JPH11235552A - Langevin type ultrasonic vibrator transducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the fitting to a connecting stick and to enable keeping the relative position of tongue pieces for lead wire connection when parts are connected. SOLUTION: One or plural notched grooves are formed on the inner peripheral edges of annular electrode plates 4a, 4b, and also an insulating cover 12 is formed into a cylinder which can be inserted on a connecting stick 11 by using synthetic resin insulating material, and on the outer periphery thereof, engaging projected lines 20 to be engaged with the notched grooves of the annular electrode plates 4a, 4b are provided. When integrally connecting the annular piezoelectric elements 3a, 3b, the annular electrode plates 4a, 4b, and metal blocks 5a, 5b by inserting the connecting stick 11 through an inserting hole 9 formed a long the central line thereof, the annular electrode plates 4a, 4b are inserted on the cylindrical insulating cover 12 fitted to the connecting stick 11 and the engaging projected lines 20 and the notched grooves of the annular electrode plates 4a, 4b are engaged with each other, thereby controlling the relative rotation of the annular electrode plates 4a, 4b to enable keeping the tongue pieces 14, 14 for lead wire connection formed on the annular electrode plates 4a, 4b in prescribed fitting positions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Langevin type ultrasonic vibrator which generates vibration by electrostriction of a piezoelectric element.

[0002]

2. Description of the Related Art As a Langevin type ultrasonic transducer of this kind, as shown in FIG.
b is arranged on the upper and lower metal blocks c,
d, and these are integrally connected by a connecting rod f and a nut j.

In such a Langevin type ultrasonic transducer, one end of a connecting rod f is screwed to a metal block c.
The annular electrode plates b, b, the annular piezoelectric element a, and the metal block d are inserted through the connecting rod f in a predetermined order so that the connecting rod f is inserted through an insertion hole e formed along the center line. The components are integrally connected by fitting and tightening a nut j on the upper end of a connecting rod f protruding from the metal block d.

Further, an annular piezoelectric element a and an annular electrode plate b,
An insulating cover k is attached to an outer peripheral portion of the connecting rod f corresponding to the height position of the connecting rod f, and the insulating cover k separates the connecting rod f from the annular piezoelectric element a and the annular electrode plates b, b. The contact state is set to prevent malfunction of the ultrasonic vibrator due to an electric short circuit.

[0005]

By the way, when the nut j screwed to the upper end of the connecting rod f is screwed in the tightening direction during the connection of the above-mentioned parts, the metal block d is thereby connected with the nut j. The annular piezoelectric element a and the annular electrode plates b, b rotate irregularly, respectively, and the tongue pieces 14 (see FIG. 3) for connecting lead wires formed on the annular electrode plates b, b are formed. The predetermined mounting position and its relative angle change. For this reason, the ring-shaped electrode plates b,
b must be held so as not to rotate, and the tightening work has been troublesome.

A heat-shrinkable tube made of Teflon is used as the insulating cover k to be attached to the outer peripheral portion of the connecting rod f. Required and costly.

An object of the present invention is to provide a Langevin type ultrasonic transducer which can solve such a conventional problem.

[0008]

According to the present invention, a metal block is arranged above and below a single or a plurality of annular piezoelectric elements, and a connecting rod is inserted into an insertion hole formed along the center line of the metal block to form the connection. A Langevin type ultrasonic transducer in which the piezoelectric element and the upper and lower metal blocks are integrally connected by a rod, and at least an outer peripheral portion of the connecting rod corresponding to the height position of the piezoelectric element is covered with an insulating cover. A single or a plurality of notched grooves are formed on the inner peripheral edge of an annular electrode plate disposed on the upper and lower surfaces of the annular piezoelectric element, and the insulating cover is attached to the connecting rod using a synthetic resin insulating material. A Langevin type ultrasonic vibrator characterized in that it is formed in a tubular shape that can be fitted to the outside, and its outer periphery is provided with engaging ridges to be engaged with the cutout grooves of the annular electrode plate.

In such a configuration, when the annular piezoelectric element and the annular electrode plate and the metal block arranged above and below the annular piezoelectric element are integrally connected by inserting a connecting rod into an insertion hole formed along the center line thereof. Each of the annular electrode plates is externally fitted to the cylindrical insulating cover externally fitted to the connecting rod, and the engaging ridge of the insulating cover is engaged with the cutout groove of each annular electrode plate. As a result, the respective annular electrode plates become relatively unrotatable, and even if a rotational force acts on the respective annular electrode plates by a screwing operation of the tightening nut screwed to the connecting rod in the tightening direction, the respective annular electrode plates are not rotated. The relative angle of the electrode plates does not change, and the tongue pieces for connecting the lead wires formed on each of the annular electrode plates can be easily held at the predetermined mounting positions.

Further, according to the present invention, a metal block is arranged above and below a single or a plurality of annular piezoelectric elements, and a connecting rod is inserted into an insertion hole formed along the center line of the metal block, and the connecting rod is In a Langevin type ultrasonic transducer in which an element and upper and lower metal blocks are integrally connected and an outer peripheral portion of a connecting rod corresponding to at least a height position of the piezoelectric element is covered with an insulating cover, The cover is formed in a tubular shape that can be fitted onto the connecting rod by using a synthetic resin insulating material, and a plurality of guide pieces having projections that press against the outer peripheral surface of the connecting rod are provided at upper and lower ends thereof. It is a Langevin type ultrasonic transducer characterized by the above.

In this configuration, the insulating cover can be attached to the connecting rod by moving the cylindrical insulating cover from the end of the connecting rod to a predetermined height position. Here, when the cylindrical insulating cover is externally fitted to the end of the connecting rod, the plurality of guide pieces provided at the end of the insulating cover are elastically expanded to facilitate the external fitting operation. Can be done. Further, in the mounted state, the projections of the guide pieces provided at the upper and lower ends of the insulating cover are pressed against the outer peripheral surface of the connecting rod, so that the insulating cover can be stably held.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

1 shows a Langevin type ultrasonic transducer according to the present invention. Reference numeral 2 denotes two annular piezoelectric elements 3a and 3b,
A piezoelectric element pair in which an annular electrode plate 4a is interposed therebetween and laminated, and an annular electrode plate 4b is arranged below the lower annular piezoelectric element 3b. Is disposed a metal block 5a as a backing plate formed in a columnar shape substantially equal to the diameter of the annular piezoelectric elements 3a and 3b. An annular piezoelectric element 3 is provided below the piezoelectric element pair 2.
A metal block 5b as a front plate having a columnar shape slightly larger than the diameters of a and 3b and having front and rear flat surfaces 6, 6 is formed. A radiation surface 7 for ultrasonic vibration is provided on a lower surface of the metal block 5b, and a female screw hole 8 for connecting a driven body is formed on the radiation surface 7.

The piezoelectric element pair 2, metal blocks 5a, 5
b, a series of insertion holes 9 is formed along the center line. That is, the insertion hole 9 has a center hole 9a vertically penetrating the metal block 5a and the annular piezoelectric elements 3a, 3b.
And the inner holes of the annular electrode plates 4a and 4b and the metal block 5b.
And a center hole 9b formed so as to extend from the upper surface of the metal block 5b to a substantially central height position.
A female screw 10 is formed at the back of the center hole 9b.
The center holes 9a and 9b of the metal blocks 5a and 5b are formed with large-diameter portions 9 'by performing counterbore processing on the end face side facing the piezoelectric element pair 2, respectively.
The inner holes a and 3b also have a size corresponding to the large diameter portion 9 '. As a result, an accommodating gap 13 for the insulating cover 12 is generated between the connecting rod 11 and the connecting rod 11 described later inserted through the insertion hole 9.

The annular electrode plates 4a, 4b are formed in a disk shape substantially equal to the diameter of the annular piezoelectric elements 3a, 3b, and as shown in FIG. 14 protrudes laterally. Notch grooves 15 are formed in the inner peripheral edges of the annular electrode plates 4a and 4b at positions different from each other by approximately 90 °, and the depth of each notch groove 15 is set to the depth of the large-diameter portion 9 ′. They are almost matched.

The piezoelectric element pair 2, metal blocks 5a, 5
b are integrally connected by a connecting rod 11 inserted through the insertion hole 9. That is, the male screw 16a formed at the lower end of the connecting rod 11 is screwed into the female screw 10 of the metal block 5b and tightened to the male screw 16b formed at the upper end of the connecting rod 11 protruding from the metal block 5a. By screwing and tightening the nut 17, the metal blocks 5a, 5b
Each component is integrally connected with the piezoelectric element pair 2 held therebetween.

The connecting rod 11 has the storage space 13.
Insulation cover 12 is mounted in advance and located inside,
The connecting rod 11 corresponding to the height position of the annular piezoelectric elements 3a, 3b and the annular electrode plates 4a, 4b is provided by the insulating cover 12.
Is covered.

As shown in FIGS. 4 to 6, the insulating cover 12 is formed in a cylindrical shape using a synthetic resin insulating material, and has an inner diameter outside the male screws 16a and 16b at both ends of the connecting rod 11. It is set to be slightly larger than the diameter. That is, the male screws 16a and 16b of the connecting rod 11 are formed by forging a round bar material, and the screw thread portion is slightly larger in diameter than the unformed portion. By making the inner diameter of the insulating cover 12 slightly larger than the outer diameter of the thread of the male screws 16a and 16b as described above, the insulating cover 12 can be fitted from the end of the connecting rod 11.

At the upper and lower ends of the insulating cover 12, a plurality of guide pieces 18 projecting in the vertical direction are provided at predetermined intervals in the circumferential direction. Each of the projections 19 is pressed into contact with the outer peripheral surface of the projection 11.

On the outer periphery of the insulating cover 12, vertically long engaging projections 20 which can engage with the cutout grooves 15 of the annular electrode plates 4a, 4b are respectively provided at positions different from each other by approximately 90 °. ing.

It is desirable that the insulating cover 12 be made of a synthetic resin insulating material having heat resistance and moderate elasticity in addition to insulating properties. The contained 66 nylon can be suitably used. Further, the insulating cover 12 has a cylindrical portion,
The guide piece 18 and the engaging ridge 20 can be integrally formed by insert molding.

In order to integrally connect the components in such a configuration, first, the male screw 16a at the lower end of the connecting rod 11 is screwed into the female screw 10 of the metal block 5b in a tightening manner. The insulating cover 12 is fitted from the upper end of the housing 11 and moved downward to a predetermined height position. Here, when the cylindrical insulating cover 12 is externally fitted to the end of the connecting rod 11, the connecting rod 1
When the male screw 16b at the upper end of one is fitted inside a plurality of guide pieces 18 provided at the end of the insulating cover 12, each guide piece 18 is elastically expanded to provide a guide action. The outer fitting operation can be easily performed. Further, in the mounted state in which the insulating cover 12 is moved to a predetermined position, the protrusions 19 of the respective guide pieces 18 provided at the upper and lower ends of the insulating cover 12 are pressed against the outer peripheral surface of the connecting rod 11. In addition, the position of the insulating cover 12 can be stably held. The insulating cover 12 may be mounted on the connecting rod 11 by the above operation before the connecting rod 11 is screwed to the metal block 5b.

Then, as described above, the metal block 5b
The annular electrode plate 4 is connected to the connecting rod 11 screwed to
b, the annular piezoelectric element 3b, the annular electrode plate 4a, and the annular piezoelectric element 3a are sequentially fitted outside. At this time, the notch grooves 15 of the annular electrode plates 4a, 4b are engaged with the insulating cover 12 so that the tongue pieces 14, 14 of the annular electrode plates 4a, 4b form a predetermined relative angle such as 180 °. The ridge 20 is engaged. Next, the metal block 5a is externally fitted to the connecting rod 11, and the metal block 5a is
A tightening nut 17 is screwed onto a male screw 16b of the connecting rod 11 protruding therefrom, and tightened.

With the screwing operation of the tightening nut 17, a rotational force is generated to rotate the metal block 5a, the annular piezoelectric elements 3a, 3b, and the annular electrode plates 4a, 4b. As described above, each of the notches 15 of the plates 4a and 4b is
, The two annular electrode plates 4a, 4b
The two are relatively unable to rotate. Thus, even if a rotational force acts on the annular electrode plates 4a, 4b, the relative angle between the annular electrode plates 4a, 4b does not change, and the annular electrode plates 4a, 4b are not changed.
The lead wire connecting tongue pieces 14, 14 formed in 4b can be easily held at predetermined mounting positions.

Thus, the components can be integrally connected while the piezoelectric element pair 2 is held between the metal blocks 5a and 5b.

The Langevin type ultrasonic vibrator 1 thus constructed is provided with the tongue pieces 14, 14 of the annular electrode plates 4a, 4b.
Input the alternating voltage via the lead wire connected to
The voltage is applied to the piezoelectric element pair 2 to generate ultrasonic vibration,
Ultrasonic waves are radiated from the radiation surface 7 on the lower surface of the metal block 5b. The lower annular piezoelectric element 3b constituting the piezoelectric element pair 2 has annular electrode plates 4a, 4b arranged above and below it.
The alternating voltage is directly applied to the upper annular piezoelectric element 3a by the annular electrode plate 4a and the lower surface of the metal block 5b electrically connected to the annular electrode plate 4b via the metal block 5b and the connecting rod 11. A voltage is applied.

In the above embodiment, the annular electrode plates 4a, 4a
b, four notches 15 on the inner peripheral edge and four engaging ridges 20 of the insulating cover 12 are provided, but the number is not limited to this, and the number is not limited to one or four. A plurality other than the above may be used.

Also, in the above embodiment, the plurality of guide pieces 18 provided at the upper and lower ends of the insulating cover 12 are projected in the vertical direction. It may be provided by dividing into a plurality of cuts along the direction.

[0029]

According to the present invention, as described above, the annular electrode plate 4 is provided.
A single or a plurality of cutout grooves 15 are formed on the inner peripheral edges of the a and 4b, and the insulating cover 12 is formed into a cylindrical shape that can be fitted onto the connecting rod 11 using a synthetic resin insulating material. On the outer periphery, an engagement ridge 20 for engaging with each of the notch grooves 15 of the annular electrode plates 4a, 4b is provided.
3b, annular electrode plates 4a, 4b and metal blocks 5a, 5
b, when they are integrally connected by the connecting rod 11,
The respective annular electrode plates 4a, 4b are externally fitted to the cylindrical insulating cover 12 mounted on the connecting rod 11, and the engaging ridges 20 of the insulating cover 12 and the cutout grooves 15 of the respective annular electrode plates 4a, 4b are formed. By engaging, the relative rotation of each annular electrode plate 4a, 4b can be regulated. As a result, the tongue pieces 14, 1 for connecting the lead wires formed on each of the annular electrode plates 4a, 4b.
4 can be easily held at a predetermined mounting position.

Further, according to the present invention, the insulating cover 12 is formed into a cylindrical shape that can be fitted onto the connecting rod 11 using a synthetic resin insulating material, and the upper and lower ends thereof are pressed against the outer peripheral surface of the connecting rod 11. Since the plurality of guide pieces 18 having the projections 19 are provided, the insulating cover 12 is externally fitted from the end of the connecting rod 11 and moved to a predetermined height position, so that the insulating cover 12
Can be easily attached to the connecting rod 11. This eliminates the need for heating at the time of mounting, unlike a conventional heat-shrinkable tube, and can reduce costs. Further, when the cylindrical insulating cover 12 is externally fitted to the end of the connecting rod 11, the plurality of guide pieces 18 provided at the end of the insulating cover 12 are elastically expanded, so that the external fitting is performed. The operation can be easily performed. In the mounted state, the projections 19 of the guide pieces 18 provided at the upper and lower ends of the insulating cover 12 are pressed against the outer peripheral surface of the connecting rod 11 to stably hold the insulating cover 12. There is an excellent effect that it can be performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of a Langevin type ultrasonic transducer according to the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is an enlarged plan view of an annular electrode plate.

FIG. 4 is an enlarged front view of the insulating cover.

FIG. 5 is an enlarged vertical sectional view of an insulating cover.

FIG. 6 is an enlarged plan view of an insulating cover.

FIG. 7 is a longitudinal sectional view of a conventional Langevin type ultrasonic transducer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Langevin type ultrasonic transducer 3a, 3b Ring-shaped piezoelectric element 4a, 4b Ring-shaped electrode plate 5a, 5b Metal block 9 Insertion hole 11 Connecting rod 12 Insulating cover 15 Notch groove 18 Guide piece 19 Projection 20 Engagement ridge

Claims (2)

[Claims] A metal block is disposed above and below a single or a plurality of annular piezoelectric elements, and a connecting rod is inserted into an insertion hole formed along the center line of the metal block. In a Langevin type ultrasonic transducer in which a metal block is integrally connected and an outer peripheral portion of a connecting rod corresponding to at least a height position of the piezoelectric element is covered with an insulating cover, A single or a plurality of cutout grooves are formed on the inner peripheral edge of the annular electrode plate disposed on the lower surface, and the insulating cover is formed in a cylindrical shape that can be fitted onto the connecting rod by using a synthetic resin insulating material. A Langevin type ultrasonic vibrator characterized in that an engaging ridge is provided on the outer periphery thereof to be engaged with the notch groove of the annular electrode plate. 2. A metal block is disposed above and below a single or a plurality of annular piezoelectric elements, and a connecting rod is inserted through an insertion hole formed along the center line of the metal block, and the connecting rod is vertically connected to the piezoelectric element by the connecting rod. In a Langevin type ultrasonic transducer in which a metal block is integrally connected and an outer peripheral portion of a connecting rod corresponding to at least a height position of the piezoelectric element is covered with an insulating cover, the insulating cover is synthesized. The connecting rod is formed in a tubular shape that can be fitted to the outside of the connecting rod by using a resin insulating material, and a plurality of guide pieces having projections that press against the outer peripheral surface of the connecting rod are provided at both upper and lower ends thereof. Langevin type ultrasonic transducer.