Measuring device and rotation detection method

Abstract

To obtain a measuring device provided with a setting change mechanism that changes various settings such as zero point adjustment while ensuring the water proofing property and dust proofing property inside a housing.SOLUTION: A measuring device comprises: a housing 3 that has a housing space formed therein; a substrate 8 that has a mounting surface 81 and is housed in the housing space; magnetic sensors 91-94 that are mounted on the mounting surface 81; and a detection unit that is provided on the outside of the housing 3 and detects the quantity of state of a medium to be measured. The housing 3 is formed with a projection 33 that is a projecting inner peripheral surface of the housing space. The projection 33 is formed with a recess 34 recessed from an outer peripheral surface of the housing toward the housing space. The substrate 8 is arranged such that the mounting surface 81 faces the projection 33.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a measurement device and a rotation detection method. [Background technology]

[0002] Measuring devices are known that measure the flow rate, pressure, temperature, differential pressure, etc. of a measurement medium, such as a fluid, and output the measurement results to an external device. Such measuring devices are equipped with a setting change mechanism for changing various settings, such as zero-point adjustment. For example, the measuring device disclosed in Patent Document 1 is equipped with a shaft (screw) and a rotary encoder as the setting change mechanism. A hole is formed in the housing of the measuring device, connecting the inside and the outside. The shaft penetrates the hole in the housing and is rotatable within the hole. The rotary encoder is mounted on a circuit board installed inside the housing. The shaft and the rotary encoder are connected inside the housing, and the rotary encoder can be rotated by rotating the shaft from outside the housing. The setting change mechanism changes various settings based on the rotation direction and rotation speed of the shaft detected by the rotary encoder. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-001383 Summary of the Invention [Problem to be solved by the invention]

[0004] In some measuring devices, the housing is required to be waterproof and dustproof to prevent breakdown of the equipment installed inside the housing. However, in conventional measuring devices, a hole is formed to connect the inside and outside of the housing in order to provide a setting change mechanism. A shaft is provided in the hole, and a gasket is used to seal the gap between the shaft and the inner surface of the hole, thereby ensuring a certain degree of waterproofness and dustproofness. However, depending on the environment in which the measuring device is used, sufficient waterproofness and dustproofness may not be ensured.

[0005] An object of the present invention is to provide a measuring device provided with a setting change mechanism for changing various settings such as zero point adjustment while ensuring waterproof and dustproof properties inside the housing. [Means for solving the problem]

[0006] The measuring device of the present invention comprises a housing having an internal storage space, a substrate having a mounting surface and housed in the storage space, a magnetic sensor mounted on the mounting surface, and a detection unit provided outside the housing for detecting the state quantity of the medium to be measured, wherein the housing has a protrusion that protrudes from the inner surface of the storage space, and the protrusion has a recess that is recessed from the outer surface of the housing toward the storage space, and the substrate is arranged with its mounting surface facing the protrusion. [Effects of the Invention]

[0007] According to the present invention, it is possible to obtain a measuring device provided with a setting change mechanism for changing various settings such as zero point adjustment while ensuring waterproofness and dustproofness of the inside of the housing. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a front view of a measurement device according to a first embodiment. [Figure 2] FIG. 1 is a side view of a measurement device according to a first embodiment. [Figure 3] FIG. 1 is a perspective view of a measurement device according to a first embodiment. [Figure 4]4 is a cross-sectional view of the measuring device taken along line IV-IV shown in FIG. 2, and is a partially enlarged cross-sectional view of part A. FIG. [Figure 5] FIG. 2 is a partially enlarged exploded perspective view showing a recessed portion of the measuring device according to the first embodiment. [Figure 6] 6 is a diagram corresponding to a cross-sectional view taken along line VI-VI in FIG. 4, and is a diagram for explaining the relationship between the rotation of the magnet and the magnetic sensor. [Figure 7] 5 is a diagram showing the relationship between the rotation angle of the magnet and the detection level of the magnetic sensor in the first embodiment. FIG. [Figure 8] FIG. 2 is a diagram showing the functional configuration related to changing various settings of the measurement device according to the first embodiment. [Figure 9] FIG. 5 is a cross-sectional view of a measuring device according to a comparative example, and corresponds to FIG. 4 of the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] A measuring device and a rotation detection method according to an embodiment of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the embodiment described below.

[0010] [Embodiment 1] Fig. 1 is a front view of the measurement device according to embodiment 1. Fig. 2 is a side view of the measurement device according to embodiment 1. Fig. 3 is a perspective view of the measurement device according to embodiment 1. The measurement device 1 is a device that measures a state quantity of a medium to be measured, typically a fluid. Examples of the state quantity of the medium to be measured include flow velocity, pressure, temperature, and differential pressure.

[0011] The measuring device 1 includes a detection unit 2. The detection unit 2 is a component that detects state quantities such as the flow rate, pressure, temperature, and differential pressure of the medium to be measured. For example, the detection unit 2 has a diaphragm (not shown) that deforms in response to the pressure of the medium to be measured, and the measuring device 1 measures the state quantity, pressure, based on the amount of deformation of the diaphragm.

[0012] The measuring device 1 includes a housing 3. Fig. 4 is a cross-sectional view of the measuring device taken along line IV-IV shown in Fig. 2, and is a partially enlarged cross-sectional view of part A. The inside of the housing 3 is hollow, and this space serves as a storage space for storing a substrate and the like, which will be described later.

[0013] 4, the housing 3 is formed with a protruding portion 33 that protrudes from the inner peripheral surface 31 of the storage space. The protruding portion 33 is formed with a recessed portion 34 that is recessed from the outer peripheral surface 32 of the housing 3 toward the storage space. Although the recessed portion 34 is recessed toward the storage space, it does not penetrate the housing 3 and does not provide communication between the inside and outside of the housing 3.

[0014] Here, the direction in which the recess 34 extends is defined as a first direction, and an X-axis parallel to the first direction is defined. In the first embodiment, the first direction is the left-right direction in the front view of FIG. 1 and the depth direction in the side view of FIG. 2. A second direction perpendicular to the first direction is defined, and a Z-axis parallel to the second direction is defined. In the first embodiment, the second direction is the up-down direction in the front view of FIG. 1 and the side view of FIG. 2. A direction perpendicular to the first and second directions is defined as a third direction, and a Y-axis parallel to the third direction is defined. In the first embodiment, the third direction is the depth direction in the front view of FIG. 1 and the left-right direction in the side view of FIG. 2.

[0015] The housing 3 is provided with a window 36 that allows the interior of the storage space to be viewed. A display unit 10 is provided within the storage space at a position that is visible through the window 36. The display unit 10 displays various setting information of the measuring device 1 and the detection results of the detection unit 2, and is, for example, an LCD (Liquid Crystal Display).

[0016] The measuring device 1 includes a shaft 4. The shaft 4 is a rod-shaped member that is inserted into a recess 34. The shaft 4 is rotatable about a central axis 35 of the recess 34.

[0017] 5 is a partially enlarged exploded perspective view of the recessed portion of the measuring device according to embodiment 1. An engagement portion 43 is formed at one end 41 of the shaft 4, which is on the entrance 34a side of the recessed portion 34 when the shaft 4 is inserted into the recessed portion 34. The shaft 4 can be rotated by engaging a tool with the engagement portion 43. The engagement portion 43 is, for example, a groove, and the shaft 4 can be rotated by engaging a flat-head screwdriver therein.

[0018] A gasket 5 is attached to the shaft 4. When the shaft 4 is inserted into the recess 34, the gasket 5 abuts against the inner peripheral surface of the recess 34 and the outer peripheral surface of the shaft 4, and rotatably supports the shaft 4. The gasket 5 prevents water and dust from entering the interior of the recess 34.

[0019] The measuring device 1 includes a magnet 6. The magnet 6 is a permanent magnet. The magnet 6 is attached to the other end 42 of the shaft 4, which is inserted into the recess 34 and is opposite the entrance 34a of the recess 34. The magnet 6 is attached to the shaft 4 so that its north and south poles are aligned perpendicular to the first direction (X-axis). By rotating the shaft 4, the directions in which the north and south poles of the magnet 6 face change. In other words, by rotating the shaft 4, the magnetic field changes as the magnet 6 rotates.

[0020] The measuring device 1 includes a lid 7. The lid 7 is attached to the entrance 34a of the recess 34 to prevent the shaft 4 from falling out of the recess 34. The lid 7 has a cylindrical shape. Even when the lid 7 is attached to the entrance 34a of the recess 34, the engagement portion 43 of the shaft 4 remains exposed. Therefore, the shaft 4 can be rotated by engaging the engagement portion 43 with a tool while the lid 7 is attached.

[0021] 4, the measuring device 1 includes a substrate 8. The substrate 8 is provided in the housing space of the housing 3. The substrate 8 has a mounting surface 81. The substrate 8 is provided such that the mounting surface 81 faces the outer peripheral surface 33a of the protruding portion 33.

[0022] The measuring device 1 includes a plurality of magnetic sensors 91 to 94. In the following description, the magnetic sensors 91 to 94 will not be distinguished from one another and will be simply referred to as the magnetic sensor 9. The magnetic sensor 9 is mounted on a mounting surface 81 of a substrate 8.

[0023] A detectable magnetic field direction is set for each of the magnetic sensors 9. In the following description, the detectable magnetic field direction set for each magnetic sensor 9 will also be simply referred to as the magnetic field detection direction.

[0024] The plurality of magnetic sensors 91 to 94 are mounted side by side on the mounting surface 81. The direction in which the plurality of magnetic sensors 91 to 94 are arranged is parallel to the second direction (Z-axis). The plurality of magnetic sensors 91 to 94 are mounted on the mounting surface 81 with their magnetic field detection directions differing from one another.

[0025] When viewed along the third direction (Y-axis), two magnetic sensors 9 are arranged symmetrically on each side of the central axis 35 of the recess 34. More specifically, on the plane of FIG. 4, above the central axis 35, a magnetic sensor 92 (first magnetic sensor) and a magnetic sensor 91 (second magnetic sensor) are arranged in that order from the side closest to the central axis 35. Below the central axis 35, a magnetic sensor 94 (first magnetic sensor) and a magnetic sensor 93 (second magnetic sensor) are arranged from the side closest to the central axis 35.

[0026] The magnetic sensors 92 and 94 are provided so that the direction of detection of the magnetic field is parallel to the first direction (X-axis), and the magnetic sensors 91 and 93 are provided so that the direction of detection of the magnetic field is parallel to the second direction (Z-axis).

[0027] By arranging the magnetic sensors 91-94 in line with the direction of magnetic field detection, when the magnet 6 rotates together with the shaft 4 and the magnetic field changes, the detection levels of the magnetic sensors 91-94 also change. The relationship between the change in the magnetic field and the detection levels of the magnetic sensors 91-94 will be described in detail later.

[0028] When viewed along the third direction (Y-axis), the position of the magnet 6 and the position where the magnetic sensors 91-94 are arranged are offset along the first direction (X-axis). More specifically, the position of the magnet 6 is offset toward the entrance 34a of the recess 34 from the position where the magnetic sensors 91-94 are arranged. If the position of the magnet 6 is offset toward the entrance 34a of the recess 34 from the position where the magnetic sensors 91-94 are arranged, the depth of the recess 34 can be made shallower. If the depth of the recess 34 is shallower, the amount by which the protrusion 33 protrudes into the storage space will be smaller. Even if the size of the housing 3 is the same, a smaller protrusion of the protrusion 33 will result in a larger storage space. This improves the degree of freedom in arranging various components in the storage space of the housing 3. Furthermore, the housing 3 can be made smaller while ensuring a large storage space, i.e., the measuring device 1 can be made smaller.

[0029] Fig. 6 is a diagram corresponding to a cross section taken along line VI-VI in Fig. 4, illustrating the relationship between the rotation of the magnet and the magnetic sensor. Fig. 7 is a diagram showing the relationship between the rotation angle of the magnet and the detection level of the magnetic sensor in embodiment 1.

[0030] 6, the state in which the north pole of magnet 6 faces the mounting surface 81 of substrate 8 is defined as 0°. Also, the rotation angle increases as shaft 4 and magnet 6 rotate counterclockwise.

[0031] The magnetic sensors 91 to 94 use the strength of the detected magnetic field as a threshold, and when they detect a magnetic field stronger than the threshold, they output that the detection level is high (H), and when they detect a magnetic field weaker than the threshold, they output that the detection level is low (L).

[0032] The detection levels of the magnetic sensors 91 to 94 change depending on the rotation angle of the magnet 6. In Fig. 7, the horizontal axis represents the rotation angle of the magnet 6, and the vertical axis represents the detection levels of the magnetic sensors 91 to 94. In the following description, the detection levels of the magnetic sensors 91 to 94 will be indicated as (detection level of magnetic sensor 91, detection level of magnetic sensor 92, detection level of magnetic sensor 93, detection level of magnetic sensor 94).

[0033] When the rotation angle of the magnet 6 is in the range of 0° to 15°, the detection levels of the magnetic sensors 91 to 94 are a (L, L, L, H). When the rotation angle of the magnet 6 is in the range of 15° to 80°, the detection levels of the magnetic sensors 91 to 94 are b (L, L, L, L). When the rotation angle of the magnet 6 is in the range of 80° to 115°, the detection levels of the magnetic sensors 91 to 94 are c (H, L, L, L). When the rotation angle of the magnet 6 is in the range of 115° to 180°, the detection levels of the magnetic sensors 91 to 94 are d (H, L, H, L). When the rotation angle of the magnet 6 is in the range of 180° to 225°, the detection levels of the magnetic sensors 91 to 94 are e (H, H, H, L). When the rotation angle of the magnet 6 is in the range of 225° to 270°, the detection levels of the magnetic sensors 91 to 94 are f (H, H, H, H). When the rotation angle of the magnet 6 is in the range of 270° to 315°, the detection levels of the magnetic sensors 91 to 94 are g(L,H,H,H). When the rotation angle of the magnet 6 is in the range of 315° to 350°, the detection levels of the magnetic sensors 91 to 94 are h(L,H,L,H). Then, once the rotation angle of the magnet exceeds 350°, the detection levels a to h are repeated again.

[0034] Therefore, for example, if the detection level changes from a to b, it can be determined that the magnet 6 and shaft 4 have rotated counterclockwise. Also, if the detection level changes from a to h without passing through b to g, it can be determined that the magnet 6 and shaft 4 have rotated clockwise. Furthermore, the rotation speed of the magnet 6 and shaft 4 can be determined from the period in which the detection level changes.

[0035] In the measuring device 1, various settings such as zero point adjustment are changed based on the rotation direction and rotation speed of the shaft 4. Figure 8 is a diagram showing the functional configuration related to changing various settings of the measuring device according to embodiment 1. The measuring device 1 includes a storage unit 11 and a control unit 12.

[0036] The storage unit 11 stores data and programs necessary for various processes performed by the control unit 12. The storage unit 11 is a semiconductor memory element such as a RAM (Random Access Memory), a ROM (Read Only Memory), or a flash memory, or a storage device such as a hard disk or an optical disk.

[0037] The control unit 12 has a determination unit 12a and a display control unit 12b. The determination unit 12a receives the detection levels transmitted from the magnetic sensors 91 to 94, and determines the rotation direction and rotation speed of the shaft 4 based on changes in the detection levels. Furthermore, based on the determined rotation direction and rotation speed, the determination unit 12a changes the settings and instructs the display control unit 12b to change the display.

[0038] The display control unit 12b changes the display on the display unit 10 based on an instruction from the discrimination unit 12a. For example, if the measurement device 1 is a device that measures the pressure of a medium to be measured and the change in various settings is a change in the unit of pressure, the display control unit 12b changes the unit displayed on the display unit 10.

[0039] The control unit 12 is, for example, an electronic circuit. Examples of the electronic circuit include an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array), a CPU (Central Processing Unit), or an MPU (Micro Processing Unit).

[0040] Comparative Example FIG. 9 is a cross-sectional view of a measuring device according to a comparative example, and corresponds to FIG. 4 of the first embodiment. In the measuring device 101 according to the comparative example, a through-hole 134 that connects the inside and the outside is formed in the housing 103. In the measuring device 101 according to the comparative example, a shaft 104 is provided so as to pass through the through-hole 134. In the measuring device 101 according to the comparative example, a rotary encoder 106 is mounted on a substrate 108 provided in the accommodation space of the housing 103. An end of the shaft 104 is connected to the rotary encoder 106 via a pin 107. The pin 107 also functions to prevent the shaft 104 from coming off. In the measuring device 101 according to the comparative example, the rotary encoder 106 rotates in conjunction with the shaft 104. In the measuring device 101 according to the comparative example, a gasket 105 is provided that contacts the outer circumferential surface of the shaft 104 and the inner circumferential surface of the through-hole 134. In the measuring device 101 according to the comparative example, the rotation of the shaft 104 is detected by the rotary encoder 106, and various settings such as zero point adjustment are changed.

[0041] As described above, in measuring device 101 according to the comparative example, through-hole 134 is formed in housing 103, which allows water and dust to enter the inside of the housing. Although gasket 105 is provided to ensure a certain degree of waterproofness and dustproofness, there are cases in which sufficient waterproofness and dustproofness cannot be ensured depending on the environment in which measuring device 101 is used.

[0042] [Summary of effects] The measuring device 1 described above comprises a housing 3 having an internal storage space, a substrate 8 having a mounting surface 81 and housed in the storage space, a magnetic sensor 9 mounted on the mounting surface 81, and a detection unit 2 provided outside the housing 3 and detecting a state quantity of the medium to be measured. The housing 3 is formed with a protruding portion 33 that protrudes from the inner circumferential surface of the storage space. The protruding portion 33 is formed with a recessed portion 34 that is recessed from the outer circumferential surface of the housing 3 toward the storage space. The substrate 8 is disposed with the mounting surface 81 facing the protruding portion 33.

[0043] The recess 34 formed in the housing 3 and into which the shaft 4 can be inserted is a recess that does not penetrate the housing 3. Therefore, unlike the measuring device 101 according to the comparative example, water and dust do not enter the storage space of the housing 3 through the recess 34. This more reliably ensures the waterproof and dustproof properties of the measuring device 1. Furthermore, a magnetic sensor is provided on the mounting surface 81 of the substrate 8 that is provided opposite the protrusion 33, making it possible to detect changes in the magnetic field when the magnet 6 rotates within the recess 34.

[0044] In the measuring device 101 according to the comparative example, the through-hole 134 formed in the housing 103 for passing the shaft 104 therethrough connects the inside and outside of the housing 103, and is therefore likely to be a weak point in ensuring pressure resistance and explosion-proof properties. On the other hand, in the measuring device 1 according to the first embodiment, no hole for passing the shaft 4 therethrough connects the inside and outside, and therefore pressure resistance and explosion-proof properties can be more reliably ensured.

[0045] Furthermore, a plurality of magnetic sensors 91-94 are mounted on the mounting surface 81, and when the direction in which the recess 34 extends is defined as a first direction, the plurality of magnetic sensors 91-94 are aligned along a second direction perpendicular to the first direction. By aligning the plurality of magnetic sensors 91-94 along the second direction, it becomes possible to determine the rotation angle and rotation speed based on changes in the detection levels of the magnetic sensors 91-94 when the magnet 6 in the recess 34 rotates.

[0046] The multiple magnetic sensors 91-93 include two first magnetic sensors 92, 94 whose magnetic field detection direction is parallel to the first direction and two second magnetic sensors 91, 93 whose magnetic field detection direction is parallel to the second direction. When viewed along a third direction perpendicular to the first and second directions, the first magnetic sensors 92, 94 are arranged symmetrically with respect to the central axis 35 of the recess 34, and the second magnetic sensors 91, 93 are arranged symmetrically with respect to the central axis 35. This arrangement of the multiple magnetic sensors 91-93 makes it possible to determine the rotation angle and rotation speed based on changes in the detection levels of the magnetic sensors 91-94 when the magnet 6 in the recess 34 rotates. Note that higher resolution can be achieved by changing the number and arrangement of the magnetic sensors 9.

[0047] The measuring device 1 further includes a shaft 4 inserted into the recess 34 and rotatable around the central axis 35 of the recess 34, and a magnet 6 attached to the shaft 4, with its north and south poles aligned in a direction perpendicular to the first direction.

[0048] The shaft 4 inserted into the recess 34 is provided without penetrating the housing 3, which more reliably ensures that the housing 3 is waterproof, dustproof, pressure-resistant, and explosion-proof. As the magnet 6 rotates together with the shaft 4, the magnetic field changes inside the housing 3. By detecting this change in the magnetic field with the magnetic sensor 9, it becomes possible to detect the rotation direction and rotation speed of the shaft 4. Therefore, the rotation direction and rotation speed of the shaft 4 can be detected without forming a through-hole in the housing 3. It becomes possible to change various settings in the measuring device 1 based on the detected rotation direction and rotation speed of the shaft 4.

[0049] Unlike the measuring device 101 according to the comparative example, the shaft 104 can be installed simply by inserting it into the recess 34, without the need for a pin 107 to be passed through the shaft 104 and the rotary encoder 106 inside the housing 103 to prevent the shaft 104 from falling out, which simplifies the assembly work of the measuring device 1. Furthermore, in the measuring device 101 according to the comparative example, the shaft 104 and the rotary encoder 106 are connected via a pin, so backlash occurs when the shaft 104 is rotated. On the other hand, the measuring device 1 according to the first embodiment does not include a rotary encoder and does not have a connection structure with a mechanism for detecting the rotation of the shaft 4, so there is no backlash and a seamless feel to the operation can be obtained.

[0050] Unlike the measuring device 101 of the comparative example, there is no need to connect the shaft 104 and the rotary encoder 106 using a pin 107 inside the housing 103, so the measuring device 1 of embodiment 1 makes it easy to replace or retrofit the shaft 4.

[0051] Furthermore, when viewed along the third direction, the magnet 6 is disposed at a position shifted toward the entrance 34a of the recess 34 along the first direction from the magnetic sensors 91-94. If the position of the magnet 6 is shifted toward the entrance 34a of the recess 34 from the position where the magnetic sensors 91-94 are arranged, the depth of the recess 34 can be made shallower. If the depth of the recess 34 is shallower, the amount by which the protrusion 33 protrudes into the accommodation space becomes smaller. Even if the size of the housing 3 is the same, a smaller protrusion of the protrusion 33 results in a larger accommodation space. This improves the degree of freedom in arranging various components in the accommodation space of the housing 3. Furthermore, the housing 3 can be made smaller while ensuring a large accommodation space, i.e., the measuring device 1 can be made smaller.

[0052] The measuring device 1 further includes a discrimination unit 12a that discriminates the rotation direction of the shaft 4 based on the detection results of the magnetic sensors 91 to 94. By including the discrimination unit 12a in the measuring device 1, the measuring device 1 can discriminate the rotation direction and rotation speed of the shaft 4 and change various settings.

[0053] The measuring device 1 further includes a gasket 5 that abuts against the inner circumferential surface of the recess 34 and the outer circumferential surface of the shaft 4 and supports the shaft 4 rotatably about a central axis 35. The gasket 5 prevents water and dust from entering the recess 34.

[0054] The measuring device 1 also includes a lid 7 that fits into the entrance 34a of the recess 34. An engagement portion 43 that can be engaged with a tool for rotating the shaft 4 is formed at the end of the shaft 4 that faces the entrance 34a of the recess 34, and the lid 7 is formed in a cylindrical shape that exposes the engagement portion 43. Because the engagement portion 43 is exposed while the lid 7 is fitted into the entrance 34a of the recess 34, the lid 7 prevents the shaft 4 from falling out, and the shaft 4 can be rotated by inserting a tool inside the lid 7.

[0055] Furthermore, the housing 3 is formed with a window 36 that allows the interior of the storage space to be viewed, and the measuring device 1 further includes a display unit 10 that is provided inside the storage space and is viewable through the window 36. Measurement results and the like obtained by the measuring device 1 can be displayed on the display unit 10.

[0056] Furthermore, the measuring device 1 further includes a display control unit 12b that changes the display on the display unit 10 based on the detection results of the magnetic sensor 9. For example, if various setting values of the measuring device 1 are displayed on the display unit 10, it is possible to change the various settings by rotating the shaft 4 while checking the setting values.

[0057] Furthermore, the method for detecting rotation of the shaft 4 of the measuring device 1 includes the steps of receiving the detection levels of the plurality of magnetic sensors 91-94 and determining the direction of rotation of the shaft 4 based on changes in the detection levels of the plurality of magnetic sensors 91-94. Because the direction of rotation and rotation speed can be detected from changes in the magnetic field that accompany the rotation of the shaft 4, there is no need to form a hole in the housing 3 that connects the inside and outside, and the various effects described above can be achieved.

[0058] 〔others〕 Some examples of combinations of the disclosed technical features are set out below.

[0059] (1) A measuring device comprising: a housing having an internal storage space; a substrate having a mounting surface and housed in the storage space; a magnetic sensor mounted on the mounting surface; and a detection unit provided on the outside of the housing for detecting the state quantity of the medium to be measured; the housing has a protrusion that protrudes from the inner circumferential surface of the storage space; the protrusion has a recess that is recessed from the outer circumferential surface of the housing toward the storage space; and the substrate is arranged with the mounting surface facing the protrusion.

[0060] (2) A measuring device as described in (1) above, in which a plurality of the magnetic sensors are mounted on the mounting surface, and when the direction in which the recess extends is defined as a first direction, the plurality of magnetic sensors are arranged in a line along a second direction perpendicular to the first direction.

[0061] (3) The measuring device of claim 2, wherein the plurality of magnetic sensors include two first magnetic sensors whose magnetic field detection direction is parallel to the first direction and two second magnetic sensors whose magnetic field detection direction is parallel to the second direction, and when viewed along a third direction perpendicular to the first direction and the second direction, the first magnetic sensors are arranged symmetrically around the central axis of the recess, and the second magnetic sensors are arranged symmetrically around the central axis.

[0062] (4) A measuring device described in any one of (1) to (3) above, further comprising: a shaft inserted into the recess and rotatable around the central axis of the recess; and a magnet attached to the shaft, with its north and south poles aligned in a direction perpendicular to the first direction, when the direction in which the recess extends is defined as a first direction.

[0063] (5) A measuring device as described in (4) above, in which the magnet is disposed at a position shifted toward the entrance of the recess along the first direction relative to the magnetic sensor when viewed along a third direction perpendicular to the first direction and the second direction.

[0064] (6) The measuring device according to (4) or (5) above, further comprising a discrimination unit that discriminates the rotation direction of the shaft based on the detection result of the magnetic sensor.

[0065] (7) A measuring device described in any one of (4) to (6) above, further comprising a gasket that abuts against the inner surface of the recess and the outer surface of the shaft and supports the shaft rotatably around the central axis.

[0066] (8) A measuring device described in any one of (4) to (7) above, further comprising a lid portion that fits into the entrance of the recess, and an engagement portion formed at the end of the shaft that is on the entrance side of the recess, with which a tool that rotates the shaft can engage, and the lid portion is formed in a cylindrical shape that exposes the engagement portion.

[0067] (9) A measuring device described in any one of (1) to (8) above, wherein the housing has a window that allows the interior of the storage space to be viewed, and further includes a display unit that is provided inside the storage space and is viewable through the window.

[0068] (10) The measuring device according to (9) above, further comprising a display control unit that changes the display on the display unit based on the detection result of the magnetic sensor.

[0069] (11) A rotation detection method for detecting the rotation direction of the shaft in a measuring device including a housing having an accommodation space formed therein, a protruding portion formed on an inner circumferential surface of the accommodation space, and a recess formed on the protruding portion and recessed from the outside toward the accommodation space, a substrate having a mounting surface facing the protruding portion and accommodated in the accommodation space, a plurality of magnetic sensors mounted on the mounting surface, a detection unit provided outside the housing for detecting a state quantity of a medium to be measured, and a shaft inserted into the recess and rotatable about a central axis of the recess, wherein when a direction in which the recess extends is defined as a first direction, the plurality of magnetic sensors are arranged in a direction perpendicular to the first direction. a rotation detection method comprising: a step of receiving detection levels of the plurality of magnetic sensors; and a step of determining a rotation direction of the shaft based on changes in the detection levels of the plurality of magnetic sensors, the plurality of magnetic sensors including two first magnetic sensors whose magnetic field detection direction is parallel to the first direction and two second magnetic sensors whose magnetic field detection direction is parallel to the second direction, the first magnetic sensors being arranged symmetrically around a central axis of the recess when viewed along a third direction perpendicular to the first direction and the second direction, the first magnetic sensors being arranged symmetrically around a central axis of the recess, and the second magnetic sensors being arranged symmetrically around the central axis. [Explanation of symbols]

[0070] 1. Measuring equipment 2. Detection unit 3. Housing 31 Inner surface 32 Outer surface 33 Protrusion 33a Outer surface 34 Recess 34a Entrance 35 Center axis 36 Windows 4 shafts 41 one end 42 other end 43 Engagement part 5 Gasket 6. Magnets 7 Lid 8 PCB 81 Mounting surface 9,91,92,93,94 Magnetic sensors 10 Display section 11 Storage section 12 Control Unit 12a Discrimination part 12b Display control unit

Claims

1. a housing having an accommodation space formed therein; a substrate having a mounting surface and accommodated in the accommodation space; a magnetic sensor mounted on the mounting surface; a detection unit provided outside the housing and configured to detect a state quantity of the medium to be measured, The housing is formed with a protruding portion that protrudes from the inner circumferential surface of the accommodation space, The protruding portion has a recess formed therein that is recessed from the outer peripheral surface of the housing toward the housing space, The substrate is disposed with the mounting surface facing the protrusion.

2. a plurality of the magnetic sensors are mounted on the mounting surface; When the extending direction of the recess is defined as a first direction, The measurement device according to claim 1 , wherein the plurality of magnetic sensors are arranged side by side along a second direction perpendicular to the first direction.

3. the plurality of magnetic sensors include two first magnetic sensors whose magnetic field detection direction is parallel to the first direction and two second magnetic sensors whose magnetic field detection direction is parallel to the second direction; The measuring device described in claim 2, wherein, when viewed along a third direction perpendicular to the first direction and the second direction, the first magnetic sensors are arranged symmetrically around the central axis of the recess, and the second magnetic sensors are arranged symmetrically around the central axis.

4. a shaft inserted into the recess and rotatable about a central axis of the recess; The measuring device of claim 1, further comprising a magnet attached to the shaft, the magnet having a north pole and a south pole aligned in a direction perpendicular to the first direction in which the recess extends.

5. The measuring device described in claim 4, wherein the magnet is arranged at a position shifted toward the entrance of the recess along the first direction relative to the magnetic sensor when viewed along a third direction perpendicular to the first direction and the second direction.

6. The measuring device according to claim 4 , further comprising a determination unit that determines the rotation direction of the shaft based on the detection result of the magnetic sensor.

7. The measuring device according to claim 4 , further comprising a gasket that abuts against an inner circumferential surface of the recess and an outer circumferential surface of the shaft and supports the shaft rotatably about the central axis.

8. Further provided is a lid portion fitted into the entrance of the recess, an engaging portion that can be engaged with a tool that rotates the shaft is formed at an end of the shaft that is on the entrance side of the recess; The measuring device according to claim 4 , wherein the lid portion is formed in a cylindrical shape that exposes the engaging portion.

9. The housing is formed with a window that allows the interior of the storage space to be viewed, The measuring device according to claim 1 , further comprising a display unit provided inside the accommodation space and visible through the window.

10. The measuring device according to claim 9 , further comprising a display control unit that changes the display on the display unit based on the detection result of the magnetic sensor.

11. A storage space is formed inside, and a protruding portion is formed on the inner circumferential surface of the storage space, a housing having a recess formed in the protruding portion and recessed from the outside toward the storage space; a substrate having a mounting surface facing the protrusion and accommodated in the accommodation space; a plurality of magnetic sensors mounted on the mounting surface; a detection unit provided outside the housing for detecting a state quantity of the medium to be measured; a shaft inserted into the recess and rotatable about a central axis of the recess, When the extending direction of the recess is defined as a first direction, the plurality of magnetic sensors are arranged side by side along a second direction perpendicular to the first direction, the plurality of magnetic sensors include two first magnetic sensors whose magnetic field detection direction is parallel to the first direction and two second magnetic sensors whose magnetic field detection direction is parallel to the second direction; when viewed along a third direction perpendicular to the first direction and the second direction, the first magnetic sensors are arranged symmetrically with respect to a central axis of the recess, and the second magnetic sensors are arranged symmetrically with respect to the central axis, receiving detection levels of the plurality of magnetic sensors; and determining the rotation direction of the shaft based on changes in the detection levels of the plurality of magnetic sensors.

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