JPH075024A - Measurement apparatus for weight of vehicle equipped with trunninon axle - Google Patents

Abstract

PURPOSE:To surely measure weight of carrying-load on a load carrier applied on a rear wheel axle of a multiple axle type vehicle even when the vehicle is inclined to the front or back, or the right or left and to reduce the cost by decreasing the number of strain detectors to be provided. CONSTITUTION:A chassis 1 is equipped with a front axle on the front side and two axles 6, 7 that are attached thereto via a trunnion axle 5 and a laminated leaf spring 8 on the rear side. A strain detector 24 is attached to the central portion of the trunnion axle 5 in the width direction thereof and a strain detector 21 is attached to the central portion of the front axle 2 so that a weight of the vehicle or the carrying-load is obtained from electric signals converted therefrom. When the weight of the vehicle and the carrying-load weight on the vehicle, the total weight is loaded to the rear axles 6, 7 via the chassis 1, trunnion axle 5 and laminated leaf spring 8 in order, so that the strain occurring in the central portion of the trunnion axle 5 corresponding to the weight is detected by the strain detector 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle weight measuring apparatus suitable for a vehicle of a type in which a common carrier spring suspended between two axles arranged at a predetermined distance is attached to a chassis via a trunnion shaft. It relates to the device.

[0002]

2. Description of the Related Art Overloading a truck or the like not only hinders the operability of the vehicle itself and causes a traffic accident, but also causes damage to the vehicle and the road surface. The manager checks whether or not the vehicle is in a state of loading below the legally required loading amount by using a vehicle weight measuring device.

Therefore, the load amount of a vehicle is measured mainly for a large vehicle such as a truck. As a conventional load amount measuring method, for example, (i) load of a load converter installed on the ground is used. With the wheels of the vehicle to be measured accurately placed on the plate, measure the wheel weight or axle weight of the vehicle, add these wheel weights, etc. to obtain the vehicle weight. A method of determining the vehicle load by subtracting the specified empty load (weight of the vehicle itself). (Ii) As disclosed in Japanese Patent Publication No. 49-21676, Japanese Patent Publication No. 3-15967, and Japanese Patent Publication No. 64-2882, a conversion device using a strain gauge on the surface of a vehicle axle or axle housing. A method to detect the surface strain of the axle or the axle housing by installing and to determine the load amount on the vehicle side from this detected value. Etc. are known.

[0004]

However, in the measuring method described in the above item (i), the load measuring device itself becomes large in size and the cost is high. The drawback is that the location and the number of installations are severely restricted.

Further, according to the measuring method of item (ii) described in the above publication, since the load measuring device is installed on the side of the vehicle, there are restrictions on the installation place and large size of the device as in the ground-installed type. However, the above-mentioned publications have their respective problems.

For example, the disclosed techniques of Japanese Patent Publication No. Sho 21-21676 and Japanese Examined Patent Publication No. 3-15967 both cause bending strain generated on the surface of the axle (axle housing) due to the applied load to the surface of the axle to be measured. The strain sensor attached is used for detection, and the detected value is converted into an electric quantity to detect an accurate load amount on the vehicle side. In these technologies, however, the front axle has one or two axles. However, in a vehicle having two rear axles (hereinafter referred to as "a vehicle having multiple axles"), it is a problem that a strain gauge device must be attached to each of the two rear axles that mainly carry a load amount. .

On the other hand, the disclosed technique of Japanese Patent Publication No. 64-2882 discloses a differential gear device (differential gear) when strain is detected in the rear axle that mainly carries the load.
Unit), strain gauges must be installed near both wheels, so that in the case of a multi-axle vehicle, as in the case of the technique of Japanese Patent Publication No. 49-21676 mentioned above, In addition to the problem that a strain detector must be attached to each of the rear axles, there is a drawback that the load amount cannot be accurately detected when the vehicle is tilted left and right.

The present invention has been made in view of the above circumstances. An object of the present invention is to reduce the number of strain detectors installed to simplify the structure and reduce the cost even if the vehicle is used. It is an object of the present invention to provide a vehicle weight measuring device for a vehicle equipped with a trunnion shaft capable of accurately measuring a load amount on the vehicle side even when the vehicle tilts in the front-rear direction, the left-right direction, or when the load is unbalanced.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is of a type in which a rear two axles are suspended by a trunnion shaft installed in a rear region of a chassis via a common bearing spring for cushioning. In the vehicle, a strain detector having a strain gauge for detecting the bending strain of the trunnion shaft is attached to the shaft surface of the trunnion shaft at a substantially intermediate position in the vehicle width direction, and a load amount is applied to the vehicle. Occasionally, the bending strain of the trunnion shaft surface, which occurs in accordance with the weight of the vehicle and / or the applied load, is configured to be detected by the strain detector, and a detection signal output from the strain detector is detected. Based on the above, the vehicle side is configured to measure the vehicle dead weight and / or the load amount described above.

Further, according to the present invention, a trunnion shaft having at least one front axle and two rear axles is provided in a rear region of the chassis, and the rear two axles are provided with a common support spring for buffering. In a suspension type vehicle, a front strain detector having a strain gauge for detecting a bending strain of the front axle is attached to the shaft surface of the front axle at a substantially intermediate position in the vehicle width direction, and the trunnion shaft is attached. A rear strain detector having a strain gauge for detecting the bending strain of the trunnion shaft is mounted on the shaft surface at a substantially intermediate position in the vehicle width direction, and based on the detection signals output from these two strain detectors. The vehicle side is configured to measure the vehicle self-weight and / or the load amount described above.

[0011]

The vehicle weight measuring device of the vehicle having the trunnion shaft configured as described above finally concentrates the load amount of the loading platform applied to the rear two axles on the trunnion shaft via the common support spring for buffering. Then, by electrically detecting the bending strain generated on the trunnion shaft surface due to the concentrated loading amount, by using one strain detector at a substantially intermediate position in the vehicle width direction of the trunnion shaft, Even if the vehicle is tilted in the front-rear direction, the left-right direction, or even if the load is unevenly loaded on the bed, the load amount should be measured accurately, and the measurement result should be known on the vehicle side. It was done.

In the case of a vehicle using double tires on the rear two axles, it is also necessary to reduce fluctuations in the measured values due to movement of the center point of the applied load due to the ground contact mode of the road surface of each pair of double tires. I have to.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle weight measuring device according to the present invention will be described below by taking a three-axle type truck in which two rear axles are connected to a chassis via a trunnion shaft as an example.

FIG. 1 is a plan view showing a chassis structure of a three-axle type truck in which a vehicle weight measuring device for a vehicle having a trunnion shaft according to an embodiment of the present invention is installed, and FIG. FIG. 3 is a side view of the truck chassis shown in FIG.

In FIGS. 1 and 2, reference numeral 1 is a ladder-type truck chassis with a bumper, for example, a steering device, an engine, a transmission, etc. (not shown) at appropriate portions in the front region thereof.
Equipped with necessary equipment. In addition, a luggage carrier (not shown) having an appropriate structure is placed from the middle region to the rear region of the chassis 1.

Reference numeral 2 denotes a front axle provided in a front region of the chassis 1, which is integrated with the chassis 1 in the front-rear direction of the truck and vertically relative to the chassis 1 via a pair of left and right overlapping leaf springs 3. Suspended for movement. This front axle 2
A pair of left and right front wheels 4 are rotatably attached to both ends of the vehicle via appropriate wheel angle changing means (not shown).

Reference numeral 5 denotes a trunnion shaft having a structure known per se, and both end regions of the trunnion shaft are fixed to two structural members of the chassis 1 in the front-rear direction and the left-right direction (vehicle width direction) of the chassis 1 in the rear region. Are provided so as to be combined with each other.

The trunnion shaft 5 is provided so as not to rotate with respect to the chassis 1. As a form of the trunnion shaft, a connection structure (not shown) of a first rear axle 6 and a second rear axle 7 described later is provided so as to be swingable (seesaw motion) with respect to the trunnion shaft 5. The form and the form in which the trunnion shaft 5 is rotatably provided with respect to the chassis 1 and the connecting structure of the first rear axle 6 and the second rear axle 7 is fixedly provided with respect to the trunnion shaft 5. However, the present invention can be applied to both formats. In the illustrated embodiment, the latter format is assumed for the time being, and the description will be continued.

Reference numerals 6 and 7 denote a first rear axle and a second rear axle, which are arranged in the rear region of the truck at a predetermined distance in the front-rear direction, and a trunnion shaft 5 via a pair of left and right common overlapping leaf springs 8. And is configured to improve stability during traveling by using appropriate torque rods 9 and 10, respectively.

In this case, the first rear axle 6 located at the front and the second rear axle 7 located at the rear are formed by appropriate means.
It is configured to be supported by a connecting structure that can swing about the trunnion shaft 5 while maintaining a predetermined interval. As a result, the first rear axle 6 and the second rear axle 7 are
The truck is suspended integrally with the chassis 1 in the front-rear direction and independently in the up-down direction so as to be relatively movable.

Further, the first rear axle 6 comprises a differential gear device 13 which meshes with a drive gear provided on the rear end side of the propeller shaft 12 which is connected to the transmission through an appropriate universal joint 11. The drive axle is configured to engage the front end of the common leaf spring 8, and the second rear axle 7 is configured to support the vehicle weight and rotate. It is configured to engage with the rear end of the overlapping leaf spring 8.

The trunnion shaft 5 and the two rear axles 6,
As for the relative position with respect to 7, due to the relationship between the drive axle and the support-dedicated shaft as described above, the trunnion shaft 5 and the overlapping leaf spring 8 are located slightly forward of the central position of the common overlapping leaf spring 8. It is set to join.

Reference numeral 14 designates a pair of left and right first rear wheels of a double tire type which are attached to both ends of the first rear axle 6 via appropriate means so as to rotate integrally with the first rear axle 6.
Reference numeral 5 denotes a pair of left and right second rear wheels of a double tire type which are rotatably attached to both ends of the second rear axle 7 through appropriate means.

The chassis 1 and each axle 2, of the four overlapping leaf springs 3 and 8 in the embodiment shown in FIGS.
The connecting structure or supporting structure for 6, 7 is configured to be performed by means known per se.

Reference numeral 21 is a front strain detector equipped with a first strain gauge 22 (see FIG. 3) for detecting bending strain of the front axle 2, which is substantially intermediate in the vehicle width direction of the front axle 2 by an appropriate means. Mounted on the shaft surface in position. As shown in FIG. 3, the first strain gauge 22 is connected to a front axle strain detection circuit 23 which is, for example, a Wheatstone bridge circuit known per se.

Reference numeral 24 is a rear strain detector equipped with a second strain gauge 25 (see FIG. 3) for detecting the bending strain of the trunnion shaft 5, and the trunnion shaft 5 is provided by an appropriate means.
Mounted on the shaft surface at a substantially intermediate position in the vehicle width direction.

As shown in FIG. 3, the second strain gauge 25 is connected to a trunnion shaft strain detecting circuit 26 which is, for example, a Wheatstone bridge circuit known per se.

Reference numeral 27 is an appropriate weight calculation circuit composed of, for example, a microcomputer or the like, and based on the detection output from the front axle strain detection circuit 23 and the detection output from the trunnion shaft strain detection circuit 26, the weight of the truck and / or Alternatively, it is configured to be able to measure the amount of load on the platform.
If the weight calculation circuit 27 is configured to store the truck weight in advance, the total weight of the vehicle can be measured.

Reference numeral 28 denotes a weight comparator in which the legally-loaded load amount of the three-axle type truck is set as a reference value. The weight comparator 28 compares the output value from the weight calculation circuit 27 with a reference value to determine whether the weight value is greater than the reference value. When the calculation output value from the calculation circuit 27 exceeds the reference value, it can be output to the alarm indicator 30 described later. The weight comparator 28 is also configured to be able to directly output the output value from the weight calculation circuit 27 to a load amount indicator 29 described later.

Reference numeral 29 is an appropriate load amount indicator provided at an appropriate portion of the truck, and is constructed so that the output value from the comparator 28 can be converted into a digital value and displayed.

Reference numeral 30 denotes an appropriate alarm indicator provided at a prominent place outside the truck so that when the output value from the arithmetic circuit 27 exceeds the reference value, its state can be electrically displayed step by step. It is configured.

The operation of the vehicle weight measuring apparatus of the illustrated example will be described below.

First, when a load of a certain weight is placed on the bed of a truck placed in a horizontal position, the weight of the front region of the chassis 1 is added to the front axle 2 via the overlapping leaf spring 3, and further, It is added to the ground (road surface) via the wheel angle changing means and the pair of left and right front wheels 4.

As a result, the pair of left and right front wheels 4 serve as a fulcrum, and the connecting portion between the front axle 2 and the overlapping leaf spring 3 serves as a point of action. At both end regions of the front axle 2, the front region of the chassis 1 is provided. Therefore, the intermediate portion of the front axle 2 slightly bends downward.

The first strain gauge 22 of the front strain detector 21 electrically detects the bending strain of the front axle 2 due to this bending, and outputs the electric signal to the front axle strain detection circuit 23.

On the other hand, the weight and load of the rear region of the chassis 1 are first applied to the trunnion shaft 5 via the two structural members of the chassis 1 and, further, the first rear axle 6 via the common leaf spring 8. Is transmitted to the second rear axle 7, and finally is applied to the ground via two pairs of left and right rear wheels 14 and 15.

As a result, the pair of left and right rear wheels 14 and 15 serve as fulcrums, and the overlapping leaf spring 8 common to the trunnion shaft 5 is provided.
As a point of action, the total weight of the rear region of the chassis 1 and the loading amount of the platform is added to both end regions of the trunnion shaft 5, and the trunnion shaft 5 slightly moves downward. It will bend.

At this time, the second strain gauge 25 of the backward strain detector 24 electrically detects the bending strain of the trunnion shaft 5 due to this bending, and outputs the electric signal to the trunnion shaft strain detection circuit 26.

Since the front axle strain detection circuit 23 and the trunnion shaft strain detection circuit 26 are connected to the weight calculation circuit 27, the weight calculation circuit 27 outputs the strain detection output from the front axle strain detection circuit 23. Based on the strain detection output from the trunnion axis strain detection circuit 26, the weight of the truck and / or the load amount of the bed is calculated, and the calculation result related to the load amount is output to the weight comparator 28, for example.

In this case, the rear strain detector 24 is attached to the shaft surface of the trunnion shaft 5 at the intermediate position in the vehicle width direction, and the front strain detector 21 is further attached to the shaft surface of the front axle 2 at the intermediate position in the vehicle width direction. Since it is mounted on the surface, even when the truck is tilted in the left-right direction and the front-rear direction, even when the ground contact situation of the double tires on the first rear wheel 14 and the second rear wheel 15 changes, accurate The amount of applied load can be calculated.

Therefore, the weight comparator 28 compares the calculation result related to the applied load amount with the legally applied load amount as the reference value, and when the calculated result related to the applied load amount exceeds the reference value, an alarm display is given. It outputs the excess condition to the container 30. At the same time, the weight comparator 28 outputs the calculation result relating to the load amount to the load amount display 29.

As a result, the weight of the load currently loaded on the truck can be easily visually recognized, and further, when the loaded amount is exceeded, the state can be known outside the vehicle.

When it is desired to determine the dead weight of the truck in operation, the weight calculation circuit 27 may be constructed so as to be able to do so.

The embodiment shown in the drawings has been described above.
The present invention is not limited to this, and can be variously modified and implemented without departing from the scope of the invention.

For example, in the illustrated embodiment, the trunnion shaft 5 is positioned above the common leaf spring 8 in common, but the trunnion shaft 5 is positioned below the common leaf spring 8 in common. Good.

In the illustrated embodiment, the front strain detector 21 and the rear strain detector 24, and the front axle strain detection circuit 23 and the trunnion shaft strain detection circuit 26 are also provided.
Although the specific structure of the above is omitted, these can be configured as a structure known per se.

Further, the specific structure in which the first rear axle 6 and the second rear axle 7 are arranged in the rear region of the truck at a predetermined distance in the front-rear direction is also a structure known per se. be able to.

In the illustrated embodiment, the front strain detector 21 and the rear strain detector 24 are connected to the front axle 2 respectively.
The trunnion shaft 5 is mounted on the shaft surface at the intermediate position in the vehicle width direction, but the intermediate position in the vehicle width direction may be substantially the intermediate position.

The strain detectors 21 and 24 may be mounted on the upper surface of the axle 2 or the trunnion shaft 5 or may be mounted on the lower surface, but the upper surface of the strain detectors 21, 24 jumps up from the road surface when the vehicle is running. It is advantageous in that it does not hit foreign matter such as stones.

In the illustrated embodiment, a three-axle type truck is described as an example, but the present invention can also be applied to a front two-axle type truck, and for vehicles other than automobiles. However, it is applicable.

[0051]

As described above, since the vehicle weight measuring device for a vehicle having the trunnion shaft according to the present invention is constructed so that the strain detector is attached to the trunnion shaft, it is attached to each axle of the rear axle. Compared to the conventional multi-axle type technology that had to be installed, the number of strain detectors installed is smaller, the configuration is simplified, and the manufacturing work is easier than that of the conventional technology. Therefore, there is an excellent effect that it is advantageous in terms of cost.

Further, since the strain detector is mounted on the shaft surface of the trunnion shaft at a substantially intermediate position in the vehicle width direction, inclination of the truck in the left-right direction and the front-rear direction, uneven loading, or the first rear Even when the load center point (load center point) varies in the vehicle width direction due to the change in the contact state of the double tires on the wheels and the second rear wheel, a more accurate load amount can be obtained as compared with the prior art. It has the effect of being sought.

Further, since the distance between the chassis of the truck and the trunnion shaft can be kept constant at all times,
The electrical wiring related to the rearward strain detector can be performed only on the chassis side, and even when the electrical wiring related to the rearward strain detector is performed, it is not necessary to provide an extra wire length, so compared to the conventional technology. The advantage is that the accuracy and durability after electrical wiring are improved.

Further, since the trunnion shaft has a structure in which it is separated from the tire through the overlapping leaf spring, the vibration from the ground is not directly transmitted to the rearward strain detector attached to the trunnion shaft, so that the vibration from the ground is not transmitted. There is also an advantage that the mounting portion of the rearward strain detector is loosened and the adverse effect on the electrical connection portion of the wiring is reduced, and the durability of the rearward strain detector is improved accordingly.

[Brief description of drawings]

FIG. 1 is a plan view showing a chassis structure of a three-axle type truck in which a vehicle weight measuring device for a vehicle having a trunnion shaft according to an embodiment of the present invention is installed.

FIG. 2 is a side view of a chassis of the truck shown in FIG.

3 is a block diagram showing an outline of an example of a vehicle weight measuring circuit used in the vehicle weight measuring device of FIG. 1. FIG.

[Explanation of symbols]

1 Chassis 2 Front Axle 3 Stacked Leaf Spring 4 Front Wheel 5 Trunnion Shaft 6 1st Rear Axle 7 2nd Rear Axle 8 Common Stacked Leaf Spring 9,10 Torque Rod 11 Universal Joint 12 Propeller Shaft 13 Differential Gear Device (Differential)・ Gear unit) 14 pair of first rear wheels 15 pair of second rear wheels 21 front strain detector 22 first strain gauge 23 front axle strain detection circuit 24 rear strain detector 25 second strain gauge 26 trunnion shaft strain detection Circuit 27 Weight calculation circuit 28 Weight comparator 29 Load amount display 30 Alarm display

Claims (2)

[Claims] 1. A vehicle of the type in which two rear axles are suspended by a trunnion shaft installed in a rear region of a chassis via a common support spring for cushioning, and the trunnion shaft has a substantially intermediate position in the vehicle width direction. A strain detector having a strain gauge for detecting the bending strain of the trunnion shaft is attached to the shaft surface, and when a load amount is applied to the vehicle, its own weight and / or
Or configured to be able to detect the bending strain of the trunnion shaft surface, which occurs in accordance with the applied load amount, with the strain detector, and based on the detection signal output from the strain detector, the vehicle dead weight on the vehicle side. and/
Alternatively, a vehicle weight measuring device for a vehicle having a trunnion shaft, which is configured to measure the load amount described above. 2. A trunnion shaft having at least one front axle and two rear axles, the trunnion shaft being installed in a rear region of the chassis, wherein the rear two axles are suspended via a common supporting spring for cushioning. In the vehicle, on the shaft surface at a substantially intermediate position in the vehicle width direction of the front axle,
A forward strain detector having a strain gauge for detecting bending strain of the front axle is attached, and on the shaft surface of the trunnion shaft at a substantially intermediate position in the vehicle width direction, for detecting bending strain of the trunnion shaft. A rear strain detector having a strain gauge is attached, and based on the detection signals output from these two strain detectors, the vehicle side and / or the load amount described above are measured on the vehicle side. A vehicle weight measuring device for a vehicle having a characteristic trunnion shaft.