Pointer reading device, physical quantity measurement device, and method for attaching a pointer reading device

Abstract

To provide a pointer reading device, a physical quantity measurement device, and a mounting method of a pointer reading device which can suppress increase in reading errors.SOLUTION: A pointer reading device 10 has a magnetic sensor 14 for detecting a magnetic field of a magnet 9 fixed to a support member 8, a measurement circuit board 13 for inputting a signal output from the magnetic sensor 14 and outputting a signal according to a rotation angle of a pointer, a substrate support part 121 for holding the measurement circuit board 13, a guide member 12 having a cylinder part 122 extending from the substrate support part 121, and a case member which has a hole part formed at a position corresponding to the support member 8 and stores the cylinder part 122 of the guide member 12 in the hole part 116. An engagement claw part 117 extending from the circumference vicinity of the hole part of the case member is engaged with the support member 8 in a state in which the cylinder part 122 is not stored in the hole part, and is energized to the cylinder part 122 in a state in which the cylinder part 122 is stored in the hole part, and engagement with the support member is released.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a pointer reading device, a physical quantity measuring device, and a method for attaching a pointer reading device.

Background Art

[0002] Conventionally, a pointer reading device for detecting the rotation of the pointer of an aneroid pressure gauge has been known (for example, Patent Document 1, etc.). In Patent Document 1, a magnet is provided at the rotation center of the pointer, and a plurality of magnetic sensors are arranged so as to face the magnet. Thus, as the magnet rotates in conjunction with the rotation of the pointer, the magnetic field by the magnet changes. Then, by detecting this change in the magnetic field with the magnetic sensors, the rotation angle of the pointer can be converted into an electrical signal.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, in order to suppress the influence on the rotation of the pointer, it is desirable to miniaturize the magnet attached to the pointer as much as possible. However, when the magnet is miniaturized, the magnetic field by the magnet becomes weak. Then, when attaching the pointer reading device to the aneroid pressure gauge, if the deviation in the attachment position of the magnetic sensor with respect to the magnet is large, the error becomes large. Therefore, even if the magnetic sensor is calibrated, there is a problem that the deviation in the position of the magnetic sensor with respect to the magnet cannot be corrected completely, and the reading error becomes large.

[0005] An object of the present invention is to provide a pointer reading device, a physical quantity measuring device, and a method for attaching a pointer reading device that can suppress an increase in reading error even when the magnet is miniaturized.

Means for Solving the Problem

[0006] The pointer reading device of the present invention is a pointer reading device that reads the rotation angle of a pointer that rotates about a rotation axis according to the physical quantity of a fluid to be measured. The pointer reading device includes a magnetic sensor that detects the magnetic field of a magnet fixed to a support member attached to the tip of the rotation axis, a measurement circuit board to which the magnetic sensor is attached, inputs a signal output from the magnetic sensor, and outputs a signal corresponding to the rotation angle of the pointer, a board support portion that holds the measurement circuit board, and a guide member having a cylindrical portion extending from the board support portion. A hole portion is formed at a position corresponding to the support member, and a case member that houses the cylindrical portion of the guide member in the hole portion. The case member extends from the vicinity of the peripheral edge of the hole portion toward the support member and has an engaging claw portion that can engage with the support member. The engaging claw portion engages with the support member in a state where the cylindrical portion is not housed in the hole portion, and is biased by the cylindrical portion in a state where the cylindrical portion is housed in the hole portion to release the engagement with the support member.

[0007] In the present invention, the support member and the case member are positioned by the engagement of the engaging claw portion of the case member with the support member to which the magnet is fixed. Then, after fixing the case member in this state, a guide member that holds the measurement circuit board to which the magnetic sensor is attached is housed in the hole portion of the case member. Thereby, the guide member and the support member are positioned. Therefore, the magnet and the magnetic sensor are positioned via the measurement circuit board, the guide member, the hole portion of the case member, and the support member, so that it is possible to suppress the positional relationship between the magnet and the magnetic sensor from being displaced. Therefore, even if the magnet is miniaturized, it is possible to prevent the reading error from increasing due to the inability to correct the displacement of the position of the magnetic sensor with respect to the magnet. In addition, the engaging claw portion that positions the case member with respect to the support member is biased by the cylindrical portion in a state where the cylindrical portion of the guide member is housed in the hole portion of the case member to release the engagement with the support member. Therefore, it is possible to suppress the rotation of the pointer from being affected by the engaging claw portion.

[0008] In the pointer reading device of the present invention, the case member preferably includes a case main body portion that is cylindrical and can accommodate the measurement circuit board and the guide member therein, a case bottom portion that covers one end side of the case main body portion and in which the hole portion is formed, and a case lid portion that covers the other end of the case main body portion and is detachably attached to the case main body portion. In this configuration, since the case lid portion is detachably attached to the case main body portion, it is possible to easily perform maintenance on the measurement circuit board, the magnetic sensor, etc. housed in the case main body portion.

[0009] In the pointer reading device of the present invention, it is preferable that a protruding portion that abuts against the guide member and biases the guide member toward the support member is formed at a position corresponding to the guide member housed in the case main body portion on the case lid portion. In this configuration, since the protruding portion that biases the guide member toward the support member is formed on the case lid portion, the guide member can be biased toward the support member when the case lid portion is attached to the case main body portion. Therefore, it is possible to suppress the position of the guide member with respect to the support member from shifting when the case lid portion is attached to the case main body portion.

[0010] The physical quantity measuring device of the present invention is characterized by including the above-described pointer reading device, the pointer that rotates about the rotation axis according to the physical quantity of the fluid to be measured, the magnet, and the support member that fixes the magnet. In this configuration, the same effects as described above can be achieved. Further, by detecting the magnetic field of the magnet attached to the pointer with a magnetic sensor, a signal corresponding to the rotation angle of the pointer corresponding to the physical quantity of the fluid to be measured can be output.

[0011] In the physical quantity measuring device of the present invention, the support member preferably includes a columnar support member main body portion, a storage recess formed at one end of the support member main body portion and housing the magnet, and a mounting portion extending from the other end of the support member main body portion and engageable with the pointer. In this configuration, since an attachment portion engageable with the pointer is provided on the support member having the storage recess for storing the magnet, the magnet can be easily attached to the pointer.

[0012] The method for attaching the pointer reading device of the present invention is a method for attaching a pointer reading device that reads the rotation angle of a pointer that rotates about a rotation axis according to the physical quantity of the fluid to be measured, from the vicinity of the periphery of the hole portion of the the pointer reading device engagement claw portion of the extends from the vicinity of the periphery of the hole portion, is attached to the tip of the rotation axis of the pointer, and fixes a magnet case member is the engaged with the support member to position the position of the hole portion of the case member with respect to the support member in a positioning step, by fixing the case member to the main body portion of the physical quantity measuring device that houses the pointer a fixing step of fixing the position of the case member with respect to the support member, detects the magnetic field of the magnet fixed to the support member a storage and release step of storing a cylindrical portion extending from a substrate support portion that supports a measurement circuit board to which a magnetic sensor is attached in the hole portion of the case member, and releasing the engagement state between the engagement claw portion and the support member by the cylindrical portion, characterized by comprising. by doing In this configuration, the same effects as described above can be achieved. In this configuration, the same effects as described above can be achieved.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0014] [First Embodiment] The physical quantity measuring device 1 according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an overview of the physical quantity measuring device 1 of the present embodiment, FIG. 2 is an exploded perspective view showing an overview of the physical quantity measuring device 1, and FIG. 3 is a cross-sectional perspective view showing an overview of the physical quantity measuring device 1. As shown in FIGS. 1 to 3, the physical quantity measuring device 1 includes an introduction member 2, a physical quantity measuring device main body 3, a Bourdon tube 4, a pointer 5, a pointer transmission mechanism 6, a scale plate 7, a support member 8, a magnet 9, and a pointer reading device 10. Thus, the physical quantity measuring device 1 of the present embodiment is configured as a Bourdon tube type pressure gauge.

[0015] [Introduction Member 2] The introduction member 2 is a so-called joint member that is attached to an attachment portion such as a pipe (not shown), and is formed of a metal member such as brass, stainless steel, or steel. The introduction member 2 includes an introduction member main body 21 and a male screw portion 22 provided at the tip of the introduction member main body 21. Inside the introduction member main body 21, a fluid introduction hole 211 for introducing the fluid to be measured from the attachment portion is formed, and the fluid introduction hole 211 is connected to the Bourdon tube 4. Further, the male screw portion 22 is screwed into the attachment portion.

[0016] [Physical Quantity Measuring Device Main Body 3] The main body 3 of the physical quantity measuring device is made of metal and formed in a bottomed cylindrical shape, and houses a Bourdon tube 4, a pointer 5, a pointer transmission mechanism 6, a scale plate 7, a support member 8, and a magnet 9 inside. And the opening of the main body 3 of the physical quantity measuring device is covered by the disk portion 1122 of the case bottom portion 112 of the pointer reading device 10 described later. Note that the main body 3 of the physical quantity measuring device is not limited to the above configuration, and may be made of resin, for example.

[0017] [Bourdon tube 4] The Bourdon tube 4 is made of metal, and the tip thereof is displaced according to the pressure of the fluid to be measured introduced therein. The physical quantity measuring device 1 of the present embodiment is configured to be able to measure the pressure of the fluid to be measured by transmitting the displacement amount of the Bourdon tube 4 to the pointer 5 via the pointer transmission mechanism 6. Further, in the present embodiment, as described above, the Bourdon tube 4 is connected to the introduction member 2 and communicates with the fluid introduction hole 211.

[0018] [Pointer 5] The pointer 5 is a member that indicates the pressure of the fluid to be measured detected by the Bourdon tube 4, and has a pointer body 51 and a rotation shaft 52. The pointer body 51 rotates about the rotation shaft 52, and indicates the scale 71 (described later) displayed on the scale plate 7 according to the pressure of the fluid to be measured detected by the Bourdon tube 4. The rotation shaft 52 passes through the shaft insertion hole 72 formed in the central portion of the scale plate 7 and is connected to the pointer transmission mechanism 6. Thereby, the displacement amount of the tip of the Bourdon tube 4 due to the pressure of the fluid to be measured can be transmitted to the pointer body 51 via the pointer transmission mechanism 6.

[0019] [Pointer transmission mechanism 6] The pointer transmission mechanism 6 is configured with a so-called internal mechanism, and is configured to expand the displacement amount of the tip of the Bourdon tube 4 and transmit it to the pointer 5.

[0020] [Scale plate 7] The scale plate 7 is arranged to face the disk portion 1122 of the case bottom 112 of the pointer reading device 10 described later, and a scale 71 is displayed on the surface. Thereby, the physical quantity measuring device 1 is configured to be able to display the pressure of the fluid to be measured by causing the pointer body 51 to indicate the scale 71. Further, a shaft portion insertion hole 72 penetrating from the front surface to the back surface is formed in the scale plate 7.

[0021] [Support member 8] FIG. 4 is a cross-sectional perspective view showing an outline of the main part of the pointer reading device 10. As shown in FIGS. 1 to 4, the support member 8 is a member for attaching the magnet 9 to the tip of the rotation shaft 52 of the pointer 5. In the present embodiment, the support member 8 has a support member main body portion 81, a storage recess 82, and a mounting portion 83.

[0022] The support member main body portion 81 is made of resin and has a columnar shape. And a storage recess 82 in which the magnet 9 is fitted and stored is provided at one end of the support member main body portion 81. Further, a claw-shaped mounting portion 83 that can be engaged with the pointer body 51 is provided at the other end of the support member main body portion 81. Thereby, in the present embodiment, the support member main body portion 81 is configured to be attachable to the pointer 5. Thus, in the present embodiment, since the support member 8 having the storage recess 82 for storing the magnet 9 is provided with the mounting portion 83 that can be engaged with the pointer 5, the magnet 9 can be easily attached to the pointer 5. Furthermore, in the present embodiment, the other end of the support member main body portion 81 and the tip of the rotation shaft 52 are adhered by an adhesive member 84 formed of a double-sided tape or the like. Note that the support member 8 is not limited to the above configuration. For example, it may be attached to the pointer only by the mounting portion without providing the adhesive member, or it may be attached to the pointer only by the adhesive member without providing the mounting portion. Further, the magnet is not limited to being fitted into the storage recess. For example, the magnet may be adhered to the end of the support member by an adhesive member.

[0023] [Pointer reading device 10] The pointer reading device 10 is a device that reads the rotation angle of a pointer body 51 that rotates about a rotation axis 52 in response to the pressure of the fluid to be measured. In the present embodiment, the pointer reading device 10 includes a case member 11, a guide member 12, a measurement circuit board 13, a magnetic sensor 14, a communication board 15, a battery 16, a first packing 171, a second packing 172, and a third packing 173.

[0024] [Case member 11] The case member 11 is a case that houses the guide member 12, the measurement circuit board 13, the magnetic sensor 14, the communication board 15, the battery 16, and the like. In the present embodiment, the case member 11 includes a case main body portion 111, a case bottom portion 112, and a case lid portion 113.

[0025] The case main body portion 111 is made of resin and has a cylindrical shape, and houses the guide member 12, the measurement circuit board 13, the magnetic sensor 14, the communication board 15, the battery 16, and the like inside. In the present embodiment, the pointer reading device 10 is attached to the physical quantity measuring device 1 so that the case main body portion 111 is disposed at a position where the scale 71 of the scale plate 7 is not displayed. Thereby, when the pointer reading device 10 is attached to the physical quantity measuring device main body portion 3, it is possible to suppress the indication of the scale 71 by the pointer 5 from becoming difficult to see. Further, in the present embodiment, claw portions 114 are formed in the vicinity of the four corners of the case main body portion 111. Then, the claw portions 114 are engaged with the engaging groove portions 115 of the case lid portion 113 described later, so that the case lid portion 113 is configured to be detachably attached to the case main body portion 111.

[0026] The case bottom portion 112 is configured to cover one end side of the case main body portion 111. In the present embodiment, the case bottom portion 112 includes a case bottom main body portion 1121 and a disk portion 1122. The case bottom body part 1121 is made of resin and is configured to cover one end of the case main body part 111. A hole part 116 is formed in the case bottom body part 1121 at a position facing the support member 8. Further, a plurality of engaging claw parts 117 extending from the vicinity of the periphery of the hole part 116 toward the support member 8 are provided in the case bottom body part 1121. Details of the engaging claw part 117 will be described later. The disk part 1122 is formed in a disk shape from a transparent resin, is disposed so as to cover the opening of the physical quantity measuring device main body part 3, and is detachably attached to the physical quantity measuring device main body part 3. Thereby, the case bottom 112 is made detachable from the physical quantity measuring device main body part 3. Further, since the disk part 1122 is formed of a transparent resin, the pointer 5 and the scale plate 7 can be visually recognized through the disk part 1122.

[0027] The case lid part 113 is disposed so as to cover the other end of the case main body part 111 and is detachably formed on the case main body part 111 as described above. Specifically, engaging groove parts 115 are formed in the vicinity of the four corners of the case lid part 113, and the claw part 114 of the case main body part 111 can be engaged with the engaging groove parts 115. Further, in the present embodiment, an annular first packing 171 is interposed between the case lid part 113 and the case main body part 111, and the space between the case lid part 113 and the case main body part 111 is sealed. Thus, in the present embodiment, since the case lid part 113 is detachably attached to the case main body part 111, it is possible to easily perform maintenance on the measurement circuit board 13, the magnetic sensor 14, etc. stored in the case main body part 111, or replace the battery 16. Furthermore, in the present embodiment, a protruding part 118 protruding toward the guide member 12 is formed on the inner surface side of the case lid part 113 that covers the case main body part 111 at a position corresponding to the guide member 12.

[0028] [Guide member 12] The guide member 12 is a member for positioning the measurement circuit board 13 to which the magnetic sensor 14 is attached at a predetermined position. In the present embodiment, the guide member 12 has a substrate support portion 121 and a cylindrical portion 122.

[0029] The substrate support portion 121 is made of resin and formed in a bottomed cylindrical shape, and is configured to house and hold the measurement circuit board 13 therein. The cylindrical portion 122 is formed in a cylindrical shape and extends from the substrate support portion 121 toward the hole portion 116 of the case bottom portion 112. And the cylindrical portion 122 is configured to be housed in the hole portion 116 of the case bottom portion 112. At this time, the cylindrical portion 122 is configured to bias the engagement claw portion 117 provided on the case bottom portion 112. Furthermore, as described above, since the protruding portion 118 is formed at a position corresponding to the guide member 12 on the case lid portion 113, when the case lid portion 113 is attached to the case main body portion 111, the guide member 12 is biased toward the support member 8 by the protruding portion 118. Therefore, it is possible to suppress the position of the guide member 12 with respect to the support member 8 from being displaced in a state where the case lid portion 113 is attached to the case main body portion 111. In the present embodiment, a second packing 172 is interposed between the protruding portion 118 and the substrate support portion 121, and a third packing 173 is interposed between the substrate support portion 121 and the case bottom portion 112.

[0030] [Measurement circuit board 13] The measurement circuit board 13 has electronic components (not shown) arranged thereon and is electrically connected to the communication board 15. And in the present embodiment, the magnetic sensor 14 is attached to the measurement circuit board 13. Thereby, the measurement circuit board 13 is configured to input a signal output from the magnetic sensor 14 and output a signal corresponding to the rotation angle of the pointer 5 to the communication board 15.

[0031] [Magnetic sensor 14] The magnetic sensor 14 is configured to include a magnetic detection element and is capable of detecting the magnetic field of the magnet 9 fixed to the support member 8. In the present embodiment, the magnetic sensor 14 is attached to the surface of the measurement circuit board 13 on the side facing the magnet 9. Accordingly, when the pointer 5 rotates, the magnet 9 attached to the tip of the rotation shaft 52 via the support member 8 rotates, and the magnetic sensor 14 is configured to be able to detect this rotation angle. Then, as described above, the signal detected by the magnetic sensor 14 according to the rotation angle of the pointer 5 is output to the communication board 15 via the measurement circuit board 13.

[0032] [Communication board 15] The communication board 15 is configured to include an antenna and the like and is capable of transmitting and receiving signals to and from an external device. In the present embodiment, the communication board 15 is configured to be able to transmit and receive Bluetooth (registered trademark) radio waves. Accordingly, the communication board 15 can output the signal output by the magnetic sensor 14 to the external device. Note that the communication board 15 is not limited to the above configuration. For example, it may be configured to be able to transmit and receive radio waves such as LPWA (Low Power Wide Area), Wi-Fi (registered trademark), NFC, or infrared rays, or it may be configured to output the signal output by the magnetic sensor 14 to the external device via a wired cable or the like. Further, the communication board 15 may be configured to output a signal input from an external device to the magnetic sensor 14. By configuring in this way, the magnetic sensor 14 can be calibrated using an external device. Also, the communication board 15 may include a storage device. By configuring in this way, for example, the communication board 15 can store data corresponding to the signal output by the magnetic sensor 14 and be configured to output the data when a predetermined data is stored. Furthermore, in the present embodiment, a battery case 151 for housing the battery 16 is provided on the communication board 15.

[0033] [Battery 16] As described above, the battery 16 is housed in one battery case 151 provided on the communication circuit board 15, and is configured to supply power to the measurement circuit board 13, the magnetic sensor 14, the communication circuit board 15, and the like. In the present embodiment, the battery 16 is configured as a so-called button-type battery including a coin-type battery. Note that the battery 16 is not limited to the above configuration, and may be configured as, for example, a cylindrical dry battery, a cylindrical rechargeable battery, a polymer battery, or the like. Further, a plurality of batteries 16 may be built in the pointer reading device 10.

[0034] [Mounting method of pointer reading device 10] Next, the mounting method of the pointer reading device 10 will be described. FIGS. 5 to 9 are diagrams showing the mounting method of the pointer reading device 10. First, as shown in FIG. 5, the support member 8 to which the magnet 9 is attached is attached to the pointer 5. Specifically, the support member 8 is attached to the pointer 5 by engaging the attachment portion 83 of the support member 8 with the pointer body 51 and adhering the support member main body portion 81 and the rotation shaft 52 with the adhesive member 84. Thus, in the present embodiment, since the attachment portion 83 engageable with the pointer 5 is provided on the support member 8, the magnet 9 can be easily attached to the pointer 5.

[0035] Next, as shown in FIGS. 6 and 7, a plurality of engaging claw portions 117 on the case bottom portion 112 are engaged with the support member main body portion 81 (positioning step). In this state, that is, in a state where the cylindrical portion 122 is not housed in the hole portion 116, the plurality of engaging claw portions 117 are inclined inward toward the center of the hole portion 116. And in this state, the disk portion 1122 of the case bottom 112 is fixed to the main body portion 3 of the physical quantity measuring device (fixing step). As a result, the position of the case bottom 112 with respect to the magnet 9 attached to the support member 8 is determined. Therefore, the magnet 9 and the magnetic sensor 14 are positioned via the measurement circuit board 13, the guide member 12, the hole portion 116, and the support member 8, so that the positional relationship between the magnet 9 and the magnetic sensor 14 can be prevented from shifting. Therefore, even if the magnet 9 is miniaturized, it is possible to prevent the positional deviation between the magnetic sensor 14 and the magnet 9 from becoming uncorrectable and the reading error from becoming large.

[0036] Next, as shown in FIGS. 8 and 9, the cylindrical portion 122 of the guide member 12 in which the measurement circuit board 13 is housed is housed in the hole portion 116 of the case bottom 112, and in this state, the case lid portion 113 is attached to the case main body portion 111. Then, the guide member 12 is biased toward the support member 8 by the protruding portion 118 of the case lid portion 113, and the cylindrical portion 122 abuts against the inner surface side of the engaging claw portion 117 of the case bottom 112 and biases the engaging claw portion 117. Specifically, the cylindrical portion 122 biases the engaging claw portion 117 outward by coming into contact with the engaging claw portion 117. For this reason, the engagement of the engaging claw portion 117 with the support member 8 is released by the biasing of the cylindrical portion 122 (housing / release step). That is, in the present embodiment, the engaging claw portion 117 engages with the support member 8 in a state where the cylindrical portion 122 is not housed in the hole portion 116, and is biased by the cylindrical portion 122 in a state where the cylindrical portion 122 is housed in the hole portion 116, and the engagement with the support member 8 is released. As a result, the engaging claw portion 117 that positions the case member 11 with respect to the support member 8 is biased by the cylindrical portion 122 in a state where the cylindrical portion 122 of the guide member 12 is housed in the hole portion 116, and the engagement with the support member 8 is released. Therefore, it is possible to suppress the rotation of the pointer 5 from being affected by the engaging claw portion 117. Even if the engagement state of the engaging claw portion 117 is released at this stage, since the case bottom 112 is fixed to the main body portion 3 of the physical quantity measuring device, the positional relationship between the magnet 9 and the magnetic sensor 14 does not shift. Note that the present invention is not limited to the above configuration. For example, a protrusion may be provided on the surface of the cylindrical portion of the engaging claw portion facing the cylindrical portion, and the cylindrical portion biases the protrusion of the engaging claw portion so that the engagement state between the engaging claw portion and the support member is released.

[0037] In the present embodiment as described above, the following effects can be achieved. (1) In the present embodiment, the engaging claw portion 117 of the case member 11 engages with the support member 8 to which the magnet 9 is fixed, so that the support member 8 and the case member 11 are positioned. Then, after fixing the case member 11 in this state, the guide member 12 that holds the measurement circuit board 13 to which the magnetic sensor 14 is attached is housed in the hole portion 116 of the case member 11. As a result, the guide member 12 and the support member 8 are positioned. Therefore, the magnet 9 and the magnetic sensor 14 are positioned via the measurement circuit board 13, the guide member 12, the hole portion 116, and the support member 8, so that it is possible to suppress the positional relationship between the magnet 9 and the magnetic sensor 14 from being displaced. Therefore, even if the magnet 9 is miniaturized, it is possible to prevent the positional deviation of the magnetic sensor 14 with respect to the magnet 9 from not being corrected and the reading error from becoming large. Further, the engaging claw portion 117 that positions the case member 11 with respect to the support member 8 is biased by the cylindrical portion 122 of the guide member 12 and the engagement with the support member 8 is released in a state where the cylindrical portion 122 of the guide member 12 is housed in the hole portion 116. Therefore, it is possible to suppress the rotation of the pointer 5 from being affected by the engaging claw portion 117.

[0038] (2) In the present embodiment, since the case lid portion 113 is detachably attached to the case main body portion 111, it is possible to easily perform maintenance on the measurement circuit board 13, the magnetic sensor 14, etc. housed in the case main body portion 111, or to replace the battery 16.

[0039] (3) In this embodiment, since the protruding portion 118 that biases the guide member 12 toward the support member 8 is formed on the case lid portion 113, the guide member 12 can be biased toward the support member 8 when the case lid portion 113 is attached to the case main body portion 111. Further, in this embodiment, since the second packing 172 is interposed between the protruding portion 118 and the substrate support portion 121, it is possible to suppress the guide member 12 from rotating due to the frictional force of the second packing 172. Therefore, it is possible to suppress the position of the guide member 12 with respect to the support member 8 from shifting in a state where the case lid portion 113 is attached to the case main body portion 111.

[0040] (4) In this embodiment, by detecting the magnetic field of the magnet 9 attached to the pointer 5 with the magnetic sensor 14, it is possible to output a signal corresponding to the rotation angle of the pointer 5 corresponding to the pressure of the fluid to be measured.

[0041] (5) In this embodiment, since the support member 8 having the storage recess 82 for storing the magnet 9 is provided with the attachment portion 83 that can be engaged with the pointer 5, the magnet 9 can be easily attached to the pointer 5.

[0042] Next, a second embodiment of the present invention will be described with reference to the drawings. The second embodiment is different from the first embodiment in that the engagement hole portion 119A through which the claw portion 114A of the case bottom portion 112A is inserted is formed in the case lid portion 113A. In the second embodiment, the same or similar components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

[0043] FIG. 10 is a perspective view showing an outline of the physical quantity measuring device 1A of this embodiment, and FIG. 11 is an exploded perspective view showing an outline of the physical quantity measuring device 1A. As shown in FIGS. 10 and 11, the physical quantity measuring device 1A includes a pointer reading device 10A, similarly to the physical quantity measuring device 1 of the first embodiment described above.

[0044] [Pointer reading device 10A] The pointer reading device 10A is a device that reads the rotation angle of a pointer body 51 that rotates about a rotation shaft 52 in accordance with the pressure of the fluid to be measured, similar to the pointer reading device 10 of the first embodiment described above. In this embodiment, the pointer reading device 10A includes a case member 11A, a guide member 12, a measurement circuit board 13, a magnetic sensor 14 (see FIG. 4), a communication board 15, a battery 16, a first packing 171, a second packing 172, and a third packing 173.

[0045] [Case member 11A] The case member 11A is a case that houses the guide member 12, the measurement circuit board 13, the magnetic sensor 14, the communication board 15, the battery 16, etc., similar to the case member 11 of the first embodiment described above. In this embodiment, the case member 11A includes a case main body portion 111A, a case bottom portion 112A, and a case lid portion 113A. And the case bottom portion 112A includes a case bottom main body portion 1121A and a disk portion 1122A. Here, in this embodiment, an engagement hole portion 119A through which the claw portion 114A is inserted is provided in the case lid portion 113A at a position corresponding to the claw portion 114A of the case main body portion 111A. Thus, in this embodiment, the case lid portion 113A is configured to be attached to the case main body portion 111A by engaging with the upper surface of the case lid portion 113A with the claw portion 114A inserted into the engagement hole portion 119A. Therefore, the attachment state of the case lid portion 113A to the case main body portion 111A can be strengthened.

[0046] In the present embodiment as described above, the following effects can be achieved. (6) In this embodiment, since the engagement hole portion 119A through which the claw portion 114A is inserted is provided in the case lid portion 113A at a position corresponding to the claw portion 114A of the case main body portion 111, the case lid portion 113A is configured to be attached to the case main body portion 111A by engaging with the upper surface of the case lid portion 113A with the claw portion 114A inserted into the engagement hole portion 119A. Therefore, the attachment state of the case lid portion 113A to the case main body portion 111A can be strengthened.

[0047] [Modification Example] Note that the present invention is not limited to the above-described embodiments, and modifications, improvements, etc. within the scope that can achieve the object of the present invention are included in the present invention.

[0048] In each of the above embodiments, the case lid portions 113, 113A were formed with protruding portions 118 that protrude toward the guide member 12 and bias the guide member at positions corresponding to the guide member 12, but the present invention is not limited to this. For example, a screw hole portion may be provided at a position corresponding to the guide member of the case lid portion, and by screwing an adjustment screw into the screw hole portion, the guide member may be configured to be biased toward the support member. Also, even when the protruding portion for biasing the guide member is not provided, it is included in the present invention.

[0049] In each of the above embodiments, the case members 11, 11A were configured to have disk portions 1122, 1122A formed of a transparent resin, but the present invention is not limited to this. For example, the case member may be configured to be attached to a transparent cover member that covers the opening of the physical quantity measuring device main body portion by an adhesive member or the like. In this case, a hole portion is provided at the case bottom portion of the case member, and a hole portion is also provided at a position corresponding to the hole portion in the transparent cover member.

[0050] In each of the above embodiments, the case lid portions 113, 113A were configured to be detachably attached to the case main body portions 111, 111A by engagement of the claw portions 114, 114A of the case main body portions 111, 111A, but the present invention is not limited to this. For example, the case lid portion may be configured to be detachably attached to the case main body portion by attachment screws or the like.

[0051] In each of the above embodiments, the magnet 9 was attached to the pointer 5 via the support member 8, but the present invention is not limited to this. For example, the magnet may be directly attached to the tip of the rotation axis of the pointer by an adhesive member or the like. In this case, the rotation axis also serves as the support member.

[0052] In each of the above embodiments, the pointer reading devices 10 and 10A were configured to be driven using the battery 16 as a power source, but the present invention is not limited thereto. For example, the pointer reading device may be configured to be driven by power supplied from an external device.

[0053] In each of the above embodiments, the physical quantity measuring devices 1 and 1A were configured to be able to measure the pressure of the fluid to be measured, but the present invention is not limited thereto. For example, the physical quantity measuring device may be configured to be able to measure physical quantities such as temperature and differential pressure.

Explanation of Reference Numerals

[0054] 1, 1A... Physical quantity measuring device, 2... Introduction member, 3... Physical quantity measuring device main body, 4... Bourdon tube, 5... Pointer, 6... Pointer transmission mechanism, 7... Scale plate, 8... Support member, 9... Magnet, 10, 10A... Pointer reading device, 11, 11A... Case member, 12... Guide member, 13... Measurement circuit board, 14... Magnetic sensor, 15... Communication board, 16... Battery, 21... Introduction member main body, 22... Male screw portion, 51... Pointer main body, 52... Rotation shaft, 71... Scale, 72... Shaft portion insertion hole, 81... Support member main body, 82... Storage recess, 83... Mounting portion, 84... Adhesive member, 111, 111A... Case main body, 112, 112A... Case bottom, 113, 113A... Case lid, 114, 114A... Claw portion, 115... Engagement groove portion, 116... Hole portion, 117... Engagement claw portion, 118... Protrusion, 119A... Engagement hole portion, 121... Board support portion, 122... Cylindrical portion, 151... Battery case, 171... First packing, 172... Second packing, 173... Third packing, 211... Fluid introduction hole, 1121, 1121A... Case bottom main body, 1122, 1122A... Disk portion.

Claims

1. A pointer reading device that reads the rotation angle of a pointer that rotates about a rotation axis according to the physical quantity of the fluid to be measured, a magnetic sensor that detects the magnetic field of a magnet fixed to a support member attached to the tip of the rotation axis, a measurement circuit board to which the magnetic sensor is attached, inputs a signal output from the magnetic sensor, and outputs a signal corresponding to the rotation angle of the pointer, a guide member having a board support portion that holds the measurement circuit board and a cylindrical portion extending from the board support portion, a case member having a hole formed at a position corresponding to the support member, and the cylindrical portion of the guide member is housed in the hole, The case member extends from near the periphery of the hole portion toward the support member and has an engaging claw portion that can engage with the support member, The engaging claw portion engages with the support member in a state where the cylindrical portion is not housed in the hole portion, and is urged by the cylindrical portion in a state where the cylindrical portion is housed in the hole portion to release the engagement with the support member A pointer reading device characterized by this.

2. In the pointer reading device according to claim 1, The case member has a case main body portion that is cylindrical and can accommodate the measurement circuit board and the guide member inside, a case bottom portion that covers one end side of the case main body portion and in which the hole portion is formed, and a case lid portion that covers the other end of the case main body portion and is detachably attached to the case main body portion. A pointer reading device characterized by this.

3. In the pointer reading device according to claim 2, On the case lid portion, a protruding portion that abuts against the guide member and biases the guide member toward the support member is formed at a position corresponding to the guide member housed in the case main body portion. A pointer reading device characterized by this.

4. The pointer reading device according to claim 1, and The pointer that rotates about the rotation axis according to the physical quantity of the fluid to be measured, The magnet, And a support member that fixes the magnet. A physical quantity measuring device characterized by this.

5. In the physical quantity measuring device according to claim 4, The support member has a columnar support member main body portion, a storage recess formed at one end of the support member main body portion for storing the magnet, and a mounting portion extending from the other end of the support member main body portion and engageable with the pointer. A physical quantity measuring device characterized by this.

6. A method for attaching a pointer reading device that reads the rotation angle of a pointer that rotates about a rotation axis according to the physical quantity of the fluid to be measured, A positioning step of positioning the position of the hole portion of the case member of the pointer reading device with respect to the support member by engaging an engaging claw portion extending from the vicinity of the periphery of the hole portion of the case member of the pointer reading device to the tip of the rotation axis of the pointer and engaging it with the support member that fixes the magnet. A fixing step of fixing the position of the case member with respect to the support member by fixing the case member to the main body portion of the physical quantity measuring device that houses the pointer. A storage / release step of storing a cylindrical portion extending from a substrate support portion that supports a measurement circuit board to which a magnetic sensor for detecting the magnetic field of the magnet fixed to the support member is attached into the hole portion of the case member, and urging the engaging claw portion by the cylindrical portion to release the engagement state between the engaging claw portion and the support member. A method for attaching a pointer reading device characterized by this.

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