JP5168944B2 - Impeller flow meter - Google Patents

Description

  The present invention relates to a flow meter for measuring a flow rate (flow velocity). In particular, the present invention relates to an impeller-type flow meter that rotates an impeller by a flow of a fluid to be measured and measures a flow rate by the rotation of the impeller.

  As disclosed in the following patent documents, an impeller-type flow meter is configured such that an impeller is rotatably provided in a tubular housing, and the rotation of the impeller is detected by a sensor fixed to the housing. The flow rate is measured.

Conventionally, a sensor is generally fixed to a housing by potting. In the invention described in Patent Document 1 below, the impeller is provided from the opening at the tube end of the housing, while the sensor is provided in a radially inward recess formed in the peripheral side wall of the housing. The recess is formed so as to reach the center of the hollow hole of the housing. Further, in the invention described in Patent Document 2 below, an opening is provided on the peripheral side wall of the housing, and an impeller and a sensor are provided on a member that closes the opening.
JP 2002-39818 A JP-A-2005-321214

  However, in the configuration in which the sensor is attached to the housing and integrated by potting, the entire flow meter needs to be replaced when the sensor fails. Further, as in the invention described in Patent Document 1, in the configuration in which a recess is provided in the protruding portion inside the hollow hole of the housing and the sensor is provided in this recess, the flow of the fluid to be measured is disturbed, and the flow rate is measured. There is a risk of adverse effects. Also, in the invention described in Patent Document 2, a member that closes the opening of the peripheral side wall of the housing is provided with a support column that protrudes to the inside of the hollow hole of the housing, and the impeller is held on this support column. The flow of the fluid to be measured may be disturbed and the flow rate measurement may be adversely affected.

  By the way, there is a case where it is desired to attach the flow rate indicator to the housing. However, if the indicator is completely fixed to the housing, the display on the indicator becomes difficult to read depending on the mounting posture of the housing to the pipe. On the other hand, if the display is simply rotatably provided in the housing, the internal wiring may be twisted when the display is rotated many times.

  In addition, in the case of a flow meter provided with a display, various electronic components are built in the display, so that it is necessary to protect it. That is, when the fluid to be measured has a high temperature, there is heat transfer from the housing to the display device, so that countermeasure is required.

  The problem to be solved by the present invention is that maintenance is easy and only the sensor part can be replaced. It is another object of the present invention to eliminate irregular protrusions in the hollow hole of the housing for sensor mounting and to prevent disturbance of the flow of the fluid to be measured. Furthermore, when an indicator is attached to the housing, the position of the indicator relative to the housing can be changed or fixed, and the internal wiring is prevented from being broken by the rotation of the indicator, and the fluid to be measured is hot. Another object is to protect the display by suppressing heat transfer from the housing.

This invention was made in order to solve the said subject, and invention of Claim 1 has a flow path in which an impeller is rotatably hold | maintained, and adjoins the outer peripheral part of the said impeller. A housing having a sensor mounting hole that does not communicate with the flow path, a sensor that detects rotation of the impeller, a sensor holder that is detachably fitted in the sensor mounting hole, and a detection signal from the sensor. An indicator for calculating and displaying a flow rate based on the outer surface of the base end of the sensor holder is formed on a circumferential surface, and the base end of the sensor holder is rotatable around the circumferential surface. The blade is fitted to the fitting portion, and when the relative rotation is made at the fitting portion between the sensor holder and the display device, a protrusion that contacts each other is provided to restrict the rotation of one or more rotations. It is a vehicle type flow meter .

According to the first aspect of the invention, since the sensor does not contact the fluid to be measured, it is possible to prevent the sensor from being broken. Even if the sensor breaks down, the sensor holder with the sensor can be attached to and detached from the housing, so that maintenance is easy and only the sensor part can be replaced. Furthermore, since the mounting position of the sensor holder with respect to the housing is on the outer peripheral side of the impeller, it is not necessary to provide irregular projections that disturb the flow of the fluid to be measured in the hollow hole of the housing.
According to the first aspect of the present invention, the indicator is rotatably provided on the sensor holder fixed to the housing. Therefore, regardless of the mounting orientation of the housing to the pipe, the indicator can be used at a position that is easy to see.
Furthermore, according to the first aspect of the present invention, the internal wiring can be prevented from being broken by restricting the rotation range of the display.

  According to a second aspect of the present invention, the housing includes a first housing and a second housing that are detachably connected to each other, and the impeller has one end serving as a bearing of the first housing. The other end is held by the bearing of the second housing, and the sensor mounting hole is formed in one of the first housing and the second housing, and the sensor holder The impeller-type flow meter according to claim 1, wherein the tip has the sensor and is fitted into the sensor mounting hole and fixed to the one housing.

  According to the second aspect of the present invention, the housing is composed of the first housing and the second housing, and the impeller is rotatably assembled in the housing when the second housing is connected to the first housing. . Because of such a configuration, maintenance of parts in the housing is easy. In addition, since the sensor holder is provided in one of the first housing and the second housing, the first housing and the second housing can be attached and detached without removing the sensor holder, and maintenance inside the housing is possible. Is easy. Conversely, the sensor can be replaced while the flowmeter is piped, and maintenance outside the housing is easy.

A third aspect of the present invention is the impeller-type flow meter according to the first or second aspect, further comprising means for positioning the display unit with respect to the sensor holder.

According to the third aspect of the present invention, the angle of the display device can be fixed with respect to the sensor holder and thus the housing.

Furthermore, the invention according to claim 4 is characterized in that the sensor holder is made of synthetic resin, and the indicator is held by the housing only through the sensor boulder. The impeller-type flow meter according to any one of Items 1 to 3 .

According to the fourth aspect of the present invention, the display is held in the housing via the synthetic resin sensor holder, thereby suppressing heat transfer from the housing even when the fluid to be measured is at a high temperature. Can be protected.

  According to the impeller-type flow meter of the present invention, since the sensor portion can be attached to and detached from the housing, maintenance is easy and only the sensor portion can be replaced. Moreover, since the sensor part is provided so as to be close to the outer peripheral part of the impeller, an irregular protrusion to the hollow hole of the housing is unnecessary, and the flow of the fluid to be measured is not disturbed. Furthermore, an indicator capable of changing the position and fixing the housing can be provided. At that time, if the rotation range of the display device is restricted, the internal wiring can be prevented from being broken. Further, if the display device is held in the housing via the sensor holder made of synthetic resin, the heat transfer from the housing can be suppressed and the display device can be protected even when the fluid to be measured is at a high temperature.

Next, an embodiment of the present invention will be described.
The impeller-type flow meter of the present invention includes a housing through which a fluid to be measured is passed, an impeller that is rotatably held in the housing, and a sensor that detects the rotation of the impeller. The fluid to be measured is liquid or gas, and the kind thereof is not particularly limited. For example, water, air, gas, oil or steam is not limited thereto.

  The housing has a flow path through which a fluid to be measured is passed, and an impeller is provided in the flow path. The flow path is provided through the housing, and one opening serves as an inlet for the fluid to be measured, and the other opening serves as an outlet for the fluid to be measured.

  The shape of the flow path is not particularly limited, but is preferably a circular hole with a cross section that passes through the housing linearly. The shape of the housing is not particularly limited, but typically it is preferably a tubular shape, particularly a straight tubular shape. In particular, it is preferable to use a circular straight pipe.

  The impeller is provided in a housing with a shaft serving as a rotation shaft thereof rotatably held by a bearing. Typically, the shaft provided in the impeller is fitted into the bearing provided in the housing, but conversely, the shaft provided in the housing may be fitted into the bearing provided in the impeller.

  When the impeller is provided with a shaft, the impeller and the shaft may be integrally formed, may be integrated by insert molding, or may be separated and separated, but can be integrally rotated via a key or the like. Also good. Further, when the bearing is provided in the housing, it is sufficient if the housing has a bearing hole for rotating and holding the shaft. Preferably, the slide bearing is accommodated in a cylindrical portion provided in the housing.

  The shaft may be disposed along the flow path (axial flow type) or may be disposed perpendicular to the flow path (tangential type). That is, when the housing is a straight tube, the shaft may be arranged along the axis of the hollow hole or may be arranged orthogonal to the axis of the hollow hole.

  The housing can be composed of a first housing and a second housing. In this case, when the first housing and the second housing are assembled to each other, it is preferable that the impeller is assembled in the housing. For example, when the tubular first housing and the second housing are connected to each other, shafts protruding from both end surfaces of the impeller are held in the respective bearings provided in the hollow holes of the respective housings. As a result, one end of the impeller is held by the bearing of the first housing, and the other end is held by the bearing of the second housing.

  The rotation of the impeller is detected by a sensor. Typically, a magnet is attached or magnetized to each blade of the impeller, and a magnetic field change due to the rotation of the impeller is detected by a magnetic sensor. The sensor is provided in the housing. At this time, a sensor holder provided with a sensor is detachably fitted into a sensor mounting hole formed in the housing.

  The sensor mounting hole is provided on the peripheral side wall of the tubular housing at a position close to the outer peripheral portion of the impeller. At this time, it is preferable that the hollow hole of the housing does not have a radially inward projecting portion. The sensor mounting hole is formed with a bottom that does not communicate with the hollow hole of the housing.

  The sensor holder is a component that is detachably fitted in the sensor mounting hole, and a sensor is provided on the tip surface thereof. In a state where the sensor holder is attached to the sensor attachment hole, the sensor is arranged so as to overlap the bottom surface of the sensor attachment hole.

  Based on the detection signal from the sensor attached in this manner, the flow rate of the fluid to be measured flowing in the housing can be calculated. The flow meter can be provided with a display for displaying the calculation result. In this case, the indicator may be connected to the flowmeter body on the housing side via a cable, but may be attached to the flowmeter body. Specifically, an indicator may be attached to the housing. The display unit is configured with a circuit board built in a case, and displays a flow rate on a plurality of 7-segment LEDs provided on the circuit board.

  When an indicator is attached to the flow meter body, the indicator can be held in the housing via the sensor holder. If the display is held in the housing only through the sensor holder made of synthetic resin, even if the fluid to be measured is hot, heat transfer from the housing to the display is suppressed, and the display circuit A board | substrate etc. can be protected.

  Moreover, when attaching a display to a flowmeter main body, it is preferable to provide a display so that position adjustment is possible with respect to a housing. When the display is provided on the housing via the sensor holder, the outer surface of the base end of the sensor holder is formed on the circumferential surface, and the display is provided at the base end of the sensor holder so as to be rotatable around this circumferential surface. You can fit the case. By providing the display unit rotatably on the sensor holder fixed to the housing, the display unit can be used in an easily viewable position regardless of the mounting orientation of the housing to the pipe.

  However, when the display unit is rotatably held with respect to the flowmeter body, the wiring from the sensor of the sensor holder to the circuit board of the display unit may be twisted if the display unit is rotated many times in the same direction. Therefore, it is preferable to restrict the rotation range by providing protrusions or the like that contact each other when the relative rotation greater than the setting is made at the fitting portion between the sensor holder and the display. In this way, the display device is configured to be rotatable by, for example, about one rotation with respect to the sensor holder.

  Within the rotation range, the indicator can rotate with respect to the flowmeter body, but it is preferable that the indicator can be positioned at a desired position. For example, by tightening a hexagon socket set screw from the flow meter body, the tip can be brought into contact with the outer peripheral surface of the sensor holder so that the indicator can be positioned with respect to the flow meter body.

  It is preferable that the sensor holder is detachably fixed to the housing, and the display unit is detachably provided to the sensor holder. In this case, if the sensor or indicator fails, only the sensor or indicator can be replaced. Furthermore, if the circuit board of the display device can be replaced, it is possible to easily cope with a failure of the circuit board.

  In addition, the sensor holder and the indicator may be provided in any one of the first housing and the second housing. Usually, a sensor holder and a display are provided on the peripheral side wall of the first housing in which the impeller is accommodated. In this case, the first housing and the second housing can be attached and detached without removing or disassembling the sensor holder and the display, and maintenance is easy. On the other hand, by providing the sensor holder and the indicator on the peripheral side wall of the housing, the sensor holder and the indicator can be replaced while the flowmeter main body is piped, and maintenance is easy.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.
1 to 9 are diagrams showing Example 1 of an impeller-type flow meter of the present invention. 1 and 2 are a plan view and an exploded view thereof, FIGS. 3 and 4 are sectional views taken along line III-III in FIG. 1 and an exploded view thereof, and FIGS. 5 and 6 are perspective views and an exploded view thereof. 7 and FIG. 8 are a sectional view taken along the line VII-VII in FIG. 1 and an exploded view thereof. FIG. 9 is a sectional view taken along the arrow IX-IX in FIG. It shows. Here, FIG. 1, FIG. 5, FIG. 6 and FIG. 9 show a use state in which a flow meter is piped.

  The impeller-type flow meter 1 of the present embodiment includes a flow meter body 2 and a display 3. The flow meter main body 2 is configured by providing an impeller 5 and a sensor holder 6 in a housing 4. The flowmeter main body 2 is used with a housing 4 provided in the middle of a pipeline through which a fluid to be measured is passed. Specifically, the housing 4 is connected and provided between the first pipe 7 and the second pipe 8 constituting the pipe line. The impeller 5 is rotated by the fluid to be measured flowing in the housing 4, the rotation is detected by the sensor 9 of the sensor holder 6, and the display 3 calculates and displays the flow rate based on the detection signal. The type of fluid to be measured is not particularly limited.

  The housing 4 includes a first housing 10 and a second housing 11 that are detachably connected to each other. Each housing 10 and 11 is comprised from the circular pipe of the same diameter, each extends linearly, and is arrange | positioned and connected on the same axis line. Each of the tubular housings 10 and 11 has a hollow hole 12 and 13 having a circular cross section that penetrates along the axis. The lengths of the housings 10 and 11 are appropriately set. In the present embodiment, the first housing 10 is formed longer than the second housing 11.

  As shown in FIG. 1, the first housing 10 has a left end portion as a connection portion to the first pipe 7, and a right end portion as a connection portion to the second housing 11. Specifically, as shown in FIG. 3, in the first housing 10, the left opening of the hollow hole 12 is formed in the screw hole 14, and the first tube 7 is screwed into the screw hole 14 and connected. The In consideration of the workability at the time of screwing, as shown in FIGS. 1 and 2, the outer peripheral portion of the left end portion of the first housing 10 is a hexagonal section 15 and can be hooked with a wrench. On the other hand, a first flange 16 having a square cross section is formed on the outer peripheral portion of the right end portion of the first housing 10. Bolt holes 17, 17,... Are formed at the four corners of the first flange 16 from the right end surface of the first flange 16 toward the left side. Each bolt hole 17 is formed to extend in the axial direction of the first housing 10. By the way, as shown in FIG. 4, the hollow hole 12 of the first housing 10 has a right opening that is formed with an enlarged diameter, and serves as a fitting hole 18 for the second housing 11.

  As shown in FIG. 1, the second housing 11 has a right end portion as a connection portion to the second pipe 8, and a left end portion as a connection portion to the first housing 10. Specifically, as shown in FIG. 3, in the second housing 11, the right opening of the hollow hole 13 is formed in the screw hole 19, and the second pipe 8 is screwed into the screw hole 19 and connected. The Considering the workability at the time of screwing, as shown in FIGS. 1 and 2, the outer peripheral portion of the right end portion of the second housing 11 is a hexagonal section 20 in section, and a wrench can be hooked. On the other hand, a second flange 21 having a cross-sectional shape corresponding to the first flange 16 is formed on the outer peripheral portion of the left end portion of the second housing 11. .. (FIG. 2) are formed at the four corners of the second flange 21 so as to penetrate the second housing 11 in the axial direction. In a state where the first flange 16 and the second flange 21 are overlapped, the bolt holes 17 and the bolt insertion holes 22 are arranged on the same axis.

  As shown in FIG. 4, the second flange 21 is provided with a short cylindrical fitting portion 23 that protrudes to the left side. The central hole of the fitting portion 23 constitutes a part of the hollow hole 13 of the second housing 11. The first housing 10 and the second housing 11 are connected by fitting the fitting portion 23 into the fitting hole 18. At this time, the first flange 16 and the second flange 21 are overlapped, and each bolt hole 17 and each bolt insertion hole 22 are arranged on the same axis. Then, as shown in FIG. 2, the first housing 10 and the second housing 11 can be connected by screwing the hexagon socket head bolts 24 into the respective bolt holes 17 through the respective bolt insertion holes 22. it can. As shown in FIGS. 3 and 4, an O-ring 25 is provided on the left end surface of the second flange 16, thereby sealing the gap between the flanges 16 and 21.

  In the connected state of the first housing 10 and the second housing 11, the hollow holes 12 and 13 having the same diameter are arranged on the same axis. Moreover, the hollow holes 12 and 13 of the respective housings 10 and 11 are connected with their inner peripheral surfaces continuously arranged without a step. The hollow holes 12 and 13 of the housings 10 and 11 connected in this way constitute a flow path 26 of the fluid to be measured. By the way, in this embodiment, as shown in FIG. 7, each of the flanges 16 and 21 having a square cross section has two adjacent sides formed in appropriate specific shapes. Accordingly, the two housings 10 and 11 can be connected by aligning the flanges 16 and 21 with the two sides as marks.

  The hollow holes 12 and 13 of the housings 10 and 11 are provided with round bar-shaped bearing holding portions 27 and 27 along the axis thereof. Each bearing holding portion 27 is hollow in each housing 10, 11 via a plurality of (three in this embodiment, three circumferentially equidistantly spaced) plate-like portions 28, 28,. It is held in the holes 12 and 13. Each plate-like portion 28 extends along the radial direction and the axial direction of the hollow holes 12 and 13 of the housings 10 and 11. In the connected state of the first housing 10 and the second housing 11, the plate-like portions 28 of the housings 10 and 11 are arranged at corresponding positions in the circumferential direction. In the case of the present embodiment, the first housing 10 and the second housing 11 are connected not by screwing but by the flanges 16 and 21, so there is a possibility that the circumferential positions of the plate-like portions 28 of the housings 10 and 11 are shifted. Absent.

  The bearing holding portion 27 of the first housing 10 is provided in the middle portion of the first housing 10, and the left end portion is formed in a tapered substantially conical shape. Each plate-like portion 28 of the first housing 10 is provided on the right side from the left end portion of the bearing holding portion 27 and has the same shape and size. Further, the bearing holding portion 27 of the first housing 10 has a cylindrical portion 29 that extends to the right side of the right end side of each plate-like portion 28. The cylindrical portion 29 is formed to open to the right side.

  On the other hand, the bearing holding part 27 of the second housing 11 is provided from the middle part of the second housing 11 to the left opening part, and the right end part is formed in a tapered substantially conical shape. Each plate-like portion 28 of the second housing 11 is provided on the left side from the right end portion of the bearing holding portion 27 and has the same shape and size. Further, the bearing holding portion 27 of the second housing 11 has a cylindrical portion 29 extending to the left side of the left end side of each plate-like portion 28. The cylindrical portion 29 is formed to open to the left side. The left end surface of the cylindrical portion 29 protrudes slightly to the left than the left end surface of the fitting portion 23. For example, it protrudes by about 1 to 3 mm.

  In each cylindrical portion 29, a slide bearing (radial bearing) 30 is fitted and provided. The slide bearing 30 is a cylindrical member, and is attached so that one end face thereof is substantially aligned with the end face of each cylindrical portion 29. Therefore, the bearing hole of the slide bearing 30 is opened and disposed in the opening of each cylindrical portion 29. In addition, a thrust bearing 31 is provided at the back of each cylindrical portion 29 (more specifically, the bearing hole of the slide bearing 30).

  The impeller 5 includes a central boss portion 32 and a plurality of (four in the illustrated example) blades 33, 33,... The impeller 5 is formed of, for example, a plastic magnet and is magnetized on the outer peripheral edge of each blade 33. At this time, N poles and S poles are alternately magnetized so that the adjacent magnetic poles 33 and 33 have different magnetic poles. On the other hand, the housings 10 and 11 are made of non-magnetic material.

  In the center of the boss portion 32 of the impeller 5, a shaft 34 is provided so as to penetrate therethrough. The shaft 34 of the present embodiment is in the shape of an elongated round bar, and the central portion in the longitudinal direction is formed in the large diameter portion 35. The cross section of the large diameter portion 35 is formed, for example, in a substantially D shape. And when forming the impeller 5 so that this large diameter part 35 is embed | buried under the boss | hub part 32 of the impeller 5, the shaft 34 is attached to the impeller 5 by insert molding. In this way, the central portion in the longitudinal direction of the shaft 34 is embedded in the boss portion 32 of the impeller 5, and the impeller 5 is fixed to the shaft 34 in the axial direction and the circumferential direction.

  The shafts 34 projecting from the left and right end surfaces of the impeller 5 are each tapered at the tip. The attachment of the impeller 5 to the housing 4 will be described. First, as shown in FIG. 4, the left end portion of the shaft 34 is rotatably held by the slide bearing 30 in the first housing 10. In this state, the impeller 5 is accommodated in the hollow hole 12 of the first housing 10, and the right end portion of the shaft 34 protrudes from the right opening portion of the first housing 10. For example, it protrudes by about 1 to 3 mm. On the other hand, as described above, the end face of the plain bearing 30 is disposed so as to protrude from the left opening of the second housing 11. Accordingly, the shaft 34 and the slide bearing 30 are disposed so as to protrude from the connection portion between the first housing 10 and the second housing 11. Accordingly, the fitting portion 23 of the second housing 11 is fitted into the fitting hole 18 of the first housing 10 while visually confirming the fitting of the right end portion of the shaft 34 to the slide bearing 30 of the second housing 11. The first housing 10 and the second housing 11 can be connected. In the connected state of both housings 10 and 11, as shown in FIG. 3, the impeller 5 rotates in the flow path 26 with both ends of the shaft 34 being held by the slide bearings 30 and 30 of the housings 10 and 11. It is held freely.

  As shown in FIG. 8, a holder mounting portion 36 is provided on the peripheral side wall of the first housing 10. In the present embodiment, a holder mounting portion 36 is provided at the center of one side surface of the first flange 16 so as to protrude in a columnar shape. At this time, the axis of the holder mounting portion 36 is arranged perpendicular to the axis of the hollow hole 12 of the first housing 10. A disc-shaped flange portion 37 is provided at the base end portion (the end portion arranged in a direction away from the first housing 10) of the holder mounting portion 36 so as to extend outward in the radial direction.

  A sensor mounting hole 38 is formed in the cylindrical holder mounting portion 36 along the axis thereof from the base end surface toward the distal end side. The cross-sectional shape of the sensor mounting hole 38 is not particularly limited, but is circular in this embodiment. The sensor mounting hole 38 is formed with a bottom so as not to communicate with the hollow hole 12 of the first housing 10. The sensor mounting hole 38 is formed without protruding radially inward from the inner peripheral surface of the hollow hole 12 of the first housing 10. The bottom portion of the sensor mounting hole 38 is disposed close to the outer peripheral portion of the impeller 5 in the first housing 10.

  The holder holder 36 is detachably provided with the sensor holder 6. Specifically, the sensor holder 6 is fitted into the sensor mounting hole 38 of the holder mounting portion 36. The sensor holder 6 is made of, for example, a synthetic resin such as PPE (polyphenylene ether), and is formed in a stepped columnar shape including a large-diameter portion 39 on the proximal end side and a small-diameter portion 40 on the distal end side.

  A magnetic sensor 9 composed of, for example, a Hall IC is provided on the tip surface of the sensor holder 6. The sensor 9 is fixed to the sensor holder 6 by potting in this embodiment. Specifically, the sensor holder 6 is formed with a hollow portion. With the sensor 9 disposed on the distal end surface of the small-diameter portion 40, the sensor 9 is made of the synthetic resin filled in the hollow portion. Fixed to. At this time, the wiring 41 from the sensor 9 is led out to the base end side of the sensor holder 6.

  The sensor holder 6 is provided with the small diameter portion 40 fitted into the sensor mounting hole 38 and the large diameter portion 39 fitted into the flange portion 37. An annular groove 42 is formed on the distal end surface of the large diameter portion 39, and the flange portion 37 is fitted into the annular groove 42. Thereby, the brim part 37 of the holder attaching part 36 is covered with the large diameter part 39 of the sensor holder 6 at the base end face and the outer peripheral face.

  The sensor holder 6 is further fixed to the holder mounting portion 36 and then to the first housing 10 by a fixing screw (not shown). In the present embodiment, the sensor holder 6 is fixed to the holder mounting portion 36 by screwing a fixing screw into the screw hole (not shown) formed in the base end surface of the flange portion 37 from the base end surface of the sensor holder 6. In this manner, in the mounting state of the sensor holder 6 to the first housing 10, the sensor 9 is disposed on the bottom surface of the sensor mounting hole 38 and the base end portion of the holder mounting portion 36 is the large diameter portion of the sensor holder 6. 39.

  The indicator 3 is rotatably attached to the large diameter portion 39 of the sensor holder 6. The display 3 is configured by housing one or a plurality of circuit boards 44, 44 in a case 43. The case 43 includes a case main body 45 and a case lid 46. The case main body 45 is formed in a substantially rectangular hollow box shape, and is formed to open downward as shown in FIG. The case lid 46 is formed in a substantially rectangular plate shape, and is detachably provided in the lower opening of the case main body 45. That is, screw insertion holes 47, 47 are vertically formed at both left and right ends of the case lid 46, and the mounting screws 48 are screwed into the screw hole forming portions 49 of the case main body 45 through the screw insertion holes 47. Thus, the case lid 46 can be provided in the lower opening of the case main body 45.

  .. Are erected at the four corners of the upper surface of the case lid 46, and the circuit board 44 is held via each column 50. In the illustrated example, a circuit board 44 is detachably provided with screws (not shown) above each support column 50, and another circuit board 44 is detachably provided above the circuit board 44. At this time, the upper and lower circuit boards 44 and 44 are detachably provided via a socket 51 that electrically connects each other.

  In the case of the illustrated example, the lower circuit board 44 is provided with a terminal board and the like, and wiring from the sensor 9 is detachably connected thereto, and a power cord 52 and a pulse output cord 53 are connected (FIG. 9). ). The power cord 52 and the pulse output cord 53 are provided through the inside and outside of the case 43 through a hole provided in the case lid 46. On the other hand, a plurality (nine in the illustrated example) of seven segment LEDs 54, 54,... Are provided in a row on the upper circuit board 44, and a plurality (three in the illustrated example) of LEDs (light emitting diodes) 55, 55 are provided. ,..., Various buttons 56, 56,.

A transparent portion 57 is provided on the upper surface of the case main body 45, and in a state where each circuit board 44 is built in the case 43, the 7-segment LEDs 54 are arranged corresponding to the transparent portion 57. Similarly, each LED 55 is visible from the upper surface of the case body 45. Further, on the upper surface of the case main body 45, “instantaneous flow rate [L / h]”, “integrated flow rate [m ³ ]”, and “total integrated flow rate [m ³ ]” are displayed at positions corresponding to the respective LEDs 55. Has been made.

  On the back surface of the case main body 45, as shown in FIGS. 7 to 9, in addition to FIG. As shown in FIG. 9, the mounting portion 58 of the present embodiment is formed in a substantially rectangular shape having a semicircular lower end portion. As shown in FIG. 8, the mounting portion 58 is formed with a mounting hole 59 that penetrates the large-diameter portion 39 of the sensor holder 6 fixed to the first housing 10 along the front-rear direction. The mounting hole 59 is a stepped circular hole, and the large-diameter hole 60 on the tip side is fitted into the large-diameter portion 39 of the sensor holder 6. An annular groove is formed at the base end of the large diameter hole 60, and an O-ring 61 is accommodated in the annular groove. The O-ring 61 seals a gap between the outer peripheral surface of the large diameter portion 39 of the sensor holder 6 and the inner peripheral surface of the mounting hole 59 of the case main body 45.

  The case body 45 is prevented from falling off from the first housing 10 by the substantially L-shaped connecting plate 62 in a state where the large-diameter hole 60 of the mounting hole 59 is fitted into the large-diameter portion 39 of the sensor holder 6. . As shown in FIG. 7, the connecting plate 62 has one piece 63 superimposed on the upper surface of the mounting portion 58, and the other piece 64 has a tip surface of the mounting portion 58, and a flange portion 37 and a large diameter portion 39 that are substantially parallel to the tip surface. It is arranged along the tip surface of the. As shown in FIG. 8, a substantially semicircular cutout 65 is formed at the lower end portion of the other piece 64 of the connection plate 62, and the cutout 65 is inserted into the outer peripheral portion of the holder mounting portion 36. In this state, as shown in FIG. 1, the connection plate 62 is fixed to the mounting portion 58 by set screws 66 and 66 at the left and right ends of the piece 63.

  In this way, the mounting hole 59 of the case 43 of the display device 3 is provided in the large diameter portion 39 of the sensor holder 6 fixed to the first housing 10 so that it cannot be dropped off. The outer surface of the large-diameter portion 39 of the sensor holder 6 is formed in a circumferential surface, and the display device 3 is rotatably held with respect to the housing 4 by fitting the large-diameter hole 60 of the mounting hole 59.

  The small-diameter portion 67 of the mounting hole 59 is provided with a first protrusion 68 that protrudes radially inward at one place in the circumferential direction (FIG. 9). On the other hand, a second protrusion 69 is provided on the base end surface of the large-diameter portion 39 of the sensor holder 6 so as to protrude toward the base end side at one place in the circumferential direction. In a state where the large-diameter portion 39 is fitted in the large-diameter hole 60, the second protrusion 69 is disposed so as to protrude to the small-diameter portion 67. As shown in FIG. 9, when the display 3 is rotated with respect to the housing 4, both the protrusions 68 and 69 come into contact with each other, so that the display 3 does not rotate more than one rotation with respect to the housing 4. Therefore, the wiring 41 connecting the sensor 9 and the circuit board 44 is prevented from being twisted.

  As described above, the indicator 3 can rotate with respect to the flow meter main body 2 within one rotation. However, the display 3 can be positioned with respect to the flow meter main body 2 by screwing the hexagon socket set screw 70 provided in the mounting portion 58 and pressing it against the outer peripheral surface of the large diameter portion 39 of the sensor holder 6. . As shown in FIG. 1, a through hole 71 is formed in the left-right direction center portion of the piece 63 of the connection plate 62, and the hexagon hole of the hexagon socket set screw 70 is exposed. Therefore, the hexagon socket set screw 70 can be rotated and advanced with the connection plate 62 attached.

The circuit board 44 of the display 3 calculates the flow rate based on the detection signal from the sensor 9 and displays it on the 7-segment LED 54. In this embodiment, the instantaneous flow rate [L / h], the integrated flow rate [m ³ ], and the total integrated flow rate [m ³ ] are calculated. The instantaneous flow rate is a temporary flow rate at that time calculated every predetermined time. The integrated flow rate is an integrated value of a flow rate that can be reset, and the total integrated flow rate is an integrated value of a flow rate that cannot be reset in principle.

  Switching among the instantaneous flow rate, the integrated flow rate, and the total integrated flow rate to be displayed on the 7-segment LED 54 is performed by pressing the switching button 72. The switch button 72 operates a button provided on the circuit board, but can be operated from the upper surface of the case 43. Each time the switching button 72 is pressed, the display of the 7-segment LED 54 is sequentially switched to the instantaneous flow rate, the integrated flow rate, or the total integrated flow rate. Whether the flow rate displayed on the 7-segment LED 54 is an instantaneous flow rate, an integrated flow rate, or a total integrated flow rate is grasped by the LED 55 that is alternatively lit whenever the switch button 72 is pressed. For example, when the instantaneous flow rate is being displayed, the LED 55 corresponding to the “instantaneous flow rate [L / h]” displayed on the upper surface of the case 43 is turned on to notify that fact. While the integrated flow rate is displayed, the integrated flow rate can be reset by long pressing the switch button 72. On the other hand, the total integrated flow rate cannot be reset from the outside of the display 3. After the case cover 46 is opened and the circuit board 44 is pulled out from the case 43, the button 56 of the circuit board 44 is operated to reset. Can do.

  Furthermore, the display 3 of the present embodiment can also output pulses to an external device (not shown) using the pulse output code 53. At this time, the flow rate per pulse can be arbitrarily set within a range of 1 to 100 liters, for example. This setting can be performed by a button 56 provided on the circuit board 44. In addition, the button 56 provided on the circuit board 44 can set a pulse constant and the like in addition to resetting the total accumulated flow described above.

  As described above, in the case of the present embodiment, when the second housing 11 is connected to the first housing 10, the impeller 5 is accommodated and attached between the housings 10 and 11. At that time, first, the left end portion of the shaft 34 of the impeller 5 is held by the slide bearing 30 of the first housing 10. In this state, the right end portion of the shaft 34 protrudes from the right opening portion of the first housing 10. Is done. The sliding bearing 30 of the second housing 11 is disposed with its end face protruding from the left opening of the second housing 11. Thus, since the shaft 34 and the bearing hole protrude at the connection portion between the first housing 10 and the second housing 11, it is visually confirmed that the shaft 34 is in the bearing hole. However, both housings 10 and 11 can be connected.

  In the case of the present embodiment, the sensor holder 6 and the display 3 are connected only to the first housing 10. Therefore, the flow meter main body 2 can be disassembled without removing the sensor holder 6 and the display 3. That is, the connection between the first housing 10 and the second housing 11 can be released without removing the sensor holder 6 and the display 3.

  On the other hand, the sensor holder 6 can be attached to and detached from the first housing 10, and the display 3 can be attached to and detached from the sensor holder 6. Therefore, the sensor holder 6 and the display 3 can be replaced while the flowmeter main body 2 is piped. Further, by removing the case lid 46 from the case main body 45, the circuit board 44 can be taken out, and each circuit board 44 can be replaced.

  In the case of the present embodiment, a sensor 9 is attached to the sensor holder 6, and the sensor holder 6 is fixed to the flowmeter main body 2. Therefore, the sensor holder 6 can be easily attached and detached, and the sensor 9 can be easily replaced. Moreover, since the sensor mounting hole 38 and the hollow hole 12 are not in communication, the sensor 9 is prevented from coming into contact with the fluid to be measured. Therefore, failure of the sensor 9 can be prevented.

  In the case of the present embodiment, the display 3 can be rotated with respect to the flow meter body 2 by fitting the sensor holder 6 and the display 3 together. Since this fitting portion is provided with an O-ring 61, it is possible to prevent water and dust from entering the display 3 from the outside.

  Furthermore, by providing the projections 69 and 68 in the sensor holder 6 and the mounting hole 59, the display 3 does not rotate more than one rotation with respect to the flow meter main body 2. Accordingly, it is possible to prevent the wire 41 connecting the sensor 9 and the display 3 from being threaded. In addition, the display 3 can be fixed to the flow meter main body 2 by tightening the hexagon socket set screw 70. In this way, regardless of the mounting posture of the flow meter main body 2 to the pipe, the display device 3 can be arranged and used at an easily viewable position.

  By the way, when the housing 4 of the flow meter main body 2 and the case 43 of the display 3 are made of metal, when the fluid to be measured is hot, heat transfer from the flow meter main body 2 to the display 3 becomes a problem. . However, in the case of the present embodiment, the indicator 3 is held by the flow meter main body 2 only through the resin sensor holder 6. By sandwiching a resin having a lower thermal conductivity than that of metal, an increase in temperature in the display 3 can be suppressed.

  In the case of the present embodiment, a plurality of plate-like portions 28, 28,... Are provided in the flow path 26 of the flow meter main body 2 on the outer side in the axial direction from the impeller 5. Each plate-like portion 28 not only holds each slide bearing 30 in the flow path 26 but also functions as a current plate for the fluid to be measured. By arranging each plate-like portion 28 as a current plate on both sides of the impeller 5, the direction of the flow of the fluid to be measured is either left to right or right to left in FIG. 1. Good. However, in the illustrated example, each plate-like portion 28 in the first housing 10 is formed longer than each plate-like portion 28 in the second housing 11, so the first housing 10 is used as the upstream side. Is preferred. That is, in FIG. 1, it is preferable to use the fluid to be measured flowing from left to right.

  FIG. 10 is a diagram showing a second embodiment of the impeller-type flow meter 1 of the present invention, and corresponds to FIG. 7 in the first embodiment. The impeller-type flow meter 1 of the second embodiment has basically the same configuration as the impeller-type flow meter of the first embodiment. Therefore, in the following description, differences between the two will be mainly described, and corresponding portions will be described with the same reference numerals.

  In the first embodiment, the case 43 of the display device 3 is rotatably provided on the sensor holder 6 fixed to the first housing 10. However, in the second embodiment, the cable is connected from the sensor holder 6 fixed to the first housing 10 to the cable. The display 3 is connected via 73. In the case of this configuration, the display 3 is not provided directly on the flow meter main body 2 but can be installed at another location. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  The impeller-type flow meter 1 of the present invention is not limited to the configuration of each of the above embodiments, and can be changed as appropriate. For example, in each of the above embodiments, the shaft 34 of the impeller 5 is an axial flow type in which the shaft 34 is disposed along the axis of the hollow holes 12 and 13 of the housing 4. , 13 may be a tangential type arranged perpendicular to the axis. In this case, the second housing 11 is a member that opens an opening in the peripheral side wall of the first housing 10 and closes the opening.

  The plate-like portion 28 only needs to have at least one for holding the cylindrical portion 29 holding the slide bearing 30 in the hollow holes 12 and 13. Therefore, the plurality of plate-like portions 28 are not necessarily provided radially from the bearing holding portion 27.

  Moreover, in each said Example, although the impeller 5 was magnetized and comprised by the plastic magnet, the material can be changed suitably. Further, permanent magnets may be embedded in each blade 33 of the impeller 5 instead of magnetization.

  Further, in each of the above embodiments, the slide bearing 30 is held in the hollow holes 12 and 13 of the respective housings 10 and 11 and the shafts 34 are provided on both end faces of the impeller 5. The shaft 34 may be held in the hollow holes 12 and 13 and the sliding bearings 30 (bearing holes) may be provided on both end faces of the impeller 5.

It is a top view which shows Example 1 of the impeller-type flow meter of this invention. FIG. 2 is an exploded view of FIG. 1. It is III-III sectional drawing in FIG. FIG. 4 is an exploded view of FIG. 3. It is a perspective view of the impeller-type flow meter of FIG. It is a perspective view which shows the state which decomposed | disassembled the indicator in FIG. It is VII-VII sectional drawing in FIG. FIG. 8 is an exploded view of FIG. 7. It is the IX-IX arrow line view in FIG. 1, and has shown the rotatable range of the indicator with respect to the flowmeter main body. It is a figure which shows Example 2 of the impeller-type flow meter of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Impeller-type flow meter 2 Flowmeter main body 3 Indicator 4 Housing 5 Impeller 6 Sensor holder 9 Sensor 10 First housing 11 Second housing 26 Flow path 30 Slide bearing 38 Sensor mounting hole 39 Base end of the sensor holder 68 First protrusion (rotation range regulating means)
69 Second projection (rotation range regulating means)
70 Hexagon socket set screw (display positioning means)

Claims (4)

A housing having a flow path in which the impeller is rotatably held, and a sensor mounting hole formed in the vicinity of the outer peripheral portion of the impeller and not communicating with the flow path;
A sensor holder that detects rotation of the impeller, and is detachably fitted in the sensor mounting hole;
A display for calculating and displaying the flow rate based on the detection signal from the sensor,
The outer surface of the base end portion of the sensor holder is formed on a circumferential surface,
The indicator is inserted into the base end of the sensor holder so as to be rotatable around the circumferential surface,
An impeller-type flow rate characterized in that, when relative rotation is performed at a fitting portion between the sensor holder and the indicator, a protrusion that contacts each other is provided to restrict one or more rotations. Total. The housing includes a first housing and a second housing that are detachably connected to each other,
The impeller has one end held by the bearing of the first housing and the other end held by the bearing of the second housing,
The sensor mounting hole is formed in one of the first housing and the second housing,
The impeller-type flow meter according to claim 1, wherein the sensor holder has the sensor on a distal end surface, and is fitted into the sensor mounting hole and fixed to the one housing. The impeller type flow meter according to claim 1 or 2, further comprising means for positioning the indicator with respect to the sensor holder . The sensor holder is formed using a synthetic resin,
The impeller flow meter according to any one of claims 1 to 3 , wherein the indicator is held in the housing only through the sensor holder .

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