JP5946176B2 - Content capacity estimation apparatus and content capacity estimation system having the same - Google Patents

Description

  The present invention is, for example, a liquid such as gasoline, liquefied gas, various chemical liquids, or an internal volume for estimating the internal volume of the liquid or the solid in a container containing a solid such as resin pellets, wood pellets, and crushed glass. The present invention relates to an estimation apparatus and an internal capacity estimation system having the internal capacity estimation apparatus.

  2. Description of the Related Art Conventionally, a fuel remaining amount detecting device as an internal volume estimating device mounted on a vehicle has a liquid level detecting means for detecting a liquid level (that is, a liquid level) of fuel in a fuel tank as a container. This liquid level detection means has a contact that slides on the resistor according to the position of the float that floats on the fuel liquid level, and outputs a voltage obtained by dividing the voltage applied across the resistor to the contact Such a configuration is generally adopted. The fuel remaining amount detecting device detects the remaining amount of fuel as the internal capacity based on the electrical characteristics of the liquid level detecting means, that is, the voltage output from the contact.

  However, in such a fuel remaining amount detection device, since the liquid level in the fuel tank of the vehicle fluctuates when the vehicle tilts or vibrates, the float follows the liquid level fluctuation in the fuel tank. As a result, the height of the float fluctuates, which causes an error in the display of the fuel gauge. In addition, in a vehicle or the like where efficiency of the space in the vehicle is required due to a request for expansion of the passenger compartment space, a fuel tank may be mounted using a gap in the vehicle. There is a problem that the shape of the tank becomes complicated and it is difficult to accurately detect the remaining amount of fuel based on the liquid level. And the technique which solves such a problem is disclosed by patent document 1. FIG.

  The fuel remaining amount measuring device 901 proposed in Patent Document 1 includes a box-shaped tank body 903 as shown in FIG. The inner space of the tank body 903 is partitioned by a soft bag-like body 905 into a fuel storage chamber 907 that stores fuel F and a pressure adjustment chamber 909 that communicates with the atmosphere. Further, the fuel remaining amount measuring device 901 includes a pressurizer assembly 913 that functions to increase the pressure in the pressure adjustment chamber 909 by sending air into the pressure adjustment chamber 909, and the pressure of the air in the pressure adjustment chamber 909. A pressure gauge 915 that outputs a pressure signal according to the control signal, and a control device. The pressurizer assembly 913 includes a cylinder 927 connected to the pressure adjustment chamber 909 via the flow passage 937, and a piston 925 that reciprocates within the cylinder 927.

  The control device of the fuel remaining amount measuring device 901 moves the piston 925 from the upper side to the lower side in the cylinder 927 via the piston rod 923 by the pressurizer actuator, and pushes a predetermined amount of air into the pressure adjustment chamber 909. The pressure gauge 915 measures the pressure in the pressure adjustment chamber 909 before and after the predetermined amount of air is pushed in. At this time, if the volume of the pressure adjustment chamber 909 is small, the pressure change after pushing becomes large, and if the volume of the pressure adjusting chamber is large, the pressure change after pushing is small. Then, the control device determines the volume of the pressure adjustment chamber 909 from Boyle's law based on the amount of air pushed into the pressure adjustment chamber 909 and the pressure in the pressure adjustment chamber 909 before and after the indentation measured by the pressure gauge 915. And the volume of the pressure adjustment chamber 909 is subtracted from the volume of the tank body 903 to detect the volume of the fuel storage chamber 907, that is, the remaining amount of fuel F. As a result, the remaining amount of fuel in the fuel tank could be accurately detected without being affected by fluctuations in the liquid level or the shape of the fuel tank.

  In the fuel remaining amount measuring device 901, the inner space of the tank main body 903 is divided into a fuel storage chamber 907 and a pressure adjustment chamber 909 by a bag-like body 905. For example, liquefied petroleum gas ( When the liquefied gas such as LPG) is used as the fuel F, the remaining amount of the fuel F may not be accurately detected, for example, the fuel F may be vaporized in the bag-like body 905. Therefore, when the liquefied gas is used as the fuel F, as shown in FIG. 9, the fuel F is directly stored in the tank body 903 without the bag-like body 905, and the liquid phase portion is used as the fuel storage chamber 907. The fuel remaining amount measuring device 901A having the pressure-adjusting chamber 909 as the gas phase portion was used.

JP-A-9-280920

  However, in the fuel remaining amount measuring device 901A described above, for example, when the liquefied gas is used as the fuel F, the fuel F is vaporized in the pressure adjusting chamber 909 and the pressure becomes very high (in the case of liquefied petroleum gas, the maximum Therefore, the pressure difference between the pressure in the pressure adjustment chamber 909 and the atmospheric pressure becomes very large. Therefore, a very large force is required to move the piston 925 so as to push the atmosphere into the pressure adjustment chamber 909. However, there is a problem that the apparatus becomes large. In addition, there is a problem in that the manufacturing cost increases due to the need for high pressure measures such as ensuring airtightness between the piston 925 and the cylinder 927 under high pressure.

  Further, the pressure that can be taken by the liquefied gas in the pressure adjustment chamber 909 is wide, and the pressure gauge that can measure such a wide range of pressure generally has low resolution (that is, the smallest unit that can be measured is large). There was a problem that the measurement accuracy of the pressure, that is, the measurement accuracy of the remaining amount of fuel was lowered.

  The present invention aims to solve this problem. That is, an object of the present invention is to provide a small-sized internal volume estimation device capable of accurately estimating the internal volume of a liquid or a solid in a container, and an internal volume estimation system having the same.

  In order to achieve the above object, an invention described in claim 1 is an internal volume estimation device for estimating an internal volume of a liquid or a solid in a container, and includes an airtight cylinder and a reciprocating movement in the airtight cylinder. A first communication that connects and connects one of the two partial spaces defined by the piston in the hermetic cylinder to the gas phase portion or the other partial space of the container. A second communication part that communicates and connects the other partial space to the gas phase part, a flow rate regulation part that regulates the flow rate of gas flowing through the first communication part, and the airtight cylinder and the piston A magnetic member fixed to one of them, a magnetic force generating coil fixed to the other of the airtight cylinder and the piston so as to exert a magnetic force on the magnetic member, and the airtight cylinder Current supply means for supplying an alternating current for generating a magnetic force for reciprocating the piston in the magnetic force generating coil, a resonance frequency detecting means for detecting a resonance frequency between the reciprocating movement of the piston and the alternating current, An internal capacity estimation device comprising internal capacity estimation means for estimating the internal capacity based on the resonance frequency detected by a resonance frequency detection means.

  The invention described in claim 2 is the invention described in claim 1, further comprising a gas phase temperature measuring means for measuring the temperature of the gas phase, wherein the content capacity estimating means is the resonance frequency. And the internal volume is estimated based on the temperature of the gas phase portion.

  In order to achieve the above object, the invention described in claim 3 is the invention described in claim 1 or 2, wherein the content of the container and the liquid or solid in the container is estimated. An internal capacity estimation system comprising: the internal capacity estimation apparatus according to claim 1 or 2, wherein the internal capacity estimation apparatus comprises the internal capacity estimation apparatus according to claim 1 or 2.

  According to the first aspect of the present invention, the space in the airtight cylinder in which the internal space is disconnected (sealed) from the outside is partitioned into two partial spaces by the piston, and one partial space is the first communicating portion. Is connected in communication with the gas phase part or the other partial space, and the other partial space is connected in communication with the gas phase part through the second communication part, so that the pressure difference between these two partial spaces is small. It can be. Thereby, a piston can be moved in an airtight cylinder with a small force.

  In addition, a flow restricting portion for restricting the flow rate of the gas flowing through the first communication portion is provided, and one of the airtight cylinder and the piston is provided with a magnetic member fixed, and the other is provided with a magnetic member. A magnetic force generating coil that applies a magnetic force to the member is provided. Then, the current supply means supplies an alternating current for generating a magnetic force for reciprocating the piston in the hermetic cylinder to the magnetic force generating coil, and the resonance frequency detecting means detects a resonance frequency between the reciprocating movement of the piston and the alternating current. . Then, the internal volume estimation means estimates the internal volume of the solid or liquid in the container based on the resonance frequency of the reciprocating movement of the piston and the alternating current.

  That is, when the piston is reciprocated in the hermetic cylinder by the magnetic force generated by supplying an alternating current to the magnetic force generating coil, the magnetic force is generated by the alternating current supplied to the magnetic force generating coil and the piston is moved in one direction. Then, the gas tries to move between the two partial spaces through the communication part, but the flow rate is regulated, so that the pressure in one partial space changes and becomes higher than the other partial space. Is changed, the piston is moved in the other direction by the pressure in the one partial space and the magnetic force of the magnetic force generating coil, and the pressure in the other partial space is changed to be higher than the one partial space. Thereafter, by repeating this state, the piston is reciprocated (that is, vibrated). In this state, the piston receives the magnetic force of the magnetic force generating coil and the pressure of each partial space. When the fluctuation state of the magnetic force coincides with the fluctuation state of the pressure, the vibration frequency of the piston and the frequency of the alternating current are obtained. And coincide with each other to enter a resonance state.

  Further, when the gas in the hermetic cylinder is pushed into the gas phase part of the container (that is, two partial spaces communicated with the gas phase part) by the movement of the piston, the smaller the gas phase part volume, the more the gas The higher the pressure in the gas phase part, the higher the pressure in the gas phase part, the greater the repulsive force against the movement of the piston, and the greater the repulsive force against the movement of the piston, the smaller the amplitude of the piston and the vibration of the piston. The frequency to perform becomes high. That is, the piston is in a resonance state at a higher frequency as the gas phase portion volume is smaller.

  From this, the frequency of the alternating current in the resonance state becomes a value corresponding to the pressure change in the gas phase portion of the container accompanying the movement of the piston. That is, since the frequency at which the resonance state occurs depends on the gas phase volume, the internal volume of the solid or liquid in the container is estimated using this resonance frequency.

  According to the second aspect of the present invention, the apparatus further includes a gas phase temperature measuring means for measuring the temperature of the gas phase inside the container, and the content capacity estimating means is a resonance between the reciprocating movement of the piston and the alternating current. Based on the frequency and the temperature of the gas phase, the internal volume of the solid or liquid in the container is estimated.

  According to the invention described in claim 3, the internal capacity estimation device is configured by the internal capacity estimation device according to claim 1 or 2.

  As described above, according to the first aspect of the present invention, when the piston is reciprocated by the magnetic force generated by supplying the alternating current to the magnetic force generating coil, the two partial spaces defined by the piston in the airtight cylinder are obtained. Therefore, the piston can be moved with a small force, and the apparatus can be downsized. Moreover, since the internal volume of the solid or liquid in the container is estimated using the resonance frequency of the reciprocating movement of the piston and the alternating current, an ammeter or the like for detecting the resonance frequency compared to the configuration using the pressure gauge Measurement with a high resolution is possible with a simple configuration using, and the internal capacity can be estimated with high accuracy.

  According to the invention described in claim 2, since the internal volume of the solid or liquid in the container is estimated based on the resonance frequency between the reciprocating movement of the piston and the alternating current and the temperature of the gas phase, The pressure in the gas phase part changes due to the temperature change in the phase part, but by using the temperature in the gas phase part, the internal capacity can be estimated in consideration of the pressure change in the gas phase part. It can be estimated more accurately.

  According to the invention described in claim 3, since the internal capacity estimation device described in claim 1 or 2 is provided, the system can be reduced in size by reducing the size of the device, and the contents The quantity can be estimated accurately.

It is a schematic block diagram of the vehicle fuel system which is one Embodiment of the internal capacity estimation system of this invention. It is a schematic block diagram of the control part of the liquid quantity estimation apparatus which the vehicle fuel system of FIG. 1 has. It is a figure explaining an example of the gaseous-phase part volume relationship information stored in the memory of the control part of FIG. It is a figure which shows the relationship between the frequency of the supplied alternating current, and the electric current amount in the electromagnetic coil of the liquid quantity estimation apparatus which the vehicle fuel system of FIG. 1 has. It is a flowchart which shows an example of the process (internal capacity estimation process) based on this invention which CPU of the control part of FIG. 2 performs. It is a figure which shows a part of structure of the 1st modification of the vehicle fuel system of FIG. It is a figure which shows the structure of the 2nd modification of the vehicle fuel system of FIG. It is a figure which shows the conventional fuel residual amount detection apparatus. It is a figure which shows the other conventional fuel remaining amount detection apparatus.

  Hereinafter, a vehicle fuel system which is an embodiment of the internal capacity estimation system of the present invention will be described with reference to FIGS.

  A vehicle fuel system described below includes a fuel tank that is mounted on a vehicle and stores liquefied petroleum gas (LPG) as fuel F of the vehicle, and a liquid amount (internal capacity) of the fuel F in the fuel tank. Is a system for estimating

  In the fuel tank containing liquefied gas such as LPG as the fuel F, the pressure changes from about 0.1 MPa to 3 MPa depending on the ambient temperature. It is difficult to ensure the driving force to push the gas against the pressure, and furthermore, the pressure range that the vaporized fuel gas can take is wide, and it can not be measured with sufficient resolution in the measurement with the pressure gauge, Therefore, it was unsuitable for use in vehicles using liquefied gas as fuel. And the vehicle fuel system of this invention demonstrated below solves such a subject and is suitable for the vehicle which used liquefied gas as fuel.

  As shown in FIG. 1, a vehicle fuel system (indicated by reference numeral 1 in the drawing) includes a fuel tank 10 as a container and a liquid amount as an internal volume estimation device that estimates the liquid amount of fuel F in the fuel tank 10. And an estimation device 6.

  The fuel tank 10 is, for example, a well-known vehicle component that is disposed under the floor of a vehicle and accommodates the fuel F of the vehicle. In the present embodiment, the fuel tank 10 is formed in a rectangular parallelepiped box shape with a volume of 100 L. ing.

  The upper wall 10a of the fuel tank 10 is connected to a fuel filling port of a vehicle (not shown), and an inflow pipe 11 for allowing the fuel F supplied from a fuel supply stand or the like to flow into the fuel tank 10, and the inflow pipe And an inflow valve 12 composed of an electromagnetic valve that opens and closes 11. The lower end of the side wall 10b of the fuel tank is connected to an injection device or the like for supplying the fuel F to an internal combustion engine (not shown), and the outflow pipe 13 for allowing the fuel F in the fuel tank 10 to flow out toward the injection device or the like. And an outflow valve 14 configured by an electromagnetic valve for opening and closing the outflow pipe 13.

  In the fuel tank 10, there are a gas phase portion 17 made of vaporized fuel F and the like, and a liquid phase portion 18 made of liquid fuel F. In the fuel tank 10, only the gas phase portion 17 exists when the fuel F is empty, and a slight space is provided even when the fuel F is full, that is, the gas phase portion 17 exists.

  The liquid amount estimation device 6 includes an airtight cylinder 20, a first pipe 28 as a first communication part, a second pipe 29 as a second communication part, an orifice 27 as a flow rate control part, a piston 30, and a magnetic A magnet 35 as a member, an electromagnetic coil 41 as a magnetic force generating coil, a coil power source unit 42 as a current supply unit, an ammeter 43 as a current amount measuring unit, and a temperature sensor 51 as a gas phase temperature measuring unit And a control unit 60.

  As shown in FIG. 1, the airtight cylinder 20 is disposed close to the fuel tank 10. In this embodiment, the airtight cylinder 20 has high corrosion resistance such as stainless steel and can withstand the pressure of the fuel F. Using a metal material that can be used, both ends are formed in a cylindrical shape closed by the upper wall portion 20a and the lower wall portion 20b. Thereby, as for the airtight cylinder 20, inner space is interrupted (sealed) from the exterior. Moreover, in this embodiment, the volume of the airtight cylinder 20 is 2L. On the inner surfaces of the upper wall portion 20a and the lower wall portion 20b of the hermetic cylinder 20, stoppers 21 and 22 for restricting the movement range of the piston 30 described later are provided.

  In addition, the airtight cylinder 20 is provided with a columnar guide pillar 25 provided coaxially with the airtight cylinder 20 between the upper wall portion 20a and the lower wall portion 20b. The guide column 25 guides the moving direction of the piston 30 so that the piston 30 moves in the axial direction (vertical direction in the drawing) of the hermetic cylinder 20. A pair of springs 26 that assist the movement of the piston 30 are provided at both ends of the guide column 25. The hermetic cylinder 20 is connected to the fuel tank 10 by a first pipe 28 and a second pipe 29.

  The first pipe 28 has one end 28 a connected to the upper end of the side wall 10 b of the fuel tank 10 and the other end 28 b connected to the upper wall portion 20 a of the airtight cylinder 20. That is, the first pipe 28 communicates and connects a first partial space, which will be described later, on the upper wall portion 20 a side of the hermetic cylinder 20 to the gas phase portion 17. The first pipe 28 is provided with an orifice 27 that regulates the flow rate of the gas flowing through the first pipe 28. Instead of providing the orifice 27, a part or the whole of the first pipe 28 may be formed with a small diameter so that the flow rate is regulated by the first pipe 28 itself.

  The second pipe 29 has one end 29 a connected to one end 28 a of the first pipe 28 and the other end 29 b connected to the lower wall portion 20 b of the airtight cylinder 20. That is, the second pipe 29 connects a second partial space, which will be described later, on the lower wall portion 20b side of the hermetic cylinder 20 to communicate with the gas phase portion 17 via one end 28a of the first pipe 28a. .

  That is, the airtight cylinder 20 is connected to the upper part of the fuel tank 10, that is, the gas phase part 17 in the fuel tank 10 through the first pipe 28 and the second pipe 29. Thereby, the airtight cylinder 20 is filled with the same gas as the gas phase portion 17.

  The piston 30 is made of, for example, a metal having high corrosion resistance such as stainless steel, and includes a piston main body portion 31 and a pair of flange portions 32a and 32b formed integrally therewith.

  The piston body 31 is formed in a cylindrical shape having a smaller diameter than the airtight cylinder 20. A pair of flange portions 32 a and 32 b having a diameter slightly smaller than the diameter of the cross-sectional shape in the internal space of the airtight cylinder 20 are provided at both ends of the piston main body 31. The piston main body 31 is provided with a through hole having substantially the same diameter as the guide column 25 along the axis, and the guide column 25 is inserted into the through hole. Thereby, the piston main body 31 is accommodated in the airtight cylinder 20 coaxially with the airtight cylinder 20, and the flange portions 32a and 32b are arranged in parallel to the upper wall portion 20a and the lower wall portion 20b of the airtight cylinder 20. ing. A slight gap is provided between the outer edges of the flange portions 32 a and 32 b and the inner surface of the peripheral wall 20 c of the airtight cylinder 20 to avoid mutual contact. The piston main body 31 is accommodated in the airtight cylinder 20 so as to be capable of reciprocating in the axial direction (vertical direction in FIG. 1).

  The piston 30 divides the internal space in the airtight cylinder 20 into two partial spaces. One of these two partial spaces is a first partial space 23 arranged on the upper wall portion 20a side of the hermetic cylinder 20, and the other is a second portion arranged on the lower wall portion 20b side of the hermetic cylinder 20. Space 24. The first partial space 23 and the second partial space 24 communicate with each other through the first pipe 28 and the second pipe 29 described above.

  That is, since the first partial space 23 and the second partial space 24 are in communication with each other, there is a pressure difference (atmospheric pressure difference) between the first partial space 23 and the second partial space 24. However, the gas moves between the first partial space 23 and the second partial space 24 over time, and the pressure difference disappears or becomes smaller.

  The magnet 35 is formed in an annular shape (cylindrical shape) whose outer diameter is the same as or smaller than the diameter of the pair of flange portions 32 a and 32 b and whose inner diameter is substantially the same as the outer diameter of the piston body portion 31. The magnet 35 is fixedly attached to the piston 30 in a state where the piston main body 31 is inserted through the magnet 35 and is sandwiched between the pair of flange portions 32a and 32b. Thereby, the piston 30 moves with the movement of the magnet 35.

  The electromagnetic coil 41 is formed in a substantially cylindrical shape, and is provided on the outer surface of the peripheral wall 20 c of the hermetic cylinder 20 so as to be coaxial with the hermetic cylinder 20. The electromagnetic coil 41 is disposed so as to exert a magnetic force on the magnet 35 provided on the piston 30 when a current is supplied from a coil power source 42 described later.

  The coil power supply unit 42 is a known AC power supply device that can output AC power (that is, AC current) such as an arbitrary waveform, frequency, voltage, and the like, and sine is supplied to the electromagnetic coil 41 via an ammeter 43 described later. It is connected so that a wave alternating current can be supplied. Note that the alternating current supplied by the coil power supply unit 42 may be a rectangular wave alternating current. The coil power supply unit 42 is electrically connected to a control unit 60 described later, and supplies a current having a frequency corresponding to a control signal from the control unit 60 to the electromagnetic coil 41.

  When an alternating current is supplied by the coil power supply unit 42, the electromagnetic coil 41 causes the magnet 35 (that is, the piston 30) to move toward the upper wall portion 20a according to the direction of the alternating current and to the lower wall portion 20b. A magnetic force that reciprocates toward the approaching direction is generated. When the piston 30 is moved in the direction approaching the upper wall portion 20a by this magnetic force, the first partial space 23 becomes smaller, and the gas in the first partial space 23 will move to the gas phase portion 17 through the first pipe 28. However, the movement is restricted by the orifice 27, and the pressure in the first partial space 23 is increased. Further, when the piston 30 is moved in a direction approaching the lower wall portion 20b, the second partial space 24 becomes smaller, and the gas in the second partial space 24 (that is, the airtight cylinder 20) is pushed into the gas phase portion 17. Thus, the pressure in the gas phase portion 17 is increased.

  The ammeter 43 is a known alternating current ammeter and is provided between the coil power supply unit 42 and the electromagnetic coil 41, and the amount of current (for example, effective) supplied from the coil power supply unit 42 to the electromagnetic coil 41. Value). The ammeter 43 is electrically connected to a control unit 60 described later, and outputs an electrical signal corresponding to the measured current amount to the control unit 60.

  The temperature sensor 51 is composed of, for example, a thermistor or a thermocouple, and is provided on the upper wall 10a of the fuel tank 10, and measures the temperature of the gas phase portion 17. The temperature sensor 51 is electrically connected to a control unit 60 described later, and outputs an electrical signal corresponding to the measured temperature of the gas phase unit 17 to the control unit 60.

  As shown in FIG. 2, the control unit 60 includes a microcomputer 61 for a known embedded device. The microcomputer 61 includes a central processing unit (CPU) 62 and a ROM (Read Only Memory). 63, a RAM (Random Access Memory) 64, and a memory 65.

  The CPU 62 controls various controls in the vehicle fuel system 1 and executes various processes including control according to the present embodiment in accordance with various control programs stored in the ROM 63.

  The ROM 63 stores various information such as the control program and parameters referred to by the control program. In particular, the ROM 63 stores a control program for causing the CPU 62 to function as various means such as frequency changing means and internal capacity estimating means. And CPU62 functions as various means mentioned above by running this control program. The RAM 64 appropriately stores data, programs, and the like necessary for the CPU 62 to execute various processes.

  The memory 65 is composed of a nonvolatile memory that can retain data even when the power is cut off, such as an EEPROM (Electrically Erasable Programmable ROM) or a flash memory. The memory 65 stores various types of information such as mathematical formulas and parameters used in the internal capacity estimation process described later (volume VT of the fuel tank 10 and the like).

  Further, as shown in an example in FIG. 3, an alternating current is supplied to the electromagnetic coil 41 to the memory 65 included in the microcomputer 61 of the control unit 60 for each temperature of the gas phase unit 17 (gas phase temperature T1). Thus, gas phase volume relationship information J1 indicating the relationship between the resonance frequency fs when the piston 30 is reciprocated (vibrated) in the hermetic cylinder 20 and the gas phase volume VA is stored.

  Here, the vapor phase volume related information J1 will be described.

  When the piston 30 is reciprocated in the hermetic cylinder 20 by the magnetic force generated by supplying an alternating current to the electromagnetic coil 41, the magnetic force is generated by the alternating current supplied to the electromagnetic coil 41 and the piston 30 moves in one direction. Then, the gas tries to move between the two partial spaces (the first partial space 23 and the second partial space 24) through the first pipe 28 and the second pipe 29, but the flow rate of the gas flowing through the pipe through the orifice 27 Therefore, if the pressure in one partial space is changed to be higher than that in the other partial space and the direction of the alternating current is changed, the pressure of the one partial space and the magnetic force of the electromagnetic coil 41 change the piston 30. Is moved in the other direction, the pressure in the other partial space changes and becomes higher than the one partial space. Thereafter, by repeating this state, the piston 30 is reciprocated (that is, vibrated). In this state, the piston 30 receives the magnetic force of the electromagnetic coil 41 and the pressure of each partial space. When the fluctuation state of the magnetic force coincides with the fluctuation state of the pressure, the vibration frequency and the alternating current of the piston 30 are changed. The frequency of the frequency coincides with that of the resonance state.

  In other words, the first partial space 23 (referred to as “space A”) exists on the flange portion 32 a side of the piston 30, and the second partial space 24 and the gas phase portion 17 exist on the flange portion 32 b side of the piston 30. (Referred to as “space B”), and these space A and space B are partitioned by the orifice 27, so that the movement of the gas accompanying the movement of the piston 30 can be regarded as independent spaces. Therefore, as the piston reciprocates, the gas in the space A and the gas in the space B are alternately compressed and function like a spring. And when an alternating current becomes a specific frequency, the elastic force by the space A and the space B is combined with the magnetic force of the electromagnetic coil 41, and a resonance state in which the piston 30 reciprocates with high efficiency occurs. And if the magnitude | size of the gaseous-phase part 17 changes, since the magnitude | size of the space B will change and the elastic force of the space B will change, the frequency which the said resonance state produces will change.

  Further, when the gas in the hermetic cylinder 20 is pushed into the gas phase portion 17 (that is, two partial spaces communicated with the gas phase portion) by the movement of the piston 30, the smaller the gas phase portion volume VA is, the smaller the gas phase portion volume VA is. The pressure of the gas phase portion 17 after the gas is pushed in becomes higher. The higher the pressure of the gas phase portion 17, the larger the repulsive force (elastic force) with respect to the movement of the piston 30, and the larger the repulsive force with respect to the movement of the piston 30. The amplitude of the piston 30 is reduced and the frequency at which the piston 30 vibrates is increased. That is, the piston 30 is in a resonance state at a higher frequency as the gas phase portion volume VA is smaller. In this resonance state, as shown in FIG. 4, the piston moving load in the electromagnetic coil 41 is reduced, and the amount of current I supplied to the electromagnetic coil 41 is minimized.

  From this, by supplying an alternating current to the electromagnetic coil 41 and measuring the current amount I while sweeping the frequency f, the frequency at which the current amount I is minimized can be obtained as the resonance frequency fs. fs is a value corresponding to the pressure change of the gas phase portion 17 accompanying the movement of the piston 30. That is, since the frequency fs at which the resonance state occurs depends on the gas phase volume VA, the gas phase volume VA has a relationship with the resonance frequency fs.

  Further, since the pressure of the gas phase portion 17 changes according to the temperature of the gas phase portion 17, the resonance frequency fs also changes according to the temperature of the gas phase portion 17 (gas phase temperature T1). That is, the gas phase volume VA has a relationship with the gas phase temperature T1.

  The gas phase volume relation information J1 is a data table or function obtained by preliminary measurement or simulation. In this embodiment, the gas phase volume information J1 is schematically shown in FIG. For each gas phase temperature T1 (for example, every 1.0 ° C., in FIG. 3, as an example, the case of T1 = 20 ° C. and 25 ° C. is shown) The information indicating the relationship is included. Note that the gas phase volume relationship information J1 shown in FIG. 3 is an example, and is appropriately set according to the system in consideration of various characteristics of the piston 30, the spring 26, the gas in the cylinder 30, and the like.

  Further, the microcomputer 61 includes an interface unit (not shown). This interface unit connects the coil power source unit 42, the ammeter 43, the temperature sensor 51, and the CPU 62, and allows various signals to be transmitted and received among them.

  Although not shown, the interface unit further connects the above-described inflow valve 12 and outflow valve 14 to the CPU 62. For example, the CPU 62 performs an inflow pipe during execution of the internal capacity estimation process described later. 11 and the outflow pipe 13 are controlled so that the pressure in the fuel tank 10 is not leaked by controlling the inflow valve 12 and the outflow valve 14 as necessary. Then, the inflow pipe 11 and the outflow pipe 13 are opened and closed. The interface unit further connects a fuel gauge (not shown) provided in the vehicle and the CPU 62, and the CPU 62 displays the estimated amount of fuel F on the fuel gauge.

  Next, an example of processing (internal capacity estimation processing) according to the present invention executed by the CPU 62 described above will be described with reference to the flowchart shown in FIG.

  When the ignition switch of the vehicle is turned on, power is supplied to the vehicle fuel system 1 and the CPU 62 of the control unit 60 starts to operate, and the CPU 62 executes a predetermined initialization process. Then, after the initialization process is completed, the CPU 62 proceeds to step S110 shown in the flowchart of FIG. 5 at a predetermined timing such as a fixed period.

  In step S110, based on the electric signal output from the temperature sensor 51, the temperature of the gas phase part 17 (gas phase temperature T1) measured by the temperature sensor 51 is acquired. Then, the process proceeds to step S120.

  In step S <b> 120, a control signal for reciprocating the piston 30 in the airtight cylinder 20 is sent to the coil power supply unit 42. The coil power supply unit 42 supplies an alternating current having a predetermined start frequency (for example, 10 Hz) to the electromagnetic coil 41 according to the received control signal. When the current is supplied from the coil power source 42, the electromagnetic coil 41 generates a magnetic force that causes the piston 30 to reciprocate. The coil power supply unit 42 supplies an alternating current to the electromagnetic coil 41 by applying an alternating voltage having a constant amplitude to the electromagnetic coil 41 in the internal capacity estimation process. The piston 30 reciprocates in the hermetic cylinder 20 by the magnetic force generated by the electromagnetic coil 41.

  In step S130, it is determined whether or not the frequency of the alternating current supplied to the electromagnetic coil 41 has reached a predetermined end frequency (for example, 1200 Hz). If the end frequency has been reached, the frequency sweep ends. As a result, the process proceeds to step S160 (Y in S130). If the end frequency has not been reached, the process proceeds to step S140 (N in S130) assuming that the frequency sweep is in progress.

  In step S140, the current amount I (effective value) measured by the ammeter is acquired based on the electrical signal output from the ammeter 43, and is sequentially stored in the RAM 64 in association with the current frequency f of the alternating current. To do. Then, the process proceeds to step S150.

  In step S150, a control signal for increasing the frequency of the alternating current supplied to the electromagnetic coil 41 by a predetermined width is sent to the coil power supply unit. The coil power supply unit 42 supplies an alternating current having a frequency obtained by multiplying the current frequency by a predetermined magnification (for example, 1.05 times) to the electromagnetic coil 41 in accordance with the received control signal. Thereby, the frequency f of the alternating current supplied to the electromagnetic coil 41 gradually changes from a low frequency to a high frequency. Then, the process returns to step S130.

  In step S160, the resonance frequency fs of the piston 30 is detected. Specifically, the current value I stored in the RAM 64 is searched for the minimum value, and the frequency f associated with the minimum current value I is detected as the resonance frequency fs. Then, the process proceeds to step S170.

  In step S170, based on the resonance frequency fs detected in step S160 and the temperature of the gas phase portion 17 measured in step S110, the volume (gas volume) of the portion corresponding to the gas phase portion 17 in the volume VT of the fuel tank 10 is determined. Phase volume VA). Specifically, by applying the resonance frequency fs to the graph showing the relationship between the resonance frequency fs specified by the gas phase temperature T1 in the gas phase volume relationship information J1 and the gas phase volume VA, the gas phase The volume VA is acquired.

  An example of obtaining the gas phase volume VA is as follows. When the gas phase temperature T1 is 20.0 ° C. and the resonance frequency fs is 150 Hz, T1 = 20.0 ° C. from the gas phase volume information J1 in FIG. A graph showing the relationship between the resonance frequency fs and the gas phase volume VA at this time is specified, and the resonance frequency fs = 150 Hz is applied to this graph to obtain the gas phase volume VA = 25L. Then, the process proceeds to step S180.

  In step S180, the gas phase volume VA calculated in step S170 is subtracted from the volume VT in the fuel tank 10 stored in the memory 65, thereby corresponding to the liquid phase portion 18 in the volume VT of the fuel tank 10. The volume VL (hereinafter referred to as the liquid phase volume VL) of the portion to be calculated is calculated. This liquid phase portion volume VL is the liquid amount VL of the fuel F in the fuel tank 10. Then, a signal for displaying the liquid amount VL is sent to a fuel gauge (not shown) mounted on the vehicle. And the process of this flowchart is complete | finished.

  Step S160 described above corresponds to the resonance frequency detection means in the claims, and steps S170 and S180 correspond to the content capacity estimation means in the claims.

  Next, an operation example according to the present invention in the above-described vehicle fuel system 1 will be described.

  When the ignition switch of the vehicle is turned on, the vehicle fuel system 1 starts operation and estimates the liquid amount VL of the fuel F in the fuel tank 10 periodically (for example, every minute).

  In the estimation of the liquid volume VL, first, after measuring the temperature of the gas phase portion 17 (gas phase temperature T1), an alternating current having a predetermined start frequency is supplied to the electromagnetic coil 41, and the frequency f of the alternating current is determined. Is gradually increased to a predetermined end frequency, and at the same time, the amount of current I supplied to the electromagnetic coil 41 is measured and stored in the RAM 64 in association with the frequency (N in S120, S130, S140, S150).

  Then, after the frequency f of the alternating current reaches the above end frequency (Y in S130), the minimum amount of the current amount I stored in the RAM 64 is detected and associated with the minimum amount of current I. The frequency is detected as the resonance frequency fs (S160).

  A graph indicating the relationship between the resonance frequency fs at the gas phase temperature T1 and the gas phase volume VA is selected from the plurality of gas phase volume relationship information J1 stored in the memory 65, and the resonance frequency fs is selected in this graph. To obtain the gas phase volume VA (S170). Then, the liquid phase part volume VL is calculated by subtracting the gas phase part volume VA from the volume VT of the fuel tank 10, and this liquid phase part volume VL is set as the liquid amount VL of the fuel F in the fuel tank 10. Displayed on the fuel gauge (S180).

  Next, an estimation example of the liquid amount VL of the fuel F in the fuel tank 10 in the vehicle fuel system 1 will be shown.

  It is assumed that the volume VT of the fuel tank 10 is 100 L, and the gas phase temperature T1 is 25.0 ° C. and the resonance frequency fs = 30 Hz in the above-described internal volume estimation process.

At this time, a graph of T1 = 25.0 ° C. is selected from the gas phase volume related information J1 shown in FIG. When the resonance frequency fs = 30 Hz is applied to the selected graph, the gas phase volume VA is acquired as 70L. When this gas phase volume VA is subtracted from the volume VT of the fuel tank 10, the liquid phase volume VL, that is, the liquid amount VL of the fuel F in the fuel tank 10 is
VL = 100-70 = 30L
It becomes. In this way, the liquid amount VL of the fuel F in the fuel tank 10 is estimated.

  The vehicle fuel system 1 according to this embodiment includes a fuel tank 10 and a liquid amount estimation device 6 that estimates a liquid amount VL of fuel F in the fuel tank 10. The liquid amount estimation device 6 includes a hermetic cylinder 20, a piston 30 that can be reciprocated in the hermetic cylinder 20, and a first part of one of two partial spaces defined by the piston 30 in the hermetic cylinder 20. A first pipe 28 connecting the space 23 to the gas phase part 17 and connecting it, a second pipe 29 connecting the other second partial space to the gas phase part 17 and connecting it, and a gas flowing through the first pipe 28 An orifice 27 for regulating the flow rate, a magnet 35 fixed to the piston 30, an electromagnetic coil 41 fixed to the hermetic cylinder 20 so as to exert a magnetic force on the magnet 35, and a piston in the hermetic cylinder 20 A coil power supply unit 42 that supplies an alternating current that generates a magnetic force that reciprocates 30 to the electromagnetic coil 41, and a temperature sensor that measures the temperature of the gas phase unit 17 (gas phase temperature T1). 51, a CPU 62 as a resonance frequency detecting means for detecting the resonance frequency fs of the reciprocating movement of the piston 30 and the alternating current, the resonance frequency fs detected by the CPU 62, and the gas phase temperature measured by the temperature sensor 51 And a CPU 62 as an internal volume estimating means for measuring the liquid amount VL of the fuel tank 10 based on T1.

  In the present embodiment, the space in the airtight cylinder 20 in which the internal space is cut off (sealed) from the outside is divided into two first partial spaces 23 and second partial spaces 24 by the piston, and one first partial space. 23 is connected in communication with the gas phase part 17 by the first pipe 28, and the other second partial space 24 is connected in communication with the gas phase part 17 by the second pipe 29. The pressure difference can be made small. Thereby, a piston can be moved in an airtight cylinder with a small force.

  In addition, an orifice 27 that regulates the flow rate of the gas flowing through the first pipe 28 is provided. A magnet 35 is fixed to the piston 30. A magnetic force is exerted on the magnet 35 in the airtight cylinder 20. An electromagnetic coil 41 is provided. The coil power source 42 supplies an alternating current that generates a magnetic force for reciprocating the piston 30 in the hermetic cylinder 20 to the electromagnetic coil 41, and the CPU 62 sets a resonance frequency fs between the reciprocating movement of the piston 30 and the alternating current. To detect. Then, the CPU 62 estimates the liquid amount VL of the fuel tank 10 based on the resonance frequency fs between the reciprocating movement of the piston 30 and the alternating current.

  That is, when the piston 30 is reciprocated in the hermetic cylinder 20 by the magnetic force generated by supplying an alternating current to the electromagnetic coil 41, the magnetic force is generated by the alternating current supplied to the electromagnetic coil 41 and the piston 30 moves in one direction. Is moved between the first partial space 23 and the second partial space 24 through the first pipe 28 and the second pipe 29, but the flow rate is restricted, so that the flow of one partial space is restricted. When the pressure changes and becomes higher than the other partial space, and the direction of the alternating current changes, the piston 30 is moved in the other direction by the pressure in the one partial space and the magnetic force of the electromagnetic coil 41, and the other portion. The pressure in the space changes and becomes higher than the one partial space. Thereafter, by repeating this state, the piston 30 is reciprocated (that is, vibrated). In this state, the piston 30 receives the magnetic force of the electromagnetic coil 41 and the pressure of each partial space. When the fluctuation state of the magnetic force coincides with the fluctuation state of the pressure, the vibration frequency and the alternating current of the piston 30 are changed. The frequency of the frequency coincides with that of the resonance state.

  When the gas in the hermetic cylinder 20 is pushed into the gas phase portion 17 (that is, the first partial space 23 and the second partial space 24 communicated with the gas phase portion 17) by the movement of the piston 30, the gas phase The smaller the volume VA, the higher the pressure of the gas phase portion 17 after the gas is pushed in, and the higher the pressure of the gas phase portion 17, the greater the repulsive force (elastic force) against the movement of the piston 30 and the movement of the piston 30. The greater the repulsive force against, the smaller the amplitude of the piston 30 and the higher the frequency at which the piston 30 vibrates. That is, the piston 30 is in a resonance state at a higher frequency as the gas phase portion volume VA is smaller.

  From this, the frequency of the alternating current in a resonance state becomes a value corresponding to the pressure change of the gas phase portion 17 accompanying the movement of the piston 30. That is, since the frequency at which the resonance state occurs depends on the gas phase volume VA, the liquid volume VL in the fuel tank 10 is estimated using this resonance frequency fs.

  Further, the fuel tank 10 further includes a temperature sensor 51 for measuring the temperature of the gas phase portion 17 (gas phase temperature T1) of the fuel tank 10, and the CPU 62 has a resonance frequency fs between the reciprocating movement of the piston 30 and the alternating current, Based on the phase temperature T1, the liquid amount VL of the fuel tank 10 is estimated.

  As described above, according to the present embodiment, when the piston 30 is reciprocated by the magnetic force generated by supplying an alternating current to the electromagnetic coil 41, the first partial space 23 partitioned by the piston 30 in the airtight cylinder 20 is provided. Since the pressure difference in the second partial space 24 can be reduced, the piston 30 can be moved with a small force, and thus the apparatus can be miniaturized. Further, since the liquid amount VL of the fuel tank 10 is estimated using the resonance frequency fs between the reciprocating movement of the piston 30 and the alternating current, the configuration is simpler using an ammeter or the like than the configuration using the pressure gauge. Measurement with high resolution is possible, and the liquid volume VL can be estimated accurately.

  Further, since the liquid amount VL of the fuel tank 10 is estimated based on the resonance frequency fs between the reciprocating movement of the piston 30 and the alternating current and the gas phase temperature T1, the gas phase is changed by the temperature change of the gas phase portion 17. Although the pressure of the portion 17 changes, the liquid volume VL can be estimated in consideration of the pressure change of the gas phase section 17 by using the gas phase temperature T1, and therefore the liquid volume VL can be estimated more accurately. .

  Further, since the vehicle fuel system 1 includes the liquid amount estimation device 6 described above, the system can be reduced in size by reducing the size of the device, and the liquid amount VL can be accurately estimated.

  In the embodiment described above, the liquid volume VL of the fuel tank 10 is estimated using the gas phase temperature T1 in addition to the resonance frequency fs. However, the present invention is not limited to this.

  For example, in an environment where the gas phase temperature T1 does not change, the above-described temperature sensor 51 is not provided. Then, the vapor phase volume relationship information J1 is created assuming that the vapor phase temperature T1 is constant. In this case, the vapor phase volume relationship information J1 includes only one graph in FIG. In the flowchart of FIG. 5, step S110 is omitted, and the gas phase volume VA is acquired using only the resonance frequency fs in step S170. With such a configuration, the liquid amount VL of the fuel tank 10 can be estimated more easily.

  In the above-described embodiment, the electromagnetic coil 41 is provided on the peripheral wall 20c of the hermetic cylinder 20. However, the present invention is not limited to this. For example, the electromagnetic coil is an upper wall portion 20a of the hermetic cylinder 20. As long as it is provided so as to exert a magnetic force on the magnet 35 provided on the piston 30 such as a configuration in which the airtight cylinder 20 and the axis are parallel to each other on the inner surface of the lower wall portion 20b and the inner surface of the lower wall portion 20b, Unless it is contrary to the purpose, the arrangement and configuration are arbitrary.

  In the above-described embodiment, the magnet 35 as the magnetic member is provided in the piston 30 and the electromagnetic coil 41 as the magnetic force generating coil is provided in the airtight cylinder 20. However, the present invention is not limited to this. For example, the magnet 35 is provided coaxially with the hermetic cylinder 20 so that the inner peripheral surface thereof overlaps the outer surface of the peripheral wall 20 c of the hermetic cylinder 20, and the electromagnetic coil 41 is disposed on the outer peripheral surface of the piston main body 31. The magnet 35 and the electromagnetic coil 41 may be arranged arbitrarily as long as the main body 31 is fixed coaxially with the main body 31 and is not contrary to the object of the present invention.

  Moreover, although the magnet 35 was provided in the piston 30 as a magnetic member, it is not limited to this, For example, it replaces with a magnet and magnetic force of the electromagnetic coil 41 is attached, such as attaching ferromagnetics, such as iron. As long as it is a magnetic member covered by, the configuration is arbitrary as long as it does not contradict the object of the present invention.

  In the above-described embodiment, the guide column 25 that guides the movement of the piston 30 is provided in the airtight cylinder 20. However, for example, the outer diameter of the piston 30 and the inner diameter of the cylinder 20 are substantially the same, and the piston 30 If it is configured to be movable in the axial direction without moving in the radial direction, the guide pillar 25 may be omitted. Of course, in this case, it is necessary to close the through hole through which the guide column 25 of the main body of the piston 30 is inserted.

  Moreover, although it was the structure provided with the 1st piping 28 as a 1st communication part in embodiment mentioned above, it is not limited to this. For example, as shown in FIG. 6, the first piping 28 and the orifice 27 are removed in the configuration of the fuel system 1 and the space between the inner surface of the peripheral wall 20c of the hermetic cylinder 20 and the piston 30 (that is, the flange portions 32a and 32b). A vehicle fuel system having a configuration in which a gap 20d is provided in the cylinder 20 and the size of the gap 20d is set so that gas movement similar to the configuration of the first pipe 28 and the orifice 27 occurs as the piston 30 reciprocates. It may be 1A. In this case, the inner surface of the peripheral wall 20c of the airtight cylinder 20 and the piston 30 correspond to the first communication portion and the flow rate restriction portion.

  In the above-described embodiment, the fuel tank 10 is formed in a rectangular parallelepiped box shape. However, the present invention is not limited to this. For example, a vehicle fuel system 1B shown in FIG. Instead of the fuel tank 10 described above, a fuel tank 10A including a first tank portion 101 and a second tank portion 102 may be used. The first tank portion 101 and the second tank portion 102 have a gas phase portion 17 and a liquid phase portion 18, respectively. The gas phase portions 17 are connected to each other by a conduit 103, and the liquid phase portions 18 are connected to each other by a conduit 104. Is connected. According to the present invention, even when the fuel tank 10A having such a complicated shape is used, the liquid amount VL of the fuel F in the fuel tank 10A can be accurately estimated.

  Moreover, although embodiment mentioned above demonstrated the vehicle fuel system which mounts in a vehicle and accommodates liquefied gas and estimates the liquid quantity, it is not limited to this. For example, it may be a liquid amount estimation system that is installed in a factory or home and that contains kerosene, gasoline, various chemicals, and the like and estimates the amount of the liquid. The apparatus and system to apply are arbitrary. Also, the liquid whose liquid quantity is to be estimated is not limited to liquefied petroleum gas, but for example, liquefied gas for industrial use such as liquid nitrogen, liquid oxygen, and ammonia, or fuel that becomes liquid at room temperature and normal pressure (kerosene) As long as the object of the present invention is not violated, the type of the chemical is arbitrary.

  In addition, the amount of liquid (internal volume) in the tank as a container is not limited to, for example, resin pellets, wood pellets, or pulverized glass such as resin pellets in a container such as a hopper or powder (hereinafter referred to as granular) You may make it measure the internal volume of solid of a thing etc.). Also in this case, as in the above-described embodiment, the gas phase volume in the container is calculated, and the internal volume is estimated by subtracting the gas phase volume from the volume of the container. However, since solids such as granular materials have a space between them, each embodiment described above in consideration of the volume occupied by the space together with the granular materials and the like, considering that the space is included in the gas phase volume. By applying the internal volume estimation process shown in (2), the internal volume in the container can be estimated in the same manner as the liquid amount.

Specifically, when the predetermined space is fully filled with granular materials, etc., only the granular material occupies X% in the predetermined space, and the space excluding the granular materials occupies the predetermined space. When the volume ratio is (100-X)%, if the volume of the container in which the granular material is accommodated is V and the volume of the gas phase is VA, the granular material and the space between them are within the container. The occupied capacity VS can be obtained by the following equation.
VS = (V−VA) / (X / 100)

For example, when a 1.0 m ³ unit housing space is filled with a granular material, the volume occupied by the granular material is 0.8 m ³ (80%) and the volume occupied by the space between the granular materials is 0.00. When the volume of the container in which the granular material is stored is 10.0 m ³ when it is 2 m ³ (20%), when the gas phase volume VA is obtained by applying the above-described internal volume estimation process, If the gas phase volume VA is 9.2 m ³ , the internal volume VS of the granular material is 1/10 of the container ((10.0−9.2) / (80/100) = 1.0 m ³ ). If the gas phase volume VA is 6.0 m ³ , the internal volume VS of the granular material becomes half the amount of the container ((10.0−6.0) / (80/100) = 5.0 m ³ ). If the phase volume VA is 2.0 m ³ , the internal volume VS of the granular material is the full capacity of the container ((10.0−2.0) / (80/100) = 10. 0 m ³ ). The apparatus and system to which the present invention is applied are not limited to such granular materials and powders, for example, as long as they do not contradict the object of the present invention, such as estimating the amount of cargo (internal capacity) in a warehouse as a container. Is optional, and the type, shape, etc. of the solid to be estimated for the content in the container are arbitrary.

  In addition, embodiment mentioned above only showed the typical form of this invention, and this invention is not limited to embodiment. That is, various modifications can be made without departing from the scope of the present invention.

1, 1A, 1B Vehicle fuel system (content capacity estimation system)
6 Liquid volume estimation device (content volume estimation device)
10 Fuel tank (container)
17 Gas phase portion 18 Liquid phase portion 20 Airtight cylinder 23 First partial space (one partial space)
24 second subspace (the other subspace)
27 Orifice (Flow control part)
28 1st piping (1st communication part)
29 2nd piping (2nd communication part)
30 piston 35 magnet (magnetic member)
41 Electromagnetic coil (Magnetic force generating coil)
42 Coil power supply (current supply means)
43 Ammeter 51 Temperature sensor (gas phase temperature measuring means)
60 Control Unit 61 Microcomputer 62 CPU (Resonance Frequency Detection Means)
65 Memory F Fuel F
J1 Gas phase volume related information VT Fuel tank volume VA Gas phase volume VL Fuel tank volume fs Resonance frequency

Claims (3)

An internal volume estimation device for estimating the internal volume of a liquid or solid in a container,
An airtight cylinder;
A piston provided in the hermetic cylinder so as to be reciprocally movable;
A first communicating portion that connects one of the two partial spaces defined by the piston in the hermetic cylinder in communication with the gas phase portion of the container or the other partial space; and
A second communicating portion that communicates and connects the other partial space to the gas phase portion;
A flow rate regulating unit regulating the flow rate of the gas flowing through the first communication unit;
A magnetic member fixed to one of the airtight cylinder and the piston;
A magnetic force generating coil fixed to the other of the airtight cylinder and the piston so as to exert a magnetic force on the magnetic member;
Current supply means for supplying an alternating current for generating a magnetic force for reciprocating the piston in the hermetic cylinder to the magnetic force generating coil;
A resonance frequency detecting means for detecting a resonance frequency between the reciprocating movement of the piston and the alternating current;
An internal capacity estimation device comprising: internal capacity estimation means for estimating the internal capacity based on the resonance frequency detected by the resonance frequency detection means. It further has a gas phase temperature measuring means for measuring the temperature of the gas phase,
The internal capacity estimation device according to claim 1, wherein the internal capacity estimation means is configured to estimate the internal capacity based on the resonance frequency and the temperature of the gas phase. In an internal volume estimation system having a container and an internal volume estimation device that estimates the internal volume of a liquid or a solid in the container,
An internal capacity estimation system, wherein the internal capacity estimation apparatus is configured by the internal capacity estimation apparatus according to claim 1.

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