The present invention relates to a measuring device for a wind tunnel test of a vehicle having a plurality of wheels, and a wind tunnel test device using the measuring device.
Conventionally, various wind tunnel test devices for performing a wind tunnel test of a vehicle have been proposed. For example, a wind tunnel test device described in Patent Document 1 is an installation type and is provided in a predetermined facility. Further, in such a wind tunnel test device, a measuring device is provided below an installation base of a vehicle, and various measurements are performed by the measuring device.
Patent Document 1: Japanese Patent Laid-open Publication No. 2021-47086
However, since the above wind tunnel test device is provided in a predetermined facility, the wind tunnel test device cannot be moved to the outside of the facility. Further, in the above wind tunnel test device, since a wind tunnel test of a plurality of types of vehicles is performed by one measuring device, there is a problem that the installation base is large and the measuring device is also large.
The present invention has been made to solve the above problem, and an object of the present invention is to provide a measuring device for a wind tunnel test and a wind tunnel test device that are portable and can be downsized.
A measuring device according to the present invention is a measuring device used for a wind tunnel test of a vehicle having a plurality of wheels. The measuring device includes a plurality of measurement modules in which each of the wheels is arranged. Each of the measurement modules includes a housing having an opening in an upper portion, a load cell accommodated inside the housing, a moving mechanism for moving the load cell inside the housing, and a lid body that closes the opening of the housing, the lid body includes a wheel support member that supports the wheel, the wheel support member is configured to be able to be arranged in an optional position of the lid body, and the load cell is configured to measure force acting on the wheel support member.
In the measuring device, the moving mechanism can be configured to move the load cell along two orthogonal directions on a horizontal plane.
In the measuring device, the wheel support member can be formed in a disk shape, the lid body can include a disk-shaped first positioning member having a first through hole into which the wheel support member is fitted, a disk-shaped second positioning member having a second through hole into which the first positioning member is rotatably fitted, and a support body portion having a third through hole into which the second positioning member is rotatably fitted, and the wheel support member can be arranged immediately below the wheel by rotation of the first and second positioning members.
The measuring device further includes at least one coupling module, and a plurality of the measurement modules can be configured by being coupled by the coupling module.
The measuring device further includes a splitter for thinning a boundary layer formed by air from a blower, and the splitter can be configured to be attachable to an end portion on a side of the blower of the measuring device.
A wind tunnel test device according to the present invention includes any of the measuring devices described above and a movable blower.
According to the present invention, there is portability, and downsizing can be achieved.
Hereinafter, an embodiment of a measuring device for a wind tunnel test according to the present invention will be described with reference to the drawings.
As illustrated in
As illustrated in
The tip member 32 is formed in a plate shape, and is formed such that an upper surface 321 of the tip member 32 and an upper surface of the main body portion 31 are continuous. An end edge on the front side of a lower surface 322 of the tip member 32 is located further on the rear side than an end edge on the front side of an upper surface. Then, a tip surface 323 connecting an end edge of the upper surface 321 and an end edge of the lower surface 322 is formed in an arcuate cross section.
The tip member 32 has a plurality of through holes 324 formed at predetermined intervals in a front-rear direction. Then, a tube member 325 communicating with the through hole 324 is attached to the lower surface 322 of the tip member 32. The tube member 325 is connected to a pressure measurement unit (not illustrated) built in the measuring device 2, and allows measurement of pressure of air flowing on an upper surface of the tip member.
On an upper surface of the measuring device 2, a boundary layer is formed as a part of an airflow flowing from the blower 1 is dragged by frictional force generated between the air flow and the measuring device 2. Here, a component of the air flow excluding the boundary layer is referred to as a main flow. That is, the air flow includes the boundary layer and the main flow in a direction away from the upper surface. The main flow has uniform flow velocity distribution in a height direction based on the upper surface. On the other hand, a flow velocity of the boundary layer, which is smaller than a flow velocity of the main flow and becomes lower as approaching the upper surface, may affect reproducibility when simulation is performed for a traveling state of a vehicle in a wind tunnel test. In view of the above, in the present embodiment, the boundary layer can be thinned by providing the splitter 3 at a tip of the measuring device 2. As a result, influence of the boundary layer on a wind tunnel test can be reduced.
It has been confirmed by the present inventor that a thickness t of the tip member 32, a length L of the tip member 32 protruding forward from the main body portion 31, and a curvature radius R of the tip surface 323 have influence in order to thin the boundary layer described above and reduce influence. For example, the thickness t of the tip member 32 is preferably 1 to 8 mm, and more preferably 3 to 5 mm. The length L of the tip member 32 protruding from the main body portion 31 is preferably 75 to 150 mm, and more preferably 100 to 125 mm. Further, the tip radius R of the tip surface 323 is preferably ⅖ to ⅗ of a thickness of the tip member 32, and more preferably, for example, ½.
Four of the splitter pieces 301 to 304 are coupled so as to be arranged in the left-right direction as described above. Further, among four of the splitter pieces 301 to 304, in the first and fourth splitter pieces 301 and 304 arranged on the right side and the left side, a side opening formed by the upper wall portion 311 and the lower wall portion 312 is closed by a plate-shaped side wall portion 315.
As illustrated in
The moving mechanism 45 is configured as described below. As illustrated in
As the load cell 44, a publicly-known load cell can be used. The load cell 44 is fixed to a wheel support member 431 of the lid body 43 described below, and detects at least one of a drag, a lift, a lateral force, and each moment generated in the vehicle 100 via a wheel 101 of the vehicle 100 supported by the wheel support member 431. Each of the load cells 44 is connected to a measuring instrument (not illustrated) accommodated in first and sixth rear modules 701 and 706 of the rear portion 7 described later. The measuring instrument accommodates a strain amplifier and a load cell indicator.
Next, the lid body 43 will be described. As illustrated in
With this configuration, the wheel support member 431 can be arranged at a desired position of the lid body 43 by rotating each of the first positioning member 432 and the second positioning member 433. Specifically, for example, positioning can be performed as described below.
First, in a state where the first positioning member 432 removed, the load cell 44 and the wheel support member 431 are moved to a predetermined position by the moving mechanism 45. At this time, in a case where the second positioning member 433 interferes with the wheel support member 431, the second positioning member 433 is also removed. Next, after an annular jig is attached around the wheel support member 431, the second positioning member 433 is rotated to bring any part of an inner periphery of the second positioning member 433 into contact with the jig. By the above, a distance of a portion where an outer peripheral surface of the wheel support member 431 and an inner peripheral surface of the second positioning member 433 are closest to each other is defined by the jig. This distance coincides with a closest distance between an outer peripheral surface of the first positioning member 432 and an inner peripheral surface of the first through hole 4320. By the above, a space formed between the wheel support member 431 and the second through hole 4330 coincides with a shape of the first positioning member 432. For this reason, when the first positioning member 432 is fitted into the second through hole 4330, positioning of the wheel support member 431 is completed.
Note that when a plurality of holes are formed on a surface of the first and second positioning members 432 and 433, the positioning members 432 and 433 can be moved by inserting a lever into the holes and then moving the lever.
The A-type coupling module 51 is formed in a rectangular parallelepiped shape elongated in the front-rear direction, and includes a plate-shaped bottom wall portion 511 having a rectangular shape in plan view, a frame-shaped side frame 512 arranged along a peripheral edge of the bottom wall portion 511, and a lid body 513 having a square shape in plan view and closing an upper opening of the side frame 512, and is formed in a rectangular parallelepiped shape having a low height as a whole. In the A-type coupling module 51, a rectangular closing plate 514 is attached to a right side surface and a left side surface of the side frame 512 in the first and sixth intermediate modules 501 and 506 arranged on both sides of the intermediate portion 5.
The B-type coupling module 52 includes a plate-shaped bottom wall portion 521 having a rectangular shape in plan view, a frame-shaped side frame 522 arranged along a peripheral edge of the bottom wall portion 521, and a lid body 523 having a square shape in plan view and closing an upper opening of the side frame 522, and is formed in a rectangular parallelepiped shape having a low height as a whole. In the B-type type coupling module 52, a rectangular closing plate 524 is attached to a right side surface and a left side surface of the side frame 522 in the first and sixth intermediate modules 501 and 506 arranged on both sides of the intermediate portion 5.
As illustrated in
The intermediate portion 5 is configured by using four of the A-type coupling modules and two of the B-type coupling modules and coupling them in the left-right direction as described above. Adjacent modules are coupled to each other by bringing the side frames 512 and 522 into contact with each other and then fixing them with a bolt or the like. Further, the first and second measurement units 4 and 6 are also coupled to each other by bringing side frames into contact with each other and then fixing them with a bolt or the like (second coupling mode).
The C-type coupling module 71 is formed in a rectangular parallelepiped shape elongated in the front-rear direction, and includes a plate-shaped bottom wall portion 711 having a rectangular shape in plan view, a frame-shaped side frame 712 arranged along a peripheral edge of the bottom wall portion 711, and a lid body 713 having a rectangular shape in plan view and closing an upper opening of the side frame 712, and is formed in a rectangular parallelepiped shape having a low height as a whole. The lid body 713 extends further to the rear than the side frame 712, and has the same length in the front-rear direction as the D-type coupling module 72. Further, a rectangular closing plate 714 is attached to a right side surface and a left side surface of the side frame 712 of the C-type coupling module 71.
The D-type coupling module 72 includes a plate-shaped bottom wall portion 721 having a rectangular shape in plan view, a frame-shaped side frame 722 arranged along a peripheral edge of the bottom wall portion 721, and a lid body 723 having a rectangular shape in plan view and closing an upper opening of the side frame 722, and is formed in a rectangular parallelepiped shape having a low height as a whole.
The E-type coupling module 73 includes a plate-shaped bottom wall portion 731 having a rectangular shape in plan view, a frame-shaped side frame 732 arranged along a peripheral edge of the bottom wall portion 731, and a lid body 733 having a rectangular shape in plan view and closing an upper opening of the side frame 732, and is formed in a rectangular parallelepiped shape having a low height as a whole.
As illustrated in
The rear portion 7 is configured by using two of each of the C-type, D-type, and E-type coupling modules and coupling them in the left-right direction as described above. Adjacent modules are coupled to each other by bringing the side frames 712,722, and 732 into contact with each other and then fixing them with a bolt or the like. Coupling to the second measurement unit 6 is also performed by bringing side frames into contact with each other and then fixing them with a bolt or the like. Further, the measuring instrument described above is accommodated in the C-type coupling module constituting the first and sixth rear modules 701 and 706. The measuring instrument is connected to an external computer via a cable, and performs data display, analysis, and the like. Since a cable is attached to the measuring instrument as described above, the C-type coupling module 71 is shorter than the adjacent E-type coupling module 73 in order to arrange the cable. For example, in a case where it is desired to extend the cable in the left-right direction, a bent portion of the cable can be arranged in a region covered with the lid body 713 of the C-type coupling module 71. Therefore, the bent portion of the cable can be prevented from being exposed.
Next, a wind tunnel test using the measuring device configured as described above will be described. First, the measuring device 2 is assembled as described above. Next, the load cell 44 and the wheel support member 431 are arranged at a position corresponding to four of the wheels 101 of the vehicle 100. First, after the load cell 44 is positioned by the moving mechanism 45, the first and second positioning members 432 and 433 are manually rotated so that the wheel support member 431 is arranged immediately above the load cell 44. At this time, a position of each of the load cells 44 is input to a computer connected to the measuring instrument.
Subsequently, as illustrated in
In the measuring device 2 configured as described above, an effect below can be obtained.
(1) Since the blower 1 and the measuring device 2 are separated and configured to be movable, and the measuring device 2 can be assembled, a wind tunnel test can be performed at a desired place as compared with a conventional non-movable installation type wind tunnel test device.
(2) In the measuring device 2 according to the present embodiment, since a plurality of the load cells 44 are used in accordance with positions of the wheels 101, the measuring device 2 can be downsized, as compared with a case where various vehicles are measured by one measuring device such as a conventional wind tunnel balance. Further, since the load cell 44 is arranged for each wheel, responsiveness of measurement can be enhanced. Further, a position of the load cell 44 can be accurately positioned by the moving mechanism 45 of each of the measurement modules 401, 402, 601, and 602, and an upper surface of each of the lid bodies 43 is flat even if a position of the wheel support member 431 is changed, so that combination of these enables accurate measurement of force received from the wheel 101. In particular, when a moment applied to a vehicle body is calculated, it is necessary to accurately position the load cell 44 at a position of the wheel 101 since calculation needs to be performed using a pitch of a wheel (for example, wheel base and tread base dimensions). Therefore, the measuring device 2 according to the present embodiment is suitable. Furthermore, by providing the load cell 44 for each of the wheels 101, thickness of the measurement modules 401, 402, 601, and 602 can be reduced. Therefore, the measuring device 2 having excellent portability can be realized.
(3) The measuring device 2 is configured by combining one type of the measurement module 401 and five types of the coupling modules 51, 52, and 71 to 73. For this reason, by appropriately combining these modules, the present invention can be applied to a wind tunnel test of vehicles having the wheels 101 that are different in number and position. For example, in the above description, a wind tunnel test of a four-wheeled vehicle is described. However, for example, as illustrated in
(4) In a conventional installation type wind tunnel test device, a suction device that sucks a boundary layer is provided, and the device is complicated and large. However, in the measuring device 2 of the present embodiment, the splitter 3 having a simple configuration is provided at a tip, so that a boundary layer can be thinned and influence can be reduced. For this reason, it is suitable for a portable measuring device, and the device can be simplified.
Although the first embodiment of the present invention is described above, the present invention is not limited to the above embodiment, and various changes can be made without departing from the gist of the present invention. Note that variations below can be appropriately combined.
(1) In the above embodiment, the load cell 44 is moved in two directions orthogonal to each other on a horizontal plane by the first rail 451 and the second rail 453, but a configuration of the moving mechanism 45 of the load cell 44 is not limited to this. That is, the load cell 44 only needs to be configured to be movable in the measurement module 401. For example, a plurality of holes can be formed at predetermined intervals in the bottom wall portion 41, the load cell 44 can be arranged at an optional position of the bottom wall portion 41, and then a bolt or the like can be inserted into the hole to fix the load cell.
(2) In the above embodiment, the wheel support member 431 is moved by two of the positioning members 432 and 433, but a configuration for arranging the wheel support member 431 at an optional position of the lid body 43 is also not limited to this. That is, another configuration may be employed as long as the wheel support member 41 can move in the lid body 43 while an upper surface of the lid body 43 remains flat. For example, in the above embodiment, the wheel support member 431 is moved by two of the positioning members 432 and 433, but three or more disk-shaped positioning members may be used. Alternatively, one disk-shaped positioning member may be used.
Further, when the wheel support member 431 is moved together with the load cell 44, the first positioning member 432 and the second positioning member 433 can be configured to rotate in conjunction with the movement. At this time, rotation of the first positioning member 432 and the second positioning member 433 can be assisted by a motor or the like. Further, a configuration of fixing the first positioning member 432 and the second positioning member 433 so as not to move after the wheel support member 431 is positioned may be included.
Further, the wheel support member 431 is formed in a rectangular shape, and a plurality of segmented insertion type blocks having a rectangular shape in plan view are inserted around the wheel support member 431 to form the lid body 43. By the above, the wheel support member 41 can be moved in the lid body 43 while an upper surface of the lid body 43 remains flat. Further, a periphery of the wheel support member 431 may be filled with a shutter that is movable forward, backward, left, and right instead of a block.
(3) In the measurement module, the first and second positioning members 432 and 433 are manually rotated, but each of the positioning members 432 and 433 can also be rotated by a drive device such as a motor. By the above, the wheel support member can be automatically positioned. This point is similar to the moving mechanism 45 that moves the load cell 44.
(4) In the above embodiment, the measuring device is configured using one type of measurement module and five types of coupling modules, but this is an example and the present invention is not limited to this. That is, the measuring device only needs to be able to be configured by using at least one of the first coupling mode in which a plurality of measurement modules are coupled to each other and the second coupling mode in which a plurality of measurement modules are coupled to each other by a coupling module. For this reason, measurement modules and coupling modules having different shapes can be further prepared, and this allows the present invention to be applied to a wind tunnel test of various vehicles having wheels different in number and position. As described above, an assembly system of the present invention is configured by including a plurality of measurement modules and at least one coupling module, and a measurement module and a coupling module are selected from them so as to configure a measuring device of a desired mode.
(5) A shape of the measurement module is not particularly limited, and can be various shapes such as a polygonal shape in addition to a rectangular shape in plan view as described above.
(6) In the above embodiment, a worker measures a position of the load cell 44 and inputs the position to a computer, but the work can be automatically performed. That is, a detector that detects a position of the load cell 44 can be provided. As the detector, for example, encoders are provided in the moving mechanism 45, and a position of each of the load cells 44 can be detected by these encoders. Further, a relative positional relationship between the load cells 44 can be measured, and a position of the load cell 44 can be detected based on the relative positional relationship. Further, in addition to an encoder, various detectors such as a potentiometer, a resolver, and a laser can be used.
(7) A configuration of the coupling module is not particularly limited, and the coupling module only needs to be configured so as to be able to be coupled to the measurement module such that an upper surface is continuous with an upper surface of the measurement module. Further, a shape of the coupling module is not particularly limited, and can be various shapes such as a polygonal shape in addition to a rectangular shape in plan view as described above.
(8) A shape of the splitter 3 is not particularly limited, and in particular, a shape of the lower wall portion 312 of the main body portion 31 is not particularly limited. Further, the measuring device 2 can be configured without providing the splitter 3.
(9) As the measuring device main body, an integrated measuring device in which a measurement module is fixed in advance can be used instead of the assembled type as in the above embodiment.
(10) A configuration of the blower 1 is not particularly limited, and a publicly-known blower can be used. In consideration of portability, it is preferable to use a plurality of blowers that can be combined according to air volume.
1: Blower
2: Measuring device
3: Splitter
31: Main body portion
32: Tip member
4: Measuring module
43: Lid body
432: First positioning member
433: Second positioning member
434: Support body member
44: Load cell
45: Moving mechanism
51, 52: Coupling module
71 to 73: Coupling module
Number | Date | Country | Kind |
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2022-003422 | Jan 2022 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2022/048637 | 12/28/2022 | WO |