JP2005125942A - Engine supporting mechanism in straddle riding type vehicle and straddle riding type vehicle having this supporting mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine supporting structure enabling an engine head to be maintained with an engine suspended at a frame and further enabling an entire rigidity of a vehicle body by utilizing the rigidity of the engine even if the engine body is so shaped as to protrude out of the frame in a vehicle width direction. <P>SOLUTION: A pair of right and left main frames 5 extending over an engine head toward the rear part of a vehicle body are connected to a head pipe 2 of a frame. It has a bracket 50 separate from the main frames and the engine. The bracket is fastened against each of the main frames and an engine head cover 52 by bolts extending in a vehicle body width direction. A minimum width in the vehicle width direction at the engine head part between the right and left main frames is made smaller than a width of the engine head and the engine head cover is supported to a place near the head pipe of the main frames. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an engine support mechanism in a straddle-type traveling vehicle such as a motorcycle, and to a straddle-type traveling vehicle including the same.

  The motorcycle engine is suspended from the main frame at a plurality of locations in the longitudinal direction of the main frame. Conventionally, as a support mechanism for this type of engine, for example, there is one described in JP-A-7-291172 (Patent Document 1). This has a structure in which the front and rear sides of the engine cylinder head and the engine head cover are fastened and supported between the main frames from the left and right directions in each of the main frames divided into left and right.

  In JP-A-8-207867 (Patent Document 2), the engine hanger has a substantially T-shape when viewed from the side, and its lower end is connected to a mounting portion provided on a cylinder head cover of a 4-cycle engine. Has been described. In Japanese Patent Application Laid-Open No. 55-123580 (Patent Document 3), a bracket formed in a substantially U-shape is fixed to a cylinder head so as to be sandwiched by a tank rail portion of a main frame. Is fixed to the front part of the tank rail part via a collar.

In Japanese Patent Laid-Open No. Sho 62-255559 (Patent Document 4), the cylinder block and the cylinder head of the front and rear cylinders have a common structure, and the upper surface of each cylinder head has a stud bolt for tightening the head. It is described that it is suspended by an engine bracket extending from the frame.
JP-A-7-291172 JP-A-8-207867 JP-A-55-123580 Japanese Patent Laid-Open No. 62-255559

  For example, in the case of relatively simple maintenance that adjusts the engine cam rotation, it is convenient to perform the operation while the engine is suspended from the main frame. In this case, the bracket fixed to the engine and the main frame is removed, and the cylinder head cover of the engine is further removed to expose the periphery of the engine head.

  In Japanese Patent Laid-Open Nos. 55-123580 and 55-123580, there is a main frame just above the engine head, and maintenance around the head is difficult if the engine is fixed to the frame. is there.

  In the one disclosed in Japanese Patent Laid-Open No. 7-291172, the engine is directly screwed to the frame, and the side surface of the engine is covered with the frame, so that the shape of the engine body cannot be exposed from the frame. In the case of a large engine, the width of the frame itself increases with the engine, which is inconvenient for passengers to get on and off.

  Further, in Japanese Patent Laid-Open No. 8-207867, the front side of the engine body is not fixed to the frame, so the rigidity of the entire body cannot be improved using the engine rigidity, and an attempt is made to secure the momentum frame rigidity. This requires a down tube that increases cost and weight.

  Therefore, the present invention makes it possible to maintain the engine head while the engine is suspended from the frame, and even if the shape of the engine body protrudes from the frame in the vehicle width direction, the engine rigidity is utilized. An object of the present invention is to provide an engine support structure capable of improving the rigidity of the entire vehicle body.

  In order to achieve the above object, the present invention provides a structure for supporting an engine in a straddle-type traveling vehicle having a structure in which the engine is suspended from a frame. A pair of left and right mainframes extending inward are connected, and the mainframe and the engine have a separate bracket, and the bracket is fastened to the mainframe and the engine head by bolts extending in the vehicle body width direction. The minimum width in the vehicle width direction of the engine head portion between the left and right main frames is configured to be smaller than the width of the engine head, and the engine head is supported near the head pipe of the main frame. It is characterized by.

  In a more detailed form of the present invention, the bracket is fastened to the main frame and the engine head so as to fix the engine head on the front side of the vehicle body with respect to the axis of the engine head to the main frame. The engine is provided with an engine head cover, and the cover and the main frame are connected via a bracket. The brackets are provided at two locations on both sides of the engine in the vehicle width direction. The bracket is fixed to the engine head and the main frame from the outside of the vehicle body along the vehicle body width direction.

  Further, the present invention is a straddle-type traveling vehicle provided with the engine support mechanism.

  As described above, according to the present invention, the engine head can be maintained in a state where the engine is suspended from the frame, and the engine body can be configured to protrude from the frame in the vehicle width direction. An engine support structure that can improve rigidity of the entire vehicle body by utilizing rigidity can be provided.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 and 2 show a motorcycle to which the vehicle body frame structure of the present invention is applied. FIG. 1 is a side view of the motorcycle and FIG. 2 is a plan view of the motorcycle.

  In the figure, reference numeral 1 denotes a vehicle body frame, and a head pipe 2 constituting the vehicle body frame 1 supports a front fork 4 on which a front wheel 3 is suspended so as to be able to turn. A pair of left and right main frames 5 extending rearward are connected to the head pipe 2, and rear arm brackets 6 are welded to the rear portions of the main frames 5.

  A seat frame 9 is welded or bolted to the rear ends of the pair of left and right main frames 5, and a backstay 10 is provided between the seat frame 9 and the rear arm bracket 6. As will be described later, an engine 11 is suspended from the main frame 5, and a rear arm 13 having a rear wheel 12 suspended from the rear arm bracket 6 is supported via a pivot shaft 14. The rear arm 13 is swung by a suspension device 15. It is possible.

  A fuel tank 16, an air cleaner, and the like are provided between the main frames 5, cover the fuel tank 16, and a seat 17 is placed on the rear side of the seat frame 9 from the front side of the main frame 5. 18 is integrally formed. An exhaust pipe 19 is connected to the front side of the engine 11, the exhaust pipe 19 is bent from the right side to the left side, and a first muffler 20 is connected at an upper left position of the engine 11, and further to the first muffler 20 The second muffler 21 is connected at a position above the wheel. Further, a carburetor 22 is connected to the rear of the engine 11, and an air cleaner 23 is connected to the carburetor 22.

  FIG. 3 shows a side view of the main frame 5 and the V-type four-cylinder engine 11 suspended from the main frame 5 as viewed from the crankshaft direction. The engine 11 is fixed at one place (A) near the head pipe 2 and three places (B, C, D) on the rear side of the vehicle body. The main frame 5 extends substantially horizontally above the engine head cover 52 toward the rear of the vehicle body, and bends below the vehicle body behind the engine. As shown in FIG. 2, the width in the vehicle width direction (H in FIG. 9 described later) in the engine head portion between the left and right main frames is configured to be smaller than the width of the engine head.

  Therefore, the engine 11 can be prevented from being covered with the frame 5, so that a design emphasizing the engine can be employed. Further, since the width of the tank rail can be made smaller than that of the engine, the width around the knee can be narrowed, and the degree of freedom of the sitting position and the legibility can be improved. Furthermore, the steering angle of the steering wheel can be increased and the rigidity of the frame can be increased.

  The fixing of the engine to the main frame in front of the vehicle body will be described. The engine head cover 52 and the main frame 5 are coupled to each other via a separate bracket 50. Near the head pipe 2 of the main frame, for example, close to 1/3 of the front and rear long head pipe side of the left and right main frames, preferably at the end of the main frame on the head pipe side, the engine head cover 52 is attached to the main frame 5. Suspended by.

  4 and 5 show the head cover 52 of the engine. 4 is a plan view thereof, and FIG. 5 is a perspective view thereof. As shown by the arrows in FIGS. 4 and 5, the head cover is detachably attached to the head portion of the engine 11 along the longitudinal direction of the vehicle body. The head cover 52 is provided with four protrusions (boss portions) 56 projecting in a mountain shape toward the main frame, and there are bolt holes 58 into which bolts are screwed. Two protrusions are formed on each of the right side and the left side of the engine with reference to the traveling direction of the vehicle body. The bracket 50 is screwed and fixed to the protrusion.

  On the other hand, as shown in FIG. 6, in each of the left and right main frames 5, a bifurcated protrusion (boss portion) 58 is formed near the head pipe 2 from below the main frame 5 toward the engine head cover 52 in a side view. Is provided. As can be seen from the AA cross section of FIG. 6 shown in FIG. 7, this projection is integrated with the main frame. Reference numeral 58 is a through hole in which a bolt is mounted. A bolt for fixing the bracket by this protrusion is attached.

  Further description will be continued based on FIG. 3 and FIG. 9, which will be described later. When viewed from the side, the triangular bracket 50 has a boss portion (56 in FIG. 5) and a boss portion ( It is fixed to 58) in FIG. The lower end of the bracket 50 is fixed to the boss portion of the head cover, and the upper end of the bracket is fixed to the boss portion of the main frame. This fixing is achieved by a bolt inserted into the bracket and the head cover or the screw hole of the main frame along the width direction of the engine. Reference numerals 60 and 62 are bolts for connecting the boss portion (58 in FIG. 6) of the main frame and the bracket 50 at two locations. Reference numerals 64 and 66 are bolts for connecting the brackets to one of the protrusions 56 arranged in the front-rear direction on the left and right sides of the head cover. Reference numeral 67 denotes an engine axis, and the engine head cover 52 is fixed to the main frame 5 on the head pipe side of the axis. Therefore, the rigidity of the main frame can be improved by utilizing the engine rigidity.

  FIG. 8 is a cross-sectional view taken along the line B-B of FIG. 3. The bolt 66 is screwed into the boss portion 58 of the engine cover, the boss portion 56 on the engine cover side, and the bolt hole of the bracket on the main frame side of the bracket 50. These are connected to each other.

  The cylinder behind the vehicle body is fixed to the main frame at the position B. Reference numeral 70 is a bracket, reference numeral 72 is a bolt for fixing the upper end of the bracket 73 to the main frame, and reference numeral 74 is a bolt for fixing the lower end of the bracket 73 to the upper part of the engine. The bolt is inserted into the engine head cover along the axial direction of the engine.

  Further, the engine is fixed at positions C and D at the rear of the engine body. Reference numeral 82 is a bolt for fixing the engine to the seat rail 86, and reference numeral 84 is a bolt for fixing the substantially lower end of the main frame 5 and the engine.

  FIG. 9 is a schematic diagram showing the connection relationship between the bracket 50, the boss portion 58 of the main frame 5, and the boss portion 56 of the engine head cover 52, as viewed from the front side or the rear side in the traveling direction of the vehicle body. .

  According to the embodiment described above, since the head cover is suspended from the main frame, the distance from the head pipe to the suspension point can be shortened, and the rigidity of the main frame around the head pipe can be ensured. Since the rigidity of the engine is generally higher than the rigidity of the frame, the rigidity of the entire vehicle body can be increased using the rigidity of the engine.

  Since the engine head cover is suspended from the frame via a separate bracket, there is room between the engine head cover and the frame by removing the bracket, so the engine head cover can be removed from the engine and removed. After that, the main frame is composed of a pair of left and right, and the engine can be exposed between the left and right frames. Therefore, maintenance around the engine head can be performed with the engine mounted on the vehicle.

  Since the rigidity of the frame can be improved by utilizing the rigidity of the engine, the down tube can be eliminated by attaching the side stand directly to the engine block, thereby reducing the weight and cost. When attaching the side stand to the engine, the strength of the attachment part of the side stand is reduced with respect to the boss of the engine, and when an excessive external force is applied, the attachment part may be damaged to protect the engine boss. The same is true for the footrest. The footrest may be attached to the engine cover.

  Further, since the rigidity of the entire vehicle body can be improved by using the rigidity of the engine to supplement the rigidity of the frame, it is not necessary to increase the rigidity of the frame more than necessary, thereby reducing the weight of the vehicle body.

  The embodiment described above can be changed as appropriate. For example, the head cover is not always essential, and the boss portion may be provided on the engine block. Furthermore, the engine may have a cylinder arranged in series.

1 is a side view of a motorcycle to which the present invention is applied. It is a top view which shows the vehicle body frame structure concerning this invention. It is a side view of the said suspension structure which shows the suspension structure of the engine with respect to a flame | frame from the vehicle body side view. It is a top view of an engine head cover. FIG. FIG. 5 is a side view corresponding to a view in the vehicle body width direction in which a pipe is enlarged from the head of the main frame. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is a schematic diagram which shows the coupling | bonding relationship of an engine head cover and a main frame using a bracket.

Explanation of symbols

2 head pipe, 5 main frame, 13 rear arm, 50 bracket, 52 head cover

Claims (6)

In the engine support structure in the saddle riding type traveling vehicle having a structure in which the engine is suspended from the frame,
A pair of left and right main frames that extend above the engine head to the rear of the vehicle body are connected to the head pipe of the frame,
The main frame and the engine have a separate bracket,
The bracket is fastened by bolts extending in the vehicle body width direction with respect to the main frame and the engine head,
The minimum width in the vehicle width direction in the engine head portion between the left and right main frames is configured to be smaller than the width of the engine head,
An engine support structure in a straddle-type vehicle, wherein the engine head is supported near the head pipe of the main frame. The structure according to claim 1, wherein the bracket is fastened to the main frame and the engine head so as to fix the engine head on the front side of the vehicle body with respect to the axis of the engine head to the main frame. The structure according to claim 1 or 2, wherein the engine is provided with an engine head cover, and the cover and the main frame are connected via a bracket. The structure according to any one of claims 1 to 3, wherein the brackets are respectively provided at two locations on both sides in the vehicle width direction of the engine. The structure according to any one of claims 1 to 4, wherein the bracket is fixed to the engine head and the main frame from the outside of the vehicle body along a vehicle body width direction. A straddle-type traveling vehicle comprising the engine support mechanism according to any one of claims 1 to 5.

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