JP2000204994A - Automatic stop control device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic stop control device for an engine to secure proper brake performance during a stop of an automobile without using a high-cost and large apparatus, such as a negative pressure pump. SOLUTION: This device is provided with a control means 2 to execute control to stop an engine 1 when a specified condition is satisfied during a stop of an automobile and an inclination detecting means 4 to detect the forward and backward inclination angle of the automobile. The control means 2 is formed such that control to stop drive of the engine 1 is avoided when an inclination angle detected by the inclination detecting means 4 exceeds a given angle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control system for automatically stopping an engine of a vehicle when the vehicle is stopped.

[0002]

As is well known, for example, when driving in an urban area by car,
When waiting for a signal for a relatively long time, it is desirable to temporarily stop the engine of the automobile to improve the fuel efficiency and protect the environment by reducing exhaust gas. For this reason, conventionally, as a device for meeting such a demand, various devices have been proposed that automatically stop the engine of a vehicle when certain conditions are satisfied when the vehicle stops. As conditions for automatically stopping the engine, it is generally selected that the vehicle speed is zero or as close to zero as possible and that the parking brake is operating. However, for example, when the vehicle is stopped on a steep slope, the foot brake is frequently used because the vehicle must be stopped reliably, so that the foot brake is operated instead of the parking brake. It is preferable that the engine is automatically stopped even when the vehicle is stopped.

However, since the foot brake is generally configured as a brake device using a brake booster utilizing the negative pressure of the engine, the engine automatically stops when the foot brake is used. In this case, the negative pressure in the brake booster decreases, and the braking performance of the foot brake decreases.

[0004] As a means for solving such a problem,
Conventionally, as described in, for example, JP-A-59-194050, there is a means for driving an electric negative pressure pump when the engine is automatically stopped to increase the negative pressure in the brake booster. However, in this means, since it is necessary to mount the electric negative pressure pump on the vehicle, the cost of the vehicle increases and the weight of the vehicle increases accordingly. Further, the burden on the battery power supply used for driving the negative pressure pump also increases.

The present invention has been conceived in view of such circumstances, and provides an appropriate braking performance when the vehicle is stopped without using expensive and large-sized equipment such as a negative pressure pump. An object of the present invention is to provide an automatic stop control device for an engine that can be secured.

[0006]

DISCLOSURE OF THE INVENTION In order to solve the above problems, the present invention employs the following technical means.

An automatic engine stop control device provided by the present invention includes a control means for executing control for stopping an engine when a certain condition is satisfied when the vehicle is stopped. A control device, comprising tilt detection means capable of detecting a front and rear tilt angle of the vehicle, and wherein the control means detects that the tilt angle detected by the tilt detection means exceeds a predetermined angle. It is characterized in that it is configured to avoid control for stopping driving of the engine.

In the present invention, the engine is not automatically stopped when the vehicle stops on a steep road surface and the front and rear inclination angles of the vehicle become larger than a predetermined angle. Accordingly, in this case, the negative pressure state in the brake booster can be appropriately maintained by driving the engine, and the vehicle can be reliably stopped using the foot brake on a steep road surface.
On the other hand, when the vehicle stops on a flat or relatively flat road surface and the front and rear inclination angles of the vehicle become small angles smaller than a predetermined angle, a certain condition for automatically stopping the engine is satisfied. The engine stops automatically at that point.
When the road surface is flat or relatively flat, the braking load is small, and the parking of the vehicle can be assured by using a parking brake that does not use a brake booster. Even if the negative pressure in the brake booster decreases due to the automatic stop of the engine, there is no particular problem with the braking performance of the car, and stopping the engine will improve the fuel efficiency of the car and reduce the exhaust gas be able to.

As described above, according to the present invention, it is possible to secure the braking performance necessary for stopping the vehicle reliably when the vehicle is stopped without mounting the electric negative pressure pump on the vehicle. Further, in the present invention, although it is necessary to mount the inclination detecting means on the automobile, the inclination detecting means is considerably less expensive in terms of parts and size compared to a conventionally used negative pressure pump. It is also quite small in weight and weight. Therefore, in the present invention, when compared with the conventional means using a negative pressure pump,
This is advantageous in reducing the cost and weight of the entire vehicle. Furthermore, since it is not necessary to drive the negative pressure pump by the battery, the burden on the battery is reduced.

[0010] Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is an explanatory diagram showing an example of an automatic engine stop control device according to the present invention.

The automatic engine stop control device according to the present embodiment includes an electronic control unit 2 for controlling the operation of an engine 1 of a motor vehicle. The electronic control unit 2 includes a vehicle speed sensor 3, The sensor 4, a brake switch 5 that is turned on when the foot brake pedal 50 is operated, and a brake switch 6 that is turned on when the parking brake lever 60 is operated are connected.
Although not shown in the drawings, devices and switches other than the above-described sensors and switches are also connected to the electronic control unit 2, and various data necessary for controlling the operation of the engine 1 are electronically controlled. It is configured to be input to the unit 2. The electronic control unit 2 includes a CPU, a memory connected thereto, and the like, and corresponds to an example of a control unit according to the present invention.

A brake device (not shown) operated by operating the foot brake pedal 50 operates with the brake booster 7 as a booster. The brake booster 7 is connected to a surge tank 10 provided on the intake side of the engine 1 by piping so that the inside thereof can be set to a negative pressure.

The tilt sensor 4 detects the front and rear tilt angles of the vehicle and transmits the value to the electronic control unit 2. Generally, the inclination angle of the front and rear of a car depends on the gradient of the road surface.
The inclination angle of the vehicle detected by the inclination sensor 4 also increases. The tilt sensor 4 includes, for example, a pendulum that always maintains a posture extending in the vertical direction regardless of the tilt angle of the vehicle, and a member provided to be tilted together with the vehicle body of the vehicle so as to be a reference for the swing angle of the pendulum. A sensor of a type that measures the inclination angle of the vehicle based on the relative angle difference with the vehicle can be used. However, the present invention is not limited to this, and other various inclination detecting means can be used.

The electronic control unit 2 is configured to execute control for automatically stopping the engine 1 based on a program stored in the memory. More specifically, general conditions for the electronic control unit 2 to automatically stop the engine 1 include, for example, that the vehicle speed detected by the vehicle speed sensor 3 is zero and one of the brake switches 5 and 6 is turned on. It is conditioned that this state continues for a certain period of time, and program data to that effect is stored in the memory of the electronic control unit 2. Of course, in the present invention, in addition to such conditions, items such as cooling water temperature, battery voltage, and engine speed may be included in the general conditions for automatically stopping the engine 1. In the engine automatic stop control device of the present embodiment, as a special condition for causing the electronic control unit 2 to automatically stop the engine 1, the condition that the inclination angle detected by the inclination sensor 4 is equal to or smaller than a predetermined value is also conditioned. Even if the above-described general conditions are satisfied, the electronic control unit 2 does not automatically stop the engine 1 if the tilt angle detected by the tilt sensor 4 exceeds a predetermined value. .

Next, the operation of the automatic engine stop control device and the operation procedure of the electronic control unit 2 will be described with reference to the flowchart shown in FIG.

First, when the vehicle in the running state stops and the vehicle speed becomes zero, and then the brake is applied for a certain period of time, and the above-described general conditions are satisfied (S1: YES). The electronic control unit 2 refers to the data of the tilt angle of the vehicle transmitted from the tilt sensor 4 to determine whether to stop driving the engine 1 or not. When the vehicle is stopped on a flat road surface, the inclination angle detected by the inclination sensor 4 is small and equal to or less than a predetermined value (S2: YES). In this case, the electronic control unit 2 Is stopped (S
3). As a result, fuel can be saved. Engine 1
When the driving of the vehicle stops, a negative pressure using the engine 1 cannot be obtained in the brake booster 7, but if the stop is on a flat road surface, the vehicle is stably stopped without requiring a large braking force. The brakes can be kept on and the vehicle can be braked by using the parking brake, so that there is no particular concern about the braking performance. After the automatic stop of the engine, for example, when the driver depresses the accelerator pedal or when the brake operating state is released and the ON signal from the brake switch 5 or the brake switch 6 is turned off, the electronic control unit 2 The engine 1 may be restarted by control.

On the other hand, when the vehicle stops on a steep road surface, the inclination angle detected by the inclination sensor 4 is a large value exceeding a predetermined value even if the above-mentioned general conditions are satisfied. Therefore, in this case, the electronic control unit 2 does not stop the engine 1 (S2: NO). Therefore, in this case, the negative pressure state in the brake booster 7 can be appropriately maintained by using the driving of the engine 1, and the operation of the brake device by operating the foot brake pedal 50 can be ensured. It can be prevented from inadvertently descending a steep road surface.

The specific structure of each part of the automatic engine stop control device according to the present invention is not limited to the above-described embodiment, and can be variously changed in design.

For example, in the present invention, the specific value of the tilt angle of the automobile, which is the threshold value for determining whether or not to automatically stop the engine, is not particularly limited. Further, the inclination detecting means according to the present invention does not need to always detect the front and rear inclination angles of the vehicle and send specific data to the electronic control unit. It may be configured to detect only whether or not the value exceeds the value and to transmit a signal to that effect to the electronic control unit only when the inclination angle exceeds a predetermined value.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example of an automatic engine stop control device according to the present invention.

FIG. 2 is a flowchart illustrating an example of an operation procedure when performing automatic stop control of an engine.

[Explanation of symbols]

 Reference Signs List 1 engine 2 electronic control unit (control means) 3 vehicle speed sensor 4 inclination sensor 5 brake switch 6 brake switch 7 brake booster

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) FA11 FB05

Claims (1)

[Claims] 1. An automatic stop control system for an engine, comprising: control means for executing control for stopping an engine when certain conditions are satisfied when the vehicle is stopped. And the control means is configured to avoid a control for stopping the driving of the engine when the tilt angle detected by the tilt detection means exceeds a predetermined angle. An automatic stop control device for an engine, comprising: