JP4135954B2 - Magnetically supported balance device for automobiles - Google Patents

Description

  The present invention relates to a technique for applying a technique for magnetically supporting a wind tunnel test model in a wind tunnel measurement section to a wheel portion of a ground transportation device using wheels by utilizing the magnetic flux restraint property of a superconducting material.

  In wind tunnel tests for automobiles and railway vehicles, a device called a moving ground plate is attached to the measurement unit floor to create the relative speed between the moving body and the ground, and it is moved at the same speed as the wind tunnel air velocity. . For this reason, the moving body model cannot be placed on the ground plate, and the model is supported in the wind tunnel measuring unit by the support (or wire) as shown in FIG. 3 (Non-Patent Document 1). It is known that when the vehicle body is supported by such a support device, interference between the support structure and the wind tunnel airflow is induced, so that the flow during actual traveling cannot be correctly simulated. In addition, since the wheel is driven while being supported by the shaft from the side of the measurement unit, large interference is induced between the shaft and the wind tunnel air flow, and high-precision measurement cannot be performed. For this reason, a method of supporting a model with a magnetic support balance device developed in the aviation field that does not use these members that cause interference has been proposed.

  The one shown in FIG. 4 (Patent Document 1) was developed and presented by the present inventors, and the magnetic support balance device 20 is a device that supports the wind tunnel model 1 in the air current by magnetic force, and supports interference. A wind tunnel test without any noise can be realized. The wind tunnel model 1 is equipped with a strong magnet body made of a magnetized material, a coil that continues to pass a current such as a superconducting coil, or a permanent magnet. The magnetic body of the wind tunnel model 1 receives a magnetic force due to a mutual magnetic action with an external magnetic field generated by energizing the coils 23 to 32 arranged around the measurement unit of the wind tunnel, and the wind tunnel model 1 is magnetically levitated. Can be supported. The external magnetic field is composed of two magnetic circuits 21 and 22 each having a predetermined distance in the axial direction of the wind tunnel including coils 23 to 26 and coils 27 to 30 as magnetic support coils, and the two magnetic circuits arranged outside the two magnetic circuits 21 and 22. It is generated by air-core coils 31 and 32 which are also perpendicular to the circuits 21 and 22 and are also magnetic support coils. When the airflow direction in the wind tunnel is taken as the x-axis, the vertical direction in which gravity acts is the z-axis, and the y-axis is taken in the direction perpendicular to the x-axis and z-axis, the magnetic circuit 21 generates a z-axis direction magnetic field 1 A pair of coils 23 and 25 and a pair of coils 24 and 26 for generating a magnetic field in the y-axis direction, and a magnetic circuit 22 generates a magnetic field in the Y direction with a pair of coils 27 and 29 for generating a Z-direction magnetic field. It comprises a pair of coils 28 and 30 to be generated. By adjusting the current flowing in each coil of the magnetic circuits 21 and 22, the strength and direction of the magnetic field in the yz plane in the magnetic circuits 21 and 22 and the rate of change in the x-axis direction are continuously changed. Can be made. In addition, by adjusting the current flowing through the air-core coils 31 and 32, the rate of change of the strength of the magnetic field in the x-axis direction as viewed in the x-axis direction can be controlled, so that 5-axis control is possible. That is, the coils 23 to 30 of the magnetic circuits 21 and 22 function as a lift coil that applies a magnetic force that opposes the lift and pitching moment acting on the wind tunnel model 1, and the air-core coils 31 and 32 are provided on the wind tunnel model 1. It functions as a drag-resistance coil that provides a magnetic force against the working drag. If this method is applied to a large model automobile, the required magnetic support balance device will be large-scale, and the model will also need a dedicated one to make the outer shape with a non-magnetic material, making the production cost enormous. It is difficult. In particular, in an actual vehicle wind tunnel test that is strongly requested by the automobile industry, since the actual vehicle is made of steel, it is difficult to apply a normal magnetic support balance device for an aircraft model.

By the way, many magnetic support devices for transportation equipment such as vehicles using the magnetic flux restraining property of superconducting materials have been proposed. The present inventors conceived that this vehicle magnetic levitation technology is applied to a magnetic support device for an actual vehicle wind tunnel test, and started research. In the prior art, all of the superconducting materials are mounted on the transportation equipment body, and the magnetic levitation mechanism of these vehicles mounts the superconducting material on the moving body corresponding to the vehicle body, and the permanent magnet of the magnetic flux generating source is installed on the track part. Is to be placed. This was a natural approach taken to minimize the portion of superconducting material that had to be kept at very low temperatures. However, in wind tunnel testing of ground transportation equipment such as automobiles, the wind tunnel test model is not in contact with the moving ground plate and needs to be separated from the floor surface due to the peculiarity of measuring aerodynamic resistance. . Also, in the case of a small model, it is difficult to attach a superconducting material together with a cooling device that maintains a cryogenic state in the internal space of a test specimen of a limited size. From the standpoint of supporting the magnetic force, it is advantageous to attach the cryogenic superconducting material inside the wheel closest to the moving ground plate, but it is more difficult in terms of work than placing it inside the vehicle body. On the other hand, in a wind tunnel test of a vehicle such as an automobile, since the automobile does not move inside the wind tunnel, there is an advantage that there is no advantage in whether the cryogenic superconducting material is attached to the automobile or the track.
JP, 2005-249614, A "Load reducing device and model used for it" Published on September 15, 2005 British technical magazine “RACETECH” August / September 2003 No.49 56 Published by RACETECH

  An object of the present invention is to provide a member that affects the air current such as a wire or a column that supports a test object in a wind tunnel test of an automobile or a railway vehicle under the special circumstances of a wind tunnel test of a ground transportation device such as an automobile. Providing a method and apparatus capable of supporting magnetic force without being placed in the measuring section, and further proposing a magnetic levitation device that can support magnetic force even in an actual steel body and is less dependent on the vehicle type and model. There is.

In the vehicle wind tunnel test method of the present invention, a magnetic flux generation source such as a permanent magnet is housed in the front and rear wheels, a superconducting material and a cooling device are arranged at positions facing the wheels, and the magnetic flux restraint of the superconducting material is performed. By using the characteristics of the body, the magnetic support of the car body was measured.
In the wind tunnel magnetic force support balance device for a vehicle according to the present invention, a moving ground plate is arranged at a position spaced apart from the floor surface in the wind tunnel measuring unit, and a magnetic flux generation source such as a permanent magnet is provided in the front and rear wheels. The superconducting material and the cooling device are arranged on the floor facing the front wheel position and the rear wheel position, and the magnetic force of the vehicle body is supported by utilizing the magnetic flux restraint property of the superconducting material.
In addition, the magnetic flux supply source adopts a structure that holds it through the wheel bearing, and a balance is installed between the superconducting material that holds the magnetic flux and the floor that supports it, and the force and moment applied to the magnetic flux source are external to the wheel. It was made to measure from.
In addition, the superconducting material support that faces each of the wheels is equipped with a mechanism that can independently adjust the position and orientation of each wheel, thereby supporting the vehicle model in the wind tunnel or the actual vehicle in a predetermined position and orientation with respect to changes in wind conditions. It was possible.

In the vehicle wind tunnel test method of the present invention, a magnetic flux generation source such as a permanent magnet is housed in the front and rear wheels, a superconducting material and a cooling device are arranged at positions facing the wheels, and the magnetic flux restraint of the superconducting material is performed. This makes it possible to easily and quickly carry out various wind tunnel tests on actual vehicles. In addition, the support interference is eliminated and the accuracy of the wind tunnel test is improved.
In the wind tunnel magnetic force support balance apparatus for a vehicle according to the present invention, a moving ground plate is disposed at a position spaced apart from the floor surface in the wind tunnel measuring unit, and a magnetic flux generation source such as a permanent magnet is provided in the front and rear wheels. The superconducting material and the cooling device are arranged on the floor surface facing the front wheel position and the rear wheel position, and the magnetic force of the vehicle body is supported using the magnetic flux restraint property of the superconducting material. Regardless of this, it is possible to provide a facility that allows a wind tunnel test on an actual vehicle or model to be easily and quickly performed without any support interference.
Further, in the vehicle wind tunnel magnetic force support balance apparatus of the present invention, the vehicle body does not move or swing even if the wheel is rotated by holding the magnetic flux generating source via the wheel bearing.
By adopting a configuration in which a balance is attached between the superconducting material that holds the magnetic flux and the floor that supports it, the force and moment applied to the magnetic flux source can be measured from the outside of the wheel.
The superconducting material support table facing each of the wheels is equipped with a mechanism capable of independently adjusting the position and orientation of each wheel, thereby supporting the vehicle model in the wind tunnel or the actual vehicle in a predetermined position and orientation with respect to changes in wind conditions. Made possible.

  FIG. 1 schematically shows a basic configuration of a magnetic force support balance apparatus for an automobile according to the present invention. Reference numeral 1 denotes a vehicle body, and an actual vehicle made of iron can be used. Reference numeral 2 denotes a wheel which is mounted on an axle 3 like a normal automobile and supports the vehicle body 1. A magnetic flux generation source 4 such as a permanent magnet is freely rotatable through a bearing 5 inside the wheel. The thing peculiar to this invention attached to the axle shaft 3 in the form of this is used. It is important that the magnetic flux generation source 4 is combined with a magnet arrangement that allows a strong magnetic flux to reach as far as possible. In this embodiment, two bar magnets 4a, 4a, 4b is arranged with the magnetic poles in opposite directions, the upper magnetic poles are connected by a magnetic circuit using a magnetic body 4c, and the lower magnetic pole is released, so that it takes the form of a horseshoe magnet. As for the configuration on the wind tunnel side, first, the balance device 7 is arranged on the pedestal 6. The balance device 7 is a device capable of measuring a required force component, for example, a 6-component force balance, and is disposed at a position facing each wheel of an automobile installed in the measurement unit. A superconducting material 10 is attached above the balance device 7 via a position and orientation adjustment device 8. The superconducting material 10 is provided with a cooling device 9 for maintaining a low temperature state in order to maintain the superconducting characteristics. Reference numeral 11 denotes a moving ground plate, which is moved at the same speed as the wind tunnel air velocity at the time of measurement, and constitutes a measuring unit floor.

  The specific configuration of the magnetic flux generation source 4 employed in the present embodiment is that two bar magnets 4a and 4b are arranged in parallel with their magnetic poles in opposite directions, and both upper magnetic poles are connected via a magnetic body 4c to form a magnetic circuit. The gap between the two bar magnets 4a and 4b was filled and fixed with a resin 4d which is a non-magnetic material. The bar magnet 4a, the magnetic body 4c, and the bar magnet 4b have the same form as a horseshoe-shaped permanent magnet. Since the magnetic force generating member 4 is rotatably attached to the axle 3 via the bearing 5, the mechanism can support the vehicle body 1 without being affected by the rotation of the wheel 2.

  When performing the test, first, the wheel 2 according to the present invention is attached to the axle 3 of the device under test. Next, the superconducting material 10 placed on the balance device 7 placed on the pedestal 6 is positioned so as to face the lower magnetic poles of the bar magnets 4a and 4b placed in the wheel 2 of the device under test. The position / orientation is adjusted by the attitude adjusting device 8. The superconducting material 10 is not brought into the superconducting state in the initial state in which the device under test is installed in the measuring section, and the magnetic flux from the bar magnets 4a and 4b penetrates the superconducting material 10. A moving ground plate 11 exists between the lower magnetic poles of the bar magnets 4 a and 4 b and the superconducting material 10, but an appropriate gap is secured between the moving ground plate 11 and the upper surface of the superconducting material 10. In addition, the position of the pedestal 6 is lowered, and the vehicle body 1 as the test body is placed on the ground plate 11. In this state, the cooling device 9 is operated, and the temperature of the superconducting material 10 is lowered so as to be in a superconducting state. In the superconducting state, the magnetic flux penetrating through the superconducting material 10 is in a restrained state and cannot move there as it is. When the entire pedestal 6 is lifted after this magnetic flux restraint state is reached, the magnetic flux swells just like a spring by the weight of the device under test, and the wheel 2 of the device under test rises from the moving ground plate 11 to a certain distance. Keep in balance. In addition, even if a vertical force is applied to the paper, the restoring force retained like a spring works and returns to the original state. A similar restoring force works for forces and torques in other directions. In this way, the vehicle body 1 of the device under test is magnetically supported in the air while maintaining a constant distance and posture. The bar magnets 4a and 4b, which are in the form of horseshoe-shaped permanent magnets via the magnetic body 4c, are held at a certain distance and posture from the superconducting material 10 by the magnetic flux. Even if the tire portion of the wheel 2 fixed to the axle 3 of the device under test is rotated by the rotation of the axle 3, it is coupled via the bearing 5, so that the bar magnet 4a in the form of a horseshoe-shaped permanent magnet, The position and orientation of 4b and the superconducting material 10 do not change.

  In this way, the vehicle body 1 of the device under test can rotate the tire in a state where it is placed on the magnetic force support mechanism using the magnetic flux restraining property of the superconducting material. If the DUT is an actual vehicle, even if a person gets inside the vehicle and blows the accelerator, the built-in magnetic flux generation source 4 does not rotate even if the tire rotates at high speed, and the vehicle body 1 moves within the measuring section. Will not. This is because the magnetic force support by the magnetic flux restraint is in operation, and naturally it cannot be done when the wheel 2 and the moving ground plate 11 are in contact. The force received by the superconducting material 10 acts on the balance device 7 via the position / orientation adjustment device 8. In addition to the force received by the body 1 of the device under test, the balance device 7 is subjected to the gravity of various devices such as the position / orientation adjusting device 8, the conductive material 10, and the cooling device 9, and this is measured before and after the wind tunnel test. If it is stored as data, the effect can be removed by data processing. That is, the aerodynamic force exerted by the airflow can be evaluated by taking a difference between the output of the balance device 7 when the wind is applied and the value in the initial state.

It is the figure which showed typically the basic composition of the magnetic force support balance apparatus for motor vehicles of this invention. It is the figure which showed in detail the embodiment of the partial structure between the wheel incorporating a magnetic flux generation source, and a superconducting substance. It is a figure explaining the form of the wind tunnel test which used the conventional motor vehicle as the to-be-tested body. It is a figure explaining the magnetic support balance apparatus for wind tunnels developed for aircrafts.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Car body 2 Wheel 3 Axle 4 Magnetic flux generation source 4a, 4b Bar magnet 4d Magnetic body 4d Filling resin 5 Bearing 6 Pedestal 7 Balance device 8 Position and orientation adjustment device 9 Cooling device 10 Superconducting substance 11 Moving ground plate

Claims (5)

  A magnetic flux generation source such as a permanent magnet is stored in the front and rear wheels, a superconducting material and a cooling device are arranged at the position facing the wheel, and the magnetic support of the vehicle body is supported by utilizing the magnetic flux restraint property of the superconducting material. A wind tunnel test method for a vehicle characterized in that it was fast.   A moving ground plate is placed in the wind tunnel measurement section at a predetermined distance from the floor, and a magnetic flux generation source such as a permanent magnet is stored in the front and rear wheels to confront the front and rear wheel positions. A wind tunnel magnetic force support balance device for a vehicle, wherein a superconducting material and a cooling device are arranged on a floor surface to be supported, and magnetic support of the vehicle body is performed using the magnetic flux restraining property of the superconducting material.   3. The vehicle wind tunnel magnetic force support balance apparatus according to claim 2, wherein the magnetic flux supply source is held via a wheel bearing so that the vehicle body does not move or swing even when the wheel is rotated. .   The vehicle wind tunnel according to claim 2 or 3, wherein a balance is attached between the superconducting material holding the magnetic flux and the floor surface supporting the same, and the force and moment applied to the magnetic flux source are measured from outside the wheel. Magnetic support balance device.   The superconducting material support table that faces each of the plurality of wheels has a mechanism that can independently adjust the position and orientation of each wheel so that the vehicle model in the wind tunnel or the actual vehicle can be supported in a predetermined position and orientation with respect to changes in wind conditions. The wind tunnel magnetic force support balance apparatus for vehicles according to any one of claims 2 to 4 characterized by things.