JPH11351005A - Fuel supply quantity control device for vehicular engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid a sense of incompatibility when an auxiliary brake is released, and to suppress the emission of black smoke and the like. SOLUTION: A vehicular engine is provided with a controller that controls the supply quantity of fuel and an auxiliary brake both depending on the vehicle speed so that the vehicle speed is kept at a predetermined target value. The engine is further provided with a means for delaying lifting restrictions on the fuel supply when the auxiliary brake is changed from its actuated condition to its standby condition, to thus prevent such sudden increases in the fuel supply quantity as possibly caused by the release of the auxiliary brake.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply control system for a vehicle engine, and more particularly to a vehicle provided with a controller for controlling a fuel supply amount and an auxiliary brake to maintain a vehicle speed at a predetermined target value. The present invention relates to a fuel supply control device for an engine.

[0002]

2. Description of the Related Art As a conventional control device of this type, for example, as shown in FIG. 2, a controller 3 is provided as control means for a nozzle 2 for supplying fuel to a vehicle engine 1, while an accelerator pedal 4 is opened. An accelerator sensor 5 for detecting the vehicle speed and a vehicle speed sensor 6 for detecting the vehicle speed are provided, and the output signals of these sensors 5 and 6 are supplied to the controller 3 so that the operation of the nozzle 2 and the auxiliary brake (not shown) are performed based on the vehicle speed. There is one in which a signal is adjusted to control a fuel supply amount and an auxiliary brake to maintain a vehicle speed at a predetermined target value.

[0003] In such a conventional fuel supply amount control device, when the vehicle speed holding switch is turned on while the vehicle is running, an accelerator pedal, a clutch pedal or a brake pedal is operated to renew the driver's will. Until the display, the fuel supply amount is automatically controlled to maintain the vehicle speed at a predetermined target value.

[0004] In the above-described auto cruise travel, the distance from the vehicle traveling ahead (inter-vehicle distance).
Is smaller than the predetermined value, the auxiliary brake is automatically operated to reduce the vehicle speed. Then, when the inter-vehicle distance becomes larger than a predetermined value based on the increase in the traveling speed of the preceding vehicle or other conditions, the operation of the auxiliary brake is released to return the supply of fuel, and the vehicle speed is returned to the target value, and Since the same auto cruise is performed, the burden on the driver is reduced.

However, conventionally, as shown in FIG. 3, not only when the accelerator pedal is depressed but also when the auxiliary brake is switched to the non-operation state in synchronization with the release of the automatic auxiliary brake signal, the auxiliary brake switching operation is performed. At the same time, the restriction on the injection amount was released. For this reason, the supply amount of fuel rapidly increases in synchronization with the release of the auxiliary brake, so that, for example, black smoke is discharged, or the output torque of the engine rapidly increases, giving a sense of incongruity to the driver. There was a problem.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to avoid a sense of incongruity associated with the release of the auxiliary brake and to suppress the emission of black smoke.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a controller for controlling a fuel supply amount and an auxiliary brake based on a vehicle speed so that the vehicle speed is maintained at a predetermined target value. The vehicle engine described above is characterized in that a means is provided for delaying the release of the fuel supply restriction accompanying the switching of the auxiliary brake from the operating state to the non-operating state. The delay means may be configured to maintain the supply restriction for a predetermined time after the release operation of the auxiliary brake, and then gradually increase the supply restriction value over time.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a control characteristic diagram showing one embodiment of a fuel supply control device for a vehicle engine according to the present invention.

In the present embodiment, for example, when the distance from the vehicle traveling ahead (inter-vehicle distance) becomes smaller than a predetermined value during traveling in auto cruise, an automatic auxiliary brake signal is output from the controller. Therefore, the vehicle speed is reduced so that the inter-vehicle distance does not become too small. When the inter-vehicle distance becomes larger than a predetermined value based on an increase in the traveling speed of a vehicle traveling ahead or other conditions, a signal indicating that the automatic auxiliary brake is released is output from the controller. The configured auxiliary brake is released.

When the auxiliary brake is released in this way, a timer (not shown) is activated, and the release of the restriction is delayed by a predetermined time T1 to maintain the supply restriction. , The supply limit value is gradually increased. Such a supply restriction is continued until the time T2 has elapsed since the release of the auxiliary brake.

Therefore, immediately after the release of the automatic auxiliary brake, the supply of fuel is gradually released with a delay, and the vehicle speed is returned to the target value, so that the emission of black smoke accompanying the rapid increase of the fuel supply amount is suppressed. At the same time, the output torque of the engine gradually increases, so that a rapid increase in vehicle speed is avoided, and a sense of discomfort is avoided.

When the accelerator pedal is depressed as shown by a two-dot chain line in FIG. 1 to increase the vehicle speed during operation of the auxiliary brake, the auxiliary brake is switched to a non-operation state in synchronization with the depression. Being operated,
Since the restriction on the fuel supply amount is immediately released as shown by the one-dot chain line in FIG. 3, the response to the driver's operation is not impaired.

In the above-described embodiment, after the release of the restriction amount is delayed by a predetermined time T1, the supply restriction value is gradually increased with the lapse of time to prevent a rapid change in the vehicle speed. However, the limit value can be increased stepwise after a predetermined time T1 has elapsed, or the limit can be gradually increased immediately after the release of the auxiliary brake to avoid a sudden increase in the supply amount. You can also.

[0014]

As is apparent from the above description, the present invention avoids a sudden increase in the supply amount observed when the auxiliary brake is released by delaying the release of the restriction of the fuel supply amount accompanying the release operation of the auxiliary brake. Therefore, the emission of black smoke, which is a concern when the auxiliary brake is released, is suppressed, and a sudden increase in the output torque of the engine is avoided, so that uncomfortable feeling is avoided.

[Brief description of the drawings]

FIG. 1 is a control characteristic diagram showing one embodiment of a fuel supply amount control device for a vehicle engine according to the present invention.

FIG. 2 is a schematic configuration diagram showing an example of a fuel supply amount control device for a vehicle engine.

FIG. 3 is a control characteristic diagram of a conventional example of a fuel supply amount control device for a vehicle engine.

[Explanation of symbols]

 Reference Signs List 1 engine 2 nozzle 3 controller 4 accelerator pedal 5 accelerator sensor 6 vehicle speed sensor

Claims (2)

[Claims] 1. A controller for controlling a fuel supply amount and an auxiliary brake based on a vehicle speed is provided.
In a vehicle engine in which the vehicle speed is maintained at a predetermined target value, a means is provided for delaying the release of the fuel supply restriction accompanying switching of the auxiliary brake from the operating state to the non-operating state. A fuel supply control device for a vehicle engine. 2. A delay means for maintaining a supply restriction for a predetermined time after the release operation of the auxiliary brake, and thereafter gradually increasing the supply restriction value with the lapse of time. The fuel supply control device for a vehicle engine according to claim 1.