JP4696844B2 - Motorcycle - Google Patents

Description

  The present invention relates to a motorcycle having an improved arrangement structure such as an expansion chamber and a silencer in an exhaust device.

  When a catalyst carrier for exhaust gas purification is provided in the exhaust device of a motorcycle, the catalyst carrier is installed in a place that impairs the appearance of the motorcycle in order to improve the purification performance. In addition, when exhaust pipes and silencers that satisfy the silencing performance are configured, the exhaust pipe length and the volume of the silencer are sufficient, which not only increases the overall weight of the exhaust system but also makes it heavy. There is a concern that a certain exhaust device moves away from the center of gravity of the vehicle body, the weight mass of the vehicle body is dispersed, and steering stability is deteriorated. Not only that, the number of fixing points for fixing the exhaust device to the vehicle body frame and the like increases, and the appearance of the motorcycle deteriorates, and the detachability of the exhaust device is impaired.

Patent Documents 1, 2, and 3 describe motorcycles in which a high-weight expansion chamber is disposed below the engine to reduce the center of gravity of the vehicle body and concentrate the weight mass.
JP 2002-303133 A Japanese Patent No. 3026684 Japanese Patent No. 2995194

  However, as described in Patent Documents 1 to 3, when the expansion chamber is disposed below the engine, the layout of the expansion chamber and the exhaust pipe is connected when the catalyst carrier is installed inside the expansion chamber. Not only does this increase the complexity of the exhaust system, but the sound deadening performance tends to be inadequate because a silencer cannot be provided in space.

  The present invention has been made in order to solve the above-described problems. In providing an exhaust device, the present invention has achieved a high noise reduction by effectively utilizing a limited space while reducing the center of gravity of the vehicle body and concentrating the weight mass. An object of the present invention is to provide a motorcycle that secures performance and exhaust gas purification performance, has good appearance around the exhaust system, and can also contribute to prevention of heat damage.

In order to achieve the above object, the motorcycle according to the present invention has an engine on the front side of a pivot bracket provided at the center of the vehicle body frame and a rear wheel suspension device on the rear side, and is installed on the pivot bracket in the vehicle width direction. A swing arm that supports the rear wheel on the pivot shaft is pivotally supported so as to swing up and down, and is buffered by the rear wheel suspension device, while an oil pan installed on the lower surface of the engine case of the engine is shifted forward of the vehicle body. Swelled downward while securing the required internal volume, and the expansion chamber of the exhaust device is disposed between the bulging part of the oil pan and the rear wheel, and below the pivot bracket and the swing arm. in the motorcycle, the expansion chamber, a large main expansion chamber volume having a catalyst therein, together constitute and a small capacity auxiliary expansion chambers, the said sub-expansion chamber Projecting so as to extend upward from the vehicle width direction one side upper part of the rear part of the expansion chamber, a noise-reducing heat insulating material is provided in the space between the outer body and the porous inner pipe on the outer surface in the vehicle width direction of the sub expansion chamber. The front part of the silencer constructed by filling is connected, the silencer is arranged on the outer side in the vehicle width direction of the swing arm, and the exhaust outlet at the rear end of the silencer is arranged at a position overlapping the swing arm in a side view of the vehicle . It is characterized by that.

  The motorcycle according to the present invention is characterized in that the link mechanism of the rear wheel suspension device is disposed inside the auxiliary expansion chamber in the vehicle width direction.

Furthermore, the motorcycle according to the present invention is provided with a megaphone-like expansion pipe that penetrates the front wall of the main expansion chamber and expands toward the inner rear, and has a straight tubular shape provided at the rear end of the expansion pipe. The catalyst is arranged in a catalyst tube .

  In the motorcycle according to the present invention, the internal space of the main expansion chamber is divided into a first expansion chamber, a second expansion chamber, and a third expansion chamber, and an outlet side of the catalyst carrier is opened into the first expansion chamber. A first communication pipe that communicates the first expansion chamber and the second expansion chamber, and a second communication pipe that communicates the second expansion chamber and the third expansion chamber with the catalyst carrier in between. It is characterized by being arranged side by side in the direction.

  The motorcycle according to the present invention is characterized in that the cross-sectional shape of the outer body of the silencer is substantially triangular, and the cross-sectional shape of the inner pipe installed therein is elliptical.

  According to the motorcycle of the present invention, since the heavy expansion chamber constituting the exhaust system is disposed below the engine and the pivot bracket, the center of gravity of the vehicle body is lowered and the heavy object is disposed near the center of gravity of the vehicle body. Thus, the weight mass can be concentrated and the running stability can be improved. In addition, since the expansion chamber arranged at a low position becomes inconspicuous, the appearance of the motorcycle is improved.

  Further, since the high-temperature exhaust gas discharged from the silencer is blocked by the swing arm with respect to the rear wheel tire, it is possible to prevent thermal damage to the tire.

  Further, a sub-expansion chamber is provided at the rear of the main expansion chamber extending in the front-rear direction below the pivot bracket, and the sub-expansion chamber is disposed on the side of the rear wheel and between the main expansion chamber and the swing arm. And by arranging the link mechanism of the rear wheel suspension device inside the auxiliary expansion chamber in the vehicle width direction, the expansion chamber volume can be increased so that it is not noticeable by effectively using the limited space inside the vehicle body. In addition, the silencing performance can be improved without impairing the appearance.

  In addition, the internal space of the main expansion chamber is divided into three expansion chambers, a heavy catalyst carrier is held in the expansion chamber on the uppermost stream side, and a communication pipe that connects the expansion chambers is sandwiched between the catalyst carriers. Since they are arranged side by side on both sides in the width direction, it is possible to reduce the center of gravity of the vehicle body and concentrate the weight mass, and to effectively utilize the internal space of the main expansion chamber to improve the exhaust gas purification performance and the silencing performance.

  Furthermore, the cross-sectional shape of the silencer's outer body is approximately triangular, and the cross-sectional shape of the inner pipe installed in it is oval. Can be made.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a left side view of a motorcycle according to the present invention, and FIG. 2 is an enlarged left side view showing a front half of a vehicle body frame, an engine, and an exhaust device. The motorcycle 1 includes a body frame 2 made of aluminum, for example, and a parallel four-cylinder water-cooled four-cycle engine 3 is suspended and mounted on the front half of the body frame 2 so as to be positioned above the engine 3. A fuel tank 4 is placed on the vehicle body frame 2.

  The engine 3 is arranged on the front side of a pivot bracket 5 provided at the center of the vehicle body frame, a cylinder assembly 7 is installed at the front upper part of the engine case 6, and an oil pan 8 is provided on the lower surface of the engine case 6. Yes. A fuel injection device (throttle body) 9 is connected to the rear portion of the cylinder assembly 7, and an air cleaner 10 installed in a recess provided on the lower surface of the fuel tank 4 is connected.

  A rider seat 12 and a passenger seat 13 are disposed behind the fuel tank 4 together with a rear cowling 14, and a radiator 15 is provided in front of the cylinder assembly 7 of the engine 3. The front half of the vehicle body is covered with a streamlined front cowling 16 made of resin, and a rear fender 17 is provided at the rear of the rear cowling 14.

  A front fork 20 that supports the front wheel 19 is pivotally supported on the front head of the body frame 2 together with a handlebar 21 and a front fender 22 so as to be steerable left and right. A swing arm 25 that supports a rear wheel 24 is pivotally supported on a pivot shaft 23 that is installed on the pivot bracket 5 in the vehicle width direction so that the rear wheel 24 can swing up and down, and the rear end of the swing arm 25 on the rear side of the pivot bracket 5. A wheel suspension device 26 is configured. The rear wheel suspension device 26 includes a cushion unit 27, the upper end of which is connected to the body frame 2, and the lower end of the rear wheel suspension device 26 is connected to the swing arm 25 via a link mechanism 28. The rear wheel 24 is buffered and suspended by a rear wheel suspension device 26.

  As shown in FIG. 2, the engine case 6 has an upper and lower divided structure including an upper case 32 and a lower case 33. The mating surface 34 of the upper case 32 and the lower case 33 is formed in a straight line shape (that is, a single flat shape) when viewed from the side of the vehicle, and is inclined forward and downward when viewed from the side of the vehicle. An oil filter 35 is installed on the front side of the engine case 6, a water pump 36 is installed on the left side, and a starter motor 37 and a breather case 38 are installed on the back side.

  A crankshaft 41, a transmission input shaft 42, and a secondary balancer shaft 43 extending in the vehicle width direction are pivotally supported at the position of the mating surface 34 of the engine case 6, and a transmission output shaft 44 is pivotally supported on the lower case 33. The order of the rotary shafts pivotally supported at the position of the mating surface 34 is the order of the secondary balancer shaft 43, the crankshaft 41, and the shift input shaft 42 from the front in the vehicle traveling direction, and the shift output shaft 44 is the shift input shaft. 42 is disposed below. The transmission output shaft 44 is provided with a drive sprocket 46 (see FIG. 1), and a drive chain 48 is wound between the driven sprocket 47 provided on the rear wheel 24.

  The engine 3 is provided with an exhaust device 50. 3 is a left side view of the vehicle body frame 2, the swing arm 25, the rear wheel suspension device 26, and the exhaust device 50, and FIG. 4 is a plan view of the exhaust device 50 as viewed in the direction of arrow IV in FIG. As shown in FIGS. 2, 3, and 4, the exhaust device 50 includes exhaust pipes 51, 52, 53, 54 corresponding to the number of cylinders of the engine 3 (four in this embodiment), and a first collecting portion 55. , 56, a second collecting portion 57, a connecting pipe 58, an expansion chamber 59, and a silencer 60. 5 is a longitudinal sectional view of the exhaust device 50 taken along the line V-V in FIG. 3, FIG. 6 is a rear view of the exhaust device 50 taken along the arrow VI in FIG. 3, and FIG. 7 is a line VII-VII in FIG. FIG. 8 is a longitudinal sectional view of the expansion chamber 59 taken along line VIII-VIII in FIG.

  The exhaust pipes 51, 52, 53, 54 are led forward and obliquely downward from an exhaust port 62 (see FIG. 2) opened on the front surface of the cylinder assembly 7 of the engine 3, and once extended downward, then curved backward. 51 and 52 gather in the first collecting portion 55 on the left side, and the exhaust pipes 53 and 54 gather in the first collecting portion 56 on the right side. Further, the ends of the first collecting portions 55 and 56 gather at the second collecting portion 57 below the crankcase 6 and in front of the oil pan 8 of the engine 3, and the downstream side of the second collecting portion 57 is connected below the crankcase 6. The connecting pipe 58 is connected to the expansion chamber 59. The second collecting portion 57 is provided with exhaust devices such as an exhaust gas sensor mounting boss 63 and an exhaust throttle valve 64.

  The oil pan 8 of the engine 3 swells downward while being shifted to the front of the vehicle body to secure the necessary internal capacity, and between the bulging portion 8a of the oil pan 8 and the rear wheel 24 and between the pivot bracket 5 and the swing. An expansion chamber 59 is disposed below the arm 25. The muffler 60 is connected to the rear right side surface of the expansion chamber 59 and is disposed on the outer side (right side) of the swing arm 25 in the vehicle width direction, and the exhaust outlet 65 at the rear end of the muffler 60 in the vehicle side view (see FIG. 3). Is arranged at a position overlapping the swing arm 25.

  The expansion chamber 59 includes a main expansion chamber 68 having a large capacity and a sub expansion chamber 69 having a small capacity. The main expansion chamber 68 is formed in a box shape extending between the oil pan 8 (the bulging portion 8a) and the rear wheel 24 below the lower end of the pivot bracket 5 and extending in the vehicle width direction. For example, it is fixed to the lower end portion of the pivot bracket 5 by three fixing brackets 71, 72, 73.

  On the other hand, the sub-expansion chamber 69 protrudes upward from the right side (right shoulder) of the rear portion of the main expansion chamber 68 and is disposed on the right side of the rear wheel 24 and between the main expansion chamber 68 and the swing arm 25. (See FIG. 5). A link mechanism 28 of the rear wheel suspension device 26 is disposed inside the auxiliary expansion chamber 69 in the vehicle width direction. The member 74 shown in FIG. 5 is a right footrest, and this footrest 74 is located substantially to the right of the sub-expansion chamber 69.

  As shown in FIGS. 4 and 7, the rear end portion of the connecting pipe 58 penetrates through the front wall of the main expansion chamber 68 and enters the inside, and the rear end portion has a megaphone-like shape whose diameter increases toward the rear. An expansion pipe 75 is connected, and a catalyst carrier 76 for exhaust gas purification is provided at the rear end of the expansion pipe 75. The catalyst carrier 76 has, for example, a structure in which a honeycomb catalyst 78 is provided inside a straight tubular catalyst tube 77.

  As shown in FIG. 7, the outer shell portion of the main expansion chamber 68 has a double wall structure in which porous inner walls 82 and 83 are provided inside the expansion chamber body 81 via a gap, and glass wool or the like is provided in the gap. Is filled with silencer insulation. The internal space of the main expansion chamber 68 is divided into a first expansion chamber 87, a second expansion chamber 88, and a third expansion chamber 89 by a baffle plate 85 and a partition wall 86, and the catalyst carrier 76 (catalyst tube 77) is formed in the partition wall 86. ) And the first series pipe 91 and the second pipe 92 are fixed through.

  The outlet side of the catalyst carrier 76 opens into the first expansion chamber 87, the first expansion chamber 87 and the second expansion chamber 88 communicate with each other through the first communication pipe 91, and the second expansion chamber 88 and the third expansion chamber 88 communicate with each other. The expansion chamber 89 communicates with the second communication pipe 92. The catalyst carrier 76, the first communication pipe 91, and the second communication pipe 92 extend in the vehicle front-rear direction, and the first communication pipe 91 and the second communication pipe 92 are arranged side by side on both sides of the catalyst carrier 76 in the vehicle width direction. It is installed. The cross-sectional shapes of the first continuous pipe 91 and the second communication pipe 92 are not circular cross-sections, but are irregular cross-sections along the internal shape of the main expansion chamber 68. The sub expansion chamber 69 communicates with the third expansion chamber 89.

On the other hand, the silencer 60 has an outer body 96 connected to the rear part of an elbow pipe 95 (see FIGS. 4 and 6) extending rightward from the upper right side of the third expansion chamber 89 . A porous inner pipe 97 is disposed, and a space between the outer body 96 and the inner pipe 97 is filled with a sound insulation material such as glass wool. The rear end opening of the inner pipe 97 serves as the exhaust outlet 65 described above.

  As shown in FIG. 6, the outer body 96 has a substantially isosceles triangular cross section, and the inner pipe 97 has an elliptical cross section. The major axis direction of the elliptical cross section of the inner pipe 97 is along the longitudinal direction of the substantially isosceles triangular section of the outer body 96.

  In the motorcycle 1 configured as described above, the exhaust gas discharged from the engine 3 is discharged from the exhaust pipes 51 to 54 → the first collecting part 55, 56 → the second collecting part 57 → the connecting pipe 58 → the expansion pipe 75 → After passing through the catalyst carrier 76 and purifying harmful components such as HC and CO by the catalyst carrier 76, the catalyst enters the first expansion chamber 87, and further enters the first series pipe 91 → second expansion chamber 88 → second communication pipe 92 → After passing through the third expansion chamber 89 → the sub-expansion chamber 69 → the silencer 60, the expansion chambers 87, 88, 89, 69 and the silencer 60 are sufficiently expanded and silenced, and then exhausted from the exhaust outlet 65 to the outside. .

  The motorcycle 1 has a heavy weight expansion chamber 59 which is a main part of the exhaust device 50 and is disposed below the engine 3 and the pivot bracket 5. Therefore, the center of gravity of the vehicle body is lowered and the expansion chamber 59, which is a heavy object, is provided. It can be placed near the center of gravity of the vehicle body to concentrate the weight mass and improve running stability. In addition, since the expansion chamber 59 arranged at a low position is not conspicuous, the appearance of the motorcycle 1 can be significantly improved.

  Further, since the silencer 60 is disposed outside the swing arm 25 in the vehicle width direction and the exhaust outlet 65 at the rear end of the silencer 60 is disposed at a position overlapping the swing arm 25 in a side view of the vehicle, the high temperature discharged from the exhaust outlet 65 is high. Exhaust gas can be shielded against the tire of the rear wheel 24 by the swing arm 25, and thermal damage to the tire can be prevented.

  Further, the expansion chamber 59 includes a main expansion chamber 68 and a sub expansion chamber 69. The main expansion chamber 68 extends in the front-rear direction below the pivot bracket 5, and the sub expansion chamber 69 projects from the rear portion. The auxiliary expansion chamber 69 is disposed on the side of the rear wheel 24 and between the main expansion chamber 68 and the swing arm 25, and the link of the rear wheel suspension device 26 on the inner side of the auxiliary expansion chamber 69 in the vehicle width direction. By disposing the mechanism 28, the volume of the expansion chamber 59 and the sub-expansion chamber 69 is increased so that the limited space inside the vehicle body is effectively used and is not conspicuous, and the appearance and engine performance are not impaired. The silencing performance can be greatly improved.

  Further, the internal space of the main expansion chamber 68 is divided into first to third expansion chambers 87, 88, 89, and the first expansion chamber 87 on the uppermost stream side holds a catalyst carrier 76 which is a heavy material, Since the communication pipes 91 and 92 that communicate between the expansion chambers 87, 88, and 89 are arranged side by side on both sides in the vehicle width direction with the catalyst carrier 76 interposed therebetween, a low center of gravity of the vehicle body and a concentration of weight mass are achieved, and the main expansion The internal space of the chamber 68 can be effectively used to greatly improve the exhaust gas purification performance and the sound deadening performance.

  Furthermore, since the cross-sectional shape of the outer body 96 of the silencer 60 is substantially triangular and the cross-sectional shape of the inner pipe 97 installed therein is elliptical, the capacity of the inner pipe 97 is increased while reducing the size of the silencer 60. Mute performance can be improved.

1 is a left side view of a motorcycle according to the present invention. The enlarged left view which shows a vehicle body frame front half, an engine, and an exhaust device. The left view of a vehicle body frame, a swing arm, a rear-wheel suspension device, and an exhaust device. FIG. 4 is a plan view of the exhaust device as viewed in the direction of arrows IV in FIG. 3. The longitudinal cross-sectional view of the exhaust apparatus which follows the VV line of FIG. FIG. 4 is a rear view of the exhaust device as viewed in the direction of arrow VI in FIG. 3. FIG. 4 is a transverse cross-sectional view of the expansion chamber along the line VII-VII in FIG. The longitudinal cross-sectional view of the expansion chamber which follows the VIII-VIII line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motorcycle 2 Body frame 3 Engine 5 Pivot bracket 6 Engine case 8 Oil pan 8a Oil pan bulging part 23 Pivot shaft 24 Rear wheel 25 Swing arm 26 Rear wheel suspension device 28 Link mechanism 50 Exhaust device 59 Expansion chamber 60 Silencer 65 Exhaust outlet 68 Main expansion chamber 69 Sub expansion chamber 76 Catalyst support 87 First expansion chamber 88 Second expansion chamber 89 Third expansion chamber 91 First communication tube 92 Second communication tube 96 Outer body 97 Inner pipe

Claims (5)

The engine is located on the front side of the pivot bracket provided at the center of the body frame, and the rear wheel suspension system is located on the rear side. The swing arm that supports the rear wheel on the pivot shaft installed in the vehicle width direction on the pivot bracket swings up and down. While freely supporting and buffering by the rear wheel suspension device, the oil pan installed on the lower surface of the engine case of the engine is bulged downward while shifting to the front of the vehicle body to ensure the required internal capacity. , between the bulge portion and the rear wheel of the oil pan, and in a motorcycle the expansion chamber is disposed in the exhaust system below the pivot bracket and the swing arm, the expansion chamber, the catalyst therein The main expansion chamber having a large capacity and a sub expansion chamber having a small capacity are provided, and the sub expansion chamber extends upward from the upper part of the rear side of the main expansion chamber in the vehicle width direction. The front part of the silencer constructed by filling the space between the outer body and the porous inner pipe with a silencing heat insulating material is connected to the outer side surface of the auxiliary expansion chamber in the vehicle width direction, and the silencing A motorcycle is arranged on the outside in the vehicle width direction of the swing arm, and the exhaust outlet at the rear end of the silencer is arranged at a position overlapping the swing arm in a side view of the vehicle . The motorcycle according to claim 1, wherein a link mechanism of the rear wheel suspension device is disposed inside the sub-expansion chamber in the vehicle width direction . A megaphone-like expansion pipe that extends through the front wall of the main expansion chamber and expands toward the inside rear is provided, and the catalyst is disposed in a straight tubular catalyst pipe provided at the rear end of the expansion pipe. The motorcycle according to claim 1 or 2. The internal space of the main expansion chamber is partitioned into a first expansion chamber, a second expansion chamber, and a third expansion chamber, the outlet side of the catalyst carrier is opened in the first expansion chamber, and the first expansion chamber and the second expansion chamber are opened. A first series of pipes that communicate with the chamber and a second communication pipe that communicates the second expansion chamber and the third expansion chamber are arranged side by side on both sides in the vehicle width direction with the catalyst carrier interposed therebetween. The motorcycle according to claim 1 or 3. The motorcycle according to claim 1 or 4 , wherein a cross-sectional shape of the outer body of the silencer is a substantially triangular shape, and a cross-sectional shape of an inner pipe installed therein is an elliptical shape .

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