Fastening structure and disassembly method

Abstract

To provide a new technology capable of easily disassembling components.SOLUTION: A fastening structure 100 comprises a first component constituting a part of a vehicle lamp, a second component constituting a part of the vehicle lamp, and a fastening member that fastens the first component and the second component. The fastening member passes through a hole formed in the second component and is screwed to a boss 20a provided on the first component, the boss 20a has a rib 20b formed therearound, and the rib 20b is configured to be detached from the first component together with the boss 20a by rotating a tool 26 around the boss 20a while the tool is engaged.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a disassembly technique for components.

Background Art

[0002] In recent years, development targeting carbon neutrality has been promoted in various fields. Therefore, for each component used in vehicles, it is desirable to disassemble and sort recyclable components. However, many components are designed with priority given to ease of assembly and prevention of disconnection between assembled components, and are not necessarily designed on the premise of being disassembled. For this reason, much time and labor are required for disassembling components, leading to an increase in component recycling costs and a decrease in the recycling rate.

[0003] Accordingly, design of components requires contrivances premised on disassembly. For example, Patent Document 1 discloses a vehicle lamp in which a housing and a lens are fixed by engaging an engaging projection provided on one of the housing and the lens with an engaging hole provided on the other. In this vehicle lamp, a tongue piece formed with the aforementioned engaging projection or engaging hole is provided on the housing or the lens, and a slit serving as breaking means is formed in the tongue piece. Thereby, when disassembling the housing and the lens, the tongue piece can be easily broken with the slit as a base point, so the engagement between the engaged engaging projection and the engaging hole is released, and disassembly of the housing and the lens is facilitated.

Prior Art Literature

Patent Literature

[0004]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0005] The aforementioned tongue-shaped tab is the engagement point between the housing and the lens, and is located in an area that is relatively easy to disassemble. However, the joining points and methods of the parts vary, and it may not always be easy to disassemble the assembled parts in the reverse order of assembly.

[0006] This invention has been made in view of these circumstances, and one of its exemplary objectives is to provide a new technology that facilitates the disassembly of parts. [Means for solving the problem]

[0007] To solve the above problems, a fastening structure according to one aspect of the present invention comprises a first component that constitutes part of a vehicle light fixture, a second component that constitutes part of a vehicle light fixture, and a fastening member that fastens the first component and the second component together. The fastening member is screwed through a hole formed in the second component and fastened to a boss provided in the first component. The boss has ribs formed around it, and the ribs are configured to detach from the first component together with the boss when the tool is engaged and the tool is rotated around the boss.

[0008] According to this embodiment, by removing the boss and fastening members such as screws from the boss, the fastening between the first and second parts is released, making it easier to separate the parts.

[0009] Multiple ribs may be formed radially from the boss. This distributes the force from the tool's rotation through multiple ribs and is applied around the boss, reducing the likelihood of excessive force being applied to only one rib, causing deformation of that rib and preventing the boss from detaching from the first part.

[0010] The boss is formed upward from the bottom of a conical recess formed in the first part, and the rib may be triangular in shape, connecting the inner surface of the recess with the outer surface of the boss. This makes it easier for stress to concentrate at the bottom when the tool is rotated.

[0011] In the first component, the thickness of the connection point between the base and the boss is thinner than the thickness of the outer part of the base. This makes it easier for the boss to detach from the connection point between the base and the boss.

[0012] The connecting portion may be located in a region where stress concentrates when the tool is rotated around the boss while the tool is engaged with the rib, or in a region near that region. This makes it easier for the connecting portion to fracture with good reproducibility.

[0013] Another aspect of the present invention is a disassembly method. This method disassembles parts by separating a boss provided on a first part, which is screwed to fasten a fastening member that fastens a first part, which is part of a vehicle light fixture, from the first part. The method involves fitting a tool, which has a recess at its tip into which the boss and rib fit, onto the boss and the rib formed around the boss, and rotating the tool around the boss to separate the rib and boss from the first part.

[0014] According to this embodiment, by removing the boss and fastening members such as screws from the boss, the fastening between the first and second parts is released, making it easier to separate the parts.

[0015] Any combination of the above components, or any conversion of the expression of the present invention between manufacturing methods, devices such as luminaires and lighting fixtures, light-emitting modules, light sources, etc., are also valid embodiments of the present invention. [Effects of the Invention]

[0016] According to the present invention, the parts can be easily disassembled. [Brief explanation of the drawing]

[0017] [Figure 1] This is a front view of the rear lamp according to this embodiment. [Figure 2] Figure 1 is a cross-sectional view of the rear light fixture, AA. [Figure 3] This is a perspective view of a component for destructive testing. [Figure 4] It is a top view of the component shown in Figure 3. [Figure 5] Figure 5(a) is a cross-sectional view along B-B shown in Figure 4, and Figure 5(b) is an enlarged view of region C shown in Figure 5(a). [Figure 6] It is an enlarged top view of a recess including a boss. [Figure 7] It is an enlarged view of a distal end portion of the tool according to the present embodiment. [Figure 8] It is a perspective view showing a state where a tool is aligned with a boss of a test piece corresponding to the body shown in Figure 3. [Figure 9] It is a view showing a state where the periphery of the boss is separated from the body by rotating the tool from the state shown in Figure 8. [Figure 10] It is a cross-sectional perspective view for explaining a state where a tool is engaged with a boss and a rib of a body. MODE FOR CARRYING OUT THE INVENTION

[0018] Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. The same or equivalent constituent elements, members and processes shown in each drawing are denoted by the same reference numerals, and repeated explanations will be omitted as appropriate. Furthermore, the embodiments are illustrative rather than limiting the invention, and not all features and combinations thereof described in the embodiments are necessarily essential to the invention.

[0019] In the present embodiment, a rear-side lamp is described as an example of a vehicle lamp, but the present invention can also be applied when the vehicle lamp is a headlamp. Figure 1 is a front view of the rear-side lamp according to the present embodiment. Figure 2 is a cross-sectional view along A-A of the rear-side lamp shown in Figure 1.

[0020] The rear lamp unit 10 shown in Figure 1 is a turn signal lamp or tail lamp, and is assembled from multiple parts made of resin material. As shown in Figure 2, the rear lamp unit 10 comprises an outer lens cover 12, an extension 14 provided inside the lens cover 12, inner lenses 16a and 16b provided below the extension 14, a reflector 18 positioned behind the inner lens 16b (towards the front of the vehicle), and a body 20 positioned behind the reflector 18.

[0021] Furthermore, the fastening structure 100 according to this embodiment comprises an extension 14, a reflector 18, a body 20, and a screw 22 as a fastening member for fastening the extension 14, the reflector 18, and the body 20. The screw 22 passes through the hole 14a formed in the extension 14 and the hole 18a formed in the reflector 18, and is screwed to a boss 20a provided on the body 20. As mentioned above, when recycling various parts is carried out in conjunction with the scrapping and dismantling of a vehicle, it is necessary to disassemble the parts.

[0022] Therefore, the boss 20a of the body 20 has ribs 20b formed around it, and the ribs 20b are configured to detach from the body 20 together with the boss 20a when the tool 26 is engaged with the ribs 20b and the tool 26 is rotated around the boss 20a. As a result, the fastening between the body 20 and the extension 14 and reflector 18 is released by removing the boss 20a together with the screw 22 without removing the screw 22 from the boss 20a, making it easier to disassemble the parts.

[0023] Next, the shape of the vicinity of the boss 20a on the body 20 side that constitutes the fastening structure 100 will be described. The parts shown in Figures 3 to 6 are models of a part of the body 20 for the purpose of destructive testing of the fastening structure. Second parts such as the screw 22 and extension 14 fixed to the boss 20a are omitted from the illustration for the sake of explanation. In the following, the parts shown in Figures 3 to 6 will be described as part of the body 20. Figure 3 is a perspective view of the parts for destructive testing. Figure 4 is a top view of the parts shown in Figure 3. Figure 5(a) is a cross-sectional view of BB shown in Figure 4, and Figure 5(b) is an enlarged view of area C shown in Figure 5(a). Figure 6 is an enlarged top view of the recess including the boss. Figure 7 is an enlarged view of the tip of the tool according to this embodiment.

[0024] As shown in Figures 3 and 4, the boss 20a is formed extending upward from the center of the bottom of the conical recess 20c formed in the body 20. Three ribs 20b are formed radially from positions offset from the center of the boss 20a. Each rib 20b has the same shape and, as shown in Figure 3, is triangular in shape, connecting the inner circumferential surface 20d of the recess 20c and the outer circumferential surface 20e of the boss 20a. As a result, the force due to the rotation of the tool 26, which will be described later, is distributed through multiple ribs 20b and applied around the boss 20a, reducing the situation in which excessive force is applied to only one rib, causing only the rib to deform and preventing the boss 20a from detaching from the body 20.

[0025] On the other hand, as shown in Figure 7, the tip of the tool 26 has a cylindrical hole 26a into which the boss 20a fits, three slits 26c formed at equal intervals on the outer wall of the hole 26a, fan-shaped notches 26d extending outwards from each slit 26c, and fan-shaped engaging portions 26e between the notches. This makes it easier for stress to concentrate at the bottom when the tool 26 is rotated.

[0026] Next, a method for destroying the fastening structure 100 will be described. Figure 8 is a perspective view showing the state in which the tool 26 is aligned with the boss 20a of the test piece corresponding to the body 20 shown in Figure 3. Figure 9 is a diagram showing the state in which the area around the boss 20a is separated from the body 20 by rotating the tool from the state shown in Figure 8.

[0027] When the tool 26 is rotated in the direction of the arrow from the state shown in Figure 8, the engaging portion 26e of the tool 26 engages with the rib 20b, causing a large stress on the rib 20b. As a result, as shown in Figure 9, the boss 20a connected to the rib 20b is fractured and separated from the body 20 by twisting. The mechanism of this fracture will be described in more detail below.

[0028] Figure 10 is a cross-sectional perspective view illustrating the state in which the tool 26 is engaged with the boss 20a and rib 20b of the body 20. As shown in Figure 10, the engaging portion 26e of the tool 26 rotates and pushes against the rib 20b, creating a D region where stress is concentrated near the bottom of the rib 20b. Since a D region occurs in each rib 20b, the shear stress generated around the base of the boss 20a makes the boss 20a more prone to twisting (see Figure 9).

[0029] Furthermore, in this embodiment, as shown in Figure 5(b), the thickness of the connecting portion 20g between the bottom portion 20f and the boss 20a is thinner than the thickness of the outer portion 20h of the bottom portion 20f. This makes it easier for the boss 20a to detach from the connecting portion 20g between the bottom portion 20f and the boss 20a. In addition, the connecting portion 20g is located in region D or a nearby region where stress is concentrated when the tool 26 is rotated around the boss 20a while the tool 26 is engaged with the rib 20b. This makes it easier for the connecting portion 20g to fracture with good reproducibility.

[0030] The angle between the inner circumferential surface 20d of the recess 20c and the outer circumferential surface 20e of the boss 20a is, for example, in the range of 40 to 50°. The thickness of the connecting portion 20g is in the range of 0.8 to 1.5 mm, and the thickness of the outer portion 20h is in the range of 1.2 to 2.0 mm. The radial length of the connecting portion 20g is in the range of 0.8 to 1.5 mm. The outer diameter of the boss 20a is in the range of 7 to 9 mm.

[0031] The invention relating to the fastening structure described above can also be considered as a disassembly method. For example, the disassembly method according to this embodiment is a method of disassembling parts by separating the boss 20a, which is provided on the body 20 to which a screw 22 fastening fasteners 22 fastening the body 20, which fastens the extension 14 and reflector 18, which also constitute part of the rear lamp 10, are attached, from the body 20. In this method, a tool 26, which has recesses (holes 26a, slits 26c, notches 26d) formed at its tip into the boss 20a and the ribs 20b formed around the boss 20a, is fitted, and the tool 26 is rotated around the boss 20a to separate the ribs 20b and the boss 20a from the body 20. As a result, the fastening between the body 20 and the extension 14 and reflector 18 is released by removing the boss 20a along with the boss 20a without removing fastening members such as screws from the boss 20a, making it easier to disassemble the parts.

[0032] Furthermore, the combination of fastening components is not limited to the above-mentioned case of the body and reflector and extension, but may also be the case of the body and reflector, or the body and extension. In addition, the lamps to which the above-mentioned fastening structure is provided may be the front lamps, not just the rear lamps.

[0033] Although the present invention has been described above with reference to the embodiments described above, the present invention is not limited to the embodiments described above, and the present invention also includes combinations and substitutions of the configurations of the embodiments as appropriate. Furthermore, it is possible to appropriately rearrange the combinations and processing order in the embodiments or to make various design changes and other modifications to the embodiments based on the knowledge of those skilled in the art, and such modified embodiments may also be included in the scope of the present invention. [Explanation of Symbols]

[0034] 10 Rear light fixture, 12 Lens cover, 14 Extension, 14a Hole, 18 Reflector, 18a Hole, 20 Body, 20a Boss, 20b Rib, 20c Recess, 20d Inner surface, 20e Outer surface, 20f Bottom, 20g Connecting part, 22 Screw, 26 Tool, 26a Hole, 26c Slit, 26d Notch, 26e Engagement part, 100 Fastening structure.

Claims

1. A first component that constitutes part of a vehicle lighting fixture, A second component that forms part of a vehicle lighting fixture, The device comprises a fastening member for fastening the first component and the second component, The fastening member is screwed through a hole formed in the second part and fastened to a boss provided in the first part. The aforementioned boss has ribs formed around it. The fastening structure is characterized in that the rib is configured to detach from the first component together with the boss when the tool is rotated around the boss while the tool is engaged.

2. The fastening structure according to claim 1, characterized in that the ribs are formed radially from the boss in multiple locations.

3. The boss is formed extending upward from the bottom of the conical recess formed in the first part, The fastening structure according to claim 2, characterized in that the rib is triangular in shape, connecting the inner circumferential surface of the recess and the outer circumferential surface of the boss.

4. The fastening structure according to claim 3, characterized in that the thickness of the connecting portion between the bottom and the boss of the first component is thinner than the thickness of the outer portion of the bottom.

5. The fastening structure according to claim 4, characterized in that the connecting portion is provided in a region or a nearby region where stress is concentrated when the tool is rotated around the boss while the tool is engaged with the rib.

6. A disassembly method for separating parts by separating a boss provided on the first part, which is screwed to fasten a fastening member that fastens a first part, which is part of a vehicle lighting fixture, to a second part, which is part of a vehicle lighting fixture, from the first part, A disassembly method characterized by fitting a tool having a recess at its tip into the boss and the rib formed around the boss, and rotating the tool around the boss to separate the rib and the boss from the first part.

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