JP4181451B2 - Vehicle measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle cooling fan suitable for measurement of acoustic characteristics such as vehicle noise characteristics.
[0002]
[Prior art]
The measurement of acoustic characteristics such as vehicle noise characteristics is performed, for example, by measuring the sound generated by the vehicle while rotating the driving wheels on a roller of a chassis dynamometer provided in a semi-anechoic sound chamber.
Here, in the measurement of such acoustic characteristics, the chassis dynamometer is provided with an opening provided on the floor surface in order to realize the measurement in accordance with the inverse square law by eliminating reflection of the sound generated by the vehicle by surrounding structures. To the bottom of the floor so that only the top of the roller is exposed.
[0003]
Moreover, it is common for a measurement facility using such a chassis dynamometer to be provided with a vehicle cooling fan for cooling the vehicle.
As a technology for such a vehicle cooling fan, a main body that generates cooling air for the vehicle cooling fan is provided under the floor so that the vehicle cooling fan does not become an obstacle to taking in and out of the vehicle chassis dynamometer. A technology is known in which the duct between the discharge part formed with the discharge port that discharges cooling air and the main body can be extended, and the discharge part is raised and lowered between the floor and the floor. (For example, JP-A-7-260634).
Prior art document information related to the invention of this application includes the following.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 07-260634
[Problems to be solved by the invention]
When a vehicle cooling fan configured to extend the conventional duct is applied as a vehicle cooling fan of the measurement facility used for the acoustic characteristics, the following problems occur.
That is, since the distance between the vehicle cooling fan main body and the discharge port is increased, and the vehicle cooling fan main body is disposed in the hangar below the floor, the resistance of the vehicle cooling fan during intake is reduced. It becomes larger and the cooling performance of the vehicle cooling fan deteriorates.
Moreover, since it cannot be excluded that the vehicle cooling fan and the structure for causing the discharge part to appear and disappear on the floor surface reflect the vehicle generated sound, the measurement accuracy of the acoustic measurement is deteriorated.
Therefore, an object of the present invention is to suppress deterioration in accuracy of acoustic measurement caused by a cooling fan without sacrificing cooling performance.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a chassis dynamometer including a rotor arranged so that the height of a traveling road floor surface and a top surface of a vehicle are substantially the same, and a dynamometer connected to the rotor. A vehicular measuring device having an opening provided in the runway floor as an entrance, a hangar provided below the runway floor, a cooling fan unit stored in the hangar, and raising and lowering the cooling fan unit And an elevating mechanism, and the cooling fan unit includes an elevating stage, a cooling fan disposed on the elevating stage, and a lid portion supported by the elevating stage provided above the cooling fan. The lid portion closes the opening of the hangar, and the upper surface of the lid portion forms a surface with a height that matches the runway floor surface. Both between the height where the discharge port of the cooling fan is positioned above the track floor, in which so as to lift the lifting stage.
[0007]
According to such a vehicle measurement device, when the acoustic characteristics of the vehicle are measured, the cooling fan unit is stored in the hangar below the floor by lowering the elevating stage, and the hangar is closed by the lid, and the cooling fan unit or The influence on the measurement by the hangar can be suppressed. In addition, when measuring characteristics other than the acoustic characteristics of the vehicle or cooling the vehicle, the elevating stage is raised to at least a height at which the discharge port of the cooling fan is located above the runway floor surface, and the cooling fan Can be used to cool the vehicle. Therefore, the vehicle can be effectively cooled as in the case where the cooling fan is installed on the floor of the semi-anechoic sound room.
[0008]
Here, in such a vehicle measurement device, the lid portion abuts against the inner surface of the hangar at a position where the lid closes the opening, and the opening of the hangar is sealed to close the inside and outside of the hangar. It is preferable to provide a sound insulating member fixed to the lid portion that performs sound insulation between them in order to more strictly eliminate the influence on the measurement by the cooling fan unit and the hangar during the acoustic characteristic measurement.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
The structure seen from the side surface of the acoustic measurement equipment according to the present embodiment is schematically shown in FIG. 1a.
As shown in the figure, the acoustic measurement equipment is a chassis dynamometer arranged under the floor of the semi-anechoic sound chamber 1 with sound absorbing material on the wall and ceiling so that only the top of the roller is exposed from the opening provided on the floor. 2 and a fan unit 3 for cooling the vehicle disposed so as to be movable up and down between a height at which the upper surface shown in FIG. 1a coincides with the floor surface and a height at which the upper surface shown in FIG. 1b is located higher than the floor surface. ing.
[0010]
FIG. 1c shows the arrangement of the chassis dynamometer 2 and the vehicle cooling fan unit 3 as viewed from above.
Here, the chassis dynamometer 2 includes a roller 21 on which vehicle driving wheels are placed, a dynamometer 22 that drives the roller 21, and a load cell 23 that measures torque applied to the dynamometer 22. The example shown is for a rear wheel drive vehicle.
Next, details of the vehicle cooling fan unit 3 will be described.
FIG. 2a shows a side view of the vehicle cooling fan unit 3 in the state lowered to the lowest position, and FIG. 2b shows a front view of the vehicle cooling fan unit 3 in the state lowered to the lowest position. FIG. 2c shows a side view of the vehicle cooling fan unit 3 in a state where it is raised to the uppermost position, and FIG. 2d shows a front view of the vehicle cooling fan unit 3 in a state where it is raised to the uppermost position.
[0011]
As shown in the figure, the vehicle cooling fan unit 3 includes an elevating stage 31, a cooling fan 32 fixed on the elevating stage 31, a support column 36 standing on the stage, and a support column 36 above the cooling fan 32. The lid 37 is supported, and the bracing 38 is provided as appropriate to maintain the strength of the vehicle cooling fan unit 3. Under the vehicle cooling fan unit 3, an elevating link 33 for elevating the elevating stage 31 of the vehicle cooling fan unit 3, a ball screw 34 for opening and closing the elevating link 33, and an elevating motor 35 for rotating the ball screw 34 are provided. An elevating mechanism is provided.
[0012]
In such a configuration, when the ball screw 34 is rotated by a motor, the elevating stage 31 moves up and down with the cooling fan 32, the support pillar 36, and the lid portion 37.
Now, such a vehicle cooling fan unit 3 is installed in a hangar having a shape dug down in the floor of the semi-anechoic sound chamber 1, and in a state where the vehicle cooling fan unit 3 is lowered to the lowest position, the lid portion 37 of the vehicle cooling fan unit 3 is provided. The height of the upper surface of the semi-anechoic sound chamber 1 is the same as the height of the floor surface of the semi-anechoic sound chamber 1 and completely closes the hangar opening. More specifically, the height of the upper surface of the lid portion 37 in a state where the inner peripheral portions of the four sides of the lower surface of the lid portion 37 are in contact with the step portion 11 provided in the opening portion of the hangar to block the opening of the hangar. Corresponds to the height of the floor surface of the semi-anechoic chamber 1.
[0013]
Here, FIG. 2e shows a configuration example of the lid portion 37. FIG.
As shown in the figure, the lid portion 37 includes a frame 371, a metal floor surface forming plate 372 that covers the upper surface of the frame 371, a simulation sheet 373 fixed to the upper surface of the floor surface forming plate 372, and four sides of the lower surface of the frame 371. It has a mouth-shaped sound insulating material 374 fixed to the lower surface of the frame 371 so as to cover the inner periphery. The simulation sheet 373 is a sheet having acoustic characteristics close to the floor surface of the semi-anechoic sound chamber 1, and on the upper surface of the lid portion 37 exposed when the vehicle cooling fan unit 3 is lowered to the lowest position, In order to simulate the acoustic characteristics of the surface, it is fixed to the upper surface of the lid portion 37. The sound insulating material 374 is in contact with the stepped portion 11 provided at the opening of the hangar and is sandwiched between the stepped portion 11 and the frame 371 when the vehicle cooling fan unit 3 is lowered to the lowest position. It is elastically deformed and the hangar is sealed and acoustically isolated from the semi-anechoic chamber 1.
[0014]
On the other hand, as shown in FIGS. 2c and 2d, the cooling fan 32 as a whole is positioned substantially on the floor surface in the state where it is raised to the uppermost position, and the discharge port of the cooling fan 32 is completely positioned above the floor surface. To position. In addition, the cooling fan 32 is almost exposed in the semi-anechoic sound chamber 1 except for the upper and lower sides. Therefore, intake of the cooling fan 32 and discharge of the cooling air are performed in the same manner as when the cooling fan 32 is installed on the floor of the semi-anechoic sound chamber 1.
[0015]
Now, such a vehicle cooling fan unit 3 is lowered to the lowest position when measuring the acoustic characteristics of the vehicle. As a result, the vehicle cooling fan unit 3 is stored in a hangar under the floor, and this hangar is sealed by the lid portion 37 so that the upper surface of the lid portion 37 forms a floor surface similar to the periphery. The influence on the measurement by the fan unit 3 or the hangar is eliminated.
[0016]
Further, when measuring characteristics other than the acoustic characteristics of the vehicle or cooling the vehicle, it is raised to the uppermost position. Then, the cooling fan 32 is operated to cool the vehicle. As a result, the vehicle can be effectively cooled as in the case where the cooling fan 32 is installed on the floor of the semi-anechoic sound chamber 1.
The embodiment of the present invention has been described above.
[0017]
【The invention's effect】
As described above, according to the present invention, it is possible to suppress deterioration in accuracy of acoustic measurement caused by the cooling fan without sacrificing the cooling performance.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing a configuration of an acoustic measurement facility according to an embodiment of the present invention.
FIG. 2 is a diagram schematically showing the structure of a vehicle cooling fan unit according to an embodiment of the present invention.
[Explanation of symbols]
1: semi-anechoic sound chamber, 2: chassis dynamometer, 3: vehicle cooling fan unit, 11: stepped portion, 21: roller, 22: dynamometer, 23: load cell, 31: lifting stage, 32: cooling fan 33: Lifting link, 34: Ball screw, 35: Lifting motor, 36: Support column, 37: Lid, 38: Bracing, 371: Frame, 372: Floor surface forming plate, 373: Simulated sheet, 374: Sound insulation material .

Claims (2)

A vehicle measuring device having a chassis dynamometer comprising a rotor arranged so that the height of a running road floor surface and a top surface of a vehicle are substantially the same, and a dynamometer coupled to the rotor,
The hangar provided below the runway floor, with the opening provided in the runway floor as an entrance,
A cooling fan unit stored in the hangar;
An elevating mechanism for elevating and lowering the cooling fan unit;
The cooling fan unit is
Elevating stage;
A cooling fan disposed on the elevating stage;
A lid portion provided above the cooling fan and supported by the elevating stage;
The elevating mechanism has a height at which the lid portion closes the opening of the hangar and the upper surface of the lid portion forms a surface that coincides with the runway floor surface, and at least the discharge port of the cooling fan A vehicle measuring apparatus, wherein the elevating stage is moved up and down between a height above the running road floor. The vehicle measurement device according to claim 1,
The sound insulation fixed to the lid, which contacts the inner surface of the hangar at the position where the lid closes the opening of the hangar, seals the opening of the hangar and performs sound insulation between the inside and outside of the hangar. A vehicle measuring device having a member.

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