JP2005257451A - On-vehicle weight detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device capable of detecting the loading weight on a vehicle at low cost. <P>SOLUTION: This device is equipped with a sensor 11 for detecting the length of an expandable/contractible coil spring 25 of a suspension linked to wheels W<SB>1</SB>-W<SB>4</SB>of the vehicle C, and an operation control means 15 having a weight conversion part 16 for calculating the weight of a loaded article on the vehicle C corresponding to the spring length of the coil spring 25 outputted from the sensor 11. The sensor 11 is equipped with a Hall element 24 fixed to a part of the coil spring 25, and a magnet 23 fixed to another part of the coil spring 25, and determines whether the laden weight calculated by the weight conversion part 16 in a weight determination part 17 exceeds the legal weight set beforehand or not. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an on-vehicle weight detection device, and more specifically, detects a weight of a load on a vehicle, a bias in a load arrangement, and the like.

Conventionally, various devices for measuring the weight of an object loaded on a vehicle have been proposed.
For example, Japanese Patent Application Laid-Open No. 5-221251 discloses an apparatus for limiting the maximum speed when a dump truck is overloaded. As shown in FIG. 6, this apparatus includes a pressure sensor 3 that detects the extension chamber pressure of the suspension cylinders 1 and 2, and a load weight calculation unit 4 that calculates the load weight based on the pressure acquired by the pressure sensor 3. And a transmission 7 that is shifted by the control valve 6 and a shift controller 5 that outputs a switching signal to the control valve 6 by a speed signal from the shift lever 8, and the load weight calculated by the load weight calculation unit 4 is excessive. The shift controller 5 cuts off the output of the switching signal to the maximum speed stage when the weight is loaded, so that the transmission 7 is not shifted to the maximum speed stage when the weight is overloaded.

However, the apparatus disclosed in the above publication has a problem that the cost increases because the pressure sensor is used to measure the loaded weight. In addition to this, load weight detection devices such as a six-component force meter, a piezoelectric meter, a piezo type, a semiconductor capacitance type, and a load cell type have been proposed, but the cost is still high.
In addition, when the load is loaded in a biased manner in the front / rear / right / left direction with respect to the vehicle, the vehicle rolls over (rotates about the axis in the direction of travel) and makes it easier for the vehicle to roll over. A device capable of automatically detecting and avoiding such danger is desired.
JP-A-5-221251

  The present invention has been made in view of the above problems, and it is an object of the present invention to provide an apparatus that can detect the load weight of a vehicle at a low cost and can detect an uneven load arrangement on the vehicle.

In order to solve the above problems, the present invention provides a sensor that detects the length of a coil spring that expands and contracts a suspension linked to a vehicle wheel,
Computation control means having a weight conversion unit for calculating the weight of the load on the vehicle according to the spring length of the coil spring output from the sensor,
The sensor includes a semiconductor element having a Hall effect fixed to a part of the coil spring or a part continuous to the part, and a magnetic body fixed to the other part of the coil spring or a part continuous to the other part. The vehicle-mounted weight detection apparatus characterized by being a magnetic displacement sensor provided with.

  With the above configuration, the distance between the semiconductor element and the magnetic body is calculated by utilizing the difference in the current value flowing through the semiconductor element according to the proximity distance between the semiconductor element having the Hall effect and the magnetic body. Therefore, it is possible to easily obtain the loaded weight in terms of the coil spring length obtained from the distance. Further, if an inexpensive Hall element is used as the semiconductor element having the Hall effect for detecting the coil spring length, the loaded weight can be measured at a low cost.

  The calculation control means includes a weight determination unit that determines whether the loaded weight calculated by the weight conversion unit exceeds a preset limit weight.

  With this configuration, for example, if a legal weight is set as the limit weight, the driver can recognize that the current load weight exceeds the legal weight, which can be used for legal compliance.

The sensors are attached corresponding to the coil springs of the respective suspensions linked to the front, rear, left and right wheels of the vehicle, and the weights applied to the wheels obtained from the sensors by the arithmetic control means are calculated. While adding up to calculate the total loading weight,
When the difference between the maximum value and the minimum value among the respective weights loaded on the wheels acquired from the sensors exceeds the predetermined value, the arithmetic control means is biased in the loading arrangement. A bias determination unit for determining that there is a device is provided.

  For example, when the load is loaded unevenly without being loaded evenly on the front, rear, left and right of the vehicle, the weight obtained from the sensor attached to the coil spring of the wheel with a large load from the load and the load is small Although the difference from the weight acquired from the sensor attached to the coil spring of the wheel becomes large, with the above configuration, simply loading the difference between the maximum value and the minimum value of the weight acquired from each sensor It is possible to detect an uneven distribution. Therefore, it is possible to know in advance the risk of rollover and rollover caused by uneven loading, which can contribute to accident prevention.

  The arithmetic control unit includes a notification circuit unit that commands the generation of a warning alarm when the weight determination unit determines that the loaded weight exceeds the limit weight.

  With this configuration, the driver can recognize the danger by issuing a warning to the driver when overloading is detected.

  The arithmetic control unit includes a notification circuit unit that commands the generation of a warning alarm when the bias determination unit determines that the stacking arrangement is biased.

  With the above configuration, the driver can recognize the danger by issuing a warning to the driver when a deviation in the loading arrangement on the vehicle is detected.

  The weight determination unit includes a drive stop control unit that does not operate the vehicle drive source when it is determined that the loaded weight exceeds the legal weight.

  With the above configuration, since it is possible to control the vehicle so that it cannot travel when overloading is detected, it is possible to forcibly prevent violation of laws and regulations regardless of the driver's intention. Examples of the drive source that the drive stop control unit stops driving include an engine and a motor.

  As is clear from the above description, according to the present invention, it is obtained by utilizing the fact that the value of the current flowing through the semiconductor element differs according to the proximity distance between the semiconductor element having the Hall effect and the magnetic body. The coil spring length can be calculated from the distance between the semiconductor element and the magnetic body, and the loaded weight can be obtained by conversion from the coil spring length. Further, if an inexpensive Hall element is used as the semiconductor element, vehicle weight detection can be performed at a low cost. Furthermore, it is possible to easily detect the deviation in the load distribution by simply obtaining the difference between the maximum and minimum weight values obtained from the sensors attached to the wheels of the vehicle, and rolling over or overturning the vehicle. It is possible to recognize accidents and prevent accidents.

Embodiments of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the on-vehicle weight detection device 10 is mounted on a vehicle C, and the coil spring 25 of each suspension linked to the front wheels W ₁ and W ₂ and the rear wheels W ₃ and W ₄ of the vehicle C. The first to fourth sensors 11A to 11D, which are magnetic displacement sensors attached to the signal amplifier, the signal amplifier 12 for amplifying the electrical signals output from the first to fourth sensors 11A to 11D, and the analog signal to a digital signal An A / D converter 13 for conversion and a main body 14 for performing weight determination and bias determination described later are provided.

Since the first to fourth sensors 11A to 11D are the same, one sensor 11 will be described as a representative with reference to FIG.
The sensor 11 includes a Hall element (semiconductor element having a Hall effect) 24 attached to a part of the outer surface of the coil spring 25 and a magnet (magnetic material) attached to the other part of the outer surface of the coil spring 25 at a position facing the Hall element 24. 23.
As shown in FIG. 4, the Hall element 24 has two pairs of input terminals and output terminals. When a current flows through one of the input terminals and the output terminals, a magnetic field generated by the magnet 23 is applied. A voltage corresponding to the strength of the magnetic field is generated at the other input terminal and output terminal.

That is, when the coil spring 25 contracts and the magnet 23 approaches the hall element 24, the magnetic field applied to the hall element 24 is strengthened and a large voltage is generated. On the other hand, when the coil spring 25 extends and the magnet 23 moves away from the hall element 24. The magnetic field applied to the Hall element 24 is weakened and the generated voltage is reduced. By utilizing this Hall effect, the total length L of the coil spring 25 can be obtained by converting the distance between the Hall element 24 and the magnet 23 from the output voltage.
FIG. 3 shows an example, and the mounting position of the Hall element 24 and the magnet 23 may be anywhere as long as it is a part of the coil spring 25 or a part continuous to the part.

  The main body 14 includes an arithmetic control unit 15 that performs various arithmetic processes, a sound generation unit 20 that issues a warning alarm, a display unit 21 that is a display that displays a warning, and an engine or motor of the vehicle C according to a command from the arithmetic control unit 15. And a drive stop control unit 22 for controlling the vehicle drive source such as the above so as not to be driven.

  The calculation control means 15 receives the electrical signals output from the first to fourth sensors 11A to 11D, converts the electrical signals to calculate the weight, and the weight conversion unit 16 calculates the weight. A weight determination unit 17 that determines whether or not the loaded weight exceeds a preset limit weight, and a bias determination that determines a bias in the loading arrangement from the respective weights acquired from the first to fourth sensors 11A to 11D. And a notification circuit unit 19 for instructing the sound generation unit 20, the display unit 21 and the drive stop control unit 22 when there is an overload or a bias in the load arrangement.

よって、車両全体重量Mは数式２で求められ、積載重量ｍは数式３で算出される。

The weight conversion unit 16 calculates the distance between the magnet 23 and the Hall element 24 based on the voltage value output from the Hall element 24, and calculates the coil spring length L _i by multiplying the distance by the number of turns of the coil spring 25, or The coil spring length L _i is calculated using the correlation obtained in advance between the distance and the coil spring length L _i, and the vehicle weight M _i loaded on the wheel W _i is converted by Equation 1 using this coil spring length L _i. To do.

Therefore, the total vehicle weight M is obtained by Expression 2, and the loading weight m is calculated by Expression 3.

Note that k _i is the spring constant of the coil spring 25, g is gravitational acceleration, L _0i is the initial length of the coil spring, and M ₀ is the weight of the vehicle itself. Further, i = 1, 2, 3, and 4, i = 1 is the left front wheel W ₁ , i = 2 is the right front wheel W ₂ , i = 3 is the left rear wheel W ₃ , and i = 4 is the right rear wheel W. Let's represent ₄ .

As shown in FIG. 5, the weight determination unit 17 determines whether or not the load weight m acquired by the weight conversion unit 16 exceeds a preset limit weight (for example, legal weight) m ₀ (S1). When m> m ₀ , the notifying circuit unit 19 instructs the sounding unit 20 to sound a warning alarm and instructs the display unit 21 to display a warning message, and / or the drive stop control unit 22. To stop the vehicle drive source such as the engine or motor (S2).

If the legal weight is set as the limit weight m ₀ as in the above configuration, the driver can recognize that the current load weight exceeds the legal weight, which can be used for compliance with the law, and the engine or motor. It is possible to forcibly prevent violations of laws and regulations by automatically stopping the vehicle drive source. Further, since the inexpensive Hall element 24 is used for detecting the length of the coil spring 25, the loaded weight can be measured at a low cost.

Next, the bias determination unit 18 calculates a difference α between the maximum value and the minimum value of the vehicle weight M _i acquired from each of the first to fourth sensors 11A to 11D using Equation 4, and the difference α is calculated in advance. It is determined whether or not the set bias allowable constant α ₀ is exceeded (S3). If α> α ₀ , it is determined that there is a bias in the stacking arrangement, and the notification circuit unit 19 alerts the sounding means 20 to a warning alarm. And / or a command to display a warning message on the display means 21 and / or a command to stop the vehicle drive source such as an engine or a motor to the drive stop control unit 22 (S4).

With the above-described configuration, it is possible to easily calculate the load distribution by simply obtaining the difference α between the maximum value Max (M _i ) and the minimum value Min (M _i ) of the weight acquired from the first to fourth sensors 11A to 11D. By detecting the bias, it is possible to prevent a rollover, a rollover accident, or the like caused by the biased load.

(A) is a side view of the vehicle carrying the vehicle-mounted weight detection apparatus of embodiment of this invention, (B) is a top view. It is a block diagram which shows a vehicle-mounted weight detection apparatus. It is drawing which shows a magnetic displacement sensor. It is drawing which shows a Hall element. It is a flowchart which shows the process sequence of a vehicle-mounted weight detection apparatus. It is drawing which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 In-vehicle weight detection apparatus 11 Sensor 11A-11D 1st-4th sensor 12 Signal amplifier 13 A / D converter 14 Main body 15 Operation control means 16 Weight conversion part 17 Weight determination part 18 Bias determination part 19 Notification circuit part 20 Sounding means 21 display means 22 drive stop control unit 23 magnet 24 Hall element 25 spring C the vehicle W ₁ to _W-4 wheels

Claims (6)

A sensor that detects the length of a coil spring that expands and contracts a suspension linked to a vehicle wheel;
Computation control means having a weight conversion unit for calculating the weight of the load on the vehicle according to the spring length of the coil spring output from the sensor,
The sensor includes a semiconductor element having a Hall effect fixed to a part of the coil spring or a part continuous to the part, and a magnetic body fixed to the other part of the coil spring or a part continuous to the other part. An on-vehicle weight detection device characterized by being a magnetic displacement sensor.   The on-vehicle weight detection device according to claim 1, wherein the calculation control unit includes a weight determination unit that determines whether the loaded weight calculated by the weight conversion unit exceeds a preset limit weight. The sensors are attached corresponding to the coil springs of the respective suspensions linked to the front, rear, left and right wheels of the vehicle, and the weights applied to the wheels obtained from the sensors by the arithmetic control means are calculated. While adding up to calculate the total loading weight,
When the difference between the maximum value and the minimum value among the weights applied to the wheels acquired from the sensors is greater than a predetermined value, the arithmetic control means is biased in the loading arrangement. The in-vehicle weight detection device according to claim 1, further comprising a bias determination unit that determines that there is a bias.   The vehicle weight detection according to claim 2, wherein the arithmetic control unit includes a notification circuit unit that commands the generation of a warning alarm when the weight determination unit determines that the loaded weight exceeds the limit weight. apparatus.   The on-vehicle weight detection device according to claim 3, wherein the arithmetic control unit includes a notification circuit unit that commands the generation of a warning alarm when the bias determination unit determines that the loading arrangement is biased.   6. The drive stop control unit according to claim 2, further comprising a drive stop control unit that does not operate the vehicle drive source when the weight determination unit determines that the loaded weight exceeds the legal weight. In-vehicle weight detection device.

Images