JP2014162425A - Vehicle body frame for saddle-riding type vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique which allows cost reduction of a vehicle body frame of a saddle-riding type vehicle.SOLUTION: A vehicle frame 11 of a two-wheeled motor vehicle 10 includes a main frame 43 extending backward from a head pipe 21 and a seat rail 44 extending backward from the main frame 43. The main frame 43 is extended to the rear of the vehicle and then downward through a bent part 51, and the part extending downward serves as a pivot part 31 for supporting the front end of a swing arm 33. The seat rail 44 is connected to the bent part 51 through right and left gusset members 52R and 52L; a cross member 53 extending in the vehicle width direction is laid on the right and left gusset members 52R and 52L; and rear suspension 61 is laid on the cross member 53 and the swing arm 33.

Description

  The present invention relates to an improvement in a body frame of a saddle-ride type vehicle.

  2. Description of the Related Art A saddle-ride type vehicle is known in which a pivot portion that supports a rear wheel suspension portion that supports a rear wheel in a swingable manner is welded to an end portion of a main frame (for example, Patent Document 1 (FIG. 1, FIG. 1) See FIG. 2).

  As shown in FIG. 1 and FIG. 2 of Patent Document 1, the main frame (1) extending diagonally downward rearward of the vehicle (the numbers in parentheses indicate the reference numerals described in Patent Document 1. The element names are partially changed. The pivot frame (2) serving as a pivot part is welded to the rear end of the pivot frame (2), and left and right seat rails (3, 3) are extended from the upper end of the pivot frame (2). 3 and 3), the cross member (11) is passed.

  In the saddle-ride type vehicle of Patent Document 1, the main frame and the pivot frame are separate members and are connected by welding, so that the number of parts increases. In addition, the processing cost for connection increases. There is a need for a technology that reduces the cost of the body frame.

Japanese Utility Model Publication No. 4-81891

  An object of the present invention is to provide a technique capable of reducing the cost of a body frame of a saddle-ride type vehicle.

  The invention according to claim 1 is a vehicle body frame of a saddle-ride type vehicle comprising a head pipe, a main frame extending from the head pipe to the rear of the vehicle, and a seat rail extending from the main frame to the rear of the vehicle to support the seat. The main frame is composed of a pipe member, and this pipe member extends downward through a bent portion after extending rearward of the vehicle, and a portion extending downward is used as a pivot portion that supports the front end of the swing arm. Is connected to the bent portion via the left and right gusset members, a cross member extending in the vehicle width direction is passed to the left and right gusset members, and a rear suspension is passed to the cross member and the swing arm. And

  The invention according to claim 2 is characterized in that the seat rail has a first curved portion that bends up or down.

  The invention according to claim 3 has a welded portion where the gusset member is welded to the main frame and a non-welded portion which is not welded between the gusset member and the main frame in the portion where the gusset member contacts the main frame. .

  The invention according to claim 4 is characterized in that the seat rail has a second curved portion that bends upward or downward, which is different from the bending direction of the first curved portion.

  In the invention according to claim 5, the seat rail includes a left seat rail and a right seat rail, and the left and right seat rails have left and right first curved portions, respectively. A seat receiving portion for receiving a seat on which an occupant sits is passed.

  In the invention according to claim 6, the vehicle body frame further has a down frame extending obliquely downward and downward from the head pipe below the main frame, and an engine as a drive source is provided on the down frame and the pivot portion. Is suspended.

  In the invention according to claim 1, the main frame is integrally provided with a pivot portion formed by bending the pipe member. Since the pivot part is integrally formed by bending the pipe material of the main frame, the number of parts can be reduced. Further, the processing cost for connection can be reduced as compared with the case where the main frame and the pivot portion are separated and connected by welding.

  Furthermore, since the left and right gusset members are connected to the bent portion of the main frame, the bent portion of the main frame is reinforced by these left and right gusset members. As a result, the rigidity of the bent portion is increased. Furthermore, since the bent portion is disposed adjacent to the cross member, the rigidity of the bent portion can be further increased by the cross member.

  In the invention which concerns on Claim 2, a seat rail has the 1st curved part which bends up or down. A seat rail having a first curved portion that bends up or down in the height direction is easily bent at the first curved portion. When the input of the rear suspension is transmitted to the seat rail via the cross member and the gusset member, the seat rail is easily bent up and down as compared with the case where the first curved portion is not provided. As a result, the input from the rear suspension can be absorbed by the seat rail.

  In the invention which concerns on Claim 3, it has a non-welded part between a gusset member and a main frame. By this non-welded portion, the connection strength between the gusset member and the main frame can be lowered. By reducing the coupling strength, it is possible to make it difficult for vibration generated by a load input from the rear suspension to be transmitted to the main frame. As a result, the vibration generated by the load input from the rear suspension can be hardly transmitted to the main frame.

  In the invention which concerns on Claim 4, in addition to the 1st music part which bends up or down, the 2nd music part which bends up or down different from this 1st music part was formed in the seat rail. When the input of the rear suspension is transmitted to the seat rail by the second curved portion provided in addition to the first curved portion, the seat rail is more easily bent up and down. As a result, vibration from the rear suspension can be further absorbed by the seat rail.

  In the invention which concerns on Claim 5, the sheet | seat receiving part is passed between the 1st music parts on either side. Since the seat receiving portion receives the seat and also serves as reinforcement between the left and right first curved portions, it is possible to increase the torsional rigidity of the vehicle body frame while suppressing an increase in the number of parts.

  In the invention according to claim 6, the engine is suspended from the pivot portion and the down frame. When the engine is not suspended from the main frame, the vibration of the engine is not easily transmitted to the main frame. Since the engine is not suspended from the main frame, the load applied to the main frame can be reduced. In addition, since no engine hanger is required in the main frame, the body frame can be simplified.

1 is a left side view of a motorcycle according to the present invention. FIG. 2 is an enlarged view of a main part of FIG. 1 (a state where a cowl member is removed). Fig. 2 is a plan view of a main part of the motorcycle (with the air cleaner removed). It is a top view of a body frame. It is a side view explaining the structure of a cross member and its peripheral part. It is sectional drawing of the sheet | seat receiving part which concerns on an Example and a comparative example. It is action explanatory drawing when a swing arm swings. It is a figure explaining the structure and arrangement | positioning of the cross member which concern on an Example and a comparative example. It is a figure explaining the structure etc. of the cross member which concerns on a modification. It is a structure figure and action explanatory view of a seat rail concerning a comparative example and an example. It is a figure explaining the mount structure of the engine which concerns on an Example and a comparative example.

  Hereinafter, embodiments of the present invention will be described in detail. In the drawings and examples, “up”, “down”, “front”, “rear”, “left”, and “right” respectively indicate directions viewed from the driver who rides the motorcycle.

Embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a motorcycle 10 includes a vehicle body frame 11, a front wheel steering unit 15 that is provided at a front portion of the vehicle body frame 11 and supports a front wheel 13 so as to be steerable, and a longitudinal intermediate portion of the vehicle body frame 11. The rear wheel suspension device 16 is provided so as to extend from the lower part in the height direction to the rear of the vehicle and swingably supports the rear wheel 14, and the drive provided between the front wheel 13 and the rear wheel 14 and suspended on the vehicle body frame 11. An engine 17 as a source, a fuel tank 18 attached to the vehicle body frame 11 above the engine 17, and a seat 19 which is disposed behind the fuel tank 18 and is attached to the vehicle body frame 11 and seats an occupant. This is a saddle-ride type vehicle in which an occupant rides on the seat 19.

  The front wheel steering section 15 is provided integrally with the steering shaft 22 and the steering shaft 22 inserted into the head pipe 21 provided at the front end of the vehicle body frame 11, the upper end of the steering shaft 22, and the vehicle obliquely. A main element is a front fork 24 that extends forward and downward, and a front wheel 13 that is attached to the lower end of the front fork 24. A front fender 25 is attached to the front fork 24 so as to cover the upper part of the front wheel 13.

  The rear wheel suspension device 16 includes a swing arm 33 extending rearward from a pivot shaft 32 provided in the pivot portion 31 of the vehicle body frame 11, a rear wheel 14 attached to a rear end 33b of the swing arm 33, and a swing arm. 33 and the rear suspension unit 34 passed between the vehicle body frames 11 are main elements. A side stand 35 is attached to the lower end of the pivot portion 31.

  A front cowl 36 and a headlight 41 that is surrounded by the front cowl 36 and faces the front of the vehicle are attached to the upper part of the front wheel steering unit 15, and the vehicle body frame 11 covers the side of the vehicle body behind the front cowl 36. Side cowls 37, 38, 39 are attached in this order from front to back.

  As shown in FIG. 2, the vehicle body frame 11 includes a head pipe 21, a main frame 43 extending from the head pipe 21 toward the rear of the vehicle, and a seat rail 44 (seat for supporting the seat 19) extending from the main frame 43 toward the rear of the vehicle. Frame 44.), a support frame 45 passed between the seat rail 44 and the main frame 43, a down frame 46 extending obliquely downward and downward from the head pipe 21 below the main frame 43, Reinforcing members 47 and 48 are provided between the down frame 46 and the main frame 43.

  The main frame 43 is composed of a pipe member. The pipe member extends rearward of the vehicle and then extends downward via a bent portion 51. A portion extending downward includes a pivot portion 31 that supports the front end of the swing arm 33. Is done.

  A gusset member 52 having a substantially triangular shape in a side view of the vehicle is welded to the bent portion 51, and the seat rail 44 extends from the gusset member 52 to the rear of the vehicle. A cross member 53 extending in the vehicle width direction is attached to the gusset member 52.

  The cross member 53 is provided with a suspension support portion 64 that supports one end 62 of the rear suspension 61. One end 62 of the rear suspension 61 is connected to the suspension support portion 64, and the rear wheel 14 is connected to the other end 63 of the rear suspension 61. A swing arm 33 is connected to support the swinging mechanism. A rear suspension 61 that absorbs an impact applied to the rear wheel 14 is passed to the swing arm 33 and the cross member 53.

Next, the configuration of the engine will be described.
The engine 17 includes a crankcase 71 and a cylinder portion 72 attached to the upper surface 71a of the crankcase 71, and a connecting tube 104 constituting an intake system 77 is connected to a rear wall 74 of the cylinder portion 72. An exhaust pipe 106 constituting an exhaust system 76 extends from the front wall 73 of 72. The engine 17 is suspended from the down frame 46 and the pivot portion 31. Details of the suspension structure of the engine 17 will be described later.

  A drive shaft 82 is provided at the rear portion 81 of the crankcase 71, a drive gear 83 is attached to the drive shaft 82, a sprocket 84 is attached to the rear wheel 14, and a drive chain 85 is wound between the sprocket 84 and the drive gear 83. The driving force of the engine 17 is transmitted to the rear wheel 14. A shift shaft 86 for shift change extends from the rear portion 81 of the crankcase 71 below the drive shaft 82, and a change pedal 88 is connected to the shift shaft 86 via a link mechanism 87.

Next, the structure of the seat rail will be described.
The seat rail 44 connected to the gusset member 52 as the connecting portion and extending rearward of the vehicle has a first curved portion 91 that bends upward, and the first curved portion 91 is located at the vehicle rearward position of the first curved portion 91. A second bent portion 92 that bends downward different from the bending direction. The first music part may be bent downward and the second music part may be bent upward.

Next, the point etc. which the main frame 43, the gusset member 52, the seat rail 44, and the support frame 45 are provided in the vehicle width direction right and left are demonstrated.
As shown in FIG. 3, the main frame 43 has a left main frame 43L provided on the left side in the vehicle width direction and a right main frame 43R provided on the right side in the vehicle width direction. The left and right gusset members 52L and 52R are joined to the bent portions 51L and 51R of the left and right main frames 43L and 43R, respectively, and the left and right seat rails 44L and 44R are connected to the rear of the vehicle from the left and right gusset members 52L and 52R. It extends to. That is, the seat rails 44L and 44R are connected to the bent portions 51L and 51R via the left and right gusset members 52L and 52R. Cross members 53 extending in the vehicle width direction are passed to the left and right gusset members 52L and 52R. The left and right seat rails 44L and 44R are connected to the left and right bent portions 51L and 51R via the left and right gusset members 52L and 52R.

  In addition, a seat receiving portion 94 that receives the seat 19 (see FIG. 2) is provided between the left and right seat rails 44L and 44R, and a rear cross plate 95 is provided behind the seat receiving portion 94.

Next, the intake system of the engine 17 will be described.
Referring also to FIG. 2, the intake system 77 includes an air cleaner 101, an intake duct 102 that extends forward from the air cleaner 101, and a throttle body to which the tip of the intake duct 102 is connected in front of the intake duct 102. 103 and a connecting tube 104 extending from the throttle body 103 to the front of the vehicle and connected to the rear wall 74 of the cylinder portion 72 are main elements.

  An intake duct 102, which is an element of the intake passage 105 that supplies intake air to the engine 17, is disposed above the cross member 53 from the rear to the front of the cross member 53. A resonator 109 is connected to the intake duct 102.

  The exhaust system 76 extends obliquely downward from the front wall 73 of the cylinder portion 72 and then changes its direction, and is connected to an exhaust pipe 106 that extends rearward of the vehicle below the crankcase 71 and the tip of the exhaust pipe 106. And a muffler 107 extending rearward of the vehicle.

  Steps 116L and 116R are provided on the pivot portions 31L and 31R so as to protrude from the left and right in the vehicle width direction and on which the occupant puts their feet. A brake pedal 117 is disposed in front of the vehicle in the right step 116R.

  As shown in FIG. 4, the vehicle body frame 11 includes a head pipe 21, a pair of left and right frames 110L and 110R attached to the head pipe 21, and a cross member 53 that connects the pair of left and right frames 110L and 110R. It can be said that it is composed.

  In this case, the pair of left and right frames 110L and 110R are extended from the head pipe 21 to the left and right in the vehicle width direction and extend rearward from the left and right main frames 43L and 43R, and from the left and right main frames 43L and 43R. Left and right pivot frames (left and right pivot portions 31L and 31R) that extend downward and support the swing arm 33 (see FIG. 3) are provided.

  Here, the axial length (L1) of the cross member 53 extending in the vehicle width direction is narrower than the distance (L2) between the left and right pivot portions 31L and 31R (L1 <L2). Since the axial length (L1) of the cross member 53 is shorter than the distance (L2) between the left and right pivot portions 31L and 31R, the bending of the cross member 53 can be suppressed to a smaller extent.

  In FIG. 2, the fuel filter 55 is disposed between the left and right main frames 43 </ b> L and 43 </ b> R along the lower surface 54 of the cross member 53. The fuel filter 55 is a secondary fuel filter interposed in the middle of a pipe (not shown) connecting between the fuel tank 18 and the throttle body 103. Since the fuel filter 55 is disposed in a space below the cross member 53 that tends to become a dead space, a limited space in the motorcycle can be effectively utilized.

Next, the structure of the gusset member 52 as the connecting portion 113 for connecting the seat rail 44 and the main frame 43 and the peripheral portion thereof will be described. As shown in FIG. The pipe member 112 includes a bent portion 51 bent downward and a pivot portion 31 extending downward from the bent portion 51. A gusset member 52 to which the seat rail 44 is connected is welded to the bent portion 51.

  Referring also to FIG. 4, the connecting portion 113 is composed of left and right gusset members 52L and 52R, and main frames 43L and 43R and seat rails 44L and 44R are connected to the left and right gusset members 52L and 52R, respectively. Is done. The left and right gusset members 52L and 52R are connected by a cross member 53 extending in the vehicle width direction, and a suspension support portion 64, which is a separate member, extends obliquely rearward and downward from the cross member 53. The upper end (one end 62) of the suspension 61 is connected. The suspension support portion 64 is a bracket 114 connected to the cross member 53.

  In FIG. 5, the cross member 53 includes a non-circular pipe having a major axis 126 having a cross section of a diameter D <b> 1 and a minor axis 125 having a diameter D <b> 2 shorter than the major axis 126. In this embodiment, the cross member 53 is a pipe member having an oval cross section. When a line passing through the minor axis 125 is a minor axis 121 and a line extending perpendicularly to the minor axis 121 and passes through the major axis 126 is a major axis 122, the rear suspension axis A is the minor axis 121 of the cross member. And at the point P. The cross member 53 is arranged in a direction in which the major axis 122 is substantially horizontal.

  Of the portion where the gusset member 52 abuts the main frame 43, a welded portion 124 between which the gusset member 52 is welded to the main frame 43 and the gusset member 52 is welded to the main frame 43. A non-welded part 123 is provided.

  The center 53C of the cross member 53 and the axis A of the rear suspension 61 passing through the upper end (one end 62) of the rear suspension 61 are separated by a distance δ within a range in which the rear suspension 61 swings. Since the center 53C of the cross member 53 and the axis A of the rear suspension 61 are separated by a distance δ, when the force is applied to the upper end of the rear suspension 61, the cross member 53 has a center 53C of the cross member 53. You will receive a torsional moment.

The operation of the body frame of the saddle-ride type vehicle described above will be described next.
4 and 5, pivot portions 31L and 31R formed by bending pipe members are integrally provided on the main frames 43L and 43R. Since the pivot portions 31L and 31R are formed by bending the pipe material of the main frames 43L and 43R, the number of parts can be reduced. In addition, the processing cost for connection can be reduced.

  Further, since the left and right gusset members 52L and 52R are connected to the bent portions 51L and 51R of the main frames 43L and 43R, the bent portions 51L and 51R of the main frames 43L and 43R are connected by the left and right gusset members 52L and 52R. Reinforced. As a result, the rigidity of the bent portions 51L and 51R increases. Further, bent portions 51 </ b> L and 51 </ b> R are disposed adjacent to the cross member 53. The cross member 53 can further increase the rigidity of the bent portions 51L and 51R.

  Non-welded portions 123L and 123R are provided between the gusset members 52L and 52R and the main frames 43L and 43R. The connection strength between the gusset members 52L and 52R and the main frames 43L and 43R can be reduced by the non-welded portions 123L and 123R. By reducing the coupling strength, it is possible to make it difficult for vibration generated by the load input from the rear suspension 61 to be transmitted to the main frames 43L and 43R. As a result, vehicle vibration can be reduced.

  Further, the center 53C of the cross member 53 and the axis A of the rear suspension 61 are separated by a distance δ. In such a case, when the cross member 53 has a circular cross section and has a short outer diameter D2, an allowable torsional moment may be reduced. On the contrary, if the cross member 53 has a circular cross section and has a long outer diameter D1, an allowable torsional moment can be increased, but the weight of the cross member 53 is increased.

  In this regard, in the present invention, the cross member 53 is prevented from increasing in outer diameter and weight, while increasing the outer diameter of the cross member 53 or increasing the plate thickness in order to exhibit the same torsional rigidity. The torsional rigidity of the member 53 can be increased.

Next, the structure of the sheet receiving portion that receives the sheet will be described. FIG. 6A is a cross-sectional view of the sheet receiving portion according to the embodiment, and FIG. 6B is a cross-sectional view of the sheet receiving portion according to the comparative example.
In the embodiment of FIG. 6A, the seat rail 44 includes a left seat rail 44L and a right seat rail 44R, and the left and right seat rails 44L and 44R are respectively the first left and right curved portions 91L and 91R. Have Between the left and right seat rails 44L, 44R at the left and right first curved portions 91L, 91R, a seat receiving portion 94 for receiving the seat 19 (see FIG. 2) on which an occupant sits is passed. The seat 19 receives the seat 19 and serves as a reinforcement between the left and right first curved portions 91L and 91R. Therefore, the torsional rigidity of the body frame 11 can be increased while suppressing an increase in the number of parts. .

  The seat receiving portion 94 has a U-shape with a cross section opened downward, and is passed between the left and right seat rails 44L and 44R. On the other hand, in the comparative example of FIG. 6B, the seat receiving portion 94B has a U shape with a cross section opened upward, and is passed between the left and right seat rails 44L and 44R.

When the sheet receiving portion 94 is passed to the position of the first curved portion 91 on the premise of a member having the same material and the same plate thickness, the structure of FIG. 6A and FIG. It becomes like this.
As shown in FIG. 6 (b), the cross section of FIG. 6 (a) is opened downward as compared with the structure that is formed between the left and right seat rails 44L and 44R. The U-shaped structure that passes between the left and right seat rails 44L, 44R bends to the first curved portions 91L, 91R when different forces are applied to the left and right seat rails 44L, 44R. It is easy to allow the occurrence of Therefore, by appropriately setting the material and the plate thickness of the seat receiving portion 94, it is possible to give the vehicle body frame 11 a predetermined torsional rigidity while giving the vehicle body frame 11 bending characteristics at the first curved portions 91L and 91R.

  In FIG. 6A, a sheet receiving portion 94 is passed between the left and right first music portions 91L and 91R. Since the sheet receiving portion 94 also serves as a reinforcement between the left and right first curved portions 91L and 91R, the number of parts is larger than when the first curved portions 91L and 91R and the sheet receiving portion 94 are configured as separate members. The torsional rigidity of the vehicle body frame 11 can be increased while suppressing the increase of.

Next, the operation when the swing arm 33 swings will be described.
FIG. 7A is an operation diagram when the swing arm 33 receives an impact from the road surface and swings counterclockwise around the pivot shaft 32. FIG. FIG. 5 is an operation diagram when the load from the road surface is released and the pivot shaft 32 swings around the pivot shaft 32 in the clockwise direction.

  In FIG. 7A, when an upward force is applied to the rear wheel 14 (see FIG. 1), the swing arm 33 swings counterclockwise upward about the pivot shaft 32. At this time, the rear suspension 61 contracts in the axial direction and absorbs the upward force.

  An upward force is applied to the axis A of the rear suspension in a stationary state, and the axis Aa of the rear suspension when the suspension contracts is an angle θa counterclockwise about the upper fulcrum (upper end) 62 of the rear suspension 61. Just move. At this time, the axis Aa of the rear suspension 61 passes on the oval pipe or in the pipe as viewed from the side of the vehicle.

  In FIG. 7B, when a downward force is applied to the rear wheel 14, the swing arm 33 swings clockwise around the pivot shaft 32. At this time, the rear suspension 61 extends in the axial direction and absorbs downward force. A downward force is applied to the axis A of the rear suspension in a stationary state, and the axis Ab of the rear suspension when the rear suspension 61 extends is an angle θb clockwise about the upper end (one end 62) of the rear suspension 61. Just move. At this time, similarly to FIG. 7A, the axis Ab of the rear suspension 61 passes on the oval pipe or in the pipe as viewed from the side of the vehicle.

Next, it will be described that the size and weight of the cross member can be suppressed by the cross-sectional shape and the arrangement of the cross member.
8A is a diagram illustrating the structure and arrangement of the cross member according to the embodiment, and FIG. 8B is a diagram illustrating the structure and arrangement of the cross member according to the comparative example 1. FIG. 8C illustrates the structure and arrangement of the cross member according to Comparative Example 2.

  As shown in Comparative Example 1 in FIG. 8B, conventionally, when the cross member 53B has a circular cross section, in order to increase the load resistance received from the rear suspension 61, the outer diameter of the cross member 53B is increased. It is possible to do. Then, the outer diameter 125B (outer diameter Db) of the cross member 53B is larger than the outer diameter D2 of the short diameter 125 of the cross member 53 of the embodiment (D2 <Db), which may lead to an increase in the weight of the vehicle body frame 11. There is sex. In addition, the height of the cross member 53B may increase.

  As shown in the embodiment of FIG. 8A, in the present invention, the cross member 53 is a non-circular cross-sectional oval pipe, and the short axis 121 of the cross member 53 and the axis A of the rear suspension 61 intersect. The cross member 53 was arranged so as to. That is, the minor axis 121 of the cross member 53 and the axis A of the rear suspension 61 are arranged non-parallel.

  Since the cross member 53 is arranged so that the minor axis 121 of the cross member and the axis A of the cross member are not parallel, the cross member 53B is a circular tube having a circular cross section as shown in FIG. Compared to the above, the enlargement of the cross member 53 can be suppressed.

  Therefore, according to the present invention, the outer diameter of the cross member 53 and the increase in the weight of the cross member 53 are suppressed as compared with the case where the outer diameter of the cross member 53 is increased or the plate thickness is increased in order to exhibit the same bending rigidity. The load resistance of the cross member 53 can be increased.

  Next, even when the cross member is a pipe having an oval cross section, if the cross member 53 is disposed so that the minor axis of the cross member faces in parallel to the axis A of the rear suspension, the load resistance received from the rear suspension 61 is not necessarily limited. Explain that it cannot be raised sufficiently.

  As shown in FIG. 8C, when the short axis 121 of the cross member is arranged parallel to the axis A of the rear suspension, compared to the case where the short axis 121 of the cross member is arranged non-parallel to the short axis 121 of the cross member. The load resistance that can be received from the rear suspension 61 is reduced.

  In FIG. 8A, in the present invention, the minor axis 121 of the cross member is disposed non-parallel to the axis A of the rear suspension 61, so that the minor axis 121 of the cross member 53 corresponds to the rear suspension 61. The load resistance can be increased compared to a case where the load is arranged parallel to the axis A.

Referring also to FIG. 5, the axis A of the rear suspension 61 when the rear suspension 61 contracts passes over an oval pipe.
In the structure of the present invention, the center 53C of the cross member 53 and the rear suspension axis A are separated by a distance δ. For this reason, a torsional moment is applied around the center 53C of the cross member 53. Assuming that the axis A of the rear suspension is separated from the center 53C of the cross member 53 and is removed from the top of the oval pipe, the length of the bracket 114 becomes longer, and a larger moment is applied to the bracket 114. It becomes easy.

  In the present invention, since the axis A of the rear suspension passes on the oval pipe, the bracket 114 can be shortened and the moment applied to the bracket 114 can be reduced. In addition, the weight of the bracket 114 can be reduced. Note that the axis A of the rear suspension may pass through the pipe, and in that case, the same effects as described above are achieved.

Further, the cross member 53 is arranged so that the major axis 122 of the cross member is in a substantially horizontal orientation.
In a saddle-ride type vehicle that does not have a link mechanism between the swing arm and the rear suspension, the height of the cross member is desired to be kept small in order to increase the stroke of the rear suspension.

  In the present invention, since the cross member 53 is arranged so that the major axis 122 of the cross member 53 is substantially horizontal, the height of the cross member 53 can be reduced while increasing the stroke of the rear suspension 61. Can do.

  Referring also to FIG. 2, the cross member 53 is disposed in a direction in which the major axis is substantially horizontal, and a suspension support portion (bracket 114) is disposed so as to extend below the cross member. Since the cross member 53 is arranged so that the long axis 122 extends substantially in the horizontal direction, even when the intake passage 105 is arranged above the cross member 53, the amount by which the intake passage 105 protrudes upward is kept small. It is done. As a result, the height of the vehicle can be kept low.

Next, the structure of a cross member according to another embodiment will be described.
As shown in FIG. 9, the cross member is a non-circular cross-sectional oval pipe, and the cross member is arranged so that the major axis of the cross member is along the axis of the rear suspension. Specifically, the cross member 53 is arranged so that the major axis 122 of the cross member 53 and the axis A of the rear suspension 61 are parallel when the vehicle is stationary.

  When the rear suspension 61 contracts or extends, the major axis 122 of the cross member 53 and the axis A of the rear suspension 61 are not parallel. However, the angle θ between the major axis 122 of the cross member 53 and the axis A of the rear suspension 61 is within ± 10 ° at most. Accordingly, the cross member 53 is arranged and passed to the left and right gusset members 52L and 52R so that the axis A of the rear suspension 61 is positioned along the major axis 122 of the cross member 53. In addition, the axis A of the rear suspension 61 is arranged so as to pass over or inside the oval pipe.

Next, the case where a curved part is formed in a seat rail is demonstrated.
FIG. 10A is a side view of the rear part of the vehicle body frame including the seat rail according to the comparative example, and FIG. 10B is a side view of the rear part of the vehicle body frame including the seat rail having the curved portion according to the first embodiment. FIG. 10C is a side view of the rear portion of the vehicle body frame including the seat rail having the curved portion according to the second embodiment. In the following description, the operation of the seat rail on the right side in the vehicle width direction has been described, but the operation of the seat rail on the left side in the vehicle width direction is the same, and the description is omitted.

As shown in the comparative example of FIG. 10A, the seat rail 44AR extending rearward from the gusset member 52R welded to the main frame 43R has no curved portion and extends substantially linearly.
As shown in Example 1 in FIG. 10B, the seat rail 44BR has a first curved portion 91BR that bends upward. The seat rail 44BR having the first curved portion 91BR that bends in the height direction has a structure that is easily bent by the first curved portion 91BR. Specifically, when the input of the rear suspension 61 (see FIG. 9) is transmitted to the seat rail 44BR via the cross member 53 and the gusset member 52R, the seat rail 44BR is compared with the case where the first curved portion is not provided. Becomes easy to bend up and down. As a result, the swing of the rear wheel can be absorbed by the seat rail 44BR.

  As shown in Example 2 in FIG. 10C, in addition to the first music part 91CR that bends upward, a second music part 92CR that bends downward differently from the first music part 91CR is used as a vehicle of the first music part 91CR. The seat rail 44CR was formed at the rear. When the input of the rear suspension 61 is transmitted to the seat rail 44CR by the second curved portion 92CR provided in addition to the first curved portion 91CR, the seat rail 44CR is more easily bent up and down. As a result, vibration from the rear suspension 61 can be further absorbed by the seat rail 44CR.

Next, the engine suspension part provided in the vehicle body frame will be described.
FIG. 11A is a diagram illustrating an engine mounting structure according to the embodiment, and FIG. 11B is a diagram illustrating an engine mounting structure according to a comparative example.

  As shown in the embodiment of FIG. 11A, the engine 17 has a front upper portion of the crankcase 71 attached to the lower end 46b of the down frame 46, and a rear upper portion and a rear lower portion of the crankcase 71 attached to the pivot portion 31. It is attached to the pivot part 31 via the engine stay. However, the engine 17 is not attached to the main frame 43.

  As shown in the comparative example of FIG. 11B, the engine 17 has a front upper portion of the crankcase 71 attached to the lower end 46 b of the down frame 46, and a rear upper portion and a rear lower portion of the crankcase 71 attached to the pivot portion 31. It is attached to the pivot portion 31 via the first engine stay 131 and the second engine stay 132 and attached to the third engine stay 133 attached to the main frame 43.

  In FIG. 11A, when the engine is not attached to the main frame (not suspended), the vibration of the engine 17 is hardly transmitted to the main frame 43. Further, the load applied to the main frame 43 can be reduced. Furthermore, since it is not necessary to attach an engine stay to the main frame 43, the vehicle body frame 11 can be simplified.

  Although the present invention has been applied to saddle riding type motorcycles in the embodiments, it can also be applied to saddle riding type tricycles, and can be applied to general saddle riding type vehicles.

  The present invention is suitable for motorcycles.

  DESCRIPTION OF SYMBOLS 10 ... Saddle-ride type vehicle (motorcycle), 11 ... Body frame, 17 ... Engine, 19 ... Seat, 21 ... Head pipe, 31R ... Left and right pivot part, 33 ... Swing arm, 34 ... Rear suspension (rear suspension unit) 43L, 43R ... left and right main frames, 44L, 44R ... left and right seat rails, 46L, 46R ... left and right down frames, 51L, 51R ... left and right bent parts, 52L, 52R ... left and right gusset members, 53 ... cross members 91L, 91R ... left and right first music parts, 92L, 92R ... left and right second music parts, 94 ... sheet receiving parts, 123L, 123R ... left and right non-welded parts, 124L, 124R ... left and right welded parts.

Claims (6)

A head pipe (21), a main frame (43L, 43R) extending from the head pipe (21) to the rear of the vehicle, and a seat rail extending from the main frame (43L, 43R) to the rear of the vehicle to support the seat (19) ( 44L, 44R) in a body frame of a saddle-ride type vehicle,
The main frame (43L, 43R) is formed of a pipe member. The pipe member extends to the rear of the vehicle and then extends downward via bent portions (51L, 51R). Pivot portions (31L, 31R) that support the front end of the arm (33),
The seat rails (44L, 44R) are connected to the bent portions (51L, 51R) via left and right gusset members (52L, 52R),
Cross members (53) extending in the vehicle width direction are passed to the left and right gusset members (52L, 52R),
A body frame of a saddle-ride type vehicle, wherein a rear suspension (34) is passed between the cross member (53) and the swing arm (33).   The body frame of the saddle-ride type vehicle according to claim 1, wherein the seat rail (44L, 44R) has a first curved portion (91L, 91R) that bends up or down.   Of the portion where the gusset member (52L, 52R) abuts on the main frame (43L, 43R), the gusset member (52L) is interposed between the gusset member (52L, 52R) and the main frame (43L, 43R). 52R) has a welded portion (124L, 124R) welded to the main frame (43L, 43R) and a non-welded portion (123L, 123R) that is not welded. Body frame of saddle riding type vehicle as described.   The seat rail (44L, 44R) has a second curved portion (92L, 92R) that bends upward or downward different from a bending direction of the first curved portion (91L, 91R). Body frame of saddle riding type vehicle as described. The seat rail (44L, 44R) includes a left seat rail (44L, 44R) and a right seat rail (44L, 44R),
Each of the left and right seat rails (44L, 44R) has left and right first curved portions (91L, 91R),
The seat receiving portion (94) for receiving the seat (19) on which an occupant sits is passed between the left and right first curved portions (91L, 91R). Item 5. A body frame of a saddle-ride type vehicle according to Item 4. The vehicle body frame (11) further includes a down frame (46L, 46R) extending obliquely rearward and downward from the head pipe (21) below the main frame (43L, 43R),
The body frame of the saddle-ride type vehicle according to claim 5, wherein an engine (17) as a drive source is suspended between the down frame (46L, 46R) and the pivot portion (31L, 31R). .

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