JPS6347920Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an improvement in the waterproof structure of a horn (hereinafter referred to as a horn) for vehicles such as automobiles and motorcycles.

An explanation will be given below using an electric (electromagnetic) horn as an example. The following three main mechanisms can be considered for water seepage inside the horn. (1) Flooding due to capillary action, (2)
When the horn is rapidly cooled and the temperature inside the horn cannot adjust to the outside temperature, a temperature difference is created, which causes expansion and contraction, which causes water droplets adhering to the outside of the horn to be sucked in, causing water intrusion.(3) Diaphragm Flooding caused by alternating positive and negative air pressure inside the horn as a result of the pumping action of the horn.

As a result of the above, if rainwater or the like enters the inside of the horn, corrosion of the contacts may cause the horn to malfunction, such as noise, and there is a problem of lack of reliability and durability. As a measure against moisture infiltration into the inside of the horn, a complete sealing method has been proposed in which adhesive, paint, or other sealant is applied to the joints of the components that make up the horn, but it is extremely difficult to ensure complete sealing. be. Furthermore, if a complete seal were to be achieved, it would be perfect as a waterproofing measure, but in terms of the acoustic performance of the horn, the balance between positive and negative pressure inside the horn would be disrupted, and the diaphragm would not be able to vibrate properly. There is a problem, and in order for the horn to operate normally, there is a limit to the airtightness inside the horn.

Therefore, in the case of a horn, it is large enough to allow air to pass from inside the horn so that the movement of the diaphragm is not adversely affected by the positive or negative pressure inside the horn. It is necessary to have ventilation holes to prevent moisture such as moisture from entering.

As a proposal in response to the above technical issues,
-There is No. 41639. This involves creating an opening that leads to the outside of the horn body, and inserting a filter made of a material with penetrating pores (pore size is 5μ) to prevent moisture from penetrating due to its surface tension. This is how it was done. However, even this proposal is insufficient as a measure against moisture penetration. In other words, the above proposal assumes that everything except the opening is completely sealed, but in the case of a normal horn, the diaphragm fixed part, the movable armature fixed part, the fixed armature fixed part, and the terminal Moisture penetrates from the fixed parts. Furthermore, the above proposal requires a filter or the like as a new component, and has drawbacks such as being disadvantageous in terms of cost.

In view of the above, in order to avoid adversely affecting the reciprocating motion of the diaphragm, this idea communicates the inside of the horn with the outside air through a ventilation hole. The aim is to provide a structure at a low cost.

One embodiment shown in the drawings will be explained. First, to explain the structure of the horn, there is an iron case body 10 that is open at one end, a diaphragm 11 that is disposed on the flange of the open end of the case body 10 so as to close the opening, and an electromagnet that drives the diaphragm 11. 12, and an interrupter 13 that intermittently energizes the electromagnet 12 through engagement with the diaphragm 11.
3 and the electromagnetic coil 14 constituting the electromagnet 12,
It is housed inside the case body 10, that is, inside the horn. At the center of the diaphragm 11, a movable armature 1 constituting the electromagnet 12 is disposed inside the horn.
5 is fixed, and a movable armature 15 is attached to the outside of the horn.
The extension member passes through the diaphragm 11 and connects the diaphragm 1 to the diaphragm 11.
6 is fixed. A fixed armature 17 is provided at the bottom of the case body 10 so as to face the movable armature 15.
passes through the case body 10 member and is fixed by a nut 18. Furthermore, a terminal 19 for electrical connection to an external power source is fixed to the outer surface of the case body 10.

Now, the above-mentioned horn is not specially provided with a ventilation hole that communicates the inside of the horn with the outside air. This is because the following was found regarding the above horn. (1)
The diaphragm fixing part, the movable armature fixing part, the fixed armature fixing part, and the terminal fixing part are joint parts of the components that make up the horn, but these joint parts inevitably have minute gaps 20. and this gap 2
It has been found that the hole 0 can serve as a ventilation hole so as not to adversely affect the reciprocating motion of the diaphragm 11.

By the way, to discuss the size of this gap from a different angle, in a dust test using JISZ8901 test dust type 8 Kanto loam (a horn is placed while the dust is floating and the horn is blown), it was found that the amount of dust inside the horn was There is no infiltration. (2) Furthermore, it was found that although the fine gaps 20 formed in the joint have a sufficient function as ventilation holes, they are too large to prevent moisture from penetrating due to surface tension.

Therefore, among the joint parts of the components that make up the horn, when assembling the diaphragm fixed part, movable armature fixed part, fixed armature fixed part, and terminal fixed part, etc., which are related to communication between the inside of the horn and the outside air. The entire external surface of the horn is used to utilize the fine gaps that naturally occur between the components as ventilation holes that communicate the inside of the horn with the outside air, and to prevent moisture from penetrating through these gaps due to its surface tension. Or at least the water repellent 2 is applied to the outer surface of the horn at the joint.
2 was applied by spraying or brushing to impart water repellency. As a water repellent, for example, room temperature water repellent KC88 (silicone content: 9 to 11%) manufactured by Shin-Etsu Silicone is effective.

An example of a water resistance test of the above-mentioned waterproof structure horn will be explained.
Test 1...JISD0203, S1 (water discharge rate 24.5/min), operate the horn for 30 minutes with 1 second blast and 4 second pause. Test 2... Watering (rainfall 150mm/h) for 10 minutes,
Next, 25 cycles of 30 minutes of standing at 60°C, 10 minutes of watering, and 60 minutes of standing at room temperature are performed. In the above Tests 1 and 2, there was no water intrusion into the inside of the horn of the waterproof structure.

As mentioned above, according to this invention, the minute gaps that occur at the joints of the components that make up the horn are used as ventilation holes that communicate the inside of the horn with the outside air. Furthermore, to prevent water from penetrating through these gaps based on the surface tension, a water repellent was applied to at least the joints to give water repellency, making it both inexpensive and extremely expensive. This has the excellent effect of providing a horn with waterproof properties.

In addition, although the above explanation has been about electric horns, this idea is extremely effective as a waterproofing measure for structures related to storing electric circuits in piezoelectric horns that generate sound by bending and vibrating a piezoelectric vibrator in an electric circuit. It is.

[Brief explanation of the drawing]

The figures show an embodiment of the waterproof structure horn according to this invention, and FIG. 1 is a sectional view thereof, and FIG. 2 is an enlarged sectional view of the main part. Note that the arrows in the figure indicate the state of ventilation between the inside of the horn and the outside air.

Claims (1)

[Scope of utility model registration request] In an electric horn that excites a diaphragm by passing an intermittent current through an electromagnetic coil, the body that constitutes the inside of the horn houses the electromagnetic coil and interrupter.
The gaps that occur at the joints of the horn's internal components such as the diaphragm and iron core (the gaps through which the JIS Z8901 test dust type 8 Kanto loam cannot pass) are used as ventilation holes that communicate the inside of the horn with the outside air. A horn with a waterproof structure, characterized in that a room temperature water repellent containing silicone in a solvent is applied to the external surface of the horn, and the gaps or vents are vent holes that allow air to pass through but not water or the above-mentioned dust.