JP2004262452A - Radiator cooling device for motorcycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce an exhaust noise while keeping the air quantity of a radiator cooling fan. <P>SOLUTION: A cooling fan 4 is placed in the rear of a radiator 1, and a cylindrical shroud 8 is arranged to surround the circumference of a blade part 7 connected to its driving motor 5 through a rotating shaft 6. The shroud 8 and the blade part 7 are integrated to be integrally rotatable. The shroud 8 is provided with inlet-side and outlet-side bellmouth parts 10, 11 in front and in the rear. The front end of the inlet-side bellmouth 10 is placed apart from the back face of the radiator 1 by a prescribed distance, and a full-circumferential clearance 15 is formed in the front end of the bellmouth 10 to form a space opened to the outside of the shroud 8 through the clearance 15 in front of the blade part 7, thereby reducing the noise while keeping the air quantity. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle radiator cooling device capable of reducing wind noise.

2. Description of the Related Art As a radiator cooling device for a motorcycle, there is a known radiator cooling device in which a cooling fan is disposed on a cooling air outlet side of a radiator, and a cylindrical shroud surrounding a blade portion of the cooling fan is disposed (Patent Document 1). reference). The shroud has a front end opening connected to the periphery of the rear surface of the radiator, and a rear end side having a cylindrical shape, in which a cooling fan is housed. It is also known that the opening in the direction of the discharge-side end of the shroud is formed in a bell-mouth shape in which the diameter is enlarged by a curved surface. In the present application, for the radiator, shroud, and cooling fan, the front, rear, and left and right directions are based on the state facing the inflow direction of the cooling air to the radiator, and the vertical direction is based on the installation state. I do.
Japanese Utility Model Publication No. 1-116233

  Surrounding the cooling fan that cools the radiator with a shroud has a great effect on securing the amount of cooling air during idling while the vehicle is stopped and running at low speed, but generates exhaust noise due to the cooling air passing through the shroud. Although the exhaust noise can be reduced to some extent by adopting the bell mouth structure, since the cooling device of the motorcycle is exposed to the outside, further exhaust noise has been required in recent years due to a demand for quieter vehicles. Reduction is required. Therefore, there is a demand for a motorcycle radiator cooling device having a greater exhaust air noise reduction effect while ensuring a necessary cooling air flow rate.

  Further, in a motorcycle, a radiator is cooled by traveling wind during traveling. However, if the entire back surface of the radiator is surrounded by a shroud as in the above-described known example, the flow of cooling exhaust air passing through the radiator may be deteriorated. At the same time, it is also required to further improve the cooling efficiency during traveling.

  Further, the presence of a motor mount stay that supports the drive motor of the cooling fan also affects the noise level. Therefore, the main object of the present invention is to provide a radiator cooling device for a motorcycle that can more effectively reduce exhaust noise, and another object is to further improve the cooling efficiency during traveling.

According to a first aspect of the present invention, there is provided a radiator cooling device for a motorcycle according to the present invention, wherein a cooling fan is disposed on a cooling air outlet side of the radiator, and a cylindrical shape surrounding a blade portion of the cooling fan. In a motorcycle radiator cooling device provided with a shroud,
The rear surface of the radiator and the suction-side opening of the shroud are separately arranged, and the shroud is configured to rotate integrally with the blade of the cooling fan.

  A second aspect of the present invention is characterized in that, in the first aspect, the opening of one or both of the suction side and the discharge side of the shroud has a bell-mouth shape whose diameter is enlarged by a curved surface.

  According to a third aspect of the present invention, in the first or second aspect, the rear surface of the radiator and the opening on the suction side of the shroud are separated from each other by 2 to 3 mm.

According to a fourth aspect of the present invention, in any one of the first to third aspects, there is provided a drive motor for driving the cooling fan, and a motor mount stay for supporting the drive motor,
The drive motor is supported from the radiator side of the motor mount stay.

According to the invention of claim 1, the rear surface of the radiator and the opening end of the bell mouth portion on the suction side are arranged apart from each other, a gap is provided between the rear surface of the radiator and the entire circumference of the shroud, and the shroud is A space opened radially outward is provided between the suction-side opening end of the shroud and the back of the radiator, allowing excess cooling exhaust air to escape to the outside of the shroud. In, the required amount of cooling air can be maintained by the cooling fan.
In addition, the shroud can be rotated integrally with the blade portion. By rotating the shroud integrally, the clearance between the shroud and the blade portion can be eliminated, thereby reducing exhaust noise and increasing wind speed. Can be.

  According to the second aspect of the present invention, in addition to the above, since one or both of the openings on the suction side and the discharge side of the shroud are formed as bell mouths, there is a further effect in reducing the exhaust noise.

  According to the third aspect of the invention, the rear surface of the radiator and the suction opening of the shroud are separated by 2 to 3 mm, so that the gap between the suction opening of the shroud and the rear surface of the radiator does not increase the exhaust noise, In addition, it is possible to prevent a decrease in air volume.

  According to the fourth aspect of the present invention, since the drive motor is supported from the radiator side by the motor mount stay, the amount of protrusion to the rear of the vehicle body can be minimized.

  A reference example will be described with reference to FIGS. In this reference example, the shroud and the blade portion are separated, but they are used to explain the arrangement relationship and dimensional relationship of each portion. 1 is a schematic sectional view of a radiator device for a motorcycle, FIG. 2 is a rear view thereof, FIG. 3 is a perspective view of a shroud, and FIG. 4 is a sectional view taken along line 4-4 in FIG.

  In these figures, the radiator 1 is a known radiator in which an upper tank 2 and a lower tank 3 are arranged vertically, and a cooling fan 4 is arranged behind the radiator 1. The cooling fan 4 is driven by a driving motor 5 and a rotating shaft 6. And a cylindrical shroud 8 disposed around the periphery of the blade 7.

  The shroud 8 has a bell-mouth shape in which both ends on the suction side or the discharge side are curved and widened, and the middle part between the suction-side bell mouth part 10 and the discharge-side bell mouth part 11 has a substantially constant diameter. The straight portion 12 is formed. Both the suction-side bell mouth portion 10 and the discharge-side bell mouth portion 11 contribute to a reduction in sound pressure and an increase in wind speed. In the discharge-side bell mouth portion 11, the exhaust portion space behind the blade 7 is narrowed by increasing the length of the straight portion 12. Even after that, it can be smoothly diffused backward.

  One end of each of a plurality of stays 13 is attached to the outer peripheral front side of the shroud 8 at an appropriate interval in the circumferential direction, for example, at an interval of 120 °, and the other end is bolted to the back surface of the upper tank 2 or the lower tank 3 of the radiator 1 by an appropriate method. Installed in.

  One end of a plurality (three in this example) of motor mount stays 14 is attached to the outer peripheral rear side of the shroud 8 at an appropriate interval in the circumferential direction, for example, at an interval of 120 °. And is attached to the rear surface of the drive motor 5 by an appropriate method such as welding.

  As is apparent from FIG. 1, the front end of the suction-side bell mouth portion 10 is arranged at a distance of D from the rear surface of the radiator 1, and this arrangement allows the front end of the suction-side bell mouth portion 10 to have a full circumference. A gap 15 is formed, and a space 16 opened to the outside of the shroud 8 through the gap 15 is formed inside the suction-side bell mouth portion 10.

  In the present example, the diameter expansion amount A of the discharge side bell mouth portion 11 is substantially the same as that of the suction side bell mouth portion 10. Further, the diameter expansion amount A of the discharge side bell mouth portion 11 also has a fixed relationship with the length B of the shroud 8, and in this embodiment, A: B is approximately 1: 4.

  The blade portion 7 has a depth width substantially equal to the length B of the straight portion 12, a front end portion thereof is separated from a back surface of the radiator 1 by a dimension G (G> D), and a rear end portion is a discharge side bell. The mouse unit 11 is separated by a dimension F longer than the length E. Also, a clearance having a dimension C is secured between the radial end and the inner surface of the straight portion 12.

  As is clear from FIGS. 2 and 4, the motor mount stay 14 has a substantially U-shaped cross section (FIG. 4) in which both sides along the length direction are bent rearward. In this example, two of the three motor mount stays 14 provided at intervals of 120 ° are narrow, and the remaining one is wide.

  Power supply cords 17 are wired on the back side of the wide motor mount stay 14, and each power supply cord 17 is accommodated in the space having the substantially U-shaped cross section, and projects outward from the motor mount stay 14 in this cross section. (Fig. 4).

  In addition, it is necessary to consider that the motor mount stay 14 has the least resistance to the exhaust air sent backward from the cooling fan 4, and it is necessary to make the interval F with the rear end of the blade 7 as large as possible. It is desirable that the attachment portion to the shroud 8 be on the outer peripheral side of the shroud 8.

  In addition, the cross-sectional shape of the motor mount stay 14 in the direction orthogonal to the streamline of the exhaust air is also important, and it is necessary to arrange the cross-sectional area to be as small as possible. In this sense, a flat plate is most preferable. In addition, a round cross section, a substantially U-shaped cross section, or the like is also possible. In the case of the substantially U-shaped cross section, it is preferable that the cross section bend the open side backward as in this example.

  Next, a description will be given of a method of determining various numerical values relating to the above-described A to G that contribute to the reduction of wind noise. The following description is based on the results of a unit test in which the measurement conditions are constant for each component and the wind speed and sound pressure of the exhaust air passing through the shroud are measured.

  FIG. 5 is a graph showing a general tendency of the change in the wind speed and the sound pressure with respect to the change in the length B of the shroud 8, and the longer the shroud 8, the more effective the sound pressure reduction, and the lower the wind speed. Therefore, about 40 mm near the intersection of the two curves is most efficient.

  FIG. 6 shows the change in the air volume when the length B of the shroud 8 is 40 mm and the ratio of A: B is changed (A = 0 is taken as 100% of the reference, and the air volume is 6 is a graph showing a general tendency of a change in the sound pressure reduction amount (A = 0 is assumed to be 0 db) and about 1:10 which is the intersection of the two curves (A / B on the horizontal axis scale in FIG. 6). Is approximately 0.13), and a range of about 1: 3 (about 0.33) where the change in the sound pressure reduction amount disappears is more preferable, and more preferably 1: 3 to 5 (about 0.33 to about 0.33). 0.2).

  The range where the ratio (A: B) is 1: 3 to 5 is the most effective range for both securing the cooling air volume by the shroud and reducing the exhaust noise, and can be set to the most advantageous range in practice. That is, if the radius of the bell mouth part is too small, it is difficult to mold, so that the ratio of 1: 5 (same as above, 0.2) is the lower limit of the most advantageous range in actual production, and is about 1: 3 or more. In this case, the effect of noise reduction does not change much, but only the bell mouth portion becomes large, so that it is not advantageous in terms of dimensions and weight. However, a particularly preferable range is about 1: 4 (approximately 0.25 in the above) and its vicinity where the amount of air blow is maximum and the change in the amount of sound pressure reduction is almost minimum. Can be efficient.

  The discharge-side bellmouth 11 is also important, and the rear end of the discharge-side bellmouth 11 has a large diameter so that the exhaust air can be smoothly diffused to the rear. Otherwise, the wind noise is increased. .

  FIG. 7 is a graph showing a general tendency of a change in the wind speed and the sound pressure with respect to a change in the clearance C between the tip of the blade portion 7 and the straight portion 12. When the clearance C is reduced, the sound pressure is reduced and the wind speed is increased.

  Therefore, it is necessary to make the clearance C as small as possible. However, the clearance C can be made as small as possible by using a resin shroud which is determined to be minimum in relation to the molding accuracy of the shroud 8 and has high molding accuracy.

  In addition, the gap D between the front end of the suction side bell mouth unit 10 and the back surface of the radiator 1 is set to about several mm, preferably about 2 to 3 mm, because the exhaust air noise increases when it is too small, and the air volume decreases when it is too large. desirable.

  Further, the clearance E between the rear end of the blade 7 and the rear end of the discharge-side bell mouth portion 11 needs to be 0 or more. If it protrudes backward for a long time, the wind noise increases.

  The larger the gap G between the front end of the blade 7 and the rear surface of the radiator 1 is, the greater the effect of reducing exhaust noise is. If the front end exits from the straight portion 12 into the bell mouth portion 10 on the intake side, exhaust air is exhausted. Since the noise becomes loud, it is necessary to take care not to project the front end to the bell mouth portion 10 on the suction side as much as possible.

  11A and 11B are diagrams according to the first embodiment, in which FIG. 11A is a diagram corresponding to FIG. 3 and FIG. 11B is a diagram illustrating a main part of the diagram corresponding to FIG. In the following description, the same functional parts as those of the previous reference example are indicated by using common symbols.

  In this embodiment, a shroud 8 having bell mouth portions formed at both ends in the front-rear direction is integrated with the tip of the blade portion 7, and a drive motor 5 is directly attached to the radiator 1 side by a motor mount stay 14. It is designed to rotate integrally with the part 7. Note that the other structures including the front and rear bell mouth structures and the like are configured in the same manner as in the previous reference example, and thus description thereof is omitted.

  Next, the operation of the present embodiment will be described. FIG. 8 is a graph showing the measurement of the air volume and the sound pressure of the exhaust air behind the shroud 8 by changing the supply voltage to the drive motor 5 for the completed vehicle having the radiator device to which the embodiment is applied. The invention, a conventional example using a shroud without a bell mouth portion, and a conventional example having a bell mouth portion but covering the back of a radiator with a shroud are shown for comparison.

  As is apparent from this figure, the radiator passing airflow is substantially the same as that of the conventional example, but the sound pressure can be reduced more than that of the conventional example, and can be sufficiently reduced to a level that does not cause discomfort to the occupant. Therefore, a significant sound pressure reduction effect can be obtained while maintaining the air volume at the conventional level.

  FIG. 9 is a graph showing, with respect to a completed vehicle having the radiator device to which the present embodiment is applied, the change over time of each water temperature at the inlet and the outlet of the radiator 1 in comparison with a conventional example without a bell mouth. As is clear from the drawing, the cooling efficiency is improved in this embodiment.

  FIG. 10 is a graph showing the frequency distribution of the sound pressure of the exhaust wind noise when the cooling fan 4 is operated at the time of idling, and the right end of each graph indicates the entire sound pressure. (A) shows the invention of the present application, and (B) shows one having the bell mouth portion of the conventional example. As is clear from this graph, the exhaust air noise during the operation of the cooling fan is lower in the present invention of (A) than in the conventional example of (B). The evaluation was enough to hear but not mind.

  As apparent from FIGS. 8 to 10, according to the present embodiment, the suction-side bell mouth portion 10 and the discharge-side bell mouth portion 11 are provided before and after the shroud 8, and the back surface of the radiator 1 and the suction side bell mouth are provided. Since the space 11 is provided separately from the bell mouth portion 10 at the front end of the suction-side bell mouth portion 10, the space 16 is opened radially outward of the shroud 8. As in the conventional case, the required amount of cooling air can be sufficiently maintained by the cooling fan 4 and the exhaust noise is further reduced.

  In addition, the provision of the discharge-side bell mouth portion 11 allows the exhaust air to be smoothly diffused rearward. In addition, the ratio A: B of the diameter expansion amount A and the length B of the shroud 8 at the rear end of the bell mouth portion 11 on the discharge side of the shroud 8 is set to 1: 3 to 5, more preferably about 1: 4. This is most effective for both securing the cooling air volume and reducing the exhaust air noise, and can be set to the most advantageous range in actual production.

  In addition, although it is not clear from FIGS. 8 to 10 that do not deal with the data during actual running, the bell mouth portions at both ends, the open space 16 and the gap 15 are provided, so that the cooling exhaust air passing through the radiator 1 during running is provided. Of these, the excess of the shroud 8 does not advance into the shroud 8 but passes through the open space 16 to the outside through the gap 15. In addition, since the cooling air can escape to the rear of the radiator 1 around the shroud 8 irrespective of the shroud 8, even if the traveling wind toward the front of the radiator 1 increases during high-speed running or the like, the cooling air is cooled. Since the wind can pass through the radiator 1 smoothly, even if the shroud 8 is present, the flow of cooling exhaust air can be made smooth during traveling and the heat radiation effect can be improved, and compared with the case where the entire back surface of the radiator is covered with the shroud. Thus, the cooling efficiency during traveling can be increased.

  Further, the shroud 8 and the blade 7 are integrated to make the clearance C between the straight portion 12 and the straight portion 12 zero, and the gap D between the front end of the discharge side bell mouth portion 11 and the back of the radiator 1 is about several mm, preferably 2 to 2 mm. 3 mm, the clearance E between the rear end of the blade 7 and the rear end of the discharge-side bell mouth 11 was set to 0 or more, and the distance F between the rear end of the blade 7 and the motor mount stay 14 was sufficient. Maintaining or increasing the air volume also by taking a large size, and making the gap G between the front end of the blade portion 7 and the rear surface of the radiator 1 as large as possible so that the front end does not extend to the bell mouth portion 10 on the suction side. In addition, it is effective in reducing exhaust noise. In addition, the stay 13 and the motor mount stay 14 are attached to the outer peripheral portion of the shroud 8, which also has an effect of reducing the exhaust noise.

  Further, since the clearance between the shroud 8 and the tip of the blade portion 7 can be made zero (0), the greatest sound pressure reduction and wind speed increasing effects can be obtained in this clearance relationship. In addition, the effect of the bell mouth structure of the above embodiment can also be enjoyed.

  In addition, the motor mount stay 14 for supporting the drive motor 5 of the cooling fan 4 on the radiator side can connect the drive motor 5 and the radiator 1 directly without using the shroud 8, so that the structure is simple and lightweight. . In addition, since the motor mount stay 14 supports the driving motor 5 from the radiator 1 side, the amount of protrusion to the rear of the vehicle body can be minimized.

  12 to 14 are modified examples of FIG. 11, in which the point that the shroud 8 rotates integrally with the blade part 7 is the same, and as (A) and (B) in each figure, The same display format is used.

  First, in the second embodiment shown in FIG. 12, the suction side bell mouth portion is omitted, and only the discharge side bell mouth portion 11 is provided. Even in this case, a smooth diffusion effect by the discharge side bell mouth portion 11 can be expected.

  On the contrary, in the third embodiment of FIG. 13, the bell mouth portion 10 on the suction side is left and the bell mouth portion 11 on the discharge side is omitted. Even in this case, a certain degree of sound pressure reduction and air volume maintenance effects can be expected.

  Note that the ratio between the diameter expansion amount of the bell mouth portion (or the rear discharge mouth bell mouth in the case of being provided at the front and rear) and the length of the shroud 8 in each of the embodiments of FIGS. As in the case of the first embodiment, the ratio can be about 1: 3 to 5, most preferably about 1: 4. In this case, in addition to the above-described effect in which the shroud 8 and the blade 7 are integrated, furthermore, The shroud 8 is most effective for both securing the cooling air flow and reducing the exhaust noise, and can be set to the most advantageous range in actual production.

  In the fourth embodiment shown in FIG. 14, the bell mouth portion is omitted and only the straight portion 12 is provided, and the effect is minimal in that the effect of the bell mouth portion cannot be expected at all. By reducing the clearance at the tip to zero (0), it is possible to expect a certain reduction in sound pressure and an effect of maintaining the air volume.

  FIG. 15 is a view showing the cooling fan 4 from the back side according to the fifth embodiment in which the motor mount stay is devised, and the three motor mount stays 14 are all in the rotation direction of the blade 7 (in the direction of arrow H). It is inclined to. By doing so, the exhaust air sent rearward while rotating in the same direction by the blades 7 comes into contact with the motor mount stay 14 inclined in the rotational direction with a small resistance, thereby reducing the exhaust noise.

FIG. 16 relates to a sixth embodiment which is a modification of FIG. 15, and the three motor mount stays 14 are not inclined in the rotation direction, but as is apparent from FIG. The entire motor mount stay 14 has a flat plate shape, and its flat surface is inclined with respect to the rotation surface of the cooling fan blade 7 so that it can be cooled in the exhaust air discharge direction immediately after being discharged from the discharge side bell mouth. The outflow direction of exhaust air, which is the direction in which the air finally flows out of the fan, is changed.
Note that the exhaust air discharge direction is the exhaust air direction on the front side of the motor mount stay, and the exhaust air outflow direction is the exhaust air direction on the rear side of the motor mount stay.

Therefore, the resistance at the time of contact with the exhaust air can also be reduced to reduce the exhaust noise, and a louver function of changing the outflow direction of the exhaust air can be obtained.

Schematic sectional view of a radiator device for a motorcycle according to a reference example Rear view Perspective view of the shroud FIG. Graph showing the effect of changing the length of the straight section Graph showing the effect of a change in the A: B ratio 4 is a graph showing an influence of a clearance change between the blade portion and the straight portion 12. Graph showing the effect of the present invention when the drive motor supply voltage changes Graph showing water temperature change of radiator Graph comparing exhaust noise when idling and when cooling fan is activated FIG. 4 is a diagram showing a main part according to the first embodiment. The figure which shows the principal part which concerns on 2nd Example. The figure which shows the principal part which concerns on 3rd Example. The figure which shows the principal part which concerns on 4th Example. The figure which shows the principal part which concerns on 5th Example. The figure which shows the principal part which concerns on 6th Example. 16 is a sectional view taken along line 17-17 of FIG.

Explanation of reference numerals

1: Radiator, 4: Cooling fan, 5: Motor, 7: Blade, 8: Shroud, 10: Bell mouth mouth on suction side, 11: Bell mouth mouth on discharge side, 12: Straight section 12, 15: Gap, 16: space

Claims (4)

A radiator cooling device for a motorcycle, in which a cooling fan is arranged on a cooling air outlet side of a radiator and a cylindrical shroud surrounding a blade portion of the cooling fan is arranged,
A radiator cooling device for a motorcycle, wherein the rear surface of the radiator and the opening on the suction side of the shroud are separately arranged, and the shroud is configured to rotate integrally with a blade of a cooling fan.   The radiator cooling device for a motorcycle according to claim 1, wherein one or both of the suction side and the discharge side of the shroud has a bell-mouth shape whose diameter is increased by a curved surface.   The radiator cooling device for a motorcycle according to claim 1 or 2, wherein a rear surface of the radiator and a suction-side opening of the shroud are separated by 2 to 3 mm. A drive motor that drives the cooling fan, and a motor mount stay that supports the drive motor,
The motorcycle radiator cooling device according to any one of claims 1 to 3, wherein the drive motor is supported from the radiator side of the motor mount stay.

Images