JP2013103565A - Frame structure of straddle-type vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a frame structure of a straddle-type vehicle, configured to improve a degree of freedom in bridge arrangement, to maintain high strength, and to allow proper rigidity to be easily set.SOLUTION: The frame structure 45 of the straddle-type vehicle includes: a head pipe 12; a main frame 13 connected with the head pipe 12 and extending rearward; a first fixing part 46 positioned in the middle of the main frame 13; a down tube 16 connected with the head pipe 12 and extending downward; a second fixing part 47 positioned in the middle of the down tube 16; and a bridge 19 disposed between the first fixing part 46 and the second fixing part 47 in a detachable manner.

Description

  The present invention relates to a frame structure of a saddle-ride type vehicle.

  A frame structure in a saddle-type vehicle in recent years, particularly in an off-road vehicle such as a dual-purpose or a motocrosser, is called a twin tube type, and is mainly made of an aluminum alloy having a pair of left and right main frames. This type of frame structure includes a pair of left and right main frames that are connected to the head pipe, a down tube that is connected to the head pipe, and an arch-shaped bridge that links and reinforces the left and right main frames and the down tube.

  The bridge is located closer to the head pipe than the engine so as not to interfere with mounting the engine on the frame structure. The front end of the bridge is joined to the down tube via a gusset, and the rear end of the bridge is welded to the main frame.

JP 2001-278159 A

  The frame structure is required to have a high strength capable of withstanding running while the engine is mounted, and at the same time, have a rigidity that can be appropriately bent to exhibit shock absorption. The arrangement of the bridge greatly affects the rigidity of the frame structure.

  However, the conventional frame structure has a low degree of freedom in the arrangement of the bridges in order to ensure the workability of mounting the engine.

  On the other hand, in the conventional frame structure, since the bridge is fixed to the main frame and the down tube, it is difficult to replace or change the bridge, and when adjusting rigidity at the prototype stage of the frame structure, etc. It was inefficient and expensive because it was necessary to prepare. Further, in the conventional frame structure, since the bridge is disposed near the head pipe, it is difficult to reduce the weight while providing high strength and high rigidity in the region where the engine is mounted.

  Therefore, an object of the present invention is to provide a frame structure of a saddle-ride type vehicle that can easily adjust an appropriate rigidity while maintaining a high strength by increasing the degree of freedom in arranging the bridges.

  In order to solve the above problems, a frame structure of a saddle-ride type vehicle according to the present invention includes a head pipe, a main frame connected to the head pipe and extending rearward, and a first fixing portion located in the middle of the main frame. And a down tube connected to the head pipe and extending downward, a second fixing portion located in the middle of the down tube, and a detachable bridge that spans between the first fixing portion and the second fixing portion. It is characterized by providing.

  According to the present invention, it is possible to provide a straddle-type vehicle frame structure capable of increasing the degree of freedom in arranging the bridges and easily adjusting appropriate rigidity while maintaining high strength.

1 is a left side view showing a motorcycle as a saddle riding type vehicle according to a first embodiment of the present invention. The left view which shows the frame structure which concerns on 1st Embodiment of this invention. The left view which shows the frame structure and engine which concern on 1st Embodiment of this invention. 1 is a perspective view showing a frame structure according to a first embodiment of the present invention. 1 is a perspective view showing a frame structure according to a first embodiment of the present invention. The left view which shows the frame structure which concerns on 2nd Embodiment of this invention. The left view which shows the frame structure and engine which concern on 2nd Embodiment of this invention. The perspective view which shows the frame structure which concerns on 2nd Embodiment of this invention. The perspective view which shows the frame structure which concerns on 2nd Embodiment of this invention.

An embodiment of a frame structure of a saddle-ride type vehicle according to the present invention will be described with reference to the drawings. [First Embodiment]
A first embodiment of a frame structure of a saddle-ride type vehicle according to the present invention will be described with reference to FIGS.

  FIG. 1 is a left side view showing a motorcycle as a straddle-type vehicle according to a first embodiment of the present invention.

  In the present embodiment, front and rear, top and bottom, and left and right expressions are based on the rider who rides the motorcycle 1.

  As shown in FIG. 1, the straddle-type vehicle according to this embodiment is a motorcycle 1. The motorcycle 1 includes a vehicle body frame 2 extending in the front-rear direction of the vehicle, a front wheel 5 positioned in front of the vehicle body frame 2, a steering mechanism 6 positioned in front of the vehicle body frame 2 and rotatably supporting the front wheel 5, A rear wheel 7 located behind the frame 2, a swing arm 8 extending rearward of the body frame 2 and rotatably supporting the rear wheel 7, and an engine 11 serving as an internal combustion engine located in the lower center of the vehicle body are provided. .

  The body frame 2 is a so-called cradle type. The vehicle body frame 2 includes a head pipe 12 positioned at the front upper end, a pair of left and right main frames 13 that are connected to the head pipe 12 and extend obliquely downward and rearward, and rear ends of the left and right main frames 13. A pair of left and right pivot frames 15 connected and depending downward, a down tube 16 connected to the head pipe 12 and extending downward, a joint member 17 connected to the down tube 16 and bifurcated, and a joint member 17 A pair of left and right lower tubes 18 connected to the branch ends and extending downward to bend and protect the lower portion of the engine 11 and connected to the lower end of the pivot frame 15, and the left and right main frames 13 and down tubes 16. And a rear frame that extends backward by connecting to the pivot frame 15 It includes 1, a.

  The head pipe 12 is the rotation center of the steering mechanism 6 and supports the steering mechanism 6 on the vehicle body frame 2.

  The left and right main frames 13 also serve as tank rails, support the fuel tank 22 positioned above the main frame 13, and suspend the engine 11 below the fuel tank 22.

  The left and right pivot frames 15 support a pivot shaft 23 that is the center of rotation of the swing arm 8.

  The rear frame 21 includes a pair of left and right seat rails 25 extending obliquely rearward and upward from the tops of the left and right pivot frames 15, and a seat rail extending rearward and obliquely upward from the center rear side of the left and right pivot frames 15. 25 and a pair of left and right seat pillar tubes 26 connected to the rear part of the vehicle. The seat rail 25 supports the seat 27 and a rear fender 28 that extends rearward of the seat 27 and covers the rear wheel 7.

  The steering mechanism 6 has a suspension mechanism (not shown) and is connected to a pair of left and right front forks 31 that rotatably support the front wheels 5, a front fender 32 that covers the top of the front wheels 5, and the top of the front forks 31. And a handle 33. The rider steers the front wheel 5 left and right with the handle 33.

  The swing arm 8 supports the rear wheel 7 so as to be swingable up and down. The rear cushion unit 35 is interposed between the swing arm 8 and the vehicle body frame 2 to buffer the force transmitted from the rear wheel 7 to the vehicle body frame 2.

  The engine 11 is, for example, a four-cycle internal combustion engine, and is positioned between the main frame 13 and the down tube 16 with the center line of a cylinder (not shown) directed in the vertical direction of the motorcycle 1. The engine 11 is connected to an exhaust muffler 36 that extends rearward of the vehicle body and exhausts the exhaust gas of the engine 11.

  The rear wheel 7 includes a driven sprocket 37. In the rear wheel 7, the drive chain 38 is wound around the driven sprocket 37 and transmits driving force from the engine 11 to the rear wheel 7.

  The motorcycle 1 further includes a tank cover 39 that covers the left and right sides of the fuel tank 22, and a frame cover 42 that covers the left and right sides of the space below the seat 27.

  Next, the frame structure according to the present embodiment will be described in detail.

  FIG. 2 is a left side view showing the frame structure according to the first embodiment of the present invention.

  FIG. 3 is a left side view showing the frame structure and the engine according to the first embodiment of the present invention.

  4 and 5 are perspective views showing a frame structure according to the first embodiment of the present invention.

  FIG. 4 is a diagram showing the bridge 19 from the lower left rear and FIG. 5 is a diagram showing the bridge 19 from the upper left rear.

  As shown in FIGS. 2 to 5, the frame structure 45 according to the present embodiment includes a head pipe 12, a main frame 13 connected to the head pipe 12 and extending rearward, and a first located in the middle of the main frame 13. It spans between the fixed part 46, the down tube 16 connected to the head pipe 12 and extending downward, the second fixed part 47 located in the middle of the down tube 16, and the first fixed part 46 and the second fixed part 47. And a detachable bridge 19.

  The main frame 13 and the down tube 16 are aluminum alloy hollow tubes. The first fixing portion 46 is a bracket fixed to the lower surface of the main frame 13 by a joining method such as welding, and has a through hole 49 through which a bolt 48 as a fastening member for fastening the bridge 19 is passed. There are a plurality of through holes 49, and the fastening position of the bridge 19 can be arbitrarily selected. There is a pair of first fixing portions 46 on the left and right main frames 13.

  The second fixing portion 47 is a bracket fixed to the back surface of the down tube 16 by a joining method such as welding. A bolt hole 52 for fastening a bolt 51 as a fastening member for fastening the bridge 19 is provided. There are a plurality of bolt holes 52, and the fastening position of the bridge 19 can be arbitrarily selected.

  The bridge 19 is a structural material that connects and reinforces the main frame 13 and the down tube 16. The bridge 19 is a hollow tube that is curved in a substantially U-shape, and includes an ear piece 53 that is positioned at the left and right tip portions where the U-character is opened, and a bracket 55 that is positioned at the abdomen of the U-character. The ear piece 53 has a bolt hole 56 for fastening a bolt 48 that passes through the through hole 49 of the first fixing portion 46. The bracket 55 has a through hole (not shown) through which the bolt 51 passes.

  The bridge 19 may have a cross-sectional shape that is open such as a U-letter shape, a C-letter shape, or an H-letter shape in addition to the hollow tube.

  On the other hand, the engine 11 can be mounted at a position sandwiched between the main frame 13 and the down tube 16 and is detachably mounted below the main frame 13 and behind the down tube 16.

  Further, the engine 11 is joined from the lower side near the lower tube 18 to a crankcase 58 that houses a crankshaft (not shown), a cylinder 59 that is joined to the top of the front half of the crankcase 58, and a top of the cylinder 59. A cylinder head 61 having an intake port (not shown) and an exhaust port (not shown), and a head cover 62 covering the top of the cylinder head 61 are provided.

  In addition to the engine 11, the motorcycle 1 includes a radiator 63 that is positioned in front of the engine 11 and fixed to the down tube 16, and is connected to the front of the cylinder head 61 and bypasses the right side of the engine to the exhaust muffler 36. An exhaust pipe 65 that guides the exhaust gas of the engine 11, an air cleaner 66 that is positioned below the seat 27 to filter the intake air of the engine 11, and a throttle body 67 that is connected to the air cleaner 66 and has a valve (not shown) that adjusts the intake air flow rate. And an intake manifold 68 for guiding the air-fuel mixture from the throttle body 67 to the cylinder head 61, and a regulator 69 that is fixed to the main frame 13 and rectifies the output of the magnet rotor (not shown) of the engine 11.

  The fuel tank 22 is sandwiched between the left and right main frames 13 or positioned above the main frame 13.

  The frame structure 45 can be adjusted by changing the rigidity of the bridge 19 by appropriately changing the cross-sectional shape of the bridge 19 and changing the rigidity of the entire frame structure 45 as appropriate.

  In addition, the frame structure 45 changes the rigidity of the bridge 19 by using an appropriate material such as an alloy or steel using a non-ferrous metal material in addition to an aluminum alloy as the material of the bridge 19, so that the rigidity of the entire frame structure 45 is appropriately changed. Can be changed and adjusted.

  Furthermore, the frame structure 45 includes a plurality of mounting positions of the bridge 19 in which at least one of the first fixing portion 46 and the second fixing portion 47 includes a plurality of mounting positions of the bridge 19, so that the rigidity of the entire frame structure 45 is appropriately changed. Can be changed and adjusted. Specifically, the frame structure 45 can change the mounting position of the bridge 19 by providing at least one of the through holes 49 of the first fixing portion 46 and the bolt holes 52 of the second fixing portion 47. The bridge 19 may be changed for each mounting position, or may be common to the mounting positions.

  The frame structure 45 according to the present embodiment changes the rigidity of the entire frame structure 45 by preparing a plurality of bridges 19 having different materials and shapes (length, thickness, cross-sectional shape, etc.) and replacing them appropriately. Can be adjusted. In addition, the frame structure 45 according to the present embodiment changes the strength of the entire frame structure 45 by preparing a plurality of bridges 19 having different materials and shapes (length, thickness, cross-sectional shape, etc.) and replacing them appropriately. It is also possible to adjust appropriately.

  Therefore, in the straddle-type vehicle frame structure 45 according to this embodiment, the bridge 19 can be attached to and detached from the main frame 13 and the down tube 16, so that the space above the engine 11 at the time of attachment / detachment can be removed by removing the bridge 19. It becomes easy to secure, and the bridge 19 does not interfere with the mounting work of the engine 11.

  Further, since the frame structure 45 of the saddle riding type vehicle according to the present embodiment can easily change the material, shape and mounting position of the bridge 19, the frame structure 45 and thus the rigidity of the vehicle body frame 2 can be easily changed and adjusted. This facilitates changes in ride comfort and operational feeling by changing the strength and rigidity of the body frame 2 in the series development of saddle riding type vehicles and minor changes in vehicle types. In addition, this improves the commonality rate of the body frame 2 excluding the bridge 19 between straddle-type vehicles of different vehicle types, and improves productivity and cost efficiency.

[Second Embodiment]
A second embodiment of the frame structure of the saddle riding type vehicle according to the present invention will be described with reference to FIGS.

  Note that in the frame structure 45A according to the present embodiment, the same components as those of the frame structure 45 of the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 6 is a left side view showing a frame structure according to the second embodiment of the present invention.

  FIG. 7 is a left side view showing the frame structure and the engine according to the second embodiment of the present invention.

  8 and 9 are perspective views showing a frame structure according to the second embodiment of the present invention.

  FIG. 8 is a diagram showing the bridge 73 from the lower left, and FIG. 9 is a diagram showing the bridge 73 from the left rear.

  As shown in FIGS. 6 to 9, the frame structure 45 </ b> A according to the present embodiment includes a head pipe 12, a main frame 13 connected to the head pipe 12 and extending rearward, and a first located in the middle of the main frame 13. The fixed portion 75, the down tube 16 connected to the head pipe 12 and extending downward, the second fixed portion 76 located in the middle of the down tube 16, and the first fixed portion 75 and the second fixed portion 76. And a detachable bridge 73.

  The first fixing portion 75 is a bracket that is fixed to the lower surface of the main frame 13 by a joining method such as welding, and has a bolt hole 77 for fastening a bolt 48 as a fastening member for fastening the bridge 73. There are a plurality of bolt holes 77, and the fastening position of the bridge 73 can be arbitrarily selected. There are a pair of first fixing portions 75 on the left and right main frames 13.

  The second fixing portion 76 is a bracket that is fixed to the back surface of the down tube 16 by a joining method such as welding, and has a bolt hole 78 of a bolt 51 as a fastening member that fastens the bridge 73. There are a plurality of bolt holes 78, and the fastening position of the bridge 73 can be arbitrarily selected.

  The bridge 73 is a structural material that connects and reinforces the main frame 13 and the down tube 16. The bridge 73 is a belt-like plate material that curves in an arc shape from the first fixing portion 75 to the second fixing portion 76. The bridge 73 spans between the main frame 13a and the down tube 16 located on the right side and between the main frame 13b and the down tube 16 located on the left side, and has a pair on the left and right. The bridge 73 can be attached and detached individually on the left and right.

  The bridge 73 overlaps the engine 11 that can be mounted at a position between the main frame 13 and the down tube 16 in a side view.

  Further, the bridge 73 includes an engine fixing portion 79 that shares the suspension of the engine 11. The engine fixing portion 79 is integrated with or integrated with a belt-like portion connecting the main frame 13 and the down tube 16, and transmits the inertial force of the engine 11 to the main frame 13 and the down tube 16.

  The bridge 73 may have a cross-sectional shape that is open such as a U-letter shape, a C-letter shape, and an H-letter shape in addition to the strip-shaped plate material, or may have a cross-sectional shape that is closed in a tubular shape.

  The frame structure 45A can change and adjust the rigidity of the bridge 73 by appropriately changing the cross-sectional shape of the bridge 73, and appropriately change and adjust the rigidity of the entire frame structure 45A.

  In addition, the frame structure 45A changes the rigidity of the bridge 73 by using an appropriate material such as an alloy using a non-ferrous metal material or steel in addition to an aluminum alloy as the material of the bridge 73, so that the rigidity of the entire frame structure 45A is appropriately changed. Can be changed and adjusted.

  Further, the frame structure 45A includes a plurality of mounting positions of the bridge 73 in at least one of the first fixing portion 75 and the second fixing portion 76, so that the mounting position of the bridge 73 is changed and the rigidity of the entire frame structure 45A is appropriately set. Can be changed and adjusted. Specifically, the frame structure 45 </ b> A can change the mounting position of the bridge 73 by providing at least one of the bolt holes 77 of the first fixing portion 75 and the bolt holes 78 of the second fixing portion 76. The bridge 73 may be changed for each attachment position or may be common to the attachment positions. Further, instead of providing a plurality of bolt holes 77 of the first fixing portion 75 and a plurality of bolt holes 78 of the second fixing portion 76, the bridge 73 may have a plurality of through holes (not shown) for the bolts 51.

  The frame structure 45A according to the present embodiment changes the rigidity of the entire frame structure 45A by preparing a plurality of bridges 73 of different materials and shapes (length, thickness, cross-sectional shape, etc.) and replacing them appropriately. Can be adjusted.

  Therefore, in the straddle-type vehicle frame structure 45A according to the present embodiment, the bridge 73 can be attached to and detached from the main frame 13 and the down tube 16, so that the space above the engine 11 at the time of attachment / detachment can be removed by removing the bridge 73. It becomes easy to secure, and the bridge 19 does not interfere with the mounting work of the engine 11.

  Further, since the frame structure 45A of the saddle riding type vehicle according to the present embodiment can easily change the material, shape and mounting position of the bridge 73, the rigidity of the frame structure 45A and the body frame 2 can be easily changed and adjusted. This facilitates changes in ride comfort and operational feeling by changing the strength and rigidity of the body frame 2 in the series development of saddle riding type vehicles and minor changes in vehicle types. This also improves the commonality rate of the body frame 2 excluding the bridge 73 between straddle-type vehicles of different vehicle types, and improves productivity and cost efficiency.

  Further, the straddle-type vehicle frame structure 45A according to the present embodiment can be arranged with the bridge 73 superimposed on the engine 11 in a side view. A large opening for attaching and detaching the engine 11 (an opening having substantially the same shape as the projection of the engine 11) is not required, and the opening area can be narrowed to make an adjustment that easily increases the strength and rigidity of the vehicle body frame 2. In addition, since the frame structure 45A can be arranged with the bridge 73 overlapped with the engine 11 in a side view, an area for arranging the bridge 73 between the head pipe 12 and the engine 11 is not required, and the fuel The tank 22 and the regulator 69 can be arranged closer to the engine 11 to reduce the size of the vehicle and increase the capacity of the fuel tank 22. On the other hand, the degree of freedom in selecting the shape of the bridge 73 in the up and down direction is increased, the range of change in strength and rigidity can be expanded, and the adjustment range can be easily expanded.

  Furthermore, in the straddle-type vehicle frame structure 45A according to this embodiment, the pair of left and right bridges 73 can be individually attached and detached, so that the engine 11, the radiator 63, the regulator 69, and the fuel tank 22 can be easily attached and detached. And excellent workability. Further, since the pair of left and right bridges 73 can be individually attached and detached, the positional accuracy of the first fixing portion 75 and the second fixing portion 76 can be improved as compared with the case where the left and right main frames 13 and the down tubes 16 are integrally assembled. It becomes possible to relax, and productivity can be improved.

  Further, since the straddle-type vehicle frame structure 45A according to the present embodiment includes the engine fixing portion 79, the engine 11 itself can also be used as a reinforcing member to adjust the rigidity.

  The body frame 2 is not limited to the cradle type. Further, the body frame 2 may have a pair of left and right down tubes 16 and may include only one main frame 13 along the center of the vehicle.

  The bridges 19 and 73 may be any of wrought materials, cast products, and forged products. Further, the bridges 19 and 73 may have attachment parts such as outfitting parts, electric parts, auxiliary machines and the like. In this case, the bridges 19 and 73 that are relatively easier to form than the vehicle body frame 2 are provided with attachment portions such as a tank cover 39, a regulator 69, and an ignition coil (not shown), so that the main frame 13 and the down tube 16 are separately provided. This eliminates the need to provide a bracket and contributes to cost reduction and workability improvement.

  Therefore, according to the straddle-type vehicle frame structures 45 and 45A according to the present embodiment, the degree of freedom of arrangement of the bridges 19 and 73 can be increased, and appropriate rigidity can be easily adjusted while maintaining high strength.

DESCRIPTION OF SYMBOLS 1 Motorcycle 2 Body frame 5 Front wheel 6 Steering mechanism 7 Rear wheel 8 Swing arm 11 Engine 12 Head pipe 13, 13a, 13b Main frame 15 Pivot frame 16 Down tube 17 Joint member 18 Lower tube 19 Bridge 21 Rear frame 22 Fuel tank 23 Pivot shaft 25 Seat rail 26 Seat pillar tube 27 Seat 28 Rear fender 31 Front fork 32 Front fender 33 Handle 35 Rear cushion unit 36 Exhaust muffler 37 Driven sprocket 38 Drive chain 39 Tank cover 42 Frame cover 45, 45A Frame structure 46 First fixed portion 47 Second fixing portion 48 Bolt 49 Through hole 51 Bolt 52 Bolt hole 53 Ear piece 55 Bracket 56 Bolt hole 58 Crank Over scan 59 cylinder 61 cylinder head 62 head cover 63 radiator 65 exhaust pipe 66 air cleaner 67 throttle body 68 intake manifold 69 regulator 73 bridge 75 first fixing part 76 second fixing portion 77 bolt hole 79 engine fixing part

Claims (5)

A head pipe,
A main frame connected to the head pipe and extending rearward;
A first fixing part located in the middle of the main frame;
A down tube connected to the head pipe and extending downward;
A second fixing portion located in the middle of the down tube;
A frame structure for a saddle-ride type vehicle, comprising: a detachable bridge that spans between the first fixing portion and the second fixing portion. The main frame has a pair on the left and right,
The bridge spans between the main frame and the down tube located on the right side, and between the main frame and the down tube located on the left side, and has a pair on the left and right. 2. The straddle-type vehicle frame structure according to claim 1, wherein the frame structure overlaps an engine that can be mounted at a sandwiched position in a side view. The straddle-type vehicle frame structure according to claim 2, wherein the bridge includes an engine fixing portion for suspending the engine. 4. The straddle-type vehicle frame structure according to claim 2, wherein the bridge is detachable on each of the left and right sides. 5. The straddle-type vehicle frame structure according to claim 1, wherein at least one of the first fixing portion and the second fixing portion includes a plurality of mounting locations of the bridge.

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