JPH063224A - Chassis dynamometer testing method - Google Patents

Abstract

PURPOSE:To reduce equipment cost and installation space and to facilitate chassis dynamometer testing method. CONSTITUTION:A flywheel 6 is mounted on a roller 3 axis of a chassis dynamometer 2, and inertia is given at acceleration/deceleration of a tested car 4. The flywheel 6 of a constant mass irrespective of the mass of the tested car 4 is mounted on the roller 3 axis, and an acceleration/deceleration time or speed is set according to the ratio of the mass of the tested car 4 to the mass of the flywheel 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chassis dynamometer test method suitable for a chassis dynamometer test of automobile exhaust gas, for example.

[0002]

2. Description of the Related Art The composition and flow rate of automobile exhaust gas change depending on the characteristics of the engine and its operating conditions, and also change depending on maintenance conditions and ambient conditions such as temperature and atmospheric pressure. this house,
Each operating condition except idling includes many factors such as speed, acceleration / deceleration, transmission position, loading state, and road conditions.

Therefore, when displaying the concentration of each component of the exhaust gas, it is necessary to carry out a test under specified operating conditions, but it is difficult to completely match the operating conditions with the specified conditions. Was conducting an exhaust gas test under operating conditions that approximately reproduce the driving pattern of an urban road.

The above-mentioned running pattern comprises a plurality of running modes in which idling, acceleration, constant speed, and deceleration operation of the test vehicle are combined. Actual driving conditions are set according to this running pattern, for example, Japanese Utility Model Laid-Open No. 63-51249. As in the publication, a driver's aid display device is installed at a position visible to the driver, a chart paper with a predetermined running pattern is set on the device, and the chart paper is wound and moved at a constant speed. , The indicator provided on the display device is moved in the direction perpendicular to the moving direction of the chart paper in accordance with the vehicle speed of the test vehicle, and while adjusting the accelerator opening degree of the test vehicle, the indicator along the pattern Move
This was done by simulating the test vehicle in each driving mode.

Due to such a test method, a chassis dynamometer that can reproduce each driving condition of an automobile at a fixed position, is easy to measure, is efficient, and has high safety has been used for this kind of test. This chassis dynamometer is equipped with multiple equivalent inertial masses, which are generally flywheels, to provide load due to the mass of the test vehicle under transient operating conditions during acceleration and deceleration of the test vehicle. Then, this was summed with the basic inertial mass specific to the chassis dynamometer and made to correspond to the mass of the test vehicle.

[0006]

However, this conventional measuring method requires a plurality of flywheels and a flywheel switching operation according to the mass of the test vehicle. This type of test equipment becomes expensive because of the storage space required for them, the installation space becomes large, and the switching operation becomes complicated, which is one of the reasons for reducing the spread to general automobile maintenance factories. Was becoming.

The present invention solves such a problem, uses a constant flywheel regardless of the mass of the vehicle, reduces the cost of the test apparatus of this type, facilitates the work, and makes the installation space compact. An object of the present invention is to provide a new and rational chassis dynamometer test method for increasing / decreasing the acceleration / deceleration time or acceleration / deceleration of a test vehicle according to the ratio of the mass of the vehicle to the flywheel.

[0008]

Therefore, in the chassis dynamometer test method of the present invention, the flywheel is installed on the roller shaft of the chassis dynamometer, and inertia is applied to the rollers during acceleration / deceleration of the test vehicle. In the dynamometer test method, a flywheel having a constant mass irrelevant to the mass of the test vehicle is installed on the roller shaft, and the acceleration / deceleration time or acceleration / deceleration of the test vehicle is determined by comparing the mass of the test vehicle with the mass of the flywheel. It is characterized by setting it according to the ratio and making it possible to obtain a new and rational test method while making this type of test equipment cheaper, easier to work, and compact in installation space.

[0009]

[Operation] By adopting a flywheel with a constant mass that is irrelevant to the mass of the test car, multiple flywheels are prepared as in the past, and it is unreasonable to select and use them according to the mass of the test car. Eliminates the complexity of work, high equipment costs, and large installation space. By setting the acceleration / deceleration time or acceleration / deceleration of the test car according to the ratio of the mass of the test car and the mass of the flywheel,
The accelerator opening of the test vehicle is set equal to that of the conventional test method, and the operating conditions equivalent to those of the test vehicle according to the conventional test method are set.For example, in a chassis dynamometer test of automobile exhaust gas, The present invention provides a new and rational test method capable of obtaining the identity of composition.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An illustrated embodiment in which the present invention is applied to a chassis dynamometer test of an automobile exhaust gas will be described below. In FIGS. 1 to 3, reference numeral 1 is a floor of a test site, and the chassis is faced to the floor 1. The dynamometer 2 is installed, and the wheels 5 of the test vehicle 4 can be ridden on the pair of rollers 3 and 3.

At one end of the rotary shaft of the rollers 3 and 3,
A dynamometer which is a power absorption device is attached, and a flywheel 6 which is an inertial mass is arranged between the dynamometer and the roller 3. The flywheel 6 has a constant mass regardless of the mass of the test vehicle 4, and in the case of the embodiment, the mass is set to the equivalent inertial mass of the vehicle that can be tested by the chassis dynamometer 2.

Therefore, the chassis dynamometer 2 is provided with a single flywheel 6 and does not have a switching mechanism therefor.

In the test site, a driver's aid display device 8 is provided at an appropriate position where the driver of the test vehicle 4 can see it. The device 8 includes a winding drum 10, a feed drum 11, and a feed gear 1 inside a display screen 9.
2, 13 are provided, and a drive motor 14 having a rotation control device is linked to the take-up drum 10, and these are provided so as to be rotatable in the same direction.

A chart sheet 15 is wound around the take-up drum 10, the feed drum 11, and the feed gears 12 and 13, and the sheet 15 has an idling mode a, an acceleration mode b, and a constant speed mode c. , The target travel pattern 16 including the deceleration mode d.

The target traveling pattern 16 is drawn in the same manner as a conventional traveling pattern in which a plurality of flywheels are selectively used according to the mass of the test vehicle 4 and the acceleration / deceleration time is kept constant. The index 17 can be moved in the moving direction of the chart sheet 15, that is, in the direction orthogonal to the time axis direction in association with the accelerator operation of the vehicle 4 or the vehicle speed.

The rotation speed of the drive motor 14 is determined by the test vehicle 4 under transient operating conditions, that is, during acceleration operation and deceleration operation.
It is variably controlled in relation to the mass ratio between the test vehicle 4 and the flywheel 6 so that the acceleration / deceleration time thereof can be adjusted.

That is, the test site is provided with a controller 18 capable of inputting various kinds of information, and an arithmetic unit 19 such as a computer capable of performing arithmetic operation based on the information stored in advance under the condition of the input from the controller 18. There is. Among them, the controller 18 controls the mass M of the test vehicle 4 and the equivalent inertial mass m of the flywheel 6, the idling time ta and the acceleration time tb in the target travel pattern 16, the constant speed time tc and the deceleration time td, and the target travel time. The standard rotation speed V of the drive motor 14 corresponding to the pattern is input.

Further, the computing unit 19 has a computing equation of a modified acceleration / deceleration time corresponding to the mass of the test vehicle 4 and a computing equation of a modified acceleration / deceleration rotational speed of the drive motor 14 based on the modified acceleration / deceleration time. Remembered Of these, the modified acceleration / deceleration time T
b and Td are Tb = (m / M) tb, Td = (m / M)
Represented by td, and the rotational speeds Vb and Vd at the time of correction acceleration / deceleration
Is Vb = (tb / Tb) V, Vd = (td / Td) V
It is possible to input these calculation results to the rotation control device of the drive motor 14 during the acceleration / deceleration operation.

Therefore, when m <M, Tb1 <tb and Td1 <td as shown by the broken line in FIG. 3, and Vb,
Vd> V. On the contrary, when m> M, Tb2> tb and Td2> td as shown by the chain line in FIG. 3, and Vb,
Vd <V. In this case, the time during constant speed operation is constant regardless of the mass of the test vehicle 4, and the rotation speed of the drive motor 14 is set to the same speed as the target traveling pattern.

In addition to the above, 20 in the drawing is an exhaust pipe of the test vehicle 4,
One end of an exhaust gas conduit 21 is connected to the pipe 20, and the other end is connected to an exhaust gas analyzer 22. Reference numeral 23 is a recorder and 24 is a tire stopper.

The chassis dynamometer 2 used in the chassis dynamometer test method thus constructed uses a flywheel 6 having a constant mass regardless of the mass of the test vehicle 4, and does not have a switching mechanism for the flywheel 6.

Therefore, as in the conventional test method in which a plurality of flywheels are selected and used according to the mass of the test vehicle, a plurality of flywheels are required or a plurality of flywheel accommodation spaces are provided. Since the switching mechanism is not required, it can be manufactured at low cost, and the accommodation space is compact, so that the installation space of the chassis dynamometer 2 can be reduced.

Next, when carrying out an automobile exhaust gas test using the chassis dynamometer 2, the test vehicle 4 is entered into the test site, the wheels 5, 5 on the drive side are ridden on the rollers 3, 3 and then stopped. .

Before or after the entry of the test vehicle 4, the mass M of the test vehicle 4 is input to the controller 18. In this case, the equivalent inertia mass m of the flywheel 6, which is a known amount,
Or the idling time t in the target driving pattern 16
The a, the acceleration time tb, the constant speed time tc, the deceleration time td, and the standard rotation speed V of the drive motor 14 corresponding to the target traveling pattern have already been input to the controller 18.

Further, before and after the entrance of the test vehicle 4, the flywheel switching operation according to the mass of the test vehicle 4 was conventionally required, but in the present invention, the constant mass is irrespective of the mass of the test vehicle 4. Since the flywheel 6 of No. 1 is used, the above-mentioned switching operation is not required, and the conventional complicated work before the test can be eliminated.

Then, one end of an exhaust gas conduit 21 is connected to the exhaust pipe 20 of the test vehicle 4 on the chassis dynamometer 2,
The other end is connected to the exhaust gas analyzer 22, and when a series of preparatory work is completed, the driver's aid display device 8 is started, and the operation of the test vehicle 4 is started.

When the driver's aid display device 8 is started, the drive motor 14 is driven at the standard rotational speed V, the chart sheet 9 is unwound from the feed drum 11, and the chart sheet 9 is wound up by the winding drum 10. Sheet 9
The target travel pattern 16 depicted in FIG. 2 appears on the display screen 9 and moves in the direction of the arrow in FIG. On the other hand, the index 17 provided on the display screen 9 moves in the direction orthogonal to the movement direction of the chart sheet 9 in association with the accelerator operation or the vehicle speed.

The driver has such a target driving pattern 1
The accelerator operation is performed while gazing at the movements of 6 and the index 17, and the test vehicle 4 travels in a simulation based on the target travel pattern 16.

First, in the idling mode a of the target traveling pattern 16, the drive motor 14 is driven at a standard rotational speed to wind up and move the chart sheet 15, and when the idling time ta has elapsed, the mode is changed to the acceleration mode b. To do. At that time, from the computing unit 19 to the drive motor 14
A rotation speed signal at the time of correction acceleration based on the correction acceleration time is output to, and the rotation speed of the motor 14 is switched.

That is, when the equivalent inertial mass of the flywheel 6 is m, the mass of the test vehicle 4 is M, and the acceleration time in the target traveling pattern 16 is tb, the corrected acceleration time Tb is
It is corrected to Tb = (m / M) tb. Therefore, m <
In the case of M, as shown by the broken line in FIG. 3, Tb1 <tb is corrected, and the accelerator pedal depression amount of the test vehicle 4 is changed to the target traveling pattern 16
On the other hand, when m> M, it is corrected to Tb2> tb as shown by the chain line in FIG. 3, and the accelerator pedal depression amount is decreased as compared with the target traveling pattern 16 when Tm2> tb. When m = M, the acceleration time tb is not modified.

Therefore, when the standard rotation speed is V, the rotational speed Vb during correction acceleration of the drive motor 14 is inversely proportional to the ratio between the corrected acceleration time Tb and the acceleration time tb.
= (Tb / Tb) V. Therefore, m <M
When it is, it is corrected to Vb> V, and when it is m> M, it is V
Corrected to b <V. When m = M, the standard rotation speed V is not corrected.

Thus, each acceleration time Tb in the acceleration mode b
When 1, Tb2, tb have elapsed, the mode is changed to the constant speed mode c. At that time, a rotational speed cancellation signal at the time of correction acceleration is output from the computing unit 19 to the drive motor 14, and the rotational speed of the motor is switched to the standard rotational speed V.

In the constant speed mode c, since the inertial force by the flywheel 6 does not act, the constant speed time tc is constant regardless of the mass of the test vehicle 4, and when the constant speed time tc has elapsed, the deceleration mode is set. Move to d. At that time, the rotational speed signal of the corrected deceleration based on the corrected deceleration time is output from the computing unit 19 to the drive motor 14, and the rotational speed of the motor 14 is switched.

That is, when the equivalent inertial mass of the flywheel 6 is m, the mass of the test vehicle 4 is M, and the deceleration time in the target traveling pattern 16 is td, the corrected deceleration time Td is
It is corrected to Td = (m / M) td. Therefore, m <
When M, Td1 <td is corrected as shown by the broken line in FIG. 3, and when m> M, Td2> as shown by the chain line in FIG.
It is modified to td. The accelerator pedal depression amount of the test vehicle 4 in this case is the same as that described above. When m = M, the deceleration time td is not modified.

Therefore, the corrected deceleration rotational speed Vd of the drive motor 14 is inversely proportional to the ratio between the corrected deceleration time Td and the deceleration time td, where V is the standard rotational speed.
= (Td / Td) V. Therefore, m <M
In case of, Vd> V is corrected, and in case of m> M, Vd> V
Corrected to d <V. When m = M, the standard rotation speed V is not corrected.

As described above, according to the present invention, the same flywheel 6 is used in common regardless of the mass of the test vehicle 4, and the deviation between the mass m of the flywheel 6 and the mass of the test vehicle 4 due to this is calculated. The acceleration / deceleration operation time is corrected in proportion to the ratio and the acceleration / deceleration is equivalently corrected, and the accelerator opening of the test vehicle 4 is adjusted by the conventional test method, that is, the target traveling pattern 1
Since the test method is similar to the test method according to 6, the operating conditions of both are equivalent, and the composition of the exhaust gas discharged from the test vehicle 4 can be treated equally.

As a means for correcting the acceleration / deceleration time or the acceleration / deceleration of the test vehicle 4, the feeding speed of the chart sheet 15 in the time axis direction can be changed according to the mass of the test vehicle 4 as in the above-mentioned embodiment. Instead of this, it is also possible to describe the traveling pattern shown by the broken line or the chain line in FIG. 3 on the chart sheet 15, and use this according to the mass of the test vehicle 4 and transfer it at a constant speed.

As another means, the chart sheet 15 on which the target traveling pattern 16 is described is statically displayed at a predetermined position on the display screen 9, and the index 17 is set according to the accelerator opening or the vehicle speed. While moving in the axial direction, the index 17 is variably moved in the time axis direction of the chart sheet 15 when the test vehicle 4 is accelerated or decelerated, that is, the index 17 is moved in the XY directions of the chart sheet 15 based on the output of the computing unit 19. It is also possible to let.

[0039]

As described above, according to the chassis dynamometer test method of the present invention, a flywheel having a constant mass irrelevant to the mass of a test vehicle is used. It is possible to eliminate the absurdity of selective use according to the mass of the car and the complexity of flywheel replacement work, as well as the high equipment cost due to multiple flywheels and the increase in installation space. Also, the present invention sets the acceleration / deceleration time or acceleration / deceleration of the test vehicle according to the ratio between the mass of the test vehicle and the mass of the flywheel, so that the accelerator opening of the test vehicle is equal to that of the conventional test method. It is possible to set the driving conditions equivalent to the driving conditions of the test vehicle according to the conventional test method. Therefore, by applying the present invention to a chassis dynamometer test of an automobile exhaust gas, an exhaust gas composition equivalent to that of a conventional test method can be obtained. Therefore, instead of the conventional test method, a new and rational test method is obtained. There is an effect that can be provided.

[Brief description of drawings]

FIG. 1 is a perspective view showing a test situation using the present invention.

FIG. 2 is an explanatory diagram showing a main part of the present invention.

FIG. 3 is a chart showing a traveling pattern of the present invention.

[Explanation of symbols]

 2 Chassis dynamometer 3 Roller 4 Test vehicle 6 Flywheel

Claims (1)

[Claims] 1. A chassis dynamometer test method in which a flywheel is installed on a roller shaft of a chassis dynamometer, and inertia is applied to the roller during acceleration / deceleration of the test car, and a fly of a constant mass irrespective of the mass of the test car is used. A chassis dynamometer test method in which a wheel is installed on the roller shaft, and an acceleration / deceleration time or acceleration / deceleration of a test vehicle is set according to a ratio of a mass of the test vehicle and a mass of a flywheel.