JPS6348044Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a high frequency switch such as a high frequency electromagnetic relay.

In high-frequency switches, it is necessary to improve isolation characteristics by preventing electrostatic or electromagnetic coupling between open terminals, but conventional switches have a complicated structure and cannot be manufactured at low cost. It was hot.

In view of the above, the object of the present invention is to provide a high frequency switch that has a simple structure, can be manufactured at low cost, has excellent isolation characteristics, and can prevent contact failure in the contact circuit. shall be.

Hereinafter, an embodiment in which the present invention is applied to an electromagnetic relay will be described with reference to the drawings. As shown in FIGS. 1 and 2, the base 1 is molded from synthetic resin, and has two recesses 11 and 12 each having side walls formed around them, and a partition wall 13 between these recesses 11 and 12. is formed. The recess 11 is for accommodating an electromagnet, and the recess 12 is for accommodating a contact circuit. A coil frame 22 in which an iron core 21 is inserted into the recess 11, a coil 23 wound around this coil frame 22, a yoke 24, and a movable iron piece 25 supported by a hinge such that it can rotate freely at the tip of this yoke 24. An electromagnet is housed in the base 1.
The yoke 24 is attached with an L-shaped fixture 26 press-fitted into the bottom of the yoke 24.
is maintained by being fixed. Rod-shaped coil terminals 27, 27 that protrude through the bottom surface of the base 1 are provided at the ends of the coil frame 22, and both ends of the coil 23 are connected to the coil terminals 27, 27.

This recess 11 is further provided with protrusions 14, 14 that protrude inward from the side wall.
4 and 14 are engaged with both ends 31 and 31 of the frame portion of the leaf spring 3. The other end of the movable iron piece 25 is adapted to press the center of the leaf spring 3, and the tongue pieces 32, 32 provided at the center of the leaf spring 3 engage the cards 4, 4 made of insulating resin. They are engaged with the holes 41, 41, respectively. Movable contact pieces 5, 5 are inserted into the cards 4, 4, respectively, and the cards 4, 4 are slidably arranged in cutouts provided in the partition wall 13, respectively.

A conductive film is formed on the entire surface of the base 1, including the inner circumferential surfaces of the recesses 11 and 12 of the base 1 and the outer circumferential surface of the base 1, by metal plating, vapor deposition, painting, or the like. Note that this conductive film is formed on at least the entire inner surface of the recess 12 and the entire outer peripheral surface of the base 1,
It is sufficient that these are continuous, and the formation of the conductive film can be omitted in other parts. Insulating member 6 to be insulated from this conductive coating
Fixed terminals 61, 62, 6 via 4, 65, 66
3 is placed in the recess 12. That is, in advance,
Fixed terminals 61, 62, 63 made of rod-shaped metal are inserted through insulating members 64, 65, 66, respectively, and these insulating members 64, 65, 66 are fitted into holes provided in the bottom of recess 12 and fixed. do. In this fixed state, the fixed terminals 61, 62, 63
penetrates the bottom surface of the base 1 and protrudes to the outside, and stands upright in the recess 12 from the bottom surface.
Since protrusions are previously formed on the inner surface of the recess 12, four protruding earth contacts 15 are formed by applying a conductive film to the protrusions. In this way, the fixed terminal 61 is inserted into the recess 12.
63 and the movable contact pieces 5, 5 constitute a contact circuit, and since the inner surface of the recess 12 is covered with a conductive film, this film acts as a shield case. Although not shown, a synthetic resin protrusion that protrudes outward from the bottom surface of the synthetic resin base 1 is integrally provided, and a conductive coating is also formed on the outer surface of this protrusion. If the conductive coating is made to be continuous with the conductive coating on the outer peripheral surface of the base 1, the conductive coating on this protrusion will also be continuous with the conductive coating on the inner surface of the recess 12, which functions as a shield case. The protrusion coated with this conductive coating can be used as a ground terminal. If such a ground terminal is not provided, an appropriate location on the outer peripheral surface of the base 1 on which the conductive film is formed will be connected to the ground of the circuit in which this electromagnetic relay is mounted.

Then, a cover 7 is attached to this base 1.
The cover 7 has a partition wall 71, and this partition wall 71
By joining the lower surface to the upper surface of the partition wall 13 of the base 1, the recess 11 and the recess 12 are completely isolated. Furthermore, since the partition wall 71 closes the opening of the notch, it also functions as a stopper for preventing the cards 4, 4 from coming off. In this way, the contact circuit, which does not like dust, can easily generate dust due to the movement of the movable iron piece 25, and dust can easily enter from the outside (because the electromagnet generates heat, holes for heat radiation may be provided).
It can be isolated from the electromagnet, and the occurrence of contact failure in the contact circuit can be reduced. If a conductive film is also provided on the inner surface of the cover 7, the contact circuit will be completely surrounded by the conductive film on the inner surface of the recess 12, thereby making the electromagnetic and electrostatic shielding more complete. You can, but
The contact circuit can be separated from the electromagnet simply by shielding the inner surface of the recess 12 of the base 1 with the conductive coating, so that a certain shielding effect can be obtained.

When the coil 23 is energized in this configuration, the movable iron piece 25 is attracted to the iron core 21 and pushes the center portion of the leaf spring 3, causing the leaf spring 3 to bend. Then card 4,
4 moves upward (in FIG. 1), the movable contact piece 5 separates from the fixed terminals 61 and 62, and the other movable contact piece 5 contacts the fixed terminals 62 and 63 to short-circuit them. When the coil 23 is de-energized,
Due to the restoring force of the leaf spring 3, the cards 4, 4 return downward (in FIG. 1), and the movable contact piece 5 connects to the fixed terminal 6.
1 and 62 to short-circuit them, and the other movable contact piece 5 separates from the fixed terminals 62 and 63 to open the space between them. When both the movable contact pieces 5, 5 are in the open state, they contact the ground contact 15 provided on the side surface of the recess 12 and are grounded, so that a static current is established between the fixed terminals in the open state via the movable contact pieces 5. Electrical or electromagnetic coupling can be prevented, and isolation characteristics are improved.

As explained above, according to the present invention, by forming a conductive film on the inner surface of the concave portion of the base, a ground contact is created with which the movable contact piece in the open state comes into contact, and it also acts as a shield case. Therefore, it has a simple structure, is easy to manufacture, and can be manufactured at low cost. Further, since the recess for the contact circuit and the recess for the electromagnet are closed and the contact circuit is isolated from the electromagnet, it is possible to reduce the occurrence of contact failure in the contact circuit.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an electromagnetic relay according to an embodiment of the present invention with the cover removed, and FIG. 2 is an exploded perspective view of the main parts. 1...Base, 15...Earth contact, 21...
Iron core, 22... Coil frame, 23... Coil, 25
...Movable iron piece, 3...Plate spring, 4...Card, 5
...Movable contact piece, 61-63...Fixed terminal, 7...
…cover.

Claims (1)

[Scope of utility model registration request] An electromagnet and a contact circuit are housed in two recesses provided in the base, each having a side wall around the periphery, and a card that transmits the movement of the electromagnet to the movable contact piece of the contact circuit is mounted on the partition wall between the two recesses. The card is slidably arranged in the cutout provided, and the two recesses are closed by a cover attached to the base to isolate the electromagnet and the contact circuit, and the opening of the cutout is closed to remove the card. A protrusion is provided on the side wall of the contact circuit storage recess to prevent the contact circuit from falling out, and the entire inner surface of the recess, including the protrusion, is conductive and electrically connected to the conductive coating formed on the outer surface of the base. A high frequency switch having a shield case formed by forming a film, and further comprising a conductive film on the protrusion serving as a protruding ground contact that comes into contact with a movable contact piece in an open state.