JPS6243384Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] This invention relates to a switching rotation shaft structure for Hz switching, switch switching, etc. used in watches, timers, etc.

[Background technology]

A typical Hz switching mechanism used in watches, timers, etc. has a Hz switching rotation axis A as shown in Figure 1, for example.
By switching and rotating at predetermined intervals,
mesh with gear B-C-D, or gear B-C'-
It meshes with D. In order to provide such a switching rotation shaft structure with a simple structure that satisfies the demand for cost reduction, the structure shown in FIGS. 2 to 4 has been proposed. That is, the switching rotation shaft 1 has a switching operation groove 2 at one end, a lever section 3 for displacing other members at the middle section, and a movable piece section 5 and a fixed section divided by a dividing groove 4 at the other end. 6, and a projection 7 is provided on the outer periphery of the movable piece 5, which is integrally molded with plastic. On the other hand, the substrate 8 that rotatably supports the switching rotation shaft 1 has positioning recesses 9a and 9b for the protrusion 7 with a predetermined interval L.
The intermediate portion 9c has a fitting hole 10 connected with a suitable straight line or curve. Therefore, the protrusion 7 of the switching rotation shaft 1 is located in the positioning recess 9a of the board 8.
When a switching operation is performed to position the positioning recess 9b from the state where the protrusion 7 is positioned, the protrusion 7 receives a force toward the groove 4 from the intermediate portion 9c of the positioning recesses 9a and 9b, causing the movable piece 5 to move inward. A deflection force is generated. This elastic force acts as a resistance to the rotating force, and reaches its maximum approximately halfway through the switching operation, and decreases as it passes through that section.
Since the switching rotation shaft 1 is applied with a force that overcomes its maximum elastic force and causes it to rotate, the protrusion 7 quickly reaches the positioning recess 9b and the switching operation is completed. For such a switching rotation shaft structure, the operating feel during switching operation is important, and appropriate operating torque and click action are required. Since only the power is used, too much deflection may lead to breakage, and there are drawbacks such as difficulty in achieving appropriate operating torque and click action, and deterioration due to the influence of temperature. .

[Purpose of invention]

Therefore, an object of the present invention is to provide a switching rotation shaft structure that has a simple structure and provides a suitable operating feel.

[Disclosure of the invention] The switching rotation shaft structure of the present invention has a movable piece part and a fixed piece part divided by a groove, and a switching rotation shaft in which a protrusion is provided on the outer periphery of the movable piece part; In a switching rotation shaft structure comprising a substrate rotatably supporting a switching rotation shaft and having fitting holes in which positioning recesses for the protrusions are formed projecting at predetermined intervals, the switching rotation shaft A protrusion having a circular cross section is formed on one of the movable piece portion and the fixed piece portion, and a protrusion having a sliding slope on the other side is formed facing each other.

(Embodiment) An embodiment of the present invention is shown in FIG. 5, and parts having the same structure as those in FIGS. 2 and 3 shown as conventional examples are given the same reference numerals and will be explained with reference to the drawings. do. That is, a cylindrical switching rotation shaft 1 integrally molded from plastic has a switching operation groove 2 at one end, a lever section 3 for changing other members at the middle part, and a dividing groove 4 at the other end. The movable piece part 5 has a movable piece part 5 and the fixed piece part 6 which are divided by the above-mentioned. A circular protrusion 11 with a cross section slightly lower than 1/2 width on the 4 side, and two symmetrical sliding inclined surfaces 13, 14 with a height approximately 1/2 the width on the split groove 4 side of the fixed piece part 6. The protrusions 12 each having an isosceles triangular cross section are formed facing each other with a slight gap G interposed therebetween. This protrusion 12
This acts as an inclined surface on which the protrusion 11 having a circular cross section of the movable piece 5 slides after the movable piece 5 is bent inward and the slight gap G becomes zero. On the other hand, on the substrate 8 that rotatably supports the switching rotation shaft 1, recesses 9a and 9b for positioning the protrusion 7 of the movable piece 5 are formed protrudingly at a predetermined interval L, and the intermediate portion 9c is It has fitting holes 10 connected by appropriate straight lines or curves.

(Operation) Next, the operation of the present invention will be explained with reference to FIGS. 6a and 6b. The switching rotation shaft 1 is rotatably supported in the fitting hole 10 of the board 8, and the protrusion 7 of the movable piece 5 is positioned in either the positioning recess 9a or 9b of the fitting hole 10. There is. In order to perform a switching operation from one of these positions to another position, when the switching rotation shaft 1 is rotated, for example, in the direction of the arrow, the protrusion 7 is first moved toward the groove 4 side by the intermediate portion 9c of the positioning recesses 9a and 9b. The movable piece part 5 bends inward in response to the force, and the circular cross-sectional protrusion 11 and the sliding inclined surfaces 13 and 14
A slight gap G between the protrusion 12 and the protrusion 12 becomes zero. As the rotation continues further, the movable piece 5 is deflected in the splitting direction of the splitting groove 4, and the protrusion 11
slides on the sliding slope 13 of the protrusion 12. The elastic force generated by the deflection of the movable piece 5 and the force required to slide on the inclined surface 13 act as resistance to the rotating force, and reach a maximum approximately in the middle of the switching operation. As it passes through that section, it becomes smaller, but since the switching rotation shaft 1 is applied with a force that overcomes these resistance forces and rotates it, that is, an operating torque, the protrusion 7 rapidly becomes smaller. The switching operation is completed when the positioning recess 9b or 9b to be positioned is reached. Here, as shown in FIG.
The force applied to the inclined surface of the protrusion 12 having 3 and 14 is F, and the inclination angle is θ, and the force in the direction perpendicular to the inclined surface is
Since F' is F cos θ, the optimum operating torque can be set by appropriately selecting the inclination angle θ.If the same elastic force is generated in the movable piece 5 as in the conventional example, then the coefficient of friction is set as μ. Operating torque is also 1/{1
-(cos ² θ+μsin θcos θ)} times, so even if the amount of deflection of the movable piece 5 is reduced, the required operating torque and click action can be obtained.

In the embodiment shown in FIG. 5, the movable piece 5 has a protrusion 11 with a circular cross section, and the fixed piece 6 has a protrusion with an isosceles triangular cross section having two symmetrical inclined surfaces 13 and 14. 12 are formed facing each other, but they may be formed in opposite directions, and the operating torque will be approximately the same regardless of whether they are rotated in the forward or reverse direction. However, as shown in FIG. A protrusion 1 having a gentle sliding slope 13' and a sharp sliding slope 14' having different slopes.
If 2' is formed on the fixed piece 6', the operating torque can be differentiated depending on the forward and reverse rotation directions.

[Effect of idea]

As described above, in the present invention, a protrusion with a circular cross section and a protrusion with a sliding slope on the other side of the movable piece and fixed piece of the conventional switching rotation shaft are formed facing each other, so new parts are required. The required operating torque and click operation can be obtained even if the deflection of the movable piece during switching operation is small without any additional addition, and these are not easily affected by temperature.Furthermore, the inclination angle of the sliding slope can be selected appropriately. This makes it possible to provide a switching rotation shaft structure that provides a desired operating feel.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing a general Hz switching mechanism, Fig. 2 is a perspective view of the same structure of the conventional example and an embodiment of the present invention, and Fig. 3 is the shape of the board fitting hole. 4 is a plan view of a conventional switching rotation shaft, FIG. 5 is a plan view of a switching rotation shaft according to an embodiment of the present invention, and FIG. 6 is a plan view showing its operation. FIG. 7 is an enlarged explanatory view thereof, and FIG. 8 is a plan view of a switching rotation shaft of another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Switching rotation axis, 4... Division groove, 5... Movable piece part, 6... Fixed piece part, 7... Projection, 8... Board,
9a, 9b...positioning recess, 10...fitting hole,
11...Protrusion having a circular cross section, 12...Protrusion having an inclined surface.

Claims (1)

[Scope of utility model registration request] A switching rotation shaft has a movable piece portion and a fixed piece portion separated by a groove, and a protrusion is provided on the outer periphery of the movable piece portion, and the switching rotation shaft is rotatably supported, and the switching rotation shaft is rotatably supported. In the switching rotation shaft structure, the switching rotation shaft structure includes a substrate having a fitting hole in which a positioning recess of the protrusion is formed protrudingly formed with an interval of . A switching rotation shaft structure characterized in that a protrusion and a protrusion having a sliding slope on the other side are formed facing each other.