JPS6321061Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a reed switch.

Conventional reed switches are made of an Fe-Ni alloy (usually called N52 because it contains 52% Ni), which has almost the same coefficient of thermal expansion as glass, as shown in Figure 1.
A pair of magnetic leads 1 and 2 made of
The pair of leads are guided out of the glass tube 3 that encloses the contact portion, and are supported and fixed to the sealing portion 4. The diameter of glass tube 3 is approximately 3
mm, and the length is about 18 mm, the diameter of leads 1 and 2 is about 0.6 mm, and the length from the sealing part 14 is about 20 mm.

When using a reed switch, use leads 1 and 2.
It involves processes such as bending, cutting to appropriate length, and electrically connecting. Lead 1, 2
Since the leads 1 and 2 are supported and fixed to the sealing part 4, there is a drawback that the glass of the sealing part 4 is likely to crack or crack due to external force applied to the leads 1 and 2 during these operations, especially external force in the direction of bending.

The object of the present invention is to provide a reed switch that eliminates this drawback.

The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 2 is a front view showing an embodiment of the reed switch according to the present invention. Referring to the same figure, the leads 1 and 2 led out from the glass tube 3 in which the contact part is sealed are cut leaving a few mm from the sealed part, and a very mild steel wire is used in place of the original lead. A wire rod which has been electrolytically copper-plated concentrically as a core material and electrolytically tin-plated after wire drawing is butt-welded to the cut ends of 1 and 2 as external circuit connection wires.

The shorter the length L from the sealed part of leads 1 and 2,
The risk of defects occurring in the sealed portion due to external forces applied to the leads is reduced. However, if the length L is short, it will be difficult to grip the electrode when welding with the external circuit connection wire 5, and there is a risk of damage to the sealing part 4 due to the heat generated during welding. In the case of a glass tube of about 3 mm, the limit of length L is about 3 mm.

The above-mentioned wire rod with an extremely soft steel wire as the core material has excellent bending performance, good bending resistance, and can be soldered.It has better performance than ordinary soft wire materials such as copper wire, and is suitable for external circuits. The connecting wire 5 has a diameter such that its tensile strength does not exceed the lead support strength of the sealing part 4, and a diameter that is not too soft when handled. For example, the diameter of leads 1 and 2 mentioned above is
In the case of 0.6 mm, the lead wire 5 of about 0.3 to 0.4 mm is good. Further, it is easy to weld to the leads 1 and 2 made of N52 material, and the strength of the welded portion is greater than the tensile strength of the external circuit connection wire 5 itself.

Since this is a reed switch in which the external circuit connection wire 5 is joined, the external force applied to the external circuit connection wire 5 is absorbed by its own deformation such as bending and stretching, and it passes through the leads 1 and 2 to the glass. It does not reach the sealing part 4 with the pipe, so the sealing part 4 is protected from external force.

The wire rod with the aforementioned extremely mild steel wire as the core material used as the external circuit connection wire 5 has the core material as the magnetic pole body.
Together with the leads 1 and 2, a magnetic circuit similar to the conventional one can be constructed, and therefore changes in the sensitivity of the reed switch can be kept to a minimum.

As explained above, according to the present invention,
It is possible to provide a reed switch that is extremely easy to handle and can prevent damage to the glass of the sealed portion due to external force when processing external circuit connection wires or assembling the reed switch into an assembly.

[Brief explanation of the drawing]

Figure 1 is a front view of a conventional reed switch, Figure 2 is a front view of a conventional reed switch.
The figure is a front view of an embodiment of the reed switch according to the present invention. 1, 2...Lead, 3...Glass tube, 4...Sealing portion, 5...External circuit connection wire made of electrically tinned extremely mild steel wire.

Claims (1)

[Scope of utility model registration request] A reed switch having a reed contact within a glass tube, wherein an electric tin-plated extremely mild steel wire is connected as an external circuit connection line to an extending portion of the lead outside the glass tube near the end of the glass tube. Switch.