JPH01301919A - Motorcycle equipped with engine having supercharger - Google Patents

Abstract

PURPOSE:To achieve compactness of a motorcycle by tilting a cylinder block to a vertical line and by forming a supercharger on the upper side of a cylinder head. CONSTITUTION:A cylinder block 10 is tilted forward to a vertical line. A carburetor 18 being arranged in the rear of a cylinder head 13, an air cleaner 23 is arranged above it. Between the carburetor 18 and the air cleaner 23 formed a supercharger 25, which is attached to the cylinder head 13. As the position of the cylinder head becomes lower by the degree the cylinder block is tilted forward, the supercharger 25 can be arranged on the upper side of the cylinder block 10 without difficulty. Thereby a compact structure of a motorcycle can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a motorcycle equipped with a mechanical supercharger driven by the shaft output of an engine.

[Conventional technology]

Mechanical superchargers driven by the engine's crankshaft, so-called superchargers, have recently become popular because they provide good throttle response without the operational delay of turbochargers. Attempts have been made to mount a motorized engine on a motorcycle.

[Problem to be solved by the invention]

By the way, this supercharger needs to be installed in the middle of the intake pipe connecting the carburetor and the air cleaner, but in modern motorcycles, the carburetor, including the engine, is installed in a limited space within the frame. Because intake system parts such as air cleaners and air cleaners are placed in a tight space, there is not much space left around the engine. For this reason, it becomes difficult to secure a space for installing the supercharger in the above-mentioned space, and there are problems such as the supercharger protruding to the side of the engine and taking up a large amount of space for installation.

Furthermore, the intake pipe connecting the supercharger, air cleaner, and carburetor must be routed while avoiding the frame and other parts around the engine, making the layout quite unreasonable. Therefore, there is a risk that the intake pipe becomes long or complicatedly bent, resulting in a large pressure loss, which poses a problem that hinders efficient supercharging.

Therefore, the present invention provides a motorcycle equipped with a supercharged engine that allows the supercharger to be placed compactly in a limited space around the engine, and also enables easy routing of the intake pipe. For the purpose of providing.

[Means to solve the problem]

Therefore, in the present invention, the cylinder block of the engine is tilted forward with respect to the vertical line, the fuel supply device is arranged behind the cylinder head located on the cylinder block, and the air cleaner is installed above the cylinder head. A mechanical supercharger driven by the shaft output of the engine is installed in the intake pipe connecting the fuel supply device and the air cleaner, and this supercharger is installed on the top surface of the cylinder head. It is a feature.

[Effect]

According to this configuration, one position of the cylinder head is lowered by the amount that the cylinder block is tilted forward, so that the supercharger can be easily arranged in the space opened above the cylinder head. Therefore, the supercharger does not protrude to the side of the engine, and the installation space for the supercharger does not take up much space. In addition, because the cylinder block is tilted forward, the position of the cylinder head is kept low, so even though the supercharger is installed on top of the cylinder head, the supercharger does not protrude significantly above the engine. Coupled with the fact that the supercharger does not take up much space for installation, it can be arranged compactly around the engine.

Furthermore, since the air cleaner, supercharger, and fuel supply system are arranged close to each other from above the engine toward the rear, the overall length of the intake pipe connecting them can be kept short, and the pipe itself is also curved. This results in a smooth structure with less turbulence, allowing for easy routing of the intake pipe.

〔Example〕

The present invention will be described below based on an embodiment shown in the drawings.

Reference numeral 1 in FIG. 2 denotes a frame, and a front fork 3 that supports a front wheel 3a is pivotally supported on a steering head vibe 2 at the front end of the frame. A pair of left and right main vibes 4 extending rearward are welded to the steering head vibe 2, and a bracket 6 for pivotally supporting a rear arm 5 is connected to the rear end of the main vibe 4. A down tube 7 is installed between the lower end of the bracket 6 and the lower surface of the front end of the main vibe 4, and an engine 8 is supported between the down tube 7 and the main vibe 4. The engine 8 of this embodiment is a four-cycle parallel four-cylinder engine, and a cylinder block IO having four cylinders is provided upright on the upper surface of the crankcase 9. A crankshaft 12 rotatably driven by a piston 11 is supported within the crankcase 9, and the cylinder block lO of the engine 8 is connected to the crankshaft 12.
It is largely tilted forward in the direction of travel with respect to the vertical line X1-X passing through the center of the vehicle.

The cylinder head 13 stacked on the top surface of the cylinder block IO has an intake port 15 that is opened and closed by an intake valve 14.
and 1. An exhaust port 17 that is opened and closed by an exhaust valve 16 is formed for each cylinder. The intake port 15 is the cylinder head 1
A downdraft type carburetor 18 constituting a fuel supply device is connected to the open end of the intake port 15 via a joint 19. This carburetor 18 is provided for each cylinder,
They are arranged in parallel in the axial direction of the crankshaft 12.

Further, between the cylinder head 13 and a head cover 20 covering the upper surface thereof, an intake camshaft 21 that drives the intake valve 14 to open and close, and an exhaust camshaft 22 that drives the exhaust valve 16 to open and close are supported. . Both camshafts 21 and 22 are rotationally driven by power transmission from the crankshaft 12, and one end of the exhaust camshaft 22 is connected to the cylinder head 13.
It is derived laterally. Further, an air cleaner 23 is arranged above the head cover 20, and the air cleaner 23 is located between the front ends of the main vibe 4 and in front of the upper part of the vaporizer 18.

On the other hand, an intake pipe 24 extending from the air cleaner 23 to the carburetor 18 is provided with a mechanical supercharger 25 that pumps the intake air purified by the air cleaner 23 toward the carburetor 18. The casing 2B of the supercharger 25 is fastened to the upper surface of the head cover 20 using bolts or the like, and is located between the head cover 20 and the air cleaner 23. Two screw-shaped rotors 27 are housed within the casing 2B.
These rotors 27 have four parts (not shown) and a convex part formed on the outer circumferential surface of the rotor 27 meshed with each other, and the casing 2
It is rotatably supported by B. A suction port 28 is opened in the upper surface of the casing 2B, located at one end in the axial direction of the rotor 27, and the suction port 28 is connected to the air cleaner 23 via an upstream intake pipe 29 extending in the vertical direction. There is. Furthermore, the casing 26 has the above-mentioned suction port 2.
A discharge port 30 for sending out pressurized intake air is located on the left side surface of the rotor 27 opposite to 9 in the axial direction, and this discharge port 30 is connected to a downstream intake pipe 31 extending rearward. It is connected to the surge tank 32 via. The surge tank 32 is located directly above the vaporizer 18,
Four distribution pipes 38 extending from this surge tank 32 are communicated with the vaporizer 1B. Therefore, in the case of this embodiment, the upstream intake pipe 29, the downstream intake pipe 31. The surge tank 32 and the distribution pipe 33 constitute an intake pipe line 24 that connects the air cleaner 23 and the carburetor 18.

Further, the rotating shaft 34 of one rotor 27 is connected to the casing 2
A belt 39 is wound between the pulleys 35.8B, which are fixed to the leading end of the rotary shaft 34 and the leading end of the exhaust camshaft 22, respectively. has been done. Therefore, the rotor 27 of the supercharger 25 is driven by the shaft output of the exhaust camshaft 22, and the pulley 86 on the exhaust camshaft 22 side is formed to have a larger diameter than the pulley 35 on the rotating shaft 34 side. Therefore, the rotational speed of the exhaust camshaft 22 is increased to at least the same as the rotational speed of the crankshaft 12 and is transmitted to the rotor 27.

Note that these pulleys 85. se and the belt 39 are covered by a belt cover 40.

Further, a fuel tank 37 is installed behind the air cleaner 23 and surge tank 32, and these fuel tanks 3
7. The air cleaner 23 and surge tank 32 are surrounded by a cover 38 that forms a conventional-shooting fuel tank.

In such a configuration, when the shaft output of the exhaust camshaft 22 is transmitted to one of the rotors 27 via the belt 39, the two rotors 27 rotate in opposite directions while meshing with each other, and the intake air purified by the air cleaner 23 is released. is sucked in through the suction port 28, and this suction air is pressurized and sent into the downstream intake pipe 31 through the discharge port 30. This pressurized intake air is led to the surge tank 32, and then is sent under pressure from the distribution pipe 33 to the intake port 15 via the carburetor 18 of each cylinder.
This starts supercharging.

By the way, in the above configuration, the cylinder block lO
By tilting the cylinder head forward, the position of the cylinder head 13 is lowered. Therefore, space can be secured above the cylinder head 13 by the amount that the position of the cylinder head 13 is lowered. The feeder 25 can be installed easily. Therefore, the supercharger 25 does not protrude significantly to the side of the engine 8, and the installation space for the supercharger 25 does not take up much width.

Further, since the cylinder head 13 is lowered due to the forward tilt of the cylinder block 10, the supercharger 25 protrudes significantly above the engine 8 even though the supercharger 25 is mounted on the top surface of the head cover 20. Coupled with the fact that the installation space does not take up much space, the supercharger 25
can be compactly arranged in a limited space around the engine 8.

Moreover, according to the above configuration, the air cleaner 23, the supercharger 25, and the carburetor 18 are arranged in close proximity to each other within the range from above to the rear of the cylinder head 13, so that the intake air is guided by the supercharger 25. The overall length of the upstream intake pipe 29 and the downstream intake pipe 31 that guides pressurized intake air to the carburetor 18 can be shortened, and these double-open pipes 29 can be shortened.
．． The shape of the pipe 31 can also be made smooth with few bends. Therefore, the intake pipes 29, 31 can be easily routed, pressure loss of intake air can be kept low, and efficient supercharging can be achieved.

Furthermore, if the supercharger 25 is installed above the cylinder block lO that is tilted forward, the relatively heavy cylinder head 1
3 and the supercharger 25 approach the front wheel 3a, so this front wheel 3a
It also has the advantage of increasing the distributed load and improving running stability.

Note that the driving means of the supercharger is not limited to a belt, but may also be a gear drive, for example, and the rotor of this supercharger is not limited to a screw shape, for example, a Roots-type supercharger combining a cocoon-shaped rotor You may also use

Furthermore, the fuel supply device is not limited to a carburetor, but may also be a fuel injection valve.

〔Effect of the invention〕

According to the present invention described in detail above, the supercharger does not protrude to the side of the engine, the space for installing the supercharger does not take up much width, and the cylinder head is moved forward as the cylinder block is tilted forward. Because the position is kept low, the supercharger does not protrude significantly above the engine.
It can be compactly placed in the limited space around the engine.

In addition, the overall length of the intake pipe that guides intake air to the supercharger and pressurized intake air to the fuel supply device can be shortened, and the shape of the intake pipe can be smooth with few bends. This allows for easy handling, minimizes the pressure loss of intake air, and enables efficient supercharging.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a side view of a supercharged engine, and FIG. 2 is a side view of a motorcycle. 8... Engine, 10... Cylinder block, 13
... cylinder head, 18 ... fuel supply device (carburetor), 23 ... air cleaner, 24 ... intake pipe line,
25...Supercharger.

Claims (1)

[Claims] The cylinder block of the engine is installed tilted forward with respect to the vertical line, and a fuel supply device is placed behind the cylinder head located on this cylinder block. At the same time, an air cleaner is placed above this cylinder head, and these fuel supply devices A mechanical supercharger driven by the shaft output of the engine is provided in the intake pipe connecting the air cleaner and the air cleaner, and the supercharger is mounted on the upper surface of the cylinder head. A motorcycle with an engine.