JPH09155289A - Bolted langevin type vibrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform driving under optimum conditions by correcting a change in vibration modes such as a variation in vibration nodes produced when a vibrator is fitted to a body to which ultrasonic waves are to be transferred of a washing tank or the like. SOLUTION: This vibrator consists of a front mass 1 consisting of a metal block, a rear mass 2 similarly consisting of a metal block, at least one piezoelectric element and an electrode plate arranged between the front mass and the rear mass, and a bolt 5 passing through the central part of these constituting parts to tighten and fix them, and is constituted so that the front mass can be fixed to a body to which ultrasonic waves are to be transferred to use it. In this case, behind the rear mass of the bolted Langevin type vibrator, an adjusting block 6 for adjusting the positions of vibration nodes is fitted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bolted Langevin type vibrator using a piezoelectric ceramic element, and in particular, when the bolted Langevin type vibrator is attached to a cleaning tank or the like, it is devised so that it can be driven in an optimum state. Regarding configuration.

[0002]

2. Description of the Related Art The structure of a conventional general bolted Langevin type vibrator and how the vibration energy distribution changes when it is attached to a cleaning tank will be described with reference to FIG. The bolted Langevin transducer is composed of a front mass 81, an electrode plate 85, a piezoelectric element 83, an electrode plate 86, a piezoelectric element 84, and a rear mass 82 in this order from the ultrasonic wave emitting surface. It is clamped and fixed by (not shown). The front mass 81 is made of a metal block, has a columnar shape, and is provided with a female screw portion at a central portion thereof into which a bolt is partially screwed. The electrode plates 85 and 86 have a structure in which a convex lead-out portion for external connection is provided in an annular shape, and the material thereof is nickel,
SUS or nickel silver is used. Piezoelectric element 8
3, 84 are made of piezoelectric ceramics such as PZT (lead titan zirconate) and have a ring-shaped cylindrical shape with a through hole in the central portion. The rear mass 82 is made of a metal block and has a circular columnar shape with a through hole provided in the central portion.

[0003]

It is known that the mechanical strength of ceramics is higher than the tensile strength by one digit or more as compared with the tensile strength. Therefore, when the piezoelectric ceramic is excited by applying a compressive stress, a large stress amplitude can be obtained and a large vibration amplitude can be obtained. The bolt-tightened Langevin-type vibrator applies such ceramic characteristics, and by adjusting the tightening pressure of the tightening bolt and applying an AC voltage to the vibrator, the vibration of the piezoelectric ceramics passes through mechanical contact. A standing wave is generated by being transmitted to the metal block (front mass, rear mass), and ultrasonic vibration occurs. At this time, the bolted Langevin type vibrator as a whole performs stretching vibration in the direction shown by arrow B with the node near the center in the longitudinal direction as a node. The vertical axis of FIG. 3 indicates the magnitude of vibration, and it is explained that normally, large vibration is performed as the distance from the vibration node increases (indicated by the solid line E1).

Such a bolted Langevin type vibrator is used by being attached to, for example, an ultrasonic cleaning tank.
In FIG. 3, the ultrasonic wave emission surface A of the front mass is attached to the ultrasonic cleaning tank, and the ultrasonic wave is emitted from the attached portion into the cleaning tank. Ultrasonic waves U radiated in this cleaning tank
Has a wavelength corresponding to its frequency, but is set to be exactly 1/2 wavelength on the surface of the cleaning liquid as shown in FIG. That is, it is set so that a standing wave is generated between the bottom surface of the cleaning tank S and the liquid surface. It should be noted that R in FIG. 4 is an ultrasonic vibrator, and drive energy is supplied from an oscillator.

However, by fixing the ultrasonic wave emitting surface in this way, the vibration mode of the bolted Langevin type vibrator is partially changed to the vibration mode shown by the dotted line E2, and the position of the vibration node is changed. Is also fluctuating. Due to the fluctuation of the vibration node in this way, the balance of the bolted Langevin type vibrator is lost, and it becomes impossible to perform driving under optimum conditions. In order to solve this, the design is performed in consideration of the change of the vibration mode according to the volume and weight of the ultrasonic receiver such as the cleaning tank to be used. In order to obtain the above, fine adjustment such as adjustment of the drive circuit is necessary, and the adjustment is troublesome.

The present invention corrects a vibration mode change such as a change in a node of vibration that occurs when a bolted Langevin type vibrator is attached to an ultrasonic wave receiving body such as a cleaning tank, An object of the present invention is to provide a bolted Langevin type vibrator that enables driving under optimum conditions.

[0007]

SUMMARY OF THE INVENTION A bolted Langevin type vibrator according to the present invention comprises a front mass made of a metal block, a rear mass made of the same metal block, and at least one piezoelectric element arranged between the front mass and the rear mass. An element and an electrode plate, and a bolt that penetrates through the central portion of each of these components and is fixed by tightening, and is used by fixing the front mass to the ultrasonic wave receiving body. It is characterized in that an adjustment block for adjusting the nodal position of vibration is attached behind the rear mass of the Langevin type vibrator.

With this configuration, the bolted Langevin type vibrator is attached to the ultrasonic wave receiving body, and even when the vibration mode changes and the vibration node changes, the adjustment for adjusting the vibration node position is located behind the rear mass. By mounting the block, the balance of the bolted Langevin type vibrator can be restored and the drive under optimum conditions can be performed. The ultrasonic transmitted object is not only the cleaning tank of the ultrasonic cleaning device, but also various ultrasonic products such as ultrasonic processing devices.

As described in claim 2, the adjusting block may be made of the same material as the rear mass.

By using the same material as the rear mass for the adjusting block in this way, the weight and the outer dimension of the adjusting block can be easily determined.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view showing a state in which a Langevin type vibrator is fixed by bolting to a cleaning tank (ultrasonic wave transmitting body) and an adjustment block is attached, and FIG. 2 is a side view showing an adjustment block attached. The bolted Langevin type vibrator has a front mass 2, an electrode plate 4b, a piezoelectric element 3b, an electrode plate 4a, a piezoelectric element 3a, in order from the ultrasonic wave emitting surface.
It is composed of a rear mass 1 and is fastened and fixed by a stud bolt 5 and a nut 6. The front mass 1 is made of a metal block made of an aluminum alloy, has a circular columnar shape, and is provided with a female screw portion 21a at a central portion thereof into which a bolt is partially screwed. Each of the electrode plates 4a and 4b has a configuration in which a convex lead-out portion for external connection is provided in a ring shape, and phosphor bronze is used as a material thereof. Piezoelectric element 3
Piezoelectric ceramics such as PZT (lead titan zirconate) are used for a and 3b, and have a circular columnar shape with a through hole provided in the central portion. The rear mass 2 is formed of a metal block using an aluminum alloy, and has an annular cylindrical shape with a through hole provided in a central portion. The stud bolt 5 that penetrates each of these components and is screwed into the female screw portion is made of stainless steel, and is fixed by tightening with a nut 7. A washer may be interposed to secure the tightened state. In the figure, 11 and 21 are flat portions for tightening. A rear mass side tip portion 51 of the stud bolt is formed to be long so as to project rearward from the rear mass, and an adjustment block 6 is attached to the tip portion 51 and is fixed by tightening with a nut 7. The adjustment block 6 is made of the same aluminum alloy as the rear mass, has a circular columnar shape with the same diameter, and has a threaded portion that is screwed into the stud bolt at the center. Further, a flat portion 61 for tightening is formed.

Adjustment of the changed vibration mode may be determined by the size of the adjustment block. In the case of this embodiment, the adjustment block is made of the same material and has the same shape as the front mass and the rear mass, so that a desired adjustment amount can be obtained by appropriately selecting the thickness n. It is also possible to use an adjustment block made of another material or shape, but it is necessary to sufficiently confirm in advance the relationship between the material and shape and the adjustment amount.

The adjustment block does not have to be fixed by stud bolts, but may be fixed by being attached to the rear of the rear mass with a joining material, for example.

[0014]

According to the present invention, a bolted Langevin type vibrator is attached to an ultrasonic wave transmitting body, and even if the vibration mode changes and the vibration node changes, the vibration node position is behind the rear mass. By mounting the adjustment block for adjustment, the balance of the bolted Langevin type vibrator can be restored and the drive under optimal conditions can be performed. That is, it becomes extremely easy to set so that an appropriate standing wave is generated in the cleaning tank. Therefore, it is possible to radiate ultrasonic waves with respect to the input power with high efficiency.

Further, even when the state of the ultrasonic wave transmitted body is changed such that the amount and type of the cleaning liquid in the attached cleaning tank is changed, the adjusting block is replaced to emit the ultrasonic wave with high efficiency. be able to.

According to the second aspect of the present invention, the adjustment block is made of the same material as the rear mass, so that the weight and the outer dimension of the adjustment block can be easily determined, and the overall adjustment work can be facilitated.

[Brief description of the drawings]

FIG. 1 is a partially exploded side view showing a bolted Langevin type vibrator according to an embodiment of the present invention.

FIG. 2 is a side view showing a bolted Langevin type vibrator according to an embodiment of the present invention.

FIG. 3 is a diagram showing a conventional example and vibration energy.

FIG. 4 is a diagram showing an example of an ultrasonic cleaning device.

[Explanation of symbols]

 1, 81 ... Front mass 2, 82 ... Rear mass 4a, 4b, 85, 86 ... Electrode plate 3a, 3b, 83, 84 ... Piezoelectric element 5 ... Stat bolt 6 ... Nut

Claims (2)

[Claims] 1. A front mass made of a metal block,
The front mass is also composed of a rear mass, which is also made of a metal block, at least one piezoelectric element and an electrode plate arranged between the front mass and the rear mass, and bolts which are fastened and fixed through the central portions of these respective components. A bolt-tightened Langevin-type oscillator that is used by fixing it to an ultrasonic transmitter. A bolt-fastened bolt that is equipped with an adjustment block for adjusting the vibration node position behind the rear mass of the Langevin-type oscillator. Langevin type vibrator. 2. The bolted Langevin type vibrator according to claim 1, wherein the adjustment block is made of the same material as the rear mass.