JPH09287469A - Supercharging engine-mounted vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To raise a filling efficiency of a combustion chamber and to improve engine performance and durability by arranging a crank chamber intake inlet on the upper side of a crank shaft, and arranging a crank chamber discharging port on the lower side of the crank shaft, in a supercharging engine-mounted vehicle in which a cylinder is forward slantly arranged. SOLUTION: In a scooter type motorcycle, an unit swing type engine unit 11 is mounted, the unit 11 comprises an engine main body and a rear wheel transmission gear 13. In the engine main body, its cylinder shaft is forward slantly arranged from a vertical direction, a connecting rod supercharging type supercharging device 50 is arranged, and pressurized air is supplied to a carburetor 54 for composing a fuel supplying device N. At this time, a crank chamber intake port 40a is arranged on the upper side of the crank shaft 64 and a crank chamber discharging port 40b is arranged on the lower side thereof, an intake port 42a for leading new air into a combustion chamber 65 is arranged on the lower side of a cylinder head 42, and the intake port 42a and the discharging port 40b communicate with each other in a cylinder lower side by a pressure intake pipe 53 and an intake control valve 251.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supercharged engine-equipped vehicle equipped with a supercharger.

[0002]

2. Description of the Related Art In recent years, for the purpose of improving engine output, for example, supercharging equipped with a connecting rod supercharging mechanism for compressing air sucked into a crank chamber by swinging the connecting rod and supplying the compressed air to a combustion chamber. A device has been proposed (see, for example, Japanese Patent Laid-Open No. 6-93869). A supercharging device including the connecting rod supercharging mechanism and a piston supercharging mechanism that compresses the air sucked into the crank chamber by the reciprocating movement of the piston is called a crank chamber supercharging device.

[0003]

When an engine equipped with such a supercharger is mounted on a vehicle, an air cleaner for performing intake air or a pressurizing intake pipe for supplying air compressed from a crank chamber to a combustion chamber is provided. Depending on the arrangement, the pressurized intake pipe may become long or the position where the traveling wind is difficult to hit. For this reason, the heat generated by supercharging accumulates in the pressurized intake pipe, and the efficiency of filling the combustion chamber is reduced, which may adversely affect the engine performance.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a vehicle equipped with a supercharged engine, in which the efficiency of filling the combustion chamber is increased and the engine performance and durability are improved.

[0005]

In order to solve the above-mentioned problems and to achieve the object, the invention according to claim 1 is arranged such that the cylinder is tilted forward and pressurized in the crank chamber by a supercharger. In a vehicle equipped with a supercharging engine that introduces fresh air into a combustion chamber through a pressurized intake pipe and an intake valve, a crank chamber intake port is disposed above a crank shaft pivotally supported by the crank chamber. To allow intake from the air cleaner, while a crank chamber discharge port is arranged below the crankshaft, and an intake port for introducing fresh air into the combustion chamber is provided below the cylinder head. It is characterized in that the outlet communicates with the lower side of the cylinder through the pressurized intake pipe.

The pressurizing intake pipe is arranged below the cylinder and hits the pressurizing intake pipe through which fresh air that has been pressurized by the cold traveling air passes and therefore has good cooling performance and increases the charging efficiency to improve engine performance. Also, the durability around the pressurized intake pipe is improved. Further, an intake port provided on the lower side of the cylinder head for introducing fresh air into the combustion chamber and a crank chamber discharge port provided on the lower side of the crankshaft communicate with each other via a pressurized intake pipe, and the same cylinder By communicating on the side, the pressurized intake pipe is shortened, the flow path resistance is reduced, and the efficiency of filling the combustion chamber is improved.

The invention according to claim 2 is characterized in that the air cleaner is arranged in front of the engine and above the crank chamber inlet in the height direction. Since the air cleaner is located in front of the engine and above the crank chamber intake port in the height direction, the cold traveling wind hits the pressurized intake pipe without being obstructed by the air cleaner, so the cooling performance is improved more reliably and the charging efficiency is improved. The engine performance is improved by the increase of. Further, since the air can be guided to the air cleaner without heat exchange with the engine, it is possible to improve the engine performance by increasing the charging efficiency and the durability by improving the cooling property of the inside of the crank chamber.

The third aspect of the present invention is characterized in that the air cleaner is arranged above or behind the engine. Since the air cleaner is located above or behind the engine, the cold running wind hits the pressurized intake pipe without being obstructed by the air cleaner, which improves cooling performance more reliably and improves the engine performance by increasing the charging efficiency. To do.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A vehicle equipped with a supercharged engine of the present invention will be described below with reference to the drawings.

First, a scooter type motorcycle in which a vehicle equipped with a supercharged engine is adopted will be described. FIG. 1 is a schematic configuration diagram of a scooter type motorcycle. In the figure, 1 is a scooter type motorcycle to which the present invention is applied, and a body frame 2 of the scooter type motorcycle is of an underbone type, and an upper end of a main frame 2b having a substantially L shape in a side view is connected to a head pipe 2a. The front end of a pair of left and right side frames 2c is connected to the lower end of the main frame 2b, both side frames 2c are raised upward, and further extended rearward. Further, the head pipe 2a has a front wheel 3 at the lower end.
A front fork 4 that pivotally supports the front fork 4 is pivotally supported to the left and right, and a steering handle 5 is fixed to the upper end of the front fork 4.

A steering wheel cover 6 is provided around the steering handlebar 5.
The periphery of the head pipe 2a is covered with a front cover 7 having a two-part structure including a front cover 7a and a rear cover 7b. Further, a footboard 8 forming a footrest portion is arranged at a connecting portion between the main frame 2b and the side frame 2c, and side covers 9 are arranged on the left and right sides of the side frame 2c. A seat 10 is arranged above the side cover 9.

A unit swing type engine unit 11 is mounted near the upper and lower bent portions of the left and right side frames 2c. The engine unit 11 includes a pivot shaft 32a horizontally arranged in the left-right direction (see FIGS. 5 and 7).
The rear wheel transmission includes an engine main body 12 that is swingably supported around and extends substantially horizontally forward, and a rear wheel transmission 13 integrally connected to a left side portion of the engine main body 12 so as to extend rearward. A rear wheel 14 is pivotally supported at the rear end portion of 13. The rear end of the rear wheel transmission 13 is supported by the side frame 2c via the rear suspension 15.

The forward leaning of the engine described here means that the engine body 12 is located in front of the pivot shaft 32a,
It means that the engine body 12 extends forward of a vertical plane passing through the crankshaft 64. Here, another embodiment of the forward leaning of the engine is shown in the external view of the main part of FIG. The cylinder axis of the engine body 12 is inclined forward from the vertical direction. Details of the parts indicated by the numbers in the figure will be described below. The swing engine unit 11 is rotatable around the pivot shaft 32a.

Next, the rear wheel drive system of the unit swing type engine unit 11 will be described. FIG. 2 is a sectional view of a rear wheel drive system in which the rear wheels rotate in the direction opposite to the engine rotation direction. The rear wheel transmission 13 of the unit swing type engine unit 11 is the transmission case 2 of the rear wheel transmission 13.
The power transmission mechanism 21 housed in the
The automatic transmission 22 includes a V-belt automatic transmission 22, a centrifugal clutch 23, an output shaft 26 and a gear train 24.

The gear train 24 includes a first gear 24j, a second gear 24k which is an internal gear, a third gear 24l and a fourth gear 2.
It is composed of 4 meters. The first gear 24j provided on the output shaft 26 is decelerated by the second gear 24k, the third gear 24l, and the fourth gear 24m and transmitted to the rear axle 25.
Since the second gear 24k is an internal gear, the rear wheel 14 rotates in the direction opposite to the engine rotation direction. That is, the rear wheel 14 can be rotationally driven in the forward direction via the power transmission mechanism 21 by the engine that rotates in the direction opposite to the rotation direction of the wheels during forward movement.

FIG. 3 is a sectional view of another embodiment of the rear wheel drive system in which the rear wheels rotate in the direction opposite to the engine rotation direction. The rear wheel transmission 13 of the unit swing type engine unit 11 includes a power transmission mechanism 21 housed in a transmission case 20 of the rear wheel transmission 13 as in the above-described embodiment, a V-belt automatic transmission 22 and a centrifugal clutch. 23 and the output shaft 26
And the gear train 24, but the structure of the gear train 24 is different.

The gear train 24 is composed of a first gear 24n, a second gear 24o and the like. The first gear 24n provided on the output shaft 26 is decelerated by the second gear 24o and transmitted to the rear axle 25 so that the rear wheels rotate in the direction opposite to the engine rotation direction.

Next, a schematic structure of the unit swing type engine unit 11 of the first embodiment will be described. 5 and 6 show a first embodiment of a unit swing type engine unit equipped with an air-cooled 4-cycle supercharged engine, FIG. 5 is a side view of the unit swing type engine unit, and FIG. 6 is a unit swing type. It is a top view of a rotary engine unit.

A unit swing type engine unit 11 is mounted near the upper and lower bent portions of the left and right side frames 2c. In this engine unit 11, a bracket 30 provided on the front side of the transmission case 20 of the rear wheel transmission 13 and a bracket 31 of the side frame 2c are supported via a link 32, and provided on the rear side of the transmission case 20. The bracket 33 and the bracket 34 of the side frame 2c are supported via the rear suspension 15, and the engine unit 11 includes the link 32 and the bracket 3.
It is rotatable about a pivot shaft 32a between the first and second gears. Further, an elastic bush (not shown) is interposed between the bracket 31 and the link 32, and the elastic bush holds the link 32 so that the link 32 is not pivotally displaced about the support shaft 32b.

A stopper 35 for restricting the upward swing of the rear wheel transmission 13 is provided. This allows
When a vehicle body is held while preventing a fall by standing a stand 11a that is rotatably supported by the engine unit 11, the engine unit 11 is pushed up and the link 32 rotates upward, but a part of the link 32 stops. It abuts 35 and prevents interference with other parts of the engine body 12.

The engine body 12 is of a forced air cooling type 4-cycle single cylinder type, and has a structure in which a cylinder block 41 and a cylinder head 42 are connected to a crankcase 40. Cylinder bore 60 of cylinder block 41
While the piston 61 is slidably inserted and arranged in the inside,
The piston 61 is connected by a connecting rod 62 to a crankshaft 64 arranged in a crank chamber 63.

A forced cooling fan 43 for supplying cooling air is mounted on the engine body 12, and cooling fins 44 for increasing a heat radiation area are provided on the cylinder block 41. Although not shown, the cylinder head 42 also has cooling fins. A front air intake 45 is provided in the side cover 9 below the seat 10, and the front air intake 45 is composed of a slit 45a and a louver 45b, and the traveling wind is guided toward the engine body 12 from the front side. In addition, the lower cover 46 below the footboard 8
Is provided with a lower air intake 47, and the lower air intake 47 is composed of a slit 47a and a louver 47b, and the traveling wind is guided toward the engine body 12 from the lower side.

The engine body 12 is provided with a connecting rod supercharging device 50. The air filtered by the air cleaner 51 is the carburetor 5 that constitutes the fuel supply device N.
4, the air is sucked into the crank chamber 63 from the crank chamber suction port 40a on the upper side of the crankcase 40 via the suction pipe 52.
The air cleaner 51 is arranged in front of the cylinder C and behind the front air intake 45, and is fixed to the cylinder block 41 or the cylinder head 42 at a position where the cold traveling wind can be sucked.

The air pressurized by the connecting rod supercharging mechanism in the engine body 12 is supplied from the crank chamber discharge port 40b below the crankcase 40 to the pressurized intake pipe 53 and the intake control valve 25.
1, the intake control valve 251 is operated in conjunction with the carburetor 54 by operating the throttle 301. By operating the intake control valve 251, the air-fuel mixture is supplied to the combustion chamber 65 from the intake port 42a below the cylinder head 42.

Since the engine unit 11 is displaced during traveling, the intake pipe 52 between the air cleaner 51 fixed to the vehicle body and the engine body 12 is provided with a bendable portion in a part or all of the portion. The carburetor 54 is fixed to the cylinder block 41, the cylinder head 42, or the air cleaner 51 via a vibration-damping rubber mount (not shown). Therefore, similarly, the pressurized intake pipe 5
The bendable portion is arranged at a part or all of the portion 3. Then, the engine unit 11 moves along with the displacement during traveling, and thus the carburetor 54, the pressurized intake pipe 53, and the intake control valve 25.
1 and the exhaust pipe 56, which will be described below, are displaced substantially integrally with the engine body 12.

Exhaust outlet 42b on the upper side of the cylinder head 42
Is connected to an exhaust pipe 56, the exhaust pipe 56 extends rearward on the right side of the engine unit 11, and a muffler 57 is connected to a rear end portion thereof.

Further, the engine body 12 has a lubricating device 4
The lubrication device 460 is provided with 60 to suck and pressurize the 2-cycle lubricating oil, and the pressurized lubricating oil is supplied to each bearing around the crankshaft 64, the piston sliding portion of the cylinder block 41, and the like. Four-cycle oil is circulated and supplied to the valve train in the cylinder head 42 by a lubricating device (not shown). The lubrication will be described in detail in the description of FIG.

In this embodiment, the crank chamber suction port 40a is provided above the crank shaft 64 pivotally supported by the crank chamber 63.
Is arranged, and the cylinder C is installed in the crank chamber intake port 40a.
From the air cleaner 51 arranged above the carburetor 5
Intake is possible via 4. On the other hand, a crank chamber discharge port 40b is arranged below the crank shaft 64, and an intake port 42a for introducing fresh air into the combustion chamber 65 is provided at the cylinder head 4
2, the intake port 42a and the crank chamber discharge port 40b are connected to the lower side of the cylinder by the pressurized intake pipe 53 and the intake control valve 251. The air cleaner 51 is arranged above the cylinder C, and the air cleaner 51 is
From the upper side into the crank chamber 63,
As the cold fresh air can be sucked in from the front of the vehicle body as compared with 3, the filling efficiency is increased. Further, since the pressurized intake pipe 53 is arranged on the lower side of the cylinder, the cold traveling wind hits the pressurized intake pipe 53 through which fresh air pressurized and risen passes without being obstructed by the air cleaner 51, so that cooling performance is improved. The engine performance and durability are improved by increasing the filling efficiency. Further, an intake port 42a provided below the cylinder head 42 that guides fresh air into the combustion chamber 65 and a crank chamber discharge port 40b provided below the crankshaft 64 are communicated with each other via a pressurized intake pipe 53. Therefore, the pressurized intake pipe 53 is shortened by communicating the same cylinder lower side, the flow path resistance is reduced, and the efficiency of filling the combustion chamber is improved. It should be noted that, in this embodiment, in addition to the structure described in the claims, many unique effects can be obtained by many unique structures. These features are described below.

First, the traveling wind is not obstructed by the air cleaner 51 which is displaced to the left side, and the cold air of the traveling wind is exhausted by the exhaust pipe 56 and the generator 250.
At the same time, the cooling property is increased and the durability is improved.

Secondly, the carburetor 54 is disposed above the engine axis L1, the carburetor 54 is located on the vehicle body frame 2 side, and the carburetor 54 is prevented from being damaged by stones during running. .

Third, on the line connecting the intake port 42a, which is one end of the intake port 105 in the cylinder head 42, and the crank chamber discharge port 40b in a top view (this is substantially coincident with the cylinder center line L2). A pressurizing intake passage 138, a pressurizing intake pipe 53, an intake control valve 251 are arranged, and a suction port 42 is provided.
Since the intake port 105 that connects a and the opening on the side of the recess 42c is also arranged on the same line, the resistance of the pressurized intake passage between the supercharger 50 and the combustion chamber 65 is reduced, and the fresh air charging efficiency is improved. , The engine performance is improved.

7 and 8 show a second embodiment of a unit swing type engine unit equipped with a water-cooled partially air-cooled 4-cycle supercharged engine, and FIG. 7 is a side view of the unit swing type engine unit. FIG. 8 is a plan view of the unit swing type engine unit. The engine unit 11 according to this embodiment is a water cooling type instead of the air cooling type shown in FIGS. 5 and 6, except that the cylinder block 41 is provided with air cooling fins and is kept air cooled, and is supplied to the cylinder through the pressurized intake pipe 53. A supercharging tank 503 that suppresses pressure fluctuations of the pressurized air is connected, and this supercharging tank 503 is arranged in the front side of the engine 100, and is arranged in a position where it is cooled by traveling wind. Therefore, the same reference numerals are given and the description thereof is omitted.

A radiator 70 is arranged in parallel with the air cleaner 51 at a position rearward of the front air intake 45 of the side cover 9. The cooling water that has cooled the engine body 12 is returned to the radiator 70 via a return pipe 71,
It is cooled by the radiator 70 and is sent again to the engine body 12 via the feed pipe 72, and the cooling water is supplied to the engine body 12.
It is circulated to a cooling water jacket (not shown) in the cylinder head 42 for cooling. Air-cooling fins are attached to the outer periphery of the cylinder 41 for air cooling. It should be noted that this embodiment also has many features described as the first to third in the description of the first embodiment, in addition to the configuration described in the claims.

A cooling water jacket may be provided on the outer circumference of the pressurized intake pipe 53 to circulate the cooling water between the radiator 70 and the radiator 70. The cooling water jacket functions as a so-called intercooler.

Next, the supercharged engine applied to each of the embodiments will be described in detail with reference to FIGS. 9 to 11. 9 is a sectional view of the supercharged engine, FIG. 10 is a sectional view taken along line XX of FIG. 9 (however, the cooling system is shown as an air-cooled supercharged engine unlike the engine of FIG. 15), and FIG.
1 is a sectional view taken along line XI-XI of FIG.

In the figure, reference numeral 100 denotes a crankshaft horizontally placed 4
This is a cycle single cylinder crank chamber supercharged engine, and a cylinder block 41 is connected to the mating surface of a crankcase 40 of this engine 100.
A cylinder head 42 is connected to the mating surface 1. A concave portion 42c forming a combustion chamber 65 is provided in a portion of the mating surface of the cylinder head 42 facing the cylinder bore 60,
A spark plug 200 is inserted in the recess 42c.

The intake port 10 is provided in the cylinder head 42.
5, the end of the exhaust port 106 is open,
The intake port 105 is led out to the lower wall side of the cylinder head 42, and the exhaust port 106 is led out to the upper wall side. Each of the ends is an intake port 42a and an exhaust outlet 42b. Further, an intake valve 107 is arranged in the combustion chamber opening of the intake port 105, and an exhaust valve 108 is arranged in the combustion chamber opening of the exhaust port 106 so that the respective openings can be opened and closed. The intake valve 107 and the exhaust valve 108 are valves. It is biased in the closing direction by a spring 109.

An intake valve 107 is attached to the cylinder head 42.
Also, a cam shaft 110 as a valve mechanism that opens and closes the exhaust valve 108 is arranged in a direction perpendicular to the plane of the drawing. A driven sprocket 201 is provided at one end of the cam shaft 110, and is connected to a drive sprocket 113 connected to the crank shaft 64 via a cam chain 48, and the cam shaft 110 is decelerated to half the rotation speed of the crank shaft 64. ing. A pair of rocker shafts 111 extending in parallel with the cam shaft 110 are arranged on the upper and lower sides of the cam shaft 110, and rocker arms 112 are swingably mounted on the rocker shafts 111. One end of the rocker arm 112 has a camshaft 1
The cam nose 10 is in contact with the other end of the intake valve 107 and the exhaust valve 108.

Cylinder bore 60 of cylinder block 41
A piston 61 is slidably inserted therein.
With the piston 61 as a boundary, the crank chamber 63 is provided by the cylinder bore 60 and the crankcase 40 on the side opposite to the combustion chamber 65.
Are formed. A small end portion 62a of a connecting rod 62 is connected to the piston 61 to a piston pin 66 via a bearing 67, and a large end portion 62b of the connecting rod 62 is connected to a crank pin 68 of a crankshaft 64 via a bearing 69. There is.

The crankshaft 64 is housed in the crank chamber 63, and a pair of disk-shaped crank webs 124 are connected by a crank pin 68, and a journal portion 125 is integrally formed on each crank web 124. And the journal portion 125 is the journal bearing 12
It is supported by the crankcase 40 via 6. Further, the journal portion 125 projects outside the crankcase 40, and the generator 250 is mounted on one of the projecting portions. Incidentally, 127 is an oil seal.

The left and right inner side walls 40c of the crankcase 40, which are orthogonal to the crankshaft 64, and the notches 41b formed in the upper and lower portions of the fitting portion 41a of the cylinder block 41 to the crankcase 40 are flush with each other. The left and right inner side walls 40c and the notches 41b are configured such that the left and right side surfaces 62c of the connecting rod 62 can be moved while facing each other with a minute gap therebetween, or they are in sliding contact with each other and are in contact with each other. The outer peripheral surface of the large end portion 62b of the connecting rod 62 is movable with respect to each other with a very small gap or is in contact with each other on the arcuate inner peripheral wall 40d formed so as to surround the crankshaft 64 of. Are in sliding contact with each other. Also, the left and right inner side walls 40c of the crankcase 40
Has a circular recess 40e into which each crank web 124 is inserted and arranged, and a slight gap is provided between the circular recess 40e and the crank web 124. Then, the connecting rod side wall 124 of the crank web 124
Both a and the left and right side surfaces 62c of the connecting rod 62 can be moved while facing each other with a minute gap therebetween, or are in contact with and are in sliding contact with each other. A ring 300 is fixedly arranged on the crankcase 40 at each of the mouths of the left and right circular recesses 40e, and the ring 300 comes into contact with the outer periphery of the protrusion of the crank web 124 to make sliding contact or almost zero.
They are facing each other with the censorship of. The ring 300 is made of a material such as plastic, rubber or carbon. Even if the ring 300 has a slightly smaller inner circumference, the ring 300 may be worn or deformed when the outer circumference of the ridge of the crank web 124 comes into sliding contact with the crank web l2, even if the accuracy is poor.
It is possible to make the gap between the outer circumference of the ridge of No. 4 and 0.

Further, the skirt portion of the piston 61 is provided with a substantially triangular recess 61a.
The portion facing the outer periphery of the skirt is a notch 61b. The small end portion 62a of the connecting rod 62 is placed in the recess 61a.
Is inserted and arranged. Is it possible to move the outer peripheral surface of the small end portion 62a of the connecting rod 62 on the inner peripheral surface of the recess 61a, and the left and right side surfaces 62c on the left and right side surfaces 61c of the recess 61a with a minute gap therebetween while facing each other? , Are in sliding contact with each other.

With the above structure, the portion surrounded by the crank chamber 63, the crank web 124 and the piston 61 is a connecting rod accommodating chamber. At the crank angle except when the piston 61 is located near the top dead center, the connecting rod 62 is at least one of the upper and lower crankcases 40.
The connecting rod accommodating chamber is divided into a suction chamber A and a compression chamber B by a connecting rod 62 by fitting in the left and right inner side walls 40c or the notch 41b of the cylinder block 41. Further, when the piston 61 is located at the top dead center, the connecting rod 62 and the left and right inner side walls 40c are not fitted, but since the skirt end of the piston 61 almost coincides with the end of the cylinder bore 60, the suction chamber by the connecting rod 62. The division between A and the compression chamber B is maintained. In this way, as the crankshaft 64 rotates clockwise from the state where the piston 61 is located at the top dead center, as shown in FIG.
By moving the connecting rod 62 to the position indicated by the dashed-dotted line, the position indicated by the dashed-two dotted line, and further by the position indicated by the solid line, the volume of the suction chamber A increases and air is sucked in, while the volume of the compression chamber B decreases and is sucked in the previous stroke. A positive displacement supercharger in which air is compressed is configured. Incidentally, such a structure is described in the above-mentioned JP-A-6-9.
It is described in detail in Japanese Patent No. 3869.

On the upper surface of the crankcase 40, there is integrally formed a suction passage 135 communicating with the suction chamber A and opening downward. A crank chamber suction port 40a is formed on the upper wall surface so as to communicate with the suction passage 135, and a downstream end of a suction pipe 52 is connected to the crank chamber suction port 40a.
An air cleaner 51 is connected to the upstream end via a carburetor 54.

A pressurizing intake passage 138 communicating with the compression chamber B and opening upward is integrally formed on the lower surface of the crankcase 40. In the pressurizing intake passage 138, the passage 1 is formed.
A partition wall 139 for partitioning the compression chamber B and the compression chamber B is integrally formed. A valve opening 140 that connects the pressurized intake passage 138 and the compression chamber B is formed in the partition wall 139, and the opening area of the valve opening 140 is set to a size that can sufficiently reduce the ventilation resistance.

The pressurized intake passage 138 has a predetermined volume larger than the cylinder stroke volume, stores the pressurized fresh air sent from the compression chamber B at each rotation of the crankshaft 64, and stores it in the crankshaft 64. It functions as a pressure accumulator for supplying pressurized intake air to the combustion chamber 65 every two revolutions.

A reed valve 142 for opening and closing the valve opening 140 is disposed on the outer surface of the partition wall portion 139. The upper end opening of the pressurized intake passage 138 is closed by a cover plate 145, and the cover plate 145 and the pressurized intake passage 138 form a pressure accumulating chamber. The cover plate 145 has a pressure intake passage 13
8 is connected to the upstream end of the pressurized intake pipe 53, and the downstream end of the pressurized intake pipe 53 is connected to the intake port 105 of the cylinder head 42. The reed valve l4
In addition to 2, a reed valve that allows the flow of fresh air toward the crank chamber and blocks the reverse flow may be further arranged on the suction passage l35 side of the crank chamber suction port 40a. When the reed valve is arranged on the suction passage l35 side, the reed valve l4
You may abolish 2.

The pressurized intake passage 138 and the intake passage 135 are arranged on the outside of the engine 100 by the bypass pipe 1.
It is communicated through 50. The bypass pipe 150 can be opened and closed by a bypass valve 151. The bypass valve 151 is opened and closed in conjunction with the throttle 301, and for example, when the throttle opening is small, the bypass pipe 150
To reduce the pressure in the pressurized intake passage 138.

An intake control valve 251 is disposed in the middle of the pressurized intake pipe 53 to control the intake amount into the combustion chamber 65 according to the engine state. Further, the air cleaner 51 is provided with a carburetor 54 that constitutes a fuel supply device N. The carburetor 54 is formed by bolting a float chamber 402 as a fuel reservoir to a cab body 401.

In the cab body 401, a bottomed cylindrical variable piston valve 405 is axially slidably inserted. Throttle cable 4 for piston valve 405
One end of 07 is connected and throttle cable 40
The extension end of 7 is connected to the throttle 301. By operating the throttle 301, the piston valve 405 moves up and down to change the passage area of the venturi portion 403 from fully closed to fully open. The needle 412 moves back and forth as the piston valve 405 moves up and down, and the amount of fuel sucked into the venturi passage of the venturi portion 403 is adjusted.

A pressure pipe 426 is attached to the cab body 401.
Of the pressure pipe 426 is connected to the inside of the pressurized intake passage 138 through the cover plate 145. Thus, the supercharging pressure in the pressurized intake passage 138 is added to the liquid surface in the float chamber 402.

The middle of the pressure pipe 426 is branched into two paths by the first and second pressure passages 426a and 426b. The first and second pressurizing passages 426a, 4
26b has a narrowed portion 430 having large and small diameter throttle holes.
a and 430b are formed. In addition, the first pressurizing passage 4
26a, the first pressurizing passage 4 is provided upstream of the throttle portion 430a.
A solenoid valve 431 for opening and closing 26a is interposed, and the solenoid valve 431 is controlled to be opened and closed by the CPU 432.

The CPU 432 is configured to read the engine speed and the throttle opening, and switch the solenoid valve 431 to the fully closed state in the low speed rotation range and to the fully opened state in the medium speed to high speed rotation range during idling. Therefore, the supercharging pressure is greatly attenuated by the small-diameter throttle hole 430b in the low intake air amount operation range such as idling, and is larger than the throttle hole 430b in the large-diameter throttle hole 430a in the high intake air amount operation range during high speed rotation. Is attenuated small.

Reference numeral 460 is a lubricating device, which is composed of a first lubricating system 461 and a second lubricating system 462 which is provided independently of the first lubricating system 461. The first lubrication system 461 connects the oil supply pipe 465 through the supply pump 464 to the first storage tank 463 filled with oil for four cycles, and the supply port 465 a of the supply pipe 465.
The camshaft 11 that constitutes the valve mechanism of the cylinder head 42
It is configured by connecting to part 0. In addition, the cam shaft 110
The oil that has lubricated the part returns to the inside of the chain chamber 110b in which the cam chain 48 is housed, where the cam chain 4
8, drive sprocket 113 and driven sprocket 2
01 are each lubricated, and thereafter, they are recovered by the first storage tank 463 through the recovery pipe 466.

In the second lubrication system 462, the main supply pipe 4 is connected to the second storage tank 470 filled with oil for two cycles.
71, the pressure feed pump 472 is connected, the first and second auxiliary supply pipes 473, 474 are connected to the pressure supply pump 472, the first auxiliary supply pipe 473 is connected to the piston sliding portion of the cylinder block 41, and the second The auxiliary supply pipe 474 is connected to the journal bearing portion of the crank chamber 63 (the left and right journal bearings 12
6, 126).

Although not shown, the pressure feed pump 472 is an improved solenoid of an electromagnetic type autolube pump.
Secure the armature to the push rod of the plunger,
This is a method of attracting the armature with a solenoid. As a result, the discharge pressure from the pressure feed pump 472 is increased, and the supercharging pressure can be overcome to supply oil.

Oil discharge port 473 of the first auxiliary supply pipe 473
a is the cylinder block 41 in the direction orthogonal to the crankshaft 64.
Of the piston 61 located at the bottom dead center and located closer to the crank chamber than the second piston ring 350 of the piston 61 located at the bottom dead center. In addition, the outer surface of the piston 61 on the crank chamber side of the second piston ring 350 has a 2 in the crankshaft direction.
Recesses 475 and 476 for storing oil are formed by cutting out in parallel. The concave portion 475 is formed by the piston 61.
Of the discharge port 473a due to the movement of
By the oil supplied from 3a and accumulated, the recess 4
Reference numeral 76 performs lubrication at the time when the discharge port 473a is closed by the piston 61 by the oil accumulated and supplied from the discharge port 473a as described below.
This prevents a trouble in lubrication caused by closing the discharge port 473a with the piston 61.

Further, an oil guide groove 481 extending in the circumferential direction of the small end portion 62a of the connecting rod 62 is formed on the outer peripheral surface thereof, and the piston 61 has this guide groove 481.
A communication hole 477 is formed so as to communicate with the lower recess 476. Further, a communication hole 47 communicating with the piston pin 66 and the bearing 67 is provided on the side of the small end portion 62a opposite to the communication hole 477.
8 are formed. As a result, the guide groove 481 supplied from the discharge port 473a and the oil recovery hole 480 described below.
Part of the oil inside is supplied to the bearing 67 from the communication hole 478, and the remaining part is supplied to the sliding surface between the small end portion 62a and the piston 61 from the communication hole 477, and further supplied to the recess 476. It has become.

Oil discharge port 474 of the second auxiliary supply pipe 474
The letter a passes through the crankcase 40 and reaches the journal bearing 126 on the right side in FIG. The oil supplied to the right journal bearing 126 is supplied to the inner peripheral walls 40c and 40d of the crankcase 40, the clearance between the circular recess 40e and the crankshaft 64, and the sliding surfaces.

A recovery hole 480 is formed, and a cover portion 136 attached to the lower portion of the crankcase 40 is further provided.
A recovery passage 483 is formed in the. Recovery passage 483
A recovery pipe 484 is connected to the recovery pipe 484.
Is connected to the second storage tank 470.

As a result, the first and second auxiliary supply pipes 473,
After the oil supplied from 474 lubricates each sliding surface,
Collected on the upper surface of the cover 136 in the suction passage 135 and collected from there. In this embodiment, the engine 100 is placed horizontally, the compression chamber B having a high supercharging pressure is arranged upward, and air is sucked from below the crankcase 40. Therefore, the lubricating oil collects at the lowermost portion of the crankcase 40 due to the interaction between the gravity and the supercharging pressure, so that the oil can be reliably collected and reused. With the oil seal 127b on the left side in FIG. 17 as a boundary, the crankcase 40 is lubricated with 2 cycle oil on the crank chamber 63 side and with 4 cycle oil on the chain chamber 110b side.

[0062]

As described above, according to the first aspect of the present invention, since the air cleaner is arranged above the cylinder, it is possible to inhale from the air cleaner into the crank chamber from above, and the new air cooler is provided on the front side of the vehicle body with respect to the crank chamber. Since air can be inhaled, the filling efficiency is increased. Further, since the pressurized intake pipe is arranged on the lower side of the cylinder, the cold traveling wind does not interfere with the air cleaner and hits the pressurized intake pipe through which fresh air pressurized and ascended passes, so that the cooling performance is good, Increased filling efficiency improves engine performance and durability. Further, an intake port provided on the lower side of the cylinder head for introducing fresh air into the combustion chamber and a crank chamber discharge port provided on the lower side of the crankshaft communicate with each other via a pressurized intake pipe, and the same cylinder By communicating on the side, the pressurized intake pipe is shortened, the flow path resistance is reduced, and the efficiency of filling the combustion chamber is improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a scooter type motorcycle.

FIG. 2 is a sectional view of a rear wheel drive system in which rear wheels rotate in a direction opposite to a rotation direction of an engine.

FIG. 3 is a cross-sectional view of another embodiment of the rear wheel drive system in which the rear wheels rotate in the direction opposite to the engine rotation direction.

FIG. 4 is an external view of essential parts showing a state where the engine is mounted.

FIG. 5 is a side view of the air-cooled four-cycle unit swing type engine unit of the first embodiment.

FIG. 6 is a plan view of an air-cooled four-cycle unit swing type engine unit according to the first embodiment.

FIG. 7 is a side view of a water-cooled 4-cycle unit swing engine unit according to a second embodiment.

FIG. 8 is a plan view of a water-cooled 4-cycle unit swing engine unit according to a second embodiment.

FIG. 9 is a cross-sectional view of a supercharged engine.

10 is a cross-sectional view taken along line XX of FIG.

11 is a cross-sectional view taken along the line XI-XI of FIG.

[Explanation of symbols]

 50 Supercharger 53 Pressurized Intake Pipe 62 Connecting Rod 63 Crank Chamber 65 Combustion Chamber 100 Engine 251 Intake Control Valve 301 Throttle C Cylinder N Fuel Supply Device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area F02M 35/16 F02M 35/16 L

Claims (3)

[Claims] 1. A vehicle equipped with a supercharged engine, wherein a cylinder is arranged forwardly, and fresh air pressurized in a crank chamber by a supercharger is introduced into a combustion chamber through a pressurized intake pipe and an intake valve. A crank chamber suction port is disposed above the crank shaft that is axially supported by the crank chamber, and a crank chamber discharge port is disposed below the crank shaft while allowing intake from an air cleaner to the crank chamber suction port. A supercharged engine characterized in that an intake port for introducing fresh air is provided under the cylinder head, and the intake port and the crank chamber discharge port are communicated with each other under the cylinder via the pressurized intake pipe. Equipped vehicle. 2. The supercharged engine-equipped vehicle according to claim 1, wherein the air cleaner is disposed in front of the engine and in a height direction above the crank chamber intake port. 3. The supercharged engine-equipped vehicle according to claim 1, wherein the air cleaner is arranged above or behind the engine.