JPH0740276Y2 - Knob structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] A sleeve-shaped shaft end fitting portion is integrally formed at a central portion of an inner bottom surface of a cup-shaped knob body made of a resin material, and the sleeve-shaped shaft end fitting portion is fitted. A collar-shaped leaf spring element is inserted into the hole, and the collar-shaped leaf spring element has a flange portion which surrounds the annular edge portion of the sleeve-shaped shaft end fitting portion over at least most of its entire circumference. It is formed.

[Industrial application field]

The present invention is a detachable knob structure used for an operation panel of an electronic device such as an audio device. A leaf spring element for elastically press-fitting the shaft end of a pull switch protruding from the surface of the operation panel is provided. The knob structure incorporated.

[Conventional technology]

Referring to FIG. 5, there is shown a representative knob structure of the type described above, in which the knob body 10 is molded from a suitable thermoplastic material and its overall appearance is cup-shaped. That is, the knob body 10 is composed of a circular plate-shaped portion 12 and an annular peripheral wall portion 14 that integrally rises from the outer peripheral edge of the circular plate-shaped portion 12, and the appearance thereof is the circular plate-shaped portion 12 as the bottom. It becomes a cup shape. A sleeve-shaped shaft end fitting portion 16 is integrally formed at the center of the inner bottom surface of the circular plate portion 12 of the knob body 10, and a collar shape is formed in the fitting hole of the shaft end fitting portion 16. Leaf spring element
Eighteen are accommodated. As shown in FIG. 5, in the fitting hole of the shaft end fitting portion 16 of the knob body 10, for example, the shaft end 20 of a pull switch protruding from the operation panel surface of an electronic device such as an audio device is a leaf spring element 18. It is inserted with the intervening. It goes without saying that the leaf spring element 18 is made of a suitable metal material.

As is well known, the cross section of the shaft end 20 of the pull switch or the like is not a perfect circle, and the cross section is formed by cutting a part of the circle into a half moon shape. That is, a flat portion along the axial direction is formed in a part of the peripheral portion of the shaft end 20 of the pull switch or the like. On the other hand, both the cross section of the fitting hole of the shaft end fitting portion 16 of the knob body 10 and the cross section of the leaf spring element 18 have the same cross section as the shaft end of the pull switch or the like. Once 20 is inserted into the fitting hole of the shaft end fitting portion 16 with the leaf spring element 18 interposed, the shaft end 20 such as a pull switch is
Relative rotational movement, that is, slippage, is prevented between the knob body 10 and the knob body 10.

Referring to FIG. 6, a portion of the leaf spring element 18 is shown in a perspective view, in which a pair of slit-shaped openings 22, 22 are formed. A band-shaped piece 24 is formed between the pair of slit-shaped openings 22 and 22, and the band-shaped piece 24 is bulged inward to function as a spring portion. That is, the shaft end 20 such as the pull switch is the leaf spring element.
When inserted into the fitting hole of the shaft end fitting portion 16 with 18 interposed, the strip-shaped piece 24 of the leaf spring element 18 elastically deforms, and the elastic holding force of the shaft end 20 causes the shaft end 20 to move. It will be held in the fitting hole of the end fitting portion 16. It should be noted that the strip or spring portion
The 24 is usually formed at a position facing a flat portion formed in a part of the peripheral portion of the leaf spring element 18 along the axial direction thereof.

In order to pull out the shaft end 20 of the pull switch or the like in the axial direction to turn on the pull switch, a pull-out force equivalent to about 5 kg is required, so that elasticity of the leaf spring element 18 with respect to the shaft end 20 is required. As the holding force, a force equivalent to at least 5 kg must be obtained.

It has already been stated that the elastic holding force of the leaf spring element 18 with respect to the shaft end 20 of the pull switch, that is, the elastic holding force equivalent to 5 kg or more can be obtained by the elastic deformation of the spring portion 24 of the leaf spring element 10. On the other hand, it means that the strength of the shaft end fitting portion 16 of the knob body 10 must be able to withstand the elastic deformation force of the spring portion 24 of the leaf spring element 10. In fact, if the wall thickness of the shaft end fitting portion 16 of the knob body 10 is too thin, cracks may occur there and the shaft end fitting portion 16 may be destroyed. As a solution to this, it is conceivable to increase the wall thickness of the shaft end fitting portion 16, but this is not a good idea for the following reason.

That is, if the wall thickness of the shaft end fitting portion 16 is increased, the portion of the shaft end fitting portion 16 will be cured most slowly during the molding of the knob body 10, and therefore the outer surface of the circular plate-shaped portion 12 This is because so-called "beard" is generated in the central region. In short, this is because the central region of the outer surface of the circular plate-shaped portion 12 hardens later than the outer peripheral region thereof, so that the central region becomes somewhat depressed.

Therefore, conventionally, the wall thickness of the shaft end fitting portion 16 is set to such a degree that “beard” cannot be generated in the central region of the outer surface of the circular plate portion 12 when the knob body 10 is molded. However, instead, the outer peripheral wall of the shaft end fitting portion 16 has a seventh
A reinforcing collar 26 made of a suitable metallic material as shown will be applied.

[Problems to be solved by the device]

As shown in FIG. 7, by using the reinforcing collar 26, the shaft end fitting portion 16 of the knob body 10 is reinforced, so that the shaft end fitting portion 16 is elastically deformed by the spring portion 24 of the leaf spring element 10. Since it can withstand the force sufficiently, damage such as cracks is avoided. However, in the conventional knob structure, since the number of parts is increased by the amount of the reinforcing collar 26, it has been pointed out that not only the product cost but also the assembling cost for assembling the reinforcing collar 26 is high.

Therefore, it is an object of the present invention to apply a knob structure that can provide sufficient strength to the shaft end fitting portion of the knob body without using an additional reinforcing collar as in the conventional case.

[Means for Solving the Problems]

In the knob structure according to the present invention, the sleeve-shaped shaft end fitting portion is integrally formed at the center of the inner bottom surface of the cup-shaped knob body made of the resin material, and the sleeve-shaped shaft end fitting portion is fitted. A collar-shaped leaf spring element is inserted in the hole to receive a predetermined shaft end. According to the present invention, in such a knob structure, one end edge of the collar-shaped leaf spring element surrounds the annular edge portion of the sleeve-shaped shaft end fitting portion over at least most of its entire circumference. A flange portion is formed, which is characterized in that it includes an annular projecting piece (48) extending from its outer edge towards the other edge of the collar-shaped leaf spring element.

[Action]

According to the knob structure as described above, the collar-shaped leaf spring element surrounds the annular edge portion of the sleeve-shaped shaft end fitting portion of the knob body over at least most of its entire circumference. The flange portion reinforces the annular edge portion of the sleeve-shaped shaft end fitting portion, that is, the weakest portion thereof.

〔Example〕

An embodiment of a knob structure according to the present invention will now be described with reference to FIGS. 1 to 4 of the accompanying drawings.

In the knob structure according to the present invention, similarly to the conventional knob structure shown in FIG. 5, the knob body 28 is molded from a suitable thermoplastic resin material, and its overall appearance is cup-shaped. That is, as shown in FIG. 1, the knob body
Reference numeral 28 denotes a circular plate-shaped portion 30 and an annular peripheral wall portion 32 that integrally rises from the outer peripheral edge of the circular plate-shaped portion 30, and its appearance is a cup shape having the circular plate-shaped portion 30 as the bottom. .
A sleeve-shaped shaft end fitting portion 34 is integrally formed at the center of the inner bottom surface of the circular plate-shaped portion 30 of the knob body 28, and the shaft end fitting portion 34 has a collar-shaped leaf spring. element
A fitting hole for accommodating the 36 is formed.

As is apparent from FIG. 2, the cross-sectional shape of the shaft end fitting portion 34 is not a perfect circle, and the cross-section is a shape obtained by cutting out a part of the circle in a half-moon shape. A flat portion along the axial direction is provided in a part of the peripheral portion of the end fitting portion 34. Further, the cross-sectional shape of the fitting hole of the shaft end fitting portion 34 and the cross-sectional shape of the leaf spring element 36 are both similar to the cross-sectional shape of the shaft end fitting portion 34, whereby the leaf spring element is formed. 36 is accommodated in the fitting hole of the shaft end fitting portion 34 in a non-rotating state. As already described with reference to FIG. 5, the shaft end fitting portion
The cross-sectional shape of the fitting hole 34 and the leaf spring element 36 is made to coincide with the cross-section of the shaft end 38 of the pull switch or the like, so that the shaft end 38 of the pull switch or the like is formed as shown in FIG. Once inserted into the fitting hole of the shaft end fitting portion 34 with the spring element 36 interposed, relative rotational movement, that is, slippage is prevented between the shaft end 38 such as a pull switch and the knob body 28. Will be.

As is apparent from FIGS. 3 and 4, a slit 40 is formed in the flat portion of the leaf spring element 36 substantially in the center thereof along the axial direction thereof.
Is formed (FIG. 3), while a strip 42 is formed by a pair of slit-shaped openings 44, 44 on the wall surface of the leaf spring element 36 on the side facing the slit 40 (FIG. 4). Similar to the case described with reference to FIG. 5, the strip 42 is raised inward and functions as a spring portion. That is, when the shaft end 38 of the pull switch or the like is inserted into the fitting hole of the shaft end fitting portion 34 with the leaf spring element 36 interposed, the strip-shaped piece of the leaf spring element 36 is formed.
42 is elastically deformed, and the elastic holding force holds the shaft end 38 in the fitting hole of the shaft end fitting portion 34.

As best shown in FIG. 4, a flange portion 46 is formed on one edge of the leaf spring element 36.
Includes an annular projecting piece 48 extending from its outer edge toward the other edge of the leaf spring element 36. Regarding the dimension and shape of the flange portion 46, when the leaf spring element 36 is housed in the fitting hole of the shaft end fitting portion 34 as shown in FIG. It is like being surrounded. As best shown in FIG. 2, the flange portion 46 surrounds the annular edge of the leaf spring element 36 over most of its perimeter (ie, all but the slit 40 of the leaf spring element 36). This reinforces the annular edge portion of the shaft end fitting portion 34, that is, the weakest portion thereof. As seen in Figure 2,
The central portion of the flat portion of the shaft end fitting portion 24 (that is, the slit 40
(Exposed areas) along the axis line
50 is formed, which reinforces the central portion and prevents cracks therefrom.

In the above-mentioned embodiment, the reason why the slit 40 is formed in the leaf spring element 36 is that the leaf spring element 36 is obtained by a relatively low cost and relatively easy manufacturing method. In short, in this embodiment, the slit 40 is inevitably left behind for manufacturing reasons of the leaf spring element 36. However, it is preferable to eliminate the slit 40 from the leaf spring element 36, and it is possible to obtain the leaf spring element 36 in which the slit 40 is eliminated according to a relatively high cost manufacturing method. Needless to say, even if the manufacturing method is relatively expensive, the cost can be reduced by mass-producing the leaf spring elements 36. When the slit 40 is removed from the leaf spring element 36, the annular edge portion of the shaft end fitting portion 34 is completely surrounded by the flange portion 46 and the annular protruding piece 48 of the leaf spring element 36. Shaft end fitting part
The ridge portion 50 is excluded from the flat portion of 34.

Further, in the above-described embodiment, the annular protruding piece 48 of the flange portion 46.
Although the width of the annular protruding piece 48 is made smaller than the axial length of the leaf spring element 36, it goes without saying that the width of the annular protruding piece 48 may be further increased.

[Effect of device]

As is apparent from the above description, according to the present invention, the collar-shaped leaf spring element surrounds the annular edge of the sleeve-shaped shaft end fitting portion of the knob body over at least most of its entire circumference. The use of the additional reinforcement collar used in the conventional knob structure, because the flange part is formed, and this flange part reinforces the annular edge part of the sleeve-shaped shaft end fitting part, that is, the weakest part thereof. Will be eliminated. Therefore, the knob structure according to the present invention has an advantage that the number of parts and the assembling cost are reduced as compared with the conventional case.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing a knob structure according to the present invention, and FIG.
The drawing is an end view taken along the line II-II in FIG. 1, showing the shaft ends of pull switches and the like, and FIG. 3 is a leaf spring element used in the knob structure of FIG. 4 is a plan view, FIG. 4 is a sectional view taken along line IV-IV in FIG. 3, FIG. 5 is a longitudinal sectional view showing a conventional knob structure, and FIG. 6 is a leaf spring used in the knob structure of FIG. FIG. 7 is a perspective view of the element, in which a part of the leaf spring element is cut out, and FIG. 7 is a vertical sectional view similar to FIG. 5, in which a reinforcing collar is incorporated in the knob structure of FIG. It is a figure shown in a state. 28 ... knob body, 30 ... circular plate portion, 32 ... annular peripheral wall portion,
34 ... Shaft end fitting portion, 36 ... Leaf spring element, 38 ... Shaft end, 40 ... Slit, 42 ... Strip-shaped piece, 44 ... Slit-shaped opening, 46 ... Flange portion 46, 48 ... Annular projecting piece, 50 ... Projection Article.

Claims (1)

[Scope of utility model registration request] 1. A cup-shaped knob body (28) made of a resin material.
Sleeve shaped shaft end fitting (34) at the center of the inner bottom surface of
And a collar-shaped leaf spring element (36) inserted into the fitting hole of the sleeve-shaped shaft end fitting portion (34) to receive a predetermined shaft end (38). In the structure, one end of the collar-shaped leaf spring element (36) surrounds the annular edge of the sleeve-shaped axial end fitting portion (34) over at least most of its entire circumference. A flange portion (46) is formed, and this flange portion (46)
Includes a ring-shaped protruding piece (48) extending from its outer edge toward the other end of the collar-shaped leaf spring element (36).