JP2635050B2 - Manufacturing method of vibration sensor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a method for manufacturing a vibration sensor used in a directional receiver, and particularly to a method for disposing a diaphragm, a piezoelectric element, and a weight in a cylindrical case. The present invention relates to a method for manufacturing a vibration sensor having a structure as described above.

[Conventional technology]

2. Description of the Related Art As a directional receiver used to determine the angle of arrival of an underwater sound wave, for example, one disclosed in Japanese Patent Application Laid-Open No. 61-255196 is described with reference to FIGS. 2 and 3. FIG.

FIG. 2 is a perspective view of a directional receiver. The directional receiver has a receiving case 2 suspended by a plurality of suspension rubbers 1.
It is configured by incorporating two vibration sensors 3 having a figure eight directional characteristic therein, and both vibration sensors 3 are arranged so that their axial directions are orthogonal to each other.

FIG. 3 is a side sectional view showing the structure of the vibration sensor 3,
As shown in this figure, the vibration sensor 3 is configured such that a piezoelectric element 4 is fixed on one surface and a cylindrical shaft 5 made of metal is provided at the center of the other surface. 7 are fixed to both inner ends of the diaphragm 7 with an adhesive 8 and each diaphragm 6
The shaft 5 is fitted and fixed to both ends of a weight 9 disposed in a cylindrical case 7 so that both diaphragms 6 have a predetermined bending, and a viscous liquid 10 is injected into the cylindrical case 7. It has become.

Reference numeral 11 denotes a stopper that seals a hole provided in the cylindrical case 7 for filling the viscous liquid 10.

The operation of the directional receiver having the above-described configuration is as follows.

That is, when the wave receiving case 2 suspended by the suspension rubber 1 underwater vibrates by receiving underwater sound waves, the vibration is transmitted to the vibration sensor 3, whereby the cylindrical case 7 and the weight 9 of the vibration sensor 3 vibrate. However, since the amount of vibration between the cylindrical case 7 and the weight 9 is different, vibration due to the difference in the amount of vibration between the two occurs in the vibration plate 3, and the vibration is generated by the piezoelectric elements 6 fixedly connected to the vibration plate 3. Is converted and output.

Therefore, of the two vibration sensors 3 arranged orthogonally to each other, the output from the piezoelectric element 6 of one of the vibration sensors 3 is set as the X-axis output, and the piezoelectric element 6 of the other vibration sensor 3 is used as the output.
As an output of the Y-axis, the arrival angle of the underwater sound wave can be obtained based on the outputs of the X-axis and the Y-axis.

The above is the configuration of the directional receiver and its operation. Conventionally, the vibration sensor 3 having the above-described structure, that is, the vibration sensor 3 having an eight-shaped directional characteristic is shown in FIGS.
It is manufactured by the procedure shown in (D).

FIG. 4 is a view showing a manufacturing process of the vibration sensor 3, in which 12 is a sheet-like solder, 13 is an oven or soldering device for melting the solder 12, 14a and 14b are assembly jigs, 15
Is a sealable injection container, 16 is a deaeration pump connected to the injection container 15, and the pump 16 and the injection container 15 constitute an injection machine for injecting the viscous liquid 10 into the cylindrical case 7. .

Therefore, when the vibration sensor 3 is manufactured, first, as shown in FIG. 4A, a piezoelectric element 4 is superimposed on a diaphragm 6 provided with a shaft 5 via a sheet-like solder 12, and After that, the solder 12 is heated and melted by the oven 13, and then the heating is stopped, whereby the diaphragm 6 and the piezoelectric element 4 are electrically connected and mechanically joined and fixed. That is, in this step, the diaphragm 6 and the piezoelectric element 4 are soldered.

Next, as shown in FIG. 2B, the two diaphragms 6 to which the piezoelectric elements 4 are soldered as described above are held in jigs 14a and 14b in a direction in which the shafts 5 face each other. , The shaft 5
A weight 9 is disposed between the weights 9, and holes 9 a provided at the center of both ends of the weight 9 are positioned so as to directly face the shaft 5. Further, after the cylindrical case 7 is disposed outside the weight 9,
The jigs 14a and 14b are moved by a predetermined amount in a direction approaching each other, and pressure is applied between the diaphragms 6.

As a result, the shafts 5 of the two diaphragms 6 are fitted and fixed in the holes 9a of the weight 9, respectively, and the peripheral edges of the diaphragm 6 are inserted into the inside of both ends of the cylindrical case 7, and these are assembled together. Thereafter, the assembly is taken out from between the jigs 14a and 14b, and an adhesive 8 is applied from the peripheral edge of each diaphragm 6 to the inner peripheral surface of the cylindrical case 7 as shown in FIG.

After the adhesive 8 has hardened, the assembly is housed in the injection container 15, submerged in the viscous liquid 10 contained in the injection container 15, and the pump 16 The viscous liquid 10 is injected from the hole 7a provided in the cylindrical case 7 while deaeration is performed.

The assembly is performed for a predetermined period of time by previously measuring the viscous liquid 10 in the cylindrical case 7. After the elapse of the period, the assembly is removed from the injection container 15 and the hole 7a is plugged with the stopper 11. To complete the vibration sensor 3 shown in FIG.

The vibration sensor 3 manufactured in this manner is the third sensor described above.
When used in the directional receiver shown in the figure, in order to eliminate initial failures, a so-called aging that is left for a fixed cycle in a separately defined low and high temperature environment, and then a receiving case is formed as a pair of two. 2 is incorporated.

In the manufacturing process described above, the mutual dimensions of the shaft 5 of the diaphragm 6 and the hole 9a of the weight 9 are selected so as not to damage the piezoelectric element 4 at the time of fitting with the jigs 14a and 14b. The vibration plate 6 is dimensioned in advance in consideration of the unevenness of its flatness so that a predetermined flexure occurs on the weight 7 side after assembling with the cylindrical case 7 or the like within a range that does not impair the elasticity.

[Problems to be solved by the invention]

However, in the above-described conventional manufacturing method, although the variation in the dimensions of the hole of the weight is finely controlled with respect to the axis of the diaphragm, it is only by this dimensional management that a sufficient fixing strength of the axis of the diaphragm with respect to the hole of the weight is obtained. Is difficult, for example, the expansion of the viscous liquid generated at the time of aging described above causes a phenomenon such that the vibration plate is pressed outward and the shaft slides in a direction to come out of the hole of the weight, and therefore, a good figure-eight shape is obtained. There is a problem that the yield of the vibration sensor that can obtain the directional characteristics is about 50%, and the cost increases.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a vibration sensor manufacturing method capable of improving the manufacturing yield and providing a low-cost and highly reliable vibration sensor. It is.

[Means for solving the problem]

In order to achieve the above-mentioned object, according to the present invention, after fixing a piezoelectric element to a diaphragm, the shaft of the diaphragm is coated with an adhesive effective for bonding between metals, and then the shaft is disposed in a cylindrical case. It is designed to fit into the hole of the weight that has been made.

[Action]

In the present invention by the above-described means, the fixing of the shaft and the weight of the diaphragm is performed not only by fitting the shaft and the hole but also by using an adhesive, so that the mechanical fixing strength between the shaft and the weight is improved. In addition, even when the vibrating plate is pressed outward due to expansion of the viscous liquid during aging, it is possible to minimize the occurrence of the phenomenon that the shaft slides out of the hole of the weight.

Accordingly, it is possible to improve the yield of manufacturing a vibration sensor having a good figure-eight directional characteristic,
Cost reduction can be measured.

〔Example〕

 Embodiments will be described below with reference to the drawings.

1 (A) and 1 (B) are manufacturing process diagrams showing one embodiment of a method for manufacturing a vibration sensor according to the present invention. In the drawing, 4 is a piezoelectric element, 5 is a shaft, 6 is a diaphragm, and 7 is a cylindrical case. Reference numeral 8 denotes an adhesive for fixing the diaphragm 6 to the cylindrical case 7, reference numeral 9 denotes a weight, and reference numeral 10 denotes a viscous liquid, which are the same as those shown in FIGS.

Reference numeral 17 denotes an adhesive for fixing the shaft 5 of the diaphragm 6 and the weight 9 in the present embodiment. Here, an epoxy-based or instant adhesive having a great effect on bonding between metals is used. Is a liquid material that has the property of hardening when exposed to air for a certain period of time.

FIG. 1A shows a state in which a liquid adhesive 17 is applied to the tip of the shaft 5 of the diaphragm 6 to which the piezoelectric element 4 is attached. The piezoelectric element 4 is fixed on the diaphragm 6 via a sheet-like solder 12 (see FIG. 4 (A)) in the same manner as in the prior art. (Refer to (A)), and is performed by heating and soldering. After fixing by the soldering, the adhesive 17 is applied to the shaft 5.

Next, the two vibration plates 6 having the adhesive 17 applied to the shaft 5, the cylindrical case 7 and the weight 9 are fixed to the jig 14 in the same manner as in the prior art.
a, 14b (see FIG. 4 (B)), and
The pressure is applied by the jigs 14a and 14b before the hardening is performed, so that the shafts 5 of both diaphragms 6 are provided at the center of both ends of the weight 9 at the center.
9a, the peripheral edges of both diaphragms 6 are inserted into the inside of both ends of the cylindrical case 7, and these are integrally assembled.
The assembly is removed from the jigs 14a and 14b, and the adhesive 17
And the peripheral portions of both diaphragms 6 are fixed to the inner peripheral surface of the cylindrical case 7 with an adhesive 8.

After the adhesives 17 and 8 have been cured (the curing time is measured in advance, and after the lapse of the time), the viscous liquid 10 is poured into the cylindrical case 7 in the same manner as in the prior art.
(See FIG. 4 (D)). After the injection, the hole 7a of the cylindrical case 7 is sealed with a stopper 11 after the injection, and FIG. 1 (B).
To complete the vibration sensor.

The vibration sensor manufactured in this manner is used for a directional receiver after fading. According to experiments, the vibration of the shaft 5 and the weight 9 caused by the expansion of the viscous liquid 10 generated at the time of fading is shown. It has been found that the use of the adhesive 17 improves the force to about two times as compared with the prior art.

〔The invention's effect〕

As described above, according to the present invention, an adhesive having an effect of bonding between metals is applied to a shaft of a diaphragm after bonding and fixing piezoelectric electrons, and then the shaft is fitted into a hole of a weight in a cylindrical case. Then, since the adhesive is cured, the viscous liquid is injected into the cylindrical case to complete the vibration sensor, so that the mechanical coupling strength between the shaft of the diaphragm and the weight is improved, The occurrence of shaft sliding due to the expansion of the viscous liquid during fading can be minimized, and as a result, the yield can be improved from about 50% to about 70% of the conventional level, and the cost can be reduced. ,
The effect is obtained that an inexpensive vibration sensor having good figure-of-eight directivity can be realized.

[Brief description of the drawings]

1 is a manufacturing process diagram showing one embodiment of a method for manufacturing a vibration sensor according to the present invention, FIG. 2 is a perspective view of a directional receiver, and FIG. 3 is used for the receiver of FIG. FIG. 4 is a manufacturing process diagram showing a conventional method for manufacturing a vibration sensor. 4 ... Piezoelectric, 5 ... Shaft, 6 ... Vibrating plate, 7 ... Cylindrical case, 8 ... Adhesive, 9 ... Weight, 10 ... Viscous liquid, 10 ...
... stopper, 17 ... adhesive

Claims (1)

(57) [Claims] A diaphragm having a piezoelectric element fixed on one side and a metal shaft on the other side is attached to both ends of a cylindrical case, and the axis of each diaphragm is attached to a weight disposed in the cylindrical case. In a method of manufacturing a vibration sensor configured by fitting provided holes, an adhesive effective for bonding between metals is applied to shafts of the two vibration plates, and then the shafts are attached to holes of the weight. A method for manufacturing a vibration sensor, comprising: