阅读说明：本技术 摩托车 (Motorcycle with a motorcycle body ) 是由 武田哲志 于 2019-08-05 设计创作，主要内容包括：本发明提供一种提高车辆的运动性能以及催化剂对于废气的净化性能的摩托车。摩托车具备发动机(9)、排出从发动机的排气口(60)排出的废气的排气管(86)、设置在排气管内并配置于发动机的前方的催化装置(81),发动机具备：收容曲轴的曲轴箱(41)、与曲轴箱连结的气缸(42)、与气缸连结的气缸盖(43),排气管具备连接发动机的排气口与催化装置的连接管(83),连接管具备具有弯曲的形状并形成一体构造的第一管(105)和在排气方向上设置于第一管的下游侧且具有弯曲的形状并形成对接结构的第二管(106),在从车辆侧面观察时,催化装置的上端部与曲轴箱和气缸的配合面(Y)的延长线(E)相比位于上方。(The invention provides a motorcycle which can improve the motion performance of the vehicle and the purification performance of the exhaust gas of a catalyst. The motorcycle is provided with an engine (9), an exhaust pipe (86) for discharging exhaust gas discharged from an exhaust port (60) of the engine, and a catalytic device (81) disposed in the exhaust pipe and disposed in front of the engine, wherein the engine is provided with: the exhaust pipe includes a connecting pipe (83) connecting an exhaust port of the engine and the catalyst device, the connecting pipe includes a first pipe (105) having a curved shape and forming an integral structure, and a second pipe (106) provided on a downstream side of the first pipe in an exhaust direction and having a curved shape and forming a butt joint structure, and an upper end portion of the catalyst device is located above an extension line (E) of a mating surface (Y) of the crankcase and the cylinder when viewed from a vehicle side.)

1. A motorcycle, characterized by comprising:

an engine;

an exhaust pipe that discharges exhaust gas discharged from an exhaust port of the engine; and

a catalyst device disposed in the exhaust pipe and disposed in front of the engine,

the engine includes a crankshaft, a crankcase for accommodating the crankshaft, a cylinder connected to the crankcase, and a cylinder head connected to the cylinder,

the exhaust pipe includes a connection pipe connecting the exhaust port of the engine and an upper end portion of the catalytic device,

the connecting pipe is provided with:

a first tube having a curved shape and forming an integral construction; and

a second pipe provided on a downstream side of the first pipe in an exhaust direction, the second pipe having a curved shape and forming a butt structure,

an upper end portion of the catalytic device is located above a line extending from a mating surface of the crankcase and the cylinder when viewed from a side of the vehicle.

2. A motorcycle according to claim 1,

the first pipe has a shape curved outward in the left-right direction from the exhaust port of the engine,

the second pipe has a shape curved from an upper end portion of the catalytic device toward a left-right direction inside, and a pipe diameter of the second pipe gradually increases from an upstream side toward a downstream side in the exhaust direction.

3. A motorcycle according to claim 1 or 2,

the lower end of the catalyst device is located at substantially the same height as the rotation axis of the crankshaft, or the lower end of the catalyst device is located above the rotation axis of the crankshaft.

4. A motorcycle according to any one of claims 1 through 3,

the exhaust pipe includes a catalyst device case that houses the catalyst device,

the catalytic device casing is provided with:

a main body portion provided to have the same diameter from an upstream side end portion to a downstream side end portion in the exhaust direction; and

a reduced diameter portion that is provided on a downstream side of the main body portion in the exhaust direction and whose tube diameter gradually decreases from an upstream side toward a downstream side in the exhaust direction,

the reduced diameter portion is disposed forward of a front end portion of the crankcase.

5. A motorcycle according to any one of claims 1 through 4,

further comprises a muffler disposed at the rear of the engine,

the exhaust pipe includes another connection pipe connecting a lower end portion of the catalytic device and the muffler,

the connection pipe extends from an upper end portion of the catalyst device toward a center in a lateral direction of the vehicle, and the other connection pipe extends from a lower end portion of the catalyst device toward the center in the lateral direction of the vehicle.

6. A motorcycle according to claim 5,

further comprises an exhaust gas sensor mounted on the other connecting pipe,

the exhaust gas sensor is disposed below the crankcase so as to overlap a center line of the vehicle in the left-right direction, and the exhaust gas sensor is located above a lower end edge of the other connection pipe.

7. A motorcycle according to any one of claims 1 through 6,

when the length in the left-right direction from the center point of the upper end portion of the catalyst device to the center point of the exhaust port of the engine is set to a first length and the length in the up-down direction from the center point of the upper end portion of the catalyst device to the center point of the exhaust port of the engine is set to a second length,

the catalytic device is configured such that the first length is longer than the second length.

Technical Field

The present invention relates to a motorcycle including a catalyst device for purifying exhaust gas.

Background

Conventionally, a motorcycle is provided with an exhaust pipe that discharges exhaust gas discharged from an exhaust port of an engine, and a catalytic device for purifying the exhaust gas is provided in the exhaust pipe. In recent years, in order to cope with the restriction of exhaust gas, it is required to improve the purification performance of a catalytic device for exhaust gas. In order to meet such a demand, it is important to dispose the catalytic device as upstream as possible of the exhaust pipe, and therefore, the catalytic device may be disposed in front of the engine.

For example, patent document 1 discloses: at least a part of the catalytic device is located forward of the crankcase when viewed from the side of the vehicle.

Disclosure of Invention

Therefore, an object of the present invention is to improve the vehicle running performance and the exhaust gas purification performance of a catalyst in a motorcycle in which a catalytic device is disposed in front of an engine.

The motorcycle engine of the invention; an exhaust pipe that discharges exhaust gas discharged from an exhaust port of the engine; and a catalyst device disposed in the exhaust pipe and in front of the engine, the engine including a crankshaft, a crankcase that houses the crankshaft, a cylinder connected to the crankcase, and a cylinder head connected to the cylinder, the exhaust pipe including a connection pipe that connects the exhaust port of the engine and an upper end portion of the catalyst device, the connection pipe including: a first tube having a curved shape and forming an integral construction; and a second pipe that is provided on a downstream side of the first pipe in an exhaust direction, that is curved to form a butt structure (Japanese モナカ), wherein an upper end of the catalyst device is positioned above an extension line of a mating surface between the crankcase and the cylinder when viewed from a side of the vehicle.

Effects of the invention

According to the present invention, in a motorcycle in which a catalyst device is disposed in front of an engine, the vehicle drivability and the exhaust gas purification performance of a catalyst can be improved.

Drawings

Fig. 1 is a right side view of a motorcycle showing an embodiment of the present invention.

Fig. 2 is a right side view showing an engine and its peripheral portion of an embodiment of the present invention.

Fig. 3 is a front view showing an engine and a peripheral portion thereof according to an embodiment of the present invention.

Fig. 4 is a plan view showing an engine and a peripheral portion thereof according to an embodiment of the present invention.

Fig. 5 is a right side view of the engine and its peripheral portion showing a state in which the clutch cover is removed in one embodiment of the present invention.

Fig. 6 is a left side view of the engine and its peripheral portion showing a state in which the magnet cover is removed in one embodiment of the present invention.

Fig. 7 is a front view showing a positional relationship of a crankshaft, a balance shaft, and an idle shaft in an embodiment of the present invention.

Fig. 8 is a right side view showing a part of an exhaust apparatus of an embodiment of the present invention.

Fig. 9 is a rear view showing a part of an exhaust apparatus according to an embodiment of the present invention.

Description of the reference numerals

1 motorcycle

9 engines

41 crankcase

42 air cylinder

43 Cylinder head

51 crankshaft

60 exhaust port

81 catalytic device

82 catalytic device casing

83 upstream side connection pipe (an example of a connection pipe)

84 silencer

85 downstream side connecting pipe (an example of other connecting pipe)

86 exhaust pipe

93 main body part

94 reduced diameter portion

105 first pipe

106 second pipe

119 downstream side exhaust gas sensor

L1 first length

L2 second length

Center line in left-right direction of M vehicle

Center point of P2 exhaust port

Center point of upper end of P3 catalytic device

Rotation axis of R1 crankshaft

Matching surface of Y crankcase and cylinder

E extended line of matching surface of crankcase and cylinder

Detailed Description

In one embodiment of the present invention, the connection pipe includes a first pipe and a second pipe. The first tube has a curved shape forming a unitary construction. The second pipe is disposed on a downstream side of the first pipe in the exhaust direction, has a curved shape, and forms a butt joint structure. In this way, by configuring the connection pipe with the first pipe and the second pipe having the abutting structure, the degree of freedom in the shape and arrangement of the connection pipe is improved as compared with the case where the connection pipe is configured with only the bent pipe having the integral structure. Therefore, the catalyst device can be disposed close to the exhaust port of the engine, and early activation of the catalyst device can be promoted by the high-temperature exhaust gas immediately after the exhaust gas is discharged from the exhaust port of the engine, thereby improving the purification performance of the catalyst for the exhaust gas.

In one embodiment of the present invention, the connecting pipe is configured such that the upper end of the catalyst device is located above an extension line of the mating surface between the crankcase and the cylinder. By adopting such a configuration, the position of the catalytic device can be increased. Therefore, the vehicle inclination angle can be sufficiently ensured, and the vehicle motion performance can be improved. Further, since the position of the catalyst device can be increased as described above, it is possible to suppress damage to the catalyst device due to flying stones or a decrease in the temperature of the catalyst device due to water coating. Therefore, the purification performance of the catalyst for exhaust gas can be maintained.