A rollover warning device for dump trucks, and a dump truck equipped with the same.

Abstract

To solve the problem that an attitude having a possibility to impair stability of a dump truck is different by inclining a cargo box and loading a load on the cargo box, and a condition that an overturning accident occurs is difficult to be grasped.SOLUTION: An overturning alarm device includes: a chassis right-left direction inclination sensor 13 for detecting a chassis inclination angle to a horizontal direction of a right-left direction of a chassis 2, and outputting a chassis inclination sensor value according to the chassis inclination angle; a cargo box inclination sensor 12 for detecting a cargo box inclination angle of the cargo box with respect to the chassis, and outputting a cargo box inclination sensor value according to the cargo box inclination angle; and a control device for calculating an overturn angle according to the cargo box inclination sensor value, comparing the overturn angle with a chassis inclination sensor value, and outputting an alarm signal to a notification device.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a rollover warning device for a dump truck.

Background Art

[0002] A dump truck is a vehicle equipped with a load box that can be tilted with the rear end as a rotation axis, and when discharging earth and sand or the like as a load, the load can be discharged by tilting the load and sliding it down.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, by tilting the load box or loading the load on the load box, the attitudes that may impair the stability of the dump truck are different, and the driver usually empirically grasps the current state of the dump truck and performs operations that do not cause rollover.

Means for Solving the Problems

[0005] Therefore, as a means for solving the above problems, the rollover warning device for a dump truck according to the present invention is a rollover warning device for a dump truck in which a load box is installed on a chassis so as to be tiltable, and includes a chassis tilt sensor that detects the chassis tilt angle with respect to the horizontal of the chassis and outputs a chassis tilt sensor value corresponding to the chassis tilt angle, a load box tilt sensor that detects the load box tilt angle and outputs a load box tilt sensor value corresponding to the load box tilt angle, and a first control device that calculates a rollover angle according to the load box tilt sensor value, compares the rollover angle with the chassis tilt sensor value, and outputs a warning signal to a notification device.

[0006] Furthermore, another rollover warning device for a dump truck according to the present invention is a rollover warning device for a dump truck in which a cargo box is tiltably mounted on the chassis, and comprises: a chassis tilt sensor that detects the chassis tilt angle with respect to the horizontal of the chassis and outputs a chassis tilt sensor value corresponding to the chassis tilt angle; a weighing scale that measures the weight of the cargo in the cargo box and outputs a weighing scale value corresponding to the weight of the cargo; and a second control device that calculates the rollover angle according to the weighing scale value, compares the rollover angle with the chassis tilt sensor value and outputs a warning signal to a notification device.

[0007] Furthermore, another rollover warning device for a dump truck according to the present invention is a rollover warning device for a dump truck in which a cargo box is tiltably mounted on the chassis, and comprises: a chassis tilt sensor that detects the chassis tilt angle with respect to the horizontal of the chassis and outputs a chassis tilt sensor value corresponding to the chassis tilt angle; a bias sensor that measures the bias of the load inside the cargo box and outputs a bias sensor value corresponding to the bias; and a third control device that calculates the rollover angle according to the bias sensor value, compares the rollover angle with the chassis tilt sensor value and outputs a warning signal to a notification device.

[0008] Furthermore, the rollover warning device for any of the aforementioned dump trucks may also include an operating unit, and the control device may include a storage unit, allowing the operating unit to store a threshold value for warnings by the notification device in the storage unit.

[0009] Furthermore, it is preferable that the dump truck is equipped with one of the aforementioned rollover warning devices. [Effects of the Invention]

[0010] According to the present invention, the risk of overturning can be detected by the notification device in accordance with the change in the dump truck's center of gravity as the cargo box tilts.

[0011] Furthermore, according to the present invention, even when cargo is loaded into the cargo box, or when the loaded cargo is unevenly distributed, the risk of overturning can be detected by the notification device according to the conditions. [Brief explanation of the drawing]

[0012] [Figure 1] (a) A side view of the dump truck 1 with the cargo box 3 lowered, and (b) a rear view. [Figure 2] This is a side view of dump truck 1 with cargo box 3 raised. [Figure 3] This is a plan view of the dump truck 1, excluding the cargo box 3, showing how load cells r1 to r4 are installed at four locations on the chassis 5, in the front, rear, left, and right positions. [Figure 4] This figure illustrates the definitions of the center of gravity heights H1'(a) and H1″(c) when dump truck 1 is on a forward-sloping ground and a rear-sloping ground, comparing them with the definition of the center of gravity height H1(b) when dump truck 1 is on level ground. [Figure 5] This is a circuit diagram showing an example of electrical signal connection between the sensor and the display device D described in the present invention. [Figure 6] This figure shows an example of a warning display shown on the screen of display device D. (b) also shows an example of a warning mark e displayed on the screen of display device D. [Figure 7] This diagram shows how dump truck 1 moves from a horizontal position (a) to a limit state (b) where it overturns to the left or right. [Figure 8] This diagram shows how dump truck 1 moves from a horizontal position (a) to a limit state (b) where it overturns in the longitudinal direction. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described in detail below with reference to the drawings. In this specification and the drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant explanations will be omitted.

[0014] The dump truck 1 described in the present invention has a load box 3 installed on a chassis 2, and the load box 3 is installed so as to be tiltable with respect to the chassis 2. The chassis 2 may be a towed vehicle, a so-called trailer. The initial center-of-gravity angle α in FIG. 1 is the angle from the chassis 2 in the traveling state where the load box 3 has been lowered to the center of gravity, and is a constant determined by the shape of the vehicle. The chassis 2 is provided with a chassis front-rear tilt sensor 11 for detecting the tilt angle β of the chassis 2 with respect to the horizontal in the front-rear direction, and the load box 3 is provided with a dump angle sensor 12 for detecting the load box 3 tilt angle γ with respect to the horizontal in the front-rear direction. The relative dump angle θ in FIG. 2 is the tilt angle of the load box 3 with respect to the chassis 2. Specifically, it is the relative angle between the tilt angle γ of the load box 3 with respect to the horizontal in the front-rear direction detected by the dump angle sensor 12 and the tilt angle β of the chassis 2, and can be obtained by θ = γ - β. In the present embodiment, the chassis front-rear tilt sensor 11 and the dump angle sensor 12 together constitute a load box tilt angle sensor. That is, the load box tilt angle sensor value is θ. However, when the tilt angle β of the chassis 2 is small, θ = γ can be set. Further, the chassis 2 is provided with a chassis left-right tilt sensor 13 (corresponding to a chassis tilt sensor) for detecting the tilt angle (roll angle Φ) of the chassis 2 with respect to the horizontal in the left-right direction. The chassis tilt sensor value is the roll angle Φ.

[0015] 〔First Embodiment〕 Outputs the relative dump angle θ calculated by the dump angle sensor 12. Using these values, the aforementioned initial center-of-gravity angle α, the hinge ground height H from the ground surface A to the hinge 4 that becomes the rotation axis of the load box 3, and the hinge center-of-gravity distance L that is the distance perpendicular to the left-right direction from the hinge 4 to the position of the center of gravity G of the dump truck 1 in a state where the load box 3 is not tilted, the center-of-gravity height H1 can be obtained by the following formula (1).

[0016]

Equation

[0017] Furthermore, the roll angle ψ can be obtained by the following formula (2) using the obtained H1 and the tire installation width W of the dump truck 1. The tire installation width W is from the outer end of one of the left and right tires to the outer end of the other tire as shown in Fig. 1(b).

[0018]

Equation

[0019] Table 1 shows an example of calculating the roll angle ψ as an example.

[0020]

Table 1

[0021] These are formulas for places where the ground is horizontal. On sloping ground, the height from the ground to the center of gravity changes, but it may not be considered as an error and may not be taken into account. Also, the change in the height from the ground to the center of gravity on sloping ground with respect to the case where the ground is horizontal may be taken into account. As shown in Fig. 4, for example, on a forward-sloping ground or a backward-sloping ground, the center of gravity height becomes higher than the center of gravity height H1 (Fig. 4(b)) when the ground is horizontal. However, the center of gravity height corresponding to the angle of the sloping ground and the dump angle is stored in the storage unit in advance, and the vehicle body angle β (the angle of the sloping ground) detected by the vehicle body front-rear inclination sensor 11 and the dump angle γ of the load box 3 detected by the dump angle sensor 12 are used to call the corresponding center of gravity height value H1´ (Fig. 4(a)) or value H1″ (Fig. 4(c)) stored in the storage unit from the storage unit and use it instead of the center of gravity height H.

[0022] ​​​A specific example of the circuit constituting the rollover warning device E for a dump truck described in the present invention is shown in Figure 5. A control device PLC is connected between the display device D, which is a notification device, and the chassis front-rear tilt sensor 11, the dump angle sensor 12, and the chassis left-right tilt sensor 13. The control device PLC outputs a warning signal by comparing the roll angle Φ and the rollover angle ψ of the chassis 2 of the dump truck 1 based on the output values ​​output from each sensor, and the display device D displays a warning based on the type of warning signal. The display device D is equipped with an operation unit, and the control device PLC is equipped with a storage unit, and by operating the operation unit, the threshold value for warnings on the display device D (notification device) can be stored in the storage unit. As a threshold value, for example, a value obtained by multiplying the rollover angle ψ by a certain percentage can be stored. An example of processing by the control device PLC is as follows. In addition to sensors 11, 12, and 13, the control device PLC may also be connected to a weighing scale installed on the chassis 5 and load cells r1 to r4 as bias sensors. Whether or not to connect load cells r1 to r4 can be selected. The control unit may be provided as buttons on the display device D, or, if the display device D is a touch panel, it may be configured as part of the interface displayed on the display. Furthermore, flash memory or a hard disk drive can be used as the storage unit. The control device PLC performs a process to compare the current roll angle Φ and rollover angle ψ of dump truck 1, for example, setting the threshold to ψ·50%, ψ·80%, or ψ·95%. ψ·80%>Φ≧ψ·50%: Warning #1 (Yellow light on) ψ·95%>Φ≧ψ·80%: Warning #2 (Red light on) Φ≧ψ·95%: Forcefully stop operation of dump truck 1. A warning signal corresponding to the right half is output according to one of the conditions in the left half. In Warning 1 and Warning 2, the threshold for triggering the warning can be adjusted and configured.

[0023] Although θ = γ - β was used to represent the inclination angle of the cargo box 3 relative to the chassis 2, it is sufficient to determine the center of gravity, and the value of the dump angle sensor 12 itself, i.e., the inclination angle γ of the cargo box 3 relative to the horizontal, can be used to replace θ. In this case, the chassis front / rear inclination sensor 11 does not need to be used to calculate the rollover angle ψ, and the dump angle sensor 12 constitutes the cargo box inclination sensor.

[0024] [Second Embodiment] Using the height h of the cargo box floor, the proportionality constant k which changes depending on the specific gravity of the cargo, and the load weight P measured by the weighing scales (load cells r1 to r4), the height of the center of gravity H1 can be determined by the following equation (3).

[0025]

number

[0026] Furthermore, using the obtained H1 and the tire contact width W of the dump truck 1, the rollover angle ψ can be determined by equation (2) shown earlier. Also, the previously mentioned <Warning Example> can be used as an example of outputting a warning.

[0027] In this embodiment, equation (3) is used as a linear approximation, but other approximation equations (second order or higher) may also be used. Equation (1) may be modified so that the initial angle α of the center of gravity is a function of the load weight P. Furthermore, the type of load cell used for the weighing scale is not limited. In addition, a pressure gauge may be provided to measure the pressure of the hydraulic fluid in the hydraulic cylinder used for dumping the cargo box 3, and the weight value may be obtained by converting the weight from the pressure measured by the pressure gauge. In this case, the pressure gauge corresponds to the weighing scale.

[0028] [Third Embodiment] With the cargo box 3 mounted on the chassis 5, load cells r1 to r4 (bias sensors) capable of measuring the weight of the cargo box 3 and its load are installed at four locations on the chassis 5, at the front, rear, left, and right positions, as shown in Figures 2 and 3. Each of the load cells r1 to r4 measures the weight when the cargo is loaded into the cargo box 3, and the vehicle bias is calculated from the weight bias. Then, in the loaded state, the distance in the longitudinal direction of the vehicle from the hinge 4 to the center of gravity position G' of the dump truck 1 when the cargo box 3 is not tilted is defined as the corrected hinge center of gravity distance L'. The relative dump angle θ calculated by the dump angle sensor 12 is output, and the center of gravity height H1 can be determined by the following equation (4) using the initial center of gravity angle α and the hinge ground clearance H mentioned above.

[0029]

number

[0030] As mentioned above, the relative dump angle θ is calculated from the inclination angle β of the chassis 2 relative to the horizontal and the inclination angle γ of the cargo box 3 relative to the horizontal. In other words, in this embodiment, the chassis front / rear inclination sensor 11 and the dump angle sensor 12 are combined to form a cargo box inclination angle sensor. Furthermore, using the obtained H1 and the tire contact width W of the dump truck 1, the rollover angle ψ can be determined by the equation (2) shown earlier. In addition, the previously mentioned <Warning Example> can be used as an example of outputting a warning.

[0031] In this embodiment, a linear approximation was used, but other approximation formulas (second order or higher) may also be used. The dump angle sensor 12 does not need to be provided (θ=0). In this case, the center of gravity height H1 may be set as a constant, or the above formula (3) may be modified by setting the center of gravity height H1 as a function based on the load weight P. Although four load cells r1 to r4 arranged in the front, rear, left, and right are used as the bias sensor, a camera may be provided and the bias may be measured by image processing. For example, the loading state of the cargo may be photographed with a camera and understood by image processing, or the area around the vehicle may be photographed with a camera and the bias may be understood from the degree of tilt of the image.

[0032] The first to third embodiments described above illustrate the lateral rollover of a vehicle, but the same principles can be applied to longitudinal rollovers (overturns). In this case, the chassis inclination sensor 11 corresponds to the chassis inclination sensor described in the claim, and the longitudinal sensor value detected by the chassis inclination sensor 11 should be compared with the calculated rollover angle. The concept of rollovers in both the lateral and longitudinal directions can be considered similarly, as shown in Figures 7 and 8. That is, a rollover occurs when the line connecting the center of gravity G and the outermost point of the tire T in contact with the ground crosses a vertical line.

[0033] Figure 6 shows an example of the output display when the dump truck rollover warning device E according to the present invention issues a warning. The output display is shown on a display device D installed in the driver's seat or other location inside the cab of the dump truck 1. The display device D displays a side view B1 of the dump truck 1 as seen from the side, and a rear view B2 as seen from the rear, side by side.

[0034] Side view B1 shows the chassis 2, the cargo box 3, and a tilt angle scale. When the cargo box 3 is tilted, the scale moves to reflect the tilt, allowing for a visual understanding of the degree to which the cargo box 3 is tilted. Alternatively, when the cargo box 3 is tilted, the cargo box portion of side view B1 may also move to reflect the tilt.

[0035] Furthermore, a display frame for showing the relative dump angle θ is provided below the side view B1, allowing the current relative dump angle θ of the cargo box 3 to be determined in concrete numerical terms.

[0036] Furthermore, the rear view B2 is displayed in a way that it tilts to match the angle of inclination when the chassis 2 is tilted relative to the horizontal in the left-right direction. This allows for a visual understanding of how much the dump truck 1 is tilted.

[0037] Furthermore, a display frame for showing the roll angle Φ is provided below rear view B2, allowing the current roll angle Φ of chassis 2 to be determined as a specific numerical value.

[0038] For example, if a roll angle Φ greater than or equal to the rollover angle ψ shown in the above-mentioned <Warning Examples> is detected, a warning mark accompanied by a "!" mark e will be displayed as shown in Figure 6. Furthermore, a warning area with a warning color such as yellow or red may be displayed on part or all of the screen. By displaying such warning marks and warning colors, the driver or operator of the dump truck 1 can visually recognize the risk of rollover before the dump truck 1 rolls over, thereby preventing rollover accidents. [Explanation of symbols]

[0039] 1 Dump truck 2 chassis 3 packing boxes 4 hinges 5 Chassis

Claims

1. A rollover warning device for a dump truck in which the cargo box is mounted on the chassis so as to be tiltable, A chassis tilt sensor that detects the chassis tilt angle relative to the horizontal and outputs a chassis tilt sensor value corresponding to the chassis tilt angle, A cargo box tilt sensor that detects the tilt angle of the cargo box and outputs a cargo box tilt sensor value corresponding to the tilt angle, The system includes a first control device that calculates the rollover angle according to the position of the dump truck's center of gravity, which changes according to the cargo box tilt sensor value, compares the rollover angle with the chassis tilt sensor value, and outputs a warning signal to the notification device. The first control device compares the calculated rollover angle with the chassis tilt sensor value using a threshold value. A rollover warning device for dump trucks, characterized by the following features.

2. A rollover warning device for a dump truck in which the cargo box is mounted on the chassis so as to be tiltable, A chassis tilt sensor that detects the chassis tilt angle relative to the horizontal and outputs a chassis tilt sensor value corresponding to the chassis tilt angle, A weighing scale that measures the weight of the cargo inside the cargo box and outputs a weight reading corresponding to the weight of the cargo, The system includes a second control device that calculates the rollover angle according to the position of the dump truck's center of gravity, which changes according to the weight scale reading, compares the rollover angle with the chassis tilt sensor value, and outputs a warning signal to the notification device. The second control device compares the calculated rollover angle with the chassis tilt sensor value using a threshold value. A rollover warning device for dump trucks, characterized by the following features.

3. A rollover warning device for a dump truck in which the cargo box is mounted on the chassis so as to be tiltable, A chassis tilt sensor that detects the chassis tilt angle relative to the horizontal and outputs a chassis tilt sensor value corresponding to the chassis tilt angle, A bias sensor that measures the uneven distribution of the cargo inside the cargo box and outputs a bias sensor value corresponding to the uneven distribution, The system includes a third control device that calculates the rollover angle according to the position of the dump truck's center of gravity, which changes according to the bias sensor value, compares the rollover angle with the chassis tilt sensor value, and outputs a warning signal to the notification device. The third control device compares the calculated rollover angle with the chassis tilt sensor value using a threshold value. A rollover warning device for dump trucks, characterized by the following features.

4. A rollover warning device for a dump truck according to any one of claims 1 to 3, It is equipped with an operating unit, and the control unit is equipped with a storage unit. The operation unit causes the memory unit to store the threshold value for which the notification device will issue a warning. A rollover warning device for dump trucks.

5. A dump truck equipped with a rollover warning device according to any one of claims 1 to 4.

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