JP7630606B2 - Muffler device - Google Patents

Description

The present invention relates to a muffler device to be installed in a saddle-type vehicle.

Generally, muffler devices for saddle-type vehicles are equipped with a muffler cover, but the wind that flows around the muffler cover during riding can generate turbulence at the rear end of the muffler cover, which can affect exhaust performance.
In response to this, a muffler cover has been provided with an intake port, and the exhaust outlet side of the tailpipe of the muffler body is bent sideways to allow the wind from the intake port to be directed at it, promoting exhaust. This is shown, for example, in Patent Document 1 below. However, this requires a lot of labor to mold and combine the tailpipe and muffler cover, and since the muffler body and muffler cover are constructed as a single unit, there are issues with reducing weight and costs.
In addition, for example, Patent Document 2 listed below shows a muffler cover that has a gap between the rear end of the muffler body and the muffler cover to take in wind from driving. However, the wind that flows in through this gap flows around the tailpipe, causing interference with the exhaust at the exhaust outlet of the tailpipe and affecting the exhaust.

Japanese Patent Application Publication No. 2006-017046 (FIGS. 3 to 8) Japanese Patent Publication No. 2009-264293 (FIGS. 2, 7 to 9)

The present invention has been made in consideration of the above-mentioned conventional technology, and has an objective of providing a muffler device to be fitted to a saddle-type vehicle that can prevent the generation of turbulence near the exhaust outlet of the tailpipe, improve exhaust flow, eliminate any impact on driving performance, and reduce the labor required for molding and assembling the tailpipe and muffler cover.

In order to solve the above problems, the present invention provides
A muffler device having a muffler body connected to a rear end of an exhaust pipe of an internal combustion engine of a saddle-type vehicle,
A tail pipe with an exhaust outlet protruding rearward is provided at the rear of the muffler body, a muffler cover spaced from the muffler body is provided around the exhaust outlet, a gap is provided between the muffler cover and the muffler body through which running wind is introduced, and an air introduction guide section is provided that guides the running wind introduced from the gap to the side of the exhaust outlet relative to the exhaust outlet, and the muffler device is characterized in that it further comprises a second muffler cover that covers the outer surface of the muffler body and has a running wind guide section that introduces the running wind between the muffler cover and the second muffler cover .

According to the above configuration,
By providing an introduction wind guide section that guides the traveling wind to the side of the exhaust outlet, the traveling wind is prevented from hitting the vicinity of the exhaust outlet, and the generation of turbulence in the vicinity of the exhaust outlet can be prevented, improving the exhaust flow and eliminating any effect on driving performance.
In addition, the tailpipe has an exhaust outlet facing rearward, which reduces the amount of work required to mold and assemble the tailpipe and muffler cover.
In addition, the running wind is introduced into the gap between the muffler cover and the muffler body from the running wind guide section between the second muffler cover and the muffler cover, improving the cooling performance of the muffler cover and preventing turbulence caused by the running wind being drawn into the exhaust outlet.

According to a preferred embodiment of the present invention,
The muffler cover has an inlet air guide hole in its rear outer side of the vehicle, spaced from the exhaust outlet and opening toward the rear, and the inlet air guide portion is located inside the muffler cover, between the exhaust outlet and the inlet air guide hole, and is erected parallel to the discharge direction of exhaust gas discharged from the exhaust outlet.
Therefore, the airflow introduced into the muffler cover can be discharged through the airflow guide hole by the airflow guide section without hitting the exhaust gas. In addition, the airflow guide section guides the introduced airflow in a direction parallel to the exhaust gas discharge direction, creating a curtain of airflow parallel to the exhaust gas discharge direction, thereby preventing the airflow from being drawn in from the outer surface of the muffler cover.

According to a preferred embodiment of the present invention,
The muffler cover is a tail cap that covers the entire rear end of the muffler body.
The muffler cover acts as a tail cap to cover the entire rear end of the muffler body, so that people around can be protected from the heat of the rear end of the muffler body.

According to a preferred embodiment of the present invention,
The muffler cover is made of resin.
Making the muffler cover out of plastic makes it possible to reduce weight and costs, and also reduces the generation of radiant heat.

According to a preferred embodiment of the present invention,
A gap is provided between the second muffler cover and the muffler body, and the second muffler cover has an intake port on its upper surface facing outwardly of the vehicle, through which airflow flows in while the vehicle is running.
The airflow from the running vehicle taken in through the intake port into the gap between the second muffler cover and the muffler body is discharged through the airflow guide hole within the muffler cover by the airflow guide section, thereby preventing the generation of turbulence caused by the running airflow flowing around the outer periphery of the second muffler cover.

According to a preferred embodiment of the present invention,
The muffler body is provided so as to be inclined upward toward the rear.
In the case of a muffler body that is inclined upward at the rear, the upper surface of the second muffler cover is likely to be exposed to the wind generated by driving, but the wind that hits it is efficiently taken in through the intake port into the gap between the second muffler cover and the muffler body.
In addition, another aspect of the present invention is
This muffler device has a muffler body connected to the rear end of an exhaust pipe of an internal combustion engine of a saddle-type vehicle, and is characterized in that a tailpipe with an exhaust outlet protruding rearward is provided at the rear of the muffler body, a muffler cover spaced from the muffler body is provided around the exhaust outlet, a gap is provided between the muffler cover and the muffler body through which running wind is introduced, and an intake wind guide section guides the running wind introduced from the gap to the side of the exhaust outlet with respect to the exhaust outlet, the muffler cover has an intake wind guide hole in its rear outer portion of the vehicle that is spaced from the exhaust outlet and opens rearward, and the rear end of the muffler cover is located rearward between the exhaust outlet of the tailpipe and the intake wind guide hole.

According to the muffler device of the present invention,
By providing an introduction wind guide section that guides the traveling wind to the side of the exhaust outlet, the traveling wind is prevented from hitting the vicinity of the exhaust outlet, and the generation of turbulence in the vicinity of the exhaust outlet can be prevented, improving the exhaust flow and eliminating any effect on driving performance.
In addition, the tailpipe has an exhaust outlet facing rearward, which reduces the amount of work required to mold and assemble the tailpipe and muffler cover.
In addition, the running wind is introduced into the gap between the muffler cover and the muffler body from the running wind guide section between the second muffler cover and the muffler cover, improving the cooling performance of the muffler cover and preventing turbulence caused by the running wind being drawn into the exhaust outlet.

1 is a schematic diagram showing a right side view of a motorcycle equipped with a muffler device according to an embodiment of the present invention, with a body cover removed. FIG. 2 is a right side view showing the exhaust pipe and the muffler device of FIG. 1 . FIG. 3 is a top view of the exhaust pipe and muffler device taken along the line III-III in FIG. 2 . FIG. 2 is a perspective view showing a relationship between a first muffler cover and a second muffler cover with respect to a muffler body in the muffler device; FIG. 2 is a right side cross-sectional view of a main portion of the muffler device. FIG. 6 is a rear outside view of the first muffler cover taken along the line VI-VI in FIG. 2 . FIG. 7 is a front inner view of the first muffler cover taken along the line VII-VII in FIG. 2 . 1 is a perspective view of the rear end side of the muffler device, as viewed from the inside rear side of the vehicle, with a first muffler cover removed. IX-IX in FIG. 2 is a cross-sectional plan view of the first muffler cover and the muffler body.

A muffler device according to one embodiment of the present invention will be described with reference to Figs. 1 to 9.
In this embodiment, a saddle-type vehicle equipped with a muffler device is a motorcycle, and the directions of front, back, left, right, up, down, etc. in the claims and the description of this specification shall conform to the directions of the vehicle (motorcycle) in this embodiment.
In the figure, arrows FR, LH, RH, and UP indicate the front, left, right, and upper sides of the vehicle, respectively.

FIG. 1 is a schematic diagram showing a right side view, excluding a body cover, of an example of a general form of a motorcycle 1 equipped with a muffler device according to this embodiment.
As shown in FIG. 1, in a motorcycle 1 of this embodiment (a "saddle-ride type vehicle" in the present invention), a body frame 2 has a main frame 21 that extends slightly downward rearward from a head pipe 20 and then bends further downward to form a bent portion 21a in a side view, and then forms a steeply inclined portion 21b to reach a pivot frame 22.

A down frame 23 extends downward at a steep angle from the head pipe 20 and is generally parallel to the steeply inclined portion 21b of the main frame 21 in a side view.
A pair of left and right seat rails 24 extend rearward from the bent portion 21 a of the main frame 21 , and the seat rails 24 are supported by a pair of left and right backstays 25 that connect the rear portions of the seat rails 24 to the pivot frame 22 .

In the vehicle body frame 2 as described above, a front fork 11 is pivotally supported on the head pipe 20, and a front wheel 12 is journalled at the lower end thereof.
A rear fork 13 is pivotally supported at its front end on a pivot frame 22 connected to the lower part of the steeply inclined portion 21b of the main frame 21, extends rearward, and a rear wheel 14 is journalled at its rear end. A rear cushion (not shown) is interposed between the rear fork 13 and the body frame 2.
A fuel tank 16 is mounted on the front of the main frame 21, and a driver's seat 17A and a pillion seat 17B for a passenger are supported by seat rails 24 and provided at the front and rear of the fuel tank 16.

In this embodiment, the motorcycle 1 is mounted with an internal combustion engine 3 below the main frame 21 and in front of the steeply inclined portion 21b. The internal combustion engine 3 is suspended from the body frame 2 with the front part of its crankcase 30 fastened to a bracket 23a attached to the lower end of the down frame 23 and the rear part of the crankcase 30 fastened to the pivot frame 22.

The internal combustion engine 3 of this embodiment is equipped with a transmission 4 at the rear of the crankcase 30, forming a so-called power unit, and is an air-cooled, single-cylinder, four-stroke cycle internal combustion engine mounted on the motorcycle 1 with its crankshaft 31 oriented in the vehicle width direction, i.e., the left-right direction, of the motorcycle 1.

At the rear of the crankcase 30, the main shaft and counter shaft (not shown) of the transmission 4 are provided in parallel with the crankshaft 31. The counter shaft penetrates the crankcase 30 to the left and protrudes to the outside, becoming the final output shaft of the power unit, and is equipped with an output sprocket (not shown) at the protruding part. A drive chain 41 is wound around the output sprocket, which is stretched over a driven sprocket 42 on the rear wheel 14 side to form a chain transmission mechanism, and power is transmitted to the rear wheel 14.

The internal combustion engine 3 is suspended on a crankcase 30 with the cylinder axis inclined forward and a cylinder block 32, a cylinder head 33, and a cylinder head cover 34 in an upright position.
An intake system 50 is provided rearward from the cylinder head 33 of the internal combustion engine 3 , connected to the intake port 35 , and leads to an air cleaner case 51 .
An exhaust pipe 55 connects to the exhaust port 36 and extends forward from the cylinder head 33 , bends downward, and extends rearward below the internal combustion engine 3 to reach the muffler device 7 on the right side of the rear wheel 14 .

2 is a right side view showing the exhaust pipe 55 and the muffler device 7 of FIG. 1, and FIG. 3 is a top view of the exhaust pipe 55 and the muffler device 7 as viewed along the arrows III-III in FIG.
As shown in FIG. 2, the muffler body 70 of the muffler device 7 connected to the rear end of the exhaust pipe 55 is inclined slightly upward toward the rear, with its rear end 70b facing toward the rear of the vehicle (see FIG. 1).
A front mounting bracket 71 is provided at the front of the upper portion of the muffler body 70, and a rear mounting bracket 72 is provided at the rear of the upper portion thereof so as to protrude upward.

In this embodiment, the front mounting bracket 71 is fastened to the pivot frame 22a, and the rear mounting bracket 72 is fastened to the lower end of the pillion step support stay 26 attached to the back stay 25 (see FIG. 1). There is no limitation as to where on the body frame 2 they are fixed.
Therefore, in this embodiment, the muffler body 70 of the muffler device 7 is fixed to the vehicle body frame 2, and the internal combustion engine 3 is also fixed to the vehicle body frame 2, so that the muffler device 7 is connected to the internal combustion engine 3 without any mutual movement.

As shown in FIG. 2, a tail pipe 74 having an exhaust outlet 74a protruding rearward is provided in a rear portion of a muffler body 70 to which the rear end of the exhaust pipe 55 is connected (see FIG. 5).
A first muffler cover (referred to as "muffler cover" in this invention) 8 is provided around the exhaust outlet 74a of the tail pipe 74 that protrudes rearward from the rear end 70b of the muffler body 70, and is attached to the muffler body 70 with a gap 81 therebetween. The first muffler cover 8 covers the entire rear end 70b of the muffler body 70 from the rear, forming a so-called tail cap (see Figures 4, 5 and 9), and is made of resin.
Therefore, people in the vicinity can be protected from the heat of the rear end portion 70b of the muffler body 70, and because it is made of resin, it is possible to reduce weight and costs, and also reduce the generation of radiant heat, protecting the surrounding area from radiant heat.

In addition, the muffler device 7 is provided with a second muffler cover (the "second muffler cover" in this invention) 9 that covers the outer surface 70a of the muffler body 70 from the upper and right side, with a gap 75 provided between it and the muffler body 70 (see Figures 3 and 5).
As shown generally in FIG. 3, a first mounting base 76 and a second mounting base 77 are provided on the right side of the muffler body 70. By engaging an engagement portion 96 provided on the inner surface of the second muffler cover 9 with the first mounting base 76 and fastening a bolt 98 through a fastening hole 97 of the second muffler cover 9 to the second mounting base 77, the second muffler cover 9 is attached with a gap 75 provided between it and the muffler body 70.

Further, from the top surface 9a to the side surface 9c of the second muffler cover 9, an intake port 90 for taking in surrounding airflow while the vehicle is running is provided facing outward from the vehicle.
Therefore, the traveling wind around the muffler device 7 that is taken in from the intake port 90 into the gap 75 between the second muffler cover 9 and the muffler body 70 is guided into the first muffler cover 8 (indicated by the dashed white arrow in Figures 2 and 3) and then discharged from the introduction wind guide hole 83 within the first muffler cover 8 by the introduction wind guide section 84 described below (see Figures 6 and 7), thereby preventing the generation of turbulence caused by the traveling wind flowing around the outer periphery of the second muffler cover 9.

FIG. 4 is a perspective view showing the relationship of the first muffler cover 8 and the second muffler cover 9 to the muffler body 70 in the muffler device 7.
As shown in Figure 4, first muffler cover 8 is attached so as to provide a gap 81 between it and the rear end 70b of muffler body 70, through which traveling wind (white arrow A in Figure 4) can be introduced, and the rear end 9b of second muffler cover 9 has a traveling wind guide portion 91 that forms a stepped combination portion so as to form a gap 82 between the front end 8a of first muffler cover 8, and traveling wind (white arrow B in Figure 4) is introduced from gap 82 of traveling wind guide portion 91 into gap 81 between first muffler cover 8 and muffler body 70, improving the cooling performance of first muffler cover 8.

The muffler body 70 of the muffler device 7 of this embodiment is tilted slightly upward at the rear, with its rear end 70b facing the rear of the vehicle (see Figures 1 and 2). With the muffler body 70 tilted upward at the rear, the upper surface 9a of the second muffler cover 9 is easily exposed to the wind from the road. However, the air that hits it can be efficiently taken in from the intake port 90 into the gap 75 between the second muffler cover 9 and the muffler body 70. The air can then be introduced into the first muffler cover 8 from the gap 75, improving the cooling performance of the first muffler cover 8 and preventing the generation of turbulence caused by the air from the road around the muffler device 7 being drawn into the exhaust outlet 74a.
In addition, since the muffler body 70 is angled upward at the rear, the traveling wind can enter through the gap 82 in the traveling wind guide portion 91 and be introduced into the first muffler cover 8, improving the cooling performance of the first muffler cover 8 and preventing the generation of turbulence caused by the traveling wind around the muffler device 7 being sucked into the exhaust outlet 74a.

5 is a right side cross-sectional view of the main part of the muffler device 7. The rear end 55a of the exhaust pipe 55 inserted into the muffler body 70 opens into the first expansion chamber 79a between the first partition plate 78a and the second partition plate 78b to release the exhaust pressure of the exhaust gas. The exhaust gas further passes through the communication pipe 78c passing through the second partition plate 78b, and enters the second expansion chamber 79b between the second partition plate 78b and the rear end plate 73 to release the exhaust pressure. The exhaust gas 74b, whose exhaust pressure has been reduced, passes through the straight tail pipe 74 penetrating the rear end plate 73, and is discharged from the exhaust outlet 74a at the rear end to the rear of the muffler device 7 with a silencing effect (black arrow 74b in FIGS. 4 and 5). The insides of the first expansion chamber 79a and the second expansion chamber 79b may be filled with glass wool or the like.
The periphery of the tail pipe 74 protruding from the rear end portion 70b of the muffler body 70 is surrounded by the first muffler cover 8. The second muffler cover 9 is provided on the outer surface 70a of the muffler body 70 with a gap 75 therebetween, as described above.
In the present invention, the structure within the muffler body 70, for example the number and arrangement of expansion chambers, is not limited to that described above, and FIG. 5 is merely an example.

6 is a rear outer surface view of the first muffler cover 8 taken along the line VI-VI in FIG. 2, and FIG. 7 is a front inner surface view of the first muffler cover 8 taken along the line VII-VII in FIG.
As shown in FIGS. 6 and 7, the first muffler cover 8 is formed in an annular shape when viewed from the front-rear direction, and has a central opening 80 surrounding the tail pipe 74 protruding rearward from the muffler body 70.

A long, vertically long, slit-shaped air intake guide hole 83 is provided penetrating from front to rear in the right part of the first muffler cover 8, i.e., the vehicle outer part 8c, and an air intake guide portion 84 is erected on the inner surface between the air intake guide hole 83 and the central opening 80, with a vertical length that exceeds the vertical length of the air intake guide hole 83.
That is, the introduction wind guide hole 83 opens toward the rear, away from the exhaust outlet 74a of the tail pipe 74, and the introduction wind guide section 84 is provided inside the first muffler cover 8, between the exhaust outlet 74a and the introduction wind guide hole 83, in the form of a vertical wall parallel to the discharge direction (black arrow in Figures 4 and 5) of the exhaust gas 74b discharged from the exhaust outlet 74a.

In this manner, in this embodiment, an air intake guide section 84 is provided that guides the running air introduced from the gap 81 between the first muffler cover 8 and the rear end section 70b of the muffler body 70 to the side of the exhaust outlet 74a relative to the exhaust outlet 74a. This prevents the running air from hitting the vicinity of the exhaust outlet 74a and prevents the generation of turbulence in the vicinity of the exhaust outlet 74a, improving the exhaust flow and eliminating any impact on driving performance.
In addition, the wind introduced into the first muffler cover 8 can be discharged from the wind introduction guide hole 83 without hitting the exhaust gas 74b (black arrow in Figures 4 and 5) by the wind introduction guide portion 84, and by guiding the wind parallel to the discharge direction of the exhaust gas 74b from the exhaust outlet 74a, an air curtain 83a of the wind is created parallel to the discharge direction of the exhaust gas 74b (see Figures 4 and 9), thereby preventing the wind from being drawn in by the outer surface of the first muffler cover 8.

Furthermore, above the wind introduction guide portion 84 inside the first muffler cover 8, there is provided a protruding support stay engagement portion 89 which engages with a muffler cover engagement portion 85d (see FIG. 8) which will be described later.
The left part of the first muffler cover 8, i.e., the vehicle inside part 8d, has two fastening holes 87, one above and one below, for fastening to a muffler cover fixing part 86 (see Figure 8) of the first muffler cover support stay 85 described below, and a ventilation hole 88 that penetrates the first muffler cover 8 from front to rear is provided between them.
Therefore, the wind generated when traveling and flowing into the gap 81 along the vehicle inner side surface of the muffler body 70 is also discharged from the ventilation hole 88 to the rear of the vehicle, forming a ventilation flow 88a parallel to the exhaust gas 74b discharged from the exhaust outlet 74a (see Figure 9).

FIG. 8 is a perspective view of the rear end side of the muffler device 7 as viewed from the inside rear side of the vehicle, with the first muffler cover 8 removed.
A straight tail pipe 74 passes through the rear end plate 73 of the muffler body 70 and protrudes rearward (see Figure 5), and a first muffler cover support stay 85, through which the protruding tail pipe 74 is inserted, is fixed to the rear end plate 73 at a welded portion 85c.

The first muffler cover support stay 85 is a sheet metal member generally shaped to close the central opening 80 of the first muffler cover 8 .
The first muffler cover support stay 85 has an upper support leg 85a and a lower support leg 85b which are bent forward, and their front ends are fixed to the rear end plate 73 at welded portions 85c.
A muffler cover fixing portion 86 is bent forward on the left portion of the first muffler cover support stay 85, i.e., on the vehicle inner side, and has fastening holes 86a at two locations.
The bent front end of the muffler cover fixing portion 86 is fixed to the rear end plate 73 at a welded portion 85c.
A muffler cover engaging portion 85d is provided on the opposite side to the muffler cover fixing portion 86, i.e., on the right side of the vehicle.

The first muffler cover 8 is positioned so as to cover the first muffler cover support stay 85 from the rear, and is fastened to the muffler body 70 by inserting fastening bolts 86b into the fastening holes 87 from the outside of the vehicle inner portion 8d and screwing them into the fastening holes 86a of the first muffler cover support stay 85.
At this time, the muffler cover engaging portion 85d of the first muffler cover support stay 85 fits into the support stay engaging portion 89 on the inner surface of the vehicle outer portion 8c of the first muffler cover 8 shown in Figure 7, and the position of the first muffler cover 8 is fixed.

Figure 9 is a plan sectional view of the first muffler cover 8 and the muffler body 70, taken along the line IX-IX in Figure 5. As this is a cross section of a slightly lower part, the tail pipe 74 is not visible.
The figure shows the lower support leg 85b of the first muffler cover support stay 85 fixed to the rear end plate 73 of the muffler body 70 at a welded portion 85c, and the vehicle inner portion 8d of the first muffler cover 8 fastened to the lower fastening hole 86a of the bent muffler cover fixing portion 86.
Also shown in the figure are the wind introduction guide portion 84 erected on the inner surface of the vehicle outer portion 8c of the first muffler cover 8 and the lower end of the wind introduction guide hole 83 opened on the outside thereof.

As shown in Figure 9, the wind flowing in from the gap 81 between the muffler body 70 and the first muffler cover 8 is separated from the exhaust outlet 74a of the tail pipe 74 by the wind introduction guide part 84 inside the first muffler cover 8, and is discharged from the wind introduction guide hole 83 to the rear of the vehicle, forming an air curtain 83a parallel to the exhaust gas 74b (black arrow in Figure 9) discharged from the exhaust outlet 74a. In Figure 9, 8b is the rear end part of the muffler cover 8.
In addition, the wind generated while traveling that flows into the gap 81 along the vehicle inner side surface of the muffler body 70 is separated from the exhaust outlet 74a by the muffler cover fixing portion 86 of the first muffler cover support stay 85, and is discharged to the rear of the vehicle through the ventilation hole 88, forming a ventilation flow 88a parallel to the exhaust gas 74b discharged from the exhaust outlet 74a.

The muffler device 7 of this embodiment is configured as described above, and its operation and effects will be described below.
That is, a tail pipe 74 with an exhaust outlet 74a protruding rearward is provided at the rear of the muffler body 70, and a first muffler cover 8 spaced apart from the muffler body 70 is provided around the exhaust outlet 74a, and a gap 81 is provided between the first muffler cover 8 and the muffler body 70 to introduce wind generated by driving.
The vehicle is also provided with an airflow guide portion 84 that guides the traveling airflow introduced from the gap 81 to the side of the exhaust outlet 74a with respect to the exhaust outlet 74a.

In the past, in order to reduce the occurrence of turbulence caused by the wind flowing around the outer periphery of the muffler cover being drawn in at the downstream end of the muffler device, the muffler cover was spaced apart from the muffler body 70 and the wind was introduced into a gap 81. In that case, however, the wind flowing in through the gap 81 would cause turbulence near the exhaust outlet 74a.
However, in this embodiment, by providing an introduction wind guide section 84 that guides the traveling wind to the side of the exhaust outlet 74a with respect to the exhaust outlet 74a, the traveling wind is prevented from hitting the vicinity of the exhaust outlet 74a and the occurrence of turbulence in the vicinity of the exhaust outlet 74a is prevented, improving the exhaust flow and eliminating any impact on driving performance.

The first muffler cover 8 has an inlet air guide hole 83 in its vehicle outer portion 8c that is spaced from the exhaust outlet 74a and opens toward the rear, and the inlet air guide portion 84 is located inside the first muffler cover 8, between the exhaust outlet 74a and the inlet air guide hole 83, and is erected parallel to the discharge direction of the exhaust gas 74b discharged from the exhaust outlet 74a.
Therefore, the wind introduced into the first muffler cover 8 can be discharged to the wind introduction guide hole 83 by the wind introduction guide portion 84 without hitting the exhaust gas 74b.
Furthermore, since the introduced wind introduction guide portion 84 guides the introduced wind in a direction parallel to the discharge direction of the exhaust gas 74b, an air curtain 83a of the wind is created in a direction parallel to the discharge direction of the exhaust gas 74b, thereby preventing the wind from being drawn in from the outer surface of the vehicle of the first muffler cover 8.

The first muffler cover 8 is a tail cap that covers the entire rear end 70b of the muffler body 70, and can protect people in the vicinity from the heat of the rear end 70b of the muffler body 70.
Furthermore, since the first muffler cover 8 is made of resin, it is possible to reduce weight and costs, and it is also possible to reduce the generation of radiant heat and protect the surrounding area from radiant heat.

The muffler device 7 is provided with a second muffler cover 9 that covers the outer surface 70a of the muffler body 70. The second muffler cover 9 has a running wind guide portion 91 that forms a stepped combination portion between the second muffler cover 9 and the first muffler cover 8 to guide the running wind.
Therefore, the running wind is introduced from the gap 82 of the running wind guide section 91 between the second muffler cover 9 and the first muffler cover 8 to the gap 81 between the first muffler cover 8 and the muffler body 70, improving the cooling performance of the first muffler cover 8.

A gap 75 is provided between the second muffler cover 9 and the muffler body 70, and the second muffler cover 9 has an intake port 90 on its upper surface 9a facing outward from the vehicle, through which airflow flows in.
Therefore, by discharging the airflow from the air intake 90 into the gap 75 between the second muffler cover 9 and the muffler body 70 through the air intake guide hole 83 by the air intake guide section 84 within the first muffler cover 8, it is possible to prevent the generation of turbulence caused by the airflow flowing around the outer periphery of the second muffler cover 9.

The muffler body 70 is tilted upward at the rear. When the muffler body 70 is tilted upward at the rear, the upper surface 9a of the second muffler cover 9 is easily exposed to the wind generated by the vehicle. However, the exposed wind can be efficiently taken in through the intake port 90 into the gap 75 between the second muffler cover 9 and the muffler body 70.

The above describes a muffler device according to one embodiment of the present invention. However, the aspects of the present invention are not limited to the above embodiment, and of course the invention can be embodied in a variety of forms within the scope of the gist of the invention. Any muffler device can be used as long as it meets the requirements of claim 1.
Furthermore, the saddle-type vehicle equipped with the muffler device of the present invention is not limited to the motorcycle shown as the general example in the embodiment, but may be motorcycles of various shapes and structures, and may also be various other saddle-type vehicles, such as three-wheeled or four-wheeled buggies.
The internal combustion engine is not limited to the air-cooled, single-cylinder, four-stroke cycle internal combustion engine of the embodiment, but may be other types of multi-cylinder internal combustion engines.
In addition, for the sake of convenience, the left and right arrangement of each device has been described as being specific to that shown in the drawings, but the left and right arrangement may be reversed to that shown in the above embodiment, and is included in the present invention.

Reference Signs List 1...motorcycle, 2...vehicle body frame, 3...internal combustion engine, 7...muffler device, 8...first muffler cover ("muffler cover" in the present invention), 8a...front end, 8b...rear end, 8c...vehicle outer part, 8d...vehicle inner part, 9...second muffler cover ("second muffler cover" in the present invention), 9a...upper surface, 9b...rear end, 9c...side, 13...rear fork, 14...rear wheel, 22...pivot frame, 23...down frame, 23a...bracket, 24...seat rail, 25...back stay, 26...pilion step support stay, 30...crankcase, 31...crankshaft, 33...cylinder head, 36...exhaust port, 55...exhaust pipe, 55a...rear end, 70... Muffler body, 70a...outer surface, 70b...rear end, 71...front mounting bracket, 72...rear mounting bracket, 73...rear end plate, 74...tail pipe, 74a...exhaust outlet, 74b...exhaust gas, 75...gap, 80...central opening, 81...gap, 82...gap, 83...introducing air guide hole, 83a...air curtain, 84...introducing air guide portion, 85...first muffler cover support stay, 85a...upper support leg, 85b...lower support leg, 85c...welded portion, 85d...muffler cover engagement portion, 86...muffler cover fixing portion, 86a...fastening hole, 86b...fastening bolt, 87...fastened hole, 88...ventilation hole, 88a...ventilation flow, 89...support stay engagement portion, 90...intake port, 91...traveling air guide portion

Claims (7)

A muffler device (7) having a muffler body (70) connected to a rear end (55a) of an exhaust pipe (55) of an internal combustion engine (3) of a saddle-type vehicle (1),
A tail pipe (74) having an exhaust outlet (74a) protruding rearward is provided at the rear of the muffler body (70),
A muffler cover (8) is provided around the exhaust outlet (74a) and is spaced from the muffler body (70),
A gap (81) is provided between the muffler cover (8) and the muffler body (70) through which running wind is introduced,
an introduced wind guide portion (84) that guides the traveling wind introduced from the gap (81) to a side of the exhaust outlet (74a) with respect to the exhaust outlet (74a) ;
The muffler device (7) is characterized in that it includes a second muffler cover (9) that covers an outer surface (70a) of the muffler body (70) and has a running wind guide portion (91) that guides running wind between the second muffler cover (9) and the muffler cover (8). The muffler cover (8) has an intake air guide hole (83) that opens rearward and is spaced apart from the exhaust outlet (74a) at a rear portion of the vehicle outer side portion (8c),
The muffler device according to claim 1, characterized in that the introduction wind guide portion (84) is located inside the muffler cover (8), between the exhaust outlet (74a) and the introduction wind guide hole (83), and is erected parallel to the discharge direction of the exhaust gas discharged from the exhaust outlet (74a). The muffler device according to claim 1 or 2, characterized in that the muffler cover (8) is a tail cap that covers the entire rear end (70b) of the muffler body (70). 4. The muffler device according to claim 1, wherein the muffler cover (8) is made of resin. A gap (75) is provided between the second muffler cover (9) and the muffler body (70),
5. The muffler device according to claim 1, wherein the second muffler cover (9) has an intake port (90) on an upper surface thereof, the intake port facing outwardly of the vehicle, for intake of wind generated during running of the vehicle. 6. The muffler device according to claim 5 , wherein the muffler body (70) is provided with an upward inclination toward the rear. A muffler device (7) having a muffler body (70) connected to a rear end (55a) of an exhaust pipe (55) of an internal combustion engine (3) of a saddle-type vehicle (1),
A tail pipe (74) having an exhaust outlet (74a) protruding rearward is provided at the rear of the muffler body (70),
A muffler cover (8) is provided around the exhaust outlet (74a) and is spaced from the muffler body (70),
A gap (81) is provided between the muffler cover (8) and the muffler body (70) through which running wind is introduced,
an introduced wind guide portion (84) that guides the traveling wind introduced from the gap (81) to a side of the exhaust outlet (74a) with respect to the exhaust outlet (74a);
The muffler cover (8) has an intake air guide hole (83) that opens rearward and is spaced apart from the exhaust outlet (74a) at a rear portion of the vehicle outer side portion (8c),
A muffler device characterized in that a rear end portion (8b) of the muffler cover (8) is located rearward between the exhaust outlet (74a) of the tail pipe (74) and the air introduction guide hole (83).

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