Title of Invention

FRONT COWL ATTACHING STRUCTURE IN A MOTORCYCLE

Abstract [Object] In a motorcycle in which a body frame supports a front 5 cowl, made of synthetic resin, located in front of a head pipe provided at a front end of the body frame, miniaturization and weight reduction of a stay on a body frame side is achieved while maintaining support strength thereof, and appearance degradation of the front cowl is also prevented. 10 [Constitution] A front cowl 31 includes an outer cowl 38 and inner cowls 39 attached to an inner side of the outer cowl 38. Lower portions of the inner cowls 39 are attached to a down tube stay 85 fixed to a down tube 8, and a rear portion of the outer cowl 15 38 is attached to a fuel tank 23 mounted on a main frame 7 . A front portion of the outer cowl 38 is supported by a head pipe stay 47 fixed to a head pipe 6 through an intervening object [Selected Drawing] 20 Fig. 2
Full Text FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
COMPLETE SPECIFICATION
[See Section 10, rule 13]
"FRONT COWL ATTACHING STRUCTURE IN A MOTORCYCLE"
HONDA MOTOR CO., LTD., a corporation of Japan having a place of business at 1-1, Minamiaoyama 2-chome, Minato-ku, Tokyo, Japan,
The following specification particularly describes the nature of the invention and the manner in which it is to be performed :-


[Detailed Description of the Invention]
[0001]
[Technical Field to Which the Invention Pertains]
The present invention relates to a motorcycle in which a body frame supports a front cowl made of synthetic resin which 5 is placed in front of a head pipe provided at a front end of the body frame and, more particularly, to an improved attaching structure of the front cowl. [0002] [Prior Art] 10 A motorcycle in which a front cowl is supported by a stay fixed to a body frame is already known according to, for example, a patent document 1 below and the like. [0003]
[Patent Document 1] 15 Japanese Patent Laid-open Publication No. Sho 61-226385 [0004] [Problems to be Solved by the Invention]
However, in the conventional motorcycle mentioned above, attaching bosses provided in the front cowl are attached 20 to the stay fixed to the body frame. With this attaching structure, when the stay is extended to a position close to the front cowl, the size of the stay becomes large. When the size of the stay is therefore reduced and the attaching bosses on a front cowl side are elongated to a stay side, there occurs 25 a disadvantage with regard to support strength for the front cowl. In addition, heat sinks are made corresponding to the attaching bosses while forming the front cowl made of synthetic

resin, and thereby the appearance of the front cowl can be
degraded.
[0005]
The present invention was accomplished in the light of 5 the above circumstances, and it is an object of the present invention to provide a front cowl attaching structure in a motorcycle, in which miniaturization and weight reduction of a stay on a body frame side is enabled while maintaining support strength thereof, and appearance degradation of a front cowl
10 is prevented. [0006] [Means for Solving the Problem]
In order to attain the aforementioned object, in a motorcycle in which a front cowl made of synthetic resin is
15 placed in front of a head pipe, the front cowl being supported by a body frame including the head pipe steserably bearing a front fork, a main frame extending rearward from the head pipe, and a down tube connected to the head pipe under the main frame and extending downward toward the rear, the invention defined in
20 claim 1 is characterized in that the front cowl includes an outer cowl and inner cowls attached to an inner side of the outer cowl, a rear portion of the outer cowl is attached to a fuel tank mounted on the main frame, a front portion of the outer cowl is supported by a head pipe stay fixed to the head pipe through
25 an intervening object, and lower portions of the inner cowls are fixed to a down tube stay fixed to the down tube. [0007]
3

According to the above-described construction of the invention defined in claim 1, the front cowl having a hollow-box shape is constructed of the outer cowl and the inner cowls, thus achieving improved rigidity and weight reduction of the front 5 cowl. In addition, the rear portion of the outer cowl is attached to the fuel tank in the front portion of the body frame, and thus it is not required to provide a stay in the body frame in order to support the rear portion of the outer cowl. Further, the rear portion of the outer cowl can be brought into proximity
10 to the fuel tank, and thus it is not required to provide particularly long projections in the rear portion of the outer cowl in order to attach the outer cowl to the fuel tank. Therefore, heat sinks are prevented from being made on the surface of the outer cowl in portions to be attached to the fuel
15 tank, and attaching strength is not deteriorated. Furthermore, since the front portion of the outer cowl is supported by the head pipe stay fixed to the head pipe through the intervening object, it is not required to provide particularly long projections in the front portion of the outer cowl in order to
20 be supported by the head pipe stay. Therefore, heat sinks are prevented from being made on the surface in the front portion of the outer cowl, and attaching strength is not deteriorated. Moreover, the lower portions of the inner cowls, attached to the inner side of the outer cowl, are attached to the down tube
25 stay, and thereby the inner cowls can be brought into proximity to the down tube stay without increasing the size of the down tube stay. Thus, sufficient attaching strength can be ensured

while avoiding an increase in the size of the down tube stay. Consequently, the head pipe stay and the down tube stay provided on a body frame side to support the front cowl can be made smaller and lighter while maintaining the support strength thereof, and 5 appearance degradation of the front cowl can also be prevented. [0008]
Moreover, in addition to the construction of the invention defined in claim 1, the invention defined in claim 2 is characterized in that projections extending rearward are
10 provided in a head light serving as the intervening object, and the front portion of the outer cowl is fixed to the* head light attached to the head pipe stay by inserting the projections into the head pipe stay. According to this construction, the head light can be positioned so that the head light can be prevented
15 from swinging right and left by the insertion of the projections into the head pipe stay. Therefore, the number of spots, in the head light, to be attached to the head pipe stay is reduced, thereby improving assembly workability. [0009]
20 [Preferred Embodiment of the Invention]
Hereinbelow, an embodiment of the present invention is described-based on an example of the present invention which is depicted in the accompanying drawings.


[Brief Description of the Drawings]
[Fig. 1] A left side view of a motorcycle. [Fig. 2] A partially-cutaway left side view of a front 15 portion of the motorcycle.
[Fig. 3] An exploded perspective view of part of a front cowl, a head pipe, a meter unit and a front portion of a body frame, viewed from right front.
[Fig. 4] An enlarged cross sectional view taken along the 20 line 4-4 of Fig. 2.
[Fig. 5] A perspective view of the front portion of the motorcycle viewed from left rear in a state where the front cowl and the meter unit are eliminated.
[Fig. 6] A cross sectional view taken along the line 6-6 25 of Fig. 2.
[0010] 25 Figs. 1 to 6 depict the example of the present invention. Fig. 1 is a left side view of a motorcycle, and Fig. 2 is a partially-cutaway left side view of a front portion of the

motorcycle. Fig. 3 is an exploded perspective view of part of a front cowl, a head pipe, a meter unit and a front portion of a body frame, which are viewed from right front. Fig. 4 is an enlarged cross sectional view taken along the line 4-4 of Fig. 5 2. Fig. 5 is a perspective view of the front portion of the motorcycle viewed from left rear in a state where the front cowl and the meter unit are eliminated. Fig. 6 is a cross sectional view taken along the line 6-6 of Fig. 2. [0011]
10 First of all, in Fig. 1, a body frame 5 of this motorcycle includes a head pipe 6 which steerably bears a front fork 12, a main frame 7 which has a vertically extending suspended portion 7a at a rear portion thereof and extends downward from the head pipe 6 toward the rear, a down tube 8 which is connected
15 to the head pipe 6 under the main frame 7 and extends downward from the head pipe 6 toward the rear at a larger inclination angle than that of a front portion of the main frame 7, a connecting plate 9 provided at a bottom end portion of the suspended portion 7a of the main frame 7, a pair of right and
20 left seat rails 10... provided continuously in the rear portion of the main frame 7 and extend upward toward the rear, and connecting frames 11... which connect middle portions of both the seat rails 10... and the connecting plate 9. [0012]
25 An axle of a front wheel WF is rotatably supported by a bottom end of the front fork 12, and a bar-shaped steering handle 13 is connected to a top portion of the front fork 12. The front

fork 12 supports a front fender 14 which covers an upper side of the front wheel WF. In addition, the connecting plate 9 bears front end portions of swing arms 15... through a pivot shaft 16 so that the swing arms 15... are vertically oscillated, and an 5 axle of a rear wheel WR is rotatably supported by rear ends of the swing arms 15.... Further, rear cushions 17... are provided between the swing arms 15... and connected portions of the connecting frames 11... and the seat rails 10.... [0013]
10 An engine E is fastened to the rear portion of the main frame 7, to a bottom end of the down tube 8 and to the connecting plate 9, and rotation power outputted from an output shaft 18 of a transmission M which constitutes a power unit P together with the engine E is transmitted to the rear wheel WR through
15 an endless chain 19. Specifically, the chain 19 is hooked onto a drive sprocket 20 fixed to the output shaft 18 and a driven sprocket 21 fixed to the rear wheel WR. [0014]
A tandem type riding seat 22 is provided on both of the
20 seat rails 10... over the rear wheel WR. In front of the riding seat 22, a fuel tank 23 is supported in a front portion of the body frame 5, that is, in the main frame 7 so that the fuel tank 23 is located above the engine E. [0015]
25 At the rear of the engine E, an air cleaner 24 is supported by the body frame 5. This air cleaner 24 is connected to a cylinder head 28 of the engine E though a connection pipe 25,


a carburetor 26 and an inlet pipe 27. Additionally, the cylinder head 28 is connected to an upstream end of an exhaust pipe 29 which is curved to round the engine E from a front side thereof to a bottom side thereof, and a downstream end of the 5 exhaust pipe 29 is connected to an exhaust muffler 30 placed on the right-hand side of the rear wheel WR. [0016]
A front cowl 31 made of synthetic resin covers the front portion of the body frame 5 from the front thereof so that the
10 engine E and the fuel tank 23 are also covered partially. In addition, a rear portion of the body frame 5 is covered by a rear cover 32 which also covers part of the carburetor 26 as well as the air cleaner 24, and a rear fender 33 which covers a rear top of the rear wheel WR is attached to the rear cover
15 32.
[0017]
In Figs. 2 to 4, the front cowl 31 includes an outer cowl 38 and a pair of right and left inner cowls 39... attached to an inner side of the outer cowl 38. 20 [0018]
The outer cowl 38 is constituted of side members 40... placed on both right and left sides of the head pipe 6 and a center connecting mender 41 which connects upper portions of front ends of the side menders 40.... An opening 42, formed by front portions 25 of both the side members 40... and the center connecting member 41, is located in a front portion of the front cowl 31, and a head light 43 which is an intervening object is placed to face

the opening 42. Additionally, openings 44..., each having a triangle shape when viewed from the side, are formed in the front portions of both of the side members 40... below the head light 43, and winkers 45... are placed to face these openings 44.... 5 Moreover, a bottom portion of a shield plate 46 extending upward is fixed to the front portion of the front cowl 31. [0019]
Referring to Fig. 5 together, a head pipe stay 47 is fixed to the head pipe 6 at a front end of the body frame 5. This
10 head pipe stay 47 includes an attaching frame 48 welded to a front face of the head pipe 6, a first support arm 49 extending frontward from the attaching frame 48, a second support arm 50 extending upward toward the front from the attaching frame 4 8 over the first support arm 49, and a support plate 51 fixed to
15 a tip of the second support arm 50. The support plate 51 is configured by integrally connecting a second plate portion 51b, which is inclined upward toward the front, to a top end of a first plate portion 51a, which is disposed along a vertical direction.
20 [0020]
A tip of the first support arm 49 is fastened to the center of the bottom of the head light 43 through an elastic member 52 using a bolt 53. In addition, the headlight 43 is provided with a pair of projections 54, 54 extending rearward from a back
25 of the headlight 43. These projections 54... are inserted into perforations 55, 55 provided in the first plate portion 51a of the support plate 51 in the head pipe stay 47. Specifically,

the center of the bottom of the head light 43, where the projections 54... are inserted through the support plate 51 of the head pipe stay 47, is attached to the tip of the first support arm 49 of the head pipe stay 47 through the elastic member 52. 5 [0021]
The second plate portion 51b in the support plate 51 of the head pipe stay 47 is provided with a plurality of, for example, three through holes 56.... A meter unit 58 is fastened onto the second plate portion 51b of the support plate 51 using screw 10 members 57... which are each inserted through those through holes 56.... [0022]
Upper brackets 61... are provided on both sides of an upper
portion of the head light 43 in a laterally protruding manner.
15 In addition, lower brackets 62... are provided on both sides of
a lower portion of the head light 43 in a laterally protruding
manner. Meanwhile, in the vicinity of the opening 42 of the
outer cowl 38, upper attaching plates 63... to be fastened to the
upper brackets 61... with screw members 65... and lower attaching
20 plates 64... to be fastened to the lower brackets 62... with screw
members 66... are provided in the side members 40... of the outer
cowl 38 in a protruding manner. Specifically, a front portion
of the outer cowl 38 is supported by the head pipe stay 47 through
the head light 43 serving as the intervening object.
25 [0023]
In Fig. 6, rear portions of both the side members 40... of the outer cowl 38 are curved to be brought into proximity to

the fuel tank 23 mounted on the main frame 7 in the body frame 5, and a rear portion of the outer cowl 38, that is, the rear portions of both the side members 40... are attached to the fuel tank 23. 5 [0024]
In order to attach the rear portions of both the side members 40..., cowl attaching brackets 67... are fixed to both sides of an upper portion of the fuel tank 23 near the front thereof. Upper portions of the cowl attaching brackets 67... are provided
10 with vertically extending screw holes 68..., and grommets 70... are fitted to upper support holes 69... provided in the cowl attaching brackets 67.... Additionally, grommets 72... are fitted into lower support holes 71... provided on both sides of a lower portion of the fuel tank 23.
15 [0025]
Meanwhile, tubular insert portions 73... whose tips can be inserted into the grommets 70... are integrally provided on upper portions on a rear side of both the side members 40... in a protruding manner. In addition, a plurality of abutting plate
20 portions 74... are integrally provided, radially extending from each of the tubular insert portions 73. In a state where the tubular insert portions 73... are inserted into the grommets 70... so that each of the abutting plate portions 74... is abutted onto outer ends of the grommets 70..., top end portions on the rear
25 side of both the side members 40... are fastened to the cowl attaching brackets 67... with screw members 75... which are screwed to the screw holes 68.... Moreover, abutting projections 76...

whose tips are abutted onto the grommets 72... are integrally provided in a protruding manner on lower portions on the rear side of both the side members 40.... At tips of the abutting projections 7 6..., engaged head portions 7 8... are integrally 5 provided through neck portions 77... which pierce the grommets 72.... The engaged head portions 78... are resiliently engaged with the grommets 72... from inside. [0026]
Referring to Figs. 3 and 4 again, a plurality of, for
10 example, four attaching bosses 81, 81... are integrally provided in portions corresponding to the inner cowls 39... on inner surfaces of the side members 40... of the outer cowl 38 . The inner cowls 39... are attached to the side members 40..., that is, to the outer cowl 38 from inside by screwing and fastening screw
15 members 83, 83..., which are inserted through the through holes 82, 82... provided in the inner cowls 39..., to the respective attaching bosses 81, 81.... [0027]
The winkers 45... facing the openings 44... are each housed
20 and fixed between the outer cowl 38 and the respective inner
cowls 39..., and windows 84... for drawing out conductors (not
shown) which are linked to the winkers 45... are provided in the
inner cowls 39....
[0028]
25 A down tube stay 85 is fixed to the down tube 8 in the
body frame 5. This down tube stay 85 includes an attaching plate
8 6 fastened to a front face of the down tube 8, a support pipe

87 extending toward both right and left sides from the attaching plate 86, and support plates 88... respectively fixed to both right and left ends of the support pipe 87. Rubbers 89... having cylindrical metal collars 90... in center portions thereof are 5 attached to both of the support plates 88.... [0029]
Meanwhile, attaching projections 91... extending over the support plates 88... are integrally provided in lower portions of the inner cowls 39... in a protruding manner, and nuts 92...,
10 each having an approximate U-shape, are attached to these attaching projections 91.... Thereafter, washers 93... abutted on the bottom of the rubbers 89... and bolts 94... inserted through the collars 90... are screwed and fastened to the nuts 92.... Thus, the lower portions of the inner cowls 39... are attached to the
15 down tube stay 85 through the rubbers 89.... [0030]
Next, effects of this embodiment are described. The front cowl 31 made of synthetic resin includes the outer cowl 38 and the pair of right and left inner cowls 39... attached to
20 the inner side of the outer cowl 38. The front cowl 31 is constructed of the outer cowl 38 and the inner cowls 39... to have a hollow-box shape, thereby achieving improved rigidity and weight reduction of the front cowl 31. [0031]
25 In addition, the rear portion of the outer cowl 38 is attached to the fuel tank 23 mounted on the front portion of the body frams 5, that is, on the main frame 7. Therefore, it

is not required to provide a stay in the body frame 5 in order to support the rear portion of the outer cowl 38. Additionally, the rear portion of the outer cowl 38 can be brought into proximity to the fuel tank 23. Therefore, it is not required 5 to provide particularly long projections in the rear portion of the outer cowl 38 in order to attach the outer cowl 38 to the fuel tank 23. Thus, heat sinks can be prevented from being made on the surface of the outer cowl 38 in portions to be attached to the fuel tank 23, and attaching strength is not
10 deteriorated. [0032]
Furthermore, since the front portion of the outer cowl 38 is supported by the head pipe stay 47 fixed to the head pipe 6 through the head light 43, it is not required to provide
15 particularly long projections in the front portion of the outer cowl 38 to be supported by the head pipe stay 47. Thus, heat sinks are prevented from being made on the surface in the front portion of the outer cowl 38, and attaching strength is not deteriorated.
20 [0033]
Further, the lower portions of the inner cowls 39..., attached to the inner side of the outer cowl 38, are attached to the down tube stay 85 fixed to the down tube 8 in the body frame 5. Therefore, the inner cowls 39... can be brought into
25 proximity to the down tube stay 85 without increasing the size of the down tube stay 85. Thus, sufficient attaching strength can be ensured while avoiding an increase in the size of the

down tube stay 85. [0034]
Consequently, the head pipe stay 47 and the down tube stay 85 provided on a body frame 5 side in order to support the front 5 cowl 31 can be made smaller and lighter while maintaining the support strength thereof, and appearance degradation of the front cowl 31 can also be prevented. [0035]
Moreover, the pair of projections 54, 54 extending 10 rearward are provided in the head light 43, and these projections 54, 54 are inserted into the perforations 55, 55 of the head pipe stay 47 so that the head light 43 is attached to the head pipe stay 47. Therefore, the head light 43 can be positioned so that the head light 43 is prevented from swinging 15 right and left by the insertion of the projections 54... into the head pipe stay 47 . Thus, the number of spots, in the head light 43, to be attached to the head pipe stay 47 is reduced, and thereby assembly workability can be improved. [0036] 20 The example of the present invention is described hereinabove. However, the present invention is not limited to the example described above and various design changes may be made without departing from the present invention as set forth in the scope of claims. 25 [0037]
[Effect of the Invention]
As described in the foregoing, according to the invention

defined in claim 1, improved rigidity and weight reduction of
the front cowl can be achieved. In addition, the head pipe stay
and the down tube stay provided on the body frame side in order
to support the front cowl can be made smaller and lighter while
5 maintaining the support strength thereof. Thus, appearance
degradation of the front cowl can be prevented.
[0038]
Further, according to the invention defined in claim 2,
the number of spots, in the head light, to be attached to the
10 head pipe stay is reduced, and thereby assembly workability can
be improved. [Explanation of the Reference Numerals]
5...BODY FRAME 6...HEAD PIPE 8...DOWN TUBE 12...FRONT FORK 23...FUEL TANK 5 31...FRONT COWL 38...OUTER COWL 39...INNER COWL 4 3...HEAD LIGHT SERVING AS INTERVENING OBJECT
47...HEAD PIPE STAY 10 54...PROJECTION
8 5...DOWN TUBE STAY

[Scope of Claims] 5 [Claim 1] A front cowl attaching structure in a motorcycle in which a front cowl (31) made of synthetic resin is placed in front of a head pipe (6), the front cowl (31) being supported by a body frame (5) including the head pipe (6) steerably bearing a front fork (12) , a main frame (7) extending rearward from the
10 head pipe (6), and a down tube (8) connected to the head pipe
(6) under the main frame (7) and extending downward toward a
rear, characterized in that the front cowl (31) includes an
outer cowl (38) and inner cowls (39) attached to an inner side
of the outer cowl (38), a rear portion of the outer cowl (38)
15 is attached to a fuel tank (23) mounted on the main frame (7), a front portion of the outer cowl (38) is supported by a head pipe stay (47) fixed to the head pipe (6) through an intervening object (43), and lower portions of the inner cowls (39) are fixed to a down tube stay (85) fixed to the down tube (8).
20 [Claim 2] The front cowl attaching structure in the motorcycle according to claim 1, characterized in that projections (54) extending rearward are provided in a head light (43) serving as the intervening object, and the front portion of the outer cowl (38) is fix_ed to the head light (43) attached to the head
25 pipe stay (47) by inserting the projections (54) into the head pipe stay (47) .

3. A front cowl attaching structure in a motorcycle substantially as hereinbefore described with reference to the accompanying drawings.
Dated this 26/ 12/2003


Documents:

1310-mum-2003-abstract(26-12-2003).doc

1310-mum-2003-abstract(26-12-2003).pdf

1310-MUM-2003-ABSTRACT(8-8-2011).pdf

1310-MUM-2003-ABSTRACT(GRANTED)-(26-3-2012).pdf

1310-MUM-2003-CANCELLED PAGES(8-8-2011).pdf

1310-mum-2003-claims(26-12-2003).doc

1310-mum-2003-claims(26-12-2003).pdf

1310-MUM-2003-CLAIMS(AMENDED)-(8-8-2011).pdf

1310-MUM-2003-CLAIMS(GRANTED)-(26-3-2012).pdf

1310-MUM-2003-CLAIMS(MARKED COPY)-(8-8-2011).pdf

1310-MUM-2003-CORRESPONDENCE(2-6-2009).pdf

1310-mum-2003-correspondence(30-11-2007).pdf

1310-MUM-2003-CORRESPONDENCE(IPO)-(26-3-2012).pdf

1310-mum-2003-correspondence(ipo)-(7-1-2004).pdf

1310-mum-2003-description(complete)-(26-12-2003).pdf

1310-MUM-2003-DESCRIPTION(GRANTED)-(26-3-2012).pdf

1310-mum-2003-drawing(26-12-2003).pdf

1310-MUM-2003-DRAWING(GRANTED)-(26-3-2012).pdf

1310-mum-2003-form 1(26-12-2003).pdf

1310-MUM-2003-FORM 1(8-8-2011).pdf

1310-mum-2003-form 13(2-6-2009).pdf

1310-mum-2003-form 18(30-11-2007).pdf

1310-mum-2003-form 2(26-12-2003).doc

1310-mum-2003-form 2(26-12-2003).pdf

1310-MUM-2003-FORM 2(GRANTED)-(26-3-2012).pdf

1310-mum-2003-form 2(title page)-(26-12-2003).pdf

1310-MUM-2003-FORM 2(TITLE PAGE)-(8-8-2011).pdf

1310-MUM-2003-FORM 2(TITLE PAGE)-(GRANTED)-(26-3-2012).pdf

1310-mum-2003-form 3(20-4-2004).pdf

1310-mum-2003-form 3(26-12-2003).pdf

1310-MUM-2003-FORM 3(8-8-2011).pdf

1310-mum-2003-form 5(26-12-2003).pdf

1310-MUM-2003-FORMAL DRAWING(30-6-2004).pdf

1310-MUM-2003-OTHER DOCUMENT(8-8-2011).pdf

1310-mum-2003-power of authority(30-6-2004).pdf

1310-MUM-2003-POWER OF AUTHORITY(8-8-2011).pdf

1310-MUM-2003-REPLY TO EXAMINATION REPORT(8-8-2011).pdf

1310-MUM-2003-SPECIFICATION(AMENDED)-(8-8-2011).pdf


Patent Number 251606
Indian Patent Application Number 1310/MUM/2003
PG Journal Number 13/2012
Publication Date 30-Mar-2012
Grant Date 26-Mar-2012
Date of Filing 26-Dec-2003
Name of Patentee HONDA MOTOR CO.,LTD.
Applicant Address 1-1,Minamiaoyama 2-chome, Minato-ku
Inventors:
# Inventor's Name Inventor's Address
1 MAMORU ISOMURA AND TOSHIO IGARASHI C/o Kabushiki Kaisha Honda Gijutsu Kenkyusho, 4-1,Chuo 1-chome,Wako-shi, Saitama
PCT International Classification Number B62J 17/02
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2003-002351 2003-01-08 Japan