JP2017178094A - Support structure of air bag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress damping performance from being influenced even if force directed rearward is applied to an air bag device.SOLUTION: A snap pin 31 is mounted on a steering wheel 10 at a front end part of a shaft part 31a extending in a longitudinal direction using a snap fit structure, and supports an air bag device 20 at a rear end part of the shaft part 31a. An elastic member 34 is arranged between a bag holder 21 and the shaft part 31a of the air bag device 20 while being mounted on the shaft 31a. A damper holder 35 is arranged between the bag holder 21 and the elastic member 34 while being mounted on the air bag device 20, and holds the elastic member 34 slidably in the longitudinal direction. At part of the damper holder 35 is formed a restricted part 35h. At a position closer to a rear side than the restricted part 35h of an outer periphery part of the snap pin 31, which overlaps with the restricted part 35h in a radial direction of the shaft part 31a, is provided a restricting part 31f that restricts the restricted part 35h from moving rearward.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a support structure for an airbag device that supports an airbag device on a steering wheel in a vehicle such as a vehicle.

  For example, Patent Document 1 describes a structure in which an airbag device 42 is used as a damper mass of a dynamic damper and supported on a steering wheel 41 by a horn switch mechanism 44 as shown in FIG. The horn switch mechanism 44 includes a snap pin 45, an elastic member 46, and a damper holder 47.

  The snap pin 45 has a shaft portion 45a extending in the front-rear direction. The snap pin 45 is attached to the steering wheel 41 at the front end portion of the shaft portion 45a by using a snap fit structure, and supports the airbag device 42 at the rear end portion of the shaft portion 45a. The elastic member 46 is disposed between the bag holder 43 and the shaft portion 45a of the airbag device 42. The damper holder 47 is disposed between the bag holder 43 and the elastic member 46 while being attached to the airbag device 42, and holds the elastic member 46.

  The horn switch mechanism 44 further includes a pin holder 48, an urging member 49, a contact holder 51, a fixed side contact portion 52, and a movable side contact portion 53 in order to operate the horn device 54 by a pressing operation on the airbag device 42. Yes. The stationary contact portion 52 is constituted by the rear end portion of the snap pin 45.

  In the support structure having the above configuration, when the airbag device 42 is not pushed down, the movable contact portion 53 is separated from the fixed contact portion 52 rearward. Both contact portions 53 and 52 are disconnected from each other, and the horn device 54 does not operate. At this time, the airbag device 42 functions as a damper mass of the dynamic damper, and the elastic member 46 functions as a spring of the dynamic damper. Therefore, when the steering wheel 41 vibrates, the elastic member 46 vibrates with the airbag device 42 while elastically deforming at a resonance frequency that is the same as or close to the vibration frequency, and absorbs vibration energy of the steering wheel 41. By this absorption, vibration of the steering wheel 41 is suppressed (damped).

  On the other hand, when the airbag device 42 is pushed down, the force applied to the airbag device 42 is transmitted to the movable side contact portion 53 and the pin holder 48 via the contact holder 51. The pin holder 48 pressed by the contact holder 51 is slid forward along the snap pin 45 against the biasing member 49 together with the elastic member 46 and the damper holder 47. Further, when the movable contact 53 moves forward together with the contact holder 51 and comes into contact with the fixed contact 52, the horn device 54 is activated.

Japanese Patent Laying-Open No. 2015-231841

  However, in the conventional support structure described in Patent Document 1, when a backward force is applied to the airbag device 42 such as by being pulled, the force is also transmitted to the damper holder 47. On the other hand, the pin holder 48 comes into contact with the flange 45b at the rear end of the snap pin 45, and the rearward movement is restricted. Therefore, the damper holder 47 moves backward while elastically deforming the elastic member 46. If the amount of movement at this time is large, the outer peripheral rear end portion of the damper holder 47 enters the gap between the rear end portion of the pin holder 48 and the peripheral wall portion 51a of the contact holder 51, which may affect the damping performance.

  This invention is made | formed in view of such a situation, Comprising: The objective can suppress that the damping performance is influenced even if the force which goes to back is applied with respect to an airbag apparatus. The object is to provide a support structure for an airbag device.

  A support structure for an airbag device that solves the above problems includes an airbag device that has a bag holder and functions as a damper mass of a dynamic damper, a shaft portion that extends in the front-rear direction, and a front end portion of the shaft portion. A snap pin is attached to the steering wheel using a snap fit structure, and a snap pin that supports the airbag device at a rear end portion of the shaft portion and between the bag holder and the shaft portion in a state of being attached to the shaft portion. Arranged between the bag holder and the elastic member in a state of being attached to the airbag device and capable of sliding the elastic member in the front-rear direction. A damper holder for holding, a restricted portion is formed in a part of the damper holder, and the snap pin A restricting portion for restricting the movement of the restricted portion to the rear is provided at a portion of the outer peripheral portion that is behind the restricted portion and overlaps the restricted portion in the radial direction of the shaft portion. It has been.

  According to said structure, an airbag apparatus functions as a damper mass of a dynamic damper, and an elastic member functions as a spring of a dynamic damper. Therefore, when the steering wheel vibrates, the vibration is transmitted to the bag holder of the airbag device via the snap pin, the elastic member, and the damper holder. The elastic member absorbs vibration energy of the steering wheel by vibrating along with the airbag device while elastically deforming at a resonance frequency equal to or close to the vibration frequency. This absorption suppresses (suppresses) the vibration of the steering wheel.

  When a rearward force is applied to the airbag device, such as by being pulled, the force is transmitted to a damper holder having a restricted portion, which tends to move rearward. However, a restricting portion is provided on the outer peripheral portion of the snap pin and behind the restricted portion. The restricting portion is provided at a location overlapping the restricted portion in the radial direction of the shaft portion. Therefore, the movement toward the rear of the restricted portion is received and restricted by the restricting portion. As a result, the damping performance is unlikely to be affected due to excessive movement of the damper holder rearward.

  In the support structure of the airbag apparatus, the shaft portion is formed of a shaft body portion that extends in the front-rear direction and covers the elastic member, and the restriction portion is formed on the shaft body portion. It is preferable.

  According to said structure, an elastic member is attached to the axial part in the state covered on the axial main-body part in an axial part. When the steering wheel vibrates, the elastic member functions as a dynamic damper spring by vibrating along with the airbag device while being elastically deformed.

  When a rearward force is applied to the airbag device and the damper holder tries to move rearward, the rearward movement of the restricted portion in the damper holder is formed on the outer peripheral portion of the shaft main body portion, and It is received and regulated by a regulation unit located on the rear side.

  In the support structure of the airbag device, the shaft portion is a main portion of the airbag device, and extends in the front-rear direction. The shaft-shaped shaft main body portion covers the shaft main body portion, and extends in the front-rear direction with respect to the coaxial body portion. It is preferable that the cylindrical member is provided in a state where the movement is restricted and the elastic member is covered, and the restricting portion is formed in the cylindrical portion.

  According to said structure, although a shaft part consists of two members, a shaft main-body part and a cylindrical part, a cylindrical part is covered and latched on the shaft main-body part, and with respect to the shaft main-body part, Movement in both the front-rear direction and the radial direction is restricted. Therefore, the shaft main body portion and the cylindrical portion function in the same manner as those in which they are integrated.

  The elastic member is attached to the shaft portion while being covered with the cylindrical portion. When the steering wheel vibrates, the elastic member functions as a dynamic damper spring by vibrating along with the airbag device while being elastically deformed.

  When a force directed backward is applied to the airbag device and the damper holder tries to move backward, the movement of the damper holder toward the rear of the restricted portion is formed on the outer peripheral portion of the tubular portion and It is received and regulated by a regulation unit located on the rear side.

  In the support structure of the airbag apparatus, the damper holder has a cylindrical shape surrounding the shaft portion, the restricted portion is provided on an inner peripheral portion of the damper holder, and the restricting portion is an intermediate portion in the front-rear direction of the shaft portion. It is preferable that it is provided in the outer peripheral part of the part.

  According to said structure, when the force which goes back is added with respect to an airbag apparatus and a damper holder tries to move back, the movement toward the back of the to-be-restricted part of the inner peripheral part of a damper holder will be carried out of a shaft part. Of the outer peripheral portion, it is received and regulated by a regulating portion located on the rear side of the regulated portion.

  In the support structure of the airbag device, a flange having a larger diameter than the other part of the coaxial body is provided on the outer periphery of the rear end of the shaft body, and the elastic member includes the flange and the It is preferable that the shaft portion is attached to the shaft portion by being covered with the restriction portion.

  According to said structure, the elastic member covered on the axial part of the snap pin is controlled by the axial part in radial movement. In addition, the elastic member is restricted from moving in the front-rear direction by a restricting portion and a flange portion disposed before and after the elastic member. As described above, the elastic member is attached to the shaft portion in a state where the movement in the radial direction and the movement in the front-rear direction are restricted.

  In the support structure of the airbag device, the bag holder penetrates in the front-rear direction and has an attachment hole having a smaller diameter than the flange portion, and the shaft main body portion is inserted through the attachment hole, and the bag holder It is preferable that a flange portion extending forward is formed around the mounting hole.

According to said structure, when the airbag of an airbag apparatus expand | swells, the force which goes back with respect to a bag holder is added.
On the other hand, the snap pin is attached to the steering wheel. The collar part formed in the rear end part of the snap pin is located behind the attachment hole of the bag holder. The collar part is formed in a larger diameter than the mounting hole. For this reason, when the bag holder moves rearward, the collar portion functions as a stopper by contacting the peripheral portion of the attachment hole in the bag holder.

  Moreover, the rigidity around the attachment hole of the bag holder is enhanced by a flange portion extending forward. For this reason, even when the airbag is inflated, a force directed rearward is applied to the bag holder, and even if the peripheral portion of the attachment hole comes into contact with the flange portion, the peripheral portion tries to maintain the shape. As a result, the phenomenon in which the bag holder and thus the airbag device moves excessively rearward is restricted.

  In the support structure of the airbag device, a biasing member that biases the airbag device away from the steering wheel, a stationary contact portion configured by a rear end portion of the snap pin, and the air A movable device that is attached to the bag device, moves away from the fixed contact portion when the airbag device is not pressed down, and contacts the fixed contact portion when the airbag device is pressed to operate the horn device. It is preferable to further include a side contact portion.

  According to the above configuration, when the airbag device is not pushed down, the airbag device is biased by the biasing member and is moved rearward from the steering wheel. The movable contact portion attached to the airbag device is also urged rearward and is separated rearward from the fixed contact portion formed by the rear end portion of the snap pin. Both contact portions are cut off from conduction, and the horn device does not operate.

  On the other hand, when the airbag device is pushed down against the biasing member, the movable contact point moves forward. When the movable contact portion comes into contact with the fixed contact portion, the horn device is activated.

  In the support structure of the airbag device, the urging member is disposed around the shaft portion and on the front side of the damper holder, and the damper holder is disposed at a rear end of the urging member at the restricted portion. It is preferable to be in contact with the part.

  According to said structure, the urging | biasing force which goes to the back of an urging | biasing member is received by the to-be-regulated part of the damper holder attached to the airbag apparatus. In this way, the restricted portion exhibits both the function of restricting backward movement by the restricting portion and the function of receiving the urging force of the urging member and transmitting it to the airbag device.

  In the support structure of the airbag device, a protrusion that is one of the restriction portion and the restricted portion and that contacts the other of the restriction portion and the restricted portion is provided at a plurality of locations around the shaft main body portion. Is preferably formed.

  According to said structure, one of a control part and a controlled part contacts the other of a control part and a controlled part in the protrusion provided in the several places around a shaft main-body part. Therefore, the friction generated between the restricting portion and the restricted portion is smaller than when the restricting portion and the restricted portion are in surface contact.

  According to the support structure of the airbag device, it is possible to suppress the vibration damping performance from being affected even when a rearward force is applied to the airbag device.

It is a figure which shows the steering wheel with an airbag apparatus in 1st Embodiment, (a) is a side view, (b) is a front view. The perspective view of the horn switch mechanism in 1st Embodiment. The perspective view of the airbag apparatus in 1st Embodiment. The disassembled perspective view which shows the structural member of the airbag apparatus in 1st Embodiment with a horn switch mechanism. In 1st Embodiment, the horn switch mechanism and the fragmentary sectional side view which shows the cross-section of the peripheral part. FIG. 6 is a partial side cross-sectional view showing a cross-sectional structure of the horn switch mechanism and its peripheral portion in a cross section different from that in FIG. 5 in the first embodiment. (A) is a sectional side view showing the relationship between the horn switch mechanism and the bag holder in the first embodiment, (b) is a side sectional view showing the components of the horn switch mechanism in an exploded manner. The fragmentary sectional side view which expands and shows the A section in FIG. The partial side sectional view which expands and shows the B section in FIG. It is a figure which shows the elastic member in 1st Embodiment, (a) is a front view, (b) is a rear view. The fragmentary sectional side view which shows the cross-section of the horn switch mechanism and its peripheral part when an airbag apparatus is pushed down from the state of FIG. It is a figure which shows 2nd Embodiment, and is a perspective view which decomposes | disassembles and shows the structural member of a horn switch mechanism. In 2nd Embodiment, the horn switch mechanism and the fragmentary sectional side view which shows the cross-section of the peripheral part. The fragmentary sectional side view which expands and shows the C section in FIG. FIG. 14 is a partial side cross-sectional view showing a cross-sectional structure of a horn switch mechanism and its peripheral portion in a cross section different from that in FIG. 13 in the second embodiment. The fragmentary sectional side view which shows the cross-section of the horn switch mechanism and its peripheral part when an airbag apparatus is pushed down from the state of FIG. In 2nd Embodiment, the side sectional view which shows the state before a cylindrical part and an elastic member are attached to a snap pin. The partial expanded side sectional view which shows the modification of the horn switch mechanism in 1st Embodiment. The fragmentary sectional side view which shows the support structure of the conventional airbag apparatus.

(First embodiment)
Hereinafter, a first embodiment embodied in a structure in which an airbag device is supported on a steering wheel for a vehicle will be described with reference to FIGS. 1 to 11.

  As shown in FIG. 1A, the vehicle is provided with a steering shaft (steering shaft) 14 that rotates about an axis L1 that is inclined so as to be higher toward the rear side. A steering wheel 10 is attached to the rear end portion of the steering shaft 14.

  In this specification, when describing each part of the steering wheel 10, the axis line L1 is used as a reference. The direction along the axis L1 is referred to as the “front-rear direction” of the steering wheel 10, and the direction in which the steering wheel 10 stands up among the directions along the plane perpendicular to the axis L1 is referred to as the “vertical direction”. Therefore, the front-rear direction and the vertical direction of the steering wheel 10 are slightly inclined with respect to the front-rear direction (horizontal direction) and the vertical direction (vertical direction) of the vehicle.

  2 to 11, for the sake of convenience, the front-rear direction of the steering wheel 10 matches the horizontal direction, and the vertical direction of the steering wheel 10 matches the vertical direction. The same applies to FIGS. 12 to 17 showing the second embodiment, FIG. 18 showing a modified example, and FIG. 19 showing the prior art.

  As shown in FIGS. 1A, 1B, and 5, the steering wheel 10 includes an airbag device (airbag module) 20 at the center. The skeleton portion of the steering wheel 10 is constituted by a core metal 12. The core metal 12 is formed of iron, aluminum, magnesium, or an alloy thereof. The cored bar 12 is attached to the steering shaft 14 at the center thereof, and rotates integrally with the steering shaft 14.

  In the cored bar 12, holding portions 12b each having a through hole 12a are provided at a plurality of locations around the central portion. The inner wall surface of each through-hole 12a has a taper shape whose diameter increases toward the rear side.

  A clip 13 is disposed on the front side of each holding portion 12b. The clip 13 is formed by bending a wire made of a metal such as spring steel having conductivity into a predetermined shape, and a part thereof is in contact with the core metal 12. A part of each clip 13 is located near the front of the through hole 12a.

  A horn device 40 is provided in the vehicle. A plurality of horn switch mechanisms 30 (see FIGS. 2 and 4) for operating the horn device 40 by a pressing operation on the airbag device 20 are provided. Each horn switch mechanism 30 has the same configuration, and is attached to the cored bar 12 with a snap-fit structure in each holding portion 12b. The airbag device 20 is supported on the core metal 12 of the steering wheel 10 via these horn switch mechanisms 30. Thus, each horn switch mechanism 30 has both the function of supporting the airbag device 20 and the switch function of the horn device 40. Furthermore, each horn switch mechanism 30 also has a function of suppressing vibrations of the steering wheel 10 using the airbag device 20, that is, a function of damping vibrations.

Next, each of the airbag device 20 and the horn switch mechanism 30 will be described.
<Airbag device 20>
As shown in FIGS. 3 to 5, the airbag device 20 is configured by assembling a pad portion 24, a ring retainer 25, an airbag (not shown) and an inflator 23 to the bag holder 21.

  The pad portion 24 includes an outer skin portion 24a whose surface (rear surface) forms a design surface, and a substantially square annular housing wall portion 24b standing on the back surface side (front side) of the outer skin portion 24a. A space surrounded by the outer skin portion 24a, the accommodating wall portion 24b, and the bag holder 21 mainly constitutes a bag accommodating space x for accommodating an airbag (not shown). A thin-walled portion 24c that is pushed and broken when the airbag is deployed and inflated is formed in a portion that forms the bag housing space x of the outer skin portion 24a.

  A plurality of locking claws 24d each having a rectangular plate shape are formed at the front end of the housing wall 24b. A locking projection 24e is formed at the front end of each locking claw 24d and protrudes away from the bag housing space x.

  Switch support portions 24f for supporting the horn switch mechanism 30 are formed at a plurality of locations of the pad portion 24, respectively. Each switch support portion 24f is formed integrally with the housing wall portion 24b so as to extend from the outer skin portion 24a of the pad portion 24 to the back surface side (front side).

  The bag holder 21 is formed by pressing a conductive metal plate. Instead, the bag holder 21 may be formed by performing die casting or the like using a conductive metal material. The peripheral part of the bag holder 21 is configured as a substantially square annular peripheral fixing part 21 a for fixing the pad part 24.

  In the periphery fixing portion 21a, slit-like claw locking holes 21b are formed at positions in front of the respective locking claws 24d, and the front end portions of the respective locking claws 24d are inserted into the slits. It has been stopped.

  An inner portion of the peripheral edge fixing portion 21a constitutes a pedestal portion 21c. A circular opening 21d is formed at the center of the pedestal 21c. Screw insertion holes 21e are formed at a plurality of locations in the vicinity of the peripheral edge of the opening 21d in the pedestal 21c. A part of the inflator 23 is attached to the pedestal 21c in a state where the inflator 23 is inserted through the opening 21d.

  More specifically, the inflator 23 has a low columnar main body 23a, and a flange portion 23b is formed on the outer peripheral surface of the main body 23a. A plurality of attachment pieces 23c are extended to the flange portion 23b outward in the radial direction of the main body 23a. In each attachment piece 23c, a screw insertion hole 23d is formed at a location in front of the screw insertion hole 21e of the bag holder 21. In the inflator 23, a portion on the rear side of the flange portion 23b is configured as a gas ejection portion 23e that ejects an expansion gas. And it is penetrated by the opening part 21d of the bag holder 21 from the front side so that the gas ejection part 23e of the inflator 23 may protrude to the bag accommodating space x side. Further, the flange portion 23b is brought into contact with the peripheral edge portion of the opening portion 21d. In this state, the inflator 23 is attached to the bag holder 21 together with the ring retainer 25.

  More specifically, the ring retainer 25 has a circular opening 25a equivalent to the opening 21d of the bag holder 21. Further, the ring retainer 25 has mounting screws 25b at a plurality of positions behind the screw insertion holes 21e of the bag holder 21. Between the ring retainer 25 and the bag holder 21, an opening portion of an airbag (not shown) that is folded so as to be deployed and inflated is disposed. The plurality of mounting screws 25b of the ring retainer 25 are connected to the screw insertion holes (not shown) provided in the peripheral portion of the opening of the airbag and the screw insertion holes 21e and 23d of the bag holder 21 and the inflator 23. It is inserted from the rear side. Further, the nut 26 is tightened from the front side to each of the mounting screws 25b after the insertion, whereby the airbag is fixed to the bag holder 21 via the ring retainer 25 and the inflator 23 is fixed to the bag holder 21.

  Attachment portions 21f for attaching the horn switch mechanism 30 are formed at a plurality of locations on the peripheral edge fixing portion 21a of the bag holder 21 so as to protrude outward in the radial direction of the circular opening 21d. Each attachment portion 21f is located at a location in front of the switch support portion 24f of the pad portion 24 described above. Each attachment portion 21f is formed with an attachment hole 21g that penetrates the attachment portion 21f in the front-rear direction. An annular flange portion 21 h extending forward is formed around the attachment hole 21 g of the bag holder 21.

  In the bag holder 21, a transmission hole 21i is penetrated at a plurality of locations around each attachment hole 21g and spaced apart from each other in the circumferential direction. In the first embodiment, the two transmission holes 21i are formed at locations facing each other across the axis (not shown) of each mounting hole 21g for each mounting hole 21g.

The airbag device 20 configured as described above is used as a damper mass of a dynamic damper.
<Horn switch mechanism 30>
As shown in FIGS. 2, 5 and 7B, each horn switch mechanism 30 includes a snap pin 31, a contact holder 32, a movable contact point 33, an elastic member 34, a damper holder 35, a support auxiliary member 36, and An urging member is provided. Next, each component of the horn switch mechanism 30 will be described.

<Snap pin 31>
The snap pin 31 is made of a conductive metal material. The support structure for the core metal 12 of the snap pin 31 will be described later. The snap pin 31 has a shaft portion 31a extending in the front-rear direction along an axis L2 that is in a parallel relationship with the axis L1 of the steering shaft 14. In the first embodiment, the shaft portion 31a is configured only by a rod-shaped shaft main body portion 31b extending in the front-rear direction. Most of the shaft main body portion 31 b except for a flange portion 31 e described later has a smaller diameter than the inner diameter of the attachment hole 21 g of the bag holder 21. The snap pin 31 is inserted through the mounting hole 21g in the shaft main body 31b.

  An annular locking groove 31c is formed at a location slightly away from the front end surface in the shaft main body 31b. In the shaft main body 31b, a portion sandwiched between the front end face and the locking groove 31c constitutes a head 31d of the coaxial main body 31b.

  A flange 31e having a larger diameter than the other part of the coaxial main body 31b is formed on the outer peripheral portion of the rear end of the shaft main body 31b. The outer diameter of the flange 31e is set larger than the inner diameter of the attachment hole 21g of the bag holder 21.

  A restricting portion 31f is formed in an annular shape over the entire circumference of the outer peripheral surface of the intermediate portion in the front-rear direction of the shaft main body portion 31b. The outer diameter of the restricting portion 31f is set larger than the inner diameter of the restricted portion 35h described later.

The rear end portion of the snap pin 31, that is, the rear end portion of the shaft main body portion 31b and the flange portion 31e constitute a fixed side contact portion.
<Contact holder 32>
As shown in FIGS. 5, 6, and 7 (b), the contact holder 32 is formed of a hard resin material having insulating properties. The contact holder 32 includes a top plate portion 32a having a substantially disc shape, and a substantially cylindrical peripheral wall portion 32b (see FIG. 7A) extending forward from the outer peripheral edge of the top plate portion 32a. The contact holder 32 covers the rear portion including the flange portion 31 e of the snap pin 31.

  In the peripheral wall portion 32b, accommodating portions 32c extending in the front-rear direction are formed at locations that oppose each other in the radial direction around the axis L2. Claw engaging holes 32d (see FIG. 2) are formed at a plurality of locations that are spaced apart from each other in the circumferential direction between adjacent housing portions 32c of the peripheral wall portion 32b.

<Moving side contact portion 33>
The movable side contact portion 33 is formed by pressing a strip-shaped metal plate having conductivity. The movable contact portion 33 includes a main body portion 33a extending in the radial direction of the contact holder 32, a pair of side portions 33b extending forward from both ends of the main body portion 33a, and outward in the radial direction from the front end of each side portion 33b. And a pair of bent portions 33c bent to the right.

  A plurality of contact projections 33d projecting forward are formed at a plurality of locations in the length direction of the main body 33a. Each bent portion 33c is formed with a contact protrusion 33e that protrudes forward.

  Most of the rear surface of the main body portion 33 a except the contact protrusion 33 d is in contact with the front surface of the top plate portion 32 a of the contact holder 32. Each side portion 33b is in contact with the inner wall surface of the housing portion 32c in an engaged state (see FIG. 9). Due to this engagement, the movable contact portion 33 is mounted in a state of being positioned on the contact holder 32. Each bent portion 33c is in contact with the bag holder 21 at the contact protrusion 33e.

<Elastic member 34>
As shown in FIGS. 7B, 8 and 9, the elastic member 34 includes a large-diameter portion 34a and a small-diameter portion 34b having an outer diameter smaller than that of the large-diameter portion 34a. It is disposed between the bag holder 21 and the shaft main body 31b while being attached to the rear portion of the shaft main body 31b. The elastic member 34 is placed on the shaft main body portion 31b between the flange portion 31e of the snap pin 31 and the restricting portion 31f. The elastic member 34 is restricted from moving in the radial direction by the shaft main body 31b. Further, the movement of the elastic member 34 in the front-rear direction is restricted by the restriction part 31 f and the flange part 31 e before and after the elastic member 34. As described above, the elastic member 34 is attached to the shaft main body 31b in a state where the radial movement and the front-rear movement are restricted.

  The large diameter portion 34a and the small diameter portion 34b have a cylindrical shape with the axis L2 of the snap pin 31 as its own axis. The large diameter portion 34 a constitutes the latter half of the elastic member 34, and the small diameter portion 34 b constitutes the front half of the elastic member 34.

The large diameter portion 34a is spaced forward from the flange portion 31e of the snap pin 31, and a gap portion is formed between the two.
A tapered hole portion 34c whose diameter increases toward the rear side is formed at the rear portion of the inner peripheral portion of the large diameter portion 34a, and a gap portion is formed between the tapered hole portion 34c and the shaft main body portion 31b. . An annular rib 34d protruding rearward is formed around the tapered hole portion 34c on the rear end surface of the large diameter portion 34a (see FIG. 10A). The annular rib 34d approaches or contacts the front surface of the flange portion 31e of the snap pin 31.

  The small diameter portion 34b has a cylindrical shape smaller in thickness than the large diameter portion 34a, and extends forward from the inner peripheral portion of the large diameter portion 34a. The front surface of the small diameter portion 34b is in contact with or close to the rear surface of the restricting portion 31f. On the outer peripheral surface of the small-diameter portion 34b, ribs 34e are formed at equal angles at four or more even locations (eight locations in the first embodiment) around the axis L2 (see FIG. 10B). . Each rib 34e is located at a position facing the other rib 34e across the axis L2. Each rib 34e extends in parallel to the axis L2. Each rib 34e is connected to the large diameter portion 34a at the rear end.

The large-diameter portion 34a, the small-diameter portion 34b, the annular rib 34d, and the rib 34e are made of an elastic material such as rubber (for example, EPDM, silicon rubber, etc.), elastomer, and the like.
The elastic member 34 configured as described above is used as a spring of a dynamic damper. Then, by tuning the size of the large-diameter portion 34a (the respective dimensions in the radial direction and the front-rear direction, etc.), the vertical and left-right resonance frequencies of the dynamic damper cause the steering wheel 10 to vibrate in the vertical direction and the left-right direction. Is set to a target vibration suppression frequency, in other words, a frequency to be controlled.

<Damper holder 35>
The damper holder 35 holds the elastic member 34 so as to be slidable in the front-rear direction, which is the direction along the axis L2, and is formed of a hard resin material having insulation properties. The damper holder 35 is disposed between the bag holder 21 and the elastic member 34 while being attached to the airbag device 20.

  The main part of the damper holder 35 is constituted by a cylindrical peripheral wall portion 35a surrounding the shaft main body portion 31b. The peripheral wall portion 35a has a large-diameter hole portion 35b and a small-diameter hole portion 35c located on the front side of the large-diameter hole portion 35b and having a smaller inner diameter than the large-diameter hole portion 35b. The outer peripheral surface of the peripheral wall portion 35 a is in contact with the inner wall surface of the peripheral wall portion 32 b of the contact holder 32. The inner peripheral surface of the large diameter hole portion 35 b is in contact with the outer peripheral surface of the large diameter portion 34 a of the elastic member 34, and the inner peripheral surface of the small diameter hole portion 35 c is in contact with the rib 34 e of the elastic member 34. In the peripheral wall portion 35a, the boundary portion (step portion) between the large diameter hole portion 35b and the small diameter hole portion 35c is spaced forward from the large diameter portion 34a of the elastic member 34, and is larger than the boundary portion (step portion). A gap is formed between the diameter 34a.

  Engaging claws (not shown) are formed at a plurality of locations separated from each other in the circumferential direction of the peripheral wall portion 35a. The damper holder 35 is attached to the contact holder 32 by engaging these engaging claws with the corresponding claw engaging holes 32 d (see FIG. 2) of the contact holder 32 from the inside.

  As shown in FIGS. 2 and 8, plate-like protrusions 35 e that protrude outward in the radial direction are formed at a plurality of locations on the front end outer peripheral portion of the peripheral wall portion 35 a that are spaced apart from each other in the circumferential direction. Yes. Each plate-like protrusion 35e is formed with a transmission protrusion 35f that protrudes forward. Each transmission protrusion 35f is engaged with the corresponding transmission hole 21i of the bag holder 21 from the rear side. Each transmission protrusion 35f has a locking claw portion 35g protruding radially outward at its front end, and this locking claw portion 35g is engaged with the peripheral portion of the transmission hole 21i in the bag holder 21. It has been stopped.

  An annular regulated portion 35h that protrudes radially inward is formed on the inner peripheral portion of the front end of the peripheral wall portion 35a. The regulated portion 35 h is located on the front side of the regulating portion 31 f of the snap pin 31. The inner peripheral portion of the restricted portion 35h overlaps the restricting portion 31f in the radial direction of the shaft main body portion 31b. The regulated portion 35h is spaced forward from each rib 34e of the elastic member 34, and a gap is formed between each rib 34e and the regulated portion 35h.

<Supporting auxiliary member 36>
As shown in FIGS. 2, 5, and 7 (b), the support auxiliary member 36 is formed of a hard resin material having insulating properties. A part of the support auxiliary member 36 is configured by a base portion 36a having an annular plate shape. The outer diameter of the base portion 36a is set to be approximately the same as the outer diameter of the rear end portion of the inner wall surface of the through hole 12a, that is, the maximum diameter of the tapered inner wall surface.

  The locking pieces 36b extend forward from a plurality of locations spaced apart from each other in the circumferential direction of the base portion 36a. A claw portion 36c projects radially inward from the front end portion of each locking piece 36b. In the base portion 36a, a plurality of engagement pieces 36d extend forward from between the locking pieces 36b adjacent in the circumferential direction. At least a part of the outer surface of each engagement piece 36d constitutes a part of a tapered surface whose diameter increases toward the rear side.

  A pair of mounting portions 36e extends rearward from the base portion 36a. Each mounting portion 36e is curved so as to bulge outward in the radial direction of the base portion 36a, corresponding to the outer shape of the shaft portion 31a of the snap pin 31.

At the rear end of each mounting portion 36e, a receiving portion 36f that is curved along the mounting portion 36e so as to bulge outward in the radial direction of the base portion 36a is formed.
The auxiliary support member 36 is fitted to the shaft portion 31a of the snap pin 31 at the base portion 36a and both the attachment portions 36e, and each claw portion 36c enters the locking groove 31c, so that the support auxiliary member 36 is attached to the snap pin 31 so as not to fall off. Has been. As described above, in the support auxiliary member 36, the outer peripheral surfaces of the plurality of engagement pieces 36d are intermittently arranged in the circumferential direction with the plurality of locking pieces 36b interposed therebetween. With such a configuration, the support auxiliary member 36 as a whole has the same form as that having a tapered outer peripheral surface whose diameter increases toward the rear side.

<Biasing member>
The biasing member is for biasing the airbag device 20 away from the steering wheel 10, and is configured by a coil spring 37 wound around the shaft main body portion 31 b of the snap pin 31. Yes. The coil spring 37 is disposed in a compressed state between the regulated portion 35 h of the damper holder 35 and the receiving portion 36 f of the support auxiliary member 36. The front end of the coil spring 37 is in contact with the receiving portion 36f, and the rear end is in contact with the restricted portion 35h. The urging force toward the rear of the coil spring 37 is received by the regulated portion 35 h of the damper holder 35 attached to the airbag device 20.

  In this way, the horn switch mechanism 30 that is unitized by a plurality of single parts and made into an assembly is configured. Therefore, when the horn switch mechanism 30 is attached or replaced, the unitized horn switch mechanism 30 can be handled as one aggregate.

  When each horn switch mechanism 30 configured as described above is attached to the bag holder 21, each horn switch mechanism 30 includes a snap pin 31, a support auxiliary member 36, and a coil spring 37. It is inserted from the rear into the mounting hole 21g of the bag holder 21 indicated by the dotted line. In the insertion process, the transmission protrusion 35 f of the damper holder 35 is inserted into the transmission hole 21 i of the bag holder 21. During this insertion, the locking claw portion 35g passes through the transmission hole 21i while being elastically deformed.

  When the insertion of the horn switch mechanism 30 is performed up to a position where the front end surface of the damper holder 35 comes into contact with the attachment portion 21f of the bag holder 21, the locking claw portion 35g is connected to the transmission hole of the bag holder 21, as shown in FIG. It is temporarily fixed to the peripheral part of 21i. This temporary fixing restricts the horn switch mechanism 30 from falling off the bag holder 21.

  At this time, as shown in FIG. 9, the contact protrusion 33 e of the movable contact portion 33 contacts the rear surface of the bag holder 21. Due to this contact, the bag holder 21 and the movable contact portion 33 are brought into conduction.

  As described above with reference to FIGS. 3 and 4, when the airbag device 20 is assembled, the locking claw 24 d of the pad portion 24 is locked to the claw locking hole 21 b of the bag holder 21. The bag holder 21 is attached to the pad portion 24. When the top plate portion 32a of the contact holder 32 comes into contact with the switch support portion 24f of the pad portion 24, each horn switch mechanism 30 is fixed to the airbag device 20 while being sandwiched between the pad portion 24 and the bag holder 21. Is done.

  In this state, as shown in FIGS. 8 and 9, the damper holder 35 slides back and forth with respect to the elastic member 34 while preventing the snap pin 31 and the bag holder 21 from contacting each other, that is, in an insulated state. Support as possible. The damper holder 35 is interposed between the shaft portion 31a of the snap pin 31 and the side portion 33b of the movable side contact portion 33 to insulate the shaft portion 31a and the side portion 33b. Further, the damper holder 35 transmits a backward biasing force of the coil spring 37 to the restricting portion 31 f of the snap pin 31. Further, the bent portion 33 c of the movable contact portion 33 is sandwiched between the housing portion 32 c of the contact holder 32 and the bag holder 21, and the contact protrusion 33 e is held in contact with the bag holder 21.

Next, an operation of assembling the airbag device 20 to the core metal 12 via the plurality of horn switch mechanisms 30 will be described.
As shown in FIGS. 2 and 5, during this operation, the snap pin 31 for each horn switch mechanism 30 is inserted from the rear into the through hole 12 a of the holding portion 12 b corresponding to the cored bar 12. With this insertion, the base portion 36a of the auxiliary support member 36 approaches the holding portion 12b, and the engagement piece 36d approaches the inner wall surface of the through hole 12a. Further, the head portion 31 d of the snap pin 31 comes into contact with the clip 13. Further, when the snap pin 31 or the like is moved forward against the urging force of the clip 13, the clip 13 is elastically deformed outward in the radial direction of the snap pin 31. When the snap pin 31 is moved to a position where the locking groove 31c faces the clip 13, the clip 13 tries to enter the locking groove 31c by its own elastic restoring force.

  On the other hand, the claw portion 36c of the support auxiliary member 36 biased forward by the coil spring 37 enters the locking groove 31c. Therefore, the clip 13 enters between the claw portion 36c and the head portion 31d while compressing the coil spring 37 backward in the process of entering the locking groove 31c. By this entry, the claw portion 36 c is positioned on the rear side of the clip 13 in the locking groove 31 c. In the clip 13, the portion located in front of the through hole 12 a is sandwiched from the front and rear by the head portion 31 d and the claw portion 36 c biased forward by the coil spring 37. In this way, the snap pin 31 is locked to the metal core 12 by the clip 13, so that each horn switch mechanism 30 is fastened to the metal core 12 and the airbag device 20 is attached to the metal core 12. . The structure in which the snap pin 31 is locked to the cored bar 12 by the elasticity of the clip 13 as it is inserted into the through hole 12a is called a snap fit structure.

Next, operations and effects of the first embodiment configured as described above will be described.
When an impact from the front due to a frontal collision (front collision) or the like is not applied to the vehicle (normal time), the airbag device 20 does not eject gas from the gas ejection portion 23e of the inflator 23, and the airbag It is kept in a folded state.

  As shown in FIGS. 5 and 6, when the airbag device 20 is not pushed down at the normal time, the urging force toward the rear of the coil spring 37 is applied to the damper holder 35 via the damper holder 35. In addition to being transmitted to the stopped bag holder 21, it is transmitted to the switch support 24 f via the damper holder 35 and the contact holder 32. The airbag device 20 to which the urging force is transmitted in this manner is moved away from the steering wheel 10 backward.

  Along with this, the movable side contact portion 33 attached to the airbag device 20 is also urged rearward, and the contact protrusion 33 d is separated rearward from the fixed side contact portion constituted by the rear end portion of the snap pin 31. . The movable side contact portion 33 and the snap pin 31 are cut off from conduction, and the horn device 40 does not operate. At this time, a backward biasing force of the coil spring 37 is applied to the restricting portion 31 f of the snap pin 31 locked to the core metal 12 by the clip 13 via the restricted portion 35 h of the damper holder 35.

  Further, a forward biasing force of the coil spring 37 is applied to the support auxiliary member 36 through the receiving portion 36f, and the claw portion 36c that has entered the locking groove 31c of the snap pin 31 in the support auxiliary member 36 is The clip 13 in 31c is pressed forward. By this pressing, the clip 13 is sandwiched from the front and rear by the head portion 31d and the claw portion 36c, and the movement is restricted.

  At this time, the load of the airbag device 20 is transmitted to the elastic member 34 mainly through the contact holder 32 and the damper holder 35. The elastic member 34 placed on the shaft main body 31b of the snap pin 31 is restricted from moving in the radial direction by the shaft main body 31b. Further, the elastic member 34 is restricted from moving in the front-rear direction by a restricting portion 31 f and a flange portion 31 e that are disposed in front of and behind the elastic member 34.

  For this reason, if vibrations in the vertical direction and the horizontal direction are transmitted to the steering wheel 10 during the normal time and during idling of the vehicle-mounted engine, the vibration is transmitted to the cored bar 12 and each horn switch. It is transmitted to the airbag device 20 via the mechanism 30. More specifically, the vibration is transmitted to the contact holder 32 and the bag holder 21 via the snap pin 31, the elastic member 34, and the damper holder 35. Transmission of vibration between the damper holder 35 and the bag holder 21 is performed through the transmission protrusion 35f and the transmission hole 21i described above.

  When vibration is transmitted as described above, the airbag device 20 functions as a damper mass of the dynamic damper according to the vibration. Further, the large-diameter portion 34a of the elastic member 34 mainly vibrates in the vertical and horizontal directions with the airbag device 20 while elastically deforming at a resonance frequency that is the same as or close to the target frequency of vibration of the steering wheel 10. Resonance) functions as a dynamic damper spring. By this resonance, vibration energy of the steering wheel 10 is absorbed, and each vibration of the steering wheel 10 in the vertical direction and the horizontal direction is suppressed (damped).

  Further, as shown in FIGS. 8 and 9, since the gap is formed in front of and behind the large-diameter portion 34a, the large-diameter portion 34a can be elastically deformed in the front-rear direction even in these gaps. . The large-diameter portion 34a is more easily elastically deformed in the front-rear direction than that in which no void portion is formed. Therefore, it becomes easy to vibrate with the airbag device 20 while elastically deforming the large-diameter portion 34a at the target resonance frequency.

  On the other hand, if the entire rear surface of the large-diameter portion 34a is separated from the flange portion 31e, a hitting sound is generated when the large-diameter portion 34a and the flange portion 31e come into contact with each other. However, when the annular rib 34d protruding rearward from a part of the rear surface of the large diameter portion 34a comes into contact with the front surface of the flange portion 31e and elastically deforms, the flange portion 31e and the large diameter portion 34a approach each other. The momentum is weakened, and the generation of hitting sound due to contact is suppressed.

  In addition, since a gap is formed between the tapered hole portion 34c of the large diameter portion 34a and the shaft main body 31b, the elastic member 34 can be elastically deformed even in this gap, and the gap is formed. Compared to those not formed, it is easy to elastically deform in the radial direction or the like.

  By the way, the outer diameter of the small diameter portion 34 b of the elastic member 34 is smaller than the inner diameter of the small diameter hole portion 35 c of the damper holder 35. An annular gap is formed between the small diameter portion 34b and the inner wall surface of the small diameter hole portion 35c.

  However, a plurality of locations spaced apart from each other in the circumferential direction of the gap are formed on the outer peripheral surface of the small diameter portion 34b and filled with elastic ribs 34e. These ribs 34e restrict elastic deformation of the small-diameter portion 34b at a portion of the gap portion that is filled with the rib 34e. Due to this restriction, the steering wheel 10 is suppressed from a phenomenon called pitching, which swings around the elastic member 34 as a fulcrum.

  On the other hand, as described above, when the rib 34e having elasticity is provided, the repulsive force generated by the rib 34e filling the gap is added to the repulsive force generated due to the elastic deformation of the large diameter portion 34a, and the elastic member 34 is It becomes difficult to elastically deform. However, the ribs 34e are only provided at a plurality of locations separated from each other in the circumferential direction of the gap (see FIG. 10B). Therefore, the increase in the repulsive force due to the addition of the rib 34e is small as compared with the case where the entire gap is filled with the rib 34e.

  Further, each rib 34e is located at a location facing the other rib 34e across the axis L2. From this, the function of regulating the elastic deformation of the small diameter portion 34b and the function of suppressing the increase of the repulsive force accompanying the addition of the rib 34e are exhibited at locations facing each other across the axis L2 of the elastic member 34. .

  In the first embodiment, the eight ribs 34e arranged at equal angles around the axis L2 have a function of restricting the elastic deformation of the small diameter portion 34b and an increase in repulsive force accompanying the addition of each rib 34e. The function to suppress is exhibited.

  Further, a part of each rib 34e tends to elastically deform so as to bulge forward when compressed in the vertical direction or the horizontal direction and elastically deformed. Here, if each rib 34e is in contact with the restricting portion 31f and the restricted portion 35h located on the front side of the rib 34e, the restricting portion 31f and the restricted portion 35h are placed in front of each rib 34e. Trying to prevent elastic deformation to. In addition, along with the contact, a frictional force is generated between each rib 34e and the restricting portion 31f or the restricted portion 35h, and each rib 34e is less likely to be elastically deformed forward.

  However, in the first embodiment, each rib 34e is spaced rearward from the restricting portion 31f and the restricted portion 35h. The gap between each rib 34e and the restricting portion 31f or the restricted portion 35h allows the rib 34e to be elastically deformed to the front side. Each rib 34e is less likely to contact the restricting portion 31f and the restricted portion 35h, and frictional force is less likely to occur with the contact.

  On the other hand, when the airbag device 20 is pushed down for the operation of the horn device 40 at the normal time, the force applied to the airbag device 20 is at least one horn switch mechanism as shown in FIG. 30 is transmitted to the movable side contact portion 33 and the damper holder 35 via the contact holder 32 at 30. This force pushes the damper holder 35 forward. The regulated portion 35 h of the damper holder 35 receives a forward force in addition to the function of directly receiving the backward biasing force of the coil spring 37.

  By transmitting this force, the damper holder 35 is moved forward while compressing the coil spring 37. Therefore, as the pressing amount of the airbag device 20 increases, the repulsive force of the coil spring 37 increases and the operation load increases. At this time, if the elastic member 34 is elastically deformed, the operation load does not increase as expected. However, in the first embodiment, the damper holder 35 slides forward with respect to the elastic member 34. A force for elastically deforming the elastic member 34 from the damper holder 35 is not easily applied. For this reason, the operation feeling when the airbag device 20 is pushed down is improved.

  Further, the movable contact portion 33 moves forward together with the contact holder 32. When at least one of the plurality of contact protrusions 33d of the movable contact portion 33 comes into contact with the rear end face (fixed contact portion) of the snap pin 31, the core 12 connected to the ground GND (vehicle body ground) and the bag holder 21 are connected. Is conducted through the clip 13, the snap pin 31, and the movable contact portion 33. By this conduction, the horn switch mechanism 30 is closed, and the horn device 40 electrically connected to the bag holder 21 is activated.

  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 inflator 23 is operated in response to the impact, and gas is ejected from the gas ejection part 23e. By supplying this gas to the airbag, the airbag is deployed and inflated. When the pressing force applied to the outer skin portion 24a of the pad portion 24 increases by the airbag, the outer skin portion 24a is broken at the thin portion 24c. The airbag continues to be deployed and inflated backward through the opening created by the break. A deployed and inflated airbag is interposed in front of the driver who leans forward due to the impact of the front collision, restrains the driver's forward tilt and protects the driver from the impact.

  When the airbag is inflated rearward, a force directed rearward is applied to the bag holder 21. On the other hand, the snap pin 31 for each horn switch mechanism 30 is attached to the steering wheel 10 by being supported by the cored bar 12 (holding part 12b). A flange 31 e formed at the rear end of each snap pin 31 is located behind the attachment hole 21 g of the bag holder 21. Moreover, the flange portion 31e has an outer diameter larger than the inner diameter of the mounting hole 21g. Therefore, when the bag holder 21 moves rearward, the flange 31e functions as a stopper by contacting the peripheral portion of the attachment hole 21g in the bag holder 21.

  Further, the rigidity around the mounting hole 21g of the bag holder 21 is enhanced by a flange portion 21h extending forward. For this reason, even when a rearward force is applied to the bag holder 21 as the airbag is inflated, and the peripheral portion of the attachment hole 21g comes into contact with the flange portion 31e, the peripheral portion tries to maintain its shape (deforms). Hateful). As a result, the phenomenon in which the bag holder 21 and thus the airbag device 20 moves excessively rearward is well regulated by the flange 31e of the snap pin 31.

  Further, as described above, since the rigidity around the attachment hole 21g of the bag holder 21 is enhanced, the portion of the flange portion 31e that overlaps the attachment hole 21g in the radial direction of the shaft portion 31a (attachment of the flange portion 31e) It is possible to reduce the portion having a larger diameter than the hole 21g.

  Further, as shown in FIGS. 8 and 9, when a backward force is applied to the airbag device 20 by being pulled by an occupant, the force has a regulated portion 35 h on the inner peripheral portion. This is transmitted to the damper holder 35, which tries to move backward. However, a regulating portion 31f is provided on the outer peripheral portion of the snap pin 31 and behind the regulated portion 35h. The restricting portion 31f is provided at a location overlapping the restricted portion 35h in the radial direction of the shaft main body portion 31b. Therefore, the movement toward the rear of the restricted portion 35h is received and restricted by the restricting portion 31f. As a result, the damping performance is unlikely to be affected due to the damper holder 35 moving excessively backward.

  The same effect as described above can be obtained by increasing the diameter of the flange portion 31e of the snap pin 31, thereby making the expanded diameter portion a restricting portion and forming a restricted portion on the outer peripheral portion of the damper holder 35. It is possible. This is because if the restricting portion is positioned behind the restricted portion, the restricting portion can restrict the backward movement of the restricted portion.

  On the other hand, when the flange portion 31e is enlarged in diameter, the outer diameter of the contact holder 32 is also increased in order to secure a radial gap with the flange portion 31e. The dimensions increase.

Therefore, when there is a request to make the support structure for the steering wheel 10 of the airbag device 20 compact, it is difficult to meet the request.
However, in the first embodiment, the regulated portion 35 h is provided on the inner peripheral portion of the damper holder 35. Further, the restricting portion 31f is provided on the outer peripheral portion of the shaft main body portion 31b on the rear side of the restricted portion 35h and overlapping with the restricted portion 35h in the radial direction of the shaft main body portion 31b. Therefore, it is not only necessary to increase the diameter of the flange portion 31e, but the restricting portion 31f can be formed to have a smaller diameter than the flange portion 31e. In fact, as described above, the collar portion 31e has a small diameter while exhibiting the function of regulating the phenomenon in which the bag holder 21 moves excessively rearward as the airbag device 20 operates. Accordingly, the radial size of the horn switch mechanism 30 can be reduced.

  In Patent Document 1 described above, a cylindrical pin holder 48 is disposed between the shaft portion 45a of the snap pin 45 and the elastic member 46 as shown in FIG. The radial size of the horn switch mechanism 44 is increased. In this respect, since the pin holder 48 is not used in the first embodiment, the size of the horn switch mechanism 30 in the radial direction can be reduced accordingly.

In this way, the support structure for the steering wheel 10 of the airbag device 20 can be made compact.
Further, in Patent Document 1, since a structure in which a part of the urging member 49 is wound around the pin holder 48 is adopted, the outer diameter of the urging member 49 becomes larger due to the influence of the pin holder 48. However, in the first embodiment, since the pin holder 48 is abolished, the outer diameter of the coil spring 37 can be reduced by the abolition.

  Furthermore, in patent document 1, since the structure which arrange | positions the elastic member 46 between the pin holder 48 and the damper holder 47 is employ | adopted, the dimension of the radial direction of the elastic member 46 receives restrictions. However, in the first embodiment, since the pin holder 48 is abolished, the size of the elastic member 34 in the radial direction can be increased by the abolition. A large volume member can be used as the elastic member 34, and the vibration suppression performance can be improved by reducing the frequency characteristics of vibrations suppressed by the elastic member 34.

(Second Embodiment)
Next, 2nd Embodiment of the support structure of the airbag apparatus 20 is described with reference to FIGS.

  As shown in FIGS. 12, 13, and 15, in the second embodiment, a snap pin 31 having a configuration different from that of the first embodiment is used. The shaft portion 31a of the snap pin 31 is composed of two members, a shaft main body portion 31b and a cylindrical portion 38.

  The shaft main body 31b is a member that forms the main part of the shaft 31a, and is formed in a bar shape extending in the front-rear direction by a conductive metal material, like the shaft main body 31b of the first embodiment. This shaft main body 31b is common to the shaft main body 31b in the first embodiment in that it has a head 31d and a locking groove 31c at the front end, and a flange 31e at the rear end. Yes. As shown in FIG. 14, the shaft main body 31b is different from the shaft main body 31b in the first embodiment in that it does not have the restricting portion 31f and in that it has the annular groove 31g. The annular groove 31g is formed over the entire circumference of the rear outer periphery of the shaft main body 31b.

  The cylindrical portion 38 is formed of a hard resin material having insulating properties. The cylindrical portion 38 has a cylindrical shape that extends in the front-rear direction and is open at both front and rear ends, and covers the rear portion of the shaft main body portion 31b by fitting. An annular protrusion 38 a is formed on the entire front surface of the inner peripheral surface of the cylindrical portion 38. Then, the annular protrusion 38a is engaged with the annular groove 31g of the shaft main body 31b, so that the tubular portion 38 is engaged with the rear portion of the shaft main body 31b in a state where movement in the front-rear direction is restricted. ing.

  As shown in FIGS. 14 and 16, a restricting portion 38 c that forms an annular shape is formed on the entire outer periphery of the front end of the tubular portion 38. The elastic member 34 is placed on the rear side of the restricting portion 38 c of the cylindrical portion 38. The annular rib 34 d in the elastic member 34 approaches or contacts the front surface of the flange portion 31 e of the snap pin 31. The front end surface of the small diameter portion 34b in the elastic member 34 is in contact with or close to the rear surface of the restricting portion 38c.

  The elastic member 34 is restricted by the cylindrical portion 38 from moving in the radial direction. Further, the elastic member 34 is restricted from moving in the front-rear direction by a restricting portion 38 c and a flange portion 31 e that are disposed in front of and behind the elastic member 34. As described above, the elastic member 34 is attached to the rear portion of the snap pin 31 in a state where the radial movement and the front-back movement of the shaft portion 31a are restricted.

  As shown in FIG. 14, protrusions 38b having a semispherical cross section are formed at a plurality of, for example, four places, spaced apart from each other at equal angles in the circumferential direction at the front end portion of the cylindrical portion 38 including the restriction portion 38c. Is formed. These protrusions 38b are in contact with the rear surface of the regulated portion 35h of the damper holder 35 at the front end surface.

Other configurations are the same as those in the first embodiment. For this reason, the same elements as those described in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.
In the second embodiment, although the shaft portion 31a of the snap pin 31 is constituted by two members, that is, the shaft main body portion 31b and the cylindrical portion 38, the cylindrical portion 38 is put on the shaft main body portion 31b and locked. Therefore, the movement of the shaft main body 31b is restricted both in the front-rear direction and in the radial direction. Therefore, the shaft main body portion 31b and the cylindrical portion 38 function in the same manner as those in which they are integrated, that is, the shaft main body portion 31b in the first embodiment.

  The elastic member 34 is attached to the shaft portion 31a in a state where the elastic member 34 is put on the cylindrical portion 38. When the steering wheel 10 vibrates, the elastic member 34 functions as a dynamic damper spring by vibrating with the airbag device 20 while being elastically deformed. Accordingly, when the airbag device 20 is not pushed down during normal vehicle operation, the vibration of the steering wheel 10 is suppressed as in the first embodiment. On the other hand, when the airbag device 20 is pushed down at the normal time and the contact protrusion 33d of the movable contact portion 33 comes into contact with the fixed contact portion of the rear end surface of the snap pin 31, as shown in FIG. As in the first embodiment, the horn switch mechanism 30 is closed and the horn device 40 is activated.

  When the rearward force is applied to the airbag device 20 by being pulled by an occupant or the like, and the damper holder 35 tries to move rearward, as shown in FIG. 14, the rear of the restricted portion 35 h in the damper holder 35. The heading movement is received and regulated by a regulating portion 38c formed on the outer peripheral portion of the cylindrical portion 38 and positioned on the rear side of the regulated portion 35h.

Therefore, according to the second embodiment, the same effect as the first embodiment can be obtained, and the following effect can be obtained.
The restricting portion 38c comes into contact with the restricted portion 35h of the damper holder 35 at the protrusions 38b provided at a plurality of locations around the shaft main body portion 31b. Therefore, it is possible to reduce the friction generated between the restricting portion 38c and the restricted portion 35h as compared with the case where they are in surface contact.

  Further, as described above, the shaft portion 31a of the snap pin 31 is constituted by two members, that is, the shaft main body portion 31b and the cylindrical portion 38 attached in a state where the shaft body 31b is put on the rear portion of the shaft main body portion 31b. Therefore, there is an advantage that the work of covering the elastic member 34 on the outer periphery of the rear portion of the snap pin 31 is facilitated. That is, when the annular elastic member 34 is put on the rear portion of the snap pin 31, the shaft portion 31a of the snap pin 31 is inserted into the elastic member 34. However, in the first embodiment, the restricting portion 31f is inserted. Hinder. However, in the second embodiment, as shown in FIG. 17, the cylindrical portion 38 can be separated from the shaft main body portion 31b. Therefore, the elastic member 34 is put on the cylindrical portion 38 in a separated state. At this time, by inserting the cylindrical portion 38 into the elastic member 34 from the rear end side, the restricting portion 38c is unlikely to obstruct the insertion. The shaft portion 31b is inserted from the head portion 31d side into the tubular portion 38 covered with the elastic member 34, and the annular protrusion 38a is locked to the annular groove portion 31g, thereby elastically forming the tubular portion 38. It can be attached to the rear part of the shaft main body 31b together with the member 34.

In addition, said each embodiment can also be implemented as a modification which changed this as follows.
As the biasing member in each of the above embodiments, there is a spring of a type different from the coil spring 37 or a member different from the spring on the condition that the airbag device 20 is biased rearward in the damper holder 35. May be used.

  In each of the above embodiments, the number of ribs 34e in the elastic member 34 may be changed on the condition that it is plural. Further, the shape of each rib 34e may be changed to a shape different from that of each of the above embodiments.

In each of the above embodiments, the rib 34e of the elastic member 34 may be formed on the inner peripheral portion instead of the outer peripheral portion of the small diameter portion 34b.
-In 2nd Embodiment, the protrusion 38b for reducing the contact area of the control part 38c and the control part 35h may be provided in the control part 35h instead of the cylindrical part 38. FIG.

In the first embodiment, as shown in FIG. 18, a protrusion 35 i corresponding to the protrusion 38 b in the second embodiment may be formed on the regulated portion 35 h of the damper holder 35.
The steering wheel to which the support structure for the airbag device is applied may be a steering wheel of a steering device in a vehicle other than a vehicle, for example, an aircraft or a ship.

  DESCRIPTION OF SYMBOLS 10 ... Steering wheel, 20 ... Air bag apparatus, 21 ... Bag holder, 21g ... Mounting hole, 21h ... Flange part, 31 ... Snap pin (constituting fixed side contact part), 31a ... Shaft part, 31b ... Shaft body part, 31e: flange part, 31f, 38c ... regulating part, 33 ... movable side contact part, 34 ... elastic member, 35 ... damper holder, 35h ... regulated part, 35i, 38b ... projecting part, 37 ... coil spring (biasing member) 38 ... cylindrical part, 40 ... horn device, L1, L2 ... axis.

Claims (9)

An airbag device having a bag holder and functioning as a damper mass of a dynamic damper;
A snap pin that has a shaft portion extending in the front-rear direction and is attached to the steering wheel at a front end portion of the shaft portion using a snap fit structure, and supports the airbag device at a rear end portion of the shaft portion;
An elastic member that is arranged between the bag holder and the shaft portion and functions as a spring of a dynamic damper in a state of being attached to the shaft portion;
A damper holder disposed between the bag holder and the elastic member in a state attached to the airbag device, and holding the elastic member slidably in the front-rear direction;
A restricted portion is formed on a part of the damper holder, and is located on the rear side of the restricted portion of the outer peripheral portion of the snap pin and overlapping the restricted portion in the radial direction of the shaft portion. The support structure of the airbag apparatus in which the control part which controls the movement to the back of the said to-be-controlled part is provided. The shaft portion has a rod shape extending in the front-rear direction, and is configured only by a shaft main body portion on which the elastic member is covered,
The support structure for an airbag device according to claim 1, wherein the restricting portion is formed in the shaft main body portion. The shaft part is a main part of the shaft and extends in the front-rear direction, and is locked in a state where the shaft body part is covered with the shaft body part and the movement in the front-rear direction is restricted with respect to the coaxial body part. And a cylindrical portion that is covered with the elastic member,
The support structure for an airbag device according to claim 1, wherein the restricting portion is formed in the cylindrical portion. The damper holder has a cylindrical shape surrounding the shaft portion,
The regulated portion is provided on an inner peripheral portion of the damper holder,
The support structure for an airbag device according to claim 2 or 3, wherein the restricting portion is provided on an outer peripheral portion of an intermediate portion in the front-rear direction of the shaft portion. On the outer periphery of the rear end portion of the shaft main body portion, a flange having a larger diameter than the other portion of the coaxial main body portion is provided,
The support structure for an airbag device according to claim 4, wherein the elastic member is attached to the shaft portion by being placed on the shaft portion between the flange portion and the restricting portion. The bag holder penetrates in the front-rear direction, and has a mounting hole having a smaller diameter than the flange portion,
The shaft main body is inserted through the mounting hole,
The support structure for an airbag device according to claim 5, wherein a flange portion extending forward is formed around the attachment hole of the bag holder. A biasing member that biases the airbag device away from the steering wheel; and
A fixed-side contact portion constituted by a rear end portion of the snap pin;
Attached to the airbag device, when the airbag device is not pressed down, it separates backward from the fixed side contact portion, and when the airbag device is pressed down, it contacts the fixed side contact portion to operate the horn device The support structure of the airbag apparatus of any one of Claims 4-6 further provided with the movable side contact part to be made. The biasing member is disposed around the shaft portion and on the front side of the damper holder,
The support structure for an airbag device according to claim 7, wherein the damper holder is in contact with a rear end portion of the urging member in the restricted portion.   3. One of the restricting portion and the restricted portion, and a plurality of protrusions that are in contact with the other of the restricting portion and the restricted portion are formed at a plurality of locations around the shaft main body portion. The support structure for an airbag device according to any one of claims 8 to 9.

Images