JP2023015370A - sensor module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensor module which can improve durability of a power receiving coil.

SOLUTION: A sensor module comprises: a sensor part which is attached to an inner peripheral surface of a tire, and detects a state in the tire; and a power receiving coil which receives radio energy supplied from the exterior, generates electric power on the basis of the received radio energy, and supplies the same to the sensor part. The power receiving coil comprises a wound part, and an elastic body is interposed between coil wires in which adjacent coil wires are spirally wound.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2023,JPO&INPIT

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor module, and more particularly to a sensor module provided inside a tire to detect the state of the tire.

2. Description of the Related Art In recent years, there has been known a device provided inside a tire, which is composed of a sensor or the like for detecting the state of the tire. In such a device, a battery is incorporated together with the sensor and the like as a power supply source for driving the sensor and the like. However, batteries inherently have the problem of running out of battery before the tire reaches the end of its life.
Therefore, in Patent Document 1, in order to eliminate the concern of the battery running out, a coil (secondary coil) is installed in place of the battery in the tire, and a coil (primary coil) is installed in the vehicle body to generate a magnetic flux toward the secondary coil. , the secondary coil penetrates the magnetic flux generated by the primary coil as the tire rotates, and the induced electromotive force is supplied to a sensor or the like as power.

JP-A-2000-255229

However, in Cited Document 1, the copper wires forming the secondary coil are wound so as to be in contact with each other. may be broken due to fretting and may not function as a device.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a sensor module capable of improving the durability of a power receiving coil.

As a configuration of the sensor module for solving the above problems, the sensor module includes a power receiving coil that is attached to the inner peripheral surface of the tire, receives electric wave energy supplied from the outside, and generates electric power based on the received electric wave energy. A sensor module comprising: a mounting seat made of an elastic body; and a sensor unit housed in the mounting seat and detecting a state inside a tire by power supply from a power receiving coil, wherein the power receiving coil has a winding portion. , the adjacent coil wires are embedded in the mounting base with an elastic body interposed between the spirally wound coil wires.
According to this configuration, it is possible to prevent disconnection of the coil wires forming the power receiving coil due to fretting, and as a result, it is possible to stably supply electric power to the sensor unit for a long period exceeding the service life of the tire. It becomes possible.
Further, as another configuration of the sensor module, the mounting pedestal includes an accommodation portion capable of accommodating the sensor portion, and a sticking portion having a sticking surface in contact with the inner peripheral surface of the tire, and the receiving coil is embedded in the sticking portion. , the bottom surface of the receiving part has an inclined part that rises from the outside to the inside, and the thickness of the elastic body from the embedded power receiving coil to the sticking surface is interposed between the adjacent coil wires of the power receiving coil a configuration in which the power receiving coil is set thicker than the thickness of the elastic body, a configuration in which the power receiving coil is exposed from the surface of the elastic body at the starting end side and the terminal side of the coil wire forming the winding portion, and the power receiving coil has a winding surface It may be configured to be attached around an axis perpendicular to the inner peripheral surface of the tire.

It is a figure which shows the attachment state of a sensor module. 2A and 2B are a plan view and a cross-sectional view of a sensor module; FIG. 1 is an exploded view of a sensor module; FIG. It is a figure which shows the type of usage of a sensor module. It is a figure which shows the other form of a receiving coil. It is a figure which shows the other form of a receiving coil. FIG. 10 is a diagram showing another form of arrangement of power receiving coils; FIG. 10 is a diagram showing another form of arrangement of power receiving coils;

Hereinafter, the present invention will be described in detail through embodiments of the invention, but the following embodiments do not limit the invention according to the claims, and all combinations of features described in the embodiments are It includes configurations that are not necessarily essential to the solution and are selectively adopted.

FIG. 1 is a diagram showing an attached state of a sensor module.
As shown in FIG. 1, the sensor module 1 includes a sensor unit 2 and a mounting base 3. As shown in FIG. The sensor unit 2 is attached to an inner liner that forms an inner peripheral surface 10s of the tire 10 via an attachment base 3 at a central portion CL in the tire width direction. For example, the sensor module 1 includes a plurality of sensors for detecting temperature, pressure, vibration, etc. in the air chamber of the tire 10 mounted on the rim wheel 15, a transmitter for transmitting detection values detected by each sensor, and It has functional parts such as a power supply unit that supplies power to operate each sensor and transmitter.

FIG. 2 is a plan view and cross-sectional view of the sensor module. FIG. 3 is a cross-sectional view of the sensor unit and the mounting base. The sensor unit 2 and mounting base 3 constituting the sensor module 1 will be described below with reference to FIGS. 2 and 3. FIG.

As described above, the sensor unit 2 includes a plurality of sensors 32 (temperature and pressure sensors); 36 (acceleration sensor) for detecting the state of the tire 10; An electronic component is housed in a case 20 and configured to function as a sensor section.

As shown in FIG. 3A, the case 20 is configured by combining, for example, a housing case 20A forming a main space for housing functional components and a cap 20B functioning as a lid for the housing case 20A. be done. As the material of the case 20, for example, a synthetic resin or the like is used from the viewpoint of weight reduction and strength of the sensor unit 2. As shown in FIG. The storage case 20A and the cap 20B are formed to have the same shape in plan view, and the shape is maintained even when the storage case 20A and the cap 20B are combined and integrated. That is, the outer shape of the sensor unit 2 matches the outer shape of the case 20 .

The accommodation case 20A is provided with an accommodation space S for accommodating functional components. The accommodation space S is formed, for example, in a cylindrical shape. The accommodation space S is formed as a cylindrical space concentric with the outer periphery of the accommodation case 20A. The accommodation space S includes a temperature/pressure sensor 32, an acceleration sensor 36, a transmission device 38 for transmitting detection values such as temperature, pressure, and acceleration detected by the temperature/pressure sensor 32 and the acceleration sensor 36, It accommodates electronic components that make up a control device 40 that controls the operations of the pressure sensor 32 and the acceleration sensor 36, the operation of the transmission device 38, and the like, and a power supply device 70 that supplies power to them.

The temperature/pressure sensor 32, the acceleration sensor 36, the transmission device 38, the control device 40, and the power supply device 70 are mounted on the circuit board 30, for example. Note that the configuration of the circuit board 30 is not limited to this.

A temperature/pressure sensor 32 and an acceleration sensor 36 are arranged on one side of the circuit board 30, and a transmitting device 38 functioning as a transmitter, a control device 40, and a part of the power supply device 70 are arranged on the other side. is placed. A connection terminal 49 is mounted on one side surface of the circuit board 30 to which an end of a coil wire extending from a power receiving coil 76 constituting a power supply device 70 (to be described later) is connected. The connection terminals 49 are inserted into the through holes 22 provided in the cap 20B when the circuit board 30 is housed in a predetermined position inside the case 20. As shown in FIG. As a result, the connection terminal 49 is exposed when the cap 20B is closed, and the ends of the coil wires can be connected with the cap 20B closed.

The temperature/pressure sensor 32 includes an introduction tube 32A for introducing the air inside the tire to a detection portion that detects the temperature and pressure of the air inside the tire. The introduction cylinder 32A extends in a direction perpendicular to the circuit board 30, and is inserted into the through hole 24 provided in the cap 20B when the circuit board 30 is housed at a predetermined position inside the case 20. As shown in FIG. As a result, even when the circuit board 30 is accommodated in the case 20, the detection section is exposed to the air inside the tire, and the state inside the tire air chamber can be measured.

The acceleration sensor 36 is, for example, a sensor capable of measuring acceleration in three axial directions, i.e., the tire width direction, the radial direction, and the circumferential direction (rotational tangential direction). Installed in the specified orientation. The measurement direction of the acceleration sensor 36 is set so as to correspond to the mounting direction M provided on the cap 20B when the circuit board 30 is housed in the case 20 . Specifically, when the circuit board 30 is accommodated in the case 20 and mounted on the tire 10 as the sensor unit 2, the measurement axes of the acceleration sensor 36 are aligned with the tire width direction, the tire front-rear direction, and the tire radial direction. are arranged on the circuit board 30 as follows.

The transmission device 38 is mounted on the circuit board 30 as a transmission circuit and has an antenna (not shown). For example, the transmitter 38 executes a predetermined program based on the acceleration sensor 36 detecting the rotation (centrifugal force) of the tire 10, and the temperature/pressure sensor 32 and the acceleration sensor 36 detect the inside of the tire 10. It transmits temperature, pressure and acceleration to the outside of the tire by wireless communication. Signals such as temperature, pressure, and acceleration transmitted by radio from the transmitter 38 are received by a radio circuit of a main unit provided in the vehicle (not shown), and, for example, a tire condition ( temperature, pressure, or presence/absence of abnormality) can be displayed.

The power supply device 70 includes, for example, a rectifying section 72, a power storage section 74, and a power receiving coil 76 as a power generating section. The rectifying section 72 is mounted on the circuit board 30 as a rectifying circuit. For the power storage unit 74, for example, a capacitor or a button-type rechargeable secondary battery can be used. Note that the form of power storage unit 74 is not particularly limited.

The power receiving coil 76 is provided on the mounting base 3 and is composed of a coil capable of generating power by receiving radio wave energy supplied from the outside. The power supply device 70 receives radio wave energy supplied from the outside by the power receiving coil 76 to generate a current that becomes power, and the rectifying unit 72 converts the generated current into a current and voltage of a predetermined standard, It is configured to store electricity in the electricity storage unit 74 . Note that the configuration of the power receiving coil 76 will be described later.

The circuit board 30 on which electronic components are mounted is housed with the temperature/pressure sensor 32 and the acceleration sensor 36 facing the opening side of the housing case 20A. It is accommodated in the accommodation space S so that it may be carried out. As a method of setting the position of the circuit board 30 with respect to the case 20, for example, by providing a protrusion on the inner wall forming the housing space S and providing a notch corresponding to the protrusion on the circuit board 30, the circuit board 30 can be positioned. Positioned relative to case 20 .

The inside of the case 20 is filled with a potting material 48 with the circuit board 30 accommodated therein. As a result, the circuit board 30 is entirely covered with the potting material 48 except for the detection portion of the temperature/pressure sensor 32 . Urethane-based resin or epoxy-based resin is preferable as the material of the potting material 48 . Even when the tire 10 rotates, especially when it rotates at a high speed, the potting material 48 absorbs the force received from the circuit board 30 when the tire 10 collides with the road surface, and sufficient resistance can be obtained.

As shown in FIGS. 2(a) and 2(b), the outer shape of the sensor unit 2 is, for example, a disk shape having a constant outer diameter. It is housed in the mounting base 3 in this state.

As particularly shown in FIG. 3B, the mounting base 3 includes a sticking portion 51 having a mounting surface 51a that is stuck to the inner peripheral surface 10s of the tire 10, and a sticking portion 51 that rises upward from the sticking portion 51. It has an accommodation wall portion 50 that forms a substantially cylindrical accommodation portion 52 as an accommodation space that can accommodate the sensor unit 2 , and a power receiving coil 76 that constitutes the power supply device 70 .

The mounting base 3 is integrally made of an elastic material (elastomer) such as natural rubber or synthetic rubber so as to follow the deformation of the tire 10 . As shown in FIG. 2A, the sticking portion 51 is formed in a plate shape having a circular outer shape in plan view. The sticking portion 51 is formed as a mounting surface 51a on which the lower surface is stuck in contact with the inner peripheral surface 10s of the tire 10 . The mounting surface 51a is formed, for example, as a flat surface before being attached to the inner peripheral surface 10s of the tire 10 .

A housing wall portion 50 that protrudes upward in a cylindrical shape is provided on the upper surface of the sticking portion 51 (the surface opposite to the mounting surface 51a). The accommodation wall portion 50 is provided on a concentric circle centered on the central axis O of the circular sticking portion 51 , and the inner peripheral surface 54 of the accommodation wall portion 50 forms an accommodation portion 52 corresponding to the outer shape of the sensor unit 2 . The housing wall portion 50 includes a peripheral surface holding portion 50a in contact with the outer peripheral surface of the sensor unit 2 housed in the housing portion 52, and a peripheral surface holding portion 50a that protrudes radially inward from the tip of the peripheral surface holding portion 50a, and the upper surface 2c of the sensor unit 2. and a top surface holding portion 50b that holds the peripheral edge portion of the . An inner diameter portion of the top surface holding portion 50b is formed as an opening portion 56 that enables accommodation of the sensor unit 2 in the accommodation portion 52, and the sensor unit 2 is accommodated by expanding the opening portion 56. As shown in FIG.

The diameter of the inner peripheral surface 54 of the housing wall portion 50 is smaller than the diameter of the outer peripheral surface 2 b of the sensor unit 2 . It adheres along the outer peripheral surface 2b of the unit 2 and exerts a restraining force.

As shown in FIG. 3, the bottom surface 60 forming the housing portion 52, in other words, the top surface on the side opposite to the mounting surface 51a of the sticking portion 51 is formed as a convex bottom surface, for example, which is higher in the central side than in the radial direction outside. be. More specifically, the bottom surface 60 includes an inclined surface portion 62 gently sloping upward from the lower end portion of the housing wall portion 50 toward the central side, and a flat surface portion formed as a flat surface parallel to the mounting surface 51a on the central side. 64.

Therefore, as shown in FIG. 3, when the sensor unit 2 is press-fitted into the housing portion 52 having the bottom surface 60, the bottom surface 2a of the sensor unit 2 causes the flat surface portion 64 to move toward the inner peripheral surface 10s of the tire . , the mounting surface 51a side is deformed into a bow shape along the curved shape of the inner peripheral surface 10s of the tire 10, and comes into close contact along the curvature of the inner peripheral surface 10s of the tire 10. In other words, the bottom surface 60 forming the housing portion 52 is pressed against the bottom surface 2 a of the sensor unit 2 . At this time, the sensor unit 2 is surrounded by the inner peripheral surface 54, the top surface holding portion 50b, and the bottom surface 60 in the housing portion 52, and is kept in close contact with the sensor unit 2, so that the sensor unit 2 is firmly restrained even when the tire 10 rolls. .

A power receiving coil 76 that constitutes the power supply device 70 is provided on the sticking portion 51 . As shown in FIGS. 2A and 2B, the power receiving coil 76 according to this embodiment is embedded in the sticking portion 51 . The receiving coil 76 is formed, for example, by winding a coil wire 77 around the center of the disk-shaped sticking portion 51 and gradually expanding radially outward. In this embodiment, the coil wire 77 is described as being wound in one plane parallel to the mounting surface 51 a of the sticking portion 51 .

The inner end portion 76A on the starting end side of the winding of the coil wire 77 extends inside the housing wall portion 50 along the housing wall portion 50, for example, the peripheral surface holding portion 50a and the top surface holding portion 50b. exposed from the boundary of Further, in the winding of the coil wire 77, for example, the outer end portion 76B on the terminal side is embedded in the sticking portion 51 and accommodated so as to traverse above the spirally formed winding portion 76C. After extending up to the wall portion 50, the inside of the containing wall portion 50 is extended along the rising direction of the containing wall portion 50, and in a covered state, for example, the peripheral surface holding portion 50a and the top surface holding portion 50b. exposed from the boundary of An inner end portion 76A and an outer end portion 76B of the receiving coil 76 are integrated by a connector 78 while maintaining an independent state.

As shown in FIG. 2(c), the power receiving coil 76, when embedded in the sticking portion 51, has a distance (thickness) a2 from the lowest portion of the coil wire 77 forming the winding portion 76C to the mounting surface 51a. A rubber layer F is provided.
However, the rubber layer F is set to have a thickness of at least 0.5 mm, preferably 0.5 mm or more.

Further, in the power receiving coil 76, when the winding portion 76C is embedded in the sticking portion 51, a gap a1 of at least 0.5 mm, preferably 0.5 mm or more, is formed between adjacent coil wires 77 and 77. , and the gap a1 is filled with rubber forming the sticking portion 51. As shown in FIG. In addition, the outer end portion 76B side of the power receiving coil 76 is at least 0.5 mm, preferably 0.5 mm, between the coil wire 77 crossing over the winding portion 76C and the coil wire 77 constituting the winding portion 76C. The gap a3 is extended to have the above gap a3, and the gap a3 is filled with the rubber forming the sticking portion 51. As shown in FIG.

Also, the thickness a2 is preferably set larger than the dimension of the gap a1 between the coil wires 77 forming the winding portion 76C, for example.

In this manner, by filling the rubber member between the adjacent coil wires 77 and the intersecting coil wires 77, even if the tire 10 is deformed and the mounting pedestal 3 is deformed following the tire 10, the power receiving coil is Since disconnection (fretting) due to contact between the coil wires 77 forming the tire 10 can be prevented, electric power can be stably supplied over the service life of the tire 10 .

The mounting base 3 is attached such that the winding portion 76C of the power receiving coil 76 is wound around an axis perpendicular to the tire surface. Winding portion 76C in power receiving coil 76 functions as a substantial power generating portion that generates induced electromotive force.

FIG. 4 is a diagram showing a usage pattern of the sensor module according to this embodiment.
The sensor module 1 according to this embodiment can be configured, for example, as a tire monitoring system together with the radio wave energy generating means 100 provided on the vehicle body 90 .
It is preferable that the radio wave energy generating means 100 be provided at a position that covers the outside of the tread surface 11 of the tire 10 on the vehicle body 90 and faces the tread surface 11 . More preferably, it should be provided at a position with respect to the radio wave energy generating means 100 where the movement of the tire 10 due to the steering operation is small. The radio wave energy generating means 100 includes a coil 102 and an inverter 104 that generate magnetic lines of force. The coil 102 is arranged with the winding axis around which the coil wire is wound directed in the radial direction of the tire 10 . The inverter 104, as shown in FIG. 4, excites the coil 102 using a battery 92 provided in the vehicle body 90 as a power supply.

The operation of this embodiment having the above configuration will be described. The tire 10 of this embodiment is attached to an axle of an automobile by tightening a rim wheel 15 with a nut. When the automobile is driven, the inverter 104 is activated and the coil 102 is excited to generate a magnetic flux G extending in the radial direction of the tire 10 .
As the tire 10 rotates as the vehicle travels, the power receiving coil 76 rotating together with the tire 10 moves along the tire circumferential direction. As a result of this movement, the magnetic flux G penetrates through the winding portion 76C of the power receiving coil 76 while changing the amount thereof, and an induced electromotive force is generated in the winding portion 76C. The induced electromotive force generated in winding portion 76</b>C is rectified by rectifying portion 72 and then stored in power storage portion 74 . The electric power stored in the power storage unit 74 is supplied as a drive source for the temperature/pressure sensor 32 , the acceleration sensor 36 , the transmission device 38 and the control device 40 .
Detected values detected by the temperature/pressure sensor 32 and the acceleration sensor 36 are emitted as radio signals via the transmission device 38 and displayed on a display device (not shown) provided on the vehicle body, or provided together with the display device. is stored in a dedicated storage device.

As described above, according to the structure for supplying power to the sensor module 1 of the present embodiment, electric power can be stably supplied to the electronic components provided inside the tire 10 without worrying about battery depletion as in the conventional case. and can be used beyond the life of the tire 10.

FIG. 5 is a diagram showing another form of the receiving coil.
In the above-described embodiment, the winding portion 76C of the receiving coil 76 is wound on the mounting base 3 from the rising portion of the housing wall portion 50 toward the outer periphery, but the present invention is not limited to this. For example, as shown in FIG. 5 , in the sticking portion 51 of the mounting base 3 , it may be wound from the vicinity of the central axis O of the sticking portion 51 . In this case, the inner end portion 76A side extends up to the containing wall portion 50 so as to cross over the winding portion 76C, and extends along the rising direction of the containing wall portion 50 similarly to the outer end portion 76B side. Let it be.

FIG. 6 is a diagram showing another form of the receiving coil. Further, in the above-described embodiment, the winding portion 76C of the power receiving coil 76 is embedded in the attachment portion 51 of the mounting base 3, but the present invention is not limited to this.
For example, if a case where the receiving coil 76 is provided as shown in FIG. 2(c) is used, the rubber member above the winding portion 76C may be omitted as shown in FIG. 6(a). . Further, considering that the inner liner that forms the inner peripheral surface 10s of the tire 10 is a rubber member, as shown in FIG. A part of the coil wire 77 may be exposed.
That is, part of the power receiving coil 76 may be exposed from the mounting base 3 as long as the coil wires 77 forming the power receiving coil 76 are prevented from contacting each other.

FIG. 7 is a diagram showing another arrangement form of the receiving coil 76. As shown in FIG. In the above embodiment, the power receiving coil 76 is provided on the mounting base 3, but the present invention is not limited to this. For example, as shown in FIG. 7, the function of the power receiving coil 76 may be separated from the mounting base 3, and the power receiving coil 76 may be configured as a power receiving coil body 76' as a component separate from the mounting base 3. FIG.
In this case, the power receiving coil body 76' can be configured, for example, as shown in FIG. 7B in a cross-sectional view. Even in this case, the mounting pedestal 3 is formed, for example, so that the spirally formed winding portion 76C and the coil wires 77 of the ends 76A and 76B extending to the sensor unit 2 do not come into contact with each other. The rubber used in the above may be used as a material and interposed between the coil wires 77, 77 so as to maintain a predetermined interval.

FIG. 8 is a diagram showing another form of arrangement of the receiving coils. Although the said embodiment demonstrated that the receiving coil 76 was directly adhere|attached to 10 s of internal peripheral surfaces of the tire 10, it is not limited to this. For example, the receiving coil 76 may be configured as shown in FIG.
The receiving coil 76 shown in FIG. 8 is provided above the housing wall portion 50 provided on the mounting base 3 . The receiving coil 76 is arranged such that the mounting surface 51a of the mounting base 3 is adhered to the inner peripheral surface 10s of the tire 10 and fixed so that the winding surface faces the radial direction of the tire 10, as in the above embodiments. It is provided on the mounting base 3 .
In this way, by providing the receiving coil 76 at a predetermined distance from the inner peripheral surface 10s of the tire 10, the tread surface 11 is stepped on the road surface and then repeatedly deformed due to kicking off the road surface. The durability of the power receiving coil 76 can be further improved because the power receiving coil 76 does not need to receive the power.

The upper part of the housing wall portion 50 of the mounting base 3 is an opening for housing the sensor unit 2 in the housing portion 52. The inner diameter D2 of the winding portion 76C of the receiving coil 76 is preferably set to be larger than the diameter D1 of the inner peripheral surface 54 of the housing wall portion 50 .

In the above embodiment, the radio wave energy generating means 100 has been described as emitting magnetic flux, but the present invention is not limited to this and radio waves may be used.

Further, although the rubber member is provided between the coil wires 77 at the winding portion 76C of the power receiving coil 76 and the like, any elastic body (material) that can be in close contact with the coil wire 77 may be used.

1 sensor module, 2 sensor unit, 3 mounting base,
10 tire, 10s inner peripheral surface, 30 attachment portion, 30a attachment surface 76 power receiving coil, 76C winding portion, 77 coil wire,
100 Radio wave energy generating means.

Claims (6)

a mounting base made of an elastic body, which is attached to the inner peripheral surface of the tire and has a receiving coil for receiving externally supplied radio wave energy and generating electric power based on the received radio wave energy;
a sensor unit that is housed in the mounting base and detects a state inside the tire by power supply from the power receiving coil;
A sensor module comprising
The power receiving coil has a winding portion, and is embedded in the mounting base with the elastic body interposed between adjacent coil wires wound in a spiral shape. module. The mounting base is
a housing section capable of housing the sensor section;
a sticking portion having a sticking surface in contact with the inner peripheral surface of the tire;
with
2. The sensor module according to claim 1, wherein the receiving coil is embedded in the attaching portion. 3. The sensor module according to claim 1, wherein the bottom surface of the accommodating portion has an inclined portion that rises from the outside toward the inside. A thickness of the elastic body from the embedded power receiving coil to the attachment surface is set to be thicker than a thickness of the elastic body interposed between adjacent coil wires in the power receiving coil. The sensor module according to claim 2 or 3. 5. The sensor module according to any one of claims 1 to 4, wherein the power receiving coil is exposed from the surface of the elastic body at a start end side and a terminal end side of the coil wire forming the winding portion. 6. The sensor module according to any one of claims 1 to 5, wherein the power receiving coil is attached with the winding surface directed around an axis perpendicular to the inner peripheral surface of the tire.

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