JP2012127653A - Ultrasonic type fluid measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively suppress propagation of vibration from a wave transmitter to a wave receiver through a flow path pipe in an ultrasonic type fluid measurement device.SOLUTION: An ultrasonic type fluid measurement device sets a lower limit temperature as LT and an upper limit temperature as UT in a use temperature range and includes a flow path pipe 10, an ultrasonic wave transmitter fixed on the flow path pipe through a first fixing pipe or directly to transmit ultrasonic waves and an ultrasonic wave receiver fixed on the flow path pipe through a second fixing pipe or directly to receive ultrasonic waves. A pair of grooves 12 is formed on any one of the flow path pipe, the first fixing pipe and the second fixing pipe arranged between the ultrasonic wave transmitter and the ultrasonic wave receiver so that a pitch in the axial direction of the pipe becomes L1. When it is defined that the frequency of an ultrasonic wave is N, a material composing a section on which the grooves are formed in the pipe is a pipe material, a wavelength of a sound wave of the frequency N in the pipe material at the temperature LT is λ1, and a wavelength of a sound wave of the frequency N in the pipe material at the temperature UT is λ2, L1 is included within a predetermined length range in which lower limit length is λ2×(1/4) and upper limit length is λ1×(1/4).

Description

  The present invention relates to an ultrasonic fluid measuring apparatus.

  Patent Document 1 discloses a flow meter that measures the flow of fluid using sound waves. The flow meter is intended to perform flow rate measurement with high accuracy by reducing excessive vibration propagation and transmitting and receiving with good S / N. The flowmeter includes a flow path for delivering a fluid, a flow rate measuring means for measuring a flow rate from a propagation time in which vibration propagates in the fluid using a pair of vibration detection means, and a vibration damping means in the flow path. Yes.

JP 2002-236042 A

  In the ultrasonic flow rate measuring device, if ultrasonic waves propagate from the transmitter directly to the receiver through the channel tube, the measurement is hindered.

  The present invention addresses such a problem, and provides an ultrasonic fluid measurement device that can more effectively suppress the propagation of vibration from a transmitter to a receiver through a channel tube. The purpose is to do.

  In the ultrasonic fluid measuring apparatus, the present inventors have conducted intensive studies in order to more effectively suppress the propagation of vibration from the transmitter to the receiver through the channel tube. As a result, the following knowledge was obtained.

  In the ultrasonic fluid measuring apparatus, the ultrasonic wave propagates not only in the fluid to be measured but also in the channel tube. By forming grooves with a pitch of λ / 4 on the surface (either the outer surface or the inner surface) of the flow channel tube, where the wavelength of the ultrasonic wave is λ, the ultrasonic wave propagating in the flow channel tube can be attenuated. This is because when the vibration propagating inside the solid constituting the tube or in the vicinity of the surface passes through the groove, if there is a groove for every quarter of the wavelength λ, the wavelength component is selected and the attenuation is increased. Because.

  That is, the ultrasonic fluid measuring device of the present invention is an ultrasonic fluid measuring device used in a predetermined temperature range in which the lower limit temperature is LT and the upper limit temperature is UT, and the flow path pipe and the first attachment pipe An ultrasonic wave transmitter that is fixed to the flow channel tube and transmits an ultrasonic wave via a direct connection or a second attachment tube or directly fixed to the flow channel tube and receives the ultrasonic wave An ultrasonic receiver, and between the ultrasonic transmitter and the ultrasonic receiver, either the flow pipe, the first attachment pipe, or the second attachment pipe, A pair of grooves are formed so that the pitch in the axial direction of the tube is L1, the frequency of the ultrasonic wave is N, a material constituting the portion of the tube where the groove is formed is a tube material, and the LT The wavelength of the sound wave of frequency N in the tube material is λ1, and the tube material in the UT When the wavelength of the sound wave of the frequency N with .lambda.2, L1 is a lower limit length λ2 × (1/4), enters the upper length to a predetermined length range to λ1 × (1/4).

  With such a configuration, it is possible to more effectively suppress the propagation of vibration from the transmitter to the receiver through the channel tube.

  The ultrasonic fluid measurement device may be configured such that the pitch in the axial direction changes continuously.

  In such a configuration, even when the wavelength of the ultrasonic wave fluctuates due to a change in temperature, it is possible to effectively suppress the propagation of vibration from the transmitter to the receiver through the channel tube.

  In the ultrasonic fluid measuring device, when L2 and L1 are constant values, the flow channel pipe or the first attachment pipe or the pipe between the ultrasonic transmitter and the ultrasonic receiver, A pair of grooves is formed in any one of the second attachment pipes so that the pitch in the axial direction of the pipe is L2, and L2 has a lower limit length of λ2 × (1/4) and an upper limit length of λ1 × ( A predetermined length range of ¼) may be satisfied and L1 ≠ L2 may be satisfied.

  With such a configuration, it is possible to effectively suppress the propagation of vibration from the transmitter to the receiver through the flow channel tube at a plurality of different temperatures.

  In the ultrasonic fluid measuring apparatus, when the depth of the groove is D, D is a predetermined value having a lower limit depth of λ2 × (1/4) and an upper limit depth of λ1 × (1/4). You may enter the depth range.

  In such a configuration, it is possible to more effectively suppress the propagation of vibration from the transmitter to the receiver through the channel tube.

  In the ultrasonic fluid measuring apparatus, an ultrasonic absorbing material may be disposed so as to cover a part of the groove.

  In such a configuration, the ultrasonic wave captured in the groove can be efficiently absorbed or attenuated by the ultrasonic absorbing material. Therefore, it is possible to more effectively suppress the propagation of vibration from the transmitter to the receiver through the channel tube.

  According to the ultrasonic fluid measurement device of the present invention, it is possible to more effectively suppress the propagation of vibrations from the transmitter to the receiver through the channel tube.

FIG. 1A is a cross-sectional view illustrating an example of a schematic configuration of an ultrasonic fluid measuring apparatus according to an example of the first embodiment, and FIG. 1B illustrates an ultrasonic wave according to an example of the first embodiment. It is sectional drawing which shows an example of the site | part in which a groove | channel is provided in a type | formula fluid measuring device, FIG.1 (c) is another example of the site | part in which a groove | channel is provided in the ultrasonic type fluid measuring device concerning the Example of 1st Embodiment. FIG. FIG. 2A is a perspective view showing an example of a mode in which grooves are formed in the ultrasonic fluid measuring apparatus according to the example of the first embodiment, and FIG. 2B is an example of the first embodiment. It is sectional drawing which shows an example of the aspect in which a groove | channel is formed in the ultrasonic fluid measuring device concerning. FIG. 3A is a cross-sectional view showing an example of a schematic configuration of an ultrasonic fluid measuring apparatus according to a first modification of the first embodiment, and FIG. 3B shows a modification of the first embodiment. It is sectional drawing which shows an example of the site | part in which a groove | channel is provided in an ultrasonic fluid measuring device, FIG.3 (c) is other of the site | part in which a groove | channel is provided in the ultrasonic fluid measuring device concerning the modification of 1st Embodiment. FIG. FIG. 4A is a plan view showing an example of a mode in which grooves are formed in the ultrasonic fluid measuring apparatus according to the example of the first embodiment, and FIG. 4B is a second view of the first embodiment. It is a top view which shows an example of the aspect in which a groove | channel is formed in the ultrasonic fluid measuring device concerning a modification, and FIG.4 (c) is in the ultrasonic fluid measuring device concerning the 3rd modification of 1st Embodiment. It is a top view which shows an example of the aspect in which a groove | channel is formed. FIG. 5 is a cross-sectional view showing an example of a mode in which grooves are formed in the ultrasonic fluid measuring apparatus according to the example of the second embodiment. FIG. 6A is a cross-sectional view showing an example of a mode in which grooves are formed in the ultrasonic fluid measuring apparatus according to the example of the third embodiment, and FIG. 6B is a modified example of the third embodiment. It is sectional drawing which shows an example of the aspect in which a groove | channel is formed in the ultrasonic fluid measuring device concerning.

(First embodiment)
FIG. 1A is a cross-sectional view illustrating an example of a schematic configuration of an ultrasonic fluid measuring apparatus according to an example of the first embodiment, and FIG. 1B illustrates an ultrasonic wave according to an example of the first embodiment. It is sectional drawing which shows an example of the site | part in which a groove | channel is provided in a type | formula fluid measuring device, FIG.1 (c) is another example of the site | part in which a groove | channel is provided in the ultrasonic type fluid measuring device concerning the Example of 1st Embodiment. FIG.

  FIG. 2A is a perspective view showing an example of a mode in which grooves are formed in the ultrasonic fluid measuring apparatus according to the example of the first embodiment, and FIG. 2B is an example of the first embodiment. It is sectional drawing which shows an example of the aspect in which a groove | channel is formed in the ultrasonic fluid measuring device concerning.

  In addition, the code | symbol was attached | subjected only in order to illustrate the correspondence of this embodiment and its Example to the last, and the structure of the fluid control valve of this embodiment is not limited to FIG. Hereinafter, the same applies to other embodiments.

  As illustrated in FIGS. 1 and 2, the ultrasonic fluid measurement device according to the first embodiment is an ultrasonic fluid measurement device used in a predetermined temperature range in which the lower limit temperature is LT and the upper limit temperature is UT. The flow path pipe 10, the first attachment pipe 20, or the ultrasonic wave transmitter 30 that is directly fixed to the flow path pipe 10 and transmits ultrasonic waves, and the second attachment pipe 40. Or an ultrasonic wave receiver 50 that is directly fixed to the flow path tube 10 and receives ultrasonic waves, and the flow path pipe 10 or the ultrasonic wave receiver 50 located between the ultrasonic wave transmitter 30 and the ultrasonic wave receiver 50 A pair of grooves 12 is formed in either the first attachment tube 20 or the second attachment tube 40 so that the pitch in the axial direction of the tube is L1, the ultrasonic frequency is N, and the groove of the tube is The material constituting the formed portion is a tube material, and the sound wave of frequency N in the tube material in LT When the wavelength is λ1 and the wavelength of the sound wave having the frequency N in the tube material at the UT is λ2, L1 is a predetermined value having a lower limit length of λ2 × (1/4) and an upper limit length of λ1 × (1/4). Enter the length range.

  With such a configuration, it is possible to more effectively suppress the propagation of vibration from the transmitter to the receiver through the channel tube.

  The ultrasonic transmitter / receiver 30 may be an ultrasonic transmitter / receiver. The ultrasonic receiver 50 may be an ultrasonic transmitter / receiver. That is, the ultrasonic transmitter 30 and the ultrasonic receiver 50 may be any ones that can realize the functions of the transmitter and the receiver at specific points in time, respectively.

  LT and UT are a lower limit value and an upper limit value of a predetermined temperature range that may vary depending on the environment in which the ultrasonic fluid measurement device (for example, a gas meter) is used, and specifically, for example, a predetermined value that is predetermined in design. The lower limit and the upper limit of the temperature range. LT and UT may be a lower limit value and an upper limit value of the usable temperature range that are determined in advance by legal standards of the ultrasonic fluid measurement device (for example, legal standards of the gas meter). Specifically, for example, LT = -30 degrees Celsius and UT = degrees Celsius + 60 degrees. Alternatively, for example, LT = -20 degrees Celsius, UT = 50 degrees Celsius. Or, for example, LT = −10 degrees Celsius, UT = 45 degrees Celsius. Alternatively, for example, LT = 0 degrees Celsius, UT = 40 degrees Celsius.

  The technical significance that the lower limit temperature is LT may mean that the temperature is LT or higher, or may mean that the temperature is higher than LT. The technical significance that the upper limit temperature is UT may mean that the temperature is UT or less, or that the temperature is less than UT. That is, the predetermined temperature range may or may not include the lower limit temperature. The predetermined temperature range may or may not include an upper limit temperature.

  The technical significance that the lower limit length is λ2 × (1/4) may mean that L1 is λ2 × (1/4) or more, or L1 is more than λ2 × (1/4). It may mean long. The technical significance of the upper limit length being λ1 × (1/4) may mean that L1 is λ1 × (1/4) or less, or L1 is from λ1 × (1/4). It may mean short. That is, the predetermined length range may or may not include the lower limit length. The predetermined length range may or may not include an upper limit length. The same applies to L2 and D described later.

  However, when the technical significance that the lower limit temperature is LT means that the temperature is equal to or higher than LT, in principle, the technical significance that the upper limit length is λ1 × (1/4) is , L1 is equal to or less than λ1 × (1/4). When the technical significance that the lower limit temperature is LT means that the temperature is higher than LT, the technical significance that the upper limit length is λ1 × (1/4) is, in principle, that L1 is It means shorter than λ1 × (1/4). That is, in principle, when the lower limit temperature is included in the predetermined temperature range, the upper limit length is included in the predetermined length range, and when the lower limit temperature is not included in the predetermined temperature range, the upper limit length is predetermined. Not included in the length range. The same applies to L2 and D described later.

  In addition, when the technical significance that the upper limit temperature is UT means that the temperature is UT or less, the technical significance that the lower limit length is λ2 × (1/4) is, in principle, , L1 means λ2 × (1/4) or more. When the technical significance that the upper limit temperature is UT means that the temperature is less than UT, the technical significance that the lower limit length is λ2 × (1/4) is, in principle, L1 Is longer than λ2 × (1/4). That is, in principle, when the upper limit temperature is included in the predetermined temperature range, the lower limit length is included in the predetermined length range, and when the upper limit temperature is not included in the predetermined temperature range, the lower limit length is the predetermined length range. Not included in the length range. The same applies to L2 and D described later.

  The pitch in the axial direction of the grooves may be in the above range at any part of the pair of grooves, but it is in the above range at all parts of the pair of grooves. It is preferable.

  The channel tube 10 or the first mounting tube 20 or the second mounting tube 40 between the ultrasonic transmitter 30 and the ultrasonic receiver 50 is transmitted from the ultrasonic transmitter 30 to the tube wall. This refers to a tube that exists in the path from when the ultrasonic wave propagates through the tube wall to reach the ultrasonic receiver 50.

  For example, as shown in FIG. 1 (b) as a filled portion, the groove 12 is formed in the first mounting tube 20 and the second mounting tube 40, and among the bases of the first mounting tube 20 and the second mounting tube 40. It is preferably formed in one of the flow channel pipes 10 (the flow channel pipe 10 between the broken line 22 and the broken line 42 in the figure) that connects the farthest ends.

  For example, as shown in FIG. 1 (c) as a filled portion, the groove 12 is a flow channel pipe 10 that connects the ends closest to each other among the base portions of the first mounting pipe 20 and the second mounting pipe 40 (in the drawing, Most preferably, it is formed in the flow channel 10) between the broken line 24 and the broken line 44.

  The groove 12 may not be provided in the flow path tube 10 but may be provided only in both the first attachment tube 20 and the second attachment tube 40 or in at least one of them.

  As shown in FIG. 2A, the groove 12 is preferably formed so as to go around the entire circumference of the pipe, but may be formed only in a part of the circumference of the pipe.

  The groove 12 is preferably formed on the outer wall of the tube, but may be formed on the inner wall of the tube.

  The pitch in the axial direction of the pipe is defined as L1 in FIG. 2B from the end on one side (left side in the figure) of the groove along the axial direction (left and right direction in the figure) of the pipe. It refers to the length to the end of the same side of the groove (left side in the figure).

  The ultrasonic frequency N is an ultrasonic frequency used for measurement in the ultrasonic fluid measuring device. Specifically, for example, it indicates the frequency of the ultrasonic wave transmitted from the ultrasonic transmitter 30 and received by the ultrasonic receiver 50.

  The flow path pipe 10, the first attachment pipe 20, and the second attachment pipe 40 may all be made of a single material, or a part thereof may be made of a material different from other parts. As a material constituting the tube, for example, polystyrene can be suitably used.

  In the case of resin, the speed varies depending on the glass component contained therein, but LPC (liquid crystal polymer), PPS (polyphenylene sulfide), epoxy resin, POM (polyacetal), phenol resin, PBT (polybutylene terephthalate), etc. Useful. When these materials having high gas resistance are selected, the applications are widened.

  As a specific example of the wavelength (λ1) of the sound wave of the frequency N in the tube material at −30 degrees Celsius and the wavelength (λ2) of the sound wave of the frequency N in the tube material at +60 degrees Celsius, for example, N = 1.46 MHzz When the tube material is polystyrene, λ1 = 1.69 mm and λ2 = 1.51 mm. Therefore, in the case of an ultrasonic fluid measuring device used in a temperature range of −30 degrees Celsius or more and +60 degrees Celsius or less, as a range of the pitch L1 in the axial direction of the pipe per pair of grooves, the pipe material is made of polystyrene. In this case, 0.38 mm ≦ L1 ≦ 0.42 mm.

  The method for forming the groove 12 is not particularly limited, and for example, a method such as mold forming or etching can be employed.

  The first attachment tube 20 and the second attachment tube 40 may not be provided. That is, the ultrasonic transmitter 30 and the ultrasonic receiver 50 may be directly attached to the flow channel tube 10.

  It is also clear that it can be used in extra-tube measurement using a wedge.

[Example]
Hereinafter, the ultrasonic fluid measuring apparatus 100 according to the example of the first embodiment will be described in detail with reference to FIGS. 1 and 2.

  The ultrasonic fluid measurement device 100 is an ultrasonic fluid measurement device used in a temperature range of −30 degrees Celsius or higher and +60 degrees Celsius or lower, and includes a flow channel tube 10 having a substantially rectangular cross section. The flow channel tube 10 constitutes a flow channel so as to allow fluid to flow from left to right in FIG. A first mounting tube 20 and a second mounting tube 40 extend on a surface of the flow channel tube 10 at a predetermined angle so as to branch from the flow channel with a main axis of the flow channel formed by the flow channel tube 10. It is formed as follows. The angle formed by the flow direction of the fluid flowing through the flow path and the main axis of the first mounting tube 20 is equal to the angle formed by the opposite direction of the flow direction and the main shaft of the second mounting tube 40. In other words, the first attachment tube 20 and the second attachment tube 40 are formed so as to be plane-symmetric with respect to a plane perpendicular to the fluid flow direction. The flow passage pipe 10 and the first attachment pipe 20 and one end of the second attachment pipe 40 are in communication with each other. An ultrasonic transmitter 30 is provided in the opening at the other end of the first attachment tube 20. An ultrasonic receiver 50 is provided at the opening at the other end of the second attachment tube 40.

  Each of the ultrasonic transmitter 30 and the ultrasonic receiver 50 is attached so that the ultrasonic wave transmitting / receiving surface faces the inside of the attachment tube. The ultrasonic wave transmitted from the ultrasonic transmitter 30 propagates through the fluid flowing through the inside of the flow path formed by the flow path pipe 10, and the first mounting pipe 20 on the inner wall of the flow path pipe 10. The light is reflected by the surface opposite to the surface on which the second mounting tube 40 is provided and reaches the ultrasonic receiver 50. The arrival time of the ultrasonic wave changes according to the flow rate of the fluid. Based on the change, the flow velocity or flow rate of the fluid is measured. As a specific method of measurement, a well-known method can be adopted, and detailed description thereof is omitted.

  The material constituting the flow channel tube 10 is polystyrene. In the present embodiment, as a suitable example of L1, L1 = 0.40 mm based on the wavelength (1.58 mm) of the ultrasonic wave (N = 1.46 MHz) at 23 degrees Celsius.

  In the present embodiment, the width (0.1 mm) and pitch (0.4 mm) of the groove 12 are constant, and the flow path pipe is formed on the outer wall of the flow path pipe 10 in parallel with a plane perpendicular to the main axis of the flow path pipe 10. It is formed over the entire circumference of ten. The position where the groove 12 is formed is a filled portion in FIG.

  In this embodiment, the width and depth of the two grooves 12 are equal and constant.

[First Modification]
FIG. 3A is a cross-sectional view showing an example of a schematic configuration of an ultrasonic fluid measuring apparatus according to a first modification of the first embodiment, and FIG. 3B shows a modification of the first embodiment. It is sectional drawing which shows an example of the site | part in which a groove | channel is provided in an ultrasonic fluid measuring device, FIG.3 (c) is other of the site | part in which a groove | channel is provided in the ultrasonic fluid measuring device concerning the modification of 1st Embodiment. FIG.

  As illustrated in FIG. 3, the ultrasonic fluid measurement device according to the present modification is an ultrasonic fluid measurement device used in a temperature range of −30 degrees Celsius or higher and 60 degrees Celsius or lower. 11, an ultrasonic wave transmitter 31 that is fixed to the flow pipe 11 directly through the first attachment pipe 21 or transmits ultrasonic waves, and a flow pipe 11 through the second attachment pipe 41 or directly. An ultrasonic receiver 51 that is fixed to the ultrasonic wave receiver 51 and receives an ultrasonic wave, and is located between the ultrasonic transmitter 31 and the ultrasonic receiver 51, the flow path pipe 11, the first attachment pipe 21, or the first. A pair of grooves is formed in any one of the two mounting tubes 41 so that the pitch in the axial direction of the tube is L1, the frequency of the ultrasonic wave is N, and the material constituting the portion of the tube in which the groove is formed Is the tube material, and the wavelength of the sound wave of frequency N in the tube material at -30 degrees Celsius is λ1, When the wavelength of the sound wave of the frequency N of the tube material in the Mr +60 degrees and .lambda.2, satisfy λ2 × (1/4) ≦ L1 ≦ λ1 × (1/4).

  With such a configuration, it is possible to more effectively suppress the propagation of vibration from the transmitter to the receiver through the channel tube.

  For example, as shown as a filled portion in FIG. 3B, the groove is the most common among the bases of the first mounting tube 21 and the second mounting tube 41 in addition to the first mounting tube 21 and the second mounting tube 41. It is preferably formed in one of the flow channel pipes 11 (the flow channel tube 11 between the broken line 23 and the broken line 43 in the figure) connecting the far ends.

  The groove is most preferably provided in both or either one of the first attachment tube 21 and the second attachment tube 41 as shown as a filled portion in FIG.

  As shown in FIG. 3 (a), the ultrasonic fluid measuring device 200 of the first modified example is provided with a flow channel tube 11 having a substantially rectangular cross section, and the flow channel tube 11 is left in FIG. In common with the ultrasonic fluid measuring apparatus 100, the flow path is configured to allow fluid to flow from right to left. However, the two attachment pipes are not formed on the same surface, but are formed so as to extend at a predetermined angle with respect to the main axis of the flow path formed by the flow path pipe 11 on one of two mutually facing surfaces that are different from each other. Is different in that it is.

  The first mounting tube 21 and the second mounting tube 41 are on a straight line that intersects the main axis of the flow channel tube 11 at a predetermined acute angle, and face each other across the flow channel formed by the flow channel tube 11. Provided.

  Each of the ultrasonic transmitter 31 and the ultrasonic receiver 51 is attached so that the ultrasonic wave transmitting / receiving surface faces the inside of the attachment tube. The ultrasonic wave transmitted from the ultrasonic wave transmitter 31 propagates in the fluid flowing through the inside of the flow path formed by the flow path pipe 11 and reaches the opposing ultrasonic wave receiver 51. The arrival time of the ultrasonic wave changes according to the flow rate of the fluid. Based on the change, the flow velocity or flow rate of the fluid is measured. As a specific method of measurement, a well-known method can be adopted, and detailed description thereof is omitted.

  In the present modification, the size of the flow path tube 11, the thickness of the tube wall, the material constituting the tube, the pitch and width of the grooves, the form of the grooves, and the like can be the same as in the embodiment, and thus detailed description thereof is omitted.

[Second Modification and Third Modification]
FIG. 4A is a development view showing an example of a mode in which grooves are formed in the ultrasonic fluid measuring apparatus of the example according to the example of the first embodiment, and FIG. 4B is the first embodiment. It is an expanded view which shows an example of the aspect in which a groove | channel is formed in the ultrasonic fluid measuring device concerning the 2nd modification of this, and FIG.4 (c) is an ultrasonic fluid concerning the 3rd modification of 1st Embodiment. It is an expanded view which shows an example of the aspect in which a groove | channel is formed in a measuring device. Here, the development view illustrates a state in which one end of the flow channel pipe in a direction perpendicular to the main axis is cut by a plane parallel to the main axis and opened. In each figure of FIG. 4, the upper end line and the lower end line coincide with each other in the restored flow channel pipe.

  As illustrated in FIG. 4A, in the ultrasonic fluid measurement device 100 of the example of the first embodiment, the pitch of the pair of grooves in the axial direction of the tube provided with the grooves is constant.

  As illustrated in FIG. 4B, in the ultrasonic fluid measurement device according to the second modification, the pitch of the grooves 13 in the axial direction of the tube provided with the grooves 13 is continuously changed. Has been.

The aspect in which the pitch of the grooves 13 continuously changes is not particularly limited. For example, as illustrated in FIG. 4 (b), the pitch is the minimum value _{L min,} the maximum value as _{L max,} between: _{L min} or _{L max,} continuously adapted to changes by one reciprocation May be. The change pattern can be set to draw a sine wave along the circumferential direction, for example.

  In the second modified example, except that the groove 12 is replaced with the groove 13 whose pitch is continuously changed, the first embodiment and the example may have the same configuration as described above. it can. Therefore, detailed description of common parts is omitted. It is also possible to apply the second modification to the first modification.

  According to the configuration of the second modification, there is a portion having a corresponding pitch according to a wavelength that continuously changes in a predetermined temperature range. Therefore, it is possible to effectively suppress the propagation of vibration from the transmitter to the receiver through the channel tube over a predetermined temperature range.

  As illustrated in FIG. 4C, in the ultrasonic fluid measurement device according to the third modification, the ultrasonic absorbing material 15 is disposed so as to cover a part of the groove. As the ultrasonic absorbing material, a porous material (such as a foamed polymer) that easily absorbs or attenuates ultrasonic waves is preferably used. As specific examples, for example, urethane foam, foamed polyimide, foamed silicon and the like can be suitably used. Further, even a soft material such as a vibration-absorbing gel made mainly of silicone can absorb ultrasonic waves.

  In the third modified example, except for the point that the ultrasonic absorbing material 15 is provided, the configuration similar to that described above for the first embodiment and the example thereof can be employed. Therefore, detailed description of common parts is omitted. It is also possible to apply the third modification to the first modification or the second modification. It is also possible to apply the third modification to the combination of the first modification and the second modification.

  According to the configuration of the third modification, the ultrasonic wave captured in the groove can be efficiently absorbed or attenuated by the ultrasonic absorbing material. Therefore, it is possible to more effectively suppress the propagation of vibration from the transmitter to the receiver through the channel tube.

(Second Embodiment)
FIG. 5 is a cross-sectional view showing an example of a mode in which grooves are formed in the ultrasonic fluid measuring apparatus according to the example of the second embodiment.

  The ultrasonic fluid measurement device according to the second embodiment is the ultrasonic fluid measurement device according to the first embodiment except that the depth of the groove 12 formed in the flow channel tube 10 is set to a predetermined value. The apparatus and the embodiment thereof can be configured in the same manner as described above. Therefore, detailed description of portions common to the first embodiment and the second embodiment is omitted. Also, modifications of the first embodiment can be applied to the second embodiment.

  As illustrated in FIG. 5, the ultrasonic fluid measurement device according to the second embodiment is an ultrasonic fluid measurement device used in a predetermined temperature range in which the lower limit temperature is LT and the upper limit temperature is UT. The frequency of the ultrasonic wave is N, the material constituting the portion of the tube where the groove is formed is a tube material, the wavelength of the sound wave of the frequency N in the tube material in the LT is λ1, and the frequency N in the tube material in the UT is When the wavelength of the sound wave is λ2 and the depth of the groove 12 is D, D is a predetermined depth where the lower limit depth is λ2 × (1/4) and the upper limit depth is λ1 × (1/4). Enter the range.

  In such a configuration, it is possible to more effectively suppress the propagation of vibration from the transmitter to the receiver through the channel tube.

(Third embodiment)
FIG. 6A is a cross-sectional view showing an example of a mode in which grooves are formed in the ultrasonic fluid measuring apparatus according to the example of the third embodiment, and FIG. 6B is a modified example of the third embodiment. It is sectional drawing which shows an example of the aspect in which a groove | channel is formed in the ultrasonic fluid measuring device concerning.

  The ultrasonic fluid measurement device of the third embodiment has the same configuration as that described above for the ultrasonic fluid measurement device of the first embodiment and its example, except for the groove configuration in the flow channel tube 10. can do. Therefore, detailed description of portions common to the first embodiment and the third embodiment is omitted. Also, modifications of the first embodiment can be applied to the third embodiment. It is also possible to apply the third embodiment to the second embodiment and its modifications.

  As illustrated in FIG. 6A, in the ultrasonic fluid measurement device according to the third embodiment, when L2 and L1 are constant values, between the ultrasonic transmitter 30 and the ultrasonic receiver 50. In addition to the groove 13 described in the first embodiment, a pair of the flow path pipe 10, the first attachment pipe 20, and the second attachment pipe 40 is provided with a pitch in the axial direction of the pipe that is L2. The groove 14 is formed, L2 falls within a predetermined length range in which the lower limit length is λ2 × (1/4) and the upper limit length is λ1 × (1/4), and L1 ≠ L2 is satisfied.

  In such a configuration, since the grooves that form pairs at different pitches are formed, it is possible to effectively suppress the propagation of vibration from the transmitter to the receiver through the channel tube at a plurality of different temperatures. .

  As illustrated in FIG. 6A, in the ultrasonic fluid measurement device according to the example of the third embodiment, the pair of grooves 12 having a pitch of L1 and the pair of grooves 14 having a pitch of L2 are: Each is provided separately without overlapping.

  On the other hand, as illustrated in FIG. 6B, in the ultrasonic fluid measurement device according to the modification of the third embodiment, a pair of grooves 12 having a pitch of L1 and a pair of grooves 13 having a pitch of L2. One is overlapping. That is, in FIG. 6B, the right groove of the pair of grooves 12 and the left groove of the pair of grooves 13 are the same.

  With this configuration, the same effect as that of the configuration of FIG.

  From the foregoing description, many modifications and other embodiments of the present invention are obvious to one skilled in the art. Accordingly, the foregoing description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure and / or function may be substantially changed without departing from the spirit of the invention.

  The ultrasonic fluid measurement device of the present invention is useful as an ultrasonic fluid measurement device that can more effectively suppress the propagation of vibrations from a transmitter to a receiver through a channel tube.

DESCRIPTION OF SYMBOLS 10 Channel pipe 11 Channel pipe 12 Groove 13 Groove 14 Groove 15 Ultrasonic absorption material 20 1st attachment pipe 21 1st attachment pipe 22 Broken line 23 Broken line 24 Broken line 30 Ultrasonic transmitter 31 Ultrasonic transmitter 40 2nd Attachment pipe 41 Second attachment pipe 42 Broken line 43 Broken line 44 Broken line 50 Ultrasonic receiver 51 Ultrasonic receiver 100 Ultrasonic fluid measuring apparatus 200 Ultrasonic fluid measuring apparatus

Claims (5)

An ultrasonic fluid measuring device used in a predetermined temperature range in which a lower limit temperature is LT and an upper limit temperature is UT,
A channel tube;
An ultrasonic wave transmitter that transmits ultrasonic waves by being fixed to the flow channel pipe directly or via the first attachment pipe;
An ultrasonic wave receiver that receives the ultrasonic waves and is fixed to the flow channel pipe directly or via a second attachment pipe,
The pitch in the axial direction of the pipe is L1 between the ultrasonic wave transmitter and the ultrasonic wave receiver, either the flow path pipe, the first attachment pipe, or the second attachment pipe. A pair of grooves is formed so that
The frequency of the ultrasonic wave is N, the material constituting the portion of the tube where the groove is formed is a tube material, the wavelength of the sound wave of the frequency N in the tube material in LT is λ1, and the tube material in the UT When the wavelength of the sound wave having the frequency N is λ2, the ultrasonic wave L1 falls within a predetermined length range in which the lower limit length is λ2 × (1/4) and the upper limit length is λ1 × (1/4). Type fluid measuring device.   The ultrasonic fluid measurement device according to claim 1, wherein the pitch in the axial direction is continuously changed. When L2 and L1 are constant values,
Either the flow pipe, the first attachment pipe or the second attachment pipe between the ultrasonic transmitter and the ultrasonic receiver has a pitch in the axial direction of the pipe of L2. A pair of grooves is formed so that
The L2 falls within a predetermined length range in which the lower limit length is λ2 × (1/4) and the upper limit length is λ1 × (1/4), and L1 ≠ L2 is satisfied. Ultrasonic fluid measuring device.   2. When the depth of the groove is D, D falls within a predetermined depth range in which the lower limit depth is λ2 × (1/4) and the upper limit depth is λ1 × (1/4). The ultrasonic fluid measuring device according to any one of 1 to 3.   The ultrasonic fluid measuring device according to claim 1, wherein an ultrasonic absorption material is disposed so as to cover a part of the groove.

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