JPS5821149Y2 - high frequency coil - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a variable inductance structure for a small-sized high-frequency coil, and aims to provide a high-frequency coil whose inductance can be easily adjusted and whose components are not damaged.

Conventional small-sized high-frequency coils generally have a structure as shown in FIG. The inductance was variably adjusted by vertical movement caused by the rotation of the screw core 7.

However, in the high-frequency coil of this structure, a screwdriver or the like is inserted from the outside into the bobbin hollow part 5 to rotate the screw core 7, but when rotating, the driver must be pressed against the groove 9 of the screw core 7. Let's do it.

At this time, when pulling out the screw core 7 from the bobbin 3, the tip of the driver is pressed against the groove 9 of the screw core 7 and pulled up while rotating, so if the pressing force is too strong,
The vicinity of the groove 9 in the screw core 7 may be damaged, or the screw core 7 may rotate idly without rising in the hollow portion of the bobbin, making it difficult to properly adjust the inductance.

Also, if the pressure with which you press the screwdriver is too weak, the screw core 7
The tip of the driver will come out of the groove 9 of the screw core before it rotates.

On the other hand, when inserting the screw core 7 into the bobbin 3, the tip of the screwdriver must be pressed against the groove 9 of the screw core and pressed down while rotating the screwdriver.
The screwdriver did not rotate and the driver immediately came off the groove 9 of the screw core 7, making it difficult to smoothly adjust the inductance.

Therefore, with regard to the vertical movement of the screw core 7, in the conventional high-frequency coil, it is necessary to slightly change the strength (pressure) with which the screw core is pressed against the groove 9 by the driver, and the driver also has separate lifting and pressing operations while rotating. It is necessary to differentiate the operations and use them properly, and the inductance adjustment work requires careful attention.The work is troublesome, and it is difficult to rotate the screw core 7 and adjust the inductance by a machine.

The present invention aims to improve the above-mentioned drawbacks, and an embodiment thereof will be described below.

FIG. 2 shows an embodiment of the present invention, in which a screw core 7 is screwed and inserted into the hollow part 5 of a hollow bobbin 3 made of synthetic resin around which a coil 1 is wound, and a conductive shield is attached to the bobbin 3. In the high-frequency coil covered with a case 10, a hole 11 in the shield case that is aligned with the bobbin hollow part 5 is provided with a driver groove 13 on the top surface, a rectangular recess 15 on the bottom surface, and an annular recess on the side surface. Adjustment part 19 with groove 17
The upper part of the screw core 7 is rotatably held by fitting the hole 11 of the shield case with the annular groove 17 of the adjustment part, and is shaped to match the shape of the recess 15 on the lower surface of the adjustment part 19. 21 is inserted into the recess 15 of the high-frequency coil.

Note that the four parts 15 of the adjustment part are the lower part 2 of the adjustment part.
3, and its lower part 23 is also inserted into the bobbin hollow part 5, and the step part 25 in which the side surface between the annular groove 17 and the lower part 23 fits in the adjustment part 19 is formed in the upper hollow part of the bobbin 3. This contributes to miniaturization of the high-frequency coil.

Further, 27 is a terminal pin.

FIG. 3 is an exploded perspective view of only the adjustment component 19 and screw core 7 taken out and disassembled.

This high frequency coil is connected to the side annular groove 17 of the adjustment component 19.
is fitted into the hole 11 of the shield case 10, and the adjustment component 19 is rotatably held on the bobbin 3. When the tip of the driver is applied to the driver groove 13 of the adjustment component 19 and rotated, the adjustment component 19 is rotated. 19 rotates.

In that case, the square recess 15 of the adjustment part 19 has a threaded core 7.
Since the upper part 21 of is inserted, the screw core 7 also rotates,
Moreover, since the screw core 7 is screwed into the bobbin hollow part 5, the screw core 7 moves up and down in accordance with the rotation.

Of course, the adjusting part 19 only rotates, and the upper part of the screw core moves up and down in the recess 15 as the screw core 7 moves up and down. It is provided between the screw core upper part 21 within the recess 15 of the component.

In other words, the high frequency coil of this invention has a constant pressure (torque).
Since the screw core 7 can be moved up and down indirectly by simply rotating the adjustment part 19 from the outside in a plane, there is no need to take the trouble of changing the pressure with which the screw core is pressed as with conventional high-frequency coils, and damage to the screw core 7 can be avoided. Also, there is no need to pull up or push down the driver.

By the way, in the above embodiment, the adjustment part 19 is held rotatably by fitting the annular groove 17 of the adjustment part 19 into the hole 11 of the shield case 10.
9 can be easily inserted into the hole 1 of the shield case 10 by providing a notch 29 in the hole 11 of the shield case 10 as shown in FIG. 4A.
1.

In addition, as shown in FIG. 4B, the shield case 10 has a protrusion 31.
This projecting piece 31 and the annular groove 17 of the adjustment component
It is also easy to fit them together.

Further, the coil 1 may be appropriately wound around the outer periphery of the bobbin 3, or when the bobbin 3 is formed, a coil formed in advance into a spiral shape from a relatively thick wire may be moded in the bobbin.

Furthermore, in the present invention, since the adjusting part 19 that the driver touches is made separately from the screw core 7, its material can also be made different from that of the screw core 7.

Therefore, it is possible to freely select a material that is easy to mold and has strong mechanical strength, as well as dimensions.

The lower surface recess 15 of the adjustment component 19 is formed into a rectangular shape so as to transmit the rotation to the screw core 7, but its shape is arbitrary.

As explained above, the present invention rotatably holds an adjustment component having a driver groove on the upper surface and a rectangular recess on the lower surface in the hollow part of the bobbin, and also screws a screw core into the hollow part of the bobbin. This is a high-frequency coil formed by inserting the upper part of the screw core, which has a shape that matches the shape of the recess on the lower surface of the adjustment part, into the recess of the adjustment part, and the screw core is rotated through the adjustment part with a constant pressure and rotational force. This makes it possible to provide a high-frequency coil with easy inductance adjustment and no damage to component parts.

Furthermore, since the upper part of the adjustment component protrudes from the shield case, it has the advantage that it is easier to rotate the screw core compared to conventional high-frequency coils, and it can also be rotated manually.

[Brief explanation of drawings]

Fig. 1: A sectional view showing a conventional high-frequency coil, Fig. 2: A sectional view showing an embodiment of the high-frequency coil of the present invention, Fig. 3:
An exploded perspective view of the adjustment parts and screw core of the present invention, Figure 4:
FIG. 3 is a top view of the present invention excluding adjustment parts. 1: Coil, 3: Bobbin, 5: Hollow part, 7: Screw core,
10: Shield case, 11: Hole, 15: Recess, 17:
Annular groove, 19: Adjustment part, 21: Upper part, 23: Lower part.

Claims (1)

[Scope of utility model registration request] In a high-frequency coil, a screw core is screwed into the hollow part of a hollow bobbin around which a coil is wound, and a shield case is placed over the bobbin. An adjustment part having a rectangular recess and an annular groove on the side is rotatably held by fitting the hole of the shield case and the annular groove of the adjustment part, and the shape of the recess on the lower surface of the adjustment part is A high-frequency coil characterized in that the upper part of the screw core having a matching shape is inserted into the recess.