JP5149345B2 - Ultrasonic transducer - Google Patents

Description

  The present invention relates to an ultrasonic vibrator that generates ultrasonic vibrations due to electric distortion of a piezoelectric element, and includes dental instruments such as calculus removal and oral surgery, medical equipment such as an ultrasonic scalpel, and processing machines such as a cutter and a file. The present invention relates to an ultrasonic transducer suitable for use in the above.

  Conventionally, a structure in which a piezoelectric element unit formed by alternately laminating a plurality of piezoelectric elements and electrode terminal plates is disposed between a front member (also referred to as a horn or an amplitude amplification horn) made of a metal block and a backing member. A Langevin type ultrasonic transducer (hereinafter simply referred to as “ultrasonic transducer”) having the following is known. The ultrasonic vibrator is housed in a cylindrical case, and a space is maintained between the inner peripheral surface of the case and the ultrasonic vibrator, for example, by a flange portion extending in a plate shape from the front member toward the inner surface of the case. An ultrasonic transducer is supported so as to be able to vibrate.

  When using an ultrasonic vibrator for dentistry such as calculus and oral surgery, medical equipment such as an ultrasonic scalpel, and a processing machine such as a cutter or file, the tip of the ultrasonic vibrator is suitable for each application. A tip such as a knife can be attached. Screws are mainly used for attaching the chip to the ultrasonic transducer. For example, a male thread extending along the center line of the truncated cone is formed at one end of the tip of the ultrasonic transducer (front member) formed in a truncated cone shape, and the female thread combined with the male thread is formed on the other side. The chip is attached to the ultrasonic transducer (front member) by forming a portion and screwing (tightening) the male screw portion into the female screw portion.

  In general, since the chip is replaced with a chip having a shape suitable for the work content to be used, there are many occasions where the chip is attached to or detached from the ultrasonic transducer (front member) disposed in the case. For example, when the inner surface of the case is formed in a cylindrical surface shape and the flange is formed in a disk shape, the ultrasonic vibrator rotates around the above-described center line with respect to the case. That is, it is difficult to tighten the male screw portion into the female screw portion, and it is difficult to loosen. As a result, it becomes difficult to attach and detach the chip to the ultrasonic transducer (front member).

  Therefore, a technique for preventing the rotation of the ultrasonic transducer relative to the case by changing the inner shape of the case and the outer shape of the flange is known. For example, as shown in FIG. 12, a part of the outer periphery of the disc-shaped flange 334 is cut into a straight line to form a D shape or an H shape (D cut or H cut), and a cylindrical case 350 is formed. A method of preventing rotation of the ultrasonic transducer (front member) 330 by forming a flat surface 354A corresponding to the notch 333A of the flange 334 on the inner surface of the flange 334 and combining the notch 333A and the flat surface 354A is known. ing. Further, as shown in FIG. 13, a cut groove 433A is formed on a part of the outer periphery of the disk-shaped flange 434, and a protrusion 454A corresponding to the cut groove 433A of the flange 434 is formed on the inner surface of the cylindrical case 450. A method for preventing the rotation of the ultrasonic transducer (front member) 430 by fitting the slit groove 433A and the projection 454A is known. Alternatively, a method of preventing the rotation of the ultrasonic transducer by forming the flange in a rectangular plate shape, forming the inner surface of the case in a rectangular cylindrical shape, and combining the outer shape of the flange and the inner surface of the case is also known. .

  In addition, the plate-like flanges extending in the radial direction are discretely arranged in the circumferential direction on the front member formed in a columnar shape, and the inner surface of the case is formed in accordance with the shape of the discretely arranged flanges And the method of preventing rotation of an ultrasonic transducer | vibrator by combining both is also proposed (for example, refer patent document 1).

Special table 2009-511206 gazette

  On the other hand, medical devices such as ultrasonic scalpels using the above-described ultrasonic vibrator, and processing machines such as cutters and files are used while being held in the hands of doctors, dentists, and workers. In other words, it is used as a handpiece. Therefore, the shape and weight of the ultrasonic transducer are required to be within a range that can be easily used as a handpiece.

  For example, the part of the case that is directly gripped by the hand needs to be formed in an outer diameter range (diameter narrowness) that can be easily gripped by the hand. It needs to be formed within a desired outer diameter range. In addition, since the entire medical device used as a handpiece needs to be formed with a weight that does not get tired even when it is gripped by hand, the ultrasonic transducers that constitute the medical device etc. It must be formed within the desired weight range.

  Then, there is a problem that it is difficult to prevent relative rotation between the case and the ultrasonic vibrator and to form the ultrasonic vibrator with a shape and weight within a desired range. For example, as shown in FIG. 12 and FIG. 13, in a method of forming a D-shape or H-shape by cutting out a plate-like flange, a method of forming a square shape, or a method of forming a cut groove, If priority is given to prevention of rotation, the outer diameter of the case will become thick and difficult to grip by hand.On the other hand, if the outer diameter of the case is within the range where it can be easily gripped by hand, it will be difficult to prevent relative rotation. there were.

  The method shown in FIG. 12 and FIG. 13 forms a contact surface extending in a direction intersecting the above-mentioned relative rotation direction on both the case and the flange, and makes the relative rotation by bringing these contact surfaces into contact with each other. It is preventing. The contact surface is formed so as to have an area where the case and the flange are not deformed or damaged even when the force applied when the chip is attached or detached. Then, the outer diameter of the flange and the outer diameter of the case are increased by the amount of the contact surface.

  On the other hand, if the case is formed in an outer diameter range that can be easily grasped by hand, the area of the contact surface described above is reduced, and the case and the flange are deformed even when the force applied when attaching and detaching the chip is large. Or there was a risk of damage.

  As a method for preventing deformation or breakage of the case when the area of the contact surface is reduced, it is conceivable that the case is formed of a metal having a higher strength than a resin or the like. However, since the specific gravity of metals and the like is heavier than that of resin, the weight of the case becomes heavy, and thus the weight of ultrasonic elements and medical equipment also becomes heavy. .

  Even in the method of disposing the plate-like flanges described in Patent Document 1 in the circumferential direction, there is a problem that it is difficult to achieve both the above-described contact surface area securing and the case diameter reduction. there were. In the case of patent document 1, the end surface which faced the circumferential direction in the plate-shaped flange arrange | positioned extending radially is the above-mentioned contact surface. In this case, in order to increase the area of the contact surface, a method of extending the plate-like flange in the radial direction or a method of increasing the plate thickness of the flange can be considered.

  In the method of extending the flange in the radial direction, the outer diameter of the case increases as in the case described above, and it is difficult to achieve both reduction in the diameter of the case. Further, in the method of increasing the thickness of the flange, since the outer diameter of the case does not increase, it is possible to achieve both reduction in the case diameter. However, by increasing the thickness of the flange, there is a problem that the weight of the flange increases and the weight of the ultrasonic vibrator, medical device, and the like increases.

  The present invention has been made to solve the above-described problems, and improves the reliability of replacement in a chip attached to and detached from an ultrasonic vibrator, and at the same time in a vibration device in which the ultrasonic vibrator is used. An object of the present invention is to provide an ultrasonic transducer capable of ensuring the ease of gripping and the ease of work.

In order to achieve the above object, the present invention provides the following means.
An ultrasonic transducer according to a first aspect of the present invention is an ultrasonic transducer having an outer tightening structure including a front member and a backing member that sandwich a piezoelectric element and an electrode plate therebetween. A support portion that extends outward in the radial direction around the axis of the front member and supports the front member, the piezoelectric element, the electrode plate, and the backing member so as to vibrate is provided. An end face extending intersecting with the circumferential direction centering on is formed, and the area of the radially outer portion of the end face is larger than the area of the inner portion. The cross-sectional shape of the piezoelectric element is preferably a circle, a regular polygon, a point-symmetric shape, or the like.

  According to the ultrasonic transducer according to the first aspect of the present invention, it is possible to make surface contact with the end surface formed on the support portion and a part of the inner surface of the housing that houses the ultrasonic transducer, for example, the end surface. By making contact with the side surface of the projecting portion formed in a simple shape, it is possible to prevent the housing and the ultrasonic transducer from rotating relative to each other about the axis when the chip is attached or detached. On the other hand, when the shape of the end face is divided into the radially outer side and the inner side and compared, the area of the outer part is formed so as to be larger than the area of the inner part, thereby ensuring the area of the end face. Therefore, it is possible to suppress the increase in weight.

  In general, when a force is applied in a direction in which the casing and the ultrasonic transducer rotate relative to each other about the axis, a larger force acts on the radially outer portion of the end face than on the radially inner portion. Therefore, when the radially outer portion and the radially inner portion are formed with the same area, the surface pressure or stress acting on the radially outer portion is greater than the surface pressure or stress of the radially inner portion. Also gets higher.

  As in the ultrasonic transducer according to the first aspect of the present invention, when the radially outer portion is formed with a larger area compared to the radially inner portion, the radially outer portion is compared with the above case. The surface pressure and stress of the portion can be reduced.

  In addition, compared with the method of increasing the plate thickness of the entire support part to increase the area of the end face, the area of the radially inner part of the end face is reduced, so the volume of the support part is reduced and the weight is increased. Can be prevented or weight can be reduced. As a result, it is possible to prevent the weight of the ultrasonic transducer from increasing or to reduce the weight. More preferably, it is desirable that the area of the radially inner portion is smaller than the area of the radially outer portion in the cross section of the support portion cut in the radial direction, like the end face. By doing in this way, the weight increase of a support part can be prevented more reliably, or weight reduction can be aimed at more effectively.

  Here, the area of the radially outer portion on the end surface is larger than the area of the inner portion, for example, in the axial length of the end surface, the radially outer portion may be longer than the inner portion. Alternatively, the pair of sides arranged opposite to each other in the axial direction on the end surface may be sides that are separated from each other continuously or discretely toward the outer side in the radial direction.

  In the invention according to the first aspect, the support portion includes a plate-like flange portion extending in the radial direction and the circumferential direction, and from the radially outer end of the flange portion in the axial direction and the circumferential direction. It is desirable to provide a plate-like outer end portion that extends.

  In this way, the ring plate-shaped flange portion is extended from the outer surface of the support portion toward the radially outer side, and the cylindrical outer end portion is extended in the axial direction from the outer end of the flange portion, thereby forming the end surface of the support portion. Of these, the area of the radially outer portion can be made larger than the area of the radially inner portion. For example, when the outer end portion is extended only in one direction from the outer end of the flange portion, the end surface is formed in an L shape, and when the outer end portion is extended in both directions, the end surface is formed in a T shape. Here, the outer end of the flange portion may be covered with the outer end portion, and the end surface on the radially outer side of the support portion may be formed only from the surface of the outer end portion, or the outer end surface and the outer end portion of the flange portion. An end surface on the outer side in the radial direction of the support portion may be formed from the surface.

  Furthermore, compared with the case where a support part is formed in plate shape, the contact area of a support part and the inner surface of a housing | casing can be increased, suppressing the weight increase of a support part. The outer end portion is a plate member that is curved in a cylindrical shape extending in the axial direction and the circumferential direction, and is in contact with the inner surface of the housing on the outer peripheral surface thereof. Therefore, the contact area between the support portion and the inner surface of the housing can be easily adjusted by adjusting the length of the outer end portion in the axial direction. Furthermore, even if the length of the outer end portion in the axial direction is increased, for example, an increase in the weight of the support portion is suppressed as compared with a case where the entire thickness of the support portion is increased.

  An ultrasonic transducer according to a second aspect of the present invention is an ultrasonic transducer having an outer tightening structure including a front member and a backing member sandwiching a piezoelectric element and an electrode plate therebetween, A support portion is provided that extends radially outward about the axis of the front member and supports the front member, the piezoelectric element, the electrode plate, and the backing member so as to be able to vibrate. The support portion is centered on the axis. At both ends in the circumferential direction, an end surface is formed that extends across the circumferential direction and contacts a part of the inner surface of the housing, and the area of the end surface is between the both ends of the support portion. Is wider than the cross-sectional area of a plane cut by a plane including the axis.

  According to the ultrasonic element according to the second aspect of the present invention, it is possible to make surface contact with the end face formed on the support portion and a part of the inner surface of the housing that houses the ultrasonic transducer, for example, the end face. By contacting the side surface of the projecting portion formed in the shape, it is possible to prevent the casing and the ultrasonic transducer from rotating relative to each other about the axis.

  On the other hand, the area of the end can be increased while suppressing an increase in the weight of the support portion or reducing the weight. That is, the area of the end face other than the end face in the plane including the axis, in other words, the area of the support section in the radial direction (cross section) when viewed from the axial direction, is the area of the end face. On the other hand, by increasing or decreasing the area of the end face as it is, it is possible to suppress an increase in weight of the support part or to reduce the weight and to increase the area of the end part.

  In the invention according to the second aspect, the support portion includes a plate-like flange portion extending along the circumferential direction and the radial direction, and the axial direction and the radial direction from the circumferential end of the flange portion. It is desirable to provide the plate-shaped side edge part extended along.

  In this way, the ring plate-like flange portion extends radially outward from the outer surface of the support portion, and the plate-like side end portion extends in the axial direction from the circumferential side end of the flange portion. The area can be made larger than the cross-sectional area of the plane cut by the plane including the axis between the end faces of the support portion. For example, the side end portion may be disposed so as to extend only in one direction from the side end of the flange portion, or may be disposed so as to extend in both directions.

In the invention according to the first or second aspect, it is preferable that the support portions are arranged at equal intervals in a circumferential direction around the axis.
By doing in this way, it becomes easy to ensure the intensity | strength of the housing | casing which accommodates an ultrasonic transducer | vibrator inside. That is, in the portion where the support portion is not disposed, the inner surface of the housing can be protruded to the vicinity of the front member. In other words, the inner surface of the housing can be projected to the area where the support portion is disposed, and the thickness from the outer surface to the inner surface of the housing can be increased. On the other hand, in the part where the support part is arrange | positioned, it can be set as the thickness similar to the case where the conventional disk-shaped support part is used. As a result, the average thickness of the casing in the circumferential direction can be increased without increasing the outer diameter of the casing, and the strength of the casing can be easily secured.

  In the invention according to the first or second aspect, the support portion is disposed at a position of a vibration node in a structure including the front member, the piezoelectric element, the electrode plate, and the backing member. It is desirable.

  By doing so, even if the ultrasonic vibrator is housed inside the housing, it becomes difficult to inhibit the vibration of the ultrasonic vibrator. When the ultrasonic vibrator is housed inside the housing, the ultrasonic vibrator is supported in a state of being spaced from the inner surface of the housing. In this state, when the piezoelectric element and the electrode plate are vibrated at the natural frequency of the ultrasonic vibrator or a frequency close to the natural frequency, for example, longitudinal vibration, the ultrasonic vibrator has an end of the front member and a backing member. A standing wave with the end of the abdomen is generated. In this case, if the support portion is disposed at the position of the node in the standing wave, it can be suppressed that the support portion affects the longitudinal vibration of the ultrasonic transducer, for example, the suppression of the longitudinal vibration.

  According to the ultrasonic transducer according to the first aspect of the present invention, the end surface is formed on the support portion that supports the ultrasonic transducer so as to vibrate, and the area of the radially outer portion of the end surface is larger than the area of the inner portion. In addition to improving the reliability of replacement of the chip attached to and detached from the ultrasonic vibrator, the handpiece using the ultrasonic vibrator is easy to hold and easy to work. There is an effect that it can be improved.

  According to the ultrasonic transducer of the second aspect of the present invention, the end surface is formed on the support portion that supports the ultrasonic transducer so as to vibrate, and the area of the end surface is set between the end surface and the end surface of the support portion. By making it wider than the cross-sectional area of the plane cut along the plane including the axis, the reliability of replacement of the chip attached to and detached from the ultrasonic vibrator is improved, and the handpiece in which the ultrasonic vibrator is used It is possible to improve the ease of gripping and the ease of work.

1 is a perspective view illustrating the overall configuration of an ultrasonic vibration device according to an embodiment of the present invention. FIG. 2 is an exploded perspective view illustrating the overall configuration of the ultrasonic transducer of FIG. It is a partial expansion perspective view explaining the structure of the front member of FIG. It is a partial enlarged plan view explaining the composition of a front member. It is a front view explaining the structure of a front member. It is a fragmentary perspective view explaining the structure of the case main body of FIG. It is a top view explaining the state by which the ultrasonic vibrator was inserted in the case main body. FIG. 8 is a cross-sectional view illustrating a state where a support portion is inserted into the groove portion of FIG. 7. FIG. 5 is a plan view for explaining another embodiment of the front member in FIG. 4. It is a front view explaining the structure of the support part of FIG. FIG. 6 is a front view for explaining still another embodiment of the front member in FIG. 4. It is a top view explaining the structure which prevents the relative rotation of the conventional front member and case. It is a top view explaining another structure which prevents the relative rotation of the conventional front member and case.

  Hereinafter, an ultrasonic vibration device 1 including an ultrasonic transducer 10 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 11. FIG. 1 is a perspective view illustrating the overall configuration of the ultrasonic vibration device 1 according to the present embodiment, and FIG. 2 is an exploded perspective view illustrating the overall configuration of the ultrasonic transducer 10 of FIG.

  The ultrasonic vibration device 1 according to the present embodiment is a medical device such as an ultrasonic scalpel or an ultrasonic plaque remover that is held in the hand, a processing machine such as an ultrasonic cutter or an ultrasonic file, in other words, a handpiece. It can be used as a handy type device. As shown in FIG. 1, the ultrasonic vibration device 1 includes an ultrasonic vibrator 10 that generates ultrasonic vibrations, and a case 50 that accommodates the ultrasonic vibrator 10 and is held by an operator. It is mainly provided.

  As shown in FIGS. 1 and 2, the ultrasonic transducer 10 includes a piezoelectric element unit 20 that generates ultrasonic vibrations, a front member 30 and a backing member 40 that hold the piezoelectric element unit 20 therebetween, Is mainly provided.

  The piezoelectric element unit 20 is a vibrator unit in which piezoelectric elements 21 and electrode plates 22 are alternately stacked, and is configured as a so-called Langevin vibrator. The piezoelectric element unit 20 is mainly composed of a piezoelectric element 21 formed in a cylindrical shape with a through hole formed in the center, and an electrode plate 22 formed in a ring plate shape.

  In the present embodiment, description will be made by applying to an example of a piezoelectric element unit 20 provided with four piezoelectric elements 21 and four electrode plates 22. The four electrode plates 22 are respectively disposed at three locations between the piezoelectric elements 21 and at one location between the piezoelectric elements 21 and the backing member 40.

  The piezoelectric element 21 is made of lead zirconate titanate (PZT) as a material, press-molded, fired, applied with conductive paste on both end faces, and polarized in the thickness direction by being polarized in oil. The piezoelectric element 21 is then ground and polished into a predetermined shape, and silver (Ag) is deposited on the upper and lower end faces adjacent to the electrode plate 22 and the backing member 40 to form a conductive layer. Further, a through-hole formed in the center of the piezoelectric element 21 is a hole through which a tightening bolt 23 used for clamping the piezoelectric element unit 20 between the front member 30 and the backing member 40 is inserted.

  The electrode plate 22 is a ring plate-like member made of a conductive material such as beryllium copper, and supplies power to the piezoelectric element 21. The electrode plate 22 is formed with a through-hole through which the tightening bolt 23 is inserted at the center, a disc portion formed to have the same diameter as the piezoelectric element 21, a radially outward projection from the disc portion, It is mainly comprised from the terminal part electrically connected. The terminal portion of the electrode plate 22 is formed in a minimum size that does not contact the case 50 or inhibit the vibration of the ultrasonic transducer 10.

  The terminal portion of the electrode plate 22 that is electrically connected to the positive electrode of the power source that supplies power to the piezoelectric element unit 20 and the terminal portion of the electrode plate 22 that is electrically connected to the negative electrode are prevented from short-circuiting each other. In order to do so, they are arranged so as to protrude in different directions. In the present embodiment, the terminal portion of the electrode plate 22 connected to the positive electrode protrudes upward in FIG. 2, and the terminal portion of the electrode plate 22 connected to the negative electrode protrudes downward in FIG. I will explain.

  FIG. 3 is a partially enlarged perspective view illustrating the configuration of the front member 30 of FIG. FIG. 4 is a partially enlarged plan view for explaining the configuration of the front member 30, and FIG. 5 is a front view for explaining the configuration of the front member 30.

  As shown in FIGS. 3 to 5, the front member 30 includes a large-diameter cylindrical portion 31 provided with a contact surface 31 </ b> A that is an end surface with which the piezoelectric element unit 20 is contacted, and an end surface that radiates ultrasonic vibration. A small-diameter cylindrical portion 32 provided with a certain vibration radiation surface 32A (see FIG. 2). Furthermore, it is formed as a metal block having a truncated cone-shaped portion whose diameter continuously decreases from the large-diameter column portion 31 toward the small-diameter column portion 32.

  The front member 30 is formed such that the length from the contact surface 31A to the vibration radiation surface 32A, that is, the length in the axial direction is, for example, λ / 4, where λ is the wavelength at the resonance frequency of the piezoelectric element unit 20. Has been. Therefore, the front member 30 functions as a horn that transmits ultrasonic vibration generated in the piezoelectric element unit 20 to the vibration radiation surface 32A.

  Further, the large-diameter cylindrical portion 31 of the front member 30 is provided with a support portion 33 that supports the ultrasonic transducer 10 so as to vibrate inside the case 50. The support portion 33 is a member that protrudes radially outward from the circumferential surface of the large-diameter cylindrical portion 31 around the central axis L of the front member 30, and is discrete at intervals of about 120 ° in the circumferential direction. It is arranged. Therefore, a pair of end surfaces 33 </ b> A and 33 </ b> A are provided at the circumferential end of the support portion 33. The front member 30 and the support portion 33 are members made of titanium (Ti), aluminum (Al), stainless steel (SUS), and the like. In this embodiment, the support portion 33 is formed integrally with the front member 30.

  The support portion 33 includes a flange-shaped flange portion 34 extending in the radial direction and the circumferential direction from the large-diameter column portion 31, and a cylinder extending in the direction along the central axis L from the radially outer end of the flange portion 34 and in the circumferential direction. And a plate-like outer end portion 35 constituting a part of the surface. The flange portion 34 is a position that becomes a node of amplitude when the ultrasonic vibrator 10 vibrates, in other words, a position λ / 4 from the vibration radiation surface 32A that is the tip of the ultrasonic vibrator 10, and the ultrasonic vibration. It is provided at a position of λ / 4 + n × λ / 2 (n = 0, 1, 2, 3,...) From the end of the fastening bolt 23 that is the rear end of the child 10. Therefore, vibration inhibition of the ultrasonic transducer 10 by the support portion 33 can be suppressed. Further, the support portion 33 is formed so that a predetermined gap is secured between the support portion 33 and a case body 51 described later in a state where the ultrasonic transducer 10 is housed in the case 50. Also by this, the vibration inhibition of the ultrasonic transducer 10 by the support portion 33 is suppressed. However, the predetermined interval between the holding portion 33 and the case main body 51 may not be secured and is not particularly limited. For example, when the ultrasonic transducer 10 is press-fitted into the case 50, the above-described interval is not ensured.

  On the other hand, the outer end portion 35 covers the radially outer end of the flange portion 34, and only the outer peripheral surface of the outer end portion 35 is arranged to constitute the outer peripheral surface of the support portion 33. The outer end portion 35 is disposed on the surface of the flange portion 34 on the contact surface 31A side, and the end surface on the radially outer side of the flange portion 34 and the outer peripheral surface of the outer end portion 35 constitute the outer peripheral surface of the support portion 33. May be arranged.

  In the present embodiment, an example in which the outer end portion 35 extends from the end of the flange portion 34 toward the piezoelectric element unit 20 side (upper side in FIG. 3), in other words, when the cross section of the support portion 33 is L-shaped. Apply and explain. The direction in which the outer end portion 35 extends may be on the piezoelectric element unit 20 side as described above, on the contrary, on the small diameter cylindrical portion 32 side, or in both directions. In other words, the support portion 33 may have a T-shaped cross section, and is not particularly limited.

  In the present embodiment, with respect to the piezoelectric element 21 having a diameter of 8.0 mm, the diameter of the support portion 33 (outer end portion 35) is 12.0 mm, and the circumferential width of the support portion 33 is 3.0 mm. The thickness of the flange portion 34 (thickness in the direction of the central axis L) is 1.0 mm, and the length of the outer end portion 35 (length in the direction of the central axis L) is 2.0 mm. Further, the radial length of the outer end portion 35 (the width from the outer peripheral surface to the inner peripheral surface of the outer end portion 35) is formed to be 1.0 mm, and the radial length (large) of the flange portion 34 is formed. The length from the circumferential surface of the diameter cylindrical portion 31 to the inner circumferential surface of the outer end portion 35) is formed to be 1.0 mm.

  The backing member 40 is formed as a cylindrical metal block having an abutting surface for abutting the piezoelectric element unit 20 at one end. Further, in the center of the backing member 40, a female screw portion is provided in which the male screw portion of the tightening bolt 23 is engaged.

  The case 50 is a part that the ultrasonic vibrator 10 is housed inside so as to be able to vibrate, and that an operator holds when holding the ultrasonic vibration device 1. As shown in FIG. 1, the case 50 includes a case main body (housing) 51 formed in a cylindrical shape, and a case tip 52 formed in a truncated cone shape that is detachably attached to the end of the case main body 51. Are mainly provided.

  FIG. 6 is a partial perspective view illustrating the configuration of the case main body 51 of FIG. FIG. 7 is a plan view for explaining a state in which the ultrasonic transducer 10 is inserted into the case body 51, and FIG. 8 is a cross-sectional view for explaining a state in which the support portion 33 is inserted into the groove portion 54 in FIG. FIG.

  As shown in FIGS. 1 and 6, the case main body 51 is formed of a lightweight and strong material such as resin, and has a cylindrical space 53 in which the ultrasonic transducer 10 is accommodated. A gap that allows vibration of the ultrasonic transducer 10 is provided between the space 53 and the ultrasonic transducer 10. Further, a groove portion 54 into which the support portion 33 is inserted is provided on the inner surface of the case main body 51 at a position corresponding to the support portion 33 of the ultrasonic transducer 10. That is, the groove portion 54 is formed on the inner surface of the case body 51 with an interval of about 120 ° in the circumferential direction, and the inner surface of the groove portion 54 is formed in a shape similar to the support portion 33 in plan view. . Contact portions 54A and 54A that come into surface contact with the case main body 51 and the ultrasonic transducer 10 relative to each other about the central axis L are located at portions of the groove portion 54 that face the end surfaces 33A and 33A of the support portion 33. Is provided.

  The case front end portion 52 accommodates the ultrasonic transducer 10 inside together with the case main body 51, and the small diameter cylindrical portion 32 of the front member 30 protrudes from a through-hole opened at the front end in a vibrable state. . The case tip 52 may be formed from the same resin as the case main body 51, or may be formed from other materials, and the material is not limited. The case tip 52 and the case main body 51 may be coupled by male screws and female screws, or may be other detachable coupling methods.

Next, the operation of the ultrasonic vibration device 1 and the ultrasonic transducer 10 having the above-described configuration will be described with reference to FIGS.
When ultrasonic vibration is generated in the ultrasonic vibration device 1, an AC voltage (drive voltage) having a resonance frequency is supplied to the ultrasonic vibrator 10 from an external power source (drive circuit). The driving voltage is supplied to the piezoelectric element 21 via the electrode plate 22 of the piezoelectric element unit 20. The piezoelectric element 21 supplied with the driving voltage vibrates at a resonance frequency, here, a frequency in the ultrasonic region.

  The ultrasonic vibrations of the plurality of piezoelectric elements 21 are transmitted to the entire ultrasonic vibrator 10, and the ultrasonic vibrator 10 vibrates ultrasonically. Since the ultrasonic transducer 10 is housed in a state where a gap is formed between the outer peripheral surface of the support portion 33 and the inner peripheral surface of the groove portion 54 of the case 50 and the inner surface of the case 50, Even inside the case 50, it can vibrate ultrasonically.

  The ultrasonic vibration in the ultrasonic transducer 10 is amplified by the front member 30 and radiated from the vibration radiation surface 32A of the small diameter cylindrical portion 32. For example, when the ultrasonic vibration device 1 is an ultrasonic knife, the knife attached to the vibration radiation surface 32A is ultrasonically vibrated.

  Here, prevention of relative rotation between the case 50 and the ultrasonic transducer 10, which is a feature of the present embodiment, will be described with reference to FIGS. 4 to 7. For example, when the ultrasonic vibration device 1 is used as an ultrasonic knife as described above, a plurality of types of knife are attached to and detached from the vibration radiation surface 32 </ b> A of the ultrasonic vibration device 1. When the female is attached and detached using the engagement of the male screw and the female screw, a force is applied to the vibration radiation surface 32A, that is, the ultrasonic transducer 10, in the rotational direction around the central axis L. On the other hand, since the case 50 is held by an operator, a force in the relative rotation direction acts between the case 50 and the ultrasonic transducer 10.

  When a force rotating around the central axis L is applied to the vibration radiation surface 32 </ b> A, the rotational force is transmitted to the support portion 33 via the small diameter cylindrical portion 32 and the large diameter cylindrical portion 3. When the support portion 33 rotates around the central axis L, the end surface 33A of the support portion 33 and the contact surface 54A of the groove portion 54 of the case body 51 come into surface contact. Thereby, relative rotation of case 50 and ultrasonic transducer 10 is prevented.

  As shown in FIG. 8, the contact surface between the end surface 33A and the contact surface 54A is formed only from the flange portion 34 because the end surface 33A is formed in an L shape by the flange portion 34 and the outer end portion 35. Wide compared to the case. Therefore, the surface pressure and stress on the contact surface are reduced, and the support portion 33 provided with the end surface 33A, the groove portion 54 of the case body 51 provided with the contact surface 54A, and the like are not easily deformed or broken. Furthermore, the choice of the material which comprises the case main body 51 becomes wide.

  On the other hand, as shown in FIG. 7, the thickness of the case body 51 (the hatched portion in FIG. 7) can be increased at a portion other than the portion where the groove portion 54 is formed in the case body 51. Therefore, it becomes easy to ensure the strength of the case body 51. That is, the inner surface of the case main body 51 can be protruded to the vicinity of the front member 30 in a portion where the support portion 33 is not disposed. In other words, the inner surface of the case main body 51 can be projected to the area where the support portion 33 is disposed, and the thickness from the outer surface to the inner surface of the case main body 51 can be increased. On the other hand, in the part where the support part 33 is arrange | positioned, it can be set as the thickness similar to the case where the conventional disk-shaped support part is used. Then, the average thickness of the case main body 51 in the circumferential direction can be increased without increasing the outer diameter of the case main body 51, and the strength of the case main body 51 can be easily secured. As a result, it is possible to ensure the strength of the case main body 51, ease of gripping in the ultrasonic vibration device 1, and ease of work.

  According to the above configuration, the end surface 33A formed on the support portion 33 and a part of the inner surface of the case 50 that accommodates the ultrasonic transducer 10, specifically, a shape in surface contact with the end surface 33A are formed. It is possible to prevent the case 50 and the ultrasonic transducer 10 from rotating relative to each other about the central axis L due to contact with the contact surface 54A of the groove 54. On the other hand, when the shape of the end face 33A is divided into the outer side and the inner side in the radial direction and compared, the area of the outer part is formed so that the area of the outer part is larger than the area of the inner part. Securement and suppression of weight increase can be achieved. As a result, the ease of work in the ultrasonic vibration device 1 can be ensured.

  In general, when a force is applied in a direction in which the case 50 and the ultrasonic transducer 10 rotate relative to each other about the central axis L, the radially outer portion of the end surface 33A is larger than the radially inner portion. Power works. Therefore, when the radially outer portion and the radially inner portion are formed with the same area, the surface pressure or stress acting on the radially outer portion is greater than the surface pressure or stress of the radially inner portion. Also gets higher. As in the ultrasonic transducer 10 according to the present embodiment, when the radially outer portion is formed with a larger area compared to the radially inner portion, the radially outer side of the end face 33A is compared with the above case. The surface pressure and stress of the portion can be reduced. As a result, the end face 33A can be prevented from being deformed or broken, and the reliability of exchanging the tip of the knife or the like can be improved.

  Furthermore, since the area of the radially inner portion of the end surface 33A is reduced compared to the method of increasing the plate thickness of the entire support portion 33 and increasing the area of the end surface 33A, the volume of the support portion 33 is reduced. In addition, weight increase can be prevented or weight reduction can be achieved. As a result, an increase in the weight of the ultrasonic transducer 10 can be prevented or reduced in weight. More preferably, in the entire cross section cut in the radial direction in the support portion 33, it is desirable that the area of the radially inner portion is smaller than the area of the radially outer portion, similarly to the end face. By doing in this way, the weight increase of the support part 33 and the ultrasonic transducer | vibrator 10 can be prevented more reliably, or weight reduction can be aimed at more effectively. As a result, it is possible to ensure the strength of the case main body 51, ease of gripping in the ultrasonic vibration device 1, and ease of work.

  As in the present embodiment, the ring plate-like flange portion 34 extends from the outer surface of the support portion 33 radially outward, and the cylindrical outer end portion 35 extends from the outer end of the flange portion 34 in the central axis L direction. Thus, the area of the radially outer portion of the end surface 33A of the support portion 33 can be made larger than the area of the radially inner portion. For example, when the outer end portion 35 is extended only in one direction from the outer end of the flange portion 34, the end surface 33A is formed in an L shape, and when the outer end portion 35 is extended in both directions, the end surface 33A is formed in a T shape. It will be. In addition, the support portion 33 is not divided into the flange portion 34 and the outer end portion 35, and the surface on the end surface 33A side and the surface on the vibration radiating surface 32A side, which are the opposing surfaces of the support portion 33, are arranged in diameter. It may be formed continuously spaced toward the outside in the direction.

  Furthermore, compared with the case where the support part 33 is formed in a plate shape, the contact area between the support part 33 and the inner surface of the case 50 can be increased while suppressing an increase in the weight of the support part 33. The outer end portion 35 is a plate member curved in a cylindrical shape extending in the central axis L direction and the circumferential direction, and can contact the inner surface of the case 50 on the outer circumferential surface thereof. In other words, a gap is provided between the outer peripheral surface of the outer end portion 35 and the inner surface of the case 50, and when the ultrasonic vibration device 1 is tilted, the outer peripheral surface of the outer end portion 35, The inner surface of the case 50 is in contact with it.

  Therefore, by adjusting the length of the outer end portion 35 in the direction of the central axis L, the contact area between the support portion 33 and the inner surface of the case 50 can be easily adjusted. Furthermore, even if the length of the outer end portion 35 in the direction of the central axis L is increased, for example, an increase in the weight of the support portion 33 can be suppressed as compared with a case where the overall thickness of the support portion 33 is increased. it can.

  Even if the ultrasonic transducer 10 of the present embodiment is housed in the case 50, the vibration of the ultrasonic transducer 10 is not easily inhibited. That is, when the ultrasonic transducer 10 is housed in the case 50, the support portion 33 comes into contact with the inner surface of the case 50, so that the ultrasonic transducer 10 is supported in a state of being spaced from the inner surface of the case 50. . In this state, when the piezoelectric element unit 20 is vibrated, for example, longitudinally vibrated at a natural frequency of the ultrasonic transducer 10 or a frequency close to the natural frequency, for example, longitudinally vibrates, the ultrasonic transducer 10 includes the end of the front member 30, and A standing wave with the end of the backing member 40 as an antinode is generated. In this case, if the support portion is disposed at the position of the node in the standing wave, it is possible to suppress the support portion 33 from affecting the longitudinal vibration of the ultrasonic transducer 10, for example, suppressing the longitudinal vibration.

FIG. 9 is a plan view for explaining another embodiment of the front member of FIG. 4, and FIG. 10 is a front view for explaining the structure of the support part of FIG.
Note that, as in the above-described embodiment, the support portion 33 of the front member 30 may be configured by the flange portion 34 and the outer end portion 35, or as shown in FIGS. The portion 133 may be configured by the flange portion 34 and the side end portions 135 and 135.

  The side end portions 135 are disposed at both ends of the flange portion 34 in the circumferential direction around the central axis L, and extend from the end of the flange portion 34 toward the contact surface 31A along the central axis L direction. It is a plate-shaped member. In other words, the side end portion 135 is a plate-like member that extends across the circumferential direction and extends in the direction of the central axis L, and the flange portion 34 and the side end portions 135 and 135 are U-shaped in a front view. Are arranged side by side. Further, the side end portion 135 is provided with an end surface 33A.

FIG. 11 is a front view for explaining still another embodiment of the front member in FIG. 4.
Furthermore, as shown in FIG. 11, the support portion 233 of the front member 230 may be composed of a flange portion 34 and side end portions 235 and 235.

  The side end portions 235 are disposed at both ends of the flange portion 34 in the circumferential direction around the central axis L, and extend from the end of the flange portion 34 to the contact surface 31A and the small diameter cylindrical portion 32 along the central axis L direction. It is a pair of plate-shaped member extended toward. In other words, the flange portion 34 and the side end portions 235 and 235 are arranged in an H shape in front view. Furthermore, the side end portion 235 is provided with an end face 33A.

  In this way, the ring plate-like flange portion 34 extends radially outward from the outer peripheral surface of the support portions 133 and 233, and the plate-like side end portion in the central axis L direction from the circumferential side end of the flange portion 34. By extending 135 and 235, the area of the end surface 33A can be made larger than the cross-sectional area of the surface cut by the plane including the central axis L between the end surfaces 33A and 33A of the support portions 133 and 233. As described above, the side end portions 135 and 235 may be disposed so as to extend only in one direction from the side end of the flange portion 34, or may be disposed so as to extend in both directions.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the description is applied to an example in which the three support portions 33 are arranged at equal intervals in the circumferential direction around the central axis L, but the number of the support portions 33 is limited to three. It may be less or more than three.

  Ultrasonic vibrator ... 10, front member ... 30, 130, backing member ... 40, piezoelectric element ... 21, electrode plate ... 22, support part ... 33,133, end face ... 33A, flange part ... 34, outer end part ... 35, case body (casing) ... 51, side end part ... 135

Claims (6)

An ultrasonic transducer having an outer fastening structure including a front member and a backing member sandwiching a piezoelectric element and an electrode plate,
The front member is provided with a support portion that extends radially outward centered on the axis of the front member, and supports the front member, the piezoelectric element, the electrode plate, and the backing member so as to vibrate,
The support portion is formed with an end surface that intersects and extends in a circumferential direction centered on the axis,
The ultrasonic transducer according to claim 1, wherein an area of the radially outer portion of the end face is larger than an area of the inner portion.   The support portion includes a plate-like flange portion extending in the radial direction and the circumferential direction, and a plate-like outer end portion extending from the radially outer end of the flange portion in the axial direction and the circumferential direction. The ultrasonic transducer according to claim 1, wherein the ultrasonic transducer is provided. An ultrasonic transducer having an outer fastening structure including a front member and a backing member sandwiching a piezoelectric element and an electrode plate,
The front member is provided with a support portion that extends radially outward centered on the axis of the front member, and supports the front member, the piezoelectric element, the electrode plate, and the backing member so as to vibrate,
At both ends of the support portion in the circumferential direction centering on the axis, an end surface that extends across the circumferential direction and that contacts a part of the inner surface of the housing is formed.
The ultrasonic transducer according to claim 1, wherein an area of the end surface is wider than a cross-sectional area of a surface obtained by cutting a space between both ends of the support portion along a plane including the axis.   The support portion includes a plate-like flange portion extending along the circumferential direction and the radial direction, and a plate-like side end portion extending from the circumferential end of the flange portion along the axial direction and the radial direction. The ultrasonic transducer according to claim 3, further comprising:   5. The ultrasonic transducer according to claim 1, wherein the support parts are arranged at equal intervals in a circumferential direction centering on the axis. 6.   The said support part is arrange | positioned in the position of the node of the vibration in the structure which consists of the said front member, the said piezoelectric element, the said electrode plate, and the said backing member, The any one of Claim 1 to 5 characterized by the above-mentioned. The ultrasonic transducer according to item 1.

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