JP2003120339A - Accelerator reaction force control device - Google Patents

Abstract

(57) [Summary] An internal combustion engine that switches between a first operation mode on a high rotation and high load side and a second operation mode on a low rotation and low load side with higher fuel efficiency than the first operation mode, In particular, it is an object of the present invention to provide an accelerator reaction force control device capable of sufficiently reducing fuel consumption when switching from the second operation mode to the first operation mode. SOLUTION: In an engine operation region B 'immediately before switching from a second operation system B to a first operation system A, the accelerator pedal depression reaction force is rapidly increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an accelerator reaction force control device.

[0002]

2. Description of the Related Art In Japanese Patent No. 2658467, a maximum engine output based on the current engine speed is calculated, and when the current engine load is close to this maximum engine output, the reaction force on the accelerator pedal is increased. Proposed.

By controlling the depression reaction force of the accelerator pedal as described above, the driver can determine whether or not the accelerator pedal can be further depressed to increase the engine output, and prevent unreasonable overtaking. It becomes possible.

[0004]

According to the above-mentioned prior art, the fuel consumption can be reduced because the accelerator pedal is not depressed even though the engine output cannot be increased. However, since the accelerator pedal may be unnecessarily depressed while the engine output is increased, this technique is used, for example, in the first operation method on the high rotation and high load side and in the fuel efficiency efficiency compared to the first operation method. Even if it is simply applied to the internal combustion engine that switches between the second operation method on the low rotation speed and low load side, the first operation method is unnecessarily excessive when switching from the second operation method to the first operation method. It is not possible to sufficiently reduce the fuel consumption by carrying out the operation of.

Therefore, an object of the present invention is to carry out the internal combustion engine by switching between the first operation system on the high rotation and high load side and the second operation system on the low rotation and low load side which has higher fuel efficiency than the first operation system. In particular, it is an object of the present invention to provide an accelerator reaction force control device capable of sufficiently reducing fuel consumption when switching from the second operation system to the first operation system.

[0006]

According to a first aspect of the present invention, there is provided an accelerator reaction force control device comprising: a first operation system on the high rotation and high load side; and a low rotation and low load with higher fuel efficiency than the first operation system. Used in an internal combustion engine that switches between the second operating system and the second operating system, and sharply increases the reaction force on the accelerator pedal in the engine operating region immediately before switching from the second operating system to the first operating system. Is characterized by.

An accelerator reaction force control device according to a second aspect of the present invention is the accelerator reaction force control device according to the first aspect, wherein the air-fuel ratio in the first operation mode is a stoichiometric air-fuel ratio or a rich air-fuel ratio. The air-fuel ratio in the second operation method is a lean air-fuel ratio.

[0008]

1 is a schematic vertical cross-sectional view of a cylinder of an in-cylinder injection type spark ignition internal combustion engine equipped with an accelerator reaction force control device according to the present invention, and FIG. 2 is a plan view of the piston of FIG. is there. In these figures, reference numeral 1 is a spark plug arranged substantially in the center of the upper portion of the cylinder, and 2 is a fuel injection valve for directly injecting fuel into the cylinder from around the upper portion of the cylinder. Further, 3 is a piston, and a concave cavity 4 is formed on the top surface thereof. 5 is an intake port,
It communicates with the inside of the cylinder through the intake valve 6. An exhaust port 7 communicates with the inside of the cylinder via an exhaust valve 8. The fuel injection valve 2 is arranged on the side of the intake port 5 where the temperature is relatively low due to the intake flow in the cylinder in order to prevent fuel vapor.

Further, the fuel injection valve 2 has slit-shaped injection holes and injects the fuel in a thin fan shape.
In order to perform the stratified charge combustion, as shown in FIG. 1, fuel is injected into the cavity 4 formed on the top surface of the piston 3 in the latter half of the compression stroke. The fuel immediately after the injection shown by the diagonal lines is liquid, but when traveling along the bottom wall 4a of the cavity 4 and spreading in the width direction, heat is absorbed from a wide area of the bottom wall 4a, so that it is easily vaporized. The fuel thus vaporized is deflected upward by the opposing side wall 4b.

As shown in FIG. 2, the opposed side wall 4b has an arc shape in a plan view. As a result, the fuel advancing on the bottom wall 4a of the cavity 4 and vaporizing is
Due to the arcuate shape of the opposing side wall 4b, they gather in the central portion and become a block of combustible air-fuel mixture in the vicinity of the spark plug 1. Thus, stratified combustion can be realized by igniting and burning the combustible mixture. Stratified combustion is a combustion method with extremely high fuel efficiency because it is possible to burn a lean air-fuel mixture in the entire cylinder and to reduce pumping loss without the need to throttle the intake air amount by a throttle valve.

The in-cylinder injection type spark ignition internal combustion engine not only performs the stratified charge combustion in which the required amount of fuel is injected only in the compression stroke, but also injects the required amount of fuel only in the intake stroke, so that the ignition timing is increased. It is also possible to perform homogeneous combustion in which the homogeneous mixture is formed in the cylinder and the homogeneous mixture is ignited and burned. Unlike the stratified combustion in which the fuel injection period is limited to the latter half of the compression stroke, such homogeneous combustion enables injection of a large amount of fuel, and thus is mainly performed on the high rotation and high load side.

The combustion air-fuel ratio in homogeneous combustion is changed from the lean air-fuel ratio near the stoichiometric air-fuel ratio to the rich air-fuel ratio near the stoichiometric air-fuel ratio according to the engine operating condition. In this in-cylinder injection spark ignition internal combustion engine, by injecting part of the required amount of fuel in the intake stroke, a slightly lean homogeneous mixture is formed in the cylinder and the remaining amount of the required amount of fuel is compressed. By forming a combustible mixture with good ignitability in the vicinity of the spark plug 1 by igniting and burning the combustible mixture and propagating the flame to the homogeneous mixture, Weak stratified combustion that can obtain high output can also be implemented.

Thus, in the direct injection spark ignition internal combustion engine, as the engine load and engine speed increase, stratified combustion, weak stratified combustion, homogeneous combustion at lean air-fuel ratio, homogeneous combustion at stoichiometric air-fuel ratio, The combustion method is switched in the order of homogeneous combustion at the rich air-fuel ratio. Here, stratified charge combustion, weakly stratified charge combustion, and homogeneous combustion with a lean air-fuel ratio are compared with homogeneous combustion with a stoichiometric air-fuel ratio or a rich air-fuel ratio because the combustion air-fuel ratio in the cylinder is lean. It is a combustion system with high fuel efficiency. Hereinafter, the homogeneous combustion at the stoichiometric air-fuel ratio and the rich air-fuel ratio will be referred to as the first operation method, and the stratified combustion, the weak stratified combustion, and the homogeneous combustion at the lean air-fuel ratio will be referred to as the second operation method having high fuel efficiency. .

FIG. 3 shows a first operating region A for implementing the first operating system on the high rotation and high load side and a second operating region B for implementing the second operating system on the low rotation and low load side. It is a map. Here, the boundary operation area B ′ is the second operation area B
From the second operation area B immediately before switching from the first operation area A to
It is the operating area within.

When the accelerator reaction force control device according to the present invention is not provided, for example, the driver changes from the current operating state a in the second operating region B to the desired operating state d in the first operating region A. When you want to increase the engine speed and engine load, simply step on the accelerator pedal
As shown by the solid line arrow, it becomes the first transient operating state b in the boundary operating region B ′, and then as shown by the dotted arrow, it becomes the second transient operating state c ′ in the first operating region A, and then by the dotted line. As shown by, the desired operating state d within the first operating region A is achieved.

Explaining such a change in the operating state with a graph showing the engine output for each engine speed with respect to the accelerator opening shown in FIG. 4, when the accelerator opening initially increases,
The engine output mainly increases without increasing the engine speed so much that the current operating state a in the second operating region B changes from the first operating state b in the boundary operating region B ′ to the first operating state b. The second transient operating state c'in the area A is reached. After that, even if the accelerator opening is increased, the engine output decreases as the engine speed increases, and the desired operating state d within the first operating region A is reached.

Thus, in order to increase the engine speed and the engine load from the current operating state a in the second operating region B to the desired operating state d in the first operating region A, the fuel efficiency is higher than that in the second operating system. The first operation method having a low fuel consumption increases the fuel consumption.

In the accelerator reaction force control device according to the present invention, as shown by the solid line in FIG. 5, any operating condition in the second operating region B changes to the high rotation and high load side as the accelerator opening increases. When the inside of the boundary operation area B'is reached, the depression reaction force of the accelerator pedal suddenly increases. FIG. 5 shows a specific case, and of course, the accelerator opening degree at which the depression reaction force of the accelerator pedal sharply increases is not constant but changes for each operating state within the boundary operating area B ′.

In order to realize the rapid increase in the stepping reaction force,
For example, in addition to the normal return spring of the accelerator pedal, another return spring connected to the accelerator pedal is provided, and when the operating state in the second operating region B is in the boundary operating region B ′, another one is provided. It suffices to fix the ends of the two return springs on the side opposite to the accelerator pedal. As a result, until the operating state reaches the boundary operating area B ',
The accelerator pedal depression reaction force is generated only by the normal return spring, but when it is within the boundary operation area B ′, the accelerator pedal depression reaction force is generated by the normal return spring and another return spring. ,
It is possible to realize a rapid increase in the pedaling reaction force.

Further, the fixed position of the end of the single return spring on the side opposite to the accelerator pedal is separated from the accelerator pedal when the operating condition in the second operating region B is in the boundary operating region B '. You may move it. Further, as shown by the alternate long and short dash line in FIG. 5, when the operating condition in the second operating region B is in the boundary operating region B ′, a constant depression reaction force may be applied to the accelerator pedal. In order to realize this, for example, a damper is connected to the accelerator pedal in addition to the return spring, and when the operating state in the second operating region B is in the boundary operating region B ′, the orifice diameter of the damper is reduced. Just do it. In any case, when the operating state deviates from the boundary operating area B ′ to the first operating area A side, the reaction force on the accelerator pedal is increased sharply and further increases according to the accelerator opening degree. If it deviates from the inside of B'to the side of the second operation region B, the reaction force on the accelerator pedal is returned to the relationship with the accelerator opening before the sudden increase.

In this way, by the accelerator reaction force control device according to the present invention, as the accelerator opening increases, the operating condition in the second operating region B changes to the high rotation and high load side and becomes in the boundary operating region B '. Since the reaction force on the accelerator pedal is suddenly increased, the current operating state a in the second operating region B is changed to the desired operating state d in the first operating region A.
When it is desired to increase the engine speed and the engine load, the driver knows that the operating condition is the first transient operating condition b within the boundary operating region B ′ by the rapid increase of the accelerator pedal reaction force. You can

If the driver desires to quickly obtain the desired operating state d, the accelerator pedal is further depressed to perform the desired operating state d via the second transient operating state c'in the first operating region A as described above. It is also possible to
However, if it is not necessary to reach the desired operating state d so quickly, when the first transient operating state in the boundary operating region B ′ is reached, the engine speed increases by waiting a short time without further pressing the accelerator pedal. As a result, the engine output drops, and due to this change in the operating state, the accelerator pedal depression reaction force is returned to the level before the sudden increase in the accelerator pedal opening. It becomes smaller, and the driver can depress the accelerator pedal until the driving state becomes the boundary operation region B ′ again and the accelerator pedal reaction force suddenly increases.

By repeating this, the operating condition is as shown by the solid lines in FIGS. 3 and 4, and the desired operating condition d without entering the first operating region A from the first transient operating condition b.
Third transient operation state c in the boundary operation area B'in the vicinity
Therefore, by further depressing the accelerator pedal from the third transient operating state c, the desired operating state d can be obtained.

By doing so, the desired operating state d in the first operating area A is changed from the current operating state a in the second operating area B.
In order to increase the engine speed and the engine load, the number of driving opportunities in the first operation method, which has lower fuel efficiency than the second operation method, is reduced, and the increase in fuel consumption can be prevented.

Of course, even if the accelerator reaction force control device according to the present invention is not provided, if the accelerator pedal is depressed very gently, the current operating state a within the second operating region B changes from the boundary operating region B '. Third transient operating state c
The desired operating state d within the first operating region A can be achieved via the. However, with such depression of the accelerator pedal, the change from the current driving state a to the desired driving state d becomes very gradual, and it is difficult to force the driver to do so. As described above, the present accelerator reaction force control device can relatively quickly realize the change from the current operating state a to the desired operating state d without significantly deteriorating the fuel consumption rate.

In the present embodiment, the stratified combustion, the weak stratified combustion, and the homogeneous combustion with the lean air-fuel ratio are carried out as the operating method in the second operating region B having high fuel efficiency.
In a cylinder injection type spark ignition internal combustion engine, if weak stratified combustion is not performed, it is excluded from the operating method in the second operation region B, and if homogeneous combustion at a lean air-fuel ratio is not performed, this is excluded. It may be excluded from the operation method in the second operation area B. Further, since there is a difference in fuel efficiency between the homogeneous combustion at the lean air-fuel ratio and the stratified combustion, the homogeneous combustion at the lean air-fuel ratio may be included in the first operating region A instead of the second operating region B. .

The present accelerator reaction force control device is not limited to use only in a cylinder injection type spark ignition internal combustion engine that switches between stratified charge combustion and homogeneous charge combustion, and the first operation method on the high rotation and high load side, The present accelerator reaction force control device can be used in any internal combustion engine that switches between the second operation method on the low rotation speed and low load side having higher fuel efficiency than the first operation method.
Of course, not only the first operation method and the second operation method,
The present accelerator reaction force control device can also be used in an internal combustion engine that can be switched to a driving system other than these.

For example, in a multi-cylinder internal combustion engine, the first operation mode is a full-cylinder operation on the high rotation and high load side, and the second operation method is a partial cylinder deactivation on the low rotation and low load side with higher fuel efficiency than the full-cylinder operation. It is good to drive. Further, in an internal combustion engine in which the opening and closing timings of intake and exhaust valves can be freely set, the first operation method is a 4-cycle operation on the high rotation and high load side, and the second operation method is a low rotation speed with higher fuel efficiency than the 4-cycle operation. It may be a two-cycle operation on the load side.

[0029]

According to the accelerator reaction force control device of the present invention, the first operation system on the high rotation and high load side and the second operation system on the low rotation and low load side having higher fuel efficiency than the first operation system are provided. In an internal combustion engine that is switched and implemented, the reaction force on the accelerator pedal is suddenly increased in the engine operating region immediately before switching from the second operating system to the first operating system. As a result, when changing the operating state from the current operating state in the first operating system to the desired operating state in the second operating system, the driver can change the engine speed when the reaction force on the accelerator pedal suddenly increases. Wait until the pedal reaction force actually rises and the pedal reaction force becomes smaller, and then step on the accelerator pedal until the pedal reaction force suddenly increases.Finally, step on the accelerator pedal where the pedal reaction force has increased. As a result, the number of operating opportunities in the first operation mode is reduced, so that the fuel consumption can be sufficiently reduced and the desired operating state can be realized relatively quickly.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view in a cylinder of a cylinder injection type spark ignition internal combustion engine according to the present invention.

2 is a piston top view of the in-cylinder injection spark ignition internal combustion engine of FIG. 1. FIG.

FIG. 3 is a map showing a first operating region and a second operating region in the direct injection spark ignition internal combustion engine of FIG.

4 is a graph showing an engine output for each engine speed with respect to an accelerator opening degree in the direct injection spark ignition internal combustion engine of FIG. 1.

FIG. 5 is a graph showing an accelerator reaction force with respect to an accelerator opening degree in the present accelerator reaction force control device.

[Explanation of symbols]

1 ... Spark plug 2 ... Fuel injection valve 3 ... piston 4 ... Cavity

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02D 41/04 310 F02D 41/04 310C F term (reference) 3D037 CA07 CB03 CB36 3G065 CA00 EA04 EA07 EA10 FA05 GA46 JA04 JA09 JA11 JA13 3G301 HA01 HA04 HA16 JA02 KA06 KA12 KA23 LA01 LB04 MA01 NB03 NE15 PF03Z

Claims (2)

[Claims] 1. An internal combustion engine for switching between a first operation system on the high rotation and high load side and a second operation system on the low rotation and low load side, which has higher fuel efficiency than the first operation system, and is used. An accelerator reaction force control device characterized by rapidly increasing a reaction force on an accelerator pedal in an engine operating region immediately before switching from the two-operation system to the first operation system. 2. The accelerator according to claim 1, wherein the air-fuel ratio in the first operation mode is a stoichiometric air-fuel ratio or a rich air-fuel ratio, and the air-fuel ratio in the second operation mode is a lean air-fuel ratio. Reaction force control device.