 34 of the internal combustion engine 2, respectively. Each cylinder 28~
The first branch exhaust passage 36 to the fourth branch exhaust passage 42 communicating with the exhaust side of the exhaust passage 34 collectively communicate with the exhaust passage 6. After rotating the turbine 10, the exhaust gas is muffled by a muffler 44 and discharged.

Such an internal combustion engine having multiple cylinders with a supercharger is provided with a fuel injection mechanism that atomizes and supplies fuel to each cylinder. The first to fourth branch air supply passages 20 to 26 include
First to fourth fuel injection valves 46 to 52 are provided to supply fuel to each cylinder 28 to 34 from a fuel system (not shown). 1st~
The operation of the fourth fuel injection valves 46 to 52 is controlled by a control section 54. The control unit 54 calculates the basic injection time based on signals from a group of sensors that detect the engine operating state, such as a pressure sensor 56, a rotation speed sensor 58, a water temperature sensor 60, a throttle valve opening sensor 62, and an air supply temperature sensor 64. do. Based on this calculated value, the first to fourth fuel injection valves 46 to 52 are controlled to supply the required amount of fuel to each cylinder 28 to 34.

Such a fuel injection mechanism is controlled to stop fuel injection in a predetermined cylinder based on a signal from a vehicle speed sensor 66 that detects vehicle speed. The traveling speed signal detected by the vehicle speed sensor 66 is input to a control circuit 68 incorporated in the control section 54 .

This control circuit 68 controls to stop fuel injection in a predetermined cylinder based on a signal input from the vehicle speed sensor 66 that is equal to or higher than a set speed. In this embodiment, each fuel injection valve is divided into two groups: first and second fuel injection valves 46.48 and third and fourth fuel injection valves 50.52. The first and second fuel injection valves 46,48 communicate with the control section 54 through the first control path 70, and the third and fourth fuel injection valves 50,52 communicate with the control section 54 through the second control path 72. The fuel injection of each group is controlled to stop in accordance with Vo and the second set speed Vo +ΔVo.

Speed control using this configuration will be explained with reference to FIG. When the internal combustion engine 2 is started, the control unit 54 of the fuel injection mechanism starts control. The control unit 54 calculates the basic injection time based on the signals input from each sensor group 56 to 64. The control circuit 68 receives information about the traveling speed (2) from the vehicle speed sensor 66 . The control circuit 68 compares the running speed ■ with the first set speed ■0, and does not perform the stop control operation when the running speed ■ is less than the first set speed vO. Thereby, the control unit 54 outputs an injection signal based on the calculated value, and the first
- Control the operation of the fourth fuel injection valves 46 to 52.

When the traveling speed (2) becomes lower than the first set speed Vo, the control circuit 68 controls to stop the fuel injection of each of the two groups of fuel injection valves in accordance with the speed. That is, the traveling speed V is the first set speed V.

or more than the second set speed (Vo+ΔVo >V>Vo)
When this is the case, the fuel injection of the first and second fuel injection valves 46 and 48 connected through the first control path 70 is controlled to stop.

As a result, the output of the internal combustion engine 2 is reduced and deceleration is achieved. At this time, all fuel injections are not stopped as in the past.
Since only one group of fuel injection valves divided into groups is stopped, there is no shock caused by a sudden drop in output. Also,
Unlike the ignition cut-off method, there is no inconvenience of emitting a large amount of unburned gas, so it can be applied to vehicles with catalyst-based exhaust gas countermeasures, and unlike the fuel cant method, there is no inconvenience caused by the air-fuel ratio mismatch at the initial stage of fuel supply. The problem of temperature rise is limited to one group of cylinders, so it does not pose a problem in terms of exhaust gas control.

The traveling speed ■ further increases and the second set speed ■00ΔVo
(V>Vo +ΔVo), the third and fourth fuel injection valves 50.52, which are connected through the second control path 72, as well as the first and second fuel injection valves 46.48 are also controlled to stop. . As a result, the output of the internal combustion engine 2 becomes zero, making it possible to achieve further deceleration and to prevent damage to the engine due to overspeed.

In this way, the 41 groups of fuel injections divided into two groups are controlled to stop sequentially by the control circuit using signals equal to or higher than the first and second set speeds, so the engine output is gradually reduced and the speed is smoothly controlled. be able to. Therefore, the drivability and riding feeling are not impaired, and the detection of the second set speed can be used as a detection of an abnormal state of the engine to prevent damage to the engine. In addition, when the speed to be controlled is reached with the throttle valve fully open and the vehicle is driven while controlling the stop of the fuel injection valve, the throttle valve tr
Compared to the speed control method based on the opening degree, in this invention, since the throttle valve is fully open, the bomb loss in the cylinder where injection is stopped decreases. As a result, fuel efficiency can be improved, and the exhaust gas temperature can be lowered by mixing fresh air into the exhaust gas. Especially in exhaust gas control vehicles equipped with catalysts,
Catalyst temperature can be lowered.

In this embodiment, the fuel injection valves were divided into two groups and stopped sequentially at a set speed, but the fuel injection valves of some cylinders may be stopped at a set speed, or the fuel injection valves of each cylinder may be stopped at a set speed. The injection may be thinned out, the injection amount may be reduced, and the number of injections may be reduced, or the injection may be thinned out in some cylinders, the injection amount may be reduced, and the number of injections may be reduced. Furthermore, it is also possible to perform control to stop fuel injection in a predetermined cylinder based on a set speed by appropriately combining these methods. Further, the sensor that detects the vehicle speed may be replaced with a sensor that detects the ignition pulse and the shift operation position of the transmission.

In this embodiment, an internal combustion engine having multiple cylinders with a supercharger is illustrated, but it goes without saying that the present invention can also be implemented in an internal combustion engine without a supercharger.

[Effects of the Invention] As described above, according to the present invention, the control circuit controls the stop of fuel injection in a predetermined cylinder in response to a signal higher than the set speed, so that the output decreases gradually without causing a sudden decrease in output as in the conventional case. Speed: i+J can be controlled smoothly without impairing drivability or ride feel. In addition, unlike the ignition cut method, it does not cause the inconvenience of unburned gas emissions, so it can be used in vehicles with catalytic exhaust gas countermeasures, and unlike the fuel cut method, mismatches in the air-fuel ratio at the initial stage of resuming fuel supply are not caused by the cylinder, but by the specified cylinder. Since the exhaust gas is in the cylinder, the rise in catalyst temperature is small and does not cause any problems in terms of exhaust gas control.

Furthermore, since a sensor is installed to detect vehicle speed,
The structure is inside the cylinder without requiring any other external mechanism.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a schematic plan view of an internal combustion engine provided with a speed control device, and Fig. 2 is a flowchart of the operation. In the figure, 2 is an internal combustion engine with multiple cylinders, 28 to 34
is a cylinder, 46 to 52 are fuel injection valves, 54 is a control unit, 56
~64 is a sensor group, 66 is a speed sensor, 68 is a control circuit,
70 is a first control path, and 72 is a second control path. Agent Patent attorney Yoshimi Saigo Agent Patent attorney Hara 1) Yukio Attorney Patent attorney Tadashi Harasaki Figure 1

Claims (1)

[Scope of Claims] (1) A fuel injection mechanism is provided to inject and supply the required amount of fuel to each cylinder depending on the engine operating state of the multi-cylinder internal combustion engine, and a signal from a sensor that detects the vehicle speed is input to the multi-cylinder internal combustion engine. 1. A speed control device for a multi-cylinder internal combustion engine, comprising a control circuit that controls to stop fuel injection in a predetermined cylinder based on a signal. 2. The fuel injection mechanism is configured by dividing each fuel injection valve that injects and supplies fuel into each cylinder of the multi-cylinder internal combustion engine into two groups, and the control circuit is configured such that the signal input from the sensor is set to a first setting. If the speed is higher than or equal to the second set speed, the above 2.
controls to stop the injection of one of the fuel injector groups divided into the groups, and stops the injection of both of the fuel injector groups divided into the two groups when the signal input from the sensor is equal to or higher than a second set speed; A speed control device for a multi-cylinder internal combustion engine according to claim g31, which is a control circuit for controlling.