JPS6287823A - Axle dynamometer - Google Patents

Abstract

PURPOSE:To enable measurement with high accuracy without remodeling the force acting on a car body through the tires of a car during running to a large extent, by constituting the titled dynamometer with a connection part, a detection part, and an angle signal transmitter. CONSTITUTION:A connection part 9 is connected to the axle of a car and tires and wheels are mounted on the axle to rotate said connection part 9. In order to measure a component force acting with the rotation thereof, a detection part 1 is connected to the axle to be measured. A detection element for measuring necessary component force is mounted and said component force is converted to an electric signal. Further, in order to take up the electric signal obtained in the rotary part 2 connected to the detection part 1 to a fixing side, a channel slip ring 3 having the proper number of outputs is mounted and an angle signal transmitter 5 accurately converting the angle of rotation of the rotary part 2 to an electric signal is arranged. Further, a circuit operating the signal showing the component force and the angle signal thereof is mounted. By this method, the signal from a dynamometer during rotation can be measured as the force acting on a car body.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an axle dynamometer for measuring various loads acting on an axle of an automobile.

The dynamic loads that act on the car body from the road surface through the tires while the car is in motion are extremely important in car body design, as they not only directly affect vehicle strength calculations and safety, but also the ride comfort for passengers and passengers. Therefore, it is desirable to be able to accurately measure various loads while the tire is rotating.

However, when measuring a load while a wheel to which a tire is attached is still rotating, the object to be measured is a complex complex force, which cannot be measured using a simple concept of a load cell. Furthermore, since each part of a typical automobile is extremely rationally designed, there is often no room to install measuring devices as is. Therefore, in order to measure the power acting on the axle of an automobile, it is necessary to extensively modify the object to be measured, making it difficult to measure it under conditions close to the actual vehicle.

SUMMARY OF THE INVENTION An object of the present invention is to provide an axle dynamometer that can measure the force acting on the axle and therefore the vehicle body through the tires of a running vehicle with high accuracy without making any major modifications to the vehicle.

This purpose is to provide an axle dynamometer having the structure described in the claims, that is, a connecting part that is connected to the axle of an automobile and rotates with tires and wheels attached thereto, and an axle dynamometer that operates as the connecting part rotates. a detection unit for converting the component force into an electrical signal; an angle signal transmitter for detecting the rotation angle of the connecting portion; and a circuit for calculating a signal representing the component force and the angle signal. This is accomplished by an axle dynamometer.

According to the axle dynamometer according to the present invention, it can be easily installed in an automobile, and no special modification is required. Therefore, the axle power under conditions close to those of the actual vehicle can be easily and accurately measured in a short time.

Hereinafter, the present invention will be disclosed with reference to the accompanying drawings, which illustrate embodiments.

FIG. 1 shows the configuration of an axle dynamometer according to the present invention, and a detection section 1 is equipped with a detection element for measuring necessary component forces, for example, six component forces. In this case, the six component forces are the three forces F acting on each axis, as shown in Figure 2.
It consists of three moments Mx and MvlMz that act on each axis: X, FY, F2°. Depending on the application, there may be component forces that do not need to be measured, but the entirety is shown here.

A detection unit 1 for measuring each of these component forces is connected to the axle to be measured, and is attached so as to receive the component force to be measured and convert the mechanical strain generated according to each component force into an electrical signal. can be constructed from strain gauge connections corresponding to each applied stress.

Various aspects of such a detection unit 1 are known, and other configurations may be adopted, so a detailed description thereof will not be given. In order to take out the electrical output obtained from the rotating part of the detection part 1 to the stationary side, a slip ring 3 with channels having an appropriate number of outputs is attached. This slip ring 3 is also sufficient as long as it can accurately extract a minute output without being affected by noise and can supply a current for operating the gauge, and there are no particular restrictions, so a detailed explanation will not be given. Detection part l
An angle signal transmitter 5 for converting the rotation angle of the rotating part 2 connected to the shaft into an accurate electrical signal is provided, for example, an encoder connected to the rotating part of the shaft to be measured by a gear mechanism 4. The encoder as the angle signal transmitter 5 receives a zero signal Z as a reference and two signals A and B for determining the rotation direction.
It is convenient to generate this. Note that the encoder as the angle signal transmitter 5 is just an example, and any resolver that can measure angles or any other device that can generate angle signals can be used in the same way.

These slip ring 3, gear mechanism 4, encoder, etc. are housed within a cover 6 because they include rotating parts.

A receptacle 8 is attached to the outside of the cover 6 in the axial direction to connect the pilot lamp 7 for indicating the zero position and cables for transmitting and receiving power and signals. It is assumed that the cover 6 allows movement in the axial direction and is restricted only to rotation in the rotational direction.

Such an axle dynamometer according to the present invention has a connecting portion 9 for connecting the portion contributing to the above-mentioned detection to the axle and for attaching a wheel integral with a tire. The axle mounting portion 9a is configured to be able to be mounted using an appropriate adapter, which will be described later, in consideration of the dimensions of the axle, the spacing between mounting holes, and the like.

The wheel mounting portion 9b is configured so that a slightly modified wheel for measurement can be mounted thereon.

FIG. 3 is a sectional view showing a state in which the axle dynamometer according to the present invention is installed in a measurable state. This shows the state in which the connecting portion 9 of the dynamometer is attached. A brake disc 13 is attached to the inside of the hub 12 for wheel attachment. Since these axle sides have not been modified in any way, they may vary in size depending on the car model, year, etc. Therefore, when installing wheels, the spacing and size of the hub 12 are often different. Therefore, the first adapter 14 is attached to the mounting hub side with a suitable bolt 10, and the axle mounting part 9 of the connecting part 9 has a mounting hole that matches the first adapter.
A and a second adapter 15 having a matching hole and tightened with a bolt 16 are interposed therebetween.

As a result, the axle dynamometer according to the present invention can be installed in many types of vehicles by simply replacing at least the first adapter 14 and without modifying the vehicle body.

Furthermore, since the axle dynamometer according to the present invention is mainly intended for measuring power in the actual state where tires are mounted,
It is necessary to install wheels with tires attached.

Therefore, a wheel 19 that is tightened with a bolt 18 is attached to the wheel attachment part 9b of the axle dynamometer connection part 9 via a wheel attachment adapter 17.

Since the mounting hole of the wheel 19 originally matches the mounting hub 12 of the axle, some modification is required to configure this embodiment. Usually, the center side of the wheel is cut out to have a slightly larger diameter, and a hole is provided to fit the wheel mounting hole of the axle dynamometer connection part 9. However, modifying the wheel itself is easier and cheaper than modifying the vehicle. Furthermore, by preparing several types of test wheels in advance, there is no need to modify them each time, and economical measurements and tests can be carried out.

The principle of measuring the power acting on an axle using the axle dynamometer according to the present invention will be explained below. Figure 4 shows
It shows the stationary coordinates indicating a state in which an external force F is applied to the automobile. In the figure, the direction of the vehicle's running resistance is vector X, the direction of vehicle weight reaction force is vector Z, the acting external force is vector F, and the rotation angle of the dynamometer is θ.

FIG. 5 shows a hector diagram in which the acting force F is decomposed into a dynamometer coordinate axis and a stationary coordinate system. In the figure, if the acting external force F is represented by the component forces FX and F2 in the stationary coordinate system, the result will be as follows.

F2=Fsin φ The dynamometer coordinate axes are as follows.

Therefore, the following relationship is established between Fx, Fz, Fx', and Fz.

F2 = FX'sinθ+F2'CO3θ Such a relationship is the same for the moments M x and M z.

When the above equation (3) is computed using an appropriate arithmetic circuit, we get
A component force measured in a rotating coordinate system can be converted to a component force in a stationary coordinate system.

FIG. 6 is a circuit diagram showing the main parts of an example circuit suitable for performing such calculations. It should be noted that a six-component force can be considered as the acting power, but here it is assumed that F and M do not rotate. Further, such calculations are not limited to the calculation circuit shown in this figure, and the same purpose can be achieved by combining microcomputers and other configurations.

The output signal from the axle dynamometer is voltage amplified by an amplifier. On the other hand, the encoder output signal passes through an amplifier down counter after phase discrimination and becomes a sin signal.

It is converted to cos and multiplied by the amplifier output. The resulting signals are subjected to an addition operation so as to satisfy the above equation (3).

In this way, according to the axle dynamometer according to the present invention,
The signals from the rotating dynamometer are easily converted to a stationary coordinate system and can be measured as forces acting on the vehicle body. As a result, it becomes possible to measure the power of a vehicle with tires attached to it without making any special modifications to the vehicle itself, thus achieving the intended purpose.

[Brief explanation of drawings]

Fig. 1 is a side view showing the configuration of the axle dynamometer according to the present invention, Fig. 2 is an explanatory diagram of six component forces, and Fig. 3 is a state in which the axle dynamometer according to the present invention is connected to the vehicle side. FIG. 4 is an explanatory diagram showing the hectoral direction of external force acting on the automobile, FIG. 5 is an explanatory diagram showing the relationship between rotating coordinates and stationary coordinates, and FIG. This is an example of a circuit diagram for signal processing of the meter. The correspondence of the main reference symbols in the figure is as follows. 1: Detection part 2: Rotating part 3 Spring ring 4: Gear mechanism 5 Two-angle signal transmitter 7: Pilot lamp 8: Receptacle 9: Connecting part F: External force M moment

Claims (1)

[Claims] 1. A connecting part (9) that is connected to the axle of an automobile and rotates with tires and wheels attached thereto, and converts component forces that act as the connecting part rotates into electrical signals. a detection unit (1) for detecting the rotation angle of the connecting unit (9), an angle signal transmitter for detecting the rotation angle of the connecting unit (9), and a circuit for calculating a signal representing the component force and the angle signal. Features an axle dynamometer. 2. In the axle dynamometer according to claim 1, the circuit for calculating the signal amplifies the signal representing the component force to a desired level and processes it in accordance with the phase of the output signal of the angle signal transmitter. An axle dynamometer configured as a circuit (Figure 6) that performs multiplication, addition and subtraction as trigonometric functions.