JP5765184B2 - Body frame structure of motorcycle - Google Patents

Description

  The present invention relates to a body frame structure of a motorcycle.

  Generally, the torsional rigidity of the vehicle body frame that greatly contributes to the handling stability of the motorcycle is determined by the rigidity from the head pipe to the pivot pipe.

  If the main frame whose front end is coupled to the head pipe is directly connected to or coupled to the pivot pipe, the torsional rigidity of the body frame is improved. However, in a motorcycle having an underbone-type body frame, it is difficult to directly connect or connect the main frame to the pivot pipe because there is a restriction due to the shape of an engine crankcase or the like.

  Therefore, like the body frame structure of a motorcycle described in Patent Document 1, the rear end portion of the main frame is connected to the pivot pipe via separate parts (a seat pillar and a plate member).

JP 2008-296832 A

  However, the vehicle body frame structure described in Patent Document 1 described above has a structure in which the front side of the pivot pipe in the suspension plate (pivot plate) on which the pivot pipe is installed is opened. For this reason, the rigidity of the suspension plate is low, and therefore the rigidity (including torsional rigidity) of the body frame may not be improved.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a body frame structure for a motorcycle that can reliably improve the rigidity of the body frame.

  The present invention provides a main frame that extends rearward and downward from the head pipe, and a swing arm that is joined to a rear portion of the main frame and extends downward, and swingably supports a rear wheel. In a motorcycle body frame structure having a pair of suspension plates, a pivot pipe is fixed to the pair of suspension plates through the suspension plates, and a rear portion of the engine is disposed above the pivot pipe. Further, an engine support portion is provided in the pair of suspension plates, and extends vertically from the bottom surface of the main frame to the pivot pipe at the rear of the engine support portion in a vehicle side view. And the front end of the vertically extending portion along the main frame to the front edge of the suspension plate A reinforcing plate having a front extending portion is disposed, and the vertical extending portion of the reinforcing plate is joined to at least the lower surface of the main frame, the upper outer peripheral surface of the pivot pipe, and the inner surfaces of the pair of suspension plates. In addition, the forward extension portion is configured to be joined to at least a side surface of the main frame and an inner side surface of the pair of suspension plates.

  According to the present invention, the pair of suspension plates are reinforced in the vehicle width direction by the vertically extending portion of the reinforcing plate, and the pair of suspension plates are reinforced in the vehicle longitudinal direction and the vehicle width direction by the front extending portion. The strength of the pair of suspension plates can be increased. As a result, the rigidity of the pair of suspension plates can be improved, and as a result, the rigidity of the body frame can be reliably improved.

1 is a left side view showing a motorcycle to which an embodiment of a body frame structure of a motorcycle according to the present invention is applied. The left view which shows the vehicle body frame of FIG. Sectional drawing which follows the III-III line | wire of FIG. The perspective view which shows the vehicle body frame of FIG. FIG. 3 is a perspective view showing the vehicle body frame of FIG. FIG. 3 is a perspective view showing the vehicle body frame of FIG. 2 as viewed from diagonally forward. The left side view which removes the left side suspension plate of the left-right pair of suspension plate in the vehicle body frame of FIG. 2, and shows with a part of engine unit. The perspective view which shows the reinforcement plate of FIG.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a left side view showing a motorcycle to which an embodiment of a body frame structure of a motorcycle according to the present invention is applied. FIG. 2 is a left side view showing the vehicle body frame of FIG. In the present embodiment, front / rear, left / right, and upper / lower expressions are based on the driver when riding the motorcycle.

  A body frame 2 of the motorcycle 1 is an underbone type, and a main frame 4 extends rearward and obliquely downward from a head pipe 3 located at the frontal portion, and a pair of left and right rear frames (from the vicinity of the rear end portion of the main frame 4) A seat rail 5) extends rearward and obliquely upward, and a rear frame (seat pillar 6) that supports the seat rail 5 is arranged behind the seat rail 5. In addition, a suspension bracket 7 is attached to the main frame 4 in the vicinity of the connecting portion with the seat rail 5, and a pair of left and right suspension plates 8 are joined to the rear end portion of the main frame 4 and extended downward. Yes.

  A front fork 10 that pivotally supports a front wheel 9 is pivotally supported on the head pipe 3 together with a handle bar 11, a headlamp 12, a front fender 13, and the like so as to be rotatable left and right. On the other hand, a swing arm 17 that pivotally supports the rear wheel 16 is supported by a pivot pipe 15 (described later) installed on the suspension plate 8 so as to be swingable in the vertical direction. A rear cushion unit 18 is connected between the rear portion of the swing arm 17 and the seat rail 5.

  As shown in FIGS. 2 and 3, a pivot pipe 15 is fixed through the pair of left and right suspension plates 8, and the upper engine support portion 20 and the pivot pipe 15 are disposed in front and above the pivot pipe 15. Lower engine support portions 21 are formed on the front and lower sides, respectively. The rear portions of the engine unit 22 (FIG. 1) are supported by the engine support portions 20 and 21, the front upper portion of the engine unit 22 is supported by the suspension bracket 7, and the engine unit 22 is suspended on the vehicle body frame 2.

  In the engine unit 22, an engine 27 in which a cylinder assembly 24 (cylinder 25 and cylinder head 26) extends from the crankcase 23 in a substantially horizontal direction, a transmission 28 that changes the rotational force from the engine 27, and the like are integrated. Is configured. The output from the transmission 28 and the like is transmitted to the rear wheel 16 via a drive chain (not shown) in the chain case 29, and the rear wheel 16 is driven.

  A storage box 30 having a bottomed box shape made of synthetic resin and having an upper surface opened is disposed at an upper portion near the connecting portion between the main frame 4 and the seat rail 5. A fuel tank 31 is supported between the seat rails 5 behind the storage box 30. The storage box 30 has a capacity capable of storing a helmet or the like.

  A seating seat 32 is provided so as to cover the upper part of the storage box 30 and the fuel tank 31. The front end portion of the seating seat 32 is pivotally supported by a seat hinge 33 provided at the front upper portion of the storage box 30. The seating seat 32 is opened and closed by lifting the rear end upward with the seat hinge 33 as an axis, and thereby, articles are taken in and out of the storage box 30, and fuel is supplied to the fuel tank 31, for example.

  The front part of the body frame 2 is covered with a front cover 34 and a leg shield 35. Further, the lower side of the seating seat 32 and the left and right sides of the storage box 30 and the fuel tank 31 are covered with a pair of left and right frame covers 36. The front cover 34, leg shield 35, and frame cover 36 are made of synthetic resin. Further, a rear fender 37 that covers the rear wheel 16 from above is disposed below the fuel tank 31. The rear fender 37 is also made of synthetic resin together with the front fender 13. A tail lamp 38 is installed at the rear end of the frame cover 36.

  By the way, the main frame 4 is formed of a square pipe having a quadrangular cross section, as shown in FIGS. The seat rail 5 and the seat pillar 6 are also formed of square pipes having a quadrangular cross section, as shown in FIGS. A suspension bracket 7 is fixed to the lower surface 4B of the main frame 4, and a pair of left and right seat rails 5 are joined (welded) to both side surfaces 4C and 4D of the main frame 4, respectively.

  Further, the pair of left and right seat pillars 6 are bent inwardly and brought toward the center in the vehicle width direction, with the side surfaces facing each other in contact with each other, as shown in FIGS. Is joined (welded) to the rear end portion 40 of the head. At this time, the width dimension W1 (FIG. 5) in the vehicle width direction of the portion of the pair of seat pillars 6 where the side surfaces facing each other are in contact with each other is set wider than the width dimension W2 (FIG. 3) of the main frame 4. The entire circumference of the rear end portion 40 of the frame 4 is configured to be able to be joined (welded) to the pair of seat pillars 6.

  Further, as shown in FIG. 7, the pair of seat pillars 6 are joined (welded) to the upper outer peripheral surface 15 </ b> A of the pivot pipe 15 that is erected on the pair of left and right suspension plates 8. As shown in FIG. 2, the pair of seat pillars 6 are joined to the rear end portion 40 of the main frame 4 and joined to the pivot pipe 15, so that the main end of which the front end portion is joined to the head pipe 3. The frame 4 is coupled to the pivot pipe 15 via the seat pillar 6 and the torsional rigidity of the vehicle body frame 2 is improved. Thereby, the steering stability of the motorcycle 1 is ensured.

  As shown in FIGS. 2 and 3, the pair of left and right suspension plates 8 have upper end edges 39 in the vicinity of the surface 4A of the main frame 4 or the surface 4A on the side surfaces 4C and 4D (upper surface 4A in this embodiment). To (welded). Further, the pair of suspension plates 8 are gradually expanded in the vehicle width direction and extended downward.

  Further, as shown in FIG. 5, the pair of left and right suspension plates 8 are joined (welded) to each other with their rear portions bent toward the center in the vehicle width direction. The rear portion of the pair of suspension plates 8 joined to each other constitutes the rear wall 41 of the suspension plate 8, whereby the pair of suspension plates 8 are configured in a box shape with the front opening.

  Now, as shown in FIGS. 6, 7, and 8, a vertical extension portion 42, a front extension portion 43, and a tip extension portion 44 are integrated inside the pair of left and right suspension plates 8. In order to avoid interference with the rear portion of the engine unit 22, a reinforcing plate 45 formed in a crank shape is disposed.

  The vertical extending portion 42 of the reinforcing plate 45 is located behind the upper engine support portion 20 in the suspension plate 8 from the lower surface 4B of the main frame 4 to the upper outer peripheral surface 15A of the pivot pipe 15 in a side view of the vehicle shown in FIG. It is configured to extend substantially vertically. As shown in FIGS. 3 and 7, the vertical extension 42 is joined (welded) to the lower surface 4B of the main frame 4, the upper outer peripheral surface 15 </ b> A of the pivot pipe 15, and the inner surfaces 8 </ b> A of the pair of suspension plates 8. The As a result, the pair of suspension plates 8 are reinforced by the vertical extending portions 42 in the vehicle width direction strength at the upper portion of the pivot pipe 15.

  As shown in FIGS. 3, 7, and 8, the front extending portion 43 of the reinforcing plate 45 extends from both sides of the upper end of the vertical extending portion 42 to the front end edge 46 of the suspension plate 8 along the main frame 4. A pair of left and right is formed extending forward. In the front extension 43, the inner edge 43 </ b> A is joined (welded) to the vicinity of the lower surface 4 </ b> B side of the side surfaces 4 </ b> C and 4 </ b> D of the main frame 4 and the outer edge 43 </ b> B is joined to the inner surface 8 </ b> A of the suspension plate 8. As a result, the pair of suspension plates 8 are reinforced by the front extension portions 43 in the vehicle front-rear direction and the vehicle width direction in the front upper portion of the pivot pipe 15.

  In particular, as shown in FIG. 3, the cross section formed by the front extension 43, the main frame 4, and the suspension plate 8 of the reinforcing plate 45 is configured in a triangular shape or a trapezoidal shape (in this embodiment, a triangular shape). Has been. Thereby, the strength in the vehicle front-rear direction and the vehicle width direction of the front upper portion of the pivot pipe 15 in the pair of suspension plates 8 is further reinforced.

  Further, as shown in FIGS. 7 and 8, the distal end extending portion 44 of the reinforcing plate 45 is bent and extended upward from the distal end (front end) of the front extending portion 43. The distal end extending portion 44 substantially closes an opening 47 (FIG. 3) having a triangular cross section formed by the front extending portion 43 of the reinforcing plate 45, the main frame 4, and the suspension plate 8. As a result, the strength in the vehicle width direction in the vicinity of the front end edge 46 of the pair of suspension plates 8 is reinforced by the tip extending portion 44.

  With the configuration as described above, the following effects (1) to (4) are achieved according to the present embodiment.

  (1) The vertically extending portion 42 of the reinforcing plate 45 disposed in the pair of suspension plates 8 is joined to the lower surface 4B of the main frame 4, the upper outer peripheral surface 15A of the pivot pipe 15, and the inner surface 8A of the suspension plate 8. The front extension 43 of the reinforcing plate 45 is joined to the side surfaces 4C and 4D of the main frame 4 and the inner side surface 8A of the suspension plate 8.

  For this reason, the upper part of the pivot pipe 15 in the pair of suspension plates 8 can be reinforced in the vehicle width direction by the vertical extension part 42, and the front upper part of the pivot pipe 15 in the pair of suspension plates 8 by the front extension part 43. Since the portion can be reinforced in the vehicle longitudinal direction and the vehicle width direction, the strength of the pair of reinforcing plates 8 can be increased. As a result, the rigidity of the pair of suspension plates 8 can be improved, and as a result, the rigidity of the body frame 2 can be reliably improved.

  (2) Since the front section 43 of the reinforcing plate 45, the main frame 4 and the suspension plate 8 have a triangular cross section, the vehicle longitudinal direction of the front upper portion of the pivot pipe 15 in the pair of suspension plates 8 In addition, the strength in the vehicle width direction can be further reinforced. As a result, the rigidity of the pair of suspension plates 8 can be further improved.

  (3) In the reinforcing plate 45, a tip extending portion 44 is bent and extended upward at the tip (front end) of the front extending portion 43, and the tip extending portion 44 extends forward of the reinforcing plate 45. An opening 47 having a triangular cross section formed by the portion 43, the main frame 4 and the suspension plate 8 is substantially closed. For this reason, the strength of the pair of main frames 8 in the vicinity of the front end edge 46 in the vehicle width direction can be reinforced, and the rigidity of the pair of suspension plates 8 can be further improved.

  (4) Since the main frame 4 extending from the head pipe 3 is coupled to the pivot pipe 15 via the seat pillar 6, the torsional rigidity of the vehicle body frame 2 can be increased, and thereby the steering stability of the motorcycle 1 can be increased. Can be secured.

  As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to this, A various deformation | transformation can be made in the range which does not deviate from the main point of this invention. For example, although the rear end portion 40 of the main frame 4 is directly joined to the seat pillar 6, it may be coupled to the seat pillar 6 via a bracket or the like.

DESCRIPTION OF SYMBOLS 1 Motorcycle 2 Body frame 3 Head pipe 4 Main frame 4A Upper surface 4B Lower surface 4C, 4D Side surface 8 Suspension plate 8A Inner side surface 15 Pivot pipe 15A Upper outer peripheral surface 16 Rear wheel 17 Swing arm 20 Upper engine support part 22 Engine unit 27 Engine 39 Upper end edge 42 Vertical extension 43 Front extension 44 Front extension 45 Reinforcement plate 46 Front edge 47 Opening

Claims (3)

A main frame extending downward and rearward from the head pipe;
In a vehicle body frame structure of a motorcycle having a pair of left and right suspension plates that are joined to the rear portion of the main frame and extend downward, swingably support a swing arm that pivotally supports a rear wheel, and suspend an engine. ,
A pair of the suspension plates has a pivot pipe fixed through the suspension plates, and an engine support portion for supporting a rear portion of the engine is provided above the pivot pipe.
Further, in the pair of suspension plates, as viewed from the side of the vehicle, a rearward extension of the engine support portion extends substantially vertically from the lower surface of the main frame to the pivot pipe, and an upper end of the vertical extension portion. A reinforcing plate having a front extension extending forward from the main plate to the front edge of the suspension plate,
The vertical extension portion of the reinforcing plate is joined to at least the lower surface of the main frame, the upper outer peripheral surface of the pivot pipe, and the inner side surfaces of the pair of suspension plates, and the front extension portion is at least the main frame. A vehicle body frame structure for a motorcycle, characterized by being joined to a side surface of the frame and an inner side surface of the pair of suspension plates. The suspension plate has an upper edge joined to the upper surface or the side surface of the main frame in the vicinity of the upper surface, expands in the vehicle width direction, and extends downward.
The vehicle body frame structure for a motorcycle according to claim 1, wherein a cross section formed by the suspension plate, the main frame, and a front extending portion of the reinforcing plate is formed in a triangular shape or a trapezoidal shape. . The reinforcing plate is integrally formed with a tip extension portion that is bent upward and extended at the tip of the front extension portion, and the tip extension portion has an opening of a triangular or trapezoidal cross section. The body frame structure for a motorcycle according to claim 2, wherein the body frame structure is configured to be substantially closed.

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