JPS6220991Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a small variable capacitor, and the projection part provided on the bottom surface of the board having the capacitor body on the top surface is brought into contact with the printed circuit board to prevent thermal effects on the capacitor body during soldering. To provide a small-sized variable capacitor which can be temporarily fixed stably by preventing the above-mentioned projections and inserting and engaging the ground terminal plate provided in the protrusion into the printed circuit board for temporary fixation. With the goal.

A conventional small variable capacitor has a rotor shaft lower end, a plurality of stator pillar lower ends, and a lower end of a ground terminal plate electrically connected to the rotor shaft protruding from the lower surface of a substrate having a capacitor body formed on the upper surface. The bottom surface of the board is brought into contact with a predetermined printed circuit board to position it, and at the same time, the lower ends of the rotor shaft, stator column, and ground terminal plate are inserted and protruded into the printed circuit board, and at this time, the lower end of the ground terminal plate is bent. The portions were temporarily fixed by being elastically engaged with the holes of the printed circuit board, and then the protruding portions at each of the lower ends were dipped in solder to be conductively fixed to the printed circuit board.

However, according to the above-mentioned conventional example, since the board is in close contact with the printed circuit board, a considerable amount of heat during soldering is transmitted through the relatively thin printed circuit board, and the characteristics are likely to be adversely affected. Furthermore, since the ground terminal plate is in the form of a thin plate, it has the disadvantage that it is easily deformed unstably when the bent terminal portion is elastically engaged, making temporary fixing work difficult.

The present invention eliminates the above-mentioned drawbacks, and an embodiment thereof will be described below with reference to the drawings.

Figure 1 shows one of the small variable capacitors of this invention.
FIG. 1 is an overall perspective view of an example.

In FIG. 1, each small variable capacitor 21 is connected to a rotor shaft 3 having four rotor plate groups 24 (only two are shown) between a resin substrate 22 and a push plate 23.
7 (shown in FIG. 3) and are electrically connected to the four stator columns 25, respectively.
6, thereby forming four sets of capacitor parts. In addition, the board 2 of each stator column 25
The two downward protrusions are respectively terminal pin parts 25a.
Additionally, four sets of trimmer capacitors 27 are installed on the top surface of the push plate 23.
can be established. The substrate 22 has a stepped portion 22a at an intermediate height position on its four circumferences, and also has a pair of engaging recesses 22b on both outer sides as shown in FIGS. Projections 38 ₁ to 38 of the same height
₄ are integrally formed. In particular, the pair of opposing protrusions 38 ₁ and 38 ₂ are provided with the engaging recess 22 on the outside respectively.
A convex portion 38a is provided extending from b. Further, the height of each of the protrusions 38 ₁ to 38 ₄ protruding from the lower surface of the substrate 22 is greater than that of the main rotor shaft 37 . Note that the number of protrusions 38 ₁ to 38 ₄ on the lower surface of the substrate 22 is not limited to four, and may be configured with only a pair of protrusions 38 ₁ and 38 ₂ (or 38 ₃ and 38 ₄ ) at opposing positions. (If only the protrusions ₃₈₃ and ₃₈₄ are provided, the pair of protrusions 38a are left.) Next, the configuration and assembly of the surroundings of the push plate 23 and the trimmer capacitor 27 will be explained.

As shown in FIGS. 4 and 7A to 7C, the press plate 23 has holes 28 at its four corners for insertion of the stator support columns 25, and four cylindrical portions 29a to 29a are provided in the extensions of each hole 28.
29d is provided. One hole 28 on the top surface of the push plate 23
Nearby, there are a pair of square holes 3 having three pin parts 30a to 30c integrally protruding from each other and having a predetermined depth on both sides.
One through hole 32 having a diameter of 1 is provided. Similarly, the pin portions 30a are provided near the other holes 28.
~30c, and holes 31 and 32 are provided.

The trimmer capacitor 27 is composed of a rotor plate 33 (having a rotor shaft 34) and a stator plate 35, respectively, as shown in FIG. As shown in FIGS. 8A and 8B, the trimmer rotor plate 33 has an oval-shaped hole 33a in the center of a semicircular thin metal plate, and has a pair of bent sides 33, each of which has both sides bent at a predetermined angle.
It has b. As shown in FIG. 4, the rotor shaft 34 has a shaft portion 34a having an oval cross section.
a is the hole 33a of the rotor plate 33 and the washer 41.
are fitted and inserted in sequence, and the shaft protrusion is then inserted into the press plate 2.
It is fitted and inserted into the hole 32 of No.3. The lower surface protrusion of the push plate 23 of the rotor shaft 34 is further connected to a ground terminal plate 4 which will be described later.
The second hole 42b and the chrysanthemum spring 43 are sequentially fitted and inserted, and finally the protruding portion is tightened to prevent it from coming out. At this time, the rotor shaft 34 is biased downward due to the springiness of the chrysanthemum spring 43 and rotates without play.

As shown in FIGS. 9A and 9B, the trimmer stator plate 35 includes a metal thin plate having a predetermined shape, a circular hole 35a, an oblong hole 35b, one recess 35c, a pair of notches 35d and 5e on one side, and the like. A notch 35f is formed on one side, a terminal 35g is formed extending on the other side, and a dielectric film 36 is adhered to each of both sides. In this case, the pair of films 36 are not only attached to the thin metal plate, but also have portions that are attached to each other in contact with each other outside the recess 35c and inside the oblong hole 35b, so the bonding strength is high. It will not peel off unnecessarily. trimmer stator plate 3
5 is the push plate 23 (the rotor plate 33 has already been assembled)
It is mounted and assembled from the outside diagonally above the top surface, 1
The pair of notches 35d and 35e are respectively connected to the pin part 30a and
30b, and one notch portion 35f is engaged with one pin portion 30c to be positioned. At this time, the hole 35a overlaps the hole 28, and the recess 35c is close to the periphery of the shaft portion 34a of the rotor shaft 34. Further, the terminal portion 35g projects outward from the push plate 23. Other stator plates 35 are similarly attached. Note that the mounting structure of the stator plate 35 is such that the notches 35d to 35f simply engage and follow the pin parts 30a to 30c, and there is no structure in which the pin parts fit and pass through the stator plate, so positioning work is not necessary. Easy to assemble and suitable for automatic assembly work. In fact, the stator plate 35 has a pin portion 30c on the outside of the push plate 23, a pair of pin portions 30a,
Since the desired positioning is achieved by contacting two points on either one of 30b, product precision is not required and manufacturing is easier than with the above-mentioned fitting and insertion structure. Further, it is not necessary to provide a small pin-shaped portion in the press die for punching the stator plate 35, and the die is not damaged.

42 is a ground terminal plate made of a thin metal plate, and as shown in FIG. 4, it has one main rotor shaft hole 42a, four trimmer rotor shaft holes 42b, and six positioning holes 4.
It has 2c. In addition, the ground terminal plate 42 has a U-shaped hole 42d in the middle of one of the extending portions to connect the inner terminal portion 42.
e is left and an engaging protrusion 42 is formed at the tip of the extension part.
F and dogleg-shaped bent terminal portions 42g are formed, and a grooved portion 42h is further formed in the longitudinal direction of the distal end of the extension portion, and the bent terminal portion 42g is unnecessary because the rib function of the grooved portion 42h is reinforced. It will not transform into.
The ground terminal plate 42 has, for example, a pair of holes 42c formed in advance on the lower surface of the push plate 23, and a pair of pin portions 23a integrally projected from the push plate 23 as shown in FIG. 7B. Furthermore, as described above, the trimmer rotor shafts 34 are inserted through and attached to the other four holes 42b, respectively, so that they are relatively fixed to the press plate 23.

The above trimmer capacitor 27 and ground terminal plate 4
The push plate 23 to which the capacitor parts 2 are assembled is attached to each cylindrical part 29a to 29 with respect to the board 22 to which the capacitor part is assembled.
d are fitted and attached to the stator pillars 25, respectively. As a result, each stator column 25 is connected to each hole 28 of the push plate 23 and the hole 3 of the trimmer stator plate 35.
5a and protrudes upward, and a nut 44 is screwed into the threaded portion at the upper end of each support column 25.

At this time, as shown in FIG. 1, the inner terminal part 42e of the ground terminal plate 42 is bent upward in the figure, and the bent terminal part 42g is bent downward in the figure, so that the engaging convex part 42f is connected to the board 22. is engaged with the engagement recess 22b and positioned so as not to wobble in the left-right direction and upward direction. In addition to this, the ground terminal plate 42 also has a
As shown in FIGS. 3, 3, and 5, another ground terminal plate 45 is disposed on the upper surface of the board 22 so as to be electrically connected to the main rotor shaft 37.
5a, and a tip bent terminal portion 45b is bent and protruded below the substrate 22 in the figure. Further, the terminal portions 35g of each trimmer stator plate 35 are also respectively bent upward in FIG.

At this time, the main rotor shaft 37 is electrically connected to the periphery of the hole 42a of the ground terminal plate 42, and the trimmer rotor plate 3
3 is connected to the main rotor plate 2 because it is electrically connected to the ground terminal plate 42 via the trimmer rotor shaft 34 and the chrysanthemum spring 43.
4. Both trimmer rotor plates 33 are at the same ground potential. Also, the trimmer stator plate 35 has nuts 44,
It is electrically connected to the corresponding stator plate group 26 via the stator support column 25 and has the same potential.

Reference numeral 46 denotes a box-shaped case made of polyethylene or the like, which has four circular holes 46a at predetermined positions on the top lid, four openings 46b at the four corners, and a pair of openings 46c at the top of a pair of opposing side walls. Further, heightwise grooves 4 each having a predetermined width are provided on the inner surface of the opposing side wall.
6d is provided. Therefore, when the case 46 is placed over the assembly of the base plate 22 and the push plate 23 as shown in FIG. are fitted to the outside of the ground terminal plates 42 and 45, respectively, and are slidably attached using these as guides, and the lower end surface of the case 46 is brought into contact with the four circumferential steps 22a of the board 22. At this time, each hole 46a of the case 46 is connected to the trimmer rotor shaft 34.
The terminal portions 35g of the trimmer stator plate 35 are inserted and protruded through the respective openings 46b.
The inner terminal portion 42e of the ground terminal plate 42 is projected through the other opening 46c. Further, the portions of the pair of ground terminal plates 42 and 45 between the engaging convex portion 42f and the bent terminal portion 42g are prevented from being displaced in the outward direction by engaging and adhering to the grooved portion 46d of the case 46. And for the inward displacement, the substrate 22
Engagement recess 2 extending from the side surface to the side surface of the convex portion 38a
2b and is regulated so as to be stably positioned and supported so as not to be unnecessarily displaced inwardly and outwardly.

The operation for attaching the thus completed small variable capacitor 21 to another printed circuit board 47 as shown in FIG. 5 will be explained. The printed circuit board 47 is provided with a hole 47a for the main rotor shaft 36, a pair of square holes 47b for terminal plates, and four holes 47c for stator supports. Therefore, a pair of ground terminal plates 42, 45
The bent terminal portions 42g and 45b are respectively inserted into and protruded from the hole 47b, and the four terminal pin portions 25a are respectively inserted into and protruded from the hole 47c, and each of the protruding portions 3
The lower ends of 8 ₁ to 38 ₄ are brought into contact with the printed circuit board 47 . At this time, each of the bent terminal parts 42g and 45b has its outer surface on the lower side of the square hole 47b in contact with the outer upper corner of the square hole 47b, and then the apex of the square hole touches the square hole as shown in FIG. They are successively elastically deformed inward until they are fitted into the outer inner surface of the square hole 47b, and the lower side of the dogleg shape is engaged with the inner lower end corner of the square hole 47b.
Therefore, the small variable capacitor 21 is connected to each bent terminal portion 4.
2g and 45b are temporarily fixed to the printed circuit board 47 in a stable manner. In this case as well, each terminal plate 42, 45 has its bent terminal portion 42g, 4, respectively.
Even during each of the above-described inward elastic deformations of 5b, the above-mentioned engagement is performed smoothly because it is stably supported by the convex portion 38a. At this time, the especially large ground terminal plate 42 has its lower bent terminal portion 42g in FIG. 6 elastically deformed inward as described above, so that the vertically extending portion in the figure is relatively outwardly. direction of elastic deformation,
In other words, the rotor plate group 24 and the stator plate group 26 receive a force in the direction of separating them, and each plate group 2
No inconvenience such as contact short circuit with 4 or 26 occurs.

Subsequently, in FIG. 6, the portions of the terminal pin portions 25a and bent terminal portions 42g, 45b which protrude downward from the printed circuit board 47 are conductively fixed to a predetermined print using solder dip. In this case, the small variable capacitor 21 is prevented from conducting heat during solder dip due to the existence of the space formed between the substrates 22 and 47 via the four protrusions 38 ₁ to 38 ₄ and is not affected by characteristic deterioration. do not have. Note that when the printed circuit board 47 is mounted on the device, a drive shaft (not shown) is connected to the main rotor shaft 37 through the hole 47a so as to be integrally rotatable therewith.

Next, the operation of the small variable capacitor 21 will be explained. The main capacity is varied by rotating the main rotor shaft 37 via the drive shaft, and the bent terminal portions 42g, 45b of each ground terminal plate 42, 45 and the four terminal pin portions 2
5a, four types of main variable capacitors are taken out. Thereafter, a driver or the like is engaged with the trimmer rotor shaft 34 of each trimmer capacitor 27 through each hole 46a of the case 46 to rotationally displace each trimmer rotor shaft 34 individually. By varying the facing area, each of the four types of main variable capacitances described above is finely variably adjusted to obtain a desired capacitance value. Note that the trimmer rotor plate 33 is provided with a bent side portion 33b as shown in FIG.
There is no unnecessary contact with the stator plate 35.

As for the method of taking out the capacitance, the capacitance is taken out to the printed circuit board 47 from between the bent terminal parts 42g, 45b and the four terminal pin parts 25a in the lower part of FIG. By connecting a circuit component between the inner terminal portion 42e and the four trimmer stator terminal portions 35g, exactly the same capacity can be obtained from the circuit component.

FIG. 11 shows another embodiment of the stator plate of the above trimmer capacitor. The above trimmer stator plate 35
The trimmer stator plate 51 of this embodiment has a dielectric film 36 adhered to both sides, but the trimmer stator plate 51 of this embodiment has a dielectric layer 52 adhered to both sides by a vapor deposition method. In this case, both sides of the concave portion of the trimmer stator plate 51 are bent and fitted into the pair of square holes 31 of the push plate 23, so that the trimmer rotor plate 33 and the stator plate 5
1 unnecessary contact is prevented.

According to the configuration of the grounding terminal plate 42, a pair of terminal parts 42g and 42e protruding downward from the substrate 22 and above from the push plate 23 can be obtained with one piece,
The configuration and assembly work are easy, and material costs can be reduced.

It is also possible to configure the other grounding terminal plates 45 in the same manner as the above-mentioned grounding terminal plate 42. In this case, the inner terminal portions are cut and raised to protrude below the board 22 and bent outward. The terminal portion may be made to protrude upward from the push plate 23.

As described above, according to the small variable capacitor according to the present invention, the approximately dogleg-shaped bent terminal portion can be temporarily fixed to the printed circuit board by elastically engaging with the hole in the printed circuit board, and the protruding portion can be temporarily fixed to the printed circuit board. A space corresponding to the height of the protrusion is formed between the variable capacitor body and the printed circuit board, and the heat during soldering is blocked by this space, thereby preventing the variable capacitor body from deteriorating its characteristics due to heat effects. In addition to these features, it also has the following features.

1. The configuration in which the portion near the lower end of the grounding terminal plate engages with the engagement recess on the outer surface of the convex portion restricts the lower end of the grounding terminal plate from shifting in the circumferential direction of the board. The convex portion functions as a wall that prevents the lower end of the grounding terminal plate from bending in the direction of falling onto the board. The case limits outward deformation of the ground terminal plate.

With this configuration, the lower end of the grounding terminal plate is securely regulated in position, and even if the folding terminal part is pressed with a fingertip, for example, during handling before temporarily fixing the small variable capacitor to the printed circuit board, it will not fold. The bent terminal part is less likely to be misaligned or bent and deformed, and the bent terminal part maintains its normal state until the temporary fixing work.
Therefore, during temporary fixing, there is no need for the troublesome work of appropriately bending each bent terminal part and correcting it to its normal state, and the temporary fixing work can be performed with good work efficiency, and furthermore, it is suitable for automating the temporary fixing work. Can respond to

2 The protrusion functions as a fulcrum when the bent terminal elastically deforms when it engages with the hole in the printed circuit board, and the short part of the bent terminal closer to the tip than the part where it is attached to the protrusion is elastic. As a result, a larger spring force is generated than when the entire ground terminal plate is elastically deformed, and the stability of temporary fixation can be improved.

3. The configuration in which the protrusion is lower than the protrusion allows the lower end of the protrusion to be separated from the printed circuit board, thereby preventing solder flux from entering the variable capacitor main body along the gap between the grounding terminal plate and the protrusion.

4. The configuration in which the grounding terminal plate is engaged and attached to the engagement recess on the outer surface of the convex portion allows the grounding terminal plate to be displaced outward until the case is attached. Therefore, after the variable capacitor main body is assembled to the board, the grounding terminal plate can be expanded outward as needed to allow access to the variable capacitor main body from the outside, and adjustment of the variable capacitor main body can be performed.

[Brief explanation of the drawing]

Figure 1 shows one of the small variable capacitors of this invention.
An overall perspective view of the embodiment, and FIGS. 2 to 4 are partially cutaway perspective views of the case of the small variable capacitor, respectively.
A lower partial perspective view, an exploded perspective view of the trimmer capacitor part, FIGS. 5 and 6 are partially cutaway side views showing the above-mentioned small variable capacitor before and after it is attached to the printed circuit board, respectively. Figures A to C are a plan view, a side view, and a vertical cross-sectional partial view taken along line C-C in Figure A, respectively, of the push plate of the small variable capacitor, and Figures 8A and B are a plan view and a side view of the trimmer rotor plate, respectively. 9A and 9B are respectively a plan view and a side view of the trimmer stator plate, and FIGS. 10 and 11 are side views of one embodiment and another embodiment of the trimmer capacitor, respectively. 21... Small variable capacitor, 22... Board,
22b... Engagement recess, 23... Push plate, 24... Rotor plate group, 25... Stator support column, 25a... Terminal pin portion, 26... Stator plate group, 27... Trimmer capacitor, 31, 47b... ...Square hole, 33...
...Trimar rotor plate, 34...Trimar rotor shaft, 3
5, 51... Trimmer stator plate, 35g, 42
e, 42g, 45b...Terminal part, 37...Main rotor shaft, 38 ₁ to _{38 4} ...Protrusion, 38a...Protrusion, 42, 45...Earth terminal plate, 42f, 45
a...Engagement convex portion, 42h, 46d...Concave portion, 4
6... Case, 47... Printed circuit board.

Claims (1)

[Claims for Utility Model Registration] A variable capacitor body and a case enclosing the variable capacitor body are provided on the upper surface of the substrate, and the lower ends of a plurality of stator columns protruding from the lower surface of the substrate are electrically connected to the rotor shaft. A small variable capacitor in which the lower end of at least one grounding terminal plate protruding from the lower surface is inserted into a predetermined printed circuit board and fixed for conduction, the board is fixed at a predetermined position between the stator pillars on the lower surface. having a protrusion that comes into contact with the printed circuit board when the variable capacitor is fixed, and at a position on the peripheral edge of the lower surface where the grounding terminal plate extends;
An engagement recess is formed on the outer surface and has a convex portion lower than the protrusion, and the ground terminal plate is locked to the inner surface of the case and extends downward, with a portion near the lower end extending below the convex portion. A small variable capacitor having a structure in which a bent terminal part is engaged with the above-mentioned engagement recessed part and bent in a substantially dogleg shape at the lower end.