JP2012160825A - Support structure of ultrasonic transceiver and formation method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a support structure of an ultrasonic transceiver which prevents the resonance frequency deviation without causing a case to be restricted by the support structure, and to provide a formation method of the support structure of the ultrasonic transceiver.SOLUTION: A support structure of an ultrasonic transceiver includes an ultrasonic transceiver 110 in which a pair of electrode terminals 113, 114 electrically connect with a piezoelectric element 112 installed on an inner bottom of a U shaped case 111 and a resin body 130 filling the opening side of the case 111. One end parts of the pair of electrode terminals 113, 114 are buried in the resin body 130 and the other end parts are fixed. As just described, the ultrasonic transceiver 110 is supported by the pair of electrode terminals 113, 114 through the resin body. Thus, the case 111 is not restricted by the support structure 100, and the resonance frequency deviation caused by the support structure 100 is prevented.

Description

  The present invention relates to a support structure for an ultrasonic transmitter / receiver in which a pair of electrode terminals are electrically connected to a piezoelectric element installed on the inner bottom of a bottomed cylindrical case, and a method for forming the same.

  An ultrasonic transceiver can transmit ultrasonic waves by applying an AC voltage of a specific resonance frequency to a piezoelectric element affixed to the inner bottom of a case and expanding and contracting it, while receiving ultrasonic waves and converting them to an AC voltage. It is a device that can be converted, and is used as an ultrasonic sensor, ultrasonic sounding body, and the like. It is also possible to configure a distance meter by performing transmission / reception with one such ultrasonic transmitter / receiver.

  Since such an ultrasonic transmitter / receiver loses its stability when vibration from the casing propagates, an ultrasonic transmitter / receiver that attempts to prevent the propagation of vibration has been developed (see, for example, Patent Document 1). In the ultrasonic sensor described in Patent Document 1, a vibration isolating material having a natural frequency of less than 40 kHz is provided between a pedestal to which a piezoelectric element is fixed and an internal structure constituting a casing, and the vibration is transmitted to the ultrasonic sensor. It is preventing.

JP 2007-315887 A

  However, when the ultrasonic transmitter / receiver is fixed to the substrate or the case through the vibration isolator as described above, even if the propagation of vibration can be prevented, the fixing strength and restraint state of each ultrasonic transmitter / receiver Due to the difference, the resonance frequency shifts and the characteristics vary in transmission and reception.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a support structure for an ultrasonic transmitter / receiver and a method of forming the support structure that can prevent a shift in resonance frequency without being restricted by the support structure. And

  (1) In order to achieve the above object, the support structure of the ultrasonic transmitter / receiver of the present invention has a pair of electrode terminals electrically connected to a piezoelectric element installed on the inner bottom of a bottomed cylindrical case. An ultrasonic transmitter / receiver; and a resin body filled on the opening side in the case, wherein the pair of electrode terminals have one end buried in the resin body and the other end fixed. . In this way, since the pair of electrode terminals supports the ultrasonic transmitter / receiver via the resin body, the case is not constrained by the support structure, and a shift in resonance frequency due to the support structure can be prevented.

  (2) Moreover, the support structure of the ultrasonic transmitter / receiver of the present invention includes an ultrasonic transmitter / receiver in which a pair of electrode terminals are electrically connected to a piezoelectric element installed on the inner bottom of a bottomed cylindrical case; And a resin body having one surface fixed and the other surface fixed to the opening end of the case. As described above, since the case is supported by the resin body and the restraint by the fixing surface is relaxed, the case is not restrained by the support structure, and the shift of the resonance frequency due to the support structure can be prevented.

  (3) Moreover, the support structure of the ultrasonic transceiver according to the present invention is characterized in that the resin body is formed of a silicon resin. As a result, the case is held so as not to be restrained, so that the resonance frequency can be maintained at a desired value.

  (4) Also, the method for forming a support structure for an ultrasonic transmitter / receiver according to the present invention is an ultrasonic transmitter / receiver in which a pair of electrode terminals are electrically connected to a piezoelectric element installed on the inner bottom of a bottomed cylindrical case A step of preparing a container, a step of packing a cloth-like body in the case, a resin material is injected into the case from above the packed cloth-like body, and one end of the pair of electrode terminals is buried The method includes a step of forming a resin body and a step of fixing the other end of the pair of electrode terminals. Thereby, since the case is supported so as not to be restrained, the shift of the resonance frequency of the ultrasonic transceiver due to the support structure can be prevented.

  (5) The method for forming a support structure for an ultrasonic transmitter / receiver according to the present invention includes an ultrasonic transmitter / receiver in which a pair of electrode terminals are electrically connected to a piezoelectric element installed on the inner bottom of a bottomed cylindrical case. Including a step of preparing a container, a step of fixing one end of the pair of electrode terminals as a free end, and a step of bonding the fixed resin body to the opening end of the case. Yes. Thereby, since the case is supported so as not to be restrained, the shift of the resonance frequency of the ultrasonic transceiver due to the support structure can be prevented.

  ADVANTAGE OF THE INVENTION According to this invention, the case of an ultrasonic transmitter / receiver is not restrained by a support structure, and the shift | offset | difference of the resonant frequency in transmission / reception of an ultrasonic wave can be prevented.

It is sectional drawing which shows the support structure of the ultrasonic transmitter / receiver which concerns on 1st Embodiment. It is sectional drawing which shows the support structure of the ultrasonic transmitter / receiver which concerns on 2nd Embodiment.

  Next, embodiments of the present invention will be described with reference to the drawings. In order to facilitate understanding of the description, the same reference numerals are given to the same components in the respective drawings, and duplicate descriptions are omitted.

[First Embodiment]
FIG. 1 is a cross-sectional view showing a support structure 100 for an ultrasonic transceiver. The support structure 100 of the ultrasonic transmitter / receiver is composed of an ultrasonic transmitter / receiver 110, a cloth-like body 120, and a resin body 130. The ultrasonic transceiver 110 includes a case 111, a piezoelectric element 112, a pair of electrode terminals 113 and 114, a terminal 116, and lead wires 117 and 118. The case 111 is made of metal such as aluminum and is formed in a bottomed cylindrical shape.

  The piezoelectric element 112 is formed in a disc shape, and is attached to the inner bottom of the cylindrical case 111. The outer bottom surface of the case 111 is a vibration surface 111a, and the piezoelectric element 112 can transmit and receive ultrasonic waves via the vibration surface 111a. Electrodes are formed on both main surfaces of the piezoelectric element 112, and the piezoelectric body of the main body is polarized.

  The pair of electrode terminals 113 and 114 has an insulating terminal 116 on one end side. The terminal 116 protects the connection between the electrode terminal 113 and the lead wire 117 and the connection between the electrode terminal 114 and the lead wire 118. The electrode terminal 113 is connected to the lead wire 117 in the terminal 116, and the lead wire 117 is connected to the electrode of the piezoelectric element 112 on the bottom side of the case 111 through the case 111. The electrode terminal 114 is connected to the lead wire 118 in the terminal 116, and the lead wire 118 is connected to the electrode on the opening side of the case 111 of the piezoelectric element 112.

  On the other hand, each of the electrode terminals 113 and 114 is fixed to a structure 140 such as a substrate or a housing at the other end side (the opposite side of the terminal 116). The electrode terminals 113 and 114 and the structure 140 are usually fixed with solder. Each of the electrode terminals 113 and 114 is formed of a material that is hard enough to support the ultrasonic transceiver 110.

  Note that the electrode terminals 113 and 114 preferably have the terminal 116, but the terminal 116 may be omitted if the electrical connection is sufficiently protected. The case 111 is preferably made of metal, but may be made of plastic or the like, and in the case of plastic, the electrode is drawn out from the piezoelectric element 112 and the lead wire 117 is connected.

  The cloth-like body 120 is provided on the piezoelectric element 112 side in the case 111. The cloth-like body 120 prevents the ultrasonic wave transmitted from the piezoelectric element 112 from propagating to the structure body 140 side. This is because if the ultrasonic wave propagates to the structure 140, the function of the ultrasonic transceiver 110 on the receiving side is hindered. The cloth-like body 120 is preferably formed of felt, but is not limited to felt as long as the material is excellent in ultrasonic wave absorption.

  The resin body 130 is filled on the opening side in the case 111 and is fixed to the inner peripheral surface of the case 111. The resin body 130 is preferably made of, for example, silicon resin. As a result, the case is held to such an extent that it is not constrained, so that the resonance frequency can be maintained at a desired value when ultrasonic waves are transmitted and received. In particular, the resin body 130 is preferably formed of a material having a Shore hardness A of 30 ° to 66 °.

  One end (terminal 116 side) of each of the electrode terminals 113 and 114 is embedded in the resin body 130, and the other end is fixed to the structure body 140. The case 111 and the terminal 116 are integrated with a soft resin body 130 such as silicon resin, and the electrode terminals 113 and 114 are fixed in a state of being floated from the structure body 140.

  Next, a method of forming the support structure 100 for an ultrasonic transceiver configured as described above will be described. First, an ultrasonic transceiver 110 is prepared in which a pair of electrode terminals 113 and 114 are electrically connected to a piezoelectric element 112 installed on the inner bottom of the case 111. Next, the cloth body 120 is packed in the case 111. Then, a fluid resin material is injected into the case 111 from above the packed cloth body 120, and one end of the electrode terminals 113 and 114 is filled and solidified to form the resin body 130. At this time, the cloth-like body 120 is sandwiched between the piezoelectric element 112 and the resin body 130.

  The viscosity of the injected resin material is preferably 30 Pa · S or more. When the viscosity of the resin material is less than 30 Pa · S, the resin material can permeate the cloth-like body 120 and reach the piezoelectric element 112 to hinder driving. The upper limit of the viscosity is such that the resin material can be injected into the case 111 as granules. After the formation of the resin body 130, the other ends of the electrode terminals 113 and 114 are fixed to the structure 140 with solder or the like.

  In this way, when the ultrasonic transceiver 110 is fixed to the structure 140, the case 111 is fixed so as not to directly touch the structure 140 such as a substrate or a housing. As a result, the case is not constrained by the support structure, and a shift in resonance frequency can be prevented in transmission / reception of ultrasonic waves.

[Second Embodiment]
In the above embodiment, the electrode terminals 113 and 114 support the ultrasonic transceiver 110 via the resin body 130, but the opening end of the case 111 may be supported by the resin body 230. FIG. 2 is a cross-sectional view showing a support structure 200 of the ultrasonic transceiver. The support structure 200 of the ultrasonic transmitter / receiver is configured by the ultrasonic transmitter / receiver 110, the cloth-like body 120, and the resin body 230.

  In the example of FIG. 2, one end of each of the electrode terminals 113 and 114 is a free end, and the other end is fixed to a structure 140 such as a housing or a substrate. A terminal 116 is formed on the free end side, but is independent from the case 111. With such a configuration, the electrode terminals 113 and 114 do not restrain the case 111.

  The resin body 230 has one surface fixed to the structure 140 and the other surface fixed to the opening end of the case 111. Since the case 111 and the terminal 116 are not integrated with the silicon resin or the like in this way, the case 111 and the terminal 116 each have a degree of freedom. However, the case 111 has a soft resin body 230 such as silicon rubber between the structure body 140 and the case 140. The terminal 116 is fixed in a state where it is floated from the structure 140. The resin body 230 is preferably made of a material having a shore hardness A of 30 ° to 66 °.

  Next, a method of forming the support structure 200 for an ultrasonic transceiver configured as described above will be described. First, an ultrasonic transceiver 110 is prepared in which a pair of electrode terminals 113 and 114 are electrically connected to a piezoelectric element 112 installed on the inner bottom of the case 111. The electrode terminals 113 and 114 are fixed to the structure 140 with solder or the like with the other ends being free ends. Next, one surface of the disc-shaped resin body 230 formed in a shape along the opening end of the case 111 is fixed to the structure 140, and the other surface of the fixed resin body 230 and the case 111 are fixed. Glue the open end.

  In this way, the case 111 is fixed via the resin body 230 so as not to directly touch the structure 140, and one end of the electrode terminals 113, 114 is made independent from the case 111 to be a free end. As a result, the case 111 is not constrained by the support structure, and the resonance frequency can be prevented from shifting.

DESCRIPTION OF SYMBOLS 100 Ultrasonic transmitter / receiver support structure 110 Ultrasonic transmitter / receiver 111 Case 111a Vibration surface 112 Piezoelectric element 113, 114 Electrode terminal 116 Terminal 117, 118 Lead wire 120 Cloth-like body 130 Resin body 140 Structure 200 Support of ultrasonic transmitter / receiver Structure 230 Resin body

Claims (5)

An ultrasonic transceiver in which a pair of electrode terminals are electrically connected to a piezoelectric element installed on the inner bottom of a bottomed cylindrical case;
A resin body filled on the opening side in the case,
One structure of the pair of electrode terminals is embedded in the resin body, and the other end is fixed. An ultrasonic transceiver in which a pair of electrode terminals are electrically connected to a piezoelectric element installed on the inner bottom of a bottomed cylindrical case;
A support structure for an ultrasonic transceiver comprising: a resin body having one surface fixed and the other surface fixed to an opening end of the case.   The support structure for an ultrasonic transceiver according to claim 1, wherein the resin body is made of silicon resin. Preparing an ultrasonic transmitter / receiver in which a pair of electrode terminals are electrically connected to a piezoelectric element installed on the inner bottom of a bottomed cylindrical case;
Packing the cloth-like body into the case;
A process of injecting a resin material into the case from above the stuffed cloth, filling one end of the pair of electrode terminals into a resin body,
And fixing the other end of the pair of electrode terminals. A method for forming a support structure for an ultrasonic transceiver. Preparing an ultrasonic transmitter / receiver in which a pair of electrode terminals are electrically connected to a piezoelectric element installed on the inner bottom of a bottomed cylindrical case;
One end of the pair of electrode terminals as a free end, and fixing the other end;
Adhering a fixed resin body to the opening end of the case, and forming a support structure for an ultrasonic transceiver.

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