JP4762652B2 - Motorcycle body frame - Google Patents

Description

  The present invention relates to a body frame of a motorcycle having a main frame having a monocoque structure (a clamshell structure or a stress skin structure).

The main frame of the monocoque structure is a stress skin structure in which no partition wall or the like is provided inside, and it is lightweight but has high rigidity, excellent appearance, and has a large volume of internal space. Thus, there is an advantage that the internal space can be effectively used (see Patent Document 1).
JP 2000-16369 A

  However, the main frame of the monocoque structure has the above-mentioned advantages, but due to space limitations of the motorcycle, it cannot take a sufficient height, and therefore vertical vibration may occur particularly in a high-speed traveling area. In addition, when the entire thickness is reduced in order to further reduce the weight, torsional deformation and bending deformation may occur.

  Accordingly, an object of the present invention is to provide a motorcycle body frame in which the rigidity of a main frame having a monocoque structure is further improved.

In order to achieve the above object, a body frame of a motorcycle according to the present invention includes a main frame having a monocoque structure, and a sub frame connected to at least one of both side portions of the main frame to reinforce the main frame. The sub-frame is connected to the front portion of the main frame and extends downward from the main frame, and is extended between the intermediate portion of the main frame in the front-rear direction and the support bracket in the front-rear direction. A reinforcing bar that extends, a front portion of the engine is supported by the support bracket, the reinforcing bar is positioned on a side of the engine, and the support bracket, the main frame, and the reinforcing bar are screwed by a fastening member. It is connected .

According to this configuration, the subframe is connected to the side of the main frame in an arrangement projecting downward with respect to the main frame of the monocoque structure, so that the rigidity of the main frame is improved. Further, since the support bracket and the reinforcing bar form a substantially L-shaped reinforcing body in a side view, the rigidity against bending deformation of the main frame is particularly improved. Further, since the reinforcing bar is located on the side of the engine, the reinforcing bar is located far away from the main frame, so that the rigidity of the main frame against torsional deformation and bending deformation can be further improved.

  In this invention, Preferably, the holding member holding a flexible elongate object is attached to the said sub-frame. According to this configuration, in addition to providing the subframe with the function of improving the rigidity of the main frame, the subframe can also have a function of holding a flexible long object passing through the side of the engine. This eliminates the need to separately provide a member for holding the flexible long object. Here, the flexible long object refers to a rope-like flexible member, and includes a cable, a hose, a harness, and the like.

  According to the motorcycle body frame of the present invention, by providing the sub-frame with both ends connected to the main frame so as to protrude downward from the main frame, the rigidity of the main frame having the monocoque structure is improved. The torsional deformation and bending deformation of the frame can be suppressed.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a side view showing a motorcycle including a body frame according to an embodiment of the present invention. In the motorcycle shown in the figure, a head pipe 2 is attached to a front end portion of a main frame 1 constituting a front half portion of a vehicle body frame FR, and a steering shaft (not shown) is rotatably inserted into the head pipe 2. The upper bracket 4 and the lower bracket 5 are supported via the front bracket 8, the front fork 8 is supported on the upper bracket 4 and the lower bracket 5, and the front wheel 9 is supported on the lower end portion of the front fork 8. A handle 10 is attached to the upper bracket 4 at the upper end of the front fork 8.

  A swing arm bracket 11 is provided at the lower rear end of the main frame 1, and a swing arm 12 is supported on the swing arm bracket 11 via a pivot shaft 13 at the front end portion so as to be swingable up and down. A rear wheel 14 is supported at the rear end of the swing arm 12. A multi-cylinder engine E is supported at the lower center of the main frame 1. A plurality of exhaust pipes 18 are connected to the cylinder head 17 of the engine E, and these exhaust pipes 18 are connected to mufflers 20 arranged one by one on the left and right sides of the rear part of the vehicle body.

  A rear frame (seat rail) 21 connected to the rear portion of the main frame 1 constitutes the rear half of the vehicle body frame FR, and a single seat 22 for riders and passengers is supported on the rear frame 21. ing. A fuel tank 19 is attached between the handle 10 and the seat 22 at the upper part of the main frame 1, that is, the upper part of the vehicle body. A resin cowling 25 that covers a portion from the front of the handle 10 to the side of the front portion of the vehicle body is attached to the front portion of the vehicle body. The rear part of the rear frame 21 is almost entirely covered with a tail cover 23 on the side surface and the rear surface, and a rear flap 24 is attached to the rear part of the rear frame 21.

  FIG. 2 is a plan view of the vehicle body frame FR. The vehicle body frame FR is formed by connecting the rear frame 21 to the rear portion of the main frame 1 as described above. The main frame 1 has a monocoque structure, and is provided with an air cleaner portion 26 containing a cleaner element (not shown) in an internal space, and is introduced into the air cleaner portion 26 on both the left and right sides near the front end. An intake port 24 for taking in the air is opened. A battery storage box 27 is provided on the right side of the middle portion of the main frame 1 in the front-rear direction. A pair of left and right access holes 28 are opened on the upper surface of the intermediate portion of the main frame 1, and a lid member (not shown) is detachably attached to the access holes 28. The lid member and its periphery are covered with a fuel tank 19 (FIG. 1) that is mounted on and mounted on the upper surface of the main frame 1. On the other hand, the rear frame 21 has a pair of left and right rail portions 29, 29 and a rear block 30 that connects the rear end portions of the rail portions 29, 29, and is substantially elongated U that opens forward in plan view. It has a letter shape. A plurality of cross members 31, 32, 33 are bridged between the rail portions 29, 29, either integrally or as a separate member.

  FIG. 3 shows a left side view of the vehicle body frame FR. The main frame 1 has a side surface shape that curves downward from the front part to the middle part in the front-rear direction, and the left part of the main frame 1 extends downward from the main frame 1. A sub-frame 34 having a shape protruding in the direction is connected. Both ends of the sub frame 34 are connected to the main frame 1 by first and second fastening members 35 and 36 made of screw bodies, thereby reinforcing the main frame 1. The sub-frame 34 is attached to a pair of front and rear mounting pieces 40 provided on the lower front edge of the main frame 1 and extends downward, and a middle portion in the vertical direction of the support bracket 37 and a middle in the front-rear direction of the main frame 1. And a reinforcing bar 38 extending in the front-rear direction. The support bracket 37 and the reinforcing bar 38 are connected by a third fastening member 41 made of a screw body.

  FIG. 4 is an enlarged side view showing in detail the attachment portion of the sub-frame 34 in the vehicle body frame FR. The support bracket 37 has a wide upper end portion and a narrow lower end portion as viewed from the side of the vehicle body, and an intermediate portion connecting the upper end portion and the lower end portion with both side edges smoothly curved inward. A pair of front and rear fixing portions 37a and 37a are formed at the upper end portion, and screw insertion holes (not shown) are formed in the respective fixing portions 37a. The fixing portion 37 a of the support bracket 37 is inserted into the screw insertion hole through the first fastening member 35 and screwed into a screw hole (not shown) provided in each attachment piece 40 of the main frame 1. It is connected to. An engine support hole 44 is provided in the lower end portion 43 of the support bracket 37 and is connected to a bracket 45 provided in the engine E by a fourth fastening member 46 such as a bolt and a nut as shown in FIG. Thus, the support bracket 37 supports the front portion of the engine E. The engine E is supported by the main frame 1 by fifth and sixth fastening members 65 and 66 provided at two places at the rear.

  The reinforcing bar 38 shown in FIG. 4 is configured by connecting end members 48 to both ends of a bar main body 47 made of a square hollow or solid pipe by welding, and is arranged in a substantially horizontal posture. The bar body 47 is bent into a shallow inverted V shape so as to slightly protrude upward. Screw insertion holes (not shown) are formed in the front end portion and the rear end portion of the reinforcing bar 38, and the third fastening member 41 is inserted into the screw insertion hole in the front end portion so that the engine support hole of the support bracket 37 The front end portion of the reinforcing bar 38 is connected to the support bracket 37 by screwing into a screw hole (not shown) provided in the vicinity of the upper portion 44, and the second fastening member 36 is inserted into the screw insertion hole at the rear end portion. The rear end of the reinforcing bar 38 is connected to the main frame 1 by screwing into a screw hole (not shown) provided in the main frame 1. A stay 49 as a holding member is fixed to the lower surface near the rear end of the bar body 47 by screw connection.

  A locking block 50, which is a holding member, is fixed to the upper surface near the front end of the bar main body 47 by welding, and an attachment member (not shown) of the cowling 25 (FIG. 1) is inserted therethrough. An insertion hole 71 is provided.

  As shown in FIG. 5, the stay 49 is formed by bending a metal plate, and a fixing piece 51 that contacts the lower surface of the bar main body 47 of the reinforcing bar 38 and a positioning that extends upward from the outer end of the fixing piece 51. It includes a piece 53, a connecting piece 54 that extends downward from the front end of the fixed piece 51, and a support piece 57 that extends from the connecting piece 54 in a direction parallel to the fixed piece 51. An insertion hole 52 is formed in the fixed piece 51, and an attachment hole 58 is formed in the support piece 57. The stay 49 is fixed to the bar main body 47 by screwing the fixing screw 55 into a screw hole (not shown) provided in the bar main body 47 through the insertion hole 52.

  A harness 59 of FIG. 5 connected to an instrument panel or the like (not shown) provided in the vicinity of the handle 10 (FIG. 1) is supported on the stay 49 via a clamp 60. The clamp 60 is made of a synthetic resin, and mounting portions 62 and 62 having stoppers 62a for retaining are formed on both ends of the C-shaped holding ring portion 61. Therefore, the clamp 60 is attached to the stay 49 by inserting both the attachment portions 62 and 62 into the attachment holes 58 of the stay 49 in a state where the harness 59 is inserted through the holding ring portion 61, so that the harness 59 is The bar body 47 is supported via the stay 49.

  On the other hand, the locking block 50 in FIG. 4 has a locking groove 50 a that opens upward, and the bottom thereof is welded to the bar main body 47. A rubber damper 64 through which a clutch hydraulic hose 63 is inserted is fitted into the locking groove 50a, and the hydraulic hose 63 is held by the bar body 47 in a vibration-damped state.

  In the above configuration, the sub frame 34 is connected to the side of the main frame 1 in a state of protruding downward from the main frame 1, so that the rigidity of the main frame 1 is improved. Here, since the support bracket 37 and the reinforcing bar 38 constituting the subframe 34 constitute an L-shaped reinforcing body in a side view, the rigidity of the main frame 1 is further improved. As a result, torsional deformation and bending deformation of the main frame 1 due to vibration particularly in a high-speed traveling region are suppressed. Further, as clearly shown in FIG. 1, the reinforcing bar 38 is located on the side of the engine E, that is, greatly separated downward from the main frame 1. The rigidity against deformation can be further improved.

  Also, the subframe 34 shown in FIG. 4 is provided with a stay 49 and a locking block 50 for holding a harness 59 and a clutch hydraulic hose 63, which are flexible long objects, respectively. A function of holding the flexible long objects 59 and 63 can be added. Thereby, it is not necessary to separately provide a member for holding the flexible long objects 59 and 63. Furthermore, since the cowling mounting insertion hole 71 is provided in the subframe 34, a function of holding the cowling 25 (FIG. 1) in the subframe 34 is also added.

  In the embodiment, the sub-frame 34 is provided only on the left side of the main frame 1 because the right side of the main frame 1 has sufficient rigidity due to the built-in battery storage box 27 shown in FIG. It is because it has. However, a subframe similar to that shown in the above embodiment can also be provided on the right side of the main frame 1.

  Further, the subframe 34 is not limited to the two parts of the support bracket 37 and the reinforcing bar 38, and may be an integrated single member or a combination of three or more members. The shape of the subframe 34 is not limited to the above embodiment.

1 is a side view showing a motorcycle including a body frame according to an embodiment of the present invention. It is a top view which shows a body frame same as the above. It is a left view which shows a body frame same as the above. It is an expansion perspective view which shows the attachment part of the sub-frame in a vehicle body frame same as the above. It is the perspective view seen from diagonally forward lower side which shows the stay attached to a sub-frame same as the above.

Explanation of symbols

FR body frame 1 main frame 34 sub frame 37 support bracket 38 reinforcement bar 49, 50 holding member 59, 63 flexible long object E engine

Claims (4)

A main frame with a monocoque structure,
A subframe connected to at least one of both side portions of the main frame to reinforce the main frame;
The sub-frame is connected to the front portion of the main frame and extends downward from the main frame, and is extended between the intermediate portion of the main frame in the front-rear direction and the support bracket in the front-rear direction. A reinforcing bar extending,
The front part of the engine is supported by the support bracket, the reinforcing bar is located on the side of the engine,
A body frame of a motorcycle in which the support bracket, the main frame, and the reinforcing bar are screw-connected by a fastening member . The motorcycle body frame according to claim 1, wherein the support bracket is screwed to the main frame by a fastening member. The motorcycle body frame according to claim 1 or 2, wherein a front portion of the engine is supported by a lower end portion of the support bracket, and the reinforcing bar is connected to a portion above the lower end portion. 4. The main frame of the monocoque structure according to claim 1, wherein the main frame of the monocoque structure has a shape that is curved downward from the front portion while being curved downward, an engine is disposed below the main frame, and a cleaner element is accommodated therein. A motorcycle body frame with an air cleaner.

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