JP2012007975A - Attachment structure of ultrasonic transducer and ultrasonic flow measuring device therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reliable ultrasonic measuring device, with a simplified process for attaching a ultrasonic transducer to a flow channel to be measured, which reduces chances of errors at site.SOLUTION: An attachment structure comprises an ultrasonic transducer 14 having a bottomed cylindrical case 1, acoustic matching layer 5, and a piezoelectric body 6, an insulator 15 made of electrical insulating material, an airtight seal material 18, and a to-be-attached part 16. The ultrasonic transducer 14 is attached to the to-be-attached part 16 through the insulator 15. The seal material 18 is inserted between the ultrasonic transducer 14 and the insulator 15, and between the insulator 15 and the to-be-attached part 16, so that vibration propagation between the ultrasonic transducer and a flow channel to be measured is reduced with secured insulation and sealability. In a process for attaching the ultrasonic transducer to the flow channel to be measured, the ultrasonic transducer is easily attached by mounting the insulator and the seal material on the flow channel to be measured in advance.

Description

  The present invention relates to an attachment structure of an ultrasonic transducer in an ultrasonic flow measurement device.

  Conventionally, the ultrasonic vibrator mounting structure used in this type of ultrasonic flow measuring device is attached to the measured flow path of the ultrasonic flow measuring device via the vibration damping body and the vibration transmission suppressing body. (For example, refer to Patent Document 1).

  FIG. 5 shows a conventional mounting structure described in Patent Document 1. In FIG. As shown in the drawing, a damping body 32 that reduces vibration of the side wall portion is wound around the outer peripheral surface of the side wall portion 31 of the ultrasonic transducer 30, and a holding portion that holds the support portion 33 of the ultrasonic transducer 30. It is attached to a measured flow path 38 of the ultrasonic flow rate measuring device via a vibration transmission suppressing body 35 having 34 and fixed by a fixed body 37. As a result, it is possible to reduce the propagation of the vibration of the piezoelectric body 36 to the attachment side, and to transmit / receive ultrasonic pulses with short reverberation.

JP-A-11-344472

  However, in the conventional configuration, it is necessary to attach the vibration damping body 32 and the vibration transmission suppressing body 35 to the ultrasonic vibrator in advance when the ultrasonic vibrator 30 is incorporated into the measured flow path 38, and the vibration damping body. Since 32 and the vibration transmission restraining body 35 have complicated shapes, workability is poor and assembly reliability is also lowered. Further, since the fixed body 37 is configured to cover the holding portion 34, the fixed body 37 is screwed after the ultrasonic transducer 30 having the vibration damping body 32 and the vibration transmission suppressing body 35 attached to the measurement channel 38. For example, it is fixed to the measured flow path 38. For this reason, only the process of attaching the ultrasonic transducer 30 to the measured flow path 38 has a problem that a considerable time and process are required.

  The present invention solves the above-mentioned problem, and the process of assembling the ultrasonic transducer to the measurement channel is simplified while maintaining the reliability as the ultrasonic flow measuring device, thereby reducing work errors. An object of the present invention is to provide an ultrasonic vibrator mounting structure with high work reliability.

  In order to solve the above-described conventional problems, an ultrasonic vibrator mounting structure according to the present invention includes an ultrasonic vibrator including a bottomed cylindrical case, an acoustic matching layer, and a piezoelectric body, and an electrically insulating property. In an attachment structure including an insulator formed of a material, a hermetic sealing material, and an attachment portion, and attaching the ultrasonic vibrator to the attachment portion via the insulator, the ultrasonic vibrator and the insulator And a sealing material between the insulator and the attached portion.

  As a result, vibration propagation between the ultrasonic transducer and the measurement channel can be reduced, and insulation and sealing properties can be secured. And an ultrasonic vibrator can be easily attached by incorporating a sealing material first.

The ultrasonic vibrator mounting structure of the present invention is a mounting structure in which a part of the ultrasonic vibrator is fixed by an insulator locking means.

  As a result, the step of attaching the ultrasonic transducer to the channel to be measured can be mounted simply by fitting the ultrasonic transducer into the rib portion of the locking means after incorporating the insulator and the seal material into the channel to be measured.

  While maintaining the reliability as the ultrasonic flow rate measuring device, the process of assembling the ultrasonic transducer to the measurement channel is simplified, and the operational reliability can be improved by reducing operational errors.

Sectional drawing which shows the attachment structure of the ultrasonic transducer | vibrator in Embodiment 1 of this invention Sectional drawing which shows the attachment structure of the ultrasonic transducer | vibrator in Embodiment 2 of this invention Sectional drawing which shows the attachment structure of the ultrasonic transducer | vibrator of Embodiment 3 of this invention Configuration diagram of ultrasonic flow rate measuring apparatus according to embodiment 4 of the present invention Sectional view showing the mounting structure of a conventional ultrasonic transducer

  According to a first aspect of the present invention, there is provided an ultrasonic vibrator including a bottomed cylindrical case, an acoustic matching layer, and a piezoelectric body, an insulator formed of an electrically insulating material, an airtight sealing material, In the mounting structure including the attached portion and attaching the ultrasonic transducer to the attached portion via the insulator, the insulator and the attached portion are disposed between the ultrasonic transducer and the insulator. The ultrasonic vibrator mounting structure, wherein the sealing material is interposed between the two.

  Thereby, it is possible to reduce the propagation of the vibration of the piezoelectric body to the measurement channel, and to transmit and receive an ultrasonic pulse with short reverberation, thereby ensuring measurement accuracy.

  In addition, by shielding the case with an insulator and increasing the conductive distance between the mounted part and the ultrasonic transducer with a compact mounting structure, abnormally high voltage is generated between the mounted part and the ultrasonic transducer due to lightning strikes, etc. Even in this case, it is possible to increase the withstand voltage leading to the leakage and prevent the ultrasonic vibrator from being damaged by the leakage current, thereby ensuring the reliability.

  In addition, by providing a sealing material between the attachment part to which the ultrasonic transducer is attached and the insulator and between the case and the insulator, a hermetic seal between the fluid to be measured and the opposite side through the sealing material is achieved. Can be secured.

  In addition, sealing materials and insulators can be attached to the parts to be attached in advance, so that the attachment of the ultrasonic transducer can be improved, and work mistakes can be reduced due to the simple structure and simple process, improving work reliability. Can do.

  In particular, according to a second invention, in the first invention, the insulator includes a locking means, and the ultrasonic vibrator is locked to the insulator by the locking means.

  As a result, it is possible to attach the sealing material and the insulator to the attached portion in advance, and then attach the ultrasonic vibrator to the insulator simply by locking with the locking means. The number of parts required for the installation can be reduced, and the mounting process can be simplified.

  In a third aspect of the invention, in particular, in the first or second aspect of the invention, a vibration propagation prevention band is provided between the insulator and the ultrasonic transducer.

  As a result, even when the vibration of the piezoelectric material propagates to the case, the vibration propagation to the insulator can be greatly reduced by the vibration propagation prevention band, the vibration propagation from the insulator to the mounted part is reduced, and the reverberation It is possible to reduce the generation of noise and transmit / receive ultrasonic pulses with short reverberation, and the S / N can be improved to improve the measurement characteristics such as the flow rate of the fluid to be measured, the measurement accuracy of the flow velocity, and the measurement range expansion.

  According to a fourth aspect of the present invention, there is provided at least a pair of the ultrasonic transducers, a measurement flow channel through which a fluid to be measured flows, a plurality of attached portions disposed to face the measurement flow channel, and the ultrasonic transducers A measurement control unit that measures an ultrasonic propagation time between the measurement control unit and a calculation unit that calculates a flow rate based on a signal from the measurement control unit, and the ultrasonic transducer is any one of the first to third units. The ultrasonic transducer is attached to the attachment portion of the measurement flow path by the attachment structure of the ultrasonic transducer of one invention.

  Accordingly, it is possible to provide a flow rate measuring device that can increase measurement accuracy, expand a measurement range, and maintain measurement characteristics over a long period of time.

  In addition, while maintaining the required reliability as an ultrasonic measurement device, it is possible to simplify the structure and process, reduce work errors, and improve work reliability.

  Hereinafter, an ultrasonic vibrator mounting structure according to an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a cross-sectional view of an ultrasonic transducer mounting structure according to Embodiment 1 of the present invention.

  As shown in FIG. 1, the case 1 has a bottomed cylindrical shape having a bottom 2, a side wall 3, and an opening 4. The acoustic matching layer 5 is fixed to the outer wall surface of the bottom 2, and the piezoelectric body 6 is fixed to the inner wall surface of the bottom 2 on the opposite side of the acoustic matching layer 5. A fixed portion 7 is formed on the outer periphery of the opening 4 of the case 1 by laminating an annular flange 8 and a sealing body 9 that closes the opening 4 to increase the thickness and thereby provide rigidity. The sealing body 9 is provided with terminals 10 a and 10 b, and the terminals 10 a and 10 b are insulated via an insulating portion 11. The piezoelectric body 6 and the terminal 10a are electrically connected by a lead wire 12. A groove 13 is provided in the piezoelectric body 6.

  As described above, the ultrasonic transducer 14 includes the piezoelectric body 6 provided inside the bottomed cylindrical case 1 and sealed with the sealing body 9, and includes the acoustic matching layer 5 and the fixing portion 7 outside the case 1. Yes.

  An insulator 15 molded of an electrically insulating material is wound around the case 1, and an aluminum alloy die is used to ensure the strength, corrosion resistance, and durability of the case 1, the insulator 15, and the measurement channel. An appropriate clearance 17 is provided between the attachment portion 16 and the insulator 15 formed of a metal material such as cast in consideration of assembly.

  A sealing material 18 formed of an airtight sealing material is provided between the fixed portion 7 and the insulator 15 and between the attached portion 16 and the insulator 15 so as to be in close contact therewith. For example, a rubber O-ring or a silicon resin is used as the sealing material 18. The insulator 15 and the fixing portion 7 are fixed to the attachment portion 16 via a fixing member 19 and a screw (not shown).

An example of a method for producing the ultrasonic transducer 14 configured as described above will be described below. Assuming that the ultrasonic transducer 14 is used in LP gas or natural gas, the bottomed cylindrical case 1 is made of stainless steel, and the acoustic matching layer 5 is made of a mixture of epoxy resin and hollow glass spheres. Select. In consideration of mass productivity, the processing method of the case 1 is not a cutting process but a forming process such as a drawing process is selected. Further, the thickness of the stainless steel of the case 1 is selected to be about 0.1 to 0.5 mm from the viewpoints of the sensitivity, structural strength, and moldability of the ultrasonic transducer 14.

  In order to form the case 1 with such a thin material, the fixing portion 7 increases the plate thickness T2 of the sealing body 9 with respect to the plate thickness T1 of the flange 8 formed by drawing the case 1 (T1 <T2). The sealing body 9 is joined by welding or the like to increase the structural strength.

  Further, since the piezoelectric body 6 is bonded and fixed to the bottom 2 made of stainless steel, vibration in the spreading direction is hindered. In order to increase the sensitivity of the ultrasonic vibrator 14, it is advantageous to use the thickness longitudinal vibration for the main mode rather than the spread vibration. However, the main mode of vibration of the piezoelectric body 6 is determined by the shape, and the allowable range for the shape and operating frequency of the piezoelectric body 6 is narrow. Therefore, as a structure in which the groove 13 is provided in the piezoelectric body 6, thickness vibration can be set as a main mode with a practically small size.

  As a specific manufacturing procedure for such a material and shape, a bottomed cylindrical case 1 having a circular bottom 2 is first formed from a stainless steel plate having a thickness of 0.2 mm. Next, the disc-like acoustic matching layer 5 is bonded to the outer wall surface of the bottom 2 and the piezoelectric body 6 is bonded and fixed to the inner wall surface with an epoxy adhesive. At this time, the electrode (not shown) divided by the groove 13 and the bottom 2 are bonded and fixed via a thin adhesive layer of 10 μm or less, so that the electric conduction between the divided electrode (not shown) and the bottom 2 is also achieved. Can be taken.

  The lead wire 12 is soldered to an electrode (not shown) of the piezoelectric body 6 and the terminal 10a. Finally, a sealing body 9 made of a stainless steel plate of about 1 mm is fixed to the flange 8 provided on the outer peripheral side of the opening 4 by electric resistance welding or the like, and sealing and electrical conduction are performed simultaneously.

  Since the piezoelectric body 6 shares the case 1 as the ground and is further covered with the case 1 and the sealing body 9, the influence of noise can be reduced. Moreover, when nitrogen or an inert gas is substituted and sealed in the case 1 during sealing, deterioration of the electrodes of the piezoelectric body 6 and the adhesive layer between the piezoelectric body 6 and the case 1 due to long-term use can be prevented. .

  The operation and action of the ultrasonic vibrator mounting structure configured as described above will be described below.

  First, regarding the insulator 15 molded with an electrically insulating material so as to surround the bottomed cylindrical case 1, if there is no insulator 15 shown in the present embodiment, the ultrasonic transducer 14 is attached to the attached portion 16. And a case where the electric insulation distance is small. In this case, when an abnormal high voltage is generated between the attached portion 16 and the ultrasonic transducer 14 due to a lightning strike or the like, a large current flows between the attached portion 16 and the ultrasonic transducer 14 and the ultrasonic transducer 14. This causes damage to the piezoelectric body 6 and the like.

  In order to prevent this damage, it is necessary to increase the electrical insulation distance in order to increase the withstand voltage leading to leakage against an abnormal high voltage. However, in order to increase the distance between the case 1 and the mounting wall 25, the mounting hole must be enlarged and the outer shape of the fixing portion 7 formed by the flange 8 or the like must be increased, which goes against miniaturization.

  However, when the insulator 15 formed of an electrically insulating material is installed as in the present embodiment, the ultrasonic transducer 14 and the attached portion 16 are shielded by an electrical insulator while being small, and the insulation distance is increased. Even if an abnormally high voltage occurs between the attached part side and the ultrasonic transducer due to lightning strikes, etc., the withstand voltage leading to leakage can be increased, and the ultrasonic transducer is prevented from being damaged by leakage current, improving reliability it can.

  In addition, since an appropriate clearance 17 is provided so that the insulator 15 can be smoothly inserted when the insulator 15 is attached to the attachment portion 16 or when the ultrasonic vibrator 14 is attached to the insulator 15, gas that is a fluid to be measured is provided. In addition, there is a risk that the liquid leaks from the attached portion 16. Therefore, the sealing material 18 can ensure the hermetic sealing property between the insulator 15 and the attached portion 16.

  Next, a method of attaching the ultrasonic transducer 14 to the attached portion 16 that brings about the maximum effect in the present embodiment will be described. First, the sealing member 18 disposed below the insulator 15 is attached to the attachment portion 16. For example, when an O-ring is used as the sealing material 18, the O-ring can be easily mounted if the recess is provided in the wall surface of the mounted portion 16, and the mounting location is also defined. Next, the insulator 15 is inserted into the attachment portion 16, and the sealing material 18 disposed on the upper side of the insulator 15 is attached. For example, when an O-ring is used as the sealing material 18, the O-ring can be easily mounted if the recess is provided in the wall surface of the mounted portion 16, and the mounting location is also defined.

  Next, the ultrasonic transducer | vibrator 14 is inserted in the to-be-attached part 16 with which the insulator 15 and the sealing material 18 were mounted | worn. Finally, the fixing member 19 is attached so as to press the upper portion of the fixing portion 7 and the insulator 15, whereby the adhesion of the sealing material 18 is increased and the ultrasonic vibrator can be fixed.

  As described above, by attaching each part to the attachment portion 16, preparation work in the previous process is not necessary, and the work can be reliably performed while visually confirming the mounting state. In particular, as for the sealing material 18, if it is mounted with a slight displacement or bent, it will lead to gas leakage or leakage from the mounted portion 16, and therefore the sealing material 18 as in the present embodiment. By using the O-ring, it is possible to improve the reliability in terms of structure and workability.

  Thus, while maintaining the reliability required as an ultrasonic measurement device, the sealing material 18 and the insulator 15 can be attached in advance to the attachment portion 16 of the measurement flow path, and the attachment properties of the ultrasonic transducer 14 are improved. Can be improved. In addition, by simplifying the shape of each part and simplifying the structure and process, work errors can be reduced and work reliability can be improved. Can be realized.

(Embodiment 2)
FIG. 2 shows a cross-sectional view of an ultrasonic transducer mounting structure according to Embodiment 2 of the present invention.

  In the present embodiment, members having the same members and functions as those of the embodiments are denoted by the same reference numerals, detailed description thereof will be omitted, and different points will be mainly described.

  An inner rib 20 is provided at an end portion of the insulator 15, and the inner rib 20 is at least in an annular symmetrical position on the inward side of the insulator 15 that annularly surrounds the fixing portion 7 of the ultrasonic transducer 14. The locking means is provided at two locations and has a shape with a certain degree of mobility so as to press the fixing portion 7. A large number of inner ribs 20 may be provided at annular positions.

  In addition, outer ribs are provided on the outer peripheral portion of the insulator 15, and the outer ribs 21 are provided at least two annularly symmetrical positions on the outward side of the insulator 15 surrounding the fixing portion 7 in an annular shape, The shape is gently formed in the vertical downward direction of FIG. 2 so that the insulator 15 can be easily inserted into the attachment portion 16, and the vertical upward direction is turned back so as not to easily come out after the insulator 15 is attached to the attachment portion 16. It has a structure. The outer rib 21 may have a certain degree of mobility.

  On the other hand, a fitting hole 22 is provided at a position corresponding to the outer rib 21 of the mounted portion 16. The fitting hole 22 has the same shape as the outer rib 21 and the insulator 15 is inserted. It is provided at a position where the outer rib 21 enters. A large number of outer ribs 21 and fitting holes 22 may be provided in an annular position, and the shape may be semicircular or semispherical.

  The operation and action of the ultrasonic transducer mounting structure according to the present embodiment configured as described above will be described below.

  First, the sealing material 18 disposed on the lower side of the insulator 15 is attached to the attached portion 16. For example, when an O-ring is used as the sealing material 18, the O-ring can be easily mounted if the recess is provided in the wall surface of the mounted portion 16, and the mounting location is also defined.

  Next, the insulator 15 is inserted into the attachment portion 16, and the sealing material 18 disposed on the upper side of the insulator 15 is attached. For example, when an O-ring is used as the sealing material 18, the O-ring can be easily mounted if the recess is provided in the wall surface of the mounted portion 16, and the mounting location is also defined.

  Next, the ultrasonic transducer | vibrator 14 is inserted in the to-be-attached part 16 with which the insulator 15 and the sealing material 18 were mounted | worn. During the insertion, the fixing portion 7 acts to spread the inner rib 20 outward, and when the fixing portion 7 reaches the sealing material 18, the inner rib 20 that has been spread to the fixing portion 7 returns to its original state and presses the fixing portion 7. Such a locking means. By using such a locking means, there is no need for a fixing body that presses the fixing portion 7, and the number of parts can be reduced. Further, it is not necessary to tighten a screw or the like in which a fixing body for holding the fixing portion 7 is attached to the attached portion 16, and the attaching process can be simplified.

  In this way, while maintaining the required reliability as an ultrasonic measurement device, it is possible to further reduce work mistakes and improve work reliability by further simplifying the shape of parts and simplifying the structure and process. Therefore, it is possible to realize a flow rate measuring device that is safe without leaking, has high measurement accuracy, and has a large measurement range.

  In addition, the mounting portion 16 and the insulator 15 are attached by using a locking means that fits the outer rib 21 into the fitting hole 22. Therefore, it is possible to improve the work reliability, and it is possible to realize a flow rate measuring device that is safe without leakage, has high measurement accuracy, and has a large measurement range.

(Embodiment 3)
FIG. 3 shows a sectional view of an ultrasonic transducer mounting structure according to Embodiment 3 of the present invention.

  In the present embodiment, members having the same members and functions as those of the first embodiment are denoted by the same reference numerals, detailed description thereof will be omitted, and different points will be mainly described.

  A vibration propagation preventing band 23 is provided between the side wall side of the bottomed cylindrical case 1 of the ultrasonic vibrator 14 and the insulator 15 so that the side wall 3 of the case 1 and the insulator 15 do not come into contact with each other. A gap of about 1 mm to 2 mm is provided.

  The operation and action of the ultrasonic vibrator mounting structure configured as described above will be described below.

The ultrasonic measurement apparatus operates by transmitting and receiving ultrasonic waves to and from the ultrasonic transducer 14 on the transmission side and the ultrasonic transducer 14 on the reception side. When driving the transmission / reception ultrasonic vibrator 14, the drive electric input is applied to the ultrasonic vibrator 14 and the piezoelectric body 6 vibrates. In addition, the case 1 tries to vibrate. On the receiving side, the received ultrasonic pulse is converted into an electric signal by the piezoelectric body 6 and at the same time, the case 1 tries to vibrate.

  When the case 1 vibrates, the vibration of the case 1 is transmitted to the receiving-side ultrasonic transducer 14 via the attached portion 16, and is combined with the vibration via the attached portion 16 and the received ultrasonic pulse on the receiving side. Therefore, it affects the amplitude and phase, and causes a measurement error.

  In order to prevent such vibration of the ultrasonic transducer 14 itself from propagating to the attached portion 16 as much as possible, a vibration propagation prevention band 23 is provided between the side wall 3 side of the case 1 and the insulator 15 to provide physical contact. To avoid vibration propagation. Note that the rigidity of the fixing portion 7 is increased due to the fixation with the sealing body 9, and the vibration of the fixing portion 7 is suppressed. Therefore, even if the fixing portion 7 and a part of the insulator 15 are in contact with each other, the measurement is affected. There is no vibration propagation.

  As described above, an ultrasonic transducer capable of transmitting and receiving ultrasonic pulses with short reverberation and capable of reducing vibration propagation to the mounting side can be obtained. Vibration propagation to the attachment side can be reduced, and S / N can be improved to improve measurement characteristics such as flow rate of fluid to be measured, measurement accuracy of flow velocity, and expansion of measurement range.

(Embodiment 4)
FIG. 4 shows a block diagram of an ultrasonic flow rate measuring apparatus showing Embodiment 4 of the present invention.

  In the present embodiment, members having the same members and functions as those of the first to third embodiments are denoted by the same reference numerals, detailed description thereof is omitted, and different points will be mainly described.

  In the ultrasonic flow rate measuring apparatus, the measurement flow channel 24, which is a measurement position of the flow velocity of the measurement fluid, is a flow channel having a width W surrounded by the flow channel wall 25. The two ultrasonic transducers 26 and 27 are attached to the attachment portion 16 of the flow path wall 25 by the mounting structure described in the second embodiment so as to face each other. The ultrasonic transducer 27 on the downstream side is disposed at a distance L and inclined at an angle θ with respect to the flow of the fluid to be measured at the velocity V. A measurement control unit 28 for transmitting and receiving ultrasonic waves is connected to the ultrasonic transducers 26 and 27, and the measurement control unit 28 calculates a flow rate based on signals from the ultrasonic transducers 26 and 27 to calculate a flow rate. An arithmetic unit 29 is provided.

  The operation and action of the ultrasonic flow rate measuring apparatus configured as described above will be described below.

  When the fluid to be measured flows through the measurement channel 24, ultrasonic waves are transmitted and received between the ultrasonic transducers 26 and 27 by the operation of the measurement control unit 28 so as to cross the measurement channel 24. That is, the elapsed time T1 until the ultrasonic wave emitted from the upstream ultrasonic transducer 26 is received by the downstream ultrasonic transducer 27 is measured. On the other hand, an elapsed time T2 until the ultrasonic wave emitted from the downstream ultrasonic transducer 27 is received by the upstream ultrasonic transducer 26 is measured. Based on the elapsed times T1 and T2 measured in this way, the flow rate is calculated by the calculation unit 29 by the following calculation formula.

  Now, assuming that the angle between the flow of the fluid to be measured and the ultrasonic propagation path is θ, the distance between the ultrasonic transducers 26 and 27 as the flow rate measurement unit is L, and the sound velocity of the fluid to be measured is C, the flow velocity V Is calculated by the following equation.

T1 = L / (C + V cos θ)
T2 = L / (C−Vcos θ)
The speed of sound C is eliminated from the equation for subtracting the reciprocal of T2 from the reciprocal of T1, and V = (L / 2 cos θ) {(1 / T1) − (1 / T2)}
Since θ and L are known, the flow velocity V can be calculated from the values of T1 and T2.

  Assuming that the flow rate of air is measured, assuming that an angle θ = 27 degrees, a distance L = 70 mm, a sound velocity C = 340 m / sec, and a flow velocity V = 8 m / sec, T1 = 2.0 / 10000 sec, T2 = 2.1 / 10000 seconds and instantaneous measurement is possible.

  Here, from the cross-sectional area s orthogonal to the flow direction of the measurement flow path 24, the flow rate Q is Q = kVs, where k is a conversion factor considering the flow velocity distribution in the cross-sectional area s. In this way, the flow rate can be obtained by the calculation unit 29.

  In ultrasonic flow rate measurement, it is important to measure the times T1 and T2 with high accuracy. In other words, it is important for the transmitting side to emit ultrasonic vibrations with little reverberation only in the fluid to be measured. It is important to receive only less reverberation.

  In the ultrasonic flow measuring device of the present embodiment, by enclosing the ultrasonic transducer 14 with the insulator 15, it is possible to ensure a large electrical insulation distance from the flow path wall 25 while maintaining a compact space, and withstand voltage resistance. It can be improved to improve lightning surge, and a highly reliable measuring device can be realized. With the insulator 15 and the sealing material 18, it is possible to realize a measuring device with excellent measurement accuracy, measurement range, lightning surge, and reliability and practicality.

  Thus, while maintaining the reliability required for the ultrasonic measurement device, the seal material 18 and the insulator 15 can be attached to the attached portion 16 in advance, and the attachment of the ultrasonic transducer 14 can be improved.

  Further, by providing a locking means for the inner rib 20 and the outer rib 21 in a part of the insulator 15, the shape of each component can be further simplified, the simple configuration and the process can be simplified. Errors can be reduced and work reliability can be improved.

  In the present embodiment, the ultrasonic vibrator is attached to the attachment portion by the attachment structure as described in the second embodiment, but the present invention is not limited to this, and is described in the first or third embodiment. Similar effects can be obtained when the mounting structure is employed.

  As described above, the ultrasonic vibrator mounting structure according to the present invention has reliability as an ultrasonic measurement device, simplifies the process of assembling the ultrasonic vibrator into the measurement channel, and reduces work errors. Therefore, the present invention can also be applied to applications such as a fluid measuring device such as a gas meter or a water meter that require high reliability.

DESCRIPTION OF SYMBOLS 1 Case 5 Acoustic matching layer 6 Piezoelectric body 14, 26, 27 Ultrasonic vibrator 15 Insulator 16 Mounted part 18 Sealing material 20 Inner rib (locking means)
23 Vibration Propagation Prevention Zone 24 Measurement Channel 28 Measurement Control Unit 29 Calculation Unit

Claims (4)

An ultrasonic transducer including a bottomed cylindrical case, an acoustic matching layer, and a piezoelectric body;
An insulator formed of an electrically insulating material;
An airtight sealing material;
A mounted portion, and
In the attachment structure for attaching the ultrasonic transducer to the attachment portion via the insulator,
The sealing material is interposed between the ultrasonic transducer and the insulator and between the insulator and the attached portion,
Ultrasonic transducer mounting structure. The insulator comprises locking means;
Locking the ultrasonic transducer to the insulator with the locking means;
The ultrasonic vibrator mounting structure according to claim 1. A vibration propagation prevention band is provided between the insulator and the ultrasonic transducer,
The ultrasonic vibrator mounting structure according to claim 1 or 2. At least a pair of the ultrasonic transducers;
A measurement channel through which the fluid to be measured flows;
A plurality of the attached portions arranged to face the measurement flow path;
A measurement control unit for measuring an ultrasonic propagation time between the ultrasonic transducers;
A calculation unit that calculates a flow rate based on a signal from the measurement control unit,
The ultrasonic transducer is attached to the attachment portion of the measurement flow path by the ultrasonic transducer attachment structure according to any one of claims 1 to 3.
Ultrasonic flow measuring device.