JPH0727131U - Noise filter - Google Patents

Abstract

(57) [Abstract] [Purpose] In a noise filter in which a filter circuit is housed and formed using a metal case and lid, the case and lid can be easily attached and removed without soldering, and A noise filter with a good case and lid. [Composition] A case 2 made of a metal having an opening on one side and provided with a square hole 5 close to the edge of the opening, and a step 10 on the inner side on four sides with respect to the upper surface, with the tip being outward. Edge plate 8 having an outer peripheral edge larger than the inner dimension of the case and having elasticity.
Using the lid 1 provided with a claw 4 that is outwardly directed substantially orthogonal to the surface of the edge plate 8 and engages with the square hole of the case at the tip of the, the filter circuit is installed on the bottom surface of the case, Lock the claw of the lid into the square hole of the case and fit it.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a box-shaped noise filter having a large current capacity flowing in a power supply line, which is inserted into a primary side power supply line to prevent malfunction of an electronic device due to electromagnetic noise.

[0002]

[Prior art]

 As shown in FIG. 3, a conventional noise filter of this type has a metal case 2 containing a filter circuit for removing electromagnetic noise and a metal lid 1 fixed by soldering 3. When the lid 1 is soldered to the 2, the solder flows into the filter circuit, and on the other hand, the solder flow is bad and the solder is defective, the lid comes off from the case, and flux is used to remove the flux during soldering. Although a solvent that dissolves and removes is used, there is a problem that the solvent is harmful to the human body, and there is a drawback that workability is poor when assembly and repair are required.

[0003]

[Problems to be solved by the device]

 In order to eliminate these drawbacks, the present invention uses a mechanical combination, not soldering, to fix the case and lid of a box-type noise filter that uses a metal case and metal lid. The purpose is to provide a box-shaped noise filter that has a simple structure and is easy to attach and detach between the case and the lid.

[0004]

[Means for Solving the Problems]

 Square holes are provided on the four sides where the lid is assembled to the metal case that constitutes the box-type noise filter, edge plates are provided on the four peripheral surfaces of the lid, and the edge holes of the case are attached to the tip of the joint surface between the edge plate and the metal case. The edge plate provided on the lid at the joining surface between the metal lid and the metal case is provided with a step to the inside of the lid and slopes outward with an outer edge of the edge plate. There is a claw on the case.By locking the square hole of the metal case and the claw on the edge of the edge plate of the metal lid, the case and the lid can be attached without soldering the case and the lid. The feature is that it is a noise filter that can be easily attached and detached and fixed and that it is excellent in shielding electromagnetic noise.

That is, the present invention is a box-shaped case in which one side is opened by a metal plate, and a square hole is provided near the opening edge, and a metal plate fitted in the case is placed inside the outer dimension of the upper surface. An elastic edge plate is provided with a step so that the outer dimension is slightly downward from the four sides of the upper surface and the outer dimension is slightly larger than the inner dimension of the case, and the outer edge of the edge plate is approximately perpendicular to the edge plate surface. The lid is fitted with claws that engage with the square holes of the case that have cut grooves on both sides that are cut inward from the end face of the bent edge plate, and the filter circuit forming parts are stored on the inner bottom of the case. The noise filter is characterized in that the edge plate of the lid is housed in the inner wall of the cover, and the claws of the lid are engaged and fitted in the square holes of the case.

[0006]

[Action]

 On the four outer peripheral surfaces of the lid, the part in contact with the top surface of the lid has a step to stop the case when the lid and case are combined, and an edge plate inclined outward is provided, and it is attached to the top of the case side plate at the tip of the edge plate. The outer edge of the edge plate that locks into the square hole is fitted with claws that face outward at approximately right angles, and the edge surfaces of the edge plates on both sides of the claw are provided with cut grooves, so noise filter parts are mounted. By pushing the edge plate of the lid into the inner wall of the case from above into the metal case, the outer edge of the edge plate of the lid comes into close contact with the inside of the metal case due to the springiness of the edge plate of the lid, and Since the lid is stepped with respect to the upper surface of the lid, the lid stops on the upper surface of the case only by pushing it into the case, and the claw at the edge of the edge plate is locked in the square hole of the case. Lock and fit the lid and case.

When the lid is removed from the case, the claw of the lid locked in the square hole of the case can be easily removed by pressing the inside of the case with a jig. In addition, the notches that are cut inward from the end faces of the edge plates on both sides of the claw on both sides of the claw can straighten the end faces of the edge plate even if the claws are attached to the end faces of the edge plate. When mated, the edge of the lid edge plate is brought into close contact with the inner peripheral surface of the case to improve the electrical conductivity between the lid made of metal and the case, and to prevent electromagnetic noise from high-frequency radiation. Prevents the generation of induced voltage in the filter circuit.

[0008]

【Example】

 An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an external perspective view showing a case and a lid of a box type noise filter according to the present invention. The case is a metal case 2 solder-plated on a brass plate or the like, and a filter circuit is provided on two opposite surfaces. The terminal mounting round holes 6 for drawing out the input terminal and the output terminal are mounted, and the square holes 5 are mounted on the four surfaces near the opened upper surface.

Like the case 2, the lid 1 has a brass plate or the like whose surface is plated with solder or the like, and is provided with a step 10 inward from the upper surface toward the inner side of the upper surface. The edge plate 8 whose outer dimension was larger than the inner peripheral dimension of the case was attached to the four surfaces of the upper surface of the lid, and the edge of the edge plate was bent at an angle slightly smaller than 90 degrees to the edge plate surface. The claws 4 are attached, and on both side surfaces of the claws 4, cut grooves 7 cut inward from the outer edge of the edge plate 8 are provided.

FIG. 2 shows a plan view in which a filter circuit is incorporated in the case 2 and a side view in which the side plate on the side surface of the case is removed, and the magnetic core 13 is partitioned by a partition plate 15 and a partition plate 15 , A common choke coil having windings 14 in the same phase on both sides, a capacitor 17 on the input side of the common choke coil, a capacitor 18 between terminals 19 on the output side, and a terminal 20 on the ground side. 16 is connected to form a filter circuit, and the filter circuit and the case are insulated by an insulating film 12 that electrically insulates the circuit and the metal case, and the circuit is fixed to the case.

The lid 1 shown in FIG. 1 is inserted into the square hole 5 shown in FIG. 2 to form a noise filter. The edge plate 8 of the lid 2 is elastic, and the outer peripheral dimension of the edge plate 8 is made at least slightly larger than the inner dimension of the case 2, and there is a step between the upper surface of the lid and the edge plate. Therefore, by attaching the lid to the case and locking and fitting the square hole 5 of the case and the claw 4 of the lid 1, the lid will not come off from the case. The lid can be easily removed by pressing the claw inward with a jig.

[0013]

[Effect of device]

 A box type noise filter using a metal case and a lid according to the present invention has a square hole that engages with a claw provided with a lid on the case, and a step on the four peripheral surfaces of the lid with respect to the top surface of the lid. The edge plate is provided with its front end facing outwards, and the tip of the edge plate is attached with a claw that is bent and attached to the surface of the edge plate at an acute angle of more than 90 degrees, and the claws are provided on both sides of the claw. The edge of the plate and the inside of the case are in close contact with each other, and the filter circuit is sealed with a metal conductor, which is effective for shielding electromagnetic noise, and also an effect of a noise filter that makes it easy to attach and remove the case and lid. Have.

[Brief description of drawings]

FIG. 1 is an external perspective view showing the shapes of a case and a lid of a noise filter according to the present invention.

2A and 2B are views showing the internal structure of a noise filter of the present invention, FIG. 2A is a plan view, and FIG. 2B is a side view showing the inside without a side case.

FIG. 3 is an external perspective view showing a structure of a conventional box-shaped noise filter and a lid.

[Explanation of symbols]

 1 Lid 2 Case 3 Soldering 4 Claw 5 Square Hole 6 Terminal Mounting Round Hole 7 Cutting Groove 8 Edge Plate 10 Stepped 12 Insulating Film 13 Magnetic Core 14 Winding 15 Partition Plate 16, 17, 18 Capacitor 19 Input Terminal, Output Terminal 20 Ground terminal

Claims (1)

[Scope of utility model registration request] 1. A box-shaped case in which one side is opened by a metal plate and a square hole is provided close to the opening edge, and a metal plate fitted to the case is provided with a step inside the outer dimension of the upper surface. , An edge plate having elasticity with the outer dimension facing downward from the four sides of the upper surface and being slightly larger than the inner dimension of the case, and an edge bent outward at substantially the right angle to the edge plate surface at the tip of the edge plate. A lid with claws that are cut inward from the end face of the plate and has a notch on both sides, and a filter circuit forming component is stored on the inner bottom of the case, and the edge of the lid is attached to the inner wall of the case. A noise filter characterized in that a plate is housed and a claw of a lid is locked and fitted into a square hole of a case.