JPH04301723A - Remaining fuel indicating device - Google Patents

Abstract

PURPOSE:To indicate the proper quantity of remaining fuel even if the volume within a tank is changed because of change in temperature within the fuel tank, and of negative pressure due to a fuel pump in a fuel remaining quantity indicating device for a vehicle equipped with the fuel tank made of resin. CONSTITUTION:There are provided a fuel sensor 2 detecting the height of fuel level and a pressure sensor 3 detecting the inner pressure of a tank 1 within the fuel tank 1 made of resin. Signals from the fuel sensor 2 are inputted into a remaining fuel quantity detection circuit 4, so that the quantity of remaining fuel is thereby detected. And signals from the pressure sensor 3 are inputted into a pressure detection circuit 5, so that the inner pressure of the fuel tank 1 is thereby detected. And these data are inputted into a remaining fuel quantity correction circuit 6, so that the detected quantity of remaining fuel is thereby corrected in response to the inner pressure of the tank 1. Following which, signals from the remaining fuel quantity correction circuit 6 are inputted into a meter drive circuit 7, so that the proper quantity of remaining fuel is thereby indicated on a meter 8.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention has a resin fuel tank in which the internal pressure inside the tank changes due to temperature changes inside the fuel tank or negative pressure caused by a fuel pump, and the volume inside the tank changes. The present invention relates to a fuel remaining amount display device for a vehicle.

0002

2. Description of the Related Art Conventionally, a fuel remaining amount display device has been known as described in Japanese Utility Model Application Laid-open No. 63-84524.

That is, the fuel tank is composed of a sender unit that detects the remaining amount of fuel using a variable sliding resistance provided in the fuel tank, and a receiver unit that indicates the remaining amount using a signal sent from the sender unit. can be,
The above sender unit includes a float that moves according to the height of the fuel liquid level and an arm that swings as the float moves, and changes the resistance value of the variable sliding resistance depending on the swing angle of the arm. This resistance value was used to detect the height of the liquid level and the remaining amount of fuel.

[0004] Furthermore, as fuel tanks become lighter and the shapes of tanks become more complex, resin tanks, which are lightweight and easy to mold, are being used instead of metal tanks. .

[0005]

[Problems to be Solved by the Invention] However, in a fuel remaining amount display device for a vehicle equipped with a resin fuel tank, it is difficult to detect the amount of fuel in the tank as described in the above-mentioned Japanese Utility Model Publication No. 63-84524. Merely detecting the amount of fuel remaining in the tank using a remaining fuel amount display device that detects the height of the liquid level in the tank did not allow for an appropriate display of the amount of remaining fuel. In other words, even though the remaining amount of fuel does not change, the internal pressure inside the tank changes due to changes in the temperature inside the tank or negative pressure from the fuel pump, causing bulges and dents in the resin tank. Ta. As a result, the volume inside the tank changed, and the height of the fuel level inside the tank changed, making it impossible to properly display the remaining amount of fuel.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to provide a fuel remaining amount display device that can display an appropriate amount of remaining fuel in a vehicle equipped with a resin fuel tank.

[0007]

[Means for Solving the Problems] The remaining fuel amount display device of the present invention includes a remaining fuel amount detection means for detecting the remaining amount of fuel in a resin fuel tank, and an output based on the output from the remaining fuel amount detection means. A remaining fuel amount display device comprising: a display means for displaying the remaining amount of fuel; a pressure detecting means for detecting the internal pressure in the tank; The invention is characterized by comprising a correction means for correcting the output from the apparatus.

[0008]

Effect of the Invention The present invention has the above-mentioned configuration, and the output from the remaining fuel amount detection means is corrected by the correction means in accordance with the output from the pressure detection means. Displays the remaining fuel amount.

[0009]

Therefore, according to the present invention, even if the internal pressure inside the tank changes due to temperature changes inside the resin fuel tank or negative pressure caused by the fuel pump, the volume inside the tank changes. Since the output from the remaining fuel amount detecting means is corrected by the correcting means in accordance with the output from the pressure detecting means, an appropriate remaining amount of fuel can be displayed on the display means.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a configuration diagram of a remaining fuel amount display device according to the present invention. A fuel sender 2 provided in a resin fuel tank 1 includes a float 2a that moves according to the height of the fuel level in the tank 1, and an arm portion 2b that swings as the float 2a moves. The main body 2c detects the height of the fuel level based on the swing angle of the arm portion 2b. Fuel sender 2 is
A variable resistor (not shown) disposed inside the main body 2c detects a resistance value corresponding to the swing of the arm portion 2b, converts this resistance value into a voltage, and adjusts the height of the fuel level. Detect. A signal from the fuel sender 2 is input to a remaining fuel amount detection circuit 4 to detect the remaining amount of fuel. Further, a pressure sensor 3 is provided inside the tank 1, and a signal from the pressure sensor 3 is inputted to a pressure detection circuit 5 to detect the internal pressure inside the tank 1.

Conventionally, the internal pressure within the tank 1 changes due to temperature changes within the tank 1 or negative pressure caused by the fuel pump (not shown), causing bulges and dents in the tank 1, causing the internal pressure inside the tank 1 to change. As the volume of tank 1 changes and the height of the liquid level in tank 1 changes accordingly, the remaining fuel meter display value does not match the target display value, as shown in Figure 2. . In FIG. 2, the solid line indicates when the internal pressure in the tank 1 is atmospheric pressure, and the dotted line indicates when the internal pressure in the tank 1 is +500 (mmAq).
The one-dot chain line is at +1000 (mmAq), and the two-dot chain line is at -350 (mmAq). For example, +100
At 0 (mmAq), the target display value is "1/4", but the meter display value is "E", and -350 (mAq).
mAq), the target display value was "3/4", but the meter display value was around "F".

Therefore, the relationship between the target display value and the meter display value at each internal pressure in the tank 1 as shown in FIG. The remaining amount of fuel and the internal pressure inside the tank 1 detected by the pressure sensor 3 are input, and the remaining amount of fuel is corrected to the target display value according to the internal pressure inside the tank 1. In the above example, when +1000 (mmAq), the target display value is "1/4" and the meter display value is "E".
Therefore, the meter display value is increased by d1 and the meter display value is corrected to "1/4". Also, -350 (mmAq
), the target display value is "3/4" and the meter display value is near "F", so the meter display value is decreased by d2 and the meter display value is corrected to "3/4". Then, the signal from the remaining fuel amount correction circuit 6 is input to the meter drive circuit 7, and an appropriate remaining amount of fuel is displayed on the meter 8.

Note that when the temperature inside the fuel tank 1 at atmospheric pressure changes, the expansion coefficient of the tank 1, the expansion coefficient of the fuel, etc. change, and therefore the correction amount for each internal pressure also changes. Therefore, if a temperature sensor is further provided in the tank 1 to detect the temperature and the correction amount is determined from the internal pressure and temperature, more accurate correction can be performed.

As described above, according to this embodiment, the internal pressure inside the tank 1 changes due to temperature changes inside the resin fuel tank 1 or negative pressure caused by the fuel pump, causing the tank 1 to swell. Even if a dent occurs and the volume inside the tank 1 changes, the remaining fuel amount detected by the fuel sender 2 is adjusted by the remaining fuel amount correction circuit 6 according to the internal pressure inside the tank 1 detected by the pressure sensor 3. Since the fuel level is corrected to the target display value, an appropriate amount of remaining fuel can be displayed on the meter 8.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a remaining fuel amount display device of the present invention.

FIG. 2 is a graph showing the relationship between target display values and meter display values at various internal pressures within a fuel tank in a conventional fuel remaining amount display device.

[Explanation of symbols]

1... Resin fuel tank, 2... Fuel sender, 3...
Pressure sensor, 4...Fuel remaining amount detection circuit, 5...Pressure detection circuit, 6...Fuel remaining amount correction circuit, 7...Meter drive circuit, 8...Meter

Claims (1)

[Claims] Claims: 1. A fuel tank comprising: a remaining fuel amount detection means for detecting the remaining amount of fuel in a resin fuel tank; and a display means for displaying the remaining fuel amount based on an output from the remaining fuel amount detection means. The remaining fuel amount display device includes a pressure detection means for detecting the internal pressure in the tank, and a correction means for correcting the output from the remaining fuel amount detection means according to the output from the pressure detection means. A distinctive feature is the remaining fuel level display device.