JPH0112428Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field of the invention] The invention is applicable to tuners of radio receivers, etc.
The present invention relates to a dial device used for frequency tuning and display.

[Technical background of the invention and its problems]

Analog systems and digital quartz lock systems are often used as dial devices for radio receivers.

In the former analog system, as illustrated in FIG.
A pulley 4 is rotatably supported by bosses 3 protruding from two or three places near the rear corner, and a variable capacitor (variable capacitor) 6 is installed on a PC board 5.
A drum 7 is fixed to the rotating shaft 6a of this variable capacitor,
A dial cord 8 wound around a small diameter portion provided on the rear end side of the tuning shaft 2 is looped between the drum and the pulley 4, and a rail is provided on the rear side of the dial panel 1 protruding along the scale plate 1a. Pointer 10 on panel 9
are slidably engaged with each other, and a part of the dial cord is clamped and fixed to the pawl 10a of the pointer 10.

In such an analog dial device, when the knob 11 attached to the front side of the tuning shaft 2 is rotated, the movement is transmitted to the drum 7 via the dial cord 8, changing the capacitance of the variable capacitor and performing tuning. At the same time, the pointer 10 is moved along the scale plate 1a to display the tuning frequency.

However, in the analog type dial device having the above configuration, since the variable capacitor 6 is mounted on the PC board 5, the dial code installation work is restricted by the design layout of the product and the component layout on the board 5. In addition, due to the need for a back plate to realize unit adjustment in the board state, it is very time-consuming to assemble, increases the number of parts, and has the disadvantage that it is difficult to improve the efficiency of the manufacturing process. .

On the other hand, the aforementioned digital quartz lock type dial device puts the frequency from the crystal oscillator into a frequency dividing circuit, tunes it to the desired frequency, and displays this as a digital quantity on an electronic display such as a liquid crystal or LED. However, this method has the disadvantage that it cannot be used in low-end products because the number of peripheral circuit parts is large and the display is also expensive.

[Purpose of invention]

This invention was developed to eliminate the above-mentioned drawbacks of analog dial devices.It eliminates constraints due to design layout and component layout, and also makes it possible to adjust the unit in the board state, improving the efficiency of the manufacturing process. It is an object of the present invention to provide a dialing device as described above.

[Summary of the idea]

In order to achieve the above-mentioned object, the dial device of the present invention has a tuning shaft that rotatably passes through the dial panel, a knob attached to the front end of the tuning shaft, and a knob on the rear surface of the dial panel that is coaxial with the tuning shaft. A cylindrical rib provided on the cylindrical rib, a drum having a sleeve loosely fitted to the rib, a dial cord that is stretched between the drum and the pulley and runs the pointer, and an inner shaft that is engaged with the synchronizing shaft. and an adjustable electronic component having a two-axis structure in which an outer shaft is engaged with the drum, and the outer shaft rotates by a smaller angle in accordance with the rotation of the inner shaft. It is something.

[Example of idea]

Hereinafter, the present invention will be explained in detail with reference to FIGS. 2 to 4.

FIG. 2 shows a plan view of the main parts of the dial device of the present invention.
0a is formed, and a bearing fitting 21a that rotatably supports the tuning shaft 21 is fitted into a through hole provided in the center thereof, and is fixed with a nut 21b.
The tuning shaft 21 has a knob 22 on the entire surface side of the panel 20.
is attached, and an adapter 23 made of a resin material or the like is attached to the rear side. Although not shown in the drawings, the vicinity of the rear end of the tuning shaft 21 is a so-called D-axis having a cross-sectional shape similar to that of a cross-section, and the inner surface of the adapter 23 that engages therewith has a shape corresponding to the D-axis.

A cylindrical rib 20b is provided on the rear surface of the concave portion 20a, coaxially with the tuning shaft 21, and a sleeve 24 provided on the drum 24 is provided near the outer end of this rib.
a is loosely fitted in a rotatable manner. A pair of bosses 25 are protruded from the rear surface of the concave portion 20a on both the left and right sides thereof, and a mounting plate 27 to which a volume (variable resistor) 26 is fixed in advance with nuts 26a is attached to these bosses with screws. It can be installed at 28.

The volume 26 has a synchronous inner shaft 26b and an outer shaft 2.
6c is composed of a double volume with a vernier having a rotation ratio of, for example, 5:1 (when the inner shaft rotates 5 times, the outer shaft rotates once), and the inner shaft 26b fits into the adapter 23, and the outer shaft The shaft 26c is the drum 24
After positioning it so that it fits into the inner hole of the mounting plate 27, it is mounted using the mounting plate 27.

Note that the inner shaft 26b and the adapter 23 are connected to the knob 2.
2 is turned too much and the pointer (to be described later) exceeds the running limit, the serration shaft is engaged so that it will slip with a moderate torque, and the outer shaft 26c and the inner hole of the drum 24 are designed to be engaged regardless of the magnitude of the torque. It is a D-axis engagement that does not cause any slip.

FIG. 3 shows the overall configuration of the dial device of the present invention.
A pulley 31 is rotatably supported on a boss 30 installed on the opposite side of the dial cord 3, which is placed between the dial cord 3 and the drum 24.
2 includes a rail panel 3 as in FIG.
A pointer 34 running along 3 is fixed.
Reference numeral 35 indicates a spring that prevents the dial cord 32 from sagging, and reference numeral 36 indicates a flat cable for taking out the output of the volume 26.

As mentioned above, in the dial device of the present invention, a double volume with a vernier having an appropriate vernier ratio is used as the volume, and its inner shaft is engaged with a tuning shaft that is rotationally driven by a knob, and
Since the outer shaft is engaged with the drum for driving the pointer, as shown in Figure 4, before the volume is installed, thread the dial cord over the pulley and drum to attach the pointer. This makes it possible to perform so-called sub-processing, making it possible to improve the efficiency of the manufacturing process. Furthermore, the number of parts is reduced, layout constraints can be avoided, and the structure can be simplified, making it possible to reduce manufacturing costs.

Further, according to the present invention, the sliding of the pointer and the rotation of the volume are linked by operating the knob, and a varicap system can be realized in which the receiving frequency can be varied by changing the resistance value of the volume.

In this case, the amount of movement L of the pointer is L=π(D+d)A However, D: Diameter of the threading part of the drum d: Thread diameter of the dial cord A: Rotation ratio of the inner and outer shafts of the volume, so the rotation of the knob and The amount of movement of the pointer and the amount of frequency change can be made to correspond one-to-one.

Further, the rotation of the knob after the pointer reaches the end of its travel can be performed with the same slip sensation as in the conventional analog threading system by employing serration shaft engagement or the like.

In the above explanation, an example has been described in which a volume is used as an adjustable electronic component for tuning, but the present invention is not necessarily limited to this, and a variable capacitor with a biaxial structure having an appropriate rotation ratio is used. However, almost the same effect as described above can be obtained.

[Effects of the invention] As described above, according to the invention, it is possible to eliminate constraints due to design layout and component layout, make it possible to adjust the unit in the board state, improve the efficiency of the manufacturing process, and furthermore, reduce the number of parts. It is possible to provide a dial device with reduced manufacturing costs due to the reduction in .

[Brief explanation of the drawing]

Fig. 1 is a perspective view illustrating a conventional analog type dial device, Fig. 2 is a plan view of essential parts showing an embodiment of the dial device of the present invention, and Fig. 3 is an entire example of the dial device of the present invention. Perspective view showing the configuration, No. 4
The figure is a perspective view for explaining the assembly process of the example of FIG. 3. 1, 20... Dial panel, 2, 21... Tuning shaft, 3, 25, 30... Boss, 4, 31... Pulley, 5... PC board, 6... Variable capacitor, 7, 2
4...Drum, 8,32...Dial code,
9,33...Rail panel, 10,34...Pointer, 11,22...Knob, 23...Adapter, 2
6...Volume, 27...Mounting plate, 35...Spring, 36...Flat cable.

Claims (1)

[Claims for Utility Model Registration] (1) A tuning shaft that rotatably passes through the dial panel, a knob attached to the front end of this tuning shaft, and a knob that is located on the same axis and outside of the tuning shaft. a cylindrical rib located at and integrally formed inside the dial panel, a drum having a sleeve loosely fitted to the rib, a dial cord that runs between the drum and the pulley and runs the pointer, and the tuning cord. engaging an inner shaft with a member interlocking with the shaft, and engaging an outer shaft with the drum;
and a variable resistor having a two-axis structure in which the outer shaft rotates by an angle smaller than the rotation of the inner shaft. (2) The dial according to claim 1 of the utility model registration, wherein the engagement between the member interlocking with the tuning shaft and the inner shaft can slip when a predetermined load is exceeded, and the drum and the outer shaft cannot slip. Device.