JP4572770B2 - Steering wheel with airbag device - Google Patents

Description

  The present invention belongs to a technical field related to a steering wheel that includes a ring portion and a pad portion and includes an airbag device disposed in the pad portion.

  2. Description of the Related Art Conventionally, a ring portion gripped by a driver of a vehicle and a pad portion located on the center side of the ring portion and connected to the ring portion via a spoke portion, and an airbag device is provided in the pad portion. The steering wheel provided is well known, and in this case, a break groove having a V-shaped cross section is seen from the driver's head side in the center axis direction of the ring portion at the substantially central portion of the cover member of the pad portion. For example, it is formed in an H shape, and when the bag portion of the airbag device is inflated and deployed, an opening is formed by breaking and deploying the cover member at the portion where the fracture groove is formed. The part is inflated and deployed.

In recent years, for example, as shown in Patent Document 1, the driver's head is accommodated in a substantially ring shape in the pad portion when viewed from the driver's head side in the ring central axis direction, and the driver's head at the time of a vehicle front collision 2. Description of the Related Art An airbag device having a bag portion (so-called donut airbag) that expands and deploys in a substantially ring shape on the side is known. In the cover member of the pad portion in which the airbag device is disposed, the portion corresponding to the central portion of the accommodated bag portion is not deployed, and the surrounding portion is inflated and deployed to the outside of the pad portion. Is developed so as to form a substantially ring-shaped opening for this purpose (this developed part is referred to as a development cover part). And accessories, such as a horn and an emblem, are arrange | positioned inside the part (normally the center part of a pad part and is called a fixed cover part) in which the cover member in the said pad part is not expand | deployed.
JP 2004-224145 A

  By the way, in an airbag device having a bag portion called a donut-shaped airbag as described above, the deployment cover portion is usually divided into a plurality of divisions that are divided into two pieces when being deployed. The rear divided portion located on the vehicle rear side with respect to the fixed cover portion in the deployment cover portion is set near the vehicle rear side end in the cover member of the pad portion. The hinge is pivoted to the rear side of the vehicle and deployed.

  However, in such a configuration of the deployment cover portion, the rear side division portion is deployed in a space between the pad portion and the ring portion on the vehicle rear side of the pad portion, so that the vehicle deformed forward in the vehicle at the ring portion. May interfere with the rear part. In particular, when the pad portion is provided closer to the rear side of the vehicle than the ring portion, the possibility of the interference increases. That is, when the ring portion is inclined at an inclination angle of 40 ° or more and 90 ° or less with respect to the vertical direction when viewed from the vehicle width direction, a part of the driver's upper body (particularly the chest) at the time of the vehicle front collision However, in order to reduce the impact force on the driver at this time, the vehicle rear side part of the ring part is deformed forward by the above contact in order to reduce the impact force on the driver. The impact energy may be absorbed. When the vehicle rear side portion of the ring portion is deformed forward in this way, the vehicle rear side portion of the ring portion and the rear side divided portion deployed as described above interfere with each other, thereby sufficiently absorbing shock energy. There is a risk that it will not be carried out at the same time, or the rear divided part may be damaged.

  The present invention has been made in view of such a point, and an object thereof is to provide a deployment cover portion in a steering wheel including an airbag apparatus having a bag portion called a donut-shaped airbag as described above. By elaborating on the configuration of this, even if the front part of the driver abuts on the vehicle rear side part of the ring part and the vehicle rear side part of the ring part deforms forward of the vehicle at the time of the vehicle front collision An object of the present invention is to improve the driver's protection performance by preventing the vehicle rear side portion of the ring portion and the deployed rear divided portion from interfering with each other.

To achieve the above object, according to the present invention, the front straight running condition of the vehicle, the rear divided parts, about the hinge portion which is set in the vicinity rear end vehicle of the cover member Pas head portion By rotating and deploying to the vehicle rear side, the driver's head in the central axis direction of the ring portion with respect to the ring portion through the space between the pad portion and the ring portion on the vehicle rear side of the pad portion is It was configured to reach the opposite position.

From Specifically, in the invention 請 Motomeko 1, a ring portion which the driver of the vehicle is gripped, and in the center side and the ring portion and connected to the pad part through a spoke portion of the ring portion Therefore, the present invention is directed to a steering wheel provided with an airbag device disposed in the pad portion.

  The airbag device is accommodated in a substantially ring shape in the pad portion as seen from the driver head side in the ring portion central axis direction and is inflated and deployed on the driver head side in the event of a vehicle front collision. The portion of the pad portion on the bag portion inflating and deploying side is constituted by a cover member, and is fixed so as to correspond to the central portion of the accommodated bag portion and not to be unfolded when the bag portion is inflated and deployed. A fixed cover portion formed around the fixed cover portion, and deployed so as to form a substantially ring-shaped opening for the bag portion to be inflated and deployed outside the pad portion when the bag portion is inflated and deployed. The pad portion, when viewed from the driver's head side in the direction of the center axis of the ring portion when the vehicle is running straight ahead, the vehicle front side end of the cover member of the pad portion and the above-mentioned Rin The ring so that the distance between the vehicle front side end of the innermost part of the portion and the vehicle rear side end of the cover member is larger than the distance between the vehicle rear side end of the cover member and the vehicle rear side end of the ring portion. The ring portion is inclined at an inclination angle of 40 ° or more and 90 ° or less with respect to the vertical direction when viewed from the vehicle width direction. A vehicle rear side portion of the ring portion is configured to be deformable forward of the vehicle by contact with the driver's upper body whose upper body has fallen forward due to a frontal collision of the vehicle. It is composed of a plurality of divided portions that are sometimes divided to be divided pieces and are located on the vehicle rear side with respect to the fixed cover portion in the deployment cover portion when the vehicle is traveling straight ahead. The rear split section is the pad The space between the pad portion and the ring portion on the vehicle rear side of the pad portion by rotating and unfolding the vehicle around the hinge portion set in the vicinity of the vehicle rear side end of the cover member. It shall be comprised so that it may pass through and the position on the opposite side to the driver | operator's head of a ring part center axis direction may be reached with respect to a ring part.

According to this invention, the rear divided portion is deployed on the rear side of the vehicle, but the timing at which the vehicle rear side portion of the ring portion is deformed forward of the vehicle is after the completion of the deployment of the rear divided portion. Before the deformation of the vehicle rear side portion of the ring portion, the vehicle has reached the position opposite to the driver head in the ring portion central axis direction with respect to the ring portion, so the vehicle rear side portion deformed in the ring portion, There is no possibility that the developed rear side division part interferes with each other. As a result, the impact force caused by the contact of the driver's ring portion with the rear portion of the vehicle can be sufficiently reduced, and the rear divided portion is damaged due to interference with the ring portion, and a part of the driver's ring portion is damaged by the driver. There is no such thing as splashing on the lower body. Therefore, the protection performance of the driver can be improved.

In the invention of claim 2, in the invention of claim 1 , the bag portion has a larger outer diameter than the ring portion when viewed from the driver's head side in the direction of the center axis of the ring portion when the inflation and deployment are completed. It shall be comprised so that a part may be covered .

As a result, the driver's chest and the like come into contact with the vehicle rear side portion of the outer circumferential side surface of the bag portion before the driver's chest and the like come into contact with the vehicle rear side portion of the ring portion. Even if it comes into contact with the ring portion later, the impact force acting on the chest or the like can be further reduced.

As described above, according to the steering wheel with an air bag device of the present invention, the front straight running condition of the vehicle, the rear division unit is set to the vicinity of the rear end vehicle of the cover member Pas head portion By rotating and deploying to the vehicle rear side around the hinge portion, the ring portion central axis direction with respect to the ring portion through the space between the pad portion and the ring portion on the vehicle rear side of the pad portion Since the vehicle rear side portion of the ring portion and the deployed rear side divided portion do not interfere with each other, the driver's protection performance is improved. Improvement can be achieved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings .

Figure 1 (in this embodiment, the vehicle height is higher minivan including trucks and buses, etc.) vehicle 1 is a steering wheel 16 according to the provided exemplary forms state of the present invention a schematic configuration of a driver's seat 2 near the A resin instrument panel 3 is disposed at the front end of the vehicle 1 and a windshield 4 is disposed above the instrument panel 3.

  As shown in FIG. 2, at the center of the instrument panel 3 in the vehicle width direction, an air conditioning operation switch 7 for adjusting the temperature and air volume of the air conditioner, a center ventilator 8 for blowing air and air, and an audio device 9 are provided. Etc. are arranged. Further, an instrument 11 such as a speedometer, an engine tachometer, and a water temperature gauge for engine cooling water is disposed on the vehicle front side portion of the driver seat 2 in the instrument panel 3, and the driver seat 2 side in the instrument panel 3. A side ventilator 12 and the like are disposed at the end portion (in the present embodiment, the vehicle right end portion).

  A steering shaft 15 is provided below the instrument 11 of the instrument panel 3 so as to incline upward toward the rear of the vehicle. A steering wheel 16 is connected to the upper end of the steering shaft 15 via a column 20. Attached.

  As shown in FIG. 3 in an enlarged manner, the steering wheel 16 includes a ring portion 17 held by a driver D who is an occupant of the vehicle 1 (in this embodiment, a person having an average physique of an American adult male), The pad portion 18 is located on the center side of the ring portion 17 and is connected to the ring portion 17 via two spoke portions 19. As will be described in detail later, an airbag device 25 (see FIG. 4) having a bag portion 26 that is inflated and deployed at the time of a vehicle front collision is disposed in the pad portion 18. The ring portion 17 is inclined at an inclination angle θ (see FIG. 1) of 40 ° or more and 90 ° or less with respect to the vertical direction when viewed from the vehicle width direction. A preferable range of the inclination angle θ is 45 ° or more and 85 ° or less. Hereinafter, the steering wheel 16 will be described as being in a rotational position (the steering angle is 0) when the vehicle 1 is in a straight forward traveling state.

  The ring portion 17 is obtained by coating a core material 17a with a synthetic resin such as a urethane material. The core material 17a has a constricted portion at a predetermined interval except for a portion corresponding to the spoke portion 19. Thus, when the ring portion 17 receives a force greater than a predetermined value from the outside in the radial direction at a portion other than the portion corresponding to the spoke portion 19, the portion that has received this force is moved inward in the radial direction. It is configured to be plastically deformed. That is, when the upper body (chest part) of the driver D comes into contact with the vehicle rear side portion of the ring portion 17 at the time of the vehicle front collision as described later, the ring portion 17 is brought into contact with the vehicle rear side of the ring portion 17 by this contact. The portion is configured to be deformable forward of the vehicle. Instead of forming the constricted portion on the core material 17a as described above, the thickness of the core material 17a may be uniformly reduced so as to be plastically deformable.

  The pad portion 18 of the steering wheel 16 is located closer to the vehicle rear side than the ring portion center axis (coincides with the axis of the steering shaft 15) when viewed from the driver's head side in the ring portion center axis direction. Is provided. The two spoke portions 19 connect the vehicle rear side portions of the left and right side edge portions of the pad portion 18 and the vehicle rear side portions of the left and right side portions of the inner peripheral surface of the ring portion 17, respectively. A space is formed between the pad portion 18 and the ring portion 17 on the front and rear sides of the pad portion 18. Of these two spaces, the front side of the pad portion 18 is formed larger than the rear side. The driver D visually recognizes the instrument 11 disposed on the front side of the ring portion 17 through the space on the front side of the pad portion 18.

  The portion on the driver's head side in the ring portion central axis direction in the pad portion 18 (the portion on the side where the bag portion 26 is inflated and deployed as will be described later) is made of resin such as polypropylene as shown in FIG. The cover member 35 is used. In the vicinity of the outer peripheral edge of the cover member 35 on the side opposite to the inner side driver's head), a cylindrical support portion 35a extending to the opposite side (column 20 side) from the driver's head in the central axis direction of the ring portion is formed. The base portion 30 made of a metal plate is supported and fixed to the support portion 35 a by caulking the pins 31 so as to form a space with the cover member 35.

  A concave portion 35 b that is recessed toward the column 20 is formed at a substantially central portion of the cover member 35, and the opening of the concave portion 35 b is covered with a decorative cover 36. The decorative cover 36 is preferably provided with an accessory such as an emblem, an operation switch of the audio device 9 or an air conditioner, or a display device using liquid crystal or EL. In this manner, when the operation switch is disposed on the decorative cover 36, the mechanism portion of the operation switch may be provided in the recess 35b. Hereinafter, the side peripheral wall portion and the bottom wall portion of the concave portion 35b in the cover member 35 including the decorative cover 36 are referred to as a cover central portion 35c, and a portion on the outer peripheral side of the cover central portion 35c in the cover member 35 (the support portion described above). 35b) is referred to as a cover outer peripheral portion 35d.

  In the present embodiment, the cover center portion 35c has a substantially circular shape when viewed from the driver's head side in the ring portion central axis direction, and is formed on the outer surface (driver head side surface) of the cover center portion 35c. The outer peripheral edge portion is substantially flush with the inner peripheral edge portion on the outer side surface (driver's head side surface) of the cover outer peripheral portion 35d (for example, a step within ± 0.5 cm). There is no need.

  An inflator 27 that is a part of the airbag device 25 is provided at a portion corresponding to the cover center portion 35c in the pad portion 18, and the inflator 27 has a substantially cylindrical case 27a. The base portion 30 is fixed in a state of penetrating the substantially central portion. A space around the inflator 27 between the cover member 35 and the base portion 30 is an accommodation portion 29 in which the bag portion 26 is accommodated. The housing portion 29 has a substantially ring shape when viewed from the driver's head side in the ring portion central axis direction, and the bag portion 26 is connected to the housing portion 29 from the driver head side in the ring portion central axis direction. It is folded and accommodated in a substantially ring shape.

  The inflator 27 includes a case 27a in which a gas generating agent (not shown) for generating gas is sealed, and the gas generating agent is ignited by a spark plug (not shown) at the time of a vehicle front collision. Thus, a gas is generated, and this gas is jetted and supplied to the bag portion 26 from the gas outlet 27b provided on the side peripheral surface of the case 27a, so that the bag portion 26 is inflated and deployed.

  A support bracket 32 is attached and fixed to the base 30 so as to straddle the inflator 27. The support bracket 32 is attached to the base 30 at both sides of the inflator 27 in the vehicle width direction, and extends from the two side plate portions 32a extending toward the bottom wall portion of the recess 35b in the cover central portion 35c, and the inflator. 27 and a top plate portion 32b for connecting the tip portions of both side plate portions 32a through the bottom wall portion. The top plate 32b and the bottom wall are bolted to each other (the bolt is not shown).

  The bag portion 26 has a bag shape, and is accommodated in the accommodating portion 29 so that the opening edge portion faces the base portion 30 side and wraps the inflator 27. The entire periphery of the opening edge portion of the bag portion 26 is fixedly attached to the periphery of the inflator 27 in the base portion 30, and the central portion of the bag bottom portion of the bag portion 26 is connected to the bottom wall portion of the concave portion 35b and the support bracket 32 in the cover central portion 35c. Is sandwiched between the top plate portion 32b. The cover central portion 35 c is located at a portion corresponding to the central portion of the bag portion 26 accommodated in the accommodating portion 29.

  The column 20 is rotatably fixed integrally to the upper end portion of the steering shaft 15 via a core member 21 so as to cover the side opposite to the driver's head in the ring portion central axis direction of the pad portion 18. . A horn plate 41 extending toward the rear of the vehicle is fixed to the surface of the core member 21 on the pad portion 18 side, and a support pin extending along the central axis direction of the ring portion is attached to the tip of the horn plate 41. 42 is fixed. On the other hand, a tray member 43 is fixed to an end of the base 30 on the column 20 side of the rear portion of the vehicle, and the tray member 43 is slidably fitted to the support pin 42. The tray member 43 is urged toward the pad portion 18 by the compression coil spring 44 and is in contact with the tip portion of the support pin 42 having a large diameter. When the driver D presses the pad portion 18 toward the column 20, the tray member 43 slides toward the horn plate 41 with respect to the support pin 42 against the urging force of the compression coil spring 44. ing.

  A first contact 45 is provided integrally with the tray member 43 on the inner peripheral portion of the tray member 43 that fits with the support pin 42, while a second contact 46 is provided on the horn plate 41 side of the support pin 42. The two contact points 45 and 46 are brought into contact with each other by sliding the tray member 43 toward the horn plate 41, whereby the horn circuit is closed and the horn sounds.

  As shown in FIGS. 3 and 4, a break groove 51 having a substantially V-shaped cross section is formed on the inner surface of the cover member 35 of the pad portion 18. That is, the breaking groove 51 is formed on the inner surface of the cover member 35 at the boundary portion between the cover center portion 35c and the cover outer periphery portion 35d, the cover center side portion at the base of the support portion 35a in the cover outer periphery portion 35d, and the cover outer periphery. It is formed at six locations in the circumferential direction in the portion 35d. Hereinafter, the fracture groove 51 formed at the boundary portion between the cover central portion 35c and the cover outer peripheral portion 35d is referred to as an inner fracture groove 51a, and the fracture formed at the cover central side portion at the base of the support portion 35a in the cover outer peripheral portion 35d. The grooves 51 are referred to as outer fracture grooves 51b, and the fracture grooves 51 formed at six locations in the circumferential direction of the cover outer peripheral portion 35d are referred to as intermediate fracture grooves 51c.

  The intermediate break groove 51c extends from the inner break groove 51a to the outer break groove 51c toward the radially outer side of the cover outer peripheral portion 35d. Thus, a portion excluding the outer peripheral end portion of the cover outer peripheral portion 35d is partitioned into six divided portions 52 in the circumferential direction by the inner fracture groove 51a, the outer fracture groove 51b, and the intermediate fracture groove 51c. Hereinafter, with respect to the cover center portion 35c, the dividing portion 52 located on the vehicle front side is referred to as a front dividing portion 52a, and the dividing portion 52 located on the vehicle rear side is referred to as a rear dividing portion 52b, which is located on the vehicle left front side. The dividing unit 52 is referred to as a left front dividing unit 52c, the dividing unit 52 located on the right front side of the vehicle is referred to as a right front dividing unit 52d, and the dividing unit 52 located on the left rear side of the vehicle is referred to as a left rear dividing unit 52e. The division part 52 located on the right rear side of the vehicle is referred to as a right rear division part 52f. The left rear side and the right rear side divided parts 52e and 52f are provided at positions corresponding to the two spoke parts 19, respectively.

  The outer breaking groove 51b is interrupted over a predetermined length in a portion corresponding to the substantially central portion in the circumferential direction of the cover outer peripheral portion 35d in each of the divided portions 52. Each interrupted portion is a portion set as a hinge portion 60 when each divided portion 52 is deployed as will be described later.

  The portion of the cover member 35 where the breaking groove 51 is formed is designed to break upon receiving the inflation and deployment pressure when the bag portion 26 of the airbag device 25 is inflated and deployed. At this time, the hinge part 60 which is the interrupted part of the outer breaking groove 51b is not broken. As a result, the front side split portion 52a is separated from the left front side and right front side split portions 52c, 52d located on both sides of the front side split portion 52a. It rotates and expand | deploys to the vehicle front side position of the pad part 18 (refer FIG. 5). The rear divided portion 52b is separated from the left rear and right rear divided portions 52e and 52f located on both sides of the rear divided portion 52b, and the vehicle is centered on the hinge portion 60 of the rear divided portion 52b. By rotating to the rear side, the pad portion 18 is deployed to the vehicle rear side position. Further, similarly, the left front side, the right front side, the left rear side, and the right rear side divided parts 52c to 52f are also separated from each other, and are rotated around the respective hinge parts 60, so that the pad part 18 is rotated. The vehicle is unfolded at positions on the left front side, right front side, left rear side, and right rear side. As described above, each of the divided portions 52 is developed as divided pieces that are divided by the expansion and deployment pressure of the bag portion 26.

  Due to the expansion of the divided portion 52, a substantially ring-shaped opening for the bag portion 26 to expand and deploy to the outside of the pad portion 18 is formed in the cover member 35 where the divided portion 52 existed before expansion. It will be. On the other hand, since the cover central portion 35c is fixed to the base portion 30 via the support bracket 32, the cover central portion 35c does not expand when the bag portion 26 is inflated and deployed. Accordingly, the cover center portion 35c corresponds to the fixed cover portion that corresponds to the center portion of the bag portion 26 accommodated in the accommodating portion 29 and is fixed so as not to be deployed when the bag portion 26 is inflated and deployed. The dividing portion 52 corresponds to a deployment cover portion that is deployed so as to form a substantially ring-shaped opening for the bag portion 26 to be inflated and deployed outside the pad portion 18 when the bag portion 26 is inflated and deployed. The unfolded cover portion is composed of a plurality of divided portions 52 (52a to 52f) which are set to be divided into pieces when they are unfolded.

  As shown in FIG. 4, the portion from the vicinity of the boundary between the cover central portion 35 c and the front split portion 52 a on the outer surface of the cover member 35 to the vicinity of the front end of the vehicle is shown in FIG. The instrument 11 is inclined toward the front side of the vehicle in the direction opposite to the driver's head in the direction of the central axis of the ring portion so that the instrument 11 can be visually recognized through the space between the portion 18 and the ring portion 17. Although this inclination is accompanied by a curve, the degree of the curve is gentler than that of the rear divided portion 52b. Thus, the vehicle front side end of the cover member 35 or the vicinity thereof is located on the opposite side of the ring portion 17 from the driver's head in the ring portion central axis direction. And the hinge part 60 of the said front side division part 52a is set to the vehicle front side end vicinity of the cover member 35, and, thereby, the hinge part 60 of the front side division part 52a is a ring part with respect to the ring part 17. Position opposite to the driver's head in the central axis direction (position away from the driver head side end of the ring portion 17 by a distance of a predetermined value x on the opposite side to the driver's head, preferably the ring portion 17 is a position separated from the driver's head opposite end by a predetermined value y).

  Further, on the outer surface of the cover member 35, a portion from the vicinity of the boundary between the cover central portion 35c and the rear divided portion 52b to the vicinity of the vehicle rear side end of the cover member 35 is directed toward the vehicle rear side in the ring portion central axis direction. It is tilted away from the driver's head. Thereby, the vehicle rear side end of the cover member 35 or the vicinity thereof is located on the opposite side to the driver's head in the ring portion central axis direction with respect to the ring portion 17. Near the side end, the hinge portion 60 of the rear divided portion 52b is set.

  The pad portion 18 is located between the vehicle front side end of the cover member 35 of the pad portion 18 and the vehicle front side end of the innermost portion of the ring portion 17 when viewed from the driver's head side in the ring portion central axis direction. Is disposed with respect to the ring portion 17 such that the distance D1 is larger than the distance D2 between the vehicle rear side end of the cover member 35 and the vehicle rear side end of the innermost portion of the ring portion 17. . Even at the position where the pad portion 18 is disposed, the rear divided portion 52b rotates to the vehicle rear side around the hinge portion 60 set near the vehicle rear end of the cover member 35. By extending the pad portion 18 through the space between the pad portion 18 and the ring portion 17 on the vehicle rear side of the pad portion 18, the ring portion 17 is opposite to the driver's head in the central axis direction of the ring portion. To reach the position.

  As shown in FIG. 5, the bag portion 26 of the airbag device 25 has a hollow portion 26 a formed at the center of the bag portion 26 from the opening formed by the development of the divided portion 52, and the hollow portion. The cover center part 35c is inflated and deployed so as to be located in the inner part 26a. As a result, the bag portion 26 is inflated and deployed in a substantially ring shape on the driver's head side when viewed from the driver's head side in the ring central axis direction.

  As shown in FIG. 6, when the bag portion 26 is completely inflated and deployed, the entire inner peripheral surface of the hollow portion 26 a is closer to the driver's head than the cover central portion 35 c at the center portion of the bag portion 26. Is swelled to the inside of the hollow portion 26a so that the hollow portion 26a is crushed. Further, the bag portion 26 has an outer diameter larger than the ring portion 17 of the steering wheel 16 and covers the ring portion 17 when viewed from the driver's head side in the ring portion central axis direction when the inflation and deployment are completed. It has become.

  As shown in FIG. 1, the vehicle 1 of the present embodiment includes a seat belt device 70 that restricts the amount of movement of the upper body of the driver D to the front of the vehicle when the vehicle crashes. That is, the seat belt device 70 includes a retractor portion 72 that winds up the seat belt 71, a lap anchor portion (not shown) to which a leading end portion of the seat belt 71 pulled out from the retractor portion 72 is attached, A tongue 74 disposed in the middle portion in the lengthwise direction is configured in a three-point system having a buckle portion 75 with which the tongue 74 is detachably engaged. The buckle part 75 is fixed to the vehicle body on the inner side in the vehicle width direction of the driver seat 2, while the retractor part 72 and the lap anchor part are on the opposite side of the buckle part 75 across the driver seat 2. It is fixed to the vehicle body outside in the width direction. The seat belt 71 withdrawn from the retractor 72 is converted from an upward direction to a downward direction by a slip guide 76 provided at an upper position on the outer side in the vehicle width direction of the driver's seat 2. It is attached to the lap anchor part. The tongue 74 is provided so as to be slidable with respect to the seat belt 71 between the slip guide 76 and the lap anchor portion. By engaging the tongue 74 with the buckle portion 75, the driver D is in a state where the seat belt 71 is worn. The retractor 72 is provided with a well-known load limiter mechanism (not shown). When the driver D tries to move forward while the upper body of the driver D falls down, the road is loaded. When the shaft of the limiter mechanism is twisted, the seat belt 71 is pulled out while maintaining a constant tension, and the amount of movement of the upper body of the driver D to the front of the vehicle is limited within a predetermined range. In the present embodiment, when the vehicle 1 collides with an obstacle while traveling straight ahead at 30 km / h, the forward movement amount at the center in the vertical direction of the chest surface (the part corresponding to the sternum) of the driver D is 20 cm or more. Limit within 30 cm or less.

  As shown in FIG. 7, when the upper body of the driver D falls down as described above at the time of a frontal collision of the vehicle, the face of the driver D (The surface on the driver's head side) is in contact with the central portion in which the hollow portion 26a is crushed. In the present embodiment, the center of the face of the driver D hits a portion within a radius of 20 cm (preferably within 10 cm) from the center of the bag portion 26 (that is, the center of the hollow portion 26a) on the deployment front end surface of the bag portion 26. I try to touch. That is, the central portion of the deployment tip surface of the bag portion 26 is not in the same state as the other portions of the deployment tip surface, even though the hollow portion 26a is in a collapsed state. However, its elasticity is low and it deforms greatly. Thereby, if the face of the driver D is brought into contact with the central portion of the deployed distal end face of the bag portion 26, the impact force acting on the face of the driver D can be reduced.

  When the ring portion 17 of the steering wheel 16 is inclined at the inclination angle θ with respect to the vertical direction when viewed from the vehicle width direction, the vehicle rear side of the outer peripheral side surface of the deployed bag portion 26 is usually provided. Since the chest of the driver D abuts on the portion and the face abuts on the deployment tip surface, the radius of the deployment tip surface of the bag portion 26 substantially matches the distance from the chest of the driver D to the center of the face. If it is set to, the face of the driver D can be easily brought into contact with the central portion of the deployed distal end surface of the bag portion 26.

  Here, at the time of a frontal collision of the vehicle, the steering wheel 16 may move toward the driver's head via the steering shaft 15 depending on the magnitude of the degree of impact. In this case, the upper body falls to the front of the vehicle. There is a possibility that the chest of the driver D abuts on the vehicle rear side portion of the ring portion 17 of the steering wheel 16 before the face of the driver D abuts on the deployment front end surface of the bag portion 26. As described above, since the outer diameter of the bag portion 26 at the time of completion of inflation and deployment is larger than that of the ring portion 17, the chest portion comes into contact with the vehicle rear side portion on the outer peripheral side surface of the bag portion 26 before contacting the ring portion 17. As a result, the chest of the driver D can be protected.

  Moreover, even if the chest of the driver D abuts against the vehicle rear side portion of the ring portion 17, as shown by the two-dot chain line in FIG. Since the impact energy is absorbed by the deformation, the impact force on the chest of the driver D can be reliably reduced in combination with the contact with the bag portion 26.

As described above, the timing at which the vehicle rear side portion of the ring portion 17 is deformed forward is after the rear side division portion 52b has already been deployed, and the rear side division portion 52b is the vehicle rear side portion of the ring portion 17. Before the deformation, the vehicle has reached the position opposite to the driver's head in the direction of the center of the ring portion with respect to the ring portion 17, so that the deformed vehicle rear side portion in the ring portion 17 and the developed rear side division The part 52b does not interfere with each other. As a result, the impact force caused by the contact of the ring portion 17 of the driver D with the rear portion of the vehicle can be sufficiently reduced, and the rear divided portion 52b is damaged due to interference with the ring portion 17 and one of them. The part is not scattered on the lower body of the driver D. Therefore, the protection performance of the driver D can be improved .

In the above embodiment , the steering wheel 16 having the two spoke portions 19 has been described. However, the two spokes extending from the left and right side edges of the pad portion 18 to the left and right sides in the vehicle width direction are provided on the steering wheel 16. A steering wheel having a total of four spoke portions, which is formed by adding a portion, may be used.

  INDUSTRIAL APPLICABILITY The present invention is useful for a steering wheel in which an airbag device having a bag portion called a donut airbag is disposed in a pad portion, and particularly a steering wheel ring portion like a steering wheel of a vehicle such as a truck. Is useful when the vehicle is inclined at an inclination angle of 40 ° or more and 90 ° or less with respect to the vertical direction when viewed from the vehicle width direction.

Steering wheel according to an exemplary shape condition of the present invention is a side view showing a schematic configuration of a driver's seat near the vehicle provided. It is the figure seen from the vehicle back diagonal upper part which shows a part of instrument panel of the said vehicle, and a steering wheel. It is the figure which looked at the said steering wheel from the driver | operator's head side of the ring part center axis direction. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. FIG. 4 is a view corresponding to FIG. 3 showing an initial state of inflation and deployment of the bag portion of the airbag device. It is sectional drawing seen from the vehicle width direction which shows the state at the time of completion of expansion | deployment of the bag part of an airbag apparatus. FIG. 2 is a view corresponding to FIG. 1 illustrating a state where a driver is in contact with a bag portion of the airbag device .

D Driver 1 Vehicle 16 Steering wheel 17 Ring portion 18 Pad portion 19 Spoke portion 25 Airbag device 26 Bag portion 27 Inflator 29 Housing portion 30 Base portion 35 Cover member 35c Cover central portion (fixed cover portion)
52 Dividing part (deployment cover part)
52a Front division part 52b Rear division part 60 Hinge part

Claims (2)

An air bag device disposed in the pad portion, the ring portion being gripped by a driver of the vehicle, and a pad portion located on the center side of the ring portion and connected to the ring portion via the spoke portion A steering wheel with
The airbag device includes a bag portion that is accommodated in a substantially ring shape in the pad portion as viewed from the driver's head side in the central axis direction of the ring portion, and that is inflated and deployed toward the driver's head side when a vehicle crash occurs. And
A portion of the pad portion on the bag portion inflating and deploying side is constituted by a cover member, and corresponds to the central portion of the accommodated bag portion and is fixed so as not to be unfolded when the bag portion is inflated and deployed. And a deployment cover portion that is provided around the fixed cover portion and is deployed so as to form a substantially ring-shaped opening for the bag portion to inflate and deploy outside the pad portion when the bag portion is inflated and deployed. Have
When the pad portion is viewed from the driver's head side in the central axis direction of the ring portion when the vehicle is running straight ahead, the pad portion includes a front end of the cover member of the pad portion and an innermost portion of the ring portion. It is arranged with respect to the ring part so that the distance between the vehicle front side end is larger than the distance between the vehicle rear side end of the cover member and the vehicle rear side end of the innermost part of the ring part. And
The ring portion is inclined at an inclination angle of 40 ° or more and 90 ° or less with respect to the vertical direction when viewed from the vehicle width direction, and when the vehicle is running straight ahead, the vehicle rear side portion of the ring portion is It is configured to be deformable forward of the vehicle by contact with the upper body of the driver who has fallen forward of the vehicle due to a frontal collision of the vehicle,
The deployment cover part is composed of a plurality of divided parts set to be divided into respective divided pieces when deployed,
In a straight forward traveling state of the vehicle, a hinge portion in which a rear divided portion located on the vehicle rear side with respect to the fixed cover portion in the deployment cover portion is set in the vicinity of the vehicle rear side end in the cover member of the pad portion The driver in the direction of the center axis of the ring portion with respect to the ring portion through the space between the pad portion and the ring portion on the vehicle rear side of the pad portion by rotating to the rear side of the vehicle around the center A steering wheel comprising an airbag device, wherein the steering wheel is configured to reach a position opposite to the head. A steering wheel comprising the airbag device according to claim 1 ,
The bag part has a larger outer diameter than the ring part and covers the ring part when viewed from the driver's head side in the central axis direction of the ring part when the inflation and deployment are completed. A steering wheel equipped with an airbag device.

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