Engine unit and vehicle including the same

• US 8,047,179 B2
• Filed: 10/09/2008
• Issued: 11/01/2011
• Est. Priority Date: 10/10/2007
• Status: Active Grant

• Current Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Original Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Inventors: Yamada, Takayuki
• Primary Examiner(s): Wolfe, Jr.; Willis
• Assistant Examiner(s): Bacon; Anthony L
• Application Number:
  US12/248,712
• Publication Number:
  US 20090095252A1
• Time in Patent Office: 1,118 Days
• Field of Search: 123/336, 123/337, 123/376, 123/184.31, 123/198.E, 123/195.R
• US Class Current: 123/336
• CPC Class Codes: F02B 61/02 for driving cycles
• CPC Class Codes: F02D 11/10 of the electric type
• CPC Class Codes: F02D 9/105 having a throttle position sensor detection of actuation F02D11/106
• CPC Class Codes: F02D 9/1065 Mechanical control linkage between an actuator and the flap, e.g. including levers, gears, springs, clutches, limit stops of the like
• CPC Class Codes: F02D 9/109 having two or more flaps
• CPC Class Codes: F02M 35/10032 specially shaped or arranged connecting duct between carburettor or air inlet duct and the plenum chamber; specially positioned carburettors or throttle bodies with respect to the plenum chamber
• CPC Class Codes: F02M 35/116 for engines with cylinders in V-arrangement or arranged oppositely relative to the main shaft
• CPC Class Codes: F02M 35/162 Motorcycles; All-terrain vehicles, e.g. quads, snowmobiles; Small vehicles, e.g. forklifts
• CPC Class Codes: F02M 69/044 for injecting into the intake conduit downstream of an air throttle valve

Abstract

An engine unit that has a throttle valve driving actuator securely fixed thereto, and in which the vibration caused on the actuator is small. The engine unit includes a V-type engine and a throttle body assembly. The throttle body assembly has first and second front and rear throttle bodies, an actuator, a transmission gear mechanism, and a casing that houses the actuator and the transmission gear mechanism. The casing has a first casing portion that is fixed to the first front and rear throttle bodies, and a second casing portion that faces the first casing portion in a width direction and is fixed to at least one of the second front and rear throttle bodies.

Claims

1. An engine unit including a V-type engine provided with a front cylinder, a rear cylinder, a front intake port connected to the front cylinder, and a rear intake port connected to the rear cylinder, and a throttle body assembly attached to the V-type engine, the throttle body assembly comprising:

a front throttle body having a front cylinder connected to the front intake port and a front throttle valve for opening and closing the front cylinder of the front throttle body;

a rear throttle body having a rear cylinder connected to the rear intake port and a rear throttle valve for opening and closing the rear cylinder of the rear throttle body;

an actuator that, in a longitudinal direction, is disposed between a center axis of the front cylinder of the front throttle body and a center axis of the rear cylinder of the rear throttle body, and drives the front and rear throttle valves;

a transmission gear mechanism that transmits power from the actuator to the front and rear throttle valves; and

a casing that houses the actuator and the transmission gear mechanism and the casing includes

a first casing portion that is fixed to the front and rear throttle bodies, and

a second casing portion that faces the first casing portion in a widthwise direction and is fixed to at least one of the front and rear throttle bodies at positions that are different than positions that the first casing portion is fixed to the front and rear throttle bodies.

2. The engine unit according to claim 1, wherein

the front throttle body includes a first front throttle body and a second front throttle body arranged in a widthwise direction,

the rear throttle body includes a first rear throttle body and a second rear throttle body arranged in a widthwise direction,

the first casing portion is fixed to the first front throttle body and the first rear throttle body, and

the second casing portion is fixed to at least one of the second front throttle body and the second rear throttle body.

3. The engine unit according to claim 1, wherein at least one of the first and second casing portions is made of resin.

4. The engine unit according to claim 3, wherein the first casing portion is made of metal and the second casing portion is made of resin.

5. The engine unit according to claim 2, wherein the throttle body assembly further includes a connecting member that mutually connects the first front throttle body, the second front throttle body, the first rear throttle body, and the second rear throttle body.

6. The engine unit according to claim 5, wherein the connecting member includes:

a first inner connecting pipe that is disposed to the rear of center axes of the first and second front throttle bodies, and is fixed to the first and second front throttle bodies;

a second inner connecting pipe that is disposed to the front of center axes of the first and second rear throttle bodies, and is fixed to the first and second rear throttle bodies as well as being fixed to the first inner connecting pipe;

a first outer connecting pipe that is disposed to the front of the center axes of the first and second front throttle bodies, and is fixed to the first and second front throttle bodies; and

a second outer connecting pipe that is disposed to the rear of the center axes of the first and second rear throttle bodies, and is fixed to the first and second rear throttle bodies.

7. The engine unit according to claim 6, wherein the connecting member includes:

a first fixing member that is fixed by at least four points at an upper portion and a lower portion of the first front throttle body and an upper portion and a lower portion of the first rear throttle body; and

a second fixing member that is fixed by at least four points at an upper portion and a lower portion of the second front throttle body and an upper portion and a lower portion of the second rear throttle body.

8. The engine unit according to claim 2, wherein the throttle body assembly further includes a stay that fixes the second casing portion and at least one of the second front throttle body and the second rear throttle body.

9. The engine unit according to claim 8, wherein the stay fixes the second casing portion and one of the second front throttle body and the second rear throttle body, whichever is arranged at a position farther from the second casing portion.

10. A vehicle provided with the engine unit according to claim 1.

11. The vehicle according to claim 10, wherein the vehicle is a motorcycle further comprising a head pipe, and left and right frames that extend to the rear from the head pipe, and the throttle body assembly is disposed between the left and right frames in a plan view.

12. The engine unit according to claim 1, wherein the first casing portion and second casing portion are directly fixed to each other.