JPH03187297A - High frequency apparatus - Google Patents

Abstract

PURPOSE:To excellently shield a circuit board in a case body from outside a case by bringing a connection wall provided at the mounting part of the body at a soft cover into surface-contact with a reception wall. CONSTITUTION:A case body 1 is formed of conductive and hard metal, and has an opening 17. A cover 2 is so formed of the metal as to mount at a mounting part 21 formed at the peripheral edge of the opening 17 of the body 1. The part 21 of the body 1 is composed of a step formed at the peripheral edge of the opening 17, and the peripheral edge 26 of the cover 2 is mechanically brought into pressure contact with both a rising reception wall 23 of the part 21 and a connection wall 22 as a receiver to be electrically connected in a state that the cover 2 is mounted at the part 21 of the body 1. Thus, a circuit board in the body is excellently shielded from outside the case.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a high frequency device that handles television VHF, UHF signals, or SHF signals, and more specifically, electromagnetically shields the inside of its case and the outside of the case. Regarding high frequency equipment that has been made possible.

(Prior Art) The case of this type of high-frequency equipment has conventionally been composed of a case body and a lid body, each of which is made of an electrically conductive material. Circuit boards such as an amplifier circuit and a distribution circuit are installed inside the case body, and the opening of the case body is closed by a lid.

(Problems to be Solved by the Invention) In the conventional high-frequency equipment described above, when a lid is attached to the opening of the case body, electrical conduction between the lid and the main body is improved to connect the circuit inside the case body and the outside of the case. In order to provide good shielding, the opening of the case body is first covered with a metal mesh or a flexible thin copper plate, and then a lid is placed over it. However, in such conventional high-frequency equipment, the lid and the case body come into contact with each other at multiple points of contact, so while the above-mentioned shielding can be achieved well, it is very difficult to cover the opening of the case body with a mesh, and the lid body There is a problem with assembly efficiency in that it takes too much time to attach the case to the case body.

The present invention has been made to solve the above-mentioned conventional problems.Since the lid body and the case body are in surface contact with each other around the entire periphery of the lid body, the circuit inside the case can be well shielded from the outside of the case. The purpose is to provide excellent high-frequency equipment that can be easily assembled.

(Means for Solving the Problems) In order to achieve the above object, the present invention takes the measures as described in the claims above, and its effects are as follows.

(Function) A lid body is attached to the retaining wall and the receiving wall that are attached to the mounting portion on the periphery of the opening of the case body. The peripheral edge of the lid comes into pressure contact with both the locking wall and the receiving wall of the case body. That is, the mounting portion of the case body and the peripheral edge of the lid come into surface contact with each other. Therefore, the circuit board housed inside the case body is well shielded from the outside of the case.

(Example) The drawings showing the embodiments of the present application will be described below.

FIGS. 1 to 5 show a television communal reception distributor as an example of high-frequency equipment. 1 is the case body,
It is made by die-casting a hard and conductive metal such as zinc alloy. Purinel hardness (H, B) is 91
It is. As for the material of the case body 1, in addition to zinc alloy, various materials having hardness as shown in Table 1 can be used. Reference numeral 2 denotes a lid body, which is formed by punching out a soft metal plate with good conductivity, such as an aluminum plate, by press working. In this example, an aluminum plate with a thickness of 1.5WrIR and a material name of 1050-0 is used, but various other materials shown in Table 2 can be used. 3 is a circuit board, which is made by mounting electronic components 5 such as a distribution transformer on a printed circuit board 4.

The case body 1 will be explained in detail in Table 1, Table 2, and Table 2 below. Reference numeral 6 denotes fastening pieces that protrude from both side walls of the case body 1, respectively.

These fixing pieces 6 are formed at the same time when the case body 1 is molded, and each has a screw hole 7 in its center. Furthermore, a wood screw 8 is screwed into each screw hole 7,
Used to fix the distributor to a plate wall surface, etc. Reference numeral 9 denotes ground pieces, which are also protruded from both side walls of the case body 1, and are formed at the same time as the case body 1 is molded. These grounding pieces 9 are provided with screw holes 10 as clearly shown in FIG.
The ground conductor 13 such as a V wire can be tightened and fixed. Next, 14 is an input terminal, and 15 is an output terminal, each of which uses a coaxial connector seat.

The outer conductor 16 of each terminal 1.4.15 is integrally formed when the case body 1 is molded. 17 is the opening of the case body 1, 18 is the bottom wall of the case body 1, and 19 is the bottom wall 18.
The circuit board fixing seats protruding from the bottom are shown. The case body 1 and the circuit board 3 are attached to the tip of each circuit board retaining seat 19.
A protruding piece 20 is provided so that it can be connected and fixed to a ground conductor by soldering. Next, 21 is the lid body 2
A stepped portion 35 provided on the inner peripheral edge of the opening 17 in the mounting portion of the
It is formed of. Attaching part 2], 22 indicates a retaining wall, and 23 indicates a receiving wall.

Next, to explain the lid body 2, 24 is the surface of the lid body 2,
25 indicates the back side. Reference numeral 26 indicates the four circumferential edges of the lid body 2.

Next, the assembly of the distributor having the above configuration will be explained. (a) A lid body 2 is prepared by stamping a soft metal plate into a rectangular shape by press working. This lid body 2 has a surface 24 from which the edges protrude around the periphery.

(b) Form the case body 1 by die-casting.

At this time, the bottom wall 18, the circuit board fixing seat 19, the retaining wall 22, and the receiving wall 23 are also formed at the same time.

(c) Taps are cut in the cylindrical body forming the outer conductor 16 of each terminal 14, 15 of the case body to form a male thread. In addition, taps are cut in the through holes drilled in the fixing piece 6 and the grounding piece 9 to form the screw hole 7 and the screw hole 10 in the case body 1.
Insulator markings that hold the center conductor 27 of the terminal are inserted into the inside of each outer conductor 16 from the inside of the case body 1.

(e) Electronic components 5 such as a distribution transformer are assembled on the printed circuit board 4 to complete the circuit board 3. Note that this step (e) is not necessarily performed after the step (d), but may be performed in advance.

(to) Insert the circuit board 3 into the case body 1 from the opening 17 side.
and fix the soldering using the protruding piece 20 of the circuit board fixing seat 19. Further, each center conductor 27 of the input terminal 14 and output terminal 15 and the circuit board 3 are connected by soldering or the like.

(g) The lid 2 is attached to the attachment part 21 provided at the periphery of the opening 17 of the case body 1. In this case, first of all, see Figure 5 (
As shown in A), the lid 2 is placed on the opening 17 of the case body 1 placed on a lower mold (not shown). As is clear from the figure, the tapered portion 2 provided on the open end side of the retaining wall 22
The lid body 2 is now placed on 9. Next, the lid body 2 is pushed downward toward the case body 1 from above using the upper mold 30. Then, as shown in FIG. 5(B), the back surface 25 of the peripheral edge 26 of the lid 2 comes into contact with the protrusion 31 of the receiving wall 23.

When the upper mold 30 is further pushed downward from the state shown in FIG.
1 bites in, the peripheral edge 26 of the soft lid 2 advances along the slope of the receiving wall 23 in the X direction in FIG. do. The lid body 2 is pressed against the locking wall 22 and the receiving wall 23 so that the lid body 2 is soft.Finally, the wood screws 8 and the tightening screws 11 are attached to complete the distributor.

In addition, when each dimension shown in FIG. 5(A) is shown, the receiving wall 23
The width W1 is 1.05 mm, and the height Hl of the protrusion 31 is Q, 8
m, the height H2 of the retaining wall 22 is 2.1cm, the width W of the upper die 30 is
2 is 2. Off.

The distributor assembled in the above manner has the peripheral edge 2 of the lid 2.
6 comes into complete surface contact with both the retaining wall 22 of the case body 1 and the receiving wall. This means that the circuit housed inside the case body 1 and the outside can be well shielded over a wide frequency band. By the way, in the case of this distributor, the loss in terms of signal leakage characteristics, which represents the shielding effect, is 13% over the frequency band of 90 to 770 MHz.
A good result of 0 dB or more was obtained.

Next, FIG. 6 shows different examples of upper molds used when attaching the lid body 2 to the case body 1.

Items with the same or equivalent functions as the previous time will be indicated with the same reference numeral and the letter e, and redundant explanations will be omitted. show). By using the upper die 30e in this example, the electrical and mechanical connection between the lid body 2 and the case body 1 can be made closer.

Next, FIG. 7 shows a BS converter exemplified as a high frequency device. In this example, the mounting part is on the case body 1f.
are provided on both sides, and a lid body 2f of the same shape is attached to each side. 33 is a flange to which a primary radiator is connected, and 34 is a waveguide for signal input.

(Effects of the Invention) As described above, in the present application, since the retaining wall and the receiving wall provided at the attachment part of the case body are in surface contact with the soft lid body, television VHF and UHF signals can be transmitted. Furthermore, even in high-frequency equipment that handles high-frequency waves such as SHF signals, the high-frequency circuit inside the case body can be effectively shielded from the outside of the case.

Moreover, even if the shielding characteristics are good,
Since there is no need to prepare any other members other than the case body and the lid for the shield, there is also the effect that it can be provided at low cost.

Furthermore, assembling the device is as simple as fitting the lid into the mounting area around the opening of the case body, making it highly suitable for mass production, which also means that inexpensive high-frequency devices can be provided. are doing.

[Brief explanation of drawings]

The drawings relate to embodiments of the present application, and FIG. 1 is a front view of a distributor exemplified as a high-frequency device, FIG. 2 is a partial sectional view taken along the line ■-■ of FIG. 3 is a partial cross-sectional view of the line 1 in FIG. 1, FIG. 4 is an exploded perspective view of the distributor, and FIG. 5(A). (B) and (C) are cross-sectional views showing the process of attaching the lid to the case body, Fig. 6 is a view showing different examples of the upper mold, and Fig. 7
The figure is an exploded perspective view of a BS converter exemplified as a high-frequency device. DESCRIPTION OF SYMBOLS 1... Case body, 2... Lid body, 3... Circuit board, 17... Opening part, 21... Mounting part, 22... Latching wall, 23... Reception wall , 24... surface, 25...
Back side, 26...periphery.

Claims (1)

[Claims] A case body made of a hard metal with good conductivity and having an opening, and a soft metal with good conductivity to be attached to a mounting part provided around the opening of the case body. The mounting portion of the case body is comprised of a stepped portion provided around the inner periphery of the opening, and when the lid body is mounted on the mounting portion of the case body, the mounting portion of the case body is A high frequency device characterized in that a peripheral edge of the lid body is mechanically pressed against both a rising receiving wall and a retaining wall serving as a receiving portion, and the two are also electrically connected.