JPS6348042Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to high-frequency switches such as switches and electromagnetic relays that open and close high-frequency signals.

Generally, high-frequency switches that open and close high-frequency signals are required to have high isolation between a movable contact piece and a fixed terminal.

In order to satisfy this requirement, in the past, when the movable contact piece is in an open state with respect to the fixed terminal, the distance between the fixed terminal and the movable contact piece is large, and the movable contact piece in this open state is grounded. This reduces the electrostatic coupling and electromagnetic coupling between the movable contact piece and the fixed terminal, and reduces the leakage of high frequency signals between them.

However, when the movable contact piece is grounded, if a potential difference occurs between the ground contact and the ground circuit of the mounted device, sufficient characteristics such as isolation between the contacts cannot be obtained. Conventionally, a shield case was made by die casting or hollowing out metal, and a movable contact piece was brought into contact with this shield case. However, this requires a large number of man-hours to process the shield case, making it difficult to manufacture it at a low cost.

The object of this invention is to provide a high frequency switch that has a simple and inexpensive structure and can provide high isolation between contacts.

This invention will be described below with reference to an illustrated embodiment.

FIG. 1 is a plan view showing a high-frequency electromagnetic relay, FIG. 2 is a sectional view taken along line A--A in FIG. 1, and FIG. 3 is a schematic exploded perspective view.

A housing is composed of a box-shaped case 1 and a cover 2 made of synthetic resin, and the case 1 is provided with a recess 1a that is surrounded by side walls and forms one room. Three rod-shaped fixed terminals 3, 4, and 5 are placed in the recess 1a, and their contact portions 3a, 4a, and 5a are placed inside the case 1, and the terminal portions 3b and
4b and 5b are fixed through the case 1 so as to protrude outside of the case 1. The ground pieces 6 and 7 are formed by bending metal plates into a U-shape and having a pair of screen parts 6b and 7b, and the ground terminal parts 6a and 7a formed by the bending are connected to the case. It penetrates through holes 1b and 1c formed in the recess 1a of No. 1 and protrudes to the outside of the case. Earth contact portions 6c and 7c are formed protruding from the screen portions 6b and 7b, respectively. These ground pieces 6, 7 and the fixed terminal 3,
4 and 5 are arranged on a straight line in the longitudinal direction of the case, and the width of the grounding pieces 6 and 7 is made larger than that of the fixed terminal to improve isolation characteristics between the fixed terminals. . The shield case 8 is formed by bending a metal plate into a U-shape.
It is inserted and fixed inside. The cards 9, 10 are slidably supported by guide grooves 1d, 1e formed in the case 1.
Movable contact pieces 11 and 12 are fixed approximately at the center of each. Both ends of the movable contact piece 11 are contactably opposed to the fixed terminals 3 and 4, and both ends of the movable contact piece 12 are contactably opposed to the fixed terminals 4 and 5. In addition, the movable contact pieces 11 and 12
Four windows 8c are formed in the side walls 8a, 8b of the shield case 8 facing the contact portions 11a, 11a, 12a, 12a, and the windows 8c are connected to the grounding pieces 6, 7 from each of the windows 8c. Ground contact portions 6c and 7c protrude from one side of the movable contact. The shield cover 13 is formed by bending a metal plate into a U-shape, and is combined with the shield case 8 so as to cover the three open sides of the shield case 8, and is attached to the side walls 8a, 8b of the shield case 8. The formed locking pieces 8d, 8d are attached to the shield cover 1.
3, the two are integrated to form a shield housing. An electromagnet consisting of an iron core 14, a coil 15, a spool 16, a yoke 17, a movable iron piece 18, and a return spring 19 is fixed in the recess 1f of the case 1. The return spring 19 is clamped at its base by the yoke 17 and the protrusion 1g of the case 1, and the pressing piece 19 at the free end
A is brought into pressure contact with the movable iron piece 18 which is hingedly supported by the yoke 17, thereby applying a restoring force to the movable iron piece 18. Both ends of the connecting plate 20 are fitted into the holes 9a and 10a of the cards 9 and 10, so that the cards 9 and 10 are interlocked. A hole 21a is formed in the center of the spring plate 21, and openings 21b, 21b are formed on both sides of the hole 21a.
This spring plate 21 is held in the case 1 by fitting the holes 21a into the protrusions 20a at both ends of the connecting plate 20, and pressing the both ends against the protrusions 1h, 1h on both sides of the case 1 so as to bend the whole. has been done.

Next, the operation of the high frequency electromagnetic relay constructed as described above will be explained.

When the coil 15 is de-energized, the movable iron piece 18 is in the return position as shown in FIG.
is urged upward by the spring force of the spring plate 21 transmitted via the connecting plate 20. Therefore, both ends of the movable contact piece 11 are in contact with the ground contact portions 6c, 6c of the ground piece 6, and the fixed terminals 3, 4 are in an open state. In addition, the movable contact piece 1
2, its contact portions 12a, 12a are fixed terminals 4, 5
The fixed terminals 4 and 5 are in a closed state.

When the coil 15 is energized in this state, the movable iron piece 18 rotates clockwise and presses the connecting plate 20 downward against the spring force of the spring plate 21. As the connecting plate 20 descends, the cards 9 and 10 also descend, and the contact portions 11a and 11a of the movable contact piece 11 are connected to the contact portions 3a and 4a of the fixed terminals 3 and 4, and the contact portions 12a and 12a of the movable contact piece 12 are connected to the contact portions 3a and 4a of the fixed terminals 3 and 4, respectively. 12a contacts the ground contact portions 7c, 7c of the ground piece 7, respectively. Therefore, the fixed terminals 3 and 4 are closed, and the fixed terminals 4 and 5 are opened. And coil 15
When the energization is stopped, the movable iron piece 18 is returned to its initial position by the spring force of the return spring 19, and the cards 9 and 10 are returned to their initial positions by the spring force of the spring plate 21.

With the above configuration, when fixed terminals 3 and 4 or between 4 and 5 are in an open state,
The movable contact piece 11 or 12 is the ground contact part 6
Contact with c, 7c. And this earth contact part 6
c and 7c are integrally formed on the ground pieces 6 and 7 and protrude from the window 8c of the shield case 8; Parts 6a, 7a
The same potential is ensured. Therefore, there is no risk of high frequency signals leaking through the movable contact piece 11 or 12 and causing the fixed terminals 3, 4 or 4, 5 to be in a closed state, and high isolation can be obtained. Moreover, the grounding pieces 6, 7 and the shield housing are not formed by hollowing out or die-casting a metal material such as brass, but are formed by pressing and bending a metal plate, and the grounding contacts 6c, 7c are also made of grounding pieces. Since the protrusions are formed by press working from 6 and 7, the processing cost and material cost are low and it is suitable for mass production.Moreover, the dimensional accuracy of the ground contact parts 6c and 7c can be improved, and the movable contact pieces 11 and 12 contact reliability can be improved.

As is clear from the above description, according to this invention, the movable contact piece that is in an open state with respect to the fixed terminal is formed to protrude from the ground piece made of a metal plate,
Since the movable contact piece was grounded by contacting it with the ground contact protruding from the window of the shield housing,
It is possible to prevent a potential difference between the ground contact portion and the ground terminal portion provided integrally with the ground piece, contributing to improvement of isolation characteristics. Also, it is only necessary to plate the ground contact with gold, but in reality, since the parts are small, it is difficult to plate only this part, and the entire member on which the ground contact is installed must be plated with gold, but this ground piece It only needs to be small as a whole, so even if the whole thing is plated with gold, it won't be expensive. As described above, it has a simple structure and can be manufactured at low cost.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway plan view showing a high-frequency electromagnetic relay that is an embodiment of this invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1, and Fig. 3 shows the main parts of this invention. It is an exploded perspective view. 1...Case, 2...Cover, 3, 4, 5...
Fixed terminal, 6, 7...Earth piece, 6c, 7c...
Earth contact section, 8... Shield case, 11, 1
2...Movable contact piece, 11a, 12a...Contact part,
13...Shield cover.

Claims (1)

[Scope of utility model registration request] A resin base having a recess surrounded by side walls to form one room, a pair of fixed terminals provided in the recess, and movable within the recess so as to contact and separate from the fixed terminals. a contact circuit consisting of a movable contact piece disposed in the movable contact piece; a ground contact part fixed in the recess so as to be located on the opposite side of the fixed terminal in the moving direction of the movable contact piece; and a ground contact part protruding outside from the base. The contact circuit has a grounding piece integrally formed with a grounding terminal portion, and a window inserted and fixed in the recess so as to be in contact with the grounding piece, from which the grounding contact portion projects. A high frequency switch characterized by comprising a shield case surrounding the.