JP2006093464A - Wiring board ground structure and refrigerator equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ground structure for preventing a wiring board from being damaged even if a lead wire for grounding is abolished.
SOLUTION: A conductor 23 electrically connected to a wiring board 20 with a through-hole 24 and a printed earth circuit pattern 27 and extended at least to the vicinity of the through-hole 24; The holding member 10 is provided with a protruding portion 14 through which the through hole 24 is inserted from the back surface of the wiring board 20 and whose upper end surface 16 protrudes from the upper surface of the wiring board 20. The fixing member 25 was inserted into the protruding portion 14, the upper portion thereof was brought into contact with the upper end surface 16 of the protruding portion 14 or through the conductor 23, and the lower portion was fitted into the main body 2.
[Selection] Figure 1

Description

  The present invention relates to a grounding structure of a wiring board.

  The wiring board for controlling the refrigerator is conventionally attached to the back of the outer box made of conductive steel plate, and is grounded by screwing the lead wire electrically connected to the wiring board to the outer box. In this case, however, a lead wire and a mounting process thereof are separately required for grounding.

  For this reason, the earth structure which abolished the said lead wire is considered, FIG. 8, FIG. 9 has shown the example (for example, patent document 1). FIG. 8 is an exploded view showing a conventional earth structure, and FIG. 9 is a longitudinal sectional view thereof. A conductive casing 50 has a flange portion erected upward to hold and fix the wiring board 54. 51 and a hole 52 drilled in the flange portion 51. The wiring board 54 on which the electronic component 55 is mounted is provided with a ground pattern 56 on the back surface, and the mounting hole 57 and the through hole 58 are provided. It is drilled. Reference numeral 60 denotes a ground plate, which has a pair of terminal pieces 62 extending downward on the left and right ends of a circular flange portion 61 and a through hole 64 at the center of the flange portion 61. In this case, the terminal piece 62 is inserted into the mounting hole 57 and mounted by solder 59 as shown in FIG.

  A screw 65 passes through the through holes 64 and 58, and screw threads of the screws are fitted into the holes 52. For this reason, the wiring board 54 is attached and fixed to the flange portion 51 of the housing 50, and the dew portion of the screw 65 is connected to the peripheral portion of the through hole 64 of the ground plate 60 in a conductive relationship.

For this reason, the ground structure of the wiring board 54 is constructed by electrically connecting the ground plate 60, the screw 65, and the hole 52 in order from the ground pattern 56 only by inserting the screw 65. The attachment process can be performed simultaneously.
JP-A-8-56086

  However, in the above configuration, an electric appliance such as a refrigerator may be subjected to an impact during installation or carry-in, and if the wiring board 54 is firmly fixed to the housing 50 with a screw 65 or the like, the impact is exerted. When the main body is deformed in response, the stress acts on the inflexible substrate and may be damaged.

  The present invention has been made paying attention to this point, and an object of the present invention is to provide a grounding structure that prevents damage to the wiring board even if the grounding lead wire is eliminated.

  In order to solve the above problems, an earth structure according to the present invention includes a conductive main body, a non-conductive holding member attached to the main body, a wiring board held by the holding member and mounted with electronic components, The wiring board includes a through hole, a conductor that is electrically connected to the printed ground circuit pattern and extends to at least the vicinity of the through hole, and a fixing that is in electrical contact with the conductor. A member is provided, and the holding member is provided with a projecting portion through which the through-hole is inserted from the back surface of the wiring board, and an upper end surface of the holding member projects from the upper surface of the wiring substrate. The upper part of the protrusion is in contact with the upper end surface of the protrusion or through the conductor, and the lower part is inserted into the main body.

  According to the present invention, since the wiring board is not fixed by the fixing member, damage to the board can be prevented and a ground circuit can be constructed through the conductor by attaching the fixing member. Can be abolished, and an earth structure excellent in assembly workability can be provided.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 7 is a rear view showing a state in which the wiring circuit cover of the refrigerator according to the present invention is removed, FIG. 1 is a cross-sectional view taken along line AA in FIG. 7, and FIG. 2 is a peripheral edge of the fixing member in FIG. It is the perspective view seen from the top which shows.

As shown in FIGS. 7 and 1, the refrigerator main body 1 forms a heat insulating box by foaming and filling a heat insulating material 3 between an outer box 2 and an inner box 4 made of conductive steel plates. The back surface of the box 2 is constituted by a back plate 2a. A recess 5 for arranging the wiring board 20 is formed on the side of the back plate 2a, and a holding member 10 is attached to the bottom surface of the recess 5 with a screw or the like. A wiring circuit cover 6 is detachably attached to the upper surface opening of the recess 5.

The holding member 10 is formed of a non-conductive, specifically flame-retardant synthetic resin, and has an outer peripheral wall 11 standing so as to cover the outer periphery of the wiring board 20. The outer peripheral wall 11 is provided with engaging portions 12 for urging the upper surface of the wiring board 20 downward at several locations, and ribs 13 erected upward from the bottom surface of the holding member 10. The wiring board 20 is attached and clamped by the joint portion 12.

Further, the bottom surface of the holding member 10 is provided with a protruding portion 14 that is erected toward the wiring substrate 20, and the upper end surface 16 of the protruding portion 14 has the wiring substrate 20 attached thereto. The through-hole 15 is provided inside the protruding portion 14.

The wiring board 20 on which the electronic component 21 such as a capacitor or a diode is mounted is fixedly attached to the holding member 10 by the engaging portion 12 and the rib 13 as described above. A through hole 24 for projecting the projecting portion 14 upward is formed in a portion of the wiring board 20 facing the projecting portion 14 of the holding member 10, and a conductor 23 is provided at the periphery of the through hole 24. Here, two mounting holes 22 for mounting are provided. As shown in FIG. 2, a ground circuit pattern 27 is printed on the back surface of the wiring board 20 and is electrically connected by soldering a conductor 23 inserted through the mounting hole 22.

The conductor 23 is a rod-shaped or plate-shaped iron wire formed in a substantially U shape, and the lower end portion 23a is inserted into the mounting hole 22 and fixed by soldering. The horizontal portion 23 b is in contact with the upper end surface 16 of the protruding portion 14, and the attachment hole 22 is disposed outside the through hole 15.

Reference numeral 25 denotes a fixing member, and here, a conductive screw is used. The fixing member 25 is inserted through the through-hole 15 and fixed by screwing into the concave portion 5 of the back plate 2a. The upper portion of the fixing member 25, here the lower end surface 25 a of the screw head, is in contact with the horizontal portion 23 b of the conductor 23 and is not in contact with the upper surface of the wiring board 20. The fixing member 25 also serves to press and fix the holding member 10 to the back plate 2a.

According to the above configuration, since the conductor 23 electrically connected to the ground circuit pattern 27 of the wiring board 20 is fixedly fitted into the back plate 2a through the fixing member 25 of the conductor, An earth circuit can be constructed and formed without using a lead wire for the use, and since a fixing member 25 for mounting the holding member 10 is diverted, no additional work process is required for the earth circuit. As a result, the assembly work efficiency can be improved. In addition, since the fixing member 25 is not in direct contact with the wiring board 20, the impact force from the fixing member 25 is not directly transmitted to the wiring board 20 even when an impact is applied to the main body side during installation or loading. The impact is alleviated and damage to the wiring board 20 can be prevented.

In the above-described configuration, the ground circuit is formed by the single conductor 23. However, as shown in FIG. Without tilting when attached, the back plate 2a can be securely fitted.

Further, the horizontal portion 23 b of the conductor 23 may be brought into contact with the lower end surface 25 a of the fixing member 25, for example, without being disposed on the upper end surface 16 of the protruding portion 14. Specifically, as shown in FIG. 4, an L-shaped fixing member 23 ′ may be used instead of the U-shaped conductor 23. In this case, by electrically biasing one end upward using the conductor 23 'as an elastic body, it can be reliably electrically connected to the fixing member 25.

Further, the conductor 23 'is formed in a plate shape instead of a rod shape, and as shown in FIGS.
By making the contact surface with a circular shape or a U-shape, electrical connection can be made more reliably.

  Furthermore, although the above-described configuration has been described as a ground structure attached to a refrigerator, it is needless to say that the present invention can be applied not only to the refrigerator but also to various electrical appliances including a conductive main body.

  INDUSTRIAL APPLICABILITY The present invention can simplify the ground structure and prevent damage to the wiring board, and can be used for a ground structure having a conductor body.

It is sectional drawing of the earth structure which shows one Embodiment of this invention. It is a perspective view which shows the periphery of the earth structure of FIG. It is a perspective view which shows other embodiment of the fixing member of FIG. It is a longitudinal cross-sectional view which shows other embodiment of a fixing member. It is a perspective view which shows other embodiment of the fixing member of FIG. It is a perspective view which shows other embodiment of the fixing member of FIG. It is a rear view of the refrigerator which shows one Embodiment of this invention. It is a disassembled perspective view which shows the conventional earth structure. It is a longitudinal cross-sectional view of the earth structure of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Refrigerator main body 2 ... Outer box 2a ... Back plate 5 ... Recessed part 10 ... Holding member 12 ... Engagement part 13 ... Rib 14 ... Projection part 15 ... Through-hole 16 ... Upper end surface 20 ... Wiring board 21 ... Electronic component 22 ... Installation Hole 23 ... conductor 24 ... through hole 25 ... fixing member 27 ... earth circuit pattern

Claims (2)

A conductive main body, a non-conductive holding member attached to the main body, and a wiring board mounted with electronic components held by the holding member are mounted on the wiring board. A conductor that is electrically connected to the ground circuit pattern and extends to at least the vicinity of the through hole, and a fixing member that is in electrical contact with the conductor, and the holding member has a back surface of the wiring board The through hole is inserted through the upper end surface of the wiring board, and the fixing member is inserted into the protruding portion. The upper portion of the fixing member is in contact with the upper end surface of the protruding portion. Or it is made to contact | abut via the said conductor, and the lower part is inserted in the said main body, The earth structure of the wiring board characterized by the above-mentioned. The refrigerator provided with the grounding structure of the wiring board according to claim 1, wherein the wiring board and the holding member are attached to the outer plate.

Images