JP2931201B2 - Electric junction box and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric connection box having a built-in electronic circuit.

[0002]

2. Description of the Related Art An electric junction box uses a bus bar to intensively perform a branch connection required for a wire harness, and there is a box in which a printed circuit board which forms an electronic circuit together with the bus bar is housed. In this case, how to connect the bus bar to the printed circuit board poses a problem. Conventionally, as shown in FIG. 11, an example of a connection structure between the bus bar and the printed circuit board is known.

FIG. 11 is a cross-sectional view showing an example of a connection structure between a bus bar, an electronic component, and a printed board described in Japanese Patent Application Laid-Open No. 2-205385. In this structure, a bus bar 2 having a burred through-hole 1 is mounted on the lower side of a printed circuit board 5 while the burring portion 3 is positioned and fitted in the through hole 4. The stepped lead terminal 7 of the component 6 is connected to the through hole 1 of the bus bar 2.
And the lead terminal 7 and the bus bar 2 are joined by soldering. In the figure, reference numeral 8 denotes solder. The portion of the lead terminal 7 above the step portion 7a is larger in diameter than the through hole 4 of the printed circuit board 5, and when the lead terminal 7 is inserted into the through hole 1 of the bus bar 2, the step portion 7a serves as a stopper. Play a role.

FIGS. 12 and 13 show Japanese Patent Application Laid-Open No. 62-181610.
FIG. 1 is a diagram showing a conventional example of an electric connection box described in Japanese Patent Application Laid-Open Publication No. H10-15095. In this electric junction box, the electronic component 6 is mounted on the upper surface of the printed circuit board 5 housed in the upper cover 10A,
An electronic circuit is constituted by a circuit conductor (not shown) on the printed board 5 and the electronic component 6. The bus bar 2 accommodated in the lower cover 10B is disposed below the printed circuit board 5, and the connection lead 11 bent and formed from the bus bar 2 and raised is fitted into the through hole 4 of the printed circuit board 5. 12 and the connection lead 11 is connected to the solder 8
To the eyelets 12. Then, the upper cover 10A and the lower cover 10B are locked to form an electric connection box with a built-in electronic circuit.

[0005]

By the way, in the conventional example shown in FIG. 11, the bus bar 2 and the printed circuit board 5 are respectively positioned and combined on a jig board, and the lead terminals 7 of the electronic component 6 are further placed thereon. Is required to be inserted into the through hole 1 of the bus bar 2 while being positioned, and then moved to the soldering process in that state, so that the process is complicated and the production efficiency is poor.

In the conventional example shown in FIGS. 12 and 13, the bus bar 2 and the printed circuit board 5 are connected by the connection lead 11 raised from the bus bar 2, so that the bus bar 2 itself has a planar size. Therefore, it is necessary to secure a sufficient one for starting the connection lead 11. In addition, the planar empty space on the bus bar 2 remaining after the connection lead 11 has been raised is wasted space. Accordingly, there is a problem that the size of the electric connection box is increased by that amount, which hinders the miniaturization of the electric junction box. Furthermore, since the connection lead 11 is formed by bending the bus bar 2 and the eyelet 12 is used to connect the printed board 5 and the bus bar 2, there is a problem that the processing is troublesome and the production efficiency is low.

The present invention has been made in consideration of the above circumstances, and provides an electrical junction box which can easily connect a printed board to a bus bar, can increase manufacturing efficiency, and can be reduced in size. With the goal.

[0008]

An electric junction box according to the present invention is mounted on a printed circuit board and short lead terminals on one surface of the printed circuit board, and the long lead terminal penetrates the printed circuit board. An electronic component protruding on the other surface, and having a through hole through which the long lead terminal protruding on the other surface side is disposed on the other surface side of the printed circuit board and separated from the printed circuit board, A bus bar joined to the long lead terminal inserted into the through-hole, an insulating plate disposed between the printed circuit board and the bus bar and having a through hole through which the long lead terminal is inserted, and mounting the electronic component; And a cover that houses the printed board, the insulating plate, and the bus bar.

According to a second aspect of the present invention, there is provided an electrical junction box according to the first aspect, wherein the through hole is provided with a tapered cylindrical burring portion projecting in a direction away from the printed circuit board. A peripheral portion of the through hole of the insulating plate is formed into a tapered cylindrical shape so as to fit on an inner periphery of the burring portion.

According to a third aspect of the present invention, there is provided the electrical junction box according to the first or second aspect, wherein a height of a bulge at a junction between the lead terminal and the bus bar is equal to or more than a predetermined value on an inner surface of the cover. In this case, a defective connection detecting unit is provided to prevent normal closing of the cover by interference.

According to a fourth aspect of the present invention, there is provided a method for manufacturing an electric junction box, wherein a printed circuit board is mounted on a lower cover by mounting electronic components with short lead terminals on the lower surface and projecting the long lead terminals of the electronic components from the upper surface. An insulating plate having a through-hole through which the long lead terminal is inserted is disposed above the printed circuit board, and the upper end of the long lead terminal is inserted above the insulating plate while being inserted into its own through-hole. A bus bar to be disposed is arranged, and the long lead terminal and the bus bar are joined in that state, and after joining, an upper cover is placed over the bus bar, and the upper cover is fixed to the lower cover. .

According to a fifth aspect of the present invention, there is provided a method for manufacturing an electrical junction box, comprising the steps of:
A tapered cylindrical burring portion protruding in a direction away from the printed circuit board is provided in the through hole.

[0013]

According to the first aspect of the present invention, the through-hole of the bus bar is inserted into the lead terminal of the electronic component protruding from the printed circuit board, thereby assembling the bus bar while positioning the bus bar with reference to the lead terminal of the electronic component. Can be.

According to the second aspect of the present invention, the peripheral portion of the through hole of the insulating plate is fitted into the burring portion of the through hole of the bus bar, thereby preventing the bus bar from being displaced from the insulating plate.

According to the third aspect of the present invention, when the joint of the lead terminal and the bus bar rises at a certain height or more and the joint is defective, the joint defective detecting section on the inner surface of the cover interferes with the joint. Can not close the cover normally,
This makes it possible to detect the occurrence of a bonding failure.

According to the fourth aspect of the present invention, the bus bar is assembled while the through-hole is inserted into the lead terminal of the electronic component, and the lead terminal and the bus bar are joined in the assembled state, and the upper cover is put on after the joining. It is easy to attach, and the joint can be checked before the upper cover is put on.

According to the fifth aspect of the present invention, since the tapered cylindrical burring portion protruding in the direction away from the printed circuit board is provided in the through hole of the bus bar, the burring portion inserts the through hole of the bus bar into the lead terminal. It acts as a guide when making it.

[0018]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded sectional view of the electric junction box of the present invention, and FIG.
3 is an exploded perspective view, FIG. 3 is an external perspective view in an assembled state, and FIG. 4 is a sectional view in an assembled state. In this electrical junction box, cover 2
Reference numeral 0 is divided into an upper cover 20A and a lower cover 20B, which are mutually locked by lock mechanisms 21A and 21B shown in FIG.

Inside the cover 20, a printed circuit board 30, an insulating plate 40, and a bus bar 50 are stacked and arranged from below. At the ends of the printed circuit board 30 and the bus bar 50, connection portions 31, 51 to the wire harnesses W1, W2 are provided as shown in FIG.

Electronic components 35 such as relays are mounted on the lower surface of the printed circuit board 30. The printed circuit board 30 has its peripheral edge placed on a receiving portion 22 projecting from the peripheral edge of the inner surface of the lower cover 20 </ b> B, and is fixed with screws 23. The electronic component 35 includes a short lead terminal 36 connected to the circuit conductor 32 of the printed circuit board 30 and a long lead terminal 37 connected to the bus bar 50, as shown in detail in FIG.
The short lead terminals 36 slightly protrude from the upper surface of the printed circuit board 30 and are soldered to the circuit conductors 32 on the printed circuit board 30. In FIG. 5, reference numeral 33 denotes solder. One long lead terminal 37 penetrates through hole 34 of printed circuit board 30 and protrudes largely upward.

On the lower surface of the insulating plate 40, a printed circuit board 30 is provided.
A concave portion 41 is formed on the upper surface of the upper surface to accommodate the projecting portion of the short lead terminal 36 when the insulating plate 40 is placed.
In the insulating plate 40, a through hole 42 through which the long lead terminal 37 penetrates is formed.
7 protrudes further up.

The bus bar 50 is formed with a through-hole 52 through which the long lead terminal 37 is inserted. As shown in FIG. 6, the through-hole 52 has a tapered cylindrical burring portion 53 projecting upward as shown in FIG. It is formed by burring. The peripheral portion 43 of the through hole 42 of the insulating plate 40 is raised in a tapered cylindrical shape so as to fit into the burring portion 53. The long lead terminal 37 is connected to the through hole 42 of the insulating plate 40.
Is inserted through the through-hole 52 of the bus bar 50, and the distal end thereof is set to a length slightly protruding from the distal end surface of the burring portion 53. Then, for example, as shown in FIG. 7, the tip of the lead terminal 37 is welded to the tip of the burring portion 53 of the bus bar 50 by melting the tip thereof by the laser irradiator 70 as shown in FIG. 8. 6 and 8, reference numeral 55 denotes a joint portion by welding. The connection between the bus bar 50 and the lead terminal 37 may be performed by soldering. However, since there is a possibility that heat is diffused at the time of soldering and a good connection state cannot be obtained, the connection is preferably performed by laser welding. desirable.

The inner surface of the upper cover 20A is sequentially laminated and is brought into close contact with the uppermost bus bar 50, and presses the laminated insulating plate 40 and bus bar 50 so as not to move. At a portion corresponding to the lead terminal 37 on the inner surface of the upper cover 20 </ b> A, a recess (bonding failure detection unit) 24 for accommodating the joint portion 55 between the burring portion 53 of the bus bar 50 and the lead terminal 37 is provided. As shown in FIG. 9, the inner bottom surface 24a of the recess 24 has a height to determine whether or not it is in contact with the top of the joint 55 when the joint 55 is formed in a good state (that is, when welding is good). Is set to Then, as shown in FIG. 10, when the joining portion 55 is not formed in a good state (that is, when welding is poor), it interferes with a portion that remains in a raised state without being melted. , So that the upper cover 20B cannot be set in a normal form and cannot be locked to the lower cover 20B.

In the electric junction box configured as described above, since the insulating plate 40 and the bus bar 50 can be assembled with reference to the lead terminals 37 of the electronic component 35, the assembly can be easily performed. Further, since the lead terminal 37 serves as a reference pin for positioning, it is not necessary to provide a separate reference pin. Further, the through hole 42 of the insulating plate 40
Is fitted to the burring portion 53 of the bus bar 50, so that the bus bar 50 and the insulating plate 40 are not displaced. In addition, when the welding failure between the bus bar 50 and the lead terminal 37 occurs, the upper cover 20A is closed, so that the welding failure can be easily found.

Next, a method of assembling the electric junction box will be described.

In assembling, first, the printed circuit board 3
0, an electronic component 35 such as a relay is mounted on the receiving portion 22 of the lower cover 20B with the mounting surface facing down.
Fix with. At this time, only the short lead terminals 36 of the electronic component 35 are soldered to the circuit conductors 32 of the printed circuit board 30, and the long lead terminals 37 are projected upward from the through holes 34 of the printed circuit board 30, so that the reference So that it can be used as

Next, the insulating plate 40 and the bus bar 50 are sequentially laminated on the printed circuit board 30 with reference to the long lead terminal 37 of the electronic component 35 projecting above the printed circuit board 30. That is, the through hole 42 of the insulating plate 40 is
7, the insulating plate 40 is placed on the printed circuit board 30, and the through-hole 52 of the bus bar 50 is inserted into the lead terminal 3.
7. In this case, since the tapered cylindrical burring portion 53 is provided in the through hole 52 of the bus bar 37, the work of fitting the lead terminal 37 can be performed smoothly and easily. Then, the bus bar 50 and the lead terminal 37 are joined by laser welding, the joint 55 is inspected visually or by image processing, and finally, the upper cover 20A is put on the bus bar 50 from above and assembled to the lower cover 20B, and the electric connection box is connected. To complete.

[0028]

As described above, according to the first aspect of the present invention, it is possible to mount an electronic component on a printed circuit board and then assemble the bus bar while using the lead terminals of the electronic component as reference pins for positioning. Since it is good, the process can be simplified and the production efficiency can be improved.
Further, since there is no need to provide a special reference pin for positioning, it is not necessary to secure a space for a connection portion other than the space occupied by the electronic components, and it is possible to improve the manufacturing efficiency and reduce the size.

According to the second aspect of the present invention, the periphery of the through hole of the insulating plate is formed into a tapered cylindrical shape so as to fit into the burring portion provided in the through hole of the bus bar. The displacement can be prevented, and the bus bar, the insulating plate, and the printed board can be integrated without play.

According to the third aspect of the present invention, when the joint between the bus bar and the lead terminal is defective, the cover cannot be closed, so that the defective connection can be easily found.

According to the fourth aspect of the present invention, the electric junction box can be manufactured efficiently while confirming the joint between the bus bar and the lead terminal only by sequentially assembling the parts in a fixed posture.

According to the fifth aspect of the present invention, since the burring portion is provided in the through hole of the bus bar, the bus bar can be smoothly assembled to the lead terminal, and the production efficiency can be further improved. .

[Brief description of the drawings]

FIG. 1 is an exploded sectional view of one embodiment of the present invention.

FIG. 2 is an exploded perspective view of one embodiment of the present invention.

FIG. 3 is a perspective view showing the appearance of the assembled state of the embodiment of the present invention.

FIG. 4 is a sectional view of an assembled state according to an embodiment of the present invention.

FIG. 5 is a detailed view of a V circle portion of FIG.

FIG. 6 is a detailed view of a VI circle portion in FIG. 4;

FIG. 7 is a perspective view showing an example of a method of joining a bus bar and a lead terminal according to one embodiment of the present invention.

FIG. 8 is a perspective view of a joint obtained by the method of FIG. 7;

FIG. 9 is a cross-sectional view showing a relationship between the bonding portion of FIG. 8 and an upper cover when the bonding portion is good.

FIG. 10 is a cross-sectional view showing a relationship between the joint shown in FIG. 8 and an upper cover when a failure occurs.

FIG. 11 is a sectional view of a conventional example.

FIG. 12 is a sectional view of another conventional example.

FIG. 13 is a detailed view of a circle XIII in FIG. 12;

[Explanation of symbols]

 Reference Signs List 20 cover 20A upper cover 20B lower cover 24 recess (bonding failure detecting portion) 30 printed board 37 long lead terminal 35 electronic component 40 insulating plate 42 through hole 43 peripheral edge 50 bus bar 52 through hole 53 burring portion

Claims (5)

(57) [Claims] A printed circuit board (30) and a short lead terminal (36) mounted on one surface of the printed circuit board (30), and a long lead terminal (37) is mounted on the printed circuit board (3).
0 and an electronic component 35 projecting to the other surface through the printed circuit board 30 and the printed circuit board 3 on the other surface side of the printed circuit board 30.
A bus bar 50 which is disposed at a distance from the first terminal and which is inserted through the long lead terminal 37 protruding to the other surface side, and which is joined to the long lead terminal 37 inserted through the through hole 52. The printed circuit board 30 and the bus bar 5
0, an insulating plate 40 having a through hole 42 through which the long lead terminal 37 is inserted, a printed circuit board 30 on which the electronic component 35 is mounted, the insulating plate 40, and a cover 20 for accommodating the bus bar 50. , 2
An electrical junction box comprising 0A and 20B. 2. The electrical junction box according to claim 1, wherein said through-hole is provided with a tapered cylindrical burring portion protruding in a direction away from said printed circuit board, and said insulating plate is provided with a through-hole. 42 is connected to the burring portion 53.
An electrical junction box, which is formed in a tapered cylindrical shape so as to fit on an inner periphery of the electrical junction box. 3. The electrical junction box according to claim 1, wherein the inner surface of the cover (20A) interferes when a height of a bulge of a joint (55) between the long lead terminal (37) and the bus bar (50) is equal to or more than a predetermined value. An electrical junction box, comprising a joint failure detecting unit 24 for preventing normal closing of a cover. 4. An electronic component 35 is mounted on the lower cover 20B by short lead terminals 36 on the lower surface thereof.
The printed board 30 having the five long lead terminals 37 protruding from the upper surface is fixed, and an insulating plate 40 having a through hole 42 through which the long lead terminals 37 are inserted is disposed above the printed board 30. A bus bar 50 to be laminated is arranged above the plate 40 while the upper end of the long lead terminal 37 is inserted into the through hole 52 of itself, and the long lead terminal 37 and the bus bar 50 are joined in this state. A method for manufacturing an electrical junction box, comprising covering an upper cover 20A above the bus bar 50 and fixing the upper cover 20A to the lower cover 20B. 5. The method for manufacturing an electric junction box according to claim 4, wherein a tapered cylindrical burring portion 53 protruding in a direction away from the printed circuit board 30 is provided in the through hole 52. Manufacturing method of electrical junction box.