Fixing member and mounting structure

This application claims priority under 35 USC 119 from Japanese patent Application No. 2006-013922, the disclosure of which is incorporated by reference herein.

1. Field of the Invention

The present invention relates to a fixing member that can be mounted to a fixed member to be fixed to a printed circuit board and that is used for fixing the fixed member to the printed circuit board, and also relates a mounting structure.

2. Description of the Related Art

A large number of electronic components are mounted on a printed circuit board (PCB). The electronic components need to be fixed to the printed circuit board and, therefore, a fixing member to which the electronic components are attached is often fixed to the printed circuit board (for example, see Japanese Utility Model Application Publication (JP-Y) No. 5-35592, Japanese Patent Application Laid-open (JP-A) No. 2002-151191, JP-A No. 11-111407, JP-A No. 9-330753, Japanese Utility Model Application Laid-open (JP-U) No. 5-27969, and JP-A No. 2005-310626). Conventional art will be described below by way of example.

As shown in FIG. 9 , conventionally, to fix an electronic component 84 to a printed circuit board 82 , a fixing member 80 is mounted to the electronic component 84 and the fixing member 80 is fixed to the printed circuit board 82 by soldering.

More specifically, the fixing member 80 includes a male connector portion 88 and the male connector portion 88 comprises a plurality of arm portions 87 F, 87 N having lug portions 99 F, 99 N, which are respectively formed at the tip ends thereof and are inserted into an insertion opening 90 in the printed circuit board 82 .

The lug portions 99 are engaged with an opening edge 90 E when inserted into the insertion opening 90 . After the male connector portion 88 is inserted into the insertion opening 90 and the lug portions 99 are engaged with the opening edge 90 E, the lug portions 99 are joined to the printed circuit board 82 by soldering so as to fix the fixing member 80 .

When inserting the male connector portion 88 into the insertion opening 90 , the male connector portion 88 may be inserted with its arm portions 87 inclined with respect to the opening edge 90 E in some cases. If an inclination angle θ with respect to a direction normal to the insertion opening 90 becomes excessively large, tip ends of the lug portions 99 come in contact with an area peripheral to the insertion opening 90 and lug portions 99 are not guided to the insertion opening 90 .

The present invention has been made to solve the above-described problems, and a first aspect of the invention provides a fixing member that can be mounted to a fixed member to be fixed to a printed circuit board, and that is used for fixing the fixed member to the printed circuit board, the fixing member comprising: a male connector portion inserted into an insertion opening formed in the printed circuit board; a plurality of arm portions provided to the male connector portion; a lug portion provided at each tip portion of the arm portions and engaged with an opening edge of the insertion opening; and a lug-guiding portion extending out from a tip end portion of at least one lug portion toward the other lug portion(s) and guiding the lug portion to the insertion opening when coming in contact with the opening edge and being further pressed.

Thus, when pressing the fixed member mounted to the fixing member so as to insert the male connector portion thereof into the insertion opening in the printed circuit board, the lug-guiding portion can guide the lug portions to the insertion opening even if the inclination angle of the male connector portion with respect to the direction normal to the insertion opening is large. Accordingly, a range of acceptable inclination angles can be broadened compared with that in the conventional art. Consequently, it is possible to obtain a fixing member having lug portions of the male connector portion which can be easily inserted into the insertion opening in the printed circuit board.

A second aspect of the invention to achieve the above object provides a fixing member according to the first aspect, wherein the two arm portions are provided and the lug-guiding portion extends out from the tip end portion of the lug portion of at least one of the arm portions.

A third aspect of the invention to achieve the object provides a fixing member according to the second aspect, wherein the lug-guiding portion extend out from the tip end of the lug portion of each of the two arm portions and the lug-guiding portions are formed so as not to interfere with each other when the lug-guiding portions come in contact with the opening edge and guide the lug portions to the insertion opening.

In the fixing member according to the above aspects, bending of the arm portions is not obstructed by interference of the lug-guiding portions with each other.

A fourth aspect of the invention to achieve the above object provides a mounting structure comprising: the fixing member according to any one of first to third aspects; a fixed member on which the fixing member is mounted and from which a terminal protrudes; and a printed circuit board having an insertion opening through which a male connector portion provided on the fixing member is inserted and an insertion hole through which the terminal of the fixed member is inserted, the fixed member being mounted by inserting the male connector portion through the insertion opening and by inserting the terminal through the insertion hole.

A fifth aspect of the invention to achieve the above object provides a mounting structure according to the fourth aspect, wherein the dimensions of the lug-guiding portion in the fixing member are set so that, when the male connector portion of the fixing member is pressed toward the insertion opening in the printed circuit board in a state in which the terminal of the fixed member is inserted into the insertion hole, the lug-guiding portion comes in contact with the opening edge and the lug portion is inserted into the insertion opening.

In the mounting structure according to the above aspects, when producing the mounting structure by mounting the fixing member on which the fixed member is mounted to the printed circuit board, mounting can be carried out even by forced insertion. Therefore, the mounting operation is considerably easier and mounting operation time is considerably reduced compared with the conventional art.

A sixth aspect of the invention to achieve the above object provides a mounting structure according to the fifth aspect, wherein the dimensions of the lug-guiding portion in the fixing member are determined based on the inclination angle of the male connector portion with respect to the direction normal to the insertion opening in the printed circuit board when the terminal of the fixed member is inserted into the insertion hole and also the lug portion is in contact with the opening edge of the insertion opening.

In the above mounting structure, appropriate dimensions of the lug-guiding portion of the fixing member can be easily set.

FIG. 1 is a side sectional view showing insertion of an electronic component mounted to a fixing member into a printed circuit board in a state in which tip ends of lug portions of the fixing member are in contact with an edge of an opening in the printed circuit board, in a first embodiment.

FIG. 2 is a partial enlarged view of the first embodiment shown in FIG. 1 .

FIGS. 3A , 3 B, and 3 C are a front view, a bottom view, and a side view, respectively, showing a male connector portion of a fixing member of a second embodiment in a state in which the male connector portion is not inserted.

FIGS. 4A , 4 B, and 4 C are a front view, a bottom view, and a side view, respectively, showing the male connector portion of the fixing member of the second embodiment during insertion.

FIGS. 5A , 5 B, and 5 C are a front view, a bottom view, and a side view, respectively, showing the male connector portion of the fixing member of the second embodiment after completion of insertion.

FIGS. 6A , 6 B, and 6 C are a front view, a bottom view, and a side view, respectively, showing a male connector portion of a fixing member of a third embodiment in a state in which the male connector portion is not inserted.

FIGS. 7A , 7 B, and 7 C are a front view, a bottom view, and a side view, respectively, showing the male connector portion of the fixing member of the third embodiment during insertion.

FIGS. 8A , 8 B, and 8 C are a front view, a rear[bottom?] view, and a side view, respectively, showing the male connector portion of the fixing member of the third embodiment completion of insertion.

FIG. 9 is a side sectional view showing insertion of an example of a conventional fixing member into a printed circuit board in a state in which tip ends of lug portions of the fixing member are in contact with an edge of an opening in the printed circuit board.

Embodiments of the present invention will be described below. In the second and following embodiments, components similar to those described already will be provided with similar reference numerals description thereof omitted.

1. First Embodiment

First, the first embodiment will be described. As shown in FIG. 1 , a fixing member 10 of the present embodiment is a member capable of being mounted to an electronic component 14 to be fixed to a printed circuit board 12 .

The fixing member 10 includes a fixing member main body 16 and a male connector portion 18 extending out from the fixing member main body 16 and the male connector portion 18 is a through-hole type connector portion.

The male connector portion 18 has two arm portions 17 F, 17 N. The arm portions 17 F, 17 N are respectively provided at their tip end sides with lug portions 19 F, 19 N to be engaged with an opening edge 20 E of an insertion opening 20 formed in the printed circuit board 12 .

From a lower face side of the electronic component 14 , a plurality of terminals 21 protrude. In the printed circuit board 12 , a plurality of insertion holes 22 are formed, into which the respective terminals 21 are inserted. In the present embodiment, as shown in FIG. 1 , an example in which two terminals 21 (or two rows of terminals) protrude will be described.

At a tip end portion of the lug portion 19 F of the arm portion 17 F that is farther from the terminals 21 , a lug-guiding portion 23 F extends out toward an inner side of the male connector portion 18 . When the lug-guiding portion 23 F is brought in contact with the opening edge 20 E and pressed further, the lug portion 19 F is guided to the insertion opening 20 (see FIGS. 1 and 2 ).

On the other hand, the lug portion 19 N of the arm portion 17 N that is closer to the terminals 21 is formed in a shape similar to a conventional shape.

In the present embodiment, the fixing member 10 is attached to the electronic component 14 and then, the terminals 21 of the electronic component 14 are inserted into the insertion holes 22 in the printed circuit board 12 and the male connector portion 18 is inserted into the insertion opening 20 .

The dimensions of the lug-guiding portion 23 F are determined in advance so that, as shown in FIG. 1 , when the terminals 21 are first inserted into the insertion holes 22 to a maximum possible depth and the male connector portion 18 is then pressed toward the insertion opening 20 , the lug portions 19 are inserted into the insertion opening 20 with the lug-guiding portion 23 F coming in contact with the opening edge 20 E. In the present embodiment, the maximum possible depth of insertion of the terminals 21 is defined as a depth at which the farther terminal 21 F from the male connector portion 18 is inserted to its base (see FIG. 1 ). In the present embodiment, a side of the lug-guiding portion 23 F closer to the opening edge 20 E is formed in a curved protruding shape.

When setting the dimensions of the lug-guiding portion 23 F as described above, the dimensions of the lug-guiding portion 23 F are determined based on an inclination angle θM of the male connector portion 18 with respect to a direction normal to the insertion opening 20 when the terminal 21 F is inserted into the insertion hole 22 F to the maximum possible depth and also the lug portions 19 are in contact with the opening edge 20 E. Thus, the appropriate dimensions of the lug-guiding portion 23 F can be easily determined.

As described above, in the fixing member 10 of the present embodiment, the dimensions of the lug-guiding portion 23 F are determined in advance so that, when the terminals 21 are first inserted into the insertion holes 22 to a maximum possible depth and the male connector portion 18 is then pressed toward the insertion opening 20 , the lug-guiding portion 23 F comes in contact with the opening edge 20 E and the lug portions 19 are inserted into the insertion opening 20 .

Accordingly, when forming a mounting structure 26 having the male connector portion 18 inserted into the insertion opening 20 in the printed circuit board 12 by pressing the electronic component 14 at which the fixing member 10 is mounted, the lug-guiding portion 23 F can guide the lug portions 19 to the insertion opening 20 even when the inclination angle θ of the male connector portion 18 with respect to the direction normal to the insertion opening 20 is large. As a result, it is possible to considerably broaden the limit of the inclination angle θ as compared with the prior art. Therefore, even when the insertion is carried out in a state in which the tip ends of the lug portions 19 are in contact with the opening edge 20 E, the electronic component 14 can be mounted on the printed circuit board 12 . Consequently, the lug portions 19 formed on the male connector portion 18 of the fixing member can be easily inserted into the insertion opening 20 in the printed circuit board 12 . In addition, when producing the mounting structure 26 the mounting operation is considerably easier, and the time of the mounting operation is considerably reduced, compared with the prior art.

2. Second Embodiment

Next, the second embodiment will be described. In place of the two arm portions 17 F, 17 N of the fixing member of the first embodiment, a fixing member of the present embodiment includes a male connector portion 38 provided with two arm portions 37 F, 37 N as shown in FIGS. 3A to 3C .

A lug portion 39 F of the arm portion 37 F that is farther from the terminals 21 (see FIG. 1 ) has a lug-guiding portion 43 F formed by bending, and a lug portion 39 N of the arm portion 37 N that is closer to the terminals 21 also has a lug-guiding portion 43 N formed by bending.

In the present embodiment, dimensions of the lug-guiding portions 43 F, 43 N are set in advance so that, when the terminals 21 are first inserted into the insertion holes 22 (see FIG. 1 ) to a maximum possible depth and the male connector portion 38 is then pressed toward the insertion opening 20 , the lug-guiding portions 43 F, 43 N come in contact with the opening edge 20 E and the lug portions 39 F, 39 N are inserted into the insertion opening 20 .

Further, in the present embodiment, as shown in FIGS. 3A to 3C , the shapes of the lug-guiding portions 43 F and 43 N are symmetric about a point on a center line 38 C of the male connector portion 38 and the lug-guiding portions 43 F and 43 N do not interfere with each other when the two arm portions 37 F, 37 N are bent toward the inner side of the male connector portion 38 , i.e., bent toward the center line 38 C of the male connector portion 38 . Thus, bending of the arm portions 37 is not obstructed by the lug-guiding portions 43 (see FIGS. 4A to 4C ).

In addition, in the present embodiment, central faces of the arm portions 37 F, 37 N except the lug-guiding portions 43 F, 43 N are positioned in the same plane 38 S that includes the center line 38 C of the male connector portion. Therefore, as shown in FIG. 4 , when the male connector portion 38 is inserted into the insertion opening 20 , corner portions 40 F 1 , 40 F 2 of an outer side of the lug portion 39 F which are symmetric about the plane 38 S come in contact with the opening edge 20 E and receive a bending force. What is mentioned above can be applied to the lug portion 39 N.

Therefore, when inserting the male connector portion 38 into the insertion opening 20 , the arm portions 37 F, 37 N are bent without twisting (see FIGS. 4A to 4C ). Accordingly, the force required for insertion of the male connector portion 38 and the retaining force thereof can be easily predicted and controlled.

Furthermore, as shown in FIGS. 5A to 5C , when the lug portion 39 F has passed through the insertion opening 20 , edge portions 41 F 1 , 41 F 2 of the outer side of the lug portion 39 F which are on opposite sides of the plane 38 S come in contact with the opening edge 20 E and receive a reaction force due to a returning force of the arm portion 37 F. What is mentioned above can be applied to the lug portion 39 N.

Accordingly, fixing is carried out with the portions of the arm portions 37 F, 37 N other than the lug-guiding portions 43 F, 43 N, i.e., the portions thereof that are not bent, and the lug portions 39 F, 39 N receive only reaction forces that are in the same directions as the bending of the arm portions 37 F, 37 N. Therefore, it is easy to predict the reaction forces received by the arm portions 37 F, 37 N and residual stress in the arm portions 37 F, 37 N and, thus, in the present embodiment the dimensions and strength of the arm portions 37 can be preferably determined.

3. Third Embodiment

Next, the third embodiment will be described. In place of the two arm portions 17 F, 17 N of the first embodiment, a fixing member of the present embodiment includes a male connector portion 58 comprising two arm portions 57 F, 57 N as shown in FIGS. 6A to 6C .

A lug portion 59 F of the arm portion 57 F farther from the terminals 21 (see FIG. 1 ) has a lug-guiding portion 63 F and a lug portion 59 N of the arm portion 57 N that is closer to the terminals 21 also has a lug-guiding portion 63 N.

In the present embodiment, the dimensions of the lug-guiding portions 63 F, 63 N are also set in advance so that, when the terminals 21 are first inserted into the insertion holes 22 (see FIG. 1 ) to a maximum possible depth and the male connector portion 58 is then pressed toward the insertion opening 20 , the lug-guiding portions 63 F, 63 N come in contact with the opening edge 20 E and the lug portions 59 F, 59 N are respectively inserted into the insertion opening 20 .

Furthermore, in the present embodiment, as shown in FIGS. 6A to 6C , the shapes of the lug-guiding portions 63 F and 63 N are symmetric about a point on a center line 58 C of the male connector portion and the lug-guiding portions 63 F and 63 N do not interfere with each other when the two arm portions 57 F, 57 N are bent toward the inner side of the male connector portion, i.e., bent toward the center line 58 C of the male connector portion. Accordingly, bending of the arm portions 57 is not obstructed by the lug-guiding portions 63 .

Moreover, in the present embodiment, central faces of the arm portions 57 F, 57 N other than the lug-guiding portions 63 F, 63 N are positioned in the same plane 58 S passing through the center line 58 C of the male connector portion. Therefore, as shown in FIGS. 7A to 7C , when the male connector portion 58 is inserted into the insertion opening 20 , a corner portion 60 F at which the lug-guiding portion 63 F comes in contact with the opening edge 20 E and a corner portion 60 N at which the lug-guiding portion 63 N comes in contact with the opening edge 20 E are positioned above and below the plane 58 S in FIG. 7B and are disposed in such positions as to be symmetric about the center line 58 C of the male connector portion about a point.

Therefore, in inserting the male connector portion 58 into the insertion opening 20 , the arm portions 57 F, 57 N are bent without twisting (see FIGS. 7A to 7C ). For this purpose, a rod portion 66 F of the arm portion 57 F, which is connected to the fixing member main body and to the lug portion 59 F, has a bent portion 68 F formed in the vicinity of a joint to the lug portion 59 F. Similarly, a rod portion 66 N of the arm portion 57 N, which is connected to the fixing member main body 16 and to the lug portion 59 N, has a bent portion 68 N formed in the vicinity of a joint to the lug portion 59 N.

Furthermore, as shown in FIGS. 8A to 8C , in the lug portions 59 F, 59 N which have passed through the insertion opening 20 , edge portions 61 F, 61 N of the outer side of the lug portions 59 which are on opposite sides of the plane 58 S respectively come in contact with the opening edge 20 E and receive reaction forces due to returning forces of the arm portions 57 F, 57 N.

In the present embodiment, even though the lug portions 59 F, 59 N respectively come in contact with the opening edge 20 E at one point and receive pressing forces as described above, bending of the arm portions 57 is not obstructed by the lug-guiding portions 63 .

Although the embodiments of the present invention have been described, the above embodiments are examples and can be practiced while being altered in various ways within the scope of the invention without departing from the gist thereof. The scope of the rights of the invention is not limited to the above embodiments.