JP3140231B2 - Shroud opening structure for cooling air intake of air-cooled internal combustion engine for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling air intake shroud structure for a vehicle air-cooled internal combustion engine having excellent sound insulation and cooling air introduction performance.

[0002]

2. Description of the Related Art A heat radiating portion of an internal combustion engine is covered with a shroud, and cooling air is introduced into the shroud through a cooling air intake opening formed in the shroud by rotation of a cooling fan integrated with a crankshaft to cool the heat radiating portion. In a scooter-type motorcycle air-cooled internal combustion engine, in order to achieve sound insulation and to prevent external rainwater from entering the shroud,
As shown in Japanese Utility Model Publication No. 63-32903, a louver in which fins extending from the inside to the outside and inclined downward from the top are arranged in parallel in the vertical direction at required intervals. It was provided in the opening.

In the shroud disclosed in the above publication, a separate outer louver having fins arranged on the extension surface of the louver of the louver is provided outside the inner louver integrated with the shroud in order to increase the width of the fin at a low cost. Although it was designed to be detachably attached, the expansion of the fin width can more reliably prevent the entry of foreign substances such as rainwater, muddy water and pebbles into the shroud, but the noise generated from the internal combustion engine and cooling fan However, even if the width of the fin is wide, it leaks to the outside along the fin, and a sufficient sound insulation effect cannot be obtained.

[0004]

SUMMARY OF THE INVENTION The present invention relates to an improvement in a cooling air intake shroud opening structure for an air-cooled internal combustion engine for a vehicle which solves such a problem. An air-cooled internal combustion engine for a vehicle that covers the shroud and cools the radiator by introducing cooling air into the shroud by rotating a cooling fan through a cooling air intake opening directed to the side of the vehicle and directed to the side of the vehicle. In the cooling air intake opening, an outer louver and an inner louver having a fixed inclination angle are formed, and the outer louver is inclined from above to below from inside to outside, and the inside louver is from inside to outside. The vehicle is characterized by being inclined forward from the rear of the vehicle.

In the present invention, since the inclination directions of the outer louver and the inner louver are changed, most of the sound waves of the noise generated by the internal combustion engine and the cooling fan are blocked by the inner louver and pass between the fins of the inner louver. Sound waves of noise are blocked by the inner louver and the outer louver having a different inclination direction, and as a result, a sufficiently high sound insulating effect is obtained.Also, foreign matter such as muddy water or pebbles jumped up by the front wheels or the like enters the shroud. Is effectively prevented.

Further, in the present invention, the outer louver is fixed by being inclined from above to below from inside to outside, and the inside louver is fixed by being inclined from back to front from inside to outside. The outer louver can prevent rainwater flowing down the vehicle body from entering the shroud, and the inner louver allows the traveling wind flowing from the front to the rear on the vehicle body outside from the cooling intake opening to the shroud. And the cooling effect can be further improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention shown in the drawings will be described. The swing-type power unit 2 mounted on the scooter-type motorcycle 1 includes an air-cooled internal combustion engine 3 in which the air-cooled internal combustion engine 3 stands up with the air-cooled internal combustion engine 3 inclined slightly backward and rearward, and a rearward portion from one lower side thereof. The extended V-belt type continuously variable transmission 4 is integrally connected to each other, and a rear wheel 5 is integrally fitted to an output shaft (not shown) of the V-belt type continuously variable transmission 4. The hanger 6 located at the front of the power unit 2 is a vehicle body 7 of the scooter type motorcycle 1.
It is attached to a bracket 8 protruding more rearward so as to be able to swing up and down.

The crankcase 9 of the air-cooled internal combustion engine 3
A variable drive pulley 11 of the V-belt type continuously variable transmission 4 is provided at the left end of the crankshaft 10 rotatably supported by the motor, and a driven variable pulley (not shown) pivotally supported at the rear of the transmission case 12. And a variable drive pulley 11, a V-belt 13 is stretched over, and as the rotational speed of the crankshaft 10 increases,
The speed ratio of the V-belt type continuously variable transmission 4 decreases steplessly,
The power of the air-cooled internal combustion engine 3 is transmitted to the rear wheels 5 via a V-belt type continuously variable transmission 4.

Further, the cylinder above the crankcase 9
14 and the cylinder head 15 above it,
The rotor 18 of the generator 17 is integrally fitted to the right end of the crankshaft 10, and a centrifugal cooling fan 19 is integrally attached to the rotor 18.

Further, a synthetic resin shroud 20 covering the air-cooled internal combustion engine 3 and the cooling fan 19 is provided with a cylinder side shroud 21 covering the cooling fan 19 and the cylinder 14 of the air-cooled internal combustion engine 3 and a head side covering the cylinder head 15. A shroud 22 and a shroud outer plate 23 covering the outside of the cylinder-side shroud 21 are provided. The cylinder-side shroud 21 and the head-side shroud 22 are detachably mounted on the crankcase 9, the cylinder 14, and the like with mounting bolts 24. It has become.

In addition, a cylindrical opening 25 concentric with the cooling fan 19 is formed in the cylinder side shroud 21.
An inner louver 26 is formed in the cylindrical opening 25, and the inner louver 26 is inclined from back to front from the inside to the outside, and the wide fins 27 are arranged at a wide interval in the front-rear direction. The shroud outer plate 23 is also formed with a cylindrical opening 28 protruding outward in close contact with the outer peripheral surface of the cylindrical opening 25 of the cylinder-side shroud 21.
An outer louver 29 is formed at 28, and the outer louver 29 is formed by arranging fins 30 having a relatively small width and having a relatively small width in a vertical direction with a narrow interval from upper to lower from the inside to the outside. I have.

The cylinder-side shroud 21 has a mounting seat 31 projecting outward at one location at the top and two locations at the bottom.
Is formed, and the mounting seat 31 is also provided on the shroud outer plate 23.
A mounting seat 32 protruding inward is formed at a location corresponding to, and a sound absorbing material 33 such as a polyurethane sponge is interposed between the cylinder side shroud 21 and the shroud outer plate 23 over the entire side surface excluding the cylindrical openings 25 and 28. The rivets 34 are fitted to the mounting seats 31 and 32, the cylinder-side shroud 21 and the shroud outer plate 23 are integrally connected to each other, and are rotated from the cylindrical opening 28 of the shroud outer plate 23 by the rotation of the cooling fan 19. Shroud 20 through cylindrical opening 25 of cylinder side shroud 21
While passing through the cooling air passage 38 in the shroud 20, the cooling air sucked into the cylinder flows to the cylinder head 15 side while touching the heat radiation fin 16, and then flows into the atmosphere from the cooling exhaust port 35 on the left rear side of the head side shroud 22. It is to be released inside.

As shown in FIG. 4, the cylinder side shroud 21 has a large number of holes surrounding the outer periphery of the cylindrical opening 25.
A sound absorbing material 33 is exposed through the hole 36 into the cooling air passage 38.

Further, a plurality of quadrangular pyramid-shaped engaging projections 37c, 37d and 37e are projected at three places on the outer surface between holes 36 provided around the outer periphery of the cylindrical opening 25 of the cylinder side shroud 21. The sound absorbing material 33 is fixed by the engaging projections 37.

Since the illustrated embodiment is configured as described above, when the air-cooled internal combustion engine 3 starts operating and the cooling fan 19 is rotated, the outside air on the right outside of the swing type power unit 2 is discharged. From the cylindrical opening 28 of the shroud outer plate 23 to the cooling air passage 38 in the shroud 20 through the cylindrical opening 25 of the cylinder side shroud 21,
Radiation fin 1 for cylinder 14 and cylinder head 15
While being touched and exchanging heat, the cylinder 14 and the cylinder head 15 are exhausted from the shroud 20 through the cooling exhaust port 35 and are sufficiently cooled.

Even if noise is generated from the air-cooled internal combustion engine 3 and the cooling fan 19 during the operation of the air-cooled internal combustion engine 3, the noise in the cooling air passage 38 is reduced by the shroud 20 that covers the air-cooled internal combustion engine 3 and the cooling fan 19. Is closed by a hole
The sound is absorbed by the sound absorbing material 33 exposed into the cooling air passage 38 from 36, and the noise level outside the swing type power unit 2 is significantly reduced.

Furthermore, since the fins 27 of the inner louver 26 and the fins 30 of the outer louver 29 have different inclination directions in the cylindrical openings 25 and 28, the fins of the inner louver 26 are different.
The sound waves of the noise that passed between 27
Since the direction can be changed by 30, the noise shielding effect is improved,
The noise level of the noise generated by the air-cooled internal combustion engine 3 and the cooling fan 19 can be further reduced.

Further, since the fins 30 of the outer louvers 29 are inclined from the upper side to the lower side from the inner side to the outer side, rainwater falling from the upper side falls from each lower edge of the fins 30 to the outside of the vehicle, and the cooling air passage 38 It is possible to prevent rainwater from invading the water as much as possible.

Moreover, since the fins 27 of the inner louver 26 are inclined from the inside toward the outside and from the rear to the front, they flow from the front to the rear on the right side of the swing type power unit 2 and pass between the fins 30 of the outer louver 29. The traveling wind can be positively introduced into the cooling air passage 38, and the flow rate of the cooling air can be increased to further increase the cooling effect.

[Brief description of the drawings]

FIG. 1 is a rear right side view of a scooter type motorcycle having a shroud opening structure for cooling air intake of an air-cooled internal combustion engine according to the present invention.

FIG. 2 is a longitudinal sectional view taken along the line II-II of FIG.

FIG. 3 is an enlarged side view of a main part of the shroud outer plate shown in FIG. 1;

FIG. 4 is an enlarged side view of the cylinder-side shroud of FIG. 1;

FIG. 5 is a sectional view taken along the line VV of FIG. 4;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Scooter type motorcycle, 2 ... Swing type power unit, 3 ... Air-cooled internal combustion engine, 4 ... V-belt type continuously variable transmission, 5 ... Rear wheel, 6 ... Hanger part, 7 ... Body, 8 ... Bracket, 9 ... Crankcase, 10 ... Crankshaft, 11 ... Variable drive pulley, 12 ... Transmission case, 13 ... V-belt, 14 ...
Cylinder, 15… Cylinder head, 16… Heat radiation fin, 17…
Generator, 18 ... rotor, 19 ... cooling fan, 20 ... shroud, 21 ... cylinder side shroud, 22 ... head side shroud, 23 ... shroud outer plate, 24 ... mounting bolt, 25 ... cylindrical opening, 26 ... inner louver, 27 ... fin, 28 ... cylindrical opening, 29 ... outside louver, 30 ... fin, 31 ... mounting seat, 32 ... mounting seat, 33 ... sound absorbing material, 34 ... rivet, 35 ... left open end, 36
... holes, 37 ... engaging projections, 38 ... cooling air passages.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F01P 5/06 502 F01P 5/06 511 F01P 11/12 F02B 77/13

Claims (1)

(57) [Claims] 1. A cover the heat radiating portion of the internal combustion engine at the shroud, the shroud internal cooling air by the rotation of the cooling fan from <br/> cooling Kazeto needful opening directed to Rutotomoni side of the vehicle is formed in the shroud the vehicle <br/> air-cooled internal combustion engine to cool the heat radiating portion is introduced into, the cooling Kazeto necessity openings, inclination
Forming an outer louver and an inner louver with a fixed bevel ,
The outer louver is inclined from top to bottom from inside to outside
And the inside louver is directed from inside to outside and from the rear of the vehicle.
A shroud opening structure for cooling air intake of an air-cooled internal combustion engine for a vehicle , characterized by being inclined forward .