Decorative member and cover body of airbag device

Abstract

To provide a decorative member which makes design flexibility less likely to be limited while securing strength, and to provide a cover body of an airbag device including the decorative member.SOLUTION: A decorative member is attached to a front plate part which covers a folded airbag and has a tear line which breaks when the airbag is deployed. The decorative member includes a decorative body 20 located at the design side of the front plate part. The decorative body 20 has: a decorative body main part 22; an engagement part 23 for attachment to the front plate part which is provided protruding on the back side of the decorative body main part 22; and a reinforcement rib 28 which extends from a base end part of the engagement part 23 to one end edge part side and the other end edge part side of the decorative body main part 22.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a decorative member attached to a covering portion having a breaking portion that covers an airbag in a folded state and breaks when the airbag is deployed, and a cover body of an airbag device including the same.

Background Art

[0002] Conventionally, an airbag device is attached to a steering wheel, which is a handle for vehicles such as automobiles. The cover body of the airbag device covers the airbag in a folded state, and when the airbag is deployed, a part thereof breaks from a breaking prediction line, that is, a tear line, by the deployment pressure, and the airbag bulges and deploys toward the occupant side.

[0003] As such a cover body, one with an emblem (ornament) attached is known. In particular, one in which the emblem is elongated and arranged along a tear line formed in the left-right direction on the cover main body is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the case of an elongated emblem, it becomes easy to receive the deployment pressure of the airbag that breaks the cover body. Therefore, it is necessary to form a reinforcing structure so that the emblem is not damaged by the deployment pressure, and the degree of freedom in the design of the emblem may be restricted by the formation of such a reinforcing structure.

[0006] The present invention has been made in view of such points, and an object thereof is to provide a decorative member that is less likely to have its design freedom restricted while ensuring strength, and a cover body of an airbag device including the same.

Means for Solving the Problems

[0007] The decorative member according to claim 1 is a decorative member attached to a covering portion that covers the folded airbag and has a breaking portion that breaks when the airbag is deployed, and includes a decorative body main body portion, an engaging portion provided so as to project from the back side of the decorative body main body portion for attachment to the covering portion, and a reinforcing rib provided behind the decorative body main body portion and extending from the base end portion of the engaging portion to one edge portion side and the other edge portion side of the decorative body main body portion, and includes a decorative body located on the design side of the covering portion.

[0008] The decorative member according to claim 2 is the decorative member according to claim 1, wherein a plurality of engaging portions are provided, and the ribs are continuous across the plurality of engaging portions.

[0009] The decorative member according to claim 3 is the decorative member according to claim 1 or 2, wherein the decorative body main body portion has a shape having a longitudinal direction.

[0010] The decorative member according to claim 4 is the decorative member according to claim 3, wherein the decorative body main body portion has a rectangular shape.

[0011] The decorative member according to claim 5 is the decorative member according to claim 3 or 4, wherein the rib is continuous from one edge portion in the longitudinal direction of the decorative body main body portion to the other edge portion via the engaging portion.

[0012] The decorative member according to claim 6 is the decorative member according to any one of claims 3 to 5, wherein a plurality of engaging portions are provided, and the rib includes a first portion that is continuous with the base end portion of each engaging portion and extends in the longitudinal direction of the decorative body main body portion, a second portion that extends obliquely in a direction intersecting the longitudinal direction from the end portion of the first portion on the side opposite to the engaging portion toward a direction away from the engaging portion, and a third portion that is continuous between the second portions and extends in the longitudinal direction of the decorative body main body portion.

[0013] The decorative member according to claim 7 is the decorative member according to any one of claims 3 to 6, and includes a engaging body that is separate from the decorative body and holds the decorative body on the covering portion with the covering portion interposed therebetween. The engaging body has an engaging body main body portion that is elongated in the same direction as the longitudinal direction of the decorative body main body portion, and a receiving portion that is provided on the engaging body main body portion and receives the engaging portion of the decorative body. The engaging body main body portion has a protruding portion that protrudes in a direction intersecting the longitudinal direction.

[0014] The cover body of the airbag device according to claim 8 includes a covering portion that covers the folded airbag and has a breaking portion that breaks when the airbag is deployed, and the decorative member according to any one of claims 1 to 7 that is attached to the covering portion.

[0015] The cover body of the airbag device according to claim 9 is the cover body of the airbag device according to claim 8, wherein the decorative member is arranged along at least a part of the breaking portion.

Advantages of the Invention

[0016] According to the decorative member described in claim 1, the rib can efficiently improve the rigidity according to the shape of the decorative body main body portion and ensure the strength, so that a further reinforcing structure for the decorative body is not required, and the degree of freedom in design is less likely to be restricted.

[0017] According to the decorative member described in claim 2, in addition to the effect of the decorative member described in claim 1, the strength of the decorative body main body portion can be improved more comprehensively.

[0018] According to the decorative member described in claim 3, in addition to the effects of the decorative member described in claim 1 or 2, by forming ribs extending in the longitudinal direction of the main body portion of the decorative body, it is difficult to cause a strength difference between both end portions and the central portion in the longitudinal direction, and local stress concentration can be suppressed.

[0019] According to the decorative member described in claim 4, in addition to the effects of the decorative member described in claim 3, while having good design properties, local stress concentration can be suppressed by the ribs.

[0020] According to the decorative member described in claim 5, in addition to the effects of the decorative member described in claim 3 or 4, at least one or more ribs are positioned in an arbitrary cross-section in the short-side direction, and the ribs can be arranged in a well-balanced manner with respect to the decorative body as a whole, and local stress concentration can be suppressed.

[0021] According to the decorative member described in claim 6, in addition to the effects of the decorative member described in any one of claims 3 to 5, the ribs can be arranged in a well-balanced manner with respect to the decorative body.

[0022] According to the decorative member described in claim 7, in addition to the effects of the decorative member described in any one of claims 3 to 6, the deployment pressure of the airbag can be easily released by the deformation of the protruding portion, and stress concentration can be suppressed.

[0023] According to the cover body of the airbag device described in claim 8, when the airbag is deployed, the decorative member can be reliably held in the covering portion against the deployment pressure of the airbag and the like.

[0024] According to the cover body of the airbag device described in claim 9, in addition to the effects of the cover body of the airbag device described in claim 8, since the decorative member can suppress deformation due to the deployment pressure of the airbag by ensuring the strength of the decorative body, by arranging the decorative member along at least a part of the fracture portion, the deployment pressure of the airbag with reduced loss due to deformation of the decorative member can be efficiently transmitted to the fracture portion, and the covering portion can be smoothly fractured from the fracture portion.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0026] Hereinafter, the first embodiment of the present invention will be described with reference to the drawings.

[0027] In FIGS. 5 and 6(c), 1 is a steering wheel as a handle (steering handle) for an automobile which is a vehicle. The steering wheel 1 includes a steering wheel body 2 as a handle body, and an airbag device 3 attached to the passenger side of the steering wheel body 2. Note that the steering wheel 1 is normally attached to a steering shaft provided in a vehicle in an inclined state. Hereinafter, with reference to the straight-ahead state of the vehicle, the steering shaft side is the rear side, the passenger side is the front side, and the direction toward the windshield (arrow A direction) is the upper side for explanation. Also, the front-rear direction and the left-right direction are explained as the directions seen from the passenger.

[0028] The steering wheel body 2 is composed of a rim portion 4 which is a grip portion that forms an annular shape, a boss portion 5 located inside the rim portion 4, and a plurality of spoke portions 6 that connect the rim portion 4 and the boss portion 5. In the present embodiment, two left and right spoke portions are illustrated, but the number is not limited to two.

[0029] Also, on the back surface portion of the boss portion 5, a substantially cylindrical boss 5a fitted to the steering shaft is provided, and a boss plate that constitutes a core body is integrally fixed to the boss 5a. Then, from the boss plate, the core metal of the spoke portion 6 extends integrally or is fixed by welding or the like. Further, the core metal of the rim portion 4 is fixed to the core metal of the spoke portion 6 by welding or the like.

[0030] Furthermore, a body cover 7 is attached to the rear side of the steering wheel body 2. The body cover 7 is also called a lower cover or a back cover. The body cover 7 covers the rear side, that is, the back side of the boss portion 5 and the left and right spoke portions 6 of the steering wheel body 2. The body cover 7 is formed of, for example, a synthetic resin.

[0031] Further, a skin portion is formed on the outer peripheral portion of the core metal of the rim portion 4 and on the outer peripheral portion of the portion of the core metal of the spoke portion 6 on the rim portion 4 side, and furthermore, all or part of the outer periphery of this skin portion is covered with natural or artificial leather or the like.

[0032] On the other hand, as shown in FIG. 5, the airbag device 3 is disposed so as to cover the front side of the boss portion 5 of the steering wheel body 2. The airbag device 3 includes a base plate as a member to be attached, a bag-shaped airbag, an inflater for inflating and deploying the airbag, and the like, and also includes a cover body 11 for covering these. The base plate is attached to the steering wheel body 2 via a horn plate or a bracket portion or the like. An airbag is stored in the base plate and an inflater is attached thereto, and the cover body 11 covers the front side of this base plate.

[0033] The cover body 11 is also called a case body, a pad, or a module cover, etc. As shown in FIG. 4, the cover body 11 includes, for example, a cover main body portion 13 which is a portion to be attached. The cover main body portion 13 is formed of, for example, a synthetic resin. The cover main body portion 13 has a front plate portion 14 as a covering portion. The front plate portion 14 constitutes the design portion of the cover body 11. The front plate portion 14 covers the front side of the folded airbag. A tear line 15, which is a planned break line as a break portion, is formed in the front plate portion 14. When the airbag is deployed, a plurality of door portions 16 (FIG. 6(b)) are formed by the cleavage of the tear line 15 due to the deployment pressure of the airbag. The tear line 15 is formed in a groove shape on the back (rear) side of the front plate portion 14 and is a weak portion that is more fragile than other portions of the front plate portion 14. The tear line 15 can be arbitrarily set according to the shape and number of the door portions 16 (FIG. 6(b)) to be set. In the present embodiment, the tear line 15 has a center tear line 15a located at the center and side tear lines 15b located on both the left and right sides connected to the center tear line 15a. The center tear line 15a is formed to extend in the left-right direction. In the illustrated example, the center tear line 15a is formed in a straight line. Also, the side tear lines 15b are formed to extend in the vertical direction, that is, in a direction intersecting or orthogonal to the center tear line 15a. The upper and lower ends of the side tear lines 15b extend across the vicinity of the upper and lower ends of the storage portion in the front plate portion 14. The center tear line 15a is connected to the vicinity of the central portion in the vertical direction of the side tear lines 15b. Therefore, the tear line 15 of the present embodiment is formed in an H shape when viewed from the front.

[0034] Also, on the back (rear) of the front plate portion 14, a peripheral plate portion 17, which is a peripheral wall protruding in a cylindrical shape such as a substantially square tube shape when viewed from the front, is formed. The portion surrounded by the front plate portion 14 and the peripheral plate portion 17 serves as a storage portion for storing the folded airbag. Although not shown, the peripheral plate portion 17 is formed with a cover body engaging portion or the like for engaging the base plate and the cover body 11.

[0035] Further, as shown in FIGS. 3(a) to 3(c) and FIG. 4, a decorative member 19 is attached to the instrument panel portion 14. The decorative member 19 is also called an emblem or an ornament, etc.

[0036] The decorative member 19 has a decorative body 20. The decorative body 20 is also called a design ornament, an upper plate, or an upper emblem, etc., and constitutes the design part of the decorative member 19. The decorative body 20 is formed of, for example, synthetic resin. The decorative body 20 includes a decorative body main body portion 22. The decorative body main body portion 22 is located along the surface on the design side of the instrument panel portion 14. The decorative body main body portion 22 is formed in a shape having a longitudinal direction. In the present embodiment, the decorative body main body portion 22 is formed in a rectangular shape. Further, the decorative body main body portion 22 has a shape surrounded by a pair of long side portions and a pair of short side portions. In the illustrated example, the decorative body main body portion 22 has a rectangular shape with a dimensional ratio of the longitudinal direction to the short side direction of 2:1 or more. Also, the decorative body main body portion 22 is formed in a flat plate shape. In the present embodiment, the decorative body main body portion 22 is curved such that the central portion in the longitudinal direction bulges slightly toward the front side with respect to both end portions.

[0037] An engaging portion 23 protrudes from the main body portion 22 of the decorative body. The engaging portion 23, also called a hook, is for attaching the decorative member 19 to the front plate portion 14. The engaging portion 23 is located on the back side of the main body portion 22 of the decorative body, that is, on the side of the front plate portion 14. The engaging portion 23 is formed in a pin shape extending in the thickness direction of the main body portion 22 of the decorative body. The engaging portion 23 has a shaft portion 25 continuous with the main body portion 22 of the decorative body. The shaft portion 25 may have an arbitrary shape, but in the present embodiment, as shown in FIG. 2, a rib portion 25a having a thickness in the short side direction of the main body portion 22 of the decorative body and protruding in the longitudinal direction, and a rib portion 25b having a thickness in the longitudinal direction of the main body portion 22 of the decorative body and protruding in the short side direction, form a cross-sectional shape. Further, an enlarged portion 26, which is a retaining portion, is integrally formed at the tip of the shaft portion 25. The enlarged portion 26 is enlarged in a direction intersecting the protruding direction of the engaging portion 23 with respect to the shaft portion 25. Therefore, the enlarged portion 26 is formed as an undercut with respect to the protruding direction of the engaging portion 23, which is the thickness direction of the main body portion 22 of the decorative body, that is, the axial direction, which is the mold release direction in the engaging portion 23. Therefore, in the present embodiment, a slide core is used when forming the engaging portion 23. The slide core is set to slide in a direction intersecting or orthogonal to the axial direction of the engaging portion 23, which is the mold release direction of the mold, that is, in the direction indicated by the arrow S shown in FIG. 1 or the like, with the engaging portion 23 interposed therebetween. That is, the slide core is set to slide in the short side direction of the main body portion 22 of the decorative body.

[0038] In the present embodiment, a plurality of engaging portions 23 are provided. In the illustrated example, three engaging portions 23 are set on the main body portion 22 of the decorative body. These engaging portions 23 are arranged at intervals in the longitudinal direction of the main body portion 22 of the decorative body. In the present embodiment, the engaging portions 23 are arranged at equal or substantially equal intervals in the longitudinal direction of the main body portion 22 of the decorative body. In the illustrated example, the engaging portions 23 are located at the central portion in the longitudinal direction of the main body portion 22 of the decorative body and near both ends, respectively. Further, in the present embodiment, the engaging portion 23 located at the central portion and the other engaging portions 23 are displaced in the short side direction of the main body portion 22 of the decorative body.

[0039] The engaging portions 23 are connected by ribs 28 for reinforcing the main body portion 22 of the decorative body. The ribs 28 are provided behind the main body portion 22 of the decorative body. The ribs 28 protrude with a protrusion amount smaller than that of the engaging portions 23 on the back side of the main body portion 22 of the decorative body. The ribs 28 are formed to extend from the base end portion of the engaging portions 23 to one end portion side in the longitudinal direction which is one edge portion side of the main body portion 22 of the decorative body and the other end portion side in the longitudinal direction which is the other edge portion side. In the present embodiment, the ribs 28 are continuous from one end portion in the longitudinal direction which is one edge portion of the main body portion 22 of the decorative body, through the base end portion of the engaging portions 23, to the other end portion in the longitudinal direction. That is, the ribs 28 are continuous between the plurality of engaging portions 23 and are arranged over the entire longitudinal direction of the main body portion 22 of the decorative body. Therefore, the ribs 28 are formed over the entire main body portion 22 of the decorative body so as to be located on an arbitrary cross section in the short side direction of the decorative body 20.

[0040] The ribs 28 are formed simultaneously when the engaging portions 23 are formed. The ribs 28 are set so as not to inhibit the structure of the slide core for forming the engaging portions 23 and the movable locus of the slide. The ribs 28 are formed along the dividing line of the slide core. In the present embodiment, the ribs 28 are formed non-parallel to the short side direction of the main body portion 22 of the decorative body.

[0041] Preferably, the rib 28 integrally has a first portion 31, a second portion 32, and a third portion 33. The first portion 31 extends in the longitudinal direction of the decorative body main body portion 22 continuous with the base end portions of the respective engaging portions 23. In the present embodiment, the first portion 31 is set on both sides of each engaging portion 23. Further, the second portion 32 extends in an inclined manner in a direction intersecting the longitudinal direction from the end portion on the side opposite to the engaging portion 23 of the first portion 31 in a direction away from the engaging portion 23. That is, the second portion 32 is inclined in a direction that does not become an under shape with respect to the sliding direction of the slide core. In the illustrated example, the second portion 32 is inclined so as to expand toward one side and the other side in the short side direction from the end portion of the first portion 31. Furthermore, the third portion 33 extends in the longitudinal direction of the decorative body main body portion 22 continuous between the second portions 32, 32. The third portion 33 is located at the long side portion of the decorative body main body portion 22. A part of the rib 28 is formed in a honeycomb shape (hexagonal shape) between the engaging portions 23, 23 by the second portion 32 and the third portion 33. The second portions 32 continuous with the first portions 31 extending outward in the longitudinal direction of the decorative body main body portion 22 from the engaging portions 23 located at both end portions in the longitudinal direction of the decorative body main body portion 22 extend in an inclined manner toward the corner portions of the decorative body main body portion 22, respectively.

[0042] Then, as shown in FIGS. 3(c) and 4, the decorative body 20 is attached to the front plate portion 14 of the cover main body portion 13 by the engaging portions 23. In the present embodiment, the decorative body 20 is attached by inserting the engaging portions 23 into the openings 35 formed in the front plate portion 14. In the present embodiment, the openings 35 are formed through the front plate portion 14. The same number of openings 35 as the engaging portions 23 are formed. In the present embodiment, three openings 35 are formed. The openings 35 are formed in a round hole shape.

[0043] In the illustrated example, the opening 35 is disposed in the mounting portion 36. In the present embodiment, the mounting portion 36 is a recess that is recessed in the front plate portion 14 and into which the decorative body 20 is fitted. The mounting portion 36 is a concave space portion that is open on the front side and surrounded by the side wall portion 37 and the bottom portion 38. The opening 35 is formed through the bottom portion 38. The mounting portion 36 is formed according to the shape of the decorative body 20. In the present embodiment, the mounting portion 36 is formed in a shape having a longitudinal direction, that is, in a longitudinal shape. In the illustrated example, the mounting portion 36 is formed in a linear shape, preferably in a rectangular shape. The mounting portion 36 is disposed along the tear line 15. In the present embodiment, the mounting portion 36 is disposed along the center tear line 15a. In the illustrated example, the mounting portion 36 is disposed along the upper portion of the center tear line 15a. The mounting portion 36 has a longitudinal direction in the left-right direction and a short direction in the up-down direction. Therefore, the decorative body 20 attached to the mounting portion 36 is disposed on the front plate portion 14 with the longitudinal direction as the left-right direction and the short direction as the up-down direction.

[0044] The decorative body 20 attached to the mounting portion 36 is preferably held in a state where the front plate portion 14 is sandwiched in the plate thickness direction by engaging the engaging portion 23 with the engaging body 40 on the back side of the front plate portion 14. That is, in the present embodiment, the decorative member 19 has a two-component configuration of the decorative body 20 and the engaging body 40.

[0045] The engaging body 40 is also called a back plate or a lower emblem, etc., and is a portion that is located behind the front plate portion 14 and is not normally exposed. The engaging body 40 is formed of, for example, a synthetic resin. As shown in FIGS. 3(b) and 3(c), the engaging body 40 includes an engaging body main body portion 42. The engaging body main body portion 42 can have various shapes as long as it can hold the decorative body 20 on the front plate portion 14 of the cover main body portion 13. In the present embodiment, similar to the decorative body main body portion 22 of the decorative body 20, it is formed in a shape having a longitudinal direction. In the illustrated example, the engaging body main body portion 42 is formed in a rectangular shape. The engaging body main body portion 42 has a longitudinal dimension and a width dimension that are substantially equal to those of the decorative body main body portion 22.

[0046] In addition, in the present embodiment, a protruding portion 42a is formed on the engaging body main body portion 42. The protruding portion 42a protrudes in the short side direction, which is a direction intersecting the longitudinal direction of the engaging body main body portion 42. In the present embodiment, the protruding portions 42a are formed at the central portion in the longitudinal direction of the engaging body main body portion 42 and at both end portions in the longitudinal direction, respectively.

[0047] Furthermore, a receiving portion 43 for receiving the engaging portion 23 of the decorative body 20 is formed on the engaging body main body portion 42. The receiving portion 43 is formed as a hole portion penetrating the engaging body main body portion 42. The number of receiving portions 43 is the same as the number of engaging portions 23. In the present embodiment, three receiving portions 43 are provided on the engaging body main body portion 42. These receiving portions 43 are arranged apart from each other in the longitudinal direction of the engaging body main body portion 42. In the present embodiment, the receiving portions 43 are arranged at equal intervals or substantially equal intervals in the longitudinal direction of the engaging body main body portion 42. In the illustrated example, the receiving portions 43 are located at the central portion in the longitudinal direction of the engaging body main body portion 42 and in the vicinity of both end portions, respectively. The protruding portion 42a of the engaging body main body portion 42 is located at the position of the receiving portion 43.

[0048] A locking portion 43a, which is a claw portion for locking the enlarged portion 26 of the inserted engaging portion 23, is formed on the inner edge portion of the receiving portion 43. The locking portion 43a has a thickness direction in the insertion / removal direction of the engaging portion 23 with respect to the receiving portion 43 and is in a plate shape that can be elastically deformed in this thickness direction.

[0049] Also, as shown in FIG. 4, on the main surface side of the engaging body main body portion 42 facing the cover main body portion 13 and the decorative body 20, the thickness is increased in a rib shape from the peripheral edge portion of the receiving portion 43 to the long side portion and the protruding portion 42a.

[0050] Next, the operation of the first embodiment will be described.

[0051] When forming the decorative body 20, a mold having a slide core is used. In FIG. 1, while opening and closing the mold in the thickness direction of the decorative body main body portion 22, which is a direction perpendicular to the paper surface, and sliding the slide core in a direction (arrow S direction) intersecting or orthogonal to the axial direction of the engaging portion 23, the decorative body 20 provided with the engaging portion 23 having the enlarged portion 26 at the tip can be easily formed, and along the dividing line of the slide core, the reinforcing rib 28 can be formed continuously from the engaging portion 23 across one end portion and the other end portion in the longitudinal direction of the decorative body main body portion 22. Thereby, the ribs 28 are arranged in a well-balanced manner throughout the decorative body main body portion 22, the overall rigidity is improved, and the strength difference due to the part is suppressed.

[0052] And, as shown in FIG. 4, when attaching the decorative member 19 to the cover main body portion 13, the pre-formed decorative body 20 is inserted into the opening portion 35 at the attachment portion 36 of the front plate portion 14 of the cover main body portion 13 while inserting the engaging portion 23 and fitted into the attachment portion 36. At this time, the rib 28 becomes a seating surface that abuts against the bottom portion 38 of the attachment portion 36. However, since the ribs 28 are evenly arranged in the longitudinal direction and the short-side direction of the decorative body main body portion 22, the decorative body 20 is stably positioned in the attachment portion 36 without rattling in the short-side direction or the longitudinal direction.

[0053] Next, the pre-formed engaging body 40 is brought close to the back of the attachment portion 36 with respect to the front plate portion 14 of the cover main body portion 13, and the tip portion of the engaging portion 23 protruding from the opening portion 35 to the back side is pushed into the receiving portion 43 of the engaging body 40, so that the enlarged portion 26 of the engaging portion 23 elastically gets over the locking portion 43a of the receiving portion 43, and the engaging portion 23 is retained without coming off in the receiving portion 43 and is rigidly fixed.

[0054] In this state, as shown in FIGS. 3(a) to 3(c), with the decorative body 20 fitted into the attachment portion 36 and the engaging body 40 overlapped behind the attachment portion 36, the decorative member 19 is held and fixed to the cover main body portion 13. The decorative body 20 and the engaging body 40 are positioned so as to have a longitudinal direction along the center tear line 15a of the tear line 15 of the cover main body portion 13, and the protruding portion 42a of the engaging body main body portion 42 of the engaging body 40 is arranged on the center tear line 15a side, that is, the lower side.

[0055] The thus-completed cover body 11 is engaged with and held to the base plate with respect to the peripheral plate portion 17 so as to cover the folded airbag attached to the base plate together with the inflator, thereby completing the airbag device 3.

[0056] The airbag device 3 is attached to the boss portion 5 of the steering wheel body 2 of the base plate, and a predetermined wiring is connected to the inflator, so that it is held by the steering wheel body 2 and constitutes the steering wheel 1.

[0057] When an automobile equipped with this steering wheel 1 collides or the like, the control device operates the inflator to supply gas to the airbag. Then, the airbag rapidly expands and deploys, and the pressure of this expansion and deployment is most greatly applied to the central portion of the front plate portion 14 of the cover main body portion 13 as shown by the arrow F in Fig. 6(a). At this time, compared with both longitudinal ends of the decorative body 20 restrained by the engaging portion 23 shown in Fig. 3(c), the stress is more greatly applied from the back side to the front side in the thickness direction of the decorative body main body portion 22 at the central portion in the longitudinal direction, that is, from the inside to the outside of the cover main body portion 13, and although an input is generated such that the decorative body main body portion 22 bends and deforms, as shown in Fig. 1, the strength difference due to the portion of the decorative body main body portion 22 is reduced by the reinforcing rib 28, so that the deformation amount due to the generation of excessive stress concentration is suppressed, and the generation of stress leading to cracking is suppressed.

[0058] Therefore, as shown in Fig. 6(a), the decorative member 19 is firmly held to the door portion 16, and there is no loss of deforming the decorative body 20 of the decorative member 19 or the like with respect to the deployment pressure of the airbag, and the load can be efficiently transmitted to the tear line 15, and a smooth cracking behavior can be obtained. Therefore, the front plate portion 14 breaks along the tear line 15 due to the deployment pressure of the airbag.

[0059] Due to the breakage of the tear line 15, as shown in FIG. 6(b), upper and lower door portions 16, 16 are formed in the front plate portion 14. These door portions 16, 16 rotate upward and downward about hinge portions 45, 45 as axes to form a protruding port 46 which is an opening for inflating the airbag. The airbag expands from this protruding port 46 in front of the occupant to protect the occupant.

[0060] Also, as shown in FIG. 6(c), among the deployed door portions 16, for the upper door portion 16, when viewed from the front, the ornament 20 of the ornament member 19 located at the tip portion collides with the body cover 7 at the 12 o'clock direction of the analog clock, that is, on the upper side. At this time, the ornament 20 has a greater stress applied from the front side to the back side in the thickness direction of the ornament main body portion 22 at the central portion in the longitudinal direction compared to both longitudinal ends constrained by the engaging portion 23 shown in FIG. 3(c), that is, from the outside to the inside of the cover main body portion 13, and an input is generated such that the ornament main body portion 22 bends and deforms. However, as shown in FIG. 1, since the strength difference due to the portion of the ornament main body portion 22 is reduced by the reinforcing rib 28, the amount of deformation due to the generation of excessive stress concentration is suppressed, the generation of stress leading to cracking is suppressed, and it is firmly held by the door portion 16.

[0061] Thus, in the ornament 20 of the ornament member 19, by forming reinforcing ribs 28 extending from the base end portion of the engaging portion 23 to one edge portion side and the other edge portion side behind the ornament main body portion 22, the rigidity can be efficiently improved according to the shape of the ornament main body portion 22 by the ribs 28, and the strength can be ensured. Therefore, since no further reinforcing structure is required for the ornament 20, it becomes difficult to limit the degree of freedom in design.

[0062] For example, when increasing the rigidity of the entire ornament member 19 by enlarging the engaging body 40, the position where the tear line 15 can be set may be limited, or the storage space for the airbag may be limited. Therefore, the degree of freedom in design may be limited, and an increase in component weight and cost may occur. In contrast, in this embodiment, such limitations are less likely to occur, and an increase in component weight and cost is also less likely to occur.

[0063] In addition, when forming the engaging portion 23 using a slide core during the formation of the decorative body 20, it is not easy to form a shape that becomes an under shape with respect to the slide direction of the slide core. However, in the present embodiment, since the rib 28 is formed so as to extend from the base end portion of the engaging portion 23 to one edge portion side and the other edge portion side of the decorative body main body portion 22, the rib 28 can be widely arranged on the decorative body 20 without generating an under shape in the slide direction of the slide core. Therefore, problems such as stress concentration being likely to occur in the portion without the rib 28 are less likely to occur. Moreover, the cost is lower than the case where the entire decorative body main body portion 22 is formed thick to ensure strength, and appearance defects such as sink marks after molding are also less likely to occur.

[0064] By setting a plurality of engaging portions 23 and forming ribs 28 continuously between these engaging portions 23, the strength of the decorative body main body portion 22 can be improved more over the entire body.

[0065] In particular, when the decorative body main body portion 22 has a shape having a longitudinal direction, by forming the rib 28 extending in the longitudinal direction of the decorative body main body portion 22 as in the present embodiment, it is possible to make it difficult to generate a strength difference between both end portions and the central portion in the longitudinal direction and suppress local stress concentration.

[0066] In the present embodiment, since the decorative body main body portion 22 has a rectangular shape, local stress concentration can be suppressed by the rib 28 while having good designability.

[0067] And since the rib 28 is continuous from one edge portion in the longitudinal direction of the decorative body main body portion 22 to the other edge portion via the engaging portion 23, at least one or more ribs 28 are positioned in an arbitrary cross section in the short side direction. Thus, the ribs 28 can be arranged in a well-balanced manner with respect to the decorative body 20, and local stress concentration can be suppressed.

[0068] In particular, by providing the rib 28 with a first portion 31 that extends in the longitudinal direction of the decorative body main body portion 22 and is continuous with the base end portion of each engaging portion 23, a second portion 32 that extends obliquely in a direction intersecting the longitudinal direction from the end portion of the first portion 31 on the side opposite to the engaging portion 23 and away from the engaging portion 23, and a third portion 33 that is continuous between the second portions 32 and extends in the longitudinal direction of the decorative body main body portion 22, the rib 28 can be arranged on the decorative body 20 in a well-balanced manner without inhibiting the sliding of the slide core used to form the engaging portion 23. Moreover, between the engaging portions 23, by inclining the second portion 32 in an expanding manner from the end portion of the first portion 31, the rib 28 can be formed in a honeycomb shape by the second portion 32 and the third portion 33, enabling the setting of a well-balanced rib 28.

[0069] In a configuration in which a decorative body 20 is held on a front panel portion 14 with a separate engaging body 40 interposed therebetween, a protruding portion 42a is formed to protrude in a direction intersecting the longitudinal direction on a longitudinally shaped engaging body main body portion 42 in the same direction as the longitudinal direction of the decorative body main body portion 22 of the decorative body 20. Therefore, compared with the case where the edge portion of the engaging body main body portion 42 is formed linearly, the deployment pressure of the airbag can be easily released by the deformation of the protruding portion 42a, and stress concentration can be suppressed.

[0070] In particular, since the protruding portion 42a is arranged on at least a part of the tear line 15, on the center tear line 15a side where the deployment pressure of the airbag concentrates in the present embodiment, the protruding portion 42a can receive and easily release stress when receiving the deployment pressure of the airbag.

[0071] By attaching the above-described decorative member 19 to the front panel portion 14 of the airbag device 3, the decorative member 19 can be reliably held on the front panel portion 14 against the deployment pressure of the airbag and the like when the airbag is deployed.

[0072] In particular, since the decorative member 19 can suppress deformation due to the deployment pressure of the airbag by ensuring the strength of the decorative body 20, by arranging this decorative member 19 along at least a part of the tear line 15, in this embodiment, along the center tear line 15a, the deployment pressure of the airbag with reduced loss due to deformation of the decorative member 19 (decorative body 20) is efficiently transmitted to the tear line 15, and the instrument panel portion 14 can be smoothly broken from the tear line 15.

[0073] In addition, in the above-described first embodiment, the rib 28 of the decorative body 20 may have a shape that continuously extends in a straight line in the longitudinal direction of the decorative body main body portion 22 as in the second embodiment shown in FIG. 7. Further, when the positions of the engaging portions 23 are shifted in the short hand direction of the decorative body main body portion 22 as in the third embodiment shown in FIG. 8, the rib 28 may have a shape that is bent in a polygonal line shape between the engaging portions 23. Furthermore, as in the fourth embodiment shown in FIG. 9, between the engaging portions 23, the second portions 32 may be directly connected to each other. In any of these cases, similar to the first embodiment, it is possible to provide the decorative member 19 that can ensure strength and is less likely to have its design freedom restricted.

[0074] Also, the number of the engaging portions 23 and the arrangement of the ribs 28 can be arbitrarily adjusted according to the shape of the decorative body main body portion 22 of the decorative body 20. That is, the engaging portion 23 may be one, two, or four or more, and the rib 28 may have an arbitrary shape as long as it extends from the base end portion of the engaging portion 23 to one edge portion side and the other edge portion side of the decorative body main body portion 22.

[0075] The decorative body main body portion 22 may have, for example, an elliptical shape as long as it has a shape with a longitudinal direction.

[0076] Also, the decorative member 19 is not limited to a two-component configuration including the decorative body 20 and the engaging body 40, and may have a one-component configuration in which the engaging portion 23 of the decorative body 20 is directly inserted into and engaged with the opening 35 of the instrument panel portion 14 for fixation.

Industrial Applicability

[0077] The present invention can be applied to, for example, an emblem attached to a cover body of an airbag device used for a steering wheel of an automobile.

Explanation of Reference Numerals

[0078] 3 Airbag device 11 Cover body 14 Instrument panel part as a covering part 15 Tear line as a breaking part 19 Decorative member 20 Decorative body 22 Decorative body main body part 23 Engaging part 28 Rib 31 First part 32 Second part 33 Third part 40 Engaging body 42 Engaging body main body part 42a Protrusion 43 Receiving part

Claims

1. A decorative member that covers an airbag in a folded state and is attached to a covering portion having a breaking portion that breaks when the airbag is deployed, comprising a decorative body main body portion, an engaging portion provided protruding from the back side of the decorative body main body portion for attachment to the covering portion, and reinforcing ribs provided behind the decorative body main body portion and extending from the base end portion of the engaging portion to one edge portion side and the other edge portion side of the decorative body main body portion, and including a decorative body located on the design side of the covering portion The decorative member is characterized by the above.

2. A plurality of engaging portions are provided, The ribs are continuous across the plurality of engaging portions The decorative member according to claim 1, characterized by the above.

3. The decorative body main body portion has a shape with a longitudinal direction The decorative member according to claim 1 or 2, characterized by the above.

4. The decorative body main body portion is rectangular The decorative member according to claim 3, characterized by the above.

5. The ribs are continuous from one edge portion in the longitudinal direction of the decorative body main body portion to the other edge portion via the engaging portion The decorative member according to claim 3 or 4, characterized by the above.

6. A plurality of engaging portions are provided, The ribs are a first portion that is continuous with the base end portion of each engaging portion and extends in the longitudinal direction of the decorative body main body portion, a second portion that extends in an inclined manner in a direction intersecting the longitudinal direction from the end portion of the first portion opposite to the engaging portion and away from the engaging portion, and a third portion that is continuous between the second portions and extends in the longitudinal direction of the decorative body main body portion The decorative member according to any one of claims 3 to 5, characterized by the above.

7. A coupling body that is separate from the decorative body and holds the decorative body on the covering portion with the covering portion interposed therebetween. The coupling body is a longitudinally elongated coupling body main body in the same direction as the longitudinal direction of the decorative body main body, and a receiving portion provided on the coupling body main body for receiving the engaging portion of the decorative body. The coupling body main body has a protruding portion that protrudes in a direction intersecting the longitudinal direction. The decorative member according to any one of claims 3 to 6, characterized in that.

8. A covering portion that covers the airbag in a folded state and has a breaking portion that breaks when the airbag is deployed, and The decorative member according to any one of claims 1 to 7 attached to the covering portion, and A cover body of an airbag device, characterized by comprising.

9. The decorative member is arranged along at least a part of the breaking portion. The cover body of the airbag device according to claim 8, characterized in that.

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