Switch structure

Abstract

To provide a switch structure capable of maintaining designability and operability by preventing distortion.SOLUTION: A switch structure 900 in which a sheet member 100 is attached onto a base material 910 having an opening 920 includes a front surface sheet member 210, an intermediate sheet member 220, and a back surface sheet member 230, wherein the front surface sheet member 210, the intermediate sheet member 220, and the back surface sheet member 230 are joined so as to be in close contact with each other to form a laminated sheet member 200, and the intermediate sheet member 220 is disposed on a neutral axis P of the laminated sheet member 200.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a switch structure in which a sheet member is attached to the surface side of a switch portion of an automobile part, a home appliance, or the like. [Background technology]

[0002] Traditionally, switches have been provided on the housings of automobile parts and home appliances to operate them. In recent years, even for push-button switches with switches, there has been a demand for seamless touch switches, which have a smooth surface and are integrated into the housing, forming an extension of the surrounding housing. For example, in the switch structure shown in Patent Document 1, the switch is placed within an opening in the base material, and a sheet member is attached to cover it. Because the sheet member is continuous with the extension of the housing, it has a smooth surface, allowing for a seamless touch switch-like design. The user then operates the switch below the sheet member by pressing and bending the sheet member from above the switch.

[0003] However, when users repeatedly press the switch, strain accumulates at the joint between the sheet material and the base material around the opening, preventing the sheet material from returning to its original shape. This causes the sheet material to remain depressed, impairing the design and causing malfunctions in the switch, making it difficult to use. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7079688 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0005] In view of the above, the present invention provides a switch structure that can prevent distortion and maintain design and operability. [Means for solving the problem]

[0006] The switch structure of the present invention is a switch structure in which a sheet member is attached onto a substrate having an opening, and is characterized in that it comprises a top sheet member, an intermediate sheet member, and a back sheet member, the top sheet member, the intermediate sheet member, and the back sheet member being joined so as to be in close contact with each other to form a laminated sheet member, and the intermediate sheet member being positioned on the neutral axis of the laminated sheet member.

[0007] According to the above features, the intermediate sheet member is disposed on the neutral axis of the laminated sheet member, and therefore is not subjected to tensile or compressive stress. Therefore, the intermediate sheet member is resistant to plastic deformation and easily returns to its original shape when the pressing force during switch operation is removed. As a result, the central intermediate sheet member is resistant to plastic deformation and easily returns to its original shape, and the entire laminated sheet member is resistant to plastic deformation and easily returns to its original shape. Furthermore, even if the sheet member is repeatedly pressed by the user to operate the switch member, it easily returns to its original shape and prevents distortion, thereby maintaining the design and operability.

[0008] Furthermore, the switch structure of the present invention is characterized in that the intermediate sheet member is made of an elastically deformable material, and the glass transition temperature of the material constituting the intermediate sheet member is higher than the glass transition temperature of the material constituting the top sheet member and the glass transition temperature of the material constituting the back sheet member.

[0009] According to the above features, the intermediate sheet member has a high glass transition temperature, and therefore is less likely to soften and warp than the top sheet member and back sheet member. Furthermore, by sandwiching the intermediate sheet member between the top sheet member and the back sheet member, the entire laminated sheet member is effectively prevented from warping downward, even when the ambient temperature rises. As a result, the sheet members easily return to their original shape and are prevented from warping, maintaining the design and operability.

[0010] Furthermore, the switch structure of the present invention is characterized in that the surface sheet member, the intermediate sheet member, and the back sheet member are translucent, and a light-shielding layer is provided on a part of the laminated sheet member.

[0011] According to the above feature, any design pattern can be projected onto the surface of the sheet member. [Effects of the Invention]

[0012] As described above, the switch structure of the present invention can prevent distortion and maintain design and operability. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1( a ) is an overall perspective view of the switch structure 900 , and FIG. 1( b ) is a plan view of the switch structure 900 . [Figure 2] A-A cross-sectional view. [Figure 3] Enlarged cross-sectional view taken along line A-A. [Figure 4] 1 is an enlarged cross-sectional view taken along the line AA, showing a state in which the laminated sheet member 200 is bent downward. [Explanation of symbols]

[0014] 100 Sheet member 200 Laminated sheet member 210 Surface sheet member 220 Intermediate sheet member 230 Back sheet member 910 Base material 920 Opening 900 Switch Structure P neutral axis DETAILED DESCRIPTION OF THE INVENTION

[0015] The sheet member 100 and switch structure 900 of the present invention will be described below with reference to FIGS. 1 to 4. The shapes of the figures referred to in the following description are conceptual or schematic diagrams for explaining preferred shapes and dimensions, and the dimensional ratios do not necessarily correspond to the actual dimensional ratios. In other words, the present invention is not limited to the dimensional ratios in the drawings. Also, FIG. 1(a) is an overall perspective view of the switch structure 900, FIG. 1(b) is a plan view of the switch structure 900, FIG. 2 is a cross-sectional view taken along line A-A, FIG. 3 is an enlarged cross-sectional view taken along line A-A, and FIG. 4 is a cross-sectional view of the enlarged cross-sectional view taken along line A-A showing the laminated sheet member 200 bent downward.

[0016] First, as shown in FIGS. 1 and 2, a switch structure 900 is built into a housing 800 of an automobile part, a home appliance, or the like. Specifically, a hard substrate 910 of the switch structure 900 is disposed on a base 810 of the housing 800. The substrate 910 has an opening 920, within which a button-type switch member 710 and a light source 720 such as an LED are optionally disposed. Then, a sheet member 100 is attached to the substrate 910 so as to cover the opening 920 from above. As a result, the sheet member 100 is continuous with the extended surface of the housing 800, and therefore the surface is smooth, realizing a seamless touch switch-like design. The substrate 910 is configured as an injection-molded resin molded product, and the substrate 910 is adhered onto the base 810, but this is not limited to this, and any existing method can be used, such as a method of joining the sheet member 100 and the substrate 910 when injection insert molding the sheet member 100, or a method of cutting and hollowing out a single piece of hard plate material to form the substrate 910 with an opening 920.

[0017] Furthermore, within the opening 920, a light-shielding layer 730 is provided on the back side of the sheet member 100 so as to resemble an arbitrary design pattern (for example, a circle in FIGS. 1 and 2). If the sheet member 100 is translucent, when the light source 720 around the switch member 710 is turned on, light that is not blocked by the light-shielding layer 730 passes through the sheet member 100, and as shown in FIG. 1, an arbitrary design pattern 740 (a circle in FIGS. 1 and 2) is projected onto the surface of the sheet member 100. This allows the user to ascertain the position of the switch member 710.

[0018] 3, the sheet member 100 is a laminated sheet member 200 made up of a top sheet member 210, an intermediate sheet member 220, and a back sheet member 230. The flat top sheet member 210 and the intermediate sheet member 220 are joined with an adhesive or the like so that they are in close contact with each other. The flat intermediate sheet member 220 and the back sheet member 230 are also joined with an adhesive or the like so that they are in close contact with each other. The laminated sheet member 200 is then attached by adhesion to the substrate 910 so as to cover the opening 920.

[0019] Furthermore, the intermediate sheet member 220 is disposed on the neutral axis P of the laminated sheet member 200. In the laminated sheet member 200, the neutral axis P is an axis along which neither compressive stress nor tensile stress occurs when the laminated sheet member 200 is folded with the laminated sheet members as valleys or peaks in a cross section cut in the lamination direction of the laminated sheet member 200 (a cross section perpendicular to the flat laminated sheet member 200, such as the AA cross section shown in FIG. 3), and is determined by the elastic modulus and thickness of each sheet member.

[0020] As shown in FIG. 4 , when a user presses the laminated sheet member 200 downward with a pressing force F1 to operate the switch member 710, the laminated sheet member 200 deforms by bending downward toward the opening 920. At this time, a tensile stress F2 is applied to the top sheet member 210 and a compressive stress F3 is applied to the back sheet member 230 near the joint between the laminated sheet member 200 and the base material 910 around the periphery of the opening 920. However, since the intermediate sheet member 220 is disposed on the neutral axis P of the laminated sheet member 200, it is not subjected to tensile or compressive stress. Therefore, the intermediate sheet member 220 is resistant to plastic deformation and easily returns to its original shape when the pressing force F1 is removed. As a result, even if the top and bottom top sheet members 210 and back sheet member 230 are deformed, the central intermediate sheet member 220 is resistant to plastic deformation and easily returns to its original shape, so the entire laminated sheet member 200 is resistant to plastic deformation and easily returns to its original shape. Furthermore, even if the sheet member 100 made of the laminated sheet member 200 is repeatedly pressed by a user to operate the switch member 710, it easily returns to its original shape and is prevented from becoming distorted, so that the design and operability can be maintained.

[0021] Furthermore, the top sheet member 210 and the back sheet member 230 of the laminated sheet member 200 are made of the same material and have the same thickness. Therefore, the neutral axis P of the laminated sheet member 200 can be easily set midway between the top sheet member 210 and the back sheet member 230, making it easy to position the intermediate sheet member 220 on the neutral axis P. Note that the top sheet member 210 and the back sheet member 230 of the laminated sheet member 200 are made of the same material and have the same thickness, but this is not limited thereto, and the material and thickness of the top sheet member 210 and the back sheet member 230 can be set as desired as long as the neutral axis P is located on the intermediate sheet member 220.

[0022] Furthermore, to improve operability when a user presses the laminated sheet member 200 to operate the switch member 710, the laminated sheet member 200 is provided with a certain degree of cushioning. For example, the top sheet member 210 can be made of a cushioning material such as urethane, elastomer, or polyvinyl chloride (PVC). The thickness of the top sheet member 210 is preferably 1.0 mm (millimeter) or less, but is not particularly limited to this.

[0023] Furthermore, elastically deformable materials such as polycarbonate (PC), ABS, polypropylene (PP), polyethylene (PE), etc. can be used as the material for the intermediate sheet member 220. The thickness of the intermediate sheet member 220 is preferably 0.5 mm or less, but is not particularly limited to this.

[0024] Furthermore, materials having cushioning properties such as urethane, elastomer, polyvinyl chloride (PVC), etc. can be used as the material for the back sheet member 230. The thickness of the back sheet member 230 is preferably 1.0 mm or less, but is not particularly limited to this.

[0025] The glass transition temperature of the material constituting the intermediate sheet member 220 is set higher than the glass transition temperature of the material constituting the top sheet member 210 and the glass transition temperature of the material constituting the back sheet member 230. The glass transition temperature can be a value measured by the DSC method in accordance with JIS K7121:1987 "Method for measuring the transition temperature of plastics."

[0026] The top sheet member 210 and the back sheet member 230 are made of a soft material with cushioning properties, and soft materials with cushioning properties tend to have a low glass transition temperature. Therefore, when the temperature of the location where the switch structure 900 is installed rises (for example, inside a car in the hot sun), the mechanical rigidity of the top sheet member 210 and the back sheet member 230 decreases and they soften, which may cause the top sheet member 210 and the back sheet member 230 to sag downward under their own weight around the opening 920. On the other hand, the intermediate sheet member 220 has a high glass transition temperature, so it is less likely to soften and sag than the top sheet member 210 and the back sheet member 230. By sandwiching the intermediate sheet member 220 between the top sheet member 210 and the back sheet member 230, the entire laminated sheet member 200 is effectively prevented from sagging downward even when the ambient temperature rises. As a result, the sheet member 100 easily returns to its original shape and is less likely to distort, maintaining its design and operability. In addition, since the intermediate sheet member 220 is made of an elastically deformable material, the cushioning properties of the entire laminated sheet member 200 are not impaired.

[0027] Furthermore, the top sheet member 210, the intermediate sheet member 220, and the back sheet member 230 of the laminated sheet member 200 are translucent, and by providing a light-shielding layer 730 on a portion of the laminated sheet member 200, any design pattern 740 can be projected onto the surface of the sheet member 100. The light-shielding layer 730 can be formed by any method, for example, by painting or printing from the back side of the back sheet member 230. When the light-shielding layer 730 is formed by painting, a light-shielding paint may be applied to the back sheet member 230, and the coating film may be cut off using a laser or the like to imitate the design pattern or letters. When the light-shielding layer 730 is formed by printing, printing is performed using a printing plate with the design pattern or letters masked so that ink does not adhere to the design pattern or letters. When the light-shielding layer 730 is formed by painting or printing, the painted or printed areas may be configured as a single layer or multiple layers. Furthermore, instead of providing the light-shielding layer 730 on the back sheet member 230, a light-shielding layer may be formed on the surface sheet member 210 side by painting, printing, etc. Furthermore, instead of providing the light-shielding layer 730 on the back sheet member 230, a light-shielding layer and a nameplate on which a design pattern or letters are printed may be attached to the back surface of the laminated sheet member 200 within the opening 920.

[0028] Furthermore, the top sheet member 210, the intermediate sheet member 220, and the back sheet member 230 of the laminated sheet member 200 are translucent, but are not limited to this. For example, the top sheet member 210, the intermediate sheet member 220, and the back sheet member 230 may not be translucent, and the light-shielding layer 730 may not be provided on a part of the laminated sheet member 200. In this case, appropriate modifications can be made, such as attaching a mark indicating the position of the switch member 710 to the top side of the laminated sheet member 200 and removing the light source 720.

[0029] The switch structure of the present invention is not limited to the above examples, and various modifications and combinations are possible within the scope of the claims and the scope of the embodiments, and these modifications and combinations are also included in the scope of rights.

Claims

1. A switch structure in which a sheet member is attached onto a substrate having an opening, A top sheet member, an intermediate sheet member, and a back sheet member, the top sheet member, the intermediate sheet member, and the back sheet member are joined together in close contact to form a laminated sheet member, A switch structure characterized in that the intermediate sheet member is disposed on the neutral axis of the laminated sheet member.

2. the intermediate sheet member is made of an elastically deformable material, The switch structure according to claim 1, characterized in that the glass transition temperature of the material constituting the intermediate sheet member is higher than the glass transition temperature of the material constituting the surface sheet member and the glass transition temperature of the material constituting the back sheet member.

3. 3. The switch structure according to claim 1, wherein the top sheet member, the intermediate sheet member, and the back sheet member are translucent, and a light-shielding layer is provided on a part of the laminated sheet member.

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