JPH058985U - PCB mounting structure - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce the number of case processing steps and the number of assembly steps required to fix the printed circuit board to the case. [Structure] A printed circuit board 2 is housed in a case 1 having a substantially U-shaped cross section. The printed circuit board 2 has cutout grooves 2a on both side edges. A pair of spacer portions 7a provided on the fixing member 7 are fitted into the respective cutout grooves 2a, and at the same time, side portions of the printed circuit board 2 are engaged with the engaging grooves 7c provided on the spacer portion 7a. Both spacers 7a are integrally connected via a connecting piece 7b. In addition, a fitting protrusion 7d that fits into a fitting hole 1c formed in the side wall 1a of the case 1 is provided on a surface of the spacer portions 7a facing the side wall 1a of the case 1. The fixing member 7 supports the printed circuit board 2 so that an insulation distance from the bottom wall 1b of the case 1 can be secured,
And, it is connected to the case 1.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a printed circuit board mounting structure for fixing a printed circuit board to a case having a pair of side walls facing each other so as to be substantially parallel to the bottom wall.

[0002]

[Prior Art]

 Generally, when a printed circuit board on which an electronic circuit such as a lighting circuit of a lighting fixture (for example, an electronic ballast) is mounted in a metal case, the printed circuit board is fixed not only to the case but also to the printed circuit board. It is necessary to keep the distance between the printed circuit board and the case at a predetermined distance so that the lead of the electronic component protruding from the board does not come into contact with the case.

In order to meet such a requirement, as shown in FIG. 3, positioning claws 3a for positioning the printed circuit board 2 in a metal case 1 having a pair of side walls 1a and having a substantially U-shaped cross section, 3b is formed, and further, as shown in FIG. 5, a spacer 4 made of an insulating material is interposed between the bottom wall 1b of the case 1 and the printed board 2. The claws 3a and 3b are provided on each side wall 1a and bottom wall 1b of the case 1, and the claw 3a formed on the side wall 1a abuts one side surface of the printed circuit board 2 and the spacer 4 and the printed board. By sandwiching the two, the movement of the printed circuit board 2 in the thickness direction is regulated, and the claw 3b formed on the bottom wall 1b is brought into contact with the peripheral edge orthogonal to the side edge of the printed circuit board 2 to prevent the printed circuit board 2 from moving. Restricts movement in the direction along the side edge. Therefore, when the printed circuit board 2 is housed in the case 1, the claw 3b is cut and raised with respect to the bottom wall 1b and the spacer 4 is arranged in the case 1, as shown in FIG. It suffices that the claw 3a is housed in the case 1 so as to come into contact with the claw 3b, and then the claw 3a is bent inward to regulate movement of the printed circuit board 2 in the thickness direction. In order to prevent the lead of the component 5 mounted on the printed circuit board 2 from coming into contact with the case 1 due to an impact from the outside, an insulation is provided between the inner peripheral surface of the case 1 and the printed circuit board 2. The seat 6 is arranged. The insulating sheet 6 is formed in a substantially U shape along the inner peripheral surface of the case 1, and through holes 6a are formed in both leg pieces so that the claws 3a can pass therethrough. That is, the insulating sheet 6 is sandwiched between the bottom wall 1b of the case 1 and the spacer 4, and the claw 3a is inserted into the through hole 6a, so that the movement of the printed board 2 in the thickness direction is restricted. The contact with the claw 3b restricts the movement of the print base plate 2 in the direction along the side edge thereof.

[0004]

[Problems to be solved by the device]

 By the way, in the above-mentioned configuration, since punching and bending are required when forming the claws 3a and 3b on the case 1, the number of processing steps is large, and the spacer is required when the printed circuit board 2 is fixed. 4 is required and bending of the claw 3a is required, which causes a problem of increasing the number of assembling steps. Further, since the metallic claws 3a and 3b are in direct contact with the printed circuit board 2 in a dot shape, the printed circuit board 2 may be cracked when an impact force is applied from the outside. Moreover, since the claw 3a abuts on the surface of the printed circuit board 2, the insulation distance may not be secured in some cases.

The present invention is intended to solve the above-mentioned problems, and reduces the man-hours for processing the case and the assembly man-hours required for fixing the printed circuit board, thereby suppressing the cracking of the printed board due to the impact force from the outside. In addition, it is another object of the present invention to provide a printed circuit board mounting structure in which a sufficient insulation distance can be secured between the case and the printed circuit board.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a printed circuit board mounting structure for fixing a printed circuit board in a case having a pair of side walls facing each other so as to be substantially parallel to the bottom wall. Each side wall has a fitting hole penetrating each other at the opposite side, and the printed circuit board has a notch groove formed at each side edge along each side wall of the case, and is formed in a shape that meshes with the notch groove. A fixing member made of synthetic resin, which includes a spacer portion having an engaging groove that engages with a part of the peripheral edge of the notched groove and a connecting piece portion that integrally connects both spacer portions, is arranged in the case. The size of the spacer section from the bottom wall of the case to the engagement groove is set to be larger than the protruding amount of the lead of the component mounted on the printed circuit board from the printed circuit board. Fit into the fitting hole Fitting protrusions is what is integrally projects.

[0007]

[Action]

 According to the above configuration, since the printed board is fixed to the case by being fitted into the fitting hole formed in the side wall of the case and fixed to the case, the printed board is fixed to the case via the fixing member made of synthetic resin which holds the printed circuit board. There is no need to form claws on the case, which reduces the man-hours required for processing the case. Moreover, since it is not necessary to bend the claws on the case, the man-hours required for assembly are also reduced. In addition, part of the fixing member made of synthetic resin is fitted in the notch groove formed in the side edge of the printed circuit board, and part of the print substrate is engaged in the engaging groove formed in the fixing member. The printed circuit board does not come into direct contact with the case, and the contact state between the printed circuit board and the fixing member is linear or planar, increasing the contact area. Can be prevented. Further, since the fixing member made of synthetic resin is interposed between the case and the printed circuit board, the insulation distance can be secured even if the case is made of metal.

[0008]

【Example】

 As shown in FIG. 1, the case 1 is formed of a metal plate such as a steel plate having a substantially U-shaped cross section in which a pair of side walls 1a facing each other on both side edges of a bottom wall 1b stand up. Although the front and rear surfaces and the upper surface of the case 1 are open in FIG. 1, the open surface may be closed by another member as necessary. Rectangle-shaped fitting holes 1c are formed in opposing portions of each side wall 1a. On the other hand, on both side edges of the printed circuit board 2, cutout grooves 2a are respectively provided at portions corresponding to the fitting holes 1c. To fix the printed circuit board 2 to the case 1, a fixing member 7 made of synthetic resin, which is an insulating material, is used.

The fixing member 7 has a pair of spacer portions 7 a fitted in the respective cutout grooves 8 of the printed circuit board 2 and a connecting piece portion disposed between the bottom wall 1 b of the case 1 and the printed circuit board 2. It is formed in a shape integrally connected by 7b. Here, the connecting piece portion 7b is formed as narrow as possible within the range allowed by the strength so as not to interfere with the arrangement of the component 5 mounted on the printed board 2. On the contrary, the spacer portion 7a is formed wide so that the contact area with the printed circuit board 2 is large. Therefore, the shape of the fixing member 7 as viewed from above in FIG. 1 is substantially H-shaped. The spacer portion 7a is formed with an engagement groove 7c that engages with the rear end edge of the cutout groove 2a formed in the printed circuit board 2. The engaging groove 7c is formed along the side edge of the printed circuit board 2, and the distance from the lower end of the spacer portion 7a in FIG. 1 to the engaging groove 7c is the distance of the component 5 mounted on the printed circuit board 2. The size is set to be larger than the size of the projection protruding from the printed circuit board 2. That is, the engagement of the printed circuit board 2 with the engagement groove 7c restricts the movement of the printed circuit board 2 in the thickness direction and prevents the leads of the component 5 from contacting the bottom wall 1b of the case 1. The distance between the wall 1b and the printed circuit board 2 is maintained. The distance between the two spacer parts 7a is set to be approximately equal to the distance between the both side walls 1a of the case 1 by the connecting piece part 7b, and a fitting hole is formed on the surface of the spacer part 7a facing the both side walls 1a. A fitting protrusion 7d that fits into the 1c is integrally provided. The fixing member 7 is fixed to the case 1 by fitting the fitting protrusion 7d into the fitting hole 1c.

When the printed circuit board 2 is housed in the case 1, an insulating sheet 6 having a substantially U-shaped cross section is arranged along the inner peripheral surface of the case 1. The insulating sheet 6 has a through hole 6a formed at a portion corresponding to the fitting hole 1c. However, when the insulating sheet 6 is housed in the case 1 and the printed board 2 is pushed into the case 1 with the fixing member 7 attached to the printed board 2, the fitting protrusion of the fixing member 7 is fitted into the fitting hole 1c of the case 1. 7d is fitted and the fixing member 7 is fixed to the case 1. At the same time, the insulating sheet 6 is sandwiched between the fixing member 7 and the case 1 and fixed to the case 1. As described above, the case 1, the printed circuit board 2, and the insulating sheet 6 are fixed to each other by the fixing member 7 as shown in FIG.

Here, since the fixing member 7 is interposed between the case 1 and the printed circuit board 2, the insulation distance between the case 1 and the printed circuit board 2 can be made relatively large. In addition, since the printed circuit board 2 and the fixing member 7 are in linear or planar contact with each other, it is possible to prevent the printed circuit board 2 from being broken by being hit by the metal member even when an impact force is applied from the outside. As the fixing member 7, it is desirable to use polypropylene or the like so as to ensure the insulating property and to absorb the impact force. Also, when the side wall 1a of the case 1 is low or the distance between both side walls 1a is small, it is difficult to secure an insulation distance between the case 1 and the printed circuit board 2 in the conventional structure having the claws in the case 1. However, since the fixing member 7 is used in the present invention, the size of the case 1 is not limited and can be formed in an arbitrary size.

The dimensional relationship between the spacer portion 9a and the connecting piece portion 9b and the connecting position in the fixing member 9 are not limited to those described above.

[0013]

[Effect of the device]

 According to the present invention, as described above, the print board is fixed to the case through the fixing member of the synthetic resin that fits in the fitting hole formed in the side wall of the case and is fixed to the case. Therefore, there is an advantage that it is not necessary to form the claws on the case, the man-hours required for processing the case are reduced, and the claws on the case are not required to be bent, so that the number of assembling steps is also reduced. Further, since a part of the fixing member made of synthetic resin is fitted in the notch groove formed in the side edge of the printed circuit board, and a part of the printed circuit board is engaged in the engaging groove formed in the fixing member, Does not come into direct contact with the case, and the contact area between the printed circuit board and the fixing member is linear or planar, resulting in a large contact area, causing the printed circuit board to crack even when an external impact force is applied. It can be prevented. Furthermore, since the fixing member made of synthetic resin is interposed between the case and the printed circuit board, the insulating distance can be secured even if the case is made of metal.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment.

FIG. 2 is a perspective view showing an example.

FIG. 3 is an exploded perspective view showing a conventional example.

FIG. 4 is a perspective view showing a conventional example.

FIG. 5 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 1 Case 1a Side wall 1b Bottom wall 2 Printed circuit board 2a Notch groove 5 Parts 7 Fixing member 7a Spacer part 7b Connecting piece part 7c Engagement groove 7d Fitting protrusion

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masayasu Shimoda 404-1 Nishinobu Suise, Himeji City, Hyogo Prefecture Ikeda Electric Co., Ltd. (72) Inventor Goro Yamaguchi 404-1 Nishinobu Suise, Himeji City, Hyogo Prefecture Ikeda Electric Co., Ltd.

Claims (1)

Claims for utility model registration: A printed circuit board mounting structure for fixing a printed circuit board in a case having a pair of side walls facing each other so as to be substantially parallel to a bottom wall. The case is equipped with a fixing member made of synthetic resin that is fixed in place and holds the printed circuit board. The case has fitting holes penetrating the facing portions of the side walls, and the printed circuit board is provided on each side wall of the case. A spacer portion provided with a notch groove formed in each of the respective side edges, and a fixing member having an engagement groove formed in a shape that meshes with the notch groove and engaging with a part of the peripheral edge of the notch groove; The spacer has a connecting piece that integrally connects the spacer, and the spacer has a dimension from the bottom wall of the case to the engagement groove set to be larger than the protruding amount of the lead of the component mounted on the printed circuit board from the printed circuit board. Was Mounting structure of a printed circuit board fitting projection to be fitted into the fitting hole on the surface facing the side wall of the case in the pacer unit is formed by integrally projecting.