JPH04191632A - Chasis dynamometer - Google Patents

Abstract

PURPOSE:To easily and accurately measure equivalent inertial quantity by dividing the control force acting on a roller by the difference between the natural deceleration and forced deceleration of the roller. CONSTITUTION:A roller 1 on which a drive wheel 2 is placed is horizontally held on a base 4 and a fly wheel 7 is connected to one end of the roller while a disc 8 and a roller speed detection sensor 9 are attached to the other end thereof. Next, a brake unit 10 for grasping the disc 8 to apply braking power to the same is provided. Subsequently, a circuit 27 storing forced deceleration generated when the roller 1 is stopped using this brake apparatus 11 and a circuit 26 storing natural deceleration obtained when the brake apparatus 11 is not used are provided. Further, a divider circuit 30 dividing the output of a strain output amplifier 29 by the difference between both decelerations taken by a subtraction circuit 28 and an inertial quantity memory circuit 31 storing the output of the divider circuit 30 are provided. By this constitution, the inertial force of the fly wheel can be calculated and actual equivalent inertial quantity can be easily and accurately measured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a chassis dynamometer device that can simulate a state in which a vehicle such as an automobile is traveling on an actual road.

[Conventional technology]

Generally, in a chassis dynamometer device, a flywheel is connected to the shaft of a roller on which the driving wheels of a test vehicle are mounted. Conventionally, the equivalent amount of inertia of this flywheel is determined by its machining dimensions and material. The nominal value was calculated based on design values such as the density of

[Problem to be solved by the invention]

However, since there is a tolerance between the design value and the actual machining dimensions, the equivalent amount of inertia is unknown, and although the chassis dynamometer device incorporates parts such as hair rings, Currently, the equivalent amount of inertia of the flywheel cannot be accurately determined because it is difficult to accurately determine the amount of inertia of these parts.

In contrast, electrical inertia type chassis dynamometer devices have been put into practical use, but in this case, calculations cannot be made using mechanical dimensions, and when verifying the amount of inertia of electrical inertia, the verification device is required. There is an inconvenience that part of the control system for controlling the chassis dynamometer device must be used.

The present invention has been made with the above-mentioned considerations in mind, and its purpose is to provide a chassis dynamometer device that can easily and accurately measure the equivalent amount of inertia without using a control system. Our goal is to provide the following.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a chassis dynamometer device in which a flywheel is connected to the shaft of a roller on which a driving wheel is mounted, and a disk that rotates together with the roller and a speed of the roller are connected to the shaft of the roller. Attaching a roller speed detection sensor to detect the speed and providing a brake unit that applies a braking force to the disc,
Furthermore, a braking force detection sensor is provided to measure the amount of braking force applied to the disc when the brake unit is operated, and the braking force acting on the roller is determined based on the output of this braking force detection sensor. Find the difference between the deceleration when the roller is naturally decelerated without operating the unit and the deceleration when the roller is forcibly decelerated by operating the brake unit, and calculate the braking force acting on the surface of the roller. By dividing by the difference between the two decelerations, the equivalent amount of inertia can be measured.

[Effect]

In the above means, the equivalent amount of inertia of the chassis dynamometer device can be measured based on Newton's equation of motion, and since the control system of the chassis dynamometer device is not used, the amount of inertia can be easily verified. can.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows the configuration of a chassis dynamometer device according to the present invention, and in this figure, 1 is a roller on which a driving wheel 2 of a test vehicle (not shown) is placed. The shaft 3 of this roller 1 is held horizontally by bearings 5 provided at appropriate intervals on a base 4, and a flywheel 7 is mechanically connected to one end of the shaft 3 via a joint 6. A disk 8 that rotates together with the roller 1 and a roller speed detection sensor 9 that detects the speed of the roller 1 are attached to the other end. A brake unit 10 holds the disc 8 and applies braking force thereto, and the brake unit 10 and the disc 8 form a brake device W11. 12 is a bearing member that holds the other end of the flywheel 7.

The detailed structure of the brake device 11 will be explained with reference to FIGS. 2 and 3. The disc 8 is attached to the roller shaft 3 by a key (not shown), and is integrally connected to the roller shaft 3. Allow it to rotate or stop.

Further, the brake unit 10 is composed of, for example, a hydraulic caliper, and its main body 12 is provided with a caliper 13 for holding the disc 8 and applying a braking force thereto. Although this caliper 13 is not shown in detail, when hydraulic pressure is applied to the cylinder part (not shown) by the brake operation circuit 14 shown in FIG. The disc 8 is pressed against the caliper 13 so that a braking force (represented by the symbol F) acts between the disc 8 and the caliper 13. In addition, in Figure 1, 1
5 is a pressure regulator for setting brake operating force, 16 is a solenoid valve for brake on/off operation, and 17 is a pressure booster.

The brake body 12 is connected to the brake slide base 1.
8, and this brake slide base 1
8 is a roller shaft 3 attached to the side surface of the base 4 on the disk 8 side.
The guide rails 19 are slidably held between a pair of guide rails 19 that are provided parallel to each other in a direction orthogonal to the guide rails 19 . Further, on the other end side of the guide rail 19, a shear beam type load cell 21 equipped with a strain gauge 20 is provided as a braking force detection sensor, and the braking force F is detected by the force (reaction force) supporting the brake unit 10. )
This is detected by the load cell 21 as a strain output.

In the present invention, the braking force acting on the surface of the roller 1 is determined, and the deceleration when the roller 1 is naturally decelerated without operating the brake unit 10 and the deceleration when the roller 1 is reduced by operating the brake unit 10 are determined. The difference between the deceleration and the deceleration when forcedly decelerated is determined, and the braking force acting on the roller 1 is divided by the difference between the two decelerations, so the configuration is as follows.

That is, in FIG. 1, 22 is an arithmetic processing section,
An F/V conversion circuit 23 that converts the speed signal output from the speed detection sensor 9 from frequency to voltage; and a differentiation circuit 2 that differentiates the speed signal from the F/■ conversion circuit 23 and outputs a differential output.
4. The changeover switch 25 that switches and outputs the differential output of the differential circuit 24, and the deceleration ( dV
o /d t) and the deceleration (d Vi+ /d t) when the braking force F is applied, that is, the brake device 11 applies the brakes to forcibly stop the roller 1. and a circuit 27 for storing both decelerations dVo /d t, dVl /d t (7
) a subtraction circuit 28 that takes the difference (=dvs/dt dVo/dt), a distortion output amplifier 29 that amplifies the distortion output that is the output from the load cell 21, and an output dV* of the subtraction circuit 27 that takes the output of the distortion output amplifier 29. /d t dVo /d
tT: Consists of a division circuit 30 that performs division and a circuit 31 that stores the output of the division circuit 30. Note that 32 is a display section.

By the way, if the length from the center of the roller l to the part on which the braking force F acts is R, and the radius of the roller 1 is R, the braking force F is the braking force F on the surface of the roller l, and the braking force F on the surface of the roller l is F.
-L/R. Therefore, the distortion output amplifier 29 is configured to output a braking force Fm expressed by F-L/R.

Then, the deceleration dVO/dt during natural deceleration of roller 1,
Between the deceleration dVS/dt during forced deceleration of roller 1, the braking force F on the surface of roller 1, and the equivalent inertia I, Fl = IX (dV, /d t-dV, /d t ) Therefore, it can be determined as 1=FB/(dVl/dt-dV./dt).

In the chassis dynamometer device having the above configuration, the rollers 1 and the flywheel 7 are accelerated and rotated by the drive wheels 3 of the test vehicle, and when a predetermined speed is reached, the acceleration by the drive wheels 3 is stopped and the flywheels 7 are allowed to decelerate naturally. At the same time, when the switch 25 is switched to the natural speed deceleration memory circuit 26 side, the deceleration dV during natural deceleration. /dt is measured and stored in the natural speed deceleration storage circuit 26.

Next, turn the switch 25 to the side 27 of the deceleration memory circuit during forced deceleration.
At the same time, when sudden braking is applied by the brake device 11, the braking force F applied to the disc 8 by the brake unit 10 is measured, and this is output as the braking force F on the surface of the roller 1 in the distortion output amplifier 29. The power F is input to the division circuit 30. On the other hand, at this time, the deceleration dV, /dt during forced deceleration is measured, and this is stored in the deceleration storage circuit 27 during forced deceleration.

Then, from the subtraction circuit 28, both the decelerations aVO/d 5
Difference between dVi /d t dVm /d t dVo
/dt is output, which is input to the division circuit 30,
The braking force F8 is the difference dv++ /d t dVo
By dividing by /dt, the inertia force of the flywheel 7 can be determined.

In the above embodiment, each deceleration was obtained by differentiating the speed, but instead of this, a speed range is determined, and from the speeds V, , V at both ends of the range, and the time T required for deceleration, Each deceleration may be determined by (VI-(2)2)/T, and FIG. 4 shows the configuration in this case. In FIG. 4, 33 is a speed calculation circuit connected to the speed detection sensor 9, 34 is a section deceleration time measuring circuit, and 35 is a deceleration calculation circuit.

〔Effect of the invention〕

As explained above, according to the present invention, the equivalent amount of inertia of a chassis dynamometer device can be measured based on Newton's equation of motion, so the actual equivalent amount of inertia can be easily and accurately measured. can do. Furthermore, since the control system of the chassis dynamometer device is not used, measurements can be performed without affecting the rotating shaft system. According to the present invention, it can be applied to both mechanical and electric chassis dynamometer devices.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention, FIG. 1 is a diagram showing a schematic configuration of a chassis dynamometer device according to the present invention, FIG. 2 is an enlarged view of a brake device part, Third
The figure is a side sectional view thereof. FIG. 4 is a block diagram showing part of the configuration of an arithmetic processing section according to another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Roller, 2... Drive wheel, 3... Roller shaft, 7... Flywheel, 8... Disc, 9...
...Roller speed detection sensor, 10... Brake unit, 21... Braking force detection sensor. 21... Braking force detection sensor Fig. 2 Fig. 3

Claims (1)

[Claims] In a chassis dynamometer device in which a flywheel is connected to the shaft of a roller on which the driving wheels of a test vehicle are mounted, a disk that rotates together with the roller and a roller speed detection sensor that detects the speed of the roller are attached to the shaft of the roller. In addition, a brake unit is provided to apply a braking force to the disc, and a braking force detection sensor is provided to measure the amount of braking force applied to the disc when the brake unit is operated, and the output of the braking force detection sensor is While determining the braking force acting on the surface of the roller based on the above, the deceleration when the roller is naturally decelerated without operating the brake unit and the deceleration when the roller is forcibly decelerated by operating the brake unit. A chassis dynamometer device, characterized in that the equivalent amount of inertia can be measured by calculating the difference between the two decelerations and dividing the braking force acting on the roller by the difference between the two decelerations.