JP2012218679A - Airbag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain reduction in vibration damping performance by contact with a constituting part of a steering wheel arranged on the front side of a flange of an inflator.SOLUTION: This airbag device 20 includes a bag holder 40 arranged in the steering wheel, an airbag 37 installed in the bag holder 40, the inflator 30 for inflating the airbag 37 backward by supplying gas G to the airbag 37, and an elastic support part 55 for elastically supporting the inflator 30 by the bag holder 40 in the flange 33 arranged in a peripheral wall part 31 of the inflator 30. The bag holder 40 is provided with an annular wall part 43 extending backward from a place of becoming the outside of the flange 33 in the radial direction of a steering shaft. The elastic support part 55 is arranged between the rear end of the wall part 43 and the flange 33, and a part of the elastic support part 55 is constituted of an annular elastic connecting part 64 made of an elastic material.

Description

  The present invention relates to an airbag device installed in a steering wheel of a vehicle or the like, and more specifically, an airbag configured to function as a damper mass of a dynamic damper by elastically supporting an inflator on a back holder by an elastic support portion. It relates to the device.

  If vibration is transmitted to the steering wheel through the steering shaft while the vehicle is traveling at high speed or the engine is idling, the driver's comfortable driving may be impaired. Therefore, a technique for suppressing (vibrating) the vibration of the steering wheel has been developed and proposed. For example, there is a technique that uses a dynamic damper including a weight and an elastic member that supports the weight on a metal core of a steering wheel. According to this technology, when vibration having the same frequency as the resonance frequency unique to the dynamic damper is transmitted from the steering wheel to the dynamic damper, the dynamic damper resonates and absorbs vibration energy of the steering wheel. This absorption suppresses (suppresses) the vibration of the steering wheel.

  On the other hand, an air bag device is incorporated in the steering wheel in order to protect the driver in the event of a vehicle collision. The airbag device includes a back holder disposed in the steering wheel, an airbag attached to the back holder, and an inflator attached to the back holder and supplying gas to the airbag. The air bag device protects the driver from impact by inflating the air bag rearward with the gas supplied from the inflator when the vehicle collides.

  Here, since the airbag device occupies most of the internal space of the steering wheel, it is difficult to incorporate the above-described dynamic damper in a recent steering wheel. Therefore, a configuration has been proposed in which the inflator is elastically supported by the elastic support portion with respect to the back holder so as to function as a damper mass of the dynamic damper.

  For example, in Patent Document 1, as shown in FIG. 10, the adapter element 103 is fixed to the peripheral wall portion 102 of the inflator 101. The adapter element 103 includes a ring-shaped flange 105 disposed on the front side of the flange 104 of the inflator 101, a pipe-shaped attachment 106 extending forward from the outer peripheral portion of the flange 105, and the inflator 101 from the front end of the attachment 106. And a disc-shaped peripheral edge 107 bent outward in the radial direction. The adapter element 103 is fastened to the flange 104 of the inflator 101 at the flange 105 by screws (not shown).

  On the other hand, a fixing flange 109 is provided on the outer periphery of the front end portion of the back holder 108, and a ring-shaped connection plate 111 disposed on the front side thereof is fastened to the fixing flange 109 with screws (not shown).

  Further, an annular rubber diaphragm 112 is disposed around the adapter element 103. The front end portion of the rubber diaphragm 112 is joined to the peripheral edge 107 of the adapter element 103, and the rear end portion is joined to the inner peripheral portion of the connection plate 111.

  The adapter element 103, the connection plate 111, and the rubber diaphragm 112 constitute an elastic support portion 113 that elastically supports the inflator 101 on the back holder 108.

JP 2001-171460 A (FIG. 2)

  By the way, in the steering wheel in which the airbag apparatus is installed as described above, in many cases, the harness connected to the components of the steering wheel, for example, the inflator 101, in the space ahead of the flange 104 of the inflator 101. Various harnesses including are arranged.

  In this regard, in Patent Document 1, the one that vibrates together with the inflator 101 (adapter element 103) and the one that elastically deforms with the vibration of the inflator 101 (rubber diaphragm 112) are more than the flange 104 of the inflator 101. Since it is located in the front, it is easy to contact the above components of the steering wheel. Due to this contact, the vibration of the inflator 101 and the elastic deformation of the rubber diaphragm 112 are hindered, and the vibration suppression (damping) performance of the dynamic damper may be deteriorated.

  The present invention has been made in view of such a situation, and the object thereof is to suppress a decrease in vibration damping performance due to contact with a component of a steering wheel disposed in front of the flange of the inflator. An object of the present invention is to provide an airbag device that can be used.

  In order to achieve the above object, an invention according to claim 1 is directed to a back holder disposed in a steering wheel rotated around a steering shaft extending in the front-rear direction, and air attached to the back holder. A bag, an inflator for supplying gas to the airbag and inflating the airbag rearward, and an annular elastic support portion for elastically supporting the inflator to the back holder at a flange provided on a peripheral wall portion of the inflator The back holder is provided with an annular wall portion extending rearward from a location that is outward from the flange in the radial direction of the steering shaft, and the elastic support portion. Is provided between the rear end of the wall portion and the flange, and a part of the elastic support portion is And gist that it is constituted by an elastic connection of the annular consisting sexual material.

  According to said structure, in an airbag apparatus, the elastic connection part of an elastic support part functions as a spring of a dynamic damper, and an inflator functions as a damper mass of a dynamic damper. For this reason, when vibration of the same frequency as the resonance frequency specific to the dynamic damper is transmitted from the steering wheel to the dynamic damper, the elastic coupling portion vibrates with the inflator while elastically deforming (the elastic coupling portion and the inflator resonate). ), Absorb the vibration energy of the steering wheel. This absorption attenuates (suppresses) the vibration of the steering wheel.

  Here, in the steering wheel, various harnesses including components connected to the steering wheel, for example, a harness connected to the inflator, are arranged in a space ahead of the flange of the inflator. For this reason, when an object that vibrates together with an inflator or an object that elastically deforms along with the vibration of the inflator (elastic connecting portion) contacts the above-described components of the steering wheel, the components cause movement of the inflator and the elastic support portion. This may hinder the vibration suppression (vibration suppression) performance of the dynamic damper.

  In this regard, according to the first aspect of the present invention, the wall portion of the back holder extends rearward from a location that is outward from the flange of the inflator in the radial direction of the steering shaft. An elastic support portion is provided between the rear end of the wall portion and the flange, and a part of the elastic support portion is constituted by an annular elastic coupling portion made of an elastic material. From this, both those that vibrate together with the inflator and those that elastically deform with the vibration of the inflator (elastic connecting portion) are located behind the flange, and the space in front of the flange Difficult to contact the components of the steering wheel. As a result, the vibration damping performance of the dynamic damper is unlikely to deteriorate due to contact with the above components.

  The invention according to claim 2 is the invention according to claim 1, wherein the peripheral wall portion of the inflator is provided with a gas ejection hole, and the elastic coupling portion of the elastic support portion and the gas ejection hole are provided. The gist is that a gas flow restricting portion that restricts the gas ejected from the gas ejection holes from flowing toward the elastic connecting portion is provided between the two.

  According to said structure, when an airbag apparatus act | operates by impacts, such as a collision, gas will be ejected from the gas ejection hole of the surrounding wall part of an inflator. The gas is regulated by the gas flow restricting portion located between the elastic connecting portion of the elastic supporting portion and the gas ejection hole so as to flow toward the elastic connecting portion and directly touch the elastic connecting portion. As a result, the gas ejected from the gas ejection holes does not directly touch the elastic connecting portion, and the elastic connecting portion is not easily affected by the heat of the gas.

  According to a third aspect of the present invention, in the second aspect of the present invention, the cup retainer that covers the inflator from the rear side is disposed between the wall portion and the cup retainer, and the air is interposed between the cup retainer. The present invention further includes an annular gas plate sandwiching a peripheral portion of the gas inlet of the bag, and an inner peripheral portion of the gas plate is bent forward as the gas flow restricting portion.

According to said structure, the peripheral part of the gas inlet of an airbag is fixed to a back holder via a gas plate and a cup retainer.
Moreover, the gas ejected from the gas ejection hole of the inflator is restricted by the gas plate and the cup retainer from directly touching the peripheral portion of the gas inlet of the airbag. Further, direct contact of the gas ejected from the gas ejection hole of the inflator with the elastic connecting portion is restricted by a portion (gas flow restricting portion) bent forward in the inner peripheral portion of the gas plate. As a result, the peripheral portion of the gas inlet of the airbag and the elastic connecting portion are not easily affected by the heat of the gas.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the wall portion of the back holder is covered with a wall covering portion made of an elastic material, and the wall covering portion The gist of the present invention is that a protrusion made of an elastic material and projecting radially inward of the steering shaft is integrally formed on the inner side surface.

  According to the above configuration, when vibration is transmitted from the steering wheel to the dynamic damper, the elastic connecting portion vibrates with the inflator while being elastically deformed. At this time, the elastic connecting portion itself or the connecting portion between the elastic connecting portion and the flange of the inflator comes into contact with the protrusion protruding from the inner side surface of the wall covering portion toward the radially inward direction of the steering shaft. Is moved more than necessary to the outside in the radial direction of the steering shaft, and contact with the wall (wall covering) is restricted.

As a result, the amount of elastic deformation of the elastic connecting portion is suppressed to the minimum necessary, and a decrease in durability of the elastic connecting portion is suppressed, and generation of noise due to contact with the wall covering portion is suppressed.
The same effect can be obtained by attaching a contact suppressing member made of a member different from the wall covering portion on the inner surface of the wall covering portion. However, in that case, the number of parts of the airbag device is increased by the amount of the contact suppression member, and a process of attaching the contact suppression member to the wall covering portion is required, which increases the number of manufacturing steps.

  In this regard, according to the invention described in claim 4, the protrusions are formed together when the wall covering portion is formed. Further, the protrusion and the wall covering portion are integrated. Therefore, compared with the case where a contact suppression member is attached, the number of parts and the number of manufacturing steps of the airbag device can be reduced.

  Moreover, the merit about the said number of parts and a manufacturing man-hour is acquired also by providing the protrusion which consists of elastic materials in the outer surface of an elastic connection part. However, in that case, the shape of the elastic connecting portion is different from the case without the protrusion, and the protrusion affects the vibration damping performance of the elastic connecting portion. In that respect, in the invention according to claim 4 in which the protrusion is provided on the inner surface of the wall covering portion, the protrusion does not have a possibility of affecting the vibration damping performance of the elastic connecting portion.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the back holder has a locking hole penetrating in the front-rear direction, and the configuration of the steering wheel. The pad cover that forms a part of the member and covers the airbag and the inflator from the rear is provided with a locking claw having a claw portion, and the pad claw is inserted into the locking hole. The claw portion is fastened to the back holder by being locked in the locking hole, and the cover plate that covers the inflator from the front is inserted into the locking hole, The gist of the invention is that a holding portion for holding the locking claw in a state where the claw portion is locked in the locking hole is provided.

  According to the above configuration, when the pad cover is fastened to the back holder, the locking claw is inserted from behind into the locking hole, and the claw portion is locked in the locking hole. The locking claw is restrained from being bent in the radial direction of the steering shaft by the holding portion of the cover plate inserted into the locking hole, and is held in a state where the claw portion is locked in the locking hole. Therefore, even if an excessive force is applied to the pad cover when the airbag is inflated, the locking claw is prevented from coming out of the locking hole.

  According to the airbag device of the present invention, it is possible to suppress a decrease in vibration damping performance due to contact with the components of the steering wheel disposed on the front side of the flange of the inflator.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows one Embodiment which actualized this invention, and is a schematic side view of the steering wheel by which the airbag apparatus was equipped internally. The perspective view of an airbag apparatus. The front view which shows a part of airbag apparatus. XX sectional drawing of FIG. FIG. 4 is a cross-sectional view taken along line YY in FIG. 3. In FIG. 5, sectional drawing which shows the state before a cover plate is fastened by a back holder. (A) is a perspective view of a back holder, (B) is a perspective view of a flange plate. (A) is a perspective view of a back holder and an elastic support part, (B) is a perspective view which shows the state by which the inflator was attached to the elastic support part of (A). The front view which shows the example of a change which provided the processus | protrusion in the inner surface of the wall part in a back holder. The fragmentary sectional view which shows the conventional airbag apparatus.

Hereinafter, an embodiment in which an airbag device of the present invention is applied to a steering wheel for a vehicle will be described with reference to FIGS.
As shown in FIG. 1, in front of the driver's seat of the vehicle, a steering shaft (steering shaft) 11 that rotates about the rotation axis L1 is inclined so as to be higher toward the driver's seat side (rear side). It is arranged. A steering wheel 12 is attached to the rear end portion of the steering shaft 11 so as to be integrally rotatable.

  In the present embodiment, when describing each part of the steering wheel 12, the rotation axis L1 of the steering shaft 11 is used as a reference. The direction along the rotational axis L1 is referred to as the “front-rear direction” of the steering wheel 12, and the direction in which the steering wheel 12 stands up is referred to as the “vertical direction” among the directions along the plane orthogonal to the rotational axis L1. Therefore, the front-rear direction and the vertical direction of the steering wheel 12 are slightly inclined with respect to the front-rear direction (horizontal direction) and the vertical direction (vertical direction) of the vehicle.

  Further, in order to specify the position of the steering wheel 12 to be rotated, in this embodiment, “up”, “down” based on the state of the steering wheel 12 when the vehicle is traveling straight, that is, the neutral state. , “Left” and “Right” shall be defined. Therefore, the left-right direction of the steering wheel 12 is the same as the vehicle width direction (vehicle width direction).

  Furthermore, the direction (side) away from the steering shaft 11 in the radial direction is referred to as radially outward (radially outward), and the direction (side) approaching the steering shaft 11 is referred to as radially inward (radially inner). To do.

  The steering wheel 12 includes a rim portion (sometimes referred to as a handle portion or a ring portion) 13, a pad cover 21, a lower cover 15, and a spoke portion (not visible in a hidden portion in FIG. 1). The rim portion 13 has a substantially annular shape centered on the steering shaft 11. The pad cover 21 is disposed at the central portion of the rim portion 13. The lower cover 15 is disposed on the front side of the pad cover 21 at the center portion. The spoke part is provided between the rim part 13 and the pad cover 21.

  Each of the above-described components (rim portion 13 and spoke portion) of the steering wheel 12 and the space surrounded by the pad cover 21 and the lower cover 15 are formed of iron, aluminum, magnesium, or an alloy thereof. A metal core (not shown) is provided. The cored bar forms a skeleton part of the steering wheel 12.

  In the space surrounded by the pad cover 21 and the lower cover 15, an airbag device 20 shown in FIGS. 2 and 4 is disposed in addition to a part of the cored bar. The airbag device 20 supplies gas G from an inflator (gas generator) 30 to an airbag 37 (see FIG. 4) when an impact is applied to the vehicle from the front due to a frontal collision (front collision) of the vehicle. The air bag 37 is inflated in front of the driver to reduce the impact transmitted to the driver. The airbag device 20 includes a back holder 40, an elastic support portion 55, a cup retainer 70, a gas plate 80, and a cover plate 90 in addition to the pad cover 21, the inflator 30, and the airbag 37. In addition, although the pad cover 21 is one of the structural members of the steering wheel 12, it also serves as the structural member of the airbag apparatus 20 here. Next, these components of the airbag device 20 will be described.

<Pad cover 21>
As shown in FIGS. 2 and 5, the pad cover 21 includes a lid portion 22 and an accommodating wall portion 23 that protrudes from the front surface of the lid portion 22 in a substantially square ring shape, and is entirely formed of a synthetic resin. Has been. The lid portion 22 and the accommodation wall portion 23 form an accommodation space 24 (see FIG. 5) for accommodating the folded airbag 37 and the like between the back holder 40. On the front surface of the lid portion 22, a planned fracture portion (not shown) having a smaller thickness and lower strength than other portions of the lid portion 22 is formed. The lid portion 22 is broken at the portion.

  Locking claws 25 are integrally formed at a plurality of locations on the front end of the housing wall 23. Each locking claw 25 includes a main body portion 26 having a rectangular plate shape, and a claw portion 27 that protrudes radially outward from the front portion of the main body portion 26 (a direction away from the accommodation space 24). In addition, illustration of the latching claw 25 is abbreviate | omitted in FIG.

<Inflator 30>
As shown in FIGS. 5 and 8B, the inflator 30 has a substantially cylindrical shape, and a gas generating agent (not shown) is accommodated therein. An axis L2 of the inflator 30 is located on the same straight line as the rotation axis L1 of the steering shaft 11. A plurality of gas ejection holes 32 are provided in the circumferential wall portion 31 of the inflator 30 at substantially equal angles in the circumferential direction, and the gas G generated by the gas generating agent is radially outward from each gas ejection hole 32. Erupted.

  An annular flange 33 is formed over the entire circumference of the peripheral wall portion 31 at a location on the peripheral wall portion 31 and in front of the gas ejection holes 32. The flange 33 has a substantially flat plate shape orthogonal to the axis L <b> 2 of the inflator 30. A plurality of locations (four locations) of the flange 33 are mounting pieces 33 </ b> A that extend more radially outward than other locations of the flange 33. A rivet insertion hole 34 is formed in each attachment piece 33A.

  A connector 36 is assembled to the front portion of the inflator 30, and a harness (not shown) serving as an input wiring for an operation signal to the inflator 30 is connected to the connector 36.

  As the inflator 30, instead of the type using the gas generating agent, a type in which a partition of a high-pressure gas cylinder filled with a high-pressure gas is broken by an explosive or the like to eject gas may be used.

<Airbag 37>
As shown in FIGS. 4 and 5, the airbag 37 is inflated by the gas G supplied from the inflator 30 and has a high strength and is formed into a bag shape by a flexible cloth such as a woven cloth. Is formed. The airbag 37 has a size that can be inflated in a region between the steering wheel 12 and the driver. The airbag 37 has a gas introduction port 38 for introducing the gas G ejected from the gas ejection hole 32 of the inflator 30 at its front end. Many portions of the airbag 37 except for the gas inlet port 38 are not shown in the figure, but are formed into a compact form by being folded on the rear side of the cup retainer 70 described later.

<Back holder 40>
As shown in FIGS. 5 and 7A, the back holder 40 is formed by pressing a metal plate. The back holder 40 includes a base 41 having a substantially square ring shape. The base 41 has a substantially flat plate shape orthogonal to the axis L <b> 2 of the inflator 30, and is located radially outward of the flange 33 of the inflator 30.

  In the base 41, locking holes 42 are formed at a plurality of locations corresponding to the locking claws 25 of the pad cover 21. Each locking hole 42 has a slit shape long in the side direction of the base 41 corresponding to each of the wide locking claws 25 and penetrates the base 41 in the front-rear direction. Claw portions 27 of the respective locking claws 25 of the pad cover 21 are inserted into the respective locking holes 42 from the rear side. Each claw portion 27 is positioned on the front side of the base portion 41 and radially outward from each locking hole 42, so that each locking claw 25 is locked to each locking hole 42 so as not to move backward. Has been. As shown in FIG. 6, the width W1 of each locking hole 42 is set to be slightly wider than the maximum thickness T1 of each locking claw 25 (thickness where the claw portion 27 bulges most). . This is a necessary condition for inserting each locking claw 25 into each locking hole 42.

  As shown in FIGS. 5 and 7A, the back holder 40 includes an annular wall portion 43 that extends rearward from the inner edge portion of the base portion 41, and a plurality of portions that extend radially inward from the rear end portion of the wall portion 43. (Four) extending portions 44 are further provided. Accordingly, the base portion 41 and each extending portion 44 are arranged in parallel to each other at a location shifted in the front-rear direction by the amount of the wall portion 43.

In the present embodiment, the wall 43 is inclined so as to approach the axis L2 toward the rear side, but may be formed so as to be parallel to the coaxial line L2.
Arc-shaped cutouts 45 are formed at a plurality of locations (four locations) between the adjacent extending portions 44 and corresponding to the mounting pieces 33A of the inflator 30. Each notch 45 is for avoiding a rivet 67 (described later) attached to the attachment piece 33 </ b> A from coming into contact with the extension 44 when the inflator 30 vibrates back and forth. The plurality of extending portions 44 have an inner shape corresponding to the outer shape of the flange 33.

  Each extending portion 44 is formed with one bolt insertion hole 46 and a plurality of through holes 47 having a diameter smaller than that of the bolt insertion hole 46. A space surrounded by the plurality of extending portions 44 serves as an opening 48 through which a rear portion of the inflator 30 is inserted.

  As shown in FIGS. 2 and 7A, mounting portions 49 for mounting a horn switch mechanism (not shown) protrude radially outward at a plurality of locations (three locations) of the base portion 41, respectively. Is formed. The horn switch mechanism is for operating a horn device (not shown) provided in the vehicle. Each mounting portion 49 is formed with a mounting hole 51 for mounting a horn switch mechanism. The horn switch mechanism attached to each attachment portion 49 is supported by a core metal (not shown) of the steering wheel 12. With this support, the airbag device 20 is in a floating state with respect to the metal core, and can be moved (displaced) in the front-rear direction by deforming each horn switch mechanism.

<Elastic support part 55>
As shown in FIGS. 4 and 8A, the elastic support portion 55 is for elastically supporting the inflator 30 on the back holder 40, and includes a front support portion 56, a rear support portion 62, and an elastic connection portion 64. Consists of.

  As shown in FIG. 5 and FIG. 7, the front support portion 56 uses a metal plate, and a flange plate 57 formed in a substantially same outer shape as the outer shape of the flange 33 of the inflator 30 (see FIG. 8B). It has. The flange plate 57 has a substantially annular shape with a slightly larger diameter than the peripheral wall portion 31 of the inflator 30. A plurality of locations (four locations) of the flange plate 57 are attachment pieces 57 </ b> A that extend more radially outward than other locations of the flange plate 57. Each attachment piece 57A has a rivet insertion hole 58 corresponding to the rivet insertion hole 34 of the attachment piece 33A. Further, a plurality of through holes 59 having a diameter smaller than that of the rivet insertion hole 58 are formed in the flange plate 57 in the vicinity of each mounting piece 57A. The flange plate 57 is mainly used as a strength member for securing the coupling strength between the front support portion 56 and the flange 33.

  Around the flange plate 57, a front cover portion 61 made of an elastic material such as an elastomer is formed. This elastic material is not filled in the rivet insertion hole 58 but is filled in the through hole 59. The flange plate 57 and the front covering portion 61 constitute a front support portion 56. In the front cover portion 61, both side portions in the thickness direction (front-rear direction) of the flange plate 57 are connected to each other through the through hole 59. Due to the connection through the through hole 59, the flange plate 57 and the front covering portion 61 are integrated. No adhesive is used for this integration.

  On the other hand, a part of the rear support portion 62 is constituted by the extending portion 44 of the back holder 40. Around each extending portion 44, a rear covering portion 63 made of an elastic material such as an elastomer is formed in the same manner as the front covering portion 61. The elastic material is not filled in the bolt insertion hole 46 but is filled in the through holes 47. The extension portion 44 and the rear cover portion 63 constitute a rear support portion 62. In the rear covering portion 63, both side portions in the thickness direction (front-rear direction) of each extending portion 44 are connected to each other through the through hole 47. By such connection through the through hole 47, each extending portion 44 and the rear covering portion 63 are integrated. No adhesive is used for this integration.

  Here, as described above, since the flange plate 57 and each extending portion 44 are arranged in parallel with each other at a location shifted in the direction along the axis L2 (front-rear direction), the front support portion 56 and The rear support portions 62 are also arranged in parallel to each other at positions shifted in the direction along the axis L2 (front-rear direction).

  The elastic connecting portion 64 is formed in an annular shape only by the same elastic material as the front side covering portion 61 and the rear side covering portion 63, and includes the front side support containing the hard member (the flange plate 57 and the extending portion 44). It is easier to elastically deform than the part 56 and the rear support part 62. The front end portion of the elastic connection portion 64 is connected to the outer edge portion of the front support portion 56, and the rear end portion of the elastic connection portion 64 is connected to the inner edge portion of the rear support portion 62. The elastic connecting portion 64 has a shape corresponding to the outer shape of the flange plate 57 and the inner shape of the extending portion 44 (see FIG. 8A).

  The elastic connecting portion 64 constitutes a dynamic damper together with the inflator 30. In the present embodiment, the elastic connecting portion 64 functions as a dynamic damper spring, and the inflator 30 functions as a damper mass.

  Further, by tuning the size, the radial thickness, the longitudinal length, etc. of the elastic connecting portion 64, the resonance frequency in the vertical direction and the horizontal direction of the dynamic damper can be adjusted in the vertical direction and the horizontal direction of the steering wheel 12. Is set to a target vibration suppression frequency (frequency to be controlled).

  Further, the periphery (inside and outside) of the wall portion 43 of the back holder 40 is covered with a wall covering portion 65 made of an elastic material such as an elastomer, like the front cover portion 61 and the rear cover portion 63.

  In addition, the elastic support part 55 which has said structure is formed by performing the following insert molding, for example. In this insert molding, the back holder 40 and the flange plate 57 are arranged as insert members in the mold, and around the extended portions 44 of the back holder 40, around the flange plate 57, and the inner edge of each extended portion 44. And an elastic material are injected between the outer edge of the flange plate 57 and the outer edge of the flange plate 57, respectively. As the elastic material is cured, the front covering portion 61, the elastic connecting portion 64, the rear covering portion 63, and the wall covering portion 65 are formed in a state of being integrated with the back holder 40 and the flange plate 57.

  The front support portion 56 of the elastic support portion 55 is overlapped with the flange 33 of the inflator 30 from the rear side. Then, a rivet 67 is inserted from the rear into each rivet insertion hole 34, 58 of each mounting piece 33A, 57A, and the front end portion of the rivet 67 is crushed, whereby the front support portion 56 is fastened to the flange 33 (caulking). Fixed).

  In the state fastened as described above, the front covering portion 61 of the front support portion 56 is elastically deformed and is in close contact with the flange 33, and the gap generated between the front support portion 56 and the flange 33 is extremely small.

<Cup retainer 70>
As shown in FIGS. 3 and 5, the cup retainer 70 is formed by pressing a metal plate. The cup retainer 70 includes an annular mounting base 72 and a cover portion 73 that bulges backward from the inner edge of the mounting base 72 and covers the inflator 30 from the rear side.

  The attachment base 72 has a substantially flat plate shape orthogonal to the axis L2 of the inflator 30 and is disposed at a position slightly rearward of the gas ejection hole 32 of the inflator 30. In the attachment base 72, bolt insertion holes 74 are formed at locations corresponding to the bolt insertion holes 46 of the extending portions 44.

  The cover portion 73 is formed with a gas discharge port 75 for discharging the gas G ejected from the inflator 30 from the cup retainer 70 to the airbag 37. A contact suppressing member 76 formed of felt is attached to the front surface of the cover portion 73 (see FIG. 4). The contact suppression member 76 is for suppressing the contact with the cover part 73 of the inflator 30 and suppressing the generation of abnormal noise associated with the contact.

<Gas plate 80>
As shown in FIGS. 4 and 5, the gas plate 80 is formed in an annular shape by pressing a metal plate. The main body 81 that forms the main part of the gas plate 80 has a substantially flat plate shape that is orthogonal to the axis L <b> 2 of the inflator 30. The main body 81 is disposed between the extension 44 of the back holder 40 and the mounting base 72 of the cup retainer 70. The main body 81 is located at substantially the same location as the gas ejection hole 32 of the inflator 30 in the front-rear direction. Bolt insertion holes 82 are formed at positions corresponding to the bolt insertion holes 46 of the extending portions 44 in the main body 81.

  Between the main body 81 of the gas plate 80 and the mounting base 72 of the cup retainer 70, a peripheral portion of the gas inlet 38 of the airbag 37 is disposed. In other words, the peripheral portion of the gas introduction port 38 of the airbag 37 is sandwiched between the gas plate 80 and the cup retainer 70 from the front and rear. The gas plate 80 is located not only behind the extending portion 44 but also behind the notch 45 (see FIG. 5). Therefore, the peripheral portion of the gas introduction port 38 of the airbag 37 is covered with the main body 81 of the gas plate 80 and the mounting base 72 of the cup retainer 70 and is not exposed.

  Further, the inner peripheral portion of the main body 81 is bent forward and constitutes an annular gas flow restricting portion 83. The gas flow restricting portion 83 is located between the elastic coupling portion 64 of the elastic support portion 55 and the gas ejection hole 32, and the gas G ejected from the gas ejection hole 32 flows toward the elastic coupling portion 64. To regulate. A contact suppressing member 84 formed of felt is attached to the inside of the gas flow restricting portion 83 in the radial direction. The contact suppressing member 84 is for suppressing the contact with the gas flow restricting portion 83 of the inflator 30 and suppressing the generation of abnormal noise accompanying the contact.

  The front end of the gas flow restricting portion 83 is formed in a tapered shape so as to approach the axis L2 toward the front side. For one thing, the corner of the front end of the gas flow restricting portion 83 is moved away from the elastic connecting portion 64 to make it difficult for the same corner made of metal and the elastic connecting portion 64 made of only an elastic material to come into contact with each other. Because. In addition, the gas G ejected from the gas ejection holes 32 is caused to flow along the gas flow restricting portion 83 so as to be away from the elastic coupling portion 64.

<Cover plate 90>
As shown in FIGS. 2 and 6, the cover plate 90 is formed by pressing a metal plate. The main part of the cover plate 90 is constituted by an annular mounting base 92. The attachment base 92 has a substantially flat plate shape orthogonal to the axis L <b> 2, and is disposed on the front side of the flange 33 of the inflator 30. In the cover plate 90, an escape hole 91 is formed at a position in front of each rivet 67. Each escape hole 91 is for avoiding the rivet 67 coming into contact with the cover plate 90 when the rivet 67 vibrates in the front-rear direction along with the elastic deformation of the elastic support portion 55.

  In the mounting base 92, bolt insertion holes 93 are formed at locations corresponding to the bolt insertion holes 46 of the respective extension portions 44. As shown in FIGS. 5 and 6, there are collars (cylindrical) at a plurality of locations between the attachment base 92 of the cover plate 90 and the extension 44 of the back holder 40 and corresponding to the bolt insertion holes 93 and 46. Shaped spacers) 94 are interposed. By these collars 94, the cover plate 90 is disposed in a state where the cover plate 90 is positioned at a predetermined distance away from the back holder 40 and the inflator 30. Then, bolts 95 are provided from the rear of the cup retainer 70 to the bolt insertion holes 74, 82, 46 of the cup retainer 70, the gas plate 80 and the back holder 40, the collar 94, and the bolt insertion holes 93 of the cover plate 90. It is inserted. A nut 96 is fastened to a bolt 95 exposed forward from the cover plate 90. By this tightening, the cup retainer 70, the gas plate 80 and the cover plate 90 are fastened to the back holder 40, and the peripheral portion of the gas introduction port 38 of the airbag 37 is connected to the back holder via the cup retainer 70 and the gas plate 80. 40 is fixed.

  The cover plate 90 further includes a cover portion 97 that bulges forward from the inner edge portion of the mounting base portion 92, and a plurality of (the same number as the locking holes 42) holding portions 98 that extend rearward from the outer edge portion of the mounting base portion 92. It has. The cover portion 97 has an annular shape, and covers the front outer peripheral portion of the inflator 30 in a separated state. The reason why the cover portion 97 is annular is that the harness connected to the connector 36 of the inflator 30 is pulled forward from the cover plate 90. A contact suppressing member 99 formed of felt is attached to a boundary portion between the attachment base 92 and the cover 97. The contact suppressing member 99 is for suppressing the contact with the cover plate 90 at the front portion of the inflator 30 and suppressing the generation of abnormal noise associated with the contact.

  The plurality of holding portions 98 are provided at locations corresponding to the locking holes 42 of the back holder 40. When the cover plate 90 is fastened to the back holder 40 as described above, each holding portion 98 is engaged. In the stop hole 42, it is inserted inside the locking claw 25 in the radial direction. Each holding portion 98 restricts the locking claw 25 from bending inward in the radial direction, and holds the locking claw 25 in a state where the claw portion 27 is locked in the locking hole 42.

In addition to the above, the cover plate 90 has the following functions.
(I) A function to catch when the inflator 30 moves excessively forward. This function is mainly exhibited by the mounting base 92 and the cover 97.

  (Ii) A function of restricting the harness arranged in front of the inflator 30 from coming into contact with the inflator 30 and preventing the vibration of the inflator 30 from being inhibited by the contact with the harness.

As described above, the steering wheel 12 of the present embodiment is configured. Next, the operation of the steering wheel 12 will be described.
In the steering wheel 12 of the present embodiment, when the driver presses the lid portion 22 of the pad cover 21 shown in FIG. 2, the back holder 40 is displaced forward together with other components of the airbag device 20. By this displacement, the horn switch mechanism is closed and the horn device is activated (sounds).

  In the airbag device 20, the gas G is not ejected from each gas ejection hole 32 of the inflator 30 and the airbag 37 is not normally ejected from the front due to a frontal collision (front collision) or the like. It is kept in a folded state.

  In the normal time, when the vehicle is traveling at high speed or the engine is idling, vibrations in the vertical direction and the horizontal direction may be transmitted to the steering wheel 12 through the steering shaft 11. In the airbag device 20, this vibration is transmitted to the inflator 30 via the back holder 40 and the elastic support portion 55 shown in FIGS. 4 and 5. At this time, in the elastic support portion 55, both the extension portion 44 and the flange plate 57 function as strength members.

  In response to the vibration, in the airbag device 20, the elastic coupling portion 64 of the elastic support portion 55 functions as a dynamic damper spring, and the inflator 30 functions as a dynamic damper damper mass.

  For example, when the steering wheel 12 vibrates in the vertical direction at a predetermined frequency, the elastic coupling portion 64 vibrates in the vertical direction with the inflator 30 while elastically deforming at a resonance frequency that is the same as or close to that frequency. Absorb twelve vertical vibrational energy. Due to this absorption, vibration in the vertical direction of the steering wheel 12 is suppressed (damped).

  When the steering wheel 12 vibrates in the left-right direction at a predetermined frequency, the elastic coupling portion 64 vibrates in the left-right direction with the inflator 30 while elastically deforming at a resonance frequency that is the same as or close to that frequency. Absorbs vibration energy in the direction. By this absorption, the vibration in the left-right direction of the steering wheel 12 is attenuated (damped).

In this way, in the present embodiment, the steering wheel 12 is damped (damped) in both the vertical and horizontal directions.
Here, in the steering wheel 12, various harnesses including components connected to the steering wheel 12, for example, a harness connected to the inflator 30, are disposed in a space ahead of the flange 33 of the inflator 30. Therefore, when an object that vibrates together with the inflator 30 (front support part 56) or an object that elastically deforms with the vibration of the inflator 30 (elastic connection part 64) contacts the above-described components of the steering wheel 12, the structure The movement of the inflator 30 and the elastic support portion 55 is prevented by the parts. There is a risk that the dynamic damper will not vibrate (resonate) at the target resonance frequency, and the vibration suppression (vibration suppression) performance of the dynamic damper may be reduced.

  In this respect, in the present embodiment, the wall portion 43 of the back holder 40 extends rearward from a location radially outward from the flange 33 of the inflator 30, and the elastic support portion 55 is connected to the rear end of the wall portion 43. It is provided between the flange 33. For this reason, both those that vibrate together with the inflator 30 (front support portion 56) and those that elastically deform with the vibration of the inflator 30 (elastic connection portion 64) are located behind the flange 33. It is difficult to contact the components of the steering wheel 12 in the space ahead of the flange 33.

  By the way, when an impact is applied to the vehicle from the front due to a front collision or the like, the driver tends to lean forward due to inertia. On the other hand, in the airbag device 20, the gas G is ejected radially outward from each gas ejection hole 32 of the inflator 30 in response to the impact. The injected gas G is supplied into the airbag 37 from the gas inlet 38. The gas G inflates the airbag 37 toward the rear side (driver side) while eliminating (deploying) the folded state. The airbag 37 that is inflated and inflated applies a pressing force to the lid portion 22 of the pad cover 21, and the lid portion 22 is broken at the planned breakage portion. The airbag 37 is continuously deployed and inflated rearward through the opening generated by the breakage. An airbag 37 that is inflated and inflated is interposed in front of the driver who wants to lean forward due to the impact of the forward collision, and the forward leaning of the driver is restrained and protected from the shock.

  At this time, among the gas G ejected from the gas ejection holes 32 as described above, the gas G flowing toward the elastic connecting portion 64 is elastic in the gas plate 80 as shown by a two-dot chain line in FIGS. The gas flow restricting portion 83 provided between the connecting portion 64 and the gas ejection hole 32 is contacted. By this contact, the flow direction of the gas G is changed to a direction different from the direction toward the elastic connecting portion 64. Therefore, it is difficult for the gas G to directly touch the elastic connecting portion 64, and the elastic connecting portion 64 is not easily affected by the heat of the gas G.

  Here, if the gas plate 80 is not used, the peripheral portion of the gas inlet 38 of the airbag 37 is sandwiched between the extended portion 44 of the back holder 40 and the mounting base 72 of the cup retainer 70. Become. In this case, the airbag 37 is covered by the extending portion 44 behind the extending portion 44 and is not easily affected by the heat of the gas G, but the airbag 37 is behind the notched portion 45 (see FIG. 5). It may be exposed and affected by the heat of the gas G.

  In this regard, in the present embodiment, a metal gas plate 80 is interposed between the peripheral portion of the gas inlet 38 of the airbag 37 and the extending portion 44 of the back holder 40, and the rear of the notched portion 45. Also, the gas plate 80 is located. For this reason, the airbag 37 is not exposed not only behind the extended portion 44 but also behind the cutout portion 45, and is not easily affected by the heat of the gas G.

  Further, in a state where the cover plate 90 is fastened to the back holder 40, each locking claw 25 is inserted into each locking hole 42. Each holding portion 98 of the cover plate 90 is inserted in each locking hole 42 and radially inward of each locking claw 25, and each locking claw 25 is detached from each locking hole 42. The holding portion 98 regulates the bending inward in the radial direction. Due to this restriction, each locking claw 25 is held in a state where the claw portion 27 is locked in the locking hole 42.

  Further, as described above, when the gas G is ejected, if there is a gap between the elastic support portion 55 and the flange 33 of the inflator 30, a part of the gas G passes through the gap and the airbag device 20 There is a risk of leaking outside.

  In this regard, in the present embodiment, in a state where the front side support portion 56 is fastened to the flange 33, the front side covering portion 61 is elastically deformed and is in close contact with the flange 33. Therefore, a gap generated between the front support portion 56 and the flange 33 is extremely small. Therefore, the gas G hardly leaks out of the airbag device 20 through this gap.

Further, if there is a gap between the elastic support portion 55 and the gas plate 80, a part of the gas G may leak out of the airbag device 20 through this gap.
In the present embodiment, in a state where the gas plate 80 is fastened to the back holder 40, the rear cover portion 63 is elastically deformed and is in close contact with the gas plate 80. Therefore, the gap generated between the rear support portion 62 and the gas plate 80 is extremely small. Therefore, the gas G hardly leaks out of the airbag device 20 through this gap.

According to the embodiment described in detail above, the following effects can be obtained.
(1) The back holder 40 is provided with an annular wall 43 that extends rearward from a location that is radially outward from the flange 33 of the inflator 30. The elastic support portion 55 is provided between the rear end of the wall portion 43 and the flange 33. A part of the elastic support portion 55 is configured by an annular elastic coupling portion 64 made of an elastic material (FIGS. 4 and 5).

  Therefore, both the one that vibrates together with the inflator 30 (front support portion 56) and the one that elastically deforms along with the vibration of the inflator 30 (elastic connection portion 64) are positioned behind the flange 33, and the flange 33 It is possible to make it difficult to come into contact with the components (harness or the like) of the steering wheel 12 in the space on the front side. As a result, it is possible to suppress a decrease in the vibration damping performance of the dynamic damper due to contact with the component parts.

(2) A gas flow restricting portion 83 is provided between the elastic connecting portion 64 and the gas ejection hole 32 (FIGS. 4 and 5).
Therefore, it is possible to restrict the gas G ejected from the gas ejection holes 32 from flowing toward the elastic connecting portion 64 and to suppress the elastic connecting portion 64 from being affected by the heat of the gas G.

  (3) An annular gas plate 80 is disposed between the wall 43 of the back holder 40 and the mounting base 72 of the cup retainer 70, and the peripheral portion of the gas inlet 38 of the airbag 37 is the main body 81 of the gas plate 80. And the mounting base 72 are sandwiched from the front and rear (FIGS. 4 and 5).

  Therefore, the gas G ejected from the gas ejection hole 32 is restricted from directly touching the peripheral portion of the gas introduction port 38 of the airbag 37 and the peripheral portion is prevented from being affected by the heat of the gas G. Can do.

(4) The gas flow restricting portion 83 is formed by bending the inner peripheral portion of the gas plate 80 forward (FIGS. 4 and 5).
Therefore, a part of the gas plate 80 (gas flow restricting portion 83) restricts the gas G ejected from the gas ejection hole 32 from flowing toward the elastic connecting portion 64, and the effect (2) is obtained. be able to.

  Further, since the gas flow restricting portion 83 is formed as a part of the gas plate 80, the number of parts of the airbag device 20 can be reduced as compared with the case where the gas flow restricting portion 83 is provided separately from the gas plate 80. Can do.

(5) The cover plate 90 which covers the inflator 30 elastically supported by the back holder 40 from the front is provided (FIGS. 2 and 5).
Therefore, what vibrates together with the inflator 30 (front support part 56) and what elastically deforms with the vibration of the inflator 30 (elastic connecting part 64) are the steering wheel 12 in the space ahead of the flange 33. The contact with the other component parts (harness etc.) can be further restricted by the cover plate 90. As a result, the effect (1) is more easily obtained.

(6) A holding portion 98 to be inserted into the locking hole 42 of the back holder 40 is provided on the cover plate 90 of (5) (FIGS. 2 and 5).
Therefore, the locking claw 25 inserted into the locking hole 42 can be held in a state where the claw portion 27 is locked to the locking hole 42. Even if an excessive force is applied to the pad cover 21 when the airbag 37 is inflated, the locking claws 25 can be prevented from coming out of the locking holes 42.

Note that the present invention can be embodied in another embodiment described below.
Utilizing the fact that the wall portion 43 of the back holder 40 is covered with a wall covering portion 65 made of an elastic material, the inner surface of the wall covering portion 65 is made of an elastic material and has a diameter as shown in FIG. A protrusion 52 that protrudes inward in the direction may be integrally formed. The protrusions 52 are preferably formed on four upper and lower inner surfaces of the wall covering portion 65 when the wall portion 43 has a substantially square ring shape. This is because when the inflator 30 functions as a damper mass, the inflator 30 vibrates a lot in the vertical direction and the horizontal direction.

  In this way, when vibration is transmitted from the steering wheel to the dynamic damper, the elastic connecting portion 64 vibrates with the inflator 30 while being elastically deformed. At this time, the elastic connecting portion 64 itself or a connecting portion between the elastic connecting portion 64 and the flange 33 of the inflator 30 contacts the protrusion 52. This contact restricts the inflator 30 from moving beyond the radial direction more than necessary and contacting the wall covering portion 65.

  As a result, the amount of elastic deformation of the elastic connecting portion 64 can be suppressed to the necessary minimum, and a decrease in durability of the elastic connecting portion 64 can be suppressed. Moreover, generation | occurrence | production of the abnormal noise by contacting the wall part 43 indirectly through the wall covering part 65 with small thickness can also be suppressed.

  A similar effect can be obtained by attaching a contact suppressing member made of felt or the like to the inner side surface of the wall covering portion 65. However, in that case, not only the number of parts of the airbag device 20 is increased by the amount of the contact suppression member, but a process of fixing the contact suppression member to the wall covering portion 65 is required, and the number of manufacturing steps increases accordingly. .

  In this regard, if the configuration of the above modification is employed, the protrusions 52 can be formed together when the wall covering portion 65 is formed. Further, the protrusion 52 and the wall covering portion 65 are integrated. Therefore, compared with the case where a contact suppression member is attached, the number of parts and the number of manufacturing steps of the airbag device can be reduced.

  Moreover, the merit about the said number of parts and manufacturing man-hours is acquired also by providing the protrusion which consists of an elastic material in the outer surface of the elastic connection part 64. FIG. However, in that case, the thickness, height, etc. of the elastic connecting portion 64 are different from those in the case where no protrusion is provided, and the protrusion has the vibration damping performance of the dynamic damper because the resonance frequency of the dynamic damper changes. affect. In that respect, if the protrusion 52 is provided on the inner surface of the wall covering portion 65, the thickness, height, etc. of the elastic connecting portion 64 will not change, and therefore the protrusion 52 may affect the vibration damping performance of the dynamic damper. Absent.

The gas flow restriction unit 83 may be configured by a separate part from the gas plate 80.
-This invention is applicable also to the airbag apparatus from which the cover plate 90 was abbreviate | omitted from the said embodiment. In this case, however, the cover plate 90 cannot be expected to suppress the contact between the elastic support portion 55 and the like and the harness.

  However, even in that case, the back holder 40 is provided with the annular wall portion 43 extending rearward, and the rear end of the wall portion 43 and the flange 33 are provided with the elastic support portion 55 having the elastic connection portion 64. There is no change in being connected by. Therefore, one that vibrates together with the inflator 30 (front support portion 56), one that elastically deforms with the vibration of the inflator 30 (elastic connecting portion 64), and the steering wheel 12 in the space ahead of the flange 33. The effect of said (1) which can suppress contact with these component parts and makes it difficult to produce the fall of the damping performance of a dynamic damper can be acquired.

  -When it is necessary to adjust the pressure of the gas G inside the airbag apparatus 20, the elastic support part 55 may be provided with the exhaust hole which penetrates the elastic connection part 64 in the thickness direction. If it does in this way, a part of gas G inside the airbag apparatus 20 will be discharged | emitted outside the airbag apparatus 20 through an exhaust hole, and the pressure of the gas G inside the airbag apparatus 20 will be adjusted. Can do.

The peripheral wall portion 31 of the inflator 30 may have an annular shape other than an annular shape.
-At least one of the back holder 40, the flange plate 57, the cup retainer 70, the gas plate 80, and the cover plate 90 may be formed by means other than pressing, for example, die casting.

  The present invention is not limited to a vehicle, and can also be applied to an airbag device that is built in a steering wheel of a steering device in another vehicle such as an aircraft or a ship. In this case, the vehicles include not only private vehicles but also various industrial vehicles.

  DESCRIPTION OF SYMBOLS 11 ... Steering shaft, 12 ... Steering wheel, 20 ... Air bag apparatus, 21 ... Pad cover, 25 ... Locking claw, 27 ... Claw part, 30 ... Inflator, 31 ... Perimeter wall part, 32 ... Gas ejection hole, 33 ... Flange 37 ... Airbag, 38 ... Gas inlet, 40 ... Back holder, 42 ... Locking hole, 43 ... Wall part, 52 ... Projection, 55 ... Elastic support part, 64 ... Elastic connecting part, 65 ... Wall covering part, 70 ... Cup retainer, 80 ... Gas plate, 83 ... Gas flow regulating part, 90 ... Cover plate, 98 ... Holding part, G ... Gas.

Claims (5)

A back holder disposed in a steering wheel rotated around a steering shaft extending in the front-rear direction, an air bag attached to the back holder, and supplying gas to the air bag, An airbag device comprising: an inflator that is inflated; and an annular elastic support portion that elastically supports the inflator on the back holder at a flange provided on a peripheral wall portion of the inflator,
The back holder is provided with an annular wall portion extending rearward from a location that is outward from the flange in the radial direction of the steering shaft,
The elastic support portion is provided between the rear end of the wall portion and the flange,
A part of said elastic support part is comprised by the cyclic | annular elastic connection part which consists of elastic materials, The airbag apparatus characterized by the above-mentioned. A gas ejection hole is provided in the peripheral wall portion of the inflator,
A gas flow restricting portion is provided between the elastic coupling portion of the elastic support portion and the gas ejection hole to restrict the gas ejected from the gas ejection hole from flowing toward the elastic coupling portion. The airbag device according to claim 1. A cup retainer for covering the inflator from the rear side;
An annular gas plate disposed between the wall retainer and the cup retainer and sandwiching a peripheral portion of a gas inlet of the airbag with the cup retainer;
The airbag device according to claim 2, wherein an inner peripheral portion of the gas plate is bent forward as the gas flow restricting portion. The wall portion of the back holder is covered with a wall covering portion made of an elastic material,
The air according to any one of claims 1 to 3, wherein a projection made of an elastic material and projecting radially inward of the steering shaft is integrally formed on an inner surface of the wall covering portion. Bag device. The back holder has a locking hole penetrating in the front-rear direction,
The pad cover that forms a part of the structural member of the steering wheel and covers the airbag and the inflator from behind is provided with a locking claw having a claw portion,
The pad cover is fastened to the back holder when the locking claw is inserted into the locking hole and the claw portion is locked to the locking hole.
The cover plate that covers the inflator from the front is provided with a holding portion that is inserted into the locking hole and holds the locking claw in a state where the claw portion is locked in the locking hole. The airbag apparatus as described in any one of Claims 1-4.

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