JPS643230Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a mounting device for a rotating body that is applied to a radio receiver, etc., and in particular, the rotating body for installing a dial thread is always kept at a predetermined mounting angle with respect to its mounting surface. The object of the present invention is to propose a mounting device for a rotating body that can be rotatably supported.

Generally, in a radio receiver, as shown in FIG. 1, a large number of rotating bodies 4 called pulleys are used to guide a dial thread 3 stretched between a dial drum 1 and a tuning shaft 2. , 4 are rotatably mounted at predetermined positions such as at both ends of the dial drum 1, the tuning shaft 2, or the frequency display scale plate 5.

Incidentally, in recent years, from the standpoint of mass producing radio receivers, the rotating body 4 disposed inside the radio receivers has been
There is a tendency to reduce the number of... as much as possible, and various measures are being taken to achieve this. For example, as shown in FIG. 2, a measure has been taken in which the dial thread 3 is bent from a predetermined portion of the rotary body 4 to replenish the reduced amount of the rotary body. However, in order to reduce the number of rotating bodies 4 by bending the dial thread 3, the dial thread 3 forms a V formed on the outer peripheral surface of the rotating body 4 by a component of the tension applied to the dial thread 3. It is necessary to prevent it from separating from the character-shaped groove portion 4a. Therefore, conventionally, as shown in FIG. 3, the rotating body 4 has been disposed at an angle with respect to a mounting surface 6 formed on a synthetic resin base 5. Accordingly, the shaft body 7 for rotatably supporting the rotating body 4 is provided to be inclined with respect to the mounting surface 6 in accordance with the inclination thereof.

However, in general, the inner diameter dimension 1 ₁ of the center hole 8 of the rotating body 4 is formed to be slightly larger than the outer diameter dimension 1 ₂ of the shaft body 7 so that the rotating body 4 can rotate smoothly. Because it is a thing, dial thread 3
When a component of the tension applied to the rotating body 4 is applied to the rotating body 4 as shown in FIG. 2, the rotating body 4 is caused to rotate as shown by the broken line in FIG. One side portion 4b of the body 4 is the mounting surface 6 or a disk-shaped shaft portion 9 integrally formed on the surface 6.
If the dial thread 3 is pressed against the front surface 9a, or if the tension of the dial thread 3 is strong, the shaft body 7 itself, which had been tilted until now, will become perpendicular to the mounting surface 6 due to the action of a component of the tension. In some cases, it was deformed so that it became. As a result, the ideal mounting angle of the rotating body 4 with respect to the mounting surface 6 as shown by the solid line in FIG. 3 could no longer be maintained. Therefore, the dial thread 3 is connected to the rotating body 4.
This has also caused accidents such as detachment from the annular V-shaped groove 4a formed on the outer peripheral surface of the cylinder.

The present invention has been developed to eliminate these conventional drawbacks.

4 and 5 show an embodiment in which the mounting device for a rotating body according to the present invention is applied to a radio receiver, FIG. 6 shows an enlarged view of the mounting device, and FIG. 7 shows the mounting device as described above. This figure shows the state before the rotating body constituting the attachment device is attached to the shaft body.

As shown in FIGS. 4 and 5, a tuning shaft 12, a printed circuit board 13 on which a variable capacitor (not shown) is fixed,
A dial drum 1 is equipped with a frequency display scale plate 14, etc., and is attached to the tuning shaft 12 and the rotary shaft of the variable capacitor.
5, a dial thread 16 is stretched across the dial thread 16. Further, at a position above the scale plate 14 of the base body 11, there are a number of rotating bodies 1 for guiding the dial thread 16 along the scale plate 14.
7, 18, 19... are arranged, and shaft bodies 20, 21, 22... for rotatably supporting these rotating bodies 17, 18, 19... are arranged on the base 1.
It is formed integrally with 1.

Among the above-mentioned shaft bodies 20, 21..., the shaft body 20 provided near the tuning shaft 12 is the sixth shaft body 20, 21...
As shown in the figure, it is provided obliquely with respect to the mounting surface 23 to which the rotating body 17 is mounted. In this embodiment, the tip 20a of the shaft 20 is inclined downward with respect to the mounting surface 23 which is substantially parallel to the surface of the scale plate 14. The rotating body 17 is rotatably supported on this shaft body 20 as described above, and the shape relationship between this shaft body 20 and the rotating body 17 is, for example, as shown in FIGS.
It is as shown in the figure.

That is, the cross-sectional shape of the body 20b of the shaft 20 is circular, and the outer diameter La of the body 20b is larger than the center of rotation of the rotating body 17 that is pivotally supported on the body 20b. The inner diameter dimension Lb of the formed center hole 17a is formed slightly larger. Therefore, the rotating body 17 is rotatably supported by the shaft 20 with some play. On the other hand, the tip 20a of the shaft body 20 is slightly bulged only in the lateral or vertical direction (in this example, the lateral direction) (see FIG. 8), and the outer diameter dimension Lc of the bulged portion 24 in the lateral direction is , is formed to be slightly larger than the outer diameter dimension La of the body portion 20b. On the other hand, the outer diameter Lc of the bulging portion 24 is slightly smaller than the inner diameter Lb of the center hole 17a of the rotating body 17.
Therefore, the shaft body 2 is inserted into the center hole 17a of the rotating body 17.
When the tip 20a of the shaft 20 is forcibly pressed in and the rotating body 17 is moved to the position shown by the broken line in FIG. ing.

Next, a protrusion 2 is provided on the side portion (in this embodiment, the upper base end of the shaft body 20 as shown in FIG. 9) that forms an obtuse angle θ between the mounting surface 23 and the axis X of the shaft body 20.
5 is formed to protrude integrally with the synthetic resin base 11. This protrusion 25 is connected to the shaft body 2 of the rotating body 17.
The main surface of the rotating body 17 is supported so that the mounting angle to 0 is always maintained at a constant mounting angle, and when the rotating body 17 rotates, the rotating surface becomes the mounting surface 23.
This restricts the angle of inclination to a predetermined angle. In other words, the protrusion 25 is provided to prevent the rotating body 17 from tilting in the direction of the arrow A in FIG. 6 due to the component of the tension applied to the dial thread 16. The protrusion 25 is integrally injection molded with the shaft body 20 and the synthetic resin base 11 when they are molded. 10 and 11 show the states before and after the peripheral portion of the shaft 20 is injection molded using a predetermined mold. First, as shown in FIG. A predetermined upper mold 26 and a lower mold 27 corresponding to the mounting surface 25 and the mounting surface 23 are brought into contact with each other, and a heated fluidized, e.g.
Synthetic resin such as ABS resin is pushed in with a plunger due to uneven injection, and then each mold 26, 27 is inserted into the first
1. Move the shaft body 2 vertically in the figure.
0. The protrusion 25, mounting surface 23, etc. are integrally molded. By the way, in this case, the upper mold 26 and the lower mold 27
The shaft body 20 and the mounting surface 23 are moved vertically.
The moving direction of each of the molds 26 and 27 must be parallel to the mounting surface 23 or the front surface 25a of the protrusion 25 in order to mold the molds. (in the direction of the arrow in FIG. 11) and the front surface 25a of the mounting surface 23 and the protrusion 25.
Since they are parallel to each other, the molds 26 and 27 can be cut out smoothly.

Next, the threading portion 12a of the synchronized shaft 12 is
As shown in FIG. 5, it is not on the extension line of the dial thread 16 that is stretched over the pair of rotating bodies 17 and 18 on the scale plate 14, and is located closer to the dial drum 15 than the position of the dial thread 16. positioned. Therefore, the dial thread 16 is bent toward the dial drum 15 at a portion of the rotating body 17 located near the tuning shaft 12. Therefore, this rotating body 17 has a dial thread 16 in the direction of arrow a in FIG.
Although a component of the tension is acting, the rotating body 17 continues to be pivotally supported by the shaft body 20 while maintaining a predetermined inclination angle due to the projection 25 described above.

In this way, in order to minimize the number of rotating bodies 17, 18 on which the dial thread 16 is installed, the rotating body 17 near the tuning shaft 12 is pivotally supported as in this embodiment. shaft body 20
is provided at an angle with respect to the mounting surface 23,
Since a protrusion 25 for preventing tilting of the rotating body is integrally provided on the mounting surface 23, the protrusion 25 prevents the rotating body 17 from tilting in the direction of the tension component of the dial thread 16. Therefore, dial thread 1
The rotational body 17 is not tilted in the direction of the tension due to the component force of the tension 6, and the side surface 17b of the rotational body 17 and the mounting surface 23 are not parallel to each other. Annular V formed on the outer peripheral surface
The dial thread 16 does not come off from inside the character-shaped groove portion 17c.

Further, the base body 11, the shaft body 20, the protrusion 25, the mounting surface 23, etc. are integrally molded by injection molding, but as shown in FIG. Since the molds 26 and 27 are formed so that their moving directions are parallel to each other, each of the molds 26 and 27 can be punched out smoothly.

As is clear from the above description, the present invention provides an obtuse angle between the mounting surface on the mounting surface and the axis of the shaft on the base end side of the shaft provided at an angle with respect to the mounting surface. A rotational position regulating protrusion is provided at a side position of the shaft to support the main surface of the rotating body and to regulate the rotational surface relative to the mounting surface of the rotating body, so that the tension applied to the dial thread can be reduced. This is extremely useful in practice, since the rotating body does not tilt in the direction of the force component, and therefore, it is possible to prevent the dial thread from separating from the V-shaped groove of the rotating body.

Furthermore, the present invention allows rotation even when a flat scale plate or the like is mounted on the mounting surface, and the mounting surface itself cannot be tilted, or even on a flat mounting surface with a large area. The body can be tilted with respect to the mounting surface, and the mounting rotation operation can be performed while maintaining this tilt angle accurately.

[Brief explanation of the drawing]

Fig. 1 is a partially omitted external perspective view showing an outline of the inside of a radio receiver incorporating a conventional mounting device for a rotating body, and Fig. 2 is a plan view of main parts showing a conventional mounting device for a rotating body. FIG. 3 is a sectional view of a main part of the rotating body mounting device shown in FIG. 2 above. Figure 4 and subsequent figures show an embodiment of the present invention.
The figure is a partially omitted external perspective view showing the internal structure of a radio receiver to which the present invention is applied, Fig. 5 is a partially omitted plan view showing the radio receiver shown in Fig. 4 above, and Fig. 6 is a rotational view. FIG. 7 is a plan view showing the state before the rotating body is attached to the shaft body; FIG. 8 is a front view showing the tip of the shaft body;
Fig. 9 is a perspective view of the main parts showing the vicinity of the shaft body and protrusion formed on the mounting surface, Fig. 10 is a vertical cross-sectional view showing the state in which the upper and lower molds are butted together, and Fig. 11 is the above-mentioned
FIG. 2 is a vertical cross-sectional view showing a state after injection molding of a shaft body, a protrusion, etc. using each of the molds shown in FIG. 11... Synthetic resin base, 12... Tuning shaft, 14... Dial plate, 15... Dial drum,
16...Dial thread, 17...Rotating body, 20...
Shaft body, 23... mounting surface, 25... protrusion.

Claims (1)

[Scope of utility model registration request] A shaft body is integrally provided obliquely to the mounting surface of the synthetic resin base, and the rotating body on which the dial string is installed is rotatably mounted on this shaft body, and the axis of this mounting surface and the shaft body on the above mounting surface. A mounting device for a rotating body, comprising a rotational position regulating protrusion that supports a main surface of the rotating body and regulates a rotational surface relative to a mounting surface of the rotating body, at a side position of the shaft forming an obtuse angle with the rotating body.