JP2005105959A - Muffler cover structure in motorcycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure a sufficient clearance between a side cover and a muffler body outer side while providing a visual sense of unity between a muffler cover and the muffler body in a motorcycle in which an exhaust muffler comprises the muffler body and a tail pipe projected rearward from the rear end face of the muffler body and a part of the outer surface of the muffler body is covered by the muffler cover. <P>SOLUTION: The muffler cover C comprises a side cover Cs of arc shape in cross section which covers at least the outer surface of the muffler body Mm and a rear cover Cr formed integrally with the rear end part of the side cover Cs, covering the roughly entire part of the rear end face of the muffler body Mn, and in which the tail pipe P is passed. The tail pipe P is offset to the outside relative to the vertical centerline L of the muffler body Mm so that a radial clearance between the side cover Cs and the outer peripheral surface of the muffler body Mn becomes maximum at the outermost part of the muffler body Mm and the tail pipe P is passed through the roughly center position of the rear cover Cr. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a muffler cover structure in a motorcycle in which an exhaust muffler disposed on a side of a rear wheel includes a muffler main body and a tail pipe protruding rearward from a rear end surface of the muffler main body.

In the above-described motorcycle, a part of the outer surface of the muffler main body, that is, an outer peripheral surface outside and a part of the rear end surface are covered with a muffler cover fixed to the muffler main body is already known (for example, (See Patent Document 1 below).
Japanese Patent No. 3408182

  In the above conventional structure, the muffler cover covers only a small part of the rear end surface of the muffler body, and the tail pipe is directly exposed from the rear end surface. Therefore, the muffler cover and the muffler body are viewed from the rear or obliquely rear. If there is a sense of unity in appearance, that is, they are clearly separated and distinctly separated as separate parts, there is a problem that the appearance is not good, and the rear end surface of the muffler body, particularly around the tail pipe, is covered with a muffler cover. It cannot be covered enough.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a muffler cover structure in a motorcycle that can solve the above-described problems of the conventional structure with a simple structure.

  In order to achieve the above object, according to a first aspect of the present invention, an exhaust muffler disposed on a side of a rear wheel includes a muffler body and a tail pipe projecting rearward from a rear end surface of the muffler body. In a motorcycle in which a part of a muffler main body is covered with a muffler cover fixed to the muffler main body, the muffler cover has an arc-shaped side cover that covers at least the outer surface of the muffler main body, and the side cover. The rear cover is formed integrally with the rear end portion of the muffler body so as to cover the entire rear end surface of the muffler body and through which the tail pipe penetrates, and the radial gap between the side cover and the outer peripheral surface of the muffler main body is The tail pipe is offset outward from the vertical center line of the muffler body so that the tail pipe penetrates the approximate center position of the rear cover and reaches the maximum at the outermost part of the muffler body. And wherein the door.

  In addition to the features of the invention of claim 1, the invention of claim 2 is characterized in that the side cover is outside of a vertical plane passing through the vertical center line of the muffler body and more than a horizontal plane passing through the vertical center line. The inner part is cut away, leaving at least a region corresponding to the outer peripheral surface of the upper muffler body.

  In addition to the features of the invention of claim 1 or 2, the invention of claim 3 is a front-rear direction at a position where the side portion of the side cover is displaced to the outer surface of the muffler body, one side of the front and rear. And is fastened with bolts at a position displaced to the other side before and after that, and the upper part of the side cover is fastened with bolts to the upper surface of the muffler body. Features.

  As described above, according to the invention of each claim, the muffler cover is formed integrally with the side cover having an arcuate cross section covering at least the outer surface of the muffler main body and the rear end portion of the side cover. The rear cover covers substantially the entire rear end surface of the main body and includes a rear cover through which the tail pipe passes. The radial gap between the side cover and the outer peripheral surface of the muffler main body is maximized at the outermost portion of the muffler main body and the rear portion. Since the tail pipe is offset outward with respect to the vertical center line of the muffler body so that the tail pipe penetrates the approximate center position of the cover, when the exhaust muffler and the muffler cover are viewed from the rear or obliquely rear, the muffler The entire rear surface and the outer surface of the rear end surface of the main body are covered in a wide range by the rear cover and the side cover of the muffler cover, respectively. Since the tail pipe protrudes, the overall appearance of the muffler cover and the muffler body can be obtained, the appearance of the muffler can be improved, the merchantability can be improved, and the side cover can be improved. Sufficient clearance can be secured between the outer part of the muffler body.

  In particular, according to the invention of claim 2, the side cover corresponds to the outer peripheral surface of the muffler body outside the vertical plane passing through the vertical center line of the muffler main body and above the horizontal plane passing through the vertical center line. Since the inner part is cut away at least, the muffler body with sufficient heat dissipation can be secured even by adopting the muffler cover that enhances the external appearance of the muffler body as described above. .

  In particular, according to the invention of claim 3, the side portion of the side cover is locked to the outer surface of the muffler body so as to be detachable in the front-rear direction at a position deviated to one of the front and rear sides. It is fastened with bolts at a position displaced to the other side, and the upper part of the side cover is fastened with bolts to the upper surface of the muffler main body, so the side cover is attached to the muffler main body while reducing the bolt tightening points as much as possible. It can be fixed and supported stably and firmly, and by performing the locking before the bolts are fastened, the side cover can be easily positioned with respect to the muffler body, and the assembly workability is good.

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

  1 to 6 show an embodiment of the present invention, FIG. 1 is an overall side view of a motorcycle, and FIG. 2 is a plan view in which a part of an exhaust muffler is broken. 1 is an enlarged view taken along arrow 3 in FIG. 2, FIG. 4 is an enlarged view taken along arrow 4 in FIG. 2, and FIG. 5 is an enlarged sectional view taken along line 5-5 in FIG. 6 is a single perspective view of the muffler cover.

  First, in FIG. 1, an engine E and its intake / exhaust system, a fuel tank T, a fuel supply system for guiding fuel from the tank T to the engine side, and the like are mounted on a body frame F of a motorcycle. A front wheel Wf is supported at the front end portion of the vehicle body frame F via a front fork 1, and a swing arm SA supporting the rear wheel Wr is pivotally connected to a substantially central lower portion of the frame F so as to be swingable up and down. A rear cushion R is interposed between the swing arm SA and the vehicle body frame F.

  The vehicle body frame F includes a head pipe H that supports the front fork 1 so as to be steerable, a down tube DT that extends downward from the head pipe H and passes through the front side of the engine E, and is slightly rearwardly lowered from the head pipe H. A main frame MF that extends rearward and extends downward through the upper and rear sides of the engine E, and a seat tube ST that has a front end integrally coupled to an intermediate portion of the main frame MF and a rear end that extends rearward. The back tube BT is integrally connected between the intermediate portion of the seat tube ST and the rear portion of the main frame MF. An engine E is coupled and supported between a rear portion of the main frame MF and a lower portion of the down tube DT, and a tandem seat S and a rear cowl 9 with a rear fender 8 are supported on the seat tube ST. The Further, a bottom portion of the fuel tank T disposed so as to straddle the main frame MF is supported on the upper portion of the main frame MF.

  A step holder 3 is integrally coupled to an appropriate position of the vehicle body frame F (lower part of the main frame MF in the illustrated example), and a footrest step 4 for a rear seat occupant is attached to the front portion of the step holder 3. Further, a muffler support bracket 3a for supporting an exhaust muffler M described later is integrally formed. Further, a side cover 7 that covers the side of the vehicle body space immediately below the front part of the seat S and directly below the fuel tank T and a lower cover 5 that covers the side of the vehicle body space immediately after the engine E can be attached to and detached from the vehicle body frame F. Installed.

  An intake pipe IP having a carburetor 6 extends rearward from the rear surface of the cylinder head CH of the engine E, and an air cleaner A is connected to the upstream end thereof. Further, an exhaust pipe EX extends forward from the front surface of the cylinder head CH, and the exhaust pipe EX gently reverses backward near the down tube DT and extends below the engine E backward. . An exhaust muffler M that is located on the right side of the rear wheel Wr and is inclined slightly rearward is connected to the rear end of the exhaust pipe EX. The exhaust muffler M is detachably mounted with a muffler cover C that covers the outer surface and the rear end surface of the muffler main body Mm.

  Next, specific configurations of the exhaust muffler M and the muffler cover C will be described with reference to FIGS. The exhaust muffler M includes a muffler body Mm that is basically formed in a cylindrical shape, and a tail pipe P that protrudes rearward from the closed rear end surface of the muffler body Mm. The front end portion of the muffler main body Mm is formed in a tapered shape, and the front end of the opening is integrally connected to the downstream end of the exhaust pipe EX. Further, a base end portion of the muffler stay 12 is integrally coupled (welded in the illustrated example) to the upper portion of the outer peripheral surface of the muffler main body Mm at a position closer to the front end and closer to the inside. It extends upward, and its tip is joined to the muffler support bracket 3a at the tip of the step holder 3 by a bolt 14 and a nut N with an elastic material 13 in between.

  The muffler cover C is formed integrally with the side cover Cs having a circular cross section covering the upper surface and the outer surface of the muffler main body Mm, and the rear end portion of the side cover Cs, and the rear end surface of the muffler main body Mm is substantially entirely covered. The rear cover Cr that covers the entire area is integrally formed with a heat-resistant synthetic resin. Therefore, no seam is formed between the side cover Cs and the rear cover Cr, and the appearance is good. .

  A plurality of nuts N ′ arranged at intervals in the front-rear direction are fixed to the upper surface of the muffler main body Mm by welding or the like, and the outer wall of the side cover Cs is connected to the outer surface corresponding to each nut N ′. A flat recessed mounting seat 15 and a bolt insertion hole 16 are provided. Accordingly, the upper side wall of the side cover Cs can be coupled to the upper surface of the muffler body Mm by the bolt 14 ′ screwed into the nut N through the bolt insertion hole 16.

  Further, on the outer surface of the muffler main body Mm, a hook piece 17 whose front end extends rearward at a position (a position near the rear end in the illustrated example) deviated to one side (the rear side in the illustrated example) from the front and rear center thereof, Further, nuts N ″ are respectively fixed at positions deviated to the other side (the front side in the illustrated example) (positions in the vicinity of the front end in the illustrated example). The inner surface of the side cover Cs corresponds to these hook pieces 17. Is integrally provided with an engaging female portion 18 that can be removably engaged with the hook piece 17 in the front-rear direction, and on the outer wall of the side cover Cs corresponding to the nut N ″, A flat mounting seat 19 and a bolt insertion hole 20 that are recessed from the outer surface are provided. Therefore, when the bolt 14 ″ is screwed into the nut N ″ through the bolt insertion hole 20 with the hook piece 17 inserted into the engaging female portion 18, the outer wall of the side cover Cs is placed on the outer surface of the muffler body Mm. Can be combined.

  Further, as apparent from FIG. 5, the arc shape of the cross section of the side cover Cs has a larger radius of curvature than the arc shape of the outer peripheral surface of the muffler body Mm, and the former arc shape is the muffler cover. In the set state of C on the muffler main body Mm, it is offset from the vertical center line L of the muffler main body Mm outward (right side in FIG. 5) by a predetermined offset amount ε.

  The side cover Cs leaves at least a region corresponding to the outer peripheral surface of the muffler main body Mm outside the vertical plane passing through the vertical center line L of the muffler main body Mm and above the horizontal plane passing through the vertical center line L (that is, In the illustrated example, the inner portion is cut away and the inner portion is left slightly below and inside (left side in FIG. 5), and the cutout portion is indicated by reference symbol X in the drawing.

  Further, the rear cover Cr is formed in a circular dish shape with the arc surface of the side cover Cs as a part of the outer peripheral arc, and a forward arc-shaped flange portion f is integrally formed on the outer peripheral edge of the rear cover Cr. Thus, the rear cover Cr and the muffler main body Mm are in a fitting form in which the rear end of the muffler main body Mm is shallowly immersed in the flat inner space of the rear cover Cr.

  An annular chamfered portion r is formed on the outer peripheral portion of the rear surface of the rear cover Cr, and a shallow circular recess 10 is formed in the central portion. A pipe insertion hole 10a through which the tail pipe P is inserted and protrudes rearward is formed at the bottom of the circular recess 10, and the pipe insertion hole 10a is substantially at the center position of the rear cover Cr having a circular dish shape. Located in.

  The tail pipe P to be inserted into the pipe insertion hole 10a is fixed to the rear end wall of the muffler main body Mm by being offset by a predetermined offset amount ε outward (right side in FIG. 5) with respect to the vertical center line L of the muffler main body Mm. Established. The offset amount ε and the offset direction of the tail pipe P with respect to the muffler body Mm are the same as the offset amount ε and the offset direction of the arc shape of the side cover Cr, and according to the offset arrangement of the tail pipe P, the side The radial gap s between the portion cover Cs and the outer peripheral surface of the muffler main body Mm is maximized at the outermost portion of the muffler main body Mm and gradually decreases from the outermost portion toward the innermost portion, and the rear cover Cr The tail pipe P can pass through the pipe insertion hole 10a at substantially the center position in a substantially concentric manner.

  Next, the operation of the embodiment will be described. In the operating state of the engine E, the muffler main body Mm of the exhaust muffler M becomes hot due to the exhaust heat, but the rear end surface and the outer surface of the muffler main body Mm are covered with the muffler cover C.

  Thus, the muffler cover C in the illustrated example is formed integrally with the side cover Cs having a circular cross section covering the upper surface and the outer surface of the muffler main body Mm, and the rear end portion of the side cover Cs. The rear cover Cr covers substantially the entire rear end surface of the Mm and the tail pipe P penetrates, and the radial gap s between the side cover Cs and the outer peripheral surface of the muffler main body Mm is defined by the muffler main body Mm. The tail pipe P is connected to the muffler main body Mm so that the tail pipe P penetrates through the approximate center position of the rear cover Cr so that it becomes maximum at the outermost part and gradually decreases from the outermost part toward the innermost part. Are offset from the vertical center line L by a predetermined offset amount ε. For this reason, when a person looks down at the exhaust muffler M and the muffler cover C from behind or obliquely from behind, substantially the entire rear surface of the muffler main body Mm, the upper surface, and the outer surface are the rear cover Cr and side cover Cs of the muffler cover C. In addition, since the tail pipe P appears to protrude from the rear cover Cr at a substantially central position (that is, substantially concentrically), the muffler cover C and the muffler body Mm as a whole can be covered. A sense of unity in appearance is obtained, and the appearance is improved. In addition, a sufficient radial clearance s can be secured between the side cover Cs and the outer peripheral surface of the muffler main body Mm, and the temperature rise of the side cover C and the muffler main body Mm can be effectively suppressed.

  By the way, the side cover Cs leaves at least a region corresponding to the outer peripheral surface of the muffler main body Mm outside the vertical plane passing through the vertical center line L of the muffler main body Mm and above the horizontal plane passing through the vertical center line L ( In other words, in the illustrated example, the inner part is greatly cut away from the area below and inside (left side in FIG. 5), and the inner part is greatly cut away. The area covered and shielded by C (particularly the side cover Cs) can be reduced as much as possible to ensure a sufficient heat radiation area. In addition, the exhaust muffler M is usually seen as if the person is looking down from the rear of the vehicle or obliquely from the rear of the vehicle even by the presence of the large cutout portion X in the side cover Cs. Can be efficiently and sufficiently covered.

  As mentioned above, although the Example of this invention was explained in full detail, this invention can perform a various design change in the range which does not deviate from the summary.

  For example, in the above-described embodiment, the step holder 3 as the muffler support member is coupled to the main frame MF. However, in the present invention, the step holder or the muffler support bracket as the muffler support member is not the main frame MF. The vehicle body frame may be supported by an appropriate part of the vehicle body frame (for example, the back tube BT or the seat tube ST), or by a vehicle-mounted component or engine body fixed to the vehicle body frame.

  In the above embodiment, the muffler cover C is formed of a heat resistant synthetic resin material. However, in the present invention, the muffler cover may be formed of another heat resistant material (for example, a metal plate, a heat insulating material, etc.). Alternatively, these materials may be appropriately combined (for example, stacked). Moreover, in the said Example, although the muffler cover C showed what integrally formed the side cover Cs and the rear cover Cr, in this invention, after forming the side cover Cs and the rear cover Cr separately, it is mutually You may make it couple | bond together.

  Further, in the above embodiment, the front end of the side cover Cs of the muffler cover C ends at a position near the rear end of the tapered cone portion of the front end portion of the muffler body Mm. However, in the present invention, the side cover The front end of Cs may be extended to the front end of the cone portion along the outer peripheral surface of the cone portion so that the outer surface and the upper surface of the cone portion are sufficiently covered.

Overall side view of a motorcycle according to an embodiment of the present invention. Plan view in which a part of the exhaust muffler is broken (enlarged view of the part indicated by arrow 2 in FIG. 1) 3 arrow view of FIG. 4 enlarged view of FIG. FIG. 5 is an enlarged sectional view taken along line 5-5. Single unit perspective view of muffler cover

Explanation of symbols

C ... Side cover Cr ... Rear cover Cs ... Side cover ε ... Offset L ... Vertical center line M ... Exhaust muffler Mm ... Muffler body P ... Tail pipe s ...・ Radial gap Wr ・ ・ Rear wheel X ・ ・ ・ Notch

Claims (3)

An exhaust muffler (M) disposed on the side of the rear wheel (Wr) includes a muffler body (Mm) and a tail pipe (P) projecting rearward from the rear end surface of the muffler body (Mm). In a motorcycle in which a part of the muffler body (Mm) is covered with a muffler cover (C) fixed to the muffler body (Mm),
The muffler cover (C) is formed integrally with the side cover (Cs) having an arcuate cross section covering at least the outer surface of the muffler body (Mm) and the rear end of the side cover (Cs). (Mm) comprises a rear cover (Cr) that covers substantially the entire rear end surface and penetrates the tail pipe (P),
The radial gap (s) between the side cover (Cs) and the outer periphery of the muffler body (Mm) is maximized at the outermost part of the muffler body (Mm), and the center position of the rear cover (Cr) is set to the tail pipe. A muffler cover structure in a motorcycle, wherein the tail pipe (P) is offset outwardly with respect to the longitudinal center line (L) of the muffler body (Mm) so that (P) penetrates.   The side cover (Cs) has an outer periphery of the muffler main body (Mm) outside the vertical plane passing through the vertical center line (L) of the muffler main body (Mm) and above the horizontal plane passing through the vertical center line (L). The muffler cover structure for a motorcycle according to claim 1, wherein an inner portion is cut away so as to leave at least a region corresponding to the surface. The side portion of the side cover (Cs) is locked to the outer surface of the muffler body (Mm) so as to be detachable in the front-rear direction at a position displaced to one side of the front-rear side, and to the other side of the front-rear side. It is characterized in that it is fastened with bolts (14 ″) at the displaced position, and the upper part of the side cover (Cs) is fastened with bolts (14 ′) to the upper surface of the muffler body (Mm). A muffler cover structure in a motorcycle according to claim 1 or 2.

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