JPS6028090B2 - Manufacturing method of reed switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a reed switch, particularly a vibration-resistant type reed switch.

For example, an IJ-doswitch having the configuration shown in FIG.
The second fixed terminals 2 and 3 are partially inserted into the enclosure 1 and sealed together, and the first fixed terminal 2
A contact piece 4 made of a spring material with good conductivity is provided on the second fixed terminal 3, and a support piece 5 made of a spring material with good conductivity is attached to the second fixed terminal 3, the tip of which is connected to the first fixed terminal 2. A movable piece 6 made of a magnetic material is mounted on the supporting piece 5 in a state extending close to the first fixed terminal 2, and the back of the contact 7 is caulked so as to have a required overlapping margin with the first fixed terminal 2. It is attached by caulking a pin.

In the figure, 8 is a stopper protruding from the back of the contact 7 so as to come into contact with the inner wall surface of the enclosure 1 in order to regulate the contact gap and magnetic gap when the external magnetic field is extinguished, and 3a and 6a are second stoppers, respectively. This is a bent portion for forming an auxiliary magnetic gap between the fixed terminal 3 and the movable piece 6 to improve the driving force of the movable piece 6 by an external magnetic field. In the reed switch configured as described above, in order to stabilize the operation when the movable piece 6 is driven by an external magnetic field, a hinge point 5a is formed on the support 5, and the movable piece 6 operates using the hinge point 5a as a fulcrum. That's what I do.

In a general IJ switch, the contact pressure between the hinge point 5a and the movable piece 6 is set to 2 to 5 degrees, but when designed as a vibration-proof type, the materials of the contact piece 4 and the support piece 5 are Increase the spring constant using a Mo spring, etc., and adjust the hinge point 5a.
The contact pressure between the movable piece 6 and the movable piece 6 must also be 30 to 40. As a result, when this reed switch is placed in an environment with a lot of vibration, the hard Mo spring material (hardness: Hv310~
For example, 48% pressed against the support piece 5 consisting of 330)
The movable piece 6 made of Fe-52%Ni alloy (hardness: Hvloo~110) may wear locally, and the wear powder may enter the auxiliary magnetic gap between the bent portions 3a and 6a, causing a feeding failure. There is. The present invention solves these problems, and improves wear resistance by applying electroless sealing to the contact portion of the movable piece 6 with the support piece 5 so as to be particularly suitable for a vibration-proof type lead switch. , the heat curing treatment of the electroless sealing film layer is performed at the same time as strain relief by heating during the heat treatment for strain relief after sealing the sealed container. Hereinafter, the present invention will be described based on one embodiment, taking the reed switch having the configuration shown in FIG. 1 as an example. First, as shown in FIG. Electroless plating is applied to the part 6b (hereinafter referred to as the hinge part), but in order to facilitate the plating process, the part 6c is
Apply electroless sealing to one end, including the part.

The chemical composition of the plating solution is Ni90-92%, P8-10%.
Electroless shark nickel plating solution was used. The processing method is as follows. (1) Deburr and surface polish the movable piece 6 by barrel polishing.

(0) Insert the tip saddle pole portion 6d of the movable piece 6 into a suitable jig.

Since there is no need to run an electric current through the lining, any material that can withstand temperatures of about 80 degrees Celsius will suffice. A plurality of movable pieces are attached to one odor control device.

(m) Pickle only the parts that require plating.

(W) Immerse only the parts that require plating in 80-90% plating solution.

A plating layer of 10 layers was produced after 3 layers of immersion.

The plating film formation rate is shown in the table below. (V)
After taking it out from the plating solution, it was baked (temporary phosphorus) for 1 hour at 200 pm.

In electroless nickel plating having the chemical composition described above, a plated film layer having a hardness as shown in FIG. 3 can be obtained by heat treatment after plating, but in the present invention, heat curing treatment is not performed at this stage.

Next, after applying Cr or Rh plating to the traverse pole portion 6d of the movable piece 6, the second fixed terminal 3, the support piece 5, and the movable piece 6 are assembled by caulking. Further, the first fixed terminal 2 and the contact piece 4 are also assembled by caulking. Next, as shown in FIG. When the glass tube 1' covered by the first and second fixed terminals 2 and 3 is moved in the direction of arrow A in the figure, the glass tube 1' The stopper 8 comes into contact with the inner wall surface, and the glass tube 1' is
When the movable contact 7 comes into contact with the contact piece 4, the movement is stopped. In this case, the tip of the first fixed terminal 2, which is the armature, and the tip of the movable piece 6 are opposed to each other with a gap. Next, when the glass tube 1' is moved in the direction opposite to the direction of arrow A, the movable piece 6 moves away from the contact piece 4 while the stopper 8 remains in contact with the falling surface of the glass tube 1'.
When the contact gap between the movable contact 7 and the contact piece 4 reaches a predetermined gap, the movement is stopped, and the sealing heat coil 11
, 12 to heat both ends of the glass tube 1' to about 700° C. and seal them.

Note that since the heating time at this time is short, the plating film layer of the movable piece 6 is not sufficiently hardened. 0 The glass sealed container 1 sealed in this way has thermal distortion (internal residual stress) in the sealed part, and if left as it is, there will be a problem in mechanical strength. This is done by heat treatment.

As mentioned above, the temperature of this heat treatment is 90-92% Ni, P
This is almost the same as the temperature of 400°C that maximizes the hardness of the 8-10% electroless nickel plating film layer, and the hardness is Hvlo
It increases approximately twice as much as oo.

In addition, the abrasion resistance is almost the same as that of hard chrome plating (2), as shown in Figure 5 (1). In the figure, 3 indicates the wear amount of the gunmetal, and 4 indicates the wear amount of the nickel electroplating. In the present invention, the hardness of the hinge portion 6b of the movable piece 6 is increased in this way, so even if the spring constant of the support piece 5 is increased and a hard piece is used as a vibration-resistant lead switch, it has excellent wear resistance. This eliminates the risk of charging failures due to abrasion powder that would occur when plating is not applied, and the hardening of the electroless glazing film layer can be performed simultaneously with the heat treatment to remove thermal distortion of the glass enclosure 1. This method does not require a hardening process, and has the advantage of shortening the manufacturing process, especially when manufacturing a vibration-resistant type ride switch.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the structure of the reed switch according to the present invention, Fig. 2 is an explanatory diagram showing the plated part of the movable piece, and Fig. 3 is an electroless plating film layer used in an example of the present invention. FIG. 4 is an explanatory diagram showing one step of the manufacturing method according to the present invention, and FIG. 5 is a graph showing the amount of wear of each material in an abrasion test. 1: Enclosed container, 1': Glass tube, 2: First fixed terminal,
3: Second fixed terminal, 4: Contact piece, 5: Support piece, 6: Movable piece, 7: Contact (movable contact) 8: Stopper, 9, 10
: Support stand, 11, 12... ．．・Heat coil. Figure 1 Figure 3 Figure 2 Figure 4 Figure 5

Claims (1)

[Claims] 1. An enclosure made of a non-magnetic material, first and second fixed terminals partially exposed inside the enclosure, a fixed contact provided on the first fixed terminal, and a second fixed terminal. A supporting piece made of a highly conductive spring material whose base end is fixed to the terminal and whose distal end extends toward the first fixed terminal, and a support piece as required for the bent part on the first fixed terminal side. A lead consisting of a movable piece made of a magnetic material whose tip end is fixed to the supporting piece with a contact overlap margin of In manufacturing the switch, first electroless plating is applied to the proximal end of the movable piece in the state of parts, which will come into contact with the support piece after assembly, and each part is attached to both ends of the enclosure. The tube is assembled inside the open tube and both ends of the tube are heated and sealed, and then the electroless plating layer of the movable piece is heated at the same time as the distortion of the enclosure is removed through a heat treatment process to remove distortion of the enclosure. A method for manufacturing a reed switch, which comprises curing the reed switch.