JPH0511598Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a buzzer assembly built into a control device for controlling the throttle or clutch of a small marine engine.

[Conventional technology]

In engine control devices used in small ships,
Some have a built-in buzzer to notify the driver of engine overheating. As shown in FIGS. 4 and 5 as an example, in a conventional control device of this type, a lever 2 for engine control and various switches 3 are attached to a metal housing 1. There are 4 buzzers.
Furthermore, a power transmission mechanism for transmitting the movement of the lever 2 to the control cable 5 is built in the housing 1. control cable 5
The other end is led to the engine, and this cable 5
Mechanical control of the engine is carried out via the Further, electrical control is performed via a wire harness 6 that connects the engine and a power source. The housing 1 is fixed to a substrate 8, that is, to the hull side, by a plurality of screws 7.

The conventional buzzer 4 includes a buzzer body case that houses a diaphragm and a drive unit for vibrating the diaphragm, and a buzzer front cover that is attached to the front side of the buzzer body case. The sound is emitted from the front lid side of this buzzer. For this reason, the front lid of the buzzer is provided with a bending process and a sound emitting hole to increase the sound pressure of the buzzer.

Although the housing 1 has some degree of waterproofing, since control devices for small boats mainly used at sea are constantly exposed to seawater, some seawater may enter the housing 1. Intrusion is inevitable. For this reason, it is desirable to wrap the buzzer 4 with a waterproof member such as a rubber cover, but if the front cover of the buzzer is covered with a cover, the sound pressure will decrease, so a cover cannot be attached to the front cover of the buzzer. Therefore, the conventional buzzer front cover has been made of a plated steel plate or coated with a coating to provide rust prevention properties.

[Problem that the invention attempts to solve]

However, since the housing 1 is a die-cast product made of aluminum or zinc and is electrically conductive, if even a small amount of seawater enters between the inner surface of the housing 1 and the buzzer 4, a current will flow, which is worse than normal rust. Causes rapid galvanic corrosion. In particular, the lead wire of the buzzer 4 is constantly energized, and the electrical ground of the small ship's engine is the ship's hull, to which the conductive housing 1 is fixed with metal screws 7. For these reasons, when moisture such as seawater adheres between the buzzer 4 and the housing 1, a leakage current flows from the buzzer 4 to the housing 1, causing early loss of function of the buzzer 4 due to electrolytic corrosion. Note that a buzzer with a plated front cover made of steel plate is itself an electrical conductor, so leakage current is likely to flow through it. In addition, even if a steel plate is painted, if a part of the paint peels off even slightly or if there is a defective paint spot near the sound hole, the housing may become damaged due to the presence of moisture.
Leakage current tends to flow between the If even a small amount of leakage current begins to flow, the above-mentioned material itself has a weak anti-corrosion ability, so electrolytic corrosion rapidly progresses, eventually leading to loss of functionality.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to prevent leakage current from occurring within the housing of an engine control device, suppress electrolytic corrosion, and maintain the function of the buzzer.

[Means for solving problems]

This invention was developed to achieve the above purpose.
A buzzer assembly housed in a metal housing 1 of an engine control device, which includes a diaphragm 13 inside.
and a metal buzzer body case 11 that incorporates a drive unit 14 for vibrating the diaphragm 13 and has a flange-shaped portion 30 on the outer periphery, and a buzzer front lid that is attached to the front side of the buzzer body case 11. 12, and the flange-shaped portion 30 that covers the entire outer circumference of the buzzer body case 11 in a watertight manner.
and an electrically insulating rubber cover 20 having an annular groove 23 that is fitted into the buzzer front cover 12 with a part of this rubber cover 20 sandwiched therebetween.
The buzzer main body case 11 is supported by the convex portion 31 on the inner surface of the housing 1 with the buzzer body case 11 separated from the housing 1, and the buzzer front cover 12 is coated with an electrically insulating resin coating 27 at least on the outer side of the buzzer. Therefore, the coated nonconductor coated metal plate 25 is molded into a predetermined shape.

[Effect]

In the buzzer assembly having the above configuration, the outer side of the buzzer body case, which does not affect the buzzer sound pressure, is covered with a rubber cover and is therefore waterproof. The front lid of the buzzer, which affects the sound pressure of the buzzer, is made of the non-conductor coated metal plate described above instead of being covered with a rubber cover, thereby making the front lid itself non-conductive and improving rust prevention. enhance In addition, this buzzer assembly is supported by the housing via a rubber cover with the front cover separated from the inner surface of the housing, and the entire circumference of the flange-shaped part that connects the front cover and the buzzer body case, as well as the buzzer The entire circumference of the main body case is watertightly covered by the rubber cover. This prevents leakage current from flowing from the buzzer to the housing even if moisture such as seawater gets into the housing. In this case, the front lid side does not need to be covered with a rubber cover, so the buzzer sound pressure does not decrease.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 to 3. The buzzer assembly 10 of this embodiment is housed in a housing 1 (see FIG. 4) of an engine control device configured in a conventional manner. 1a is the housing back cover.

The buzzer assembly 10 includes a buzzer body case 11 made of metal, and a buzzer front cover 12 attached to the front side of the buzzer body case 11. Inside the buzzer main body case 11, a diaphragm-shaped metal diaphragm diaphragm 13 and a well-known drive unit 14 using an electromagnetic coil for vibrating the diaphragm 13 are provided. A terminal portion 15 is provided on the rear side of the buzzer main body case 11, and lead wires 16 and 17 are drawn out. One lead wire 16 is connected to the electromagnetic coil of the drive unit 14, and the other lead wire 17 is connected to the buzzer body case 11. Therefore, a voltage is also applied to the diaphragm 13. The above structure may be the same as the conventional one.

The outside of the buzzer body case 11 is watertightly covered with a rubber cover 20 made of a material that is electrically insulating and has rubber elasticity. This rubber cover 20 is open at one end and has a rear wall 21 at the other end.
It has a short cylindrical shape closed by. The rear wall 21 is provided with a through hole 22 through which the lead wires 16 and 17 are passed. Furthermore, an annular groove 23 is provided on the inner circumferential side of the front edge portion 20a of the rubber cover 20 over the entire circumference thereof.

A nonconductor coated metal plate 25 is used as the material for the buzzer front cover 12. This nonconductor coated metal plate 2
5, as shown in FIG. 3 as a partially enlarged cross-sectional view, a polyester resin or the like is applied to one side of a mild steel substrate 26 having a thickness of, for example, about 0.2 to 0.3 mm, that is, the surface that will be the outside of the buzzer. The electrically insulating resin coating 27 made of vinyl chloride resin etc. has a thickness of 0.1 mm or more.
It is coated to a thickness of around 0.2,
This is a so-called color coated steel sheet. However, board 2
A non-ferrous metal may be used as the material of 6. Resin coating 2
7 is firmly fixed to the substrate 26 so as not to peel off from the substrate 26 even when press working or caulking is performed. Further, the other side of the substrate 26 is coated with anti-rust paint 28. However, the resin coating 27 may be coated on both sides of the substrate 26.

The buzzer front cover 12 is made by bending the above-mentioned nonconductor coated metal plate 25 into a predetermined front cover shape using a press and by opening a sound hole 29. As shown in FIG. 1, the peripheral edge of the buzzer front cover 12 is caulked to the flange-shaped front edge of the buzzer main body case 11 over its entire circumference. This flange-shaped portion 30 is fitted in the annular groove 23 formed in the rubber cover 20 in a watertight manner.

Further, the front edge 20a of the rubber cover 20 faces a protrusion 31 integrally provided on the inner surface of the housing 1, and its position in the front-rear direction is regulated by the protrusion 31. Furthermore, a plurality of support parts 32 (only some of which are shown) are protruded from the inner surface of the housing 1 around the rubber cover 20, and these support parts 32 hold the outer peripheral part of the rubber cover 20 so that it does not move. has been done. In other words, the buzzer body case 1
1 and the buzzer front cover 12 are supported by the housing 1 via an electrically insulating rubber cover 20.

In the buzzer assembly 10 configured as described above, a voltage is applied through the lead wires 16 and 17, and when the engine overheats, current flows through the drive section 14 and the diaphragm 13 vibrates. In the buzzer assembly 10, the outside of the buzzer body case 11, which does not affect the sound pressure of the buzzer, is covered with a rubber cover 20 as a waterproof member. The main body case 11 is prevented from coming into contact with moisture. In addition, the buzzer front cover 12 side, which affects the buzzer sound pressure,
It is made nonconductive by using a nonconductor coated metal plate 25 as its material, and is supported by the housing 1 via an electrically insulating rubber cover 20. Therefore, even if moisture adheres to the inner surface of the housing 1, leakage current will not flow from the buzzer front cover 12 to the housing 1, and therefore electrolytic corrosion will not occur, and the buzzer front cover 12 itself has anti-rust properties. Because it has excellent properties, corrosion is not promoted.

Moreover, the nonconductor coated metal plate 25 used as the material for the buzzer front cover 12 is already coated with a resin coating 27 at the material acquisition stage before pressing, etc.
Resin coating 2 without painting after caulking 1
7 exhibits excellent rust prevention ability. This eliminates the need for time-consuming post-processing such as plating or painting after processing or assembling parts.Furthermore, existing equipment such as press molds and assembly lines can be used as is, allowing new You don't have to make any major investments.

[Effect of idea]

As described above, according to the present invention, even if moisture such as seawater enters the housing of an engine control device with a built-in buzzer used for small ships, conductors such as water droplets will not adhere to the front cover and the housing. Since direct adhesion to the buzzer body case is avoided, leakage current that causes electrolytic corrosion can be prevented from flowing between the buzzer and the housing, which is highly effective in suppressing the occurrence and progression of corrosion. In addition, the manufacturing process is simple because there is no need for plating or painting after processing or assembling the parts of the buzzer front cover.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a part of an engine control device equipped with a buzzer assembly showing one embodiment of the present invention;
The figures are a perspective view of the buzzer assembly shown in Figure 1, Figure 3 is a sectional view of a portion of the non-conductor coated metal plate used for the buzzer front cover, Figure 4 is a side view of the engine control device, and Figure 5 is a side view of the engine control device. The figure is its front view. DESCRIPTION OF SYMBOLS 1... Housing, 10... Buzzer assembly, 11... Buzzer body case, 12... Buzzer front cover, 13... Vibration plate, 14... Drive unit, 20...
...Rubber cover, 25...Nonconductor coated metal plate, 2
7...Resin coating.

Claims (1)

[Scope of utility model registration request] A buzzer assembly is housed in a metal housing 1 of an engine control device, and this buzzer assembly includes a diaphragm 13 and a diaphragm 1 inside.
a metal buzzer main body case 11 having a built-in drive unit 14 for vibrating the buzzer body 3 and having a flange-like portion 30 on the outer periphery; a buzzer front cover 12 attached to the front side of the buzzer main body case 11; An electrically insulating rubber cover 2 that covers the entire outer circumference of the buzzer body case 11 in a watertight manner and has an annular groove 23 that fits into the flange-shaped portion 30.
0, and the buzzer body case 11 is supported on the convex portion 31 on the inner surface of the housing 1 with a part of the rubber cover 20 sandwiched therebetween and the buzzer front cover 12 separated from the housing 1. In addition, the buzzer front cover 12 has an electrically insulating resin coating 27 on at least the outer side of the buzzer.
A buzzer assembly for an engine control device of a small boat, characterized in that it is formed by molding a nonconductor-coated metal plate 25 coated with a metal plate 25 into a predetermined shape.