JP2013095399A - Tire air pressure measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire air pressure measuring device which is separated from an air valve to prevent interference during mounting and simplify mounting work, and suppresses a moment applied to the air valve by a centrifugal force generated during traveling.SOLUTION: The tire air pressure measuring device 10 includes: a seat surface 14 coming into contact with an outer peripheral surface of a wheel rim 100 into which a pneumatic tire is mounted and having an air valve insertion hole to which the air valve 30 is inserted; a mounting surface coming into contact with a drop portion 100g of the outer peripheral surface of the rim 100; first and second storing parts 11, 12 which are respectively disposed on both sides of the seat surface 14 and protruded from the seat surface 14; an electronic device measuring the air pressure of the pneumatic tire and transmitting the air pressure information; and a flat-type battery driving the electronic device and having an electrolyte. The electronic device and the battery are stored in the first and second storing parts 11, 12, and a plate surface of the battery is parallel to the mounting surface.

Description

  The present invention relates to a tire pressure measuring device that is disposed in a pneumatic tire assembled to a vehicle wheel, measures the air pressure in the pneumatic tire, and transmits the measured air pressure information to a receiving device installed in the vehicle.

  TPMS (Tire Pressure Monitoring System) is a system that knows in real time the state of air pressure in a pneumatic tire assembled on a vehicle wheel and issues a warning to the driver when an abnormality occurs. It has already been decided that TPMS must be installed in the United States, and that it is mandatory to install in new cars in Europe. In Japan, legislation is also being considered.

One type of TPMS is a direct TPMS that includes a sensor (transmitter) installed in a tire and a vehicle-side receiver that receives tire pressure information from the sensor. As a direct TPMS sensor, a direct TPMS sensor having a structure in which an electronic device for measuring tire air pressure and transmitting air pressure information is modularized and integrally mounted on the rear side of the air valve has been developed ( (See Patent Documents 1 and 2).
In addition, a direct TPMS sensor has been developed in which a module and an air valve are separated, a plate-like fixture is removably attached to the module, and the air valve is inserted and fixed in an insertion hole provided in the fixture (patent) Reference 3).

JP 2007-253934 A JP 2009-154700 A JP 2006-15909 A

  However, in the case of the TPMS sensor described in Patent Documents 1 and 2, since the total length of the TPMS sensor is the sum of the length of the air valve and the length of the module, the wheel rim (rim) has a narrow width. Depending on the shape, the TPMS sensor may interfere with the wall of the rim, making it difficult to attach to the rim. Furthermore, in the case of the sensor for TPMS described in Patent Document 1, a relatively heavy module is connected to the rear side of the air valve, so that the module is lifted outward in the radial direction of the wheel by the centrifugal force during traveling. As a result, a moment centering on the valve hole of the rim acts on the air valve, and the rubber seal of the air valve is repeatedly pressed and cracked due to running and stopping of the vehicle, and air may leak.

On the other hand, in the case of the sensor for TPMS described in Patent Document 3, the module and the air valve are separated from each other in the width direction of the rim via the fixture. For this reason, the module floats outward in the radial direction of the wheel due to the centrifugal force during traveling, and the moment around the valve hole of the rim acts on the fixture, the periphery of the valve hole of the fixture is deformed, and the fixture is removed from the air valve. There is a possibility of withdrawal. In the technique described in Patent Document 3, in order to resist the centrifugal force described above, the fixture is designed in advance at an angle larger than the angle formed by the sidewall and the drop portion of the rim, and after the fixture is attached to the rim. A spring force is applied to press the module against the rim.
For this reason, in a state where no centrifugal force is applied (zero speed) or a state where a smaller centrifugal force is assumed, the fixture does not have a shape along the rim, and the air valve is pulled out by the spring force of the fixture. There is a possibility that air is leaked due to the force acting in the direction (the fixture is lifted from the sidewall).

  In addition, the sensor for TPMS has a built-in battery for driving the sensor. Centrifugal force acts on the battery as the vehicle runs, and the electrolyte in the battery is biased depending on the installation angle of the battery, reducing the battery output. Sometimes.

  Therefore, the object of the present invention is to separate the air valve and prevent interference during installation, simplify the installation work, and suppress the moment applied to the air valve due to running centrifugal force and the decrease in output of the driving battery. An object of the present invention is to provide a tire pressure measuring device.

The tire pressure measuring device according to the present invention is in contact with the outer peripheral surface of a rim of a wheel assembled with a pneumatic tire, and is in contact with a drop portion of the outer peripheral surface of the rim and a seat surface portion having an air valve insertion hole through which an air valve is inserted. The air pressure in the pneumatic tire is measured by transmitting the air pressure information by measuring the air pressure in the pneumatic tire and the first housing portion and the second housing portion that are arranged on both sides of the mounting surface and the seat surface portion, respectively. An electronic device, and a flat battery for driving the electronic device, the battery having an electrolyte, and the electronic device and the battery are accommodated in the first accommodating portion and the second accommodating portion, The plate surface of the battery is parallel to the mounting surface.
According to such a tire pressure measuring device, a portion that accommodates an electronic device and a battery and is relatively heavy is divided into two components, a first housing portion and a second housing portion, A seat surface portion having an air valve insertion hole is disposed between the first housing portion and the second housing portion. Therefore, the positions of the center of gravity of the first housing part and the second housing part and the position of the air valve insertion hole are close to each other in the direction of the center axis of the wheel, and the moment acting on the position of the air valve insertion hole of the air valve when the vehicle is running is reduced. can do. As a result, the moment applied to the air valve by the centrifugal force during traveling can be suppressed, and air leakage or the like can be prevented.
Furthermore, since the battery plate surface is parallel to the mounting surface (ie, the drop portion), when the traveling centrifugal force acts in a direction perpendicular to the drop portion, the electrolyte in the battery is longer than the plate surface. Although it is biased toward the short thickness direction, it is evenly distributed without being biased toward the plate surface direction, so that the bias of the electrolyte in the battery is reduced as a whole, and the output of the battery is prevented from being lowered.

It is preferable that a connecting rib or an attachment rib is formed so as to be connected to the first housing portion and the second housing portion and to surround the seat surface portion.
The connecting rib connects the first housing portion and the second housing portion, and is formed in a substantially U-shaped cross section that opens in the central axis direction of the wheel.
As described above, when at least one of the connecting rib or the mounting rib is provided, the rigidity of the seat surface portion around the air valve insertion hole is increased, and the seat surface portion is not easily deformed even when a load due to centrifugal force is applied, and the air valve is inserted into the air valve. Problems such as falling out of the hole are suppressed.

The electronic device and the battery are separately housed in the first housing portion and the second housing portion, and a conductive member that electrically connects the electronic device and the battery is disposed in an internal space of the connecting rib. Preferably.
Thus, by arranging the conductive member using the internal space of the connecting rib, space saving is achieved, and the conductive member is securely held in the high-strength connecting rib, and the reliability is improved.

The seat surface portion is preferably made of metal, and the first housing portion and the second housing portion are preferably made of a coating resin insert-molded on the seat surface portion.
In this way, the vicinity of the air valve insertion hole, which is likely to be loaded by the centrifugal force during travel, can be formed of a high-strength metal, and the first storage portion and the second storage portion are formed of the coating resin to reduce weight. In addition, since the first housing portion and the second housing portion are not formed of metal, it is possible to prevent the transmission signal from the wireless antenna of the electronic device from being shielded.

  According to the present invention, it is possible to prevent interference with the vehicle wheel during installation by making it separate from the air valve, simplify the installation work, and the moment applied to the air valve by the traveling centrifugal force and the output of the driving battery A tire pressure measuring device that suppresses the decrease can be obtained.

It is an external view which shows the state which attached the tire pressure measuring apparatus which concerns on the 1st Embodiment of this invention to the outer peripheral surface of the rim | limb of a wheel. It is radial direction sectional drawing in alignment with the AA of FIG. It is an external appearance perspective view of a tire pressure measuring device. It is sectional drawing which follows the XX line of FIG. It is sectional drawing which follows the YY line of FIG. It is a see-through | perspective perspective view which shows the electronic device and battery which were accommodated in the tire pressure measuring apparatus. It is a perspective view which shows the structure of an electronic device and a battery. It is a figure which shows the effect | action by this invention. It is process drawing which shows an example which insert-molds and manufactures a tire pressure measuring apparatus.

Hereinafter, embodiments of the present invention will be described.
FIG. 1 is an external view showing a state in which a tire pressure measuring device 10 according to a first embodiment of the present invention is attached to an outer peripheral surface of a wheel rim 100 of an automobile wheel.
The wheel rim 100 has a substantially cylindrical shape, and a tire (not shown) is accommodated between an outer flange 100a and an inner flange 100b formed at both ends thereof. An outer bead sheet 100c that receives a bead of the tire is formed inside the outer flange 100a. A drop part 100g having the smallest diameter is formed inside the outer bead sheet 100c, and the outer bead sheet 100c and the drop part (outer side) 100g are smoothly connected via the outer side wall part 100e. An inner bead sheet 100d is formed inside the drop part 100g via an inner sidewall part 100f, and the inner bead sheet 100d is connected to the inner flange 100b.
The “outside” and “inside” in the names of the parts correspond to the positions when the wheel is attached to the vehicle.

In addition, a rim side air valve insertion hole 100h (see FIG. 2) through which the air valve 30 is inserted is opened in the outer side wall portion 100e. The tire pressure measuring device 10 is attached to the outer peripheral surface of the wheel rim 100 while contacting the side wall portion 100e and the drop portion 100g of the wheel rim 100 with the back surface of the seat surface portion 14 (see FIG. 3). Here, the back surface of the seat surface portion 14 is in contact with the outer peripheral surface of the rim. Specifically, the side surface 14t of the back surface of the seat surface portion 14 is in contact with the outer sidewall portion 100e and the connection phase between the outer sidewall portion 100e and the drop portion 100g. In addition, the mounting surface 14 s serving as the bottom surface portion of the back surface of the seat surface portion 14 is in contact with the drop portion. Further, it is not necessary to provide a space between the attachment surface 14s and the drop part.
Normally, the tire pressure measuring device 10 can be fixed to the wheel rim 100 by the mounting force of the air valve 30, but the tire pressure measuring device 10 may be bonded to the wheel rim 100 with a double-sided tape or the like. Further, the seat surface portion 14 is formed with an air valve insertion hole 14h (see FIG. 3), and the air valve insertion hole 14h (see FIG. 3) is concentric with the rim side air valve insertion hole 100h (see FIG. 2). An air pressure measuring device 10 is arranged. The air valve 30 is fixedly inserted through the air valve insertion hole 14h and the rim-side air valve insertion hole 100h.
In the tire pressure measuring device 10, a cylindrical first housing portion 11 and a second housing portion 12 are formed so as to protrude on both sides of the seat surface portion 14, and the first housing portion 11 and the second housing portion 12 are formed. Assuming that the line connecting the centers of the housing portions 12 (the direction in which the first housing portion 11 and the second housing portion 12 are arranged) is the longitudinal direction L, the L direction is parallel to the circumferential direction of the wheel rim 100. .

  The wheel rim 100 can be manufactured, for example, by rolling a steel plate having a predetermined shape into a cylindrical shape and roll forming, but is not limited thereto. In addition, although a so-called two-piece automobile wheel is formed by welding a substantially disc-shaped disk 101 to the wheel rim 100, the present invention is not limited to a two-piece automobile wheel, and can be applied to any wheel. Can do.

FIG. 2 is a radial cross-sectional view taken along line AA in FIG. 1 and shows a state where a pneumatic tire 150 is assembled to the wheel rim 100.
In FIG. 2, an air valve 30 is a so-called snap-in valve and has a structure in which a valve stem is covered with rubber. The air valve 30 includes a rubber body 31 including a valve stem and the like that is exposed to the outside of the wheel rim 100 in the axial direction, and a rubber base 32 positioned on the outer side wall on the outer peripheral surface of the wheel rim 100. An annular recess 32a is formed on the base 32 side. The groove width of the annular recess 32a is standardized to 3.8 mm and the diameter is 15 mm. The diameter of the rim side air valve insertion hole 100h is smaller than 15 mm (usually standardized to 11.3 + 0.4 (mm) or 11.5 ± 0.2 (mm)), and the annular recess 32a bites into the rim side air valve insertion hole 100h. Thus, air sealability is ensured. Further, the diameter of the air valve insertion hole 14h of the tire pressure measuring device 10 is smaller than the diameter of the annular recess 32a and larger than the diameter of the rim-side air valve insertion hole 100h (for example, a diameter of 12 to 14 mm).

When the air valve 30 is inserted from the tire pressure measuring device 10 side in a state where the positions of the air valve inserting hole 14h of the tire pressure measuring device 10 and the rim side air valve inserting hole 100h are aligned, the annular recess 32a has a rim with a small diameter. Since it is compressed by the side air valve insertion hole 100h, excessive pressure is not applied to the air valve insertion hole 14h. In this way, the edge of the base portion 32 comes into contact with the surface of the seat surface portion 14 while the air valve 30 is inserted into the air valve insertion hole 14h and the rim-side air valve insertion hole 100h.
Although the air valve insertion hole 14h and the rim-side air valve insertion hole 100h may have the same diameter, the positional relationship between the drop portion 100g and the rim-side air valve insertion hole 100h differs depending on the wheel. It is preferable that the hole 14h has a larger diameter than the rim-side air valve insertion hole 100h.

  The air valve used in the present invention is not limited to a snap-in valve, and for example, a clamp-in valve that fastens the valve body to a wheel rim with a nut can be applied. These air valves are defined in, for example, JIS-D4207 and JATMA (Japan Automobile Tire Association).

On the other hand, in FIG. 2, the tire pressure measuring device 10 is configured such that the seat surface portion 14 follows the shape formed by the drop portion 100g from the outer sidewall portion 100e so as to contact the outer sidewall portion 100e and the drop portion 100g. In addition, the top surfaces of the first housing portion 11 and the second housing portion 12 are substantially parallel to the drop portion 100g. Therefore, the tire pressure measuring device 10 has a substantially rectangular cross-sectional shape when viewed from the positions of the first housing portion 11 and the second housing portion 12.
Thus, by designing the shape and dimensions of the tire pressure measuring device 10 in accordance with the shapes and dimensions of the outer sidewall portion 100e and the drop portion 100g, the tire pressure measuring device 10 can be connected to the outer hump 100x of the wheel rim 100. The inner hump 100y can be positioned radially inward from the line B (see FIG. 1) connecting the apexes of the inner hump 100y. In this case, the tire pressure measuring device 10 does not protrude outward from the line B, so that the tire bead is prevented from interfering with the tire pressure measuring device 10 and being damaged when the tire 150 is replaced.

  Next, a detailed configuration of the tire pressure measuring device 10 according to the first embodiment will be described with reference to FIGS. 3 is an external perspective view of the tire pressure measuring device 10, FIG. 4 is a cross-sectional view taken along line XX in FIG. 3, and FIG. 5 is a cross-sectional view taken along line YY in FIG. 6 is a perspective view showing an electronic device and a battery housed in the tire pressure measuring device 10, and FIG. 7 is a perspective view showing a configuration of the electronic device and the battery.

  In FIG. 3, the tire pressure measuring device 10 is long in the longitudinal direction L, and the first housing portion 11 and the second housing portion 12 are disposed on both sides of the seat surface portion 14 when viewed in the L direction. Furthermore, when viewed in a direction perpendicular to the mounting surface 14s, the first housing portion 11 and the second housing portion 12 protrude from the surface of the seat surface portion 14 (the surface opposite to the mounting surface 14s). As shown in FIG. 2, the seat surface portion 14 has a substantially plate shape having a cross-sectional shape bent in a "<" shape, and the air valve is inserted into the side surface 14t of the seat surface portion 14 in contact with the sidewall portion 100e at substantially the center position. A hole 14h is formed. In addition, the seat surface part 14 has connected the 1st accommodating part 11 and the 2nd accommodating part 12 by the drop part 100g side. On the other hand, when viewed in a direction perpendicular to the mounting surface 14 s, the seat surface portion 14 has an arc shape extending from the upper surfaces of the first housing portion 11 and the second housing portion 12 to the side wall portion 100 e side.

Further, a connecting rib 15 and a mounting rib 17 are formed at both end edges of the seat surface portion 14 in the W direction (width direction perpendicular to the L direction), respectively. The connecting rib 15 and the mounting rib 17 are connected to the first accommodating portion 11 and the second accommodating portion 12, respectively, and are formed so as to surround the seat surface portion 14 (that is, the air valve insertion hole 14h). The mounting rib 17 is located on the outer side wall portion 100e side, and the connecting rib 15 is located on the drop portion 100g side. As shown in the sectional view 5, the connecting rib 15 is raised higher than the mounting rib 17. In addition, it is not essential to provide both the connecting rib and the mounting rib on both sides of the seat surface portion 14.
As described above, when at least one of the connecting rib or the mounting rib is provided, the rigidity of the seat surface portion 14 around the air valve insertion hole 14h is increased, and the seat surface portion 14 is not easily deformed even when a load due to centrifugal force is applied. Inconveniences such as the air valve 30 falling out of the air valve insertion hole 14h are suppressed.

The seat surface portion 14 is formed integrally with the connecting rib base 15x (see FIGS. 5 and 9) and the mounting rib 17 by press-molding a metal plate such as a steel plate, and the first accommodating portion 11 and the second accommodating portion 12 are formed. Is made of a coating resin that is insert-molded on the seat surface portion 14.
In this way, the vicinity of the air valve insertion hole 14h that is easily loaded by the centrifugal force during traveling can be formed of a high-strength metal, and the first storage portion 11 and the second storage portion 12 are formed of a coating resin. To reduce weight. Furthermore, by not forming the first housing portion 11 and the second housing portion 12 from metal, it is possible to prevent transmission signals from the wireless antenna 25 and the like of the electronic device 20 described below from being shielded.
As shown in FIG. 5, the connecting rib 15 is configured by covering the surface of the connecting rib base 15 x with a coating resin 60 for forming the first storage portion 11 and the second storage portion 12.

Here, as shown in FIGS. 6 and 7, a battery (in this example, a button battery) 40 is accommodated in the internal space of the first accommodating portion 11, and the electronic device 20 is disposed in the internal space of the second accommodating portion 12. Contained. Further, the battery 40 and the electronic device 20 are electrically connected by conductive members (for example, copper pieces) 51 and 52 extending in the L direction, and the electronic device 20 is driven.
As shown in FIG. 7, the electronic device 20 includes a pressure sensor (diaphragm in this example) 22 that measures the pressure of a pneumatic tire, and a processing device that controls the entire electronic device 20 (in this example, a semiconductor circuit). 23, a transmitter (in this example, a wireless transmission chip) 24 that wirelessly transmits pressure information measured by the pressure sensor 22, a wireless antenna 25 used for transmitting pressure information, and a printed circuit board 21 on which these components are mounted. Is provided.

4 is a cross-sectional view taken along line XX in FIG. 3 (that is, along the L direction). In this example, the tire pressure measuring device 10 is symmetric with respect to the center line CL with the air valve insertion hole 14h as the center. In addition, the battery 40 and the electronic device 20 are disposed in the internal spaces of the first housing portion 11 and the second housing portion 12, respectively. Furthermore, the back surfaces of the first storage portion 11 and the second storage portion 12 are the side surface 14t and the mounting surface 14s (the surfaces in contact with the side wall portion 100e and the drop portion 100g, the mounting surface in FIG. 4). 14s only) and these surfaces are in contact with the outer peripheral surface of the wheel rim 100.
The battery 40 and the electronic device 20 may be fixed by filling a filling resin or the like in the internal spaces of the first housing portion 11 and the second housing portion 12.

FIG. 5 is a cross-sectional view taken along line YY in FIG. 3 (that is, along the W direction). The connecting rib 15 and the mounting rib 17 are also formed by press molding, and conductive members 51 and 52 are arranged inside the connecting rib 15. Here, as described above, the connecting rib 15 is configured by covering the surface of the connecting rib base 15 x with the coating resin 60 for forming the first storage portion 11 and the second storage portion 12. The conductive members 51 and 52 may be fixed by filling the connecting ribs 15 with a filling resin.
Thus, by arranging the conductive members 51 and 52 using the internal space of the connecting rib 15, the space is saved and the conductive members 51 and 52 are securely held in the high-strength connecting rib 15. And increased reliability.
Here, the present invention is characterized in that the plate surface 40s of the battery 40 is parallel to the mounting surface 14s. When the plate surface 40s of the battery 40 is parallel to the mounting surface 14s (that is, the drop portion 100g), when the traveling centrifugal force acts in a direction perpendicular to the drop portion 100g, the electrolyte in the battery 40 is transferred to the plate surface 40s. Although it is biased in the direction of the shorter thickness t, it is evenly distributed without being biased in the direction of the plate surface 40s, and as a whole, the bias of the electrolyte in the battery 40 is reduced, and the output of the battery is reduced. Suppress.
In the present invention, the battery 40 is a flat battery and contains an electrolytic solution. Here, the “flat shape” means a substantially cylindrical shape having a maximum diameter D in the plate surface direction of the bottom surface larger than the thickness t, and is not limited to the cylindrical shape, and the length D of one side is larger than the thickness t. May be a large quadrangular prism shape.
A positive electrode and a negative electrode are respectively disposed on the opposing bottom surfaces of the flat battery.

  Next, another operation according to the present invention will be described with reference to FIG. In the present invention, the portion that accommodates the electronic device 20 and the battery 40 and is relatively heavy is divided into two components, a first housing portion 11 and a second housing portion 12, and these first portions are divided. A seat surface portion 14 having an air valve insertion hole 14 h is disposed between the housing portion 11 and the second housing portion 12. Accordingly, when the origin of the moment acting on the tire pressure measuring device 10 by the centrifugal force when the vehicle is traveling is 14Ce (center of the air valve insertion hole 14h to which the air valve 30 is attached), the first housing portion 11 and the second housing portion 12 are used. Since the distance La in the wheel axis direction O between the center of gravity 10Ce of the (tire pressure measuring device 10) and the origin 14Ce is shortened, the moment can be reduced (FIG. 8A). As a result, the moment applied to the air valve by the centrifugal force during traveling can be suppressed, and air leakage or the like can be prevented. The centrifugal force is generated by the rotation of the tire, and a vector of the centrifugal force is generated outward and perpendicular to the wheel center axis. The centrifugal force causes a moment to act on the origin 14Ce with the distance La as an arm.

  On the other hand, in the case of the technique described in Patent Document 3, the air valve 30 and the casing 1000 (the heavy part accommodating the electronic device or the like) are separated from each other in the wheel axis direction, and both are coupled by the fixture 200. . Therefore, when the distance Lb in the wheel axis direction between the center of gravity 1000Ce of the casing 1000 and the origin 14Ce is longer than La (FIG. 8B), and the fixture 200 cannot withstand centrifugal force, the casing about the origin 14Ce is the center. Together with the body 1000, it floats from the drop part of the wheel rim. Then, there is a possibility that the floating amount will eventually increase and exceed the limit of the holding force of the air valve 30, or the fixture 200 may be deformed near the origin 14Ce, and the air valve 30 may come off from the fixture 200. Needless to say, similar problems occur when the housing 1000 is attached to the rear side of the base portion 32 of the air valve 30 as in the technique described in Patent Document 1.

As described above, according to the tire pressure measuring device of the present invention, the moment applied to the air valve due to the centrifugal force during traveling can be suppressed, and air leakage and the like can be prevented. Further, by separating the tire pressure measuring device from the air valve, it is possible to prevent interference with the wheel rim at the time of mounting, and to simplify the mounting operation. Furthermore, a general-purpose air valve can be freely selected and used as appropriate, so an air valve that has already been established with safety can be used, and an air valve suitable for a tire or a wheel (for example, a snap-in valve is used for a low-speed wheel and 210 km) A clamp-in valve is used for high-speed wheels exceeding / h).
Furthermore, since the tire pressure measuring device according to the present invention has a structure in which the first housing portion and the second housing portion are arranged on both sides of the seat surface portion, the direction in which the first housing portion and the second housing portion are arranged is arranged. Longer and shorter in the vertical direction (width direction). Therefore, it can be mounted without interfering with a wheel having a narrow rim width such as a light vehicle, and can be applied to various wheels having different sizes and shapes.

Furthermore, as shown in FIG. 4, in the present invention, the seat surface portion 14 (the air valve insertion hole 14 h) is positioned between the first housing portion 11 and the second housing portion 12. Accordingly, since the weight is distributed to the first accommodating portion 11 and the second accommodating portion 12, the origin 14Ce is generated by the centrifugal force of the accommodating portion 11 with the arm from the origin 14Ce to the center of gravity of the first accommodating portion 11. And the moment generated at the origin 14Ce due to the centrifugal force of the accommodating part 12 with the arm from the origin 14Ce to the center of gravity of the second accommodating part 12 cancel each other, so that the moment acting on the origin 14Ce is reduced, and the air valve It is difficult to apply a load to the air and air leakage can be suppressed.
In particular, when the tire pressure measuring device 10 is symmetric with respect to the center line CL, the moment acting in the L direction is further reduced. Preferably, when the masses of the constituent parts of the tire pressure measuring device 10 on the left and right of the center line CL are adjusted substantially evenly, the moment acting in the L direction is further reduced. In this case, for example, a balancer may be attached to the lighter one of the battery 40 and the electronic device 20. Further, the weights of both the first housing part 11 and the second housing part 12 may be balanced.
Further, as shown in FIG. 4, in the present embodiment, it is preferable that the attachment surface 14s, which is the back surface of the seat surface portion 14, has a curved shape along the drop portion 100g (not shown). For this reason, even if a moment that swings in the L direction is applied, the drop portion 100g supports the tire air pressure measuring device 10, so that it is difficult to directly apply a load to the air valve.

FIG. 9 is a process diagram showing an example of manufacturing the tire pressure measuring device 10 by insert molding. First, the seat surface portion 14 is formed integrally with the connecting rib base 15x and the mounting rib 17 by press forming a metal plate such as a steel plate (FIG. 9A). Are formed respectively.
Next, as illustrated in FIG. 9B, the covering resin 60 that becomes the first housing portion 11 and the second housing portion 12 is insert-molded in the seat surface portion 14. Thus, the edge portion 14e of the seat surface portion 14 is covered with the first storage portion 11 and the second storage portion 12, respectively, and the connection rib base 15x is covered with the coating resin 60, whereby the connection rib 15 is formed. As the coating resin 60, for example, glass fiber reinforced plastic can be used.

The present invention is not limited to the above embodiment. For example, the shapes of the seat surface portion, the first housing portion and the second housing portion, the connecting rib and the mounting rib are not limited, and the number of the connecting rib and the mounting rib is not limited.
In addition, the electronic device 20 and the battery 40 are integrated into an assembly, and the assembly is accommodated in the first accommodating portion 11 (or the second accommodating portion 12) and the balancer weight 55 having substantially the same mass as the assembly. You may accommodate in the 2nd accommodating part 12 (or 1st accommodating part 11) which is the other accommodating part.
The battery is not particularly limited as long as it is a flat battery.

DESCRIPTION OF SYMBOLS 10 Tire pressure measuring device 14s attachment surface 11 1st accommodating part 12 2nd accommodating part 14 Seat surface part 14h Air valve insertion hole 15 Connecting rib 17 Attachment rib 20 Electronic device 30 Air valve 40 Battery 40s Battery plate surface 51, 52 Conductive member 100 Wheel rim (rim)
100g Drop part 150 Pneumatic tire O Wheel axial direction

Claims (4)

A seat surface portion having an air valve insertion hole through which an air valve is inserted, in contact with the outer peripheral surface of a rim of a wheel assembled with a pneumatic tire;
Of the outer peripheral surface of the rim, a mounting surface in contact with the drop part,
A first accommodating portion and a second accommodating portion, which are respectively arranged on both sides of the seat surface portion and project from the seat surface portion;
An electronic device for measuring the air pressure in the pneumatic tire and transmitting the air pressure information;
A flat battery for driving the electronic device and having an electrolyte, and
The electronic device and the battery are accommodated in the first accommodating portion and the second accommodating portion,
A tire pressure measuring device in which a plate surface of the battery is parallel to the mounting surface.   2. The tire pressure measuring device according to claim 1, wherein at least one of a connecting rib or a mounting rib is formed so as to be connected to the first housing portion and the second housing portion and surround the seat surface portion. The electronic device and the battery are separately housed in the first housing portion and the second housing portion,
The tire pressure measuring device according to claim 2, wherein a conductive member that electrically connects the electronic device and the battery is disposed in an internal space of the connecting rib.   The tire pressure measuring device according to any one of claims 1 to 3, wherein the seat surface portion is made of metal, and the first housing portion and the second housing portion are made of a coating resin insert-molded on the seat surface portion. .

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