Flow velocity sensor and flow velocity detection method

Abstract

To provide a flow velocity sensor and a flow velocity detection method, enabling flow velocity of fluid to be measured in a wide flow velocity range.SOLUTION: A flow velocity sensor 10 detecting flow velocity of water in a water pipe is provided, comprising a detection unit 100 which has; main body portions 210, 310 which can be deformed by reception of pressure of the fluid; and a sensor portion 220 (320) detecting deformation amount of the main body portion 210 (310). The main body portion 210 (310) comprises: a deformation portion 212 (312) in which the sensor portion 220 (320) is provided; and a pressure reception portion 213 (313) deforming the deformation portion 212 (312) by reception of the pressure of the fluid. The detection unit 100 includes, a highly sensitive detection unit 200 and a low sensitive detection unit 300, a ratio of a pressure reception area of a pressure reception portion 213 of the highly sensitive detection unit 200 to rigidity of the deformation portion 212 of the highly sensitive detection unit 200, is greater than a ratio of a pressure reception area of a pressure reception portion 313 of the low sensitive detection unit 300 to rigidity of the deformation portion 312 of the low sensitive detection unit 300.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a flow velocity sensor for detecting the flow velocity of a fluid in a pipe and a flow velocity detection method using the flow velocity sensor. [Background technology]

[0002] Conventionally, there is known a technique for detecting the flow velocity of a fluid in a water pipe. For example, Patent Document 1 discloses a method for measuring the flow rate (flow velocity) in a water pipe using a flexible detection plate. A strain gauge is provided on the surface of the detection plate. The strain gauge detects the deflection of the detection plate caused by pressure from the fluid in the water pipe, and measures the flow rate in the water pipe based on the detected value.

[0003] In a configuration in which such a detection plate is used to measure the flow rate in a water pipe, if the detection plate is formed to be relatively easily deformed in order to accurately detect the flow rate at a low flow rate, the detection plate may be plastically deformed by the pressure of the fluid. This may make it difficult to detect the flow rate at a high flow rate. Also, if the detection plate is formed to have a high rigidity in order to detect the flow rate at a high flow rate, the detection plate will be less likely to bend, making it difficult to detect the flow rate at a low flow rate. This raises the concern that the range of flow velocities that can be detected will be narrowed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 1-150859 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and the problem it aims to solve is to provide a flow velocity sensor and a flow velocity detection method that can detect the flow velocity of a fluid over a wide flow velocity range. [Means for solving the problem]

[0006] The problem to be solved by the present invention has been described above, and the means for solving this problem will now be described.

[0007] That is, in claim 1, a flow velocity sensor for detecting the flow velocity of a fluid in a pipe is provided with a detection unit having a main body portion deformable by receiving pressure of the fluid and a sensor portion for detecting the deformation amount of the main body portion, and the main body portion has a deformation portion on which the sensor portion is provided, and a pressure receiving portion for deforming the deformation portion by receiving pressure of the fluid. ,before The detection section includes a high-sensitivity detection section and a low-sensitivity detection section, and a ratio of a pressure-receiving area of ​​the pressure-receiving section of the high-sensitivity detection section to a rigidity of the deformation section of the high-sensitivity detection section is greater than a ratio of a pressure-receiving area of ​​the pressure-receiving section of the low-sensitivity detection section to a rigidity of the deformation section of the low-sensitivity detection section. The high-sensitivity detection section is disposed in a pair on either side of the low-sensitivity detection section in the flow direction of the fluid, and a predetermined gap is formed between the high-sensitivity detection section and the low-sensitivity detection section. It is something.

[0008] In claim 2, A flow velocity sensor for detecting the flow velocity of a fluid in a pipe, the flow velocity sensor comprising a detection section having a main body section deformable under pressure of the fluid and a sensor section for detecting the amount of deformation of the main body section, the main body section having a deformation section in which the sensor section is provided, and a pressure-receiving section for deforming the deformation section under pressure of the fluid, the detection section including a high-sensitivity detection section and a low-sensitivity detection section, the ratio of a pressure-receiving area of ​​the pressure-receiving section of the high-sensitivity detection section to a rigidity of the deformation section of the high-sensitivity detection section being greater than a ratio of a pressure-receiving area of ​​the pressure-receiving section of the low-sensitivity detection section to a rigidity of the deformation section of the low-sensitivity detection section, a flow velocity detection method for detecting the flow velocity of the fluid based on a detection result by the sensor section using the flow velocity sensor, the detection result by the sensor section of the high-sensitivity detection section that has undergone plastic deformation is corrected with the detection result by the sensor section of the low-sensitivity detection section to detect the flow velocity of the fluid. It is something. Effect of the Invention

[0011] The present invention has the following advantages.

[0012] According to claim 1, the flow velocity of a fluid can be detected in a wide range of flow velocities. In addition, the high-sensitivity detection portion can be prevented from being plastically deformed.

[0013] In claim 2, The flow velocity of a fluid can be detected over a wide range of flow velocities, and the flow velocity of a fluid can be detected with high accuracy. [Brief description of the drawings]

[0016] [Figure 1] FIG. [Diagram 2] FIG. 1 is a perspective view of a flow velocity sensor according to a first embodiment. [Diagram 3](a) A side view showing the flow velocity sensor when the flow velocity is less than V1, (b) A side view showing the flow velocity sensor when the flow velocity is V1 or more and less than V2, and (c) A side view showing the flow velocity sensor when the flow velocity is V2 or more. [Figure 4] (a) A graph showing the change in actual flow velocity over time, (b) A graph showing the change in the detected value of the flow velocity sensor over time, and (c) A graph showing an example of correction of the detected value of the high sensitivity detection unit. [Diagram 5] 5 is a graph showing the relationship between the strain detected by the sensor unit and the actual flow velocity. [Figure 6] 6 is a graph showing an example of a detection result of a flow velocity. [Figure 7] 1A is a front view of a first modified example of the flow velocity sensor, FIG. 1B is a front view of a second modified example of the flow velocity sensor, and FIG. [Figure 8] FIG. 11 is a perspective view of a flow velocity sensor according to a second embodiment. [Figure 9] (a) A side view showing the flow velocity sensor when the flow velocity is less than V1, (b) A side view showing the flow velocity sensor when the flow velocity is V1, and (c) A side view showing the flow velocity sensor when the flow velocity is V2 or more. [Figure 10] 5 is a graph showing the relationship between the strain detected by the sensor unit and the actual flow velocity. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] In the following description, the directions indicated by the arrows U, D, F, and B in the drawings are defined as the upward direction, downward direction, forward direction, and backward direction, respectively. Note that the drawings used in the following description are schematic diagrams, and the shapes and dimensions of each component are appropriately exaggerated for the convenience of explanation. Therefore, the specific shapes and dimensions of each component are not limited to those shown in the drawings.

[0018] A management system 1 using a flow velocity sensor 10 according to an embodiment of the present invention will be described below with reference to FIG.

[0019] The management system 1 manages the fluid in the flow path using a flow velocity sensor 10. More specifically, the management system 1 can acquire and confirm the flow velocity of water flowing in a water pipe 2 (flow path). In the following description, it is assumed that water flows from the front to the rear in the water pipe 2.

[0020] The management system 1 acquires the water flow velocity through a branch section 3, which is a flow path that branches upward in the middle of a water pipe 2 buried underground. The upper part of the branch section 3 is connected to a fire hydrant 4 in a fire hydrant box 5. The fire hydrant box 5 is buried so as to be located above the water pipe 2. The fire hydrant box 5 opens upward. An openable lid (not shown) is provided on the opening. The fire hydrant 4 is capable of supplying water flowing through the water pipe 2 to a supply destination such as a hose as necessary. The fire hydrant 4 is equipped with an appropriate on-off valve. A space communicating with the branch section 3 is formed inside the fire hydrant 4.

[0021] The management system 1 includes a flow velocity sensor 10, a communication unit 20, a battery 30, and a server 40.

[0022] The flow velocity sensor 10 detects the flow velocity of water inside the water pipe 2. The configuration of the flow velocity sensor 10 will be described in detail later.

[0023] The communication unit 20 is a device for exchanging information between the flow velocity sensor 10 and another device (a server 40 in this embodiment). The communication unit 20 can exchange information with the server 40 via an appropriate line. The communication unit 20 is connected to the flow velocity sensor 10 via an appropriate lead wire. The communication unit 20 is disposed inside the fire hydrant box 5.

[0024] The battery 30 serves as a power source for the flow velocity sensor 10 and the communication unit 20. The battery 30 is connected to the flow velocity sensor 10 and the communication unit 20 via lead wires. The battery 30 is disposed inside the fire hydrant box 5.

[0025] The server 40 performs appropriate processing in response to requests from other devices. The server 40 includes a calculation device (e.g., a CPU, etc.), a storage device (e.g., a HDD, etc.), and an input / output device (e.g., a mouse, a keyboard, a display, etc.). The server 40 receives signals from the flow velocity sensor 10 (signals from sensor units 220 and 320, which will be described later) via the communication unit 20, and can obtain a detection value of the water flow velocity in the water pipe 2 based on the signals.

[0026] The server 40 can also perform a process for correcting the detected value of the flow velocity. The correction process will be described in detail later. The server 40 can also communicate with an appropriate terminal (for example, a PC, a smartphone, a tablet terminal, etc.).

[0027] The configuration of a flow velocity sensor 10 according to a first embodiment of the present invention will be described in detail below with reference to Figs. 1 to 3. As shown in Fig. 1, the flow velocity sensor 10 is fixed to a fire hydrant 4 via a mounting rod 6 extending vertically along a branching portion 3. The upper end of the mounting rod 6 is fixed inside the fire hydrant 4. The lower end of the mounting rod 6 is located at the connection portion between the branching portion 3 and the water pipe 2. The flow velocity sensor 10 is fixed to the lower end of the mounting rod 6 and is provided so as to be located inside the water pipe 2. The flow velocity sensor 10 has a detection unit 100.

[0028] 2 and 3 is capable of detecting the flow velocity of water with high and low sensitivity. The detection unit 100 includes a high-sensitivity detection unit 200 and a low-sensitivity detection unit 300.

[0029] The high-sensitivity detection unit 200 detects the flow velocity of water with relatively high sensitivity. The high-sensitivity detection unit 200 includes a main body 210 and a sensor 220.

[0030] The main body 210 shown in Figs. 2 and 3 is a part that can be elastically deformed by receiving the pressure of water flowing through the water pipe 2. The main body 210 is formed in a plate shape with the plate surface facing the water flow direction (front-rear direction). The main body 210 is formed in a substantially rectangular shape that is long vertically when viewed from the front. The thickness dimension of the main body 210 is appropriately set from the viewpoint of detecting the water flow velocity with high sensitivity. The main body 210 is formed of a flexible material. For example, a metal material such as stainless steel can be used as the material of the main body 210. The main body 210 includes a fixed portion 211, a deforming portion 212, and a pressure-receiving portion 213.

[0031] The fixing portion 211 is a portion that is fixed to the lower end of the mounting rod 6. The fixing portion 211 constitutes the upper end of the main body portion 210. The fixing portion 211 is formed with a hole 211a through which a fastener (not shown) such as a bolt used for fixing is inserted. In the example shown in the figure, a pair of holes 211a are formed on the left and right.

[0032] The deformation portion 212 is a portion where the sensor unit 220 described later is provided. The deformation portion 212 constitutes a portion of the upper portion of the main body portion 210 below the fixed portion 211. Specifically, the deformation portion 212 is a portion of the main body portion 210 within the range of the vertical width of the sensor unit 220 provided on the main body portion 210.

[0033] The pressure-receiving portion 213 is a portion that deforms the deformation portion 212 when it receives the pressure of water flowing through the water pipe 2. The pressure-receiving portion 213 constitutes a portion of the main body portion 210 that is lower than the deformation portion 212. The pressure-receiving portion 213 is inserted through the branch portion 3 and is provided so that at least a lower portion is located inside the water pipe 2 (see FIG. 1).

[0034] The sensor unit 220 detects the amount of deformation (strain) of the deformation unit 212. More specifically, the sensor unit 220 detects the amount of deformation of the deformation unit 212 when the main body unit 210 is bent in the front-rear direction as an electric signal. A strain gauge can be used as the sensor unit 220. The sensor unit 220 is arranged so that the direction in which it can detect strain (measurement axis direction) faces the up-down direction. The sensor unit 220 is provided on the front and rear surfaces of the deformation unit 212. The sensor unit 220 is connected to the communication unit 20 and the battery 30 via lead wires. The sensor unit 220 is also waterproofed. For example, coating with a protective tape or the like can be used as the waterproofing.

[0035] The low-sensitivity detection unit 300 detects the water flow velocity with a relatively low sensitivity. That is, the low-sensitivity detection unit 300 detects the water flow velocity with a lower sensitivity than the high-sensitivity detection unit 200. The low-sensitivity detection unit 300 includes a main body unit 310 and a sensor unit 320. The low-sensitivity detection unit 300 is formed separately from the high-sensitivity detection unit 200. The low-sensitivity detection unit 300 is disposed to the side (left) of the high-sensitivity detection unit 200. The configuration of the low-sensitivity detection unit 300 is generally similar to the configuration of the high-sensitivity detection unit 200, with some exceptions. Therefore, detailed descriptions of the main body unit 310 and the sensor unit 320 will be omitted below as appropriate.

[0036] 2 and 3 is a portion on the left side of the main body 210 that is elastically deformable under the pressure of water flowing through the water pipe 2. As shown in Fig. 2, the main body 210 and the main body 310 are arranged side by side in the left-right direction (plate surface direction).

[0037] Body portion 310 is formed in the same manner as body portion 210, except that the thickness dimension is larger than the thickness dimension of body portion 210. That is, body portion 310 is formed in a plate shape similar to body portion 210 in dimensions other than the thickness dimension. Therefore, the area of ​​body portion 310 in a front view is similar to the area of ​​body portion 210 in a front view. The thickness dimension of body portion 310 is appropriately set from the viewpoint of detecting the water flow velocity with low sensitivity.

[0038] The main body 310 includes a fixed portion 311, a deformation portion 312, and a pressure-receiving portion 313. The fixed portion 311 (hole portion 311a), the deformation portion 312, and the pressure-receiving portion 313 are generally similar to the respective portions of the main body 210 (the fixed portion 211 (hole portion 211a), the deformation portion 212, and the pressure-receiving portion 213).

[0039] The sensor unit 320 detects the amount of deformation (strain) of the deformation unit 312. The sensor unit 320 is provided on each of the front and rear surfaces of the deformation unit 312. The configuration of the sensor unit 320 is similar to that of the sensor unit 220 of the high-sensitivity detection unit 200.

[0040] In the flow velocity sensor 10 as described above, the main body 210 of the high-sensitivity detection section 200 is formed to be more easily deformed than the main body 310 of the low-sensitivity detection section 300. More specifically, the ratio of the pressure-receiving area of ​​the pressure-receiving section 213 to the rigidity of the deformable section 212 of the high-sensitivity detection section 200 is formed to be larger than the ratio of the pressure-receiving area of ​​the pressure-receiving section 313 to the rigidity of the deformable section 312 of the low-sensitivity detection section 300. The larger the ratio of the pressure-receiving area to the rigidity, the easier the member is to deform.

[0041] Here, "rigidity" refers to the degree to which a member is difficult to deform. In plate-shaped members such as main body portion 210 and main body portion 310, the greater the thickness dimension or width dimension (left-right dimension) of the member, the higher the rigidity (the harder it is to deform). If the rigidity is high, the strength of main body portion 210 and main body portion 310 improves, but the amount of change in deforming portion 212 and deforming portion 312 decreases, making it difficult for sensor portion 220 and sensor portion 320 to detect (the sensitivity decreases). In other words, there is a trade-off between rigidity and sensitivity.

[0042] Moreover, the "pressure-receiving area" is the area of ​​the surface that receives the pressure of water flowing through the water pipe 2. In this embodiment, the "pressure-receiving area" refers to the area of ​​the portions of the pressure-receiving portion 213 and the pressure-receiving portion 313 that protrude into the water pipe 2 when viewed from the front. The larger the pressure-receiving area, the more easily the member is subjected to water pressure, and therefore the more easily the member is deformed. In this embodiment, the high-sensitivity detection portion 200 and the low-sensitivity detection portion 300 are arranged so that the pressure-receiving areas of the pressure-receiving portion 213 and the pressure-receiving portion 313 are the same, and so that the pressure-receiving areas of the pressure-receiving portion 213 and the pressure-receiving portion 313 protrude into the water pipe 2 by the same area.

[0043] In this embodiment, the thickness dimension of the main body 210 (deformation portion 212) of the high-sensitivity detection portion 200 is smaller than the thickness dimension of the main body 310 (deformation portion 312) of the low-sensitivity detection portion 300, and the width dimensions of the deformation portion 212 and the deformation portion 312 are the same. Therefore, the rigidity of the deformation portion 212 is smaller than the rigidity of the deformation portion 312.

[0044] In this embodiment, the pressure receiving area of ​​the pressure receiving portion 213 is the same as that of the pressure receiving portion 313. From the above, it can be said that the ratio of the pressure receiving area of ​​the pressure receiving portion 213 to the rigidity of the deformation portion 212 of the high-sensitivity detection portion 200 is greater than the ratio of the pressure receiving area of ​​the pressure receiving portion 313 to the rigidity of the deformation portion 312 of the low-sensitivity detection portion 300.

[0045] The following describes how the flow velocity of water flowing through the water pipe 2 is detected using the flow velocity sensor 10 as described above.

[0046] 3, in the detection unit 100 (high-sensitivity detection unit 200 and low-sensitivity detection unit 300) of the flow velocity sensor 10, the main body unit 210 and the main body unit 310 are deformed by the pressure of the water flowing inside the water pipe 2. Specifically, the main body unit 210 and the main body unit 310 receive the pressure of the water flowing from the front to the rear at the front surfaces of the pressure-receiving unit 213 and the pressure-receiving unit 313. The amount of deformation (strain) of the deforming unit 212 and the deforming unit 312 that are deformed as a result is detected by the sensor unit 220 and the sensor unit 320.

[0047] The detection results of the sensor units 220 and 320 are transmitted to the server 40 by the communication unit 20. The server 40 detects the flow velocity based on the detection results. The server 40 detects the flow velocity by converting the deformation amount (strain) detected by the sensor units 220 and 320 based on the characteristics (dimensions, rigidity, etc.) of the main body units 210 and 310, for example. In this way, the management system 1 can detect the flow velocity using the flow velocity sensor 10.

[0048] In this embodiment, the sensor unit 220 and the sensor unit 320 are provided on both the front and rear sides of the deformation unit 212 and the deformation unit 312. This allows the flow velocity sensor 10 to detect flow velocities in both the front and rear directions. The server 40 determines the direction in which water flows (flow direction) based on the detection values ​​of the front and rear sensor units. Furthermore, the server 40 can nullify (cancel) distortion of each deformation unit due to temperature changes by using the detection values ​​of the front and rear sensor units.

[0049] In addition, the server 40 can detect the flow velocity using the detection results of the high-sensitivity detection unit 200 or the low-sensitivity detection unit 300, whichever is more suitable for detecting the flow velocity, depending on the flow velocity of the water flowing through the water pipe 2.

[0050] A flow velocity detection method using the flow velocity sensor 10 will be described below with reference to FIGS.

[0051] First, the range of flow velocities that can be detected by the high-sensitivity detection section 200 and the low-sensitivity detection section 300 of the flow velocity sensor 10 will be described with reference to FIGS.

[0052] The graph shown in Fig. 4 shows the change over time in the flow velocity of water flowing through the water pipe 2. The two-dot chain line in Fig. 4(a) shows the actual flow velocity of water flowing through the water pipe 2. The actual flow velocity increases over time until halfway through, and then decreases over time.

[0053] 4(b) and 4(c), the solid line and the dashed line (thick line) respectively indicate the flow velocity detection values ​​of the high-sensitivity detection unit 200 and the low-sensitivity detection unit 300. If the detection values ​​of the high-sensitivity detection unit 200 and the low-sensitivity detection unit 300 shown in the above graphs match the actual flow velocity, this indicates that the detection of the flow velocity by the flow velocity sensor 10 is accurate.

[0054] The graph shown in Fig. 5 shows the relationship between the detection results (strain) of the sensor units 220 and 320 in the detection unit 100 (high-sensitivity detection unit 200 and low-sensitivity detection unit 300) and the actual flow velocity. Fig. 5 shows the detection results before and after the plastic deformation of the high-sensitivity detection unit 200. Note that in Fig. 5, the range of strain (elastic region) in which the deforming units 212 and 312 can elastically deform is shown by a solid line and a dashed dotted line, and the range of strain (plastic region) that exceeds the elastic region (where plastic deformation may occur) is shown by a dashed line.

[0055] FIG. 3(a) shows a case where the flow velocity of water in the water pipe 2 is low (for example, about 0.1 m / s). In this state, the water pressure is low, so the deformation amount of the deformation part 312 of the low-sensitivity detection part 300 is small. For this reason, it is difficult for the sensor part 320 to detect the flow velocity until it reaches a certain level. Specifically, as shown in FIG. 4(b), the detection value of the low-sensitivity detection part 300 is lower than the actual flow velocity until the flow velocity is equal to or higher than V1. Also, as shown in FIG. 5, the sensor part 320 does not detect the strain until the flow velocity approaches V1. In other words, it is difficult for the low-sensitivity detection part 300 to detect a range of flow velocities (flow velocity range) below V1.

[0056] On the other hand, as shown in Fig. 3(a), even in the case of a low flow velocity, the deformation amount of the deformation portion 212 of the high-sensitivity detection portion 200 is large. This makes it easy to perform detection by the sensor portion 220. Specifically, as shown in Fig. 4(b), the detection value of the high-sensitivity detection portion 200 generally coincides with the actual flow velocity in the flow velocity range below V1 (part where the flow velocity is increasing). That is, in the above flow velocity range, the high-sensitivity detection portion 200 can detect the flow velocity with high accuracy.

[0057] FIG. 3(b) shows a case where the flow velocity is higher than that in FIG. 3(a). In this state, the amount of change in the deformed portion 212 and the deformed portion 312 is larger than when the flow velocity is less than V1. As shown in FIG. 4(b), until the flow velocity becomes V2 or more, the detection values ​​of the high-sensitivity detection portion 200 and the low-sensitivity detection portion 300 both roughly match the actual flow velocity. That is, in the flow velocity range of V1 or more and less than V2 (more specifically, in the flow velocity range of V1 or more and less than V2 in FIG. 4(b), where the flow velocity increases with time), both the high-sensitivity detection portion 200 and the low-sensitivity detection portion 300 can detect the flow velocity with high accuracy. Note that, as shown in FIG. 5, in the range less than V2, the strain of the deformed portion 212 and the deformed portion 312 is in the elastic region.

[0058] FIG. 3(c) shows a case where the flow velocity is high (for example, about 2.0 m / s). In this state, the amount of change in the deformable portion 212 and the deformable portion 312 becomes even larger. In this case, the deformable portion 212 of the high-sensitivity detection portion 200, which has low rigidity, may deform excessively. As shown in FIG. 5, when the flow velocity is V2 or more, the strain of the deformable portion 212 becomes a plastic region, and the deformable portion 212 deforms beyond the range in which it can be elastically deformed (see also FIG. 4(b)). For example, when the flow velocity becomes V3, which is greater than V2, the deformable portion 212 undergoes plastic deformation. In this case, as shown in FIG. 4(b), the detection value of the high-sensitivity detection portion 200 exceeds the actual flow velocity. For this reason, the high-sensitivity detection portion 200 cannot accurately detect a flow velocity range greater than V2.

[0059] On the other hand, as shown in Fig. 5, the deformation portion 312 of the low-sensitivity detection portion 300, which has high rigidity, is in the elastic region even when the flow velocity becomes V3, so that the sensor portion 320 can detect it. As shown in Fig. 4(b), the detection value of the low-sensitivity detection portion 300 roughly matches the actual flow velocity in the flow velocity range of V2 or more. That is, in the above flow velocity range, the low-sensitivity detection portion 300 can detect the flow velocity with high accuracy.

[0060] As described above, the flow velocity sensor 10 can detect the water flow velocity over a wide range of flow velocities by using both the high-sensitivity detection section 200 and the low-sensitivity detection section 300. That is, when the flow velocity is low, the flow velocity can be detected using the high-sensitivity detection section 200, which is relatively easy to deform and suitable for detecting low flow velocities. On the other hand, when the flow velocity is high, the flow velocity can be detected using the low-sensitivity detection section 300, which is relatively difficult to deform and suitable for detecting high flow velocities.

[0061] Here, as shown in Fig. 4(b) and Fig. 5, when the strain of the deformed portion 212 becomes a plastic region and the deformed portion 212 undergoes plastic deformation, the high-sensitivity detection portion 200 continues to detect a detection value that is a predetermined amount larger than the actual flow velocity. That is, as shown in Fig. 5, the high-sensitivity detection portion 200 continues to detect a value obtained by adding the amount of deformation (plastic strain) caused by the plastic deformation to the original amount of deformation (amount of deformation before plastic deformation) of the deformed portion 212. Therefore, as shown in Fig. 4(b), after the deformed portion 212 undergoes plastic deformation, it becomes difficult for the high-sensitivity detection portion 200 to detect the flow velocity with high accuracy even if the flow velocity becomes less than V2. Furthermore, in the flow velocity range less than V1, both the high-sensitivity detection portion 200 and the low-sensitivity detection portion 300 cannot detect the flow velocity accurately.

[0062] Therefore, the management system 1 (server 40) makes it possible to correct the detection results by the high-sensitivity detection unit 200 using the detection results by the low-sensitivity detection unit 300 when the main body 210 of the high-sensitivity detection unit 200 undergoes plastic deformation.

[0063] Fig. 4(c) shows an example in which the detection value of the high-sensitivity detection unit 200 that has undergone plastic deformation is corrected. In the example shown in Fig. 4(c), the error in the detection value of the high-sensitivity detection unit 200 at time tx is corrected, so that the detection value of the high-sensitivity detection unit 200 after time tx is made to roughly coincide with the actual flow velocity. Note that the correction of the detection result will be described in detail later.

[0064] Next, an example of actually acquiring a flow velocity using the flow velocity sensor 10 as described above will be described with reference to FIG.

[0065] The graph shown in Fig. 6 shows the detection results (flow velocity) of the detection unit 100 (high-sensitivity detection unit 200 and low-sensitivity detection unit 300) at a certain time. In this embodiment, the server 40 obtains the detection results at times t1, t2, and t3 at a predetermined time interval (e.g., 15-minute intervals). Note that the above-mentioned time intervals are not limited to the above example, and various time intervals can be adopted.

[0066] Furthermore, the server 40 corrects the detection results as necessary based on the detection values ​​of the flow velocity sensor 10 at each time.

[0067] 6 shows that the flow velocities detected by the high-sensitivity detection unit 200 and the low-sensitivity detection unit 300 at time t1 are in a flow velocity range below V1. As described above, in a flow velocity range below V1, it is difficult for the low-sensitivity detection unit 300 to detect an accurate detection value (see FIGS. 4 and 5). For this reason, in a flow velocity range below V1, the server 40 invalidates the detection result of the low-sensitivity detection unit 300 among the above detection results, and obtains the flow velocity based on the detection result of the high-sensitivity detection unit 200. In this case, no correction of the detection result is performed.

[0068] FIG. 6 also shows that the flow velocities detected by the high-sensitivity detection unit 200 and the low-sensitivity detection unit 300 at times t2 and t3 are in the flow velocity range of not less than V1 and not more than V2.

[0069] Here, when the detection results of the high-sensitivity detection unit 200 and the low-sensitivity detection unit 300 indicate a flow velocity equal to or greater than V1 and less than V2, the server 40 determines whether or not the detection results need to be corrected based on each detection result.

[0070] Specifically, when the high-sensitivity detection unit 200 is plastically deformed as described above, a difference occurs between the detection result of the high-sensitivity detection unit 200 and the detection result of the low-sensitivity detection unit 300. The server 40 determines that an error has occurred when the difference between the detection results is equal to or greater than a predetermined range. In this case, the server 40 determines that the detection value needs to be corrected. The predetermined range can be set based on, for example, the ratio (%) of the difference between the detection result of the low-sensitivity detection unit 300 and the detection result of the high-sensitivity detection unit 200.

[0071] 6 shows an example in which the flow velocities detected by the high-sensitivity detection unit 200 and the low-sensitivity detection unit 300 at time t2 are roughly the same, and the difference in flow velocities is within a predetermined range. In this case, the server 40 determines that correction of the detection value is not necessary, and acquires the flow velocity based on the detection results of the high-sensitivity detection unit 200 and the low-sensitivity detection unit 300. In this case, the server 40 may acquire the flow velocity using only one of the detection results of the high-sensitivity detection unit 200 and the low-sensitivity detection unit 300, or may acquire the flow velocity using both detection results (for example, by calculating the average value of both detection results).

[0072] 6 also shows an example in which the difference in flow velocity detected by the high-sensitivity detection unit 200 and the low-sensitivity detection unit 300 at time t3 is equal to or greater than a predetermined range. That is, in the example shown in FIG 6, it is considered that the flow velocity in the pipe becomes equal to or greater than V2 between time t2 and time t3, and plastic deformation occurs in the main body 210 of the high-sensitivity detection unit 200. In this case, the server 40 determines that correction of the detection value is necessary and corrects the detection value.

[0073] When the server 40 determines that the detection value needs to be corrected, it notifies the administrator or user of the management system 1 that the correction process will be performed, for example, by an input / output device such as a display. The above notification is not limited to the input / output device, and can be performed, for example, by an appropriate terminal.

[0074] In the correction process, the server 40 calculates the plastic strain, which is the difference between the detection value of the high-sensitivity detection unit 200 before the plastic deformation shown in FIG. 5 and the detection value of the high-sensitivity detection unit 200 after the plastic deformation, as the measurement error.

[0075] The measurement error can be calculated by various methods. For example, in the flow velocity range of V1 or more and less than V2, the detection result of the low-sensitivity detection unit 300 is considered to be generally accurate, so the difference between the detection results of the low-sensitivity detection unit 300 and the high-sensitivity detection unit 200 in that flow velocity range can be calculated as the measurement error. In addition, the difference between the detection results of the high-sensitivity detection unit 200 before and after plastic deformation (see FIG. 5) can be calculated as the measurement error.

[0076] Next, the server 40 subtracts the measurement error from the detection value of the high-sensitivity detection unit 200 after the plastic deformation. This corrects the detection result of the high-sensitivity detection unit 200. After tx in FIG. 4(c), the detection result of the high-sensitivity detection unit 200 after the correction is shown. The detection value after the correction is roughly consistent with the actual flow velocity.

[0077] As described above, in this embodiment, in the flow velocity range (flow velocity range of V1 or more and less than V2) where both the high-sensitivity detection unit 200 and the low-sensitivity detection unit 300 can detect accurate detection values, the difference between the detection values ​​(measurement error) can be obtained, and the detection value of the high-sensitivity detection unit 200 can be corrected by the amount of the measurement error. By performing the correction, even if the deformation unit 212 has undergone plastic deformation, it is possible to continue detecting the flow velocity using the high-sensitivity detection unit 200.

[0078] Furthermore, if the deformation portion 212 again undergoes plastic deformation after the above correction has been performed, the server 40 repeats the above correction.

[0079] The above-described flow velocity measurement method is an example, and the flow velocity measurement method using the flow velocity sensor 10 is not limited to the above-described example. For example, in the above-described example, the server 40 acquires the detection results at times t1, t2, and t3 at predetermined time intervals, but the present invention is not limited to this embodiment, and the server 40 may be configured to constantly acquire the detection results.

[0080] As described above, the flow velocity sensor 10 according to this embodiment has the following features: A flow velocity sensor 10 for detecting the flow velocity of a fluid in a pipe (water in a water pipe 2), a body portion (body portion 210 and body portion 310) that is deformable under pressure of the fluid; a sensor unit (sensor unit 220 and sensor unit 320) for detecting the amount of deformation of the main body unit (main body unit 210 and main body unit 310); The detector 100 has The main body portion (main body portion 210 and main body portion 310) is a deformation section (deformation section 212 and deformation section 312) in which the sensor section (sensor section 220 and sensor section 320) is provided; a pressure receiving portion (pressure receiving portion 213 and pressure receiving portion 313) that receives pressure from the fluid and deforms the deformation portion (deformation portion 212 and deformation portion 312); having The detection unit 100 includes: The high-sensitivity detection unit 200 and the low-sensitivity detection unit 300 are included. The ratio of the pressure-receiving area of ​​the pressure-receiving portion 213 of the high-sensitivity detection portion 200 to the rigidity of the deformation portion 212 of the high-sensitivity detection portion 200 is greater than the ratio of the pressure-receiving area of ​​the pressure-receiving portion 313 of the low-sensitivity detection portion 300 to the rigidity of the deformation portion 312 of the low-sensitivity detection portion 300. With this configuration, the flow velocity of the fluid can be detected over a wide range of flow velocities. That is, when the flow velocity of the fluid is low, the flow velocity can be detected using the high-sensitivity detection unit 200, which is relatively easy to deform and suitable for detecting low flow velocities. On the other hand, when the flow velocity of the fluid is high, the flow velocity can be detected using the low-sensitivity detection unit 300, which is relatively difficult to deform and suitable for detecting high flow velocities. In this way, by using the high-sensitivity detection unit 200 and the low-sensitivity detection unit 300, the flow velocity of the fluid can be detected over a wide range of flow velocities.

[0081] In addition, the main body 210 of the high-sensitivity detection unit 200 and the main body 310 of the low-sensitivity detection unit 300 are Each of them is formed in a plate shape and arranged side by side in the plate surface direction. This configuration makes it possible to miniaturize the flow velocity sensor 10. That is, by arranging the plate-shaped high-sensitivity detection section 200 and low-sensitivity detection section 300 side by side in the plate surface direction, it is possible to miniaturize the dimension in the plate thickness direction.

[0082] In addition, the flow velocity detection method according to this embodiment includes: A flow velocity detection method for detecting a flow velocity of the fluid based on a detection result by the sensor unit (sensor unit 220 and sensor unit 320) using the flow velocity sensor 10, The detection result by the sensor unit 220 of the high-sensitivity detection unit 200 is corrected by the detection result by the sensor unit 320 of the low-sensitivity detection unit 300 to detect the flow velocity of the fluid. With this configuration, the flow velocity of the fluid can be detected with high accuracy. In other words, the high-sensitivity detection unit 200, which is relatively susceptible to deformation, may undergo plastic deformation if the fluid flow velocity becomes higher than expected. In this case, however, by correcting the detection result of the high-sensitivity detection unit 200 using the detection result of the low-sensitivity detection unit 300, the flow velocity can be detected accurately even after plastic deformation.

[0083] The configuration of the detection section 100 (the high-sensitivity detection section 200 and the low-sensitivity detection section 300) of the flow velocity sensor 10 is not limited to the above-mentioned example. In the following, each modified example of the detection section 100 will be described with reference to FIG.

[0084] Each of the modified examples described below differs from the detection unit 100 in that the thickness dimensions of the main body 210 of the high-sensitivity detection unit 200 and the main body 310 of the low-sensitivity detection unit 300 are the same.

[0085] In the detection unit 100A according to the first modified example shown in Fig. 7(a), the main body 210 and the main body 310 are formed by dividing a single plate-shaped member into left and right halves. Specifically, the width dimension (left and right dimension) of the lower part of the main body 210 is larger than that of the upper part, and the width dimension of the upper part of the main body 310 is larger than that of the lower part. The width dimensions of the upper part of the main body 210 and the lower part of the main body 310 are the same, and the width dimensions of the lower part of the main body 210 and the upper part of the main body 310 are the same.

[0086] In the detection unit 100A, the sensor unit 220 and the sensor unit 320 are provided on the upper part of each main body part (main body part 210 and main body part 310). That is, the upper part of each main body part corresponds to the deformation part 212 and the deformation part 312. Therefore, the width dimension of the deformation part 212 is formed smaller than the width dimension of the deformation part 312. Therefore, the rigidity of the deformation part 212 is smaller than the rigidity of the deformation part 312.

[0087] In the detection unit 100A, the pressure receiving portion 213 and the pressure receiving portion 313 are formed on the lower portion of the main body portion 210 and the main body portion 310. Therefore, the width dimension of the pressure receiving portion 213 is formed larger than the width dimension of the pressure receiving portion 313. Therefore, the pressure receiving area of ​​the pressure receiving portion 213 is larger than the pressure receiving area of ​​the pressure receiving portion 313.

[0088] In the detection unit 100A as described above, the ratio of the pressure receiving area of ​​the pressure receiving portion 213 to the rigidity of the deformation portion 212 is also greater than the ratio of the pressure receiving area of ​​the pressure receiving portion 313 to the rigidity of the deformation portion 312. Therefore, the detection unit 100A has substantially the same effect as the detection unit 100.

[0089] 7(a), in the detection unit 100A, the width dimension of the upper part of the main body part 310 is made larger by forming the width dimension of the upper part of the main body part 210 smaller, and the width dimension of the lower part of the main body part 310 is made smaller by forming the width dimension of the lower part of the main body part 210 smaller by forming the both parts together, so that the overall shape is rectangular when viewed from the front. This makes it possible to make the detection unit 100A more compact in the width direction.

[0090] 7(b), a detection unit 100B according to a second modified example has a single plate-shaped member with a slit to form the main body 210 and the main body 310. Specifically, a slit extending from the lower right corner of the plate-shaped member in a front view toward the diagonal corner is formed to form the main body 210 and the main body 310 divided into left and right halves. In addition, the detection unit 100B has a common fixing portion 311.

[0091] In the detection unit 100B, the width dimension of the left main body portion 210 is formed to increase toward the bottom. On the other hand, the width dimension of the right main body portion 310 is formed to decrease toward the bottom. In the detection unit 100B, the sensor portion 220 and the sensor portion 320 are provided on the upper portion of each main body portion (main body portion 210 and main body portion 310). That is, the upper portion of each main body portion corresponds to the deformation portion 212 and the deformation portion 312, and the portion below the deformation portion corresponds to the pressure receiving portion 213 and the pressure receiving portion 313.

[0092] In detection unit 100B, the width dimension of deforming portion 212 is smaller than the width dimension of deforming portion 312, and therefore the rigidity of deforming portion 212 is smaller than the rigidity of deforming portion 312. Furthermore, detection unit 100B receives water pressure at pressure receiving portion 213 and the lower portion of pressure receiving portion 313. The width dimension of the lower portion of pressure receiving portion 213 is larger than the width dimension of the lower portion of pressure receiving portion 313, and therefore the pressure receiving area of ​​pressure receiving portion 213 is larger than the pressure receiving area of ​​pressure receiving portion 313.

[0093] In the detection unit 100B as described above, the ratio of the pressure receiving area of ​​the pressure receiving portion 213 to the rigidity of the deformation portion 212 is also greater than the ratio of the pressure receiving area of ​​the pressure receiving portion 313 to the rigidity of the deformation portion 312. Therefore, the detection unit 100B has substantially the same effect as the detection unit 100.

[0094] 7(b), in the detection unit 100B, the high-sensitivity detection unit 200 and the low-sensitivity detection unit 300 are integrally formed. This can improve the ease of attachment and detachment of the detection unit 100B.

[0095] The detection unit 100C according to the third modified example shown in FIG. 7(c) is formed by forming an appropriate notch or the like in a single plate-shaped member. Specifically, the detection unit 100C has a narrow portion 100Cb, which is smaller in width than the upper end 100Ca, below the upper end 100Ca constituting the common fixing portion 211. The detection unit 100C also has a wide portion 100Cc, which is larger in width than the upper end 100Ca, below the narrow portion 100Cb. The wide portion 100Cc has a pair of slits extending upward from the lower end and spaced apart in the left-right direction. By forming the pair of slits, a central portion 100Cd is formed between the slits. The width of the central portion 100Cd is the same as the width of the narrow portion 100Cb.

[0096] In the detection unit 100C, the sensor unit 220 is provided in the narrow width portion 100Cb. That is, the portion of the narrow width portion 100Cb where the sensor unit 220 is provided corresponds to the deformation portion 212. In addition, in the detection unit 100C, the portion below the deformation portion 212 (a portion including the entire wide width portion 100Cc) corresponds to the pressure receiving portion 213.

[0097] In addition, in the detection unit 100C, the sensor unit 320 is provided in the central portion 100Cd. That is, the portion of the central portion 100Cd where the sensor unit 320 is provided corresponds to the deformation portion 312. In addition, in the detection unit 100C, the portion below the deformation portion 312 corresponds to the pressure receiving portion 313. That is, in the detection unit 100C, the pressure receiving portion 213 of the main body portion 210 of the high-sensitivity detection unit 200 includes the main body portion 310 of the low-sensitivity detection unit 300 (the deformation portion 312 and the pressure receiving portion 313).

[0098] In the detection section 100C, the width dimension of the deformable section 212 is the same as the width dimension of the deformable section 312. In addition, the pressure receiving area of ​​the pressure receiving section 213 is larger than the pressure receiving area of ​​the pressure receiving section 313.

[0099] In the detection unit 100C described above, the ratio of the pressure-receiving area of ​​the pressure-receiving portion 213 to the rigidity of the deformation portion 212 is also greater than the ratio of the pressure-receiving area of ​​the pressure-receiving portion 313 to the rigidity of the deformation portion 312. Therefore, the detection unit 100C has substantially the same effect as the detection unit 100.

[0100] 7(c), in the detection unit 100C, the high-sensitivity detection unit 200 and the low-sensitivity detection unit 300 are integrally formed. This can improve the ease of attachment and detachment of the detection unit 100C.

[0101] A second embodiment of the present invention will be described below.

[0102] In the first embodiment described above, as shown in FIG. 2, the high-sensitivity detection section 200 and the low-sensitivity detection section 300 are arranged side by side in the left-right direction. However, as in the second embodiment shown in FIGS. 8 and 9, it is also possible to arrange the high-sensitivity detection section 200 and the low-sensitivity detection section 300 in the front-to-back direction.

[0103] 8, the flow velocity sensor 10A according to the second embodiment of the present invention has a pair of high-sensitivity detection sections 200 arranged in front and behind the low-sensitivity detection section 300. The high-sensitivity detection section 200 and the low-sensitivity detection section 300 of the flow velocity sensor 10A are generally similar to the high-sensitivity detection section 200 and the low-sensitivity detection section 300 of the flow velocity sensor 10 according to the first embodiment.

[0104] A predetermined gap is formed between the high-sensitivity detection section 200 and the low-sensitivity detection section 300. The predetermined gap is formed so that the high-sensitivity detection section 200 can contact the low-sensitivity detection section 300 without the opposing sensor sections (sensor section 220 and sensor section 320) coming into contact with each other, and the deformation amount of the high-sensitivity detection section 200 is within the elastic range (see FIGS. 9(b) and (c)). The gap can be formed, for example, by disposing a spacer between the high-sensitivity detection section 200 and the low-sensitivity detection section 300.

[0105] As shown in Fig. 9(a), when the flow rate of water in the water pipe 2 is relatively slow, the main body 210 of the pair of high-sensitivity detection parts 200 that receives the water pressure (upstream side) deforms within the range of the gap with the low-sensitivity detection part 300. Also, as shown in Fig. 9(b) and (c), when the flow rate is relatively fast, the main body 210 comes into contact with the main body 310 of the low-sensitivity detection part 300. Also, the main body 310 deforms together with the main body 210 by receiving pressure through the main body 210.

[0106] 9 and 10, a flow velocity detection method using the flow velocity sensor 10A will be described for different flow velocities. Specifically, the flow velocity detection method will be described using a relatively small flow velocity V1 and a relatively large flow velocity V2 as references.

[0107] 9(a) shows a case where the flow velocity of water in the water pipe 2 is less than V1. In this state, the water pressure is low, so the main body 210 of the high-sensitivity detection unit 200 deforms within the gap between it and the low-sensitivity detection unit 300. As shown in FIG. 10, in the flow velocity range below V1, the low-sensitivity detection unit 300 hardly deforms. For this reason, the server 40 invalidates the detection result of the low-sensitivity detection unit 300 in the flow velocity range below V1, and acquires the flow velocity based on the detection result of the high-sensitivity detection unit 200.

[0108] 9(b) shows a case where the flow velocity of water in the water pipe 2 is V1. In this state, the main body 210 comes into contact with the main body 310.

[0109] When the flow velocity of the water in the water pipe 2 is greater than V1 (for example, V2), as shown in Figures 9(c) and 10, the main body 310 is deformed by indirectly receiving the water pressure via the main body 210. In a range of flow velocities greater than V1, the server 40 acquires the flow velocity based on the detection result of the low-sensitivity detection unit 300.

[0110] In the flow velocity sensor 10A as described above, when the high-sensitivity detection section 200 deforms by a predetermined amount or more, it comes into contact with the low-sensitivity detection section 300, and the deformation is suppressed, thereby preventing the high-sensitivity detection section 200 from deforming excessively and becoming plastically deformed.

[0111] Furthermore, in this embodiment, a pair of high-sensitivity detection sections 200 are arranged to sandwich the low-sensitivity detection section 300 at the front and rear, so that flow velocities in both the forward and backward directions can be detected.

[0112] In the above flow velocity sensor 10A, the shapes of the main body 210 and the main body 310 are configured similarly to the shapes of the main body 210 and the main body 310 of the flow velocity sensor 10 according to the first embodiment, but are not limited to this. For example, from the viewpoint of further improving the sensitivity of the high-sensitivity detection section 200, the width dimension of the deformation section 212 of the main body 210 may be made smaller than the width dimension of the pressure-receiving section 213. In addition, various shapes can be adopted as the shapes of the main body 210 and the main body 310.

[0113] Also in this embodiment, the detection result by the high-sensitivity detection unit 200 may be corrected with the detection result by the low-sensitivity detection unit 300 to obtain the flow velocity.

[0114] As described above, the flow velocity sensor 10A according to this embodiment has the following features: The high-sensitivity detection unit 200 is disposed in a pair on either side of the low-sensitivity detection unit 300 in the flow direction of the fluid, Between the high-sensitivity detection section 200 and the low-sensitivity detection section 300, a predetermined gap is formed. This configuration makes it possible to suppress plastic deformation of the high-sensitivity detection section 200. In other words, when the high-sensitivity detection section 200 deforms by a predetermined amount or more, it comes into contact with the low-sensitivity detection section 300, and the deformation is suppressed, so that it is possible to suppress the high-sensitivity detection section 200 from deforming excessively and causing plastic deformation.

[0115] Although each embodiment of the present invention has been described above, the present invention is not limited to the above configurations, and various modifications are possible within the scope of the invention described in the claims.

[0116] For example, in each of the above embodiments, an example was shown in which the flow velocity sensor 10 (10A) was installed in a fire hydrant 4, but the installation target of the flow velocity sensor 10 (10A) is not limited to a fire hydrant 4, and the flow velocity sensor 10 (10A) can be applied to various equipment such as valves.

[0117] In the above embodiment, the sensor unit 220 and the sensor unit 320 are provided on both sides of the main body unit 210 and the main body unit 310, but the present invention is not limited to this. For example, the sensor unit 220 and the sensor unit 320 may be provided on only one side of the main body unit 210 and the main body unit 310 in the front-rear direction.

[0118] In the second embodiment, the sensor unit 220 and the sensor unit 320 are provided in both the high-sensitivity detection unit 200 and the low-sensitivity detection unit 300, but the present invention is not limited to this. For example, the sensor unit 220 may be provided only in the high-sensitivity detection unit 200, and the sensor unit 320 may not be provided in the low-sensitivity detection unit 300. In this case, the server 40 acquires the flow velocity using only the detection value detected by the sensor unit 220.

[0119] In addition, in the above embodiment, an example is shown in which the main body portion 210 and the main body portion 310 of the flow velocity sensor 10 (10A) are formed in a plate shape, but the shape of the main body portion 210 and the main body portion 310 is not limited to a plate shape and can be formed in any shape.

[0120] In the above embodiment, the flow velocity sensor 10 (10A) is fixed to the mounting rod 6, but the present invention is not limited to this. For example, the flow velocity sensor 10 (10A) may be fixed directly to the fire hydrant 4 without using the mounting rod 6.

[0121] In the above embodiment, the flow velocity sensor 10 (10A) detects the flow velocity of water in the water pipe 2, but is not limited to this. The flow velocity sensor 10 (10A) can detect the flow velocity of fluids in various pipes. [Explanation of symbols]

[0122] 10 Flow Sensor 100 Detector 200 High sensitivity detector 300 Low sensitivity detector

Claims

1. A flow velocity sensor for detecting a flow velocity of a fluid in a pipe, a body portion that is deformable under pressure of the fluid; A sensor unit for detecting a deformation amount of the main body portion; A detection unit having The main body portion is a deformation portion provided with the sensor portion; a pressure receiving portion that receives pressure from the fluid and deforms the deformation portion; having The detection unit is A high-sensitivity detection unit and a low-sensitivity detection unit are included, a ratio of a pressure receiving area of ​​the pressure receiving portion of the high-sensitivity detection portion to a rigidity of the deformation portion of the high-sensitivity detection portion is greater than a ratio of a pressure receiving area of ​​the pressure receiving portion of the low-sensitivity detection portion to a rigidity of the deformation portion of the low-sensitivity detection portion, The high-sensitivity detection unit is disposed in a pair on either side of the low-sensitivity detection unit in the flow direction of the fluid, A predetermined gap is formed between the high-sensitivity detection portion and the low-sensitivity detection portion. Flow velocity sensor.

2. A flow velocity sensor for detecting a flow velocity of a fluid in a pipe, comprising: a body portion that is deformable under pressure of the fluid; A sensor unit for detecting a deformation amount of the main body portion; A detection unit having The main body portion is a deformation portion provided with the sensor portion; a pressure receiving portion that receives pressure from the fluid and deforms the deformation portion; having The detection unit is A high-sensitivity detection unit and a low-sensitivity detection unit are included, a ratio of a pressure receiving area of ​​the pressure receiving portion of the high-sensitivity detection portion to a rigidity of the deformation portion of the high-sensitivity detection portion is greater than a ratio of a pressure receiving area of ​​the pressure receiving portion of the low-sensitivity detection portion to a rigidity of the deformation portion of the low-sensitivity detection portion; A flow velocity detection method for detecting a flow velocity of the fluid based on a detection result by the sensor unit using the flow velocity sensor, comprising: a flow velocity of the fluid is detected by correcting a detection result by the sensor unit of the high-sensitivity detection unit that has undergone plastic deformation with a detection result by the sensor unit of the low-sensitivity detection unit. Flow velocity detection method.

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