JPS6035228Y2 - Axial lead type cylindrical capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an axial lead type cylindrical capacitor that is small, forms a minute capacitance, and is easy to manufacture.

Conventionally, as shown in FIG. 1, this type of capacitor is provided with opposing electrodes 2 and 3 separated by a part of the circumferential surface on the outer circumferential surface of a cylindrical dielectric body 1 with open ends. 2
, 3, cap terminals 4 and 5 are attached to the electrodes 2 and 3 to seal both open ends of the dielectric 1, and these cap terminals 4,5
It is constructed by leading out lead terminals 6 and 7 in an axial manner.

However, according to this conventional method, the counter electrodes 2 and 3
When applying electrodes 2 and 3, it is difficult to make the interval constant, and it is difficult to obtain a stable capacitance.In order to increase or decrease the capacitance value, it is necessary to change the interval between electrodes 2 and 3. , 3 are separated by a part of the outer circumferential surface of the dielectric 1, there is a limit to the range of increase or decrease, and this has the drawback of not being suitable for miniaturization.

The present invention was made in consideration of these points, and
The purpose of this is to provide an axial lead type cylindrical capacitor that is small and can easily obtain a minute capacitance and can increase the range of capacitance variation. By providing a plurality of grooves that alternately extend in parallel from each end to the vicinity of the opposite end, and by grinding the outer peripheral surface of the electric body into these grooves to change the depth of each groove. This is characterized in that an electrode whose capacitance value can be adjusted is formed to obtain an edge capacitance between the electrodes formed in adjacent grooves.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, 11 is a cylindrical dielectric with open ends,
As shown in a cross-sectional view in FIG. 3, a plurality of grooves 12, 13, 14. extend in the longitudinal direction from each end to the vicinity of opposing ends on the outer peripheral surface. 15, and 1
6, 17, 18 grooves 19 are provided, and grooves 12, 13, 14, 15 extending from one end and grooves 16, 17, 18, 19 extending from the other end are arranged alternately at approximately equal intervals. It is.

20.21, 22, 23 and 24, 25, 26.27
is the groove 12. 13. Within 14.15 and 16.1
7.18.19 is a capacitor electrode provided inside.

In other words, these electrodes are provided so that the edge capacitances between adjacent electrodes are connected in parallel.

The capacitance of these electrodes is adjusted by grinding the outer peripheral surface of the dielectric 11 and changing the depth of the groove.

28 and 29 (29 not shown) are terminal electrodes provided on both open end faces of the dielectric 11, and are connected to electrodes provided in the grooves, respectively.

In other words, one terminal electrode 28 and one capacitor electrode 20, 2
1, 22, and 23 are connected, and the other terminal electrode 29 and the other capacitor electrode 24, 25, 26, and 27 are connected, respectively.

Reference numerals 30 and 31 designate lead terminals, each of which has one end inserted into the open end of the dielectric 11 so as to seal the same, and is electrically connected to the terminal electrode 28 and 29, respectively. 33, and the other ends thereof are guided outward in opposite longitudinal directions, and are formed in an axial shape substantially coaxially.

In this case, the cap terminals 32 and 33 must be attached so as not to short-circuit with the capacitor electrodes facing each other.

The axial lead type cylindrical capacitor of the present invention is constructed as described above, but in manufacturing it, first, the entire outer peripheral surface and both opening end surfaces of the cylindrical dielectric are coated with
Electrodes are applied to the entire surface by a method such as spraying, and then the unnecessary electrodes are removed by polishing the outer peripheral surface of the dielectric material using a centerless polishing device, etc., and each electrode is formed independently only in the grooves provided on the outer peripheral surface. After that, the cap terminal to which the lead terminal is attached is inserted into the open end of the dielectric material to be electrically connected to the terminal electrode.

FIG. 4 shows another embodiment of the capacitor of the present invention, in which the terminal electrodes 28 and 29 are formed by extending to a part of the inner peripheral surface of the dielectric 11, and Case terminals 34 and 35 (35 are not shown) to which lead terminals 30 and 31 are attached are connected to each electrode part, and the rest will be explained as they are the same as the previous embodiment. is omitted.

FIG. 5 shows still another embodiment of the capacitor of the present invention, in which recessed steps 36 are formed on the outer peripheral surface of both ends of the dielectric 11.
．． 37 (37 is not shown), and a terminal electrode is provided on the surface of this recessed step.The remaining points are the same as those of the previous embodiment, so a description thereof will be omitted.

In this case, it goes without saying that each of the recessed step portions 36, 37 is connected to the one group of grooves, and the terminal electrodes 28, 29 thereof are electrically connected to the capacitor electrodes in the grooves.

In addition, each electrode is formed by applying a full-surface electrode to the entire outer circumferential surface of the dielectric by means such as spraying, and then polishing the outer circumferential surface to form a capacitor electrode in the groove and a terminal electrode at the end, respectively. Just do it.

Further, by adjusting the degree of polishing of the outer circumferential surface to increase or decrease the remaining amount of the capacitor electrode, it is possible to adjust the minimum capacitance.

As another example, although not shown, an inner electrode is provided on the entire inner circumferential surface of the dielectric 11 in which concave stepped portions are formed on the outer circumferential surface of both ends of the dielectric 11, as shown in FIG. can also be configured.

In this way, when applying an internal electrode to the entire inner peripheral surface of the dielectric, the electrode is applied to the entire surface of the dielectric by electroless plating or dipping, which is suitable for mass production, and then By polishing the outer circumferential surface, a capacitor electrode in the outer circumferential groove, a terminal electrode at the end of the outer circumferential surface, and an inner surface electrode on the inner circumferential surface may be formed, respectively.

When inner electrodes are provided in this way, the capacitance of the entire capacitor is calculated by adding the edge capacitance between adjacent capacitor electrodes, and the capacitance in the thickness direction of the dielectric between each capacitor electrode and inner electrode. However, the capacitance in the thickness direction is due to the fact that the area of the capacitor electrode is not very large, and the dielectric material that is added in parallel to the edge capacitance between a pair of adjacent capacitor electrodes. The capacitance in the thickness direction is not very large because they are connected in series, and by forming additional capacitance in the thickness direction, the same small capacitance as expected can be obtained. Furthermore, it is possible to achieve further miniaturization.

It should be noted that the drawings merely illustrate embodiments of the present invention, and the present invention is not limited thereto.

In particular, it is optional to combine or change the shapes of the dielectric and the terminals without departing from the spirit of the present invention. For example, the shape of the dielectric 11 may be changed to a bottomed cylinder with an open end. or use lead terminals 30.31
It is completely optional to connect the terminal directly to the terminal electrode without using a cap terminal or the like.

Furthermore, if necessary, the entire capacitor of the present invention may be provided with an insulating exterior.

Furthermore, the number of grooves on the outer circumferential surface of the dielectric is not limited to the number of grooves in the embodiment as long as there are a plurality of grooves from each end.

As described above, the present invention uses a cylindrical dielectric material in which a plurality of grooves are formed, which extend alternately from each end to the vicinity of the opposite end in the longitudinal direction on the outer circumferential surface. This is to obtain an edge capacitance between the electrodes.

Therefore, the grooves on the outer peripheral surface of the dielectric can be obtained at the same time as the dielectric is molded, so the depth of the grooves, the width between adjacent grooves, etc. are always constant, and the grooves are always stable. It is suitable for obtaining a high capacity.

In addition, in this invention, multiple electrodes are provided facing each other in the longitudinal direction of the dielectric, and the capacitance of each edge capacitance is connected in parallel to increase the capacitance. The body can inevitably be made smaller in both the longitudinal direction and the diameter.

Further, in the present invention, since the outer surface electrode on the outer peripheral surface is obtained by polishing the outer peripheral surface after applying the electrode on the entire surface of the outer peripheral surface, it is an excellent invention for industrial use because the manufacturing thereof is extremely easy.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a conventional capacitor, Figure 2, Figure 4,
5 is a perspective view showing an embodiment of the capacitor of the present invention, and FIG. 3 is a sectional view of the dielectric portion of the capacitor of the present invention shown in FIG. 11... Cylindrical dielectric, 12. 13. 14.
15.16,17,18,19... groove, 20
,21,22.23.24.25.26.27...
...External electrode, 28.29...Terminal electrode, 30
, 31...Lead terminal, 32, 33...
・Cap terminal, 34.35...Case terminal,
36.37... Concave step.

Claims (1)

[Scope of utility model registration request] A cylindrical dielectric body, and a plurality of strips formed on the outer circumferential surface of the dielectric body so as to extend alternately in parallel from each end to the vicinity of the opposing ends, and having different widths along the depth direction. a groove, a capacitor electrode provided on the entire inner wall surface of each groove, and a connection with each capacitor electrode provided on both ends of the dielectric and extending to these ends. An axial lead type cylindrical capacitor comprising a terminal electrode having a cylindrical shape, and two lead terminals having one end connected to each of the terminal electrodes and the other end extending outward in the longitudinal direction of the dielectric.