JP4850113B2 - Ultrasonic probe for high temperature and manufacturing method thereof - Google Patents

Description

  The present invention relates to an ultrasonic probe for high temperature used for an ultrasonic flaw detection test, ultrasonic thickness measurement, acoustic emission (AE) measurement, and the like, and a method for manufacturing the same.

  Ultrasonic waves can be concentrated in a specific direction in an object, and are reflected at different interfaces of acoustic impedance, that is, (density) × (sound speed). Therefore, this property can be used for ultrasonic flaw detection tests, ultrasonic thickness measurement, and the like. Moreover, since an ultrasonic wave is generated when a crack progresses, it can be used for the measurement of acoustic emission (AE) which measures the presence or absence of crack progress etc. by attaching an ultrasonic sensor. Hereinafter, these test or measurement sensors are collectively referred to as “ultrasonic probe”.

As an ultrasonic probe for an ultrasonic flaw detection test, there is one disclosed in Patent Document 1.
The ultrasonic probe of Patent Document 1 is a probe of an ultrasonic flaw detector in which an ultrasonic transmission member attached to a flaw detection object is laminated with a vibrator sandwiched between a pair of electrodes. The vibrator is formed of lithium niobate, and the vibrator and the ultrasonic transmission member are directly joined with an aluminum-based brazing material to form a heat resistant electrode layer. With the above configuration, the ultrasonic probe of Patent Document 1 increases the allowable temperature limit for heat resistance to 550 to 600 ° C.

  However, since the ultrasonic probe of Patent Document 1 directly joins the transducer and the ultrasonic transmission member with an aluminum-based brazing material, the yield due to brazing failure is low, stable quality is difficult to obtain, and the manufacturing time is short. Is long and manufacturing cost is high. In addition, aluminum brazing filler metals have alloy components such as magnesium added to aluminum and have a melting point of about 600 ° C, and the brazing part will deteriorate over time immediately below the melting point. The temperature is high (550 to 600 ° C.), but the performance deteriorates drastically when used repeatedly for a long time. For this reason, when it uses continuously for a period of several years, use temperature is restrict | limited to about 450 degreeC or less. Further, when the sensor mounting position is high temperature, the brazed portion is softened, and when it is severe, the joint is peeled off and accurate measurement cannot be performed.

In order to solve the above problem, the present applicant has developed and applied for an ultrasonic probe for high temperature shown in FIG.
This high-temperature ultrasonic probe has a conductive pedestal 12 having a detection outer surface 12a in contact with the surface to be measured 1 and a detection inner surface 12b which is a plane having an arbitrary angle with respect to the detection outer surface 12a, and a detection inner surface 12b. A plate-like piezoelectric element 16 that is in close contact via a first heat-resistant soft metal (first electrode) 14a, and a conductive material that pressurizes the piezoelectric element 16 toward a detection inner surface 12b via a second heat-resistant soft metal (second electrode) 14b. Pressure member 18, heat-resistant urging member (laminated disc spring) 20 that urges pressure member 18 toward detection inner surface 12 b, and contact with heat-resistant urging member 20 to receive a reaction force of the urging force. Reaction force receiving member 22. Further, the ultrasonic probe includes a main body 10. One end of the main body 10 is connected to a pedestal 12, and a first heat-resistant soft metal 14a, a piezoelectric element 16, a second heat-resistant soft metal 14b, a pressure member 18, a heat-resistant biasing member 20, It has the hollow cavity 11 which accommodates the reaction force receiving member 22, and has the receiving member moving means 21 which can move the reaction force receiving member 22 toward the detection inner surface 12b at the other end. The reaction force receiving member 22 is made of an insulator, whereby the pedestal 12 and the pressure member 18 are electrically insulated from each other. Due to the deformation of the first heat-resistant soft metal 14a and the second heat-resistant soft metal 14b, the piezoelectric element 16, the detection inner surface 12b, and the pressure member 18 are in close contact with each other.

  The high-temperature ultrasonic probe configured as described above sandwiches the piezoelectric element 16 between the pressure member 18 and the detection inner surface 12b via the first heat-resistant soft metal 14a and the second heat-resistant soft metal 14b, In addition, since the first heat-resistant soft metal 14a and the second heat-resistant soft metal 14b are deformed by the urging force of the heat-resistant urging member 20, the piezoelectric element 16, the detection inner surface 12b, and the pressure member 18 are brought into close contact with each other. It has the feature of eliminating different boundary surfaces and reducing noise reflection. In addition, it can be manufactured without using special processes such as brazing in a vacuum furnace, increasing yield, stabilizing quality, shortening manufacturing time and reducing manufacturing cost, and can be used repeatedly over a long period of time Even in this case, there is little performance degradation and accurate measurement is possible even when the mounting position is high.

Japanese Patent Publication No. 07-46095 JP 2005-304777 A

However, the conventional high-temperature ultrasonic probe has the following problems. In the manufacturing process of the high-temperature ultrasonic probe, the receiving member moving means 21 is rotated and moved to the base 12 side, and the first heat-resistant soft metal 14a and the second heat-resistant soft metal are caused by the elastic force of the heat-resistant biasing member 20. 14b is deformed to bring the piezoelectric element 16 and the pedestal 12 and the pressure member 18 into close contact with each other, but when the receiving member moving means 21 is rotated, the rotational force is applied to the pressure receiving member 22, the heat-resistant urging member 20 and It is transmitted to the second heat-resistant soft metal 14a, the piezoelectric element 16, the first heat-resistant soft metal 14a, and the pedestal 12 through the pressure member 18, and slip may occur between these members. In this case, since the adhesiveness of the piezoelectric element 16 is lowered, there is a problem that the ultrasonic transmission characteristics are deteriorated and the yield is lowered.
Further, since the applied pressure at this time depends on the amount of contraction of the spring, the relationship between the amount of contraction of the spring and the applied pressure is obtained in advance, and the number of rotations of the screw is rotated by an amount corresponding to the amount of contraction with respect to the required applied force. It was necessary to let them. However, since the screw is tightened against the reaction force of the spring, the screw part bites in and it is difficult to rotate the screw smoothly, and an accurate pressure is applied for play of the screw part and assembly accuracy of each member. It was difficult.

  The present invention has been made in view of the above-described problems. An ultrasonic probe for high temperature which can improve ultrasonic transmission characteristics and improve yield by improving adhesiveness of a piezoelectric element, and its manufacture. It is an object to provide a method.

In order to solve the above-described problems, the high-temperature ultrasonic probe and the manufacturing method thereof according to the present invention employ the following means.
(1) The high-temperature ultrasonic probe of the present invention includes a conductive pedestal having a detection outer surface that is brought into contact with a surface to be inspected and a detection inner surface that is a plane having an arbitrary angle with the detection outer surface, and the detection inner surface. A first electrode made of a heat-resistant soft metal in close contact with the plate, a plate-like piezoelectric element in close contact with the first electrode sandwiched between the first electrode and the pedestal, and the piezoelectric element with the first electrode A second electrode made of a heat-resistant soft metal that is in close contact with the piezoelectric element in a sandwiched manner, and a heat-resistant biasing member that elastically biases the piezoelectric element toward the detection inner surface via the second electrode A pressing member that presses the heat-resistant biasing member toward the detection inner surface, and one end connected to the pedestal, and the first electrode, the piezoelectric element, the second electrode, and the heat-resistant biasing inside A main body for housing the member and the pressing member, and the pressing member screwed into the main body And a support means for receiving a reaction force from the pressing member on the other end side of the main body, and the supporting means is configured to apply a pressing force to the pressing member from the outside toward the detection inner surface. It has 1 through-hole, The said pressing member has a receiving part which receives the said pressing force, It is characterized by the above-mentioned.

According to the above configuration, since a predetermined load (pressing force) is directly applied to the pressing member by an external force, the heat-resistant biasing member is deformed with an accurate load, and the first electrode, the piezoelectric element, and the second electrode are accurately detected. Weight can be added. This also makes it possible to easily restrain the rotation of the pressure member around the axis relative to the pedestal even when a rotational force is applied by the support means. Therefore, in the manufacturing process, in a state where the rotation of the pressure member around the axis with respect to the pedestal is constrained, the support means is rotated around the axis and moved in the axial direction so that the heat-resistant urging member is accurately attached. Since compression can be performed with an appropriate load, the pressing member does not rotate even if the support means is rotated. For this reason, no slip occurs between the second electrode, the piezoelectric element, the first electrode, and the pedestal, so that the adhesion between them is accurately maintained.
Therefore, according to the present invention, the ultrasonic transmission characteristics can be improved by improving the adhesion of the piezoelectric element, the yield can be improved, and the measurement accuracy can be improved.

(2) In the above high-temperature ultrasonic probe,
The support means includes a screw member screwed into the main body and having the first through hole, and an auxiliary screw part screwed into the screw member, and the screw member is opened at a position facing the pressing member. The auxiliary screw part is screwed into the second through hole of the screw member to contact and support the pressing member. That is, even when the electrode is deformed and the deformation amount of the heat-resistant urging member is reduced, an external load is applied to give a predetermined amount of deformation to the heat-resistant urging member, and the auxiliary screw component is turned to closely contact the holding member. Thus, a predetermined pressure can be maintained.

In the manufacturing process of the high-temperature ultrasonic probe having the above-described configuration, the heat-resistant biasing member is compressed by applying an accurate load to the pressing member by an external force to apply a load toward the detection inner surface, and a pressure member for the base The rotation of the support member is rotated around the axis in a state where the rotation of the pressure member is constrained, and the support member is moved in the axial direction so as to be in close contact with the pressing member. By heating the whole, the first electrode and the second electrode are deformed (plastically deformed), and the adhesion between the first electrode and the second electrode and a member in contact with the first electrode and the second electrode is improved.
At this time, when the deformation of the first electrode and the second electrode is large, the shrinkage amount of the heat-resistant biasing member is reduced, and the compression force inside the main body is reduced. For this reason, if an impact force is applied during use of the ultrasonic probe, there is a risk that the adhesion of the electrode is impaired.
In the present invention, in this case, a predetermined load can be applied to the inside by rotating the auxiliary screw part about the axis and moving it to a position where it comes into contact with the pressing member. That is, a predetermined load is continuously applied to the pressing member during heating. At this time, a gap is generated between the screw member and the pressing member due to shrinkage due to plastic deformation of the heat-resistant biasing member in addition to thickness reduction due to the deformation of the first electrode and the second electrode. It can be adjusted to a predetermined weight depending on the part. In addition, by continuing to add a load from the outside during high-temperature heating, even if the spring characteristics of the heat-resistant biasing member change in temperature due to changes in the Young's modulus of the spring material or plastic deformation, a constant load is maintained inside the body. It can be fixed with an auxiliary screw.
By using the auxiliary screw component, for example, even if the outer peripheral screw of the support member is seized, the function can be easily maintained.

(3) In the above-described high-temperature ultrasonic probe, the heat-resistant biasing member is a plurality of disc springs made of a heat-resistant metal, and the plurality of disc springs are arranged to align the central axes of the plurality of disc springs. A column member is inserted into the central hole of the column member, and the thermal expansion coefficient of the column member is substantially equal to or smaller than the thermal expansion coefficient of the disc spring. With this configuration, the central axes of the plurality of disc springs can be matched. Further, it is possible to prevent the disc spring from biting into the support member due to thermal expansion during heating.

(4) Further, the present invention is the above-described method for manufacturing a high-temperature ultrasonic probe according to (1), wherein (a) the pedestal is connected to one end of the main body, and is directed from one end of the main body to the other. Preparing a state in which the first electrode, the piezoelectric element, the second electrode, the heat-resistant biasing member, the pressing member, and the supporting means are arranged in order, (b) pressing against the pressing member from the outside Applying pressure to shrink the heat-resistant biasing member and applying compressive stress to the first electrode, the piezoelectric element, and the second electrode; and (c) rotating the support means to rotate the support means. Fixing the compressive stress applied to the first electrode, the piezoelectric element, and the second electrode by receiving a part or all of the reaction force from the pressing member by the supporting means. And (d) Steps (b) and (c) above are completed. Thereafter, the first electrode and the second electrode are deformed by heating the main body and the entire member accommodated therein, and the first electrode and the second electrode, and a member in contact with the first electrode and the second electrode, A step of improving the adhesion of the substrate.

(5) Further, the present invention is the method for manufacturing a high-temperature ultrasonic probe according to (2), wherein (a) the pedestal is connected to one end of the main body, and the one end of the main body is directed from one end to the other. Preparing a state in which the first electrode, the piezoelectric element, the second electrode, the heat-resistant biasing member, the pressing member, and the supporting means are arranged in order, (b) pressing against the pressing member from the outside Applying pressure to shrink the heat-resistant biasing member and applying compressive stress to the first electrode, the piezoelectric element, and the second electrode; and (c) rotating the support means to rotate the support means. Fixing the compressive stress applied to the first electrode, the piezoelectric element, and the second electrode by receiving a part or all of the reaction force from the pressing member by the supporting means. And (d) Steps (b) and (c) above are completed. Then, the first electrode and the second electrode are deformed by heating the main body and the entire member accommodated therein while applying a load to the pressing member, and the first electrode and the second electrode are deformed. A step of increasing the adhesion between the second electrode and a member in contact with the second electrode; and (e) after the step (d), the auxiliary screw component is rotated and moved in the axial direction to rotate the auxiliary screw component. And a step of supporting the pressing member.

According to the manufacturing methods of the above (4) and (5), the heat urging member is moved by rotating the supporting means around the axis and moving in the axial direction in a state where the rotation around the axis of the pressing member with respect to the base is constrained. Since compression is possible, the pressing member does not rotate even if the support means is rotated. For this reason, no slip occurs between the second electrode, the piezoelectric element, the first electrode, and the pedestal, and the adhesion between them is maintained. Moreover, since a weight is added from the outside, an accurate weight is added. Therefore, by improving the adhesion of the piezoelectric element, the ultrasonic transmission characteristics can be improved and the yield can be improved.
Moreover, according to the manufacturing method of said (5), in the state which added external force even when the clearance gap produced between the screw member and the pressing member in the manufacturing process, or when the shrinkage amount of the heat-resistant biasing member decreased, By rotating the auxiliary screw part about the axis and moving it to a position where it comes into contact with the pressing member, the gap can be filled, so that the adhesiveness of the piezoelectric element can be maintained.

  According to the present invention, it is possible to improve the ultrasonic transmission characteristics by improving the adhesion of the piezoelectric element, and to obtain an excellent effect that the yield can be improved.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

[First Embodiment]
FIG. 1 is a cross-sectional view of a high-temperature ultrasonic probe A according to the first embodiment of the present invention. As shown in this figure, the ultrasonic probe for high temperature includes a pedestal 12, a first electrode 14a, a piezoelectric element 16, a second electrode 14b, a heat-resistant biasing member 20, a pressing member 30, a main body 10, and support means 29. Is provided. In the following description, the “one end” of the main body 10 is an end portion on the inspection target surface 1 side, and the “other end” of the main body 10 is an end portion opposite to the one end.

The pedestal 12 is a conductive member, and in this example, the pedestal 12 is connected to the main body 10 by a screw portion 13a. Here, the screw portion 13 a includes a male screw portion formed on the outer peripheral surface of the pedestal 12 and a female screw portion formed on the inner peripheral surface of the main body 10. The pedestal 12 has a detection outer surface 12a that is brought into contact with the inspection target surface 1 and a detection inner surface 12b that is a plane having an arbitrary angle with respect to the detection outer surface 12a. In the present embodiment, the detection inner surface 12b is parallel to the detection outer surface 12a.
The contact surface between the detection outer surface 12a and the surface 1 to be inspected is connected so as not to generate a boundary surface having greatly different acoustic impedance by means not shown (for example, contact medium, pressure bonding, welding, brazing, adhesion).

  The first electrode 14 a is in close contact with the detection inner surface 12 b of the pedestal 12. The second electrode 14b is in close contact with the piezoelectric element 16 so as to sandwich the piezoelectric element 16 with the first electrode 14a. Both the first electrode 14a and the second electrode 14b are flat plates made of a heat-resistant soft metal that is plastically deformed in a state where a predetermined compressive load is applied in a predetermined temperature range (for example, 100 to 600 ° C.). The heat-resistant soft metal is preferably made of, for example, gold, silver, copper, aluminum, or an alloy thereof. The second electrode 14 b is in close contact with the conductive flat plate 31, and the second plate 14 b is uniformly weighted by the conductive flat plate 31. The conductive flat plate 31 is connected to a cable 2 in which a conductive wire is covered with a heat-resistant insulating material.

  The piezoelectric element 16 has a flat plate shape and is in close contact with the first electrode 14a so as to sandwich the first electrode 14a with the pedestal 12. The piezoelectric element 16 is preferably a lithium niobate single crystal having a Curie point near 1200 ° C.

The heat-resistant urging member 20 elastically urges the piezoelectric element 16 toward the detection inner surface 12b via the second electrode 14b.
The heat-resistant urging member 20 is a compression spring made of a heat-resistant metal having a high elastic modulus in a predetermined temperature range (for example, 100 to 600 ° C.), for example, a laminated disc spring made of inconel or austenitic stainless steel. In order to obtain the amount of deflection and the spring constant required in a predetermined temperature range, the disc springs are preferably stacked in series and used in layers.

  In order to align the central axis of the disc spring, the support member 18 is placed through the central hole of the disc spring. The disc spring support member is made of a material having a thermal expansion coefficient equal to or smaller than that of the disc spring material, and is designed so that the disc spring does not bite into the support member 18 due to thermal expansion during heating. ing. Further, the support member 18 is provided with a through hole through which the cable 2 is passed.

  Further, a heat-resistant insulating member 17 is sandwiched between the support member 18 and the conductive flat plate 31, and the disc spring support member 18 and the second electrode 14b are electrically insulated from each other. The heat-resistant insulating member 17 is provided with a through hole through which the cable 2 is passed. The heat-resistant insulating member 17 is preferably made of ceramics.

  One end of the main body 10 is connected to the pedestal 12 with a screw portion 13a, and the first electrode 14a, the piezoelectric element 16, the second electrode 14b, the conductive flat plate 31, the heat-resistant insulating member 17, and the support are formed inside (hollow portion 11). The member 18 and the heat urging member 20 are accommodated. In this example, the main body 10 is composed of two hollow cylindrical body members 10a and 10b that are screwed together and coupled to each other with a screw portion 13b. In this example, the two main body members 10a and 10b are composed of conductive members. The body members 10a and 10b and the pedestal 12 may be integrally molded.

The support means 29 is screwed into the main body 10 and receives a reaction force from the pressing member 30 on the other end side of the main body 10 with respect to the pressing member 30. In the present embodiment, the support means 29 is a screw member 24 that is screwed into the main body 10 with the screw portion 13b. The screw member 24 has a first through hole 25 for applying a pressing force from the outside to the pressing member 30 toward the detection inner surface 12b. The holding member 30 is provided with a through hole for passing the cable 2. The diameter of the hole is sufficiently smaller than the diameter of the first through hole 25 provided in the screw member 24, and a receiving portion 32 that receives a pressing force from the outside is provided in a portion of the pressing member 30 that is smaller than the first through hole 25. .
Since the support means 29 is configured as described above, it can be moved in the axial direction (vertical direction in FIG. 1) by rotating around the axis to compress the heat-resistant biasing member 20.

  According to the high-temperature ultrasonic probe A having the above configuration, heat resistance is applied by applying a load (pressing force) to the receiving portion 32 from the outside through the first through hole 25 of the screw member 24. The member 20 is contracted, and the piezoelectric element 16 is sandwiched between the conductive plate 31 and the detection inner surface 12b via the first electrode 14a and the second electrode 14b, and the first electrode 14a and the second electrode 14b are deformed ( Since the piezoelectric element 16 and the detection inner surface 12b and the conductive flat plate 31 are brought into close contact with each other by plastic deformation), a boundary surface having greatly different acoustic impedances can be eliminated, and reflection as noise can be reduced.

  Further, since the conductive flat plate 31 and the column member 18 are electrically insulated from each other, a voltage is applied between the first electrode 14a and the second electrode 14b, or the first electrode 14a and the second electrode 14b. By measuring the voltage between the electrodes 14b, an ultrasonic flaw detection test, an ultrasonic thickness measurement, an acoustic emission (AE) measurement, and the like can be performed.

  Next, with reference to FIG. 2A, FIG. 2B, and FIG. 2C, the manufacturing method of the ultrasonic probe A for high temperature of this embodiment is demonstrated.

As shown in FIG. 2A, a pedestal 12 is connected to one end of the main body 10, and the first electrode 14a, the piezoelectric element 16, the second electrode 14b, the conductive flat plate 31, and the heat-resistant insulation are sequentially arranged from one end of the main body 10 to the other end. A state is prepared in which the member 17, the support material 18, the heat-resistant biasing member 20, the pressing member 30, and the support means 29 (screw member 24) are arranged.
Next, a load is applied by the press 43 toward the detection inner surface 12 b with respect to the pressing member 30 through the push rod 41. The application of the load to the pressing member 30 also serves to restrain the rotation of the pressing member 30 around the axis. In this embodiment, the pressing rod 41 is sandwiched between the press 43 and the pressing member 30, and the pressing member 30 is pressed by the press 43 via the pressing rod 41. As a result, the heat-resistant urging member 20 is contracted. The push bar 41 is formed with a hole and a groove for taking out from the side surface through the cable 2, and also serves to protect the cable 2 from being subjected to a press load.

Next, as shown in FIG. 2B, in a state where the rotation of the pressing member 30 around the axis is constrained, the screw member 24 is brought into close contact with the pressing member 30 by rotating the supporting means 29 around the axis and moving in the axial direction. Let The degree of adhesion can also be read by a change in press load.
Next, the first electrode 14a and the second electrode 14b are deformed (plastically deformed) by heating the main body 10 and the entire members accommodated therein using the heating furnace 42, and the first electrode 14a. And the adhesiveness of the 2nd electrode 14b and the member which contacts these is improved. The heating temperature is 600 ° C., for example.
After the heating is stopped, when the high-temperature ultrasonic probe A is cooled to about room temperature, it is taken out from the heating furnace 42.
FIG. 2C shows a diagram in which a connector 44 is attached to the first through hole 25 of the screw member 24 to obtain a final product.

In the present embodiment, an example in which the press 43 is pressed and then heated while being pressed is shown. However, after pressurizing with the press and the pressing member 30 and the screw member 24 are brought into close contact with each other, the pressurization may be stopped and heating may be performed. . In addition, in order to re-adjust the weight that is cooled after heating and relieved by the plastic deformation of the electrode, the weight may be applied again by the press 43, and the screw member 24 may be further rotated to compensate the weight. Further, a weight may be applied by a press, and the screw member 24 may be rotated at a normal temperature after heating to be in close contact with the pressing member 30.
Moreover, although the pressing member 30 is configured in a flat plate shape in the present embodiment, it may be integrated with the push rod 41 and applied with a load by the press 43 directly or via a jig.

According to the above-described embodiment, in the manufacturing process, the piezoelectric element 16, the first electrode 14 a, and the second electrode 14 b are pressed, and the support means 29 is rotated around the axis and moved in the axial direction, thereby heat-resistant biasing. Since the member 20 can be compressed, even if the support means 29 is rotated, no slip occurs between the second electrode 14b, the piezoelectric element 16, the first electrode 14a and the pedestal 12. Is retained. In addition, a predetermined pressure can be accurately applied from the outside.
Therefore, according to the present invention, it is possible to improve the ultrasonic transmission characteristics by improving the adhesion of the piezoelectric element 16 and improve the yield.

[Second Embodiment]
FIG. 3 is a cross-sectional view of the high-temperature ultrasonic probe B according to the second embodiment of the present invention. In the present embodiment, the configuration of the support means 29 is different from that of the first embodiment.
In the present embodiment, the support means 29 includes a screw member 24 that is screwed into the main body 10 and an auxiliary screw component 28 that is screwed into the screw member 24. The screw member 24 further includes a second through hole 26 that opens at a position facing the pressing member 30. The auxiliary screw component 28 is screwed into the through hole 26 of the screw member 24 and supports the holding member 30 in contact therewith. Other configurations are the same as those in the first embodiment.

  Next, with reference to FIGS. 4A to 4C, a method for manufacturing the high-temperature ultrasonic probe B of the present embodiment will be described.

, Pedestal 12, first electrode 14 a, piezoelectric element 16, second electrode 14 b, heat-resistant urging member 20, pressing member 30, main body 10, and support means 29.
As shown in FIG. 4A, a pedestal 12 is connected to one end of the main body 10, and the first electrode 14 a, the piezoelectric element 16, the second electrode 14 b, the heat-resistant biasing member 20, and the presser are sequentially arranged from one end to the other end of the main body 10. A state in which the member 30 and the support means 29 (the screw member 24 and the auxiliary screw component 28) are arranged is prepared. At this time, the auxiliary screw component 28 is not protruded from the end surface of the screw member 24 on the pressing member 22 side.
Next, a predetermined load is applied by the press 43 toward the detection inner surface 12 b with respect to the pressing member 30 through the push rod 41. The application of the load to the pressing member 30 also serves to restrain the rotation of the pressing member 30 around the axis.

Next, as shown in FIG. 4B, in a state where the rotation of the pressing member 30 around the axis is constrained, the screw member 24 is rotated around the axis and moved in the axial direction to compress the heat-resistant biasing member 20.
Next, the first electrode 14a and the second electrode 14b are deformed (plastically deformed) by heating the main body 10 and the entire member accommodated therein while applying a load to the pressing member 30, The adhesion between the first electrode 14a and the second electrode 14b and the member that contacts them is enhanced. The heating temperature is 600 ° C., for example. When the heating is finished, the high-temperature ultrasonic probe B is taken out from the heating furnace 32.

  In the above process, when the deformation of the first electrode 14a and the second electrode 14b is large, the shrinkage amount of the heat-resistant urging member 20 is reduced, and the compression force inside the main body is reduced. For this reason, if an impact force is applied during use of the ultrasonic probe, there is a risk that the adhesion of the electrode is impaired. At this time, in addition to the thickness reduction due to the deformation of the first electrode 14a and the second electrode 14b, there is a gap between the screw member 24 and the pressing member 30 due to the shrinkage due to the plastic deformation of the heat-resistant biasing member 20. Although this occurs, as shown in FIG. 4C, this can be adjusted to a predetermined load by the auxiliary screw component 28. That is, even when the first electrode 14a and the second electrode 14b are deformed and the deformation amount of the heat-resistant urging member 20 is reduced, an external load is applied to give a predetermined deformation amount to the heat-resistant urging member 20, thereby assisting. A predetermined pressurizing force can be maintained by rotating the screw component 28 and bringing it into close contact with the pressing member 24.

Further, by continuously applying a load from the outside during high-temperature heating, even if the spring characteristics of the heat-resistant biasing member 20 change in temperature due to a change in the Young's modulus of the spring material or plastic deformation, or the main body 10 and the electrode 14, piezoelectric Even when a difference in thermal expansion during heating due to a difference in thermal expansion coefficient from the element 16, the heat-resistant biasing member 20, the pressing member 30, etc. occurs, the auxiliary screw component 28 is maintained with a constant weight maintained inside the main body. Can be fixed. In this case, the auxiliary screw component 28 is preferably moved after the main body 10 and the members accommodated therein are cooled to about room temperature.
By using the auxiliary screw component 28, for example, even if the outer peripheral screw of the screw member 24 is seized, the function can be easily maintained.

FIG. 5 is a diagram showing the performance test results of the present invention (A) and the prior arts (B-1) and (B-2). In the prior art (high-temperature ultrasonic probe in FIG. 6), the second electrode 14b, the piezoelectric element 16, the first electrode 14a, and the pedestal 12 slip between each other, and the adhesion between them deteriorates. The yield is about 20%, and in the failure example (B-1), the reflected echo cannot be identified from the bottom surface (detected outer surface 12a of the base 12). In the successful example (B-2), the echo height sensitivity was 28 dB (45%).
On the other hand, in the present invention (A), the yield was about 100%, and the echo height sensitivity was improved by 8 dB compared with the successful example (B-2) of the prior art.
Therefore, from this performance test result, it was proved by the present invention that the ultrasonic transmission characteristics can be improved and the yield can be improved by improving the adhesion of the piezoelectric element.

  Although the embodiments of the present invention have been described above, the embodiments of the present invention disclosed above are merely examples, and the scope of the present invention is not limited to these embodiments. . The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

It is sectional drawing of the ultrasonic probe for high temperature concerning 1st Embodiment of this invention. It is a figure for demonstrating the manufacturing method of the ultrasonic probe for high temperature concerning 1st Embodiment of this invention. It is another figure for demonstrating the manufacturing method of the ultrasonic probe for high temperature concerning 1st Embodiment of this invention. It is another figure for demonstrating the manufacturing method of the ultrasonic probe for high temperature concerning 1st Embodiment of this invention. It is sectional drawing of the ultrasonic probe for high temperature concerning 2nd Embodiment of this invention. It is a figure for demonstrating the manufacturing method of the ultrasonic probe for high temperature concerning 2nd Embodiment of this invention. It is another figure for demonstrating the manufacturing method of the ultrasonic probe for high temperature concerning 2nd Embodiment of this invention. It is another figure for demonstrating the manufacturing method of the ultrasonic probe for high temperature concerning 2nd Embodiment of this invention. It is a figure which shows the performance test result of this invention (A) and prior art (B-1) and (B-2). 6 is a cross-sectional view of a high-temperature ultrasonic probe disclosed in Patent Document 2. FIG.

Explanation of symbols

A, B Ultrasonic probe for high temperature 1 Inspection target surface 2 Cable 10 Main body 10a, 10b Main body member 11 Hollow portion 12 Base 12a Detection outer surface 12b Detection inner surface 13a, 13b, 13c Screw portion 14a First electrode 14b Second electrode 16 Piezoelectric element 17 Heat-resistant insulating member 18 Strut member 20 Heat-resistant biasing member 25 First through hole 24 Screw member 26 Second through-hole 28 Auxiliary screw component 29 Support means 30 Holding member 31 Conductive flat plate 32 Receiving portion 41 Push rod 42 Heating furnace 43 Press

Claims (5)

A conductive pedestal having a detection outer surface that is brought into contact with the surface to be inspected and a detection inner surface that is a plane having an arbitrary angle with the detection outer surface;
A first electrode made of a heat-resistant soft metal in close contact with the detection inner surface;
A plate-like piezoelectric element that is in close contact with the first electrode in a form sandwiching the first electrode with the pedestal;
A second electrode made of a heat-resistant soft metal that is in close contact with the piezoelectric element so as to sandwich the piezoelectric element with the first electrode;
A heat-resistant biasing member that elastically biases the piezoelectric element toward the detection inner surface via the second electrode;
A pressing member that presses the heat urging member toward the detection inner surface;
One end is connected to the pedestal, and a main body that houses the first electrode, the piezoelectric element, the second electrode, the heat-resistant biasing member, and the pressing member inside,
A support means for screwing into the main body and receiving a reaction force from the pressing member on the other end side of the main body with respect to the pressing member;
The support means has a first through hole for applying a pressing force to the pressing member from the outside toward the detection inner surface,
The high-temperature ultrasonic probe, wherein the pressing member has a receiving portion that receives the pressing force. The support means includes a screw member screwed into the main body and having the first through hole, and an auxiliary screw part screwed into the screw member.
The screw member has a second through hole that opens at a position facing the pressing member,
2. The high-temperature ultrasonic probe according to claim 1, wherein the auxiliary screw component is screwed into a second through hole of the screw member to contact and support the pressing member. The heat-resistant urging member is a plurality of disc springs made of a heat-resistant metal,
In order to align the central axis of the plurality of disc springs, a support member is inserted through the central hole of the plurality of disc springs,
The high-temperature ultrasonic probe according to claim 1 or 2, wherein a thermal expansion coefficient of the support member is substantially equal to or smaller than a thermal expansion coefficient of the disc spring. A method for producing an ultrasonic probe for high temperature according to claim 1,
(A) The pedestal is connected to one end of the main body, and the first electrode, the piezoelectric element, the second electrode, the heat-resistant biasing member, the pressing member, Preparing a state in which the support means is disposed;
(B) applying a pressing force to the pressing member from the outside to contract the heat-resistant biasing member, and applying a compressive stress to the first electrode, the piezoelectric element, and the second electrode;
(C) rotating the support means to bring the support means into intimate contact with the pressing member and receiving part or all of the reaction force from the pressing member with the supporting means; the first electrode; the piezoelectric element; After the step of fixing the compressive stress applied to the second electrode and (d) the steps (b) and (c) are completed, the main body and the entire member accommodated therein are heated. And a step of deforming the first electrode and the second electrode to improve adhesion between the first electrode and the second electrode and a member in contact with the first electrode and the second electrode. Manufacturing method of tentacles. A method for producing an ultrasonic probe for high temperature according to claim 2,
(A) The pedestal is connected to one end of the main body, and the first electrode, the piezoelectric element, the second electrode, the heat-resistant biasing member, the pressing member, Preparing a state in which the support means is disposed;
(B) applying a pressing force to the pressing member from the outside to contract the heat-resistant biasing member, and applying a compressive stress to the first electrode, the piezoelectric element, and the second electrode;
(C) rotating the support means to bring the support means into intimate contact with the pressing member and receiving part or all of the reaction force from the pressing member with the supporting means; the first electrode; the piezoelectric element; After the step of fixing the compressive stress to be applied to the second electrode and (d) the steps (b) and (c) are finished, the main body and the inside thereof are applied with the load applied to the pressing member. Heating the entire accommodated member to deform the first electrode and the second electrode to increase the adhesion between the first electrode and the second electrode and the member in contact therewith; and (E) After the step (d), the step of supporting the pressing member with the auxiliary screw component by rotating the auxiliary screw component and moving it in the axial direction includes a step for high temperature use. Manufacturing method of acoustic probe

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