JPH0539614Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the structure of a threaded portion of a threaded core in a bobbin for a high-frequency coil.

[Prior art]

The threaded core inside the cylindrical part of the high-frequency coil is usually threaded onto a plurality of vertically extending ribs provided on the inner surface of the cylindrical part, so that it can be rotated smoothly with a small torque.

However, the miniaturization of high-frequency coils has progressed rapidly, and even a relatively large type that inserts a terminal pin into a circuit board can fit into a cube with a side of 6 mm.The screw core, which is a component of the high-frequency coil, has also become extremely small. Precision of the threaded part is required.

FIG. 4 is a cross-sectional view of a conventional high-frequency coil bobbin.
Shows that it is screwed together. If the screw core 1 is screwed together with even a slight inclination, the torque will increase and the small screw core 1 will be easily damaged when rotated. Further, while moving up and down, it rotates with a small torque, and the screw core 1 may move due to vibrations or the like, causing a change in inductance.

〔assignment〕

An object of the present invention is to provide a bobbin for a high-frequency coil in which a normal screw core is always screwed.

[Means to solve the problem]

The high-frequency coil bobbin of the present invention has a first rib on the inner surface of the cylindrical part around which the coil is wound, which extends vertically and into which the screw core is screwed, and which has a height compared to the first rib. is lower, and at least at one end of the cylindrical portion, the second rib extends closer to the end than the first rib.
It is characterized by having a plurality of ribs.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a high-frequency coil bobbin according to the present invention will be described below with reference to FIGS. 1 and 2.
FIG. 1 is a sectional view taken along the line AA in FIG. 2, and FIG. 2 is a plan view.

The high-frequency coil bobbin of the present invention has four elongated first ribs 6 and four second ribs 7 extending from the lower end to near the upper end on the inner surface of the cylindrical part 5 around which the coil is wound. . A screw core 8 indicated by a dotted line is screwed into the first rib 6 .

The height of the second rib 7 is lower than that of the first rib 6, and the height is such that when the straight screw core 8 is inserted into the cylindrical part 5, it almost comes into contact with the periphery of the screw core 8. Further, the upper side of the second rib 7 extends closer to the upper end of the cylindrical portion 5 than the first rib 6.

Since the second rib 7 has the role of guiding the screw core 8 straight downward along the inner surface of the cylindrical portion 5 without tilting it, it may extend to the upper end. When the screw core 8 is inserted from below,
The lower end of the first rib 6 is placed above the lower end of the second rib 7. Note that 13 is a terminal pin.

By providing two types of ribs on the inner surface of the cylindrical part 5 in this way, the screw core 8 inserted into the cylindrical part 5 is guided by the second rib 7 and moves downward, so that the screw core 8 is guided by the second rib 7 and moves downward. 6. Use self-tap to screw in correctly. When screwed together for the first time, the screw core 8 does not tilt as in the conventional case.

FIG. 3 is a partial perspective view showing another embodiment of the high frequency coil bobbin of the present invention.

In FIG. 3, a plurality of first ribs 10 into which the screw core 8 is screwed together and a plurality of second ribs 11 which guide the screw core 8 are provided on the inner surface of the cylindrical portion 12, respectively. Unlike the first embodiment, a second rib 11A is also provided continuously above the first rib 10.

When the second rib is provided continuously at the end of the first rib, it is also possible to exclude the second rib that is provided independently.

It goes without saying that the high-frequency coil bobbin of the present invention can also be applied to a bobbin with a long cylindrical portion for a delay line.

〔effect〕

As described above, in the high-frequency coil bobbin of the present invention, the rib for inserting the screw core straight into the cylindrical portion without tilting is provided separately from the rib to be screwed together.

Therefore, even if the screw core becomes smaller, it will not be screwed into the rib in an inclined state, and the torque will not change unfavorably. In particular, it can contribute to miniaturization of high-frequency coils.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the bobbin for high frequency coils of the present invention, Fig. 2 is a plan view, Fig. 3 is a partial perspective view showing another embodiment, and Fig. 4 is a conventional bobbin for high frequency coils. FIG. 6...first rib, 7...second rib.

Claims (1)

[Scope of utility model registration request] A first rib that extends vertically on the inner surface of the cylindrical part around which the coil is wound and into which the screw core is screwed; A bobbin for a high frequency coil, characterized in that a plurality of second ribs are provided at one end, each of which extends closer to the end than the first rib.