JPS6149773B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a relay contact magnet used in a polar sealed relay, in which a porous sintered magnet 1 has a gas adsorbent 2 having gas adsorption ability such as activated alumina held on its surface. The present invention relates to a relay characterized in that a sintered magnet 1 is attached near relay contacts. Platinum-based metals such as Rh were often used for the contacts of low-load relays, but due to the catalytic activity of platinum-based metals, the organic gas present around the contacts turns into polymers, forming so-called brown powder. However, contact failures such as poor contact and increased contact resistance may occur, affecting the reliability and life of the relay. In particular, relays that are sealed with a case made of plastic material tend to be a problem because a relatively large amount of organic gas is generated from the molding material. Therefore, the permanent magnet (Ba
Attempts have been made to utilize the porous nature of ferrite magnets to adsorb internal organic gases, and this has been reported to have some effect on the reliability and lifespan of relays. However, commercially available
Ba ferrite magnets alone have small adsorption characteristics and have a limited effect on relay performance. The present invention has been made in view of the above points, and it is an object of the present invention to provide a relay that utilizes the gas adsorption property of a porous magnet and further improves the adsorption property of organic gas. It is. The present invention will be explained in detail below. A Ba ferrite magnet is used as the porous sintered magnet. In addition, as the adsorbent, one having excellent gas adsorption ability such as activated alumina, molecular sieve, and activated carbon is used. This adsorbent is pulverized to a diameter of about 1 μm, and this powder is mixed with a two-component epoxy resin (or adhesive). The resin with which the adsorbent powder is mixed is not limited to epoxy resin, and may be silicone resin or the like, but it is preferable to mix the resin:adsorbent at a ratio of 1:2. A mixture of resin 3 and adsorbent 2 is applied to the surface of porous sintered magnet 1 to a thickness of about 1 mm as shown in Fig.
The composite layer 4 of the resin 3 and the adsorbent 2 is laminated on the magnet 1 by drying and curing at a temperature of 2 to 3 hours. Thereafter, the surface of the composite layer 4 is polished with #800 emery paper to a thickness of about 0.2 mm. The magnet 1 having the adsorbent 2 laminated on its surface is installed, for example, in a polarized switching type reed relay as shown in FIG. In Figure 1, 5 is the terminal, 6 is the actuator, and 7
is a coil, and 8 is a plastic case that seals them. Therefore, the organic gas generated inside the relay is attracted to the porous magnet 1. Here, as shown in FIG. 1, the magnet 1 is placed near the relay contact consisting of the end of the terminal 5 and the tip of the actuator 6, and the organic gas that is likely to be generated around the contact is It is designed to be adsorbed efficiently. Note that the adsorption effect can be further enhanced by heating the adsorbent 2 in a vacuum and subjecting it to degassing treatment. As mentioned above, in the present invention, a gas adsorbent such as activated alumina is layered on the surface of the porous sintered magnet, so that the organic gas inside the relay and the porous magnet adsorb the gas. The adsorbent can supplement the adsorption performance of porous sintered magnets, which are strongly adsorbed by other adsorbents and have small adsorption properties, and can completely eliminate the influence of organic gases on relay performance. It is something. Moreover, the magnet is placed near the contacts inside the relay, and by the action of the magnetic field of the magnet, the charged particles in the arc generated from the contacts are quickly absorbed by the porous magnet and the gas. It can be adsorbed to the agent. Next, the present invention will be specifically explained using examples. Example 1 Activated alumina was ground into powder of approximately 1μ.
Degassing treatment was performed by heating to 250°C in a vacuum of 10 ^-5 Torr. This activated alumina powder was mixed in a two-component epoxy resin:activated alumina powder ratio of 1:2. Apply this mixture to the surface of the Ba ferrite magnet.
It was applied to a film thickness of mm and dried and cured at 90°C for 2.5 hours. Thereafter, the surface of the laminate was polished with #800 emery paper to give a film thickness of 0.2 mm. In this way
Activated alumina is layered on Ba ferrite magnet. This stuff contains cumene (C ₉ H ₁₂ ) as an organic gas.
An adsorption test was conducted in which the material was adsorbed for 5 minutes at 5200 ppm at 20°C. The results are as shown in Table 1.

[Table] 8 to 10 times the amount of adsorption was obtained compared to a conventional example using only a Ba ferrite magnet without stacking activated alumina. Example 2 A molecular sieve was laminated on a Ba ferrite magnet in the same manner, and the same adsorption test as in Example 1 was conducted. The results are shown in Table 2.

[Table] Example 3 Activated carbon was laminated on a Ba ferrite magnet in the same manner as in Example 1, and the same adsorption test as in Example 1 was conducted. The results are shown in Table 3.

【table】 [Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of a relay using the magnet of the present invention, FIG. 2a is a perspective view of the same magnet, and FIG.
Figure b is an enlarged sectional view of the same as above, where 1 is a magnet, 2
is an adsorbent.

Claims (1)

[Claims] 1 A gas adsorbent with gas adsorption ability such as activated alumina is held on the surface of a porous sintered magnet,
A relay characterized in that this sintered magnet is attached near relay contacts.