JP3003259B2 - Water pressure switching device in chassis dynamometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water pressure switching device for a chassis dynamometer.

[0002]

2. Description of the Related Art As shown in FIG. 3, a flat belt type chassis dynamometer includes a pair of rotating drums 21 and 22 arranged side by side. A load supporting device 24 formed of a water bearing shown in FIG.
Are provided, and these constitute a belt rotating body 25. In the example of FIG. 3, the belt rotating body 25 is
Four sets are provided for the wheel. At least one rotating drum 2 of the belt rotating body 25 thus configured
A load device such as a dynamometer (not shown) is connected to the rotation shafts 1 and 22. In addition, in FIG. 4, 20 is a wheel.

[0003]

Water is circulated and supplied from a water tank (not shown) to a load supporting device used in the above-mentioned chassis dynamometer. The pump pressure needs to be high when the vehicle speed is low. However, the pump functions as a water bearing even if the pressure gradually decreases as the vehicle speed increases. However, usually, even when the vehicle speed becomes high, since the water is circulated at a high pressure as it is, there is a problem that the amount of water increases.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a water pressure switching device in a chassis dynamometer which switches a water pressure in accordance with a vehicle speed to adjust a water amount.

[0005]

According to the present invention, in order to achieve the above object, an endless metal belt is hung between a pair of rotating drums arranged side by side, and the metal belt is provided between the pair of rotating drums. A belt rotating body is supported from below by a load supporting device utilizing incompressible liquid, and the belt rotating body is provided corresponding to each wheel of the vehicle, and at least one of the belt rotating bodies is provided. In a chassis dynamometer to which a load device is connected, a parallel body of a low pressure and a high pressure pump is connected to a passage for supplying a liquid from a liquid tank to the load support device for using the liquid, and when the vehicle speed is equal to or less than a preset value, both are connected. The pump is driven, and the operation of the high-pressure pump is stopped when the vehicle speed exceeds a preset value.

[0006]

The low-pressure pump and the high-pressure pump are both driven when the vehicle speed is lower than a set value. Thereafter, when the vehicle speed gradually increases and exceeds the set value, a stop command is given to the high-pressure pump. In this way, the amount of water can be reduced by stopping the high-pressure pump according to the vehicle speed.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. In FIG. 1, a load support device 24 supports a load on the metal belt 23 by forming a water film between the base 27 and the metal belt 23. The load supporting device 24 is provided with a sliding member (not shown) mounted on the upper portion of the base 27 and a drainer 28 surrounding the outer periphery of the base 27 on which the sliding member is mounted. On the surface of the base 27 (the surface facing the metal belt), a plurality of ports 30 having water jet holes 29 are arranged in tandem in the running direction of the belt 23. A plurality of the vertically arranged ports 30 are arranged in a direction perpendicular to the running direction of the belt 23, and a thin water film is formed between the surface of the base 27 and the belt 23. 31 is a water receiving cover.

A passage 32 is formed in the base 27 so as to communicate with the water ejection hole 29. Water from a water tank 34 is supplied to a water supply port 33 of the passage 32 via a parallel body 37 of a high-pressure pump 35 and a low-pressure pump 36. Supplied. 38 is a check valve inserted on the low pressure pump side. High pressure pump 35 and low pressure pump 36
When the vehicle speed detected by the vehicle speed detector 39 is lower than a predetermined value, both the pumps 35 and 36 are operated, and when the vehicle speed becomes higher than the predetermined value, the operation of the high-pressure pump 35 is stopped. . Reference numeral 40 denotes a drain port, and the water collected in the drain port 40 is returned to the water tank 34 by a drain duct (not shown).

Next, the operation of the above embodiment will be described. First, the vehicle is put on the metal belt 23 of the belt rotating body 25, and the operation of the vehicle is started. The vehicle speed detector 39 sends out a vehicle speed output when the vehicle starts operating. When the vehicle speed output is equal to or less than a preset value, the high-pressure pump 35 and the low-pressure pump 36
Are operated. Water tank 3 by operation of both pumps
The water of No. 4 is supplied from the water supply port 33 to the passage 32, and thereafter,
The water is ejected from the water ejection hole 29 as high-pressure water to form a predetermined water film. As a result, the metal belt 23 is supported by the water film of the incompressible liquid. As a result, when the vehicle is driven and the wheels 20 are rotated, the metal belt 23 runs smoothly. When the metal belt 23 starts running smoothly and the vehicle speed detector 39 detects that the vehicle speed output is equal to or higher than a preset vehicle speed output, the operation of the high-pressure pump 35 is stopped.

When the operation of the high-pressure pump 35 is stopped, the water film becomes only the water pressure from the low-pressure pump 36. As shown in FIG. 2, the required water pressure is inversely proportional to the vehicle speed. If the pressure rises, the required water pressure can be reduced, so that the operation is not hindered even if the operation is performed only by the low pressure pump 36 as shown by the characteristic curve B. As described above, when the vehicle speed becomes equal to or higher than the predetermined value, the operation of the high-pressure pump 35 can be stopped and the operation can be continued with only the low-pressure pump 36, so that the amount of water can be significantly reduced.

The characteristic curve C of FIG. 2 is controlled by using a motor driven by a known inverter. In the case of motor control by an inverter, the characteristic curve C can be continuously varied. There is an advantage that can be driven by.

[0012]

As described above, according to the present invention,
Since the water pressure of the load support device is switched in accordance with the vehicle speed, the amount of water can be adjusted, and unnecessary water is not required.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of the present invention.

FIG. 2 is a characteristic curve diagram showing a relationship between a vehicle speed and a required water pressure.

FIG. 3 is a schematic configuration explanatory view showing a conventional example.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

[Explanation of symbols]

21, 22 ... rotating drum, 23 ... endless metal belt, 24
... load supporting device, 25 ... belt rotating body, 26 ... vehicle, 2
7 ... Base, 28 ... Draining part, 29 ... Water outlet, 30 ... Port, 35 ... High pressure pump, 36 ... Low pressure pump, 37 ... Parallel body, 38 ... Check valve, 39 ... Vehicle speed detector.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01M 17/00-17/02 B65G 15/60

Claims (2)

(57) [Claims] An endless metal belt is hung between a pair of rotating drums arranged side by side, and the metal belt is supported from below by a non-compressible liquid-using load supporting device provided between the pair of rotating drums. In a chassis dynamometer in which a belt rotator is provided corresponding to each wheel of a vehicle, and a load device is connected to at least one of the belt rotators, a load using the liquid is provided. A parallel connection of a low pressure and a high pressure pump is connected to the passage for supplying the liquid from the liquid tank to the support device, and when the vehicle speed is equal to or less than a predetermined value, both pumps are driven so that the vehicle speed is equal to or more than a predetermined value. A water pressure switching device in a chassis dynamometer, wherein the operation of the high pressure pump is stopped and the operation is performed only by the low pressure pump when the pressure becomes high. 2. The chassis dynamometer according to claim 1, wherein :
Low pressure and high pressure pumps
A pump with a motor by Ete inverter control
Water pressure switching device in a chassis dynamometer.