JP2006337258A - Ultrasonic flowmeter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure a fixed distance between ultrasonic sensors, and to prevent a damage thereof. <P>SOLUTION: In this ultrasonic flowmeter 10 having a passage pipe 11 wherein fluid flows, the ultrasonic sensors 12A, 12B arranged at a distance L in the axial direction of the passage pipe, and a case 13 for covering the ultrasonic sensors or the like, the flow rate of the fluid flowing in the passage pipe is measured from the difference of a propagation time of an ultrasonic wave through the fluid between the ultrasonic sensors. The case is equipped with a cylindrical part 17, and ends 18A, 18B blocking both sides of the cylindrical part, and penetrated by the passage pipe. A fixing mechanism 20 for fixing the passage pipe to the ends is provided inside the case. In the fixing mechanism, a ring-shaped deformable member 21 into which the passage pipe is inserted is pressed in the axial direction by a bolt 23 and deformed in the radial direction, and the deformed deformable member presses the circumference of the passage pipe and the ends of the case, to thereby fix the passage pipe to the ends. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ultrasonic flowmeter that measures the flow rate of a fluid flowing in a flow path using ultrasonic waves.

  As shown in FIG. 7, the ultrasonic flowmeter 100 has a plurality of ultrasonic sensors 102 and 103 attached to a flow path pipe 101 through which a fluid flows, from one ultrasonic sensor 102 to the other ultrasonic sensor 103, and The flow rate of the fluid flowing in the flow pipe 101 is measured based on the difference in the propagation time of the ultrasonic waves when propagating the ultrasonic waves from the other ultrasonic sensor 103 to the one ultrasonic sensor 102 through the fluid. To do.

  In such an ultrasonic flowmeter 100, the plurality of ultrasonic sensors 102 and 103 and the ultrasonic sensor 102 and 103 attachment portions in the flow channel pipe 101 are covered with the case 104 and shielded from the outside. At this time, the flow path pipe 101 is passed through the through holes 108 of the end portions 106 and 107 that respectively close both sides of the cylindrical portion 105 of the case 104, and between the inner wall surface of the through hole 108 and the flow path pipe 101. It is fixed (fixed) to the end portions 106 and 107 by an intervening adhesive.

  In particular, in the ultrasonic flowmeter described in Patent Document 1, a groove is formed in the inner wall surface of the through hole 108 of the end portions 106 and 107 in the case 104, and the flow pipe 101 made of synthetic resin bites into the groove. Thus, the flow path pipe 101 is fixed to the end portions 106 and 107.

Japanese Patent Laying-Open No. 2005-10077

  However, in both of these background arts, when an excessive force is applied to the flow path pipe 101, the flow path pipe 101 moves away from the end portions 106 and 107 of the case 104, and the ultrasonic sensor 102 is moved. , 103 may come into contact with these end portions 106 and 107 and come off from the flow channel pipe 101. For this reason, the distance between the ultrasonic sensors 102 and 103 may change, or the ultrasonic sensors 102 and 103 may be damaged.

  In particular, when the flow path pipe 101 is fixed to the end portions 106 and 107 of the case 104 by using an adhesive, the adhesive changes over time due to gas, liquid, ultraviolet rays, etc. outside the case 104, The above situation is likely to occur.

  Further, when the synthetic resin channel pipe 101 is bitten into the grooves on the inner wall surfaces of the end portions 106 and 107 of the case 104, the coupling between the end portions 106 and 107 and the channel pipe 101 due to this biting is not necessarily strong. That's not true. For this reason, also in this case, a situation occurs in which the flow path pipe 101 is easily detached from the end portions 106 and 107 due to an excessive force acting on the flow path pipe 101.

  In the ultrasonic flow meter 100, cables 109 and 110 connected to the ultrasonic sensors 102 and 103 respectively extend from the end portions 106 and 107 of the case 104 to the outside of the case 104. For this reason, handling of the cables 109 and 110 becomes complicated. Furthermore, an excessive force acts on the cables 109 and 110 to move the ultrasonic sensors 102 and 103 with respect to the flow path pipe 101, and the distance between the ultrasonic sensors 102 and 103 is changed. There is a possibility that the 102 and 103 come into contact with the end portions 106 and 107 and are damaged.

  An object of the present invention is made in consideration of the above-described circumstances, and can securely secure a distance between a plurality of ultrasonic sensors attached to the flow path by securely fixing and holding the flow path to the case. Another object is to provide an ultrasonic flowmeter that can prevent damage to the ultrasonic sensor.

  The invention according to claim 1 is a flow path through which a fluid flows, a plurality of ultrasonic sensors arranged at a predetermined distance in the axial direction of the flow path, and the ultrasonic sensors and the flow paths described above. An ultrasonic flowmeter for measuring the flow rate of the fluid flowing in the flow path from the difference in propagation time of the ultrasonic wave through the fluid between the ultrasonic sensors. The case includes a cylindrical part and an end part that closes both sides of the cylindrical part and penetrates the flow path, and fixes the flow path to the end part of the case. However, the fixing mechanism is deformed in the radial direction when the ring-shaped deformable member inserted through the flow path is pressed in the axial direction by the pressing member. The deformable deformable member is the end of the flow path and the case. By pressing, it is characterized in that the flow channel is configured to secure to the end portion of the case.

  According to a second aspect of the present invention, there is provided a flow path through which a fluid flows, a plurality of ultrasonic sensors arranged at a predetermined distance in the axial direction of the flow path, and the ultrasonic sensors and the flow paths described above. An ultrasonic flowmeter for measuring the flow rate of the fluid flowing in the flow path from the difference in propagation time of the ultrasonic wave through the fluid between the ultrasonic sensors. The case includes a cylindrical part and an end part that closes both sides of the cylindrical part and penetrates the flow path, and fixes the flow path to the end part of the case. However, the fixing mechanism is provided inside or inside the case, and the fixing mechanism is disposed at the end of the case and moves in the radial direction of the flow path. It was configured to fix this flow path to the end of the case It is an feature.

  According to a third aspect of the present invention, there is provided a flow path through which a fluid flows, a plurality of ultrasonic sensors arranged at a predetermined distance in the axial direction of the flow path, and the ultrasonic sensors and the flow paths described above. An ultrasonic flowmeter for measuring the flow rate of the fluid flowing in the flow path from the difference in propagation time of the ultrasonic wave through the fluid between the ultrasonic sensors. The case includes a cylindrical part and an end part that closes both sides of the cylindrical part and penetrates the flow path, and fixes the flow path to the end part of the case. Is provided inside or inside the case, and the fixing mechanism is configured such that one or a plurality of protrusions provided on the outer periphery of the flow path are fitted into a recess formed at the end of the case. To fix the flow path to the end of the case. It is characterized in that it has been.

  According to a fourth aspect of the present invention, there is provided a flow path through which a fluid flows, a plurality of ultrasonic sensors arranged at a predetermined distance in the axial direction of the flow path, and the ultrasonic sensors and the flow paths described above. An ultrasonic flowmeter for measuring the flow rate of the fluid flowing in the flow path from the difference in propagation time of the ultrasonic wave through the fluid between the ultrasonic sensors. The case includes a cylindrical part and an end part that closes both sides of the cylindrical part and penetrates the flow path, and fixes the flow path to the end part of the case. Is provided inside or inside the case, and the fixing mechanism is formed by screwing a screw part formed on the outer periphery of the flow path and a screw part formed on the end of the case, The flow path is configured to be fixed to the end of the case. The one in which the features.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the fixing mechanism for fixing the flow path to the end of the case is provided at one or both of the two ends. It is characterized by this.

  According to a sixth aspect of the present invention, in the third aspect of the present invention, the flow path is provided with a sub-projection that can contact the inner surface of the end of the case at a position away from the ultrasonic sensor by a certain distance. It is characterized by that.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the cables connected to each of the plurality of ultrasonic sensors attached to the flow path are combined into one. It is fixed to the end of the case and is configured to be guided out of the case.

  According to the first and fifth aspects of the present invention, the fixing mechanism that fixes the flow path to the end of the case is configured such that the ring-shaped deformable member inserted through the flow path is pressed by the pressing member in the axial direction. The deformable deformable member is deformed in the radial direction, and the deformed deformable member presses the flow path and the end of the case, thereby fixing the flow path to the end of the case. Thus, even when an excessive force is applied to the flow path, the flow path can be prevented from moving with respect to the end portion of the case. For this reason, it can prevent that the ultrasonic sensor attached to the flow path contacts the edge part of a case, and the distance between ultrasonic sensors changes, and can prevent damage to this ultrasonic sensor.

  In addition, since the fixing mechanism that fixes the flow path to the end of the case is provided inside or inside the case, it is possible to suppress the secular change of the fixing mechanism due to gas, liquid, ultraviolet rays, etc. outside the case, and this fixing It is possible to prevent an unexpected external force from acting on the mechanism, and as a result, it is possible to satisfactorily secure the flow path by the fixing mechanism for a long period of time.

  According to the second and fifth aspects of the present invention, the fixing mechanism is configured such that a stop member that is disposed at the end of the case and moves in the radial direction of the flow path presses the flow path. Is fixed to the end of the case, it is possible to prevent the flow path from moving relative to the end of the case even if an excessive force is applied to the flow path. For this reason, it can prevent that the ultrasonic sensor attached to the flow path contacts the edge part of a case, and the distance between ultrasonic sensors changes, and can prevent damage to this ultrasonic sensor.

  In addition, since the fixing mechanism that fixes the flow path to the end of the case is provided inside or inside the case, it is possible to suppress the secular change of the fixing mechanism due to gas, liquid, ultraviolet rays, etc. outside the case, and this fixing It is possible to prevent an unexpected external force from acting on the mechanism, and as a result, it is possible to satisfactorily secure the flow path by the fixing mechanism for a long period of time.

  According to the third and fifth aspects of the present invention, the fixing mechanism is configured such that one or a plurality of protrusions provided on the outer periphery of the flow path are fitted into the recess formed at the end of the case. Since the channel is fixed to the end portion of the case, the fixing mechanism can prevent the channel from moving with respect to the end portion of the case even when an excessive force is applied to the channel. For this reason, it can prevent that the ultrasonic sensor attached to the flow path contacts the edge part of a case, and the distance between ultrasonic sensors changes, and can prevent damage to this ultrasonic sensor.

  In addition, since the fixing mechanism that fixes the flow path to the end of the case is provided inside or inside the case, it is possible to suppress the secular change of the fixing mechanism due to gas, liquid, ultraviolet rays, etc. outside the case, and this fixing It is possible to prevent an unexpected external force from acting on the mechanism, and as a result, it is possible to satisfactorily secure the flow path by the fixing mechanism for a long period of time.

  According to the fourth and fifth aspects of the present invention, the fixing mechanism is configured such that the screw portion formed on the outer periphery of the flow channel and the screw portion formed on the end portion of the case are screwed together, thereby Since the case is fixed to the end of the case, the fixing mechanism can prevent the channel from moving relative to the end of the case even when an excessive force is applied to the channel. For this reason, it can prevent that the ultrasonic sensor attached to the flow path contacts the edge part of a case, and the distance between ultrasonic sensors changes, and can prevent damage to this ultrasonic sensor.

  In addition, since the fixing mechanism that fixes the flow path to the end of the case is provided inside or inside the case, it is possible to suppress the secular change of the fixing mechanism due to gas, liquid, ultraviolet rays, etc. outside the case, and this fixing It is possible to prevent an unexpected external force from acting on the mechanism, and as a result, it is possible to satisfactorily secure the flow path by the fixing mechanism for a long period of time.

  According to the sixth aspect of the present invention, the channel is provided with the sub projection that can contact the inner surface of the end of the case at a position away from the ultrasonic sensor by a certain distance. Therefore, when the ultrasonic sensor attached to the flow path is assembled in the case, the ultrasonic sensor is attached to the end of the case during the assembling operation by contacting the sub projection with the inner surface of the end of the case. It is possible to reliably prevent contact with the part.

  According to the seventh aspect of the present invention, since the cables connected to each of the plurality of ultrasonic sensors are bundled together and fixed to the end of the case, the ultrasonic waves are applied by the external force acting on the cables. It is possible to prevent the sensor from moving with respect to the flow path. For this reason, while being able to ensure the distance between ultrasonic sensors uniformly, the damage by the ultrasonic sensor colliding with the edge part of a case can be prevented.

  In addition, since the cables connected to the plurality of ultrasonic sensors are gathered together and guided to the outside of the case, handling of these cables can be facilitated.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

[A] First embodiment (FIGS. 1 to 3)
1A and 1B show a first embodiment of an ultrasonic flowmeter according to the present invention, in which FIG. 1A is a front view and FIG. 1B is a perspective view. FIG. 2 is a cross-sectional view showing the ultrasonic flowmeter of FIG.

  The ultrasonic flowmeter 10 shown in FIGS. 1 and 2 measures the flow rate of a fluid flowing in a flow path of a semiconductor manufacturing apparatus or various apparatuses in a plant. The acoustic wave sensors 12A and 12B and the case 13 are included.

  The flow path pipe 11 is made of synthetic resin, and a fluid flows inside. Specifically, the material of the flow path pipe 11 is PTFE resin, alternative Teflon (registered trademark) resin (Dellin), tetrafluoroethylene resin, trifluorochloroethylene resin, tetrafluoroethylene / hexafluoropropylene Resin, vinyl fluoride resin, tetrafluoroethylene / ethylene copolymer resin, perfluoroalkoxy polymer resin, PEEK resin, PES resin, ABS resin, cellulose acetate, butyrate, epoxy resin, polyester resin, urea resin, melamine resin, Diallyl phthalate resin, polyethylene, polypropylene, polystyrene, acrylic resin, polyacetal, polycarbonate, polyimide, polyamide, polyphenylene oxide, modified phenylene oxide, polyphenylene sulfide, polysulfone, methylpentene polymer, PE Resin, a liquid crystal polymer, silicone, rigid Enviro, soft Enviro, quartz, SUS303, SUS304, SUS304L, SUS316, SUS316L, SUS317,64 titanium, acrylic resins, epoxy resins, silicone.

  The ultrasonic sensors 12A and 12B are attached at a predetermined distance L in the axial direction of the flow path pipe 11, and are fixed to the outer periphery of the flow path pipe 11 using, for example, an adhesive. Each ultrasonic sensor 12 </ b> A, 12 </ b> B includes a disk-shaped vibrator 14 and an electrode 15. The vibrator 14 is made of a piezoelectric element such as PZT (lead zirconate titanate) ceramics. The electrode 15 applies a voltage to the vibrator 14 or picks up a voltage generated in the vibrator 14.

  Cables (lead wires) 16A and 16B are connected to the respective electrodes 15 of the pair of ultrasonic sensors 12A and 12B. A voltage is applied from the outside to the electrodes 15 of the ultrasonic sensors 12A and 12B through these cables 16A and 16B, and the voltages generated at the electrodes 15 of the ultrasonic sensors 12A and 12B are detected. The ultrasonic sensors 12A and 12B are generally driven by an ultrasonic voltage of 30 KHz to 1 MHz.

  The case 13 includes a cylindrical portion 17 and end portions 18A and 18B that are fitted on both sides of the cylindrical portion 17 and close the cylindrical portion 17. The case 13 covers the pair of ultrasonic sensors 12A and 12B attached to the flow path pipe 11 together with the flow path pipe 11 where the ultrasonic sensors 12A and 12B are arranged. A passage pipe 11 extends outward through the ends 18A and 18B.

  The ultrasonic flowmeter 10 configured as described above transmits an ultrasonic wave from one ultrasonic sensor 12A in a state where a fluid flows in the flow path pipe 11, and the other ultrasonic wave is transmitted through the fluid. The ultrasonic wave is received by the sensor 12B, the ultrasonic wave is transmitted from the other ultrasonic sensor 12B, and the ultrasonic wave is received by one ultrasonic sensor 12A via the fluid. In each of these cases, the propagation time when the ultrasonic wave propagates between the pair of ultrasonic sensors 12A and 12B is obtained. The flow rate of the fluid flowing in the flow path pipe 11 is measured from the difference in propagation time, and the flow rate of the fluid is measured.

  Therefore, when measuring the flow rate, the distance L between the pair of ultrasonic sensors 12A and 12B needs to be kept constant. That is, when an external force is applied to the flow path pipe 11, the flow path pipe 11 moves relative to the end portions 18 </ b> A and 18 </ b> B of the case 13, so that the ultrasonic sensors 12 </ b> A and 12 </ b> B attached to the flow path pipe 11 It is necessary to avoid a situation in which the distance L between the ultrasonic sensors 12A and 12B varies due to contact with the end portions 18A and 18B. Further, the ultrasonic sensors 12A and 12B may be damaged by contacting the end portions 18A and 18B. In order to avoid these situations, the ultrasonic flowmeter 10 is provided with a fixing mechanism 20 that fixes the flow path pipe 11 to the end portions 18A and 18B of the case 13.

  The fixing mechanism 20 includes a deformable member 21, a washer 22, and a bolt 23 as a pressing member, and is arranged at one end 18A of the case 13, or both ends 18A and 18B. In the present embodiment, fixing mechanism 20 is arranged only at one end 18A. The fixing mechanism 20 is disposed in the case space 25 surrounded by the cylindrical portion 17 and the end portions 18A and 18B in the case 13, and inside the end portion 18A, as described below. An accommodation recess 24 for accommodating the fixing mechanism 20 is formed in the end 18 </ b> A where the fixing mechanism 20 is disposed around the passage pipe 11.

  The deformable member 21 is formed in a ring shape as shown in FIG. The deformable member 21 is housed in the housing recess 24 of the end portion 18 </ b> A of the case 13 with the washer 22 and the flow path pipe 11 inserted therethrough. The deformable member 21 is made of rubber or resin. The variable member 21 is not limited to the ring shape, and is deformed in the radial direction by being pressed in the axial direction by the pressing member, such as an annular member partially cut away. Any member can be used as long as it can fix the flow pipe 11 to the end 18A by pressing the flow pipe 11 and the end 18A of the case 13 by this deformation.

  That is, the material of the deformable member 21 is specifically nitrile rubber, hydrogenated nitrile rubber, fluorine rubber, tetrafluoroethylene rubber, silicone rubber, chloroprene rubber, butyl rubber, urethane rubber, polyethylene rubber, ethylene propylene rubber. , Shrimp chlorohydrin rubber, acrylic rubber, chlorosulfonated polyethylene rubber, natural rubber, styrene butadiene rubber, tetrafluoroethylene resin, trifluorochloroethylene resin, tetrafluoroethylene / hexafluoropropylene resin, fluorinated vinyl resin , Tetrafluoroethylene / ethylene copolymer resin, perfluoroalkoxy polymer resin, PEEK resin, PES resin, ABS resin, cellulose acetate, butyrate, epoxy resin, polyester resin, urea resin, melamine resin, diallyl phthalate resin, polyethylene , Polypropylene, polystyrene, acrylic resin, polyacetal, polycarbonate, polyimide, polyamide, polyphenylene oxide, modified phenylene oxide, polyphenylene sulfide, polysulfone, methylpentene polymer, PET resin, liquid crystal polymer, silicone, hard resin, soft resin, etc. Resin.

  The bolt 23 has a cylindrical shape, and the flow pipe 11 is inserted on the inner side, and a male screw part 27 is formed on the outer side. The male screw portion 27 is screwed into a female screw portion 26 formed in the housing recess 24 of the end portion 18 </ b> A of the case 13. As shown in FIG. 2, the bolt 23 has its male threaded portion 27 screwed into the female threaded portion 26 of the end portion 18A, thereby pressing the deformable member 21 in the axial direction via the washer 22. The deformation member 21 is deformed in the radial direction. That is, the deformable member 21 is deformed in the direction in which the inner diameter is reduced, and is deformed in the direction in which the outer diameter is increased. Thereby, the deformable deformable member 21 presses the outer peripheral surface of the flow channel pipe 11 with the reduced inner diameter, and presses the wall surface of the accommodating recess 24 of the end 18A with the increased outer diameter. For this reason, the flow path pipe 11 is firmly fixed to the end portion 18A through the deformable deformable member 21.

  Cables 16A and 16B extending from the pair of ultrasonic sensors 12A and 12B are combined into one cable 19. The cable 19 is fixed to the end portion 18 </ b> A of the case 13 by, for example, press-fitting and guided to the outside of the case 13. When the cable 19 is press-fitted and fixed, even if an external force is applied to the cable 19, the external force is not transmitted to the cables 16A and 16B. Therefore, the ultrasonic sensors 12A and 12B are applied to the flow path pipe 11 by the external force. It is prevented from moving. The cables 16A and 16B are combined into one cable 19 to be fixed to the case 13 at one location.

  With the configuration as described above, the following effects (1) to (4) are achieved according to the above embodiment.

  (1) The fixing mechanism 20 that fixes the flow channel pipe 11 to the end portion 18A of the case 13 is configured such that the ring-shaped deformable member 21 inserted through the flow channel pipe 11 is pressed in the axial direction by the bolt 23 in the radial direction. The deformable deformable member 21 presses the outer peripheral surface of the flow channel pipe 11 and the wall surface of the accommodating recess 24 of the end portion 18 </ b> A, thereby fixing the flow channel pipe 11 to the end portion 18 </ b> A of the case 13. Therefore, even when an excessive force is applied to the flow path pipe 11, the flow path pipe 11 can be prevented from moving with respect to the end portion 18 </ b> A of the case 13. Therefore, it is possible to prevent the ultrasonic sensors 12A and 12B attached to the flow path pipe 11 from coming into contact with the end portions 18A and 18B of the case 13 to change the distance L between the ultrasonic sensors 12A and 12B. It is possible to prevent the ultrasonic sensors 12A and 12B from being damaged.

  (2) The fixing mechanism 20 (the deformable member 21, the washer 22, the bolt 23) for fixing the flow path pipe 11 to the end portion 18A of the case 13 is surrounded by the cylindrical portion 17 and the end portions 18A and 18B in the case 13. It is arrange | positioned in the case space 25 and the inside of 18 A of edge parts. For this reason, the secular change of the fixing mechanism 20 (particularly the deformable member 21) due to gas, liquid, ultraviolet rays, or the like outside the case 13 can be suppressed, and an unexpected external force can be prevented from acting on the bolt 23 of the fixing mechanism 20. it can. As a result, the fixing and holding of the flow path pipe 11 by the fixing mechanism 20 can be secured satisfactorily for a long time.

  (3) Cables 16 </ b> A and 16 </ b> B connected to the pair of ultrasonic sensors 12 </ b> A and 12 </ b> B are combined into one cable 19 and fixed to the end 18 </ b> A of the case 13. From this, it is possible to prevent the ultrasonic sensors 12 </ b> A and 12 </ b> B from moving with respect to the flow path pipe 11 due to an external force acting on the cable 19. For this reason, the distance L between the ultrasonic sensors 12A and 12B can be kept constant, and damage due to the ultrasonic sensors 12A and 12B colliding with the end portion 18A of the case 13 can be prevented.

  (4) Since the cables 16A and 16B connected to the pair of ultrasonic sensors 12A and 12B are combined into one cable 19 and guided to the outside of the case 13, the cables 16A and 16B Handling (handling) can be facilitated.

“B” Second Embodiment (FIG. 4)
4A and 4B show a second embodiment of the ultrasonic flowmeter according to the present invention, in which FIG. 4A is a cross-sectional view corresponding to FIG. 2, and FIG. 4B is taken along line IV-IV in FIG. It is sectional drawing. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  This embodiment differs from the first embodiment in the structure of the fixing mechanism 30 that fixes the flow path pipe 11 to the end portion 18A of the case 13. The fixing mechanism 30 is also installed at one or both of the end portions 18A and 18B of the case 13. In this embodiment, the fixing mechanism 30 is installed only in the end portion 18A, and is further disposed in the case space 33 surrounded by the inside of the end portion 18A and the cylindrical portion 17, and the end portions 18A and 18B.

  This fixing mechanism 30 has a set screw 31 as one or a plurality of set members, and this set screw 31 is disposed in a bulging portion 32 that bulges into the case 13 at the end 18A of the case 13. Is done. Further, the flow path pipe 11 penetrates the bulging portion 32 of the end portion 18A. The set screw 31 is screwed in the bulging portion 32 of the end portion 18A so as to be movable in the radial direction of the flow channel pipe 11, and the tip of the set screw 31 presses the outer peripheral surface of the flow channel pipe 11, thereby The flow path pipe 11 is fixed to the bulging portion 32 of the end portion 18A.

  Specifically, the set screw 31 is a cross-recessed pan head screw, a hexagon socket head cap screw, a hexagon socket stop screw, a slotted set screw, a square set screw, a cross head countersunk screw, a slotted countersunk screw, Hexagon bolts, bind small screws, flat small screws, round flat small screws, truss small screws, round countersunk screws, etc., the tip shapes are chamfered, flat, round, half-bar, tip, all A point, a point, a hollow point, and a cutting edge.

  The set screw 31 is made of PTFE resin, alternative Teflon (registered trademark) resin (Derlin), tetrafluoroethylene resin, trifluorochloroethylene resin, tetrafluoroethylene / hexafluoropropylene resin, fluoridation Vinyl resin, tetrafluoroethylene / ethylene copolymer resin, perfluoroalkoxy polymer resin, PEEK resin, PES resin, ABS resin, cellulose acetate, butyrate, epoxy resin, polyester resin, urea resin, melamine resin, diallyl phthalate resin, Polyethylene, polypropylene, polystyrene, acrylic resin, polyacetal, polycarbonate, polyimide, polyamide, polyphenylene oxide, modified phenylene oxide, polyphenylene sulfide, polysulfone, methylpentene polymer, PET resin, Crystalline polymer, silicon, hard resin, soft resin, quartz, high purity quartz (purity 99.999wt%) SUS303, SUS304, SUS304L, SUS316, SUS316L, SUS317, 64 titanium, acrylic resin, epoxy resin, silicon, BsBM, aluminum, phosphorus Bronze, gray cast iron, SS, SC, etc.

  Therefore, the second embodiment also provides the following effects (5) and (6) in addition to the same effects as the effects (3) and (4) of the first embodiment.

  (5) The fixing mechanism 30 is configured such that a plurality of set screws 31 that are disposed at the end portion 18 </ b> A of the case 13 and move in the radial direction of the flow path pipe 11 press the outer peripheral surface of the flow path pipe 11. The passage pipe 11 can be prevented from moving with respect to the end portion 18A of the case 13. Therefore, the ultrasonic sensors 12A and 12B attached to the flow path pipe 11 can prevent the distance L between the ultrasonic sensors 12A and 12B from changing due to contact with the end portion 18A or 18B of the case 13, and Damage to these ultrasonic sensors 12A and 12B can be prevented.

  (6) A fixing mechanism 30 for fixing the flow path pipe 11 to the end portion 18A of the case 13 is provided in the case space 33 surrounded by the cylindrical portion 17 and the end portions 18A and 18B in the case 13. From this, it is possible to suppress the secular change of the fixing mechanism 30 (particularly the set screw 31) due to gas, liquid, ultraviolet rays, etc. outside the case 13, and to generate an unexpected external force on the set screw 31 of the fixing mechanism 30. As a result, the fixed holding of the flow path pipe 11 by the fixing mechanism 30 can be ensured for a long period of time.

[C] Third embodiment (FIG. 5)
FIG. 5 shows a third embodiment of the ultrasonic flowmeter according to the present invention, in which (A) is a cross-sectional view corresponding to FIG. 2, and (B) is along the line VV in FIG. 5 (A). It is sectional drawing. In the third embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

  This embodiment is different from the first embodiment in the structure of the fixing mechanism 40 that fixes the flow path pipe 11 to the end portion 18A of the case 13. The fixing mechanism 40 is also installed at one or both of the end portions 18A and 18B of the case 13. In the present embodiment, the fixing mechanism 40 is installed only at the end portion 18A, and is further disposed in the case space 45 surrounded by the inside of the end portion 18A and the cylindrical portion 17, and the end portions 18A and 18B.

  The fixing mechanism 40 includes a main projection 41 and a sub projection 42 formed on the flow path pipe 11, and a fitting recess 43 and an introduction recess 44 formed on the end 18 </ b> A of the case 13. The One or more main protrusions 41 protrude in the radial direction of the flow channel pipe 11 and are provided on the outer periphery of the flow channel pipe 11. The main projection 41 is integrally formed on the flow path pipe 11 or attached by an adhesive or a screw.

  A through hole 46 through which the flow pipe 11 passes is formed in the end 18A, and the fitting recess 43 and the introduction recess 44 are formed in communication with the through hole 46. Among these, the introduction concave portion 44 is formed inside the end portion 18A along the longitudinal direction of the through hole 46 from the inner wall surface 47 of the end portion 18A. The fitting recess 43 communicates with the innermost portion of the introduction recess 44 and is formed inside the end portion 18 </ b> A. The fitting recess 43 rotates from the innermost portion of the introduction recess 44 around the center of the through hole 46 by an angle θ. It is formed. The dimension in the axial direction of the flow path pipe 11 in the fitting recess 43 is set to be substantially the same as the dimension in the axial direction of the flow path pipe 11 in the main projection 41.

  Therefore, the main projection 41 is introduced into the introduction recess 44 when the flow path pipe 11 is inserted through the through hole 46 of the end 18 </ b> A and reaches the innermost portion of the introduction recess 44. 11 is fitted into the fitting recess 43 by being rotated by the angle θ. Thereby, the flow path pipe 11 is fixed to the end portion 18A of the case 13, and the movement in the axial direction is restricted.

  The sub-projection portion 42 is provided on the flow pipe 11 so as to contact the inner wall surface 47 of the end portion 18A when the main projection portion 41 is fitted in the fitting recess 43 of the end portion 18A. The sub protrusion 42 is further installed at a position separated by a predetermined distance S from the ultrasonic sensor 12A attached to the flow path pipe 11. Similarly to the main projection 41, the sub projection 42 is integrally formed with the channel pipe 11 or attached to the channel pipe 11 with an adhesive or a screw.

  Since it was configured as described above, according to the above embodiment, in addition to the same effects as the effects (3) and (4) of the first embodiment, the following effects (7) to ( Play 9).

  (7) The fixing mechanism 40 is configured such that one or a plurality of main projections 41 provided on the outer periphery of the flow path pipe 11 are fitted into the fitting recesses 43 formed in the end portion 18A of the case 13. The flow path pipe 11 is fixed to the end 18 </ b> A of the case 13. For this reason, even when an excessive force is applied to the flow pipe 11, the flow pipe 11 is prevented from moving in the axial direction of the flow pipe 11 with respect to the end portion 18 </ b> A of the case 13 by the fixing mechanism 40. it can. This movement prevention in the axial direction of the flow path pipe 11 is further ensured by the sub projection 42 coming into contact with the inner wall surface 47 of the end 18A. As a result, it is possible to prevent the ultrasonic sensors 12A and 12B attached to the flow channel pipe 11 from coming into contact with the end portion 18A of the case 13 and change the distance L between the ultrasonic sensors 12A and 12B. Damage to the sonic sensors 12A and 12B can be prevented.

  (8) A fixing mechanism 40 for fixing the flow path pipe 11 to the end portion 18A of the case 13 is provided in the case space 45 surrounded by the cylindrical portion 17, the end portions 18A and 18B of the case 13, and inside the end portion 18A. Is provided. From this, it is possible to suppress the secular change of the fixing mechanism 40 (particularly the main protrusion 41 and the sub protrusion 42) due to gas, liquid, ultraviolet rays, etc. outside the case 13, and the fixing mechanism 40 (particularly the main protrusion 41 and the sub protrusion 42). Unexpected external force can be prevented from acting on the protrusions 42), and as a result, the fixing and holding of the flow path pipe 11 by the fixing mechanism 40 can be secured satisfactorily for a long time.

  (9) The main protrusion 41 is fitted into the fitting recess 43 of the end 18A, and the ultrasonic sensors 12A and 12B are separated from the ultrasonic sensor 12A by a predetermined distance S during the assembling work. The sub-projection portion 42 provided at this position contacts the inner wall surface 47 of the end portion 18A. Accordingly, it is possible to prevent the ultrasonic sensor 12A from coming into contact with the end portion 18A during the assembling work and the distance L between the ultrasonic sensors 12A and 12B to change or the ultrasonic sensors 12A and 12B to be damaged.

[D] Fourth embodiment (FIG. 6)
6A and 6B show a fourth embodiment of the ultrasonic flowmeter according to the present invention, in which FIG. 6A is a cross-sectional view corresponding to FIG. 2, and FIG. 6B is an enlarged view of a VI part in FIG. . In the fourth embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The fourth embodiment differs from the first embodiment in the structure of a fixing mechanism 50 that fixes the flow path pipe 11 to the end portions 18A and 18B of the case 13. This fixing mechanism 50 is also installed at one of the end portions 18A or 18B of the case 13 or at both the end portions 18A and 18B. In the present embodiment, the fixing mechanism 50 is provided at the end portions 18A and 18B, and is further disposed inside the end portions 18A and 18B.

  The fixing mechanism 50 includes a male screw portion 51 formed on the outer periphery of the flow channel pipe 11 and a female screw portion 52 provided on the inner peripheral surface of the through hole 55 through which the flow channel pipe 11 penetrates at the end portions 18A and 18B. It is configured.

  The flow path pipe 11 is formed such that the outer peripheral diameter of the part to which the ultrasonic sensors 12A and 12B are attached is larger than the outer peripheral diameter of the other part, and the male screw part 51 is formed at the boundary part where the outer peripheral diameters are different. . Accordingly, a stepped portion 53 is formed between the portion where the ultrasonic sensors 12 </ b> A and 12 </ b> B are attached and the male screw portion 51 in the flow path pipe 11.

  The threaded pipe 51 is fixed to the end portions 18A and 18B by screwing the male threaded portion 51 of the flow channel pipe 11 into the female threaded portions 52 of the end portions 18A and 18B of the case 13, but at this time, the end portion 18A is fixed. The inner wall surface 54 of 18B abuts on the stepped portion 53 of the flow path pipe 11, so that the axial movement of the flow path pipe 11 is reliably regulated.

  With the configuration as described above, according to the above-described embodiment, in addition to the same effects as the effects (3) and (4) of the first embodiment, the following effects (10) and Play (11).

  (10) The fixing mechanism 50 is configured such that the male thread part 51 formed on the outer periphery of the flow path pipe 11 and the female thread part 52 formed on the end portions 18A and 18B of the case 13 are screwed together, whereby the flow path pipe 11 Is fixed to the end portions 18 </ b> A and 18 </ b> B of the case 13. Therefore, even when an excessive force is applied to the flow path pipe 11, it is possible to prevent the flow path pipe 11 from moving relative to the end portions 18 </ b> A and 18 </ b> B of the case 13 by the fixing mechanism 50. Therefore, the ultrasonic sensors 12A and 12B attached to the flow pipe 11 can be prevented from coming into contact with the end portions 18A and 18B of the case 13 to change the distance L between the ultrasonic sensors 12A and 12B. Damage to the ultrasonic sensors 12A and 12B can be prevented.

  (11) A fixing mechanism 50 (a male screw portion 51 and a female screw portion 52) for fixing the flow path pipe 11 to the end portions 18A and 18B of the case 13 is provided inside the end portions 18A and 18B of the case 13. From this, it is possible to suppress the secular change of the fixing mechanism 50 (particularly the male screw portion 51) due to gas, liquid, ultraviolet rays, etc. outside the case 13, and it is possible to prevent an unexpected external force from acting on the fixing mechanism 50. As a result, the fixing and holding of the flow path pipe 11 by the fixing mechanism 50 can be secured well for a long period of time.

  As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to this.

1st Embodiment of the ultrasonic flowmeter which concerns on this invention is shown, (A) is a front view, (B) is a perspective view. It is sectional drawing which shows the ultrasonic flowmeter of FIG. It is a disassembled perspective view which shows the ultrasonic flowmeter of FIG. FIG. 4 shows a second embodiment of the ultrasonic flowmeter according to the present invention, (A) is a cross-sectional view corresponding to FIG. 2, and (B) is a cross-sectional view taken along line IV-IV in FIG. 4 (A). . FIG. 5 shows a third embodiment of an ultrasonic flowmeter according to the present invention, in which (A) is a cross-sectional view corresponding to FIG. 2, and (B) is a cross-sectional view taken along line VV in FIG. . 4 shows a fourth embodiment of an ultrasonic flowmeter according to the present invention, in which (A) is a cross-sectional view corresponding to FIG. 2, and (B) is an enlarged view of a portion VI in FIG. 6 (A). It is sectional drawing which shows the conventional ultrasonic flowmeter.

Explanation of symbols

10 Ultrasonic flow meter 11 Channel pipe (channel)
12A, 12B Ultrasonic sensor 13 Case 16A, 16B, 19 Cable 17 Cylindrical portion 18A, 18B End portion 20 Fixing mechanism 21 Deformable member 23 Bolt (holding member)
30 Fixing mechanism 31 Set screw (set member)
40 Fixing Mechanism 41 Main Projection Part 42 Sub Projection Part 43 Fitting Recess 50 Fixing Mechanism 51 Male Thread Part 52 Female Thread Part L Distance S Predetermined Distance

Claims (7)

A flow path through which the fluid flows, a plurality of ultrasonic sensors arranged at a predetermined distance in the axial direction of the flow path, and a case covering these ultrasonic sensors and the ultrasonic sensor arrangement portion of the flow path. Have
An ultrasonic flowmeter that measures the flow rate of fluid flowing in the flow path from the difference in propagation time of ultrasonic waves through the fluid between the ultrasonic sensors,
The case includes a cylindrical portion, and an end portion that closes both sides of the cylindrical portion and penetrates the flow path,
A fixing mechanism for fixing the flow path to the end of the case is provided inside or inside the case,
In the fixing mechanism, the deformable member inserted through the flow path is deformed in the radial direction by being pressed in the axial direction by the pressing member, and the deformed deformable member is deformed by the end of the flow path and the case. An ultrasonic flowmeter configured to fix the flow path to the end of the case by pressing a portion. A flow path through which the fluid flows, a plurality of ultrasonic sensors arranged at a predetermined distance in the axial direction of the flow path, and a case covering these ultrasonic sensors and the ultrasonic sensor arrangement portion of the flow path. Have
An ultrasonic flowmeter that measures the flow rate of fluid flowing in the flow path from the difference in propagation time of ultrasonic waves through the fluid between the ultrasonic sensors,
The case includes a cylindrical portion, and an end portion that closes both sides of the cylindrical portion and penetrates the flow path,
A fixing mechanism for fixing the flow path to the end of the case is provided inside or inside the case,
The fixing mechanism is fixed to the end portion of the case by a stop member disposed at the end portion of the case and moving in the radial direction of the flow channel, pressing the flow channel. An ultrasonic flowmeter characterized by being configured to perform. A flow path through which the fluid flows, a plurality of ultrasonic sensors arranged at a predetermined distance in the axial direction of the flow path, and a case covering these ultrasonic sensors and the ultrasonic sensor arrangement portion of the flow path. Have
An ultrasonic flowmeter that measures the flow rate of fluid flowing in the flow path from the difference in propagation time of ultrasonic waves through the fluid between the ultrasonic sensors,
The case includes a cylindrical portion, and an end portion that closes both sides of the cylindrical portion and penetrates the flow path,
A fixing mechanism for fixing the flow path to the end of the case is provided inside or inside the case,
The fixing mechanism is configured such that one or a plurality of protrusions provided on the outer periphery of the flow channel are fitted into a recess formed in the end portion of the case, so that the flow channel is connected to the end portion of the case. An ultrasonic flowmeter configured to be fixed to A flow path through which the fluid flows, a plurality of ultrasonic sensors arranged at a predetermined distance in the axial direction of the flow path, and a case covering these ultrasonic sensors and the ultrasonic sensor arrangement portion of the flow path. Have
An ultrasonic flowmeter that measures the flow rate of fluid flowing in the flow path from the difference in propagation time of ultrasonic waves through the fluid between the ultrasonic sensors,
The case includes a cylindrical portion, and an end portion that closes both sides of the cylindrical portion and penetrates the flow path,
A fixing mechanism for fixing the flow path to the end of the case is provided inside or inside the case,
The fixing mechanism fixes the channel to the end portion of the case by screwing a screw portion formed on the outer periphery of the channel and a screw portion formed on the end portion of the case. An ultrasonic flowmeter characterized by being configured to perform.   The ultrasonic flowmeter according to claim 1, wherein a fixing mechanism for fixing the flow path to the end portion of the case is provided at one or both of the two end portions.   The ultrasonic flowmeter according to claim 3, wherein the flow path is provided with a sub-projection that can contact the inner surface of the end of the case at a position away from the ultrasonic sensor by a certain distance. The cables connected to each of the plurality of ultrasonic sensors attached to the flow path are combined into one, fixed to the end of the case, and configured to be guided out of the case. The ultrasonic flowmeter according to claim 1.

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