Ultrasonic receiver transmitter

A technology for receiving transmitters and ultrasonic waves, which is applied in the directions of sound wave re-radiation, instruments, sensors, etc., can solve the problems such as the decrease of reflection sensitivity, and achieve the effect of small change in electrostatic capacity and high reflection sensitivity

Inactive Publication Date: 2006-05-10

NIPPON CERAMIC CO LTD

1 Cites 12 Cited by

AI-Extracted Technical Summary

Problems solved by technology

[0005] However, this method has the following problems: Although this method can obtain improvement effects such as suppressing changes in the electrostatic capacity of the ultrasonic transc...

Method used

As shown in Figure 4, the situation of the ultrasonic receiver-transmitter of embodiment 1 in the past is that electrostatic capacity changes with temperature change, like this, shift occurs with the resonance point of the inductance of transformer used in circuit, as ...

Abstract

To solve the problem that a temperature compensating capacitor used as a remedy for change in electrostatic capacity due to change in temperature, increase in reverberation time, and inability of obstacle detection in a close range is high-cost, and that the reflection sensitivity is deteriorated when invar alloys or the like of low thermal expansion are adhered between a bottomed cylindrical case and a piezoelectric element, to the opposite side of the piezoelectric element on the side of the case in the shape of a cylinder with bottom or to both sides of a piezoelectric element, in a conventional ultrasonic wave transmitting and receiving device. In the ultrasonic wave transmitting and receiving device, annularly formed invar alloys or the like of low thermal expansion are embedded in an annular groove provided on the surface for adhesion of the piezoelectric element of the bottomed cylindrical case by adhesion, press-fitting or the like, and the piezoelectric element is adhered on it. In this way, obstacles can be stably detected in a wide range of temperature without using a temperature compensating capacitor and without deterioration of reflection sensitivity.

Application Domain

Piezoelectric/electrostrictive transducersMagnetostrictive transducers +2

Technology Topic

Close rangeElectricity +9

Image

Examples

Experimental program(1)

Example Embodiment

[0029] Example

[0030] figure 1 A schematic longitudinal cross-sectional view showing an ultrasonic receiver/transmitter according to an embodiment of the present invention. Figure 2 (a) is a schematic plan view and a longitudinal cross-sectional view of the bottomed cylindrical housing of the ultrasonic receiver and transmitter according to the embodiment of the present invention, and Figure 2 (b) and Figure 2 (c) show another embodiment of the present invention A schematic plan view and a longitudinal cross-sectional view of the bottomed cylindrical housing of the ultrasonic receiver/transmitter of. figure 1 In this, an annular groove 7 is provided inside the bottom surface of a bottomed cylindrical housing 2 made of aluminum material, etc., and a plate 3 made of a low thermal expansion alloy processed into the same ring shape is inserted into the device by bonding or press-fitting. In the groove 7 of the bottomed cylindrical shell, the piezoelectric element 1 is attached to it to form a single-sided waviness vibrator. In addition, the groove 7 provided on the bottomed cylindrical casing 2 and the plate material 3 made of the low thermal expansion alloy embedded therein may be not ring-shaped as shown in FIG. 2(b). In addition, as shown in Figure 2(c), it is also possible to divide the sheet material 3 made of a low thermal expansion alloy into several pieces and insert them so that they are located near the bonding surface of the piezoelectric element 1, and then attach the piezoelectric element to it. 1 to form a single-sided waviness vibrator. The input and output leads 5a are led out from the piezoelectric element 1 on the side opposite to the bonding surface of the piezoelectric element 1 and the bottomed cylindrical housing 2 by soldering, and the input and output leads 5b are drawn from the bottomed cylindrical housing 2 Lead out.

[0031] The side of the bonding surface of the piezoelectric element 1 with the bottomed cylindrical case 2 is electrically connected to the plate 3 made of low thermal expansion alloy or the like and the bottomed cylindrical case 2, and the piezoelectric element 1 is electrically connected to the input and output leads 5a And the bottomed cylindrical housing 2 is electrically connected with the input and output leads 5b. A sound absorbing material 6 made of foamed silicon or the like is placed on the upper surface of the piezoelectric element 1, and then a sealant 4 made of silicon material, polyurethane material, etc. is filled into the inside of the bottomed cylindrical housing 2 from the upper surface.

[0032] Such as Figure 4 As shown, in the case of the ultrasonic receiver and transmitter of the conventional embodiment 1, the electrostatic capacitance changes with temperature, so that the resonance point of the inductance of the transformer used in the circuit is shifted, such as Figure 5 As shown, the reverberation is increased. As a countermeasure, connect the ultrasonic receiver transmitter and the temperature compensation capacitor with opposite temperature characteristics in parallel to prevent the electrostatic capacitance from changing with temperature.

[0033] In the present invention, since the electrostatic capacitance is suppressed from changing with the temperature of the ultrasonic receiver and transmitter itself, the same temperature characteristics can be achieved even without using a temperature compensation capacitor. Figure 5 It is a schematic diagram showing the reverberation time of the ultrasonic receiver and transmitter of the conventional embodiment 1. Figure 6 It is a schematic diagram showing the reverberation time of the ultrasonic receiver transmitter according to the embodiment of the present invention. Moreover, comparing the ultrasonic receiving and transmitting device of the conventional embodiment 2 with the conventional ultrasonic receiving and transmitting device of the first embodiment, although the reflection sensitivity is lowered, the embodiment of the present invention can prevent this, that is, it can ensure the same as the conventional ultrasonic receiving and transmitting device. The reflection sensitivity of Example 1 is equivalent. Figure 7 It is a graph showing the comparison of the reflection sensitivity of the ultrasonic receiving/transmitting device of the conventional example 1 and the example 2 and the ultrasonic receiving/transmitting device of the embodiment of the present invention.

[0034] The present invention is not only limited to the reversing sensor, but can also be applied to various fields using an anti-drip (anti-drip) ultrasonic receiver and transmitter.

PUM

Description & Claims & Application Information

We can also present the details of the Description, Claims and Application information to help users get a comprehensive understanding of the technical details of the patent, such as background art, summary of invention, brief description of drawings, description of embodiments, and other original content. On the other hand, users can also determine the specific scope of protection of the technology through the list of claims; as well as understand the changes in the life cycle of the technology with the presentation of the patent timeline. Login to view more.