JPH0234578Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a fuel tank remaining amount warning device for automobiles.

(Prior Art) Generally, a fuel tank for an automobile is provided with a remaining amount warning device that issues a warning signal when the remaining amount of fuel reaches a predetermined lower limit amount. In this case, this device is provided with a detector that detects the lower limit liquid level position of the fuel when the remaining amount of fuel reaches a predetermined lower limit amount.

In the above configuration, in order to prevent the warning device from operating due to ripples in the liquid level in the fuel tank before the remaining fuel reaches the lower limit amount, this warning device It is configured as shown in Publication No.-5558.

That is, a ripple suppression case is provided that covers the detector, and this case has a fuel flow hole that communicates between the inside and outside of the case, and the resistance during fuel flow in this flow hole prevents ripples in the liquid surface of the fuel inside the case. It can be suppressed.

(Problems to be Solved by the Invention) By the way, with the above configuration, when the remaining fuel is stored above the lower limit amount, the activation of the warning device due to ripples in the liquid level is suppressed; however,
For example, when a car turns, the inertial force of the fuel causes the liquid level of the fuel to tilt over a relatively long period of time. Therefore, if this liquid level is lower than the detector, the fuel in the case will flow out of the case through the communication hole. Therefore, even if the remaining amount of fuel is stored above a predetermined lower limit amount, the detector is activated and issues a warning, resulting in the inconvenience that an appropriate remaining amount state is not detected.

(Purpose of the invention) This invention was made with attention to the above-mentioned circumstances.When a car turns, accelerates, or brakes, the inertia of the fuel causes the liquid level of the fuel to remain relatively long. It is an object of the present invention to suppress issuing of a warning regarding the remaining amount if the remaining amount of fuel is stored at a predetermined lower limit amount or more even when the amount of fuel is displaced over a period of time.

(Structure of the device) The feature of this device to achieve the above object is that a case is provided to cover the detector, and fuel that exceeds the lower limit of the remaining fuel level flows into this case. The main advantage is that the structure is configured so that it is easy to carry out the process, and at the same time, the outflow of fuel inside the case is suppressed.

(Example) Hereinafter, an example of this invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a fuel tank, and although this fuel tank 1 is not shown, it is installed in an automobile. A detector 3 is provided at the bottom of the fuel tank 1, and the detector 3 is covered with a case 4 made of resin. On the other hand, a fuel gauge unit 5 is provided on the upper surface of the fuel tank 1, and the detector 3
and the fuel gauge unit 5 are connected by an electric wire 6. Further, the detector 3 and the case 4 are supported by the fuel gauge unit 5 via a support rod 7.

In FIGS. 2 and 3, the detector 3 detects the lower limit liquid level position (shown by the two-dot chain line A in FIG. 2) when the remaining fuel reaches a predetermined lower limit.
This detector 3 has a reed switch 8 and a float 9 that floats on the surface of the fuel. The float 9 is also provided with a magnet 10 that closes the contact 8a of the reed switch 8 when the remaining fuel reaches the lower limit liquid level. The fuel gauge unit 5 receives a detection signal caused by the closure of the contact 8a and outputs a warning signal to a display means (not shown).

In the above configuration, the vertical hole 12 that communicates between the inside of the case 4 at a position slightly above the lower limit liquid level of the fuel and the bottom outer surface side of the case 4 is provided in the case 4.
is formed. This vertical hole 12 has a diameter of, for example, 4
It is said to have a circular cross section of about mm. Then, the lower end flat plate portion 7a of the support rod 7 is press-fitted into this vertical hole 12, and the case 4 is supported by the lower end of the support rod 7 by this press-fitting.

The gap between the vertical hole 12 and the flat plate portion 7a at the lower end of the support rod 7 is a first fuel flow passage 13, through which fuel flows into the case 4 or flows out from the case 4. It is considered possible.
On the other hand, a through hole is formed that communicates the bottom inside the case 4 with the outer surface of the bottom, and this through hole is connected to the second
A fuel flow path 14 is provided. This second fuel flow path 1
4 has a circular cross section with a diameter of about 1 mm, for example, and the second fuel flow passage 14 is a microhole having a smaller cross-sectional area than the first fuel flow passage 13 described above.

In addition, the bottom plate of the case 4 has a diameter of 1 mm, for example.
Air circulation holes 15 of about mm are formed.

(effect) Next, the effect of the above configuration will be explained.

In FIG. 2, when the liquid level in the fuel tank 1 is almost horizontal and the liquid level is above the lower limit liquid level position A as shown by the solid line in the figure, for example, the car is turning to the right. , the liquid level of the fuel in the fuel tank 1 excluding the case 4 (hereinafter simply referred to as the liquid level in the fuel tank 1) is indicated by the two-dot chain line B in the figure.
Suppose it is tilted as shown in . In this case, since the upper end of the first fuel flow passage 13 is located slightly above the lower limit liquid level position A, the fuel tank 1
The liquid level B inside easily exceeds the upper end of the first fuel flow passage 13 upward. Therefore, the fuel quickly flows into or out of the case 4 through the first fuel flow passage 13, so that the liquid level B' in the case 4 becomes equal to the liquid level B in the fuel tank 1 as shown in the figure. It will match immediately.

At this time, as described above, the upper end of the first fuel flow passage 13 is located above the lower limit liquid level position A, and the liquid level in the case 4 is higher than the upper end of the first fuel flow passage 13. Since B' is located above, even if this liquid level B' is slightly inclined, the float 9 on this liquid level B' is positioned sufficiently above the lower limit liquid level position A, and therefore, the contact point 8a is not closed.

Next, contrary to the above, the car turns to the left, the fuel level tilts in the opposite direction, and the fuel tank 1
When the liquid level in the case 4 is about to fall below the upper end of the first fuel flow passage 13 (as shown by the two-dot chain line C in the same figure), a part of the fuel in the case 4 is first transferred to the first fuel flow path 13. The fuel flows out of the case 4 through the flow path 13 and the second fuel flow path 14.

This outflow causes the liquid level C′ in case 4 to rise to the first level.
When it reaches the upper end of the fuel flow passage 13,
The outflow of fuel is stopped through the first fuel flow path 13, and thereafter, the fuel in the case 4 flows out only through the second fuel flow path 14. In this case, since the second fuel flow passage 14 is a minute hole, the fuel will gradually flow out through the second fuel flow passage 14, and the liquid level C' in the case 4 will be lower than the fuel tank 1.
It will take a predetermined time for the liquid to drop to the liquid level C inside. In other words, even if the liquid level C in the fuel tank 1 falls below the lower limit liquid level position A at the detector 3 position, the liquid level C' in the case 4 will be at the lower limit from this point on for the above-mentioned predetermined time. It is maintained above the liquid level position A to prevent the contact 8a from closing.

By the way, during normal driving of a car, the car does not turn in either the left or right direction for a long period of time, but after turning in one direction, it turns in the other direction after a short period of time, or it is forced to go straight. It is.

Therefore, if a right turn is performed in reverse before the liquid level C' in the case 4 falls to the lower limit liquid level position A, the inclination of the liquid level will be reversed again. Then, as described above, the fuel quickly flows into the case 4 through the first fuel flow passage 13 and the float 9
is prevented from falling further, that is, contact 8a is prevented from closing.

On the other hand, if the almost horizontal liquid level in the fuel tank 1 falls to the vicinity of the lower limit liquid level position A, even if the liquid level in the fuel tank 1 tilts due to turning of the car, etc., the fuel will First fuel flow passage 13
The amount of water flowing into the case 4 through the filter is reduced. Therefore, subsequent inflow and outflow of fuel into and out of the case 4 is performed mainly through the second fuel flow path 14, and as a result, the liquid level in the case 4 follows the liquid level in the fuel tank 1, and this case The liquid level in 4 reaches near the lower limit liquid level position A. Then,
Depending on the position of the float 9 above the liquid level in the case 4, the contact 8a is opened or closed, and when the contact 8a is closed, the detector 3 causes the fuel gauge unit 5 to output a remaining fuel warning signal. The output of the warning signal in this case does not pose any problem since the liquid level has reached the vicinity of the lower limit liquid level position A as described above, and is rather appropriate.

Note that when fuel flows into or out of the case 4 as described above, air flows out from or flows into the case 4 through the air circulation hole 15, and the fuel flows into or out of the case 4. The outflow is becoming smoother.

Further, although the above example is based on the illustrated example, the first fuel flow passage 13 may be formed so as to penetrate the side wall of the case 4.

(Effect of the invention) According to this invention, the first fuel flow path is provided which communicates the inside of the case slightly above the lower limit liquid level with the outside of this case, while the bottom part inside this case communicates with the outside of this case. A second fuel flow passage communicating with the outside of the case is provided, and this second fuel flow passage is formed to be a microhole with a smaller cross-sectional area than the first fuel flow passage, so that it is in an almost horizontal state. When the remaining fuel level is located above the lower limit liquid level position and the fuel level repeatedly tilts in various directions due to the inertia of the fuel, the liquid in the fuel tank that is tilted in a certain direction may The surface easily exceeds the upper end of the first fuel flow passage. Therefore, the fuel quickly flows into the case through this first fuel flow passage, and the liquid level in the case is maintained above the lower limit liquid level position.

Next, if the above slope is reversed and the liquid level in the fuel tank falls below the lower limit liquid level position at the detector position, the fuel in the case will flow out only through the second fuel flow path. It happens. By the way, since this second fuel flow passage is formed as a microhole as described above, it takes a certain amount of time for the liquid level in the case to drop to the liquid level in the fuel tank. This prevents the detector from immediately performing a detection operation just because the voltage drops.

Therefore, when the remaining fuel is above the lower limit, in other words, until the fuel becomes insufficient, even if the liquid level in the fuel tank repeats various inclinations when the car turns left and right, etc. , the issuing of a remaining amount warning is suppressed, and an appropriate remaining amount state is detected.

[Brief explanation of the drawing]

The figures show an embodiment of this invention, in which Fig. 1 is an overall side view of the remaining amount warning device, Fig. 2 is a partially enlarged sectional view of Fig. 1, and Fig. 3 is a sectional view taken along the - line in Fig. 2. It is. DESCRIPTION OF SYMBOLS 1... Fuel tank, 3... Detector, 4... Case, 13... First fuel flow path, 14... Second fuel flow path.

Claims (1)

[Scope of utility model registration request] A remaining amount warning device for an automobile fuel tank is provided with a detector for detecting the lower limit liquid level position of the remaining fuel in the fuel tank, and a case that covers the detector, the device comprising: a detector for detecting the lower limit liquid level position of the remaining fuel; A first fuel flow passage is provided that communicates between the inside of the case located slightly above the case and the outside of the case, and a second fuel flow passage is provided that communicates the bottom of the inside of the case with the outside of the case. A remaining amount warning device for a fuel tank for an automobile, characterized in that the second fuel flow passage is formed to be a microhole having a smaller cross-sectional area than the first fuel flow passage.