JP6919184B2 - Air resistance reduction device - Google Patents

Description

The present invention relates to an air resistance reducing device, and more particularly to an air resistance reducing device for improving fuel efficiency.

A device has been proposed in which a flat plate extending in the horizontal direction is attached to a vertical wall surface that receives wind power in a moving body such as a ship having a superstructure or a large vehicle such as a truck, and the flat plate generates a circulating vortex. For example, see Patent Documents 1 and 2).

In these devices, the circulation vortex generated by the flat plate flows from the upper side to the lower side along the wall surface with the rotation axis direction as the left-right direction when viewed in the left-right direction of the moving body. In addition, two circulating vortices are generated on the left and right with the central part in the left-right direction as the boundary when viewed in the vertical direction of the moving body, and flow from the side to the center along the wall surface with the rotation axis direction as the vertical direction. There is.

In the above device, such a circulating vortex is generated, and the wind that tries to collide with the wall surface during the movement of the moving body is diverted to the upper side or the side of the wall surface to reduce the air resistance received by the wall surface.

Japanese Unexamined Patent Publication No. 60-110575 Jitsukaisho 62-184092

By the way, the wind that is about to collide with the wall surface is a composite wind of a traveling wind and a natural wind generated by the movement of a moving body. When the wind direction of the synthetic wind (the angle formed by the synthetic wind with respect to the moving direction of the moving body) becomes large, the two circulating vortices lined up in the left-right direction when viewed in the vertical direction of the moving body shift to the leeward side of the synthetic wind, or the wind. The upper vortex becomes smaller and the circulating vortex becomes unstable. Therefore, there is a problem that the air resistance increases due to an increase in collision with the wall surface without diverting the wind that is about to collide with the wall surface.

An object of the present invention is to provide an air resistance reducing device capable of stabilizing a circulating vortex and improving fuel efficiency.

In the air resistance reducing device of the present invention that achieves the above object, the cab and the van are arranged in order from the front to the rear, and the cab is mounted on a truck whose height is lower than the height of the van. In the air resistance reducing device, the upper front surface of the van located above the cab is provided with two enclosures adjacent to the central portion of the truck in the left-right direction as a boundary, and the enclosures are forward from the upper front surface thereof. It is characterized in that it is composed of a baffle plate protruding toward the rear, and is formed in a semi-annular shape with the lower side open when viewed from the front to the rear.

According to the present invention, by providing two semi-annular enclosures whose lower side is open in the upper part of the front surface, it is possible to enclose each of the two circular vortices in the left-right direction generated when the truck moves by the two enclosures. Therefore, even if the angle between the wind direction of the synthetic wind and the moving direction of the moving body becomes large, the two enclosures prevent the circulating vortex from shifting to the leeward side of the synthetic wind and the vortex on the windward side becoming smaller. , The circulation vortex can be stabilized. As a result, the wind that is about to collide with the wall surface while the truck is moving deviates to the upper side or the side of the wall surface, which is advantageous in reducing the air resistance received by the wall surface and can improve fuel efficiency.

It is a perspective view which illustrates the 1st Embodiment of the air resistance reduction apparatus of this invention. It is a left side view of the circulation vortex generated by the air resistance reduction device of FIG. 1 as viewed from the left side of the vehicle. It is a top view of the circulation vortex generated by the air resistance reduction device of FIG. 1 as viewed from above of the vehicle. It is a front view which looked at the circulation vortex generated by the air resistance reduction device of FIG. 1 from the front view of a vehicle. FIG. 5 is a relationship diagram illustrating the relationship between the wind direction (yaw angle) of the synthetic wind and the running resistance coefficient (Cd value) in the vehicle of FIG. FIG. 5 is a perspective view illustrating a state in which the air resistance reducing device of FIG. 1 is wrapped inside an air deflector. It is a perspective view which illustrates the 2nd Embodiment of the air resistance reduction apparatus of this invention. It is a perspective view which illustrates the 3rd Embodiment of the air resistance reduction apparatus of this invention.

Hereinafter, embodiments of the air resistance reducing device of the present invention will be described. In the figure, x is the front-rear direction of the vehicle, y is the left-right direction of the vehicle orthogonal to the x direction, and the z direction is the vertical direction.

As illustrated in FIG. 1, the air resistance reducing device 20 of the first embodiment is a device mounted on a large vehicle 10 such as a truck as a moving body to reduce the air resistance of the vehicle 10.

In the vehicle 10, a cab (driver's cab) 13 is arranged as a front portion on the front side of the chassis 12 supporting the wheels 11 in the x direction, and a van (loading platform) 14 is arranged as a rear portion on the rear side. In the vehicle 10, the total height Hc, which is the height of the cab 13 from the ground, is lower than the total height Hb of the van 14. The vehicle 10 is provided with a gap 15 (not shown in the drawing because it is closed by the following air resistance reducing device 20 in this embodiment) between the cab 13 and the van 14.

The air resistance reducing device 20 is provided with two enclosures adjacent to the front upper portion 17 of the van 14 existing above the roof 16 which is the upper surface of the cab 13 when viewed from the front to the rear in the x direction, with the central portion in the y direction as a boundary. 21 is provided. The enclosure 21 is composed of baffle plates 22 to 24 protruding forward in the x direction from the upper front portion 17, and is formed in a semi-annular shape in which the lower side is open when viewed from the front to the rear in the x direction.

Further, the air resistance reducing device 20 includes a closing plate 25 that closes the enclosure 21 and also closes the gap 15 between the cab 13 and the van. In addition, the air resistance reducing device 20 is provided with a rounded portion 26 at a corner portion existing on the outer side of the enclosure 21.

The enclosure 21 is composed of one first baffle plate 22, two second baffle plates 23, and one third baffle plate 24. In the enclosure 21, the first baffle plate 22 forms the upper part of the front upper portion 17, the second baffle plate 23 forms the side portion of the front upper portion 17, and the third baffle plate 24 forms the central portion of the front upper portion 17. Surrounding. The enclosure 21 has a U-shape that opens downward, and has a shape that is recessed from the lower side to the upper side when viewed from the front to the rear in the x direction.

The first baffle plate 22, the second baffle plate 23, the third baffle plate 24, and the block plate 25 are erected vertically from the front upper portion 17 and are joined to the front upper portion 17.

The first baffle plate 22 extends from the central portion of the upper front surface 17 toward both sides in the y direction. The first baffle plate 22 is arranged so as to be separated from the upper end edge of the front upper portion 17 toward the center side, and when viewed in the y direction, a space having a triangular cross section and a lower portion on the upper side of the front space of the front upper portion 17. A space with a trapezoidal cross section is formed on the side. Specifically, the space having a triangular cross section is formed from the upper surface of the front upper portion 17 and the first baffle plate 22, and the space having a trapezoidal cross section is formed from the roof 16 and the closing plate 25, the front upper portion 17, and the first. It is formed from the lower surface of the baffle plate 22.

The second baffle plate 23 is an end portion of the first baffle plate 22 in the y direction and extends downward from the first baffle plate 22 in the z direction. The second baffle plate 23 extends from the first baffle plate 22 to the lower end of the cab 13 and the van 14, that is, the chassis 12, and closes the side of the gap 15 between the cab 13 and the van 14. There is. The second baffle plate 23 is arranged so as to be separated from the side edge of the front upper portion 17 to the center side, and when viewed in the z direction, the front space of the front upper portion 17 is defined by the third baffle plate 24. A space with a triangular cross section is formed on the outer side of the space, and a space with a trapezoidal cross section is formed on the inner side. Specifically, the space having a triangular cross section is formed from the outer surface of the front upper portion 17 and the second baffle plate 23, and the space having a trapezoidal cross section is the inner surface of the front upper portion 17 and the second baffle plate 23. , And a third baffle plate 24.

The third baffle plate 24 is arranged at the center of the first baffle plate 22 in the y direction, and extends downward from the first baffle plate 22 in the z direction to the closing plate 25. The third baffle plate 24 divides a portion surrounded by one first baffle plate 22 and two second baffle plates 23 into left and right in the y direction.

The block plate 25 is arranged in the lower part of the upper front portion 17 and extends in the y direction. The closing plate 25 extends from one second baffle plate 23 to the other second baffle plate 23, and closes above the gap 15 provided between the cab 13 and the van 14.

The rounded portion 26 is provided at the corner of the enclosure 21 arranged on the side side when viewed in the x direction. The rounded portion 26 is formed in a columnar shape having a right-angled triangular cross section in which the hypotenuse is recessed inward, and the surface of the upper front surface 17 facing the center forms a cylindrical surface. The rounded portion 26 may be formed in a triangular prism, for example, as long as the corners formed at right angles by the first baffle plate 22 and the second baffle plate 23 can be made smooth.

The front-rear length Df of the air resistance reducing device 20 in the x direction, that is, the front-rear length Df of the baffle plates 22 to 24 is set to be about the same length as the front-rear length Dc of the gap 15. The total width Wf of the air resistance reducing device 20 in the y direction, that is, the total width Wf of the first baffle plate 22 is wider than the width Wr of the roof 16 in the y direction and narrower than the width Wc of the cab 13 in the y direction. It is set. The total height Hf of the air resistance reducing device 20 in the z direction, that is, the total height Hf from the ground to the upper surface of the first baffle plate 22 is higher than the total height Hc of the cab 13 and less than or equal to the total height Hb of the van 14. Is set to.

Next, the principle of reducing the air resistance by the air resistance reducing device 20 will be described. When the vehicle 10 travels forward in the x direction, a circulation vortex 27 is generated inside the enclosure 21 and a circulation vortex 28 is generated outside.

As illustrated in FIG. 2, when viewed in the y direction, the circulating vortex 27 exists below the first baffle plate 22, and the cross section is generated in a trapezoidal space. The circulation vortex 28 exists above the first baffle plate 22 and is generated in a space having a triangular cross section. The circulation vortices 27 and 28 flow from the upper side to the lower side (clockwise when viewed from the left side to the right side in the y direction) along the upper front portion 17 with the rotation axis direction as the y direction. That is, the circulation vortices 27 and 28 are generated inside a right triangle having the roof 16, the closing plate 25, and the upper front surface 17 as two sides sandwiching a right angle.

As illustrated in FIG. 3, when viewed in the z direction, the circulating vortices 27 and 28 are generated on the left and right sides of the central portion in the y direction. The circulation vortex 27 is generated in a space having a trapezoidal cross section inside the second baffle plate 23. The circulation vortex 28 is generated in a space having a triangular cross section on the outside of the second baffle plate 23. The circulation vortices 27 and 28 flow from the side to the center along the upper front portion 17 with the rotation axis direction as the z direction, and flow counterclockwise on the left side in the y direction and clockwise on the right side in the y direction. ing. That is, when viewed in the z direction, the circulation vortices 27 and 28 are generated inside the isosceles triangle having both corners at the front center of the cab 13 and the front surface of the van 14.

As illustrated in FIG. 4, the circulating vortex 27 has a fan shape that requires the lower central portion of the enclosure 21 when viewed from the front to the rear in the x direction when expressed schematically. That is, the two enclosures 21 generate a pair of left and right fan-shaped circulation vortices 27 and a circulation vortex 28 that covers the circumference of the fan-shaped circulation vortex 27 in a U shape on the upper front surface 17.

The rounded portion 26 is provided so as to close the gap between the enclosure 21 and the circulation vortex 27. The shape of the inside of the rounded portion 26 may be any shape that does not come into contact with the circulation vortex 27, and may be formed along the shape of the circulation vortex 27.

As illustrated in FIG. 3, the wind acting on the vehicle 10 is a composite wind of a traveling wind and a natural wind blown at an angle. Here, Vt is the traveling wind speed, Vw is the natural wind speed, Φ is the natural wind direction, VR is the synthetic wind speed, and Ψ is the synthetic wind direction (hereinafter referred to as yaw angle). The yaw angle Ψ increases as the traveling wind speed Vt decreases, and increases as the natural wind direction Φ increases.

Even if the yaw angle Ψ increases by 3 ° to 5 ° or more, that is, the angle formed by the synthetic wind with respect to the moving direction of the vehicle 10 increases, the circulating vortex 27 generated inside the enclosure 21 is stable without being affected by it. doing. Specifically, even if the yaw angle Ψ increases by 3 ° to 5 ° or more, the pair of left and right circulating vortices 27 generated inside the enclosure 21 due to the second baffle plate 23 and the third baffle plate 24 are of synthetic wind. The circulation vortex 27 is stably maintained by avoiding shifting to the leeward side or becoming smaller on the leeward side.

As described above, in the air resistance reducing device 20, when the vehicle 10 travels forward in the x direction, even if the yaw angle Ψ becomes large, the two enclosures 21 generate a circulation vortex 27 inside the enclosure 21. Can be maintained stably. As a result, the synthetic wind flows outside the right triangle due to the circulation vortices 27 and 28 when viewed in the y direction, and flows outside the isosceles triangle due to the circulation vortices 27 and 28 when viewed in the z direction. As a result, collision with the upper front surface 17 can be avoided, and the van 14 is peeled off at the roof (upper surface) and the side surface (a phenomenon in which the pressure resistance increases due to the deceleration of the flow velocity passing through the corner and the backflow in the peeling area). Therefore, it is advantageous to reduce the air resistance of the vehicle 10 and improve the fuel efficiency.

In particular, in this air resistance reducing device 20, two enclosures 21 adjacent to each other on the left and right border the central portion of the front upper portion 17 in the y direction. Therefore, even if the yaw angle Ψ becomes large, it is possible to prevent the pair of left and right circulating vortices 27 from interfering with each other by this boundary, that is, the third baffle plate 24. This is advantageous for stabilizing the circulation vortex 27 generated inside the enclosure 21.

Further, in the air resistance reducing device 20, the upper part of the gap 15 between the cab 13 and the van 14 is closed by the closing plate 25. That is, the blocking plate 25 prevents the running wind from falling in the gap 15 when viewed in the y direction. This is advantageous in avoiding collision of the traveling wind descending through the gap 15 with the underfloor structure of the chassis 12 and suppressing peeling under the floor.

In addition, in the air resistance reducing device 20, the side of the gap 15 between the cab 13 and the van 14 is closed by the second baffle plate 23. That is, the second baffle plate 23 prevents the traveling wind from crossing the gap 15 when viewed in the z direction. This is advantageous in suppressing peeling on the side surface of the van 14 of the traveling wind that crosses the gap 15.

The air resistance reducing device 20 may be manufactured at a lower cost than the air deflector mounted on the roof 16 by forming two enclosures 21 by the baffle plates 22 to 24.

The air resistance reducing device 20 is arranged so that the first baffle plate 22 is separated from the upper end edge of the upper front surface 17 and the second baffle plate 23 is separated from the side edge of the upper front surface 17 toward the center side. Therefore, the two enclosures 21 simultaneously generate a circulation vortex 27 generated inside the enclosure 21 and a circulation vortex 28 generated outside the enclosure 21 in the front space of the upper front surface 17. By generating the inner circulation vortex 27 and the outer circulation vortex 28 of the front upper portion 17 in this way, it becomes advantageous to avoid the synthetic wind colliding with the front upper portion 17 and the running resistance is reduced. can. If the running resistance can be reduced only by the circulation vortex 27 generated inside the enclosure 21, the enclosure 21 may be arranged on the peripheral edge of the upper front surface 17.

As illustrated in FIG. 5, the effect of the air resistance reducing device 20 will be described with reference to the relationship between the yaw angle Ψ and the Cd value (air resistance coefficient). Here, A is a configuration without an air resistance reducing device 20, B is a configuration of a conventional technique (for example, a configuration with only one baffle plate or a configuration with only one enclosure), and C is a configuration. As the air resistance reducing device 20, only two enclosures 21 are provided (excluding the configuration that closes the gap 15 as in the first embodiment), D is added to the configuration C, and the cab 13 and the second baffle plate 23 are used. A configuration in which the side of the gap 15 between the vans 14 is closed, E is added to the configuration D, and the upper part of the gap 15 between the cab 13 and the van 14 is closed by the closing plate 25 (configuration of the first embodiment). The same configuration as). Further, the low yaw angle referred to here is, for example, a range of −5 ° to + 5 °, and the high yaw angle is a range other than that.

In the configuration B, the Cd value is lower than that in the configuration A at a low yaw angle, that is, when the circulation vortices 27 and 28 are maintained, but at a high yaw angle, that is, the circulation vortices 27 and 28 are not present. In a stable state, the Cd value is higher than that of the configuration A.

In the configuration C, the Cd value is substantially the same as that of the configuration B at a low yaw angle, but the Cd value is lower than that of the configuration B at a high yaw angle. This is a result of stably maintaining the position and size of the circulation vortex 27 generated inside the enclosure 21 by the two enclosures 21 as described above.

In the configuration D, the Cd value is substantially the same as that of the configuration C at a low yaw angle, but the Cd value is lower than that of the configuration C at a high yaw angle. In particular, the configuration D is more effective as the yaw angle Ψ is larger. This is a result of reducing the crossing of the synthetic wind by closing the side of the gap 15 between the cab 13 and the van 14 by the second baffle plate 23 as described above.

The Cd value of the configuration E is lower than that of the configuration D over the entire range. This is a result of reducing the descent of the synthetic wind by blocking the upper part of the gap 15 between the cab 13 and the van 14 by the closing plate 25 as described above.

As described above, the air resistance reducing device 20 can have a minimum configuration B in which two enclosures 21 are provided at least in the space in front of the upper front surface 17. Further, the second baffle plate 23 does not have to extend to the chassis 12.

Further, in this embodiment, the enclosure 21 is composed of four baffle plates 22 to 24, but one baffle plate may be formed in an m shape to form two enclosures 21. The two baffle plates may be formed in a semicircular shape, and a third baffle plate may be provided at the center thereof to form two enclosures 21. In addition, although the baffle plates 22 to 24 and the closing plate 25 are configured as separate bodies, the baffle plates formed in an annular shape may be arranged adjacent to each other in the y direction to form two enclosures.

Circulation vortices 27 and 28 are stable by experiments and tests regarding the installation position, length, thickness, presence / absence of R (roundness) at the tip (front end in the x direction), and inward bending of the baffle plates 22 to 24. It is advisable to find and set the optimum form that can be maintained. For example, the first baffle plate 22 and the second baffle plate 23 may be arranged in a grid shape instead of a U shape. By arranging in a grid shape, it is advantageous to maintain the circulating vortex 28 outside the enclosure 21. The position of the block plate 25 is preferably a position where the block plate 25 does not protrude upward from the roof 16. By arranging the closing plate 25 in this way, it is possible to prevent the protruding portion from becoming a running resistance, which is advantageous in reducing the running resistance.

The front-rear length Df of the air resistance reducing device 20 may be a length that can avoid contact with the cab 13 when the cab 13 is tilted forward in the x-direction, and may be a length equal to or greater than the front-rear length Dc. However, the front-rear length Df is a right-angled triangle with the roof 16 and the closing plate 25 and the front upper portion 17 having two sides sandwiching a right angle when viewed in the y direction, or the front center of the cab 13 when viewed in the z direction. , The length that does not protrude outward from the isosceles triangle whose vertices are both corners on the front surface of the van 14 is preferable. If the front-back length Df becomes long and protrudes from the right triangle seen in the y direction or the isosceles triangle seen in the z direction, the air resistance reducing device 20 will be exposed to the synthetic wind, and the extra air resistance may increase. There is.

As illustrated in FIG. 6, the total width Wf of the air resistance reducing device 20 is narrower than the total width Wd of the air deflector 18, and the total height Hf of the air resistance reducing device 20 is set lower than the total height Hd of the air deflector 18. Will be done. The total width Wd of the air deflector 18 is wider than the width Wr of the roof 16 and is set to be equal to or less than the width Wc of the cab 13, and the total height Hd is set to be equal to or less than the total height Hb of the van 14. By setting the total width Wf and the total height Hf of the air resistance reducing device 20 in this way, when the air deflector 18 is attached, the front portion of the air resistance reducing device 20 wraps inside the air deflector 18. Therefore, the labyrinth seal formed by the air deflector 18 and the air resistance reducing device 20 can prevent the wind from flowing into the gap formed between the air deflector 18 and the van 14. This is advantageous in reducing the air resistance when the air deflector 18 is attached, and the fuel consumption can be improved as compared with the case where the air deflector 18 is attached alone. When the air deflector 18 is attached, no circulation vortex is generated by the air resistance reducing device 20.

As illustrated in FIG. 7, the air resistance reducing device 20 of the second embodiment is different from the first embodiment in that the refrigerator 19 plays a part of the enclosure 21. In other words, the air resistance reducing device 20 of the second embodiment does not change the overall dimensions from the first embodiment, and the first wind guide so as to avoid the refrigerator 19 protruding forward in the x direction from the upper front surface 17. A plate 22 and a third baffle plate 24 are provided.

As described above, the air resistance reducing device 20 can also be applied to the vehicle 10 equipped with the refrigerator 19, and can reduce the air resistance and improve the fuel efficiency.

As illustrated in FIG. 8, the air resistance reducing device 20 of the third embodiment is different from the first embodiment in that the baffle plates 22 to 24 constituting the enclosure 21 are not joined to the front upper portion 17. .. Further, it is different from the second baffle plate 23 in that it is provided with a closing plate 29 that closes the side of the gap 15 between the cab 13 and the van 14.

In the air resistance reducing device 20 of the third embodiment, the third baffle plate 24 is joined to the roof 16, and the first baffle plate 22 and the second baffle plate 22 are interposed via the third baffle plate 24. 23 is joined to the roof 16. The block plates 25 and 29 are joined to either the cab 13 or the van 14. Further, the third baffle plate 24 has a trapezoidal shape with the roof 16 and the closing plate 25 as the lower base and the first baffle plate 22 as the upper base when viewed in the y direction. By extending the third baffle plate 24 to the front of the roof 16, when viewed in the z direction, it is possible to avoid mutual interference between the pair of left and right circulating vortices 27 generated inside the enclosure 21. This is advantageous for maintaining the circulation vortex 27 in a stable manner, and can improve fuel efficiency.

As described above, the baffle plates 22 to 24 need only protrude from the front upper portion 17 toward the front in the x direction, and may not be joined to the front upper portion 17.

10 Vehicle 13 Cab 14 Van 17 Front upper part 20 Air resistance reduction device 21 Enclosure 22 to 24 Baffle plate

Claims (5)

In an air resistance reduction device mounted on a truck in which a cab and a van are arranged in order from the front to the rear and the height of the cab is lower than the height of the van.
The upper front surface of the van located above the cab is provided with two enclosures adjacent to the left-right central portion of the truck as a boundary, and the enclosures are provided with a wind guide projecting forward from the upper front surface. An air resistance reduction device made of plates and formed in a semi-annular shape with the lower side open when viewed from the front to the rear. The air resistance reducing device according to claim 1, wherein the enclosure is arranged so as to be separated from the upper end edge and the side end edge of the upper front surface toward the center side. The enclosure is arranged above the upper part of the front surface and extends in the left-right direction of the truck , and is arranged at both ends of the first baffle plate and extends in the vertical direction of the truck. Claim 1 is composed of two second baffle plates and a third baffle plate arranged at the center of the first baffle plate in the left-right direction and extending in the vertical direction of the truck. Or the air resistance reducing device according to 2. The truck has a gap between the cab and the van.
The air resistance reducing device according to any one of claims 1 to 3, further comprising a closing plate extending in the left-right direction of the truck to close the lower side of the enclosure and the upper part of the gap. The truck has a gap between the cab and the van.
The air resistance reducing device according to any one of claims 1 to 4, further comprising a closing plate extending in the vertical direction of the truck and closing the side of the gap.

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