JP2010184079A - Ultrasonic probe and ultrasonic treatment device, and manufacturing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic probe which is improved in performance for transmission of ultrasonic vibration. <P>SOLUTION: The ultrasonic probe 28, which is a metal-made ultrasonic probe for transmitting ultrasonic vibration, has at least one part of the metal tissue that has anisotropy along the direction to transmit the ultrasonic vibration. The metal tissue, which has anisotropy along an axial direction, facilitates the ultrasonic vibration to be transmitted in the axial direction, allowing improvement of the ultrasonic probe 28 in performance for transmission of ultrasonic vibration. In an ultrasonic treatment device, the treatment performance to coagulate and dissect the tissue of a human body is improved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a metallic ultrasonic probe that transmits ultrasonic vibrations, an ultrasonic treatment apparatus having the ultrasonic probe, and methods for manufacturing the same.

  In the ultrasonic incision and coagulation apparatus disclosed in Patent Document 1, an ultrasonic probe is used. Such an ultrasonic probe is long and has a rod shape, and transmits ultrasonic vibration in the axial direction from the proximal end side to the distal end side. The ultrasonic probe is formed by cutting a metal bar blank into a product shape.

JP 9-38099 A

  The metal structure of the blank is isotropic and remains isotropic after cutting. With regard to an isotropic metal structure, the orientation directions of a large number of crystals in the metal structure are random. For this reason, it is easy for ultrasonic vibrations to be transmitted in directions other than the axial direction, and in the transmission of ultrasonic vibrations in the axial direction by the ultrasonic probe, lateral vibrations and abnormal noises are generated. There is a risk that the ultrasonic vibrations of the dampens.

  The present invention has been made paying attention to the above-mentioned problem, and the object thereof is an ultrasonic probe with improved ultrasonic vibration transmission performance, an ultrasonic treatment apparatus having the ultrasonic probe, and It is to provide a manufacturing method thereof.

  In the first embodiment of the present invention, the ultrasonic probe is a metallic ultrasonic probe that transmits ultrasonic vibrations, and the metal structure of at least a part of the ultrasonic probe is anisotropic in the transmission direction of the ultrasonic vibrations. It has the characteristics.

  In the second embodiment of the present invention, an ultrasonic treatment apparatus includes the ultrasonic probe.

  In the third embodiment of the present invention, the method of manufacturing an ultrasonic probe is a method of manufacturing a metal ultrasonic probe that transmits ultrasonic vibrations, and a step of preparing a material for forming the ultrasonic probe; And a step of extending at least a part of the raw material by cold forging in a direction which is a transmission direction of ultrasonic vibrations.

  In a fourth embodiment of the present invention, a method for manufacturing an ultrasonic treatment apparatus includes the method for manufacturing the ultrasonic probe.

  In the ultrasonic probe according to the first embodiment of the present invention, since the metal structure has anisotropy in the transmission direction of the ultrasonic vibration, the ultrasonic vibration is easily transmitted in the original transmission direction. The transmission performance has been improved.

  In the ultrasonic treatment apparatus according to the second embodiment of the present invention, since the ultrasonic vibration transmission performance is improved in the ultrasonic probe, the treatment performance of the ultrasonic treatment apparatus is improved.

  The ultrasonic probe manufacturing method of the third embodiment of the present invention is suitable for manufacturing the ultrasonic probe of the first embodiment.

  The manufacturing method of the ultrasonic treatment apparatus according to the fourth embodiment of the present invention is suitable for manufacturing the ultrasonic treatment apparatus according to the second embodiment.

The side view which shows the ultrasonic treatment apparatus of one Embodiment of this invention. 1 is a top view showing an ultrasonic probe according to an embodiment of the present invention. The schematic diagram which shows the metal structure state of a blank. The schematic diagram which shows the metal structure state of the ultrasonic probe of one Embodiment of this invention. The figure which shows the experimental result about the attenuation | damping characteristic of the ultrasonic probe of one Embodiment of this invention, and the conventional ultrasonic probe. The figure which shows the experimental result about the frequency change of the ultrasonic probe of one Embodiment of this invention, and the conventional ultrasonic probe. The front view which shows the cold rotary swaging apparatus used for the manufacturing method of the ultrasonic probe of one Embodiment of this invention. The longitudinal cross-sectional view which shows the metal mold | die structure of the cold rotary swaging apparatus used for the manufacturing method of the ultrasonic probe of one Embodiment of this invention. The side view which shows the preparatory process of the manufacturing method of the ultrasonic probe of one Embodiment of this invention. The side view which shows the heating process of the manufacturing method of the ultrasonic probe of one Embodiment of this invention. The cross-sectional view which shows the heating process of the manufacturing method of the ultrasonic probe of one Embodiment of this invention. The fragmentary longitudinal cross-section side view which shows the expansion process of the manufacturing method of the ultrasonic probe of one Embodiment of this invention. The cross-sectional view which shows the expansion process of the manufacturing method of the ultrasonic probe of one Embodiment of this invention. The side view which shows the polygonal column shaping | molding process of the manufacturing method of the ultrasonic probe of one Embodiment of this invention. The cross-sectional view which shows the polygonal column shaping | molding process of the manufacturing method of the ultrasonic probe of one Embodiment of this invention. The side view which shows the bending shaping | molding process of the manufacturing method of the ultrasonic probe of one Embodiment of this invention. The side view which shows the connection part formation process of the manufacturing method of the ultrasonic probe of one Embodiment of this invention. The fragmentary longitudinal cross-section side view which shows the groove | channel formation process of the manufacturing method of the ultrasonic probe of one Embodiment of this invention.

  An embodiment of the present invention will be described with reference to the drawings.

  With reference to FIG. 1 thru | or FIG. 6, the ultrasonic treatment apparatus of this embodiment is demonstrated.

  A schematic configuration of the ultrasonic treatment apparatus will be described with reference to FIG.

  In the ultrasonic treatment apparatus, the sheath unit 20, the handle unit 22, and the transducer unit 24 are connected from the distal end side to the proximal end side. The transducer unit 24 incorporates an ultrasonic transducer 26 that generates ultrasonic vibrations. The proximal end portion of the ultrasonic probe 28 is connected to the distal end portion of the ultrasonic transducer 26 by screw fastening. The ultrasonic probe 28 has a long rod shape, and is inserted into the handle unit 22 and the sheath unit 20 from the proximal end side to the distal end side. In the sheath unit 20, an ultrasonic probe 28 is inserted through a long sheath 30 that is inserted into the body. Further, in the ultrasonic probe 28, an annular rubber lining is extrapolated at a position that is a node position of ultrasonic vibration, and the rubber lining is supported by the inner surface of the sheath 30, so that the ultrasonic wave is applied to the sheath 30. The probe 28 is held. The distal end portion of the ultrasonic probe 28 protrudes from the distal end opening of the sheath 30, and a treatment portion 32 for treating living tissue is formed at the distal end portion of the ultrasonic probe 28. A jaw 34 is disposed at the distal end of the sheath 30, and the jaw 34 is opened / closed with respect to the treatment portion 32 of the ultrasonic probe 28 by opening / closing the pair of handles 31 of the handle unit 22. The living tissue is grasped by the treatment portion 32 and the jaw 34 of the ultrasonic probe 28, and the ultrasonic vibration generated by the ultrasonic transducer 26 is transmitted in the axial direction from the proximal end portion to the distal end portion of the ultrasonic probe 28. By treating the treatment unit 32 with ultrasonic vibration, treatments such as coagulation and incision can be performed on the living tissue.

  The ultrasonic probe 28 used in the ultrasonic treatment apparatus will be described with reference to FIG.

  A large-diameter portion 36 is formed at the proximal end portion of the ultrasonic probe 28. A connecting portion 39 having a male screw connected to the ultrasonic transducer 26 is formed at the proximal end portion of the large diameter portion 36. A tapered portion 38 is formed on the distal end side of the large diameter portion 36. In the taper portion 38, the outer diameter is reduced from the proximal end side to the distal end side, and ultrasonic vibration is increased and transmitted. A straight portion 40 is formed on the tip side of the tapered portion 38. The straight portion 40 is a long straight line, and transmits ultrasonic vibration in the axial direction. In the straight portion 40, a lining groove 42 into which a rubber lining is extrapolated is formed over the entire circumference at a position that is a node position of ultrasonic vibration. A bending portion 44 is formed on the distal end side of the straight portion 40. The bending portion 44 is gently curved in the lateral direction perpendicular to the axial direction of the straight portion 40 from the proximal end side to the distal end side.

  The metal structure of the ultrasonic probe 28 will be described with reference to FIGS.

  As a material of the ultrasonic probe 28, a metal material having a high acoustic effect, biocompatibility, low Young's modulus, high fracture strain and high fracture strength is used, preferably titanium material, particularly preferably α + β titanium alloy. Used. In this embodiment, a titanium alloy of JIS 60 type Al of 6%, V4%, and remaining Ti is used.

  The metal structure is formed of a large number of crystals, and each crystal has an orientation indicating the direction of the crystal axis. 3 and 4, the arrow indicates the orientation direction of the crystal C. As shown in FIG. 3, in the blank, the orientation directions of a large number of crystals C are random, and the metal structure is isotropic. On the other hand, as shown in FIG. 4, in the ultrasonic probe 28 of the present embodiment, the orientation directions of a large number of crystals C are constant at the bending portions 44, the straight portions 40, and the tip portions of the tapered portions 38. Therefore, the metal structure has anisotropy. In particular, the orientation direction of the crystal C coincides with the axial direction of the ultrasonic probe 28, that is, the transmission direction of ultrasonic vibration, and the metal structure of the ultrasonic probe 28 has anisotropy in the transmission direction of ultrasonic vibration. Become. In the case where the metal structure has anisotropy, the orientation direction of all the crystals in the metal structure does not have to be constant, and crystals having different orientation directions may be included. If the orientation direction of 50% or more of all the crystals is constant, it can be said that the metal structure has anisotropy. In particular, the orientation direction of 60% or more of the crystals is preferably constant.

  Whether the metal structure is isotropic or anisotropic can be determined by various methods. For example, by collecting a test piece having a test surface parallel to the axial direction from the ultrasonic probe 28 and corroding the test surface with a corrosive liquid such as nital, the test surface is directly observed using a microscope. It is possible to determine whether the metal structure is isotropic or anisotropic. Further, by using an electron back scattering pattern (hereinafter referred to as EBSP), it is possible to make an easier and more accurate determination. That is, in EBSP, it is possible to automatically detect the orientation directions of hundreds of thousands to millions of crystals from the deviation of the reflection angle with respect to the incident angle of the test light on the test surface. In the present embodiment, it is detected which direction is the 001 direction, the 011 direction, or the 111 direction. Then, the distribution of the number of crystals in each azimuth direction is calculated, and if the number of crystals is evenly distributed in each azimuth direction, it can be determined that the metal structure is isotropic, and the distribution is biased toward one azimuth direction. If it does, it can be judged that a metal structure is anisotropic. In practice, the detection result for the master sample piece and the detection result for the test piece collected from the ultrasonic probe 28 are compared to quantitatively evaluate how much the azimuth directions match, and isotropic Whether it is sex or anisotropic is automatically determined by a computer.

  In the ultrasonic probe 28, when the metal structure has anisotropy in the axial direction, the ultrasonic vibration is easily transmitted in the axial direction. Therefore, the transmission performance of the ultrasonic vibration in the ultrasonic probe 28 is improved. . Therefore, in the ultrasonic treatment apparatus, treatment performance for coagulating and incising human body tissue is improved.

  With reference to FIG. 5, the attenuation characteristics of the ultrasonic probe based on actual experimental results will be described. In the experiment, the same ultrasonic vibration was applied to the base connecting portion of the conventional isotropic ultrasonic probe manufactured by cutting and the ultrasonic probe of this embodiment having anisotropy. Then, ultrasonic vibration was transmitted from the proximal end side to the distal end side, and the amplitude width at the bending portion of the distal end portion was measured for about 21 seconds. FIG. 5 shows the results of the experiment. As shown in FIG. 5, in the conventional ultrasonic probe having isotropic properties, the amplitude width in the bending portion is relatively large even when time passes, approximately 80.0 [μm] and 90.0 [μm]. It is understood that the ultrasonic vibration is attenuated and hardly transmitted in the axial direction. On the other hand, in the ultrasonic probe of the present embodiment having anisotropy, the amplitude width of the bending portion is stable at a relatively small value of approximately 13.0 [μm] over time, and the ultrasonic vibration is attenuated. It is understood that it is not transmitted easily in the axial direction.

  Further, in the ultrasonic probe 28, when the metal structure has anisotropy in the axial direction, the actual frequency with respect to the target frequency in the treatment portion 32 at the distal end portion of the ultrasonic probe 28 is compared with the case of isotropic. For a given frequency, the variation among the plurality of ultrasonic probes 28 is reduced.

  With reference to FIG. 6, the variation in the actual frequency with respect to the target frequency between the plurality of ultrasonic probes based on the actual experimental result will be described. In the experiment, 15 ultrasonic probes were prepared for each of the conventional isotropic ultrasonic probe manufactured by cutting and the anisotropic ultrasonic probe according to the present embodiment. Then, ultrasonic vibration was applied to the connecting portion at the base end to transmit the ultrasonic vibration from the base end side to the tip end side, and the frequency at the large diameter portion and the frequency at the bending portion were measured. FIG. 6 shows the results of the experiment. As shown in FIG. 6, in the conventional ultrasonic probe having isotropic property, the maximum frequency in the bending portion is 47.6 [kHz] and the minimum with respect to the target frequency 47.0 ± 1.5 [kHz]. The frequency is 47.2 [kHz], the variation is 0.4 [kHz], and it is understood that the variation is large. On the other hand, in the ultrasonic probe of this embodiment having anisotropy, the maximum frequency in the bending portion is 46.5 [kHz], the minimum frequency is 46.3 [kHz], and the variation is 0.2 [kHz]. It is understood that the variation is small.

  With reference to FIG. 7A thru | or FIG. 14, the manufacturing method of the ultrasonic treatment apparatus of this embodiment is demonstrated.

  The manufacturing method of the ultrasonic treatment apparatus of this embodiment is the same as the conventional manufacturing method except for the manufacturing method of the ultrasonic probe 28. Therefore, only the method for manufacturing the ultrasonic probe 28 will be described in detail.

  With reference to FIG. 7A and 7B, the cold rotary swaging apparatus used for the heating process of the manufacturing method of the ultrasonic probe 28 and an extending process is demonstrated.

  The cold rotary swaging apparatus has a thick cylindrical header 46. The central hole of the header 46 forms an insertion hole 48 through which a metal cylindrical blank 62 is inserted in the axial direction. On one end side of the header 46, a pair of moving grooves 50 extend from the insertion hole 48 of the header 46 to the outer peripheral surface in the radial direction so as to face each other with respect to the insertion hole 48 of the header 46. In each moving groove 50, a surface-reducing mold 52, a wedge plate 54, and a backer 56 are arranged in parallel in the radial direction from the inside to the outside. With respect to the molding surface 74 in the radially inner portion of the surface-reducing mold 52, the cross section perpendicular to the axial direction has a concave arc shape. In the moving groove 50, the surface-reducing mold 52, the wedge plate 54, and the backer 56 can move in the radial direction, and the backer 56 can protrude outward in the radial direction from the outer peripheral surface of the header 46. The header 46 is rotatably supported with the central axis of the header 46 as a rotation central axis, and can be driven to rotate together with the surface-reducing mold 52, the wedge plate 54 and the backer 56. A large number of cylindrical rollers 58 having a central axis parallel to the central axis of the header 46 are juxtaposed in the circumferential direction of the header 46 at predetermined intervals on the radially outer side of the header 46. Each roller 58 has the same outer diameter, is rotatably supported by the outer race 60 around the central axis of the roller 58, and can be driven to rotate in a direction opposite to the rotation direction of the header 46. By rotating and driving the header 46 and the roller 58, the surface-reduction mold 52, the wedge plate 54, and the backer 56 are moved inward in the radial direction due to the collision between the roller 58 and the backer 56, and in the radial direction due to centrifugal force. Repeat outward movement. Further, the cold rotary swaging device is provided with a moving mechanism for moving the blank 62 in the axial direction thereof and inserting / removing it into / from the insertion hole 48 of the header 46. With the header 46 and the roller 58 being rotationally driven, the blank 62 is inserted into the insertion hole 48 of the header 46 by the moving mechanism, and the molding surface 74 of the surface-reducing mold 52 is repeatedly pressed against the blank 62. The cross-sectional area of the blank 62 is reduced, the blank 62 is stretched in the axial direction, and surface reduction molding is performed. Further, the cold rotary swaging device is provided with a stopper mechanism that restricts the movement of the surface-reducing mold 52 from the predetermined restricting position to the inside in the radial direction. The restriction position can be arbitrarily adjusted with respect to the radial direction. In the present embodiment, as the restricting position, a radially outer insertion position for inserting / removing the blank 62 with respect to the insertion hole 48 of the header 46, a radially inner molding position for reducing the surface of the blank 62, and the blank 62 And an intermediate contact position for heating the surface-reducing mold 52 by friction.

  With reference to FIG. 8 thru | or FIG. 14, each process of the manufacturing method of the ultrasonic probe 28 is demonstrated in detail.

Preparation process (Figure 8)
A metal cylindrical blank 62 is prepared as a material for the ultrasonic probe 28. In the blank 62, the orientation direction of a large number of crystals in the metal structure is random, and the metal structure is isotropic. In the present embodiment, a blank 62 made of a titanium alloy of the above-described JIS 60 type Al 6%, V4%, and the balance Ti is used. The outer diameter of the blank 62 is set to be equal to the outer diameter of the large-diameter portion 36 of the ultrasonic probe 28 that is the final product, and the overall length of the blank 62 is set based on the volume of the ultrasonic probe 28 that is the final product. The For example, the outer diameter and total length of the blank 62 are set to 8 mm and 170 mm.

  In the blank 62, one direction orthogonal to the axial direction is defined as a horizontal direction, and a direction orthogonal to the axial direction and the horizontal direction is defined as a vertical direction.

Heating process (FIGS. 9A and 9B)
The blank 62 is heated to a temperature at which surface reduction molding by cold rotary swaging can be easily performed by friction between the surface reduction molding die 52 and the blank 62.

  That is, in the cold rotary swaging apparatus, the header 46 and the roller 58 are driven to rotate after the regulation position of the surface-reducing mold 52 is adjusted to the insertion / extraction position on the radially outer side. For example, the rotation speed of the header 46 is set to 100 rpm, and the rotation speed of the roller 58 is set to 1000 rpm. Subsequently, one end of the blank 62 is inserted into the insertion hole 48 of the header 46. Then, the regulation position of the surface-reducing mold 52 is moved radially inward to adjust the contact position, and the surface-reducing mold 52 is rotated for a predetermined time while being in contact with the blank 62 to reduce the surface-reducing mold. The blank 62 is heated to a predetermined temperature at which surface reduction molding by cold rotary swaging can be easily performed by frictional heat between the blank 52 and the blank 62. This temperature is sufficiently lower than 920 ° C. which is the β transformation point of the α + β titanium alloy. For example, the friction time is set to 10 seconds, and the heating temperature is set to 500 to 600 ° C.

Drawing process (FIGS. 10A and 10B)
One end side portion of the blank 62 is stretched by surface reduction molding by cold rotary swaging.

  That is, after the blank 62 is heated, the restriction position of the surface-reducing mold 52 is further moved inward in the radial direction and adjusted to the molding position. Then, the blank 62 is moved in the axial direction and inserted into the insertion hole 48 of the header 46, and the molding surface 74 of the surface-reduction molding die 52 is repeatedly pressed against the blank 62, so that one end side portion of the blank 62 Reduce the cross-sectional area of the and stretch the part. By the surface reduction molding, the bending portion 44 of the ultrasonic probe 28, the straight portion 40, the bending portion preparation portion 44j that becomes the taper portion 38, the straight portion preparation portion 40j, and the taper portion preparation portion 38j are formed. About the other end part of the blank 62 which is not surface-reduced, the large diameter part preparation part 36j used as the large diameter part 36 of the ultrasonic probe 28 is made. When the area reduction ratio is large, the area reduction molding is performed in multiple steps. When the number of surface-reduction moldings is small and the area reduction rate in each surface-reduction molding increases, the deformation resistance increases and the blank 62 may be cracked. On the other hand, if the number of surface-reduction moldings is increased, the surface roughness of the blank 62 after molding increases and becomes a textured surface, which is not preferable. The number of surface reduction moldings is appropriately set in consideration of the above conditions. For example, the area reduction rate in each area reduction molding is 20%, the number of area reduction moldings is 3 times, the outer diameter of one end portion of the blank 62 is reduced from 8 mm to 4 mm, and the overall length of the blank 62 is 170 mm to 450 mm. Stretch to. After the surface reduction molding is completed, the restriction position of the surface reduction molding die 52 is moved radially outward to adjust the insertion / extraction position, and the blank 62 is moved in the axial direction to be removed from the insertion hole 48 of the header 46. .

  By extending the one end side portion of the blank 62 in the axial direction by area reduction forming by cold rotary swaging, the orientation direction of the crystal of the metal structure in the portion is aligned with the axial direction of the blank 62, and the metal structure is in the axial direction. Will have anisotropy. That is, the metal structure has anisotropy in the axial direction at the tip of the bending part preparation part 44j, the straight part preparation part 40j, and the taper part preparation part 38j.

Polygonal column forming process (FIGS. 11A and 11B)
The bending part preparation part 44j of the blank 62 is shape | molded by polygonal column shape by cold press. In the present embodiment, an octagonal prism shape is selected as the polygonal prism shape.

  That is, in the cold press, a pair of octagonal column forming dies 64u and 64d is used. Here, let the direction used as the axial direction of the blank 62 at the time of pressing be an axial direction of the metal molds 64u and 64d. Regarding the molding surfaces 76u and 76d of the pair of octagonal column molding dies 64u and 64d, the cross-sectional shapes orthogonal to the axial direction are the bottom sides so as to form three sides of the octagonal column shape on one side and the other side, respectively. Has a trapezoidal shape arranged on the pressing direction side. At the time of press molding, a gap is formed between both side portions of the molding surfaces 76u and 76d for the pair of octagonal column molding dies 64u and 64d. That is, at the time of press molding, three side surfaces of one side and the other side of the octagonal column shape are formed by the molding surfaces 76u and 76d of the pair of octagonal column molding dies 64u and 64d, and the side of the molding surfaces 76u and 76d. The surplus wall protrudes as a flash 66 in the gap between the two portions. In this way, the surplus is allowed to escape into the gap, so that excessive pressure is applied to the bending portion preparation portion 44j in the molds 64u and 64d to prevent cracking. The remaining two side surfaces of the octagonal prism shape are formed by appropriately removing the flash 66 by punching or the like.

  In the polygonal column forming step, the orientation direction of the crystal of the metal structure of the bending part preparation unit 44j is not changed, and the metal structure maintains the anisotropy in the axial direction.

Bending molding process (Figure 12)
The bending portion preparation portion 44j of the blank 62 is bent to the curvature of the bending portion 44 of the final product by cold pressing.

  That is, in the cold press, a pair of bending molds 68u and 68d are used. Here, the vertical direction, the distal end side, and the proximal end side of the blank 62 during pressing are the longitudinal direction, distal end side, and proximal end side of the molds 68u and 68d. In the pair of bending molds 68u and 68d, the upper die 68u is brought into point contact with the leading end portion of the bending portion preparing portion 44j and presses the leading end portion toward the lower die 68d. The molding surface 78d of the lower mold 68d has a convex curved surface that is inclined in the lateral direction that is the pressing direction of the upper mold 68u from the proximal end side to the distal end side along the axial direction. The cross-sectional shape orthogonal to the direction has a curvature equal to the curvature of the bending portion 44 of the final product. At the time of breath molding, the tip of the bending portion preparation portion 44j is point-contacted by the upper die 68u and pressed toward the lower die 68d, and one side portion of the bending portion preparation portion 44j is pressed against the molding surface 78d of the lower die 68d. Thus, the bending part preparation part 44j is bent. By using point contact instead of surface contact in this way, generation of dents and increase in load are prevented.

  Also in the bending forming process, the orientation direction of the crystal of the metal structure of the bending part preparation unit 44j is not changed, and the metal structure maintains the anisotropy in the axial direction.

Connecting part forming step (FIG. 13)
The base end portion of the large-diameter portion preparation portion 36j is cut to form a male screw or the like, thereby forming a connection portion preparation portion 39j that becomes the connection portion 39 of the ultrasonic probe 28.

Groove forming process (Fig. 14)
The lining groove preparation part 42j used as the lining groove 42 is formed in the straight part preparation part 40j by the surface reduction shaping | molding by cold rotary swaging.

  The details of the groove forming step are the same as those of the drawing step described above. However, in cold rotary swaging, a surface-reducing mold 70 for forming a lining groove is used. Here, the axial direction, the radial direction, and the circumferential direction of the blank 62 during molding are defined as the axial direction, radial direction, and circumferential direction of the mold 70. On the molding surface 80 of the surface-reducing molding die 70, radially inward protruding portions 72 for forming the lining groove are extended in the circumferential direction. About the end surface of the protrusion part 72, the cross-sectional shape orthogonal to an axial direction has comprised the concave arc shape which has a curvature equal to the curvature of the lining groove 42 of a final product.

  In the groove forming step, the anisotropy in the axial direction of the metal structure is further improved in the lining groove preparation portion 42j.

Stress removal process The semi-finished product of the ultrasonic probe 28 is annealed at a temperature equal to or lower than the β transformation point to remove the residual stress. For example, a method of hanging from the ceiling is employed to ensure free deformation, and annealing is performed at 750 ° C. for 1 hour in an argon gas atmosphere.

Surface finishing step The oxide film adhering to the outer surface of the semi-finished product of the ultrasonic probe 28 is removed by pickling, blast shot or the like.

Bending correction process When bending deformation occurs in the ultrasonic probe 28 by the annealing process, the bending is corrected and the straightness of the ultrasonic probe 28 is recovered.

  Hereinafter, the technical significance of the ultrasonic probe and the manufacturing method thereof according to the present embodiment will be described in detail.

  When an ultrasonic probe is manufactured by cutting from a blank made of titanium as in the past, a large amount of cutting waste is generated, resulting in a decrease in material yield, and titanium is hard and difficult to process. As a result, the processing time increases and productivity decreases. On the other hand, when an ultrasonic probe is manufactured using forging, the problem of a decrease in material yield due to generation of cutting waste is solved. Forging is roughly divided into hot forging and cold forging. As mentioned above, titanium material has high hardness, so it is difficult to form by cold forging. Generally, forging of titanium material is hot forging. Used. In addition, if anisotropy occurs in the metal structure of the blank due to cold forging, the workability of the blank deteriorates, and it becomes difficult to form the blank accurately by cold pressing. In general, the use of cold forging is avoided when performing the above. In short, in order to prevent a decrease in material yield in machining titanium materials, those skilled in the art should naturally choose hot forging when using a method other than cutting. In particular, when additional machining is performed after forging, it is not usually the case that cold forging is selected. Here, in hot forging, since the forming is performed at a temperature equal to or higher than the β transformation point, even after the blank is stretched in the axial direction, the metal structure after stretching becomes isotropic. In both cutting and hot forging, the metal structure after processing is isotropic, and since the ultrasonic probe was manufactured using hot forging, the metal structure became isotropic and the transmission performance of ultrasonic vibration was improved. Because it is not necessarily reduced, it is usually impossible to recognize the issue that the transmission performance of ultrasonic vibrations is reduced because it is isotropic, focusing on the isotropic and anisotropy of the metal structure It ’s okay. On the other hand, this embodiment overcomes the difficulty of forming a titanium material in cold forging by heating the blank by friction between the reduced surface mold used for cold rotary swaging and the blank, Furthermore, the possibility of making the metal structure anisotropic in the ultrasonic probe is conceived, and in addition, the final product, the ultra-thin product, which is usually avoided because of the difficulty of additional processing, is to be avoided. This is the first time that the idea of maintaining the acoustic probe is maintained, and as a result, the transmission performance of the ultrasonic vibration is improved.

  In the above-described embodiment, the titanium-made ultrasonic probe has been described. For example, a stainless steel ultrasonic probe can be made anisotropic by using cold forging, and the metal structure can be made anisotropic. As a result of anisotropy, the transmission performance of ultrasonic vibration is improved.

  Further, in the above-described embodiment, the metal blank is stretched and the metal structure is made anisotropic by surface reduction molding by cold rotary swaging, but by other cold forging such as spatula drawing and forward extrusion. The metal structure can be made anisotropic also by stretching.

  28 ... Ultrasonic probe, 62 ... Material (blank).

Claims (4)

  An ultrasonic probe for transmitting ultrasonic vibration, wherein the metal structure of at least a part of the ultrasonic probe has anisotropy in the transmission direction of ultrasonic vibration.   An ultrasonic treatment apparatus comprising the ultrasonic probe according to claim 1. A method of manufacturing a metal ultrasonic probe for transmitting ultrasonic vibrations,
Preparing a material for forming an ultrasonic probe;
Stretching at least a portion of the material by cold forging in a direction that is a transmission direction of ultrasonic vibrations;
An ultrasonic probe manufacturing method comprising:   An ultrasonic treatment apparatus manufacturing method comprising the ultrasonic probe manufacturing method according to claim 3.

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