JPS6348376B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coaxial relay, and more particularly to a coaxial relay in which a reed switch and a coil are housed in a cylindrical body having a magnetic circuit function.

Coaxial relays used to connect/disconnect high-frequency signal transmission lines such as video signals and PCM signals have a similar configuration to coaxial lines in order not to impair the transmission characteristics of the signals. That is, it consists of a reed switch as an internal conductor, a cylindrical body as an external conductor, a reed switch driving coil, a magnetic case serving as a magnetic circuit for the coil, etc., and are arranged coaxially.

The conventional schematic configuration of such a coaxial relay is
Shown in side sectional view in the figure. In the figure, 1 indicates elastic lead pieces 11 and 12 made of a highly magnetic conductive material.
2 is a cylindrical external conductor made of a non-magnetic material such as copper (Cu) and open at both ends; 3 is fitted around the outer periphery of the external conductor 2, and a coil 4 is wound around it. The bobbin 5, which is a synthetic resin molded product, is a cylindrical case made of a highly magnetically conductive material that is open at both ends and is fitted around the outer periphery of the bobbin 3.

With the above configuration, reed piece 1 of reed switch 1
1 and 12 are connected to the inner conductor of a coaxial cable (not shown), and the outer conductor 2 is connected to the outer conductor, which is a braided wire of the coaxial cable, and when a current is applied to the coil 4 to excite it, the contacts of the reed switch 1 come into contact. Then, the internal conductor line of the coaxial cable connected to the lead pieces 11 and 12 is connected, and when the excitation current is cut off, the contact of the reed switch 1 is separated and the line is cut off.

The configuration of the above coaxial relay has an external conductor 2 disposed between the reed switch 1 and the bobbin 3, so the overall outer diameter is large and the size can be increased when a large number of coaxial relays are arranged in a certain space. do. Also,
Since the lead pieces 11, 12 and the outer conductor 2 are close to each other, there is a problem in that the electrostatic capacitance between them adversely affects the transmission characteristics.

The present invention aims to solve the above conventional problems, and for this purpose, a reed switch with a coil wound thereon is housed in a cylindrical body equipped with a magnetic circuit function for driving the reed switch. A novel coaxial relay is provided in which the lead piece is the inner conductor of the coaxial line and the cylinder is the outer conductor.

Hereinafter, the coaxial relay of the present invention will be described in detail with reference to the drawings.

Fig. 2 is a drawing for explaining one embodiment of the present invention, in which Fig. a is a side sectional view, Fig. b is a side sectional view of the cylinder, and Fig. c is an enlarged cross-sectional view of the part indicated by A in Fig. B. 1, and parts equivalent to those in FIG. 1 are given the same reference numerals. Reference numeral 6 denotes a cylindrical body made of a highly magnetic conductive material, with a plurality of protrusions 61 formed at the openings at both ends, and the entire surface of which is plated to improve conductivity.

To describe the coaxial relay having the above configuration in more detail, the cylindrical body 6 has a plurality of protrusions 61 formed in the openings at both ends for fixing the coil 4 and connecting to the external conductor of the external coaxial line. A cylindrical base body 62 consisting of Cu plating 63 and a
By applying Ag plating 64 to the entire surface, it has high electrical conductivity and high magnetic conductivity. A bobbin 3 around which a coil 4 is wound is fitted onto the outer periphery of a reed switch 1 from which lead pieces 11 and 12 are led out at both ends, and the cylindrical body 6 is fitted onto the outer periphery of this bobbin 3. Then, align the cylindrical body 6 with the recess provided on the end face of the bobbin 3.
The cylindrical body 6 is locked to the bobbin 3 by bending and engaging a part of the protrusion 61 . The remaining protrusions 61 serve as terminals for connection to an external conductor of an external coaxial line.

As is clear from the figure, the cylindrical body 6 covers the coil 4 and extends further in the length direction with a sufficient length.
The bent engagement protrusion 61 is connected to the lead pieces 11 and 12.
The magnetic circuit is constructed in a good shape. The reed switch 1 is adhesively fixed to the bobbin 3 with an adhesive (not shown), or alternatively, it may be fixed with an elastic body, such as a rubber plug, fitted to the end of the bobbin 3.

With the above configuration, coaxial cables (not shown) are arranged at both ends, and the outer conductor of the coaxial cable is soldered to the protrusion 61, which is a terminal of the cylinder 6, and the inner conductor is soldered to the lead pieces 11 and 12. In this way, the cylindrical body 6 of the coaxial relay functions as the outer conductor of the coaxial line, and the lead pieces 11 and 12 function as the inner conductors as well.

The coaxial relay of the present invention is not limited to being connected to a coaxial cable as described above, but for example,
A matrix switch can be constructed by connecting a coaxial relay to a matrix circuit pattern formed on two printed wiring boards arranged in parallel so as to be orthogonal between the printed wiring boards.
In this case, the signal on one printed wiring board is converted from the planar line transmission mode to the coaxial line transmission mode at the end of the coaxial switch, and then converted and transmitted back to the planar line transmission mode on the other printed wiring board.

By using the coaxial relay of the present invention in the matrix switch, the coaxial relays can be arranged in parallel at high density, making it possible to significantly reduce the overall size of the matrix switch.

Also, by energizing the coil 4, the lead piece 1
1 and 12 are excited, magnetic poles of opposite polarity are generated between their contacts, and they attract and attract each other, but the cylindrical body 6
Due to its magnetic conductivity, it becomes a large magnetic path, with similar magnetic poles at both ends, and because the entire diameter is small, the density of the magnetic field also increases. Bent engagement protrusion 6
Since the tip of lead piece 1 is close to lead pieces 11 and 12, the magnetic field from this protrusion 61
1 and 12 will be strongly affected.

The cylindrical body 6 functions as the outer conductor of the coaxial line, but this outer conductor has a ground potential, and since the lead pieces 11 and 12, which are the inner conductors, are connected to the lead pieces 11 and 12 via the coil 4, the distance between them is lower than in the past. Capacitance is low.

Note that the configuration of the coaxial relay is not limited to that of the above embodiment, and may be implemented in a self-holding type coaxial relay with a built-in permanent magnet, a two-way line switching type coaxial relay, and other coaxial relays to which the present technology is applicable. In addition, plating performed to ensure high conductivity of the cylindrical body is not limited to Ag, and other metals with good conductivity can be used. But that's fine.

As is clear from the above description, the coaxial relay of the present invention can be made smaller and lighter than the conventional coaxial relay, and the lead pieces 11 and 12 and the cylindrical body 6
Since the transmission characteristics can be improved by reducing the capacitance between the two, extremely significant effects can be obtained when applied to this type of coaxial relay.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of the schematic configuration of a conventional coaxial relay, and FIG. 2 is an embodiment of the coaxial relay of the present invention.
Figure a is a side sectional view, figure b is a side sectional view of the cylinder, and figure c is an enlarged sectional view of section A in figure b. In the figure, 1 is a reed switch, 2 is an outer conductor, 3 is a bobbin, 4 is a coil, 5 is a case, 6 is a cylinder, 11 and 12 are lead pieces, 61 is a projection, and 62
63 indicates copper plating, and 64 indicates silver plating.

Claims (1)

[Claims] 1. A reed switch with lead pieces drawn out on both sides, a reed switch driving coil wound around the outside of the reed switch, and a conductor connection part at both ends that covers the coil and is longer than the length of the wound coil. 1. A coaxial relay comprising a cylindrical body having magnetic permeability and electrical conductivity, wherein the lead piece serves as an inner conductor of a coaxial line, and the cylindrical body serves as an outer conductor.