JPS6355337A - Traveling speed control method for vehicle - Google Patents

Abstract

PURPOSE:To reduce fuel-cut impact and to limit the vehicle speed reliably, by classifying cylinders into three groups and carrying out fuel cut in step corresponding to the vehicle speed. CONSTITUTION:Cylinders of engine 1 are classified into three groups A1-A3 so as to control fuel injection valves 6-8 for respective cylinder groups independently. A controller 12 receives a signal from a vehicle speed sensor 13, and when the vehicle speed exceeds over a first limit level, fuel supply to a first cylinder A1 is cut. When the vehicle speed exceeds over a second limit level higher than the first limit level, fuel supply to the first and second cylinders A1, A2 cut. When the vehicle speed increases furthermore and exceeds over a third limit level, fuel supply to the first to third cylinders A1-A3 is cut. Since fuel is cut in step, it causes low impact and the vehicle speed can be limited reliably.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for regulating and controlling the maximum traveling speed of a vehicle equipped with an electronically controlled multi-cylinder internal combustion engine.

[Conventional technology]

The maximum traveling speed of vehicles equipped with electronically controlled multi-cylinder internal combustion engines is regulated based on vehicle speed (hereinafter simply referred to as vehicle speed).
It has been common practice to cut the fuel supply to each cylinder in the internal combustion engine when the speed reaches a point where There was a problem that caused a huge impact.

Therefore, Japanese Patent Application Laid-Open No. 58-131333 as a prior art proposes regulating the vehicle speed to the maximum speed by changing the air-fuel ratio of the air-fuel mixture for each cylinder to rich or lean when the vehicle speed reaches the maximum speed. However, another proposal proposes regulating the vehicle speed to the maximum traveling speed by cutting the fuel supply to any cylinder among a plurality of cylinders when the vehicle speed reaches the maximum speed.

[Problem that the invention seeks to solve]

However, in the case of the former regulation method in which the air-fuel ratio is changed to rich or lean, there is a problem in that when the air-fuel ratio is made rich, fuel consumption increases.
There is a problem in that when the air-fuel ratio is made lean, the temperature of the exhaust gas increases, reducing the durability of the exhaust gas purification device.

In addition, with the latter method of cutting fuel supply to any cylinder among multiple cylinders, there is no problem such as an increase in fuel consumption, but on the other hand, when driving downhill, the vehicle speed is lower than the maximum regulated speed. There is a risk that a situation may occur that exceeds the limit.

The present invention provides a method for solving the above problems.

[Means for solving problems]

In order to achieve this object, the present invention divides the cylinders in an electronically controlled multi-cylinder internal combustion engine installed in a vehicle into three cylinder groups, and when the speed of the vehicle exceeds a first regulation value, the first cylinder cut the fuel supply to the cylinders in the second cylinder group, and cut the fuel supply to the cylinders in the second cylinder group when the speed of the vehicle exceeds a second regulation value that is suitably higher than the first regulation value; The fuel supply to the cylinders in the third cylinder group is cut when the speed exceeds a third regulation value that is appropriately higher than the second regulation value.

[Action/effect of the invention]

In this way, when the speed of the vehicle (vehicle speed) exceeds the first regulation value, the supply of fuel to the cylinders in the first cylinder group is cut, and even with this, the vehicle speed does not decrease and is lower than the first regulation value. When the second regulation value, which is larger than the second regulation value, is exceeded, the fuel supply to the cylinders in the second cylinder group is cut off, and even then, the vehicle speed does not decrease and exceeds the third regulation value, which is even larger than the second regulation value. In this way, the fuel supply to the cylinders in the third cylinder group is cut, so that the fuel supply cut in response to vehicle speed regulation can be divided into three cylinder groups and performed in three stages.

Therefore, while it is possible to reliably control the vehicle speed so that it does not exceed the maximum speed limit, it is also possible to reduce the impact caused by the fuel supply cut. Since it does not change the air-fuel ratio, it does not increase fuel consumption or reduce the durability of the exhaust gas purification device.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, reference numeral 1 indicates a three-cylinder internal combustion engine mounted on a vehicle (not shown), and each cylinder in the internal combustion engine 1, that is, a first cylinder A1, a second cylinder An intake passage 5 with a throttle valve 4 from an air cleaner 3 is connected to the intake manifold 2 for the A2 and third cylinders A3, and is used to inject and supply fuel to each of the cylinders Al, A2, and A3. A fuel injection valve 6.7.8 is provided.

The internal combustion engine 4 includes a rotation sensor 9 for detecting the rotation speed of the crankshaft in the internal combustion engine 1, and the intake passage 5 includes an intake pressure sensor 9 for detecting the intake pressure downstream of the throttle valve 4. The throttle valve 4 is provided with a sensor 10, and a throttle sensor 11 for detecting the opening position of the throttle valve 4.

Reference numeral 12 in the figure indicates input signals from the rotation sensor 9, the intake pressure sensor 10, the throttle sensor 11, and the vehicle speed sensor 13 of the vehicle. 7. 8 shows an electronic control unit for controlling fuel injection from 8;

The electronic control unit 12 stores the basic injection amount as a two-dimensional map using the intake pressure downstream of the throttle valve 4 and the engine speed as parameters.
Built-in OM, each cylinder Al.

A2. Based on the rotation speed detected by the rotation sensor 9 and the intake pressure detected by the intake pressure sensor, the fuel injection amount from the fuel injection valve 6, 7.8 for each of A3 is determined.
In addition to a main routine that controls the basic injection amount read from the two-dimensional map, it also includes an interrupt routine that performs the following control during the main routine.

This interrupt routine is executed in response to detection signals from the vehicle speed sensor 13 and the throttle sensor 11, as shown in the flowchart of FIG.
．． By cutting the fuel injection from 8 or releasing the fuel injection force 7, the vehicle speed is controlled so as not to exceed the maximum speed.

That is, in step S1, it is determined whether or not fuel injection is being cut in the third cylinder A3, and if fuel injection is not being cut, it is determined in step S2 whether or not fuel injection is being cut in the second cylinder A2. And then the second
When the fuel injection of the cylinder A2 is not being cut, it is determined in step S3 whether or not the first cylinder A1 is cutting the fuel injection, and when the fuel injection of the first cylinder A1 is not being cut, the process moves to step S4.

In this step S4, whether the vehicle speed or the first regulation value Nl(
For example, if the vehicle speed does not exceed the first regulation value N1, it returns to the main routine, but if the vehicle speed exceeds the first regulation value N1. If so, fuel injection to the first cylinder A1 is cut in step S5.

Next, in step S6, the vehicle speed is set to a second regulation value N2 (for example, 1
20km/h), and if the vehicle speed does not exceed the second regulation value N2, the system returns to the main routine and continues the fuel injection cut state for the first cylinder A1. do.

However, even if the vehicle speed is in the state where fuel injection is cut to the first cylinder A1, if it exceeds the second regulation value N2, fuel injection to the second cylinder A2 is cut in step S7.

Next, in step S8, it is determined whether the vehicle speed exceeds a third regulation value N3 (for example, 140 km/h), which is suitably larger than the second regulation value N2, and the vehicle speed is determined to be military speed or the third regulation value. If the value does not exceed N3, leave it as is\
Returning to the main routine, the first cylinder A1 and the second cylinder
Although the state of fuel injection cut for cylinder A2 continues,
Even if the vehicle speed is in a state where the fuel injection to the first cylinder A1 and the second cylinder A2 is cut, if the vehicle speed exceeds the third regulation value N3, the fuel injection to the third cylinder A3 is cut in step S9.

On the other hand, during the transition from step S6 to step S7, in step 10 the throttle valve 4
In step Sll, it is determined whether the opening degree of the throttle valve 4 is larger than the opening degree TA (for example, 75°) close to full open, by determining whether the change amount dTA/dT per unit time in the opening degree of the throttle valve 4 is K-dTA/dT (however, , where K is a constant), and determine whether the opening degree of the throttle valve 4 is greater than the opening degree T.
When the amount of change in the opening of the throttle valve 4 is smaller than A, and when the amount of change in the opening of the throttle valve 4 is smaller than -dTA/dT, it is determined that the vehicle is not being accelerated, and the process moves to step S7. When the opening degree is larger than the opening degree TA, or the amount of change in the opening degree of the throttle valve 4 is
When it is greater than /dT, the vehicle is being accelerated, so at this time, in step S12, the vehicle speed is appropriately greater than the second regulation value N2 by a speed α and smaller than the third regulation value N3. Vehicle speed (e.g. 13
0km/h) and determines whether the vehicle speed is over N2.
If the vehicle speed does not exceed N2+α, the process proceeds to step S8, but if the vehicle speed exceeds N2+α, fuel injection to the second cylinder A2 is cut in step 13, and from step 10 to step 13. This is to avoid a decrease in acceleration when the opening degree of the throttle valve 4 is large or when the throttle valve 4 is opened rapidly.

In step S1, when the fuel injection to the third cylinder A3 is cut off, step S1
In step 4, it is determined whether the vehicle speed exceeds a vehicle speed (for example, 135 km/h) that is smaller than N3 by an appropriate speed β, and if the vehicle speed exceeds N3-β, the process directly returns to the main routine. Then, the fuel cut state for the third cylinder A3 continues, but when the vehicle speed is equal to or lower than N3-β, the fuel injection cut state for the third cylinder A3 is canceled in step S15.

Further, in step S2, when fuel injection to the second cylinder A2 is in a cut state, step 316
In step S1, it is determined whether or not the vehicle speed exceeds N2 by an appropriate speed θ (for example, 130 km/h).
In step 7, it is determined whether the vehicle speed exceeds the vehicle speed (for example, 125 km/h) which is smaller than N2+θ by an appropriate speed γ, and if the vehicle speed exceeds N2+θ−γ, the process immediately returns to the main routine. Return, 2nd cylinder A
The fuel injection cut state for the second cylinder A2 continues, but when the vehicle speed is below N200-γ, the fuel injection cut state for the second cylinder A2 is canceled in step 31H. When the vehicle speed is equal to or lower than N2+θ in step 516, it is determined in step 319 whether the vehicle speed exceeds a vehicle speed (for example, 115 km/h) smaller than N2+θ by an appropriate speed γ, and the vehicle speed is determined to be N2+θ. 2 If it exceeds 10-γ, leave it as is\
Returns to the main routine, but the vehicle speed is N2+θ-γ
When it is below, the process moves to step 31B and the state of fuel injection cut for the second cylinder A2 is canceled.

Furthermore, in step S3, when the fuel injection to the first cylinder Al is cut off, step S20
It is determined whether the vehicle speed exceeds a vehicle speed (for example, 110 km/h) that is smaller than the first regulation value Nl by an appropriate speed l (for example, 110 km/h), and if the vehicle speed exceeds N1-η, the Well, return to the main routine and continue the fuel cut state for the first cylinder AI, but if the vehicle speed is N
When it is below l-η, the fuel injection cut state for the first cylinder A1 is canceled in step S21.

Then, by performing the above control every revolution of the crankshaft in the internal combustion engine 1 or at appropriate time intervals,
When the speed of the vehicle (vehicle speed) exceeds the first regulation value, the fuel supply to the first cylinder A1 is cut, and the vehicle speed does not decrease due to this, and the second regulation value is greater than the first regulation value. If the fuel supply power to the second cylinder A2 is exceeded, the fuel supply power to the second cylinder A2 is cut, and if the vehicle speed does not decrease even after this and exceeds the third regulation value, which is even larger than the second regulation value, the fuel supply power to the third cylinder A3 is cut. Cutting the fuel supply in response to vehicle speed regulations, such as cutting the fuel supply.
Three cylinders At, A2. It is divided into A3 and carried out in three stages.

Here, the vehicle speed when cutting fuel injection,
The reason why the vehicle speed when canceling the fuel injection cut is shifted is that if the vehicle speed when cutting the fuel injection and the vehicle speed when canceling the fuel injection cut are the same, the fuel cut will be made in the relevant vehicle speed range. This is to avoid this, since this would result in repeated cycles of fuel cut and release.

The above embodiment is applied to a three-cylinder internal combustion engine, in which the first cylinder AI is placed in the first cylinder group, the second cylinder A2 is placed in the second cylinder group, and the third cylinder A3 is placed in the third cylinder group. However, in the case of a four-cylinder internal combustion engine, the first cylinder is in the first cylinder group, the second and third cylinders are in the second cylinder group, and the third cylinder is in the third cylinder group. In the case of a 6-cylinder internal combustion engine, the first and second cylinders are in the first cylinder group, the third and fourth cylinders are in the second cylinder group, and , the fifth cylinder and the sixth cylinder may be divided into a third cylinder group, and the present invention can be similarly applied to other multi-cylinder internal combustion engines.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a flowchart. 1...Internal combustion engine, A1...1st cylinder, A2...
...Second cylinder, A3...Third cylinder, 2...Intake manifold, 3...Air cleaner, 4...Throttle valve, 5...Intake passage, 6,7. 8...
Fuel injection valve, 9... Rotation sensor, 10... Intake pressure sensor, 11... Throttle sensor, 13
...Vehicle speed sensor, 12...Electronic control unit.

Claims (1)

[Claims] (1) The cylinders in an electronically controlled multi-cylinder internal combustion engine installed in a vehicle are divided into three cylinder groups, and when the vehicle speed exceeds the first regulation value, fuel supply to the cylinders in the first cylinder group is cut. When the speed of the vehicle exceeds a second regulation value that is appropriately higher than the first regulation value, fuel supply to the cylinders in the second cylinder group is cut, and further, when the speed of the vehicle exceeds the second regulation value, A method for controlling the running speed of a vehicle, characterized in that fuel supply to cylinders in a third cylinder group is cut when a third regulation value, which is appropriately higher than the third regulation value, is exceeded.