JP4459161B2 - Scooter type vehicle frame structure - Google Patents

Description

  The present invention relates to a frame structure of a scooter type vehicle in which a pair of left and right side frames are joined to a head pipe that supports a front fork that pivotally supports a front wheel so as to be steerable.

A pair of left and right side frames integrally having a down frame portion hanging downward from the head pipe and a lower frame portion extending rearward from the lower end of the down frame portion are joined to the head pipe at the front ends. A scooter type vehicle that is reinforced by a pair of left and right down tubes disposed below the vehicle is known from Patent Document 1, for example.
Japanese Patent No. 3423487

  By the way, in the scooter type vehicle disclosed in Patent Document 1, the rear ends of the side frame and the down tube are connected and fixed to each other with a suspension bracket, and the vehicle body frame side pivot shaft of the link mechanism provided between the vehicle body frame and the power unit is used. In such a frame structure, a large load is applied to the connection part of the side frame and the down tube to the suspension bracket. Therefore, the side frame and the down tube are enlarged and the body frame side pivot shaft is used. Although it is desired to increase the rigidity of the surroundings, if the side frame and the down tube are increased in size, the overall weight increases and the space behind the floor is reduced.

  The present invention has been made in view of such circumstances, and is a scooter-type vehicle that can sufficiently increase the rigidity around the vehicle-body-side pivot shaft while avoiding an increase in the size of the side frame and can increase the space behind the floor. It is a first object to provide a frame structure.

  Further, in the scooter type vehicle disclosed in Patent Document 1, the side frame integrally includes a down frame portion that hangs downward from the head pipe and a lower frame portion that extends rearward from the lower end of the down frame portion. And a support pipe that supports the passenger seat is joined to the side frame, which increases the number of parts and the number of assembling steps of the vehicle body frame.

  The present invention has been made in view of such circumstances, and a second object of the present invention is to provide a frame structure of a scooter type vehicle that can reduce the number of parts and the number of assembly steps.

In order to achieve the first object, the invention according to claim 1 is a frame of a scooter type vehicle in which a pair of left and right side frames are joined to a head pipe that supports a front fork that pivotally supports a front wheel. In the structure, the pair of left and right side frames includes a lower frame portion that passes below the floor, and a bent portion that is bent upward at the rear end of the lower frame portion and forward with respect to the rear extension axis of the lower frame portion. And a rising frame portion that rises upward from the bent portion behind the floor and bypasses the bent portion from below the pair of left and right lower frame portions. Front end portions of a pair of left and right rear subframes arranged so as to extend to the rear of the left and right lower frame portions respectively And the rear end portions of both rear subframes are connected to the side frames on the rear side of the bent portion, and the two side subframes are connected to the rear subframes. The pivot plate is provided, and the vehicle body frame side pivot shaft of the link mechanism provided between the head pipe, the vehicle body frame including the both side frames and the rear sub frame, and the power unit is supported by the pivot plate. And

  According to a second aspect of the invention, in addition to the configuration of the first aspect of the invention, the middle part of the two rear sub-frames is bent so as to be close to the rising frame part side of the two side frames. And

  In order to achieve the second object in addition to the first object, the invention according to claim 3 is a front fork that pivotally supports a front wheel in addition to the configuration of the invention according to claim 1 or 2. In a scooter type vehicle frame structure in which a pair of left and right side frames are joined to a head pipe that supports the vehicle so as to be steerable, the both side frames include a down frame portion that hangs downward from the head pipe, and the down frame The lower frame portion connected to the lower end of the portion, the rising frame portion connected to the rear end of the lower frame portion via the bent portion, and a seat extending rearward from the upper end of the rising frame portion to support the riding seat The rail portion is integrally formed, and each single pipe is bent.

  Furthermore, in addition to the configuration of the invention described in claim 3, the invention described in claim 4 includes the side frame and a pipe member that reinforces the side frame with a smaller diameter than the side frame. It is characterized by being arranged side by side so as to form a pair in the front, lower and rear.

  Furthermore, in the invention according to claim 5, in addition to the structure according to any one of claims 1 to 4, the vehicle body frame side pivot shaft of the link mechanism is more forward than the rear surface of the rising frame portion and the lower It is arranged below the frame part.

  Note that the center frames 14 and 54, the rear subframes 18 and 61, the U-shaped portion 32, and the connecting frame 55 of the embodiment correspond to the pipe member of the present invention.

According to the present invention, the pair of left and right side frames includes a lower frame portion that passes below the floor, and a bent portion that is bent upward at the rear end of the lower frame portion and forward with respect to the rear extension axis of the lower frame portion. And a rising frame portion that rises upward from the bent portion behind the floor and extends behind the rising frame portion around the bent portion from below the lower frame portion. And the rear end of each rear subframe is connected to the lower frame, and the rear end of the rear subframe is connected to the side frame behind the bent portion. The pivot frame on the vehicle body frame side of the link mechanism is supported on the pivot plate provided between the side frame and the side frame. Of while avoiding an increase in size it is possible to enhance the vehicle body frame side pivot axis of the rigid, it is possible to enlarge the space behind the floor by avoiding the increase in size of the side frames.

  In particular, according to the invention described in claim 2, it is possible to shorten the wheel base by arranging the power unit on the front side while avoiding interference of the power unit with the rear sub-frame.

  In particular, according to the invention described in claim 3, the side frame is integrally formed of a down frame portion, a lower frame portion, a rising frame portion and a seat rail portion, and a single pipe is bent. As a result, the number of parts can be reduced, and the number of steps for assembling the body frame can be reduced.

  In particular, according to the invention described in claim 4, it is possible to configure a lightweight and highly rigid body frame.

  In particular, according to the fifth aspect of the present invention, the vehicle body frame side pivot shaft of the link mechanism can be arranged as far as possible to shorten the wheel base.

  Embodiments of the present invention will be described below based on the embodiments of the present invention shown in the accompanying drawings.

  1 to 5 show a first embodiment of the present invention. FIG. 1 is a side view of a scooter type vehicle, FIG. 2 is a side view of a vehicle body frame, FIG. 4 is a front view taken along the arrow 4 in FIG. 2, and FIG. 5 is a longitudinal side view showing the structure of the link mechanism.

  First, in FIG. 1, a front fork 11 on which a front wheel WF is pivotally supported is supported so as to be steerable on a head pipe 12 at a front end of a vehicle body frame FA provided in a scooter type vehicle having a low floor type floor 26. Handle grips 22 are provided at both ends of a bar-shaped steering handle 21 connected to the upper portion of the front fork 11, respectively. Further, in the vehicle body frame FA, the front portion of the power unit P including the engine E and the transmission M that shifts the power from the engine E and transmits it to the rear wheels WR can swing up and down via the link mechanism 42. The rear wheel WR is supported at the rear part of the power unit P, and a rear cushion unit 23 is provided between the rear part of the vehicle body frame FA and the rear part of the power unit P.

  The vehicle body frame FA includes the head pipe 12, a pair of left and right side frames 13 whose front ends are joined to the head pipe 12, and the front portion of the side frame 13 from the head pipe 12 between the side frames 13. Before connecting the center frame 14 that hangs downward through the vicinity, the main pipe 15 that hangs down from the head pipe 12, and the front portions of the side frames 13, and before the lower end of the main pipe 15 is joined. A cross member 16, a connecting frame 17 disposed below the floor 26 to reinforce the center frame 14 and both side frames 13, and a pair of left and right rear subframes 18 attached to the side frames 13. , Both side frames 13... And a rear cross member 19 connecting the rear ends.

  The vehicle body frame FA is covered with a vehicle body cover 24 made of synthetic resin. The vehicle body cover 24 is provided under the leg shield 25 for covering the front of the driver's feet and the leg shield 25 for placing the rider's feet. A continuous floor 26 and a side cover 27 that is connected to the floor 26 and covers the rear part of the vehicle body from both sides are provided. On the side cover 27, a storage box 28 and a fuel tank 29 disposed behind the storage box 28 are provided. A tandem-type riding seat 30 is provided so as to be openable and closable from above.

2 to 4, the side frame 13 includes a down frame portion 13 a that hangs downward from the head pipe 12, and a lower frame portion 13 b that continues to the lower end of the down frame portion 13 a and extends rearward below the floor 26. The lower frame portion 13b is integrally connected to the rear end of the lower frame portion 13b through a bent portion K that is bent forward with respect to the rearward extension axis of the lower frame portion 13b and upward from the bent portion K behind the floor 26. The rising frame portion 13c that rises and the seat rail portion 13d that extends rearward from the upper end of the rising frame portion 13c to support the riding seat 30 are integrally formed, and a single pipe is bent and formed. .

  A gusset 31 is provided between the main pipe 15 and the head pipe 12 suspended from the head pipe 12, and an upper end portion of the down frame portion 13 a included in the side frame 13 is joined to both the head pipe 12 and the gusset 31. The upper portion of the center frame 14 is connected to the main pipe 15 and may be welded as in this embodiment or may be fastened using bolts.

  The lower frame portion 13b includes a horizontal portion 13ba extending substantially horizontally rearward from the lower end of the down frame portion 13a, and an inclined portion 13bb inclined upward from the rear end of the horizontal portion 13ba.

  The connecting frame 17 is disposed above the lower frame portion 13b of the both side frames 13 and below the floor 26, and is formed in a substantially U shape with the front end closed in a plan view and the rear end portion. The U-shaped portion 32 connected to the inclined portion 13bb in the lower frame portion 13b of the both side frames 13, and the down frame portion 13a in the both side frames 13 near the center in the width direction of the front end portion of the U-shaped portion 32. And a support portion 33 connected to the continuous portion of the lower frame portion 13b. In this embodiment, the U-shaped portion 32 is formed by bending a single pipe material having a smaller diameter than the side frame 13. In addition, the support portion 33 constituted by a pair of left and right pipe members 34, 34 is located at two locations near the center in the width direction of the front end portion of the U-shaped portion 32. And connecting the connecting portion of the lower frame portion 13b.

  Thus, in a side view, the lower frame portion 13b of the side frame 13 and the U-shaped portion 32 having a smaller diameter than the side frame 13 and disposed above the lower frame portion 13b are opposed to each other below the floor 26. It will be arranged so that it may line up and down.

  The center frame 14 has a horizontally-long rectangular cross-sectional shape in which the width W1 in the vehicle width direction (see FIG. 4) is larger than the width W2 in the front-rear direction (see FIG. 2), and is composed of a rectangular tube-like pipe. It may be a thing and may be cast-molded. The lower end of the center frame 14 whose upper portion is connected to the main pipe 15 is joined to the center in the width direction of the front end portion of the U-shaped portion 32 in the connection frame 17. Thus, in a side view, the down frame portion 13a of the side frame 13 and the center frame 14 that looks like a pipe material having a smaller diameter than the down frame portion 13a are arranged in a pair in front of and behind the floor 26. Will be placed.

  A pair of left and right rear subframes 18 at least partially disposed behind the rising frame portion 13c are attached to both the side frames 13 in this embodiment. In this embodiment, the rear subframe 18 The frame 13 is disposed so as to bypass the bent portion K from below the lower frame portion 13b and extend to the rear of the rising frame portion 13c, and the front end of the rear subframe 18 is joined to the U-shaped portion 32 of the connecting frame 17. The rear end of the rear sub-frame 18 is joined to the lower surface of the side frame 13 closer to the front of the seat rail portion 13d.

  Moreover, the middle part of both rear subframes 18 is bent so as to be close to the rising frame part 13c side of the side frame 13, and the side frames 13 and both rear subframes are below the bent part. Pivot plates 36 are respectively provided between 18.

  The rear subframe 18 is made of a pipe material having a smaller diameter than that of the side frame 13, and in a side view, the lower frame portion 13b and the rising frame portion 13c of the side frame 13, and the rear subframe 18 made of a small diameter pipe material, Are arranged so as to form a pair below and behind the floor 26.

  As clearly shown in FIG. 1, a radiator 37 is disposed between the down frame portions 13 a of the both side frames 13 and the center frame 14, and the upper surface of the floor 26 is below the vertical center position CP of the radiator 37. Set to position.

  As clearly shown in FIG. 4, the pair of left and right support arms 38 provided on the upper portion of the radiator 37 is elastically supported by a pair of left and right stays 39 provided on the front cross member 16. Also, the left and right ends of the guard pipe 40 that covers the lower portion of the radiator 37 from the front side are joined to the front surfaces of the lower ends of the down frame portions 13a of the side frames 13 and the stay 41 directed toward the center of the guard pipe 40. Further, the lower center of the radiator 37 is elastically supported.

  Referring also to FIG. 5, a support plate 43 is fixed to the lower frame portion 13 b and the rising frame portion 13 c of the side frame 13 (that is, the bent portion K) so as to protrude rearward. A bracket 44 is provided below the engine E in the power unit P.

  Thus, the link mechanism 42 is connected to the pair of left and right first link arms 46 rotatably supported on the pivot plate 36 via the body frame side pivot shaft 45 and the other end of the first link arm 46. A second link arm 48 whose one end portion is rotatably connected via a shaft 47, and a power unit side pivot shaft fixed to the other end portion of the second link arm 48 and rotatably supported by the bracket 44. 49, a restriction arm 51 having one end connected to the power unit side pivot shaft 49 and extending upward, and an intermediate portion rotatably supported on the support plate 43 via the pivot 50, And an elastic member 52 attached to the end, and the rotation of the restricting arm 51 causes the elastic member 52 to rise on the side frame 13. A position in contact resiliently the lower rear surface of the said regulation plate portion 43a provided on the support plate 43 the elastic member 49 is restricted between a position in contact spring from the front.

  In addition, the vehicle body frame side pivot shaft 45 of the link mechanism 42 is disposed in front of the rear surface of the rising frame portion 13c in the side frame 13, and the power unit side pivot shaft 49 is arranged in front wheel WF as shown in FIG. Is arranged in a virtual arc C passing through the center of rotation of the front wheel WF with the handle grip 22 as a center on a projection view onto a plane orthogonal to the rotation axis of the front wheel WF.

  Next, the operation of the first embodiment will be described. The vehicle body frame FA includes a down frame portion 13a hanging downward from the head pipe 12 and a lower frame portion 13b extending rearward from the lower end of the down frame portion 13a. A pair of left and right side frames 13 respectively, a center frame 14 that hangs downward from the head pipe 12 between the side frames 13, and a center frame 14 and both side frames disposed above the lower frame portion 13b. .. Are provided below the floor 26 which is a low floor type, so that the positions of the lower frame portions 13b of the side frames 13 are set sufficiently below. The head pipe 12 between the side frames 13 and the side frames 13 The connecting frame 17 that reinforces the center frame 14 that hangs downward is disposed above the lower frame portion 13b and below the floor 26, thereby forming a flat floor 26 with sufficient footrest space. Thus, the usability can be improved and the balance between the longitudinal rigidity and the torsional rigidity of the vehicle body frame FA can be improved.

  Such an effect is not only the connection frame 17 having the U-shaped part 32 and the support part 33, but also a straight line between the rear part of the lower frame part 13b of the side frame 13 and the down frame part 13a in a substantially horizontal plane. This can also be achieved by configuring the connecting frame so as to be tied together.

  In addition, since the center frame 14 has a horizontally-long rectangular cross section, the rigidity of the center frame 14 is enhanced while facilitating securing the space for installing the center frame 14 disposed in front of the floor 26 in the front-rear direction. Can do.

  The connection frame 17 is formed in a substantially U shape with the front end closed in plan view, and the rear end portion is connected to both side frames 13 and the front end width of the U shape portion 32. It has a support portion 33 that connects the side in the center of the direction to the side frame 13, and forms a flat floor 26 with sufficient footrest space while ensuring sufficient rigidity, improving usability, The torsional rigidity of the vehicle body frame FA can be adjusted.

  Such an effect can be achieved even if the center frame 14 is omitted.

  Further, a gusset 31 is provided between the main pipe 15 and the head pipe 12 suspended from the head pipe 12, and upper ends of the down frame portions 13 a included in both side frames 13 are joined to both the head pipe 12 and the gusset 31. As a result, the joint rigidity between the side frames 13 and the head pipe 12 can be increased, and the upper part of the center frame 14 is connected to the main pipe 15, so that the upper rigidity of the center frame 14 can be increased.

  In addition, the side frame 13 includes a down frame portion 13a that hangs downward from the head pipe 12, a lower frame portion 13b that continues to the lower end of the down frame portion 13a and extends rearward under the floor 26, and a lower frame portion. 13b, which is connected to the rear end of the floor 26 and rises upward behind the floor 26, and a seat rail portion 13d extending rearward from the upper end of the rise frame 13c. Thus, the number of parts can be reduced, and the number of assembling steps of the vehicle body frame FA can be reduced.

  Further, the side frame 13, the center frame 14 having a smaller diameter than the side frame 13 and reinforcing the side frame 13, the U-shaped portion 32 of the connecting frame 17, and the rear subframe 18 are located in front and below the floor 26 in a side view. Since they are arranged side by side so as to form a pair at the rear, it is possible to configure a light and highly rigid body frame FA.

  Further, a radiator 37 is arranged between the down frame portions 13a of the both side frames 13 and the center frame 14, and the space of the flat floor 26 is enlarged, and the vertical length of the radiator 37 is increased to increase the capacity of the radiator 37. And the cooling performance of the engine E can be improved. In addition, since the upper surface of the floor 26 is set at a position lower than the vertical center position CP of the radiator 37, the position of the floor 26 can be set as low as possible to improve boarding / exiting performance.

  Further, a pair of left and right rear subframes 18, at least a part of which are arranged behind the rising frame portion 13 c, are attached to both the side frames 13, and between the side frames 13 and the reside frames 13. The vehicle body frame side pivot shaft 45 of the link mechanism 42 provided between the vehicle body frame FA and the power unit P is supported on the pivot plate 36 provided on the vehicle body frame, so that the vehicle body frame side pivot shaft is avoided while increasing the size of the side frame 13. The rigidity around 45 can be increased, and the rear space of the floor 26 can be expanded by avoiding the enlargement of the side frame 13.

  In addition, since the vehicle body frame side pivot shaft 45 of the link mechanism 42 is disposed in front of the rear surface of the rising frame portion 13c, the vehicle body frame side pivot shaft 45 of the link mechanism 42 is disposed at the front position as much as possible. Can be shortened.

  Further, since the middle part of both rear subframes 18 is bent so as to be close to the rising frame part 13c side of the side frames 13, the power unit P while avoiding interference with the rear subframes 18 ... It is possible to shorten the wheel base by arranging P.

  Further, the power unit side pivot shaft 49 of the link mechanism 42 is disposed in a virtual arc C passing through the center of rotation of the front wheel WF with the handle grip 22 as a center on the projection onto the plane orthogonal to the rotation axis of the front wheel WF. As a result, the power unit side pivot shaft 49 of the link mechanism 42 can be arranged as far forward as possible to further shorten the wheel base.

  6 to 10 show a second embodiment of the present invention, FIG. 6 is a side view of a scooter type vehicle, FIG. 7 is a side view of a vehicle body frame, FIG. 8 is a plan view as viewed in the direction of arrow 8 in FIG. 9 is a front view taken along arrow 9 in FIG. 7, and FIG. 10 is a side view showing the structure of the link mechanism.

  In the description of the second embodiment, the portions corresponding to the first embodiment are indicated by the same reference numerals and are not illustrated in detail.

  First, in FIG. 6, in the body frame FB provided in the scooter type vehicle having the low floor type floor 26, the front part of the power unit P composed of the engine E and the transmission M can swing up and down via the link mechanism 72. A rear cushion unit 23 is provided between the rear part of the vehicle body frame FB and the rear part of the power unit P.

  Referring to FIGS. 7 to 9 together, the vehicle body frame FB includes the head pipe 12, a pair of left and right side frames 53 whose front end portions are joined to the head pipe 12, and pipe members and both sides. A center frame 54 that hangs downward from the head pipe 12 through the vicinity of the front portion of the side frame 53 between the frames 53... And extends below the floor 26 of the vehicle body cover 24. A connection frame 55 connected to the side frames 53, and a support stay 56 disposed below the connection frames 55 to connect the side frames 53 and connect the lower end of the center frame 54 to each other. , The front cross-mesh for connecting the front portions of the side frames 53 and joining the lower ends of the main pipes 15. The first intermediate cross member 58 that connects the bar 57 and the intermediate portions of the side frames 53, and the second intermediate portion that connects the intermediate portions of the side frames 53 behind the first intermediate cross member 58. An intermediate cross member 59, a rear cross member 60 connecting the rear ends of the side frames 53, and a pair of left and right rear subframes 61 attached to the side frames 53 are provided.

The side frame 53 includes a down frame portion 53a that hangs downward from the head pipe 12, a lower frame portion 53b that continues to the lower end of the down frame portion 53a and extends rearward below the floor 26, and a rear frame portion 53b. A rising frame portion 53c which is integrally connected to the end via a bent portion K bent forward and to the rear extension axis of the lower frame portion 53b and rises upward from the bent portion K behind the floor 26; A single pipe having a larger diameter than the center frame 54 is bent and formed integrally with a seat rail 53d extending rearward from the upper end of the rising frame 53c to support the riding seat 30. The seat rail portions 53d of the side frames 53 are closer to each other as they move rearward. It is formed to be inclined.

  Thus, the front cross member 57 connects between the intermediate portions of the down frame portions 53a of the side frames 53, and the first intermediate cross member 58 is an upper portion of the rising frame portion 53c of the side frames 53. The second intermediate cross member 60 connects the intermediate portions of the seat rail portions 53d in the side frames 53.

  The upper ends of the down frame portions 53a in both side frames 53 are joined to the head pipe 12, and a lower gusset 62 is provided between the lower portion of the joint portion of the down frame portions 53a to the head pipe 12 and between the head pipes 12. Provided. Further, an upper gusset 63 is provided between an upper portion of the joint portion of the down frame portions 53a... To the head pipe 12 and between the head pipes 12, and an upper end portion of the center frame 54 is joined to the upper gusset 63.

  The lower frame portion 53b includes a horizontal portion 53ba extending substantially horizontally rearward from the lower end of the down frame portion 53a, and an inclined portion 53bb inclined upward from the rear end of the horizontal portion 53ba.

  The connecting frame 55 is disposed above the lower frame portion 53b of the side frame 53 and below the floor 26 and extends in the front-rear direction. The front end is joined to the lower portion of the down frame portion 53a in the side frame 53, and the rear The end is joined to the inclined portion 53bb in the lower frame portion 53b of the side frame 53.

  A pair of left and right rear subframes 61, at least a part of which are arranged behind the rising frame portions 53c, are attached to the side frames 53. In this embodiment, the rear subframe 61 The frame 53 is disposed so as to bypass the bent portion K from below the lower frame portion 53b and extend to the rear of the rising frame portion 53c, and the front end of the rear subframe 61 is more than the joint portion of the rear end of the connecting frame 55. The front end is joined to the front rear surface of the inclined portion 53bb in the lower frame portion 53b, and the rear end of the rear sub frame 61 is joined to the lower surface of the side frame 53 near the front portion of the seat rail portion 53d.

  Moreover, the middle part of both rear subframes 61 is bent so as to be close to the rising frame part 53c side of the side frame 53, and both side frames 53 and both rear subframes are below the bent part. 61... Are respectively provided with pivot plates 64.

  The rear subframe 61 is made of a pipe material having a smaller diameter than that of the side frame 53. In side view, the lower frame portion 53b and the rising frame portion 53c of the side frame 53, and the rear subframe 61 made of a small diameter pipe material, Are arranged so as to form a pair below and behind the floor 26.

  As clearly shown in FIG. 6, a radiator 37 is disposed between the down frame portions 53 a of both the side frames 53 and the center frame 54, and the upper surface of the floor 26 is below the center position CP in the vertical direction of the radiator 37. Set to position.

  As clearly shown in FIG. 9, the pair of left and right support arms 38, 38 provided on the upper portion of the radiator 37 are elastically supported by a pair of left and right stays 65, 65 provided on the front cross member 57. Further, the left and right ends of the guard pipe 40 that covers the lower portion of the radiator 37 from the front side are joined to the front surfaces of the lower ends of the down frame portions 53a of the side frames 53, and the stay 41 directed toward the center portion of the guard pipe 40. Further, the lower center of the radiator 37 is elastically supported.

  Referring also to FIG. 10, a support plate 67 is fixed to the rear subframe 61 located on the left side in a state of facing the front in the traveling direction of the motorcycle so as to protrude rearward, and the engine E in the power unit P is fixed. A bracket 44 is provided at the lower part.

  Thus, the link mechanism 72 is provided at the other end of the pair of left and right first link arms 74 rotatably supported on the pivot plate 64 via the vehicle body frame side pivot shaft 73 and the first link arms 74. A second link arm 76 having one end rotatably connected via a connecting shaft 75, and a power unit side pivot fixed to the other end of the second link arm 76 and rotatably supported by the bracket 44. The second link arm 76 is located outside the second link arm 76 located on the left side with the shaft 77 and the two second link arms 76 facing forward in the traveling direction of the motorcycle and via the connecting pipe 78. And an arm 79 whose one end is connected to the middle of the power unit and whose other end is connected to the end of the power unit side pivot shaft 77, and a second link arm 76 on the left side. One end of the arm 79 is connected to the power unit side pivot shaft 77 and extends upward, and the other end is connected to the support plate 67 via a pivot 80, and a restriction arm 81 is provided. The intermediate portion is connected to the support plate 67 via a rubber bush 82 and a connecting shaft 83.

  In addition, the restriction arm 81 is integrally provided with a restriction protrusion 84 that protrudes upward, and a recess 85 that accommodates the restriction protrusion 84 is provided in the support plate 67, and the restriction arm 81 around the axis of the pivot 80 is provided. The rotation is restricted within a range in which the restricting protrusion 84 can move within the recess 85.

  In addition, the vehicle body frame side pivot shaft 73 of the link mechanism 72 is disposed in front of the rear surface of the rising frame portion 53c in the side frame 53, and the power unit side pivot shaft 77 is arranged in the front wheel WF as shown in FIG. Is arranged in a virtual arc C passing through the center of rotation of the front wheel WF with the handle grip 22 as a center on a projection view onto a plane orthogonal to the rotation axis of the front wheel WF.

  Next, the operation of the second embodiment will be described. The vehicle body frame FB includes a down frame portion 53a hanging downward from the head pipe 12 and a lower frame portion 53b extending rearward from the lower end of the down frame portion 53a. A pair of left and right side frames 53, respectively, a center frame 54 that hangs downward from the head pipe 12 between the side frames 53, and a front end portion above the lower frame portions 53b of the side frames 53. Are connected to the down frame portions 53a and the rear end portions are connected to the lower frame portions 53b, and the lower frame portions 53b of the side frames 53 are connected to each other. Side frame from the head pipe 12 between the support stay 56 and both side frames 53. 53, and a center frame 54 that hangs downward through the vicinity of 53 and has a lower end connected to the support stay 56, and the connecting frame 55 is disposed below the floor 26, which is a low floor type. The positions of the lower frame portions 53b of the side frames 53 are set sufficiently downward to reinforce the side frames 53 and the center frame 54 suspended downward from the head pipe 12 between the side frames 53. The support stay 56 and the connecting frame 55 are arranged above the lower frame portion 53b and below the floor 26, thereby forming a flat floor 26 with sufficient footrest space and improving usability. The balance between the longitudinal rigidity and the torsional rigidity of the body frame FB can be improved.

  The side frame 53 includes a down frame portion 53a that is suspended downward from the head pipe 12, a lower frame portion 53b that is continuous with the lower end of the down frame portion 53a and extends rearward under the floor 26, and a lower frame portion. 53b and a rising frame portion 53c that rises upward behind the floor 26 and a seat rail portion 53d that extends rearward from the upper end of the rising frame portion 53c are integrally formed, and each single pipe is bent. Thus, the number of parts can be reduced, and the number of assembling steps for the body frame FB can be reduced.

  Further, the side frame 53, the center frame 54 having a smaller diameter than the side frame 53, and the rear sub frame 61 having a smaller diameter than the side frame 53 are paired at the front, lower and rear of the floor 26 in a side view. Therefore, a lightweight and highly rigid body frame FA can be configured.

  Further, a radiator 37 is arranged between the down frame portions 53a of the both side frames 53 and the center frame 54. The space of the flat floor 26 is expanded, and the radiator 37 is increased in vertical length to increase the capacity of the radiator 37. And the cooling performance of the engine E can be improved. In addition, since the upper surface of the floor 26 is set at a position lower than the vertical center position CP of the radiator 37, the position of the floor 26 can be set as low as possible to improve boarding / exiting performance.

  Further, a pair of left and right rear sub-frames 61, at least a part of which are arranged behind the rising frame portion 53c, are attached to both the side frames 53, and between the side frames 53 and the reside frames 53. The vehicle body frame side pivot shaft 73 of the link mechanism 72 provided between the vehicle body frame FB and the power unit P is supported on the pivot plate 64 provided on the vehicle body frame, so that the vehicle body frame side pivot shaft is avoided while increasing the size of the side frame 53. The rigidity around 73 can be increased, and the rear space of the floor 26 can be expanded by avoiding an increase in the size of the side frame 53.

  In addition, since the vehicle body frame side pivot shaft 73 of the link mechanism 72 is disposed in front of the rear surface of the rising frame portion 53c, the vehicle body frame side pivot shaft 73 of the link mechanism 72 is disposed as far as possible in the wheel base. Can be shortened.

  Further, since the middle part of both rear sub-frames 61 is bent so as to be close to the rising frame part 53c ... side of the side frames 53 ..., the power unit P avoids interference with the rear sub-frames 61 ... It is possible to shorten the wheel base by arranging P.

  Further, the power unit side pivot shaft 77 of the link mechanism 72 is disposed in a virtual arc C passing through the center of rotation of the front wheel WF with the handle grip 22 as a center on the projection onto the plane orthogonal to the rotation axis of the front wheel WF. As a result, the power unit side pivot shaft 77 of the link mechanism 72 can be arranged as far forward as possible to further shorten the wheel base.

  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.

It is a side view of the scooter type vehicle of 1st Example. It is a side view of a body frame. FIG. 3 is a plan view taken in the direction of arrow 3 in FIG. 2. FIG. 4 is a front view taken along arrow 4 in FIG. 2. It is a vertical side view which shows the structure of a link mechanism. It is a side view of the scooter type vehicle of 2nd Example. It is a side view of a body frame. FIG. 8 is a plan view taken along arrow 8 in FIG. 7. FIG. 9 is a front view taken along arrow 9 in FIG. 7. It is a side view which shows the structure of a link mechanism.

DESCRIPTION OF SYMBOLS 11 ... Front fork 12 ... Head pipe 13 ... Side frame 13a ... Down frame part 13b ... Lower frame part 13c ... Rising frame part 13d ... Seat rail part 14 ... Center frame 18 as a pipe member ... Rear subframe 26 as a pipe member ... Floor 32 ... U-shaped portion 36 as a pipe member ... Pivot plate 42 ... Link mechanism 45 ... Body frame side pivot shaft F ... Body frame K ... Bending part P ... Power unit WF ... Front wheel

Claims (5)

In the frame structure of a scooter type vehicle in which a pair of left and right side frames (13, 53) are joined to a head pipe (12) that supports a front fork (11) that pivotally supports a front wheel (WF).
The pair of left and right side frames (13, 53) includes a lower frame portion (13b, 53b) that passes under the floor (26) and a rear frame at the rear end of the lower frame portion (13b, 53b). Standing frame portion that is integrally connected via a bent portion (K) bent forward with respect to the rearward extension axis of the portions (13b, 53b) and rises upward from the bent portion (K) behind the floor (26) (13c, 53c)
A pair of left and right rear sub-frames arranged so as to extend from behind the pair of left and right lower frame portions (13b, 53b) to the rear of the rising frame portion (13c, 53c), bypassing the bent portion (K). 18 and 61) are connected to the pair of left and right lower frame parts (13b and 53b), respectively, and the rear end parts of both rear subframes (18 and 61) are connected to the bent part (K). It is connected to the side frames (13, 53) on the rear side,
Pivot plates (36, 64) are provided between the side frames (13, 53) and the rear sub-frames (18, 61).
Link mechanism (42, 72) provided between the vehicle body frame (FA, FB) and the power unit (P) including the head pipe (12), the both side frames (13, 53), and the rear subframe (18, 61). The vehicle body frame side pivot shaft (45, 73) is supported by the pivot plate (36, 64).   The intermediate part of both the rear sub-frames (18, 61) is bent so as to be close to the rising frame part (13c, 53c) side of the both side frames (13, 53). The frame structure of a scooter type vehicle.   The both side frames (13, 53) include a down frame part (13a, 53a) hanging downward from the head pipe (12) and the lower frame part connected to the lower end of the down frame part (13a, 53a). (13b, 53b), the rising frame portion (13c, 53c) connected to the rear end of the lower frame portion (13b, 53b) via the bent portion (K), and the riding seat (30) are supported. The seat frame portion (13d, 53d) extending rearward from the upper end of the rising frame portion (13c, 53c) is integrally formed, and each single pipe is bent. The frame structure of the scooter type vehicle according to 1 or 2.   The side frame (13, 53) and pipe members (14, 32, 18; 57, 55, 61) that reinforce the side frame (13, 53) with a smaller diameter than the side frame (13, 53). The frame structure of the scooter type vehicle according to claim 3, wherein the frame structure is arranged side by side so as to form a pair in front, below and behind the floor (26) in a side view.   The vehicle body frame side pivot shaft (45, 73) of the link mechanism (42, 72) is forward of the rear surface of the rising frame portion (13c, 53c) and below the lower frame portion (13b, 53b). The frame structure of the scooter type vehicle according to any one of claims 1 to 4, wherein the frame structure is arranged.

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