JP3745635B2 - Power supply shield plate fixing structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shield plate fixing structure of a power supply device that reduces switching noise leaking from a switching circuit portion of a switching power supply to an input power supply side by a shield plate.
[0002]
[Prior art]
The switching power supply device outputs a desired voltage after switching a DC input power supply. Although this type of power supply device can be formed efficiently and in a small size, noise is generated by switching, and the noise leaks to the input power supply side. Therefore, a noise filter is provided on the input power supply side of the switching circuit part, and the switching circuit part Attenuating noise generated in
[0003]
FIG. 5 is a perspective view showing a main part of the switching power supply, in which a switching circuit portion (not shown) is accommodated in the switching circuit portion accommodating space 1. The substrate 2 is equipped with a noise filter for attenuating switching noise leaking from the switching circuit section to the input power supply side, but noise from the switching circuit section is induced in the coil constituting the noise filter as it is. The standard cannot be satisfied.
[0004]
Therefore, a shield plate 3 is provided between the substrate 2 and the switching circuit unit to shield noise induced from the switching circuit unit. The shield plate 3 has a structure in which the substrate 2 on which the noise filter is mounted is fixed with screws or the like and then fixed to the housings 4a and 4b with screws.
[0005]
[Problems to be solved by the invention]
However, in order to fix the substrate to the shield plate as shown in FIG. 6, the shield plate 3 needs to be strong enough to fix the substrate 2. Also, when the shield plate is attached to the housing, the strength required to fix the shield plate itself is required. Therefore, the shield plate must be of a predetermined thickness. In addition, there is a problem that the weight and space increase.
[0006]
It is an object of the present invention to reduce the material cost and prevent an increase in weight and space by not requiring an application for mechanically fixing the shield plate.
[0007]
[Means for Solving the Problems]
In order to achieve this object, the present invention is configured as follows.
[0008]
First, according to the present invention, a noise filter circuit unit that prevents leakage of noise generated in a switching circuit unit that switches an input power source to the input power source side via a connection line, and leakage from the switching circuit unit to the noise filter circuit unit by induction A shield plate provided between the switching circuit unit and the noise filter circuit unit, a temporary fixing unit for temporarily fixing the shield plate to the substrate of the noise filter circuit unit, and a noise filter circuit unit and temporary fixing And a fixing part for fastening the shield plate to the casing together.
[0009]
The temporary fixing portion includes a first temporary fixing portion that restricts movement of the shield plate in the first direction, and a second temporary fixing portion that restricts movement of the shield plate in the second direction orthogonal to the first direction. It is characterized by having.
[0010]
The first temporary fixing portion is provided with a first direction movement restriction notch provided on the substrate on which the noise filter circuit portion is mounted, and a first direction movement restriction provided on the shield plate to be engaged with the first direction movement restriction notch. The second temporary fixing portion is a shield for engaging the second direction movement restriction notch provided on the mounting bracket for fixing the substrate to the housing and the second direction movement restriction notch. It is comprised from the 2nd direction movement control protrusion provided in the board, It is characterized by the above-mentioned.
[0011]
In addition, a first temporary fixing portion that restricts the movement of the substrate that is slid and accommodated in the U-shaped shield plate in the sliding direction, and a second temporary fixing portion that restricts the movement of the shield plate in the thickness direction It is provided with.
[0012]
The first fixing portion includes a first protrusion provided on the U-shaped bent portion of the shield plate, and a notch that is provided on the substrate and abuts against the protrusion and restricts movement of the substrate in the sliding direction. The fixing portion is provided at a bent portion of the shield plate, and is configured by second and third protrusions that freely slide the substrate by sandwiching the substrate and restrict movement in the thickness direction of the substrate. To do.
[0013]
With this structure, the mounting strength is ensured by the fixing part, and the shield plate is only used for the purpose of the original shield, and the mechanical use of the shield plate is temporary fixing until the board is fixed by the fixing part. The thickness can be reduced because it only needs to fulfill its function.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is an exploded perspective view of a power supply device using a shield plate to which the present invention is applied. A substrate 10 on which a noise filter (not shown) is mounted is attached to a mounting bracket 12 with screws or the like. 12 and the protrusions 14a and 14b of the shield plate 14 formed in a U shape on the substrate 10 are temporarily fixed by engaging with each other.
[0015]
In this way, the mounting plate 12 and the shield plate 14 temporarily fixed to the substrate 10 are fixed together with the casings 16a and 16b by a method such as screwing, whereby the entire mounting is performed. The right space of the shield plate 14 is a space in which the switching circuit unit is accommodated.
[0016]
FIG. 2A is a perspective view showing a state where the mounting bracket 12 is attached to the board 10 to which the mounting bracket 12 is screwed, showing a portion of the mounting bracket 12 in FIG. The substrate 10 is provided with a notch 10a in the short side direction from the upper end side.
[0017]
FIG. 2B is a perspective view showing the shield plate 14 formed by being bent in a U-shape, and a protrusion 14a formed by extrusion from the upper surface to the lower surface at a position where it engages with the notch 12a of the mounting bracket 12. And a protrusion 14b that is formed by extrusion from the upper surface to the lower surface is provided at a position that engages with the notch 10a of the substrate 10.
[0018]
Although not shown in FIG. 2, the lower mounting bracket 12 is also provided with a notch similar to the notch 12a, and the lower portion where the shield plate 14 is folded is also provided with a protrusion similar to the protrusion 14a. It has been.
[0019]
The substrate 10 corresponds to a noise filter circuit portion, the notches 10a and 12a and the protrusions 14a and 14b correspond to temporary fixing portions, and the mounting bracket 12 corresponds to a fixing portion.
[0020]
3 is a partial cross-sectional view showing an engaged state of the shield plate 14 and the mounting bracket 12, and FIG. 3A is a cross-sectional view in the direction of AA in FIG. 1, showing the vicinity of the notch 12 a of the mounting bracket 12. ing. In FIG. 3A, the mounting bracket 12 is screwed to the substrate 10, and a notch 12 a is provided near the bent portion of the mounting bracket 12.
[0021]
The upper surface of the shield plate 14 that is folded back is provided with a protrusion 14a that is formed by being extruded from the upper surface toward the lower surface. The protrusion 14a is provided at a position that engages with the notch 12a of the mounting bracket 12.
[0022]
3B is a cross-sectional view in the BB direction in FIG. 3A, that is, a partial cross-sectional view when viewed from the direction of the arrow C when the lower surface side of the folded portion of the shield plate 14 is cut. When the protrusion 14a provided on the shield plate 14 is engaged with the notch 12a provided, the leftward movement of the shield plate 14 in FIG. 3B is restricted.
[0023]
3C is a partial cross-sectional view in the DD direction in FIG. 1, and the protrusion 14b of the shield plate 14 is engaged with the notch 10a provided on the upper side of the substrate 10 as shown in FIG. 3C. The movement in the longitudinal direction of the substrate 10 in FIG.
[0024]
FIG. 4 shows another embodiment, and FIG. 4A shows a stage in which the substrate 10 is inserted while being slid onto the protrusions 24a to 24f provided on both side surfaces of the shield plate 24 formed in a U-shape. 4B is a perspective view showing a state in which the end of the notch 10b provided in the substrate 10 comes into contact with the projection 24g of the shield plate after the slide of the substrate 10 is finished and the position in the slide direction is regulated. FIG.
[0025]
Protrusions 24 a to 24 f for sandwiching and sliding the substrate 10 are provided on both side surfaces of the U-shaped shield plate 24, and the projections 24 b and 24 e are above the substrate 10 in the longitudinal direction. It is provided so that it may become parallel. The protrusions 24a, 24c, 24d, and 24f are provided on the lower side of the substrate 10 so as to be parallel to the surface of the substrate 10, and the substrate 10 slides while the substrate 10 is sandwiched between the upper protrusion and the lower protrusion. It is comprised so that it can do and the movement of the thickness direction of the board | substrate 10 is controlled.
[0026]
A protrusion 24g provided on the left folded portion of the shield plate 24 so that the longitudinal direction is perpendicular to the surface of the substrate 10 abuts against the notch end portion of the substrate 10 when the substrate 10 reaches a predetermined position by sliding. The movement of the substrate 10 in the sliding direction is restricted.
[0027]
With this configuration, the substrate 10 is slid while being sandwiched between the protrusions 24a to 24f, and when the mounting bracket 22a comes into contact with the protrusion 24g, the substrate 10 reaches a specified position. Movement is restricted and the temporary fixed position is reached. In this state, the fixing of the whole is completed by fixing the mounting brackets 22a to 22c attached to the substrate 10 to the substrate 10 by a method such as screwing and the both sides of the shield plate 24 to the casing by a method such as screwing. To do.
[0028]
The above embodiment is merely an example, and the shape and thickness of the housing, the substrate, and the mounting bracket, and the number, position, and type of screws can be appropriately changed according to the actual one.
[0029]
【The invention's effect】
As described above, according to the present invention, the substrate on which the mounting bracket is mounted is temporarily fixed to the shield plate, and then the mounting bracket and the shield plate are fastened to the housing together. The strength is provided by the mounting bracket, and the shield plate only needs to achieve the original purpose of the shield #. Therefore, the thickness can be reduced, and the material cost can be reduced and the space in the power source can be effectively utilized.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an entire power supply device using a shield plate to which the present invention is applied. FIG. 2 is a perspective view showing a portion of the substrate and the shield plate in FIG. 1. FIG. FIG. 4 is a plan view and perspective view showing another embodiment. FIG. 5 is a perspective view showing the structure of a conventional apparatus. FIG. 6 is an enlarged view of the shield plate and substrate shown in FIG. Perspective view [Explanation of symbols]
10: Substrate 10a, 10b, 12a: Notch 12, 22a, 22b, 22c: Mounting bracket 14: Shield plates 14a, 14b, 24a-24g: Projections 16aa, 16b: Housing

Claims (1)

A noise filter circuit unit for preventing leakage to the input power source side via a connection line of noise generated in the switching circuit unit for switching the input power source;
A shield plate provided between the switching circuit unit and the noise filter circuit unit to shield noise leaked by induction from the switching circuit unit to the noise filter circuit unit;
E Bei a temporarily fixing part for temporarily fixing the shield plate to the substrate of the noise filter circuit unit, and a fixing portion for co-fastening fixing the shield plate and said noise filter circuit section said temporarily fixed to the housing,
The temporary fixing portion includes a first temporary fixing portion that restricts movement of the shield plate in a first direction and a second temporary fixation that restricts movement of the shield plate in a second direction orthogonal to the first direction. Consists of
The first temporary fixing portion includes a first direction movement restriction notch provided on a substrate on which the noise filter circuit portion is mounted, and a first direction provided on the shield plate for engaging with the first direction movement restriction notch. The second temporary fixing portion includes a second direction movement restriction notch provided on a mounting bracket for fixing the substrate to the housing, and the second direction movement restriction notch. And a second direction movement restricting projection provided on the shield plate for engagement with the shield plate.

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