JP2008162527A - Vehicle body frame for motorcycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the number of parts and man-hour of machining in a vehicle body frame for a motorcycle provided with a head pipe and a main frame constituted by joining a plurality of frames obtained by press-molding and rearwardly downwardly extending from the head pipe. <P>SOLUTION: The main frame 14A is constituted to two divisions in a vertical direction such that an upper frame half body 31 having a downwardly opened approximately U shape lateral cross section shape and a lower frame half body 32A having an upwardly opened approximately U shape lateral cross section shape are welded to each other. At both sides of a lower end of the upper frame half body 31, upper flanges 35 arranged in left and right symmetrical while having a surface continued along a longitudinal direction of the main frame 14A are integrally continuously provided. At both sides of an upper end of the lower frame half body 32A, lower flanges 36, 37 joined to the both upper flanges 35 respectively are integrally continuously provided. Engine mounting parts 39, 40, 41 are formed at a plurality of positions of a support plate 38 downwardly extending from outer ends of both lower flanges 36, 37. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention includes a head pipe that supports a front fork that pivotally supports a front wheel so as to be steerable, and a main frame that extends rearward and downward from the head pipe, and a plurality of frame components formed by press-molding a metal plate material. The present invention relates to a motorcycle body frame that is joined to form the main frame.

It has been common practice to construct a motorcycle body frame by welding a plurality of pipe materials, but the frame structure becomes complicated, and metal plate materials are pressed from the viewpoint of manufacturing cost. In some cases, a vehicle body frame is configured by welding a plurality of frames (see, for example, Patent Document 1).
JP 2000-095170 A

  In the one disclosed in Patent Document 1, a main frame is configured by abutting two frames formed by press-molding a metal plate material in the middle and welding the flange portions of both frames. However, an engine hanger and a front member for supporting the engine are required to be welded later, which increases the number of parts and the processing time.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a body frame of a motorcycle that can reduce the number of parts and the number of processing steps.

  In order to achieve the above object, a first aspect of the present invention includes a head pipe that supports a front fork that pivotally supports a front wheel so that the front fork can be steered, and a main frame that extends downward from the head pipe. A body frame of a motorcycle in which a plurality of frame structural members formed by press molding are joined to form the main frame, wherein the main frame has a substantially U-shaped cross-sectional shape opened downward. A half body and a lower frame half body having a substantially U-shaped cross-sectional shape opened upward are joined to each other so as to be vertically divided into two parts. And an upper flange that projects from both the left and right sides and has a continuous surface along the longitudinal direction of the main frame, and is arranged symmetrically. Lower flanges respectively joined to the upper flanges are provided on both sides of the upper end of the half body so as to protrude from both the left and right sides, and are integrally connected to at least a part of the outer ends of the lower flanges and extend downward. Engine mounting portions are formed at a plurality of locations on the support plate.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect of the invention, the lower frame half is welded to the front portion of the upper frame half, and the front lower frame member, and the engine mounting portion. The rear lower frame member is welded to the rear portion of the upper frame half, and the plate thickness of the rear lower frame member is set larger than the plate thickness of the front lower frame member.

  According to a third aspect of the present invention, in addition to the configuration of the second aspect of the invention, the lower frame half is continuously welded to the upper frame half from the front end to the rear end.

  According to a fourth aspect of the invention, in addition to the configuration of the second aspect of the invention, the outer end of the lower flange included in the front lower frame member is opposed to the outer end of the upper flange from the outside and is in contact with the outer end. The plate portion extends upward and is integrally connected, and a recess for fitting the upper flange from above is formed on the upper surface of the lower flange of the rear lower frame member.

  According to the first aspect of the present invention, since the plurality of engine mounting portions are provided on the support plate integrally formed in the lower frame half, the number of parts can be reduced and the engine mounting portions can be formed by post-processing. The processing man-hours can be reduced. Further, since the engine mounting portion is formed at the time of press molding, the relative position between the engine mounting portions is determined without being affected by the joining of the upper frame half body and the lower frame half body, thereby improving the mounting accuracy of the engine. be able to. In addition, the main frame that extends backward and downward from the head pipe has a vertically divided structure, so that the amount of broken material can be reduced when the metal plate is pressed, and the left and right upper flanges of the upper frame half are connected to the main frame. Therefore, the left and right upper flanges and the left and right lower flanges can be welded at the same time, so that productivity can be improved.

  According to the invention of claim 2, the lower frame half is composed of the front lower frame member and the rear lower frame member, and the plate thickness of the rear lower frame member is set larger than the plate thickness of the front lower frame member. In addition, the main frame can be reduced in weight by thickening only the rear lower frame member on the side of the engine mounting portion that requires strength in the lower frame half.

  According to the invention described in claim 3, the strength of the main frame is stabilized by continuous welding of the upper frame half and the lower frame half, and productivity can be increased by continuously welding the three parts. it can.

  According to the fourth aspect of the present invention, the relative positions of the upper frame half and the lower frame half can be easily determined when the upper frame half and the lower frame half are welded to each other.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples of the present invention shown in the accompanying drawings.

  1 to 6 show a first embodiment of the present invention. FIG. 1 is a side view of a motorcycle, FIG. 2 is a side view of a vehicle body frame and an engine, and FIG. 3 is an exploded perspective view of a head pipe and a main frame. 4 is an enlarged sectional view taken along line 4-4 in FIG. 2, FIG. 5 is an enlarged sectional view taken along line 5-5 in FIG. 2, and FIG. 6 is an enlarged sectional view taken along line 6-6 in FIG.

  In the following description of the embodiments, the front and rear and the left and right refer to the traveling direction of the scooter type motorcycle.

  1 and 2, a body frame FA of the motorcycle includes a head pipe 13 that pivotally supports a front fork 11 and a steering handle 12 that pivotally support a front wheel WF, and a rear lowering from the head pipe 13. And a pair of left and right seat rails 15 that extend stepwise rearward in stages, with the front end joined to an intermediate portion near the rear portion of the main frame 14A. A four-cycle engine E that exerts power for driving the rear wheel WR supported on the rear portion of the swing arm 16 that is supported so as to be swingable is supported, and the power from the engine E passes through the chain transmission means 17. It is transmitted to the rear wheel WR. A rear cushion 18 is provided between the swing arm 16 and the seat rail 15.

  An intake system 20 connected to an upper side surface of a cylinder head 19 provided in the engine E includes an air cleaner 21 disposed on the upper front side of the engine E, a throttle body 22 having an upstream end connected to the air cleaner 21, and the throttle An intake pipe 23 connecting the body 22 and the cylinder head 19 is provided. An exhaust system 24 is connected to the lower side surface of the cylinder head 19, and an exhaust muffler 25 at the downstream end of the exhaust system 24 is disposed on the right side of the rear wheel WR.

  A fuel tank 26 is disposed above the rear side of the engine E. Thus, the vehicle body frame FA, a part of the engine E, and the fuel tank 26 are covered with a vehicle body cover 28, and are supported by the seat rails 15 on the vehicle body cover 28 above the fuel tank 26. A passenger seat 29 is provided.

  4 to 6 together, the main frame 14A includes an upper frame half 31 having a substantially U-shaped cross-sectional shape opened downward, and a substantially U-shaped cross-sectional surface opened upward. The upper frame half 31 and the lower frame half 32A are welded to each other in this embodiment.

  Moreover, the lower frame half body 32A is composed of a front lower frame member 33A welded to the front portion of the upper frame half body 31 and a rear lower frame member 34A welded to the rear portion of the upper frame half body 31. The body 31, the front lower frame member 33A, and the rear lower frame member 34A are each formed by press molding of a metal plate material.

  The plate thickness of the rear lower frame member 34A is set larger than the plate thickness of the front lower frame member 33A. For example, when the plate thickness of the front lower frame member 33A is 2.3 mm, the rear lower frame member 34A. The plate thickness of the upper frame half 31 is set to be thinner than the plate thickness of the lower frame half 32A, for example, 2.0 mm.

  Upper flanges 35, 35 that extend to the left and right sides and have continuous surfaces along the longitudinal direction of the main frame 14 </ b> A are disposed substantially on the left and right sides of the lower half of the upper frame half 31 so as to be integrally provided. The Further, lower flanges 36, 36 respectively welded to the upper flanges 35 are provided on both sides of the upper end of the front lower frame member 33A in the lower frame half body 32A so as to project in the left and right sides, and are integrally connected. Lower flanges 37, 37 welded to the upper flanges 35 are respectively provided on both sides of the upper end of the rear lower frame member 34 </ b> A in the half body 32 </ b> A so as to project from the left and right sides.

  Thus, the lower flange 36 of the front lower frame member 33A in the lower frame half 32A and the lower flange 37 of the rear lower frame member 34A are connected to the upper flange 35 of the upper frame half 31 from the front end thereof. It is continuously welded to the rear end, for example, by seam welding or laser welding.

  As described above, the upper frame half 31 and the lower frame half 32A including the front lower frame member 33A and the rear lower frame member 34A are joined to form the main frame 14A. The shape is formed in an elliptical shape with the vertical axis as the major axis, and the joint surface 30 of the upper frame half 31 and the lower frame half 32A is disposed at a position offset downward from the cross-sectional center C of the main frame 14A. The

  Further, the lower flanges 37 of the rear lower frame member 34A in the lower frame half 32A are formed so as to protrude outward from the upper flanges 35 of the upper frame half 31. In addition, support plates 38 and 38 extending downward are integrally and continuously connected at right angles to at least a part of the lower flanges 36... 37 in the lower frame half 32 A, in this embodiment, the outer ends of the lower flanges 37. In addition, engine mounting portions 39..., 40... 41.

  On the other hand, the crankcase 42 of the engine E is provided with brackets 43, 44, 45, which are in contact with the engine mounting members 39, 40, 41, from the inside. Are fastened with bolts 46 and nuts (not shown), brackets 44 are fastened to engine mounting portions 40 with bolts 47 and nuts 52 (see FIG. 5), and brackets 45 are fastened to engine mounting portions 40. 48 and a nut (not shown).

  A gusset 49 is provided between the head pipe 13 and the front lower frame member 33A in the lower part of the front end of the main frame 14A, that is, the lower frame half body 32A. The air cleaner 21 in the intake system 20 is supported by the front end portion of the main frame 14A. The air cleaner 21 includes both sides of the front end upper portion of the main frame 14A, that is, both sides of the front end of the upper frame half 31. Are attached to the weld nuts 50, 50 fixed to the inner surface of the front end portion of the upper frame half 31. The bolts 51, 51 inserted through the mounting plate 21 a... And the upper frame half 31 are screwed and tightened to be attached to the front end of the main frame 14 </ b> A.

  On the other hand, the front portion of the swing arm 16 is pivotally supported by a pivot 54 disposed at the rear end portion of the main frame 14A. The pivot 54 includes the upper frame half 31 and the pivot frame 54. The lower frame half body 32A is fixed to the joint between the upper frame half body 31 and the lower frame half body 32A so as to be sandwiched between the joint surfaces with the rear lower frame member 34A. Further, support pipes 55 are provided between the pivot 54 and the intermediate portion of the both seat rails 15.

  Next, the operation of the first embodiment will be described. A main frame 14A extending rearwardly downward from the head pipe 13 has an upper frame half 31 having a substantially U-shaped cross section opened downward, and opened upward. Since the lower frame half body 32A having a substantially U-shaped cross-sectional shape is joined to the upper and lower parts so as to be joined to each other, the amount of broken material should be reduced when the metal plate material is press-formed. Can do. Further, the upper frame 35 of the upper frame half 31 and the lower flanges 36, 37, etc. of the lower frame half 32A are joined to each other to form the main frame 14A, and the upper flange is formed from both sides of the main frame 14A. 35 and the lower flanges 36, 37, etc. project laterally, so that the main frame 14A can be given sufficient strength against the stress acting on the main frame 14A from the left and right direction, and the cross section of the main frame 14A Since the shape is an elliptical shape with the vertical direction as the major axis direction, the main frame 14A can be given sufficient strength against stress acting on the main frame 14A from the vertical direction. That is, even if the plate thickness is reduced, the main frame 14A can be given sufficient strength, and the main frame 14A, that is, the motorcycle can be reduced in weight.

  Further, the engine mounting portions 39... Are provided at a plurality of locations (three locations in the first embodiment) of the support plates 38 that hang downward from the outer ends of the lower flanges 37 of the rear lower frame member 34A in the lower frame half body 32A. .., 41... Are formed, so that the number of parts can be reduced and the number of processing steps can be reduced by eliminating the need for forming the engine mounting portion by post-processing. Further, since the engine mounting portions 39, 40, 41, ... are formed at the time of press molding, the relative positions between the engine mounting portions 39, 40, 41, 41 are the upper frame half body 31 and the lower frame half body 32A. It is determined without being affected by the joining, and the mounting accuracy of the engine E can be increased.

  Moreover, the lower frame half body 32A is composed of a front lower frame member 33A welded to the front portion of the upper frame half body 31, and a rear lower frame member 34A welded to the rear portion of the upper frame half body 31. Since the plate thickness of the frame member 34A is set to be larger than the plate thickness of the front lower frame member 33A, the lower frame half body 32A is behind the engine mounting portions 39, 40, 41, etc. that require strength. The main frame 14A can be reduced in weight by thickening only the subordinate frame member 34A.

  Further, since the lower frame half body 32A is continuously welded to the upper frame half body 31 from the front end to the rear end, the strength of the main frame 14A is increased by continuous welding of the upper frame half body 31 and the lower frame half body 32A. As a result, the three parts 31, 33A, 34A can be continuously welded to increase productivity.

  Further, since the joint surface 30 of the upper frame half 31 and the lower frame half 32A is disposed at a position offset downward from the cross-sectional center C of the main frame 14A, it is required for the lower frame half 32A. The amount of the metal plate material can be reduced, and the arc portion at the lower part of the main frame 14A is reduced, so that the main frame 14A and the engine E arranged below the main frame 14A are arranged in a compact manner. This can contribute to downsizing.

  Further, a pivot 54 that swingably supports the front end of the swing arm 16 is provided at the joint between the upper frame half 31 and the lower frame half 32A, and is disposed at the rear end of the main frame 14A. The pivot 54 having a high stress load is provided at the joint portion of the upper and lower flanges 35, 37, which have high rigidity, so that the rigidity of the vehicle body frame FA can be ensured.

  7 and 8 show a second embodiment of the present invention. FIG. 7 is a sectional view corresponding to FIG. 4 of the first embodiment, and FIG. 8 is a sectional view corresponding to FIG. 5 of the first embodiment. It is.

  It should be noted that the parts corresponding to the first embodiment are only shown with the same reference numerals, and detailed description thereof is omitted.

  The main frame 14B constituting a part of the vehicle body frame FB includes an upper frame half 31 having a substantially U-shaped cross-sectional shape opened downward and a lower frame having a substantially U-shaped cross-sectional shape opened upward. The frame half 32B is welded to each other so that it is vertically divided into two parts.

  In addition, the lower frame half body 32B is formed with a front lower frame member 33B welded to the front portion of the upper frame half body 31 and a thicker wall than the front lower frame member 33B, and the rear portion of the upper frame half body 31 is formed. The upper frame half 31, the front lower frame member 33B, and the rear lower frame member 34B are each formed by press molding of a metal plate material.

  Upper flanges 35, 35 that extend to both the left and right sides and have continuous surfaces along the longitudinal direction of the main frame 14 </ b> B are disposed substantially on the left and right sides of the upper frame half 31 so as to be integrally provided. The Further, lower flanges 36, 36 respectively welded to the upper flanges 35 are provided on both sides of the upper end of the front lower frame member 33B in the lower frame half body 32B so as to project from both the left and right sides, and are integrally connected. Lower flanges 57, 57 welded to the upper flanges 35 are respectively provided on both sides of the upper end of the rear lower frame member 34 </ b> B in the body 32 </ b> B so as to project from the left and right sides.

  Thus, on the outer end of the lower flange 36 in the front lower frame member 33B of the lower frame half body 32B, there are upper restricting plate portions 56, 56 that face and contact the outer end of the upper flange 35 from the outside. On the upper surface of the lower flange 57... Of the lower frame half body 32 B of the lower frame half body 32 B, recesses 58 and 58 for fitting the upper flange 35. The

  Further, the lower flanges 57 of the rear lower frame member 34B in the lower frame half 32B are formed so as to protrude outward from the upper flanges 35 of the upper frame half 31. Support plates 38, 38 hanging downward are integrally and perpendicularly connected to the outer ends of the ..., and an engine mounting portion 39 for mounting the engine E at a plurality of, for example, three locations of the support plates 38 .... ..., 40 ..., 41 ... are formed.

  According to the second embodiment, in addition to the same effects as the first embodiment, the upper frame half 31 and the lower frame half are also welded to each other between the upper frame half 31 and the lower frame half 32B. The relative position of 32B can be easily determined.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. It is.

1 is a side view of a motorcycle according to a first embodiment. It is a side view of a body frame and an engine. It is a disassembled perspective view of a head pipe and a main frame. FIG. 4 is an enlarged sectional view taken along line 4-4 of FIG. FIG. 5 is an enlarged sectional view taken along line 5-5 in FIG. FIG. 6 is an enlarged sectional view taken along line 6-6 of FIG. It is sectional drawing of 2nd Example corresponding to FIG. 4 of 1st Example. It is sectional drawing of 2nd Example corresponding to FIG. 5 of 1st Example.

Explanation of symbols

11 ... front fork 13 ... head pipes 14A, 14B ... main frame 31 ... upper frame half 32A, 32B ... lower frame half 33A, 33B ... front lower frame member 34A, 34B: Rear lower frame member 35: Upper flanges 36, 37, 57 ... Lower flange 38 ... Support plates 39, 40, 41 ... Engine mounting portion 56 ... Restriction plate portion 58 ..Recesses FA, FB ... Body frame WF ... Front wheels

Claims (4)

  A head pipe (13) that supports the front fork (11) that pivotally supports the front wheel (WF) so as to be steerable, and a main frame (14A, 14B) that extends rearward and downward from the head pipe (13). In a vehicle body frame of a motorcycle in which a plurality of frame constituent members formed by press-molding plate members are joined to form the main frame (14A, 14B), the main frame (14A, 14B) is generally opened downward. The upper frame half (31) having a U-shaped cross section and the lower frame half (32A, 32B) having a substantially U-shaped cross section opened upward are welded to each other. The upper frame half (31) is divided into two parts at the lower end on both sides of the upper frame half (31) and extends to the left and right sides and the length of the main frame (14A, 14B). An upper flange (35) that has a continuous surface along the direction and is symmetrically disposed is integrally connected, and the upper flanges (32A, 32B) are provided on both sides of the upper flange (32A, 32B). 35) lower flanges (36; 37, 57) respectively joined to the left and right sides and integrally connected to each other, and are integrally connected to at least a part of the outer ends of the lower flanges (36; 37, 57). A vehicle body frame for a motorcycle, wherein engine mounting portions (39, 40, 41) are formed at a plurality of locations on a support plate (38) extending downward.   The lower frame half (32A, 32B) includes a front lower frame member (33A, 33B) welded to a front portion of the upper frame half (31), and the engine mounting portion (38, 39, 40). A rear lower frame member (34A, 34B) welded and joined to the rear portion of the upper frame half (31). The thickness of the rear lower frame member (34A, 34B) is the front lower frame member (33A). 33B), the body frame of the motorcycle according to claim 1.   The body frame of the motorcycle according to claim 2, wherein the lower frame half (32A, 32B) is continuously welded to the upper frame half (31) from the front end to the rear end.   At the outer end of the lower flange (36) of the front lower frame member (33B), a regulating plate portion (56) that faces and contacts the outer end of the upper flange (35) from the outside extends upward. A recess (58) for fitting the upper flange (35) from above is formed on the upper surface of the lower flange (57) of the rear lower frame member (34B). Item 2. A motorcycle body frame according to Item 2.

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