Patent Publication Number: US-2021171146-A1

Title: Airbag device for saddle-type vehicles

Description:
TECHNICAL FIELD 
     The present invention relates to an airbag device for saddle-type vehicles. 
     BACKGROUND ART 
     In the related art, an airbag device for saddle-type vehicles in which an airbag retainer accommodating a folded airbag and an inflator adapted to generate gas for causing the airbag to expand are separately disposed is known. 
     Also, an airbag device in which a sectioning plate is provided at a midpoint inside a pipe member configuring a part of a vehicle body frame and a gas path for guiding gas generated by an inflator into an airbag unit is directly formed is disclosed (Patent Literature 1, for example). 
     Also, an airbag device in which an inflator and a retainer accommodating an airbag are separated and a gas supply path on a side closer to the inflator is connected to a portion of the retainer facing an opening portion of the airbag is disclosed (Patent Literature 2, for example). 
     CITATION LIST 
     Patent Literature 
     [Patent Literature 1] Japanese Patent Laid-Open No. 2003-104262 
     [Patent Literature 2] Japanese Patent Laid-Open No. 08-301031 
     SUMMARY OF INVENTION 
     Technical Problem 
     The airbag device disclosed in Patent Literature 1 requires working inside a main frame, and working of the frame is complicated. 
     Incidentally, for an airbag device for saddle-type vehicles, it is desirable to compactly dispose the airbag device and to deploy the airbag vertically upward to the maximum extent for appropriately protecting passengers. 
     The present invention was made in view of the aforementioned circumstances, and an object thereof is to enable, in an airbag device for saddle-type vehicle, simple configuration of the airbag device, compact disposition thereof, and deployment vertically upward of an airbag. 
     Solution to Problem 
     According to the present invention, there is provided an airbag device for saddle-type vehicles including: inflator ( 53 ); an airbag ( 52 ) adapted to be expanded by gas discharged from the inflator ( 53 ); and a retainer ( 52   a ) accommodating the airbag ( 52 ), in which the inflator ( 53 ) and the retainer ( 52   a ) are disposed as separate members, the retainer ( 52   a ) is provided on a turning axis (L) of a handle stem ( 20   a ) in a side view of a vehicle, the inflator ( 53 ) is provided around a head pipe ( 14 ) in a top view of the vehicle, and the retainer ( 52   a ) and the inflator ( 53 ) are coupled to each ether with a gas path ( 51 ). 
     Also, in the aspect of the present invention, the retainer ( 52   a ) may be provided between grip portions ( 23   g ) of a handle ( 23 ) in a plan view of the vehicle. 
     Also, in the aspect of the present invention, the gas path ( 51 ) may be provided to bridge an upper portion of the head pipe ( 14 ) from a vicinity of the head pipe ( 14 ). 
     Also, in the aspect of the present invention, the gas path ( 51 ) may be provided to bridge an upper portion of the head pipe ( 14 ) from a side portion of the head pipe ( 14 ). 
     Also, in the aspect of the present invention, the gas path ( 54   c ) may be provided to bridge an upper portion of the head pipe ( 14 ) from a front portion of the head pipe ( 14 ). 
     Also, in the aspect of the present invention, the gas path ( 54   c ) may be provided to bridge an upper portion of the head pipe ( 14 ) from a rear portion of the head pipe ( 14 ). 
     Advantageous Effects of Invention 
     The airbag device for saddle-type vehicles according to the present invention includes: the inflator; the airbag adapted to be expanded by gas discharged from the inflator; and the retainer accommodating the airbag, the inflator and the retainer are disposed as separate members, the retainer is provided on a turning axis of the handle stem in a side view of the vehicle, the inflator is provided around the head pipe in a top view of the vehicle, and the retainer and the inflator are coupled to each other with the gas path. 
     With this configuration, it is possible to dispose the airbag device using a space between components of the vehicle by providing the retainer and the inflator as separate members, to realize space saving for the airbag device, and to compactly dispose the airbag device. Also, it is possible to deploy the airbag in the vertical direction when the airbag is deployed upward. Also, it is possible to simply configure the airbag device. 
     Also, in the aforementioned configuration, the retainer may be provided between grip portions of the handle in a plan view of the vehicle. 
     With this configuration, it is possible to deploy the airbag using the space between the grips of the handle and to improve a degree of freedom in designing the airbag. 
     Also, in the aforementioned configuration, the gas path may be provided to bridge the upper portion of the head pipe from the vicinity of the head pipe. 
     With this configuration, it is possible to dispose the gas path around the head pipe and to shorten the length of the gas path. In this manner, it is possible to reduce the amount of gas required to deploy the airbag and a time required for the deployment. 
     Also, in the aforementioned configuration, the gas path may be provided to bridge the upper portion of the head pipe from the side portion of the head pipe. 
     With this configuration, it is possible to dispose the gas path on a side of the head pipe and to shorten the length of the gas path. In this manner, it is possible to reduce the amount of gas required to deploy the airbag and a time required for the deployment. 
     Also, in the aforementioned configuration, the gas path may be provided to bridge the upper portion of the head pipe from the front portion of the head pipe. 
     With this configuration, it is possible to dispose the gas path in front of the head pipe and to shorten the length of the gas path. In this manner, it is possible to reduce the amount of gas required to deploy the airbag and to reduce a time required for the deployment. 
     Also, in the aforementioned configuration, the gas path may be provided to bridge the upper portion of the head pipe from the rear portion of the head pipe. 
     With this configuration, it is possible to dispose the gas path behind the head pipe and to shorten the length of the gas path. In this manner, it is possible to reduce the amount of gas required to deploy the airbag and to reduce a time required for the deployment. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a left side view of a motorcycle provided with an airbag device according to a first embodiment of the present invention. 
         FIG. 2  is a perspective view of a peripheral portion of a handle when seen from an upper side. 
         FIG. 3  is a left side view of the peripheral portion of the handle. 
         FIG. 4  is a diagram illustrating a state of an inflator and a retainer when the handle is turned. 
         FIG. 5  is a left side view illustrating a configuration in which an inflator is disposed in front of a head pipe according to a second embodiment of the present invention. 
         FIG. 6  is a left side view illustrating a configuration in which the inflator is disposed behind the head pipe according to the second embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENT 
     Hereinafter, embodiments of the present invention will be described with reference to drawings. Note that notation of directions such as front, rear, left, right, upper, and lower in the description are assumed to be the same as those relative to a vehicle body unless particularly indicated otherwise. Also, the reference sign FR in each drawing represents the front side of the vehicle, and the reference sign UP represents the upper side of the vehicle. 
       FIG. 1  is a left side view of a motorcycle  1  provided with an airbag device according to a first embodiment of the present invention.  FIG. 1  illustrates a state in which an airbag  52  that will be described later has been expanded and deployed. Note that for components provided as pairs on the left and right sides, only components on the left side including reference signs are illustrated in  FIG. 1 . 
     The motorcycle  1  is a scooter-type saddle-type vehicle provided with a vehicle body frame  10 , a steering system  11  adapted to support a front wheel  2  in a steerable manner, a power unit  12  supported at a rear portion of the vehicle body frame  10 , a rear wheel  3 , and a seat  13  in which a passenger is seated in a straddling manner. 
     The vehicle body frame  10  includes a head pipe  14  provided at a front end of the vehicle body frame  10 , a main frame  15  extending from the head pipe  14  toward the rear lower side, and a pair of left and right lower frames  16 ,  16  extending backward from a lower end portion of the main frame  15 . Further, the vehicle body frame  10  includes a pair of left and right rear frames  17 ,  17  extending backward from the lower frames  16 ,  16  toward the rear upper side. The head pipe  14  is disposed at the center of the vehicle width similarly to the front wheel  2 . 
     The steering system  11  includes a steering shaft  20  pivotally supported at the head pipe  14  and a pair of left and right front forks  21 ,  21  disposed on both left and right sides of the front wheel  2  to support the front wheel  2 . Also, the steering system  11  further includes a bridge member  22  secured to a lower end of the steering shaft  20  to couple upper portions of the left and right front forks  21 ,  21  and a handle  23  secured to an upper end of the steering shaft  20 . The handle  23  for steering is connected to the steering shaft  20  via a handle post  23   a  secured to the upper end of the steering shaft  20 . 
     The head pipe  14  is inclined backward relative to the vertical direction by an amount of a predetermined caster angle set in the motorcycle  1  in a side view of the vehicle. The steering shaft  20  is inserted into and pivotally supported by the head pipe  14  and is disposed to foe inclined backward in a side view of the vehicle. 
     The power unit  12  is a unit swing engine provided with functions of an engine as a drive source for the rear wheel  3  and a swing arm supporting the rear wheel  3 . The power unit  12  is pivotally supported by the vehicle body frame  10  so as to be freely swingable via a link member  24  provided at a front end portion of the power unit  12 . 
     The seat  13  is provided above the rear frame  17 . The seat  13  includes a front-side seat  13   a  in which a driver is seated and a rear-side seat  13   b  in which a fellow passenger is seated, in an integrated manner. 
     A pair of left and right step floors  25 ,  25  on which the driver places his/her left and right feet are provided on the front lower side of the front-side seat  13   a.    
     The motorcycle  1  includes a vehicle body cover  26  adapted to cover the vehicle body such as the vehicle body frame  10 . 
     The vehicle body cover  26  includes a front cover  27  adapted to cover upper portions of the head pipe  14  and the steering system  11  from the front side and from the left and right sides and an inner cover  28  continued from a rear edge of the front cover  27  and adapted to cover the upper portions of the head pipe  14  and the steering system  11  from the rear side. 
     Also, the vehicle body cover  26  includes a center cover  29  located on the front lower side of the front-side seat  13   a  and an undercover  30  covering the vehicle body from the lower side below the step floors  25 ,  25 . Also, the vehicle body cover  26  further includes a rear-side cover  31  covering the rear frames  17 ,  17  from sides below the seat  13 . 
     A wind screen  32  inclined toward the rear upper side in a side view of the vehicle is attached to an upper portion of the front cover  27 . A headlight  33  is provided in a front surface of the front cover  27 . 
     The motorcycle  1  includes a front fender  34  and a rear fender  35 . 
     A meter  36  adapted to display information regarding the motorcycle  1  such as a vehicle speed is disposed in front of the handle  23 . A rear-view mirror  37  is attached to the handle  23 . 
     A front portion of the center cover  29  is continued from a lower portion of the inner cover  28 . The center cover  29  is located inside left and right legs of the driver stretched from the front-side seat  13   a  to the step floors  25 ,  25 . 
     A straddled space  38  recessed downward is sectioned by the inner cover  28 , the center cover  25 , and the front surface of the front-side seat  13   a  in a side view of the vehicle. The passenger can straddle the motorcycle  1  via the straddled space  38  when the passenger rides on and gets off the motorcycle  1 . 
     The motorcycle  1  includes an airbag device  50  adapted to protect the passenger from impact. An inflator  53  of the airbag device  50  is disposed between the head pipe  14  and the front cover  27  in a side view of the vehicle. Also, a retainer  52   a  of the airbag device  50  is located on an axial center L of the head pipe  14  that serves as a turning axis of a handle stem  20   a  in a side view of the vehicle. 
     Next, the airbag device  50  will be described using  FIGS. 2 and 3 . 
     The airbag device  50  is configured of the airbag  52 , the retainer  52   a,  the inflator  53 , and a connection tube  51 . 
     Note that the inflator  53  is connected to a control unit (not illustrated) of the motorcycle  1 , and an acceleration sensor (not illustrated) is connected to the control unit. 
     The airbag  52  is accommodated in the retainer  52   a  in a folded state. The inflator  53  is adapted to generate gas for causing the airbag  52  to expand. The retainer  52   a  and the inflator  53  are connected to each other with the connection tube  51 . Also, gas generated in the inflator  53  is supplied to the airbag  52  inside the retainer  52   a  via the connection tube  51  to cause the airbag  52  to expand. 
     Note that the connection tube  51  is configured of a flexible pressure-resistant tube. Also, a connection tube  51  adapted to be deformed in a case in which the pressure therein steeply increases is used. The connection tube  51  may be configured of an airbag base cloth. 
     The retainer  52   a  is disposed above the handle stem  20   a . The handle stem  20   a  is secured to the steering shaft  20  so as to be not able to relatively turn, in a state in which the upper end of the steering shaft  20  inserted into the head pipe  14  is inserted thereinto. In this manner, the steering shaft  20  turns around the axial center L of the head pipe  14  that serves as a turning center, along with the handle stem  20   a  in response to an operation of turning the handle  23 . 
     The handle post  23   a  is attached to an upper end of the handle stem  20   a,  and two handle holders  23   b  are provided in an upper surface of the handle post  23   a  in an aligned manner in the left-right, direction of the vehicle. Also, the retainer  52   a  is attached to the handle holders  23   b.    
     The handle holders  23   b  are adapted to hold the handle  23 , and a center portion  23   c  of the handle  23  is held by the two handle holders  23   b.  The handle  23  is configured of the center portion  23   c,  rising portions  23   r  extending toward the upper and the outer side on both left and right sides of the center portion  23   c,  and grip portions  23   g  each extending in the outer direction of the vehicle from the upper portions of the rising portions  23   r.    
     The retainer  52   a  is attached to the upper portions of the handle holders  23   b  and is disposed between the rising portions  23   r  of the handle  23 . Also, an upper end of the connection tube  51  is connected to the lower surface of the retainer  52   a,  and the connection tube  51  is configured to pass between the handle holders  23   b.    
     The connection tube  51  extends toward the lower and rear side from the lower surface of the retainer  52   a  and extends downward and in the left-side direction of the vehicle below the handle post  23   a.  The inflator  53  is disposed on the left side of the head pipe  14 , and the connection tube  51  is connected to a connection pipe  53   a  of the inflator  53 . The connection tube  51  is connected to the inflator  53  by inserting the connection pipe  53   a  into the lower end thereof. 
     Thus, the connection tube  51  is disposed along the head pipe  14  and the handle stem  20   a  to bridge the upper portion of the head pipe  14  from the vicinity (from a side portion in this embodiment) of the head pipe  14 . 
     The connection pipe  53   a  is provided in a rear surface of the inflator  53  in the front-back direction of the vehicle, and a rear end of the connection pipe  53   a  is directed toward the upper portion of the head pipe  14 . In other words, the connection pipe  53   a  extends backward from the inflator  53  and thereafter extends inward of the vehicle and upward. 
     The inflator  53  is attached to the head pipe  14  via a stay  55 , and the stay  55  extends obliquely forward in a plan view of the vehicle beyond the head pipe  14 . Also, the inflator  53  is attached to a front end portion of the stay  55 . 
     The inflator  53  is disposed in the vicinity of the head pipe  14  and is disposed inside the vehicle beyond the outer surface of the front cover  27 . Also, the inflator  53  is located on the left side of the head pipe  14  in the left-right direction of the vehicle. Note that a key cylinder and a handle locking mechanism (not illustrated) are provided on the right side of the head pipe  14 . 
     Also, the inflator  53  passes through the upper end of the head pipe  14  in front of the head pipe  14  and located below a plane R that perpendicularly intersects the turning axis of the handle stem  20   a  in a side view of the vehicle, as illustrated in  FIG. 3 . In addition, the connection pipe  53   a  is provided at a location at which the connection pipe  53   a  overlaps the head pipe  14  in a side view of the vehicle. 
     The connection tube  51  connecting the connection pipe  53   a  to the retainer  52   a  is configured to have specific loosening in a state in which the handle  23  is held in a straight traveling direction. 
     Next, effects of the first, embodiment of the present invention with the aforementioned configuration will be described. 
     First, effects of the airbag device  50  illustrated in  FIGS. 1 to 4  will be described. 
     In a case in which the acceleration sensor (not illustrated) of the motorcycle  1  detects an acceleration that is equal to or greater than a predetermined value, the control unit (not illustrated) operates the inflator  53 . In this manner, the inflator  53  generates gas. 
     The gas generated by the inflator  53  Is supplied to the airbag  52  in the retainer  52   a  via the connection pipe  53   a  and the connection tube  51 . 
     Then, the airbag  52  is expanded by the gas that has flowed thereinto, and the airbag  52  cleaves a part of the retainer  52   a  and is deployed upward beyond the retainer  52   a.  Also, the impact generated when the airbag  52  is deployed are received by the head pipe  14  via the retainer  52   a,  the handle holder  23   b,  the handle post  23   a,  and the handle stem  20   a.    
       FIG. 4  is a diagram illustrating a state of the inflator and the retainer when the handle is turned. 
     In  FIG. 4 , the state A is a state in which the handle  23  has been turned left, and the state B is a state in which the handle  23  has been turned right. Note that in the state A and in the state B, the handle  23  is in a state in which the handle  23  has been turned up to its limit, and the maximum turning range of the handle  23  is restricted by a handle stopper (not illustrated) provided between the bridge member  22  and the main frame  15 . 
     Also, the handle  23 , the retainer  52   a,  and the connection tube  51  in a state in which the handle  23  is not turned in the state A and in the state B are represented by two-dotted dashed lines. 
     In a case in which the handle  23  is turned left in the state A, the upper end of the connection tube  51  is pulled to the right by the handle holder  23   b  provided on the left side of the vehicle. Also, the connection tube  51  is connected to the connection pipe  53   a  from the lower surface of the retainer  52   a  through the lower side of the handle post  23   a,  the handle stem  20   a,  and the vicinity of the side surface of the head pipe  14 . 
     The connection tube  51  is provided with loosening, and motion of the handle  23  is not restricted even in a case in which the handle  23  is turned to the limit. 
     In this manner, even when the inflator  53  is disposed on the left side of the head pipe  14 , the loosening of the connection tube  51  prevents the left turning of the handle  23  from being inhibited. 
     When the handle  23  is turned right, in the state B, the connection tube  51  between the handle holders  23   b  moves to the left, where the inflator  53  is disposed. In this case, only the amount of loosening of the connection tube  51  increases, and the connection tube  51  does not restrict the turning of the handle  23 . Also, since the connection pipe  53   a  inserted into the lower end of the connection tube  51  extends toward the upper portion of the head pipe  14 , even when the connection tube  51  is loosened, the loosened portion is directed toward the side of the head pipe  14 . 
     In this manner, the connection tube  51  does not affect operations of the handle  23  in the state A and in the state B. Also, since the inflator  53  and the retainer  52   a  are connected to each other with the connection tube  51 , the airbag device  50  can operate even in a state in which the handle has been turned. 
     Also, since the connection tube  51  follows the periphery of the head pipe  14  even in a case in which the handle  23  has been turned, it is possible to reduce a space in which the connection tube  51  moves. 
     Also, since the retainer  52   a  is disposed above the handle stem  20   a  and on the axial center L of the head pipe  14  that is the turning axis of the handle stem  20   a,  the retainer  52   a  is present on the axial center L even when the handle  23  is turned. 
     In other words, the position of the retainer  52   a  does not change even when the retainer  52   a  rotates, in the state A and in the state B. It is thus possible to deploy the airbag  52  above the handle stem  20   a  regardless of the turning of the handle  23 . 
     Further, since the inflator  53  and the retainer  52   a  are provided as separate members, the retainer  52   a  accommodating the airbag  52  is disposed above the handle holder  23   b.  In this manner, the upper surface of the retainer  52   a  is disposed at a lower position as compared with a case in which the inflator  53  and the retainer  52   a  are disposed in an integrated manner. 
     Since the airbag  52  is disposed above the handle holder  23   b  and between the grip portions  23   g  of the handle  23  on the upper side of the handle stem  20   a,  it is possible to deploy the airbag  52  from a location that is close to the upper body of the passenger of the motorcycle  1 . In this manner, it is possible to compactly configure the airbag  52  and to reduce the volume inside the airbag  52 . Also, it is possible to reduce the amount of gas required for the deployment and to compactly configure the retainer  52   a.  Further, it is possible to shorten the time required for the deployment. 
     As described above, according to the embodiment to which the present invention is applied, the airbag device for the motorcycle  1  includes the inflator  53 , the airbag  52  adapted to be expanded by gas discharged from the inflator  53 , and the retainer  52   a  accommodating the airbag  52 . Also, the inflator  53  and the retainer are disposed as separate members, and the retainer  52   a  is provided on the axial center L that, is a turning axis of the handle stem  20   a  in a side view of the motorcycle  1 . Also, the inflator  53  is provided around the head pipe  14  in a top view of the motorcycle  1 , and the retainer  52   a  and the inflator  53  are coupled to each other with the connection tube  51  (gas path). 
     With this configuration, since the retainer  52   a  and the inflator  53  are provided as separate members, one integrated space is not needed for the disposition. Also, it is possible to dispose the retainer  52   a  and the inflator  53  using a space between other components and to realize space saving for the airbag device  50 . 
     Also, it is possible to deploy the airbag  52  in the vertical direction when the airbag  52  is deployed. Since an opened space on the turning axis of the handle stem  20   a  is used in the motorcycle  1 , it is possible to deploy the airbag  52  in the vertical direction. By deploying the airbag  52  in the vertical direction in front of the upper body of the driver, it is possible to extend a time until the driver is brought into contact with the airbag  52  at the time of collision and to extend a time required until the deployment of the airbag  52  is completed. In this time, it is possible to improve a degree of freedom in designing the deployable airbag. 
     Since the space on the turning axis of the handle stem  20   a  is used as a space for viewing the meter  36 , and the retainer  52   a  is disposed on the turning axis of the handle stem  20   a,  it is possible to reduce the region that blocks the sight of the driver as compared with the case of the disposition along with the inflator  53 . In this manner, it is possible to dispose the airbag  52  near the upper body of the driver while securing the sight required for driving. 
     Also, since impact generated when the airbag  52  is deployed is received by the head pipe  14  connected to the main frame  15 , the orientation of the retainer  52   a  is unlikely to deviate, and the airbag  52  can be deployed upward. 
     Also, the retainer  52   a  is provided between the grip portions  23   g  of the handle  23  in a plan view of the vehicle. 
     With this configuration, it is possible to deploy the airbag  52  using the space between the grip portions  23   g  of the handle  23  and to improve a degree of freedom in designing the airbag  52 . 
     Also, in a case in which a brake is applied to the front wheel  2 , the handle  23  is returned to the straight traveling position, and it is thus possible to deploy the airbag  52  in front of the driver. 
     Also, the connection tube  51  is provided to bridge the upper portion of the head pipe  14  from the vicinity of the head pipe  14 . 
     With this configuration, it is possible to dispose the connection tube  51  around the head pipe  14  and to shorten the length of the connection tube  51 . In this manner, it is possible to reduce the amount of gas required to deploy the airbag  52  and a time required for the deployment. Also, It is possible to shorten the connection tube  51  and thereby to reduce the weight of the airbag device  50 . 
     Next, a second embodiment of the present invention will be described. 
       FIG. 5  is a left, side view illustrating a configuration in which an inflator is disposed in front of a head pipe according to the second embodiment of the present invention, and  FIG. 6  is a left side view illustrating a configuration in which the inflator is disposed behind the head pipe according to the second embodiment of the present invention. 
     In the configuration illustrated in  FIG. 5 , an inflator  53  and a retainer  52   a  are provided as separate members and are connected to each other via a gas path portion  54 . 
     The gas path portion  54  is adapted to supply gas generated by the inflator  53  into the retainer  52   a,  and the gas flows into the airbag  52  inside the retainer  52   a.  The airbag  52  then expands. 
     The gas path portion  54  is attached to a handle post  23   a.  The gas path portion  54  is configured to have an inverted L shape in a side view and is configured of a lower portion  54   a  extending downward and an upper portion  54   b  attached to the handle post  23   a.    
     In addition, a gas path  54   c  is provided inside the gas path portion  54 , and the gas is supplied from the inflator  53  to the retainer  52   a  via the gas path  54   c.    
     The lower portion  54   a  of the gas path portion  54  extends toward the front and obliquely lower side from the front of the handle post  23   a  in parallel with a handle stem  20   a.  Also, the inflator  53  is attached to the front surface of the lower portion  54   a.  In addition, the lower end of the inflator  53  is disposed in accordance with the lower end of the lower portion  54   a  and is disposed in a space below the meter  36  in a state in which handles  23  are not turned. In this manner, the inflator  53  is disposed around the head pipe  14  and in front of the head pipe  14 . 
     Also, the upper portion  54   b  of the gas path portion  54  extends along a plane that perpendicularly intersects a turning axis of the handle stem  20   a,  and the retainer  52   a  is attached to the upper surface of the upper portion  54   b.    
     The lower surface of the upper portion  54   b  of the gas path portion  54  is attached to the upper surface of the handle post  23   a,  and the left and right handles  23  are attached to the handle post  23   a  with the upper portion  54   b  interposed therebetween. Lower ends  23   d  of the left and right handles  23  are configured to be fixedly provided at the handle post  23   a  and turn integrally with the handle post  23   a.    
     Also, the upper portion  54   b  of the gas path portion  54  is disposed between the lower ends  23   d  of the left and right handles  23 , and the retainer  52   a  is disposed between the left and right handles  23 . 
     In this manner, the gas path portion  54  is provided to bridge the upper portion of the head pipe  14  from the vicinity (the front portion in the configuration illustrated in  FIG. 5 ) of the head pipe  14 . 
     In the configuration illustrated in  FIG. 6 , the inflator  53  and the retainer  52   a  are provided as separate members and are connected to each other via a gas path portion  54 . 
     Also, similarly to the configuration illustrated in  FIG. 5 , the inflator  53  and the retainer  52   a  are connected to each other with the gas path portion  54 . 
     The gas path portion  54  is attached to the handle post  23   a,  and the gas path portion  54  is configured in the inverted L shape in a side view. In addition, the gas path portion  54  is configured of the lower portion  54   a  extending downward and the upper portion  54   b  attached to the handle post  23   a.    
     The lower portion  54   a  of the gas path portion  54  extends toward the front and obliquely lower side from the back of the handle post  23   a  in parallel with the handle stem  20   a.  Also, the inflator  53  is attached to the rear surface of the lower portion  54   a.  In this manner, the inflator  53  is disposed around the head pipe  14  and behind the head pipe  14 . 
     The upper portion  54   b  of the gas path portion  54  extends along the plane that perpendicularly intersects the turning axis of the handle stem  20   a,  and the retainer  52   a  is attached to the upper surface of the upper portion  54   b.    
     In the configuration illustrated in  FIG. 6 , the upper portion  54   b  of the gas path portion  54  is disposed between the left and right handles  23  similarly to the configuration illustrated in  FIG. 5 . In addition, the retainer  52   a  is disposed on the upper surface of the upper portion  54   b  of the gas path portion  54 . In this manner, the retainer  52   a  is disposed between the left and right handles  23 . 
     Also, the gas path portion  54  is provided to bridge the upper portion of the head pipe  14  from the vicinity (from the rear portion in the configuration illustrated in  FIG. 6 ) of the head pipe  14 . 
     Next, effects of the configurations illustrated in  FIGS. 5 and 6  of the airbag device according to the second embodiment will be described. 
     First, effects of the airbag device  50   a  illustrated in  FIG. 5  will be described. 
     In a case in which the handles  23  are turned, the inflator  53  and the retainer  52   a  turn along with the handles  23 . Therefore, the inflator  53  and the retainer  52   a  do not inhibit motion of the handles  23 , and the retainer  52   a  is located on the turning axis of the handle stem  20   a  even when the handles  23  are turned. 
     The load of the airbag device  50   a  is supported by the head pipe  14  via the handle post  23   a  and the handle stem  20   a,  and operations of the handles  23  are less affected. 
     Also, since the inflator  53  is disposed around the head pipe  14 , and the retainer  52   a  is disposed between the handles  23 , the distance between the inflator  53  and the retainer  52   a  is shortened. Further, since a clearance is provided between the rear surface of the lower portion  54   a  of the gas path portion  54  and the handle stem  20   a,  a space through which wirings for switches attached to the handle  23  are made to pass is configured. 
     Further, since the inflator  53  is disposed in front of the handle stem  20   a,  the upper surface of the retainer  52   a  is disposed at a lower position as compared with a case in which the inflator  53  and the retainer  52   a  are disposed in an integrated manner. 
     In addition, in a case in which the inflator  53  operates, the gas generated by the inflator  53  passes through the gas path  54   c  provided inside the gas path portion  54  and is supplied to the airbag  52  inside the retainer  52   a.  The airbag  52  inside the retainer  52   a  is expanded by the gas that has flowed thereinto. In this manner, the airbag  52  cleaves a part of the retainer  52   a  and is deployed toward the rear upper side beyond the retainer  52   a.    
     In the airbag device  50   b  illustrated in  FIG. 6  as well, the inflator  53  and the retainer  52   a  do not inhibit motion of the handle  23 , and the retainer  52   a  is located on the turning axis of the handle stem  20   a  even when the handle  23  is turned. 
     The gas path portion  54  extends toward the front lower side in parallel with the handle stem  20   a  while being brought into contact with the rear portion of the handle post  23   a.  Thus, a large space can be provided inside the front cover  27  in front of the handle stem  20   a  and the head pipe  14 . 
     Operations of the airbag device  50   b  is similar to the aforementioned airbag device  50   a,  and the gas generated by the inflator  53  passes through the gas path  54   c  and is supplied to the airbag  52  inside the retainer  52   a.  The airbag  52  cracks the retainer  52   a  and is deployed toward the rear upper side beyond the retainer  52   a.    
     Since the inflator  53  is provided around the head pipe  14  and behind the head pipe  14 , it is possible to dispose the airbag device  50   b  without affecting configurations of wirings and the like inside the front cover  27 . 
     Also, although the motorcycle  1  has been described as an example of the saddle-type vehicles in the aforementioned embodiments, the present invention is not limited thereto, and the present invention can be applied to a three-wheel saddle-type vehicle provided with two front wheels or rear wheels or a saddle-type vehicle provided with four or more wheels. 
     REFERENCE SIGNS LIST 
       1  Motorcycle 
       14  Head pipe 
       15  Main frame 
       20  Steering shaft 
       20   a  Handle stem 
       22  Bridge member 
       23  Handle 
       23   a  Handle post 
       23   b  Handle holder 
       23   c  Center portion 
       23   d  Lower end 
       23   g  Grip portion 
       23   r  Rising portion 
       27  Front cover 
       32  Wind screen 
       50  Airbag device 
       50   a  Airbag device 
       50   b  Airbag device 
       51  Connection tube 
       52  Airbag 
       52   a  Retainer 
       53  Inflator 
       53   a  Connection pipe 
       54  Gas path portion 
       54   a  Lower portion 
       54   b  Upper portion 
       54   c  Gas path 
       55  Stay