Sensor module

Abstract

A sensor module (100) is disposed on the outside of a cover (3) attached to an opening (2) of a container (1) in which a contained object is contained, and is housed in a housing (10), the sensor module (100) being provided with a sensor unit (20) and a lens unit (32). The sensor unit (20) has a transmission / reception unit (21) and a calculation unit. The transmission / reception unit (21) includes a transmission unit (21a) that transmits radio waves that pass through the lid (3) and reach the internal space (1a) of the container, and a reception unit (21b) that receives radio waves that are reflected by the contained object (5) in the internal space (1a). The lens unit (32) is disposed so as to face the transmission / reception unit (21). The calculation unit calculates the remaining amount of the contained object (5) on the basis of the time from the transmission of the radio waves by the transmission unit (21a) to the reception of the reflected waves by the reception unit (21b).

Description

Technical Field

[0001] The present disclosure relates to a sensor module. Background Art

[0002] For example, in cold regions like Hokkaido, kerosene is used as the primary fuel for heating appliances in buildings. To ensure continuous use of the heating appliances during the winter, a fuel tank located outdoors is often used as a kerosene supply source, capable of supplying kerosene from outside to the indoor heating appliances. However, to maintain continuous use of the heating appliances, it is desirable to refill the fuel tank before the kerosene is depleted, rather than after it has been depleted. To achieve this, a dedicated remaining fuel level sensor is installed in the fuel tank.

[0003] Patent Document 1 discloses a non-contact, minute position change detection sensor that uses a photoelectric sensor to detect when the kerosene level in a fuel tank has fallen below a specified level. This non-contact, minute position change detection sensor is used by embedding its housing around a fuel tank's remaining level indicator, thereby functioning as a remaining level detection sensor for detecting the remaining kerosene level in the fuel tank. The remaining level indicator includes a floating indicator that moves up and down as the remaining kerosene level in the fuel tank changes. By using this indicator as a measurement object and detecting its position change with the photoelectric sensor, it is possible to detect when the kerosene level in the fuel tank has fallen below a specified level. Patent Document 1 also discloses that this detection signal, along with an ID identifying the fuel tank, is transmitted via a public communication network such as a telephone line to a fuel retailer or management company that manages the fuel tank. This allows the fuel tank to be refilled before it runs out.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2006-234673 Summary of the Invention

[0007] The non-contact minute position change detection sensor described in Patent Document 1 has only one photoelectric sensor, and therefore can only detect whether the kerosene has become less than a specified amount. Assume that in order to detect multiple specified amounts, the desired number of photoelectric sensors is required. In this case, it is necessary to stagger the photoelectric sensors in a direction (for example, circumferential direction) different from the moving direction (up and down direction) of the indicator mark. Therefore, the size of the non-contact minute position change detection sensor becomes larger. In addition, not all existing fuel tanks have a remaining amount display with a floating indicator mark, so in fuel tanks that do not have such a remaining amount display, there is a concern that the non-contact minute position change detection sensor described in Patent Document 1 cannot detect that the kerosene has become less than a specified amount.

[0008] The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide a sensor module that can use an existing container (fuel tank) as it is and can detect various remaining amounts (predetermined amounts) of a content (kerosene).

[0009] One embodiment of the sensor module disclosed herein is the following sensor module, which is arranged on the outside of a lid mounted on the opening of a container and is accommodated in a shell, the container accommodating a content, the sensor module including a sensor unit and a lens unit, the sensor unit including a transceiver unit and a calculation unit, the transceiver unit including a transmitter unit for transmitting radio waves and a receiver unit for receiving radio waves, the transmitter unit transmitting the radio waves that pass through the lid and reach the internal space of the container, the receiver unit receiving the reflected waves after the radio waves are reflected by the content in the internal space, the lens unit being arranged to be opposite to the transceiver unit of the sensor unit and having a bottom wall for allowing the radio waves and the reflected waves to pass through, the calculation unit calculating the remaining amount of the content based on the time from the time the transmitter transmits the radio waves to the time the receiver receives the reflected waves.

[0010] According to this embodiment, since the sensor module is located outside the lid, there is no need to modify the existing container to install the sensor module. The remaining amount of the contents within the container can be calculated while maintaining the original state. Furthermore, since the remaining amount of the contents is calculated using radio waves, it is easier to detect (calculate) multiple remaining amounts of the contents, unlike when measuring the position of an indicator mark. Furthermore, by calculating the time it takes for the radio waves to be directly reflected by the contents and then received, the remaining amount of the contents can be calculated. This allows a single sensor module to detect multiple remaining amounts of the contents with high resolution.

[0011] In another embodiment of the sensor module of the present disclosure, a bottom wall of the lens portion abuts against an upper surface of the cover.

[0012] According to this embodiment, since the bottom wall of the lens portion abuts against the upper surface of the cover, it is possible to suppress reflection of radio waves transmitted from the transmitter and reflected waves after the radio waves are reflected by the contents at the boundary between the upper surface of the cover and the bottom wall of the lens portion.

[0013] In another embodiment of the sensor module disclosed herein, the shell has a snap-fitting portion, the cover has a snap-fitting portion, the snap-fitting portion is snap-fitted with the snap-fitting portion, the sensor module is detachably fixed relative to the container, and the lens portion is formed integrally with the cover.

[0014] According to this embodiment, the work of supporting the lens portion on the cover, the housing, or the like becomes unnecessary, and the gap between the lens portion and the cover can be eliminated.

[0015] In still another embodiment of the sensor module of the present disclosure, the lens portion is supported by the housing via a biasing mechanism that exerts a biasing force in a direction toward the upper surface of the cover.

[0016] According to this embodiment, even if the sensor module moves in a direction away from the cover, the bottom wall of the lens portion can continue to contact the upper surface of the cover.

[0017] In another embodiment of the sensor module disclosed herein, the housing has an engaging portion, and the cover has an engaged portion, and the engaging portion engages with the engaged portion, so that the closed space formed by the housing and the cover becomes watertight.

[0018] According to this embodiment, even when the sensor module is placed outdoors, rainwater does not intrude into the closed space.

[0019] In another embodiment of the sensor module disclosed herein, the shell has a snap-fitting portion, which can be snapped with the snap-fitting portion of the snap-fitting component that can be fixed to the container. By snapping the snap-fitting portion with the snap-fitting portion, the closed space formed by the shell, the snap-fitting component and the cover becomes watertight.

[0020] According to this embodiment, by using the engaged member, the sensor module can be detachably fixed to the container without modifying the container and the lid. In addition, even if the sensor module is arranged outdoors, rainwater will not intrude into the enclosed space.

[0021] In another embodiment of the sensor module disclosed herein, it further includes a power supply unit and an external communication unit, wherein the power supply unit has the function of supplying power to the sensor unit and the external communication unit, and the external communication unit wirelessly transmits the remaining amount of the container calculated by the calculation unit to the outside using a wireless signal.

[0022] According to this embodiment, the sensor module can be continuously driven without using an external power source, and the remaining amount of the contents can be known at a location far from the container without visually checking the inside of the container. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is an exploded view showing a state in which the sensor module of the first embodiment is separated from the fuel tank.

[0024] Figure 2 This is an exploded perspective view of the sensor module.

[0025] Figure 3 This is an exploded perspective view of the sensor module.

[0026] Figure 4 It is a cross-sectional view showing a sensor module mounted on a fuel tank.

[0027] Figure 5 It is a cross-sectional view showing a sensor module according to a modified example of the first embodiment mounted on a fuel tank.

[0028] Figure 6 This is an exploded view showing a state in which the sensor module according to the second embodiment is separated from the fuel tank.

[0029] Figure 7 This is an exploded perspective view of the sensor module.

[0030] Figure 8 This is an exploded perspective view of the sensor module.

[0031] Figure 9 It is a cross-sectional view showing a sensor module mounted on a fuel tank. DETAILED DESCRIPTION

[0032] The following describes in detail embodiments of the sensor module disclosed herein using the accompanying drawings. It should be noted that the embodiments described below are intended to illustrate the sensor module and do not limit the sensor module to these embodiments. Therefore, the sensor module disclosed herein can be implemented in a variety of ways without departing from its essence.

[0033] [First embodiment]

[0034] [Sensor module structure]

[0035] like Figure 1 As shown, the sensor module 100 of the first embodiment of the present disclosure is mounted on the outside of a lid 3 that closes the opening 2 of a fuel tank 1 (an example of a container), and is housed in a housing 10 for use. The fuel tank 1 includes a tank body 1b (an example of a container body) and a cylindrical opening 2 protruding from the tank body 1b. The internal space 1a of the tank body 1b is connected to the inner space of the opening 2, and kerosene 5 (an example of a content) is injected from the opening 2 and supplied to the internal space 1a. As a result, kerosene 5 is stored in the internal space 1a. The sensor module 100 detects the remaining amount of kerosene 5 stored in the internal space 1a of the fuel tank 1. The lid 3 is made of resin and is screwed to the opening 2 to close the opening 2.

[0036] like Figures 2 to 4 As shown, the sensor module 100 includes a sensor unit 20 and a lens unit 32. The sensor unit 20 includes a transceiver IC 21 (an example of a transceiver) and a calculation IC 22 (an example of a calculation unit).

[0037] like Figure 2 、 Figure 3 As shown, the transceiver IC 21 and the calculation IC 22 are mounted on different surfaces of the first substrate 40. The transceiver IC 21 has a transmitter 21a and a receiver 21b. It should be noted that the transceiver IC 21 and the calculation IC 22 can also be mounted on the same surface of the first substrate 40.

[0038] The transmitting unit 21a of the transceiver IC 21 has the function of externally transmitting radio waves modulated from the signal to be transmitted, while the receiving unit 21b has the function of demodulating the radio waves from the outside and receiving the signal. The transceiver IC 21 can use the receiving unit 21b to receive the radio waves transmitted from the transmitting unit 21a. The transceiver IC 21 mounted on the first substrate 40 modulates the signal to be transmitted and transmits the radio waves from the transmitting antenna (not shown) of the transmitting unit 21a, and demodulates the radio waves received from the receiving antenna (not shown) of the receiving unit 21b. The calculation IC 22 has the function of calculating the remaining amount of kerosene 5 stored in the internal space 1a of the fuel tank 1 based on the time it takes for the radio waves transmitted from the transmitting antenna to be received by the receiving antenna.

[0039] The sensor module 100 includes a power supply unit 60 including a power supply IC 61 and a battery unit 62. The power supply IC 61 is mounted on the same surface of the first substrate 40 as the surface on which the calculation IC 22 is mounted. The battery unit 62 is configured to include a battery 62a and a battery holder 62b that holds the battery 62a. The battery holder 62b that holds the battery 62a is mounted on the surface of the second substrate 50. The transceiver IC 21, the calculation IC 22, and the power supply IC 61 mounted on the first substrate 40 receive power from the battery 62a mounted on the second substrate 50 to operate. It should be noted that the power supply IC 61 can also be mounted on a surface of the first substrate 40 that is different from the surface on which the calculation IC 22 is mounted. In addition, when the sensor module 100 does not include a second substrate 50, the battery holder 62b can also be configured to be mounted on the first substrate 40.

[0040] An external communication IC 90 (an example of an external communication unit) is mounted on the same surface of the second substrate 50 as the surface on which the battery unit 62 is mounted. An external communication antenna 91 for transmitting signals generated by the external communication IC 90 to the outside is formed in a pattern on the same surface of the second substrate 50 as the surface on which the external communication IC 90 is mounted. The external communication antenna 91 may be formed using a dedicated antenna component rather than a pattern.

[0041] like Figure 2 、 Figure 4As shown, the first substrate 40 and the second substrate 50 are electrically connected via a connecting component 80. The connecting component 80 can be any component such as FFC (Flexible Flat Cable) or FPC (Flexible Printed Circuit) that electrically connects the first substrate 40 and the second substrate 50. At this time, connectors 82 electrically connected to both ends of the connecting component 80 are mounted on the first substrate 40 and the second substrate 50. That is, the first substrate 40 and the second substrate 50 are electrically connected via the connector 82 mounted on the first substrate 40, the connecting component 80, and the connector 82 mounted on the second substrate 50. It should be noted that the above structure may be replaced by a wiring harness including electric wires and plugs and sockets respectively mounted on the first substrate 40 and the second substrate 50, may be composed of a connector for substrate-to-substrate connection, or may be other structures.

[0042] The lens portion 32 is formed integrally with the substrate holder 30. The substrate holder 30 is made of resin and has a bottomed cylindrical shape including a bottom wall 31 and a peripheral wall 33 provided upright from the outer edge of the bottom wall 31. The substrate holder 30 holds the first substrate 40 and the second substrate 50 described later. The lens portion 32 has a shape that bulges from the bottom surface of the substrate holder 30 toward the opening side. The first substrate 40 is fixed to the substrate holder 30 so that the transceiver IC 21 abuts against the top surface 32a of the lens portion 32. That is, the lens portion 32 is bulged to a height such that the transceiver IC 21 abuts against the top surface 32a when the first substrate 40 is fixed to the substrate holder 30. It should be noted that the bottom wall 31 constitutes a part of the lens portion 32.

[0043] On the peripheral wall 33 of the substrate holder 30, a plurality of (in the present embodiment, four) supporting protrusions 34 extending along the upright setting direction of the peripheral wall 33 are arranged evenly in the circumferential direction. The first substrate 40 and the second substrate 50 are fixed to the substrate holder 30 by being supported by the supporting protrusions 34. On the first substrate 40 and the second substrate 50, through holes are formed at positions corresponding to the supporting protrusions 34, and the supporting protrusions 34 pass through the through holes. The supporting protrusions 34 may not be multiple, but may be one. It should be noted that the supporting protrusions 34 may be formed integrally with the substrate holder 30, or may be arranged on the substrate holder 30 by methods such as pressing in or bonding.

[0044] As a method for securing the first substrate 40 and the second substrate 50 to the substrate holder 30 via the support protrusions 34, for example, the tip of the support protrusions 34 can be heated to melt and then heat-welded to the second substrate 50. Alternatively, the tip of the support protrusions 34 can be formed into a split pin shape to secure the first and second substrates 40, 50. Alternatively, internal threads can be formed at the tip of the support protrusions 34 and secured using external threads. Any method can be employed as long as the first and second substrates 40, 50 can be secured to the substrate holder 30.

[0045] When supported on the support protrusion 34, a spacer 42 is disposed between the first substrate 40 and the second substrate 50, inserted through the support protrusion 34. The spacer 42 separates the first substrate 40 and the second substrate 50 from each other. Alternatively, the above structure may be replaced by a configuration in which the base end portion of the support protrusion 34 has a larger diameter and the tip portion has a smaller diameter relative to the outer diameter of the support protrusion 34, with a step provided between the base end portion and the tip portion. Furthermore, a through hole having an inner diameter sufficient to penetrate the base end portion of the support protrusion 34 is formed in the first substrate 40, while a through hole having an inner diameter sufficient to penetrate the tip portion of the support protrusion 34 but not the base end portion is formed in the second substrate 50. Thus, when the first and second substrates 40, 50 are inserted into the support protrusion 34, the second substrate 50 is supported by the step between the base end portion and the tip portion of the support protrusion 34. Therefore, even without the spacer 42, the first and second substrates 40, 50 are fixed in a separated state. It should be noted that the first substrate 40 and the second substrate 50 may be arranged using support protrusions 34 having different outer diameters. In this case, the spacer 42 is also unnecessary.

[0046] When the sensor module 100 includes the second substrate 50, the first substrate 40 and the second substrate 50 can be fixed to the cover 3 (see FIG. 3 ) by using at least one supporting protrusion 34 and a spacer 42 for maintaining a constant distance between the opposing surfaces of the first substrate 40 and the second substrate 50. Figure 4 ). Alternatively, the first substrate 40 may be fixed to the cover 3 using at least one supporting protrusion 34, and the second substrate 50 may be fixed to the cover 3 using other supporting protrusions (not shown). Furthermore, both the first substrate 40 and the second substrate 50 may be fixed to the cover 3 using other methods. “Fixed to the cover 3” includes both direct fixation to the cover 3 and indirect fixation to the cover 3 via other components. Furthermore, the supporting protrusion 34 and / or other supporting protrusions may be formed integrally with the cover 3, integrally with the lens portion 32, or separate therefrom.

[0047] The transceiver IC 21 (having a transmitting antenna and a receiving antenna not shown) mounted on the first substrate 40 is covered by the substrate holder 30. Here, “covered by the substrate holder 30” includes the following: Figure 4 As shown, the peripheral wall 33 of the substrate holder 30 is in contact with the first substrate 40, and the transceiver IC 21 is completely housed within the substrate holder 30. However, this also includes the case where there is a gap between the peripheral wall 33 of the substrate holder 30 and the first substrate 40. In this case, the transceiver IC 21, the transmitting antenna (not shown), and at least a portion of the receiving antenna (not shown) can be visually recognized through the gap between the peripheral wall 33 of the substrate holder 30 and the first substrate 40.

[0048] The substrate holder 30 can be fixed to the lid 3 using, for example, double-sided tape. Specifically, the bottom wall 31 of the substrate holder 30 is brought into contact with the upper surface 3c of the lid 3. The substrate holder 30 can be fixed to the lid 3 using, for example, an adhesive, or other methods. By fixing the substrate holder 30 to the lid 3, the first substrate 40 and the second substrate 50, which are fixed to the substrate holder 30 using the support protrusions 34, are also fixed relative to the lid 3 and the fuel tank 1. By fixing the substrate holder 30 to the lid 3, the bottom wall 31 of the substrate holder 30 can be reliably brought into contact with the upper surface 3c of the lid 3, even when the height of the lid 3 varies depending on the type of fuel tank 1.

[0049] The lens portion 32 is arranged at a position opposite to the transceiver IC 21 of the sensor portion 20, and the transceiver IC 21 is in close contact with the top surface 32a of the lens portion 32. However, the transceiver IC 21 and the top surface 32a of the lens portion 32 can also be separated. In addition, in the present embodiment, the lens portion 32 has a lens function by changing the thickness and / or shape. Since the substrate holder 30 has the lens portion 32, the efficiency of transmitting and receiving radio waves from the transceiver IC 21 can be improved. Specifically, the lens portion 32 is composed of three cylinders whose outer diameters become smaller as they move from the bottom wall 31 toward the opening side. It should be noted that the lens portion 32 in the present embodiment is a convex lens shape, but it can also be a concave lens shape. Any lens shape can be adopted according to the purpose. In addition, the lens portion 32 of the substrate holder 30 may not have a lens function.

[0050] The cover 3 has a cover portion 3a and a fixing portion 3b. The cover portion 3a has a bottomed cylindrical shape and an internal thread is formed on the inner side surface. The cover 3 is fixed to the fuel tank 1 by screwing the internal thread into the external thread formed on the outer side surface of the opening portion 2 of the fuel tank 1. The bottom of the cover portion 3a is an upper surface 3c for fixing the substrate holder 30. The fixing portion 3b extends radially outward from the side surface of the cover portion 3a. The outer edge of the fixing portion 3b becomes a peripheral wall 3d that is erected relative to the radial direction, and an internal thread 3e (an example of a clamped portion) is formed on the inner peripheral surface of the peripheral wall 3d.

[0051] The housing 10 is made of resin or metal and has a bottomed cylindrical shape with an inner diameter larger than the outer diameter of the cover 3. An external thread 10b (an example of a locking portion) is formed on the outer peripheral surface of the peripheral wall 10a of the housing 10. When the substrate holder 30 and the sensor module 100 are fixed to the cover 3, the external thread 10b of the housing 10 is screwed into the internal thread 3e of the cover 3. An annular seal 15 is arranged at the boundary between the peripheral wall 10a of the housing 10 and the peripheral wall 3d of the fixing portion 3b of the cover 3 (see FIG. 1 ). Figure 4 ), thereby, the first space 11 (an example of a closed space) that is closed by the cover 3 and the housing 10 and accommodates the sensor module 100 can be set as a structure that maintains a watertight state.

[0052] The internal thread 3e of the fixing portion 3b of the cover 3 and the external thread 10b of the peripheral wall 10a of the shell 10 may also be reversed. Specifically, an external thread (an example of a clamped portion) is formed on the outer peripheral surface of the peripheral wall 3d of the fixing portion 3b and an internal thread (an example of a clamping portion) is formed on the peripheral wall 10a of the shell 10, and the external thread and the internal thread are screwed together. At this time, an annular seal 15 is arranged at the boundary between the peripheral wall 10a of the shell 10 and the peripheral wall 3d of the fixing portion 3b. According to such a structure, the first space 11 that is closed by the cover 3 and the shell 10 and accommodates the sensor module 100 can also be maintained in a watertight state. The seal 15 for maintaining the watertight state may be an O-ring, a caulking agent, a hydrophobic material may be applied to the threaded portion, or other methods may be used. It should be noted that in Figure 2 、 Figure 3 In the figure, the seal 15 is omitted.

[0053] [Sensor module operation]

[0054] Next, use Figure 4The operation of the sensor module 100 will be described. The sensor module 100, located outside the lid 3 of the fuel tank 1, modulates the transmission pulse signal generated by the transceiver IC 21 mounted on the first substrate 40 into a radio wave at predetermined intervals (e.g., every 10 minutes). This signal is then transmitted from the transceiver IC 21's (not shown) transmitting antenna toward the interior space 1a of the fuel tank 1. The transmitting antenna transmits a millimeter-wave radio wave that passes through the resin lens 32 and lid 3 and is reflected by the kerosene 5. This radio wave is, for example, an electromagnetic pulse. The radio wave incident on the interior space 1a of the fuel tank 1 is reflected by the liquid surface 5a of the kerosene 5, becoming a reflected wave that travels toward the sensor module 100. The reflected wave passes through the lid 3 and lens 32 and is received by the receiving antenna (not shown). The reflected wave (electromagnetic pulse) received by the receiving antenna is demodulated into a received pulse signal and then input into the calculation IC 22. The calculation IC 22 measures the time from when the transmitting antenna transmits an electromagnetic pulse to when the receiving antenna receives the reflected wave (hereinafter referred to as the propagation time). Based on this propagation time, the remaining amount of kerosene 5 in the internal space 1a of the fuel tank 1 is calculated. The calculation IC 22 pre-stores the propagation time when kerosene 5 is fully accumulated in the internal space 1a of the fuel tank 1 to the upper limit (hereinafter referred to as the full level) (hereinafter referred to as the full level propagation time). The remaining amount of kerosene 5 is calculated based on the ratio or difference between the full level propagation time and the propagation time. The calculation of the remaining amount is not limited to comparing the full level propagation time with the propagation time. Alternatively, the remaining amount may be calculated by storing the propagation time when the kerosene 5 is completely exhausted or 50% full, and using this as the basis for calculating the remaining amount.

[0055] When the remaining amount of kerosene 5 in fuel tank 1 falls below, for example, 50% of the full amount (hereinafter referred to as "below the predetermined amount"), calculation IC 22 outputs a signal indicating the remaining amount of kerosene 5. The signal output from calculation IC 22 is input to external communication IC 90 via connector 80. Upon receiving the signal indicating the remaining amount of kerosene 5 from calculation IC 22, external communication IC 90 transmits a wireless signal containing the remaining amount of kerosene 5 and the unique number indicating the fuel tank 1 from external communication antenna 91 to the outside of sensor module 100. Fuel retailers and management companies that receive this wireless signal can then ascertain the remaining amount of kerosene 5 in fuel tank 1. It should be noted that the signal output from calculation IC 22 or the wireless signal transmitted from external communication IC 90 may not indicate the remaining amount of kerosene 5, but rather the ratio of the remaining amount of kerosene 5 to the full amount.

[0056] By using the sensor module 100, fuel stores and management companies can receive wireless signals transmitted from the external communication antenna 91 within their stores or offices when the kerosene 5 in the fuel tank 1 falls below a specified level. This allows them to monitor the remaining kerosene 5 every 10 minutes. This eliminates the need for fuel stores and management companies to visit the location of the fuel tank 1 and measure the remaining kerosene 5. Having learned that the kerosene 5 remaining in the fuel tank 1 is below the specified level, the fuel store and management company can appropriately refill the fuel tank 1 with kerosene 5. Furthermore, the owner of the fuel tank 1 can monitor the remaining kerosene 5 every 10 minutes by receiving the wireless signals transmitted from the external communication antenna 91 at home. Therefore, the owner can request the fuel store or management company to refill the kerosene 5 if the kerosene 5 remaining in the fuel tank 1 falls below the specified level.

[0057] [Effects of the sensor module]

[0058] According to the sensor module 100 of this embodiment, since the sensor module 100 is positioned outside the lid 3, there is no need to modify the existing fuel tank 1 in order to install the sensor module 100 therein. The remaining amount of kerosene 5 in the fuel tank 1 can be calculated while maintaining its original state. Furthermore, since the remaining amount of kerosene 5 is calculated using radio waves, unlike conventional methods that measure the position of an indicator mark, multiple remaining amounts of kerosene 5 can be easily detected (calculated). Furthermore, the remaining amount of kerosene 5 is calculated by calculating the time it takes for the radio waves to be directly reflected by the kerosene 5 and then received. Therefore, the remaining amount of kerosene 5 can be detected with high resolution using a single sensor module 100.

[0059] According to the sensor module 100 of this embodiment, the sensor module 100 can be stably fixed to the cover 3 while the bottom wall 31 of the lens portion 32 abuts against the upper surface 3c of the cover 3. Furthermore, since the transceiver IC 21 of the sensor unit 20 can be positioned opposite the lens portion 32, which includes the bottom wall 31 of the substrate holder 30 and functions as a lens, when the radio waves transmitted from the transmitter 21a and the reflected waves resulting from the reflection of the radio waves by the kerosene 5 continuously pass through the upper surface 3c of the cover 3 and the lens portion 32 including the bottom wall 31, it is possible to suppress the radio waves from being reflected at the boundary between the upper surface 3c of the cover 3 and the bottom wall 31 of the lens portion 32.

[0060] According to the sensor module 100 of this embodiment, even if the height of the cover 3 varies depending on the type of fuel tank 1, the bottom wall 31 of the substrate holder 30 can be continuously in contact with the upper surface 3c of the cover 3, and the transceiver IC 21 of the sensor unit 20 can be arranged at a position opposite to the bottom wall 31 of the lens unit 32 having a lens function, thereby improving the efficiency of transmitting and receiving radio waves.

[0061] According to the sensor module 100 of this embodiment, rainwater does not intrude into the first space 11 even when the sensor module 100 is placed outdoors.

[0062] According to the sensor module 100 of the present embodiment, the remaining amount of kerosene 5 can be known at a location away from the fuel tank 1 without visually checking the interior of the fuel tank 1 or the like.

[0063] According to the sensor module 100 of this embodiment, by using millimeter waves for radio waves, radio waves can be transmitted through resin. Therefore, even if the sensor module 100 is placed outside the resin cover 3 of the fuel tank 1, the remaining amount of kerosene 5 in the fuel tank 1 can be calculated through the cover 3. If the radio waves are infrared or visible light, for example, the cover 3 must be partially or entirely made of a transparent or translucent resin or have holes in it in order to allow light to pass through. However, by using millimeter waves for radio waves, the cover 3 does not need to be made of a transparent or translucent material or have holes. It can be made of a non-light-transmitting colored insulating material used in existing covers 3, and there is no risk of holes compromising watertightness. If the cover 3 is made of metal, replacing it with a resin cover 3 sold as a special product by the manufacturer of the fuel tank 1 allows the remaining amount of kerosene 5 in the fuel tank 1 to be calculated through the cover 3. This allows the manufacturer of the fuel tank 1 to ensure the safety and reliability of the cover 3's installation relative to the opening 2. Therefore, the reliability of the conventional function of the fuel tank 1 is not impaired.

[0064] [Modification of the first embodiment]

[0065] Next, a modification of the first embodiment of the present disclosure will be described. Figure 5 As shown in FIG. 1 , this modification differs from the first embodiment in that the cover 3 and substrate holder 30 are integrated. Otherwise, the structure is the same as the first embodiment. Therefore, in the description of this modification, the same reference numerals are used for the same structures as the first embodiment, and detailed description of the same structures will be omitted.

[0066] According to this modification, since the cover 3 and the substrate holder 30 are integrated, the portion corresponding to the bottom surface of the bottom wall 31 of the substrate holder 30 in the first embodiment becomes the upper surface 3c of the cover 3. In this modification, the time and effort required to secure the substrate holder 30 to the upper surface 3c of the cover 3 is eliminated, and the gap between the bottom wall 31 of the substrate holder 30 and the upper surface 3c of the cover 3 can be eliminated.

[0067] [Second embodiment]

[0068] Next, use Figures 6 to 9The second embodiment of the present disclosure will be described. This embodiment differs from the first embodiment in the structure of the cover 3 and housing 10, as well as the method for supporting the first and second substrates 40 and 50. Otherwise, the structure is the same as the first embodiment. Therefore, in the description of this embodiment, the same reference numerals will be used for the same structures as the first embodiment, and detailed description of the same structures will be omitted.

[0069] like Figures 7 to 9 As shown, the sensor module 100 of this embodiment includes a housing 10, a sensor unit 20, a lens unit 32, a shield 35, and a cover 18. The housing 10 is made of resin or metal and has a cylindrical shape with an inner diameter larger than the outer diameter of the cover 3. The space within the cylinder of the housing 10 is divided into a first space 11 (an example of a closed space) and a second space 12 by a partition wall 13. The partition wall 13 has a recessed portion 13a with a rectangular cross-section extending from the first space 11 toward the second space 12. A communication hole 14 is formed in the bottom wall 13b of the recessed portion 13a, which is a rectangular through-hole that connects the first space 11 and the second space 12.

[0070] The transceiver IC 21, the transmitting antenna 21c (an example of a transceiver and a transmitting unit), the receiving antenna 21d (an example of a transceiver and a receiving unit), and the calculation IC 22 that constitute the sensor unit 20 are mounted on the same side of the board surface of the first substrate 40. Of the two side board surfaces of the first substrate 40, the board surface on the opposite side to the board surface on which the elements constituting the sensor unit 20 are mounted is opposed to the bottom wall 13b. That is, the board surface of the first substrate 40 on which the elements constituting the sensor unit 20 are mounted is not opposed to the bottom wall 13b of the housing 10. The first substrate 40 is accommodated in the recess 13a of the first space 11 of the housing 10 (see Figure 9 The outer shape of the first substrate 40 is slightly smaller than the inner dimension of the recess 13a. The first substrate 40 is supported on the bottom wall 13b by four compression coil springs 44 (an example of a biasing mechanism).

[0071] The lens portion 32 is formed in a protective cover 35. The protective cover 35 is made of resin and has a bottomed prismatic shape. It is embedded in the recessed portion 13a of the first space 11 and accommodates the first substrate 40 inside. That is, the transceiver IC 21, the transmitting antenna 21c, the receiving antenna 21d, and the calculation IC 22 mounted on the first substrate 40 are covered by the protective cover 35. Here, the protective cover 35 covers not only the following components: Figure 9While the case where the entire first substrate 40 is housed within the shield 35 as shown, this also includes a case where the entire first substrate 40 is not housed within the shield 35. Specifically, this also includes a case where the shield 35 is disposed with a gap relative to the first substrate 40, and at least a portion of at least one of the transceiver IC 21, the transmitting antenna 21c, the receiving antenna 21d, and the computational IC 22 is visually recognizable from the gap between the side surface of the shield 35 and the first substrate 40.

[0072] The shield 35 is supported on the bottom wall 13b of the recess 13a using, for example, four cotter pins, or support pins 46, each having claws 46a. Specifically, the four support pins 46 extend from the outside of the shield 35 through four holes formed in the shield 35, the first substrate 40, and the bottom wall 13b. The claws 46a at the tips of the support pins 46 hook onto the partition wall 13 on the side of the second space 12, thereby supporting the shield 35. Four compression coil springs 44 are inserted through each of the four support pins 46 between the first substrate 40 and the bottom wall 13b. The elastic force of the compression coil springs 44 pushes the shield 35 and the first substrate 40 away from the bottom wall 13b, pressing the tips of the transmitting antenna 21c and the receiving antenna 21d against the bottom wall 35a of the shield 35, where they are in close contact. Furthermore, by using the compression coil spring 44 to press the shield 35, the shield 35, the transmitting antenna 21c, and the receiving antenna 21d can be securely and tightly attached to the upper surface 3c of the cover 3, even when the height of the cover 3 varies depending on the type of fuel tank 1. It should be noted that the shield 35 and the first substrate 40 can be fixed to the bottom wall 13b using screws instead of the support pins 46. Furthermore, at least one of the front ends of the transmitting antenna 21c and the receiving antenna 21d can be separated from the bottom wall 35a of the shield 35.

[0073] In this embodiment, the lens portion 32 is formed by varying the thickness of the bottom wall 35a of the shield 35, which faces the front end of the transmitting antenna 21c and the front end of the receiving antenna 21d. This allows the bottom wall 35a of the shield 35 to function as a lens. By providing the bottom wall 35a with a lens function, the efficiency of transmitting and receiving radio waves can be improved. While the lens portion 32 in this embodiment has a convex lens shape, it can also be a concave lens shape. Any lens shape can be adopted depending on the intended purpose. It should be noted that the bottom wall 35a of the shield 35 does not necessarily have to function as a lens.

[0074] A second substrate 50 is housed in the second space 12 of the housing 10. The first substrate 40 and the second substrate 50 are electrically connected via a connecting member 80 disposed in the communication hole 14. A battery unit 62 and an external communication IC 90 are mounted on the second substrate 50. The battery unit 62 includes a battery 62a and a battery holder 62b, which serve as a power source for operating the sensor module 100. An external communication antenna 91 is patterned on the second substrate 50 to transmit signals generated by the external communication IC 90 to the outside. The second substrate 50 is secured to the partition wall 13 with four screws 52.

[0075] An internal thread 12b is formed on the inner peripheral surface of the peripheral wall 10a of the housing 10 that defines the second space 12. The external thread 18a formed on the cover 18 is screwed into the internal thread 12b, thereby forming the second space 12 into a closed space. An annular seal 19 is arranged at the boundary between the peripheral wall 10a of the housing 10 and the cover 18 (see Figure 9 ), thereby maintaining the second space 12 in a watertight state. It should be noted that the cover 18 is made of resin. Figure 7 、 Figure 8 In the figure, the seal 19 is omitted.

[0076] In this embodiment, the sensor module 100 is fixed to the lid 3 of the fuel tank 1 by engaging with a fixing component 70 (an example of a member to be engaged). The fixing component 70 has a circular plate shape with a through hole 71 in the center, and has a peripheral wall 72 as an annular side wall that is erected from the outer edge of the circular shape over the entire circumference. The through hole 71 has an inner diameter that can be externally fitted into the opening portion 2 of the fuel tank 1. In addition, an internal thread 73 (an example of a portion to be engaged) is formed on the inner circumferential surface of the peripheral wall 72. By screwing the lid 3 and the opening portion 2 together while the fixing component 70 is externally fitted into the opening portion 2 of the fuel tank 1, the opening portion 2 is closed, and the fixing component 70 is clamped by the box body 1b of the fuel tank 1 and the lid 3 and fixed to the fuel tank 1.

[0077] When the fixing member 70 is fixed to the fuel tank 1, the external thread 10b (an example of a snap-fitting portion) formed on the outer peripheral surface of the peripheral wall 10a of the housing 10 of the sensor module 100 that divides the first space 11 is screwed into the internal thread 73 of the fixing member 70. As a result, the sensor module 100 is fixed to the cover 3 (fuel tank 1). At this time, the bottom wall 35a of the shield 35 of the sensor module 100 abuts against the upper surface 3c of the cover 3. An annular seal 15 is arranged at the boundary between the peripheral wall 10a of the housing 10 and the peripheral wall 72 of the fixing member 70 (see Figure 9 ), thereby, the first space 11 of the housing 10 divided by the cover 3 and the fixing member 70 is maintained in a watertight state. Figure 7 、 Figure 8 In the figure, the seal 15 is omitted.

[0078] According to the sensor module 100 of the present embodiment, the sensor module 100 can be detachably fixed to the cap 3 of the fuel tank 1 without modifying the fuel tank 1 by using the fixing member 70 .

[0079] [Other Implementation Methods]

[0080] (1) In the sensor module 100 of the first embodiment described above, when the substrate holder 30 and the cover 3 are separate bodies, the bottom wall 31 of the substrate holder 30 can be brought into contact with the upper surface 3 c of the cover 3 by fixing the substrate holder 30 to the cover 3 using double-sided tape or the like. However, the present invention is not limited thereto. The substrate holder 30 may be directly supported by the housing 10, or the first substrate 40 may be supported by the housing 10 while the substrate holder 30 is supported by the first substrate 40. The substrate holder 30 may be supported by the housing 10 directly or indirectly.

[0081] (2) In the second embodiment described above, the fixing member 70 is fixed to the fuel tank 1 by being sandwiched between the lid 3 and the tank body 1b, but the present invention is not limited to this. The fixing member 70 may be fixed to the fuel tank 1 by integrating the fixing member 70 with the lid 3 using a method such as bonding. Alternatively, the fixing member 70 may be fixed to the fuel tank 1 by forming the fixing member 70 integrally with the fuel tank 1. Furthermore, the fixing member 70 may be fixed to the fuel tank 1 by bonding or other methods. Any method may be used as long as the fixing member 70 can be stably fixed to the fuel tank 1.

[0082] (3) In the second embodiment described above, the fixing member 70 and the housing 10 are separate components, but they may be integrated with each other via a hinge or the like.

[0083] (4) In the second embodiment, the housing 10 housing the sensor module 100 is fixed to the fixing member 70 by screwing, but the present invention is not limited thereto. For example, the peripheral wall 10a of the housing 10 may be fixed by being pressed into the peripheral wall 72 of the fixing member 70.

[0084] (5) In the above embodiment, the transmission / reception IC 21 and the calculation IC 22 are mounted on the first substrate 40 , and the external communication IC 90 is mounted on the second substrate 50 . However, each IC may be mounted on any substrate.

[0085] (6) In the second embodiment described above, the compression coil spring 44 is used to ensure close contact between the shield 35 and the first substrate 40 and the upper surface 3c of the cover 3. However, the present invention is not limited to this embodiment. Instead of the compression coil spring 44, a leaf spring or elastic rubber may be used. Alternatively, the bottom wall 35a of the shield 35 may be brought into contact with the upper surface 3c of the cover 3 by screwing the external thread 10b and the internal thread 73 together.

[0086] (7) In each of the above embodiments, the sensor module 100 is configured to operate by the battery 62 a , but may be configured to operate by a commercial power source.

[0087] (8) In the first embodiment, the lens portion 32 including the bottom wall 31 of the substrate holder 30 can be configured to function as a lens, and in the second embodiment, the lens portion 32 of the bottom wall 35a of the shield 35 can be configured to function as a lens. However, the present invention is not limited thereto. If the cover 3 can be modified to a shape suitable for the sensor module 100, the upper surface 3c of the cover 3 can also be configured to function as a lens. Alternatively, the substrate holder 30, the shield 35, and the cover 3 can both function as lenses. In this case, for example, the lens portion 32 of the substrate holder 30 or the shield 35 can function as a lens for radio waves transmitted from the transmitting antenna, while the cover 3 can function as a lens for reflected waves received by the receiving antenna.

[0088] (9) In the above embodiment, after the remaining level of kerosene 5 falls below 50%, the remaining level of kerosene 5 is transmitted via wireless signals every 10 minutes. However, this is not limiting. For example, after the remaining level of kerosene 5 falls below 50%, a wireless signal may be transmitted each time the remaining level reaches 40%, 30%, or 20%, that is, each time the kerosene 5 decreases by 10%. Alternatively, after the remaining level of kerosene 5 falls below 20%, a wireless signal may be transmitted each time the kerosene 5 decreases by, for example, 3%. In this manner, by increasing the frequency of wireless signal transmission as the fuel tank 1 approaches emptying, the fuel tank 1 can be reliably replenished with kerosene 5 before the fuel tank 1 becomes empty.

[0089] Industrial Applicability

[0090] The present disclosure can be utilized in a sensor module.

[0091] Description of Reference Numerals

[0092] 1: Fuel tank (container)

[0093] 2: Opening

[0094] 3: Lid

[0095] 3c: Upper surface

[0096] 3e: Internal thread (engaged portion)

[0097] 5: Kerosene (content)

[0098] 10: Shell

[0099] 10b: External thread (engaging part)

[0100] 11: Space 1 (enclosed space)

[0101] 15: Seals

[0102] 20: Sensor part

[0103] 21: Transceiver IC (transceiver unit)

[0104] 21a: Sending unit

[0105] 21b: Receiving unit

[0106] 21c: Transmitting antenna (transceiver, transmitter)

[0107] 21d: Receiving antenna (transmitter, receiver)

[0108] 22: Calculation IC (Calculation Unit)

[0109] 31: Bottom wall

[0110] 32: Lens

[0111] 44: Compression coil spring (force applying mechanism)

[0112] 60: Power supply unit

[0113] 70: Fixing component (engaged component)

[0114] 90: IC for external communication (external communication department)

[0115] 100: Sensor module.

Claims

1. A sensor module, arranged outside a cover mounted on an opening of a container and housed in a housing, wherein the container houses a content. The sensor module includes a sensor unit and a lens unit. The sensor unit includes a transceiver unit and a computing unit, wherein the transceiver unit includes a transmitter unit for transmitting radio waves and a receiver unit for receiving the radio waves. The transmitting unit transmits the radio wave through the lid and reaches the inner space of the container. The receiving unit receives a reflected wave of the radio wave reflected by the contained object in the internal space. The lens portion is arranged to face the transceiver portion of the sensor portion and has a bottom wall that allows the radio wave and the reflected wave to pass therethrough. The calculation unit calculates the remaining amount of the stored goods based on a time period from when the transmitting unit transmits the radio wave to when the receiving unit receives the reflected wave.

2. The sensor module according to claim 1, wherein: The bottom wall of the lens portion abuts against the upper surface of the cover.

3. The sensor module according to claim 1, wherein The housing has a snap-fit ​​portion. The cover has a locked portion, The sensor module is detachably fixed to the container by the engagement of the engagement portion and the engaged portion. The lens portion is formed integrally with the cover. The sensor module according to claim 1 , wherein: The lens portion is supported by the housing via an urging mechanism that exerts a force in a direction toward the upper surface of the cover. The sensor module according to claim 1 , wherein: The housing has a snap-fit ​​portion. The cover has a locked portion, The engagement between the engaging portion and the engaged portion creates a watertight closed space formed by the housing and the cover. The sensor module according to claim 1 , wherein: The housing has an engaging portion that can engage with an engaged portion of an engaged member that can be fixed to the container. The engagement between the engaging portion and the engaged portion creates a watertight closed space formed by the housing, the engaged member, and the cover.

7. The sensor module according to any one of claims 1 to 6, wherein: It also has a power supply unit and an external communication unit. The power supply unit has a function of supplying power to the sensor unit and the external communication unit. The external communication unit wirelessly transmits the remaining amount of the stored items calculated by the calculation unit to the outside using a wireless signal.

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