JPH0126161B2 - - 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 integrally formed 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. The molds of part 2 for forming the operating part of are shown. 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.

Figures 4 and 5 show a preformed holder 1.
This is an example of an electrical component in which a rotating body 3 is attached. A thin flange portion 1d is formed around the shaft hole 1a of the holder 1, and a recess 1e is formed in the holder 1, for example.
It seems as if it has been formed. The reason why the thickness is made so thin as to not cause any problem in terms of strength is that the shrinkage amount in the thickness direction of the thin flange of the rotating body attached here is small, and strong clamping force is not generated.

A shaft hole 1 provided in the center of this thin flange portion 1d
While supporting the shaft portion 3c of the rotating body 3 at a,
A plurality of locking portions 3g are formed on at least one of the operating portion 3b and the drive portion 3a, extending angularly apart from the shaft portion 3c in the radial direction and supported by the thin flange portion 1d. . Here, three locking portions 3g are arranged at equal angles. This prevents the rotating body 3 from falling off the holder 1. In this case, since it is the thin flange portion 1d that pivotally supports the rotating body 3, the locking portion 3g provided on the operating portion 3b due to shrinkage during molding of the rotating body 3
This part is held by the driving part 3a, but as mentioned above, this part is thin and the length of the shrinkage is short, and the amount of shrinkage is small, and the part is not held all the way around the periphery of the shaft hole 1a, but at multiple points. Therefore, the rotating body 3 rotates with a moderate amount of friction. A desired rotational torque can be applied to the rotating body 3 by selectively setting the shape and dimensions such as the thickness of the thin flange portion 1d and the number and size of the locking portions 3g.

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, 4 is an insulating case, and the upper surface of this case has circular holes 4a and 4.
b and the square hole 4c constitute one set, and the plurality of sets are arranged in parallel in the longitudinal direction of the insulating case 4. circular hole 4
A is a rotating body 5 of a tuning variable resistor, which will be described later.
Further, rotary bodies 6 of band switching switches each having a cross-shaped drive groove are rotatably housed in another circular hole 4b, and a worm gear 7 for rotating a rotary body 5 of a variable resistor is housed in a square hole 4c. 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 holder.

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 circuit 17 printed on the insulating substrate 9. In FIG. In the figure, reference numeral 14 denotes a slider receiver which has a pair of engagement protrusions 14a and a holder 14b for the slider 15 on its upper surface, and a plurality of contact pieces 15a are attached to the slider receiver 14 by insert molding. A slider 15 is attached, and the contact piece 15a comes into sliding contact with the resistance circuit 17. 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 and 11 are terminals connected to both ends of the resistance circuit 17, and 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 support shaft 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. 9 is pivotally supported on the holder 8 with an appropriate rotational torque by the molding method shown in FIG. 4,
Of course, such a rotating body is also used as a rotating body for other parallel variable resistors and switches.

According to the present invention described above, a thin flange portion is formed on the circumferential surface of the shaft hole, and at least one of the operating portion and the driving portion is angularly spaced apart from the shaft portion in the radial direction. Since a plurality of locking portions are formed that extend from the holder and are supported by the thin flange portion, there is no need to individually assemble the rotating body to the holder as in the conventional case, and the rotational torque is also independent of the holder or the holder. By providing an appropriate number or size of locking portions on the rotating body, it can be easily set as desired and mass-produced at low cost, and its practical value is extremely large.

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, but it goes without saying that it can be implemented with a variable resistor, a single switch, etc. by replacing the holder with an insulating cover, etc. The range of applications is extremely wide.

[Brief explanation of drawings]

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 sectional view of an electrical component showing molding problems similar to FIG. 2, FIGS. 4 and 5 show examples of the present invention, and FIG. 5 is a sectional view taken along the line V-V in FIG. 4, FIG. 6A is a plan view of a tuner embodying the present invention, FIG. 6B is a side view of the tuner shown in FIG. 6A, and FIG. 7 is a diagram of the tuner. FIG. 8 is a plan view of a variable resistor mounted on an insulating substrate, and a sectional side view of a main part of the variable resistor in which a rotating body is pivotally supported on a holding part. 1, 8... Holder, 1a... Shaft hole, 1d... Thin flange portion, 2... Molding mold, 3, 5, 6... Rotating body, 3
a, 5a...drive unit, 3b, 5b...operation unit, 3c,
5c...Shaft part.

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 the electrical component that is built into the electrical component so as to be rotatable and not detachable, a thin flange portion is formed on the circumferential surface of the shaft hole, and the shaft portion is formed on at least one of the operation portion and the drive portion. In contrast, an electrical component comprising a plurality of locking portions extending angularly apart from each other in a radial direction and supported by the thin flange portion. 2. The electrical component according to claim 1, wherein the locking portions are formed in three pieces spaced apart at equal angles. 3. The electrical component according to claim 1 or 2, wherein the holding body and the rotating body are made of the same type of synthetic resin material. 4. The electrical component according to claim 1 or 2, wherein the holding body and the rotating body are made of different synthetic resin materials. 5. Claim 1, characterized in that the operating section is a knob, the drive section is a rotor section, and the rotating body is used as a switch for an electrical device.
Electrical parts listed in section. 6. The electric device according to claim 1, wherein the operating portion has teeth, the driving portion is connectable to a variable resistor, and the rotating body is configured as a variable resistor of an electrical device. parts. 7. The electrical component according to claim 5 or 6, wherein the holder is a cover for a switch or a variable resistor. 8. The electrical component according to claim 1, wherein a large number of rotating bodies are provided on the holding body.