JPS6318111Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an improvement of a mercury switch.

A mercury switch that fills a glass tube with fluid mercury is installed with the tube axis aligned with the direction of gravity when assembling a relay incorporating the switch or mounting the relay on equipment. However, in order to apply the switch to be mounted on a vehicle, it is necessary to use an appropriate anti-vibration protection device to assemble and mount the switch so that vibrations and shocks are not applied to the switch. Otherwise, vibration will cause mercury to enter the switch contacts, resulting in unintended contact bridging (open contacts are shorted by mercury).
This will lead to deterioration of the reliability of the device.

FIG. 3 is a vertical cross-sectional view (a) and perspective views (b) and (c) of the main components of a conventional mercury switch cut along the tube axis, and the outline of its configuration and its problems will be explained with reference to the figures.

In the figure, reference numeral 1 denotes a fixed electrode sealed in the upper end of a glass tube 4 to which a contact 6 is welded. 2 is glass tube 4
It is a sealed tube having an upper circular open end 9 located on the lower end side, and the lower part of the sealed tube 2 is diaphragm-diametered to form a pinch welding point 15. 3 is an armature whose lower end is supported by welding (11 is the welding point) on the tube wall near the open end 9 of the sealed tube 2, and the U-shaped bent portion 8 of the armature 3 is infiltrated into the mercury reservoir 5. be done.

As shown in the perspective view C, a large number of capillary grooves 12 are formed on both sides of the armature 3, a mercury wet film is formed, and a stable switching function is obtained by bringing the armature 3 into contact with the contact 6 of the fixed pole 1.

The mercury reservoir 5 filled in the glass tube 4 of the switch is filled with the minimum amount of mercury to ensure that mercury infiltration with the armature 3 is not interrupted by vibration or impact. If the amount of mercury filled is large, the level of the mercury reservoir 5 will be pushed upward, and the amount of mercury in the mercury wet film formed by the capillary grooves 12 will also increase, reducing the vibration resistance of the switch function.

On the other hand, as the mercury switch operates, the wet mercury film on the surface of the armature 3 that is in contact with the contact 6 evaporates, and this evaporated mercury solidifies on the inner wall of the glass tube 4 and forms a circulation path back to the mercury reservoir 5. For,
The height of the sealed tube 2 was a barrier. That is, there is a problem in that it is not possible to improve vibration resistance by keeping the level of the filled mercury reservoir 5 low with the conventionally configured sealed tube.

The purpose of the present invention was to solve the above-mentioned disadvantages, and in order to achieve the purpose, the open end 9 of the sealed tube 13, which supports the armature 3 on the tube wall and defines the inside of the tube as a mercury reservoir 5, has an open upper end. is bent inward and a hole 7 for mercury inflow is formed in the wall of the sealed tube 13.
This improves the vibration resistance of the mercury switch.

Hereinafter, regarding an embodiment of the present invention, FIG. 1 is a vertical cross-sectional view, which is the same as that cited in the explanation of the switch configuration, and FIG. The explanation will be made according to a sectional view of the stop tube.

This invention reduces the amount of mercury filled in the tube to the minimum necessary amount.
In addition, the following sealed tube 13 is used to prevent bridges between contacts due to mercury scattering to the contact portions through the mercury wet film of the armature 3 under external environmental conditions such as vibrations for switch operation. That's what I did.

As mentioned above, since the mercury in the mercury reservoir 5 circulates within the tube, the sealing tube 13 is provided with a hole 7 in its wall for mercury to flow into the tube. The lower the height of the hole 7, the less the amount of mercury filled in the tube.
Due to the relative position of the lower edge of the U-shaped bent part 8 and the level of the mercury reservoir 5, it may be separated from the mercury reservoir due to vibration etc., so it is also related to the height position of the welding point 11 that supports the armature 3. It is not desirable for the switch function to be lowered from the schematically illustrated position.

On the other hand, in order to prevent the mercury in the mercury reservoir 5 from scattering to the switch contact 6 above, the periphery of the open end 9 of the sealed tube 13 is bent inward to form a shape and bend 10. However, the open end 9 of the molded bend 10 is connected to the armature 3.
The size is set so that it does not interfere with the operation of the This shape has the effect of alleviating fluctuations in the mercury level inside the sealed tube 13 due to vibrations and shocks.

Although two holes 7 are provided in the wall of the sealed tube 13 in FIG. 2 on the left and right symmetrically with respect to the tube axis, a large number of holes 7 may be provided at the same height around the tube wall.

Although the mercury switch used in the explanation of the above embodiment is an example of a switch with a switching contact configuration, the gist of the present invention is not limited to the exemplified switch type, and the mercury switch with other contact configuration (single contact configuration switches, etc.).

As described above, the mercury switch that employs the sealed tube of the present invention achieves the desired vibration resistance function, and
In the switch of this invention, bridging between contacts occurred when applying low frequency vibration with an amplitude of 10 mm, but the bridging failure did not occur even when the same vibration was applied as described above with an amplitude of 20 mm, and there was no problem with touching, opening, and the operation of the switch. Good results have been confirmed in terms of time characteristics, no different from conventional products.

[Brief explanation of drawings]

FIGS. 1 and 2 are a sectional view taken along the switch tube axis and a sectional view of the sealed tube, showing an embodiment of the present invention.
FIG. 3A is a vertical cross-sectional view of a conventional mercury switch, FIG. 3B is a perspective view of a sealed tube, and FIG. 3C is a perspective view of an armature. In the figure, 2 and 13 are sealed tubes, 3 is an armature, 4 is a glass tube, 6 is a contact, 5 is a mercury reservoir, 7 is a hole, 9 is the open end of the sealed tube, and 10 is the bend of 9. This is the molding part.

Claims (1)

[Claims for Utility Model Registration] A sealed tube with an open top for immersing an armature in a mercury reservoir is provided, and the armature is attached to the sealed tube by welding between the outer wall of the sealed tube and the end of the armature. 1. A mercury switch, characterized in that the sealed tube has an upper opening edge bent inward and has a hole for mercury inflow in the tube wall.