JP4832179B2 - Truck load detection device - Google Patents

Description

  The present invention relates to an apparatus for detecting a load amount of a truck by detecting an air pressure of an air spring in a truck in which a rear wheel is attached to a chassis frame via an air spring.

Conventionally, as a measurement of the load capacity of a truck, each wheel is accurately placed on a loading plate equipped with a load transducer, and the weight obtained based on the signal from each load transducer is added, and further, the vehicle itself is calculated from this weight. The weight is calculated by subtracting the weight. However, a loading plate equipped with a load transducer as described above is very limited in terms of installation location and number of installations because the device is large and the cost of the device itself and its installation is significant. It was. Therefore the number of vehicles can receive the measurement of the load weight was insufficient only very slightly, to prevent overloading is.
In order to solve this problem, load signals from detectors that detect the load attached to the axle and detect the load are guided to the indicator installed in the vehicle cab via the cable. A device that calculates and displays weight (for example, see Patent Document 1) has been proposed. Since this device is always mounted on the vehicle, it is not necessary to place the vehicle on a loading plate installed on a flat place, and the load weight can be measured at an arbitrary place.

However, in the conventional load detection device, since the load is calculated from the strain generated on the axle, the detector itself is relatively expensive, and a strain detector for measuring the strain is attached to each axle. There is a problem that the apparatus becomes complicated as a whole due to necessity, and the unit price of the apparatus is significantly increased.
Further, in the conventional load detection device, an indicator for displaying the load weight is provided only in the vehicle cab. For this reason, when it is desired to know the loading weight during the loading operation, it is necessary to go to the operator's cab each time, and there is a problem that there is no degree of freedom such as performing the loading operation while viewing the display.
It is an object of the present invention to output a value from which an error equal to the difference between the loading amount at the time of starting the engine and the loading amount at the time of restarting the engine is removed as a loading amount, which is relatively simple in configuration and compared. Another object of the present invention is to provide a low-priced truck load detection device.
Another object of the present invention is to provide a truck load detection device capable of monitoring the load weight at any location outside the cab.

The invention according to claim 1 is a truck load detection device in which the rear wheel 12 is attached to the chassis frame 16 via air springs 17 and 18 as shown in FIGS.
The characteristic configuration is that the air pressure sensors 36 and 37 that can detect the air pressure of the air springs 17 and 18, the load amount is calculated based on the detection output of the air pressure sensors 36 and 37, and the load obtained by this calculation A controller 38 for outputting the amount and a load amount display means 41 for displaying the load amount output by the controller 38, and an engine sensor 51 for detecting the stop or start of the engine and outputting it to the controller 38 is provided. Is provided with a memory 39, and the controller 38 uses the detected output of the air pressure sensors 36 and 37 when the engine is started based on the detection output of the engine sensor 51 to calculate the load amount calculated when the engine is started. The controller 38 is configured to store the quantity as a quantity in the memory 39, and the controller 38 receives the energy from the detection output of the engine sensor 51. When the gin is stopped again, the difference obtained by subtracting the load amount at the time of starting the engine stored in the memory 39 from the load amount calculated based on the detection output of the air pressure sensors 36 and 37 at the time of re-stop is obtained. The controller 38 is configured to store the load error in the memory 39, and the controller 38 subtracts the load error stored in the memory 39 from the load amount calculated based on the detection output of the air pressure sensors 36 and 37 after the engine is stopped again. It is configured to output the value as a load .
In the truck load detection device according to the first aspect of the invention, it is necessary to provide the air pressure sensors 36 and 37 for detecting the air pressure of the air springs 17 and 18 for attaching the rear wheel 12 to the chassis frame 16. It is not necessary to attach a sensor for detecting strain or load generated on the front axle to the front axle. Therefore, the number of detectors itself is reduced and the degree of freedom of design is improved compared to the conventional case where distortion detectors are required to be attached to both the front axle and the rear axle. Since the number of man-hours for mounting them also decreases, it is possible to obtain a truck load detection device that is relatively simple and relatively inexpensive.
When loading the load, the truck 10 lays one side edge of the loading platform 10b on the loading place, loads the load from the one side edge, and completes the loading from the one side edge. , The other side edge may be laid on the loading place, and the load may be loaded again from the other side edge. In this case, the engine is stopped and a load is loaded, and the vehicle 10 is moved by starting the engine while loading the load. When the engine is started during loading, the air pressure detected by the air pressure sensors 36 and 37 may increase, and the loading amount calculated by the controller 38 based on the detection output of the air pressure sensors 36 and 37 may increase. May contain errors. In this case, the controller 38 stores the difference obtained by subtracting the load amount at the start of the engine from the load amount calculated when the engine is stopped again in the memory 39 as a load error, and is calculated after the engine is stopped again. The value obtained by subtracting the loading error stored in the memory 39 from the loaded amount is output as the loaded amount. Since this load error is stored in the memory as the difference between the load amount at the time of starting the engine and the load amount at the time of restarting the engine, the load amount output from the controller 38 after the engine is stopped again is Then, an error equal to the difference between the load amount at the time of starting the engine and the load amount at the time of restarting the engine is output as a value from which the error has been removed. Therefore, the load amount display means 41 can display a relatively accurate load amount of the load from which the error output by the controller 38 is removed.

The invention according to claim 2 is the invention according to claim 1, the air pressure in the air spring 17, 18 to be overloading the memory 39 is stored as the threshold value, the controller 38 of the air pressure sensor 36 The detected output is compared with the threshold value, and when the detected output of the air pressure sensors 36 and 37 is less than the threshold value, the controller 38 outputs a loadable signal as a load amount, and the detected output of the air pressure sensors 36 and 37 is equal to or greater than the threshold value. In some cases, the controller 38 outputs an overload signal as a load amount.
Although the load applied to the rear axle changes depending on the load amount and the position of the load, as will be proved in an embodiment described later, when the load having an allowable load amount is loaded, the load applied to the axle thereafter shows a substantially constant value. . Further, the load applied to the rear axle and the air pressure of the air springs 17 and 18 that support the axle after that increase linearly. Therefore, when a load having a load capacity allowed on the truck 10 is loaded on the loading platform, there is no great difference in the air pressures of the air springs 17 and 18 that support the rear axle of the truck. Therefore, storing the air pressure of the air springs 17, 18 to be overloaded as a threshold, the air pressure of the air springs 17, 18 for supporting the rear wheel 12 as measured in comparison with the threshold, the measured value is the threshold In the invention according to claim 2, in which it is determined that the load is overloaded when the load exceeds the limit, it is relatively accurately known whether the loaded load is less than the permitted load amount or whether the load amount has been reached. Can do.

The invention according to claim 3 is the invention according to claim 1 or 2, wherein the load amount display means 41 includes a transmitter 42 capable of transmitting radio waves including the load amount output by the controller 38 as data, A receiver 43 that receives the radio wave transmitted by the transmitter 42 and extracts the load amount output by the controller 38 from data included in the received radio wave; and a display device 44 that displays the load amount extracted by the receiver 43. It is provided with.
In the truck load amount detection apparatus according to the third aspect, when the driver loads a load on the loading platform of the truck 10, the receiver 43 in the load amount display means 41 is carried together with the display 44, and the display If the vehicle is installed at a location that can be seen even during the loading operation, the driver can recognize the total weight of the loaded baggage, for example, at the loading site other than the driver's cab by the information displayed on the display 44. .

  The truck load detection device of the present invention calculates the load based on the air pressure sensor that can detect the air pressure of the air spring that attaches the rear wheel to the chassis frame, and the detection output of the air pressure sensor. A controller for outputting the loaded amount, and a load amount display means for displaying the loaded amount output by the controller. In this truck load detection device, it is necessary to provide an air pressure sensor, but it is not necessary to attach a sensor for detecting strain or load generated on the front axle to the front axle. Therefore, the number of detectors itself is reduced and the degree of freedom of design is improved compared to the conventional case where distortion detectors are required to be attached to both the front axle and the rear axle. Since the number of man-hours for mounting them also decreases, it is possible to obtain a truck load detection device that is relatively simple and relatively inexpensive.

  In this case, a memory is provided in the controller, the air pressure of the overloaded air spring is stored as a threshold value, the controller compares the detection output of the air pressure sensor with the threshold value, and the detection output of the air pressure sensor is less than the threshold value. If the controller 38 outputs the loadable signal as the load amount, and the controller outputs the overload signal as the load amount when the detection output of the air pressure sensor is equal to or greater than the threshold value, it is added to the rear axle. Although the load varies depending on the load and the position of the load, if a load with an allowable load is loaded, the load applied to the axle thereafter shows a substantially constant value, so that the loaded load is less than the allowable load. It is possible to know relatively accurately whether or not the load capacity has been reached.

  The load amount display means transmits a radio wave including the load amount output by the controller as data, and the controller receives the radio wave transmitted by the transmitter and outputs the data from the received radio wave. A receiver that extracts the loaded capacity and a display that displays the loaded capacity extracted by the receiver, the driver can carry the receiver with the display when loading the load on the truck bed. By installing the indicator at a place where it can be seen even during the loading operation, the driver recognizes the total weight of the loaded luggage, for example, at the loading site other than the operator's cab by the information displayed on the indicator. be able to.

Further , the controller stores the difference obtained by subtracting the load amount at engine start from the load amount calculated when the engine is stopped again as a load error in the memory, and the load amount calculated after the engine is stopped again. Since the value obtained by subtracting the load error stored in the memory is output as the load amount, the value equal to the difference between the load amount when the engine is started and the load amount when the engine is stopped is removed. Can be output as the loading capacity.

Next, the best mode for carrying out the present invention will be described with reference to the drawings.
As shown in FIG. 5, the truck 10 has a cab 10 a and a loading platform 10 b mounted on a chassis frame 16, and the chassis frame 16 is provided with front wheels 11 and rear wheels 12 which are wheels. As shown in FIG. 1, the truck load detection device of the present invention is intended for an air suspension vehicle in which rear wheels 12, 12 are attached to a chassis frame via air springs 17, 18. That is, the truck 10 is provided with front wheels 11 and 11 and rear wheels 12 and 12 which are wheels on the left and right, respectively, and the left and right front wheels 11 and 11 can rotate on both ends of a front axle (not shown) extending in the vehicle width direction. Mounted on. On the other hand, the left and right rear wheels 12, 12 are fixed to both ends of a rear axle 13 (FIG. 3) extending in the vehicle width direction, and the rear axle 13 is rotatably held by an axle housing 14. Left and right air springs 17 and 18 are provided between the rear wheels 12 and 12 and the chassis frame 16 (FIGS. 2 and 3), respectively.

  As shown in FIG. 2, the left and right air springs 17 and 18 support the chassis frame 16, and the chassis frame 16 includes a pair of side frames 16 a and 16 b extending in the traveling direction of the track 10. Left air springs 17 and 17 are respectively provided on the left side frames 16a before and after the axle housing 14 holding the axle 13 (FIG. 3), and the right air springs 18 are provided on the right side frames 16b before and after the axle housing 14. , 18 are respectively arranged. These air springs 17, 17, 18, 18 are provided with a pair of suspension beams 19a, 19b. The left suspension beam 19a is bonded to the left air springs 17 and 17 respectively in front and rear. The right suspension beam 19b is bonded to the air springs 18 and 18 at the front and rear. Both ends of the axle housing 14 are respectively attached to the longitudinal center of the suspension beams 19a and 19b, and the axle housing 14 is installed on the pair of suspension beams 19a and 19b.

  A pair of radius rods 21 and 21 are attached between the axle housing 14 and the pair of side frames 16a and 16b, and a stabilizer 22 is provided between the pair of side frames 16a and 16b and the pair of suspension beams 19a and 19b. Provided. The stabilizer 22 is formed by fixing the base ends of stabilizer arms 22b and 22c to both ends of a stabilizer bar 22a extending in the vehicle width direction, and the tips of the stabilizer arms 22b and 22c are attached to a pair of suspension beams 19a and 19b. The radius rods 21 and 21 and the stabilizer arms 22b and 22c serve as tension bars or pull-back bars between the axle housing 14 and the pair of side frames 16a and 16b.

  The left and right air springs 17 and 18 have the same structure, and the left air spring 17 will be described as a representative. As shown in detail in FIG. 3, the air spring 17 includes a plate 17a fixed to the chassis frame 16 and a suspension. It has a base 17b attached to the end of the beam 19a and a rubber film 17c formed in a cylindrical shape. The rubber film 17c is connected between the plate 17a and the base 17b, and compressed air is supplied to the air spring 17 from an air tank 29 described later via a leveling valve 32. Further, a contact rubber 17d made of rubber is fixed to the upper surface of the base 17b, and the plate 17a comes into contact with the top of the rubber 17d when the compressed air in the air spring 17 is discharged. The air spring 17 is configured to absorb vibration generated by unevenness of the road surface during traveling of the truck 10 by the elasticity of the compressed air stored in the air spring 17 and not to be transmitted to the chassis frame 16.

Returning to FIG. 1, an air tank 29 that supplies compressed air to the left and right air springs 17, 18 is connected to the left and right air springs 17, 18 by an air pipe 31, and the right air spring 18, the air tank 29, A right leveling valve 35 is interposed in the air line 31 between them, and a left leveling valve 32 is interposed in the air line 31 between the left air spring 17 and the air tank 29. The right leveling valve 35 and the left leveling valve 32 have the same structure. The left leveling valve 32 will be described as a representative example. As shown in detail in FIG. 3, the leveling valve 32 is a three-port / three-position switching valve. The port 32a is connected to the air tank 29, the outlet port 32b is connected to air springs 17 and 17 that support the front and rear of the suspension beam 19a, and the exhaust port 32c is opened to the atmosphere. The valve 32 is fixed to the chassis frame 16, and a base end of a lever 32 d is pivotally attached to the valve 32. The tip of the lever 32d is pivotally attached to the suspension beam 19a via a link 32e. When the lever 32d is in a horizontal state as indicated by a solid line, the inlet port 32a and the outlet port 32b are blocked. However, loading the load on the loading platform of the truck 10 reduces the vehicle height so that the lever 32d is indicated by a broken line. When the vehicle is directed upward, the inlet port 32a and the outlet port 32b communicate with each other so that compressed air is supplied to the air springs 17 and 17 to increase the vehicle height. On the other hand, the truck bed 10 height is increased by a score Kudaro luggage, until the lever 32d is lever 32d is horizontal in communication and the exhaust port 32c and outlet port 32b when the now downwardly as indicated by a broken line The compressed air is discharged from the inside of the air spring 17 so that the vehicle height is always kept constant.

  Returning to FIG. 1, compressed air is supplied to the left and right air springs 17 and 18 from the air tank 29 via the leveling valves 32 and 35, respectively, and the air pressure of the compressed air supplied to the left and right air springs 17 and 18 is reduced. Detectable air pressure sensors 36 and 37 are provided. The air pressure sensors 36 and 37 in this embodiment are respectively attached to the left and right air springs 17 and 18, and the detection outputs of the left and right air pressure sensors 36 and 37 are connected to the control input of the controller 38. The controller 38 is provided with a memory 39, in which the air pressure of the air springs 17 and 18 overloading the truck 10 is stored as a threshold value. The controller 38 compares the detection outputs of the air pressure sensors 36 and 37 with a threshold value. When the detection outputs of the air pressure sensors 36 and 37 are less than the threshold value, the controller 38 outputs a stackable signal as a load amount. When the detection outputs of the air pressure sensors 36 and 37 are equal to or greater than the threshold value, the controller 38 is configured to output an overload signal as a load amount.

  A load amount display means 41 for displaying the load amount output from the controller 38 is connected to the controller 38. The load amount display means 41 in this embodiment includes a transmitter 42 capable of transmitting a radio wave including the load amount output by the controller 38 as data, a radio wave transmitted by the transmitter 42, and a received radio wave. A receiver 43 that extracts the load amount output from the controller 38 from the included data, and a display 44 that displays the load amount extracted by the receiver 43 are provided.

  As shown in FIG. 4, the transmitter 42 includes a power circuit 42a, a radio frequency (RF) circuit 42b, a modulation circuit 42c, a transmitting antenna 42f, and a CPU 42e, and the controller 38 is connected to the CPU 42e. The transmitter 42 is directly provided on the truck 10, and the power supply circuit 42a is a truck battery. The power supply circuit 42a supplies power to the CPU 42e, and the load amount calculated by the controller 38 under the control of the CPU 42e and supplied to the CPU 42e is modulated by the modulation circuit 42c as a binarized code from the CPU 42e, and the RF circuit 42b. It is configured to be capable of being amplified and transmitted from the transmitting antenna 42f.

  On the other hand, the receiver 43 includes a power circuit 43a, a radio frequency (RF) circuit 43b, a demodulation circuit 43c, an antenna 43f, and a CPU 43e, and a display 44 is connected to the CPU 43e. The receiver 43 is housed in a portable case together with the display 44, and the power supply circuit 43a is a battery built in the case. The radio wave emitted from the transmitter 42 is received by the receiving antenna 43f and supplied to the RF circuit 43b. The power supply circuit 43a supplies power to the CPU 43e, and the CPU 43e controls the RF circuit 43b and the demodulation circuit 43d. Then, the RF circuit 43b takes in only signals necessary for demodulation from the radio wave received by the receiving antenna 43f, and reproduces the load amount output by the controller 38 in the demodulation circuit 43d. The reproduced load amount is supplied from the CPU 43e to the display unit 44, and the display unit 44 is configured to display the load amount.

The operation of the thus configured truck load detection apparatus will be described.
The driver stops the truck 10 at the luggage collection place and loads the luggage. When loading, the driver carries the receiver 43 in the load amount display means 41 together with the display 44, and installs the display 44 in a place where it can be seen even during the loading operation. For example, in the case where a forklift is used for loading a load, the installation location may be the vicinity of the driver's seat of the forklift. When the loading of the load is started, the load on the loading platform 10b (FIG. 5) of the truck 10 fluctuates, the left and right air springs 17 and 18 are compressed, and the vehicle height is lowered. When the vehicle height is lowered, as shown in FIG. 3, the lever 32d of the leveling valve 32 faces upward as indicated by the broken line, and the inlet port 32a and the outlet port 32b communicate with each other so that the compressed air flows to the air springs 17, 17. Supplied. As a result, the air pressure of the compressed air inside the air springs 17 and 17 rises and the air spring 17 extends so as to push up the suspension beam 19a to increase the vehicle height, and the vehicle height is always kept constant.

  Returning to FIG. 1, the air pressures of the left and right air springs 17 and 18 are always detected by the air pressure sensors 36 and 37, and the vehicle height is kept constant by increasing the air pressure. , 37 also increases as the load capacity increases. On the other hand, the controller 38 compares the detection outputs of the air pressure sensors 36 and 37 with the threshold values stored in the memory 39, and the controller 38 outputs a stackable signal when the detection outputs of the air pressure sensors 36 and 37 are less than the threshold values. When the detection output of the air pressure sensors 36 and 37 is equal to or greater than the threshold value, the controller 38 outputs an overload signal as a load amount. Here, since the threshold value stored in the memory 39 is the air pressure of the air springs 17 and 18 in which the truck 10 is overloaded, when the controller 38 outputs a loadable signal, the total weight of the loaded luggage Means that the load amount has not yet reached, and when the controller 38 outputs an overload signal, it means that the total weight of the loaded load exceeds the allowable load amount of the truck 10.

  The load amount output by the controller 38 is transmitted from the transmitter 42 in the load amount display means 41, and the transmitted radio wave is received by the receiver 43 carried by the driver. The transmitter 42 extracts the load amount calculated by the controller 38 from the data included in the transmitted radio wave, and the display unit 44 displays the load amount extracted by the receiver 43. Here, since the indicator 44 is installed at a place where the driver can visually recognize even during the loading operation, when the information displayed on the indicator 44 changes from the loadable signal to the overloading signal. The driver can recognize on the spot that the total weight of the loaded luggage has reached the allowable loading capacity of the truck 10.

In the above-described embodiment, the case where the leveling valve 32 is operated during the loading of the load and the vehicle height is always kept constant has been described, but the leveling valve 32 is not operated during the loading of the load, A case where the leveling valve 32 is configured to operate when an engine (not shown) is started will be described as another embodiment of the present invention.
As shown in FIG. 1, the truck 10 according to another embodiment is provided with an engine sensor 51 that detects stop or start of an engine (not shown) and outputs it to the controller 38. The controller 38 is provided with a memory 39, and the controller 38 calculates the load amount calculated based on the detection outputs of the air pressure sensors 36 and 37 at the time of starting when the engine is started based on the detection output of the engine sensor 51. Is stored in the memory 39 as a load at the time of engine start.

Further, when the controller 38 detects that the engine has been stopped again by the detection output of the engine sensor 51, the controller 38 calculates the load amount at the time of the restart based on the detection outputs of the air pressure sensors 36 and 37 at the time of the stop. The difference obtained by subtracting the loading amount at the time of starting the engine stored in the memory 39 from the loading amount obtained by the calculation is configured as a loading error. The controller 38 is configured to store the obtained stacking error in the memory 39.
The controller 38 calculates the load amount based on the detection outputs of the air pressure sensors 36 and 37, and outputs the load amount obtained by this calculation. The controller 38 after the engine is stopped again, A value obtained by subtracting the loading error stored in the memory 39 from the loading amount calculated based on the detection output of the air pressure sensors 36 and 37 after the engine is restarted is output as the loading amount.

The operation of the load detection device for another truck configured as described above will be described.
The driver stops the truck 10 at the luggage collection point and loads the luggage with the engine stopped. When loading, the driver carries the receiver 43 in the load amount display means 41 together with the display 44, and installs the display 44 in a place where it can be seen even during the loading operation. When loading of the load is started, the load on the loading platform 10b (FIG. 5) of the truck 10 fluctuates, the left and right air springs 17, 18 are compressed, and the air pressure of the compressed air inside the air springs 17, 18 rises. , Vehicle height goes down. The air pressures of the left and right air springs 17 and 18 are always detected by the air pressure sensors 36 and 37. When the air pressure rises, the air pressure detected by the air pressure sensors 36 and 37 also rises. The load amount is calculated based on the detection outputs of the air pressure sensors 36 and 37, the load amount obtained by this calculation is output, and the load amount display means 41 displays the load amount of the load output by the controller 38. To do.

  Here, for example, the truck 10 may lay one side edge of the loading platform 10b on a loading place and load a load from the one side edge. In this case, when the loading from the one side edge is completed, it is necessary to move the truck 10 and lay the other side edge on the loading place and load the load again from the other side edge. Therefore, when the loading of the luggage carried out from one side edge is finished with the engine stopped, the engine is started to move the vehicle 10. Then, the controller 38 detects that the engine has been started based on the detection output of the engine sensor 51, and the load amount calculated based on the detection outputs of the air pressure sensors 36 and 37 at the start of the engine is used as the load at the start of the engine. The quantity is stored in the memory 39. Thereafter, the truck 10 is moved by the power of the started engine, lays the other side edge of the loading platform 10b at the loading place, and stops the engine again.

  When the engine is started, the leveling valves 32 and 35 are also operated, and the vehicle height is lowered by loading from one side edge. Therefore, at the time of starting the engine, as shown in FIG. Is in an upward state as indicated by a broken line. Accordingly, when the engine is started and the leveling valve 32 is operated, the leveling valve 32 communicates the inlet port 32a and the outlet port 32b and supplies compressed air to the air springs 17 and 17. As a result, the air pressure of the compressed air inside the air springs 17 and 17 increases, and the air spring 17 extends so as to push up the suspension beam 19a, thereby increasing the vehicle height. By supplying compressed air in this way, the air pressure inside the air springs 17 and 18 rises, and the air pressure detected by the air pressure sensors 36 and 37 also rises. For this reason, before the engine is started and after the engine is started and the truck 10 is moved, the load amount calculated by the controller 38 based on the detection outputs of the air pressure sensors 36 and 37 is different.

  On the other hand, after the truck 10 is moved and the other side edge of the loading platform 10b is laid on the loading place, loading of the luggage is started after the engine is stopped again. When the controller 38 detects that the engine has been stopped again by the detection output of the engine sensor 51, the controller 38 calculates the load amount when the engine is stopped based on the detection outputs of the air pressure sensors 36 and 37 at the time of the restart. To do. This load amount may differ from the load amount at the time of starting the engine for the reasons described above. For this reason, the controller 38 stores the difference obtained by subtracting the loading amount at the time of starting the engine stored in the memory 39 from the loading amount calculated when the engine is stopped again as a loading error in the memory 39.

  After the engine is stopped again, loading of a load from the other side edge is started, the left and right air springs 17 and 18 are compressed again, and the air pressure of the compressed air inside the air springs 17 and 18 rises. As a result, the air pressure detected by the air pressure sensors 36 and 37 also increases, and the controller 38 calculates the load amount based on the detection output of the air pressure sensors 36 and 37. However, the load amount obtained by this calculation is based on the load amount calculated when the engine is stopped again, and is not based on the load amount before the vehicle is moved. For this reason, the load amount calculated after restarting the engine includes an error equal to the difference between the load amount at the time of starting the engine and the load amount at the time of restarting the engine.

  On the other hand, the controller 38 after the engine is stopped again calculates the load amount based on the detection output of the air pressure sensors 36 and 37, but based on the detection output of the air pressure sensors 36 and 37 after the engine is stopped again. A value obtained by subtracting the loading error stored in the memory 39 from the calculated loading amount is output as the loading amount. Since this load error is stored in the memory as the difference between the load amount at the time of starting the engine and the load amount at the time of restarting the engine, the load amount output from the controller 38 after the engine is stopped again is Then, an error equal to the difference between the load amount at the time of starting the engine and the load amount at the time of restarting the engine is output as a value from which the error has been removed. The load amount display means 41 displays a relatively accurate load amount of the load from which the error output by the controller 38 is removed.

Next, examples of the present invention will be described.
<Example 1>
A truck having a front wheel attached to the chassis frame via a leaf spring and a rear wheel attached to the chassis frame via an air spring and having an allowable load capacity of 14 tons was prepared. In addition, 14 packages of 1 ton were prepared as packages. Changes in the load applied to the front axle and the rear axle when the luggage was sequentially loaded from the front of the truck bed were measured.
<Example 2>
Fourteen pieces of the same luggage as in Example 1 were sequentially loaded from the rear on the same truck bed as in Example 1. Thus, the change of the load applied to the front axle and the rear axle when the luggage was sequentially loaded from the rear of the truck bed was measured.

<Example 3>
The same 14 pieces of luggage as in Example 1 were sequentially loaded from the left front on the same truck bed as in Example 1, and then sequentially loaded from the right front. Thus, the change of the load applied to the front axle and the rear axle when the load was sequentially loaded from the left and right front of the truck was measured.
<Example 4>
The relationship between the load applied to the rear axle and the air pressure of the air spring that supports the rear axle was measured by a pressure sensor. The result is shown in FIG.

<Comparison test and evaluation>
FIG. 6 shows changes in the load applied to the front axle and the rear axle measured in the first to third embodiments. As is apparent from FIG. 6, in the first embodiment, the load applied to the front axle increases with the start of loading, and thereafter, the load applied to the rear axle gradually increases to reach an allowable loading capacity. This is considered to be due to the fact that, in Example 1, the load was loaded from the front of the loading platform, so that the initial load was mainly supported by the front axle. On the other hand, in the second embodiment, the load applied to the rear axle increases with the start of loading, and thereafter, the load applied to the front axle gradually increases to reach the permitted loading capacity. This is considered to be due to the fact that the load at the beginning of loading is mainly supported by the rear axle because the load is loaded from behind the loading platform in the second embodiment. Further, in the third embodiment, both the loads applied to the front axle and the rear axle are increased with the start of loading. This is because in Example 3, since the load was loaded from the front of one side of the loading platform, even if the initial load was supported by the front axle, the load was sequentially loaded and the load was gradually twisted and supported by the rear axle. It is thought to be caused by

On the other hand, in the state in which all the loads corresponding to the load capacity allowed for the truck are mounted on the loading platform, that is, in the part A in FIG. 6, the difference in load applied to the rear axle in the first to third embodiments is only 50 to 50. It can be seen that the value is almost constant with no difference of 60 kg. Further, as shown in FIG. 7, it can be seen that when the load applied to the rear axle increases, the air pressure of the air spring that supports the axle thereafter increases linearly. Therefore, even if the air pressure of the air spring that supports the rear axle of the truck loaded with the load of the load allowed on the truck is loaded, there is no great difference.
Therefore, from the results of FIGS. 6 and 7, the air pressure of the overloaded air spring is stored as a threshold value, the air pressure of the air spring supporting this rear wheel is measured and compared with the threshold value, and the measured value There turns out that no more differences significantly payload be determined that overloading when exceeding the threshold value, results in the loading amount detecting apparatus of the present invention is seen that it would be relatively correct.

It is a block diagram which shows the air circuit and electric circuit of the loading capacity detection apparatus of the truck of this invention embodiment. It is a top view which shows the state in which the rear wheel was attached to the chassis frame via the air spring. It is a side view which shows the state in which the rear wheel was attached to the chassis frame via the air spring. It is a conceptual diagram which shows the structure of the load amount display means. It is a side view of the truck which has the load amount detection apparatus. It is a figure which shows the change of the load added to the front axle and the rear axle in an Example. It is a figure which shows the relationship between the load added to the rear axle in an Example, and the air pressure in an air spring.

Explanation of symbols

12 Rear wheel 16 Chassis frame 17, 18 Air spring 36, 37 Air pressure sensor 38 Controller 39 Memory 41 Loading amount display means 42 Transmitter 43 Receiver 44 Display 51 Engine sensor

Claims (3)

A load detection device for a truck in which a rear wheel (12) is attached to a chassis frame (16) via an air spring (17, 18),
An air pressure sensor (36, 37) capable of detecting the air pressure of the air spring (17, 18);
A controller (38) for calculating the load amount based on the detection output of the air pressure sensor (36, 37) and outputting the load amount obtained by the calculation;
Wherein the controller (38) Bei give a and a load display device for displaying the load amount outputted (41),
An engine sensor (51) for detecting stop or start of the engine and outputting it to the controller (38) is provided,
The controller (38) is provided with a memory (39),
The controller (38) calculates the load amount calculated based on the detection output of the air pressure sensor (36, 37) at the time of engine start when the engine is started by the detection output of the engine sensor (51). Is stored in the memory (39) as a load amount of
The controller (38) is configured to calculate the load amount calculated based on the detection output of the air pressure sensor (36, 37) when the engine is stopped again when the engine is stopped again by the detection output of the engine sensor (51). The memory (39) is configured to store, in the memory (39), a difference obtained by reducing the load at the time of starting the engine stored in the memory (39) as a loading error.
The controller (38) loads a value obtained by subtracting the loading error stored in the memory (39) from the loading amount calculated based on the detection output of the air pressure sensor (36, 37) after the engine is stopped again. An apparatus for detecting a load amount of a truck, characterized by being configured to output as a quantity. Stored air pressure becomes the previous SL overloading the memory (39) air springs (17, 18) as a threshold value, compared with the threshold detection outputs of the controller (38) the air pressure sensor (36, 37) When the detection output of the air pressure sensor (36, 37) is less than the threshold value, the controller (38) outputs a loadable signal as a load amount, and the detection output of the air pressure sensor (36, 37) 2. The truck load amount detection device according to claim 1, wherein when the value is equal to or greater than the threshold value, the controller (38) outputs an overload signal as a load amount. The load display device (41) is received the controller (38) originating capable transmitter radio moistened with payload outputted as data (42), a radio wave which the transmitter (42) is sent And a receiver (43) for extracting the load amount output by the controller (38) from the data included in the received radio wave, and a display (44) for displaying the load amount extracted by the receiver (43). The truck load detection device according to claim 1 or 2, further comprising:

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