JPH0575274B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to the structure of an ultrasonic transducer that transmits and receives ultrasonic signals into water or liquid using a ceramic vibrator. The present invention relates to the structure of an ultrasonic transducer that transmits and receives ultrasonic signals having directivity in a specific direction by arranging ultrasonic vibrating elements and controlling the phase of the transmitted and received signals of each ultrasonic vibrating element. The present invention also relates to the structure of an ultrasonic transducer particularly suitable for transmitting and receiving high-frequency ultrasonic signals.

(Prior Art) When transmitting and receiving ultrasonic signals having directivity in a specific direction, a so-called method is generally used in which a large number of ultrasonic transducers are arranged at specific intervals and the phase of the transmitted and received signals of each transducer is controlled. A phased array transducer is used.

In a phased array vibrator, it is important that the vibrators are arranged at predetermined intervals. In particular, when transmitting and receiving high-frequency ultrasonic signals, high alignment accuracy is required. For example, when transmitting and receiving a 500kHz ultrasonic signal, the wavelength of the ultrasonic signal is 3 mm, so if an ultrasonic transducer is arranged for every half wavelength of the ultrasonic signal, the arrangement interval will be 1.5 mm. . in this case,
The arrangement accuracy of each ultrasonic transducer is required to be approximately 0.1 mm. When transmitting and receiving such high-frequency ultrasonic waves, generally an array of ceramic vibrating elements is used, but it is extremely difficult to physically arrange the individual vibrating elements with such high precision.
In addition, productivity in the manufacturing process is extremely poor.

Therefore, when arranging such high-frequency ultrasonic transducers, for example, as described in Japanese Patent Publication No. 55-12254, a single transducer is cut at specific intervals to form a transducer array. A method is used.
In the method disclosed in Japanese Patent Publication No. 55-12254, as shown in Fig. 2, a single ultrasonic transducer 1 is fixed to a sound wave absorber 2, and the single transducer 1 is cut at specific intervals. ,
As shown in FIG. 3, an array of vibrators 1a to 1n is formed on the sound wave absorber 2. In this case, the acoustic wave absorber 2 acts as a bucking material, and the ultrasonic transducers 1a to 1n generate ultrasonic waves in the direction of the surface facing the acoustic wave absorber 2, and therefore in the direction of the open surface of the ultrasonic transducers 1a to 1n. A wave surface for transmitting and receiving signals is formed.

When using a transducer array as shown in Fig. 3 in a transducer for underwater detection, transducer arrays 1a to 1n
cannot be directly exposed to water. Normally, when used for underwater detection, as shown in Figure 4,
It is used by being stored in the storage chamber 4 of the watertight container 3.
In this case, it is necessary that the acoustic wave transmitting/receiving surfaces of the vibrators 1a to 1n are in close contact with the inner surface 3A of the storage chamber 4. The sound wave transmitting/receiving surface is the storage interior surface 2A
If it is free from the air, the efficiency of transmitting and receiving sound waves will be extremely poor. Note that the watertight container 3 is made of a sound-transmitting material such as urethane material.

The array of transducers 1a to 1n is stored on the interior surface 3A of the chamber.
When the transducer is brought into close contact with the transducer, a method of bonding the radiation surfaces of each vibrator with an adhesive or a method of molding the entire vibrator array with a molding material such as urethane rubber can be considered. In this case, it is necessary to prevent the adhesive or molding material from entering the gap between the vibrator arrays. In the case of a high frequency transducer, as mentioned above, the arrangement interval of the vibrators is extremely small. Therefore, if the adhesive or molding material enters between the vibrator arrays, interference will occur between the vibrators, which will adversely affect the phase control of each vibrator. Furthermore, the adhesive or molding material applies a load to the vibrator, changing the vibration characteristics of each vibrator.

As a means to prevent such adverse effects, it is conceivable to insert a sound insulating material such as cork material between adjacent vibrators in advance. However, inserting sound insulating material one by one between a large number of vibrator arrays is extremely inefficient. Also, the thickness of the sound insulating material needs to precisely match the arrangement gap of the transducers, and if the transducer gap is extremely small as mentioned above, the sound insulating material such as cork should be Machining is not easy due to machining accuracy.

(Problems to be Solved by the Invention) The present invention provides an ultrasonic transducer for underwater detection, particularly when manufacturing an ultrasonic transducer suitable for transmitting and receiving high-frequency ultrasonic waves. To,
To realize an ultrasonic transducer that functions well by allowing the sound wave radiation surface of a vibrator to be brought into close contact with the inner surface of a watertight container without using a sound insulating material and without an adhesive or a molding material intruding into a gap between the vibrators.

(Means and actions for solving the problem) An ultrasonic transducer that solves the above problem has a large number of ultrasonic transducer elements tightly fixed at predetermined intervals on a sound wave transmitting material, and The facing surface of the array fixing surface is brought into close contact with the inner surface of the molding material of the watertight container, and ultrasonic waves are transmitted and received through the sound-transmitting material and the molding material, which eliminates the troublesome tight fixation of individual transducer elements and the molding material. Parts are missing.

The manufacturing method also includes the steps of: bringing one electrode surface of the opposing first and second electrodes of a single ultrasonic transducer into close contact with a sound wave transmitting material; A step of cutting the sonic transducers at specific intervals to form an array of a large number of ultrasonic vibrating elements on the sonic transmissive material, and placing the array of the sonic transmissive material in a watertight container formed of a molding material. This method consists of a step of storing the facing surface of the array fixing surface of the ultrasonic transducer elements so as to be in close contact with the inner surface of the mold material, thereby omitting the troublesome step of tightly fixing the individual mold materials of the transducer elements.

(Example) FIG. 1 shows a cross-sectional view of an ultrasonic transducer embodying the present invention, in which 3 shows a watertight container, 4 shows a sound insulating material, 5 shows an ultrasonic vibrator, and 6 shows a sound wave transmitting material.

The watertight container 3 is made of a molded material such as urethane rubber, and houses the ultrasonic transducer 5 in a watertight structure.

As shown in FIG. 5, the ultrasonic transducer 5 is composed of an array of a large number of ultrasonic transducer elements 5a to 5n, each of which has a minute gap Δd.
They are arranged at regular intervals d. The ultrasonic vibration elements 5a to 5n are arranged in close contact with and fixed on the sound wave transmitting material.

In the above, the array of ultrasonic transducer elements 5a to 5n is, for example, as shown in FIG. After being closely fixed, the ultrasonic transducer 5 is cut together with the electrodes 7 and 8 at regular intervals d. In this case, the sound wave transmitting material 6 is generally made of a plastic material such as urethane rubber. Therefore, when cutting the ultrasonic vibrator 5, as shown in FIG.
If the holding materials 9 and 10 are fixed in the arrangement direction of the vibrator elements 5a to 5n and then cut, the transducer elements 5a to 5n can be cut while maintaining the arrangement accuracy with high accuracy. Note that the holding materials 9 and 10 may be bonded to both ends of the vibrator 5 with an adhesive or the like, and removed after cutting. Further, as the holding materials 9 and 10, any material can be used as long as it has enough strength to maintain the alignment accuracy of the vibrating elements during the process of cutting the vibrator 5. The same material may be used.

In FIG. 1, ultrasonic vibration elements 5a to 5n
After the array is manufactured as described above, in the watertight container 3, the surface opposite to the array fixing surface of the ultrasonic vibration elements of the sound-transmitting material is tightly fixed to the inner surface of the watertight container 3. Each of the ultrasonic vibration elements 5a to 5n transmits and receives ultrasonic waves through the tightly fixed portion and the sound wave transmitting material.

On the other hand, the sound insulating material 4 is used to insulate the ultrasonic waves radiated from the ultrasonic transducer 5 from areas other than the fixed part of the sound transmitting material 6, and is made of a material such as urethane foam or cork material. Sound insulation materials are used. Note that the sound insulating material 4 does not need to be in close contact with the excitation surface of the ultrasonic transducer 5, and it is preferable that the sound insulating material 4 be in light contact so as not to cause a load effect on the vibrations of the transducer elements 5a to 5n.

In the above description, the array of transducer elements 5a to 5n is described as being housed in a pre-formed watertight container 3, but it is also possible to mold the entire array of transducer elements 5a to 5n with a molding material. . That is, after forming the array of the vibration elements 5a to 5n, and placing the sound insulation material 4 on the radiation surface other than the fixed portion of the sound wave transmitting material 6 among the sound wave radiation surfaces of the vibration elements 5a to 5n, the sound insulation material 4 Alternatively, the entire sound wave transmitting material 6 may be molded with urethane rubber or the like.

(Effects of the Invention) The ultrasonic transducer of the present invention having the above configuration transmits and receives ultrasonic waves through a sonic transmitting material and a molding material in which a large number of ultrasonic vibrating elements are closely fixed at predetermined intervals, Since the troublesome part of closely fixing a large number of transducer elements and molding material is eliminated, a uniform predetermined arrangement of ultrasonic transducer elements is ensured, and each of the ultrasonic transducer elements can be vibrated with the same characteristics, and Ultrasonic signals can be transmitted and received efficiently.

In addition, in the manufacturing method of the present invention, the array of ultrasonic transducer elements is manufactured by cutting a single transducer, so the arrangement precision of the ultrasonic transducer elements can be made high, and the individual transducer elements can be Since the troublesome step of closely fixing the mold material is omitted, it can be manufactured relatively easily.

[Brief explanation of the drawing]

Figure 1 is an embodiment of the present invention, Figures 2 and 3 are diagrams for explaining the manufacturing process of a conventional ultrasonic transducer, and Figure 4 is for underwater detection using a conventional ultrasonic transducer. An example of a configuration of a transducer, FIG. 5 is an overview of the main parts of an ultrasonic transducer used in an embodiment of the present invention, and FIGS. 6 and 7 are diagrams for explaining the manufacturing process. show.

Claims (1)

[Scope of Claims] 1. A large number of ultrasonic transducer elements arranged at predetermined intervals are housed in a watertight container made of a molded material, and ultrasonic waves are transmitted and received into water or a liquid to transmit or receive ultrasonic waves into the water or liquid. In ultrasonic transducers that detect medium targets,
A large number of the ultrasonic transducer elements are tightly fixed at predetermined intervals on the sound wave transmitting material, and the surface opposite the arrangement fixing surface of the sound wave transmitting material is tightly contacted with the inner surface of the mold material of the watertight container, and the sound wave transmitting material and the mold are tightly fixed. An ultrasonic transducer characterized by transmitting and receiving ultrasonic waves through a material. 2 Opposing first and second of a single ultrasonic vibration element
A process of bringing one electrode surface of the electrode into close contact with a sound wave transmitting material, and cutting a single ultrasonic vibrator that is in close contact with the sound wave transmitting material at specific intervals to generate a large number of ultrasonic vibrations on the sound wave transmitting material. forming an array of elements;
an ultrasonic transducer comprising the step of housing the array in a watertight container formed of a molding material so that the surface of the ultrasound transmitting material opposite to the array fixing surface of the ultrasonic vibrating elements is in close contact with the inner surface of the molding material. Production method.