JP4829008B2 - Cross wind blower and blow method - Google Patents

Description

  The present invention relates to a cross wind blowing device and a blowing method for performing a cross wind stability test of a vehicle.

  FIG. 13 is a cross-sectional view showing a part of the crosswind fan 1 of the prior art. The crosswind air blower 1 is a device for performing a stability test by crosswind on the traveling vehicle 3. The cross-wind blower 1 has a plurality of blowers 2. The air blowing means 2 are arranged along the predetermined parallel direction X and are adjacent to the test paths 4 extending in the parallel direction X, respectively. The blown gas blown by each blower 2 travels in the horizontal orthogonal direction Y perpendicular to the test path 4. A test wind simulating a cross wind traveling in the orthogonal direction Y can be created by the blown gas blown by each blowing means 2. A cross wind blower is disclosed in Non-Patent Document 1, for example.

  Each blowing means 2 is disposed in a cylindrical cylindrical portion 5. The cylindrical part 5 is connected to a rectangular cylindrical part 6 having a rectangular cylindrical shape. The rectangular cylindrical portion 6 has a larger diameter in the parallel direction than the cylindrical portion 5. The rectangular cylindrical portions 6 provided for each blowing means 2 are arranged adjacent to each other in the parallel direction X. By providing the rectangular tube portion 6, the blown gas blown from the blowing means 2 is spread in the parallel direction X.

  For example, six rectangular cylinders 6 having a parallel direction X dimension of about 3 m are arranged adjacent to each other in the parallel direction X, so that the air blowing region 9 having a parallel direction X dimension of 18 m can be formed in the test path 4. In the entire blowing area 9, the test wind advances in the orthogonal direction Y over the parallel direction X. By running the vehicle 3 in the parallel direction X and passing the air blowing area 9 formed on the test path 4, the stability of the vehicle 3 due to cross wind can be tested.

  In addition, examples of fluid experimental devices for blowing gas onto a test body include a rotary wind tunnel, a suction wind tunnel, and a blow-out wind tunnel. The prior art regarding a rotary wind tunnel is disclosed by patent document 1, for example. Further, for example, Patent Document 2 discloses a conventional technique related to a blow-out type wind tunnel. Such a conventional wind tunnel device has a small area in which gas can be sprayed and cannot be used for the cross wind stability test. The cross wind blower of the prior art has a configuration different from that of the wind tunnel device, and is realized by a plurality of blowers arranged in the parallel direction in order to enlarge the region in which the gas can be blown in the parallel direction.

Automotive Standard (JASO Z108, 2004 minor revision) Automotive-Crosswind stability test method Japanese Patent Laid-Open No. 7-83789 JP 2003-65890 A

  FIG. 14 is a diagram for explaining a beat sound generated by two blowers. FIG. 14 (1) is a graph showing the rotational speeds of the impellers of the first blower and the second blower, respectively. FIG. 14 (2) is a graph showing the time change of the noise sound pressure generated in the first blower. FIG. 14 (3) is a graph showing the time change of the noise sound pressure generated in the second blower. FIG. 14 (4) is a graph showing the time change of the synthesized noise sound pressure obtained by superimposing two noise sound pressures generated by the first blower and the second blower. Each blower generates noise having frequencies f1 and f2 that are proportional to the rotational speed of the impeller. When the rotational speed of the impeller is constant, the frequencies f1 and f2 of the noise generated by each blower are constant regardless of changes over time.

  In order to generate a test wind having a uniform speed in the parallel direction X in the crosswind fan of the prior art, each fan is given a command of the same rotational speed. However, the rotation speeds of the impellers of all the blowers are rarely the same. Therefore, as shown in FIG. 14 (1), there is a slight difference | R2-R1 | between the rotational speed R1 of the impeller of the first blower and the rotational speed R2 of the impeller of the second blower. As a result, a slight frequency deviation | f2-f1 | is generated between the frequency f1 of the noise generated by the first blower and the frequency f2 of the noise generated by the second blower. This frequency deviation | f2-f1 | is constant regardless of the time change.

  In this case, as shown in FIG. 14 (4), the noise and sound pressure generated for each blower is combined to be synthesized with a period (1 / (| f2-f1 |)) related to the frequency deviation | f2-f1 |. The intensity of noise and sound pressure changes. A roaring sound is generated due to the intensity change of the noise sound pressure. The roaring sound has a problem in that it is uncomfortable for an operator who performs a crosswind stability test. In addition, the roaring sound has a problem that the influence of noise on the surrounding environment is large.

  Accordingly, an object of the present invention is to provide a cross air blowing device and an air blowing method capable of reducing a roaring sound.

The present invention is a cross wind blower used for a cross wind stability test of a vehicle,
An impeller for blowing the blown gas, rotationally driving the impeller so that the number of rotations can be changed, and at least three or more blowing means arranged in a predetermined parallel direction;
Control means capable of individually controlling each air blowing means,
Rotation command so that the impeller rotates at a reference rotation speed capable of generating a reference flow velocity of the blown gas predetermined in the crosswind stability test with respect to the odd-numbered or even-numbered blowing means counted from one of the parallel directions give,
A rotation change command for alternately changing the rotation speed of the impeller to a rotation speed larger than the reference rotation speed and a rotation speed smaller than the reference rotation speed with respect to the remaining air blowing means. And a control means for controlling the rotational speed of the impeller of each blower means.

According to the present invention, the air blowing units arranged in the parallel direction blow the blown gas. As a result, it is possible to generate a test wind that passes through a wide area extending in the parallel direction. Further, in the state where the test wind is generated, the control means changes the rotational speed of the impeller in the odd-numbered or even-numbered air blowing means counted from one side in the parallel direction with time, so that the one from the parallel direction is changed. The rotational speed difference between the impellers in the odd-numbered or even-numbered blower means and the impellers in the remaining blower means can be changed with time.

As the rotational speed of one impeller approaches the rotational speed of the other impeller, the period of the beat sound generated due to the rotation of the two impellers becomes longer. Moreover, the cycle of the roaring sound generated due to the rotation of the two impellers is shortened because the rotational speed of one impeller is away from the rotational speed of the other impellers. In the present invention, since the rotational speed difference between the two impellers can be changed with the passage of time, the period of the beat sound can be changed with the passage of time. Can be avoided.
Moreover, the rotational speed change width of the impeller can be increased by alternately changing the rotational speed of the impeller relative to the reference rotational speed. As a result, it is possible to increase the change in the period of the beat sound with the passage of time, and it is possible to more reliably avoid the continuous generation of the beat sound having a constant period. In addition, by changing the rotation speed relative to the reference rotation speed, it is possible to suppress variations in the speed of each blown gas necessary to perform the crosswind stability test, and to suppress deterioration in accuracy of the crosswind stability test. .
In addition, at a rotational speed that alternately changes over time, the blowing means that rotates the impeller at the reference rotational speed, and the rotational speed that is larger than the reference rotational speed and the rotational speed that is smaller than the reference rotational speed. Since the air blowing means for rotating the impeller are alternately arranged in the parallel direction, the air blown by the former air blowing means and the latter air blowing means are mixed with each other, and the speed of the air blowing gas in the parallel direction It is possible to prevent the distribution from greatly varying with respect to the reference flow velocity.

The present invention, the control means, at a rotational speed range capable of generating a flow rate of the blowing gas to a predetermined be acceptable within the flow rate range in the crosswind stability test, the rotation change command rotational speed of the impeller, the blowing of the residual It is characterized by giving to a means .

  According to the present invention, even if the rotational speed of the impeller is changed by the control means, the flow rate of the generated blown gas can be kept within the allowable flow rate range. As a result, it is possible to avoid the occurrence of a humming sound having a constant period while suppressing variations in the flow velocity of each blown gas necessary for performing the cross wind stability test.

Further, in the present invention, the control means outputs a rotation change command for changing at least one of an amplitude and a period for changing the rotational speed of the impeller of the remaining blowing means as time passes. It is characterized by giving to a means .

  According to the present invention, by changing either the amplitude or the period, the period of the beat sound with the passage of time is further made non-uniform, and it is further ensured that the beat sound with a constant period is continuously generated. It can be avoided. For example, the cycle for changing the magnitude of the rotational speed may be changed randomly with time.

Further, in the invention, it is preferable that the control unit gives a rotation change command for continuously changing the number of rotations of the impeller of the remaining blowing unit with time, to the remaining blowing unit. And

  According to the present invention, it is possible to make the change in the period of the beat sound with the passage of time continuous, and to reduce discomfort given to the operator.

In the present invention, the remaining air blowing means includes a plurality of air blowing means,
Control means amplitude for changing the rotational speed of the size of the blades vehicles, the period and the phase of at least one, the rotation change command varied for each wheel, characterized in providing the remainder of the blowing means.

  According to the present invention, with respect to the rotational speed of the impeller, at least one of the amplitude, the period, and the phase for changing the magnitude is made different for each impeller. Thus, even when the rotational speeds of the two impellers are changed with the passage of time, the difference in rotational speeds with the passage of time of the two impellers can be prevented from becoming constant with the passage of time. It is possible to more reliably avoid the occurrence of a beat sound having a constant period.

Further, the present invention is a blower method for blowing a blown gas used in a crosswind stability test of a vehicle using at least three or more blower means that are arranged in a predetermined parallel direction and capable of changing the rotation speed of an impeller. And
Rotation commands for rotating the impeller at a reference rotational speed capable of generating a reference flow velocity of the blown gas predetermined in the cross wind stability test for the odd-numbered or even-numbered air blowing means counted from one of the parallel directions , respectively. As well as
A rotation change command for alternately changing the rotation speed of the impeller to a rotation speed larger than the reference rotation speed and a rotation speed smaller than the reference rotation speed with respect to the remaining air blowing means. given Ete, a blowing method, characterized in that for blowing the blowing gas in a region extending in parallel direction by the blowing means.

According to the present invention, by giving a rotation command to each blowing means, each blowing means arranged in the parallel direction blows the blown gas. As a result, the test wind can be generated in a wide area extending in the parallel direction. In a state where the test wind generated, by providing rotational change instruction odd-numbered or even-numbered blower means counting from one of the parallel direction, the blade in the odd-numbered or even-numbered blower means counting from one of the parallel direction The number of revolutions of the car can be changed over time, and the difference in the number of revolutions between the impeller in the odd-numbered or even-numbered blower means and the impeller in the remaining blower means counted from one side in the parallel direction over time. It can be changed over time.

As the rotational speed of one impeller approaches the rotational speed of the other impeller, the period of the beat sound generated due to the rotation of the two impellers becomes longer. Moreover, the cycle of the roaring sound generated due to the rotation of the two impellers is shortened because the rotational speed of one impeller is away from the rotational speed of the other impellers. In the present invention, since the rotational speed difference between the two impellers can be changed with time, the beat sound period changes with time and a constant beat sound is generated continuously. Can be avoided.
Moreover, the rotational speed change width of the impeller can be increased by alternately changing the rotational speed of the impeller relative to the reference rotational speed. As a result, it is possible to increase the change in the period of the beat sound with the passage of time, and it is possible to more reliably avoid the continuous generation of the beat sound having a constant period. In addition, by changing the rotation speed relative to the reference rotation speed, it is possible to suppress variations in the speed of each blown gas necessary to perform the crosswind stability test, and to suppress deterioration in accuracy of the crosswind stability test. .
In addition, at a rotational speed that alternately changes over time, the blowing means that rotates the impeller at the reference rotational speed, and the rotational speed that is larger than the reference rotational speed and the rotational speed that is smaller than the reference rotational speed. Since the air blowing means for rotating the impeller are alternately arranged in the parallel direction, the air blown out by the former air blowing means and the latter air blowing means are mixed with each other, and the speed of the air blowing gas in the parallel direction It is possible to prevent the distribution from greatly varying with respect to the reference flow velocity.

According to the first aspect of the present invention, it is possible to avoid the occurrence of a constant periodic beat sound by changing the rotational speed difference between the two impellers over time. By preventing the occurrence of a beating sound with a constant period, it is possible to prevent the intensity of unpleasant noise sound pressure from changing periodically, and to reduce the influence of noise on the surrounding environment. Moreover, the discomfort felt by the operator performing the crosswind stability test can be reduced, and the working environment in which the crosswind stability test is performed can be improved.
In addition, by changing alternately the state where the rotational speed of the impeller is large and the state where the rotational speed of the impeller is small with respect to the reference rotational speed, the rotational speed variation range of the impeller can be increased. . As a result, it is possible to increase the change in the period of the beat sound with the passage of time, and to further reduce unpleasant noise. In addition, by changing the rotation speed relative to the reference rotation speed, it is possible to suppress variations in the speed of each blown gas necessary to perform the crosswind stability test, and to suppress deterioration in accuracy of the crosswind stability test. .
In addition, at a rotational speed that alternately changes over time, the blowing means that rotates the impeller at the reference rotational speed, and the rotational speed that is larger than the reference rotational speed and the rotational speed that is smaller than the reference rotational speed. The blown gas blown out by the blowing means that rotates the impeller is mixed with each other, and the velocity distribution of the blown gas in the parallel direction can be prevented from greatly varying with respect to the reference flow rate.

  According to the second aspect of the present invention, in the cross wind stability test, the rotation change command for the rotational speed of the impeller is given within a range in which the flow velocity of the blown gas can be generated within a predetermined allowable flow velocity range. As a result, unpleasant noise can be reduced, and variations in the flow velocity of each blown gas can be suppressed to prevent a decrease in accuracy of the crosswind stability test.

According to the third aspect of the present invention, by changing at least one of the amplitude and the period for changing the rotation speed of the impeller with the passage of time, the period of the beat sound with the passage of time is further increased. As non-uniformity, it is possible to more reliably avoid the continuous generation of a beat sound having a constant period.

According to the fourth aspect of the present invention, by continuously changing the magnitude of the rotational speed of the impeller as time elapses, the time change of the beat sound period becomes continuous and is given to the operator. Discomfort can be reduced.

According to the fifth aspect of the present invention, at least one of the amplitude, the period, and the phase for changing the rotational speed of the two impellers is made different for each impeller. As a result, even when the rotational speeds of the two impellers are changed with the passage of time, the rotational speed difference between the two impellers can be prevented from becoming constant with the passage of time. It is possible to more reliably avoid the continuous generation of a roaring sound.

According to the sixth aspect of the present invention, it is possible to avoid the continuous generation of a roaring sound with a constant period by changing the rotational speed difference between the two impellers over time. By preventing the generation of a beat sound having a constant period, it is possible to reduce unpleasant noise. As a result, the influence of noise on the surrounding environment can be reduced, and the discomfort felt by the operator performing the cross wind stability test can be reduced, and the work environment in which the cross wind stability test is performed can be improved.

  FIG. 1 is a cross-sectional plan view showing a part of the cross air blower 20 according to the first embodiment of the present invention. FIG. 2 is a side sectional view showing the cross air blower 20. FIG. 3 is a plan view showing the cross air blower 20. 1 is a view as seen from the section line II in FIG. 2, and FIG. 2 is a view as seen from the section line II-II in FIG.

  The crosswind fan 20 is a device for performing a crosswind stability test. As shown in FIG. 3, in the cross wind stability test, a test wind 26 corresponding to the cross wind is blown to the vehicle 25 traveling on the test road 24 by the cross wind blower 20. And it is a test which investigates driving | running | working behaviors, such as a lateral slip of the vehicle 25 resulting from the test wind sprayed. The test road 24 extends in a straight line along a predetermined vehicle traveling direction. The cross wind blower 20 blows the test wind that travels across the vehicle traveling direction onto the vehicle 25 traveling on the test road 24. The cross wind blower 20 is disposed in a direction orthogonal to the vehicle traveling direction. The crosswind stability test method is defined in the automotive standard (JASO Z108).

  The cross wind blower 20 includes a plurality of blowers 21. The plurality of blowers 21 are respectively arranged facing the test path 24 and are arranged in a line along a predetermined parallel direction X. The parallel direction X is a direction extending in parallel to the vehicle traveling direction. In this specification, the direction from the upstream in the vehicle travel direction to the downstream in the parallel direction X is referred to as a parallel direction one X1, and the direction from the downstream in the vehicle travel direction to the upstream in the parallel direction X is referred to as the other parallel direction X2. Therefore, the parallel direction one X1 and the vehicle traveling direction coincide. A direction that is orthogonal to the parallel direction X and extends horizontally is referred to as an orthogonal direction Y. The direction proceeding from the cross air blower 20 to the test path 24 is referred to as the orthogonal direction one Y1, and the direction opposite to the orthogonal direction one Y1 is referred to as the orthogonal direction other Y2. Accordingly, one of the orthogonal directions Y1 is a direction from the upstream to the downstream in the flow direction of the blown gas, and is the flow direction of the blown gas. A direction perpendicular to the parallel direction X and the orthogonal direction Y is referred to as a partition direction Z. In this embodiment, the partition direction is set to the vertical direction.

  In the present embodiment, the blower 21 is realized by an axial blower. Since each air blower 21 has the same configuration, only one air blower will be described, and description of the remaining air blowers will be omitted. As shown in FIGS. 1 and 2, each blower 21 has a blower 22 and a duct body 23. The air blowing means 22 is a means capable of blowing gas, and includes an impeller 30 serving as a moving blade, and a rotary drive 31 that rotationally drives the impeller 30 around the rotation axis L22. The rotation axis L22 is set for each of the air blowing means 22, extends in the orthogonal direction Y, and is arranged at intervals in the parallel direction X.

  The rotation drive unit 31 is realized by an electric motor, and more specifically, is realized by an AC electric motor that can steplessly change the rotation speed and is inverter-driven. By rotating the impeller 30 around the rotation axis L22 by the rotary drive 31, the blown gas in the other direction Y2 perpendicular to the impeller 30 is sucked toward the impeller 30, and the one in the orthogonal direction from the impeller 30. It is blown out to Y1. In this way, the air blowing means 22 can blow the blown gas in one direction Y1 in the orthogonal direction.

  The duct body 23 is formed in a cylindrical shape and serves as a casing body that houses the air blowing means 22. Moreover, the duct body 23 becomes a blower outlet formation body for blowing out the blowing gas blown by the blowing means 22. The duct body 23 is fixed to a predetermined installation body such as a floor surface. The duct body 23 is generally formed in a cylindrical shape, and includes a cylindrical portion 32, a connecting cylindrical portion 33, and a rectangular cylindrical portion 34. The duct body 23 is arranged in the order of the cylindrical portion 32, the connecting cylindrical portion 33, and the rectangular cylindrical portion 34 as it proceeds in the orthogonal direction one Y1.

  The cylindrical portion 32 is formed in a cylindrical shape in which both end portions 32 a and 32 b in the orthogonal direction are opened, and supports the blowing unit 22. The cylindrical portion 32 is formed in a cylindrical shape that is coaxial with the rotation axis L <b> 22 set in the blowing means 22. The diameter of the cylindrical portion 32 is formed to be slightly larger than the diameter of the impeller 30. The other end Y <b> 2 side 32 a in the orthogonal direction of the cylindrical portion 32 is open and formed, and forms a suction port 35 of the blower 21.

  The connecting cylinder portion 33 is formed in a cylindrical shape in which both end portions 33 a and 33 b in the orthogonal direction are opened, and connects the cylindrical portion 32 and the rectangular cylinder portion 34. The other end Y2 side end 33a in the orthogonal direction of the connecting cylinder part 33 is connected to the one end Y1 side 32b in the orthogonal direction of the cylindrical part 32, and the one end Yb side 33b in the orthogonal direction of the connecting cylinder part 33 is It continues to the other end Y2 side 34a in the orthogonal direction.

  The rectangular cylindrical portion 34 is formed in a cylindrical shape in which both ends 34 a and 34 b in the orthogonal direction are opened, and faces the test path 24. The rectangular cylindrical portion 34 is formed in a square frame shape by the four side walls 16, 17, 18, and 19. The rectangular tube portion 34 is formed coaxially with the central axis of the cylindrical portion 32. One end 34 b in the orthogonal direction of the rectangular cylinder 34 is formed to be open and form an outlet 36 of the blower 21.

  The four side walls 16 to 19 of the rectangular cylinder part 34 define the air outlet 36. Of the four wall surfaces 16 to 19, the pair of side walls 16 and 17 that are opposed to each other with an interval in the partition direction Z extend in the parallel direction X. Of these two side walls 16, 17, the side wall 16 disposed below is the lower wall 16, and the side wall 17 disposed above is the upper wall. The other pair of wall surfaces 18 and 19 facing each other with an interval in the parallel direction X extend in the partition direction Z. Of these two wall surfaces 18 and 19, the side wall 18 arranged in the parallel direction one X1 becomes the parallel direction one X1 side wall 18, and the side wall 19 arranged in the parallel direction other X2 becomes the parallel direction other X2 side wall 19.

  In this embodiment, as shown in FIG. 1, the opening dimension H2 of the rectangular cylinder part 34 in the parallel direction X is formed larger than the inner diameter dimension H1 of the cylindrical part 32 (H2> H1). As shown in FIG. 2, the opening dimension H3 in the partitioning direction of the rectangular cylinder part 34 is formed smaller than the inner diameter dimension H1 of the cylindrical part 32 (H3 <H1). Therefore, as shown in FIG. 1, in the connecting cylinder portion 33, the dimension in the parallel direction of the opening increases in diameter θ1 and the dimension in the partitioning direction of the opening decreases in diameter θ2 as it proceeds in the orthogonal direction Y1.

  In the duct body 23, an internal space 37 is formed so that gas can pass in the orthogonal direction Y from the suction port 35 formed in the cylindrical portion 32 to the blowout port 36 formed in the rectangular tube portion 34. The blower 21 can suck the gas outside the duct body from the suction port 35 and blow it out from the blowout port 36 by rotating the impeller 30 of the blower unit 22.

  By arranging the rectangular cylindrical portions 34 of the duct bodies 23 in the parallel direction X in a state where they are in contact with each other, the blown gas can be blown to a wide area in the parallel direction X. Specifically, the cross-wind blower 20 can blow the blown gas over the blow area 27 whose cross section perpendicular to the orthogonal direction Y is rectangular. The parallel direction dimension of the blower area 27 is a dimension obtained by multiplying the parallel direction dimension H2 of the rectangular cylindrical portion 34 by the number (n) of the blowers 21 (H2 × n). In addition, the partition direction dimension of the air blowing area 27 is the partition direction Z dimension of the partition direction dimension H3 of the rectangular tube portion 34. As described above, the air blowing region 27 has a rectangular cross-sectional shape perpendicular to the vertical elevation.

  In the present embodiment, the cross air blower 20 has five or more blowers 21. In this case, the cross-wind blower 20 can blow the blown gas in the orthogonal direction Y over the rectangular blow area 27 having a parallel dimension of approximately 15 m (= 3 × 5 m) or more and a partition dimension of approximately 2 m. it can. In this way, by blowing the blown gas over the blowing region 24 extending in a wide range in the parallel direction X, it is possible to blow a test wind simulating a cross wind to the traveling vehicle. Moreover, the number of the air blowers 21 which the cross wind blower 20 has may be two or more, and may be five or less and the number of five or more.

  Moreover, each air blower 21 has a wind direction changing means for changing the wind direction of the test wind. By the wind direction changing means, the cross wind blowing device 20 can blow the blown gas in a direction crossing the parallel direction X. The wind direction changing means includes a wind direction changing member 40 and an angular displacement driving device 41 for driving the wind direction changing member 40 to be angularly displaced. As shown in FIG. 2, the wind direction changing member 40 is arranged in one direction Y <b> 1 perpendicular to the duct body 23. In other words, the wind direction changing member 40 is disposed below the rectangular cylinder portion 34 in the duct body 23 in the flow direction of the blown gas.

  FIG. 4 is a front view showing a part of the wind direction changing member 40 and the angular displacement driving device 41. FIG. 5 is a plan view showing a part of the wind direction changing member 40. In FIG. 5, a state where each wind direction changing member 40 is arranged at the reference position is indicated by a solid line, and a state where each wind direction changing member 40 is angularly displaced from the reference position is indicated by a two-dot chain line.

  The wind direction changing means has a plurality of wind direction changing members 40. Each of the wind direction changing members 40 is formed in a rectangular plate shape, and is arranged with an interval in the parallel direction X. Each wind direction changing member 40 extends in the partition direction Z in the longitudinal direction, and extends between the lower wall 16 and the upper wall 17 of the duct body 23. The wind direction changing member 40 is supported by the duct body 23 so as to be angularly displaceable around a predetermined angular displacement axis L40. In the present embodiment, the angular displacement axis L40 passes through the other end Y2 in the orthogonal direction of the wind direction changing member 40.

  In the reference state in which each wind direction changing member 40 is located at a predetermined reference position, the width direction of the wind direction changing member 40 extends in parallel to the orthogonal direction Y. At the reference position, each wind direction changing member 40 is formed in a tapered shape in which the dimension in the thickness direction, in other words, the dimension in the parallel direction becomes smaller as it proceeds from the other Y2 end in the orthogonal direction to the one in the orthogonal direction Y1. In a state where each wind direction changing member 40 is displaced from the reference state by a predetermined inclination angle α around the angular displacement axis L40, the width direction of the wind direction changing member 40 is inclined at the inclination angle α with respect to the orthogonal direction Y. In the present embodiment, each wind direction changing member 40 is configured to be angularly displaceable about the angular displacement axis L40 within an angle range of ± 30 degrees from the reference state. As a result, the blown gas can be blown along any direction that intersects the parallel direction X.

  When the blown gas blown out from the duct body 23 collides with the wind direction changing member 40, it advances along the surface of the wind direction changing member 40. Therefore, in the reference state in which the wind direction changing member 40 is parallel to the orthogonal direction Y, the blown gas flows in the orthogonal direction Y. On the other hand, in a state where the wind direction changing member 40 is inclined with respect to the orthogonal direction Y, the blown gas flows while being inclined with respect to the orthogonal direction Y. In this way, the wind direction changing member 40 guides the blown gas.

  In this embodiment, each wind direction change member 40 is each connected by the parallel link mechanism. The parallel link mechanism includes a plurality of first link members 42 that individually connect the wind direction changing members 40 and a second link member 43 that connects the first link members 42 so as to be angularly displaceable. . The first link member 42 is configured to be rotatable around the angular displacement axis L40. By displacing the second link member 43, each wind direction changing member 40 together with the first link member 42 is angularly displaced about the angular displacement axis L40.

  The angular displacement drive unit 41 angularly drives the second link member 43 around a parallel axis L43 parallel to the angular displacement axis L40, whereby each wind direction changing member 40 is angularly displaced in conjunction with each other. In the present embodiment, the angular displacement drive machine 41 is realized by an electric motor, and the output shaft of the motor and the second link member 43 are connected via a connecting rod 44.

  By angularly driving the output shaft of the motor of the angular displacement driving device 41, each wind direction changing member 40 can be angularly driven around the corresponding angular displacement axis L40. The blower 21 includes an angle sensor that detects an angular displacement amount with respect to the reference position of the wind direction changing member 40. In the present embodiment, the angle sensor is realized by an encoder that detects the amount of rotation of the output shaft of the angular displacement driver 41.

  FIG. 6 is a block diagram showing an electrical configuration of the cross air blower 20. As described above, each blower 21 includes the rotation drive 31, the inverter circuit 45 for driving the rotation drive 31, the angular displacement drive 41, and the angle sensor 46 that detects the angular position of the wind direction changing member 40. Respectively. In addition to the plurality of blowers 21, the cross wind blower 20 includes a control unit 47 that individually gives a control command to each blower 21.

  The control means 47 has an input unit to which a command from the worker is input, and a rotation command is input from the worker through the input unit. When the rotation command is input, the control unit 47 gives the rotation command including the set rotation number to the inverter circuit 45 of each blower 21. In response to the rotation command given from the control means 47, the inverter circuit 45 gives a drive current corresponding to the set rotation speed to the rotary drive machine 31. The rotary drive machine 31 rotates the impeller 30 at a set rotation speed when a drive current is applied from the inverter circuit 45. The cross-wind blower 20 can set the set rotational speed steplessly by rotating the rotary drive 31 by the inverter circuit 45.

  The angle sensor 46 provides angle information indicating the angle position of the wind direction changing member 40 to the control means 47. The control means 47 gives a drive command to the angular displacement drive machine 41 based on the angle information given from the angle sensor 46. The angular displacement drive machine 41 can change the wind direction of the blown gas blown from each blower 21 by driving each wind direction changing member 40 in an angular displacement manner in response to a drive command given from the control means 47. it can.

  The control means 47 is realized by a computer. The control means 47 includes a storage unit, an arithmetic processing unit, an input unit, and an output unit. The storage unit stores a predetermined operation program. The input unit gives information given from the operator, the inverter circuit 45 and the angle sensor 46 to the arithmetic processing unit. The arithmetic processing unit reads an operation program stored in the storage unit, outputs an operation result based on information provided from the input unit according to the read operation program, and provides the output result to the output unit. The output unit gives the output result given from the arithmetic processing unit to the inverter circuit 45 and the angular displacement driver 41 as a control command. For example, the storage unit includes a storage circuit such as a RAM and a ROM, and the arithmetic processing unit includes a processing circuit such as a CPU. The input unit and the output unit are composed of input / output interfaces.

FIG. 7 is a diagram for explaining the beat sound generated by the two blowers in the present embodiment. FIG. 7A is a graph showing the rotational speeds of the impellers of the first blower and the second blower. FIG. 7 (2) is a graph showing the temporal change of the noise sound pressure generated in the first blower. FIG. 7 (3) is a graph showing the time change of the noise sound pressure generated in the second blower. FIG. 7 (4) is a graph showing the time change of the synthesized noise sound pressure obtained by superimposing two noises generated by the first blower and the second blower. The frequency f1 of the noise sound pressure of the first blower is set constant. On the other hand, the noise sound pressure frequencies f2 ₁ , f2 ₂ , and f2 ₃ of the second blower slightly change with time. In FIG. 7 (3), the frequency of the noise and sound pressure of the second blower appears constant because the change is minute, but actually changes slightly with the passage of time.

  Each blower 21 generates noise having frequencies f1 and f2 proportional to the rotational speeds R1 and R2 of the impeller. Specifically, the noise frequencies f1 and f2 are multiplication values (α × β) obtained by multiplying the number α of blades formed on the impeller by the number of rotations β per second of the impeller. Generally, the noise of the blower is dominated by the amplitude of the frequency (α × β × n) obtained by multiplying the multiplication value (α × β) by n. Here, n is a positive integer. Among the frequencies (α × β × n) obtained by multiplying the multiplication value (α × β) by n, noise having a primary frequency where n = 1 is dominant.

  In this embodiment, ten blades are formed on the impeller. In this case, when the rotational speed, which is the rotational speed per minute that the impeller is rotationally driven, is 730 rpm (revolution per minute), the noise frequency is about 121 Hz (= (730/60). × 10). When the rotational speed R of the impeller is constant regardless of the time change, the frequency f of the noise generated by the blower is also constant regardless of the time change. Hereinafter, the rotation speed means the number of rotations per minute of the impeller, and is a value proportional to the rotation speed of the impeller.

  The control means 47 can individually control each blower 21 by giving a rotation command to the inverter circuit 45 for each blower 21 individually. Moreover, the control means 47 can give the rotation speed change command which changes rotation speed with progress of time. The inverter circuit 45 to which the rotational speed change command is given sequentially changes the rotational speed of the corresponding impeller as time passes.

  The control means 37 determines the difference | R2-R1 | between the rotation speed R1 of the impeller of the first blower and the rotation speed R2 of the impeller of the second blower as time elapses. Change. In other words, a rotational speed change command for sequentially changing the rotational speed of the impeller of the second blower with the passage of time with respect to the rotational speed of the impeller of the first blower is given to the inverter circuit of the second blower. . The second blower is at least one blower among the plurality of blowers. The first blower is at least one blower among the remaining blowers except the second blower.

  The control means 47 sets the rotation speed R1 of the impeller of the first blower as the reference rotation speed R0. Here, the reference rotational speed R0 is the rotational speed of the impeller capable of generating a predetermined reference flow velocity of the blown gas in the cross wind stability test.

  As an example, in the present embodiment, the reference flow velocity that is the wind speed of the blown gas blown from the blower outlet 36 is defined as 20 m / s. In this case, the reference rotation speed R0 is 730 rpm. By rotating the impeller at the reference rotation speed R0 of 730 rpm, the flow rate of the blown gas blown from the blowout port 36 can be set to 20 m / s, which is the reference flow rate. However, the reference flow velocity and the reference rotation speed R0 may be other than the values described above.

  The control means 47 maintains the rotational speed R1 of the impeller of the first blower so as to be a constant reference rotational speed R0 regardless of the passage of time. Therefore, as shown in FIG. 7 (2), the frequency f1 and the period (1 / f1) of the noise sound pressure generated in the impeller of the first blower are constant regardless of the passage of time.

  Moreover, the control means 47 changes sequentially the rotation speed R2 of the impeller of a 2nd air blower with time progress. Therefore, as shown in FIG. 7 (3), the frequency f2 and period (1 / f2) of the noise sound pressure generated in the impeller of the second blower change with time.

  In the present embodiment, in the cross wind stability test, the rotational speed R2 of the impeller of the second blower is changed in a fluctuation range within the rotational speed range in which the flow speed of the blown gas can be maintained within a predetermined allowable flow speed range. . In other words, the control means 47 sequentially changes the rotation speed of the impeller of the second blower within the fluctuation range between the upper limit rotation speed R3 and the lower limit rotation speed R4 with the passage of time. Here, the upper limit rotational speed R3 is the rotational speed of the impeller that is as large as possible than the reference rotational speed R0 within a range that does not affect the wind speed. The lower limit rotational speed R4 is the rotational speed of the impeller that is as small as possible than the reference rotational speed R0 within a range that does not affect the wind speed. The control means 47 should just change the rotation speed of the impeller of a 2nd air blower between upper limit rotation speed R3 and lower limit rotation speed R4 mentioned above. Therefore, the fluctuation range of the rotation speed of the impeller of the second blower may be narrower than the width between the upper limit rotation speed R3 and the lower limit rotation speed R4.

  In the present embodiment, the control means 47 sets the rotation speed R2 of the impeller of the second blower to the rotation speed R5 that is larger than the reference rotation speed R0 and the rotation speed R6 that is smaller than the reference rotation speed R0. It changes alternately with progress. Moreover, the control means 47 changes the rotation speed R2 of the impeller of a 2nd air blower at random along time passage. In other words, the rotational speed R2 of the impeller of the second blower is changed up and down aperiodically with time. Moreover, the control means 47 makes the change amount per unit time small regarding the rotation speed R2 of the impeller of a 2nd air blower, and makes it change smoothly with progress of time.

  In this way, the control means 47 slightly changes the rotational speed R2 of the impeller of the second blower with the passage of time. Therefore, the rotational speed difference | R2-R1 | of the impellers of the two blowers can be slightly changed with time. As described above, the frequencies f1 and f2 of noise generated from the impeller are proportional to the rotational speeds R1 and R2 of the impeller. Therefore, in the present embodiment, the deviations | f2-f1 | of the frequencies f1 and f2 of noise generated by the two blowers are proportional to the deviations | R2-R1 | of the rotational speeds R1 and R2 of the impellers of the two blowers. Thus, it can be changed over time.

  When the rotational speed difference between the first blower and the second blower is small, the combined noise including the noise generated by each impeller includes a beat sound. The beat sound has a period related to the deviation | f2-f1 | of the frequencies f1 and f2 of the noises of the two impellers. The period of the beat sound is the reciprocal (1 / (| f2-f1 |)) of the deviation | f2-f1 | of the noise frequencies f1 and f2 of the two impellers. In the present embodiment, the deviation | f2-f1 | of the frequencies f1 and f2 changes with time. Therefore, as shown in FIG. 7 (4), the period of the beat sound (1 / Δf1, 1 / Δf2, 1 / Δf3) ) Also changes over time.

  Specifically, the rotation speed R2 of the impeller of the second blower approaches the rotation speed R1 of the impeller of the first blower, so that the period of the beat sound generated due to the rotation of the two impellers is long. Become. Further, the rotational speed R2 of the impeller of the second blower is away from the rotational speed R1 of the impeller of the first blower, so that the period of the beat sound generated due to the rotation of the two impellers is shortened. In the present embodiment, the period (1 / Δf1 to 1 / Δf3) of the beat sound included in the synthesized noise is elapsed by changing the rotational speed difference | R2-R1 | of the two impellers with the passage of time. As a result, it can be changed aperiodically. As a result, it is possible to avoid the continuous generation of a beat sound having a constant period as shown in FIG.

  FIG. 8 is a flowchart showing the control operation of the blower of the control means 47. First, the plurality of blowers 21 and the control unit 47 are electrically connected, and the control unit 47 prepares a state in which all the blowers 21 can be controlled. Next, when the control means 47 is operated by the worker and an activation command is given, the process proceeds to step s1, and the control means 47 starts the control operation of the blower.

  In step s1, the control means 47 gives a rotation command to the inverter circuit 45 of each air blower 21 in order at intervals. The control means 47 gives a rotation command to the inverter circuit 45 so as to rotate at the reference rotation speed R0. The inverter circuit 45 to which the rotation start command is given sends a current to the corresponding rotary drive 31 to rotate the impeller at the reference rotation speed R0 and maintain the rotation state. When the control means 47 gives a rotation command to each inverter circuit 45, the process proceeds to step s2.

  In step s2, it is determined whether or not a beat noise reduction command has been input in advance. The beat noise reduction command is input from the input unit by an operator or the like before or during the blower control. When the roaring sound reduction command is input, the control unit 47 stores the input of the roaring sound reduction command in the storage unit. If the control means 47 reads the information memorize | stored in a memory | storage part and judges that the roaring sound reduction command is input, it will progress to step s3. If it is determined that no beat noise reduction command is input, the process proceeds to step s4.

  In step s3, the control means 47 gives a rotation speed change command to the corresponding blower 21 among the plurality of blowers 21 as described above. The rotation change command is a command for sequentially changing the rotation speed of at least one impeller as time passes. For example, a rotation change command is given to the inverter circuit 45 of the even-numbered blower 21 counted from one side in the parallel direction. In this case, the odd-numbered blowers 21 counted from one side in the parallel direction are the first blowers described above, and the even-numbered blowers 21 counted from the one side in the parallel direction are the second blowers described above.

  The control means 47 gives the rotation change command which changes the rotation speed of an impeller for every unit time with respect to the air blower 21 which should give a command. In the present embodiment, the control means 47 is a rotation change command for randomly changing the change in the rotational speed with respect to time so that the temporal change in the rotational speed of the impeller fluctuates aperiodically with respect to the reference rotational speed R0. Is supplied to the corresponding inverter circuit 45.

  The inverter circuit 45 to which the rotation change command is given sends a current to the corresponding rotary drive 31 to rotate the impeller 30 at the rotation speed commanded every time. In this way, the control circuit 47 gives a command to change the rotation speed every predetermined unit time, whereby the inverter circuit 45 changes the rotation speed of the impeller every predetermined unit time. When the control means 47 starts transmitting a rotation change command to the corresponding blower 21, the process proceeds to step s4.

  In step s4, the control means 47 determines whether or not an end command is given. The termination command is given from the input unit by an operator or the like. If it is determined that the end command is not given, the process returns to step s2, and steps s2 to s4 are repeated. While step s2 to step s4 are repeated, the vehicle 25 is caused to travel on the test road 24, and the cross wind stability test is performed.

  If an end command is given in step s4, the process proceeds to step s5. In step s5, the control means 47 ends the blower control operation.

  As described above, according to the present embodiment, the fans arranged in the parallel direction X blow the blown gas. As a result, it is possible to generate a test wind that passes through a wide area extending in the parallel direction X. In the state where the test wind is generated, the control means 47 changes the rotational speed difference | R2-R1 | of each impeller between the first blower and the second blower to change with time as shown in FIG. Change with it. In other words, minute rotation speed fluctuations that do not affect the wind speed are given randomly or periodically. As a result, as shown in FIG. 7 (4), the period (1 / (| f2-f1 |) of the beat sound generated by the two blowers can be changed non-periodically with the passage of time. It is possible to avoid the humming sound being continuously generated.

  By preventing the generation of a beating sound having a constant period in this way, it is possible to prevent the intensity of unpleasant noise sound pressure from changing periodically, and to reduce the influence of noise on the surrounding environment. Moreover, the discomfort felt by the operator performing the crosswind stability test can be reduced, and the working environment in which the crosswind stability test is performed can be improved.

  Moreover, in this embodiment, the flow rate fluctuation | variation with the ventilation gas which blows with a 1st air blower and the ventilation air which blows with a 2nd air blower is changed by changing the rotation speed R2 of a 2nd air blower within the fluctuation range which does not affect a wind speed. Can be suppressed. In many cases, the crosswind that is actually blown to the traveling vehicle has a uniform velocity distribution in the parallel direction X that is the vehicle traveling direction. In the present embodiment, as described above, the variation in the flow velocity of each blown gas in the parallel direction X can be suppressed, so that the test wind can be brought closer to the crosswind that will be blown to the actually traveling vehicle. And the stability test can be performed with high accuracy.

  Further, in the present embodiment, the rotation speed R2 of the second blower is changed without greatly deviating from the reference rotation speed R0 by changing the rotation speed to the reference rotation speed R0 (R0 ± ΔR). The width (2 × ΔR) can be increased. By increasing the fluctuation range of the rotational speed in this way, it is possible to increase the change in the period of the roaring sound with the passage of time, and more reliably avoid the continuous generation of the roaring sound with a constant period. be able to. In addition, by preventing a significant deviation from the reference rotational speed R0, it is possible to suppress variations in the speed of each blown gas necessary for performing the crosswind stability test, and to suppress a decrease in accuracy of the crosswind stability test.

  Further, in the present embodiment, by setting the rotation speed R1 of the first blower to the reference rotation speed R0 regardless of the passage of time, the flow velocity of the test wind blown from the cross wind blower 20 is determined in the cross wind stability test. Therefore, it is possible to prevent a large deviation from a predetermined reference flow velocity, and a crosswind stability test can be accurately performed.

  Further, the odd-numbered blowers 21 counted from one side in the parallel direction are set as the first blowers, and the even-numbered blowers 21 counted from the one side in the parallel direction are set as the second blowers. As a result, the blown gases blown out by the first blower and the second blower are mixed with each other, and the velocity distribution of the blown gases in the parallel direction X can be prevented from greatly varying with respect to the reference flow velocity.

  Here, the same effect can be obtained by using the odd numbered blower 21 counted from one side in the parallel direction as the second blower and the even numbered blower 21 counted from the parallel direction as the first blower. In addition, a first state in which the odd-numbered blower 21 is the first blower and the even-numbered blower is the second blower, and the odd-numbered blower 21 is the second blower and the even-numbered blower is the first blower. The state may be switched alternately every predetermined time.

  Moreover, in this embodiment, the change of the rotation speed with respect to time is changed aperiodically so that the time change of the rotation speed R2 of the impeller of the second blower becomes a random change. In this way, by changing the rotation speed difference | R2−R1 | between the two blowers at random, it is possible to enhance the effect of reducing the beat noise obtained by superimposing the noises of the first blower and the second blower. Moreover, the magnitude | size of the rotation speed of the impeller of a 2nd air blower is changed continuously with progress of time. As a result, the change in the period of the beat sound with the lapse of time can be made continuous, and the discomfort given to the operator can be reduced. Moreover, in this embodiment, the rotational drive machine 31 is implement | achieved by the alternating current electric motor by which inverter drive control is carried out. Thus, by arbitrarily changing the frequency of the current applied to the rotary drive 31, the rotation speed of the impeller can be easily variable continuously. Further, the rotation speed of the second blower can be changed with a slight fluctuation range with respect to the reference rotation speed R0, and the beat sound is prevented from becoming periodic, thereby preventing the deviation of the flow velocity distribution in the parallel direction. it can.

  Further, in the present embodiment, it is determined in step s2 in the blower control operation whether a roaring sound reduction command is input. This makes it possible for the operator to select a noise reduction priority mode that prevents the beat sound from becoming constant, and a uniform flow velocity distribution priority mode that matches the rotation speed setting command values of all the fans. Can be improved. Further, in step s1, by supplying a rotation command to each blower in order at intervals of time, it is possible to suppress power required at the start-up as compared with the case where a rotation command is simultaneously given.

  FIG. 9 is a graph showing changes over time in the rotational speed of each blower according to the second embodiment of the present invention. In 1st Embodiment mentioned above, the change of the rotation speed with respect to time was changed aperiodically so that the time change of the rotation speed of the impeller 30 of a 2nd air blower might become a random change. The present invention is not limited to this, and the number of revolutions of at least one impeller may be changed with time.

  In 2nd Embodiment of this invention, the magnitude | size of the rotation speed of the impeller of a 2nd air blower is changed periodically with progress of time. In the present embodiment, the change in the rotational speed with respect to time is periodically changed so that the temporal change in the rotational speed R2 of the impeller of the second blower becomes a sine wave change. Thus, even if it is a case where the magnitude | size of the rotation speed of the impeller of a 2nd air blower is changed periodically, the effect similar to 1st Embodiment can be acquired. Moreover, in 2nd Embodiment, the structure except changing the rotation speed of the impeller of a 2nd air blower periodically is the same as that of 1st Embodiment.

  FIG. 10 is a graph showing the change over time in the rotational speed of each blower according to the third embodiment of the present invention. In 3rd Embodiment of this invention, the period T1, T2, T3, T4 which changes the magnitude | size of the rotation speed of the impeller of a 2nd air blower is changed with progress of time. For example, a waveform that gradually increases the period of changing the magnitude of the rotational speed R2 of the impeller of the second blower with time and a waveform that gradually decreases the period are sequentially repeated. Further, the cycle for changing the magnitude of the rotational speed may be changed periodically according to a predetermined rule, or may be changed randomly. In 3rd Embodiment of this invention, the structure except changing the period of the rotation speed of the impeller of a 2nd air blower temporally is the same as that of 1st Embodiment.

  In this way, by changing the period of changing the rotation speed of the impeller of the second blower with the passage of time, the period of beat sound with the passage of time is further made non-uniform, and the period is constant. It is possible to more reliably avoid the continuous generation of a roaring sound. In the present embodiment, the amplitude A that changes the magnitude of the rotational speed is the same as in the first embodiment. As a result, the rotation speed R2 of the impeller of the second blower can be prevented from greatly fluctuating with respect to the reference rotation speed R0.

  FIG. 11 is a graph showing temporal changes in the rotational speed of each blower according to the fourth embodiment of the present invention. In 4th Embodiment, the amplitude which changes the magnitude | size of the rotation speed of the impeller of a 2nd air blower is changed with progress of time. For example, the amplitude which changes the magnitude | size of rotation speed R2 of the impeller of a 2nd air blower is changed at random with time progress. Further, the amplitude for changing the magnitude of the rotational speed may be periodically changed according to a predetermined rule. In 4th Embodiment of this invention, the structure except changing the amplitude A of the rotation speed of the impeller of a 2nd air blower temporally is the same as that of 1st Embodiment.

  In this way, by changing the amplitude for changing the rotation speed of the impeller of the second blower with the passage of time, the period of the beat sound with the passage of time is further made non-uniform, and the cycle is constant. It is possible to more reliably avoid the continuous generation of a roaring sound.

  Further, in combination with the third embodiment and the fourth embodiment, the period and the amplitude for changing the rotation speed of the impeller of the second blower are changed randomly or according to a predetermined rule as time passes. Also good. As a result, the period of the beat sound with the passage of time can be made more non-uniform, and it is possible to more reliably avoid the generation of a beat sound having a constant period.

  FIG. 12 is a graph showing changes over time in the rotational speed of each blower according to the fifth embodiment of the present invention. In 4th Embodiment, the amplitude and period which change the magnitude | size of the rotation speed of the impeller of a 1st air blower and a 2nd air blower are changed with progress of time. Moreover, the amplitude and period which change the magnitude | size of the rotation speed of the impeller of a 1st air blower and a 2nd air blower are each mutually different. Accordingly, the rotational speed of the impeller of the second blower is sequentially changed with time with respect to the rotational speed of the first impeller.

  In the present embodiment, the rotational speed of the first blower is also changed with time. Thus, while changing the magnitude | size of the rotation speed of two air blowers with time passage, and making at least one of those amplitudes and periods differ, the rotation speed difference of two air blowers is accompanied with time passage. It can be changed and it can be avoided that the period of the beat sound becomes constant.

  Moreover, you may change the phase of two rotation speed changes other than the amplitude and period in the rotation speed change of two air blowers. Therefore, at least one of the amplitude, the period, and the phase for changing the magnitude of the rotational speed of the two impellers may be different for each impeller. Further, by making all the amplitude, period and phase for changing the rotational speed of the two impellers different from each other, it is possible to more reliably avoid the beat sound period from becoming constant.

  Further, it is possible to more reliably avoid the beat sound period from becoming constant by changing at least one of the rotation speed period, the amplitude, and the phase with the passage of time for at least one of the two blowers. it can. That is, the second and third embodiments may be combined with the fourth embodiment. For example, when dividing a fan into n groups and changing the phase with a constant period, the synthesized noise and sound pressure is lowered by changing the rotation speed for each group by shifting the phase by 360 / n. be able to.

  Each embodiment mentioned above is only illustration of this invention, and can change a structure within the scope of the invention. For example, in the present embodiment, the change in the rotational speed of the blower over time is a sinusoidal waveform, but this is not a limitation. For example, the rotational speed change of the blower may be a triangular wave shape or a rectangular wave shape, or the rotational speed may be changed in a pulse shape. In the first to third embodiments, the even-numbered blower is counted as the second blower from one side in the parallel direction, but at least one of the multiple blowers may be the second blower. Also in the fourth embodiment, the first blower and the second blower may be any of a plurality of blowers.

  In the fourth embodiment, the plurality of fans are classified into two groups of fans having different rotational speed changes, but may be classified into two or more groups of fans having different rotational speed changes. Moreover, you may vary the amplitude, the period, and the phase which change the rotation speed magnitude | size of each impeller about all the air blowers.

  In the present embodiment, the rotational speed of the impeller is changed with the passage of time. However, the same effect can be obtained even when the rotational speed of the impeller is changed with the passage of time. Moreover, in this embodiment, you may change the rotation speed of a 1st or 2nd air blower up and down with progress on the basis of rotation speeds other than reference | standard rotation speed R0. In the present embodiment, the control means 47 gives the rotation change command, but the present invention is not limited to this. For example, the inverter circuit may have a program indicating the rotation speed change command in advance. In this case, when a rotation command is given from the control means 47, the inverter circuit may generate a current so as to change the rotation speed by executing a program.

  In addition, it is preferable that the operator can adjust at least one of the amplitude, the period, and the phase that change the rotational speed. The operator adjusts at least one of the amplitude, the period, and the phase, and determines the amplitude, the period, and the phase of the rotation speed of each blower as an initial setting. By storing the value in the control unit 47 and changing the rotation speed with the stored initial setting value, it is possible to realize a cross wind blower with as little noise as possible and with little speed fluctuation.

  Further, the above-described method for blowing the cross wind fan is also included in the present invention. Specifically, a rotation command for rotating the impeller is given to each of a plurality of air blowing units that can change the rotation speed of the impeller in a predetermined parallel direction, and the rotation speed of at least one impeller is set to the time. A rotation change command to be changed with progress is given to the corresponding blowing means, and the blowing gas is blown to the region extending in the parallel direction by each blowing means to blow the blowing gas used for the crosswind stability test of the vehicle. This is also included in the present invention.

It is a plane sectional view showing a part of cross wind blower 20 which is a 1st embodiment of the present invention. It is side surface sectional drawing which shows the crosswind air blower. It is a top view which shows the cross wind fan. 3 is a front view showing a part of a wind direction changing member 40 and an angular displacement driving device 41. FIG. 4 is a plan view showing a part of a wind direction changing member 40. FIG. 3 is a block diagram showing an electrical configuration of the cross air blower 20. FIG. It is a figure for demonstrating the beat sound which arises with two air blowers in this embodiment. 7 is a flowchart showing a blower control operation of the control means 47. It is a graph which shows the time change of the rotation speed of each air blower of 2nd Embodiment of this invention. It is a graph which shows the time change of the rotation speed of each air blower of 3rd Embodiment of this invention. It is a graph which shows the time change of the rotation speed of each air blower of 4th Embodiment of this invention. It is a graph which shows the time change of the rotation speed of each air blower of 5th Embodiment of this invention. It is sectional drawing which shows a part of cross wind blower 1 of a prior art. It is a figure for demonstrating the beat sound produced by two air blowers.

Explanation of symbols

20 Cross-wind blower 21 Blower 22 Blower means 30 Impeller 47 Control means R0 Reference rotational speed R1 Rotational speed of impeller of first blower R2 Rotational speed of impeller of second blower f1 Noise of first blower f2 Noise of second blower noise

Claims (6)

A cross wind blower used for a cross wind stability test of a vehicle,
An impeller for blowing the blown gas, rotationally driving the impeller so that the number of rotations can be changed, and at least three or more blowing means arranged in a predetermined parallel direction;
Control means capable of individually controlling each air blowing means,
Rotation command so that the impeller rotates at a reference rotation speed capable of generating a reference flow velocity of the blown gas predetermined in the crosswind stability test with respect to the odd-numbered or even-numbered blowing means counted from one of the parallel directions give,
A rotation change command for alternately changing the rotation speed of the impeller to a rotation speed larger than the reference rotation speed and a rotation speed smaller than the reference rotation speed with respect to the remaining air blowing means. And a control means for controlling the rotational speed of the impeller of each air blowing means. The control means gives a rotational change command of the rotational speed of the impeller to the remaining blower means within a rotational speed range in which the flow speed of the blown gas can be generated within an allowable flow speed range predetermined in the cross wind stability test. The cross wind fan according to claim 1, wherein The control means provides the remaining blowing means with a rotation change command for changing at least one of an amplitude and a period for changing the rotational speed of the impeller of the remaining blowing means as time elapses. The cross-wind blower according to claim 1 or 2 , characterized by the above. 2. The control device according to claim 1 , wherein a rotation change command for continuously changing the magnitude of the rotational speed of the impeller of the remaining air blowing device as time elapses is given to the remaining air blowing device. The cross wind blower according to any one of to 3 . The remaining air blowing means includes a plurality of air blowing means,
Control means, wherein, characterized in that providing the rotational speed of the size of the blades vehicles amplitude varying, periodic and phase of at least one, the rotation change command varied for each impeller, the remainder of the blowing means Item 5. The cross-wind blower according to any one of Items 1 to 4 . Lined in a predetermined parallel direction, using at least three or more blowing means capable of changing the rotation speed of the impeller, a blowing method for blowing the blowing gas used in the crosswind stability test of the vehicle,
Rotation commands for rotating the impeller at a reference rotational speed capable of generating a reference flow velocity of the blown gas predetermined in the cross wind stability test for the odd-numbered or even-numbered air blowing means counted from one of the parallel directions , respectively. As well as
A rotation change command for alternately changing the rotation speed of the impeller to a rotation speed larger than the reference rotation speed and a rotation speed smaller than the reference rotation speed with respect to the remaining air blowing means. given Ete, blowing method which comprises causing blown the blowing gas in a region extending in parallel direction by the blowing means.

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