Liquid level detection device for a tank of a vehicle

Abstract

A liquid level detection device for a tank of a vehicle is provided. The device includes: a main detection portion that detects the liquid level of liquid in the tank to output a liquid level detection signal corresponding to the liquid level; and an auxiliary float assembly having an auxiliary float arranged to float on the liquid surface of the liquid in the tank. A gyro sensor is mounted to the auxiliary float, and an angle detection signal corresponding to the tilt angle of the tank is output by the gyro sensor. A controller determines a final liquid level value by correcting a liquid level value obtained from the liquid level detection signal based on the angle detection signal.

Description

Technical Field

[0001] The present disclosure relates to a liquid level detection device for a tank for a vehicle, and more particularly, to a liquid level detection device that more accurately detects the liquid level in a tank for a vehicle (such as a fuel tank or a urea water tank) regardless of the driving state of the vehicle, the shape of the tank, etc. Background Art

[0002] Generally, a fuel tank for a vehicle is provided with a liquid level detection device for detecting a liquid level of fuel, wherein the liquid level of the fuel indicates the remaining amount of fuel remaining in the fuel tank. Furthermore, in addition to the liquid level detection device, the vehicle is also provided with a remaining amount display device, which displays the liquid level of the fuel detected by the liquid level detection device, that is, the current remaining amount of fuel can be recognized by the driver. Therefore, the driver can confirm the remaining amount of fuel displayed by the remaining amount display device, thereby replenishing the fuel when necessary.

[0003] In a typical vehicle, a level detection device that detects the liquid level of the fuel is configured to output an electrical signal corresponding to the liquid level of the fuel (e.g., the remaining amount of fuel) interlocked with the position of a float, and for this purpose, the float is installed to move according to the change in the liquid level of the fuel in the fuel tank. As described above, a device installed in a fuel tank to detect the liquid level of the fuel by using a float that moves according to the change in the liquid level of the fuel is generally called a fuel sender.

[0004] The fuel remaining amount display device for a vehicle calculates the remaining amount of fuel based on a signal output from a fuel sender, and based on this, the device displays the remaining amount of fuel by calculating a fuel metering value and a remaining fuel drivable distance of a trip computer (not shown), which are vehicle driving information in a dashboard. Meanwhile, in the case of a vehicle to which a selective catalytic reduction (SCR) system has been applied, a urea water tank may also be installed together with the fuel tank, and the shapes of the fuel tank and the urea water tank differ depending on the vehicle type.

[0005] For example, in the case of commercial buses, minibuses, passenger cars, etc., the shapes of the fuel tank and the urea water tank have a low height and a wide width mainly due to the restricted vehicle layout characteristics. In particular, the urea water tank stores urea water, and in the SCR system, since the urea water is continuously used to remove nitrogen oxides during vehicle operation, the urea water needs to be filled into the urea water tank like filling fuel.

[0006] In addition, in order for the driver to recognize the remaining amount of urea water stored in the urea water tank, the urea water tank is provided with a liquid level detection device for detecting the liquid level of urea water like the fuel tank. As liquid level detection devices installed in the fuel tank and the urea water tank, a float type and a floating arm type are known. In the float type, a transmitter probe is vertically fixedly installed in the tank, and a float is coupled to move in a vertical longitudinal direction on the transmitter probe.

[0007] In the float type, when vertically moving interlocked with the change of the liquid level in the tank, the float moves along the transmitter probe, and an electrical signal according to the position of the float moving along the transmitter probe is output from the liquid level detection device. In the float arm type, the float is set in a state of being coupled to the end of the float arm, and when the float vertically moves interlocked with the change of the liquid level in the tank, the float arm rotates, and at this time, an electrical signal according to the movement of the float arm is output from the liquid level detection device.

[0008] However, in the conventional liquid level detection device, that is, in the transmitter for detecting the liquid level of the fuel in the fuel tank and the transmitter for detecting the liquid level of the urea water in the urea water tank, a liquid level detection error due to the inclination of the vehicle may occur. In particular, in a tank having a low height and wide width shape, an error may easily occur in the liquid level detection due to the inclination of the vehicle, and as the remaining amount error increases, a small amount or a large amount may be detected compared with the actual remaining amount in the tank.

[0009] In addition, if the vehicle is operated or driven on a slope, and if the vehicle is driven on a road with continuous or repeated uphill or downhill slopes, it is difficult to detect the exact level of the remaining amount in the tank, and the exact level in the vehicle may not be identified and displayed, and therefore fuel or urea water may not be replenished in time.

[0010] Figure 1 , Figure 2A and Figure 2B 1 is a diagram for explaining the problem of the prior art, and has shown that a liquid level detection error may occur in a float type fuel sender, for example, on a ramp. As shown in the figure, a float type fuel sender 10 includes a sender probe 11 vertically fixedly installed in a fuel tank 1, and a float 12 arranged to be coupled to be guided to the sender probe 11 along its vertical longitudinal direction. In this configuration, the float 12 moves along the sender probe 11 interlocked with the liquid level change of the fuel in the fuel tank 1, and an electrical signal corresponding to the liquid level of the fuel (for example, the remaining amount of fuel) according to the position of the float 12 on the probe 11 is output from the head 13 of the fuel sender 10.

[0011] refer to Figure 1 , Figure 2A and Figure 2B, showing the state of the fuel tank when the vehicle is on flat ground and on a slope, and the fuel tank 1 for the vehicle is kept in a horizontal state on flat ground (see Figure 1 ), but the fuel tank 1 is tilted to either side on the ramp (see Figure 2A and Figure 2B ). On the other hand, as shown in the drawings, the liquid surface of the fuel in the fuel tank 1 is always kept horizontal by gravity regardless of the inclination of the fuel tank. Therefore, even if the liquid level (e.g., the remaining amount) of the fuel in the fuel tank 1 is the same, the position and height of the liquid surface in the probe 11 are inevitably different from each other on a flat ground and on a slope, and the position and height of the float 12 that is always located on the liquid surface of the probe 11 are inevitably different from each other on a flat ground and on a slope.

[0012] Therefore, in the conventional liquid level detection device, a liquid level detection error occurs in which the liquid level is detected differently on flat ground and on a slope, and thus a difference is inevitably shown even in the remaining amount of fuel displayed on the instrument panel as the remaining amount display device.

[0013] The above information disclosed in this section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. Summary of the invention

[0014] Therefore, the present disclosure provides a liquid level detection apparatus that can more accurately detect the liquid level in a tank for a vehicle, such as a fuel tank or a urea water tank, regardless of the driving state of the vehicle or the shape of the tank.

[0015] To achieve this purpose, according to an exemplary embodiment of the present disclosure, there is provided a liquid level detection device for a tank of a vehicle, which includes: a main detection part configured to detect the liquid level of the liquid in the tank to output a liquid level detection signal corresponding to the liquid level; an auxiliary float assembly including an auxiliary float and a gyro sensor, the auxiliary float being arranged to float on the liquid surface of the liquid in the tank, the gyro sensor being mounted to the auxiliary float and being arranged so that an angle detection signal corresponding to the tilt angle of the tank is output in the gyro sensor; and a controller configured to determine a final liquid level value by correcting a liquid level value obtained from the liquid level detection signal based on the angle detection signal. In particular, the main detection part may include: a transmitter probe mounted in the tank; a main float being arranged to move along the transmitter probe interlocked with a change in the liquid level of the liquid in the tank; and a head for generating and outputting a liquid level detection signal according to the position of the main float in the transmitter probe.

[0016] In addition, the auxiliary float assembly may include: a base portion installed to be vertically movable along a fixed structure in the tank; a gyro sensor portion having a gyro sensor connected and supported to the base portion by an arm and configured to output an angle detection signal corresponding to a rotation angle and an inclination angle; and an auxiliary float arranged to float on a liquid surface of a liquid in the tank and installed so that the gyro sensor portion is rotatable. The fixed structure in the tank may be a pipe fixedly arranged vertically and longitudinally in the tank, and the base portion may be arranged in a cylindrical shape to fit into the outer circumference of the pipe and thus be rotatable in the pipe while being vertically movable along the pipe.

[0017] In addition, the arm can be provided in the form of a hollow tube, a wire can be installed along the inside of the arm, the wire is connected to the gyro sensor to transmit an angle detection signal, and the wire passes through the inside of the arm and is then wound around the tube in a spiral form to be connected to the outside of the auxiliary float assembly. The gyro sensor part can be installed to be rotatable above the auxiliary float, and a groove part having a predetermined depth is formed in the upper part of the auxiliary float, and at least a part of the gyro sensor part rotating on the auxiliary float can be inserted into the groove part.

[0018] The auxiliary float and the gyro sensor part may have a rectangular parallelepiped shape, and a groove part may be formed at a certain depth on the upper part of the auxiliary float, and an end part of the rotating gyro sensor part may be inserted into the groove part. The gyro sensor part may be hinge-coupled to a central position of the auxiliary float in a longitudinal direction, and the arm may be connected to a portion spaced a predetermined distance from a portion of the gyro sensor part hinge-coupled to the auxiliary float.

[0019] In addition, a drain hole may be formed through an upper portion of the auxiliary float, through which the liquid filled in the groove portion may be drained. The gyro sensor portion may include: a housing rotatably coupled to the auxiliary float; a case accommodated in and fixed to an interior of the housing; a gyro sensor inserted into and fixed to an interior of the housing; and a cover installed in the housing into which the housing and the gyro sensor are inserted to close the interior of the housing.

[0020] The main detection part may include: a transmitter probe installed in a tank; and a main float configured to move along the transmitter probe interlocked with changes in the liquid level of the liquid in the tank, and, in the controller, when the inclination angle of the gyro sensor part obtained from the angle detection signal is α, the length of a connecting line perpendicularly connected to the longitudinal axis of the transmitter probe of the main detection part in the gyro sensor part is the base length, and the distance between the point in the axis of the transmitter probe at which the connecting line is perpendicularly connected and the main float is the height, and the height can be calculated from α and the base length using the relationship of "tanα=height / base length", and the corrected final liquid level value is obtained as a value obtained by adding or subtracting the height from the liquid level value obtained from the liquid level detection signal.

[0021] In addition, in the controller, the tilt direction of the tank can be determined from the angle detection signal, and the height can be added or subtracted from the liquid level value according to the tilt direction of the tank. The controller can be configured to perform correction when a state in which the angle obtained from the angle detection signal corresponds to a predetermined normal area is maintained for a set time and the liquid level value obtained from the liquid level detection signal is a predetermined lower limit value or more.

[0022] In addition, in the controller, the normal area is 0 or greater and can be set as an area of ​​a predetermined maximum inclination angle or less, and the controller can be configured to determine that the angle obtained from the angle detection signal corresponds to a state of the normal area when the absolute value of the angle obtained from the angle detection signal is 0 or greater and the maximum inclination angle or less.

[0023] Therefore, according to the liquid level detection device for a tank for a vehicle of the present disclosure, it is possible to more accurately detect the liquid level in a tank for a vehicle (such as a fuel tank or a urea water tank) regardless of the driving state of the vehicle, the tank shape, etc., and more accurately detect the remaining amount of fuel or urea water in the tank regardless of changes in the operating state of the vehicle by enabling error correction of the tank capacity. As a result, it is possible to replenish fuel and urea water at an appropriate time before the fuel or urea water is exhausted, thereby improving the efficiency of vehicle operation and preventing damage to components or engine shutdown due to exhaustion of fuel and urea water, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other features of the present disclosure will now be described in detail with reference to exemplary embodiments of the present disclosure shown in the accompanying drawings, which are given hereinafter by way of illustration only and therefore do not limit the present invention, and in which:

[0025] Figure 1 , Figure 2A and Figure 2B It is a diagram for explaining the problems of the prior art.

[0026] Figure 3 is a perspective view illustrating a liquid level detecting apparatus according to an exemplary embodiment of the present disclosure.

[0027] Figure 4 is an enlarged perspective view illustrating an auxiliary float and a gyro sensor part of an auxiliary float assembly in a liquid level detection apparatus according to an exemplary embodiment of the present disclosure.

[0028] Figure 5 are exploded perspective views respectively illustrating configurations of an auxiliary float assembly in a liquid level detection apparatus according to exemplary embodiments of the present disclosure.

[0029] Figure 6 is an assembly perspective view showing a gyro sensor portion, an arm, a base portion, and a wire in a configuration of an auxiliary float assembly in a liquid level detection apparatus according to an exemplary embodiment of the present disclosure.

[0030] Figure 7 is a diagram showing a state in which a housing into which a gyro sensor has been inserted is accommodated and fixed to an inner space of a housing of a gyro sensor part in an exemplary embodiment of the present disclosure.

[0031] Figure 8 is a diagram showing a state of the liquid level detection apparatus according to the present disclosure when the vehicle is located on flat ground and the tank maintains a horizontal state without being tilted.

[0032] Fig. 9 and Fig.10 is a diagram showing a state of the liquid level detection apparatus according to the present disclosure when the vehicle is on a slope and the tank is inclined.

[0033] Figures 11 to 13 2 is a diagram showing a state of the gyro sensor unit in the liquid level detection state of the present disclosure.

[0034] Fig.14 and Fig.15 It is a diagram for explaining the liquid level correction method in the present disclosure.

[0035] Fig.16 is a diagram showing the correction logic in the present disclosure.

[0036] Fig.17 is a diagram showing a configuration for detecting a liquid level in the present disclosure.

[0037] It should be understood that the drawings are not necessarily drawn to scale, presenting somewhat simplified representations of various features illustrating the basic principles of the present disclosure. Specific design features of the present disclosure as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes, will be determined in part by specific intended applications and use environments. In the drawings, throughout the several figures of the drawings, reference numerals refer to the same or equivalent parts of the present disclosure. DETAILED DESCRIPTION

[0038] It should be understood that the terms "vehicle" or "vehicular" or other similar terms used herein generally include motor vehicles, such as passenger cars including sport utility vehicles (SUVs), buses, trucks, various commercial vehicles, water craft including various boats and ships, aircraft, etc., and include hybrid vehicles, electric vehicles, combustion, plug-in hybrid vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum).

[0039] Although the exemplary embodiments are described as using multiple units to perform the exemplary processes, it should be understood that the exemplary processes can also be performed by one or more modules. In addition, it should be understood that the term controller / control unit refers to a hardware device including a memory and a processor, and is specifically programmed to perform the processes described herein. The memory is configured to store the modules, and the processor is specifically configured to execute the modules to perform one or more processes, which will be further described below.

[0040] The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. As used herein, the singular forms "one", "an" and "the" are also intended to include plural forms, unless the context clearly indicates otherwise. It will be further understood that the terms "include" and / or "comprise" when used in this specification specify the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or their groups. As used herein, the term "and / or" includes any and all combinations of one or more associated listed items.

[0041] Unless otherwise specified or apparent from the context, as used herein, the term "about" should be understood as being within the normal tolerance range in the art, such as within 2 standard deviations of the mean. "About" can be understood as being within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless the context clearly indicates otherwise, all numerical values ​​provided herein are modified by the term "about".

[0042] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present disclosure relates can easily implement the present disclosure. However, the present disclosure is not limited to the exemplary embodiments described herein and may also be embodied in other forms.

[0043] The present disclosure can be applied to a tank (such as a fuel tank and a urea water tank) storing a liquid (such as a fuel tank or a urea water tank) in a vehicle, and relates to a liquid level detection device for a tank of a vehicle, which can more accurately detect a liquid level indicating a remaining amount of liquid in the tank. In particular, the present disclosure relates to a liquid level detection device that can more accurately detect a liquid level in a tank regardless of a driving state of the vehicle (e.g., a road state such as a flat ground and a slope), a tank shape, etc.

[0044] The liquid level detection device according to the present disclosure can improve a known float type transmitter, which includes a transmitter probe vertically installed inside a tank, and a float coupled to be vertically movable along the transmitter probe, and is used by additionally installing a float for correction in the tank, and at this time, the additionally installed float is installed with a gyro sensor.

[0045] As described above, the main feature of the present disclosure is that even if the liquid surface in the tank has tilted, the liquid level (e.g., the remaining amount of liquid) can be measured more accurately by additionally using a separate float equipped with a gyro sensor. In the following description, the transmitter can be understood as the same meaning as a liquid level detection device for detecting the liquid level in the tank to output and transmit an electrical signal, and can be a fuel transmitter configured to detect the liquid level of the fuel in the fuel tank, or a urea water transmitter for detecting the liquid level of urea water in the urea water tank.

[0046] Figure 3 1 is a perspective view showing a liquid level detection device according to an exemplary embodiment of the present disclosure, and as shown in the figure, the liquid level detection device according to the exemplary embodiment may include a separate float mounted with a gyro sensor as described above in addition to the components of a known float type transmitter including a probe and a float. In the following description, in order to distinguish the floats, the known float coupled to the probe to move vertically in the longitudinal direction is referred to as a "main float", and the float newly added in the present disclosure (i.e., the separate float mounted with a gyro sensor as described above) is referred to as an "auxiliary float".

[0047] refer to Figure 1 , the probe 110 of the liquid level detection device 100 may be installed to be vertically disposed inside a tank (not shown), and may be supported by a head 130 fixedly mounted outside the tank and a support member 140 mounted inside the tank in a state of being coupled to the head 130. The head 130 includes a component for generating and transmitting an electrical signal as an internal component, and may be fastened and mounted to an outer side surface of the tank to be positioned outside the tank.

[0048] The support 140 may include a tube 141 coupled to the head 130 and a plate 142 coupled to the tube 141, and the lower end portion of the probe 110 may be coupled to the plate 142. At this time, the probe 110 may be supported in a state of being coupled to the head 130 and the support 140 inside the tank, the upper end portion of the probe 110 may be coupled to the head 130 via the holder 131, and the lower end portion of the probe 110 may be supported in a state of being coupled to the plate 142 of the support 140 to prevent shaking.

[0049] The main float 120 may be coupled to the probe 110 to be vertically movable in the longitudinal direction, and may be provided in a cylindrical shape and assembled and coupled to the probe 110 to be in a form in which the probe 110 penetrates the inside thereof. In the present disclosure, the main float 120 is a known float of a conventional float type transmitter that has been applied to a vehicle, and is a float coupled to the probe 110 to be vertically guided in the longitudinal direction thereof.

[0050] In the present disclosure, when the main float 120 moves along the probe 110 in interlock with the change in the liquid level in the tank, an electrical signal (that is, a liquid level detection signal) according to the position of the main float 120 on the probe 110 may be output from the head 130. In addition, since the fact that the electrical signal according to the position of the main float 120 (for example, the liquid level detection signal of the float type transmitter) is output from the head 130 of the float type transmitter is known, a detailed description thereof will be omitted. Therefore, the liquid level detection signal output from the head 130 may be transmitted to the instrument panel, and thus, the current remaining amount of fuel (or urea water) calculated from the liquid level detection signal may be displayed through the instrument panel.

[0051] Meanwhile, the liquid level detection device 100 according to the exemplary embodiment of the present disclosure may further include an auxiliary float assembly 150 having an auxiliary float 151 mounted with a gyro sensor separated from a main detection part configured to detect the liquid level in the tank, and the auxiliary float assembly 150 may also be installed inside the tank. In particular, the main detection part refers to a conventional float type transmitter including a probe 110 and a main float 120.

[0052] In an exemplary embodiment of the present disclosure, the auxiliary float assembly 150 may be installed to be supported by the supporter 140 inside the tank, and may include an auxiliary float 151, a gyro sensor portion 152, an arm 156, and a base portion 158. In particular, the auxiliary float 151 is a float configured to float on the liquid surface in the tank like the main float 120, which is also a float that vertically moves interlocked with the liquid surface change in a state of contact with the liquid surface in the tank.

[0053] When the vehicle is on a flat surface, the liquid level in the tank is in a horizontal state, and even if the vehicle is on a slope, the liquid level in the tank always remains in a horizontal state, and at this time, the auxiliary float 151 should float in a state that always maintains the same angle with the above liquid level. In other words, the auxiliary float 151 is set to always float in a horizontal state like the liquid level, and Figure 4 is an enlarged perspective view illustrating an auxiliary float 151 and a gyro sensor part 152 of an auxiliary float assembly in a liquid level detection apparatus according to an exemplary embodiment of the present disclosure.

[0054] like Figure 4 As shown in FIG, the auxiliary float 151 may have a rectangular parallelepiped shape, and a groove portion 151a having a predetermined depth may be formed at an upper portion of the auxiliary float 151. The groove portion 151a provides a space for rotation and operation of a gyro sensor portion 152 described later, and specifically, the gyro sensor portion 152 installed above the auxiliary float 151 serves as an interference avoidance space that allows rotation within a predetermined angle range without interfering with the auxiliary float 151.

[0055] The hinge coupling portion 151c to which the gyro sensor part 152 is rotatably coupled may be formed on the upper portion of the auxiliary float 151, and the hinge coupling portion 151c may be formed at a central position in the longitudinal direction on the upper portion of the auxiliary float 151. The hinge coupling portion 151c may be formed to protrude upward from both the left and right sides of the upper portion of the auxiliary float 151, which is a portion to which the gyro sensor part 152 is hinge-coupled in the auxiliary float 151, and to which a hinge pin 153c of the gyro sensor part 152 may be rotatably coupled.

[0056] The portion to which the arm 156 is connected in the gyro sensor portion 152 may be a portion spaced apart from the hinge pin 153c by a predetermined distance, which is a portion hinge-coupled to the auxiliary float 151, and, for example, the arm 156 may be connected to one side end portion in the longitudinal direction in the gyro sensor portion 152. Therefore, the gyro sensor portion 152 may be freely rotatable around the hinge coupling portion 151c and the hinge pin 153c above the auxiliary float 151, and in particular, the gyro sensor portion 152 is relatively rotated by an amount corresponding to the inclination of the tank relative to the liquid surface in the tank and the fixed member with respect to the auxiliary float 151 which always maintains a horizontal state together with the liquid surface.

[0057] As described above, the amount, angle, etc., by which the gyro sensor portion 152 has been relatively rotated with respect to the auxiliary float 151 may be a value corresponding to the inclination of the tank, and when the gyro sensor portion 152 learns rotation information such as the amount or angle by which the gyro sensor portion 152 has been relatively rotated, the inclination of the tank may be estimated. As a result, the rotation information of the gyro sensor portion 152 relatively rotated with respect to the auxiliary float 151 as described above may be used as information for correcting the liquid level obtained by the main float 120.

[0058] As described above, the present disclosure can detect the angle at which the gyro sensor part 152 has relatively rotated with respect to the auxiliary float 151 that always floats on the liquid surface in a horizontal state, and correct the liquid level obtained by the main float 120 using the detected angle information.

[0059] exist Figure 4 , reference numeral 151b is a discharge hole formed through the upper portion of the auxiliary float 151, and the discharge hole 151b can discharge the liquid filled in the groove portion 151a of the auxiliary float 151 to the outside, and can be formed to immediately discharge the liquid if the liquid stored in the tank (such as fuel or urea water) is filled in the groove portion 151a of the auxiliary float 151.

[0060] Figure 5 are exploded perspective views respectively showing configurations of auxiliary float assemblies in a liquid level detection apparatus according to an exemplary embodiment of the present disclosure, and Figure 6 is an assembly perspective view showing a gyro sensor portion, an arm, a base portion, and a wire in a configuration of an auxiliary float assembly in a liquid level detection apparatus according to an exemplary embodiment of the present disclosure.

[0061] exist Figure 6 In the figure, the auxiliary float is omitted, and the gyro sensor portion 152 shown as above is hinge-coupled so that it can be in the auxiliary float ( Figure 4 151 in the figure) and freely rotate above (see Figure 4 ), and at this time, the hinge pin 153c becomes the rotation center of the gyro sensor unit 152.

[0062] refer to Figure 5The gyro sensor portion 152 may include a housing 153a, a cover 153b, a housing 154, and a gyro sensor 155, and has a hinge pin 153c formed to protrude laterally from both the left and right surface portions of the housing 153a. The housing 153a provides an accommodation space for accommodating the gyro sensor 155, and may be formed in a rectangular parallelepiped shape so that its internal space accommodates the gyro sensor 155, and the housing 153a may be integrally fixed to close the internal space above the housing 153a in a state where the gyro sensor 155 has been accommodated in the internal space.

[0063] The gyro sensor 155 may be accommodated inside the housing 153a and the cover 153b in a state of being inserted and fixed to the case 154, and a wire 159 for external connection and transmission of an angle detection signal may be connected to the gyro sensor 155 inserted into the case 154. The case 154 in which the gyro sensor 155 is inserted may be accommodated in the internal space of the housing 153a and fixed by a method such as bonding, and the gyro sensor 155, the case 154, the housing 153a, and the cover 153b may rotate together in a state of being all integrated.

[0064] Figure 7 1 is a diagram showing a state in which a shell having a gyro sensor inserted therein has been accommodated and fixed to an internal space of a housing of a gyro sensor portion in an exemplary embodiment of the present disclosure, and the shell 154 can be completely fixed to the interior of the housing 153a by a method such as bonding, so that the gyro sensor, the shell 154 and the housing 153a can all rotate as a whole without the shell 154 moving within the housing 153a.

[0065] In addition, when the cover 153b is assembled over the housing 153a in a state where the housing 154 in which the gyro sensor 155 is inserted is already accommodated in the internal space of the housing 153a, it can be fixed by a sealing process between the cover 153b and the housing 153a to completely seal the internal space of the housing 153a and maintain airtightness. In addition, the arm 156 can be provided in the form of a thin and slender rod that integrally connects the housing 153a and the base portion 158, and can have a configuration in which a first rod 157a integrally coupled to the housing 153a and a second rod 157b integrally formed on the base portion 158 are connected to each other.

[0066] The arm 156 may be provided in the form of a hollow tube so that a wire 159 for transmitting an angle detection signal is inserted therein and wired, and the wire 159 may be wired into the first rod 157a after penetrating the cover 153b through the internal space of the housing 153a in a state connected to the gyro sensor 155 inside the housing 154. In addition, the wire 159 having passed through the inside of the first rod 157a and the second rod 157b of the arm 156 in the gyro sensor portion 152 may extend into the base portion through the inner hole 158a of the base portion 158, and then be wound around the tube 141 of the support 140 in a spiral form to be connected to the head 130 which becomes the outside of the auxiliary float assembly 150.

[0067] Therefore, when the gyro sensor 155 operates, the electrical signal output from the gyro sensor 155 can be transmitted to the head 130 via the wire 159. The base portion 158 can be coupled to move vertically along the tube 141 of the support 140, which is vertically and longitudinally fixedly disposed in the tank and can be provided in a cylindrical shape to be assembled into a state of being fitted into the outer circumference of the tube 141 of the support 140.

[0068] As described above, in a state where the base portion 158 is coupled to the outer periphery of the tube 141 of the support member 140, the wire 159 that has passed through the inside of the arm 156 passes as shown in FIG. Figure 5 The inner hole 158a of the base portion 158 in the embodiment extends into the base portion 158, and then Figure 3 In the embodiment, it can be wound in a spiral form around the outer circumference of the tube 141 of the support member 140.

[0069] The base portion 158 may freely move vertically along the tube 141 of the support 140, and may be installed to freely rotate in the tube 141 of the support 140. Therefore, when the base portion 158 vertically moves or rotates in the tube 141 of the support 140, the arm 156, the gyro sensor portion 152 connected by the arm, and the auxiliary float 151 may all move together.

[0070] However, when the liquid level in the tube 141 of the support 140 changes according to the inclination of the tank, the gyro sensor portion 152 coupled to the tube 141 of the support 140 via the arm 156 and the base portion 158 rotates relative to the auxiliary float 151 which always maintains a horizontal state at the liquid surface.

[0071] In the present disclosure, the support member 140 and the tube 141 constituting the support member are fixed structures integrally fixed to the tank and should move with the tank, and if the tank is tilted, the entire support member 140 including the tube 141 should be tilted integrally with the tank. In addition, if the vehicle, the tank, and the support member 140 therein are tilted, the arm 156, the base portion 158, the wire 159, etc. are tilted together, and the gyro sensor portion 152 above the auxiliary float 151 is relatively rotated corresponding to the inclination of the auxiliary float and the tank. At this time, the auxiliary float 151 can support the gyro sensor portion 152, the arm 156, the base portion 158, the wire 159, etc. in a state of floating horizontally on the liquid surface in the tank, and enable the gyro sensor portion 152 to rotate in a state of maintaining a horizontal state at the liquid surface when the vehicle and the tank are tilted.

[0072] Figure 8 is a diagram showing a state of the liquid level detection device when the vehicle is on flat ground and the tank is kept in a horizontal state without being tilted, and Fig. 9 and Fig.10 is a diagram showing the state of the liquid level detection device when the vehicle is on a slope and the tank is tilted. Figures 8 to 10 It can be seen that when the storage tank 1 is kept horizontal, the liquid level in the storage tank is also kept horizontal, and even if the storage tank is tilted to either side, the liquid level in the storage tank is always kept horizontal by gravity.

[0073] Likewise, since the liquid surface in the tank is always kept horizontal regardless of the horizontal state or inclination of the tank 1, the auxiliary float 151 floating on the liquid surface is also always kept horizontal like the liquid surface without having its posture always tilted to either side. On the other hand, the gyro sensor portion 152 rotatably hinge-coupled to the auxiliary float 151 can be integrally connected and fixed to the base portion 158 via the arm 156, and at this time, the tube 141 coupled to the mounted support 140 causes the base portion 158 to tilt together with the tank 1.

[0074] Therefore, if the vehicle body, tank 1, and tube 141 of support 140 are tilted on the ramp, even if the liquid surface is kept in a horizontal state, gyro sensor portion 152 connected to base portion 158 via arm 156 can be rotated above auxiliary float 151 interlocked with the tilt of tank 1. At this time, the amount and angle at which gyro sensor portion 152 is relatively rotated and tilted with respect to auxiliary float 151 kept in a horizontal state will vary according to the amount and angle at which tank 1 is tilted.

[0075] In other words, the signal output by the gyro sensor 155 of the gyro sensor portion 152 is an angle detection signal indicating the angle of the gyro sensor portion 152 relative to the horizontal line, and the angle detection signal indicates a value corresponding to the inclination of the tank 1. As a result, if the angle detection signal output by the gyro sensor 155 is applied as a correction signal with respect to the liquid level detection signal according to the position of the main float 120, more accurate liquid level information in the tank reflecting the inclination of the tank 1 can be obtained.

[0076] Figures 11 to 13 1 is a diagram showing the state of the gyro sensor portion in the liquid level detection state, and shows only a cross section of the upper portion of the main float 120 including the groove portion 151a. When the tank is kept in a horizontal state without being tilted, as shown in FIG. Fig.11 As shown in FIG. 1 , the auxiliary float 151 and the gyro sensor portion 152 thereon are also in a horizontal state.

[0077] However, if the tank is tilted to either side, the auxiliary float 151 can be kept horizontal together with the liquid level in the tank, but the gyro sensor part 152 thereon is in a state of relative rotation with respect to the auxiliary float 151, as shown in FIG. Fig.12 and Fig.13 In an exemplary embodiment, when the auxiliary float 151 and the gyro sensor part 152 have a rectangular parallelepiped shape, a groove part 151a having a rectangular shape into which an end portion of the rotating gyro sensor part 152 can be inserted may be formed on an upper portion of the auxiliary float 151 at a certain depth.

[0078] If the tank is tilted a certain level or more, the gyro sensor portion 152 can rotate in a state where at least a portion has been inserted into the groove portion 151a of the auxiliary float 151, and if the tank is further tilted significantly and the front end portion or the rear end portion of the gyro sensor portion 152 contacts the bottom surface of the groove portion 151a of the auxiliary float 151, the rotation of the gyro sensor portion 152 can be restricted.

[0079] Meanwhile, a method for correcting the liquid level detected by the main float 120 and the probe 110 using the angle detection signal of the gyro sensor 155 will be described as follows. Fig.14 and Fig.15 is a diagram for illustrating the liquid level correction method, and if the angle α detected by the gyro sensor 155 is used, tanα can be known, where α refers to the inclination angle of the entire gyro sensor portion 152 including the gyro sensor 155, and tanα refers to the inclination gradient of the gyro sensor portion 152 (gradient (%) = tanα×100).

[0080] In addition, a relationship of "tan α = height / base length" is established between the gradient, the height, and the base length. Specifically, the base is a connecting line connected perpendicularly to the longitudinal axis of the probe 110 in the gyro sensor section 152, the base length is the length of the connecting line, and the length of the connecting line is a constant fixed value and is therefore a predetermined constant.

[0081] The height is the distance between the point where the connecting line vertically connects the axis of the probe 110 and the main float 120. Of course, the axis of the probe 110 represents the axial direction (e.g., longitudinal direction) line of the probe 110, and the connecting line is a line perpendicular to the axis of the probe 110. Therefore, if tanα, which is the gradient of the gyro sensor portion 152, is available from the signal of the gyro sensor 155, the base length is a known value, so that the height can be calculated from tanα and the base length.

[0082] During the calibration, the final liquid level value in the tank can be determined by correcting the liquid level value detected by the main float 120 and the probe 110 (which is a conventional liquid level detection value) by subtracting or adding the calculated height. In particular, the final liquid level value in the tank is a liquid level value corrected using the detection information of the gyro sensor 155 to reflect the inclination of the tank, and the liquid remaining amount (e.g., fuel remaining amount, urea water remaining amount, etc.) calculated using the corrected liquid level value is displayed on the instrument panel (e.g., a remaining amount display device).

[0083] Fig. 9 , Fig.12 and Fig.14 The tilted state of the tank 1 when the vehicle travels downhill is shown, and even if the actual remaining amount of liquid (e.g., fuel or urea water) in the tank is the same when the vehicle travels downhill, the liquid level detected by the main float 120 becomes a value lower than the liquid level detected on flat ground. During the correction, since a correction should be performed for converting the liquid level detected by the main float 120 into a liquid level on flat ground using a height value obtained from a signal of the gyro sensor 155, a positive (+) correction may be performed that determines a final liquid level (e.g., a value converted into a liquid level on flat ground) by adding a height value obtained from a signal of the gyro sensor 155 at the liquid level detected by the main float 120.

[0084] on the other hand, Fig.10 , Fig.13 and Fig.15The tilt state of the tank 1 when the vehicle travels uphill is shown, and the liquid level detected by the main float 120 becomes a higher value than the liquid level detected on flat ground when the vehicle travels uphill. Therefore, during the correction, a negative (-) correction can be performed, which determines the final liquid level by subtracting the height value obtained from the signal of the gyro sensor 155 at the liquid level detected by the main float 120. If the tilt angle of the tank is a positive (+) value when the vehicle travels uphill, the angle detected by the gyro sensor 155 also becomes a positive (+) value, and conversely, when the tilt angle of the tank is a negative (-) value when the vehicle travels downhill, the angle detected by the gyro sensor 155 also becomes a negative (-) value.

[0085] As described above, it is possible to determine from the signal of the gyro sensor 155 whether the vehicle is traveling uphill or downhill, thereby determining the inclination angle of the vehicle and the tank, and further, determine whether to perform a positive (+) correction of adding the height value to the liquid level detected by the main float 120 and the probe 110, or to perform a negative (-) correction of subtracting the height value from the detected liquid level.

[0086] Fig.16 is a diagram showing the correction logic, and Fig.17 is a diagram showing a configuration for liquid level detection. Fig.16 1 is a diagram showing a correction logic set in the controller 160 of the liquid level detection device 100, and the controller 160 may be a dashboard controller or may be a separate controller installed in the head 130 of the liquid level detection device 100. The controller 160 may be configured to use a general liquid level detection signal generated in and output from the head 130 and an angle detection signal output from the gyro sensor 155 as inputs to calculate a final liquid level value therefrom according to the vertical position of the main float 120 on the probe 110.

[0087] refer to Fig.16 To describe, first, in the controller 160, a lower limit value of the liquid level as the minimum remaining value in the tank can be preset, and a normal angle area before the vehicle dumps can be preset. At this time, the normal angle area can be defined as an area of ​​the maximum tilt angle or less before the vehicle dumps based on the absolute value of the angle detected by the gyro sensor 155, and therefore, the maximum tilt angle can be set in the controller 160.

[0088] In other words, the normal angle region may be defined as an angle region from 0 to the maximum tilt angle or less. Therefore, the controller 160 may be configured to determine whether the liquid level in the tank 1 detected by the main float 120 and the probe 110 (which is the liquid level before correction) is the liquid level lower limit value or greater, and at the same time, determine whether the angle detected by the gyro sensor 155 corresponds to the normal angle region, and if the state that the detected liquid level in the tank is the liquid level lower limit value or greater and the angle detected by the gyro sensor 155 is the normal angle region is maintained for a set time, the liquid level calculation and correction are performed in the liquid level detection device 100.

[0089] In addition, in the liquid level calculation and correction process, the value of tanα is obtained from the angle detection signal of the gyro sensor 155 in the controller 160, and the height value can be calculated by multiplying the value of tanα by a predetermined base length. At this time, a filter for reducing fluctuations can be applied to filter the calculated height value, and the filtered height value can be used to correct the liquid level in the tank detected by the main float 120 and the probe 110.

[0090] In response to determining that the liquid level in the tank detected by the main float 120 and the probe 110 is less than the liquid level lower limit value, or the angle detected by the gyro sensor 155 is not in the normal angle region, correction may be prevented from being performed by using 0 as the height value. The fact that the angle detected by the gyro sensor 155 is not in the normal angle region (that is, the absolute value of the angle detected by the gyro sensor 155 is greater than the maximum tilt angle) indicates that this may be a state in which the vehicle has overturned.

[0091] In the process of correcting the liquid level in the tank detected by the main float 120 and the probe 110 using the height value, the controller 160 can be configured to determine the tilt direction of the vehicle, the tank, and the gyro sensor unit 152 from the signal of the gyro sensor 155, and calculate the final liquid level value by performing a negative (-) correction, which subtracts the calculated height value from the liquid level in the tank detected by the main float 120 and the probe 110 when the angle value detected by the gyro sensor 155 indicates a positive value of uphill driving.

[0092] On the other hand, in the case of downhill driving in which the angle value detected by the gyro sensor 155 indicates a negative value, the final liquid level value is calculated by performing a positive (+) correction that adds the calculated height value to the liquid level in the tank detected by the main float 120 and the probe 110. As described above, if the final liquid level value is determined by the controller 160, the remaining amount display device 200 may be configured to display the remaining amount of fuel corresponding to the final liquid level value determined by the controller 160.

[0093] Therefore, according to the present disclosure, the liquid level value detected by the main float 120 and the probe 110 can be corrected using the angle detection signal output from the gyro sensor 155, thereby obtaining the tilt direction of the vehicle and the tank and the liquid level value in the tank that more accurately reflects the degree thereof.

[0094] As described above, although the exemplary embodiments of the present disclosure have been described in detail, the scope of the present disclosure is not limited thereto, and various modifications and improvements by those skilled in the art are defined using the basic concepts of the present disclosure. The appended claims are also included within the scope of the present disclosure.

Claims

1. A liquid level detection device for a tank of a vehicle, comprising: a main detection unit configured to detect a liquid level of the liquid in the tank to output a liquid level detection signal corresponding to the liquid level; an auxiliary float assembly, comprising an auxiliary float and a gyro sensor, the auxiliary float being arranged to float on a liquid surface of the liquid in the tank, the gyro sensor being mounted to the auxiliary float and being configured to output an angle detection signal corresponding to an inclination angle of the tank; as well as a controller configured to determine a final liquid level value by correcting a liquid level value obtained from the liquid level detection signal based on the angle detection signal, Wherein, the auxiliary float assembly comprises: a base portion mounted to be vertically movable along a fixed structure in the tank; a gyro sensor unit having a gyro sensor connected and supported to the base unit through an arm and configured to output the angle detection signal corresponding to the tilt angle; and An auxiliary float is provided to float on the liquid surface of the liquid in the tank and is installed so that the gyro sensor portion can rotate.

2. The liquid level detection device for a tank of a vehicle according to claim 1, wherein: The main detection unit comprises: a transmitter probe mounted in the tank; a main float arranged to move along the transmitter probe interlocked with changes in the level of the liquid in the tank; and A head is used to generate and output the liquid level detection signal according to the position of the main float in the transmitter probe.

3. The liquid level detection device for a tank of a vehicle according to claim 1, wherein: The fixed structure in the tank is a pipe fixedly arranged vertically and longitudinally in the tank, and wherein the base portion is provided in a cylindrical shape to fit into the outer circumference of the pipe and thus rotatable on the pipe while being vertically movable along the pipe.

4. The liquid level detection device for a tank of a vehicle according to claim 3, wherein: The arm is configured in the form of a hollow tube, wherein a wire is installed along the interior of the arm, the wire is connected to the gyro sensor to transmit the angle detection signal, and wherein the wire passes through the interior of the arm and is wound around the tube in a spiral form to be connected to the outside of the auxiliary float assembly.

5. The liquid level detection device for a tank of a vehicle according to claim 1, wherein: The gyro sensor part is installed to be rotatable above the auxiliary float, and wherein a groove part having a predetermined depth is formed in an upper portion of the auxiliary float, and at least a portion of the gyro sensor part rotating on the auxiliary float is inserted into the groove part.

6. The liquid level detection device for a tank of a vehicle according to claim 5, wherein: The auxiliary float and the gyro sensor part have a rectangular parallelepiped shape, and wherein the groove part into which an end portion of the rotating gyro sensor part is inserted is formed at a certain depth on the upper portion of the auxiliary float.

7. The liquid level detection device for a tank of a vehicle according to claim 6, wherein: The gyro sensor part is hinge-coupled to a central position of the auxiliary float in a longitudinal direction, and wherein the arm is connected to a portion spaced apart a predetermined distance from a portion of the gyro sensor part hinge-coupled to the auxiliary float.

8. The liquid level detection device for a tank of a vehicle according to claim 5, wherein: A discharge hole is formed through the upper portion of the auxiliary float, through which liquid filled in the groove portion is discharged.

9. The liquid level detection device for a tank of a vehicle according to claim 1, wherein: The gyro sensor unit includes: a housing rotatably coupled to the auxiliary float; a housing received in and secured to the interior of the housing; a gyro sensor inserted into and fixed to the interior of the housing; and A cover is installed in the housing in which the case and the gyro sensor are inserted to close the interior of the housing.

10. The liquid level detection device for a tank of a vehicle according to claim 1, wherein: The main detection unit comprises: a transmitter probe mounted in the tank; and a main float arranged to move along the transmitter probe interlocked with changes in the level of the liquid in the tank, and Wherein, in the controller, When the tilt angle of the gyro sensor portion obtained from the angle detection signal is α, the length of a connection line perpendicularly connected from the gyro sensor portion to the longitudinal axis of the transmitter probe of the main detection portion is the base length, and the distance between a point at which the connection line is perpendicularly connected in the longitudinal axis of the transmitter probe and the main float is the height, and The height is calculated from the α and the base length by the controller using the relationship of “tan α=height / base length”, and a corrected final liquid level value is obtained as a value obtained by adding or subtracting the height from the liquid level value obtained from the liquid level detection signal.

11. The liquid level detection device for a tank of a vehicle according to claim 10, wherein: The controller is configured to determine a tilt direction of the tank from the angle detection signal, and to add or subtract the height from the liquid level value according to the tilt direction of the tank.

12. The liquid level detection device for a tank of a vehicle according to claim 1, wherein: The controller is configured to perform the correction when a state in which the angle obtained from the angle detection signal corresponds to a predetermined normal area is maintained for a set time and the liquid level value obtained from the liquid level detection signal is a predetermined lower limit value or more.

13. The liquid level detection device for a tank of a vehicle according to claim 1, wherein: The normal area is 0 or greater, and the controller is configured as an area of ​​a predetermined maximum inclination angle or less, and wherein the controller is configured to determine that the angle obtained from the angle detection signal corresponds to the state of the normal area in response to determining that the absolute value of the angle obtained from the angle detection signal is 0 or greater and the maximum inclination angle is or less.

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