Water passage detection device

Abstract

This water passage detection device comprises a casing and a sensor disposed on the casing, wherein: a flow path through which fluid flows is formed in the casing; the sensor detects deformation of the casing; the casing has a sensor contact part with which the sensor is in contact; and the sensor contact part is the portion of the casing that is thinnest.

Description

Water flow detection device

[0001] The present invention relates to a water flow detection device equipped with a sensor that detects deformation of a member.

[0002] Patent Document 1 describes a water flow switch having a flow path. The water flow switch includes a flow switch and a differential pressure operated opening / closing unit. The flow switch detects the flow rate in the flow path. The differential pressure operated opening / closing unit opens the flow path based on the flow rate detected by the flow switch.

[0003] Japanese Patent Application Laid-Open No. 2007-285992

[0004] In the field of water flow switches as described in Patent Document 1, it is desirable to make it easier to detect that a fluid is flowing through a flow path.

[0005] An object of the present invention is to provide a water flow detection device that can easily detect that a fluid is flowing through a flow path.

[0006] A water flow detection device according to one embodiment of the present invention comprises a housing and a sensor disposed in the housing, wherein a flow path through which a fluid flows is formed within the housing, the sensor detects deformation of the housing, the housing has a sensor contact portion with which the sensor is in contact, and the sensor contact portion is the thinnest part of the housing.

[0007] A water flow detection device according to one embodiment of the present invention comprises a housing and a sensor disposed in the housing, wherein a flow path through which a fluid flows is formed within the housing, the sensor detects deformation of the housing, the housing has a sensor contact portion with which the sensor is in contact, an inlet and an outlet are formed in the housing, and the sensor contact portion does not overlap with a straight line connecting the inlet and the outlet at the shortest distance when viewed in a fourth direction perpendicular to the direction in which the inlet and the outlet are arranged.

[0008] According to the water flow detection device according to one embodiment of the present invention, the water flow detection device can easily detect that a fluid is flowing through a flow path.

[0009] FIG. 1 is a perspective view showing the appearance of the water flow detection device 1. FIG. 2 is a view of the water flow detection device 1 as viewed in the negative direction of the Z axis. FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2. FIG. 4 is a cross-sectional view taken along line B-B in FIG. 2. FIG. 5 is a diagram showing an example of the output of the sensor 11. FIG. 6 is a diagram showing a water flow detection device 1a according to a first modified example of the water flow detection device 1. FIG. 7 is a diagram showing a water flow detection device 1b according to a second embodiment. FIG. 8 is a cross-sectional view taken along line A-A in the water flow detection device 1b. FIG. 9 is a diagram showing a water flow detection device 1c according to a first modified example of the water flow detection device 1b. FIG. 10 is a diagram showing a water flow detection device 1d according to a second modified example of the water flow detection device 1b. FIG. 11 is a diagram showing a water flow detection device 1e according to a third modified example of the water flow detection device 1b.

[0010] [First embodiment] A water flow detection device 1 according to a first embodiment of the present invention will now be described with reference to the drawings. Fig. 1 is a perspective view showing the appearance of the water flow detection device 1. Fig. 2 is a view of the water flow detection device 1 as seen in the negative direction of the Z axis. Fig. 3 is a cross-sectional view taken along line A-A in Fig. 2. In Fig. 3, the couplings 20 and 21 are omitted. Fig. 4 is a cross-sectional view taken along line B-B in Fig. 2.

[0011] In this embodiment, directions are defined as follows. As shown in FIGS. 1 and 2 , the Z-axis direction is the direction in which the block 100 and the retainer cover 102 are aligned. The positive direction of the Z-axis is the direction in which the block 100 and the retainer cover 102 are aligned in this order. The negative direction of the Z-axis is the direction in which the retainer cover 102 and the block 100 are aligned in this order. The X-axis direction is the direction in which the joints 20 and 21 are aligned in this order. The positive direction of the X-axis is the direction in which the joints 20 and 21 are aligned in this order. The negative direction of the X-axis is the direction in which the joints 21 and 20 are aligned in this order. The X-axis direction is perpendicular to the Z-axis direction. The Y-axis direction is perpendicular to the Z-axis and X-axis directions. In this embodiment, the first direction DIR1 coincides with the positive direction of the Z-axis. The second direction DIR2 coincides with the positive direction of the X-axis. The third direction DIR3 coincides with the negative direction of the X-axis. The third direction DIR3 is opposite to the second direction DIR2. The fourth direction DIR4 coincides with the Y-axis direction. The fourth direction DIR4 is perpendicular to the second direction DIR2.

[0012] The water flow detection device 1 detects that a fluid FL is flowing within the water flow detection device 1. The fluid FL is, for example, water. The water flow detection device 1 is connected to a member such as a hose for transporting the fluid FL. The water flow detection device 1 includes, for example, a coupling 20 and a coupling 21. The fluid FL flows into the water flow detection device 1 via the coupling 20. Similarly, the fluid FL flows out of the water flow detection device 1 via the coupling 21. As shown in FIGS. 1 to 4 , the water flow detection device 1 includes a housing 10 and a sensor 11.

[0013] As shown in FIGS. 1 to 3 , the housing 10 has a rectangular parallelepiped shape with long sides extending along the X-axis and short sides extending along the Y-axis. As shown in FIG. 3 , the housing 10 has an inner circumferential surface IS and an outer circumferential surface OS. The fluid FL flows within the housing 10. Specifically, as shown in FIG. 3 , the housing 10 is formed with an inlet Et, a flow path FP, and an outlet Ex. The inlet Et and the outlet Ex are aligned in this order in the second direction DIR2. The inlet Et is formed on a surface of the housing 10 located at the end of the housing 10 in the negative direction of the X-axis. The outlet Ex is formed on a surface of the housing 10 located at the end of the housing 10 in the positive direction of the X-axis. The flow path FP is formed within the housing 10. The flow path FP is surrounded by the inner circumferential surface IS of the housing 10. The flow path FP connects the inlet Et and the outlet Ex. The fluid FL passes through the housing 10 in the order of the inlet Et, the flow path FP, and the outlet Ex. Specifically, the fluid FL flows into the housing 10 from the inlet Et. After passing through the inlet Et, the fluid FL reaches the flow path FP. The fluid FL flows through the flow path FP. After passing through the flow path FP, the fluid FL reaches the outlet Ex. The fluid FL flows out of the housing 10 via the outlet Ex.

[0014] As shown in FIGS. 1 to 3, the housing 10 includes a block 100, a plate 101, a retaining cover 102, a plurality of bolts 103, and a seal 104.

[0015] As shown in FIGS. 1 to 3 , the block 100 has a rectangular parallelepiped shape with long sides extending in the second direction DIR2 and short sides extending in the fourth direction DIR4. The flow path FP is formed within the block 100. Therefore, the block 100 has a shape with an inner circumferential surface IS and an outer circumferential surface OS. An inlet Et is formed at the end of the block 100 in the negative direction of the X axis. An outlet Ex is formed at the end of the block 100 in the positive direction of the X axis. A portion of the flow path FP is exposed from the block 100. Specifically, the center of the flow path FP in the X axis direction and its vicinity are exposed from the block 100. More specifically, the center of the flow path FP in the X axis direction and its vicinity are located on the positive side of the Z axis relative to the block 100. Both ends of the flow path FP in the X axis direction are not exposed from the block 100. As shown in FIG. 3 , a recess DE is provided on the surface of the block 100 located at the end in the positive direction of the Z axis. The recess DE protrudes in the negative direction of the Z axis. The recess DE has a ring shape when viewed in the Z axis direction. The material of such a block 100 is, for example, SUS (Steel Use Stainless Steel).

[0016] As shown in FIGS. 2 and 3 , the plate 101 has a plate shape with long sides extending in the second direction DIR2 and short sides extending in the fourth direction DIR4. The plate 101 has a first main surface SF1a and a second main surface SF2a aligned in the Z-axis direction. The first main surface SF1a and the second main surface SF2a are aligned in this order in the negative direction of the Z-axis. The plate 101 is located between the retaining cover 102 and the block 100 in the Z-axis direction. The plate 101 is in contact with the block 100. Specifically, the outer peripheral edge of the second main surface SF2a is in contact with the block 100. The thickness of the plate 101 in the Z-axis direction is thinner than the thickness of the block 100 in the Z-axis direction. The plate 101 covers the portion of the flow path FP that is exposed from the block 100. The plate 101 is in contact with a portion of the flow path FP. Specifically, the second main surface SF2a is in contact with the portion of the flow path FP that is exposed from the block 100. Therefore, the second main surface SF2a is in contact with the vicinity of the center of the flow path FP in the X-axis direction. Such a plate 101 can be made of a material such as SUS, resin, glass, etc.

[0017] As shown in FIGS. 1 to 3 , the retaining cover 102 has a plate shape with long sides extending along the X-axis and short sides extending along the Y-axis. As shown in FIGS. 1 and 2 , the retaining cover 102 has a through-hole Th1 formed therein. The through-hole Th1 penetrates the retaining cover 102 in the Z-axis direction. The through-hole Th1 is formed at and near the center of the retaining cover 102 in the X-axis and Y-axis directions. As a result, the center and near the center of the plate 101 in the X-axis and Y-axis directions are not in contact with the retaining cover 102. The outer periphery of the plate 101 is in contact with the retaining cover 102. As shown in FIG. 2 , the retaining cover 102 has a plurality of through-holes Th2 formed therein. Each of the plurality of through-holes Th2 penetrates the retaining cover 102 in the Z-axis direction. Each of the plurality of through-holes Th2 is located around the through-hole Th1 when viewed in the Z-axis direction.

[0018] As shown in FIGS. 1 and 2 , the multiple bolts 103 are located on the positive side of the retaining cover 102 along the Z axis. Each of the multiple bolts 103 is located in one of the multiple through holes Th2. Each of the multiple bolts 103 embedded in the multiple through holes Th2 presses the retaining cover 102 in the negative direction of the Z axis. In this case, the plate 101 is pressed in the negative direction of the Z axis. This fixes the plate 101 to the block 100.

[0019] The seal 104 has a ring shape. As shown in FIG. 3 , the seal 104 is located within the recess DE. Therefore, the seal 104 surrounds the sensor 11 and the through-hole Th1 when viewed in the Z-axis direction. The seal 104 prevents the fluid FL from leaking out of the water flow detection device 1 between the block 100 and the retaining cover 102. Such a seal 104 may be an O-ring, a packing, or the like.

[0020] 3, the flow path FP in the housing 10 includes a flow path FP0, a flow path FP1 (first flow path), a flow path FP2 (second flow path), a flow path FP3, and a flow path FP4. The fluid FL passes through the housing 10 in the order of the inlet Et, the flow path FP0, the flow path FP1, the flow path FP2, the flow path FP3, the flow path FP4, and the outlet Ex.

[0021] The flow path FP0 is connected to the inlet Et. The flow path FP0 extends along the X-axis. The fluid FL flows through the flow path FP0 in the positive direction of the X-axis.

[0022] The flow path FP1 (first flow path) extends in the positive direction of the Z axis (first direction DIR1). The flow path FP1 is connected to the flow path FP0. The fluid FL that has passed through the flow path FP0 reaches the flow path FP1. The flow direction of the fluid FL in the flow path FP1 changes from the positive direction of the X axis to the positive direction of the Z axis. Specifically, in this embodiment, the block 100 includes an obstacle ObS (see FIG. 3). The obstacle ObS has a shape that protrudes in the positive direction of the Z axis from the lower end near the center of the block 100. The obstacle ObS is in contact with the end of the flow path FP1 in the positive direction of the X axis. As a result, the fluid FL flowing in the positive direction of the X axis through the flow path FP0 collides with the obstacle ObS in the flow path FP1. As a result, the flow direction of the fluid FL in the flow path FP1 changes from the positive direction of the X axis to the positive direction of the Z axis. The fluid FL flows through the flow path FP1 (first flow path) in the positive direction of the Z axis (first direction DIR1).

[0023] The flow path FP2 (second flow path) extends in the positive direction of the X axis (second direction DIR2). The flow path FP2 is connected to the flow path FP1. Specifically, the end of the flow path FP2 (second flow path) in the negative direction of the X axis (third direction DIR3) is located at the end of the flow path FP1 (first flow path) in the positive direction of the Z axis (first direction DIR1). The fluid FL flowing through the flow path FP1 in the positive direction of the Z axis reaches the end of the flow path FP2 in the negative direction of the X axis.

[0024] At the end of the flow path FP2 (second flow path) in the negative direction of the X axis (third direction DIR3), the flow direction of the fluid FL changes from the positive direction of the Z axis (first direction DIR1) to the positive direction of the X axis (second direction DIR2). Specifically, the sensor contact portion CP of the plate 101 contacts the end of the flow path FP2 (second flow path) in the positive direction of the Z axis (first direction DIR1). Therefore, the fluid FL flowing from the end of the flow path FP2 in the negative direction of the X axis toward the positive direction of the Z axis collides with the sensor contact portion CP. There is no obstacle ObS in the flow path FP2 that prevents the fluid FL from moving in the positive direction of the X axis. Therefore, the flow direction of the fluid FL that has moved into the flow path FP2 changes from the positive direction of the Z axis to the positive direction of the X axis. The fluid FL flows through the flow path FP2 (second flow path) in the positive direction of the X axis (second direction DIR2). The end of the flow path FP2 in the positive direction of the X axis is in contact with a part of the block 100. Therefore, the fluid FL flowing in the positive direction of the X axis through the flow path FP2 collides with a part of the block 100.

[0025] Flow path FP3 extends along the Z-axis. The end of flow path FP3 in the positive direction of the Z-axis is located at the end of flow path FP2 in the positive direction of the X-axis. The fluid FL that has passed through flow path FP2 flows through flow path FP3 in the negative direction of the Z-axis. The end of flow path FP3 in the negative direction of the Z-axis is in contact with a part of block 100. Therefore, the fluid FL flowing through flow path FP3 in the negative direction of the Z-axis collides with a part of block 100.

[0026] The flow path FP4 extends along the X-axis. The end of the flow path FP4 in the negative direction of the X-axis is located at the end of the flow path FP3 in the negative direction of the Z-axis. The fluid FL that has passed through the flow path FP3 flows through the flow path FP4 in the positive direction of the X-axis. The end of the flow path FP4 in the positive direction of the X-axis is connected to the inlet Et.

[0027] As shown in FIGS. 1 to 4 , the sensor 11 has a rectangular shape with long sides extending along the X-axis and short sides extending along the Y-axis. The sensor 11 is disposed in the housing 10. The sensor 11 is disposed in the thinnest part of the housing 10. In this embodiment, the thinnest part of the housing 10 is the plate 101. Specifically, the thickness of the housing 10 is the shortest distance between the inner circumferential surface IS and the outer circumferential surface OS of the housing 10. The plate 101 is a part of the housing 10. Therefore, the thickness of the part of the housing 10 where the plate 101 is located is the thickness of the plate 101 in the Z-axis direction. The thickness of the plate 101 is thinner than, for example, the thickness of the retaining cover 102, which is a part of the housing 10. The thickness of the plate 101 is also thinner than the thickness of the block 100, which is a part of the housing 10. The thickness of the block 100 is the distance between the inner circumferential surface IS and the outer circumferential surface OS of the block 100. Therefore, the plate 101 is the thinnest part of the housing 10. For this reason, the sensor 11 is disposed on the plate 101. The sensor 11 is disposed at or near the center of the first main surface SF1a. The sensor 11 is not in contact with the retaining cover 102. The sensor 11 is located inside the through-hole Th1 when viewed in the Z-axis direction.

[0028] In the above configuration, the housing 10 has a sensor contact portion CP with which the sensor 11 comes into contact. The sensor contact portion CP is located on the plate 101. Therefore, the thickness of the sensor contact portion CP is the thinnest portion of the housing 10. In other words, the thickness of the sensor contact portion CP is the thinnest among the thicknesses of the housing 10. The sensor contact portion CP is located at or near the center of the plate 101.

[0029] In this embodiment, the sensor 11 is specifically a piezoelectric sensor. As shown in Fig. 4, the sensor 11 includes a piezoelectric film 111, a first electrode 110, a second electrode 112, and a detection circuit (not shown). The first electrode 110, the piezoelectric film 111, and the second electrode 112 are arranged in this order in the negative direction of the Z axis.

[0030] 2 and 4, the piezoelectric film 111 has a rectangular shape with long sides extending along the X-axis and short sides extending along the Y-axis. As shown in Fig. 4, the piezoelectric film 111 has a first main surface SF1b and a second main surface SF2b aligned in the Z-axis direction.

[0031] The piezoelectric film 111 generates electric charges according to the amount of deformation of the piezoelectric film 111. For example, the polarity of the electric charges generated when the piezoelectric film 111 is stretched in the X-axis direction is opposite to the polarity of the electric charges generated when the piezoelectric film 111 is stretched in the Y-axis direction. Specifically, the piezoelectric film 111 is a film formed from a chiral polymer. An example of a chiral polymer is polylactic acid (PLA), particularly poly-L-lactic acid (PLLA). PLLA has a helical main chain structure. PLLA exhibits piezoelectricity in which the molecules are oriented when stretched uniaxially. The piezoelectric film 111 has a piezoelectric constant of d14. As shown in FIG. 2 , the uniaxial stretching direction OD of the piezoelectric film 111 forms a 45-degree angle with respect to the X-axis direction and the Y-axis direction. This 45-degree angle includes, for example, an angle of approximately 45 degrees ±10 degrees. As a result, the piezoelectric film 111 generates electric charges when stretched in the X-axis direction or the Y-axis direction. For example, when the piezoelectric film 111 is stretched in the X-axis direction, it generates a positive charge. When the piezoelectric film 111 is stretched in the Y-axis direction, it generates a negative charge. The magnitude of the charge depends on the differential value of the deformation of the piezoelectric film 111 due to stretching or compression.

[0032] The first electrode 110 is, for example, a reference electrode connected to a reference potential. The first electrode 110 is fixed to the first principal surface SF1b with an adhesive (not shown) such as OCA. The first electrode 110 covers the first principal surface SF1b.

[0033] The second electrode 112 is, for example, a signal electrode. The second electrode 112 is fixed to the second main surface SF2b with an adhesive (not shown) such as OCA. The second electrode 112 covers the second main surface SF2b.

[0034] The detection circuit is electrically connected to the first electrode 110 and the second electrode 112. The detection circuit converts the charge generated by the piezoelectric film 111 into a voltage signal. The detection circuit generates a digital signal by AD converting the voltage signal.

[0035] The sensor 11 detects deformation of the housing 10. Specifically, the sensor 11 is fixed to the plate 101 with an adhesive (not shown). When the fluid FL flows through the flow path FP, the plate 101 in contact with the flow path FP is deformed. The sensor 11 is deformed in accordance with the deformation of the plate 101. The sensor 11 outputs a signal corresponding to the deformation of the sensor 11.

[0036] The sensor 11 detects the deformation of the plate 101, thereby detecting that the fluid FL is flowing through the flow path FP. A detailed description will be given below with reference to FIG. 5. FIG. 5 is a diagram showing an example of the output of the sensor 11. The horizontal axis in FIG. 5 represents time. The vertical axis in FIG. 5 represents the value of the signal output by the sensor 11. Time t2 in FIG. 5 is a time after time t1. Time t3 is a time after time t2. Time t4 is a time after time t3.

[0037] In the example shown in FIG. 5 , the fluid FL begins to flow into the water flow detection device 1 at time t1. At this time, the fluid FL begins to pass through the flow path FP. At this time, the fluid FL, flowing in the positive direction of the Z axis from the end of the flow path FP2 in the negative direction of the X axis, collides with the plate 101. Furthermore, the plate 101, which is provided near the flow path FP, vibrates due to the flow (vibration) of the fluid FL that occurs when the fluid FL passes through the flow path FP. This causes the plate 101 to deform. Therefore, as shown in FIG. 5 , between time t1 and time t2, the sensor 11 outputs a signal having a positive or negative polarity with respect to the reference potential VE.

[0038] After time t2, water continues to flow through the water flow detection device 1. Therefore, the fluid FL continues to flow through the flow path FP. In this case, the fluid FL vibrates the plate 101. That is, the plate 101 deforms. This deforms the sensor 11 provided on the plate 101. Therefore, between time t2 and time t3, the sensor 11 outputs a signal having a positive or negative polarity with respect to the reference potential VE. While water continues to flow through the water flow detection device 1, the magnitude of the force applied to the plate 101 is unlikely to change. Therefore, the amount of deformation of the plate 101 between time t2 and time t3 while water continues to flow through the water flow detection device 1 is smaller than the amount of deformation of the plate 101 between time t1 and time t2. Therefore, the magnitude of the signal value between time t2 and time t3 is smaller than the magnitude of the signal value between time t1 and time t2.

[0039] At time t3, the inflow of the fluid FL into the water flow detection device 1 stops. At this time, the fluid FL no longer collides with the plate 101. Therefore, the plate 101 attempts to return to its pre-deformation shape. Therefore, between time t3 and time t4, the sensor 11 outputs a signal having a positive or negative polarity with respect to the reference potential VE. After time t4, the inflow of the fluid FL into the water flow detection device 1 continues to stop. Therefore, the plate 101 does not deform. As a result, after time t4, the value of the signal output by the sensor 11 matches the reference potential VE.

[0040] (Effect) According to the water flow detection device 1, the sensor 11 can more easily detect that the fluid FL is flowing through the flow path FP. Specifically, the housing 10 has a sensor contact portion CP. The sensor contact portion CP is the thinnest portion of the housing 10. Therefore, when the fluid FL flows through the flow path FP, the sensor contact portion CP is the portion of the housing 10 that is most susceptible to deformation. The sensor 11 is in contact with the sensor contact portion CP, which is the most susceptible to deformation in the housing 10. Therefore, when the fluid FL flows through the flow path FP, the sensor 11 is likely to deform in accordance with the deformation of the sensor contact portion CP. As a result, the sensor 11 can more easily detect that the fluid FL is flowing through the flow path FP.

[0041] The water flow detection device 1 makes it easier for the sensor 11 to detect that the fluid FL is flowing through the flow path FP. Specifically, the fluid FL flows through the flow path FP1 (first flow path) in the positive direction of the Z axis. The end of the flow path FP1 in the positive direction of the Z axis is connected to the end of the flow path FP2 in the negative direction of the X axis. Therefore, the fluid FL that has passed through the flow path FP1 flows in the positive direction of the Z axis through the end of the flow path FP2 (second flow path) in the negative direction of the X axis. Here, the sensor contact portion CP is in contact with the end of the flow path FP2 in the positive direction of the Z axis. In the above configuration, the fluid FL flowing in the positive direction of the Z axis through the end of the flow path FP2 in the negative direction of the X axis collides with the sensor contact portion CP. In this case, a force in the positive direction of the Z axis is applied to the sensor contact portion CP. This makes it easier for the sensor contact portion CP to deform in the Z axis direction. Therefore, when the fluid FL flows through the flow path FP, the sensor 11 in contact with the sensor contact portion CP is likely to deform in the Z-axis direction, making it easier for the sensor 11 to detect that the fluid FL is flowing through the flow path FP.

[0042] The sensor contact portion CP is in contact with the end of the flow path FP2 in the positive direction of the Z axis. The fluid FL flowing in the positive direction of the Z axis from the end of the flow path FP2 in the negative direction of the X axis collides with the sensor contact portion CP, which is the portion of the housing 10 that is most susceptible to deformation. Here, the sensor contact portion CP is the thinnest portion of the housing 10. Therefore, the sensor contact portion CP is the portion of the housing 10 that is most susceptible to deformation. In other words, in this embodiment, the flow path FP is formed so that the fluid FL collides with the thinnest portion of the housing 10 (the sensor contact portion CP). Therefore, in the water flow detection device 1, the sensor 11 is more likely to deform when the sensor 11 is provided at the sensor contact portion CP, which is the thinnest portion of the housing 10. Furthermore, the sensor 11 is more likely to deform when the fluid FL collides with the sensor contact portion CP where the sensor 11 is provided. This makes it easier for the sensor 11 to detect that the fluid FL is flowing through the flow path FP for two reasons.

[0043] In the water flow detection device 1, the flow path FP is provided near the plate 101. The plate 101, which is provided near the flow path FP, is likely to vibrate due to the flow (vibration) of the fluid FL that occurs when the fluid FL passes through the flow path FP. Therefore, the sensor 11 provided on the plate 101 is likely to be deformed by the flow (vibration) of the fluid FL that occurs when the fluid FL passes through the flow path FP. As a result, the sensor 11 can easily detect that the fluid FL is flowing through the flow path FP.

[0044] Other Configurations of the Water Flow Detection Device 1 Other configurations of the water flow detection device 1 will be described below with reference to FIG. 3 . As shown in FIG. 3 , the sensor contact portion CP is located between the inlet Et and the outlet Ex in the X-axis direction (first direction DIR1). In this case, the sensor contact portion CP does not overlap with the straight line SL connecting the inlet Et and the outlet Ex at the shortest distance when viewed in the Y-axis direction (fourth direction DIR4), which is perpendicular to the direction in which the inlet Et and the outlet Ex are aligned. In this embodiment, the direction in which the inlet Et and the outlet Ex are aligned is the X-axis direction, which is perpendicular to the Y-axis direction. In this embodiment, the sensor contact portion CP is located on the positive side of the Z-axis with respect to the straight line SL.

[0045] (Effect) In the water flow detection device 1, the sensor contact portion CP does not overlap with the straight line SL connecting the inlet Et and the outlet Ex at the shortest distance when viewed in the Y-axis direction. When viewed in the Y-axis direction, the sensor contact portion CP is spaced apart from the straight line SL. Therefore, in the water flow detection device 1, the direction of travel of the fluid FL in the flow path FP is changed to bring the sensor contact portion CP, which is spaced apart from the straight line SL, into contact with the flow path FP. Specifically, when the fluid FL collides with the obstacle ObS, the direction of travel of the fluid FL changes from the positive direction of the X-axis to the positive direction of the Z-axis. When the fluid FL collides with the plate 101, the direction of travel of the fluid FL changes from the positive direction of the Z-axis to the positive direction of the X-axis. When the fluid FL collides with the obstacle ObS or the plate 101, the housing 10 is more likely to vibrate. Therefore, the sensor 11 provided on the plate 101 of the housing 10 is more likely to deform. As a result, the sensor 11 can more easily detect that the fluid FL is flowing through the flow path FP.

[0046] [First Modification of Water Flow Detection Device 1] A water flow detection device 1a according to a first modification of the water flow detection device 1 will now be described with reference to the drawings. Fig. 6 is a diagram showing the water flow detection device 1a according to the first modification of the water flow detection device 1.

[0047] As shown in FIG. 7 , the water flow detection device 1a differs from the housing 10 shown in FIG. 6 in that it further includes an object 30. The object 30 is disposed in the flow path FP. The object 30 is not fixed to the housing 10. The outer diameter ID30 of the object 30 is smaller than the inner diameters ID1 and ID2 of the flow path FP. In the example shown in FIG. 6 , the inner diameter ID1 is the inner diameter of the flow path FP in the X-axis direction. The inner diameter ID2 is the inner diameter of the flow path FP in the Z-axis direction. In the example shown in FIG. 6 , the inner diameter of the flow path FP in the Y-axis direction is omitted, but the outer diameter ID30 is smaller than the inner diameter of the flow path FP in the Y-axis direction. As a result, when a fluid FL flows through the flow path FP, the object 30 moves within the flow path FP. The outer diameter ID30 of the object 30 is larger than the inner diameters of the fittings 20 and 21. As a result, the object 30 does not move out of the housing 10. Such an object 30 is, for example, a bead having a spherical shape.

[0048] (Effect) According to the water flow detection device 1a, the sensor 11 can more easily detect deformation of the housing 10. Specifically, the object 30 is placed in the flow path FP. When the fluid FL flows through the flow path FP, the object 30 moves within the flow path FP. This causes the object 30 to come into contact with the plate 101. The impact of the object 30 coming into contact with the plate 101 makes it easier for the plate 101 to deform in the Z-axis direction. As a result, the sensor 11 can more easily detect deformation of the plate 101.

[0049] According to the water flow detection device 1a, the sensor 11 can more easily detect deformation of the housing 10. Specifically, an object 30 is placed in the flow path FP. When a fluid FL flows through the flow path FP, the object 30 is likely to change the flow of the fluid FL. Specifically, the object 30 is likely to change the continuous flow of the fluid FL into an intermittent flow. When the fluid FL flows intermittently through the flow path FP, intermittent deformation is likely to occur in the plate 101. As a result, the sensor 11 can more easily detect deformation of the plate 101.

[0050] Second Embodiment A water flow detection device 1b according to a second embodiment will now be described with reference to the drawings. Fig. 7 is a view showing the water flow detection device 1b according to the second embodiment. In Fig. 7, the rotor 105 is seen through. Fig. 8 is a cross-sectional view of the water flow detection device 1b taken along line A-A.

[0051] As shown in FIG. 7 , the water flow detection device 1b differs from the water flow detection device 1 in that it includes a housing 10b that is different from the housing 10. The housing 10b differs from the housing 10 in that it does not include the plate 101. In this modification, the block 100 is in contact with the retaining lid 102. In this modification, the block 100 and the retaining lid 102 are aligned in this order in the negative direction of the Y axis. In this modification, the sensor 11 is not provided on the plate 101, and therefore the sensor 11 is provided, for example, on a surface of the block 100 that is located at the end in the positive direction of the Z axis.

[0052] As shown in FIG. 8 , the housing 10b differs from the housing 10 in that it further includes a rotor 105. The rotor 105 is located within the block 100. The rotor 105 is surrounded by the block 100 and the retaining cover 102. The rotor 105 has, for example, a columnar shape extending along the Y-axis. The rotor 105 has a columnar shape with a central axis CAX extending in a fourth direction DIR4 (extending along the Y-axis). The rotor 105 rotates around the central axis CAX. The rotor 105 has one or more recesses DR. Each of the one or more recesses DR is recessed in a direction (outer-inner direction DOI) from the outer peripheral surface OS1 of the rotor 105 toward the central axis CAX.

[0053] The rotor 105 is located between the inlet Et and the outlet Ex. The rotor 105 is located in a flow path FP. The rotor 105 transports the fluid FL that has passed through the inlet Et to the outlet Ex, which is located on the positive side of the Z axis relative to the inlet Et. Specifically, in the housing 10b, the flow path FP includes a flow path FP5 and a flow path FP6. The flow path FP5 is located between the inlet Et and the rotor 105. The flow path FP6 is located between the rotor 105 and the outlet Ex. The flow path FP6 is located on the positive side of the Z axis relative to the flow path FP5. The fluid FL flows through the flow path FP5 in the positive direction of the X axis. The fluid FL that has passed through the flow path FP5 reaches the rotor 105. The fluid FL that has reached the rotor 105 enters one or more recesses DR. As the rotor 105 rotates around the central axis CAX, the fluid FL that has entered one or more recesses DR advances in the positive direction of the Z axis. As a result, the fluid FL reaches the flow path FP6. The fluid FL reaches the outlet Ex via the flow path FP6.

[0054] The one or more recesses DR are provided at equal intervals on the outer peripheral surface OS1 of the rotor 105. Therefore, when the rotor 105 rotates around the central axis CAX, the fluid FL flows into the flow path FP6 at predetermined intervals. In other words, the rotor 105 changes the continuous flow of the fluid FL into an intermittent flow.

[0055] In this modification, similar to the first embodiment, the sensor contact portion CP is located between the entrance Et and the exit Ex in the X-axis direction (second direction DIR2) (see FIG. 8). The sensor contact portion CP does not overlap with the line SL that connects the entrance Et and the exit Ex in the shortest distance when viewed in the Y-axis direction (fourth direction DIR4). In this modification, the sensor contact portion CP is located on the positive side of the Z-axis with respect to the line SL.

[0056] (Effect) In this modified example, the rotor 105 rotates to cause the fluid FL to travel from the inlet Et to the outlet Ex, which is located on the more positive side of the Z axis than the inlet Et. When the rotor 105 is rotating, the continuous flow of the fluid FL changes to an intermittent flow. When the fluid FL flows intermittently through the flow path FP, the housing 10 becomes more likely to vibrate. When the housing 10 vibrates, the sensor 11 becomes more likely to deform. Therefore, when the fluid FL flows through the flow path FP, the sensor 11 becomes more likely to deform.

[0057] [Modification 1 of Water Flow Detection Device 1b] A water flow detection device 1c according to Modification 1 of the water flow detection device 1b will now be described with reference to the drawings. Fig. 9 is a diagram showing the water flow detection device 1c according to Modification 1 of the water flow detection device 1b. In Fig. 9, the rotor 105 is seen through.

[0058] 9, the water flow detection device 1c differs from the water flow detection device 1b in that it includes a housing 10c that is different from the housing 10b. The housing 10c differs from the housing 10b in that it further includes a plate 101. The plate 101 is located between the block 100 and the retaining cover 102. The plate 101 contacts the outer peripheral surface OS of the rotor 105.

[0059] In the water flow detection device 1c, the sensor 11 is provided on the plate 101. In the example shown in FIG. 9, the sensor 11 overlaps the rotor 105 when viewed in the Y-axis direction. The thickness of the plate 101 is the thinnest among the thicknesses of the housing 10. Therefore, when the rotor 105 rotates, the plate 101 is the most susceptible to deformation in the housing 10. The sensor 11 is provided on the plate 101, which is the most susceptible to deformation in the housing 10. Therefore, the sensor 11 can more easily detect deformation of the housing 10. As a result, the sensor 11 can more easily detect that the fluid FL is flowing through the flow path FP.

[0060] Other configurations of the plate 101 in this modification are the same as those of the plate 101 in the first embodiment, and therefore descriptions thereof will be omitted. Also, other configurations of the rotor 105 in this modification are the same as those of the rotor 105 in Modification 1, and therefore descriptions thereof will be omitted.

[0061] [Modification 2 of Water Flow Detection Device 1b] A water flow detection device 1d according to Modification 2 of the water flow detection device 1b will now be described with reference to the drawings. Fig. 10 is a diagram showing the water flow detection device 1d according to Modification 2 of the water flow detection device 1b.

[0062] As shown in FIG. 10 , the water flow detection device 1d differs from the water flow detection device 1b in that it includes a housing 10d that is different from the housing 10b. The housing 10d also differs from the housing 10b in that it includes a plate 101. In this modification, the plate 101 is located on the positive side of the Z axis relative to the rotor 105. The sensor contact portion CP contacts a portion of the flow path FP6. After passing through the rotor 105, the fluid FL collides with the sensor contact portion CP. For the same reasons as in the first embodiment, the sensor contact portion CP is prone to deformation. The sensor 11 is provided on the sensor contact portion CP. Therefore, the sensor 11 is prone to deformation when the fluid FL flows through the flow path FP. As a result, the sensor 11 can more easily detect that the fluid FL is flowing through the flow path FP.

[0063] Other configurations of the plate 101 in this modification are the same as those of the plate 101 in the first embodiment, and therefore descriptions thereof will be omitted. Also, other configurations of the rotor 105 in this modification are the same as those of the rotor 105 in Modification 1, and therefore descriptions thereof will be omitted.

[0064] [Modification 3 of Water Flow Detection Device 1b] A water flow detection device 1e according to Modification 3 of the water flow detection device 1b will now be described with reference to the drawings. Fig. 11 is a diagram showing the water flow detection device 1e according to Modification 3 of the water flow detection device 1b.

[0065] As shown in FIG. 11 , the water flow detection device 1e differs from the water flow detection device 1b in that it includes a housing 10e that is different from the housing 10b. The housing 10e differs from the housing 10b in that both the inlet Et and the outlet Ex are located at the end of the block 100 in the negative direction of the X axis. Therefore, in this modification, the sensor contact portion CP is not located between the inlet Et and the outlet Ex in the X-axis direction (second direction DIR2). In this modification, the sensor contact portion CP is located on the positive side of the X axis relative to the inlet Et and the outlet Ex. In this modification, the outlet Ex is located on the positive side of the Z axis relative to the inlet Et, as shown in FIG. 11 . Furthermore, the flow path FP6 located between the rotor 106 and the outlet Ex is located on the positive side of the Z axis relative to the flow path FP5 located between the rotor 106 and the inlet Et. In this modification, the sensor contact portion CP does not overlap with the straight line SL connecting the entrance Et and the exit Ex at the shortest distance when viewed in the Y-axis direction (fourth direction DIR4) perpendicular to the direction in which the entrance Et and the exit Ex are aligned. In this modification, the direction in which the entrance Et and the exit Ex are aligned is the Z-axis direction perpendicular to the Y-axis direction.

[0066] The water flow detection device 1e also differs from the water flow detection device 1b in that it includes a rotor 106 that is different from the rotor 105. In the water flow detection device 1e, the rotor 106 is not located between the inlet Et and the outlet Ex. As shown in Fig. 11, the rotor 106 is located on the positive side of the X-axis relative to the inlet Et and the outlet Ex.

[0067] The fluid FL flowing through the flow path FP5 in the positive direction of the X-axis reaches the rotor 106. The rotor 106 is provided with one or more recesses DR, similar to the rotor 105. When the rotor 106 rotates around the central axis CAX, the fluid FL that has reached the rotor 106 proceeds in the positive direction of the Z-axis. As a result, the fluid FL reaches the flow path FP6. The fluid FL that has reached the flow path FP6 flows through the flow path FP6 in the negative direction of the X-axis.

[0068] The one or more recesses DR are provided at equal intervals on the outer peripheral surface OS2 of the rotor 106. Therefore, when the rotor 106 rotates about the central axis CAX, the fluid FL flows into the flow path FP6 at predetermined intervals. Therefore, in this modification, similar to the water flow detection device 1b, the rotor 106 changes the continuous flow of the fluid FL into an intermittent flow.

[0069] 11, the rotor 106 is larger than the rotor 105 of the water flow detection device 1b. However, the size of the rotor 106 is not limited to the example shown in FIG. 11, and the rotor 106 may be larger or smaller than the rotor 105.

[0070] Such a water flow detection device 1e has the same effects as the water flow detection device 1b.

[0071] The water flow detection device according to the present invention is not limited to the water flow detection devices 1, 1a to 1e, and can be modified within the scope of the invention. The configurations of the water flow detection devices 1, 1a to 1e may be combined in any manner.

[0072] The X-axis, Y-axis, and Z-axis directions are defined for the purpose of explanation. Therefore, the X-axis, Y-axis, and Z-axis directions during actual use of the water flow detection devices 1, 1a to 1e do not necessarily have to coincide with the X-axis, Y-axis, and Z-axis directions in each embodiment and each modified example. For example, the long side of the block 100 may extend along the Y-axis, or the short side of the block 100 may extend along the X-axis.

[0073] The first direction DIR1, the second direction DIR2, the third direction DIR3, and the fourth direction DIR4 are defined for the purpose of explanation. Therefore, the first direction DIR1, the second direction DIR2, the third direction DIR3, and the fourth direction DIR4 in the actual use of the water flow detection device 1, 1a to 1e do not necessarily have to coincide with the first direction DIR1, the second direction DIR2, the third direction DIR3, and the fourth direction DIR4 in each embodiment and each modified example.

[0074] The fluid FL does not necessarily have to be water, but may be oil or the like.

[0075] In the water flow detection device 1, the flow path FP does not necessarily have to have the shape shown in FIG. 3 . For example, in the water flow detection device 1, the flow path FP may include only one flow path (hereinafter referred to as the third flow path) extending along the X-axis. In this case, the fluid FL flows through the third flow path in the first direction DIR1. At this time, the sensor contact portion CP is in contact with a portion of the third flow path. In this case, when the fluid FL flows through the third flow path, the sensor contact portion CP in contact with the third flow path vibrates in the Z-axis direction. Therefore, similar to the water flow detection device 1 according to the first embodiment, the sensor 11 can easily detect deformation of the sensor contact portion CP.

[0076] In the water flow detection device 1, the flow path FP does not necessarily have to have the shape shown in Fig. 3. For example, the flow path FP may have a U-shape when viewed in the Y-axis direction. In this case, the inlet Et and the outlet Ex are each provided at, for example, the end of the block 100 in the negative direction of the Z-axis. In this case, the sensor contact portion CP is in contact with the end of the U-shaped flow path FP in the positive direction of the Z-axis.

[0077] The housing 10 does not necessarily have to have the seal 104 .

[0078] The seal 104 does not necessarily have to be an O-ring or a packing.

[0079] In the example shown in Figure 5, the value of the signal (hereinafter referred to as the first signal) output by the sensor 11 from time t1 to time t2 is greater than the value of the signal (hereinafter referred to as the second signal) output by the sensor 11 from time t2 to time t3. Therefore, in the example shown in Figure 5, if the sensor 11 detects a first signal having a value greater than the value of the second signal, the sensor 11 may determine that the time at which the first signal was detected is the water flow start time. However, the sensor 11 does not necessarily have to be configured to determine the start of water flow based on the first signal and the second signal.

[0080] Similarly, in the example shown in Figure 5, the value of the signal (hereinafter referred to as the third signal) output by sensor 11 from time t3 to time t4 is greater than the value of the second signal. Therefore, in the example shown in Figure 5, if sensor 11 detects a second signal having a value greater than the value of the second signal, it may determine that the time at which it detected the first signal is the water flow end time. However, sensor 11 does not necessarily have to be configured to determine the water flow end based on the second and third signals.

[0081] In the water flow detection devices 1b to 1e, the rotor 105 changes the continuous flow of the fluid FL into an intermittent flow. However, the water flow detection devices 1b to 1d may also include a member other than the rotor 105 that changes the continuous flow of the fluid FL into an intermittent flow.

[0082] It should be noted that the first electrode 110 does not necessarily have to be a reference electrode, and the second electrode 112 does not necessarily have to be a signal electrode. For example, the first electrode 110 may be a signal electrode, and the second electrode 112 may be a reference electrode.

[0083] In the water flow detection device 1, the sensor 11 does not necessarily have to perform water flow detection by detecting vibrations generated as a result of the fluid FL colliding with the plate 101. The sensor 11 may perform water flow detection by detecting the flow (vibrations) of the fluid FL generated when the fluid FL passes through the flow path FP.

[0084] The water flow detection device 1 does not necessarily have to include the joints 20 and 21. A member such as a hose may include the joints 20 and 21.

[0085] The portion of the flow path FP that is exposed from the block 100 does not necessarily have to be located at or near the center of the flow path FP in the X-axis direction. For example, at least one of both end portions of the flow path FP in the X-axis direction may be exposed from the block 100.

[0086] The block 100 and the plate 101 may be formed integrally. Specifically, a portion of the housing 10 may be made thinner so that it functions as the plate 101. In this case, the housing 10 does not necessarily have to include the retaining cover 102 for fixing the plate 101 to the block 100.

[0087] In addition, when the block 100 and the plate 101 are integrally formed, the housing 10 may be constructed by disposing a lid other than the retaining lid 102 on the opposite side of the integrally formed block 100 and plate 101. In this case, the flow path FP is formed by the integrally formed block 100 and plate 101 and the separate lid. In this case, the housing 10 can be fabricated from two members, the integrally formed block 100 and plate 101 and the separate lid.

[0088] The present invention has the following structure:

[0089] (1) A water flow detection device comprising: a housing; and a sensor disposed in the housing, wherein a flow path through which a fluid flows is formed within the housing; the sensor detects deformation of the housing; the housing has a sensor contact portion with which the sensor is in contact; and the sensor contact portion is the thinnest part of the housing.

[0090] (2) The water flow detection device described in (1), wherein the housing has a shape with an inner peripheral surface and an outer peripheral surface, the inner peripheral surface surrounds the flow path, the thickness of the housing is the shortest length between the inner peripheral surface and the outer peripheral surface, and the thickness of the sensor contact portion is the thinnest among the thicknesses of the housing.

[0091] (3) The water flow detection device according to (1) or (2), wherein the housing has an inlet and an outlet, the fluid flows into the housing from the inlet, the fluid flows out of the housing from the outlet, and the flow path connects the inlet and the outlet.

[0092] (4) A water flow detection device according to any one of (1) to (3), wherein the flow path includes a first flow path and a second flow path, the first flow path extends in a first direction, the second flow path extends in a second direction, a third direction is opposite to the second direction, an end of the second flow path in the third direction is provided at an end of the first flow path in the first direction, the fluid flows through the first flow path in the first direction, the flow direction of the fluid changes from the first direction to the second direction at the end of the second flow path in the third direction, the fluid flows through the second flow path in the second direction, and the sensor contact portion is in contact with the end of the second flow path in the first direction.

[0093] (5) The water flow detection device according to any one of (1) to (4), further comprising an object, the object not fixed to the housing, the object being disposed in the flow path, and the outer diameter of the object being smaller than the inner diameter of the flow path.

[0094] (6) A water flow detection device described in any of (1) to (5), wherein the housing has a plate and a block, the block has a rectangular parallelepiped shape with long sides extending in a second direction and short sides extending in a fourth direction perpendicular to the second direction, the plate has a plate shape with long sides extending in the second direction and short sides extending in the fourth direction, the plate is in contact with the block, the flow path is formed within the block, the plate is in contact with a portion of the flow path, and the sensor contact portion is located on the plate.

[0095] (7) A water flow detection device comprising: a housing; and a sensor disposed in the housing, wherein a flow path through which a fluid flows is formed within the housing; the sensor detects deformation of the housing; the housing has a sensor contact portion with which the sensor is in contact; the housing has an inlet and an outlet; and the sensor contact portion does not overlap with a straight line connecting the inlet and the outlet at the shortest distance when viewed in a fourth direction perpendicular to the direction in which the inlet and the outlet are arranged.

[0096] (8) The water flow detection device according to (7), wherein the inlet and the outlet are arranged in this order in a second direction, and the sensor contact portion is located between the inlet and the outlet in the second direction.

[0097] (9) The water flow detection device according to (7) or (8), wherein the fluid flows into the housing from the inlet, the fluid flows out of the housing from the outlet, and the flow path connects the inlet and the outlet.

[0098] (10) A water flow detection device described in any of (7) to (9), wherein the housing further includes a rotor, the rotor is located in the flow path, the rotor has a columnar shape with a central axis extending in the fourth direction, the rotor rotates around the central axis, the inward-outward direction is a direction from the outer peripheral surface of the rotor toward the central axis, and the outer peripheral surface of the rotor has one or more recesses recessed from the outer peripheral surface of the rotor toward the inward-outward direction.

[0099] (11) The water flow detection device according to any one of (1) to (10), wherein the sensor is a piezoelectric sensor including a piezoelectric film.

[0100] 1, 1a to 1e: Water flow detection device 10, 10b: Housing 100: Block 101: Plate 11: Sensor CP: Sensor contact part FL: Fluid FP, FP0 to FP6: Flow path

Claims

1. A housing and A sensor disposed in the housing; It is equipped with A flow path through which a fluid flows is formed in the housing, The sensor detects a deformation of the housing, the housing has a sensor contact portion with which the sensor is in contact, The sensor contact portion is a portion of the housing that is thinnest in cross-sectional view. Water flow detection device.

2. The housing has a shape having an inner circumferential surface and an outer circumferential surface, The inner circumferential surface surrounds the flow path, the thickness of the housing is the shortest length between the inner circumferential surface and the outer circumferential surface, The thickness of the sensor contact portion is the thinnest among the thicknesses of the housing. The water flow detection device according to claim 1 .

3. The housing has an inlet and an outlet formed therein, The fluid flows into the housing through the inlet, The fluid flows out of the housing through the outlet, The flow path connects the inlet and the outlet. The water flow detection device according to claim 1 or 2.

4. The flow path includes a first flow path and a second flow path, The first flow path extends in a first direction, The second flow path extends in a second direction, The third direction is opposite to the second direction, an end of the second flow path in the third direction is provided at an end of the first flow path in the first direction, The fluid flows through the first flow path in the first direction, a flow direction of the fluid at an end of the second flow path in the third direction changes from the first direction to the second direction, The fluid flows through the second flow path in the second direction, The sensor contact portion is in contact with an end portion of the second flow path in the first direction. The water flow detection device according to claim 1 or 2.

5. The water flow detection device further includes an object, The object is not fixed to the housing; the object is disposed in the flow path; The outer diameter of the object is smaller than the inner diameter of the flow path. The water flow detection device according to claim 1 or 2.

6. The housing includes a plate and a block. The block has a rectangular parallelepiped shape having a long side extending in a second direction and a short side extending in a fourth direction perpendicular to the second direction, The plate has a plate shape having a long side extending in the second direction and a short side extending in the fourth direction, the plate is in contact with the block; The flow path is formed in the block, the plate is in contact with a portion of the flow path; The sensor contact is located on the plate. The water flow detection device according to claim 1 or 2.

7. the sensor is a piezoelectric sensor including a piezoelectric film; The water flow detection device according to claim 1 or 2.