JP3466490B2 - Motorcycle with swing power unit - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing type power system in which a power unit including an engine, a power transmission device and drive wheels is vertically swingably connected to a vehicle body frame. The present invention relates to a motorcycle including a unit. 2. Description of the Related Art Generally, an engine mounted on a motorcycle or the like is provided with an exhaust gas purifying device provided in an exhaust pipe connected to the engine. This exhaust gas purification device is usually provided with a catalytic converter in which a granular or honeycomb-shaped catalyst body is packed in a muffler-shaped container, in the middle of an exhaust pipe, and through which exhaust gas passes in the same manner as a filter or the like. HC is a air pollutants, CO, and NO _X, etc., and is adapted to chemical change to harmless _{H 2 O, CO 2, N} 2 or the like. As this exhaust gas purifying device, for example, as disclosed in Japanese Utility Model Publication No. Sho 61-494, an exhaust gas purifying device in which a honeycomb-shaped catalyst body as described above is mounted inside a flat purifying cylinder is used. In the lower part of the exhaust pipe, the short axis of the purification cylinder is placed along the vertical direction, so that the minimum ground clearance of the motorcycle itself is as high as possible, and there is little effect when tilting the vehicle body There is. However, as in the motorcycle disclosed in the above-mentioned publication, even if an exhaust gas purification device is provided in an exhaust pipe so that the minimum ground clearance can be as high as possible, the minimum ground clearance is required. The height is still the distance between the exhaust purification device and the road surface. That is, the exhaust gas purification device is most susceptible to road surface interference. When the exhaust purification device receives an impact from a road surface via an exhaust pipe, the carrier as a catalyst may be separated. [0005] Further, such a structure is a so-called so-called motorcycle in which a power unit including an engine, a power transmission device and driving wheels, which is often seen in a scooter type motorcycle, is connected to a vehicle body frame so as to be vertically swingable. When applied to a motorcycle having a swing type power unit, the exhaust pipe connected to the engine also swings together with the power unit, so that the exhaust gas purification device easily comes into contact with the road surface. This trend is
This is remarkable in a scooter-type motorcycle in which the body is small and small-diameter wheels are mounted. On the other hand, in a scooter type motorcycle,
Some vehicles have a storage case for storing a helmet or the like at the rear of the vehicle body. Usually, the storage case is arranged above the exhaust pipe, but when the exhaust pipe is equipped with the exhaust purification device as described above, a large amount of heat is generated from the catalyst of the exhaust purification device. The effect of heat from the catalyst body through the outer cylinder of the vessel is affected by the heat to the storage case and the storage items such as the helmet stored therein.
To avoid this, it is effective to dispose the storage case forward of the exhaust pipe, but in this case, there is a new problem that it interferes with the cylinder of the engine or is affected by heat from the cylinder. Occurs. The present invention has been made in view of such circumstances, and in a motorcycle provided with a swing-type power unit, an exhaust purification device mounted on an exhaust pipe is provided on a road surface caused by rocking of the power unit. It is an object of the present invention to provide a motorcycle having a swing type power unit capable of mounting a relatively large-capacity storage case in a form less affected by heat without being subjected to interference. SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned object, and a storage case is provided between a vehicle body frame and a seat. The lower end edge of the vehicle body side cover is provided to be inclined obliquely upward so as to gradually cover upward from the side of the engine while covering the side of the engine. A power transmission unit for transmitting the power of the driving wheels to the driving wheels and a power unit in which the driving wheels are unitized, a front portion thereof is swingably supported by the body frame, and the engine and the engine
The drive wheels are disposed substantially on the vehicle body center line extending in the front-rear direction, the power transmission device is disposed offset to one side of the vehicle body center line, and the exhaust pipe connected to the engine is a vehicle body.
It is offset toward the other side of the center line and extends obliquely upward so as to gradually increase upward from the front of the engine to the rear of the vehicle body. The muffler is provided at the rear of the exhaust pipe,
Offset the center line of the vessel out of the center line of the exhaust pipe.
An exhaust purification device is provided inside the silencer,
Side view so as to be located between the lower end of the casing that straddles the engine of the power unit and the power transmission device and the lower end of the vehicle body side cover located above the power unit , and
The muffler is positioned so that it is offset toward the vehicle center line with respect to the center line.
Are, moreover, the portion where the exhaust gas purifying device is attached
Behind the silencer, the silencer is opened without being covered
It is characterized in that there. According to the motorcycle having the swing type power unit of the present invention, the exhaust purification device is provided inside the muffler.
Because it is arranged above the lower end of the casing that straddles the engine and the power transmission device of the power unit, that is, because the exhaust gas purification device is arranged to be protected from the road surface by the casing of the power unit, Even if the power unit swings up and down, the exhaust gas purifying device hardly receives interference from the road surface. Further, a portion of the muffler to which the exhaust gas purifying device is attached is between the lower end of the casing of the power unit in side view and the lower end of the vehicle body side cover located above the power purifying unit.
Since the silencer is open behind the part where the device is attached , that is, the wind path when the vehicle is running beside the power unit , the exhaust purification device of the silencer must be installed.
The running wind hits the attached part smoothly. In addition, as described above, the traveling wind is applied to the exhaust muffler mounting part of the silencer.
And can be cooled effectively, so that exhaust gas purification such as storage cases
To other members located near the silencer to which the device is attached
Prevent heat damage . In addition, as described above,
The air purifier is biased toward the vehicle centerline with respect to the muffler centerline.
The exhaust gas purifier is located on the opposite side of the silencer.
Compared to the case where
Effectively protect the purifier. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an overall side view of a scooter-type motorcycle provided with a swing type power unit to which the embodiment is applied. In FIG. 1, reference numeral 1 denotes a vehicle body frame extending rearward from the front (left side in the figure) of the vehicle body, reference numeral 2 denotes an engine, reference numeral 3 denotes a power transmission device, reference numeral 4 denotes wheels 4a and tires 4b.
These are the rear wheels that are the drive wheels with
The power transmission device 3 and the rear wheel 4 are configured as a swing power unit 5. The power unit 5 has a front part with respect to a rear part of the body frame 1 and a bracket 6a.
And a link mechanism 6 composed of a link 6b so as to be swingable in a vertical direction, and supported by the vehicle body frame 1 via a suspension 7. In FIG. 1, reference numeral 8 denotes a steering wheel, 9 denotes a front wheel in which a tire 9b is mounted on a wheel 9a, 10 denotes a front fork mounted on the body frame 1 to support the front wheel,
11 is a seating seat whose front end is hinged and can be opened and closed,
12 is a storage case such as a helmet provided under the seat 11, 13 is a fuel tank, 14 is a vehicle body cover,
5 is a rear fender. Here, the storage case 12
Above the swing type power unit 5, more specifically,
Second catalytic converter 55 of exhaust gas purifying device 53 described later
It is located at a position forward of the vehicle body than above and above a cylinder 17 arranged substantially horizontally with the engine 2. The vehicle body side cover 14a of the vehicle body cover 14 that covers the storage case 11 has
The engine 2 is inclined obliquely upward so as to cover the side of the engine 2 and to gradually increase upward as it goes from the side of the engine 2 to the rear. As shown in FIGS. 2 and 3, the engine 2 is of a two-cycle single cylinder type, and includes a crankcase 16 and a cylinder block 17a and a cylinder head 17b integrally fixed to the crankcase 16. Crankshaft 1 rotatably supported by a cylinder 17 and a crankcase 16 via a bearing 18
9, a piston 21 slidably fitted in the cylinder block 17a and connected to the crankshaft 19 via a connecting rod 20, and a plug 22 mounted on the cylinder head 17b. In this case engine 2
Are arranged horizontally so as to be substantially horizontal in the front-rear direction. The crankcase 1 of the crankshaft 19
6, an AC generator 2 composed of a stator 23a and a rotor 23b is provided at a protruding end on the right side of the vehicle body (upward in FIG. 3).
The third rotor 23b is integrally fixed. On the outer surface of the rotor 23b, a cooling fan 24 having a fin 24b formed on the outer peripheral surface of a disk-shaped base 24a is integrally fixed. The stator 23a is
It is fixed to the crankcase 16. The engine 2 has a shroud 25 as a whole.
The shroud 25 has a slit-shaped intake port 25a at a position facing the cooling fan 24. When the engine 2 is operated, that is, when the crankshaft 19 rotates, the cooling air is cooled. The fan 24 rotates and outside air is introduced into the shroud 25 from the intake port 25a, so that the engine 2 is cooled. That is, the engine 2 operates in the operating state,
4 is a forced air cooling type that cools itself. A carburetor 26 constituting an intake system is provided at the rear of the cylinder block 17a of the engine 2.
And the air cleaner 27 are connected to each other,
An exhaust pipe 28 constituting an exhaust system is connected to a front part of a. The cylinder block 17 in the exhaust pipe 28
A secondary air supply path 29 that supplies secondary air into the exhaust pipe 28 is connected near the connection to the connection point a. The secondary air supply path 29 is provided with an air cleaner 30 fixed to the front outer surface of the storage case 12 and communicating with the storage case 12.
And a reed valve 31 connected to the downstream side of the air cleaner 30 and a cylinder block 17a in the exhaust pipe 28.
A supply pipe 32 which is connected near the connection portion to and extends upward;
It comprises a flexible bendable hose 33 connecting the supply pipe 32 and the downstream side of the reed valve 31. According to the secondary air supply path 29, when the engine 2 is operated and the exhaust gas flows from the engine 2 (cylinder 17) to the exhaust pipe 28, the inside of the supply pipe 32 and the inside of the hose 33 are in a negative pressure state. As a result, the reed valve 31 is opened, and the air in the storage case 12 is introduced into the exhaust pipe 28 via the air cleaner 30, the reed valve 31, the hose 33 and the supply pipe 32. Then, the unburned gas flowing through the exhaust pipe 28 immediately after being discharged from the engine 2 reacts with the introduced air and burns. This prevents unburned gas from being discharged to the outside. Next, the power transmission device 3 will be described with reference to FIG. 3. The power transmission device 3 is conventionally known, and includes a case main body 34a provided integrally with the crankcase 16 of the engine 2 and a case main body 34a. Body 34a
A transmission system 35 is provided in a transmission case 34 including a side cover 34b for closing the side opening of the transmission case 35. That is, the transmission case 34 functions as a casing that extends over the engine 2 and the power transmission device 3. The transmission system 35 includes a drive pulley 36 of a centrifugal variable diameter structure fixed to a protruding end of the crankshaft 19 of the engine 2 on the left side of the vehicle body (lower side in FIG. 3) and rotated integrally with the crankshaft 19. A driven pulley 37 having a variable diameter structure disposed behind (right side in FIG. 3) the drive pulley 36.
And a drive belt 38 having a V-belt structure wound between the pulleys 36 and 37, and the rotation of the driven pulley 37 provided on the side cover 34 b side (left side of the vehicle body) of the driven pulley 37 and transmitted to the rear wheel 4. And a plurality of reduction gear groups (reduction mechanisms) provided between the driven pulley 37 and the rear wheel 4 for connecting the power transmission shaft 40 of the clutch mechanism 39 and the axle 41 of the rear wheel 4. 42. According to the transmission system 35, when the drive pulley 36 rotates together with the crankshaft 19, the rotation is transmitted to the driven pulley 37 by the drive belt 38, and when the rotation of the crankshaft 19 becomes higher than a certain value. The clutch mechanism 39 is connected to rotate the power transmission shaft 40, and this rotation is transmitted to the axle 41 of the rear wheel 4 via the reduction gear group 42. In the driving pulley 36, as the speed increases, that is, as the rotation of the crankshaft 19 increases, the weight roller 43 provided on the driving pulley 36 moves by centrifugal force, so that the driving pulley 36 As the width decreases, the effective radius of the drive belt 38 wound around the drive pulley 36 increases. In addition, the drive belt 38 moves forward as a whole. At this time, the width of the driven pulley 37 is increased, and the effective radius of the drive belt 38 wound around the driven pulley 37 is reduced. With such an operation, the effective radius of the drive belt 38 wound around the driving pulley 36 and the driven pulley 37 changes due to the change in the rotation speed of the crankshaft 19, and the rotation speed of the crankshaft 19, that is, the running speed, changes. The gear is automatically changed. Here, as shown in FIG. 3, the power unit 5 is disposed on a substantially vehicle body center line in which the engine 2 and the rear wheel 4 extend in the front-rear direction. (Left side with respect to the vehicle body). By the way, the exhaust pipe 28 is located at the center line of the vehicle body.
Offset to the other side (right side of the body)
Have been. The exhaust pipe 28 is connected to the front part of the cylinder block 17a of the engine 2 and extends downward forward once, then bends to the right side of the vehicle body, extends rearward of the vehicle body right below the engine 2 and passes below the engine 2. rear,
An exhaust pipe main body 28a, which extends substantially rearwardly along the rear portion of the engine 2 and further extends rearward, and has a front end portion expanded in a trumpet shape, and a muffler connected to cover a rising portion of the exhaust pipe main body 28a. 28b,
A muffler main body 44 having an exhaust duct 44a is attached to a tip of the muffler 28b. Here, the exhaust pipe 28
The silencer 28b provided at the rear of the
Offset so that it is more outward than the center line of tube 28
Is provided. Here, the tip of the exhaust duct 44a is
As shown in FIG. 1, it is attached so as to face downward when viewed from the side. In the muffler 28b and the muffler main body 44, a partition plate 45 and a partition plate 4 for partitioning the upstream side and the downstream side are provided.
6 and 47 are provided, so that the first and second exhaust pipe main bodies 48 are provided in the silencer 28b from the upstream side.
a and 48b, and third and fourth exhaust chambers 49a and 49b are formed in the muffler body 44, respectively. In addition,
The third exhaust chamber 49a and the fourth exhaust chamber 49b communicate with each other through a hole (not shown) formed in the partition plate 47. The first exhaust chamber 48a and the second exhaust chamber 48b communicate with each other through a communication pipe 50, and the second exhaust chamber 48b and the fourth exhaust chamber 49b communicate with each other through a communication pipe 51. The third exhaust chamber 49a and the inside of the duct 44a at the end of the silencer main body 44 are communicated by the communication pipe 52. As a result, the exhaust gas generated in the engine 2 flows from the exhaust pipe main body 28a to the first exhaust chamber 48a → the communication pipe 50.
→ second exhaust chamber 48b → communication pipe 51 → fourth exhaust chamber 49
The air is discharged from the duct 44a to the outside through a labyrinth path such as b → third exhaust chamber 49a → communication pipe 52. The exhaust pipe 28 is provided with an exhaust purification device 53. The exhaust gas purifying device 53 includes an exhaust pipe main body 28.
a first catalytic converter 54 provided at a bent portion, which is a front end of the exhaust pipe main body 28a, and a second catalytic converter 5 provided inside the muffler 28b and at the tip of the exhaust pipe main body 28a.
5 The first catalytic converter 54 has a number of holes formed in the exhaust pipe main body 28a, and a cloth (cloth) 54a covering the holes (not shown) and carrying a catalyst substance on the outer periphery of the exhaust pipe main body 28a. Is spirally wound, and is provided with a so-called cross catalyst body. The second catalytic converter 55 has a honeycomb-shaped multi-channel member made of ferritic stainless steel having a plurality of honeycomb-shaped passages formed in the axial direction, or a flat plate made of the same material and a corrugated plate laminated on each other. It is composed of a metal catalyst body 55a formed by winding into a cylindrical shape,
The metal catalyst 55a is mounted coaxially with the exhaust pipe main body 28a at the tip of the exhaust pipe main body 28a. The first and second catalytic converters 5
4 and 55, the engine 2 flowing through the exhaust pipe main body 28a
Exhaust gas is composed of air pollutants (HC,
CO, NO _X, etc.) are chemically changed into harmless H ₂ O, CO ₂ , N _2, etc., and the silencer 28b and the silencer body 4
It is discharged to the outside through 4. Incidentally, the second catalytic converter 55
Is provided at the end of the exhaust pipe main body 28a. As shown in FIG. 2, this position is higher than the lower end of the transmission case 34 of the power unit 5, and more specifically, the power extending in the front-rear direction when viewed from the side. a above the center line L ₁ of the unit 5, and is lower than the lower end of said body side cover 14a. That is, the second catalytic converter 55 is disposed so as to be located between the lower end of the transmission case 34 of the power unit 5 and the lower end of the vehicle body side cover 14a located above the second catalytic converter 55 in side view. The second catalytic converter 55 is disposed near the rim of the wheel in a side view. Further, as shown in FIG. 3, the second catalytic converter 55
4 and a power unit 5 in plan view.
Outside line (in FIG. 3, the inlet 25 of the shroud 25)
a) is disposed closer to the vehicle center line.
Further , the second catalytic converter 55 is provided inside the silencer 28b.
The center line of the vehicle body with respect to the center line of the silencer 28b.
Side (rear wheel 4 side) . Further, the silencer 28b is fixed to a vehicle body frame (not shown) via a bracket 28bb provided at an upper front end, and the second catalytic converter 55 is disposed near a fixed portion of the silencer 28b. I have. The silencer 28b is open behind the portion where the second catalytic converter 55 is mounted without any cover or the like. That is,
Behind the portion where the catalytic converter 55 is attached,
The silencer 28b is opened without being covered by a member such as a cover.
Has been released. According to the scooter type motorcycle equipped with the swing type power unit having the above-described structure, the second catalytic converter 55 mounted on the exhaust pipe 28 is located above the lower end of the power unit 5, more specifically, in a side view. in a relatively high position it is disposed above the center line L ₁ extending in the front-rear direction. Therefore, while the motorcycle is traveling,
Even if the power unit 5 swings up and down via the link mechanism 6, the portion of the silencer 28b around the second catalytic converter 55 hardly comes into contact with the road surface. As a result, the function of the second catalytic converter 55 is maintained for a long time. Further, the portion of the silencer 28b to which the exhaust gas purification device (specifically, the second catalytic converter 55) is attached is located on the side of the power unit 5 along the wind path when the vehicle is running, and the exhaust gas purification device (the second 2 catalytic converter
Behind the part where the barter 55) is attached, the silencer
28b is opened without being covered by members such as covers.
And therefore has, it is possible to apply smoothly running wind to the portion fitted with an exhaust purification device of the silencer 28b, Therefore, the muffler 28b for accommodating relatively a second catalytic converter 55 becomes a high temperature, and it It can be cooled effectively. Further, since the storage case 12 is disposed at a position forward of the vehicle body than above the second catalytic converter 55 and above the cylinder 17 disposed substantially horizontally with the engine 2, the storage case 12 Does not interfere with the cylinder 17 of the engine 2 and the storage case 12
High temperature second catalytic converter 55 and engine 2
Less susceptible to heat. The second catalytic converter 55 of the exhaust purification device 55 is arranged near the rim of the wheel in a side view, that is, the rear wheel 4 supporting the second catalytic converter 55 in a cantilever state. Of the muffler 2 accommodating the second catalytic converter 55
8b can have a large capacity. In addition, silencer 2
In 8b, the outer diameter of the silencer can be increased in order to increase the separation distance between the second catalytic converter 55 and the outer plate of the silencer 28b. The second catalytic converter 55 is connected to the silencer 28b.
Inside the vehicle body with respect to the center line of the silencer 28b.
Because it is arranged to be biased toward the core wire , even if the silencer 28b
The second catalytic converter 55 is unlikely to be directly impacted even when the outer side of the second member is deformed. Further, since the second catalytic converter 55 is disposed closer to the center line of the vehicle than the outer line of the power unit 5 in plan view, even when an external force is applied from the outside, the second catalytic converter 55 is not affected by the second catalyst. It hardly acts on the converter 55, and the second catalytic converter 55 is hardly affected by an impact. Further, since the second catalytic converter 55 is disposed inside the vehicle body cover 14, the external force is unlikely to act on the second catalytic converter 55 as described above, so that the second catalytic converter 55
Is hard to receive impact. Further, since the tip of the exhaust duct 44 extending from the muffler body 44, that is, the tip of the tail pipe is directed downward in a side view, the temperature of the exhaust gas rises due to the effect of the catalyst of the exhaust purification device 53. Also, the exhaust gas is discharged downward, and does not cause heat damage to the rear one. Furthermore, since the secondary air supply path 29 is fixed to the front outer surface of the storage case 12, the secondary air supply path 29 is isolated from mud and water to prevent mud and the like from entering the secondary air. it can. As described above, according to the motorcycle provided with the swing type power unit according to the present invention, the exhaust purification device is provided inside the muffler and the engine and the power transmission device of the power unit. Since the exhaust unit is disposed above the lower end of the straddling casing, that is, the exhaust purification device is disposed so as to be protected from the road surface by the casing of the power unit, the power unit swings up and down during traveling, for example. Even so, the exhaust gas purification device does not receive interference from the road surface and the load of the exhaust gas purification device does not peel off, so that the exhaust gas value reduction effect can be maintained for a long time. Further, the portion of the muffler to which the exhaust purification device is attached is between the lower end of the casing of the power unit in side view and the lower end of the vehicle body side cover located above, and behind the portion to which the exhaust purification device is attached. because the muffler is <br/> opened, that is, because it is Kazenotoorimichi at the time of vehicle operation on the side of the power unit, silencer exhaust
The traveling wind can be smoothly applied to the portion to which the purification device is attached , so that the exhaust purification device having a relatively high temperature and the muffler that houses the exhaust purification device can be effectively cooled. Further, as described above, since the exhaust gas purifying device mounting portion of the muffler can be effectively cooled , the exhaust
Other parts located near the silencer with the purifier installed
Heat damage to the material can be prevented . Furthermore, as mentioned above
Exhaust gas purifier inside the silencer with respect to the center line of the silencer
Exhaust gas purification device
Is located on the opposite side of the silencer.
Exhaust gas purification device can be effectively protected against impact
You.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall side view showing an embodiment in which the present invention is applied to a scooter type motorcycle. FIG. 2 is a side view of a power unit. FIG. 3 is a partial cross-sectional plan view of a power unit. [Description of Signs] 1 ... Body frame 2 ... Engine 3 ... Power transmission device 4 ... Rear wheels (drive wheels) 5 ... Power unit 12 ... Storage case 14 ... Body cover 14a ... Body side cover 17 ...... cylinder 28 ...... exhaust pipe 28b ...... muffler 34 ...... transmission case (casing) 53 ...... exhaust purification device _{L 1} ...... centerline

Continuation of front page (56) References JP-A-2-95994 (JP, A) JP-A-1-290909 (JP, A) JP-A-2-61312 (JP, A) JP-A-1-148676 (JP) , A) Japanese Utility Model Showa 50-71605 (JP, U) Japanese Utility Model Showa 54-30120 (JP, U) Japanese Utility Model Utility Model 1-111091 (JP, U) Japanese Utility Model Showa 61-494 (JP, Y2) (58) Field surveyed (Int.Cl. ⁷ , DB name) B62M 7/02 B60K 13/04 F01N 3/10

Claims (1)

(57) [Claim 1] A storage case is provided between a vehicle body frame and a seat, and the storage case is covered by a vehicle body side cover. A power transmission device that covers the side and is inclined obliquely upward so as to gradually go upward from the side of the engine toward the rear, and a power transmission device that transmits power of the engine to driving wheels; A power unit formed as a unit, the front portion of which is swingably supported by the vehicle body frame, the engine and the drive wheels are disposed on a substantially vehicle center line extending in the front-rear direction, and the power transmission device Is offset to one side of the vehicle center line, and the exhaust pipe connected to the engine is offset to the other side of the vehicle center line.
To the rear of the vehicle from the front of the engine, and extend obliquely upward so as to gradually move upward.
A silencer is located behind the trachea, and the center line of the silencer is exhausted.
An exhaust purification device is provided outside of the center line of the pipe, and an exhaust purification device is provided inside the muffler. So that it is located between the lower end of the vehicle body side cover and the center line of the silencer
They are arranged unevenly on the vehicle body center line side Te, moreover, the exhaust purification
The silencer is a member behind the part where the
A motorcycle having a swing-type power unit, which is open without being covered by a motorcycle.