CN110914142A

CN110914142A - Vehicle body frame structure

Info

Publication number: CN110914142A
Application number: CN201880047358.6A
Authority: CN
Inventors: 井口贵正; 高桥伸也
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2017-07-20
Filing date: 2018-06-06
Publication date: 2020-03-24
Anticipated expiration: 2038-06-06
Also published as: PH12020500097A1; JPWO2019017102A1; JP6739650B2; CN110914142B; WO2019017102A1; BR112020000404B1; BR112020000404A2

Abstract

The vehicle body frame structure is provided with a head pipe (21), a main frame (22) extending to the rear of the head pipe (21), and a seat rail (30) extending to the rear of the main frame (22), wherein at least one of the main frame (22) and the seat rail (30) has a curved portion (37) curved when viewed from a first direction, and is formed by combining a plurality of press frame bodies (45I, 45O), the plurality of press frame bodies (45I, 45O) have a bulging portion (45bs) forming a closed cross-sectional structure (30cs) when combined with each other, a joint portion (sp) joining the plurality of press frame bodies (45I, 45O) to each other is provided to a joint flange (45e) extending from the bulging portion (45bs) of the joined press frame bodies (45I, 45O), and a plate bending portion (45e5) standing on the bulging portion (45bs) from a base end of the joint flange (45e) to the joint portion (45e5) (sp) is longer at the bent portion (37) than a normal portion of the frame other than the bent portion (37).

Description

Vehicle body frame structure

Technical Field

The present invention relates to a vehicle body frame structure.

The present application claims priority based on application No. 2017-141151 filed on the sun in 2017, month 07, and 20, the contents of which are incorporated herein by reference.

Background

Conventionally, in a vehicle body frame structure of a motorcycle, there is a technique of using a press frame as a frame constituent member and combining the press frame by welding (for example, see patent document 1).

Prior art documents

Patent document

Patent document 1: japanese laid-open patent publication No. 2015-189426

Disclosure of Invention

Summary of The Invention

Problems to be solved by the invention

However, in the above vehicle body frame structure, stress concentration to the welding portion in the frame bent portion is a problem, and an influence of strain from the plate bent portion of the stress concentration portion to the welding portion is a problem.

Therefore, an object of the present invention is to suppress the influence of strain from a plate bending portion to a welding portion in a vehicle body frame structure using a press frame.

Means for solving the problems

In order to solve the above problem, the present invention has the following configuration.

(1) A vehicle body frame structure according to an aspect of the present invention includes: a head pipe; a main frame extending rearward of the head pipe; and a seat rail extending rearward of the main frame, at least one of the main frame and the seat rail having a curved portion that curves downward when viewed from a first direction and formed by a combination of a plurality of press frame bodies, the plurality of press frame bodies having a bulging portion that forms a closed cross-sectional structure when combined with each other, a joint portion at which the plurality of press frame bodies are joined to each other being provided at a joint flange extending from the bulging portion of the joined press frame bodies, a distance from a plate bending portion at a base end of the joint flange that makes the bulging portion stand up to the joint portion being longer at the curved portion than a frame normal portion other than the curved portion.

(2) In the vehicle body frame structure according to the above (1), the bent portion may be increased in thickness with respect to the frame normal portion in a second direction intersecting the first direction.

(3) In the vehicle body frame structure according to the above (2), the bent portion may be bent as viewed from a third direction intersecting the first direction and the second direction.

(4) In the vehicle body frame structure according to any one of the above (1) to (3), at least one of the main frame and the seat rail may have the curved portion, and a cross-sectional reduced portion that reduces a cross-sectional shape of the frame may be provided around the curved portion.

Effects of the invention

According to the vehicle body frame structure described in the above (1) of the present invention, in the frame having the bent portion that is bent when viewed from the first direction, stress is likely to concentrate at the bent portion when a load is applied to the frame. In particular, the bent portion of the plate in the bent portion is easily deformed. In contrast, by separating the joint portion in the bent portion of the frame from the plate bent portion and extending the distance from the plate bent portion to the joint portion, the influence of the deformation generated in the plate bent portion on the joint portion can be suppressed.

According to the vehicle body frame structure described in the above (2) of the present invention, the rigidity of the bent portion can be increased to suppress deformation.

According to the vehicle body frame structure described in the above (3) of the present invention, since the bending portion of the frame is further required to have rigidity, the effect of increasing the thickness of the bending portion is improved.

According to the vehicle body frame structure described in the above (4), when a load is input to the frame, the stress is dispersed by the reduced cross-section portion provided around the bent portion, and the reduced cross-section portion deforms favorably together with the bent portion, whereby the load on the joint portion of the bent portion can be suppressed.

Drawings

Fig. 1 is a left side view of a motorcycle according to an embodiment of the present invention.

Fig. 2 is a left side view of the body frame of the motorcycle.

Fig. 3 is a plan view of the vehicle body frame.

Fig. 4 is a left side view showing a main part of the seat rail of the vehicle body frame.

Fig. 5 is a V-V sectional view of fig. 4.

Fig. 6 is a perspective view of a partial section including the seat rail described above.

Fig. 7 is a plan view of the periphery of the seat rail.

Fig. 8 is a left side view of the periphery of the connection portion between the main frame and the pivot frame of the vehicle body frame.

Fig. 9 is a cross-sectional view IX-IX of fig. 8.

Fig. 10 is a perspective view of the periphery of the connecting portion as viewed from the front side.

Fig. 11 is a rear perspective view of the periphery of the connecting portion.

Fig. 12 is a plan view of the periphery of the cross member of the seat rail.

Fig. 13 is a perspective view of the periphery of the cross member.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. The directions such as front, rear, left, right, and the like in the following description are the same as those in the following description of the vehicle unless otherwise noted. In the drawings used in the following description, arrow FR indicating the front of the vehicle, arrow LH indicating the left of the vehicle, arrow UP indicating the upper side of the vehicle, and line CL indicating the left-right center of the vehicle body are shown at appropriate positions.

As shown in fig. 1, the present embodiment is applied to a motorcycle 1 as a saddle-ride type vehicle. The front wheel 2 of the motorcycle 1 is supported by the lower end portions of a pair of right and left front forks 3. The upper portions of the left and right front forks 3 are supported by a head pipe 21 at the front end portion of the vehicle body frame 20 via a steering rod 4. A steering handle 6 for steering is attached to an upper portion of the steering rod 4.

The rear wheel 7 of the motorcycle 1 is supported by the rear end of the swing arm 8. The front end of the swing arm 8 is supported by a pivot pipe 25 at the front-rear middle portion of the vehicle body frame 20. The term "intermediate" used in the present embodiment refers not only to the center between both ends of the object but also to the inner range between both ends of the object.

The rear wheel 7 is connected to an engine 10, which is a prime mover of the motorcycle 1, via a chain transmission mechanism 7a disposed on the left side of the rear portion of the vehicle body, for example. Lower ends of a pair of left and right rear shock absorbers 9 are connected to rear portions of left and right arms of the swing arm 8.

Engine 10 is mounted on vehicle body frame 20. The engine 10 has a cylinder 12 standing upward toward the front of a crankcase 11.

An intake passage 13 is connected to a rear portion of the cylinder 12. An exhaust pipe 14 is connected to a front portion of the cylinder 12. The exhaust pipe 14 extends rearward from the front and lower sides of the engine 10, and is connected to an exhaust muffler (not shown) disposed on the right side of the rear portion of the vehicle body, for example.

A fuel tank 15 for storing fuel of the engine 10 is disposed above the engine 10. A seat 16 on which a driver and a rear passenger sit is disposed behind the fuel tank 15. A pair of left and right main steps 17 for putting the driver's feet thereon and a pair of left and right rear seat steps 18 for putting the rear fellow passenger thereon are disposed on both sides of the lower portion of the vehicle body.

Referring to fig. 2 and 3, the body frame 20 is formed by integrally joining a plurality of steel materials by welding or the like.

The vehicle body frame 20 includes a head pipe 21, a single main frame 22 extending rearward and downward along the vehicle body left-right center rearward of the head pipe 21, and a pivot frame 23 joined to a rear lower end portion 48 of the main frame 22 and extending in the vertical direction.

The main frame 22 extends rearward from the head pipe 21 in a side view so as to narrow the vertical width toward the rear. The main frame 22 has a front half portion slightly expanded laterally outward in a plan view, and then extends rearward with a substantially uniform lateral width. The main frame 22 is integrally curved toward the rear lower side in a side view. The front portion of the main frame 22 is curved relatively gently, whereas the rear portion of the main frame 22 is curved with an enhanced curvature. The rear portion of the main frame 22 is sometimes referred to as a bent portion 22 w.

The pivot frame 23 is provided continuously below the rear lower end portion 48 of the main frame 22. The upper end portion 49 of the pivot frame 23 constitutes the connecting portion 47 together with the rear lower end portion 48 of the main frame 22. A rear hanger bracket 24 that supports the rear portion of the crankcase 11 of the engine 10 is fixed to a front lower portion of the pivot frame 23. A pivot pipe 25 for supporting the tip end of the swing arm 8 is fixed to the vertical middle portion of the pivot frame 23. The pivot pipe 25 has left and right side portions projecting to the left and right outer sides of the pivot frame 23. The front lower end portions of a pair of left and right support pipes 26 are joined to the outer peripheral surfaces of the left and right side portions of the pivot pipe 25.

The vehicle body frame 20 includes a single down frame 27 extending rearward and downward from the lower portion of the head pipe 21 along the vehicle body left-right center. The down frame 27 extends rearward and downward at a steeper inclination than the main frame 22 in side view. A front hanger bracket 28 that supports the front portion of the crankcase 11 of the engine 10 is integrally formed at the lower end portion of the down frame 27. The upper portion of the down frame 27 is formed to have a wider front-rear width toward the upper side in a side view. The upper portion of the down frame 27 constitutes a gusset portion 27g integrally joined to the lower front portion of the main frame 22. The front edge portion of the down frame 27 is formed linearly in side view, whereas the rear edge portion of the down frame 27 is formed in a curved shape protruding forward in side view.

The vehicle body frame 20 includes: a pair of left and right seat rails 30 having front end portions joined to the rear portion of the main frame 22 and extending substantially horizontally rearward from the front end portions; a pair of left and right support pipes 26 having front end portions joined to the pivot pipe 25 and extending from the front end portions upward and rearward in a vertically lower manner. The left and right support pipes 26 support the front and rear intermediate portions of the left and right seat rails 30 from below. The left and right seat rails 30 extend to the rear end portion of the vehicle body frame 20. Rear end portions of the left and right seat rails 30 are coupled to each other via a rear cross member 34. The front end portions of the left and right seat rails 30 are coupled to each other via a first front cross member (cross member) 31. The front-rear intermediate portions of the left and right seat rails 30 are coupled to each other via a second front cross member (cross member) 32. The front and rear intermediate portions of the left and right seat rails 30 are also connected to each other via a cross pipe 33 at a position rearward of the second front cross member 32.

Referring also to fig. 1, the vehicle body frame 20 has a so-called rhombic frame structure in which the engine 10 is used as a part of the frame structure. The engine 10 is mounted on the vehicle body frame 20 so as to be surrounded by the main frame 22, the down frame 27, and the pivot frame 23 in a side view. The front portion of the crankcase 11 of the engine 10 is supported by the front hanger bracket 28, and the rear portion of the crankcase 11 is supported by the rear hanger bracket 24. The down frame 27 and the pivot frame 23 are coupled to each other via the crankcase 11 of the engine 10.

The fuel tank 15 is formed in a saddle shape with its lower portion straddling the main frame 22 in the left-right direction. The rear portion of the fuel tank 15 extends rearward so as to overlap the front portions of the left and right seat rails 30 in the front-rear direction. A rear bracket portion 15a rubber-supported by the second front cross member 32 is provided at the rear end portion of the fuel tank 15. On the left and right inner surfaces of the saddle-shaped lower portion of the fuel tank 15, receiving members 15b having a U-shape that opens forward in a side view are provided in a left-right pair. The left and right receiving members 15b are locked from behind to cylindrical support rubbers (not shown) held on the left and right outer side surfaces of the main frame 22, and the front portion of the fuel tank 15 is supported by the vehicle body frame 20 by the rubbers.

The main frame 22, the pivot frame 23, the down frame 27, and the left and right seat rails 30 are formed by combining press frame bodies formed by press working steel plates.

As shown in fig. 8 and 9, the main frame 22 is configured by integrally joining a pair of left and right main

press frame bodies

42L and 42R. The left and right main

press frame bodies

42L, 42R are respectively integrated steel plate press-formed members. The left and right main press frame bodies (first press frame bodies) 42L, 42R integrally have outer wall portions 42a facing the vehicle width direction outer sides (left and right direction outer sides), upper wall portions 42b rising from upper edges of the outer wall portions 42a toward the vehicle width direction inner sides, upper joining flanges 42d rising upward from front end edges of the upper wall portions 42b, lower wall portions 42c rising from lower edges of the outer wall portions 42a toward the vehicle width direction inner sides, and lower joining flanges 42e rising downward from front end edges of the lower wall portions 42c, respectively.

The left and right main

press frame bodies

42L, 42R are brought into contact with the upper and lower joining

flanges

42d, 42e in the vehicle width direction. The upper and lower joining

flanges

42d and 42e are integrally joined by a plurality of spot welding portions (joining portions) sp arranged along a flange longitudinal direction (front-rear direction, longitudinal direction of the main frame 22) orthogonal to a flange rising direction (up-down direction).

This makes up the integral main frame 22 having a rectangular closed cross-sectional structure (first closed cross-sectional structure) 22cs formed by the left and right outer side walls 22a and the upper and

lower walls

22b, 22 c. Hereinafter, the portions of the left and right main

press frame bodies

42L, 42R other than the upper and lower joining

flanges

42d, 42e may be referred to as bulging portions (first bulging portions) 42bs forming the closed cross-sectional structure 22cs of the main frame 22.

Referring to fig. 8 and 9, the pivot frame 23 is configured by integrally joining a pair of left and right pivot

press frame bodies

43L and 43R. The left and right pivot press frames (second press frames) 43L and 43R are each an integral steel plate press-formed member. The left and right pivot

press frame bodies

43L, 43R respectively integrally have an outer wall portion 43a facing the outside in the vehicle width direction, a front wall portion 43b rising from the front edge of the outer wall portion 43a toward the inside in the vehicle width direction, and a rear wall portion 43c rising from the rear edge of the outer wall portion 43a toward the inside in the vehicle width direction.

The front end portion of the front wall portion 43b of one of the left and right pivot

press frame bodies

43L, 43R (e.g., the left pivot press frame body 43L) is displaced forward in a stepwise manner by the thickness of the front end portion of the front wall portion 43b of the other of the left and right pivot

press frame bodies

43L, 43R (e.g., the right pivot press frame body 43R). Thereby, the front end portion of the front wall portion 43b in the other of the left and right pivot

press frame bodies

43L, 43R enters the inside of the cross section in the one of the left and right pivot

press frame bodies

43L, 43R. The front end portions of the front wall portions 43b of the left and right pivot

press frame bodies

43L, 43R overlap each other in the thickness direction, and the front end portions are integrally joined to each other by, for example, arc welding. In the figure, symbol bd represents a weld.

Similarly, the front end portion of the rear wall portion 43c of one of the left and right pivot

press frame bodies

43L, 43R (e.g., the left pivot press frame body 43L) is displaced rearward in a stepwise manner by the thickness of the front end portion of the rear wall portion 43c of the other of the left and right pivot

press frame bodies

43L, 43R (e.g., the right pivot press frame body 43R). Thereby, the front end portion of the rear wall portion 43c in the other of the left and right pivot

press frame bodies

43L, 43R. The front end portions of the rear wall portions 43c of the left and right pivot

press frame bodies

43L, 43R are overlapped with each other in the thickness direction, and the front end portions are integrally joined to each other by, for example, arc welding.

This makes up the integral pivot frame 23 having the rectangular closed cross-sectional structure (second closed cross-sectional structure) 23cs formed by the left and right outer side walls 23a and the front and

rear walls

23b, 23 c. Hereinafter, a portion of the left and right pivot

press frame bodies

43L, 43R where the closed cross-sectional structure 23cs of the pivot frame 23 is formed may be referred to as a bulging shape portion (second bulging shape portion) 43 bs. A reinforcing member 49g is fixed in the closed cross-sectional structure 23cs of the pivot frame 23.

Referring to fig. 2, the down frame 27 is formed by integrally joining a pair of left and right down-press frame bodies. The left and right downward stamping frame bodies are respectively integral steel plate stamping forming components. The left and right downward press frame bodies are joined to each other at the front edge portion of the down frame 27 by the same method as the left and right pivot

press frame bodies

43L, 43R. At the rear edge portion of the down frame 27, the left and right down press frame bodies are joined to each other by the same method as the left and right main

press frame bodies

42L, 42R. In the figure, reference numeral 27h denotes a rear engaging flange of the down frame 27.

Referring to fig. 4 to 7, the left and right seat rails 30 are each configured by integrally joining an outer seat press frame body 45O located on the outer side in the vehicle width direction and an inner seat press frame body 45I located on the inner side in the vehicle width direction. The inner and outer seat press frames (press frames) 45I and 45O are respectively integral steel plate press-formed members. The inner and outer seat press frames 45I, 45O each integrally include an outer wall portion 45a facing outward in the vehicle width direction, an upper wall portion 45b rising inward in the vehicle width direction from an upper edge of the outer wall portion 45a, an upper joining flange 45d rising upward from a front end edge of the upper wall portion 45b, a lower wall portion 45c rising inward in the vehicle width direction from a lower edge of the outer wall portion 45a, and a lower joining flange (joining flange) 45e rising downward from a front end edge of the lower wall portion 45 c.

The inner and outer seat press frames 45I, 45O are in contact with each other in the vehicle width direction via the upper and lower joining

flanges

45d, 45 e. The upper and lower joining

flanges

45d and 45e are integrally joined by a plurality of spot-welded portions (joining portions) sp arranged along a flange longitudinal direction (also a front-rear direction, a longitudinal direction of the seat rail 30) orthogonal to a flange rising direction (vertical direction).

This makes up the integrated seat rail 30 having the rectangular closed cross-sectional structure 30cs formed by the left and right outer side walls 30a and the upper and

lower walls

30b, 30 c. Hereinafter, the portions of the inner and outer seat press frame bodies 45I, 45O other than the upper and lower joining

flanges

45d, 45e may be referred to as bulging shape portions 45bs forming the closed cross-sectional structure 30cs of the seat rail 30.

The left and right support pipes 26 are integrally formed of circular steel pipes, respectively. The rear upper ends of the left and right support pipes 26 are connected to the front-rear intermediate portions of the left and right seat rails 30, respectively.

The seat rail 30 is formed with a lower protrusion 35 in a triangular shape protruding downward in a side view at a front-rear intermediate portion connecting the support pipes 26. The rear upper end portion of the support pipe 26 is inserted into the front inclined portion 35a of the lower protruding portion 35 from the front lower side. The lower protruding portion 35 is formed with a cylindrical insertion portion 35c extending along the rear inclined portion 35 b. For example, an oblong welding hole 35d is formed in the side wall of the insertion portion 35 c. The insert portion 35c is joined to the support pipe 26 by arc welding, for example, along the inner peripheral edge of the welding hole 35 d. The rear inclined portion 35b of the lower protruding portion 35 is substantially parallel to the inclination of the support pipe 26 and the front-low rear-high inclination of the rear portion of the seat rail 30 in a side view.

The front-rear intermediate portion of the seat rail 30, which forms the lower protruding portion 35, is connected to a front half portion 36 that extends linearly in the front-rear direction in side view via a bent portion 37. The lower engagement flange 45e includes a first straight portion 45e1 along the front half 36 of the seat rail 30, a second straight portion 45e2 along the front inclined portion 35a of the lower protruding portion 35, and a curved portion 45e3 formed between the two straight portions 45e1, 45e2 in a circular arc shape in side view. The bent portion 45e3 is included in the bent portion 37 of the seat rail 30.

A widened portion 45e4, which is increased in the flange rising height with respect to the portion other than the bent portion 45e3, is formed at the center portion in the flange longitudinal direction of the bent portion 45e3 of the lower joining flange 45 e. The widened portion 45e4 has spot welded portions sp arranged at two locations in the longitudinal direction of the flange, for example. The spot-welded portion sp is separated from the flange base end of the lower joining flange 45e, compared with the spot-welded portion sp of, for example, the two straight portions 45e1 and 45e2 except the bent portion 45e 3.

A plate bending portion 45e5 between the lower joining flange 45e and the lower wall portion 45c in the inner and outer seat press frame bodies 45I, 45O is formed at the flange base end of the lower joining flange 45 e. The plate bending portion 45e5 is formed along the flange longitudinal direction (the longitudinal direction of the seat rail 30). The front end edge of the lower joining flange 45e is formed along the flange longitudinal direction, but the front end edge of the widened portion 45e4 is formed so as to protrude in a trapezoidal shape from the front end edges of the two straight portions 45e1 and 45e 2.

When a seating load or an upward load when supporting the rear portion of the vehicle body is applied to the seat rail 30 at the rear portion thereof, stress is likely to concentrate on the curved portion 37 of the seat rail 30, the cross section of which greatly changes. In particular, the various sheet bent portions 45e5 in the bent portion 37 are liable to be strained. Therefore, by setting the spot welding portion sp to be distant from the bent portion 45e5 particularly at the center portion of the bent portion 37 (the center portion of the bent portion 45e3 of the lower joining flange 45e), it is possible to suppress a load on the spot welding portion sp due to the influence of strain of the bent portion 45e 5.

Referring to fig. 7, the seat rail 30 has a frame widening portion 38 that increases the width in the vehicle width direction with respect to a frame normal portion other than the curved portion 37 at the same position in the front-rear direction as the curved portion 37. The rigidity of the bent portion 37 is improved and strain is suppressed by the frame widening portion 38. The seat rail 30 has a frame bent portion 39 that is bent in the vehicle width direction in a plan view at the same position as the bent portion 37 in the front-rear direction. The frame widening portion 38 has a high effect of increasing the frame rigidity and suppressing strain at the front-rear intermediate position where the vertical bending portion 37 and the vehicle width direction frame bending portion 39 are present.

The lower projecting portion 35 of the seat rail 30 is formed with a reduced width portion (cross-sectional reduced portion) 35e that displaces both sides of the seat rail 30 in the vehicle width direction toward the inside of the frame in a region forward and upward of the insertion portion 35c for the support pipe 26. The reduced width portion 35e has a reduced cross-sectional shape in which the frame width of the seat rail 30 is reduced in a region above and in front of the insertion portion 35 c. The constricted portion 35e can alleviate stress concentration on the bent portion 37 when a load is input to the seat rail 30. That is, when a load is input to the seat rail 30, the stress and deformation are dispersed to the bent portion 37 and the constricted portion 35e, and the load on the spot welding portion sp of the bent portion 37 can be suppressed.

The correspondence of separating the spot welding portion sp from the plate bending portion 45e5 and the correspondence of providing the reduced width portion 35e adjacent to the bent portion 37 are not limited to the application to the concave bent portion 37, and are also applicable to the convex bent portion. The present invention is not limited to the application to the curved portion 37 of the seat rail 30, and may be applied to the curved portion 22w of the main frame 22.

As described above, the vehicle body frame structure of the present embodiment includes the head pipe 21, the main frame 22 extending rearward of the head pipe 21, and the seat rail 30 extending rearward of the main frame 22. At least one of the main frame 22 and the seat rail 30 (for example, the seat rail 30) has a bent portion 37 that is bent when viewed from a first direction (vehicle width direction), and is formed by combining a plurality of press frame bodies 45I and 45O. The plurality of press frame bodies 45I, 45O have bulging shape portions 45bs that form a closed cross-sectional structure 30cs when combined with each other. A joint (spot welding portion sp) where the plurality of press frame bodies 45I and 45O are joined to each other is provided in a joining flange 45e extending from the bulging shape portion 45bs of the joined press frame bodies 45I and 45O. The distance from the plate bending portion 45e5 that raises the bulging-out shaped portion 45bs in the base end of the joining flange 45e to the joining portion (spot welding portion sp) is longer at the bent portion 37 than at a normal portion of the frame other than the bent portion 37.

According to this structure, in the seat rail 30 having the bent portion 37 that is bent downward as viewed from the first direction, stress is likely to concentrate on the bent portion 37 when a load is applied to the seat rail 30. In particular, the bent portion 45e5 of the bent portion 37 is easily deformed. Therefore, by separating the engagement portion in the bent portion 37 of the seat rail 30 from the plate bent portion 45e5 to extend the distance from the plate bent portion 45e5 to the engagement portion, the influence of the deformation generated at the plate bent portion 45e5 on the engagement portion can be suppressed.

In the vehicle body frame structure, the bent portion 37 is increased in thickness in a second direction (front-rear direction) intersecting the first direction with respect to the frame normal portion.

With this structure, the rigidity of the bent portion 37 can be increased to suppress deformation.

In the vehicle body frame structure, the bent portion 37 is bent when viewed from a third direction (vertical direction) intersecting the first direction and the second direction.

According to this structure, since the bending portion of the frame is required to be more rigid, the effect of increasing the thickness of the bent portion 37 is increased.

In the vehicle body frame structure, at least one of the main frame 22 and the seat rail 30 has the curved portion 37, and a reduced width portion 35e for reducing the frame sectional shape is provided around the curved portion 37.

According to this configuration, the load applied to the joint portion of the bent portion 37 can be suppressed by dispersing the stress when the load is applied to the frame by the reduced width portion 35e provided around the bent portion 37, and by favorably deforming the reduced width portion 35e together with the bent portion 37.

As shown in fig. 8 to 11, a connecting portion 47 integrally connecting the main frame 22 and the pivot frame 23 to each other is formed by a rear lower end portion 48 of the main frame 22 and an upper end portion 49 of the pivot frame 23. The connecting portion 47 joins the left and right outer side walls 49a and the rear wall portion 49c of the rectangular cross-sectional upper end portion 49 of the pivot frame 23 to the outer sides of the left and right outer side walls 48a and the rear wall portion 48c of the rectangular cross-sectional rear lower end portion 48 of the main frame 22 in an overlapping manner. The connecting portion 47 is formed by welding the front wall portion 49b of the upper end portion 49 of the pivot frame 23 to the inner side of the front wall portion 48b of the rear lower end portion 48 of the main frame 22 in an overlapping manner. The main frame 22 and the pivot frame 23 are joined integrally by, for example, arc welding.

For example, an oblong welding hole (opening) 49d is formed in the left and right outer side walls 49a of the upper end portion 49 of the pivot frame 23. The left and right outer side wall portions 49a of the upper end portion 49 of the pivot frame 23 are joined to the left and right outer side wall portions 48a of the rear lower end portion 48 of the main frame 22 superposed thereinside by arc welding, for example, along the inner peripheral edge of the welding hole 49 d.

Notches 49e for separating the left and right outer side wall portions 49a from the front wall portion 49b are provided at left and right front side corner portions of the upper end portion 49 of the pivot frame 23. The front wall portion 49b is inserted into the main frame 22 through the left and right cutouts 49e independently from the left and right outer side wall portions 49 a.

For example, an oblong welding hole (opening) 48d is formed in a pair on the left and right sides in the front wall portion 48b of the rear lower end portion 48 of the main frame 22. The front wall portion 48b of the rear lower end portion 48 of the main frame 22 and the front wall portion 49b of the upper end portion 49 of the pivot frame 23 overlapped thereinside are joined to each other by arc welding, for example, along the inner peripheral edge of the left and right welding holes 48 d.

A bulging portion 48e for avoiding a weld bd on the front side of the upper end portion 49 of the pivot frame 23 is formed on the base end side of the lower joining flange 42e of the rear lower end portion 48 of the main frame 22. A widened portion 48f that increases the flange height is formed in the lower joining flange 42e at the same height as the bulging portion 48 e. The expanded portion 48f facilitates the provision of spot welding portions sp avoiding the bulging portion 48 e.

The rear portion of the upper end portion 49 of the pivot frame 23 is cut away so that the height of the upper end is lower than the front wall portion 49b and the left and right outer side wall portions 49 a. The rear wall portion 49c of the upper end portion 49 of the pivot frame 23 is overlapped with the rear wall portion 48c of the rear lower end portion 48 of the main frame 22 from behind with a smaller overlapping margin than the front wall portion 49b and the left and right outer side wall portions 49 a. In this state, the rear wall portion 49c of the upper end portion 49 of the pivot frame 23 and the rear wall portion 48c of the rear lower end portion 48 of the main frame 22 are joined by arc welding, for example. A cutout 49f avoiding the upper engagement flange 42d of the main frame 22 is formed in the rear wall portion 49c of the upper end portion 49 of the pivot frame 23.

The configuration is not limited to the configuration in which the left and right outer side walls 49a and the rear wall portion 49c of the upper end portion 49 of the pivot frame 23 are overlapped and joined to the outer sides of the left and right outer side walls 48a and the rear wall portion 48c of the rear lower end portion 48 of the main frame 22, and the front wall portion 49b of the upper end portion 49 of the pivot frame 23 is overlapped and joined to the inner side of the front wall portion 48b of the rear lower end portion 48 of the main frame 22. For example, the mutually overlapping wall portions may be replaced by the main frame 22 and the pivot frame 23, the mutually overlapping wall portions may be inverted inside and outside, or the wall portions may be overlapped in a different pattern from that described above.

In the structure in which all of the main frame 22 and the pivot frame 23 are inserted into the cross section of the other, it is difficult to absorb assembly errors due to component unevenness. That is, in the structure in which the main frame 22 and the pivot frame 23 are fitted to each other so-called sleeve fitting, a gap or interference may occur between the two.

In the present embodiment, the left and right outer side walls 49a and the front wall 49b of the upper end portion 49 of the pivot frame 23 are formed as separate single support pieces, and the upper ends thereof are free ends, so that errors in the left-right direction and the front-rear direction are easily absorbed. The left and right outer side walls 49a and the front wall 49b of the upper end portion 49 of the pivot frame 23 are set so as to press and overlap the left and right outer side walls 49a and the front wall 48b of the rear lower end portion 48 of the main frame 22, and therefore, they can be joined together with a gap therebetween suppressed.

As described above, the vehicle body frame structure of the present embodiment includes the head pipe 21, the main frame 22 extending rearward of the head pipe 21, and the pivot frame 23 extending downward of the main frame 22. A connecting portion 47 for connecting the main frame 22 and the pivot frame 23 to each other is provided between the main frame 22 and the pivot frame 23. The connecting portion 47 abuts and joins a part of one of the main frame 22 and the pivot frame 23 from the outer side of the closed cross-sectional structures 22cs, 23cs of the other of the main frame 22 and the pivot frame 23, and abuts and joins the remaining part of the one of the main frame 22 and the pivot frame 23 from the inner side of the closed cross-sectional structures 22cs, 23cs of the other of the main frame 22 and the pivot frame 23.

According to this structure, when the main frame 22 and the pivot frame 23 are fitted to each other by a so-called sleeve inserted inside the closed cross-sectional structures 22cs and 23cs, if the connecting portion 47 is loosened or interfered by an assembly error, the frame connection becomes difficult. Therefore, by abutting and joining a part of one frame from the outside of the other frame and abutting and joining the remaining part of the one frame from the inside of the other frame, assembly errors are easily absorbed and frame connection can be easily and reliably performed.

In the vehicle body frame structure, the connecting portion 47 has an opening (

welding holes

48d, 49d) in which the inner peripheral edge serves as a joint portion in at least one of the main frame 22 and the pivot frame 23.

According to this structure, the length of the joint portion can be increased to improve the joint strength.

In the vehicle body frame structure, the main frame 22 is formed by combining a plurality of

press frame bodies

42L and 42R. The plurality of

press frame bodies

42L and 42R have a bulging portion 42bs that forms the closed cross-sectional structure 22cs when combined with each other. A joint portion (spot welding portion sp) where the plurality of

press frame bodies

42L and 42R are joined to each other is provided in the joining

flanges

42d and 42e extending from the bulging portion 42bs of the joined

press frame bodies

42L and 42R so as to be bent.

According to this structure, the plurality of

press frame bodies

42L, 42R forming the main frame 22 are joined by the joining

flanges

42d, 42e bent and extended from the bulging portion 42bs, whereby strain of the closed cross-section structure 22cs caused by joining the plurality of

press frame bodies

42L, 42R to each other can be suppressed.

In the vehicle body frame structure, the pivot frame 23 is formed by combining a plurality of

press frame bodies

43L and 43R. The plurality of

press frame bodies

43L and 43R have bulging shaped portions 43bs that form a closed cross-sectional structure 23cs when combined with each other. A joint portion (spot welding portion sp) where the plurality of

press frame bodies

43L and 43R are joined to each other is provided at a portion where the bulging portion 43bs of the other of the joined

press frame bodies

43L and 43R enters the inside of the bulging portion 43bs of the one and overlaps with each other.

According to this structure, the plurality of

press frame bodies

43L, 43R forming the main frame 22 are joined at the overlapping portions of the bulging portions 43bs, and thereby, the arrangement space of the engine 10, the electrical components, and the like around the pivot frame 23 is easily secured as compared with the case where the joining flanges extending from the bulging portions 43bs are provided.

In the vehicle body frame structure, the connecting portion 47 may be configured to bring a part of the pivot frame 23 into contact and engagement with the outer side of the closed cross-sectional structure 22cs of the main frame 22 in the vehicle width direction, and to bring the remaining portion of the pivot frame 23 into contact and engagement with the inner side of the closed cross-sectional structure 22cs of the main frame 22 in the vehicle longitudinal direction.

According to this configuration, even if the joint flanges stand up in the front-rear direction of the main frame 22, the pivot frame 23 and the main frame 22 can be easily and reliably connected while avoiding interference between the pivot frame 23 and the joint flanges.

Referring to fig. 12 and 13, the first front cross member 31 connecting the front end portions of the left and right seat rails 30 to each other forms a stay portion 31a extending forward and abutting against the upper wall portion 22b of the main frame 22. The front end portions of the left and right seat rails 30 are integrally joined to the upper wall portion 22b of the main frame 22 via the first front cross member 31. The first front cross member 31 is provided with a cutout 31b avoiding the upper joint flange 42d of the main frame 22.

The front end portions of the left and right seat rails 30 are formed with a front extension portion 30e1 and a lower extension portion 30e2 to ensure a welding length to the left and right outer side wall portions 22a of the main frame 22. The front extension portion 30e1 and the lower extension portion 30e2 are flush with the upper and lower joining

flanges

45d, 45e of the seat rail 30, and lower end edges thereof are integrally joined to the left and right outer side walls 22a of the main frame 22 by arc welding, for example. The welding strength of the front end portion of the seat rail 30 is increased by joining the front extension portion 30e1 and the lower extension portion 30e2 to the main frame 22. Thus, even if a moment that tends to swing up and down about the front end portion acts on the seat rail 30 due to the load input to the seat rail 30, the joint strength against the moment can be secured.

A second front cross member 32 that connects the front-rear intermediate portions of the left and right seat rails 30 to each other is provided apart from the rear of the first front cross member 31. The second front cross member 32 is provided with a tank support portion 32a that supports the rear end portion of the fuel tank 15. The first front cross member 31 and the second front cross member 32 are integrated via a connecting portion 40 disposed between the left and right seat rails 30. The coupling portion 40 has a pair of left and right coupling pieces 40a extending along the upper joining flanges 45d of the left and right seat rails 30. The left and right connecting pieces 40a form an opening 40 b. The first front cross member 31, the second front cross member 32, and the connecting portion 40 (the left and right connecting pieces 40a) constitute an integrated cross member 40C.

The left and right coupling pieces 40a have a gap with the left and right seat rails 30, and are not joined to the left and right seat rails 30. This reduces the welding cost and suppresses the influence of the welding strain on the first and second

front cross members

31 and 32. The first and second

front cross members

31 and 32 are separated from each other by a non-joint region R1 with respect to the seat rail 30 and are integrated with each other.

The structure of the connecting portion 40 is not limited to the structure having the pair of connecting pieces 40a extending along the inside in the vehicle width direction of the left and right seat rails 30, and may be various structures for connecting the first and second

front cross members

31, 32, such as a structure having a single connecting piece that extends forward and rearward while being separated inward in the vehicle width direction between the left and right seat rails 30.

As described above, the vehicle body frame structure of the present embodiment includes the head pipe 21, the main frame 22 extending rearward of the head pipe 21, the plurality of seat rails 30 extending rearward of the main frame 22, and the plurality of

cross members

31 and 32 connecting the plurality of seat rails 30. The plurality of

cross members

31 and 32 are separated from each other with respect to the non-joint region R1 of the seat rail 30, and are integrated with each other via the connecting portion 40 disposed in the non-joint region R1.

According to this configuration, since the plurality of

beams

31 and 32 separated from each other are integrated via the connection portion 40, the number of components and the number of assembly steps can be reduced. Further, the plurality of

cross members

31 and 32 and the coupling portion 40 can be integrally formed as an integral member, and the accuracy of the relative position between the plurality of

cross members

31 and 32 can be improved.

In the vehicle body frame structure, the coupling portion 40 includes a plurality of coupling pieces 40a along the plurality of seat rails 30 and an opening 40b formed between the plurality of coupling pieces 40 a.

According to this structure, the weight reduction can be achieved when the plurality of

cross members

31 and 32 and the connecting portion 40 are formed as an integral member, and the seat rail 30 can be reinforced by the connecting piece 40 a.

In the vehicle body frame structure, the plurality of

cross members

31 and 32 are disposed between the front end portions and between the front and rear intermediate portions of the plurality of seat rails 30, respectively.

According to this structure, the front end portions of the plurality of seat rails 30 connected to the main frame 22 can be reinforced by the cross member 31, and the front-rear intermediate portions of the seat rails 30, which are likely to generate bending stress, can be reinforced by the cross member 32.

In the vehicle body frame structure, the cross member 31 provided between the front end portions of the plurality of seat rails 30 has a stay portion 31a joined to the main frame 22.

With this structure, the joint strength between the front end portion of the seat rail 30 and the main frame 22 can be increased. Moreover, the seat rail 30 and the main frame 22 can be easily positioned by the stay portion 31 a.

In the vehicle body frame structure, the cross member 32 provided between the front and rear intermediate portions of the plurality of seat rails 30 includes a tank support portion 32a that supports the fuel tank 15.

According to this configuration, the functionality can be improved by providing the tank support portion 32a for the fuel tank 15 at the front-rear intermediate portion of the seat rail 30.

The present invention is not limited to the above-described embodiments, and the straddle-type vehicle includes all vehicles in which a driver rides straddling a vehicle body, and includes not only a motorcycle (including a bicycle with a prime mover and a scooter-type vehicle), but also a three-wheeled vehicle (including a vehicle having a front wheel and a rear wheel in addition to the front wheel and the rear wheel) or a four-wheeled vehicle.

The configuration of the above embodiment is an example of the present invention, and various modifications are possible without departing from the scope of the present invention, such as replacing the components of the embodiment with known components.

Description of the reference numerals

1 Motor bicycle (straddle type vehicle)

15 fuel tank

20 vehicle body frame

21 head pipe

22 Main frame

23 Pivot frame

30 seat track

31 first front beam (Beam)

31a stay part

32 second front beam (Beam)

32a tank support

22cs closed section structure (first closed section structure)

23cs closed section Structure (second closed section Structure)

30cs closed cross-section structure

35e reduced width part (section reduced part)

37 bending part

40 connecting part

40a connecting sheet

40b opening part

42bs bulge shape part (first bulge shape part)

43bs bulge shape part (second bulge shape part)

45bs bulge shape part

42d, 42e joining flanges

42L, 42R left and right main press frame (first press frame)

43L, 43R left and right pivot press frame (second press frame)

45I, 45O inner and outer seat stamping frame (stamping frame)

45e lower joint flange (joint flange)

45e5 board bend

47 connecting part

48d, 49d welding holes (opening part)

R1 non-junction region

sp spot welding part (joint part)

Claims

1. A vehicle body frame structure is provided with:

a head pipe;

a main frame extending rearward of the head pipe; and

a seat rail extending rearward of the main frame,

at least one of the main frame and the seat rail has a bent portion that is bent downward when viewed from a first direction and is formed by a combination of a plurality of stamped frame bodies,

a plurality of the press frame bodies have bulging shape portions that form a closed cross-sectional structure when combined with each other,

a joining portion where the plurality of press frame bodies are joined to each other is provided to a joining flange extending from the bulging shape portion of the joined press frame bodies,

a distance from a plate bending portion of the base end of the joining flange that makes the bulging shape portion stand up to the joining portion is longer at the bent portion than a frame normal portion other than the bent portion.

2. The vehicle body frame structure according to claim 1,

the bent portion increases in thickness relative to the frame normal portion in a second direction intersecting the first direction.

3. The vehicle body frame structure according to claim 2,

the bent portion is bent as viewed from a third direction intersecting the first direction and the second direction.

4. The vehicle body frame structure according to any one of claims 1 to 3,

at least one of the main frame and the seat rail has the curved portion, and a cross-sectional reduced portion that reduces a cross-sectional shape of the frame is provided around the curved portion.