JPS5919515Y2 - Corrosion resistant transmitter - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a transmitter that excites and transmits ultrasonic waves by electromagnetic vibration, electrostrictive vibration, piezoelectric vibration, or the like.

Conventionally, as shown in FIG. 1, this type of transmitter has a diaphragm 5 on which a vibrator 7 is mounted and a diaphragm 5 having a painted surface 6 attached to a fixing plate attached to a main body 1 via bolts 3 and a seal ring 8. 2, it is configured to be supported via a support 4 made of an elastic material, for example rubber.

As is known, the transmitter is made of metallurgically non-magnetic metal materials, such as aluminum alloys, austenitic stainless steels, titanium alloys, and the like.

Among these materials, aluminum alloys are widely used because they have the advantage of being lightweight, but they have the disadvantage of poor corrosion resistance, which causes corrosion problems when used in seawater environments.

The reason for this is as shown in FIG. 2, a gap 10 between the main body 1 and the fixed plate 2, and a peeled part 11.
This is because seawater enters into the aluminum alloy and causes crevice corrosion to occur in the aluminum alloy that is the material.

The purpose of this invention is to provide a corrosion-resistant wave transmitter that does not cause crevice corrosion due to the above-mentioned conditions.The diaphragm equipped with a vibrator is supported on a fixed plate fixed to the main body via an elastic body. The transmitter is characterized in that the surface of the diaphragm and the outer peripheral surface of the fixed plate are covered with an elastic body, and the covering elastic body and the supporting elastic body are integrally formed. be.

An embodiment of the present invention will be described below with reference to the drawings.

Among the symbols shown in FIGS. 3 and 4, the same symbols as those shown in FIG. 1 indicate the same parts.

3 and 4, reference numeral 13 denotes a coating layer 13b covering the surface of the diaphragm 5 and a coating layer 1 covering the outer peripheral surface of the fixed plate 2.
3C and the support part 13a interposed between the diaphragm 5 and the fixed plate 2 are integrally connected, and is made of an elastic material such as rubber.

As shown in FIG. 4, the coating layer 13C fills a part of the seal ring groove 9 and compresses the seal ring 8 to prevent seawater from entering.

14 is a titanium layer or a resin layer that covers the outer surface of the main body 1 in contact with the fixed plate 2, that is, the outer surface exposed to seawater, etc.; 15 is an anticorrosive agent filled in the seal ring groove 9; ~44%, polystyrene polymer 35~
39%, siloxane resin 5-19%, and silica collector powder 1-30%.

The rest of the structure is the same as the conventional example shown in FIG. 1, so the explanation will be omitted.

In this embodiment, as described above, the elastic coating layer 13C and the titanium layer or the resin layer 14 are interposed between the main body 1 and the fixed plate 2, so that the close contact between the two layers 13C and 14 prevents seawater from entering from the outside. can be prevented.

Furthermore, since the elastic coating layer 13b provided on the surface of the diaphragm 5, the elastic coating layer 13C provided on the outer peripheral surface of the fixed plate 2, and the elastic support portion 13a are integrally formed, both of them 5, 2 and the elastic support 13 are formed integrally. It is possible to prevent seawater from entering from the outside between each of a.

In the event that seawater enters the seal ring groove 9,
Since the zinc in the composition of the anticorrosive agent 15 dissolves preferentially to the aluminum alloy, the aluminum alloy of the fixed plate 2 is protected from corrosion.

Furthermore, the eluted zinc becomes basic zinc hydroxide and makes the invading seawater basic, thereby stabilizing the passive film formed on the aluminum alloy surface.

Therefore, according to this embodiment, it is possible to completely prevent the occurrence of corroded parts 10 to 12 as in the conventional example shown in FIG.

After the product of the present invention and the conventional product were immersed in artificial seawater for 1000 hours, they were disassembled and the state of corrosion was examined, and it was found that the conventional product had a lot of damage due to crevice corrosion in the above-mentioned areas.

For example, the distribution of corrosion pits generated on the joint surface of the fixed plate was as shown in FIG.

However, no damage due to corrosion was observed in the product of the present invention.

As explained above, according to the present invention, it is possible to prevent the occurrence of crevice corrosion, improve the reliability of the product, and extend the life of the product.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a conventional transmitter, Figure 2 is a diagram showing corrosion damage to the same transmitter, Figure 3 is a sectional view of the corrosion-resistant transmitter of the present invention, and Figure 4 is an example of the same. FIG. 5 is an explanatory diagram showing corrosion pits in the conventional product. 2... Fixed plate, 5... Vibration plate, 9...
...Seal ring groove, 13a to 13C...
Elastic body, 14...Titanium layer, 15...
Anticorrosion agent.

Claims (1)

[Scope of utility model registration request] 1. In a wave transmitter in which a diaphragm equipped with a vibrator is supported on a fixed plate fixed to a main body via an elastic body, the surface of the diaphragm and the outer peripheral surface of the fixed plate are covered with an elastic body. Also, a corrosion-resistant wave transmitter characterized in that the covering elastic body and the supporting elastic body are integrally formed. 2. The corrosion-resistant wave transmitter according to claim 1, which is a registered utility model, characterized in that a titanium layer or a resin layer is provided on the bonding surface of the main body that contacts the fixing plate. 3. The corrosion-resistant wave transmitter according to claim 1 or 2, wherein the seal ring groove provided in the fixed plate is coated with or filled with an anticorrosion agent.