JPH0438513Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an electrolytic capacitor, and particularly to a lead wire shape suitable for mounting the electrolytic capacitor on a printed circuit board.

Conventionally, when inserting lead wires of electronic components such as electrolytic capacitors into through-holes in printed circuit boards, it is necessary to insert them to prevent the lead wires from falling out or tilting the electronic components before soldering after installation. The shape of the terminal part has been devised so that it is easy to fall out and is difficult to fall off.

Figure 1 shows the shape of the lead wire portion in a conventional electrolytic capacitor.A set of rod-shaped lead wires 2 protrudes from one end face of the electrolytic capacitor body 1, and extends from the protruding base to approximately the thickness of the printed circuit board. The lead wire 2 is bent outward at a steep angle at a position where the lead wire 2 protrudes outward, forming a first bent portion 4. Next, the lead wire 2 is bent inward at the top where the distance between the lead wires is maximum, and the bent portion is bent outward. 6 is formed, and an inclined part 8 is formed so that the distance between the lead wires becomes narrower inward from here, and the distance of this inclined part 8 is approximately the same as the protruding part of the lead wire from the main body 1. The wires are bent again at this third bent portion 10 and become parallel again to reach the lead wire end 12.

When inserting an electrolytic capacitor having a lead wire shape configured in this manner into a printed circuit board, the lead wire end 12 is inserted into a through hole in the printed circuit board formed at an equal distance from the ends of the lead wires. When pushed in at a right angle, the lead wire 2 is inserted sequentially from its tip 12 toward the main body 1.
Since the distance between the through holes of the substrate is short, the portion from the third bent part 10 to the second bent part 6 via the inclined part 8 is compressed into a narrow width by the elasticity of the lead wire, and is inserted. The printed circuit board is fixed between the first bent part 4 and the main body 1 by a so-called snap action in which the first bent part 4 suddenly returns outward due to elasticity.
Since the electrolytic capacitor is bent at a steep angle at the first bent portion 4 of the lead wire 2, it is retained without falling off from the printed circuit board.

FIG. 2 is another example showing the terminal structure of a conventional electrolytic capacitor, which has terminals processed from a plate-shaped metal plate, and shows a set of plate-shaped terminals on the sealing plate 14 of the capacitor body 1. 16 are fixed by rivets 18. The plate-shaped terminals 16 are mounted facing each other so as to be rotationally symmetrical when viewed from above, and protrude outward from the mounting base to the rivet 18 to form a dogleg shape at the center of the plate-shaped terminal 16. It is then bent inward and narrowed again until it is approximately the same distance as the attachment base to the rivet 18, and this becomes the tip 20. Furthermore, this plate-shaped terminal 16 is formed so that it becomes gradually thinner toward the tip.

Insertion of a terminal having such a structure into a printed circuit board involves inserting the tips of the plate terminals 16 into a through hole on the printed circuit board provided approximately the same distance as the distance between the tips 20 of the plate terminals 16. 20 is inserted, and when the capacitor body 1 is twisted and pressed in the right angle direction, the plate-shaped terminal 16 is compressed narrowly by the elasticity and is inserted, and then returns to its original shape from the dogleg-shaped bent part due to the elasticity. While returning to the rivet 18, it is pushed to the base of the rivet 18, and the insertion is completed. The electrolytic capacitor thus attached is fixed by being pressed against the printed circuit board by the elasticity of the plate-shaped terminal 16 projecting outward.

In all of the conventional terminal structures just described, the so-called snap action utilizes the elasticity of the lead wire or plate-shaped terminal, and when the terminal is installed, the elasticity causes the terminal to suddenly return to its original position, which is transmitted to the board. This causes the inconvenience that other electronic components inserted earlier may fall out or become tilted. In addition, it is necessary to insert the terminal against the elasticity of the terminal, so it is necessary to apply a considerable amount of force when inserting it. Especially when the terminal is a rod-shaped lead wire with a diameter of about 1 mm or more, the terminal as shown in Figure 1 is It is not easy to process it into a shape, and furthermore, it has the disadvantage that it requires considerable force to insert into the board.

This invention relates to a lead wire shape that improves the conventional drawbacks, and aims to provide an electrolytic capacitor that can be easily attached to a printed circuit board and eliminates accidents such as falling out. This invention will be explained in detail based on examples.
FIG. 3 is a perspective view showing the electrolytic capacitor of this invention, in which the upper end surface of a cylindrical electrolytic capacitor body 30 is sealed with a sealing material 32 made of an elastic material such as rubber, and the end surface portion 34 of the outer case is inside. It is curled and tightly sealed. Then, from the surface of the sealing material 32, a rod-shaped anode lead wire 36 and a cathode lead wire 3 are connected.
8 are each pulled out, and these lead wires 3
6 and 38 are formed to be spirally rotated in the same direction. FIG. 4 is a plan view of the electrolytic capacitor shown in FIG. 3 viewed from the upper surface on the terminal side, in which the anode lead wire 36 and the cathode lead wire 38 drawn out from the surface of the sealing material 32 are rotated counterclockwise, respectively.
It protrudes toward the top and reaches the lead wire ends 40 and 42.

In the terminal of this invention constructed in this way, the two lead wires 36 and 38 are simply rotated in a spiral pattern, so as is clear from FIG. 3, the distance between the pair of lead wires 36 and 38 is , L1 of the protruding base from the sealing material 32, L2 of the intermediate portion, and L3 of the lead wire tips 40 and 42 are at the same distance.

When inserting the electrolytic capacitor of this invention into a printed circuit board, the distance between the lead wire tips 40 and 42 is L.
Insert the ends of the lead wires 40 and 42 into the through holes on the printed circuit board, which are provided at approximately equal intervals as shown in Figure 3, and then push them in while rotating the electrolytic capacitor body in a spiral manner.The lead wire spacing is always the same, so it snaps into place. It can be inserted all the way to the base of the capacitor body without needing to do so. Therefore, unlike in the conventional case, vibrations due to the snapping operation do not occur, and other parts inserted earlier will not fall out or be tilted. Also, since the lead wire is bent in a spiral, it will not fall out unless the electrolytic capacitor body is rotated.

Furthermore, this invention has the advantage that it can be processed in an extremely short time because it is not necessary to bend it into a complicated shape as in the conventional method. Particularly in the case of lead wires with large diameters, it is difficult to bend them at steep angles, and it is difficult to achieve precision.However, with the structure of the present invention, there are no steep angle parts, which makes processing easier and reduces the size. Accuracy also increases.

As described above, the lead wire shape of this invention is easy to insert into a printed circuit board, is difficult to come off, and does not generate vibrations during insertion, so it is extremely excellent as a lead wire shape for mounting on a printed circuit board.

[Brief explanation of the drawing]

Figure 1 is a front view showing the lead wire shape of a conventional electrolytic capacitor, Figure 2 is a perspective view showing another terminal structure of a conventional electrolytic capacitor, and Figure 3 is a lead wire shape of the electrolytic capacitor of this invention. The perspective view and FIG. 4 are plan views showing the lead wire shape of FIG. 3 viewed from the upper surface on the terminal side. 30... Capacitor body, 32... Sealing material, 3
6... Anode lead wire, 38... Cathode lead wire.

Claims (1)

[Scope of utility model registration request] In an electrolytic capacitor having a structure in which a pair of rod-shaped lead wires protrudes from one end surface of a cylindrical capacitor body, the pair of rod-shaped lead wires are oriented clockwise or counterclockwise so that the distance between the two lead wires is always constant. The lead wire shape of an electrolytic capacitor is characterized by a spirally bent shape.