JP5510344B2 - Fuel level measuring device - Google Patents

Description

  The present invention relates to a fuel remaining amount measuring device, and in particular, a fuel remaining amount measurement that can accurately measure the remaining amount of fuel even when the fuel tank is deformed due to changes in the internal pressure of the fuel tank or changes in the atmospheric pressure and temperature of the outside. Relates to the device.

  Conventionally, there are various types of fuel remaining amount measuring devices provided in a fuel tank of an automobile or the like, and as one of them, using a vertically long detection electrode (sensor) extending in the vehicle vertical direction, A configuration is employed in which the position where the detection electrode contacts the fuel is detected to detect the liquid level.

  For example, a combination of a reference electrode in which the detection unit is always immersed in the liquid, a gas-phase electrode that is always outside the liquid, and a liquid surface electrode that intersects the liquid surface, and the capacitance due to contact / non-contact between the electrode and the liquid There has been proposed a liquid level sensor configured to detect the liquid level from the change of the above (Patent Document 1).

  In the conventional fuel tank 100, for example, as shown in FIG. 9, a liquid level sensor 114 for detecting the liquid level F of the fuel is erected on the bottom surface 20, and the level of the liquid level F detected by the liquid level sensor 114 is increased. The remaining amount of fuel was calculated based on this.

JP 2010-025782 A

  However, as shown in FIG. 10, the fuel tank 100 expands and deforms in the vertical direction of the vehicle due to reasons such as an increase in temperature and a decrease in atmospheric pressure, and an increase in the internal pressure of the fuel tank 100. There are things to do. When the fuel tank 100 is deformed, the relationship between the height of the fuel level and the remaining amount of fuel is different from that before the fuel tank is deformed. Therefore, the liquid level sensor 114 simply detects the fuel level. When the remaining amount of fuel is obtained, there is a problem in that an accurate remaining amount of fuel cannot be detected.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a fuel remaining amount measuring apparatus that can accurately measure the remaining amount of fuel even when the fuel tank is deformed.

The invention described in claim 1 includes a liquid level sensor that detects a liquid level of fuel stored in the fuel tank, and extends toward the bottom surface of the fuel tank, and a tip is stored in the fuel tank. It has an auxiliary liquid level sensor that detects the immersion length, which is the length from the liquid level of the fuel to the tip, and the liquid level detected by the liquid level sensor and the auxiliary Based on the immersion length detected by the liquid level sensor, a tank deformation amount detecting means for detecting a tank deformation amount that is a deformation amount of the fuel tank, and based on the tank deformation amount detected by the tank deformation amount detecting means, The tank capacity characteristic determining means for determining the tank capacity characteristic indicating the relationship between the fuel level and the fuel remaining amount, and the fuel tank liquid level detected by the liquid level sensor and the tank capacity characteristic determined by the tank capacity characteristic determining means. Z A fuel gauge to display the fuel quantity determining means for determining the remaining fuel amount, the fuel quantity determined by the remaining fuel amount determining means in the interior of the fuel tank Te,
The present invention relates to a fuel remaining amount measuring apparatus.

In the fuel remaining amount measuring device, the liquid level sensor detects the liquid level of the fuel in the fuel tank, and at the same time, the tank deformation amount detecting means detects the tank deformation amount, and the tank is detected based on the detected tank deformation amount. The capacity characteristic determining means determines the tank capacity characteristic, and the remaining fuel quantity determining means obtains the remaining fuel quantity from the liquid level detected by the liquid level sensor and the tank capacity characteristic.
In the fuel remaining amount measuring device, the liquid level sensor detects the fuel level, that is, the distance from the bottom of the fuel tank to the fuel level, and the auxiliary level sensor detects the auxiliary level sensor. Is detected, that is, the distance from the fuel level to the tip of the auxiliary liquid level sensor.
Next, the distance from the bottom surface of the fuel tank to the tip of the auxiliary liquid level sensor is obtained by subtracting the immersion length from the liquid level.

  According to a second aspect of the present invention, the tank capacity characteristic determining means includes a storage unit storing tank capacity characteristics corresponding to a plurality of tank deformation amounts, and a tank deformation amount detected by the tank deformation amount detection means. The fuel remaining amount measuring apparatus according to claim 1, further comprising: a reading unit that reads out a tank capacity characteristic corresponding to 1 from the storage unit.

  In the fuel remaining amount measuring apparatus, when the tank deformation amount is detected by the tank deformation amount detection unit, the reading unit of the tank capacity characteristic determination unit obtains the tank capacity characteristic corresponding to the tank deformation amount from the storage unit. By reading, the tank capacity characteristic is determined.

  A third aspect of the present invention relates to the fuel remaining amount measuring apparatus according to the first or second aspect, wherein the tank deformation amount detecting means detects a deformation amount in the height direction of the fuel tank.

  In the fuel remaining amount measuring device, the tank deformation amount detecting means detects the deformation amount in the height direction of the fuel tank and sets it as the deformation amount of the fuel tank.

According to a fourth aspect of the invention, the tank deformation amount detection means, an immersion length of the liquid level detected by the liquid level sensor in a modification before and and after deformation prior Symbol fuel tank detected by said auxiliary liquid level sensor The fuel remaining amount measuring apparatus according to claim 3, further comprising: a fuel remaining amount calculating unit that calculates the tank deformation amount.

In the fuel remaining amount measuring device, the difference in distance from the bottom surface of the fuel tank to the tip of the auxiliary liquid level sensor before and after the deformation of the fuel tank corresponds to the deformation amount of the fuel tank. The amount of deformation of the fuel tank is obtained by subtracting the distance before deformation from the distance.

  According to a fifth aspect of the present invention, the liquid level sensor is fixed at one end to the bottom of the fuel tank and extends from the bottom surface of the fuel tank toward the ceiling surface. Is wound around a guide provided above the liquid level of the fuel tank, folded back toward the bottom surface of the fuel tank, urged toward the bottom surface of the fuel tank by a spring at the other end, and the auxiliary liquid level sensor The fuel remaining amount measuring apparatus according to claim 4, wherein the remaining fuel level measuring apparatus is formed at the other end of the liquid level sensor.

  In the fuel remaining amount measuring apparatus, the liquid level sensor detects the distance from the bottom surface of the fuel tank to the fuel level, and the auxiliary liquid level sensor detects the immersion length of the auxiliary liquid level sensor, that is, the spring. Detect elongation.

  Next, the distance from the bottom surface of the fuel tank to the tip of the auxiliary liquid level sensor is obtained by subtracting the extension of the spring from the liquid level.

  Since the difference in spring elongation before and after deformation of the fuel tank corresponds to the amount of deformation of the fuel tank, the amount of deformation of the fuel tank is obtained by subtracting the elongation of the spring before deformation from the elongation of the spring after deformation.

  The invention according to claim 6 is characterized in that the liquid level sensor is formed at one end and is always immersed in the fuel, and a vapor reference measurement unit that is formed at the center and is always located outside the liquid. A liquid level measuring unit formed between the fuel reference measuring unit and the vapor reference measuring unit so as to intersect the liquid level of the fuel and detecting the fuel level, and the other end of the liquid level sensor The auxiliary liquid level sensor located in the position is formed so as to intersect with the liquid level of the fuel, and relates to the fuel remaining amount measuring device according to claim 5 for detecting the immersion length.

  In the fuel remaining amount measuring device, the liquid level measuring unit in the liquid level sensor is partly below the liquid level of the fuel and the remaining part is located outside the liquid. Show. Therefore, the liquid level in the fuel tank is obtained by measuring the capacitance of the liquid level measurement unit and comparing it with the capacitances of the fuel reference measurement unit and the vapor reference measurement unit.

  On the other hand, since the auxiliary liquid level sensor is located in the liquid from the tip to the liquid level, and located above the liquid level outside the liquid, the auxiliary liquid level sensor shows a capacitance according to the immersion length. Therefore, the immersion length is determined by measuring the capacitance of the auxiliary liquid level sensor.

According to a seventh aspect of the present invention, the liquid level sensor is erected at the bottom of the fuel tank and extends toward the ceiling surface of the fuel tank, and the auxiliary liquid level sensor is erected on the ceiling surface. The fuel remaining amount measuring apparatus according to any one of claims 1 to 4, which extends toward a bottom surface.

  The operation of the fuel remaining amount measuring device is as described in the third aspect.

  According to an eighth aspect of the invention, the liquid level sensor is formed at one end and is always immersed in the fuel, and the vapor reference measurement unit is formed at the other end and always located outside the liquid. And a liquid level measuring unit formed between the fuel reference measuring unit and the vapor reference measuring unit so as to intersect the liquid level of the fuel and detecting the fuel level, wherein the auxiliary liquid level sensor is a fuel. The fuel remaining amount measuring device according to claim 7, wherein the fuel remaining amount measuring device is formed so as to intersect the liquid level of the fuel and detects the immersion length.

  The operation of the fuel remaining amount measuring device is as described in the fifth aspect.

  According to the first aspect of the present invention, since the remaining fuel amount is determined in consideration of not only the liquid level detected by the liquid level sensor but also the tank capacity characteristic, the remaining fuel amount even when the fuel tank is deformed. There is provided a fuel remaining amount measuring device capable of accurately measuring fuel consumption.

  According to the invention of claim 2, since the tank capacity characteristic is determined by reading out the tank capacity characteristic corresponding to the actually detected tank deformation amount from the storage unit, the configuration of the tank capacity characteristic determining means is simplified. A fuel remaining amount measuring apparatus capable of determining the tank capacity characteristic with high reliability can be provided.

  According to the invention of claim 3, since the deformation of the fuel tank mainly occurs in the height direction, the configuration of the tank deformation amount detecting means can be simplified by omitting the means for detecting the deformation other than the height direction. A fuel remaining amount measuring device is provided.

  According to the invention of claim 4, since the deformation amount of the fuel tank is obtained from the liquid level detected by the liquid level sensor and the immersion length detected by the auxiliary liquid level sensor, the configuration of the tank deformation amount detecting means is simplified. A fuel remaining amount measuring device is provided.

  According to the invention of claim 5, one end of the liquid level sensor is fixed to the bottom surface of the fuel tank, wrapped around a guide provided in the vicinity of the fuel tank ceiling surface, folded back toward the fuel tank bottom surface, and the other end. Therefore, the fuel remaining amount measuring device is provided in which the occurrence of an error due to the deflection of the liquid level sensor due to deformation of the fuel tank is effectively suppressed.

  According to the sixth aspect of the present invention, the liquid level and the auxiliary liquid level sensor detect the liquid level and the immersion length in the fuel tank by the change in capacitance. There is provided a fuel remaining amount measuring device that can easily extract and process detection results.

  According to the seventh aspect of the invention, since the guide and spring near the fuel tank ceiling surface can be omitted, the configuration of the tank deformation amount detecting means can be simplified as compared with the fifth aspect of the invention.

  According to the eighth aspect of the present invention, the tank deformation amount detecting means is configured as compared with the fourth aspect of the present invention, and the detection results of the liquid level sensor and the auxiliary liquid level sensor are taken out of the fuel tank. A fuel remaining amount measuring device that is easy to process is provided.

FIG. 1 is a cross-sectional view illustrating a configuration of a fuel tank according to the first embodiment. FIG. 2 is a plan view illustrating a configuration of a tank deformation amount detection sensor 11 provided in the fuel tank according to the first embodiment. FIG. 3 is an explanatory diagram showing an outline of a tank capacity characteristic curve stored in a computer included in the fuel tank according to the first embodiment. FIG. 4 is a cross-sectional view showing the fuel tank according to Embodiment 1 deformed in the height direction. FIG. 5 is a cross-sectional view illustrating a configuration of a fuel tank according to the second embodiment. FIG. 6 is a plan view illustrating a configuration of a liquid level sensor provided in the fuel tank according to the second embodiment. FIG. 7 is a plan view showing a configuration of an auxiliary liquid level sensor provided in the fuel tank according to the second embodiment. FIG. 8 is a cross-sectional view showing the fuel tank according to the second embodiment that is deformed in the height direction. FIG. 9 is a cross-sectional view showing a configuration of a conventional fuel tank. FIG. 10 is a cross-sectional view showing the fuel tank shown in FIG. 9 deformed in the height direction.

1. Embodiment 1
Hereinafter, an example of a fuel tank provided with the fuel remaining amount measuring device of the present invention will be described with reference to the drawings. In FIG. 1 and subsequent figures, the arrow UP indicates the upper side of the vehicle body.

  The fuel tank 10 is a container having a substantially box shape as shown in FIG. 1, and its shape is determined by the shape of a vehicle body or the like to be installed and the component arrangement. The material of the fuel tank 10 is selected in consideration of resistance to corrosion by fuel (gasoline etc.), mechanical strength, impact resistance and safety in the event of a collision.

  A mounting surface 22 such as a pump module is provided in the ceiling surface 30 that is the upper surface of the vehicle body of the fuel tank 10, and the internal fuel does not leak outside by a lid portion 28 that closes the mounting port 22 from the outside. So that it is sealed. The mounting port 22 protruding in a cylindrical shape above the vehicle is sealed with a lid portion 28, and the lid portion 28 is fixed with a screw lid 120 screwed with a male screw provided on the outer peripheral surface of the mounting port 22.

  At this time, if the mounting port 22 protrudes from the box-shaped fuel tank 10, space efficiency may be reduced when the mounting port 22 is assembled to the vehicle body. Therefore, the mounting port 22 should be provided so as to be submerged inside the fuel tank 10. desirable. In this case, it is necessary to provide a space in the fuel tank 10 in which the attachment port 22 and the screw lid 120 can be cleared.

  As a result, a concave portion 24 whose outer surface is recessed is formed on the upper surface of the vehicle body of the fuel tank 10, and a portion inside the concave portion 24 on the ceiling surface 30 is a convex portion 26 protruding toward the lower side of the vehicle body inside the fuel tank 10. Is formed. Therefore, when the fuel tank 10 is filled with fuel, the liquid level F exceeds the height of the convex portion 26, and the convex portion 26 is immersed in the fuel.

  The fuel tank 10 is generally formed of a steel plate or resin, and a vapor layer is secured by a method such as providing unevenness on the upper side surface of the vehicle body as shown in FIG. In other words, the volatile fuel evaporates due to the outside air temperature or heat from the engine or the like, and fills the voids in the fuel tank 10 as volatile gas (vapor). If the entire tank is filled with fuel at this time, the generated volatile gas of the fuel loses escape and the inside of the fuel tank 10 is pressurized. In order to prevent this, a certain amount of air gap (vapor layer) is set in the upper part of the fuel tank 10 to secure a escape space for the pressure of the volatile gas.

  Further, in the fuel tank 10 that secures the vapor layer as described above, pressurization and depressurization are continuously repeated by the fuel temperature up and down (the influence of the temperature, the heat from the road surface and the exhaust pipe) and the fuel consumption, Mechanical stress continues to be applied. For this reason, making the upper surface of the fuel tank 10 into a complicated uneven shape increases the mechanical strength of the fuel tank 10 itself, and also has a meaning as a countermeasure against changes in internal pressure.

  Further, a pump unit (not shown) may be provided inside the fuel tank 10, and the internal fuel may be pumped out by a pump and sent out to the outside by a fuel hose (not shown).

  Hereinafter, the configuration of the fuel remaining amount measuring apparatus 1 provided in the fuel tank 10 will be described. As shown in FIG. 1, the fuel remaining amount measuring apparatus 1 has one end on a pedestal portion 13A of a sensor guide guide 13 fixed to the bottom surface 20 of the fuel tank 10 and a pedestal portion 13A for detecting the deformation amount of the fuel tank 10. The tank deformation amount detection sensor 11 is fixed, and is positioned directly above the pedestal 13A and above the liquid level at the time of maximum fuel remaining in the fuel tank 10, and the tank deformation amount detection sensor 11 is wound around the tank deformation amount detection sensor 11. The guide 12 is provided. The tank deformation amount detection sensor 11 extends from one end portion fixed to the pedestal portion 13 </ b> A toward the ceiling surface 30 of the fuel tank 10 and is wound around the guide 12. The tank deformation amount detection sensor 11 wound around the guide 12 is folded back toward the bottom surface 20. At the top of the sensor guide 13, a sensor guide 13 </ b> B that guides the tank deformation amount detection sensor 11 that is folded back toward the bottom surface 20 is provided. A spring 16 is attached between the tank deformation amount detection sensor 11 and the bottom surface 20 of the fuel tank 10, and the tank deformation amount detection sensor 11 is urged toward the vehicle lower side by the spring 16.

  For example, as shown in FIG. 2 (A), the tank deformation amount detection sensor 11 has a structure in which a liquid level sensor 14 is provided at one end and a central part, and an auxiliary liquid level sensor 15 is provided at the other end. Yes. The liquid level sensor 14 has a structure in which an electrode 14D is provided on the surface of a base 11A formed of a bendable insulator such as a resin film having a longitudinal direction in the vehicle vertical direction. 11A is provided with an electrode 15A. A spring fixing hole 11 </ b> B for fixing the spring 16 is formed closer to the tip of the auxiliary liquid level sensor 15 of the tank deformation amount detection sensor 11.

  The liquid level sensor 14 determines the remaining amount of fuel remaining in the fuel tank 10 from the electric capacity that varies depending on the length of the electrode 14D in contact with the fuel and the length of the portion in contact with air. It is a capacitance sensor to detect.

  The electrode 14D is formed at one end of the tank deformation detection sensor 11 and is always immersed in fuel. The fuel reference measurement unit 14A is at the center of the tank deformation detection sensor 11 and the liquid level F when the fuel remaining amount is maximum. Is also positioned between the fuel reference measurement unit 14C, the fuel reference measurement unit 14A, and the steam reference measurement unit 14C. The liquid level measurement is performed between the fuel reference measurement unit 14C and the fuel reference measurement unit 14C. It is divided into part 14B.

  As shown in FIG. 2B, the electrode 14D includes a common lead wire 14F connecting the fuel reference measurement unit 14A, the liquid level measurement unit 14B, and the vapor reference measurement unit 14C, and the fuel reference measurement unit 14A and the liquid level measurement. Output side lead wire 14G for outputting the capacitance in each of the unit 14B and the vapor reference measurement unit 14C, a comb-like electrode 14H projecting horizontally from the common lead wire 14F at a predetermined interval, and an output side lead And a comb-like electrode 14I projecting horizontally from the line 14G at a predetermined interval. The comb electrodes 14H and the comb electrodes 14I are alternately arranged.

  The common lead wire 14F and the output-side lead wire 14G in the electrode 14D are electrically connected to an external computer 40 at a terminal 14J provided at the end of the liquid level sensor 14, and the fuel detected by the liquid level sensor 14 is detected. The liquid level is transmitted to the computer 40 as fuel liquid level information.

  As a method of electrically detecting the liquid level in the liquid level sensor 14, for example, there is a method of measuring the capacitance between the electrodes 14D. When the fuel in the fuel tank is consumed, the space between the electrodes 14D becomes occupied by what was previously occupied by the fuel, and the capacitance decreases. Therefore, it can be detected that the fuel has been consumed by detecting the decrease in the capacitance. At this time, more accurate detection can be performed by comparing the measured values based on the values detected by the vapor reference measuring unit 14C provided in the air in advance and the fuel reference measuring unit 14A always present in the liquid. It can be carried out.

  The auxiliary liquid level sensor 15 also has an electric capacity that varies depending on the length of the electrode 15A that is in contact with fuel such as gasoline and the length of the part that is in contact with air. It is an electrostatic capacitance sensor which detects the immersion length which is the distance to the liquid level of a fuel.

  As shown in FIG. 2B, the electrode 15A is connected to the output-side lead wire 15B that outputs electrostatic capacitance and the common lead wire 14F of the liquid level sensor 14 through one of the terminals 14J. A common lead wire 15E, a comb-like electrode 15C projecting horizontally from the common lead wire 15E at a predetermined interval, and a comb-like electrode 15D projecting horizontally from the output-side lead wire 15B at a predetermined interval Have. Comb electrodes 15C and comb electrodes 15D are alternately arranged.

  A terminal 15F is provided at the end of the common lead wire 15E of the electrode 15A on the side connected to the common lead wire 14F of the liquid level sensor 14 and the end of the output side lead wire 15B on the liquid level sensor 14 side. The terminal 15F located at the end of the common lead wire 15E connected to the common lead wire 14F is also used as the terminal 14J of the liquid level sensor 14. The electrode 15A is electrically connected to an external computer 40 via a terminal 15F, and the immersion length of the tank deformation amount detection sensor 11 detected by the auxiliary liquid level sensor 15 is transmitted to the computer 40.

  As a method of electrically detecting the immersion length of the auxiliary liquid level sensor 15, for example, there is a method of measuring the capacitance of the electrode 15A. When the fuel in the fuel tank is consumed or the liquid level of the fuel tank 10 is expanded and the liquid level of the fuel is lowered, the space between the electrodes 14 </ b> D is occupied by what was previously occupied by the fuel by air. As a result, the capacitance decreases.

  The computer 40 is based on the storage unit 41 storing the tank capacity characteristics corresponding to various tank deformation amounts, and the detection results of the liquid level sensor 14 and the auxiliary liquid level sensor 15 before and after the deformation of the fuel tank 10. The calculation unit 43 calculates the remaining amount of fuel from the liquid level after deformation of the fuel tank 10 detected by the liquid level sensor 14 and the tank capacity characteristic corresponding to the tank deformation amount. And a reading unit 42 that reads out the tank capacity characteristic corresponding to the amount of tank deformation obtained in (4) from the storage unit 41. Here, the tank capacity characteristic is a characteristic indicating the relationship between the fuel level in a certain tank deformation amount and the fuel remaining amount in the fuel tank. An example of the tank capacity characteristic stored in the storage unit 41 is shown in FIG.

  In the calculation unit 43 of the computer 40, the fuel level before and after deformation of the fuel tank 10 input from the liquid level sensor 14, and the before and after deformation of the fuel tank 10 input from the auxiliary liquid level sensor 15. The tank deformation amount of the fuel tank 10 is obtained from the immersion length of the subsequent tank deformation amount detection sensor 11. Then, the tank deformation amount is input to the reading unit 42. The reading unit 42 reads the tank capacity characteristic corresponding to the input tank deformation amount from the storage unit 41 and inputs it to the calculation unit 43. The calculation unit 43 obtains the true remaining fuel amount from the deformation amount of the fuel tank 10 and the input tank capacity characteristic. Therefore, the calculation unit 43 corresponds to the fuel remaining amount determination unit in the present invention. The calculation unit 43 also constitutes the tank deformation amount detecting means of the present invention together with the auxiliary liquid level sensor 15.

Hereinafter, a procedure for obtaining the remaining amount of fuel in the fuel tank 10 will be described.
First, as shown in FIG. 2, for the fuel tank 10 before deformation, the liquid level sensor 14 measures the liquid level A0, and the auxiliary liquid level sensor 15 measures the immersion length B0. In the computer 40, based on the liquid level A0 measured by the liquid level sensor 14 and the immersion length B0 measured by the auxiliary liquid level sensor 15, the length L0 (L0 = L0 = the spring 16 before the fuel tank 10 is deformed). A0-B0) is obtained. Here, the length L0 of the spring 16 is a distance from the front end of the tank deformation amount detection sensor 11 to the bottom surface 20 of the fuel tank 10 before the fuel tank 10 is deformed, in other words, from the front end of the auxiliary liquid level sensor 15. It is also the distance to the bottom surface 20 of the fuel tank 10.

  Next, as shown in FIG. 4, for the fuel tank 10 that has been deformed in the height direction, the liquid level sensor 14 measures the liquid level A1, and the auxiliary liquid level sensor 15 measures the immersion length B1. In the computer 40, based on the liquid level A1 measured by the liquid level sensor 14 and the immersion length B1 measured by the auxiliary liquid level sensor 15, the length L1 (L1 = L1 = L1) of the spring 16 after the fuel tank 10 is deformed. A1-B1) is obtained. Here, the length L1 of the spring 16 is the distance from the front end of the tank deformation detection sensor 11 to the bottom surface 20 of the fuel tank 10 after the fuel tank 10 is deformed, in other words, from the front end of the auxiliary liquid level sensor 15. It is also the distance to the bottom surface 20 of the fuel tank 10.

  The calculation unit 43 in the computer 40 then calculates a change ΔL in the spring length due to the deformation of the fuel tank 10 by the following equation: ΔL = L1−L0. The change ΔL in the spring length is also the amount of deformation of the fuel tank 10.

  Here, in the storage unit 41, as shown in the graph of FIG. 3, various deformation amounts ΔL (for example, ΔL = −10 mm, −5 mm, 0 mm, 5 mm, The tank capacity characteristic curve indicating the tank capacity characteristic relating to the relationship between the fuel level corresponding to 10 mm) and the remaining fuel amount is stored.

  The reading unit 42 reads a tank capacity characteristic curve corresponding to the deformation amount ΔL of the fuel tank 10 obtained by the equation: ΔL = L1−L0 from the relationship curve in FIG. In the calculation unit 43, the fuel level corresponding to the liquid level A1 is obtained by applying the liquid level A1 to the inputted tank capacity characteristic curve. For example, when the deformation amount ΔL is 5 mm, the computer 40 selects a tank capacity characteristic curve corresponding to ΔL = 5 mm in FIG. Then, the remaining fuel amount corresponding to the liquid level A1 is read on the selected tank capacity characteristic curve, and this remaining fuel amount is displayed as a true remaining fuel amount on a fuel meter (not shown).

  According to the fuel remaining amount measuring apparatus 1 of the first embodiment, the correct fuel remaining amount is measured even when the fuel tank 10 is deformed in the height direction.

  Further, since the liquid level of the fuel tank 10 before and after the deformation of the fuel tank 10 and the immersion length of the auxiliary liquid level sensor 15 are both measured as changes in capacitance, the processing in the computer 40 and the fuel gauge Easy to display.

  Further, since the tank deformation amount detection sensor 11 provided with the liquid level sensor 14 and the auxiliary liquid level sensor 15 is always in a tensioned state by the biasing force of the spring 16, an error caused by the tank deformation amount detection sensor 11 slackening. Occurrence is effectively suppressed.

2. Embodiment 2
Hereinafter, another example of the fuel remaining amount measuring apparatus of the present invention will be described with reference to the drawings. Unless otherwise noted in FIGS. 5-7, the same reference numerals as in FIGS. 1-4 indicate the same elements as those shown in FIGS.

  As shown in FIGS. 5 and 8, the fuel remaining amount measuring apparatus 2 according to the second embodiment includes a liquid level sensor 14 erected from the bottom surface 20 of the fuel tank 10 toward the ceiling surface 30, and the fuel tank ceiling. And an auxiliary liquid level sensor 15 erected from the surface toward the bottom surface 20 and a computer 40 to which the liquid level sensor 14 and the auxiliary liquid level sensor 15 are connected.

  As shown in FIG. 6 (A), the liquid level sensor 14 has a structure in which an electrode 14D is provided on the surface of a base 14E formed of a foldable insulator such as a resin film having a longitudinal direction in the vehicle vertical direction. The static capacity for detecting the remaining amount of fuel remaining in the fuel tank 10 based on the electric capacity that varies depending on the length of the electrode 14D in contact with fuel such as gasoline and the length of the portion in contact with air. It is a capacitance sensor.

  In the liquid level sensor 14, the electrode 14D includes a fuel reference measurement unit 14A that is always immersed in the fuel, and a vapor reference measurement unit 14C that is always positioned above the liquid level F when the remaining amount of fuel is maximum. The fuel reference measurement unit 14A is located between the fuel reference measurement unit 14A and the vapor reference measurement unit 14C, and is divided into a liquid level measurement unit 14B that measures the liquid level of the fuel in the fuel tank 10.

  As shown in FIG. 6B, the electrode 14D includes a common lead wire 14F connecting the fuel reference measurement unit 14A, the liquid level measurement unit 14B, and the vapor reference measurement unit 14C, and the fuel reference measurement unit 14A and the liquid level measurement. Output side lead wire 14G for outputting the capacitance in each of the unit 14B and the vapor reference measurement unit 14C, a comb-like electrode 14H projecting horizontally from the common lead wire 14F at a predetermined interval, and an output side lead And a comb-like electrode 14I projecting horizontally from the line 14G at a predetermined interval. The comb electrodes 14H and the comb electrodes 14I are alternately arranged.

  The common lead wire 14F and the output lead wire 14G in the electrode 14D are electrically connected to the computer 40 at a terminal 14J provided at the end of the liquid level sensor 14.

  The method for electrically detecting the liquid level in the liquid level sensor 14 is as described in the first embodiment.

  As shown in FIG. 7A, the auxiliary liquid level sensor 15 has a structure in which an electrode 15A is provided on the surface of a base 15G formed of a bendable insulator such as a resin film whose longitudinal direction is the vehicle vertical direction. The distance from the tip of the auxiliary liquid level sensor 15 to the liquid level of the fuel from the electric capacity that varies depending on the length of the electrode 15A in contact with fuel such as gasoline and the length of the portion in contact with air. It is a capacitance sensor that detects a certain immersion length. The auxiliary liquid level sensor 15 has a front end that is immersed in the fuel stored in the fuel tank 10 but does not contact the bottom surface 20 of the fuel tank 10.

  As shown in FIG. 7B, the electrode 15A includes a pair of output-side lead wires 15B that output electrostatic capacitance, and a comb projecting horizontally from one of the output-side lead wires 15B at a predetermined interval. 15C and a comb-like electrode 15D protruding in the horizontal direction at a predetermined interval from the other of the output side lead wires 15B. Comb electrodes 15C and comb electrodes 15D are alternately arranged.

  The output side lead wire 15B in the electrode 15A is electrically connected to the external computer 40 via the terminal 15F, and the immersion length of the tank deformation amount detection sensor 11 detected by the auxiliary liquid level sensor 15 is transmitted to the computer 40. The

  The method for electrically detecting the immersion length of the auxiliary liquid level sensor 15 is as described in the first embodiment.

  Hereinafter, a procedure for obtaining the remaining amount of fuel in the fuel tank 10 will be described.

  First, as shown in FIG. 5, for the fuel tank 10 before deformation, the liquid level sensor 14 measures the liquid level A0, and the auxiliary liquid level sensor 15 measures the immersion length B0. In the computer 40, fuel is supplied from the tip of the auxiliary liquid level sensor 15 before the fuel tank 10 is deformed based on the liquid level A 0 measured by the liquid level sensor 14 and the immersion length B 0 measured by the auxiliary liquid level sensor 15. A distance L0 (L0 = A0−B0) to the bottom surface 20 of the tank 10 is obtained.

  Next, as shown in FIG. 8, for the fuel tank 10 that has been deformed in the height direction, the liquid level sensor 14 measures the liquid level A1, and the auxiliary liquid level sensor 15 measures the immersion length B1. In the computer 40, fuel is supplied from the tip of the auxiliary liquid level sensor 15 after the fuel tank 10 is deformed based on the liquid level A 1 measured by the liquid level sensor 14 and the immersion length B 1 measured by the auxiliary liquid level sensor 15. A distance L1 (L1 = A1-B1) to the bottom surface 20 of the tank 10 is obtained.

  Next, the computer 40 obtains the deformation amount ΔL of the fuel tank 10 by the following equation: ΔL = L1−L0.

  The procedure for obtaining the remaining amount of fuel from the deformation amount ΔL of the fuel tank 10 and the deformed liquid level A1 is as described in the first embodiment.

  In addition to the features of the fuel remaining amount measuring apparatus 1 according to the first embodiment, the fuel remaining amount measuring apparatus 2 according to the second embodiment includes a guide 12 for winding the tank deformation amount detecting sensor 11 and a tank deformation amount detecting sensor 11. Since the spring 16 that urges the other end toward the bottom surface 20 is unnecessary, the configuration is simpler than that of the fuel remaining amount measuring apparatus 1 of the first embodiment.

DESCRIPTION OF SYMBOLS 1 Fuel remaining amount measuring apparatus 2 Fuel remaining amount measuring apparatus 10 Fuel tank 11 Tank deformation detection sensor 11A Base 11B Fixing hole 12 Guide 13 Sensor guide guide 13A Pedestal part 13B Sensor guide part 14 Liquid level sensor 14A Fuel reference measurement part 14B Liquid Position measurement unit 14C Steam reference measurement unit 14D Electrode 15 Auxiliary liquid level sensor 15A Electrode 20 Bottom surface 30 Ceiling surface 40 Computer 100 Fuel tank

Claims (8)

A liquid level sensor for detecting the liquid level of the fuel stored in the fuel tank;
The fuel tank extends toward the bottom of the fuel tank, and the tip is immersed in the fuel stored in the fuel tank, and the immersion length is a length from the liquid level of the fuel to the tip. A tank deformation amount detection having an auxiliary liquid level sensor for detecting, and detecting a tank deformation amount which is a deformation amount of the fuel tank based on a liquid level detected by the liquid level sensor and an immersion length detected by the auxiliary liquid level sensor Means,
Tank capacity characteristic determining means for determining a tank capacity characteristic indicating a relationship between a fuel level and a fuel remaining amount based on the tank deformation amount detected by the tank deformation amount detecting means;
A fuel quantity determining means for determining a fuel remaining amount in the interior of the fuel tank based on the tank capacity characteristics determined in liquid level and the tank capacity characteristic determining means of the fuel tank detected by the liquid level sensor,
A fuel gauge that displays the fuel remaining amount determined by the fuel remaining amount determining means;
A fuel remaining amount measuring device.   The tank capacity characteristic determination means stores a tank capacity characteristic corresponding to a plurality of tank deformation amounts, and stores a tank capacity characteristic corresponding to the tank deformation amount detected by the tank deformation amount detection means. The fuel remaining amount measuring device according to claim 1, further comprising: a reading unit that reads from the unit.   The fuel remaining amount measuring device according to claim 1, wherein the tank deformation amount detecting means detects a deformation amount in a height direction of the fuel tank. The tank deformation amount detecting means, the fuel remaining of obtaining the tank deformation amount from the immersion length and the detected liquid level detected by the liquid level sensor in the auxiliary liquid level sensor in the front and rear deformation deformation before Symbol fuel tank remaining fuel amount measuring device according to claim 3, further comprising a quantity calculator. The liquid level sensor
Fixed to the bottom of the fuel tank at one end;
The fuel tank extends from the bottom surface of the fuel tank toward the ceiling surface, is wound around a guide provided above the liquid level at the time of maximum fuel remaining in the fuel tank, is folded back toward the fuel tank bottom surface, and the other end And is biased toward the bottom of the fuel tank by a spring at the part,
The fuel remaining amount measuring apparatus according to claim 4, wherein the auxiliary liquid level sensor is formed at the other end of the liquid level sensor. The liquid level sensor is formed at one end and is always immersed in the fuel, a fuel reference measurement unit, a vapor reference measurement unit formed at the center and always located outside the liquid, a fuel reference measurement unit, and a vapor reference measurement. A liquid level measuring unit that is formed so as to intersect the liquid level of the fuel and that detects the liquid level of the fuel,
6. The fuel remaining amount measuring device according to claim 5, wherein an auxiliary liquid level sensor located at the other end of the liquid level sensor is formed so as to intersect with a liquid level of the fuel and detects the immersion length. Wherein the liquid level sensor is provided upright on the bottom of the fuel tank extends toward the ceiling surface of the fuel tank, the auxiliary liquid level sensor extends toward the bottom surface is erected on the top surface The fuel remaining amount measuring apparatus according to any one of claims 1 to 4 . The liquid level sensor is formed at one end and is always immersed in fuel, a fuel reference measurement unit that is formed at the other end and is always located outside the liquid, a fuel reference measurement unit, and a vapor reference. A liquid level measuring unit that is formed so as to intersect the liquid level of the fuel between the measuring unit and that detects the liquid level of the fuel, and
The fuel remaining amount measuring device according to claim 7, wherein the auxiliary liquid level sensor is formed so as to intersect with a liquid level of the fuel, and detects the immersion length.

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