Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01G—WEIGHING
  • G01G19/00—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups
  • G01G19/08—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups for incorporation in vehicles

Definitions

• TITLE Device and method for measuring axle load
• the present invention relates to a device for measuring axle load on a vehicle with leaf-spring suspension according to the preamble of patent claim 1, and a method for measuring axle load on a vehicle with leaf- spring suspension according to the preamble of patent claim 5.
• a truck has to comply with many different legal requirements and regulations. These requirements often vary from country to country and/or from market to market.
• One example of such a requirement is the maximum permitted axle load.
• the simplest and safest way of complying with valid rules is for the vehicle to be equipped with sensors which measure the load on each axle. When the vehicle is equipped with air suspension, the axle load is calculated by means of the pressure in the air bellows. For leaf-spring-mounted axles, the axle load has to be measured in a different way. Many vehicle manufacturers provide systems which measure the axle load on leaf-spring-mounted axles as optional equipment .
• the object of the invention is therefore to produce a device for measuring axle load on a vehicle with leaf- spring suspension which can be mounted in a space- saving and simple manner and also a method for measuring axle load on a vehicle with leaf-spring suspension in as simple and reliable a manner as possible .
• the method according to the invention achieves the L0 object by detecting the rotation of the spring shackle of a leaf spring.
• the axle load can L5 be obtained by measuring the rotation of the spring shackle of a leaf spring.
• the advantage of this is that the axle load can be obtained by measuring at one end of the leaf spring instead of measuring on the axle or in the center of the leaf spring. This leads to the
• axle load detector according to the invention being usable where a conventional measuring device cannot be mounted owing to lack of space .
• the axle load detector comprises a potentiometer.
• the advantage of this is that the conversion to axle load can be effected with discrete components.
• the axle load detector comprises an optical pulse generator.
• the advantage of this is that the conversion to axle load can be effected digitally in a simple manner. 5
• the axle load detector comprises a mechanical ratio.
• the advantage of this is that the entire active range of the sensor can be utilized.
• the rotation of the spring shackle of a leaf spring is detected.
• the advantage of this method is that it is possible to obtain the axle load by measuring at one end of the leaf spring instead of measuring on the axle or in the center of the leaf spring.
• the detection of the rotation of the spring shackle is carried out with a bracket connected to a sensor.
• the advantage of this is that the length of the bracket can be adapted so that the entire measuring range of the sensor can be utilized.
• FIG. 1 shows an advantageous embodiment of an axle load detector according to the invention.
• Fig. 1 shows an axle load detector 1 according to the invention. It comprises a bracket 2 which is mounted on a spring shackle 7.
• the axle load detector 1 also comprises a sensor 5 which is mounted on a frame 9 by means of a mounting angle 6.
• the sensor 5 is provided with a sensor arm 4 which is connected to the bracket 2 via a link arm 3.
• the front end of the leaf spring 8 is suspended from the frame 9 by means of a spring mounting and a spring bolt (not shown) .
• This spring mounting allows the front end to rotate around the spring bolt.
• the rear end of the leaf spring 8 is attached to a spring shackle 7.
• the spring shackle 7 is an articulated mounting which connects the rear end of the leaf spring 8 to the frame.
• the spring shackle 7 is on the one hand attached in an articulated manner to the leaf spring 8 by a spring bolt, and on the other hand attached in an articulated manner by a spring bolt to a spring mounting 10 mounted on the frame.
• the mechanical ratio between the rotation of the spring shackle 7 and the rotation of the sensor 5 is determined by the length of the bracket 2 together with the length of the sensor arm 4.
• the angular movement detected by the sensor 5 will be the same as the rotation of the spring shackle 7.
• a sensor often has a greater detection angle than the angle through which the spring shackle can rotate. It is therefore advantageous to make the distance from the point of rotation of the bracket 2 to the attachment of the link arm 3 greater than the distance from the point of rotation of the sensor arm 4 to the attachment of the link arm 3. In this way, a mechanical ratio is obtained, so that the active range of the sensor can be utilized as effectively as possible. This increases the resolution and the accuracy in measurement. For example, a spring shackle rotation of 40 degrees can be transformed into a sensor detection of 150 degrees in this way.
• the senor 5 is a potentiometer.
• the sensor 5 can also be of a different type. It may be suitable to use, for example, an optical pulse generator. It is also possible to use capacitive or magnetic sensors.
• the sensor 5 is connected to a unit which converts the signal of the sensor into a value which corresponds to the current axle load, for example a load-indicating unit or a control unit.
• This unit can either be a freestanding unit, for example a load-indicating unit which only calculates and indicates axle load, or it can be integrated into an existing control unit.
• the unit is positioned in the cab, but it is possible to position it anywhere on the vehicle. It is also possible to integrate a conversion function into the sensor so that the output signal of the sensor is directly proportional to the axle load.
• the conversion to axle load can take place in a discrete analog manner, a digital analog manner, or completely digitally.
• the signal-processing is carried out with discrete components.
• the analog signal is converted to a digital signal which is signal-processed with a processor.
• the signal- processing is carried out with a processor without the signal having to be converted first.
• the conversion method is selected depending on inter alia which sensor is used and the characteristic of the output signal.
• the signal-processing carried out by the conversion function can include inter alia compensating for the linearity of the signal, compensating for external temperature, low-pass filtering the signal etc.
• the current axle value can be indicated on a display, for example in the instrument. If the current axle value exceeds a predefined value, for example a maximum permitted axle load, the control unit can also give an alarm that a non-permitted state is present. This function can be used when the vehicle is being loaded, for example . When the permitted load for an axle is exceeded, a signal is given, and the loading can be stopped, or the load can be redistributed so that maximum use is made of the loading capacity.
• a predefined value for example a maximum permitted axle load
• This function can also be used while underway. This may apply for, for example, a truck with what is known as a pusher axle.
• a truck with what is known as a pusher axle.
• the load and thus the pressure on the other axles is increased. If the load on, for example, the front axle thus becomes too great, the unit warns that this is the case. The driver must then lower the pusher axle again. If the driver has lifted the pusher axle so as to increase the load on the driving axle in order, for example, to be able to get away in slippery road conditions, he can lower the pusher axle again as soon this is possible.
• the maximum measured axle load can be saved, for example, or the time for which the axle load exceeded a predefined load can be saved. This information may be important for service or for detecting overloading.
• the method comprises the step of detecting the rotation of the spring shackle of a leaf spring.
• the rotation of the spring shackle is advantageously detected with a bracket which is mounted on the spring shackle.
• the bracket transmits the rotation of the spring shackle to a sensor via a link arm.
• the rotation of the spring shackle is proportional to the load acting on the axle, that is to say the axle load.
• the output signal of the sensor is signal-processed in a suitable manner so that a value which corresponds to the axle load is obtained. This axle load value can be indicated on a display.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Vehicle Body Suspensions (AREA)
• Force Measurement Appropriate To Specific Purposes (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=20286092

Family Applications (1)

Country Status (4)

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Family Cites Families (9)

• 2001
  • 2001-11-23 SE SE0103928A patent/SE520499C2/sv not_active IP Right Cessation
• 2002
  • 2002-10-21 AU AU2002339820A patent/AU2002339820A1/en not_active Abandoned
  • 2002-10-21 WO PCT/SE2002/001909 patent/WO2003044472A1/en not_active Application Discontinuation
  • 2002-10-21 EP EP02778166A patent/EP1451539A1/de not_active Withdrawn

Non-Patent Citations (1)

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