Operating knob, shaft member, and operating member

Abstract

To provide an operation member in which an elastic part of a spring is not plastically deformed when an operation knob is attached to a shaft member, the operation knob can be surely attached to the shaft member, and attachment / detachment of the operation knob can be repeated.SOLUTION: An operation knob attached to a distal end portion of a shaft member, wherein a fitting hole into which the distal end portion of the shaft member is inserted is formed, an elastic member that elastically abuts against a side surface of the distal end portion is provided on a side surface of the fitting hole, and a protrusion that is fitted into a slit formed in the distal end portion is formed on a bottom portion of the fitting hole.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an operating knob, a shaft member, and an operating member. [Background technology]

[0002] Conventionally, in the configuration of an operating member in which a shaft member is inserted into a fitting hole formed in an operating knob and attached, a type in which a spring-like elastic portion provided in the fitting hole elastically abuts against the outer periphery of the shaft member to generate a holding force has been widely adopted. The structure of a conventional operating member will be explained with reference to Figures 9 to 12. Figure 9 is a cross-sectional view of a conventional operating member. Figure 10 is a diagram showing a conventional shaft member. Figure 11 is a diagram showing a conventional operating knob. Figure 12 is a diagram showing a conventional spring.

[0003] 10(A) is a side view of the shaft member 6, and (B) is a front view as viewed from the axial direction. As shown in Fig. 10, the shaft member 6 has a cylindrical main body portion 61 and a tip portion 62 formed on the tip side of the main body portion 61 and having an outer circumferential surface with an arc-shaped portion 64 and a flat portion 65. An annular recess 63 is formed in the circumferential direction in the arc-shaped portion 64. The tip portion 62 has a substantially D-shape as viewed from the axial direction due to the arc-shaped portion 64 and the flat portion 65.

[0004] Fig. 11 is a view of the operating knob 7 as seen from the fitting hole 71 side. As shown in Fig. 11, the operating knob 7 is formed with a fitting hole 71 into which the tip portion 62 of the shaft member 6 is inserted. The cross-sectional shape of the fitting hole 71 is substantially the same as the cross-sectional shape of the tip portion 62, that is, a roughly D-shape. A spring 8 is provided on the side surface of the fitting hole 71 so as to be inscribed within the fitting hole 71. An elastic portion 83 of the spring 8 protrudes inward.

[0005] 12(A) is a front view of spring 8 as viewed from the axial direction, and (B) is a side view. As shown in FIG. 12, spring 8 has an arc-shaped portion 81 and a flat portion 82, is cylindrical, and allows tip portion 62 to be inserted, and has a substantially D-shaped cross section. A portion of arc-shaped portion 81 is formed to protrude inward as elastic portion 83. Spring 8 is fitted so that its D-shape is inscribed in the D-shape of fitting hole 71, with its orientation aligned with the D-shape of fitting hole 71.

[0006] 9, the operating knob 7 is attached to the shaft member 6 by inserting the spring 8 with the D-shaped shaft member 6 and the D-shaped spring 8 aligned so that the flat portion 65 of the tip end 62 of the shaft member 6 contacts the inner surface of the flat portion 82 of the spring 8. At this time, the elastic portion 83 of the spring 8 engages with the annular recess 63, thereby preventing the operating knob 7 from falling off the shaft member 6. Summary of the Invention [Problem to be solved by the invention]

[0007] In the prior art, during the process of attaching the operating knob 7 to the shaft member 6, the elastic portion 83 of the spring 8 is strongly pushed outward by the arc-shaped portion 64 of the shaft member 6, causing a large amount of deformation, which can cause the spring material to exceed its elastic limit and undergo plastic deformation (crush). When plastic deformation occurs, problems such as a decrease in holding force, the generation of rattles, and the operating knob coming off can easily occur, and in applications where the operating knob 7 is repeatedly attached and detached, this can lead to a decrease in durability.

[0008] In view of the above-mentioned problems, the present disclosure aims to provide an operating member that does not cause plastic deformation of the elastic part of the spring when attaching the operating knob to the shaft member, that allows the operating knob to be securely attached to the shaft member, and that allows the operating knob to be repeatedly attached and detached. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the operating knob of the present disclosure is an operating knob attached to the tip of an axial member, and has a fitting hole formed therein into which the tip of the axial member is inserted, an elastic member is provided on the side of the fitting hole that elastically abuts against the side of the tip, and a protrusion is formed on the bottom of the fitting hole that fits into a slit formed in the tip.

[0010] In addition, the shaft member of the present disclosure is a shaft member whose tip is inserted into a fitting hole of an operating knob, and has a cylindrical main body portion and a tip portion formed on the tip side of the main body portion and having an arc-shaped portion and a flat portion on the outer circumferential surface, wherein a ring-shaped recess is formed in the circumferential direction of the arc-shaped portion, and a slit is formed in the axial direction of the tip portion.

[0011] The operating member of the present disclosure comprises an operating knob that is attached to the tip of an axial member, the operating knob having a fitting hole formed therein into which the tip of the axial member is inserted, an elastic member that elastically abuts against the side of the tip, and a protrusion that fits into a slit formed in the tip at the bottom of the fitting hole; and an axial member whose tip is inserted into the fitting hole of the operating knob, the axial member having a cylindrical main body and a tip formed on the tip side of the main body and having an arc-shaped portion and a flat portion on its outer circumferential surface, the arc-shaped portion having an annular recess formed circumferentially, and a slit formed in the tip in the axial direction, and when the tip of the axial member is inserted all the way to the bottom of the fitting hole, the protrusion is fitted into the slit. [Effects of the Invention]

[0012] According to the present disclosure, by providing a slit at the tip of the shaft member, the tip elastically bends and reduces in diameter when the operating knob is attached to the shaft member, thereby relatively reducing the amount of deformation acting on the elastic portion of the spring. As a result, plastic deformation of the elastic portion is prevented, the operating knob can be securely attached to the shaft member, and the operating knob can be repeatedly attached and detached.

[0013] In addition, a protrusion is formed at the bottom of the fitting hole, and when the shaft member is inserted into the fitting hole of the operating knob, the protrusion is fitted into the slit, so that when the operating knob is attached to the shaft member, the tip portion is less likely to contract in diameter, and the elastic portion securely engages with the annular recess, ensuring that the operating knob is securely held on the shaft member. [Brief explanation of the drawings]

[0014] [Figure 1] 3A and 3B are diagrams illustrating the structure of an operating member. [Figure 2] FIG. 2 is a diagram showing the structure of a shaft member. [Figure 3] 10A and 10B are diagrams showing the structure of an operation knob. [Figure 4] FIG. 2 is a diagram showing the structure of a spring. [Figure 5] 10A and 10B are diagrams showing a state in which an operating knob is attached to a shaft member. [Figure 6] 10A and 10B are diagrams showing modified examples of the protrusions. [Figure 7] 10A and 10B are diagrams showing modified examples of the protrusions. [Figure 8] 10A and 10B are diagrams showing modified examples of the protrusions. [Figure 9] FIG. 10 is a diagram showing the structure of a conventional operating member. [Figure 10] FIG. 10 is a diagram showing the structure of a conventional shaft member. [Figure 11] 1A and 1B are diagrams showing the structure of a conventional operating knob. [Figure 12] FIG. 1 is a diagram showing a conventional spring structure. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The drawings are merely examples, and the present disclosure is not limited thereto.

[0016] 1 is a schematic cross-sectional view of one embodiment of an operating member 1 of the present disclosure, showing a state in which an operating knob 3 is attached to a tip end portion 22 of a shaft member 2. The shaft member 2 comprises a main body portion 21 and a tip end portion 22, and an annular recess 23 is formed at a predetermined position on the outer periphery of the tip end portion 22.

[0017] A fitting hole 31 is provided in the operating knob 3, and a spring 4 is fitted into the fitting hole 31. The cross section of the spring 4 is substantially D-shaped, and an elastic portion 43 formed on a part of the spring 4 protrudes inward.

[0018] The tip portion 22 of the shaft member 2 is inserted into the spring 4 in the fitting hole 31. The elastic portion 43 engages with the annular recess 23 of the shaft member 2, thereby preventing the operating knob 3 from falling off the shaft member 2.

[0019] A slit 26 is formed in the axial direction in the tip portion 22 of the shaft member 2. In addition, a protrusion 32 is formed at the bottom of the fitting hole 31. Because the protrusion 32 enters the slit 26, the tip portion does not bend and reduce in diameter, and therefore the elastic portion 43 reliably engages with the annular recess 23, making it difficult for the operating knob 3 to fall off the shaft member 2.

[0020] The details of the shaft member 2 will be described with reference to Fig. 2. Fig. 2 is a diagram showing the details of the shaft member 2. The shaft member 2 comprises a main body portion 21 and a tip portion 22, and an annular recess 23 is formed at a predetermined position on the outer periphery of the tip portion 22. The tip portion 22 is provided with a flat portion 25, which faces a flat portion 42 (see Figs. 1 and 3) of the spring 4 in a fitting hole 31 provided in the operating knob 3, thereby determining its position around the axis. Furthermore, the tip portion 22 is formed with a single slit 26 extending in the axial direction.

[0021] The cross section of tip portion 22 is approximately D-shaped, and circumferential positioning is possible with flat portion 25. Slit 26 is provided to facilitate elastic deformation of tip portion 22 in the diameter contraction direction, and the width, depth, length and remaining thickness of slit 26 are designed taking into consideration the amount of diameter contraction, strength and durability of the tip portion.

[0022] Details of the operating knob 3 will be described with reference to Figure 3. Figure 3 is a diagram showing details of the operating knob 3. The fitting hole 31 of the operating knob 3 has a substantially D-shaped cross section, similar to the tip portion 22. A protrusion 32 that protrudes in the axial direction is formed at the bottom of the fitting hole 31. The protrusion 32 has a size and shape that allows it to be fitted into the slit 26. A spring 4 is fitted into the inner periphery of the fitting hole 31, closely fitting to the D-shape of the fitting hole. An elastic portion 43 protrudes inward from the spring 4.

[0023] The details of spring 4 will be described with reference to Figure 4. Figure 4 is a diagram showing the details of spring 4. Spring 4 is an annular member, and has an arc-shaped portion 41 and a flat portion 42, giving it a generally D-shaped cross section. An elastic portion 43 that protrudes inward is formed in part of arc-shaped portion 41, and elastic portion 43 elastically abuts against the outer periphery of shaft member 2 to provide holding force. A thin-walled metal spring or the like can be used as the material for spring 4. Flat portion 42 of spring 4 is positioned opposite flat portion 25 of tip portion 22, ensuring rotation transmission and positioning around the shaft.

[0024] The process of attaching the operating knob to the shaft member will be described with reference to Fig. 5. Fig. 5 is a diagram showing the process of attaching the operating knob to the shaft member, where (A) shows the attachment process of this embodiment and (B) shows the attachment process of the prior art.

[0025] The manner in which the operating knob 3 of this embodiment is attached to the shaft member 2 will be described with reference to (A). First, with the spring 4 (see FIG. 4) held at a predetermined position in the fitting hole 31, when the tip portion 22 of the shaft member 2 is inserted into the spring 4 by aligning the D-shaped portion of the tip portion 22 with the D-shaped portions of the fitting hole 31 and the spring 4, the tip portion 22 is pressed toward the axis by the elastic portion 43, and the tip portion 22 is elastically deflected by the slits 26 to reduce its diameter (left side of the figure). The reduced diameter of the tip portion 22 reduces the pressure on the elastic portion 43 of the spring 4, and the deformation of the elastic portion 43 remains within the elastic range, allowing the tip portion 22 to be inserted without plastic deformation (crushing).

[0026] As the insertion progresses, the elastic portion 43 of the spring 4 engages with the annular recess 23 (right side of the figure). This establishes locking in the axial and circumferential directions. In addition, when the tip of the protrusion 32 at the bottom of the fitting hole 31 enters the opening of the slit 26 and the protrusion 32 is positioned within the slit 26, the diameter reduction of the tip portion 22 is physically restricted. This ensures the engagement between the elastic portion 43 and the annular recess 23.

[0027] Once attached, the preload of spring 4 and engagement with annular recess 23 work together to securely hold operating knob 3, and when knob 3 is rotated, flat portion 42 and flat portion 25, which have a substantially D-shaped cross section, engage with each other to reliably transmit position around the axis, allowing shaft member 2 and operating knob 3 to rotate together. Furthermore, because protrusion 32 enters slit 26, the diameter of tip portion 22 is prevented from shrinking, improving the stability of the holding force over long periods of use.

[0028] In this embodiment, the elastic portion 43 is unlikely to undergo plastic deformation when the operating knob 3 is attached to the shaft member 2, so the operating knob 3 can be attached to and detached from the shaft member 2 repeatedly.

[0029] Next, the manner in which the operating knob 7 of the prior art is attached to the shaft member 6 will be described with reference to (B). When the tip portion 62 of the shaft member 6 is inserted into the spring 8 (see FIG. 12), the tip portion 62 pushes and expands the elastic portion 83. At this time, the tip portion 62 does not contract in diameter as in the embodiment (A), and therefore the elastic portion 83 may undergo plastic deformation beyond its elastic deformation range. When the tip portion 62 is further inserted to the bottom of the fitting hole, the elastic portion 83 engages with the annular recess 63. If the elastic portion 83 is plastically deformed and crushed at this time, the engagement between the elastic portion 83 and the annular recess 63 will be insufficient, causing the operating knob 7 to rattle or become more likely to fall off the shaft member 6.

[0030] In the prior art, when the operating knob 7 is attached to the shaft member 6, the elastic portion 83 may be plastically deformed and crushed, which makes the operating knob 7 prone to rattle relative to the shaft member 6 and fall off.

[0031] (Variation 1) A first modification of the protrusion 32 will be described with reference to Fig. 6. Fig. 6 is a diagram showing the first modification of the protrusion 32. Note that the spring 4 is not shown in Fig. 6. As shown in Fig. 6, the shape of the protrusion 32 may be a tapered shape whose cross section is triangular and narrows at the end. This shape improves the guiding properties of the protrusion 32 as it enters the slit 26, and allows the protrusion 32 to be reliably fitted into the slit 26 all the way to its base.

[0032] (Variation 2) A second modification of the protrusion 32 will be described with reference to Fig. 7. Fig. 7 is a diagram showing the second modification of the protrusion 32. Note that the spring 4 is not shown in Fig. 7. As shown in Fig. 7, it is also effective to form the base of the protrusion 32 to be almost upright and to have a tapered tip, and after attachment, the base of the protrusion 32 comes into contact with the inner surface of the slit 26, firmly restricting the reduction in diameter of the tip 22 and stably attaching the operating knob 3.

[0033] (Variation 3) A third modification of the protrusion 32 will be described with reference to FIG. 8. FIG. 8 is a diagram showing the third modification of the protrusion 32. As shown in FIG. 8, the width of the protrusion 32 (the vertical width in FIG. 8) may be set slightly larger than the opening width of the slit 26. This shape causes the tip portion 22 to expand slightly outward (the tip portion 22 bulges out slightly) when the operation knob 3 is attached to the shaft member 2, and the engagement between the protrusion 32 and the slit 26 physically prevents the tip portion 22 from reducing in diameter. In addition, the engagement between the elastic portion 43 and the annular recess 23 becomes stronger. This prevents rattling and falling off of the operation knob 3 during and after attachment, improving stability.

[0034] While the present disclosure has been described above in accordance with the embodiments and modifications, it is not limited to the above and may be modified as appropriate. The material of spring 4, the width of flat portion 42, the protruding height and cross-sectional shape of elastic portion 43, the dimensions and shape of protrusion 32, and the dimensions and remaining thickness of slit 26 in tip portion 22 are optimized based on the required insertion force, retention force, rotational torque characteristics, number of durability cycles, and usage environment (temperature, vibration, etc.). For example, the allowable values ​​for the remaining slit thickness and protrusion diameter differ between when a metal shaft material is used and when a resin shaft material is used.

[0035] During the assembly process, after holding the spring 4 in the specified position within the fitting hole 31, simply press the operating knob 3 axially to reduce the diameter of the tip portion 22, allowing for easy insertion. After installation is complete, the spring 4 is securely fixed by the engagement between the annular recess 23 and the elastic portion 43 of the spring 4, thereby simplifying and stabilizing the installation process.

[0036] The present disclosure is not limited to the above-described embodiments. For example, whether spring 4 is molded as an integral part or as a separate member, and whether protrusion 32 is molded as an integral part or formed as a separate member and fixed by fitting, adhesive, or the like, can be selected according to manufacturing conditions. Furthermore, the shape and size of flat portion 25 with a substantially D-shaped cross section of tip portion 22 and flat portion 42 of spring 4 can be changed according to the rotation angle accuracy and torque requirements.

[0037] As described above, the operating member 1 of the present disclosure has the effect of suppressing plastic deformation of the elastic portion 43 of the spring 4 when the operating knob 3 is attached, and also has the effect of preventing the operating knob 3 from coming loose after attachment, improving rotation transmission performance and long-term retention. [Industrial Applicability]

[0038] The present invention can be suitably applied to structures such as rotary switches in which an operating knob is attached to a shaft member. [Explanation of symbols]

[0039] 1 Operating member 2 Shaft member 21 Main body 22 Tip 23 Annular recess 24 Arc-shaped part 25 Flat area 26 Slit 3 Control knob 31 Fitting hole 32 Protrusion 4 springs 41 Arc-shaped part 42 Flat area 43 Elastic part

Claims

1. An operating knob attached to the tip of the shaft member, a fitting hole into which the tip end of the shaft member is inserted is formed, An elastic member is provided on a side surface of the fitting hole, and elastically contacts a side surface of the tip portion, A protrusion is formed at the bottom of the fitting hole to fit into the slit formed at the tip. Operation knob.

2. The protrusions are tapered at their tips compared to their bases. The operating knob according to claim 1 .

3. A shaft member whose tip is inserted into a fitting hole of an operating knob, A cylindrical main body, a tip portion formed on a tip side of the main body portion and having an arc-shaped portion and a flat portion on an outer circumferential surface; and an annular recess is formed in the circumferential direction of the arc-shaped portion, A slit is formed in the tip portion in the axial direction. Shaft member.

4. The operating knob according to claim 1; The shaft member according to claim 3; An operating member comprising: When the tip end of the shaft member is inserted up to the bottom of the fitting hole, the protrusion is fitted into the slit. Operating member.

5. The elastic member is elastically deformed and engaged with the annular recess. The operating member according to claim 4 .

6. The projection has a tip end portion elastically expanded in diameter. The operating member according to claim 4 .

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