JP6546073B2 - Ultrasonic flow meter - Google Patents

Description

  The present invention relates to an ultrasonic flowmeter that measures the flow rate of a fluid to be measured.

Conventionally, various techniques related to an ultrasonic flowmeter that measures the flow rate of a fluid to be measured have been proposed.
For example, a gas meter described in Patent Document 1 below is an ultrasonic flowmeter that detects the flow velocity of gas flowing in a measurement unit with a pair of ultrasonic flow velocity sensors and calculates the flow rate of gas from the detected flow velocity. is there.

  An elastic O-ring is mounted on the outer periphery of the measurement unit, and a measurement area partitioned by the O-ring is formed around the measurement unit. Therefore, the internal leak which gas leaks from the inside of a measurement area, or gas intrudes into a measurement area is prevented by the sealing performance of O ring.

JP, 2013-113791, A

  However, the measurement unit on which the O-ring having elasticity is mounted is in the shape of a square tube, and has a flat portion and a corner portion. Therefore, the thickness of the O-ring on the corner of the measurement unit is thinner than the thickness of the O-ring on the flat surface of the measurement unit, and a gap is easily formed in the thinner O-ring. Internal leakage may occur.

  Then, this invention is made in view of the point mentioned above, and makes it a subject to provide the ultrasonic flowmeter which can prevent the internal leak around a flow measurement unit.

  The invention according to claim 1 made to solve this problem is an ultrasonic flowmeter, comprising: a meter housing having a hollow portion provided with an opening on one side; and the meter for forming the hollow portion A partition which extends from the inner wall of the other side of the housing and divides the space in the hollow portion into a substantially U-shape, a first elastic seal member which is substantially U-shaped and is fitted to the partition, and (1) A flow rate measurement unit attached to the partition wall through being fitted to an elastic seal member and having a rectangular cross section, and fastened to the one side surface of the meter housing, A cover that covers and closes the opening, and a second elastic seal member interposed between the cover and the one side surface of the meter housing, the second elastic seal member being the opening of the meter housing An annular seal portion surrounding the annular seal portion and the annular seal portion corresponding to the partition wall And an end portion of the partition wall has a first fitting groove portion which is divided on both sides by an opening side end wall, and the end portion of the first elastic seal member Has a second fitting groove disposed between the first fitting groove and the flow rate measuring unit, and the first fitting groove and the second fitting groove are provided on the opening side of the meter housing And forming a flush seal arrangement portion in which the opening side outer surface of the flow rate measurement unit is continuous, and inserting the linear seal portion of the second elastic seal member in the flush seal arrangement portion. It features.

  The invention according to claim 2 is the ultrasonic flowmeter according to claim 1, wherein the partition wall is provided continuously across the entire end face facing the first elastic seal member. And the first elastic seal member is provided continuously over the entire area of the end face facing the end face of the partition wall having the first fitting portion, and is fitted to the first fitting portion. It is characterized by having a fitting portion.

  The invention according to claim 3 is the ultrasonic flowmeter according to claim 1 or 2, wherein the second fitting groove portion of the end portion of the first elastic seal member is the second of the partition walls. (1) It is characterized in that it is locked to the fitting portion.

  The invention according to claim 4 is the ultrasonic flowmeter according to any one of claims 1 to 3, wherein the flow rate measuring unit extends from the inner wall of the meter casing to the hollow portion The hollow portion of the meter housing is provided with a guide portion for guiding the wiring in the hollow portion.

  In the ultrasonic flowmeter of the invention according to claim 1, an opening is provided on one side surface of the meter housing, and a cover for covering and closing the opening is fastened. A second elastic seal member is interposed between the cover and one side surface of the meter housing. The annular seal portion of the second elastic seal member surrounds the opening of the meter housing. The opening of the meter housing is connected to the hollow portion of the meter housing. Therefore, by sealing between the cover and one side surface of the meter housing by the annular seal portion of the second elastic seal member, the hollow portion of the meter housing is airtightly held.

  In the hollow portion of the meter housing, a partition that divides the space into a substantially U-shape extends from the inner wall on the other surface side forming the hollow portion of the meter housing. A substantially U-shaped first elastic seal member is fitted in the partition wall. A flow rate measurement unit having a rectangular cross section is fitted in the first elastic seal member. By these fitting, the flow rate measurement unit is attached to the partition wall via the first elastic member.

  The end of the partition has a first fitting groove. The first fitting groove is divided on both sides by the open end wall of the partition wall. The end of the first elastic seal member has a second fitting groove. The second fitting groove portion is disposed between the first fitting groove portion of the partition wall and the flow rate measurement unit when the flow rate measurement unit is attached to the partition wall.

  Therefore, when the flow rate measurement unit is attached to the partition through being fitted to the first elastic seal member, the first fitting groove portion of the partition, the second of the first elastic seal member is attached to the opening side of the meter housing. A flush seal arrangement portion in which the fitting groove portion and the opening side outer surface of the flow rate measurement unit are continuous is formed. The linear seal portion of the second elastic seal member corresponding to the partition wall is fitted in the flush seal arrangement portion.

  That is, in the flow rate measurement unit, the cross section of the portion fitted to the first elastic seal member is configured in a rectangular shape with four outer surfaces. Of the four outer surfaces constituting the rectangular cross section, the three outer surfaces excluding the outer surface on the open side are sealed by the substantially U-shaped first elastic seal member, and the outer surface on the open side is the linear seal of the second elastic seal member Sealed in the department. Therefore, in the flow rate measurement unit, no gap is generated on the four outer surfaces of the rectangular cross section.

  Furthermore, in the flow rate measurement unit, of the four corners of the rectangular cross section, the two corners formed by the three outer surfaces excluding the opening-side outer surface are sealed by the substantially U-shaped first elastic seal member. Be done. On the other hand, on the outer surface on the opening side, the remaining two corner portions formed at both ends in the rectangular cross-sectional direction abut against the substantially U-shaped first elastic seal member and the linear seal portion of the second elastic seal member. Sealed by Therefore, in the flow rate measurement unit, no gap is generated on the four corners of the rectangular cross section.

  Therefore, in the ultrasonic flowmeter of the invention according to claim 1, it is possible to prevent internal leakage around the flow measurement unit.

  Furthermore, in the ultrasonic flowmeter according to the invention as set forth in claim 1, the linear seal portion of the second elastic seal member intervenes between the flush seal arrangement portion and the cover, whereby the opening side end wall of the partition wall and the cover It is possible to prevent internal leakage at the open end wall of the partition wall as well.

  Furthermore, in the ultrasonic flowmeter of the invention according to claim 1, the end portion of the first elastic seal member is obtained by interposing the linear seal portion of the second elastic seal member between the flush seal arrangement portion and the cover. Because the space between the cover and the cover is sealed, it is possible to prevent internal leakage at the end of the first elastic seal member.

  In the ultrasonic flowmeter of the invention according to claim 2, the partition wall has the first fitting portion, and the first elastic seal member has the second fitting portion. The 1st fitting part of a partition is continued and provided in the whole area of the end face which counters a 1st elastic seal member. The second fitting portion of the first elastic seal member is provided continuously over the entire end face facing the end face of the partition wall having the first fitting portion. When the first elastic seal member is fitted to the partition wall, the first fitting portion and the second fitting portion are fitted over the entire area of the end face where the partition wall and the first elastic seal member face each other Are fitted continuously. Therefore, in the ultrasonic flowmeter of the invention according to claim 2, it is possible to reliably fit the first elastic seal member to the partition wall.

  In the ultrasonic flowmeter of the invention according to claim 3, since the second fitting groove portion of the end portion of the first elastic seal member is locked to the first fitting portion of the partition wall, the first elastic seal member is used. It is possible to reliably complete the fitting to the partition wall.

  In the ultrasonic flowmeter of the invention according to claim 4, the guide portion is provided in the hollow portion of the meter housing, and the wire detachable from the flow rate measuring unit extends out to the hollow portion. When the wiring is attached to the flow rate measurement unit, the wiring is guided by the guide portion in the hollow portion of the meter housing so that the wiring is not pinched by the first elastic seal portion or the second elastic seal portion. Is possible. Therefore, in the ultrasonic flowmeter according to the third aspect of the present invention, it is possible to prevent an internal leak caused by the wire being pinched by the first elastic seal portion or the second elastic seal portion.

It is a disassembled perspective view showing schematic structure of the ultrasonic flowmeter concerning this embodiment. It is a perspective view showing the meter case of an ultrasonic flowmeter. It is a front view showing the meter case of an ultrasonic flowmeter. It is sectional drawing showing the meter housing cut | disconnected along the AA of FIG. It is sectional drawing showing the meter housing cut | disconnected along the BB line of FIG. It is a perspective view showing the flow measurement unit of an ultrasonic flowmeter. It is a front view showing the flow measurement unit of an ultrasonic flowmeter. It is a perspective view showing special packing of an ultrasonic flowmeter. It is a perspective view showing special packing of an ultrasonic flowmeter. It is a front view showing special packing of an ultrasonic flowmeter. It is a top view showing special packing of an ultrasonic flowmeter. It is a side view showing special packing of an ultrasonic flowmeter. It is sectional drawing showing the special packing cut | disconnected along the C-C line of FIG. It is a front view showing the cover packing of an ultrasonic flowmeter. It is sectional drawing showing the cover packing cut | disconnected along the DD line of FIG. It is sectional drawing showing the cover packing cut | disconnected along the EE line of FIG. It is a perspective view showing the meter case where the flow rate measurement unit was attached via special packing. It is a front view showing a meter case to which a flow rate measurement unit was attached via special packing. FIG. 19 is a cross-sectional view of the meter housing taken along line F-F of FIG. 18; FIG. 21 is an enlarged cross-sectional view of a region H of FIG. 19; It is sectional drawing showing the meter housing cut | disconnected along line G-G of FIG. It is sectional drawing which expanded and represented the area | region I of FIG. It is a front view showing the ultrasonic flowmeter with which the cover was attached to meter housing via cover packing. FIG. 24 is a cross-sectional view showing a meter housing cut along a line J-J in FIG. 23. It is sectional drawing which expanded and represented the area | region L of FIG. FIG. 24 is a cross-sectional view of the meter housing taken along line K-K in FIG. 23. It is sectional drawing which expanded and represented the area | region M of FIG. It is a perspective view showing the meter case of an ultrasonic flowmeter. It is a front view showing the meter case of an ultrasonic flowmeter.

[1. Outline of Ultrasonic Flowmeter]
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The ultrasonic flowmeter of the present embodiment is a fuel gas meter that measures the flow rate of a fuel gas (for example, a city gas or an LP gas).

  As shown in FIG. 1, the ultrasonic flowmeter 1 of the present embodiment includes a meter housing 100, a flow rate measurement unit 200, a dedicated packing 300, a cover packing 400, a cover 500, a wiring portion 600, and the like. Details of the meter housing 100, the flow rate measurement unit 200, the special packing 300, and the cover packing 400 will be described later.

  The cover 500 is formed in a substantially box shape in which the inside is recessed by a predetermined depth, and a plurality of counterbore holes 502 are provided in the vicinity of the edge. The plurality of counterbored holes 502 are used when the cover 500 is screwed into the meter housing 100.

  The wiring unit 600 includes a relay connector 602 attached to the meter housing 100, a wire 604 connected to the relay connector 602, a connector terminal 606 provided at the tip of the wire 604, and the like. The connector terminal 606 is to be plugged into the flow rate measurement unit 200.

[2. Form of meter case constituting ultrasonic flowmeter]
As shown in FIG. 2 and FIG. 3, the meter housing 100 is formed in a substantially rectangular parallelepiped shape, and the inlet 104 and the outlet 106 are provided to project on both ends of the upper surface 102. The fuel gas is supplied at the inlet 104, and the fuel gas is discharged at the outlet 106. The meter housing 100 is provided with a hollow portion 108 which is recessed inside. An opening 110 of the hollow portion 108 is provided on the side surface 112 of the meter housing 100.

  The inner wall 114 forming the hollow portion 108 of the meter housing 100 is provided with a pair of partition walls 116 and 118 at substantially the same distance from both ends of the meter housing 100 in the longitudinal direction. The pair of partition walls 116 and 118 are provided in a state of standing in parallel from the back side in the hollow portion 108 of the meter housing 100 to the opening 110. The hollow portion 108 of the meter housing 100 is divided into an inlet buffer portion 120, a central space portion 122, and an outlet buffer portion 124 by the pair of partition walls 116 and 118.

  In the inlet buffer portion 120, a first circular opening 126 is provided through the inner wall 114 on the back side. Through the first circular opening 126, the inflow port 104 and the inlet buffer portion 120 are connected in series (see FIG. 5).

  In the central space portion 122, a second circular opening 128 is provided through the inner wall 114 on the back side, and the protruding portion 130 is provided in a standing state. The relay connector 602 described above is attached to the second circular opening 128 (see FIGS. 28 and 29 described later). The protrusion 130 is provided from the back side in the hollow portion 108 of the meter housing 100 to the opening 110 (see FIG. 4).

  Each partition wall 116, 118 is provided with a mounting recess 132, 134 in which the opening 110 side of the meter housing 100 is opened. As also shown in FIGS. 4 and 5, on the end face of the mounting recess 132, a stepped portion 136 with a convex-shaped cross section is continuously provided over the entire area in the longitudinal direction. Similarly, on the end face of the mounting recess 134, a step 138 with a convex-shaped cross section is continuously provided over the entire area in the longitudinal direction.

  Between the mounting recess 132 and the side surface 112 of the meter housing 100, a pair of opening side end walls 116A and 116B located on the opening 110 side of the meter housing 100 are provided. The pair of open side end walls 116A and 116B correspond to the end walls of the partition wall 116 and are continuous with the side surface 112 of the meter housing 100 in the same plane. Similarly, between the mounting recess 134 and the side surface 112 of the meter housing 100, a pair of open end walls 118A and 118B located on the opening 110 side of the meter housing 100 are provided. The pair of open end walls 118A and 118B correspond to the end walls of the partition wall 118, and are continuous with the side surface 112 of the meter housing 100 in the same plane.

  An annular groove 140 is provided around the opening 110 of the meter housing 100. Each opening side end wall 116A, 116B of the partition wall 116 is provided with a linear first fitting groove portion 142, 144 continuous with the annular groove portion 140. Each of the first fitting groove portions 142 and 144 has a positional relationship in which both groove directions coincide with each other and both groove surfaces and groove surfaces of the annular groove portion 140 are on the same plane. Similarly, in the open end walls 118A and 118B of the partition wall 118, linear first fitting groove portions 146 and 148 continuous with the annular groove portion 140 are provided. Each of the first fitting groove portions 146 and 148 has a positional relationship in which both groove directions coincide with each other and both groove surfaces and groove surfaces of the annular groove portion 140 are on the same plane.

  The side surface 112 of the meter housing 100 is provided with a plurality of screw holes 150 near its edge. The plurality of screw holes 150 correspond to the plurality of counterbore holes 502 provided in the cover 500 described above, and are used when the cover 500 is screwed to the meter housing 100.

[3. Form of flow rate measuring unit constituting ultrasonic flowmeter]
As shown in FIG. 6 and FIG. 7, the flow rate measurement unit 200 is provided with a substantially square tubular measurement flow passage portion 202. The cross section (that is, the outer periphery) perpendicular to the longitudinal direction of the measurement flow passage portion 202 is rectangular. An inlet 204 and an outlet 206 are provided at both ends of the measurement channel 202. In the measurement flow passage portion 202, the fuel gas flows from the inlet portion 204 toward the outlet portion 206.

  The measurement channel portion 202 is provided with a circuit case 208 on the center upper side in the longitudinal direction. The circuit case 208 incorporates a pair of ultrasonic transducers (not shown). The flow rate measurement unit 200 measures the flow rate of the fuel gas flowing in the measurement flow passage 202 based on the values measured by the pair of ultrasonic transducers.

  An output port 210 is provided on the top surface of the circuit case 208. The connector terminal 606 described above is inserted into the output port 210.

  A pair of ribs 212 facing each other is provided across the rectangular outer periphery of the measurement flow passage portion 202 on the outer side of the measurement flow passage portion 202 closer to the inlet portion 204 than the circuit case 208. Similarly, a pair of ribs 214 facing each other is provided across the rectangular outer periphery of the measurement flow passage portion 202 on the outer side of the measurement flow passage portion 202 on the outlet portion 206 side than the circuit case 208. A rectangular groove portion 216 is formed by a pair of ribs 212 on the rectangular outer periphery of the measurement flow passage portion 202, and a rectangular groove portion 218 is formed by a pair of ribs 214.

[4. Form of exclusive packing which constitutes ultrasonic flowmeter]
The special packing 300 described above is made of rubber or the like and has elasticity. As shown in FIGS. 8 to 13, the exclusive packing 300 includes a main body 302 that is substantially U-shaped in a front view.

  A fitting groove portion 304 having a concaved cross section is continuously provided on the outer surface of the main body 302 over the entire longitudinal direction. The fitting groove portion 304 is fitted into the step portions 136 and 138 of the mounting recesses 132 and 134 provided in the meter housing 100 described above. At this time, the outer side surface of the main body 302 is opposed to the end surface of each of the mounting concave portions 132 and 134 provided with the step portions 136 and 138.

  A fitting convex portion 306 having a U-shaped cross section is continuously provided on the inner surface of the main body 302 over the entire longitudinal direction. The rectangular grooves 216 and 218 of the flow rate measurement unit 200 described above are fitted in the fitting convex portion 306.

  An opening-side end surface 308 is provided at one end of the main body 302, and an opening-side end surface 310 is provided at the other end of the main body 302. Each open end face 308, 310 has a positional relationship in which both surfaces are in the same plane.

  The opening-side end surface 308 provided at one end of the main body 302 is provided with a second fitting groove portion 312 having a concave-shaped cross section that allows the fitting groove portion 304 and the fitting protrusion portion 306 to be continuous. Similarly, on the opening side end face 310 provided at the other end of the main body 302, there is provided a second fitting groove 314 of concave cross section for connecting the fitting groove 304 and the fitting projection 306 continuously. . Each of the second fitting grooves 312 and 314 has a positional relationship in which both groove directions coincide with each other and both groove surfaces are on the same plane.

[5. Form of cover packing that constitutes ultrasonic flowmeter]
The material of the cover packing 400 described above is rubber or the like, and has elasticity. As shown in FIGS. 14 to 16, the cover packing 400 includes an annular seal portion 402 and a pair of linear seal portions 404 and 406. Both of the pair of linear seal portions 404 and 406 are located in the annular seal portion 402, and both ends thereof are continuous with the inside of the annular seal portion 402.

  As shown in FIG. 15, the annular seal portion 402 has a cross-section that gradually widens in cross-sectional view from the back side to the front side in FIG. Furthermore, the surface on the narrow side has a rounded shape, and the end face on the wide side is a flat surface, and a rounded projection 402A is formed at the central portion of the flat end surface over the entire longitudinal direction. It is provided.

  The linear seal portion 404 has a cross-section that is gradually wider in cross-sectional view from the back side to the front side in FIG. 14 as illustrated in FIG. Furthermore, on the wide side plane, a rounded projection 404A is provided over the entire area in the longitudinal direction, and on the end face across the width side, a protrusion is provided on both ends in the width direction A substantially U-shaped linear uneven portion 404B is provided. The same applies to the linear seal portion 406 with respect to these points.

[6. Attaching Flow Measurement Unit and Dedicated Packing to Meter Case]
As shown in FIG. 17 to FIG. 22, the flow rate measurement unit 200 is attached to the meter housing 100 via the special packing 300. Therefore, when the flow rate measurement unit 200 is attached to the meter housing 100, first, the exclusive packing 300 is attached to the meter housing 100.

  For this purpose, the special packings 300 are attached to the mounting recesses 132 and 134 of the partition walls 116 and 118 of the meter housing 100 from the opening 110 side of the meter housing 100. At this time, as shown in FIG. 22, the fitting groove portion 304 of the special packing 300 is fitted into the step portion 136 of the dividing wall 116, whereby the special packing 300 is attached to the dividing wall 116. Although this point is not illustrated, the same applies when the special packing 300 is attached to the partition wall 118, and the fitting groove 304 of the special packing 300 is fitted into the step portion 138 of the partition 118.

  Thus, when the dedicated packings 300 are attached to the partition walls 116 and 118 of the meter housing 100, as shown in FIG. 17, the opening side end faces 308 and 310 of the dedicated packings 300 are meter housings. It is located on the side of the opening 110 of 100.

  Next, the flow rate measurement unit 200 is attached to each of the exclusive packings 300 in the meter housing 100 from the opening 110 side of the meter housing 100. At this time, as shown in FIG. 22, the rectangular groove portion 216 of the flow rate measuring unit 200 is fitted into the fitting convex portion 306 of the exclusive packing 300, whereby the flow rate measuring unit is mounted on the dedicated packing 300 attached to the partition wall 116. 200 is attached. Although this point is not illustrated, the same applies when the flow rate measurement unit 200 is attached to the dedicated packing 300 of the partition wall 118 (see FIG. 21), and the fitting convex portion 306 of the dedicated packing 300 The rectangular groove 218 is fitted.

  In this manner, when the flow rate measurement unit 200 is attached to each dedicated packing 300 in the meter housing 100, as shown in FIG. 17, the opening outer surface 202A of the measurement flow path portion 202 of the flow rate measurement unit 200. Is located on the opening 110 side of the meter housing 100. The opening-side outer surface 202A of the measurement flow channel portion 202 is one of the four outer surfaces constituting the rectangular outer periphery of the measurement flow channel portion 202.

  In addition, as shown in FIG. 20, the rectangular cross section of the portion of the flow rate measurement unit 200 attached to the dedicated packing 300 of the partition wall 116 (rectangular groove portion 216 of the measurement flow path portion 202 of the flow rate measurement unit 200) Among the four outer surfaces constituting the same, the three outer surfaces except the open-side outer surface 202A are in close contact with the special packing 300 attached to the partition wall 116.

  Furthermore, in the special packing 300, the end portions 312A and 314A of the second fitting groove portions 312 and 314 are provided on the end surfaces 136A and 136B of the step portion 136 provided in the mounting recess 132 (see FIG. 2) of the partition 116. I am engaged and stopped.

  Although this point is not illustrated, the same applies to the exclusive packing 300 of the partition wall 118. That is, for the rectangular cross section of the portion of the flow rate measurement unit 200 attached to the dedicated packing 300 of the partition wall 118 (rectangular groove portion 218 of the measurement flow passage portion 202 included in the flow rate measurement unit 200), the four outer surfaces constituting it Among them, the three outer surfaces except the open side outer surface 202A are in close contact with the special packing 300 attached to the partition wall 118 without any gap.

  Furthermore, the end portions 312A and 314A of the second fitting grooves 312 and 314 of the special packing 300 are provided to the end surfaces 138A and 138B (see FIG. 2) of the step portion 138 provided in the mounting recess 134 of the partition wall 118. I am engaged and stopped.

  The rectangular groove portions 216 and 218 of the measurement flow path unit 202 included in the flow rate measurement unit 200 are, as shown in FIGS. 17 and 18, portions provided on the opening side outer surface 202A Name it as 216A, 218A.

  As shown in FIG. 18, on the opening 110 side of the meter housing 100, the first fitting grooves 142 and 144 of the partition 116, the second fitting grooves 312 and 314 of the special packing 300, and the flow rate measurement unit 200. The seal groove S1 is formed by arranging the third fitting groove 216A in a straight line. The seal groove portion S1 is continuous with the annular groove portion 140.

  In the seal groove portion S1, as shown in FIG. 20, the first fitting groove portion 142 of the partition 116, the second fitting groove portion 312 of the special packing 300, the third fitting groove portion 216A of the flow rate measuring unit 200, and The two insertion grooves 314 and the first insertion grooves 144 of the partition 116 are butted together in the order of description without any gap. Thus, the groove surfaces of the first fitting grooves 142 and 144, the second fitting grooves 312 and 314, and the third fitting grooves 216A are flush with each other in the same plane. That is, the groove surface of the seal groove portion S1 is in a flat state without a gap.

  As shown in FIG. 18, on the opening 110 side of the meter housing 100, the first fitting grooves 146 and 148 of the partition wall 118, the second fitting grooves 312 and 314 of the special packing 300, and the flow rate measurement unit 200. Seal groove S2 is formed by arranging the third fitting groove 218A in a straight line. The seal groove portion S2 is continuous with the annular groove portion 140.

  In the seal groove S2, although not shown, the first fitting groove 146 of the partition wall 118, the second fitting groove 312 of the special packing 300, the third fitting groove 218A of the flow rate measuring unit 200, and the second fitting of the special packing 300. The grooved portion 314 and the first fitting groove portion 148 of the partition wall 118 butt together in the order described without gaps. Thus, the groove surfaces of the first fitting grooves 146 and 148, the second fitting grooves 312 and 314, and the third fitting grooves 218A are flush with each other in the same plane. That is, the groove surface of the seal groove portion S2 is in a flat state without a gap.

  When the flow rate measurement unit 200 is attached to each of the dedicated packings 300 in the meter housing 100, the flow rate measurement unit 200 is positioned above the protrusion 130, as shown in FIGS.

[7. Attaching the cover and cover packing to the meter case]
As shown in FIGS. 23 to 27, in the ultrasonic flowmeter 1 of the present embodiment, the cover 500 is attached to the meter housing 100 via the cover packing 400. Therefore, when the cover 500 is attached to the meter housing 100, the cover packing 400 is attached to the meter housing 100 first.

  For that purpose, the annular seal portion 402 of the cover packing 400 is fitted in the annular groove portion 140 with the surface on the narrow side in cross sectional view (see FIG. 15) directed to the annular groove portion 140 of the meter housing 100. Further, the linear seal portion 404 of the cover packing 400 is fitted in the seal groove portion S1 with the end face (see FIG. 15) provided with the linear uneven portion 404B facing the seal groove portion S1 of the meter housing 100. Be This point is the same as when the linear seal portion 406 of the cover packing 400 is fitted into the seal groove S2 of the meter housing 100.

  Thereafter, as illustrated in FIG. 23, in the state in which the cover 500 is disposed in the meter housing 100, the respective screws 504 are passed through the respective counterbored holes 502 of the cover 500. Each screw 504 is screwed into each screw hole 150 provided on the side surface 112 of the meter housing 100. Thereby, the cover 500 is screwed to the meter housing 100, and the cover 500 is fixed to the side surface 112 of the meter housing 100.

  Thus, when the cover 500 is attached to the meter housing 100, as shown in FIG. 27, the linear seal portion 404 fitted in the seal groove S1 is pressed by the cover 500. At this time, the first fitting grooves 142 and 144 of the partition 116, the second fitting grooves 312 and 314 of the special packing 300, and the third fitting grooves 216A of the flow rate measuring unit 200 are butted against each other to form a gap. It is flat and flush, and contacts the linear seal portion 404 of the cover packing 400 without any gap.

  Accordingly, the rectangular cross section of the portion attached to the special packing 300 of the partition wall 116 (rectangular groove portion 216 of the measurement flow passage portion 202 of the flow rate measurement unit 200) is in the following sealing state.

  Of the four outer surfaces constituting the rectangular cross section, the three outer surfaces excluding the open outer surface 202A contact the dedicated packing 300 of the partition 116 without any gap, and the remaining outer outer surface 202A is the cover packing 400. It contacts the linear seal part 404 without a gap.

  Furthermore, the linear seal portion 404 of the cover packing 400 and the special packing 300 abut each other on the both end corner portions of the opening outer surface 202A (both end corner portions of the third fitting groove portion 216A) without a gap. Contact. In addition, the special packing 300 is in contact with the two corners formed by the three outer surfaces except the opening-side outer surface 202A without a gap.

  With such a seal configuration, no gap is generated around the rectangular groove 216.

  These points also apply to the linear seal portion 406 fitted into the seal groove S2. That is, when the cover 500 is attached to the meter housing 100, although not shown, the linear seal portion 406 fitted in the seal groove S2 is pressed by the cover 500. At this time, the first fitting grooves 146 and 148 of the partition wall 118, the second fitting grooves 312 and 314 of the dedicated packing 300, and the third fitting grooves 218A of the flow rate measuring unit 200 are abutted against each other, It is in a flat state, and contacts the linear seal portion 406 of the cover packing 400 without any gap.

  Therefore, the rectangular cross section of the portion attached to the dedicated packing 300 of the partition wall 118 (rectangular groove portion 218 of the measurement flow passage portion 202 of the flow rate measurement unit 200) is in the following sealing state.

  Of the four outer surfaces constituting the rectangular cross section, the three outer surfaces excluding the open outer surface 202A contact the dedicated packing 300 of the partition 118 without any gap, and the remaining outer outer surface 202A is the cover packing 400. It contacts the linear seal part 406 without any gap.

  Furthermore, the linear seal portion 404 of the cover packing 400 and the special packing 300 abut each other on the both end corners of the opening outer surface 202A (both end corners of the third fitting groove 218A) without a gap. Contact. In addition, the special packing 300 is in contact with the two corners formed by the three outer surfaces except the opening-side outer surface 202A without a gap.

  With such a seal configuration, no gap is generated around the rectangular groove 218.

  Further, as shown in FIG. 25, when the linear seal portion 404 fitted in the third fitting groove portion 216A of the flow rate measurement unit 200 is pressed by the cover 500, the projection 404A of the linear seal portion 404 (see FIG. 16). ) Is crushed. Although this point is not illustrated, the same applies to the linear seal portions 404 fitted into the first fitting grooves 142 and 144 of the partition 116 or the second fitting grooves 312 and 314 of the special packing 300, respectively. is there. Furthermore, although not shown, each of the first fitting grooves 146 and 148 of the partition wall 118, each second fitting groove 312 and 314 of the special packing 300, or the third fitting groove 218A of the flow rate measuring unit 200 is fitted. The same applies to the linear seal portion 406. Thereby, the sealing performance of each seal groove part S1, S2 improves.

  Although not shown, when the annular seal portion 402 of the cover packing 400 fitted in the annular groove portion 140 of the meter housing 100 is pressed by the cover 500, the projection 402A (see FIG. 15) of the annular seal portion 402 is crushed. Be Thus, the hollow portion 108 of the meter housing 100 (that is, the inlet buffer portion 120, the central space portion 122, and the outlet buffer portion 124) is airtightly held.

[8. Wiring installation]
As shown in FIGS. 28 and 29, the relay connector 602 is attached to the second circular opening 128 provided in the inner wall 114 of the meter housing 100. The wires 604 connected to the relay connector 602 extend long from the inner wall 114 of the meter housing 100 to the hollow portion 108 (central space portion 122). A connector terminal 606 is provided at the tip of the wire 604.

  In order to assemble the ultrasonic flowmeter 1 of the present embodiment, first, the wire 604 is guided to an appropriate position in the hollow portion 108 (central space portion 122) of the meter housing 100. Next, the special packing 300 is attached to the meter housing 100. Next, the flow rate measurement unit 200 and the cover packing 400 are attached to the meter housing 100. Thereafter, the cover 500 is fixed to the meter housing 100.

  Among these assembling operations, in the first operation in which the wire 604 is guided to an appropriate position in the hollow portion 108 (central space portion 122) of the meter housing 100, the protrusion in the hollow portion 108 (central space portion 122) The wire 604 is hooked on the portion 130, and the connector terminal 606 of the wire 604 is disposed above the hollow portion 108 (the central space portion 122).

  In this manner, when the wire 604 is guided to an appropriate position in the hollow portion 108 (central space portion 122) of the meter housing 100, the wire 604 from the inner wall 114 in the hollow portion 108 (central space portion 122). Lifting is suppressed. Thereby, for example, the wires 604 can be prevented from overlapping on the step portions 136 and 138, the annular groove portion 140, the first fitting groove portions 142, 144, 146, 148 and the like in the meter housing 100. The special packing 300 or the cover packing 400 is fitted into the step portions 136 and 138, the annular groove portion 140, and the first fitting groove portions 142, 144, 146 and 148 in the meter housing 100. Therefore, the exclusive packing 300 and the cover packing 400 can be attached to the meter housing 100 without sandwiching the wire 604.

  The connector terminal 606 disposed at the upper side in the hollow portion 108 (central space portion 122) of the meter housing 100 is inserted into the output port 210 of the flow rate measurement unit 200.

[9. Summary]
As mentioned above, in the ultrasonic flowmeter 1 of this embodiment, the opening 110 is provided in the side surface 112 of the meter housing | casing 100, and the cover 500 which covers and closes the opening 110 is fastened by screwing. A cover packing 400 intervenes between the cover 500 and the side surface 112 of the meter housing 100. The annular seal portion 402 of the cover packing 400 surrounds the opening 110 of the meter housing 100. The opening 110 of the meter housing 100 is continuous with the hollow portion 108 of the meter housing 100.

  Therefore, by sealing between the cover 500 and the side surface 112 of the meter housing 100 by the annular seal portion 402 of the cover packing 400, the hollow portion 108 of the meter housing 100 (that is, the inlet buffer portion 120, central space portion 122 and the outlet buffer section 124) are held airtight.

  In the hollow portion 108 of the meter housing 100, the partition walls 116 and 118 extend from the inner wall 114. Each partition wall 116, 118 is provided with a mounting recess 132, 134 in which the opening 110 side of the meter housing 100 is opened. The space in the hollow portion 108 is divided into the inlet buffer portion 120, the central space portion 122, and the outlet buffer portion 124 by the partition walls 116 and 118 provided with the mounting recesses 132 and 134, respectively.

  The partition wall 116 is provided with a pair of open end walls 116A and 116B located on the both sides of the mounting recess 132 provided in the partition wall 116 with the side surface 112 of the meter housing 100. The pair of open side end walls 116A and 116B are continuous with the side surface 112 of the meter housing 100.

  Similarly, in the partition wall 118, a pair of open end walls 118A and 118B located between the attachment recess 134 provided in the partition wall 116 and the side surface 112 of the meter housing 100 are provided. The pair of open side end walls 118A and 118B are continuous with the side surface 112 of the meter housing 100.

  A substantially U-shaped dedicated packing 300 is fitted from the opening 110 side of the meter housing 100 in each of the attachment recesses 132 and 134 of the partition walls 116 and 118. The flow rate measurement unit 200 is fitted into the dedicated packing 300 from the opening 110 side of the meter housing 100. On both sides of the flow rate measurement unit 200, the pair of open side end surfaces 308 and 310 of the dedicated packing 300 is between the pair of open side end walls 116A and 116B of the partition 116 and the pair of open side end walls 118A of the partition 118. It is disposed between 118B.

  In the flow rate measurement unit 200, the cross section of the part (each rectangular groove part 216, 218 of the measurement flow path part 202) fitted in the exclusive packing 300 is formed in a rectangular shape by four outer surfaces. The flow rate measurement unit 200 has an opening-side outer surface 202A that constitutes one side of the rectangular cross section and is disposed between the pair of opening-side end surfaces 308 and 310 of the special packing 300.

  Among the four outer surfaces constituting the rectangular cross section, the three outer surfaces excluding the opening side outer surface 202A are in close contact with the special packing 300 from one end to the other end in the rectangular cross section direction.

  On the other hand, on the opening 110 side of the meter housing 100, the first fitting grooves 142 and 144 of the pair of opening side end walls 116A and 116B of the partition 116, and the second of the pair of opening side end surfaces 308 and 310 of the special packing 300. The seal groove S1 having the same groove surface by having the fitting grooves 312 and 314 and the opening-side outer surface 202A (the third fitting groove 216A of the flow rate measurement unit 200) adjacent to each other is “uniform It is formed as a "seal arrangement part".

  Similarly, on the opening 110 side of the meter housing 100, the first fitting groove portions 146 and 148 of the pair of opening side end walls 118A and 118B of the dividing wall 118, the pair of opening side end surfaces 308 and 310 of the special packing 300, The seal groove portion S2 whose groove surfaces are flush with each other by (the third fitting groove portion 218A of) the opening-side outer surface 202A of the flow rate measurement unit 200 is formed as “a flush seal arrangement portion”. Ru.

  The linear seal portions 404 and 406 of the cover packing 400 intervene between the seal grooves S 1 and S 2 and the cover 500.

  That is, in the flow rate measurement unit 200, the cross section of the part (each rectangular groove part 216, 218 of the measurement flow path part 202) fitted in the exclusive packing 300 is formed in a rectangular shape by four outer surfaces. Of the four outer surfaces constituting the rectangular cross section, the three outer surfaces excluding the opening outer surface 202A are sealed by the substantially U-shaped special packing 300, and the opening outer surface 202A is a linear seal portion 404 of the cover packing 400. , 406. Therefore, in the flow rate measurement unit 200, no gap is generated on the four outer surfaces of the rectangular cross section.

  Furthermore, in the flow rate measurement unit 200, of the four corners of the rectangular cross section of the measurement flow channel portion 202, the two corners formed by the three outer surfaces excluding the opening outer surface 202A are substantially U-shaped. Is sealed by a dedicated packing 300 of On the other hand, on the open side outer surface 202A, the remaining two corners formed at both ends in the rectangular cross-sectional direction abut against the substantially U-shaped exclusive packing 300 and the linear seal parts 404 and 406 of the cover packing 400. Sealed by Therefore, in the flow rate measurement unit 200, no gap is generated on the four corners of the rectangular cross section.

  Therefore, in the ultrasonic flowmeter 1 of the present embodiment, it is possible to prevent the internal leak around the flow measurement unit 200.

  Furthermore, in the ultrasonic flowmeter 1 of the present embodiment, the linear seal portion 404 of the cover packing 400 is interposed between the seal groove portion S1 and the cover 500, whereby the pair of opening side end walls 116A and 116B of the partition wall 116 Since the space between the covers 500 is sealed, it is possible to prevent internal leakage at the pair of open end walls 116A and 116B of the partition wall 116 as well. Similarly, by interposing the linear seal portion 406 of the cover packing 400 between the seal groove portion S2 and the cover 500, the space between the pair of open end walls 118A and 118B of the partition wall 118 and the cover 500 is sealed. It is also possible to prevent internal leakage at the pair of open end walls 118A, 118B of the partition wall 118.

  Furthermore, in the ultrasonic flowmeter 1 of the present embodiment, the linear seal portions 404 and 406 of the cover packing 400 intervene between the seal groove portions S1 and S2 and the cover 500, whereby the pair of opening sides of the special packing 300 is obtained. Since the end surfaces 308 and 310 and the cover 500 are sealed, it is possible to prevent internal leakage at the pair of open end surfaces 308 and 310 of the special packing 300 as well.

  Further, in the ultrasonic flowmeter 1 of the present embodiment, the attachment recesses 132 and 134 of the partition walls 116 and 118 have the step portions 136 and 138 having convex shapes, and the special packing 300 has a concave shape. A groove 304 is provided.

  When the dedicated packing 300 is fitted in the mounting recess 132, 134 of each partition 116, 118, the end face of each mounting recess 132, 134 of each partition 116, 118 faces the dedicated packing 300. The step portions 136 and 138 are continuously provided over the entire end surface of the mounting recess 132 and 134 of the partition walls 116 and 118, respectively. Similarly, when the dedicated packing 300 is fitted into the mounting recess 132, 134 of each partition 116, 118, the outer surface of the special packing 300 faces the mounting recess 132, 134 of each partition 116, 118. Do. A fitting groove portion 304 is provided continuously along the entire outer surface of the special packing 300.

  Therefore, when the dedicated packing 300 is fitted in the mounting recess 132, 134 of each partition 116, 118, the mounting recess 132, 134 of the partition 116, 118 and the dedicated packing 300 extend over the entire area facing each other. The convex-shaped step portions 136 and 138 and the concave fitting groove portion 304 are continuously fitted by the concavo-convex fitting structure. Therefore, in the ultrasonic flowmeter 1 of the present embodiment, it is possible to reliably fit the special packing 300 in the mounting concave portions 132 and 134 of the partition walls 116 and 118, respectively.

  Further, in the ultrasonic flowmeter 1 of the present embodiment, the pair of first fitting groove portions 142 and 144 are provided on the pair of opening side end walls 116A and 116B of the partition 116, and the pair of opening side end surfaces 308 of the special packing 300 , 310 are provided with a pair of second fitting grooves 312, 314, and a third fitting groove 216A is provided on the opening-side outer surface 202A of the flow rate measurement unit 200. The pair of first fitting groove portions 142 and 144, the pair of second fitting groove portions 312 and 314, and the third fitting groove portion 216A are arranged in series, which corresponds to "a flush seal arrangement portion". The seal groove S1 is formed.

  Similarly, a pair of first fitting groove portions 146 and 148 are provided in the pair of opening side end walls 118A and 118B of the partition wall 118, and a pair of second fitting side portions on the pair of opening side end surfaces 308 and 310 of the special packing 300. The grooves 312 and 314 are provided, and the third fitting groove 218A is provided on the opening side outer surface 202A of the flow rate measurement unit 200. The pair of first fitting groove portions 146 and 148, the pair of second fitting groove portions 312 and 314, and the third fitting groove portion 218A are arranged in series, which corresponds to "a flush seal arrangement portion". The seal groove S2 is formed.

  Since each of the seal groove portions S1 and S2 formed in such a manner has an elongated groove shape, the linear seal portions 404 and 406 of the cover packing 400 can be easily fitted in the seal groove portions S1 and S2. Therefore, in the ultrasonic flowmeter 1 according to the present embodiment, the linear seal portions 404 and 406 of the cover packing 400 can be reliably made between the seal grooves S1 and S2 corresponding to the "same seal arrangement portion" and the cover 500. It is possible to intervene.

  Further, in the ultrasonic flowmeter 1 of the present embodiment, the end portions 312A and 314A of the second fitting groove portions 312 and 314 provided in the exclusive packing 300 are attached to the attachment recesses 132 and 134 of the partition walls 116 and 118, respectively. Since the end faces 136A, 136B, 138A, 138B of the provided step portions 136, 138 are locked, it is possible to reliably fit the special packing 300 into the mounting recesses 132, 134 of the partition walls 116, 118. Can be completed.

  Further, in the ultrasonic flowmeter 1 of the present embodiment, the protrusion 130 is provided in the hollow portion 108 (central space portion 122) of the meter housing 100, and the output of the flow rate measurement unit 200 is provided via the connector terminal 606. A wire 604 removable from the port 210 extends to the hollow portion 108 (central space portion 122).

  When the wire 604 is attached to the flow rate measurement unit 200, the wire 604 is guided by the protrusion 130 in the hollow portion 108 (central space portion 122) of the meter housing 100, whereby the dedicated packing 300 or the cover packing 400 is obtained. It is possible to prevent the wire 604 from being pinched. Therefore, in the ultrasonic flowmeter 1 of the present embodiment, it is possible to prevent internal leakage caused by the wiring 604 being pinched by the special packing 300 or the cover packing 400.

  As mentioned above, in the ultrasonic flowmeter 1 of this embodiment, since the various internal leaks mentioned above are prevented, exact flow measurement is possible.

  Incidentally, in the present embodiment, the side surface 112 of the meter housing 100 is an example of “one side surface of the meter housing”. The dedicated packing 300 is an example of the “first elastic seal member”. The cover packing 400 is an example of the “second elastic seal member”. Opening side end wall 116A, 116B, 118A, 118B is an example of "an end of a partition." The opening side end surfaces 308 and 310 are examples of the “end portion of the first elastic seal member”. Each of the step portions 136 and 138 is an example of the “first fitting portion”. The fitting groove portion 304 is an example of the “second fitting portion”. The protrusion 130 is an example of a “guide”.

[10. Other]
The present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention.

  For example, in the ultrasonic flowmeter 1 of the present embodiment, the annular groove portion 140, the first fitting groove portions 142, 144, 146, and 148, the second fitting groove portions 312 and 314, and the third fitting groove portions 216A. , 218A may not be provided. That is, it is not necessary to provide each groove in which the cover packing 400 is fitted.

  In such a case, when the flow rate measurement unit 200 is attached to the meter housing 100 via the special packing 300, the open end walls 116A, 116B, 118A, 118B, and the open end surfaces 308, 310 and the opening-side outer surface 202A are configured to be flush with the side surface 112 of the meter housing 100.

  Furthermore, the "open seal arrangement portion" is constituted by the opening side end walls 116A and 116B, the opening side end surfaces 308 and 310, and the opening side outer surface 202A, and the cover packing is formed on the "same seal arrangement portion". 400 linear seals 404 are placed.

  Similarly, each open end wall 118A, 118B, each open end face 308, 310, and the open outer surface 202A constitute a "same seal arrangement portion", and on the "same seal arrangement portion" The linear seal portion 406 of the cover packing 400 is placed.

  The annular seal portion 402 of the cover packing 400 is placed on the side surface 112 of the meter housing 100.

  In the ultrasonic flowmeter 1 of the present embodiment, the wire 604 may be guided in the hollow portion 108 (central space portion 122) of the meter housing 100 by the “guide portion” other than the protrusion 130. In such a case, for example, a plurality of hooks may be provided as “guide portions” along the route to which the wire 604 is to be placed, and the hooks may be used to constrain and guide the wire 604.

Reference Signs List 1 ultrasonic flow meter 100 meter housing 108 hollow part 110 hollow part opening 112 side of meter housing 114 inner wall 116, 118 partition wall 116A, 116B opening end wall 118A, 118B opening end wall 130 protrusion 132, 134 attachment Recesses 136 and 138 Stepped portion 142 and 144 First fitting groove portion 146 and 148 First fitting groove portion 200 Flow rate measuring unit 202A Opening side outer surface 216A and 218A Third fitting groove portion 300 Special packing 304 Fitting groove portion 308 and 310 Opening side End face 312, 314 second fitting groove 400 cover packing 402 annular seal portion 404, 406 linear seal portion 500 cover 604 wiring S1, S2 seal groove

Claims (4)

A meter housing having a hollow portion provided with an opening on one side;
A partition wall extending from an inner wall of the other side surface of the meter casing forming the hollow portion, which partitions the space in the hollow portion into a substantially U-shape;
A first elastic seal member which is substantially U-shaped and is fitted to the partition;
A flow rate measurement unit attached to the partition through being fitted to the first elastic seal member, and having a rectangular cross section;
A cover which is fastened to the one side of the meter housing and covers and closes the opening of the meter housing;
And a second elastic seal member interposed between the cover and the one side surface of the meter housing.
The second elastic seal member has an annular seal portion surrounding an opening of the meter housing, and a linear seal portion dividing the annular seal portion corresponding to the partition wall,
The end portion of the partition wall has a first fitting groove portion divided on both sides by an open end wall,
The end of the first elastic seal member has a second fitting groove disposed between the first fitting groove and the flow rate measurement unit,
A flush seal arrangement portion in which the first fitting groove portion, the second fitting groove portion, and the opening-side outer surface of the flow rate measurement unit are continuous is formed on the opening side of the meter housing,
The ultrasonic flowmeter characterized in that the linear seal portion of the second elastic seal member is fitted in the flush seal arrangement portion. The partition wall has a first fitting portion provided continuously over the entire area of the end surface facing the first elastic seal member,
The first elastic seal member is provided continuously over the entire end face facing the end face of the partition wall having the first fitting portion, and the second fitting portion is fitted to the first fitting portion. The ultrasonic flowmeter according to claim 1, wherein the ultrasonic flowmeter comprises:   The ultrasonic flowmeter according to claim 2, wherein the second fitting groove portion of the end portion of the first elastic seal member is locked to the first fitting portion of the partition wall. It has a wire that extends from the inner wall of the meter casing to the hollow portion and is detachable from the flow rate measurement unit,
The ultrasonic flow rate according to any one of claims 1 to 3, wherein a guide portion for guiding the wiring in the hollow portion is provided in the hollow portion of the meter housing. Total.

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