JPS6246046B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, a rotary body such as a knob or shaft of a variable resistor or a switch, and a holder such as a cover that rotatably supports the rotary body are integrally molded and assembled. can be rotated without
This invention relates to an electrical component that is built into the device so that it cannot be removed.

Recently, the demand for miniaturization of electrical components has permeated all fields, and tuning tuners incorporated in television sets are no exception. However, this type of tuner requires a large number of band switching switches and tuning variable resistors to be attached to a single frame, so miniaturizing each component causes the inconvenience of complicating assembly and manufacturing. As a result, parts management must be extremely strict. Therefore, it can be said that miniaturization of this type of electrical components results in higher costs.

Therefore, based on the general demand for miniaturization of such electrical components, it is desired that electrical components of this type can be provided particularly economically and at low cost.

By the way, if an attempt is made to provide this type of electrical component economically and inexpensively, for example, by integrally molding the rotating body and its holder, it can be manufactured without assembly and without component management.

However, the above-mentioned integral molding method has various problems, and these problems have not been solved in the past, so it is not generally used.

The conventional problems in the integral molding method will be explained below.

Referring to FIGS. 1 to 3, 1 in the figures is an insulating frame or stator which is pre-molded from a thermoplastic synthetic resin material such as polyethylene terephthalate and has a shaft hole 1a. It is a holder that holds the rotating body 3 in a rotatable manner and cannot fall off. Reference numeral 2 indicates a mold for forming the rotating body 3 by sandwiching the holding body 1 and pressing it on both sides, 2a is a first mold for forming a driving part such as a rotor part, and 2b is a mold for forming a knob, etc. 2A and 2B respectively show second molds for forming the operating portions of FIGS. Reference numeral 3 denotes a rotating body formed by the mold 2, which includes a driving section 3a and an operating section 3b.
and a shaft portion 3c, each of which is integrally molded. That is, the rotating body 3 is made of a thermoplastic synthetic resin material such as polyacetal that is injected into the cavity of the mold 2 from the gate side of the mold 2, that is, from the direction of the hole 3d. During molding, polyacetal is transferred from the drive part 3a on the gate side to the shaft hole 1 of the holder 1.
a, enters the operating part 3b, is completely filled leaving a hole 3d, and is cooled and hardened.

In this case, what should be noted in particular is that the holder 1 is molded and hardened prior to molding the drive section 3a, etc., and these dissimilar molding materials may be used, for example, when the melting point of the holder 1 is higher than the melting point of the drive section 3a. This is relatively high. Therefore, even during molding of the drive portion 3a, no integration phenomenon due to welding occurs at the interface between these two molding materials. Furthermore, even if the same type of molding material is used, for example, the holding body 1
By making the surface smooth, it is possible to prevent the members of the drive section 3a from biting into the boundary surface, and the rotating body 3 is rotatably supported by the holder 1. However, in practice, as shown in FIG. 2, when the rotating body 3 is cooled, the material contracts in the direction of the arrow.
Although there is a gap between the circumferential surface 3e of the rotating body 3 and the shaft hole 1a which are in contact with the shaft hole 1a of the holder 1,
At the upper and lower boundary surfaces 3f, due to contraction, the rotating body 3 is strongly pressed against the holding body 1, and a phenomenon occurs in which the rotating body 3 clamps the holding body 1, thus making it impossible for the rotating body 3 to rotate. A problem arises.

In order to prevent such a problem, as shown in FIG. 3, if the operating portion 3b of the rotating body 3 is eliminated, there is a drawback that the rotating body 3 is removed from the holder 1.

Therefore, it has been difficult to provide the rotating body 3 with a suitable rotational torque while integrally molding the rotating body 3 so as to be pivotally supported on the holder 1 so as not to fall off.

The present invention solves the above-mentioned conventional drawbacks and molding problems, and embodiments of the present invention will be described below with reference to FIGS. 4 to 8.

FIG. 4 shows that a truncated conical inclined surface 1b is formed on the circumferential surface of the shaft hole 1a of a pre-formed holder 1.
On the other hand, the rotating body 3 is formed with a conical inclined surface facing this conical inclined surface 1b, and as shown in FIG. A conical inclined surface 1c is formed, and the rotating body 3 is shown having a conical inclined surface facing this conical inclined surface 1c.

According to these, the gap generated between the truncated conical shaft hole 1a and the conical inclined surface 1c absorbs the pressure contact force due to contraction generated at the interface between the driving part 3a of the rotating body 3 and the holding body 1. It can be absorbed by minute movement in the direction of the arrow. Therefore, the rotating body 3 is rotatably supported on the holder 1 so that the axes of the shaft hole 1a and the shaft portion 3c of the rotating body 3 coincide, and there is no play in the radial direction of the shaft.
Moreover, the rotating body 3 does not come out of the shaft hole 1a of the holder 1 due to the upper and lower driving parts 3a and the operating part 3b. Therefore, by selectively setting the shapes and dimensions of the conical inclined surfaces 1b and 1c, an appropriate rotational torque can be applied to the rotating body 3.

6A and 6B show an example in which the present invention is implemented in a tuning block, with FIG. 6A being a partially cutaway plan view and FIG. 6B being a side view. In the figure, reference numeral 4 denotes an insulating case, and on the upper surface of this case, circular holes 4a, 4b and square holes 4c constitute a set, and the plurality of sets are arranged in parallel in the longitudinal direction of the insulating case 4. A rotary body 5 of a tuning variable resistor to be described later is rotatably housed in the circular hole 4a, and a rotary body 6 of a band switching switch having a cross-shaped drive groove is rotatably housed in another circular hole 4b. Also, in the square hole 4c is a worm gear 7 that rotates the rotating body 5 of the variable resistor.
is stored and visible from the outside. In the figure, reference numeral 8 denotes a holding body such as a stator part or a frame body to which the rotating bodies 5 and 6 according to the present invention are attached by molding, and the insulating case 4 is attached to the upper part by welding or the like, and the insulating case 4 is attached to the lower part by welding or the like. An insulating substrate 9 is held.

10 and 11 are terminals, and 12 is a terminal holding portion.

Resistance circuits of variable resistors and contact circuits of switches corresponding to the rotating bodies 5 and 6 are printed on the insulating substrate 9, and the variable resistors and switches are arranged in parallel on this circuit. Since the method of molding and attaching the rotating bodies 5 and 6 to the holding body 8 in the example is the same as in the previous embodiment, an example of the variable resistor will be described here.

FIG. 7 shows a plan view of one of the tuning trimmer variable resistors 13 arranged in parallel on the resistance circuits 17 and 18 printed on the insulating substrate 9. In FIG. In the figure, 14 indicates a pair of engagement protrusions 14 on the top surface.
a and a holder 14b for the slider 15, the slider 15 having a plurality of contact pieces 15a is attached to the slider receiver 14 by insert molding, and the slider 15 is provided with a plurality of contact pieces 15a. Piece 15a is the resistance circuit 17
sliding into contact with. Note that 16 is an eyelet integral with the intermediate terminal and is caulked onto the slider 15 so that the slider 15 and the slider receiver 14 can rotate. 10,1
1 is a terminal connected to both ends of the resistance circuit 17;
Further, 18 is a lead, and this lead 18 is connected to the resistance circuit of another adjacent variable resistor.

FIG. 8 shows a rotating body 5 according to the present invention that drives the slider receiver 14 of the variable resistor 13 shown in FIG.
5d' is a slot that engages with a pair of protrusions 14a of the slider receiver 14, and 5d is a cavity connected to this slot. 5a is a drive unit, 5b
is an operating section, 5f is a pointer, and 5e is a toothed section formed on the circumferential surface of the operating section 5b, and the toothed section (not shown) of the spindle of the worm gear 7 described above is screwed into this toothed section 5e to hold it. Rotating the rotating body 5 pivotally supported by the body 8,
The resistance value of the rotating body 5 is adjusted by further rotating the slider receiver 14 described above. The rotating body 5 shown in FIG. 8 is pivotally supported on the holder 8 with an appropriate rotational torque by the molding method shown in FIG.
Of course, such a rotating body is used as a rotating body for other parallel variable resistors and switches.

According to the present invention described above, a conical inclined surface is formed on the circumferential surface of the shaft hole, and a conical inclined surface corresponding to the conical inclined surface is formed on the shaft part, and after molding and cooling, the two come into pressure contact with each other, so that the shaft hole and The axes of the shafts are aligned and there is no play in the shaft radial direction. In addition, there is no need to individually assemble the rotating body to the holding body as in the past.
It can be mass-produced at a low cost, and its practical value is extremely high.

It should be noted that the application of the rotating body in the present invention is not limited to the tuning block of the embodiment, and it goes without saying that the variable resistor can be implemented as a single switch, and the holder can be replaced with an insulating cover. The range of applications is extremely wide.

[Brief explanation of the drawing]

Figures 1 to 3 show conventional examples.
The figure is a vertical cross-sectional view showing the method of molding the electrical component, Figure 2 is a vertical cross-sectional view of the electrical component showing problems in molding, and Figure 3 is a vertical cross-sectional view of the electrical component showing problems in molding.
The figure is a longitudinal cross-sectional view of an electrical component showing molding problems similar to FIG. 2, FIGS. 4 and 5 are examples of the present invention, and FIG.
FIG. 5 is a vertical cross-sectional view of an electrical component similar to that in FIG. 4, FIG. 6A is a plan view of a tuner embodying the present invention, and FIG.
Figure B is a side view of the tuner shown in Figure 6A, Figure 7 is a plan view of the variable resistor mounted on the insulating substrate of the tuner, and Figure 8 shows the main components of the rotary body pivoted on the holder. FIG. 1, 8...Holding body, 1a...Shaft hole, 1b, 1c
... Inclined surface, 2 ... Molding mold, 3, 5, 6 ... Rotating body, 3a, 5a ... Drive section, 3b, 5b ... Operation section, 3c, 5c ... Shaft section.

Claims (1)

[Scope of Claims] 1. A rotating body comprising a holder having a shaft hole, a shaft portion that engages with the shaft hole, and an operating portion and a driving portion integrally formed with the shaft portion of the holding body. However, in an electrical component that is built in such a way that it cannot be removed and is rotatably formed, a conical inclined surface is formed on the circumferential surface of the shaft hole, and a conical inclined surface facing the conical inclined surface is formed on the shaft part. An electrical component characterized by: 2. The electrical component according to claim 1, wherein the conical inclined surface is formed only at one end of the shaft hole and the shaft portion on the operating section side. 3. The electrical component according to claim 1 or 2, wherein the conical inclined surface has a shape that opens toward the operating section. 4. The electrical component according to claim 1, 2, or 3, wherein the holding body and the rotating body are made of the same type of synthetic resin material. 5. The electrical component according to claim 1, 2 or 3, wherein the holding body and the rotating body are made of different synthetic resin materials. 6. Claim 1, characterized in that the operation part is a knob, the drive part is a rotor part, and the rotating body is used as a switch for an electrical device.
Electrical parts listed in section. 7. The electric device according to claim 1, characterized in that the operating portion has teeth, the drive portion is connectable to a variable resistor, and the rotating body is configured as a variable resistor of an electrical device. parts. 8. The electrical component according to claim 6 or 7, wherein the holder is a cover for a switch or a variable resistor. 9. The electrical component according to claim 1, wherein a large number of rotating bodies are provided on the holding body.