JP2004342398A - Electromagnetic relay - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a tightly sealed electromagnetic relay mounted on a substrate as an onboard use to maintain its airtightness inside even with repeated heat stress action. <P>SOLUTION: In the airtight electromagnetic relay 1 with a cover 2, a terminal 3 and a base 4 adhered and fixed with a sealant 6, a notched part 5 is provided at a corner part 7 of the cover 2, and the sealant 6 is injected in the notched part 5 for adhesion and fixing. With this, an expansion and contraction deformation of the corner part 7 of the cover 2 is restrained when the heat stress repeatedly acts on the electromagnetic relay 1, which prevents an interface exfoliation between the cover 2 and the sealant 6 and enables the electromagnetic relay 1 to maintain its airtightness. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electromagnetic relay, and more particularly, to a hermetically sealed electromagnetic relay mounted on a board, which is suitable for use in vehicles and the like.
[0002]
[Prior art]
FIG. 3 shows an example of a conventional sealed electromagnetic relay. As shown in FIG. 3, the hermetic electromagnetic relay 15 adheres and fixes the cover 16, the base 18, and the terminal 17 with a sealant 19.
[0003]
Patent Literature 1 and Patent Literature 2 are examples of prior art of a closed electromagnetic relay. These documents describe an electromagnetic relay sealed with a cover, and Patent Literature 2 describes a technique that particularly focuses on a sealing operation (injection of a sealant). However, Patent Literature 1 and Patent Literature 2 do not describe a technique relating to prevention of peeling of a cover and a sealant.
[0004]
[Patent Document 1]
JP-A-6-150798 [Patent Document 2]
JP-A-7-085760
[Problems to be solved by the invention]
Generally, in order to confirm whether the sealed electromagnetic relay is of a quality that sufficiently satisfies the customer's trust, solder heat stress when mounting on the board or use environment is assumed, and the severer condition of -40 ° C To + 125 ° C. repeatedly to check whether the hermeticity is maintained.
[0006]
The cover 16, the terminals 17, and the base 18 constituting the electromagnetic relay 15 are bonded and fixed by a sealant 19. When such severe cooling / heating stress repeatedly acts on the electromagnetic relay 15, the cover 16 as a component also repeats expansion and contraction. At this time, a stress is generated between the interfaces due to a difference in thermal expansion coefficient between the cover 16 and the sealant 19. When the stress repeatedly acts, the adhesive strength between the cover 16 and the sealant 19 cannot be endured, and minute separation occurs between the interfaces. Further, there has been a problem that the peeling grows by repeatedly applying the thermal stress, and it is finally impossible to maintain the hermeticity. Here, the place where peeling occurs is the corner portion 20 where the stress is concentrated most.
[0007]
Therefore, an object of the present invention is to provide an electromagnetic relay which can prevent the cover and the sealant from peeling off and can maintain hermeticity.
[0008]
[Means for Solving the Problems]
The hermetic electromagnetic relay of the present invention for bonding and fixing the cover, the base and the terminal with a sealant has a notch at one or more corners of the cover, and the sealant is injected into the notch. ing.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, the present invention will be described with reference to the drawings.
[0010]
FIG. 1A is a perspective view before injecting a sealant according to one embodiment of the present invention, and FIG. 1B is a view after injecting a sealant according to one embodiment of the present invention. It is a perspective view. As shown in FIG. 1, the cover 2, the terminal 3, and the base 4, which are components of the electromagnetic relay 1, are adhered and fixed by a sealant 6 and hermetically closed.
[0011]
The electromagnetic relay 1 of the present embodiment has a structure in which each corner 7 of the cover 2 has three cutouts 5 at each corner, and a sealing agent 6 is injected into the cutout 5 and bonded and fixed. I have. In this embodiment, the cutouts 5 are provided at all corners. However, it is more reliable to provide the cutouts at all corners where peeling is possible. Even if a notch is provided, the effect of preventing peeling is recognized.
[0012]
FIG. 2A is a perspective view before injecting a sealant according to the second embodiment of the present invention, and FIG. 2B is a perspective view before injecting a sealant according to the second embodiment of the present invention. It is a perspective view showing after performing. As shown in FIG. 2, the cover 9, the terminals 10, and the base 11, which are components of the electromagnetic relay 8, are adhered and fixed by a sealant 13 and hermetically closed. The electromagnetic relay 8 of the present embodiment has a cutout 12 at each corner 14 of the cover 9, and has a structure in which the sealing agent 13 is injected into the cutout 12 and bonded and fixed. . In the second embodiment, since the corner has one notch, the sealing agent can be easily injected.
[0013]
As the first embodiment, the second embodiment, and the comparative example, 50 conventional closed-type electromagnetic relays shown in FIG. 3 were prepared, and after performing a cooling / heating cycle, an appearance inspection was performed. The conventional sealed electromagnetic relay of the comparative example does not have a cutout for injecting the sealant 19 into the corner 20 of the cover 16. The first embodiment, the second embodiment, and the comparative example were manufactured in the same shape except for the difference in the notch at the corner of the cover, and were manufactured under the same conditions, such as injection of a sealing agent.
[0014]
The cooling / heating cycle was carried out in a pattern in which a test sample was put in an environmental test tank, and the temperature setting at −40 ° C. and + 125 ° C. was alternately switched every 30 minutes. As a result of the appearance inspection, in the case of the comparative example, a gap of 7/50 was found at the corner of the cover due to the peeling off of the sealant. However, in the first and second embodiments of the present invention, both of them were used. In both cases, no peeled (0/50) was observed.
[0015]
As shown in the above thermal cycle test results, the electromagnetic relay in which the sealing agent of the present invention was injected and bonded and fixed was provided with cutouts at the corners of the cover, so that the cover corner when thermal stress was applied was formed. Because the expansion and contraction deformation of the part is suppressed, it is assumed that the separation between the cover and the sealant interface is prevented, and the long-term sealing performance is improved and the reliability is higher than the conventional electromagnetic relay. Become.
[0016]
【The invention's effect】
As described above, the electromagnetic relay of the present invention is provided with a notch at a corner of the cover, and by injecting and sealing a sealant, even when the electromagnetic relay is repeatedly subjected to cold / heat stress, the cover and the cover are not removed. There is an effect that peeling between sealant interfaces hardly occurs, a long-term sealing property is improved, and reliability is high.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an electromagnetic relay according to a first embodiment of the present invention, FIG. 1A is a view showing a state before a sealant is injected, and FIG. The figure which shows the state after injection | pouring.
FIG. 2 is a perspective view showing an electromagnetic relay according to a second embodiment of the present invention, FIG. 2 (a) is a view showing a state before a sealant is injected, and FIG. The figure which shows the state after injection | pouring.
FIG. 3 is a perspective view showing a conventional sealed electromagnetic relay.
[Explanation of symbols]
1, 8, 15 Electromagnetic relays 2, 9, 16 Covers 3, 10, 17 Terminals 4, 11, 18 Base 5, 12 Notch 6, 13, 19 Sealant 7, 14, 20 Corner

Claims (1)

In a sealed electromagnetic relay for fixing a cover, a base, and a terminal with a sealant, the cover has a notch at one or more corners, and the sealant is injected into the notch. An electromagnetic relay characterized by the following.

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