JPH07235706A - Conductive cord connection device for piezoelectric unit - Google Patents

Abstract

PURPOSE:To securely connect a lead wire without injecting an insulating bonding material into a protruding coupling pipe by fixing a connection terminal piece to an end of the lead wire with a flexible tongue piece. CONSTITUTION:One a connection terminal piece 30 fixed to the tip end of a lead wire 10 is inserted into a protruding coupling pipe 6, a plate-shaped coupling end 21 is inserted into an engagement groove 34. The tip end of the coupling end 21 first makes contact with a protruding engagement edge 38a, and a flexible tongue piece 36 is sightly inclined with respect to a front edge 37 corresponding to the amount of protrusion of the engagement edge 38a owing to pushing by the lower surface of the coupling end 21. As the tip end of the coupling end 21 further enters, an engagement hole 22 is located on the engagement edge 38a to reciprocate the flexible tongue piece 36 and hence permit the flexible tongue piece to be inserted into the engagement hole 22. At this position the front end of the coupling end 21 is located on the front surface of a second protruding edge 39. Even though with this situation the connection terminal piece 30 is pulled, the engagement edge 38a is engaged with an edge of the engagement hole 22 and is hereby prevented from being separated. Hereby, a lead wire is securely connected without the need of injection of the bonding material into the coupling pipe 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a struck electrode at one end of a piezoelectric element and an output terminal at the other end thereof. In the piezoelectric unit that is designed to extract the voltage from the terminal,
The present invention relates to a connecting device for electrically connecting an output terminal and a lead wire.

[0002]

2. Description of the Related Art As shown in FIG. 9, a piezoelectric unit u of this type has cylindrical piezoelectric elements 3 and 4 arranged in series with an output terminal 2 in between, and the piezoelectric elements 3 and 4 are made of a resin such as polypropylene. A needle-like connecting end portion 7 formed on the output terminal 2 in a connecting projecting tube 6 that is housed in an insulative covering 5 made of a material and projecting in a middle portion of the outer periphery of the insulative covering 5. Further, the hit electrode 8 also serving as a ground electrode is provided on the outer end of the piezoelectric element 3.
Is provided, and the fixed side ground electrode 9 is provided on the outer end of the other piezoelectric element 4.
Is provided so that the hit ends of the electrodes 8 and 9 project from both side ends, and when the hit electrode 8 is hit by the hitting element a, the piezoelectric elements 3 and 4 are distorted. Is generated to generate electric charges, and the output voltage is taken out from the needle-shaped connecting end portion 7 by the lead wire 10. The piezoelectric element 4 on one side may be omitted.

[0003]

By the way, in the conventional connection between the needle-like connecting end portion 7 and the lead wire 10, as shown in FIG. The needle-like connecting end portion 7 is inserted so as to be inserted into the central conductive core 11 in the outer skin layer 12 of the lead wire 10 so as to be electrically connected, and the lead wire 10 is fixed as the adhesive material 13 is solidified. It was fixed in the connecting projection tube 6. Therefore, the work of injecting the insulating adhesive material 13 is required as a pre-process, and the adhesive material 13 overflows to the outside of the connecting projecting tube 6 when the lead wire 10 is inserted into the connecting projecting tube 6. It required a troublesome post-treatment to remove this after connecting 10.

According to the present invention, the insulating adhesive 13 is provided in the connecting projection 6.
It is an object of the present invention to provide a connecting device having a configuration capable of firmly connecting the lead wire 10 without injecting the lead wire.

[0005]

According to the present invention, the connecting end portion is constituted by a plate-like connecting end portion having a fitting hole formed therein, and a fitting groove into which the plate-like connecting end portion is inserted is formed. An engaging projection edge which is continuous with the bottom of the fitting groove and a front edge, is tiltable downward about the front edge, and can be fitted into the fitting hole of the connecting end at a rear portion thereof is projected upward. The flexible tongue has a connecting terminal piece provided at the bottom of the fitting groove and fixed to a lead wire.

[0006]

In this structure, the plate-like connecting end portion is inserted into the fitting groove by inserting the connecting terminal piece into the connecting projecting pipe, and the plate-like connecting end portion is inserted in the inserting process. After the engaging projection edge is pressed and the flexible tongue is tilted downward, the engagement projection edge is fitted into the fitting hole of the plate-like connecting end portion and the connecting terminal piece is attached to the plate-like connecting end portion. It is fixed, and the lead wire and the output terminal are electrically connected.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a diagram in which the present invention is applied to a piezoelectric unit U similar to that described in detail with reference to FIG. 10. The configuration of the output terminal 20 is different and the connecting terminal piece 30 is applied to the lead wire 10. It has a special feature. The same components as those described above are designated by the same reference numerals and the description thereof will be omitted.

Here, as shown in FIGS. 1, 3 and 4, a plate-like connecting end portion 21 extends from the side periphery of the output terminal 20,
The plate-like connecting end portion 21 is projected into the connecting projecting tube 6 which is formed in a middle portion of the outer periphery of the insulating cover 5. The plate-like connecting end portion 21 has a fitting hole 22 formed therein, and a guide tip 23 formed by thinning the fitting hole 22 toward the tip and dropping both side corners.
Is equipped with.

On the other hand, the connection terminal piece 30 is formed by bending a plate piece, and as shown in FIG.
At the trailing edge, the connection band edge 3 wrapped around the core wire of the lead wire 10
1, 31 are formed, and the connection band edges 31, 31 ensure electrical connection with the lead wire 10. Further, U-shaped fitting and inserting edges 32, 32 are formed on the both side edges of the front portion by bending twice, and a fitting groove 34 which substantially matches the sectional shape of the plate-like connecting end portion 21 is formed together with the bottom 33 thereof. There is.

A flexible tongue piece 36, which is connected to the bottom portion 33 and a front edge 37 and is tiltable downward about the front edge 37, is connected to the bottom portion 33 of the fitting groove 34. . A projecting ridge-shaped engaging projection edge 38a that can be fitted into the fitting hole 22 of the plate-like connecting end portion 21 is provided behind the front edge 37 of the flexible tongue piece 36.
Is projected upwards. Furthermore, this flexible tongue piece 36
A second projecting edge 39 is bent at the tip of the.

In this structure, when the connecting terminal piece 30 fixed to the tip of the lead wire 10 is inserted into the connecting projecting tube 6,
The plate-like connecting end portion 21 is inserted into the fitting groove 34.
At this time, the insertion action is smoothly performed by the above-mentioned guide tip 23, and the fitting insertion edge 3 is provided on both sides of the plate-like connecting end portion 21.
2, 32 are fitted on the outside. Then, in the insertion process, the tip of the connecting end portion 21 first comes into contact with the engaging projection edge 38a, and the connecting end portion 2
By the pushing operation by the lower surface of No. 1, the flexible tongue piece 36 moves the front edge 37 as shown in FIG.
Slightly tilt around. When it further enters, the fitting hole 22 is positioned on the engaging projection edge 38a, the flexible tongue piece 36 moves back, and is inserted into the fitting hole 22 as shown in FIG. In this position, the front end of the connecting end portion 21 is located on the front surface of the second projecting edge 39.

In this state, even if the connecting terminal piece 30 is pulled, the engagement projection edge 38a is inserted into the fitting hole 22, and the engagement projection edge 38a engages with the edge portion of the fitting hole 22. Together, they will be unable to leave. Thus, the plate-like connecting end portion 21 and the connecting terminal piece 30
The output terminal 20 is connected to the lead wire 10 by the mechanical connection by
Will be electrically connected to. On the other hand, when disconnecting the lead wire 10, the lead wire 1
0, or pull from the outside as shown in Fig. 5
When the projecting edge 39 is pushed down, the flexible tongue piece 36 inclines downward around the front edge 37, the engaging projecting edge 38a is easily separated from the fitting hole 22, and the connection is released. .

As shown in FIG. 6, the above-mentioned second projecting edge is
It may be used as the engaging protrusion 38b. In this case, the protrusion that forms the engaging protrusion 38a is used as the guide protrusion 40. Both side edges of the engaging protruding edge 38b have a trapezoidal shape that is inclined inward toward the tip and narrows toward the tip of the flexible tongue piece 36. Therefore, both side edges of the engaging protruding edge 38b will be described later. When it is inserted into the fitting hole 22, the guide edge serves as a guide edge.

In this structure, the connecting terminal piece 30 fixed to the tip of the lead wire 10 is inserted into the connecting projection 6 so that the plate-like connecting end 21 is inserted into the fitting groove 34. Then, in the insertion process, the tip of the connecting end portion 21 is first
The flexible tongue piece 36 abuts on the guide protrusion 40, and the flexible tongue piece 36 slightly tilts around the front edge 37 as shown in FIG. 6A in accordance with the protrusion amount of the guide protrusion 40. When it further enters, the engaging projection edge 38b is inclined due to a slight tilting by the guide projection 40, and therefore the engagement projection edge 38b is pushed by the tip of the connecting end portion 21 (at this time, the guide projection 40 is fitted. When the fitting tongue 22 is not fitted into the fitting hole 22), the flexible tongue piece 36 further tilts, the connecting end portion 21 crosses over the engaging protruding edge 38b, and the fitting hole 22 is positioned on the engaging protruding edge 38b. The flexible tongue piece 36 moves back and is inserted into the fitting hole 22 as shown in FIG.

Even if the connecting terminal piece 30 is pulled in this state, a desired moderation force is produced because the engaging projection edge 38b is inserted into the fitting hole 22. Thus, the plate-like connecting end portion 21
And output terminal 2 by mechanical connection with connection terminal piece 30
0 is electrically connected to the lead wire 10.

By the way, if the inner surface of the connecting projection tube 6 is a circular hole, a large hole is formed in the connecting projection tube 6 between the upper and lower surfaces of the plate-like connecting end portion 21, and the inside of the hole is formed. Then, the connection terminal piece 30 is erroneously inserted and the fitting groove 34 cannot be fitted into the connecting end portion 21 with certainty, which causes a problem such as a connection failure. Therefore, as shown in FIGS. 3 and 4, by forming thick portions 6a, 6a in the connecting projecting pipe 6 at the portions facing the upper and lower sides of the connecting terminal piece 30, as many holes as possible are formed. It is made smaller, and the problem due to the above-mentioned incorrect insertion is solved.

Further, in such a mounted state, it is necessary to insulate the outside. Therefore, the plate-like connecting end portion 21 and the connecting terminal piece 30 are insulated by the insulating sleeves 41a and 41b.
Therefore, it is electrically protected from the outside. The configuration will be described.

As shown in FIGS. 1 and 8, the insulating sleeve 41a is adapted to be externally fitted to the connecting projecting pipe 6 for insulation. In this structure, the insulating coating 41a including the fitting portion 41 having the inner diameter equal to the outer diameter of the connecting projection tube 6 is slidably fitted to the end portion of the lead wire 10 in advance, and the insulating coating is formed. In a state in which 41a is separated from the connection terminal piece 30, a fitting operation of the connection terminal piece 30 and the plate-like connecting end portion 21 is performed, and then the insulation coating 41a is attached on the lead wire 10 as shown by an arrow in the figure. The connecting projection tube 6 is moved to the outside so that the connecting projection tube 6 is externally fitted by the fitting portion 41.

The insulating coating 41a may be fixed to the end portion of the lead wire 10 in advance. In this structure, a gap is formed between the inner surface of the insulating coating 41a and the peripheral portion of the connection terminal piece 30 so that the connecting projecting tube 6 can be fitted therein, and the insertion simultaneously connects the plate-like connecting end portion 21. Mechanical connection with the terminal piece 30 and coating with the insulating coating 41a are performed. Further, in this configuration, the inner diameter of the insulating coating 41 is made sufficiently larger than the outer diameter of the connecting projecting tube 6 to facilitate the fitting, and the insulating coating 41a is constituted by a heat shrinkable tube. After the connection, heating may be applied to bring the insulating coating 41a into close contact.

FIGS. 7 and 8 show another structure whose design is slightly different from those of FIGS. Here, in FIG. 7, the insulating coating 41b is adhered to the connecting terminal piece 30 in advance. With this configuration, the connection terminal piece 30 can be tightly covered by externally fitting the insulation coating 41b made of a heat-shrinkable tube on the connection terminal piece 30 and heating it. The insulating coating 41b is inserted into the connecting projection tube 6 as it is, and is externally fitted to the plate-like connecting end portion 21 to perform the above-mentioned electrical connection.

FIG. 9 shows another structure of the insulating cover 5, in which the connecting projection 6 is L-shaped. In this case, the plate-shaped connecting end 21 may be formed by bending the output terminal 20 into an L shape and extending. As described above, various structures can be proposed for the insulating coating 5.

[0023]

According to the present invention, the plate-like connecting end portion having the fitting hole formed therein is connected to the output terminal so as to project the plate-like connecting end portion into the connecting projecting tube of the piezoelectric unit, and the lead wire. At the end of the fitting groove, a connecting terminal piece having a flexible tongue having an engaging projection edge formed on the bottom of the fitting groove is fixed, and the connecting terminal piece is inserted into the connecting projection tube, The plate-like connecting end is inserted into the fitting hole, and the engaging projection is inserted into the fitting hole, whereby the connecting terminal piece is mechanically and electrically connected to the plate-like connecting end. Therefore, there is an excellent effect that the connection between the lead wire and the output terminal can be simply and surely secured without the need to inject the adhesive into the connecting projection tube.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view showing a conductive cord connecting device of a piezoelectric unit U according to the present invention.

FIG. 2 is a partially cutaway perspective view of a plate-like connecting end portion 21 and a connecting terminal piece 30.

FIG. 3 is a partially cutaway side view of a piezoelectric unit U.

FIG. 4 is a cross-sectional view of FIG. 3A-A.

5 is a vertical cross-sectional side view showing the connecting operation of the plate-like connecting end portion 21 and the connecting terminal piece 30. FIG.

FIG. 6 shows a plate-like connecting end portion 21 and a connecting terminal piece 30 having another structure.
FIG. 7 is a vertical cross-sectional side view showing the connecting operation of FIG.

FIG. 7 is a vertical cross-sectional side view of a main part showing another configuration.

FIG. 8 is a vertical cross-sectional side view of a main part showing still another configuration.

9 is a perspective view showing another configuration of the piezoelectric unit U. FIG.

FIG. 10 is a vertical sectional side view of a piezoelectric unit u having a conventional configuration.

[Explanation of symbols]

 U Piezoelectric unit 3,4 Piezoelectric element 5 Insulating coating 6 Connecting projection tube 8 Striking electrode 10 Lead wire 20 Output terminal 21 Plate-like connecting end 22 Fitting hole 30 Connection terminal piece 33 Bottom 34 Fitting groove 36 Flexible tongue Piece 37 Front edge 38a, 38b Engaging projection edge 39 Second projection edge 40 Guide projection 41a, 41b Insulation coating

Claims (3)

[Claims] Claim: What is claimed is: 1. A piezoelectric element is enclosed in an insulating coating, a hit electrode is connected to one electrode of the piezoelectric element, and a hit end of the piezoelectric element is projected outward from an end of the cover and the piezoelectric element is formed. An output terminal is connected to the electrode on the other side of the element, and a connecting end extending laterally from the output terminal is projected into a connecting projecting tube connected to the peripheral surface of the insulating coating body to lead to the connecting end. In a piezoelectric unit configured to electrically connect wires, the connecting end portion is configured by a plate-like connecting end portion in which a fitting hole is formed, and a fitting groove into which the plate-like connecting end portion is inserted is formed. An engaging projection edge that is formed, is continuous with the bottom portion of the fitting groove at the front edge, can be tilted downward about the front edge, and can be fitted into the fitting hole of the connection end portion at the rear portion is projected upward. The flexible tongue is attached to the end of the lead wire with the connecting terminal piece provided at the bottom of the fitting groove. Conductive cord connection apparatus for a piezoelectric unit to symptoms. 2. The conductive cord connecting device for a piezoelectric unit according to claim 1, wherein a thick portion is formed on a portion of the inner surface of the connecting projecting tube that faces the upper and lower surfaces of the connecting end portion. 3. The end portion of the lead wire is provided with an insulating coating member that surrounds the outer peripheral surface of the connecting terminal piece and is tightly fitted to the inner surface or the outer surface of the connecting projecting tube. 1. A conductive cord connecting device for a piezoelectric unit according to 1.