JP4729848B2 - Manufacturing method of matching member, ultrasonic sensor using matching layer, and fluid flow measuring apparatus using ultrasonic sensor - Google Patents

Description

The present invention relates to a method for manufacturing an alignment member , an ultrasonic sensor using the same, and a flow measurement device for a gas or liquid fluid using the ultrasonic sensor.

  Conventionally, a method for manufacturing a matching layer used for an ultrasonic sensor or the like is, for example, as shown in (b) after mixing a microballoon 2 and a resin 3 in a container 1 as shown in FIG. The container 1 is installed in the centrifuge 4 and driven.

  And, as shown in (c), in the mixture of the microballoon 1 and the resin 2, only the first resin layer 5 mainly composed of the microballoon 1 having a low specific gravity using the specific gravity difference and the resin 3 having a high specific gravity are used. The first resin layer 5 is separated, and then only the first resin layer 5 is taken out and used as an alignment member. After processing, the alignment layer is used (see Patent Document 1).

Further, a method is disclosed in which a mixture produced by mixing a glass balloon and a resin in a container is used as it is as an alignment member without using a centrifuge (see Patent Document 2).
Japanese Examined Patent Publication No. 9-264161 JP 2001-365842 A

  However, in this conventional manufacturing method, only the first resin layer having a resin attached around the microballoon and the resin having a heavy specific gravity are used as the alignment member while the second resin layer mainly composed of the resin is formed. It is only the first resin layer.

  Therefore, since the remaining second resin layer is discarded, there is a problem that the portion that can be collected from the manufactured alignment member is limited and the production efficiency is low.

  In addition, a glass balloon and a resin are mixed in the container to create a mixture, and then the resin is thermally cured in the process of curing the resin. It will flow to the bottom.

  For this reason, the wall surface of the upper portion of the alignment member is in a deficient state of the resin portion, and the wall surface of the upper portion of the alignment member that has been thermoset in this state is formed with a nest.

  As a result, the upper portion of the matching member cannot be used as a matching layer because the unevenness of the wall surface is large, and this portion is discarded, resulting in a lower production efficiency of the matching layer.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems. An alignment member manufacturing method, an ultrasonic sensor, and an ultrasonic wave, in which the entire peripheral side wall surface of the alignment member is smooth and can be collected from the prepared alignment member as an alignment layer. An object of the present invention is to provide a flow measuring device equipped with a sensor.

In order to solve the above-mentioned conventional problems, the manufacturing method of the alignment member according to the present invention provides a suction port at an upper portion of a storage chamber formed of a hollow cylindrical storage body, and sucks from the suction port. a mixture of a thermosetting bonding material consisting of hollow spheres and the epoxy resin in the storage chamber is accommodated, then the method of manufacturing the alignment member curing the bonding material multistage manner increasing the temperature by heating,
Wherein said binding material is retained to the retaining part of the top of the container by sucking from the suction port, the reduce the viscosity of the binding material prior to curing by heating, the bonding material which is retained in the retaining part Is supplied to the side wall surface of the storage chamber, and the alignment member can maintain a smooth wall surface.

  The matching layer manufacturing method, the ultrasonic sensor using the matching layer, and the fluid flow measurement device using the ultrasonic sensor according to the present invention can extract the matching increase in which the wall surface is smooth from the matching member. The matching layer production efficiency can be increased because the matching layer having large irregularities is not sorted and discarded.

And the production efficiency of the ultrasonic sensor which mounts this matching layer also increases, and the production stability of the fluid flow measuring device equipped with this ultrasonic sensor can be remarkably improved.

The present invention, a suction port provided in the upper portion of the housing chamber formed by a hollow cylindrical housing body, a thermosetting bonding material consisting of hollow spheres and the epoxy resin in the storage chamber by sucking from the suction port In the aligning member for curing the binding material by heating in a multistage manner by heating, and sucking from the suction port into the staying portion at the upper part of the storage body. the binding material is retained, it said to lower the viscosity of the binding material prior to curing by heating, but which is adapted to supply the binding material being retained in the retaining part on the side wall surface of the containing chamber portion, thereby An alignment member having a smooth wall surface structure is obtained.

Preferably, the mixture of the hollow sphere and the binding material is cured and then cut into a predetermined length.

The matching member prepared by the above method can be used as a matching layer of an ultrasonic sensor. More specifically, a matching layer is installed on an outer wall surface of a cylindrical case in which a piezoelectric body is fixed to an inner wall surface via an adhesive layer. An ultrasonic sensor was used.

Then, at least a pair of the ultrasonic sensors are arranged in the fluid flow direction, and the fluid flow measuring device is configured to measure the velocity and / or flow rate of the fluid based on the ultrasonic propagation time between the ultrasonic sensors. It is possible.

  Hereinafter, embodiments 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 is a schematic process diagram showing a flow of a manufacturing method of an alignment member and an alignment layer in the first embodiment.

  A storage chamber 8 which is a through hole having a predetermined volume is provided in a storage body 7 shown in FIG. 1A, and a hollow sphere 9 made of glass is stored in the storage chamber 8. The hollow spheres 9 each have a particle size of 10 to 100 um, and the average particle size is about 60 um. The true density is about 0.14 to 0.18 g / cm3.

  The hollow sphere 9 made of glass has a lighter specific gravity than other fillers, has heat resistance and impact resistance, and improves physical properties such as dimensional stability and moldability when used as a filler. it can.

  The composition of the glass used is borosilicate glass. More specifically, after a raw material such as silicon oxide, boric acid, calcium carbonate, sodium carbonate or sodium sulfate is melted at a high temperature of 1000 ° C. or higher to form a glass containing a large amount of sulfur, the glass is pulverized, The fine powder is dispersed and retained in the flame to make the sulfur component foam as a foaming agent component.

As a method for filling the hollow sphere 9 into the storage chamber 8, a filter 10 such as filter paper is installed on the lower surface of the storage body 7, and the storage body 7 is installed on a vibration device that vibrates at a predetermined frequency. There is a method in which the hollow sphere 9 is put into the storage chamber 8 of the storage body 7 little by little or a predetermined amount while being vibrated by the apparatus.

  Further, there is a method in which the storage body 7 is naturally dropped from a predetermined height, the fall of the storage body 7 is stopped by some kind of storage body cradle, and the impact force (impact vibration) is used. This is a method of filling the hollow sphere 9 into the storage chamber 8 by filling the storage chamber 8 with a small amount or a fixed amount and letting the storage body 7 drop naturally from a predetermined height. In this case, the method of filling the hollow sphere 9 into the storage chamber 8 having a predetermined volume is not limited to the vibration device or the impact excitation.

  As shown in FIG. 1A, after the filter 10 is also installed on the upper surface of the storage chamber 8 of the storage body 7 filled with the hollow sphere 9, the binding material 11 is supplied and impregnated in the storage chamber 8.

  FIG. 1B shows a method of filling the binding material 11 into the storage chamber 8 filled with the hollow spheres 9.

  In order to impregnate the binding material 11, a suction port 12 is provided, and an alignment member creation jig 13 that encloses the storage body 7 is installed in a container 14 filled with the binding material 11. The suction member 12 of the alignment member creation jig 13 shown in FIG. 1B is not limited to one, and a plurality of suction ports may be provided.

  Then, as shown in FIG. 1B, the bonding material 11 in the container 14 is sucked by the vacuum pump 15 from the suction port 12 of the alignment member creation jig 13. In this way, under the low-pressure atmosphere, voids existing between the hollow spheres 9 in the storage chamber 8 are removed, and the bonding material 11 is filled between the hollow spheres 9 instead.

  The filter 10 installed on the lower side of the storage chamber 8 is for preventing the hollow sphere 9 therein from leaking, and the filter 10 provided on the upper side does not suck the hollow sphere 9 together when the binding material 11 is sucked. Because. Here, filter paper was used for the filter 10. In addition, if the objective of the filter 10 mentioned above is achieved, it will not stick to a material.

  Here, an epoxy resin that is a thermosetting resin compound was used as the bonding material 11.

  This is because the epoxy resin has little change in the shape of the resin after curing and has excellent long-term stability. Above all, the affinity with the surface of the hollow sphere 9 is high, so the binding force with the hollow sphere 9 is stably improved. To do. The epoxy resin used is a two-component curable epoxy resin. The main agent is a bisphenol A liquid epoxy resin, and the curing agent is tetrahydromethylphthalic anhydride.

The main agent and curing agent were mixed at an optimal mixing ratio and used as an epoxy resin. The specific gravity is about 1.0 to 1.2 g / cm ³ . However, the two-part curable epoxy resin is not particularly concerned here, and one-part curable epoxy resin may be used if the purpose is achieved.

  When the bonding material 11 is sucked, it is desirable to set the atmosphere and the matching layer creation jig 5 to a temperature at which the bonding material 11 is not cured and a temperature at which the viscosity of the bonding material 11 is lowered. The suction of the binding material 11 can be performed efficiently.

  Moreover, the material of the storage body 7 and the alignment member creation jig 13 was made of brass having high thermal conductivity in consideration of later heat curing. In addition, if a predetermined alignment member can be manufactured, it does not stick to a material.

When an epoxy resin is used as the binding material 11, as the curing condition of the epoxy resin this time, it is heated from room temperature, and after 80 ° C. × 2 h, a curing step of 150 ° C. × 1 h is performed through 120 ° C. × 2 h. Suction was performed at 60 ° C., which is lower than the gelation temperature of the epoxy resin.

  As shown in FIG. 2A, the housing 7 is contained in the alignment member creating jig 13 and the binding material 11 is sucked as shown in FIG. While the space between the hollow spheres 9 filled in the storage chamber 8 is filled with the binding material 11 and the mixture 16 of the hollow sphere 9 and the binding material 11 is filled, the binding material 11 that has passed through the storage chamber 8 further defines the storage chamber 8. Over this, as shown in FIG. 2 (b), the staying portion 17 of the binding material 11 is formed.

  As shown in FIG. 2 (b), it is left for a predetermined time in the state where the staying portion 17 exists. There may be a plurality of storage chambers 8 included in the storage body 7 as shown in FIG. When there are a plurality of storage chambers 8, the number of alignment members that can be manufactured at a time increases, so that the production efficiency for a predetermined manufacturing time increases.

  FIG. 3 shows an example of a storage body 7 having a plurality of storage chambers 8. The diameter of the cross-sectional area of the storage chamber 8 used at this time is 11 mm. In addition, although the cross-sectional shape of the storage body 7 and the storage chamber 8 has circular shape, it does not stick to this shape.

  In the thermostatic oven for heating and curing, the alignment member creating jig 13 is left with the housing body 7 included, and is cured by heating. In the heat curing process, the curing conditions are as follows: room temperature increases from about 27 ° C. to 80 ° C., takes about 30 minutes, is held at 80 ° C. for 2 hours, is increased to 120 ° C. over 20 minutes, and is then left at 120 ° C. for 2 hours. The temperature is raised to 150 ° C. over 20 minutes, and then the heating temperature after standing at 150 ° C. for 1 h is raised in multiple stages.

  Then, it was cooled to room temperature in a thermostat and taken out. The alignment member 18 manufactured and taken out in this manner has no staying portion 17 of the bonding material 11 and can obtain a smooth side wall surface.

  As shown in FIG. 1 (c), the mixture 16 is heat-cured together with the storage body 7, then cooled to room temperature, and a cured product using a rod-like jig is taken out from the storage body 7, and this is aligned with the alignment member 18. Get as.

  Then, as shown in FIG. 1D, this alignment member 18 is cut into a predetermined thickness by a dicing apparatus or the like to obtain a target alignment layer 19.

The surface of the container 7 including the inner wall surface of the storage chamber 8 and the surface of the alignment member creation jig 13 are covered with a material having releasability such as Teflon ( registered trademark ), so that the bonding material is cured and adhered. It is easy to peel off, and the inner wall of the storage chamber 8 is made highly peelable so that the alignment member 18 can be easily pulled out.

  The state of the mixture 16 of the hollow sphere 9 and the binding material 11 in the storage chamber 8 after the storage material 8 filled with the hollow sphere 9 is impregnated with the binding material 11 and the state of the binding material 11 are shown in FIG. As shown in (b), the suction time of the binding material 11 is adjusted so that the staying portion 17 of the binding material 11 exists above the mixture 16 in the storage chamber 8.

  The capacity of the staying portion 17 is also affected by the capacity of the storage chamber 8, but the amount that the binding material 11 of the staying portion 17 moves down along the inner wall of the storage chamber 8 after the mixture 16 is thermoset. Is the right amount.

The staying portion 17 on the storage body 7 has a lower viscosity before the bonding material 11 is heat-cured, and the gap between the hollow sphere 9 and the mixture 16 of the bonding material 11 in the storage chamber 8 and the wall surface interface in the storage chamber 8. After the stagnant portion 17 disappears and the mixture 16 is cured, the container 7 is taken out from the alignment member creation jig 13,
The alignment member 18 is removed.

  The side wall surface of the alignment member 18 can be formed smoothly with the bonding material 11.

(Embodiment 2)
FIG. 4 shows a method for manufacturing an alignment member according to Embodiment 2 of the present invention.

  As shown in FIG. 4, a retention portion 17 for the binding material 11 is provided on the mixture 16 of the hollow sphere 9 and the binding material 11 in the storage chamber 8. The heating process is carried out together with the storage body 7 in the state of the storage chamber 8 shown in FIG.

  The heating conditions are the same as those shown in the first embodiment. Due to the temperature rise in the heating step, the viscosity of the binding material 11 decreases before the staying portion 17 in the storage chamber 8 is heated and undergoes a curing reaction, and flows toward the lower portion of the staying portion 17 storage chamber 8.

  At that time, since the binding material 11 from the staying portion 17 moves between the mixture 16 in the stock storage chamber 8 and the inner wall interface of the storage chamber 8 and coats the outermost surface of the mixture 16, the binding material 11 is cured. The manufactured alignment member 18 has a side wall surface that is smoothly formed of the bonding material 11.

The alignment member 18 manufactured in the second embodiment of the present invention is compared with the side wall surface of the conventional alignment member manufactured without providing the staying portion 17.

  The storage chamber 8 of the storage body 7 is filled with a hollow sphere 9 that is a glass hollow body. The filling method is a method of filling the storage chamber 8 with a small amount of the hollow sphere 9 while allowing the storage body 7 to freely fall from a predetermined height.

  At this time, the hollow sphere 9 is filled with about 90 to 95% of the height of the side wall of the storage chamber 8. After that, the housing member 7 was included in the alignment member creation jig 13, and the two-component epoxy resin was sucked by a vacuum pump.

  Thereafter, the storage body 7 was taken out from the alignment member creation jig 13, and a mixture 16 of the hollow sphere 9 and the binding material 11 and a staying portion 17 of the binding material 11 were provided on the mixture 16 as shown in FIG. 2.

  The contents of the storage chamber 8 as shown in FIG. Curing conditions were as follows: room temperature increased from about 27 ° C. to 80 ° C. for about 30 minutes, held at 80 ° C. for 2 hours, then increased to 120 ° C. over 20 minutes, then left at 120 ° C. for 2 hours, then over 20 minutes The temperature is raised to 150 ° C., and then the heating temperature after standing at 150 ° C. for 1 h is raised in multiple stages.

  Then, it was cooled to room temperature in a thermostat and taken out.

  The alignment member 18 manufactured and taken out in this manner has no staying portion 17 of the bonding material 11 and can obtain a smooth side wall surface.

  On the other hand, after the mixture 16 was filled in the storage chamber 8, the alignment member 18 was created by raising the heating temperature in multiple stages in the same manner as described above without providing the staying portion 17 of the binding material 11.

  In this case, the alignment member taken out from the storage body 7 has an unfilled portion of the binding material 11 formed on the surface of the upper portion of the side wall, and the surface is uneven.

Since the unevenness is not sufficiently filled with the bonding material 11, it is a surface roughened portion where the hollow spheres 9 are peeled off. This generation rate occurs about 20 to 50% of the side wall length of the alignment member. The portion where the unevenness is generated is usually the upper portion of the alignment member side wall.

  This is because the viscosity of the bonding material 11 rapidly decreases immediately before heat-curing, so that the bonding material 11 that was initially on the side wall surface travels between the interface between the alignment member side wall surface and the inner wall of the storage chamber 8 due to gravity. This is because it moves and concentrates on the upper part of the alignment member.

As described above, according to the second embodiment, the staying portion 17 of the binding material 11 provided on the mixture 16 in the storage chamber 8 decreases the viscosity of the binding material 11 before heat curing.

  And since it moves between the interface of the side wall surface of the mixture 16 and the inner wall surface of the storage chamber 8 and is heated and cured in a state where the surface of the mixture 16 is covered with the bonding material 11, an alignment member 18 having a smooth side wall surface is created. can do.

(Embodiment 3)
FIG. 5 shows a method for manufacturing an alignment member according to Embodiment 3 of the present invention.

  As shown in FIG. 5, the bonding material 11 is additionally filled from above the storage chamber 8 onto the mixture 16 of the hollow sphere 9 and the binding material 11 filled in the storage chamber 8.

  FIG. 5 shows a method in which the bonding material 11 is dropped from the device 20 containing the bonding material 11 onto the storage chamber 8 filled with the mixture 16. By this method, a layer of the bonding material 11 can be provided on the mixture 16 as well as a method of sucking the bonding material 11.

  As a result, as in the first and second embodiments, the wall surface of the mixture 16 is coated on the side wall surface of the mixture 16 before heat-curing, so that the smooth alignment member 17 can be manufactured.

(Embodiment 4)
FIG. 6 shows an ultrasonic sensor using the matching layer 19 obtained by any of the first to third embodiments.

  The cylindrical case 21 made of a conductive material has a top portion 22, and the piezoelectric body 23 is bonded to the inner wall surface of the top portion 22 and the matching layer 19 is bonded to the outer wall surface.

  The lower open portion of the cylindrical case 21 is closed by a terminal plate 25 connected to one terminal 26. The other terminal 26 penetrates through the terminal plate 25 through an electrically insulating material 27 and is connected to a conductor 28 that contacts the lower surface of the piezoelectric body 23. A plurality of vertical grooves 29 are formed in the piezoelectric body 23.

  When a voltage is applied to the piezoelectric body 23 from the terminals 24 and 26 via the conductor 28, the piezoelectric body 23 vibrates due to a piezoelectric phenomenon.

  6 vibrates at about 500 KHz, and the vibration is transmitted from the case 21 to the matching layer 19, and the vibration of the matching layer 19 propagates to the gas as a sound wave.

  In general, the matching layer 19 and the top portion 22 are bonded by an adhesive. However, if minute irregularities exist on the wall surface of the matching layer 19, the adhesive starts from the irregularities and the adhesive rises to the matching layer wall surface. Since the adhesive may reach the surface of the matching layer, if the matching layer wall surface is uneven, it cannot be used as an ultrasonic sensor component.

On the other hand, since the matching layer 19 collected from the matching member 18 produced by the manufacturing method of the above embodiment has a smooth side wall surface, the phenomenon in which the adhesive reaches the matching layer 19 surface does not occur. In addition, since all of the manufactured matching layers 19 can be assembled into an ultrasonic sensor, the production efficiency is not reduced.

  Further, the ultrasonic sensor using the matching layer 19 is used in a fluid flow measuring device.

  That is, at least a pair of ultrasonic sensors are arranged on the upstream side and the downstream side in the fluid flow direction of the flow path, and the time until the ultrasonic wave transmitted from one ultrasonic sensor is received by the other ultrasonic sensor, The ultrasonic propagation time can be detected and the fluid flow rate can then be measured.

  In addition, the flow rate can be measured by calculating by involving elements such as the cross-sectional area of the flow path based on the flow velocity.

  As described above, since the ultrasonic sensor has high performance, the flow velocity and / or flow rate can be measured with high accuracy.

  As described above, the matching layer manufacturing method, the ultrasonic sensor using the matching layer, and the fluid flow measurement device using the ultrasonic sensor according to the present invention include a smooth side wall surface of the matching member. Since the smoothness of the side wall of the matching layer taken from the surface is stable, all of the manufactured matching layers can be used, greatly contributing to the improvement of manufacturing efficiency, and applied to applications such as gas and liquid fluid flow measurement devices it can.

Process explanatory drawing which shows the manufacturing process of the alignment member (A) Perspective view of an alignment member creation jig containing a storage body (b) Cross-sectional view of an alignment member creation jig provided with a stay portion on the storage body The perspective view of the storage body provided with the some storage chamber Manufacturing process diagram of staying portion and mixture in storage chamber before heat curing in Embodiment 2 of the present invention Manufacturing process diagram for additionally adding a binding material to the storage chamber in Embodiment 3 of the present invention Cross-sectional view of an ultrasonic sensor using the matching layer of the present invention Manufacturing process diagram of conventional alignment members

DESCRIPTION OF SYMBOLS 7 Storage body 8 Storage chamber 9 Hollow sphere 11 Binding material 13 Matching member preparation jig 16 Mixture 18 Matching member 19 Matching layer 21 Cylindrical case 22 Top part 23 Piezoelectric body

Claims (5)

A suction port provided in the upper portion of the housing chamber formed by a hollow cylindrical housing body, and a mixture of a thermosetting bonding material consisting of hollow spheres and the epoxy resin in the storage chamber by sucking from the suction port In the method of manufacturing an alignment member that is housed and then heated in multiple stages by heating to cure the binding material,
Wherein said binding material is retained to the retaining part of the top of the container by sucking from the suction port, the reduce the viscosity of the binding material prior to curing by heating, the bonding material which is retained in the retaining part Is supplied to the side wall surface of the inside of the storage chamber. The method of manufacturing an alignment member according to claim 1, wherein the mixture of the hollow sphere and the binding material is cured and then cut into a predetermined length. An ultrasonic sensor comprising, as a matching layer, a matching member molded by the manufacturing method according to claim 1. 3. A cylindrical case, a piezoelectric body fixed to the inner wall surface of the cylindrical case, and an alignment member molded by the manufacturing method according to claim 1 or 2 installed on the outer wall surface of the cylindrical case via an adhesive layer. Ultrasonic sensor provided as a layer. 5. A fluid flow measurement in which at least a pair of the ultrasonic sensors according to claim 3 or 4 are arranged in a fluid flow direction, and the velocity and / or flow rate of the fluid is measured based on an ultrasonic propagation time between the ultrasonic sensors. apparatus.

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