JPH0227539Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a closed magnetic circuit type high frequency coil which is made difficult to come off from the groove when the lead of the winding wound around the bobbin is pulled out from the groove provided in the collar of the coil, and which has a reduced height.

Figure 1 shows a closed magnetic circuit type in which a bobbin 1 with a base is provided with three flanges 2, a winding 3 is wound between the flanges 2, and the tip of the bobbin 1 is fitted into a hole 5 on the top surface of a pot core 4. FIG. 2 is a partially sectional side view showing a conventional high-frequency coil. The cross section shows a groove provided in the collar 2, and 8 is a screw core for adjusting inductance. These days, this kind of high frequency coil has a side of 5mm.
In some cases, the size of the flange 2 that protrudes around the bobbin 1 around which the winding 3 is wound is 1 mm or less. In such a case, when the lead 6 is pulled out to the base side through the groove provided in the collar 2 after winding the winding 3 and connected to the terminal pin 7, the lead 6 is pulled out of the groove that has become shallow due to the winding 3. It easily came off, making it difficult to work in the production of high-frequency coils. Also, since the pot core 4 is configured to cover the winding part of the bobbin 1 from above the uppermost collar 2, the height of the high frequency coil is equal to the thickness of the top surface of the pot core 4 added to the uppermost collar 2. It was not possible to make it lower than the current position, which was an obstacle when aiming for miniaturization.

The present invention aims to solve various technical problems of small-sized closed magnetic circuit type high frequency coils.

In this invention, the bobbin into which the screw core is screwed is provided with a plurality of flanges whose outer diameter increases the lower the position, and the uppermost flanges are located at the tip of the bobbin and cover the windings of the pot core. The high frequency coil is characterized by being fitted into a hole on the top surface.

The following is a second example of the high frequency coil of the present invention.
This will be explained with reference to FIGS. FIG. 2 is a partially sectional side view, and FIG. 3 is an exploded perspective view. Note that in FIG. 2, the case of the high frequency coil is omitted.

In FIGS. 2 and 3, 10 is a bobbin with a base made of synthetic resin, 11 to 13 are collars, 14 is a pot core, 15 is a metal case, and 16 is a terminal pin.

In the bobbin with base 10, a cylindrical bobbin part 19 around which a winding 18 is wound is integrally formed on a base part 17, and a terminal pin 16 is implanted under the base part 17. A flange 11 is formed at the tip of the bobbin portion 19, and a flange 12 and a flange 13 are sequentially formed therebelow. A groove 20 reaching the periphery of the bobbin part 19 is formed in each collar at a position opposite to each other with the bobbin part 19 interposed therebetween. A winding 18 is wound between the collars, and its leads 21 are pulled out through the groove 20 and under the base part 17 and connected to the terminal pins 16. The outer diameter of the circular collar is increased as it goes lower, with collar 11 being the smallest and collar 13 being the largest.

The winding 18 wound between the flanges is shown by a dashed line in FIG. 3, and its outer diameter is set not to exceed the outer diameter of the upper collar.

A screw core 22 is screwed inside the bobbin portion 19.

The cylindrical pot core 14 is open at the bottom and has a hole 24 in the top surface 23, and is made of sintered ferrite, and the collar 11 of the bobbin with base 10 is fitted into the hole 24 so as not to protrude upward from the top surface 23. let The lower end of the pot core 14 abuts on the collar 13 and covers the winding 18 of the bobbin 10 with a base. The inner diameter of the pot core 14 remains the same in the upper and lower positions.

The case 15 covers the pot core 14 and fits into the base portion 17 of the base-equipped bobbin 10. 25
26 is a hole for adjusting the screw core 22;
is a grounding lug.

The high frequency coil of the present invention configured in this way has an outer diameter larger as the lower collars are located, and the amount of winding wire 18 that can be wound between the collars is determined by the outer diameter of the upper collars. Determined by the outer diameter. Even when the most number of turns are made, the outer diameter of the upper tsuba will not be exceeded. Therefore, since the lower collar, which has a larger outer diameter than the upper collar, leaves room on the outside of the winding 18, it has a groove 20 deeper than the upper collar, and the lead 21 drawn out downward. is less likely to come off from the groove 20, and workability during manufacturing is improved.
Further, the uppermost collar 11 of the bobbin with base 10 is formed at the tip and is fitted into the hole 24 of the pot core 14. Since the pot core 14 is not located on the collar 11, the height can be reduced by the thickness of the upper surface 23 compared to the conventional case.

The closed magnetic circuit type high frequency coil of the present invention having such advantages is not limited to the embodiments.
For example, the inner diameter of the pot core 14 is made larger toward the bottom in the same way as the outer diameter of the collar changes, and the distance between the inner surface and the screw core 22 is changed by vertical movement of the screw core 22 to widen the variable range of inductance. You can also do that. In addition, in the embodiment, a bobbin 10 with a base is used.
was used, but the base and bobbin portion may be separate pieces. The pot core 14 can be attached to the base bobbin 10 by various known methods, such as by placing its lower end on the base portion 17 or by holding its inner surface in contact with the side surface of the collar. Furthermore, it goes without saying that the shape of the collar and the cross-sectional shape of the bobbin portion around which the winding wire 18 is wound may be round or square.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional side view showing a conventional high frequency coil, Fig. 2 is a partially sectional side view showing an embodiment of the high frequency coil of the present invention, and Fig. 3 is an exploded perspective view of the high frequency coil of the present invention. be. 1, 10...Bobbin with base, 2, 11, 1
2, 13... Tsuba, 3, 18... Winding wire, 4, 14...
... Pot core, 5, 24 ... Hole, 6, 21 ... Lead, 7, 16 ... Terminal pin, 8, 22 ... Screw core, 15 ... Case, 17 ... Base part, 19
...Bobbin part, 20...Groove, 23...Top surface, 25
...Hole, 26...Lug.

Claims (1)

[Scope of utility model registration request] The bobbin to which the screw core is screwed is provided with a plurality of flanges whose outer diameter increases as the position goes lower.The flanges have grooves that reach the periphery of the bobbin, and A high-frequency coil characterized in that the collar fits into a hole on the upper surface of a pot core that covers the winding, and the outer diameter of the winding wound between the collar does not exceed the outer diameter of the upper collar.