Flowmeter

Abstract

To provide a technology capable of fastening annealed resin by a bolt and a nut without deforming the resin.SOLUTION: An exhaust pipe 10 has an exhaust port 11 for discharging measured fluid from the inside of the exhaust pipe 10 to the outside, and a first flange part 13 formed so as to project outward from a lower end 12 of the exhaust pipe 10. The first flange part 13 has a nut installation part 110 formed by recessing a part thereof, and a nut presser for pressing a nut installed in the nut installation part 110. Inner machine cases 20 and 30 have second flange parts 21 and 31 formed to project outward from the upper ends of the inner machine cases 20 and 30. The second flange parts 21 and 31 have holes through which bolts are inserted, and bolts 190 are inserted into the holes from the backsides of the second flange parts 21 and 31 and screwed to nuts 150 to fasten the inner machine cases 20 and 30 and the exhaust pipe 10.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present application relates to a flow meter that measures the flow rate of a fluid to be measured. [Background technology]

[0002] Patent Document 1 describes a synthetic resin cover mounting device, in which a slope is formed on the front half of the flanges spaced apart from one another around the periphery, making the surface thicker on the outside, and a metal collar that is slightly smaller in height than the rear half of the flange is fitted into a through hole drilled in each flange, and a bolt is inserted through the metal collar to fasten it.

[0003] In this device, the synthetic resin cover is attached to the main body by screwing a bolt into a screw hole provided on the main body, but it is also possible to attach the synthetic resin cover to the main body by embedding a metal nut in the main body and screwing the bolt into the nut. In this case, if the main body into which the nut is embedded is also made of synthetic resin, when molding the main body, insert molding is often used in which the nut is set in the mold beforehand and molded integrally with the nut. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 57-73407 Summary of the Invention [Problem to be solved by the invention]

[0005] When molding synthetic resin, annealing is often performed to remove residual stress. If annealing is performed during insert molding, the insert part is heated as well as the resin due to the heating temperature during annealing, and heat accumulates. This causes the temperature of the resin around the insert part to differ from the temperature of the other resin, which may cause the resin to deform when re-hardened.

[0006] An object of the present application is to provide a technique that makes it possible to fasten annealed resin with bolts and nuts without deforming the resin. [Means for solving the problem]

[0007] In order to achieve the above object, the flow meter of the present application comprises a flow measurement unit that measures the flow rate of a measured fluid flowing therethrough, a relay case to which the flow measurement unit is attached from the outside, which receives the measured fluid that has flowed inside the flow measurement unit and relays it toward a discharge path that discharges the measured fluid, and a discharge case made of synthetic resin that is attached on top of the relay case and forms the discharge path, wherein the discharge case has a discharge port that discharges the measured fluid from inside the discharge case to the outside, and a first flange portion formed by protruding outward from the lower end of the discharge case, the first flange portion having a nut installation portion formed by recessing a portion of it, and a nut presser made of an elastic body that holds a nut installed on the nut installation portion, the relay case has a second flange portion formed by protruding outward from the upper end of the relay case, the second flange portion has a hole through which a bolt is inserted, and the relay case and the discharge case are fastened together by inserting the bolt into the hole from the back side of the second flange portion and screwing it into the nut.

[0008] According to the flow meter of the present application, the discharge case made of resin is not molded together with the nut by insert molding, so that it is possible to fasten the annealed resin with the bolt and nut without deforming the resin.

[0009] The nut installation section has a nut installation chamber having a bottom surface and a side wall, and a hole formed in front of the nut installation chamber that is rectangular in plan view. The bottom surface is formed with a hole through which the bolt is inserted, the top surface and the front surface of the nut installation chamber are open, and the shape of the side wall in plan view is approximately the same as the rear half of the shape of the nut in plan view. The nut holder has a plate-shaped nut holder section that holds the head of the nut installed in the nut installation chamber, a plate-shaped nut holder plate that extends downward from the front edge of the nut holder section, and a plate-shaped nut holder plate that extends downward from the front edge of the nut holder section in parallel with the nut holder plate. The nut installation chamber has a plate-shaped locking plate extending downward, and the front hole of the nut installation chamber has a step in a plan view, forming a narrow portion and a wide portion, a nut pressing plate is inserted into the narrow portion and a locking plate is inserted into the wide portion, and when a nut is installed in the nut installation chamber and the nut presser is fitted from above the nut installation section, the rotation of the nut installed in the nut installation chamber is restricted by the side wall and the nut pressing plate, and its upward movement is restricted by the nut pressing portion and the locking plate.

[0010] As a result, the rotation of the nut installed in the nut installation chamber is restricted by the side wall and the nut holding plate, and its upward movement is restricted by the nut holding portion and the locking plate. Therefore, during the process of tightening the bolt to the nut, the nut does not rotate, improving the efficiency of the tightening work, and after tightening, the bolt is less likely to loosen from the nut.

[0011] The present invention is characterized in that a locking portion is formed on the back surface of the nut holder portion, and is constructed by connecting a cylindrical portion and a dome-shaped portion in this order downward. During the process of fitting the nut holder into the nut installation portion, the locking portion is inserted into a hole formed in a portion of the first flange portion adjacent to the nut installation chamber, and the nut holder is locked to the first flange portion via the locking portion.

[0012] This makes it possible to further improve the locking force of the nut holder with respect to the nut installation portion.

[0013] In addition, the longitudinal length of the narrow portion of the hole in the nut installation chamber is approximately the same as the width of the nut holding plate, and when the bolt pushes up the nut during the process of fastening the relay case and the discharge case, the locking force of the locking plate against the nut holder causes the nut holding portion to rotate around the locking plate as an axis, and accordingly, the nut holding plate also rotates, with the lower end of the nut holding plate abutting against the wall of the narrow portion of the hole, restricting further rotation.

[0014] This prevents the nut holder from easily coming off the nut setting portion even if the bolt pushes the nut upward during the fastening process. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view showing an external appearance of a flow meter according to an embodiment of the present application. [Diagram 2] 1A is a diagram showing the fastening structure on the exhaust pipe side, and FIG. 1B is a diagram showing the manner in which the inner unit case is attached to the exhaust pipe. [Diagram 3] FIG. 2 is a perspective view showing a state before ((a)) and after ((b)) a nut is installed on the nut installation portion. [Figure 4] 1A and 1B are diagrams showing the state before (a) and after (b) the nut holder is attached to the nut setting part. [Diagram 5] 13 is a diagram showing the process of fastening the exhaust pipe and the inner unit case with a bolt. FIG. [Figure 6] 11 is a cross-sectional view showing a state in which the exhaust pipe and the inner unit case have been fastened together with bolts. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, the embodiments of the present application will be described in detail with reference to the drawings. In the drawings used in the following description, some basic configurations may be omitted, and the dimensional ratios of the depicted parts are not necessarily accurate. In each drawing, the front-rear direction D1, the up-down direction D2, and the left-right direction D3 are as shown in each drawing.

[0017] 1 shows the appearance of a flow meter 1 according to an embodiment of the present application. As shown in FIG. 1, the flow meter 1 includes an exhaust pipe 10 and two inner machine cases 20 and 30.

[0018] The exhaust pipe 10 has a generally rectangular parallelepiped shape, and has an exhaust port 11 formed in a generally central portion in the left-right direction D3 (longitudinal direction). A first flange portion 13 that protrudes outward is formed at a lower end portion 12 of the exhaust pipe 10. The lower surface (not shown) of the exhaust pipe 10 is open.

[0019] Since the indoor unit cases 20 and 30 have the same shape, the shape of the indoor unit case 20 will be described as a representative example. The indoor unit case 20 is also substantially rectangular like the exhaust pipe 10, but the length in the left-right direction D3 is substantially half the length of the exhaust pipe 10. A hole is formed in the rear side surface (not shown) of the indoor unit case 20 for connecting a flow rate measurement unit (not shown) that measures the flow rate of a fluid to be measured (e.g., fuel gas such as city gas or LP gas). A second flange portion 21 that protrudes outward is formed in the upper end portion (not shown) of the indoor unit case 20. The upper surface (not shown) of the indoor unit case 20 is open.

[0020] The exhaust pipe 10 and the inner unit cases 20, 30 are fastened with bolts and nuts as described below, and a flow rate measurement unit is connected to each of the inner unit cases 20, 30. Then, the exhaust pipe 10 and the inner unit cases 20, 30 connected to the flow rate measurement units are stored in an outer case (not shown) in a fastened state.

[0021] The fluid to be measured flows into the outer case from an inlet (not shown) provided in the outer case, passes through the flow rate measuring unit, flows into the inner machine cases 20 and 30, passes through the exhaust pipe 10, and flows out of the outer case from an outlet (not shown) provided in the outer case. During this process, the flow rate of the fluid to be measured is measured by the flow rate measuring unit.

[0022] 2(a) shows a fastening structure 100 on the exhaust pipe 10 side of the fastening structures for fastening the exhaust pipe 10 and the inner engine cases 20, 30. Note that the fastening structure 100 shown in FIG. 2(a) shows one formed on the front side of the first flange portion 13 (see FIG. 1). Components constituting the fastening structure 100 include a nut installation portion 110, two nuts 150, 150, and a nut holder 170.

[0023] The nut setting portion 110 is provided with nut setting chambers 111, 111 in which the nuts 150, 150 are set. Since the nut setting chambers 111, 111 have the same shape, the shape of one of the nut setting chambers 111 will be described as a representative.

[0024] The nut installation chamber 111 has a bottom surface 112 and a side wall 113. The bottom surface 112 is formed with a hole 112A through which the shaft 191 of the bolt 190 (see FIG. 2(b)) is inserted. The side wall 113 stands upward from an edge portion 112B of the bottom surface 112. The height of the side wall 113 is approximately the same as the height of the nut 150. The shape of the side wall 113 in plan view is the same as the shape of the nut 150 in plan view. However, since the front of the nut installation chamber 111 is open, that is, since the side wall 113 is not formed in front of the nut installation chamber 111, the shape of the side wall 113 in plan view matches the shape of the rear half of the shape of the nut 150 in plan view from the left-right direction D3. In this way, the nut installation chamber 111 is formed recessed from the upper surface of the first flange portion 13.

[0025] Between the nut installation chambers 111, a hole 120 having a circular shape in plan view is formed. In addition, in front of the nut installation chambers 111, 111, a hole 130 having a generally rectangular shape in plan view is formed. In the hole 130, a step is formed in the front-rear direction D1 in plan view, and a first portion 131 having a narrow width in the front-rear direction D1, a wide second portion 132, and a narrow third portion 133 are formed from left to right in the left-right direction D3.

[0026] The nut holder 170 is made of an elastic body and serves to hold the nuts 150, 150 in a state in which they are installed in the nut installation chambers 111, 111, respectively (see FIG. 3(b)). The nut holder 170 has a nut holder portion 171 that is rectangular in plan view. A hole 171A is formed in the nut holder portion 171 to insert the tip end of the shaft 191 of the bolt 190 when the tip end protrudes from the surface of the nuts 150, 150.

[0027] Two plate-shaped nut pressing plates 172A, 172B and one plate-shaped locking plate 173 are formed downward from the front edge portion 171B of the nut pressing portion 171. A locking claw 173A is provided at the lower end of the locking plate 173. A locking portion 174 is formed on the back surface 171C of the nut pressing portion 171. The locking portion 174 has a cylindrical portion 174A and a dome-shaped dome portion 174B. The cylindrical portion 174A and the dome portion 174B are connected, and at the connection portion, the diameter of the dome portion 174B is set to be longer than the diameter of the cylindrical portion 174A. A slit 174C is formed from the dome portion 174B in the up-down direction D2 to at least a part of the cylindrical portion 174A.

[0028] The first portion 131 and the third portion 133 of the hole 130 have the same width and are slightly wider than the thicknesses of the nut pressing plates 172A and 172B. The second portion 132 of the hole 130 has a width slightly wider than the thickness including the locking claws 173A of the locking plate 173. Furthermore, the lengths of the first portion 131 and the third portion 133 in the left-right direction D3 are substantially the same as the lengths of the nut pressing plates 172A and 172B in the left-right direction D3.

[0029] When fastening the inner engine cases 20, 30 to the exhaust pipe 10 using the fastening structure 100 configured as above, first, the nuts 150, 150 are placed in the nut installation chambers 111, 111 as shown by the arrow A1 in Fig. 3(a). Fig. 3(b) shows a state in which the nuts 150, 150 are placed in the nut installation chambers 111, 111.

[0030] Next, as shown by the arrow A2 in FIG. 4(a), the nut holder 170 is fitted into the nut installation part 110 from above. At this time, the locking plate 173 of the nut holder 170 is inserted into the second part 132 of the hole 130, and the locking claw 173A comes into contact with the front upper edge part 132A of the second part 132 of the hole 130, so that the locking plate 173 is deformed backward due to its elasticity. Then, when the locking claw 173A reaches the lower edge part 132B from the upper edge part 132A and passes through the lower edge part 132B, the locking plate 173 returns to its original state due to its elasticity, and the locking plate 173 is locked to the lower edge part 132B via the locking claw 173A. Similarly, the locking portion 174 of the nut holder 170 is inserted into the hole 120, but when the dome portion 174B of the locking portion 174 abuts against the upper edge portion 120A of the hole 120, the dome portion 174B shrinks toward the center due to its elasticity and the slits 174C. This causes the dome portion 174B to move downward through the hole 120. Then, when the dome portion 174B reaches the lower edge portion 120B from the upper edge portion 120A and passes through the lower edge portion 120B, it returns to its original state due to its elasticity, and the locking portion 174 is locked to the lower edge portion 120B via the dome portion 174B.

[0031] 2(b), the nuts 150, 150 are installed in the nut installation portion 110, and the inner unit cases 20, 30 are placed under the exhaust pipe 10 in a state in which the nut holder 170 is fitted into the nut installation portion 110, and the lower surface of the first flange portion 13 of the exhaust pipe 10 is aligned with the upper surfaces of the second flanges 21, 31 of the inner unit cases 20, 30. Then, bolts 190, 190 are inserted into holes (not shown) formed in the second flanges 21, 31 of the inner unit cases 20, 30 from the lower surface side of the second flanges 21, 31 and fastened.

[0032] FIG. 5 shows a state where the bolt 190 on the inner unit case 20 side has been tightened and the bolt 190 on the inner unit case 30 side is in the process of being tightened. As shown in FIG. 5, the bolt 190 on the inner unit case 30 side pushes the nut 150 upward during the tightening process. As a result, the vicinity of the right end 171D of the nut pressing portion 171 of the nut pressing portion 170 is also pushed upward. However, at this time, since the locking plate 173 is locked, the pressing plate 172B is deformed so as to rotate counterclockwise around the locking plate 173 as an axis. Therefore, the right lower end 172B1 of the pressing plate 172B also rotates counterclockwise around the locking plate 173 as an axis, so that the right lower end 172B1 abuts against the right wall 133A of the third portion 133 of the hole 130, and further rotation is restricted. Therefore, even if the bolt 190 pushes the nut 150 upward during the fastening process, the nut holder 170 can be prevented from easily coming off the nut setting portion 110.

[0033] FIG. 6 shows a state where the bolt 190 has been fastened to the nut 150. As shown in FIG. 6, of the two opposing side surfaces 151A and 151B of the side surface 151 of the nut 150, the rotation of the rear side surface 151A is restricted by the side wall 113 of the nut installation chamber 111, and the rotation of the front side surface 151B is restricted by the back surface 172A2 of the pressing plate 172A. Furthermore, the rotation of the side surfaces 151C and 151D adjacent to both sides of the rear side surface 151A is also restricted by the side wall 113. In this way, the rotation of the nut 150 is restricted by the side wall 113 and the back surface 172A2 of the pressing plate 172A. Therefore, in the process of fastening the bolt 190 to the nut 150, the nut 150 does not rotate, improving the efficiency of the fastening operation, and after fastening, the bolt 190 is less likely to loosen from the nut 150.

[0034] As described above, the flowmeter 1 of this embodiment includes a flow measurement unit that measures the flow rate of the measured fluid flowing therein, inner unit cases 20, 30 to which the flow measurement unit is attached from the outside, through which the measured fluid that has flowed inside the flow measurement unit flows and which relays the measured fluid toward a discharge path that discharges the measured fluid, and an exhaust pipe 10 made of synthetic resin that is attached to and overlaps the inner unit cases 20, 30 to form a discharge path, the exhaust pipe 10 including an exhaust port 11 that discharges the measured fluid from inside the exhaust pipe 10 to the outside, and a first flange portion 12 formed by protruding outward from a lower end portion 13 of the exhaust pipe 10. 13, the first flange portion 13 has a nut installation portion 110 formed by recessing a portion of it, and a nut holder made of an elastic body that holds the nut installed on the nut installation portion 110, and the inner engine case 20, 30 has a second flange portion 21, 31 formed by protruding outward from the upper end portion of the inner engine case 20, 30, the second flange portion 21, 31 has a hole through which a bolt is inserted, and the bolt 190 is inserted into the hole from the back side of the second flange portion 21, 31 and screwed into the nut 150 to fasten the inner engine case 20, 30 and the exhaust pipe 10.

[0035] In this way, in the flow meter 1 of this embodiment, the exhaust pipe 10 made of resin is not molded together with the nut 150 using insert molding, so that it is possible to fasten the exhaust pipe 10 with a bolt and nut without deforming the annealed resin.

[0036] The nut installation section 110 has a nut installation chamber 111 having a bottom surface 112 and a side wall 113, and a hole 130 that is rectangular in plan view and formed in front of the nut installation chamber 111. A hole through which a bolt 190 is inserted is formed in the bottom surface 112. The top surface and front surface of the nut installation chamber 111 are open. The shape of the side wall 113 in plan view is approximately the same as the rear half of the shape of the nut 150 in plan view. The nut holder 170 has a plate-shaped nut holder section 171 that holds the head of a nut installed in the nut installation chamber 111, plate-shaped nut holder plates 172A, 172B that extend downward from a front edge portion 171B of the nut holder section 171, and plate-shaped locking members 172A, 172B that extend downward from the front edge portion of the nut holder section 171 alongside the nut holder plates 172A, 172B. and a plate 173, and the hole 130 in front of the nut installation chamber 111 is provided with a step in a plan view, and narrow first and third portions 131 and 133 and wide second portion 132 are formed, and nut pressing plates 172A and 172B are inserted into the narrow first and third portions 131 and 133, and a locking plate 173 is inserted into the wide second portion 132. When the nut 150 is installed in the nut installation chamber 111 and the nut presser 170 is fitted from above the nut installation section 110, the rotation of the nut 150 installed in the nut installation chamber 111 is restricted by the side wall 113 and the nut pressing plates 172A and 172B, and the upward movement of the nut 150 installed in the nut installation chamber 111 is restricted by the nut pressing portion 171 and the locking plate 173.

[0037] As a result, the rotation of the nut 150 installed in the nut installation chamber 111 is restricted by the side wall 113 and the nut holding plates 172A, 172B, and its upward movement is restricted by the nut holding portion 171 and the locking plate 173. Therefore, during the process of fastening the bolt 190 to the nut 150, the nut 150 does not rotate, improving the efficiency of the fastening work, and after fastening, the bolt 190 is less likely to loosen from the nut 150.

[0038] In addition, a locking portion 174 is formed on the back surface 171C of the nut holding portion 171, and is configured by connecting a cylindrical cylinder portion 174A and a dome-shaped dome portion 174B downward in this order. During the process of fitting the nut holding portion 170 into the nut installation portion 110, the locking portion 174 is inserted into a hole 120 formed in a portion of the first flange portion 13 adjacent to the nut installation chamber 111, and the nut holding portion 170 is locked to the first flange portion 13 via the locking portion 174.

[0039] This makes it possible to further improve the locking force of the nut holder 170 with respect to the nut setting portion 110.

[0040] In addition, the longitudinal length of the narrow first portion 131 and the narrow third portion 133 of the hole 130 of the nut installation chamber 111 is approximately the same as the width of the nut holding plates 172A, 172B. When the bolt 190 pushes up the nut 150 during the process of fastening the inner engine cases 20, 30 and the exhaust pipe 10, the nut holding portion 171 rotates around the locking plate 173 as an axis due to the locking force of the locking plate 173 against the nut holder 170, and accordingly, the nut holding plates 172A, 172B also rotate, and the lower ends of the nut holding plates 172A, 172B abut against the walls of the narrow first portion 131 and the narrow third portion 133 of the hole 130, restricting further rotation.

[0041] This prevents the nut holder 170 from easily coming off the nut setting portion 110 even if the bolt 190 pushes the nut 150 upward during the fastening process.

[0042] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention.

[0043] (1) In the above embodiment, the fastening structure 100 is provided on the exhaust pipe 10, but it may be applied to other members made of synthetic resin. [Explanation of symbols]

[0044] 1...flow meter, 10...exhaust pipe (exhaust case), 11...exhaust port (exhaust port), 12...lower end portion, 13...first flange portion, 20, 30...inner unit case (relay case), 110...nut installation portion, 111...nut installation chamber, 112...bottom surface, 113...side wall, 120, 130...hole, 131...first portion, 132...second portion, 133...third portion, 150...nut, 170...nut holder, 171...nut holder portion, 171C...rear surface, 172A, 172B...nut holder plate, 173...locking plate, 174...locking portion, 174A...cylindrical portion, 174B...dome portion, 190...bolt.

Claims

1. a flow rate measuring unit that measures a flow rate of a fluid to be measured flowing therethrough; a relay case that is attached to the flow rate measurement unit from the outside, receives the fluid to be measured that has flowed through the inside of the flow rate measurement unit, and relays the fluid to a discharge path that discharges the fluid to be measured; a discharge case made of synthetic resin and attached to the relay case to form the discharge path; Equipped with The discharge case is an outlet for discharging the fluid to be measured from inside the discharge case to the outside; a first flange portion formed by protruding outward from a lower end portion of the discharge case; having The first flange portion is A nut installation portion formed by recessing a part of the plate; A nut holder made of an elastic body that holds the nut installed on the nut installation portion; having the relay case has a second flange portion formed to protrude outward from an upper end portion of the relay case, The second flange portion has a hole through which a bolt is inserted, The bolt is inserted into the hole from a rear side of the second flange portion and screwed into the nut to fasten the relay case and the discharge case.

1. A flow meter comprising:

2. The nut installation portion is a nut installation chamber having a bottom surface and a side wall; A hole having a rectangular shape in a plan view formed in front of the nut installation chamber; having A hole through which the bolt is inserted is formed in the bottom surface, The upper surface and the front surface of the nut installation chamber are open, The planar shape of the side wall is substantially the same as the rear half of the planar shape of the nut, The nut holder is A plate-shaped nut pressing portion that presses the head of the nut installed in the nut installation chamber; A plate-shaped nut pressing plate extending downward from a front edge portion of the nut pressing portion; A plate-shaped locking plate extending downward from a front edge portion of the nut holding portion in parallel with the nut holding plate; having The hole in front of the nut installation chamber is provided with a step in plan view, and a narrow portion and a wide portion are formed, The nut pressing plate is inserted into the narrow portion, The locking plate is inserted into the wide portion, When the nut holder is fitted from above the nut installation section with the nut installed in the nut installation chamber, the rotation of the nut installed in the nut installation chamber is restricted by the side wall and the nut holder plate, and the upward movement of the nut is restricted by the nut holder and the locking plate.

2. The flow meter of claim 1.

3. A locking portion is formed on the back surface of the nut pressing portion, the locking portion being configured by connecting a cylindrical portion and a dome portion downward in this order, In the process of fitting the nut holder to the nut installation portion, the locking portion is inserted into a hole formed in a portion of the first flange portion adjacent to the nut installation chamber, and the nut holder is locked to the first flange portion via the locking portion.

3. The flow meter of claim 2.

4. The length of the narrow portion of the hole of the nut installation chamber in the longitudinal direction is approximately the same as the width of the nut pressing plate, When the bolt pushes up the nut during the process of fastening the relay case and the discharge case, the locking force of the locking plate against the nut holder causes the nut holder to rotate about the locking plate as an axis, and the nut holder plate also rotates accordingly, with the lower end of the nut holder plate abutting against the wall of the narrow portion of the hole, restricting further rotation.

3. The flow meter of claim 2.

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