JPS6224126A - Wind velocity controller of cooling fan for chasis dynamometer - Google Patents

Abstract

PURPOSE:To always keep the wind velocity at the target value, by detecting the wind velocity of a cooling fan with a wind velocity detector to be compared with a wind velocity command signal by a PI adjuster. CONSTITUTION:Firstly, when v1 is inputted as vehicle speed command (target vehicle speed), a speed controlling amplifier 1 inputs a vehicle signal corresponding to the v1 and a variable speed motor 2 rotates at the revolutions corresponding to the v1. A cooling fan 3 generates a wind velocity of Wv1. A wind velocity detector 5 detects a signal corresponding to the Wv1 to be compared by a PI adjuster 6. Then, the PI adjuster 6 performs a proportional integration of the deviation (v1-Wv1) and the results are inputted into a speed control amplifier 1 so that the cooling fan 3 will raise the revolutions corresponding to the v1 to generate a wind velocity Wv1. Thus, the wind velocity v1 can be obtained by the vehicle speed command v1 to always ensure the execution of a wind velocity control following the vehicle speed thereby enabling accurate provision of the wind velocity corresponding to an engine, tire or the like of a test vehicle.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a cooling fan wind speed control device in a chassis dynamometer suitable for controlling the cooling fan wind speed of an engine such as an automobile or a tire.

[Background of the invention]

Conventional systems control the speed of the cooling fan drive motor to match the vehicle speed. However, there is a problem in that the speed of the drive motor and the wind speed do not always match, and the difference between the vehicle speed and the wind speed is large, making it impossible to accurately control the wind speed. An example of this type of wind speed control device is Japanese Utility Model Application No. 54-11401.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a cooling fan wind speed control device in a chassis dynamometer that applies wind speed to the engine, tires, etc. of a test vehicle that is equivalent to that when the test vehicle is traveling on the road.

[Summary of the invention]

In order to achieve the above object, the present invention detects the wind speed of the cooling fan using a wind speed detector and compares it with a vehicle speed command signal using a PI controller to ensure that the wind speed always reaches the target vehicle speed.

[Embodiments of the invention]

An embodiment of the apparatus of the present invention will be described below with reference to the drawings. 1st
The figure is a characteristic diagram showing the relationship between the number of rotations of a cooling fan and the wind speed, and FIG. 2 is a block diagram showing an embodiment of the apparatus of the present invention.

The configuration and operation will be explained with reference to the drawings. 1 is a speed control amplifier, and this amplifier 1 has P, 1. The output of the controller 6 is proportionally amplified and a speed control signal is given to the variable speed motor 2 (for example, a DC motor). 3 is a cooling fan, and the cooling fan 3 is mechanically directly connected to the variable speed electric motor 2. 4
is a speed detector, the speed detector 4 generates a signal proportional to the rotation speed of the variable speed electric motor 2, and the wind speed detector 5 generates a signal proportional to the wind speed of the cooling fan 3. The controller 6 compares the vehicle speed command and the detected wind speed signal, performs proportional integration, and outputs the result to the speed control amplifier 1.

Next, the operation of the device of the present invention will be explained. First, when vl shown in FIG. 1 is input as a vehicle speed command (target vehicle speed), the speed control amplifier 1 inputs a vehicle speed signal corresponding to V, and the variable speed
The motive 2 also rotates at a rotation speed equivalent to v1, and the cooling fan 3 turns W.
Generates a wind speed of Vt.

On the other hand, the wind speed detector 5 detects a signal corresponding to Wv, and P
, 1. Compare using controller 6. P.1. The controller 6 proportionally integrates the deviation (V knee Wv□) and inputs it to the speed control amplifier 1, so the cooling fan 3 increases to the rotational speed of V□ and generates the wind speed WV1. Therefore, the wind speed V□ is obtained by the vehicle speed command v1, and the wind speed control that always follows the vehicle speed is executed, which has the effect of improving accuracy.

(Effects of the Invention) According to the device of the present invention, since it is possible to accurately apply a wind speed corresponding to the vehicle speed to the engine or tires of a test vehicle, there is an effect that the road running condition can be accurately reproduced.

[Brief explanation of drawings]

FIG. 1 is a characteristic diagram showing the rotational speed and wind speed of a general metallurgical fan, and FIG. 2 is a block diagram showing the configuration of a cooling fan wind speed control device in a chassis dynamometer.

Claims (1)

[Claims] In a chassis dynamometer on which a test vehicle is mounted and equipped with a cooling fan driven by a variable speed electric motor, a cooling fan drive electric motor speed control circuit is provided in the minor loop of the wind speed control system to achieve a target vehicle speed, Cooling fan wind speed control in a chassis dynamometer, characterized in that a controller is provided in the main loop to output the deviation between the cooling fan wind speed and the target vehicle speed, and the cooling fan wind speed is controlled to the target vehicle speed. Device.