Motorcycle airbag device

Abstract

Disclosed is an airbag device for a motorcycle which makes it possible to achieve a reduction in size and weight by effectively using the vehicle body frame of the motorcycle and to ensure freedom of layout.　The airbag device 10 is mounted to a motorcycle 1 comprising a vehicle body frame 2 that has a main pipe 21. The airbag device 10 comprises an airbag 31 provided to the exterior of the main pipe 21 and an inflator 32 provided in the interior of the main pipe 21. An inflating / deploying gas from the inflator 32 is supplied to the airbag 31 via a gas flow pipe 40.

Description

[Technical field]

[0001] The present invention relates to an airbag device for a motorcycle. [Background technology]

[0002] Known motorcycle airbags include a type worn by the rider and a type mounted on the motorcycle, the latter of which is disclosed in, for example, Patent Documents 1 and 2.

[0003] In Patent Document 1, an airbag module including an airbag, an inflator, and a retainer is disposed between the steering wheel and the passenger seat, and the lower part of the retainer of the airbag module is supported via a support frame on the upper parts of a pair of left and right main frames of the vehicle body frame. Inside the retainer, an airbag is attached above the inflator, and the upper part of the airbag is covered by a lid.

[0004] In Patent Document 2, an airbag is arranged along a cylindrical steering wheel with both ends closed, and the communication holes of the steering wheel are connected to the inside of the airbag. Also, the inflator is housed in a stem pipe that passes through a head pipe at the front end of the body frame, and the upper end of the stem pipe is connected to the steering wheel by a conduit so that gas generated in the stem pipe when the inflator is activated can be guided to the airbag. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-123338 A [Patent Document 2] JP 2003-237662 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, there is room for improvement in conventional motorcycle airbag devices. For example, in Patent Document 1, the retainer that houses the inflator is required to have a structure that ensures pressure resistance at the initial stage of airbag deployment, which causes a problem that the weight and size of the entire airbag module are relatively large. In addition, the location of the airbag module is limited to the upper part of the main frame in front of the passenger seat, which limits the freedom of layout.

[0007] In addition, in Patent Document 2, since the airbag and the inflator are arranged in the steering system, the relative position of the airbag to the occupant moves when the occupant turns the steering wheel, and there is a problem that the airbag deployment direction is unstable. Also, the location of the airbag and the inflator is limited to the steering system, so the degree of freedom of layout is low.

[0008] An object of the present invention is to provide an airbag device for a motorcycle that can be made smaller and lighter by effectively utilizing the body frame of the motorcycle, while also ensuring freedom of layout. [Means for solving the problem]

[0009] A motorcycle airbag device according to one embodiment of the present invention is an airbag device mounted on a motorcycle having a body frame with a main pipe, and comprises an airbag and an inflator that supplies gas for inflating the airbag, the inflator being provided inside the main pipe and the airbag being provided outside the main pipe, and the gas for inflating from the inflator being supplied to the airbag via a gas flow path pipe.

[0010] According to this aspect, since the inflator is provided inside the main pipe, which is part of the body frame that requires high rigidity, the main pipe can be ensured to have pressure resistance to withstand the impact from the inflator generated at the initial stage of airbag deployment. This makes the strength design required of conventional retainers unnecessary. Therefore, even if a conventional retainer is provided (for example, in the embodiment described below, a housing is provided), the design and structure can be simplified, and the airbag device as a whole can be made smaller and lighter.

[0011] In addition, since the inflator is provided inside the main pipe, while the airbag is provided outside the main pipe, the two can be arranged separately. This increases the degree of freedom in layout regarding the arrangement of both the inflator and the airbag. In addition, since the two are arranged on the main pipe side, not in the steering system of the motorcycle, this also contributes to ensuring the stability of the direction of deployment of the airbag.

[0012] The present invention is applicable to any type of motorcycle that has a frame, such as the following: scooter, adventure, tourer, sports tourer, scrubber, classic (retro), American (cruiser), naked, street fighter, off-road supermotard, super sports, street, mini bike, three-wheeled trike, four-wheeled buggy, etc., and also to jet skis that travel on the surface of water such as the sea, lakes, and rivers, snowmobiles that travel on snow, and sidecars that are coupled to the side of motorcycles. [Brief description of the drawings]

[0013] [Figure 1] 1 is a perspective view showing the appearance of a motorcycle on which an airbag device according to an embodiment is mounted; [Diagram 2] FIG. 2 is a perspective view showing the motorcycle of FIG. 1 with some mounted parts such as a seat removed. [Diagram 3]FIG. 2 is a perspective view showing a body frame of the motorcycle of FIG. 1. [Figure 4] 2 is an enlarged side view of the front side of the vehicle body frame, showing the airbag device according to the embodiment together with a main pipe of the vehicle body frame. FIG. [Diagram 5] 5 is an enlarged side cross-sectional view showing a schematic view of part A in FIG. 4. [Figure 6] FIG. 2 is a perspective view showing a state in which an airbag is inflated and deployed in the motorcycle of FIG. 1. [Figure 7] FIG. 11 is an enlarged side view of the front side of the body frame, showing an airbag device according to a modified example of the embodiment together with a main pipe of the body frame. [Figure 8] 8 is an enlarged side cross-sectional view that illustrates a schematic view of part B in FIG. 7. [Figure 9] 1 is a diagram showing an example of the arrangement of an inflator of an airbag device relative to a body frame of a motorcycle. [Figure 10] 11 is a diagram showing another example of the arrangement of an inflator of an airbag device relative to a body frame of a motorcycle. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] A motorcycle airbag device according to a preferred embodiment of the present invention will be described. In this document, up and down, left and right, and front and rear are defined as follows. When a rider sits on the seat in a normal position, the direction the rider faces is referred to as the front, and the opposite direction is referred to as the rear. In addition, when a rider sits on the seat in a normal position, the right side of the rider is referred to as the right direction, and the left side of the rider is referred to as the left direction. Similarly, when a rider sits on the seat in a normal position, the direction of the rider's head is referred to as the up direction, and the direction of the rider's waist is referred to as the down direction, and the coordinate axes are referred to as the up and down directions.

[0015] As shown in Figures 1 and 2, a motorcycle 1 has a body frame 2 that forms the skeleton of the motorcycle, a seat 3 on which a rider sits astride, and a steering system 4 that is steered by the rider. The seat 3 is provided on the upper rear side of the body frame 2, and the steering system 4 is supported at the front end of the body frame 2 so as to be steerable. The steering system 4 supports a front wheel at the lower end of a front fork 5, and has a handlebar 6 at the upper end of the front fork 5. An airbag device 10 is mounted between the seat 3 and the steering system 4.

[0016] The vehicle body including the vehicle frame 2 is partially covered with various covers, one of which is a module cover 11 for an airbag device 10. A meter system 12 is disposed in front of the module cover 11, a fuel tank 13 is disposed behind the module cover 11, and a seat 3 is disposed behind the fuel tank 13. An engine 14 is mounted below the fuel tank 13.

[0017] 2 and 3, the body frame 2 has main pipes 21, 21. The main pipes 21, 21 constitute the main frame of the motorcycle 1, and support various main components of the motorcycle 1. For example, the main pipes 21, 21 support the fuel tank 13 and the engine 14. Here, a pair of main pipes 21, 21 are provided on the left and right, and extend so as to surround the four corners of the engine 14.

[0018] The main pipe 21 has the strength to withstand vibrations and shocks from the engine 14 and the road surface, as well as the rigidity against bending and twisting. The main pipe 21 is made of a metal such as steel or an aluminum alloy, and is composed of a pipe-shaped portion.

[0019] The body frame 2 also has a head pipe 22, a pair of left and right pivot frames 23, 23, and a pair of left and right seat frames 24, 24. The head pipe 22 and the pivot frames 23, 23 are connected by main pipes 21, 21, and the seat frames 24, 24 extend rearward from upper parts of the pivot frames 23, 23. The head pipe 22 is provided at the front end of the body frame 2 in the center of the vehicle width, and rotatably supports a front fork 5 of the steering system 4. The seat 3 is provided on the seat frames 24, 24.

[0020] The main pipes 21, 21 have, for example, top tubes 21a, 21a and down tubes 21b, 21b. The top tubes 21a, 21a form a tank rail and support the fuel tank 13. The engine 14 is mounted in front of the pivot frames 23, 23 between the top tubes 21a, 21a and the down tubes 21b, 21b.

[0021] The above-mentioned body frame 2 is one example of a frame structure (cradle-type frame) of the motorcycle 1, but various frame structures can be used as long as they have a pipe-shaped portion for housing an inflator 32 (see FIG. 4) of the airbag device 10 (i.e., as long as they have a main pipe 21). To list them, frame structures such as a single cradle frame, double cradle frame, semi-double cradle frame, diamond frame, backbone frame, truss frame, and twin spar frame can be used.

[0022] Next, the airbag device 10 will be described with reference to FIG. The airbag device 10 has an airbag 31 and an inflator 32 that supplies gas for inflating and deploying the airbag 31. The airbag device 10 also has a housing 33 that houses the airbag 31. The above-mentioned module cover 11 is attached to a part (upper part) of the housing 33 so as to cover the airbag 31. The module cover 11 is formed of, for example, resin.

[0023] In the airbag device 10, at least the airbag 31 and the housing 33 are modularized (unitized) to form an airbag module 34, and the inflator 32 is configured independent of the airbag module 34. In this embodiment, the airbag module 34 is modularized including the module cover 11.

[0024] The airbag 31 is a bag body that is inflated and deployed when gas is supplied from the inflator 32. The airbag 31 is formed by joining (for example, sewing or bonding) a plurality of base fabrics made of, for example, nonwoven fabric at appropriate positions. The airbag 31 is stored in the housing 33, for example, in a folded state.

[0025] The inflator 32 is electrically connected to a control device (not shown) and is activated when the motorcycle 1 collides. For example, when the motorcycle 1 collides, the impact is detected by an impact sensor, and a signal detected by the impact sensor is sent to the control device. When the control device determines that the airbag device 10 needs to be activated, it sends an ignition current to the inflator 32. When the inflator 32 is activated, it instantly generates gas. In this embodiment, the generated gas for inflation and deployment is supplied from the inflator 32 to the airbag 31 via the gas flow path pipe 40.

[0026] As the inflator 32, various types of inflators can be used, such as those filled with a gas generating agent, compressed gas, or both. That is, the inflator 32 may be a pyrotechnic type that generates gas by burning explosives, or a hybrid type that combines explosives and compressed gas. However, from the viewpoints of mounting the inflator 32 in the main pipe 21 and suppressing the thermal load on the airbag 31, the hybrid type is preferable.

[0027] As an example of the hybrid type, the inflator 32 has a bottomed cylinder 51, which is divided into a powder loading chamber and a compressed gas loading chamber via a partition. The inflator 32 has a gas discharge section 52 via a sealing plate on the side of the compressed gas loading chamber opposite to the powder loading chamber. When an ignition current is sent to the inflator 32, the powder in the powder loading chamber is ignited, and the gas generating agent in the powder loading chamber is ignited by the generated heat. As a result, the pressure in the powder loading chamber increases, the partition is broken, and the compressed gas in the compressed gas loading chamber is warmed by the heat from the powder loading chamber. Then, the sealing plate is broken by the pressure increase in the compressed gas loading chamber, and the compressed gas is released from the multiple ejection holes of the gas discharge section 52 and supplied to the airbag 31 via the gas flow pipe 40.

[0028] The airbag device 10 is provided in association with the main pipe 21, which is one of the components of the vehicle body frame 2. Specifically, the airbag 31 is provided outside the main pipe 21, and the inflator 32 is provided inside the main pipe 21.

[0029] 4, the inflator 32 is provided inside the down tube 21b of the main pipe 21. The down tube 21b is formed, for example, as a pipe-shaped portion extending rearward from the lower portion of the head pipe 22. Above the down tube 21b, there is a top tube 21a, which is formed as a pipe-shaped portion extending rearward from the upper portion of the head pipe 22. The frame structure shown in FIG. 4 differs partially from the frame structure shown in FIG. 3.

[0030] On the other hand, an airbag module 34 including an airbag 31 is attached to the outer surface of the main pipe 21 outside the main pipe 21. For example, a housing 33 of the airbag module 34 is attached to the outer surface of the top tube 21a. The housing 33 is formed, for example, in a shallow dish shape overall, and the airbag 31 is fixed to a bottom wall 33a of this shallow dish shape. An upper part of the housing 33 is covered with a module cover 11. The housing 33 has fastening points 35, 35 at which it is fixed to the top tube 21a by bolts, for example.

[0031] FIG. 5 shows an enlarged view of the configuration around the gas flow passage pipe 40. The airbag 31 has a gas inlet 31a, and the main pipe 21 has a gas outlet 21c. The gas inlet 31a and the gas outlet 21c are connected by a gas flow path pipe 40.

[0032] For example, the gas inlet 31a is an opening formed on the lower surface of the airbag 31, and the gas for inflation and deployment from the inflator 32 is introduced into the inside of the airbag 31 through the gas inlet 31a. The gas outlet 21c is an opening formed on the upper surface of the down tube 21b, and the gas for inflation and deployment from the inflator 32 is discharged to the outside of the down tube 21b through the gas outlet 21c. The opening diameters of the gas inlet 31a and the gas outlet 21c are approximately the same as the piping diameter of the gas flow passage pipe 40.

[0033] The gas release section 52 is located near the gas outlet 21c. The gas inlet 31a and the gas outlet 21c are located on the axis of the gas flow passage pipe 40. The gas release section 52 is also located on this axis. That is, the gas inlet 31a, the gas outlet 21c, and the gas release section 52 are located on approximately the same line. This arrangement allows the gas from the gas release section 52 to be rapidly introduced into the gas inlet 31a.

[0034] The gas flow path pipe 40 is made of, for example, metal. The gas flow path pipe 40 is located between the top tube 21a and the down tube 21b of the main pipe 21. The gas flow path pipe 40 is connected to the housing 33 and the main pipe 21 so as to connect between the gas inlet 31a and the gas outlet 21c. The gas flow path pipe 40 is a cylindrical member that is open at both the top and bottom ends and extends in the vertical direction.

[0035] The upper end 40a of the gas flow passage pipe 40 is formed in a flange shape, and is fixed to the housing 33 via fastening means 60. Specifically, the upper end 40a of the gas flow passage pipe 40 is fixed to the bottom wall 33a of the housing 33 via the fastening means 60 including a bolt 61 and a nut 62. Here, the fastening means 60 is also used to fix the airbag 31 to the bottom wall 33a.

[0036] A lower end 40b of the gas flow passage pipe 40 is formed into a flange shape and is welded to the main pipe 21. Specifically, the lower end 40b of the gas flow passage pipe 40 is welded to the upper surface of the down tube 21b in the vicinity of the periphery of the gas outlet port 21c.

[0037] The gas flow passage pipe 40 is formed to a size that allows the inflator 32 to be inserted therethrough. Therefore, the piping diameter of the gas flow passage pipe 40 is larger than the outer diameter of the cylindrical body 51 of the inflator 32. With this size relationship, the inflator 32 can be inserted into the gas flow passage pipe 40 from the upper end 40a side thereof, and then discharged from the lower end 40b of the gas flow passage pipe 40, and disposed inside the down tube 21b.

[0038] 4 and 5, there is a storage space 70 for storing the inflator 32 inside the main pipe 21 (here, the down tube 21b), and the storage space 70 is a closed space in the down tube 21b except for the gas outlet port 21c. The storage space 70 communicates with the space inside the gas flow passage pipe 40 and also communicates with the space inside the airbag 31. These three spaces are closed airtight as a whole. Therefore, the gas from the inflator 32 is supplied to the airbag 31 without escaping to the outside.

[0039] The storage space 70 may be, for example, a space formed over the longitudinal direction of the down tube 21b. In this case, both longitudinal ends of the down tube 21b are closed. In another example, the storage space 70 may be a part of the space in the longitudinal direction of the down tube 21b. In this case, a partition or a seal member is provided between both longitudinal ends of the down tube 21b to form a closed space. As one example, a seal member 71 may be interposed between the outer surface of the inflator 32 and the inner surface of the main pipe 21 (down tube 21b). At least a part of the storage space 70 is formed by such a seal member 71. The seal member 71 may be, for example, an O-ring.

[0040] The inflator 32 is stored in the storage space 70 without being exposed to the outside of the storage space 70. That is, all components of the inflator 32, including the cylindrical body 51 and the gas discharge portion 52, are stored in the storage space 70. In the storage space 70, the inflator 32 is fixed to the main pipe 21 (down tube 21b). For example, the inflator 32 is fixed by a screw or the like. Alternatively, the inflator 32 is fixed by crimping a separately provided attachment.

[0041] When the inflator 32 is activated upon collision of the motorcycle 1, gas for inflation and deployment is released from the gas discharge portion 52 of the inflator 32, flows into the gas flow pipe 40, and then flows into the airbag 31. The airbag 31 receiving the gas rapidly inflates, rupturing the module cover 11, and inflates and deploys in front of the rider (see FIG. 6).

[0042] 7 and 8 show an airbag device 100 according to a modified embodiment. Unlike the above-mentioned airbag device 10, in the airbag device 100, the inflator 32 is provided inside the intermediate frame pipe 21e of the main pipe 21. The intermediate frame pipe 21e connects the top tube 21a and the down tube 21b. The intermediate frame pipe 21e has a gas outlet 121c and a storage space 170, similar to the gas outlet 21c and the storage space 70 of the down tube 21b. For example, the gas outlet 121c is formed on the front surface of the intermediate frame pipe 21e, and the storage space 170 is a closed space in the intermediate frame pipe 21e except for the gas outlet 121c.

[0043] In the airbag device 100, the airbag module 34 is modularized including the gas flow passage pipe 140. The gas flow passage pipe 140 is a cylindrical member with both ends open, formed by bending metal, for example, and extends in a substantially J-shape. The gas flow passage pipe 140 is connected to the housing 33 and the intermediate frame pipe 21e so as to connect between the gas inlet 31a of the airbag 31 and the gas outlet 121c of the intermediate frame pipe 21e.

[0044] For example, one end 140a of the gas flow passage pipe 140 is formed into a flange shape and is welded to the housing 33. Specifically, the one end 140a is welded to the bottom wall 33a of the housing 33. The airbag 31 is fixed to the bottom wall 33a of the housing 33 near the periphery of this welded point by the above-mentioned fastening means 60 (bolts 61 and nuts 62). The other end 140b of the gas flow passage pipe 140 is formed into a flange shape and is fixed to the intermediate frame pipe 21e by bolts 161 (fastening means). Specifically, the other end 140b is fixed to the front surface of the intermediate frame pipe 21e near the periphery of the gas outlet 121c by the bolts 161.

[0045] Unlike the gas flow passage pipe 40, the gas flow passage pipe 140 does not need to be formed to a size that allows the inflator 32 to be inserted therethrough. Here, the inflator 32 is inserted into the main pipe 21 from an insertion hole 200 formed in the main pipe 21. For example, the insertion hole 200 is formed in the upper surface of the top tube 21a, and the inflator 32 is inserted from the insertion hole 200 through the top tube 21a into the intermediate frame pipe 21e and disposed in the storage space 170. The insertion hole 200 is covered by an installed component of the motorcycle 1, for example, the fuel tank 13. In another embodiment, the insertion hole 200 may be covered by the meter system 12. In this way, the insertion hole 200 can be hidden by effectively using existing installed components of the motorcycle 1, and a structure can be achieved in which water is not directly sprayed on the inflator 32.

[0046] As another modified example, the inflator 32 may be disposed inside the top tube 21a of the main pipe 21. For example, as shown by the dashed line in Fig. 7, the inflator 32' may be disposed inside the top tube 21a below the fuel tank 13.

[0047] In some modified embodiments, a plurality of inflators 32 may be provided at a plurality of locations in the main pipe 21. For example, in the example shown in FIG. 4, the inflators 32 may be provided in each of the pair of left and right down tubes 21b, 21b. In the example shown in FIG. 7, the inflators 32, 32' may be provided in the intermediate frame pipe 21e and the top tube 21a, respectively. Furthermore, as in the example shown in FIG. 9, the inflators 32 may be provided in each of the top tube 21a and the down tube 21b in a semi-double cradle frame. As in the example shown in FIG. 10, the inflators 32 may be provided in each of the pair of left and right top tubes 21a, 21a and the pair of left and right down tubes 21b, 21b in a double cradle frame.

[0048] Although not described in detail, when multiple inflators 32 are used, a gas flow path pipe 40 (140) is provided corresponding to each inflator 32 so that the inflation gas from each inflator 32 is supplied to the airbag 31 via the corresponding gas flow path pipe 40.

[0049] The effects of the present embodiment described above will now be described. As described above, the airbag devices 10, 100 according to the embodiment are mounted on the motorcycle 1 equipped with the body frame 2 having the main pipe 21, and include the airbag 31 provided outside the main pipe 21 and the inflator 32 provided inside the main pipe 21. The airbag devices 10, 100 are configured such that inflation and deployment gas from the inflator 32 is supplied to the airbag 31 via the gas flow passage pipes 40, 140.

[0050] According to this embodiment, since the inflator 32 is provided inside the main pipe 21, which is a part of the body frame 2 that requires high rigidity, the main pipe 21 can be ensured to have pressure resistance strength to withstand the impact from the inflator 32 generated at the initial stage of airbag deployment. This makes the strength design required for the retainer that conventionally houses the inflator unnecessary.

[0051] Particularly, in relation to this embodiment, the housing 33 that stores the airbag 31 does not need to have a large strength, so the design and structure of the housing 33 can be simplified. This is further expected by surrounding a part (the housing 33) of the airbag module 34 with the top tube 21a, the head pipe 22, the down tube 21b, etc., which have high rigidity. Therefore, the housing 33 only needs to ensure the storage capacity of the airbag 31, the fastening structure (fastening points 35) and waterproofness of the airbag module 34, and the minimum necessary housing strength, and can have a simple structure. Therefore, the airbag device 10, 100 as a whole can be made smaller and lighter.

[0052] Furthermore, since the inflator 32 is provided inside the main pipe 21, while the airbag 31 is provided outside the main pipe 21, the two can be arranged separately. This increases the degree of freedom in layout regarding the arrangement of both the inflator 32 and the airbag 31. For example, layouts such as those shown in Figures 4, 7, 9 and 10 are possible. Furthermore, since both are arranged on the main pipe 21 side, not the steering system 4 of the motorcycle 1, this also contributes to ensuring stability in the direction of deployment of the airbag 31.

[0053] Furthermore, while the inflator 32 and the airbag 31 are disposed apart, the gas for inflation and deployment from the inflator 32 can be supplied to the airbag 31 through the gas flow passage pipes 40, 140. The gas for inflation and deployment from the inflator 32 is ejected into the storage spaces 70, 170 in the main pipe 21 and then flows into the gas flow passage pipes 40, 140, and the main pipe 21 has high rigidity as described above. By effectively utilizing this high rigidity, the portion of the main pipe 21 where the storage spaces 70, 170 are located functions as a gas pipe.

[0054] Furthermore, the presence of the gas flow passage pipes 40 and 140 can reduce the amount of residue from the inflator 32 reaching the airbag 31.

[0055] In addition, the simplified structure of the housing 33 described above reduces the size of the airbag module 34, improving the ease of mounting the airbag module 34 on a vehicle. Furthermore, the use of the hybrid inflator 32 eliminates the need to provide the airbag 31 with a thick, heat-resistant reinforcing cloth or the like, and therefore the airbag module 34 can be made smaller and lighter.

[0056] The above-described embodiment is intended to facilitate understanding of the present invention, and is not intended to limit the present invention. The elements of the embodiment, as well as their arrangement, materials, conditions, shapes, sizes, etc., are not limited to those exemplified, and may be modified as appropriate.

[0057] Additional considerations regarding various implementations: [Embodiment 1] In an airbag device mounted on a motorcycle having a body frame with a main pipe, Airbags and an inflator that supplies gas for inflating and deploying the airbag; The inflator is provided inside the main pipe, The airbag is provided outside the main pipe, An airbag device for a motorcycle, wherein the gas for inflation and deployment from the inflator is supplied to the airbag via a gas flow passage pipe. [Embodiment 2] The airbag has a gas inlet, The main pipe has a gas outlet, A motorcycle airbag device as described in embodiment 1, wherein the gas inlet and the gas outlet are connected by the gas flow path pipe. [Embodiment 3] The vehicle further includes a housing that houses the airbag and is attached to an outer surface of the main pipe, A motorcycle airbag device as described in embodiment 2, wherein the gas flow passage pipe is connected to the housing and the main pipe so as to connect between the gas inlet and the gas outlet. [Embodiment 4] A motorcycle airbag device as described in embodiment 3, wherein the gas flow passage pipe is welded to one of the housing and the main pipe, and fixed to the other of the housing and the main pipe via a fastening means. [Embodiment 5] The inflator has a gas discharge portion that discharges gas for inflation and deployment, A motorcycle airbag device according to any one of embodiments 2 to 4, wherein the gas release portion is configured to be positionable within the main pipe in the vicinity of the gas outlet. [Embodiment 6] A motorcycle airbag device as described in embodiment 5, wherein the gas inlet, the gas outlet and the gas release section are configured to be positionable on approximately the same line. [Embodiment 7] A motorcycle airbag device according to any one of embodiments 2 to 6, wherein the gas flow passage pipe is formed to a size that allows the inflator to be inserted therethrough. [Embodiment 8] The main pipe has a storage space therein for storing the inflator. A motorcycle airbag device according to any one of embodiments 2 to 7, wherein the storage space is a closed space except for the gas outlet. [Embodiment 9] A motorcycle airbag device as described in embodiment 8, wherein at least a portion of the closed space is formed by a sealing member interposed between an outer surface of the inflator and an inner surface of the main pipe. [Embodiment 10] A motorcycle airbag device as described in any one of embodiments 1 to 9, wherein the inflator is provided inside the top tube of the main pipe. [Embodiment 11] A motorcycle airbag device according to any one of embodiments 1 to 9, wherein the inflator is provided inside the down tube of the main pipe. [Embodiment 12] A motorcycle airbag device according to any one of embodiments 1 to 9, wherein the inflator is provided inside an intermediate frame pipe that connects the top tube and down tube of the main pipe. [Embodiment 13] A motorcycle airbag device according to any one of embodiments 1 to 9, wherein the inflator is provided in a plurality of locations inside the main pipe. [Embodiment 14] 14. A motorcycle airbag device as described in any one of claims 1 to 13, wherein the inflator is an insertion hole formed in the main pipe, and is sized so that it can be inserted into the inside of the main pipe through an insertion hole covered by an mounted component on the motorcycle. [Explanation of symbols]

[0058] 1...motorcycle, 2...body frame, 3...seat, 4...steering system, 5...front fork, 6...handle, 10...airbag device, 11...module cover, 12...meter system, 13...fuel tank, 14...engine, 21...main pipe, 21a...top tube, 21b...down tube, 21c...gas outlet, 21e...intermediate frame pipe, 22...head pipe, 23...pivot frame, 24...seat frame, 31...airbag, 31a...gas inlet, 32, 32'... inflator, 33... housing, 33a... bottom wall, 34... airbag module, 35... fastening point, 40... gas flow passage pipe, 40a... upper end, 40b... lower end, 51... cylinder, 52... gas discharge portion, 60... fastening means, 61... bolt, 62... nut, 70... storage space, 71... sealing member, 100... airbag device, 121c... gas outlet, 140... gas flow passage pipe, 140a... one end, 140b... other end, 161... bolt, 170... storage space, 200... insertion hole

Claims

1. In an airbag device mounted on a motorcycle having a body frame with a main pipe, Airbags and an inflator that supplies gas for inflating and deploying the airbag; a housing that houses the airbag and is attached to an outer surface of the main pipe, The inflator is provided inside the main pipe, the airbag is provided outside the main pipe and has a gas inlet, The main pipe has a gas outlet, The gas for inflation and deployment from the inflator is supplied to the airbag through a gas flow passage pipe connecting the gas inlet and the gas outlet, The gas flow passage pipe is welded to one of the housing and the main pipe, and is fixed to the other of the housing and the main pipe via a fastening means.

2. In an airbag device mounted on a motorcycle having a body frame with a main pipe, Airbags and an inflator that supplies gas for inflating and deploying the airbag; The inflator is provided inside the main pipe, the airbag is provided outside the main pipe and has a gas inlet, The main pipe has a gas outlet, The gas for inflation and deployment from the inflator is supplied to the airbag through a gas flow passage pipe connecting the gas inlet and the gas outlet, The main pipe has a storage space therein for storing the inflator. The storage space is a closed space except for the gas outlet, An airbag device for a motorcycle, wherein at least a portion of the closed space is formed by a seal member interposed between an outer surface of the inflator and an inner surface of the main pipe.

3. The inflator has a gas discharge portion that discharges gas for inflation and deployment, 3. The motorcycle airbag device according to claim 1, wherein the gas discharge portion is configured so as to be capable of being positioned in the vicinity of the gas outlet port within the main pipe.

4. 4. The motorcycle airbag device according to claim 3, wherein said gas inlet, said gas outlet and said gas release portion are configured to be positionable on substantially the same line.

5. 3. The motorcycle airbag device according to claim 1, wherein the gas flow passage pipe is formed to a size that allows the inflator to be inserted therethrough.

6. 3. The motorcycle airbag device according to claim 1, wherein the inflator is provided inside a top tube of the main pipe.

7. 3. The motorcycle airbag device according to claim 1, wherein the inflator is provided inside a down tube of the main pipe.

8. 3. The motorcycle airbag device according to claim 1, wherein the inflator is provided inside an intermediate frame pipe that connects a top tube and a down tube of the main pipe.

9. 3. The motorcycle airbag device according to claim 1, wherein the inflator is provided in a plurality of positions inside the main pipe.

10. 3. The motorcycle airbag device according to claim 1, wherein the inflator is sized to be insertable into the main pipe through an insertion hole formed in the main pipe and covered by an installed component of the motorcycle.

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