JPH03200059A - Air-fuel ratio meter - Google Patents

Abstract

PURPOSE:To recognize the present air-fuel ratio and also to easily realize the economical air-fuel ratio by converting the output value of a sensor of oxygen concn. into the indicated value of air-fuel ratio and dis-playing this indicated value. CONSTITUTION:A sensor 13 of oxygen concn. generates electromotive force V correspondent to the difference of oxygen concn. of both the atmosphere A and exhaust gas E. The characteristics of the electromotive force of the sensor 13 are quickly changed by the oxygen conen. contained in exhaust gas while keeping the theoretical air-fuel ratio KO (=14.6) as a border. When the air-fuel ratio K is concentrated, the electromotive force V is made large (e.g.>=0.8). When it is diluted, the electromotive force V is made small (e.g. <=0.2V). An air-fuel ratio meter 14 is constituted of both a voltage/air-fuel ratio conversion part 31 by which the output voltage of the sensor 13 is converted into the indicated value of the air-fuel ratio and an indication part 32 for displaying the indicated value of air-fuel ratio. The indication part 32 is concretely constituted of an LED indication part and equipped with a figure such as '8' - '18' showing the air-fuel ratio and also the coloring indication of the present air-fuel ratio is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an air-fuel ratio meter that is installed and used in the cabin of an automobile.

[Prior Art] In conventional automobiles, especially those equipped with fuel injection devices, an oxygen concentration sensor is installed in the exhaust path, and the output value of this oxygen concentration sensor is transferred to the on-board computer. The fuel injection amount is feedback-controlled based on the current air-fuel ratio converted from the output value of the oxygen concentration sensor.

[Problems to be Solved by the Invention] However, in conventional automobiles, there is no means for informing the driver of the current air-fuel ratio, resulting in the following disadvantages (1) to (3).

■Since the driver cannot know the current air-fuel ratio, he cannot drive within an economical air-fuel ratio range such as the stoichiometric air-fuel ratio, and cannot drive in a manner that achieves low fuel consumption.

■Since the driver cannot know the current air-fuel ratio, it is difficult to set the fuel supply amount to achieve the output air-fuel ratio.

■Since the driver cannot know the current air-fuel ratio, it is difficult to prevent engine damage caused by an excessively low air-fuel ratio.

■For vehicles that are equipped with an oxygen concentration sensor to control fuel supply, the driver cannot check the output status of the oxygen concentration sensor, so it is necessary to determine if there is a failure such as a disconnection of the oxygen concentration sensor. I can't.

The present invention enables a driver to know the current air-fuel ratio, easily achieves an economical air-fuel ratio or a power air-fuel ratio, and prevents damage to the engine due to an excessively lean air-fuel ratio, or The purpose of the present invention is to make it possible to reliably and easily determine the occurrence of a failure in an oxygen concentration sensor.

[Means for Solving the Problems] The present invention as set forth in claim 1 has an air/fuel stop needle that is connected to an oxygen concentration sensor installed in the exhaust path of an automobile and that can be installed in a vehicle interior, and that detects the oxygen concentration. The output value of the sensor is converted into an air-fuel ratio display value, and the air-fuel ratio display value is displayed.

According to a second aspect of the present invention, the air-fuel ratio display value is displayed using at least one of colors, letters, and sounds.

[Operation] According to the present invention, an air-fuel stop needle having an air-fuel ratio display function can be installed and used in the vehicle interior, and as a result, the driver can know the current air-fuel ratio. For this reason, the following ■
There are ~■ effects.

■Since the driver can know the current air-fuel ratio, he or she can drive within an economical air-fuel ratio range, such as the stoichiometric air-fuel ratio, and can drive in a manner that achieves low fuel consumption.

■Since the driver can know the current air-fuel ratio, it is easy to set the fuel supply amount to achieve the output air-fuel ratio.

■Since the driver can know the current air-fuel ratio, he can predict and prevent engine damage caused by an excessively low air-fuel ratio.

■For vehicles equipped with an oxygen concentration sensor to control fuel supply, the driver can check the output status of the oxygen concentration sensor via the display result of the air/fuel stop needle. It is possible to reliably and easily determine the occurrence of a failure such as a sensor disconnection.

[Example] Fig. 1 is a schematic diagram showing an automobile equipped with the air fuel stop needle of the present invention, Fig. 2 is a perspective view showing an example of the air fuel stop needle, and Fig. 3 is a block diagram showing the air fuel stop needle. 4 is a diagram showing the output characteristics of the oxygen concentration sensor, and FIG. 5 is a schematic diagram showing an example of the oxygen concentration sensor.

In the automobile 10, an oxygen concentration sensor 13 is installed in the exhaust manifold 12 of the internal combustion engine 11. On the other hand, in the automobile 10, an air fuel stop needle 14 is installed in the front of the driver's seat in the vehicle interior, and a voltage signal line extending from the oxygen concentration sensor 13 is connected to the air fuel stop needle 14. Note that 15 is a battery.

The oxygen concentration sensor 13 utilizes the oxygen ion conductivity of a zirconia solid electrolyte, for example, as shown in FIG. This is an oxygen concentration cell in which gas A (oxygen concentration is known) is introduced and the outside is exposed to exhaust gas E (oxygen concentration unknown). The oxygen concentration sensor 13 generates an electromotive force V according to the difference in oxygen concentration between the atmosphere A and the exhaust gas E. As shown in FIG. 4, the electromotive force characteristics of the oxygen concentration sensor 13 change rapidly at the stoichiometric air-fuel ratio KO (=14.6) depending on the oxygen concentration in the exhaust gas.
When the air-fuel ratio K is high, the electromotive force V is high (for example, 0.8v
or more), and when it is thin, it becomes low (for example, 0.2 V or less).

The air/fuel stop needle 14 is connected to the oxygen concentration sensor 1 as shown in FIG.
The air-fuel ratio converter 31 includes a voltage/air-fuel ratio converter 31 that converts the output voltage of No. 3 into an air-fuel ratio display value, and a display unit 32 that displays the air-fuel ratio display value.

Specifically, the display section 32 is composed of an LED display section 33, as shown in FIG. The LED display section 33 is provided with numbers representing the air-fuel ratio, such as degrees 8° to 18°, and can display the current air-fuel ratio in color. For example, the following (a)
~(c).

(a) The output voltage of the oxygen concentration sensor 13 is between 0.2v and 0.2v.
When the voltage is 8V, the air-fuel stop needle 14 changes the air-fuel ratio display value to, for example, "1".
For example, an appropriate value within the range of 4” to 16°
The LED display unit 33 is determined to be ``15°'', and the LED display section 33
”Display the following parts in green.

(b) When the output voltage of the oxygen concentration sensor 13 is 0.2V or less, the air-fuel stop needle 14 determines the air-fuel ratio display value to be an appropriate value in the range of 14" or less, for example, "10", and
The ED display section 33 displays this portion below 10° in red, indicating a faint dangerous condition.

(c) When the output voltage of the oxygen concentration sensor 13 is 0.8V or more, the air-fuel ratio meter 14 displays the air-fuel ratio display value, for example, '16''.
For example, the LED display section 33 determines that the above range is '17'', and displays the part below this ' ] 7'' in yellow,
Display a dark state.

The display unit 32 can also display a stable air-fuel ratio display value from the air-fuel ratio meter 14 by sound. At this time, display section 3
2, for example, an air-fuel ratio display sound having a different volume or tone can be emitted for each stage of the current air-fuel ratio, which is divided into three stages, for example, rich, proper, and light. Also, display section 3
2 can also emit an air-fuel ratio alarm display sound only when the air-fuel ratio is too low and a danger should be predicted.

As shown in FIG. 2, the air-fuel ratio meter 14 is equipped with a display sound adjustment switch 34 that can stop sending out the air-fuel ratio display sound or adjust its volume.

Next, the operation of the above embodiment will be explained.

According to the above embodiment, the air-fuel ratio meter 1 has an air-fuel ratio display function.
4 can be installed and used inside the vehicle, and as a result,
The driver can know the current air-fuel ratio. For this reason, there are the following effects.

■Since the driver can know the current air-fuel ratio, he or she can drive within an economical air-fuel ratio range, such as the stoichiometric air-fuel ratio, and can drive in a manner that achieves low fuel consumption.

■Since the driver can know the current air-fuel ratio, it is easy to set the fuel supply amount to achieve the output air-fuel ratio.

■Since the driver can know the current air-fuel ratio, he can predict and prevent engine damage caused by an excessively low air-fuel ratio.

■For vehicles equipped with an oxygen concentration sensor to control fuel supply, the driver can check the output status of the oxygen concentration sensor via the display result of the air-fuel ratio meter. The occurrence of a failure such as a disconnection can be reliably and easily determined.

[Effects of the Invention] As described above, according to the present invention, the driver can know the current air-fuel ratio, easily achieve an economical air-fuel ratio and an output air-fuel ratio, and prevent excessively lean air-fuel ratios. It is possible to prevent damage to the engine caused by this, or to reliably and easily determine the occurrence of a failure in the on-vehicle oxygen concentration sensor.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing an automobile equipped with the air-fuel ratio meter of the present invention, Fig. 2 is a perspective view showing an example of the air-fuel ratio meter, Fig. 3 is a block diagram showing the air-fuel ratio meter, and Fig. 4 is an oxygen A diagram showing the output characteristics of the concentration sensor, and FIG. 5 is a schematic diagram showing an example of the oxygen concentration sensor. DESCRIPTION OF SYMBOLS 10... Automobile, 13... Oxygen concentration sensor, 14... Air-fuel ratio meter, 31... Voltage/air-fuel ratio conversion part, 32.33... Display part.

Claims (2)

[Claims] (1) An air-fuel ratio meter that is connected to an oxygen concentration sensor installed in the exhaust path of a car and can be installed inside the vehicle,
An air-fuel ratio meter that converts the output value of an oxygen concentration sensor into an air-fuel ratio display value and displays the air-fuel ratio display value. (2) The air-fuel ratio meter according to claim 1, wherein the air-fuel ratio display value is displayed using at least one of colors, letters, and sounds.