JPS624251B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel gauge for an automobile that measures the amount of fuel remaining in a fuel tank of an automobile.

As a conventional fuel gauge for automobiles, for example, the one shown in FIG. 1 is described in the new edition of Automobile Engineering Handbook (published by Tosho Publishing Co., Ltd., February 1971), pages 10-71. In the figure, reference numeral 1 denotes a float that is floated on the fuel liquid surface, and this float 1 is rotatably supported by a base 3 via an L-shaped float lever 2. In addition, float lever 2 has
A slider 4 is attached near the rotation fulcrum 2a,
Furthermore, a sliding resistor (wire-wound resistor) 5 is provided at a location corresponding to the slider 4.

Then, the float 1 is moved up and down according to the height of the fuel liquid level, and this change in up and down is taken as a change in resistance value, and the pointer of a meter etc. is caused to swing based on this change in resistance value to measure the remaining amount of fuel. ing.

However, such conventional fuel gauges for automobiles measure the remaining amount of fuel by the movement of a float that corresponds to the height of the fuel level. There was a problem in that when the amount of fuel remaining in the fuel tank was high, the meter etc. also fluctuated violently, making it impossible to accurately read the remaining amount of fuel.

In recent years, the fuel tanks of automobiles have tended to become flatter, so as mentioned above, the fluctuations in the fuel level during driving are becoming more severe, making it difficult to accurately measure the remaining amount of fuel while driving. It was becoming more difficult.

On the other hand, when the vehicle is stopped, the meter pointer moves slowly when checking the remaining amount of fuel or when refueling, and it takes time to check, causing problems such as fuel overflow.

The present invention was made by focusing on such conventional problems, and includes at least two sets of fuel measuring units having different responsiveness corresponding to the state of the vehicle when the vehicle is stopped and when the vehicle is running, in the fuel tank. It is an object of the present invention to solve the above-mentioned problems by disposing the fuel measuring section and selectively switching the fuel measuring section according to the state of the vehicle.

The present invention will be explained below based on the drawings.

FIG. 2 is a diagram showing a basic configuration example of the present invention. First, to explain the configuration, reference numeral 6 in the same figure is a fuel tank, and inside this fuel tank 6 is a first fuel meter that has a different responsiveness depending on the state of the vehicle when the vehicle is stopped and when the vehicle is running. Department
U ₁ and a second fuel measuring section U ₂ are provided.
The first fuel measurement unit U ₁ is a measurement unit with quick response that corresponds to a state where the liquid level fluctuates little, such as when the car is stopped, while the second fuel measurement unit U ₂ is a measurement unit that can handle the liquid level when the car is running. This is a measurement unit with slow response that can handle conditions with severe fluctuations. The response delay time is, for example, approximately 20 to 30 seconds in response to liquid level fluctuations.

Output terminals 7a and 7b of the first and second fuel measuring sections _U1 and _U2 are respectively connected to a changeover switch _U3 . A signal line from the vehicle speed signal generating means _S1 is led to the changeover switch _U3 . Furthermore, an ignition switch device _S2 or a fuel supply switch device _S3 can be used instead of the vehicle speed signal generating means _S1 .

Vehicle speed signal generating means S ₁ or each switch device S ₂ ,
For example, the following signals are output from _S3 etc.

That is, first, the vehicle speed signal generating means _S1 outputs a constant level voltage when the vehicle speed is zero, and outputs a vehicle speed (discrimination) signal of 0V when the vehicle speed is other than zero (during running). Further, the ignition switch device _S2 outputs a constant level voltage when the ignition switch is in the OFF state, and outputs an ignition switch signal of 0V when the ignition switch is in the ON state. Furthermore, the oil supply switch is turned on from the oil supply switch device _S3 .
When in the OFF state, a constant level voltage is output, and when in the OFF state, a 0V fuel switch signal is output.

The changeover switch _U3 is driven by the above-mentioned signal, and is switched to the first fuel measuring section _U1 side when the vehicle is stopped or refueling, and is switched to the second fuel measuring section _U2 side when the vehicle is running.

Furthermore, a detection circuit U ₄ and a display U ₅ are connected in sequence to the output terminal of the changeover switch U ₃ .

Next, the effect will be explained.

Assume that the vehicle speed signal from the vehicle speed signal generating means _S1 is used as the drive signal for the changeover switch _U3 .

When the vehicle speed is zero, that is, when the vehicle is stopped, the changeover switch _U3 is switched to the first fuel measuring section _U1 side by the vehicle speed signal. Then, the amount of fuel remaining in the fuel tank 6 when the vehicle is in a stopped state is measured by the first fuel measuring section _U1 with quick response, and the measured signal is guided to the detection circuit _U4 .

The measurement signal is converted by the detection circuit U ₄ into a signal necessary to drive the display U ₅ , and the remaining fuel amount value corresponding to the measurement signal value is appropriately displayed on the display U ₅ .

On the other hand, when the vehicle shifts to a running state, the output level of the vehicle speed signal generating means _S1 changes to 0V, and the changeover switch _U3 is switched to the second fuel measuring section _U2 side.

Due to the response delay effect of the second fuel measuring section _U2 , the second fuel measuring section _U2 smoothes out and captures the severe fluctuations in the liquid level, and even when driving, the remaining fuel amount is displayed correctly on the display _U5 . Is displayed.

Even if a fuel supply switch or ignition switch signal or the like is used instead of the vehicle speed signal as the drive signal for the changeover switch _U3 , the above effect is the same.
In other words, when the fuel level gradually rises when the ignition of the vehicle is turned off or when refueling, the increase in the amount of fuel is measured by the first fuel measuring unit _U1 , and the progress of refueling is immediately displayed on the display _U5 . be done. When the fuel is not refueled or when the ignition is on, the second fuel measurement unit _U2 measures the fuel.

Next, a first embodiment of the present invention will be described with reference to FIGS. 3A, B, and C to FIG. 7.

In each of the figures from FIG. 3 onwards, the same or equivalent members or parts as in FIG.

The first embodiment includes first and second fuel measuring units U ₁ and U ₂
It is constructed using a parallel plate capacitance method.

First, to explain the configuration, in FIG. 3A, reference numeral 8 is a mounting plate for the fuel tank, and on the lower surface side of this mounting plate 8, first electrode plates 9b, 9b and a ground line 11b are pasted on the surface. A deposited phenol laminate 12 is attached. The first electrode plates 9b, 9b and the ground line 11b are manufactured by etching a phenol copper-clad laminate. As shown in FIG. 5, first electrode plates 9a, 9a are also provided on the back side of the phenol laminate 12.
And a ground line 11a is attached and formed.

Reference numeral 13 denotes a case that houses the phenol laminate 12 and the like, and the opposing side plate in this case 13 is made of a metal plate, and the second electrode plate 14a,
It is also used as 14b. Grooves 15 are provided on both sides of the two opposing second electrode plates 14a and 14b.
A pair of spacers 15, 15 provided with a are integrally attached. Spacers 15, 15 are also second
Like the electrode plates 14a and 14b, they can be made of a metal member.

Furthermore, first and second fuel introduction holes 16 and 17 are formed at substantially opposite positions in the lower portions of the two electrode plates 14a and 14b, respectively, as shown in FIGS. 3B and 4. ing. These first and second
The fuel introduction holes 16 and 17 are provided with filters 16a and 17a, respectively, and the first fuel introduction hole 16
The filter 16a on the side is similar to the filter 17 on the other side.
The filter mesh is coarser than that in A. Due to the difference in the coarseness of this filter, the first
The amount of fuel passing through the fuel introduction hole 16 per unit time is larger than that of the second fuel introduction hole 17.

And opposing groove portions 15a, 1 in case 13
The edge of the phenol laminate 12 is fitted into the 5a, and the phenol laminate 12 is assembled to the case 13, so that the interior of the case is divided into two. After this assembly, the end plug 18 is fitted to the lower end of the case 13 to seal the lower end of the case.

By the above assembly, a first capacitor _C1 is formed between the first electrode plates 9a, 9a on one side, the second electrode plate 14a and the ground line 11a, and the first electrode plate 9b, on the other side, A second capacitor _C2 is formed between the second electrode plate 14b and the ground line 11b. Furthermore, a first fuel measuring unit U ₁ is configured by the first capacitor C ₁ , the first capacitor side case body (half of the case 13), and the first fuel introduction hole 16,
On the other hand, the second capacitor C ₂ , the second capacitor side case body, and the second fuel introduction hole 17 constitute a second fuel measuring section U ₂ .

Incidentally, the dimensions and shapes of the first electrode plates 9a, 9a, 9b, and 9b are adjusted to correspond to the internal shape of the fuel tank 6, etc., so that the capacitance changes linearly with changes in fuel immersion. As shown in FIG. 3A, the longitudinally intermediate portion is formed to be narrower.

Further, the second fuel measuring section U ₂ is similar to the first fuel measuring section U _{1 .}
However, due to the difference in the amount of fuel passing through the first and second fuel introduction holes 16 and 17 per unit time, the response is slow, and as mentioned above, the response delay time is about 20 to 30 seconds due to liquid level fluctuations. It is made to have.

In FIG. 3A, the symbol U indicates a changeover switch U ₃
and a processing circuit including a detection circuit _U4, etc., and 19 is a harness.

FIG. 6 shows a state in which the first and second fuel measuring sections U ₁ and U ₂ configured as described above are installed in the fuel tank 6. As shown in FIG. In the figure, 21 is fuel. FIG. 7 shows the configuration including the processing circuit. In the first embodiment, the detection circuit _U4 is the CR oscillator.
It consists of U ₄ a and a D/A converter U ₄ b.

Next, the effect will be explained.

Since the operation of the changeover switch _U3 is the same as that of the basic configuration shown in FIG. 2, only the differences from the above will be described.

In the first embodiment, the first and second fuel measuring sections
The measurement signals from U ₁ and U ₂ are the first electrode plates 9a and 9
It is taken out as a change in the total capacitance corresponding to the ratio of fuel immersion into the second electrode plates 14a, 14b, etc. The measurement signal is converted by the CR oscillator U ₄ a into a pulse train signal having a repetition frequency corresponding to the capacitance value, and further guided to the D/A converter U ₄ b. D/A converter
U ₄ b converts this pulse train signal into an analog voltage for driving the indicator U ₅ , and the remaining fuel amount is displayed on the indicator U ₅ using this analog voltage.

Next, FIGS. 8 and 9 show a second embodiment.

This second embodiment includes first and second fuel measuring sections.
U ₁ and U ₂ are configured using a float type (resistance type).

To explain the structure, the inside of the case 13 is divided into two by a partition plate 22 attached to the mounting plate 8, forming a first chamber 13a and a second chamber 13b. And the first chamber 13a and the second chamber 13
A first fuel introduction hole 16 and a second fuel introduction hole 17 are respectively formed in the lower surface portion of b. The fact that these first and second fuel introduction holes 16 and 17 are provided with filters with different mesh sizes is that
This is the same as in the embodiment. Furthermore, floats 23 are provided in the first chamber 13a and the second chamber 13b, respectively.
a and 23b are housed so as to be movable in the vertical direction in FIG. 24a, 24b are float guides, 2
5a and 25b are sliders attached to each float 23a and 23b. And further slider 2
Resistors 26a and 26b are disposed on both sides of the partition plate 22 corresponding to resistors 5a and 25b, respectively. The resistors 26a and 26b are formed of printed resistors, for example, and are set as shown in FIG. slider 25a,
The resistance value per unit length is varied along the sliding direction of 25b. The lower end of the resistor 26 is led out to the mounting plate 8 side via a printed lead wire 27, and both ends of the resistor 26 are connected to the harness 19. And the slider 25b is a resistor 26b
and the printing lead wire 27 at the same time. Note that printed lead wires and the like are provided on the resistor 25a side as well, as described above.

Next, the operation will be explained. In this second embodiment, the measurement signals from the first and second fuel measurement units U ₁ and U ₂ are taken out as changes in the resistance values of the resistors 26a and 26b. This change in resistance value is converted into an analog voltage by appropriate means as a drive signal for the display _U5 . The switching operation of the changeover switch _U3 is the same as that of the basic configuration shown in FIG. 2 above.

In the first and second embodiments, in order to make the amount of fuel passing through the first fuel inlet hole 16 and the second fuel inlet hole 17 different per unit time, a filter is attached to each of the two holes. However, a filter with an appropriate mesh size may be provided only in the second fuel introduction hole 17, and the first fuel introduction hole 16 may be left as a through hole.

In addition, although only two sets of the fuel measuring section, the first and second sets, are provided, depending on the condition of the vehicle, three or more sets may be provided, and these may be selectively switched according to each usage condition. Good too.

As described in detail above, according to the present invention, at least two sets of fuel measuring units having different responsiveness corresponding to a state corresponding to when the vehicle is stopped and a state corresponding to when the vehicle is running are disposed in the fuel tank. Since the fuel measuring section is selectively switched depending on the usage condition of the vehicle, it is possible to reduce fluctuations in the fuel level when the vehicle is stopped or refueled, and when the fuel level changes when the vehicle is running. The effect is that the amount of fuel in the tank can be accurately measured at all times in any severe condition.

In addition to the above-mentioned common effects, each of the embodiments also provides the following effects.

That is, first, each fuel measuring section is housed in a case,
Each case has a fuel inlet hole with a different amount of fuel passing through per unit time to make the response different, so there is no need for a mechanical switching mechanism in each fuel meter itself, and the response characteristics can be adjusted according to the vehicle condition. This increases reliability and maintains accurate measurement accuracy at all times.

Furthermore, since an ignition switch signal or the like is used as a signal for selectively switching the fuel measuring section according to the state of the vehicle, each fuel measuring section can be automatically switched according to the state of the vehicle.

[Brief explanation of the drawing]

Figure 1 is a side view showing a conventional automobile fuel gauge.
FIG. 2 is a block diagram showing an example of the basic configuration of an automobile fuel gauge according to the present invention, and FIGS. 3A, B, and C are fuel measurements applied to the first embodiment of the automobile fuel meter according to the present invention. FIG. 4 is a partially cutaway perspective view of the case of the same fuel measuring section as above, FIG. 5 is a sectional view of the fuel measuring section corresponding to the - line in FIG. 3B, and FIG. Fig. 3 is a partially cutaway side view showing the state in which the fuel measuring section is installed in the fuel tank, Fig. 7 is a block diagram showing the entire first embodiment, and Fig. 8 is a second embodiment of the present invention. FIG. 9 is a front view showing the fuel measuring section applied to the example with a portion cut away, and FIG. 9 is a side view showing the fuel measuring section same as above with a portion cut away and some members omitted. 6... Fuel tank, 9a, 9b... First electrode plate, 13... Case, 14a, 14b... Second electrode plate, 16, 17... First and second fuel introduction holes,
16a, 17a...Filter, _S1 ...Vehicle speed signal generating means, _S2 ...Ignition switch device, _S3
... Fuel supply switch device, U ₁ , U ₂ ... 1st, 2nd
fuel measuring section, U ₃ ... changeover switch, U ₅ ... display.

Claims (1)

[Scope of Claims] 1. At least two sets of fuel measuring units having different responsivity corresponding to a state corresponding to when the vehicle is stopped and a state corresponding to when the vehicle is running are disposed in a fuel tank, A fuel meter for an automobile, characterized in that the fuel measuring section is selectively switched. 2. As a means of varying responsiveness according to vehicle conditions, each fuel measuring section is housed in a case,
Claim 1, wherein each case is provided with a fuel inlet hole having a different amount of fuel passing through per unit time.
Automotive fuel gauge as described in section. 3. An ignition switch signal,
A fuel gauge for an automobile according to claim 1 or 2, which uses either a fuel fill switch signal or a vehicle speed signal.