JP4933478B2 - Transport vehicle - Google Patents

Description

  The present invention relates to a transport vehicle such as a dump truck that is suitably used for transporting, for example, crushed stones mined in open-pit mines, quarries, mines, etc., or excavated earth and sand.

  In general, a large transport vehicle called a dump truck has a loading platform (vessel) that can be raised and lowered on the body frame, and a collection site with a large amount of crushed stone or earth and sand to be transported on the loading platform. It conveys and conveys toward the etc. (for example, refer patent document 1).

  This type of conventional transport vehicle is a self-propelled vehicle body, can be tilted (lifted) on the vehicle body, and can be expanded and contracted between the cargo bed and the vehicle body. And a hoist cylinder that extends when the object to be transported is discharged from the loading platform and tilts the loading platform obliquely rearward of the vehicle body.

  And after the vehicle has self-propelled to the pick-up site with earth and sand or crushed stones loaded in the loading platform, the hoist cylinder is extended to lift the loading platform diagonally rearward, and this lifting action follows the tilting direction of the loading platform. To discharge earth and sand and crushed stones to the collection site. On the other hand, after the discharge operation is completed, for example, the hoist cylinder is reduced by its own weight on the loading platform side. As a result, the loading platform is laid down so as to gradually fall by its own weight to a position where it is seated on the vehicle body.

  In addition, when a large amount of earth and sand is rapidly discharged from the loading platform, the loading platform is lifted up and a very large impact is applied to a machine such as a hoist cylinder. For this reason, Patent Document 1 includes a tilt angle detector that detects the tilt angle of the cargo bed, and when the cargo bed tilts beyond a certain angle, the rise in the tilt angle is suppressed to prevent machine failure. A configuration is disclosed.

JP 2006-347502 A

  By the way, in the transport vehicle according to Patent Document 1 described above, when the tilt angle detector fails and normal detection cannot be performed, the increase in the tilt angle cannot be suppressed as protection control. In addition, in order to detect the failure of the tilt angle detector, the detection result of the tilt angle detector is monitored, and when the movement of the loading platform does not change, or the detection result of the tilt angle detector is out of the normal range. In this case, a configuration in which it is determined that an abnormality has occurred in the tilt angle detector can be considered. However, it is difficult to confirm small movements of the loading platform from the cab in a large transport vehicle. In addition, since the loading platform is frequently attached and removed for maintenance or the like, the normal range may change depending on the loading state of the loading platform. For this reason, if only the detection result of the tilt angle detector is monitored, there is a problem that a failure of the tilt angle detector cannot be detected accurately.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a transport vehicle that can detect a failure of a tilt angle detector.

  In order to solve the above-described problems, the present invention provides a self-propelled vehicle body, a cargo bed provided on the vehicle body so as to be tiltable, and the cargo bed provided between the cargo bed and the vehicle body at an angle. The present invention is applied to a transport vehicle comprising: a loading platform tilting device, a tilt angle detector that detects a tilt angle of the loading platform, and a control device that controls the loading platform tilting device using a detection result of the tilt angle detector. The

  According to a first aspect of the present invention, there is provided a seating detector for detecting a state in which the loading platform is seated on a vehicle body, and the control device is configured to detect the angle detected by the tilt angle detector and the seating detector. When the detection state by the inclination angle detector and the seating detector are determined to be normal, the detection angle by the inclination angle detector and the detection state by the seating detector are different. The detector abnormality determining means determines that at least one of the inclination angle detector and the seating detector is abnormal.

  According to a second aspect of the present invention, there is provided command signal output means for outputting a command signal for swinging the cargo bed upward and downward with respect to the cargo bed tilting device, and the detector abnormality determination means includes the command signal. When the output means is outputting a command signal, the tilt angle detector and the seating detector are determined to be normal.

  According to a third aspect of the present invention, the tilt angle detector is configured using an angle sensor that directly detects the tilt angle of the loading platform.

  According to a fourth aspect of the present invention, the loading platform tilting device is configured by using a hoist cylinder that moves the loading platform in the upward and downward directions by extending and contracting the rod, and the tilt angle detector includes the rod of the hoist cylinder or A stroke sensor that indirectly detects the tilt angle of the loading platform from the displacement of the piston is used.

  As described above, according to the first aspect of the present invention, since the tilt angle of the loading platform is detected using the tilt angle detector, the control device increases the tilt angle using the detection result of the tilt angle detector. Suppressing protection control can be performed. Further, since the seating state of the cargo bed is detected using the seating detector, it is possible to accurately grasp whether or not the cargo bed is seated on the vehicle body. For this reason, the control device can determine, for example, whether or not to allow the vehicle to travel according to the seating state of the loading platform.

  The detector abnormality determining means determines that the tilt angle detector and the seating detector are normal when the detection result by the tilt angle detector matches the detection result by the seating detector, and tilts when they are different. It is determined that at least one of the angle detector and the seating detector is abnormal. For this reason, when it is determined by the detector abnormality determining means that an abnormality has occurred, the inclination angle detector and the seating detector can be inspected, repaired, replaced, etc., and control based on erroneous detection results is prevented. be able to.

  According to the second aspect of the present invention, the detector abnormality determining means includes the inclination angle detector and the seating detection when the command signal output means is outputting a command signal for swinging the cargo bed upward and downward. It is determined whether or not the vessel is normal. For this reason, when the loading platform switches between the seating state and the seating state, the detector abnormality determination means determines whether each detector is normal, so that the two states of the seating state and the seating state are determined. Thus, it is possible to confirm the normality and abnormality of each detector, and to improve the detection accuracy of the abnormal state.

  According to the invention of claim 3, since the inclination angle detector is constituted by the angle sensor, the inclination angle of the cargo bed can be directly detected using the angle sensor.

  According to the invention of claim 4, since the inclination angle detector is configured by using the stroke sensor, the inclination angle of the loading platform is indirectly determined from the displacement amount of the rod of the hoist cylinder that becomes the loading platform tilting device by using the stroke sensor. Can be detected.

  Hereinafter, a dump truck will be described as an example of a transport vehicle according to an embodiment of the present invention and will be described in detail with reference to the accompanying drawings.

  First, FIG. 1 to FIG. 6 show a first embodiment. In the figure, reference numeral 1 denotes a dump truck as a transport vehicle for transporting earth and sand. The dump truck 1 includes a self-propelled vehicle body 2 and a loading platform 8 which is supported by the vehicle body 2 so as to be rotatable and loads earth and sand. The loading platform 8 is generally constituted by a hoist cylinder 10 (described later) that discharges earth and sand by inclining the loading platform 8 with respect to the vehicle body 2.

  Here, left and right front wheels 3 are rotatably provided on the front side of the vehicle body 2, and left and right rear wheels 4 are rotatably provided on the rear side of the vehicle body 2. An engine 5 is mounted on the front side of the vehicle body 2, and a cab 6 that defines a cab is provided above the engine 5. In addition, a loading platform support bracket 7 that rotatably supports a loading platform 8 described later is provided at the rear end of the vehicle body 2.

  Reference numeral 8 denotes a cargo bed positioned on the rear side of the cab 6 and rotatably attached to the vehicle body 2. The cargo bed 8 is formed in a bottomed box shape for loading a large amount of cargo such as earth and sand. A flange portion 8A that covers the cab 6 from above is provided on the portion side. Here, the bottom side of the loading platform 8 is supported on the loading platform support bracket 7 of the vehicle body 2 by using a support shaft 9, and a hoist cylinder 10 described later is expanded and contracted to thereby extend the front side of the loading platform 8 (side 8 </ b> A side). Pivots up and down with the support shaft 9 as a fulcrum. Then, the platform 8 is tilted with respect to the vehicle body 2 by rotating from the lowered position shown in FIG. 1 to the raised position shown in FIG. 2, and the sediment 8 is slid down along the inclined platform 8, so that the platform 8 It is configured to quickly discharge a large amount of earth and sand loaded on the soil to the soil removal site.

  Reference numeral 10 denotes a pair of hoist cylinders (only one is shown) serving as a loading platform tilting device that is provided between the vehicle body 2 and the loading platform 8 and tilts the loading platform 8. The hoist cylinder 10 is composed of a multi-stage (for example, two-stage) hydraulic cylinder, and as shown in FIG. 3, an outer cylinder portion 10A located on the outer side and the outer cylinder portion 10A are provided to be extendable and contractible. It is comprised by the inner cylinder part 10B and the piston rod 10C and piston 10D which were provided in this inner cylinder part 10B so that expansion-contraction was possible. And the inside of the outer cylinder part 10A of the hoist cylinder 10 is defined by the inner cylinder part 10B, the piston rod 10C and the piston 10D into three chambers of rod side oil chambers 10E and 10F and a bottom side oil chamber 10G. At this time, the rod-side oil chamber 10F communicates with either the rod-side oil chamber 10E or the bottom-side oil chamber 10G via a port 10H provided in the inner cylinder portion 10B.

  When the pressure oil is supplied into the bottom side oil chamber 10G from a hydraulic pump 11 described later, the hoist cylinder 10 extends downward along with the piston rod 10C, and the inner cylinder portion 10B When the maximum extension occurs, only the piston rod 10C further extends downward. As a result, the hoist cylinder 10 rotates the loading platform 8 to the raised position inclined obliquely rearward with the support shaft 9 as a fulcrum.

  On the other hand, in the hoist cylinder 10, when pressure oil is supplied from the hydraulic pump 11 into the rod-side oil chamber 10 </ b> E with the piston rod 10 </ b> C extended to the maximum, only the piston rod 10 </ b> C first shrinks, and thereafter the inner cylinder portion 10 </ b> B. Is reduced together with the piston rod 10C. As a result, the hoist cylinder 10 rotates the loading platform 8 to the lowered position with the support shaft 9 as a fulcrum.

  Next, a hydraulic circuit for driving the hoist cylinder 10 will be described with reference to FIG. In the figure, 11 is a hydraulic pump, and the hydraulic pump 11 is driven by the engine 5 to discharge pressurized oil, and constitutes a hydraulic source together with the tank 12.

  Reference numerals 13 and 14 denote a pair of main pipelines connecting the hydraulic power source to the bottom side oil chamber 10G and the rod side oil chamber 10E of the hoist cylinder 10, and the pressure oil discharged from the hydraulic pump 11 passes through the main pipelines 13 and 14. The hoist cylinder 10 is configured to expand and contract by being supplied to and discharged from the bottom side oil chamber 10G and the rod side oil chamber 10E of the hoist cylinder 10.

  A check valve 15 is provided between the hoist cylinder 10 and a directional control valve 17 which will be described later, and is provided in the middle of the main pipeline 14. The check valve 15 is connected to the rod side of the hoist cylinder 10 from the hydraulic pump 11. The flow of pressurized oil to the oil chamber 10E is allowed and the reverse flow is prevented. A relief valve 16 is connected to the main line 14 between the hoist cylinder 10 and the check valve 15, and the relief valve 16 relieves pressure oil in the rod side oil chamber 10 </ b> E of the hoist cylinder 10 to the tank 12. Is.

  Reference numeral 17 denotes a hydraulic pilot type directional control valve located between the hydraulic power source and the hoist cylinder 10 and provided in the middle of the main pipelines 13 and 14. The directional control valve 17 is, for example, from an operation lever device 18 described later. When pilot pressure is supplied to the hydraulic pilot portion 17A, the neutral position (a) is switched to the loading platform raising position (b), and when pilot pressure is supplied to the hydraulic pilot portion 17B, the loading platform is lowered from the neutral position (a). It can be switched to position (c) or free lowered position (d).

  When the directional control valve 17 is switched to the loading platform raising position (b), the hoist cylinder 10 is extended to raise the front side of the loading platform 8, and the directional control valve 17 is switched to the loading platform lowering position (c). When the hoist cylinder 10 is reduced, the front side of the loading platform 8 is lowered, and when the direction control valve 17 is switched to the free lowering position (d), the front side of the loading platform 8 is lowered by its own weight. ing.

  Reference numeral 18 denotes an operation lever device as a command signal output means. The operation lever device 18 outputs a command signal for swinging the loading platform 8 upward and downward. Specifically, the operation lever device 18 is configured by, for example, a pressure reducing valve type pilot valve, and has an operation lever 18 </ b> A that is operated by an operator in the cab 6. The operation lever device 18 switches the direction control valve 17 by supplying pilot pressure as a command signal to the hydraulic pilot portions 17A and 17B of the direction control valve 17 in accordance with an operation on the operation lever 18A. .

  In this case, when the operation lever 18A is operated in the direction indicated by the arrow A, the pilot pressure is supplied to the hydraulic pilot portion 17A of the direction control valve 17, and the direction control valve 17 is switched to the loading platform lifting position (b). On the other hand, when the operation lever 18A is operated in the direction indicated by the arrow B, the pilot pressure is supplied to the hydraulic pilot portion 17B of the direction control valve 17, and the direction control valve 17 is moved to the loading platform lowering position (c) or the free lowering position (d). It is configured to be switched.

  Reference numeral 19 denotes an operation lever sensor provided in the operation lever device 18, and the operation lever sensor 19 outputs a detection signal corresponding to the operation direction (command signal) of the operation lever 18A to the controller 22 described later.

  Reference numeral 20 denotes an angle sensor as a tilt angle detector that directly detects the tilt angle of the loading platform 8. The angle sensor 20 is provided near the support shaft 9, for example, and is provided on the rear side of the vehicle body 2. . Then, as shown in FIG. 2, the angle sensor 20 detects the inclination angle θ of the loading platform 8 when the loading platform 8 rotates to the raised position with the support shaft 9 as a fulcrum, and according to the inclination angle θ. The angle signal S1 is output to the controller 22 described later.

  Reference numeral 21 denotes a seating sensor as a seating detector for detecting whether or not the loading platform 8 is seated on the vehicle body 2, and the seating sensor 21 is provided between the loading platform 8 and the vehicle body 2 as shown in FIGS. It is comprised by the contact-type sensor etc. which are located in the upper side of the vehicle body 2, and detects whether the protrusion 21A of the detection target provided in the loading platform 8 side is contacting or separating. That is, the seating sensor 21 detects the behavior of the loading platform 8 on the vehicle body 2 (what state the loading platform 8 is in). When the loading platform 8 is seated on the vehicle body 2, the seating sensor 21 outputs a seating signal S2 to the controller 22 described later. On the other hand, when the loading platform 8 is away from the vehicle body 2, the seating sensor 21 is configured not to output the seating signal S2.

  A controller 22 is a controller, and an operation lever sensor 19, an angle sensor 20, and a seating sensor 21 are connected to the input side of the controller 22. Also, an alarm buzzer 23 and a display 24 as notification means are connected to the output side of the controller 22. Here, the alarm buzzer 23 and the indicator 24 are provided, for example, in the cab 6 and emit an alarm sound (buzzer sound) according to an operation signal from the controller 22 and display an alarm state. In addition, a storage device 25 is connected to the controller 22.

  Then, when the hoist cylinder 10 is extended to discharge the sediment loaded on the loading platform 8 of the dump truck 1, signals from the operation lever sensor 19, the angle sensor 20, and the seating sensor 21 are input to the controller 22. At this time, the controller 22 performs protection control that suppresses the lift of the cargo bed 8 when the tilt angle of the cargo bed 8 exceeds a predetermined tilt angle.

  Further, the controller 22 executes detector abnormality determination processing (detector abnormality determination means) described later while the operation lever device 18 outputs a command signal. When the controller 22 determines that an abnormality has occurred in either the angle sensor 20 or the seating sensor 21, the controller 22 outputs an operation signal to the alarm buzzer 23 to generate an alarm sound, an alarm lamp, a monitor screen, etc. Is displayed on the sensors 20 and 21. As a result, the controller 22 uses the alarm buzzer 23 and the indicator 24 to notify that an abnormality has occurred in each of the sensors 20 and 21 and alerts the operator in the cab 6. Further, the controller 22 records in the storage device 25 that an abnormality has occurred in each of the sensors 20 and 21.

  The dump truck 1 according to the present embodiment has the above-described configuration, and the operation thereof will be described next.

  First, when the seating state of the loading platform 8 is detected by the seating sensor 21, the dump truck 1 is excavated using a hydraulic excavator or the like (not shown) in a state where the loading platform 8 is held at the lowered position shown in FIG. After loading the earth and sand on the loading platform 8, it self-travels to a desired earth discharging place.

  Next, when the operator in the cab 6 operates the operation lever 18A of the operation lever device 18 in the direction of arrow A in FIG. 3 to extend the hoist cylinder 10, the loading platform 8 uses the support shaft 9 as a fulcrum as shown in FIG. The earth and sand slide down along the inclined loading platform 8 and are discharged to a soil discharging place.

  Here, when the inclination angle θ of the loading platform 8 exceeds a predetermined inclination angle, the controller 22 activates the alarm buzzer 23 to alert the driver in the cab 6 and from the hydraulic pump 11 to the hoist. The flow rate of the pressure oil supplied to the cylinder 10 is decreased. As a result, the hoist cylinder 10 is gently extended to automatically reduce the speed at which the loading platform 8 is inclined, and the earth and sand can be gradually slid down along the loading platform 8 whose inclination gradually increases. Therefore, it is possible to prevent the cargo bed 8 from sliding down in a state where a large amount of earth and sand are gathered, and to prevent negative pressure from being generated in the hoist cylinder 10.

  When the earth and sand are released, the operator in the cab 6 operates the operation lever 18A of the operation lever device 18 in the direction indicated by the arrow B in FIG. Thereby, the loading platform 8 rotates to the lowered position shown in FIG. 1 with the support shaft 9 as a fulcrum, and is seated on the vehicle body 2.

  Here, the detector abnormality determination processing executed by the controller 22 during the earth and sand discharging operation described above will be described with reference to FIGS.

  First, the controller 22 starts by turning on an engine switch (not shown) for starting the engine 5. At this time, the controller 22 executes a detector abnormality determination process separately from the protection control for suppressing the lift of the loading platform 8.

  In step 1, a detection signal from an operation lever sensor 19 provided in the operation lever device 18 is read. Next, in step 2, based on the detection signal from the operation lever sensor 19, whether or not the operation of raising or lowering the loading platform 8 is being performed, that is, the operation lever device 18 outputs a command signal for raising or lowering. It is determined whether or not. And when it determines with "NO" at step 2, in order to confirm ON / OFF of an engine switch, it transfers to step 9 mentioned later. On the other hand, if “YES” is determined in Step 2, the process proceeds to Step 3.

  In step 3, the angle signal S1 from the angle sensor 20 is read, and in step 4, the seating signal S2 from the seating sensor 21 is read.

  Next, in step 5, it is determined whether or not the detection result of the inclination angle θ based on the angle signal S1 matches the detection result of the seating state based on the seating signal S2. Specifically, for example, a maximum angle (maximum seating angle) θa that may be detected as a seating state is determined in advance. In addition, a minimum angle (minimum seating angle) θb that can be detected as a state where the loading platform 8 is separated from the vehicle body 2 (seated state) is determined in advance. At this time, the maximum seating angle θa and the minimum seating angle θb may be the same value (θa = θb). As shown in FIGS. 5 and 6, the detection errors of the angle sensor 20 and the seating sensor 21 are taken into consideration. The maximum seating angle θa may be larger than the minimum seating angle θb (θa> θb).

  When the seating signal S2 is output and the seating state is determined, it is determined whether the inclination angle θ based on the angle signal S1 is smaller than the maximum seating angle θa (θ <θa). At this time, when the tilt angle θ is smaller than the maximum seating angle θa, the tilt angle θ becomes a value within the seating range shown in FIG. 5, so that the detection result of the tilt angle θ by the angle signal S1 and the seating state by the seating signal S2 Match the detection result. On the other hand, when the tilt angle θ is larger than the maximum seating angle θa, the tilt angle θ becomes a value outside the seating range shown in FIG. 5, so the detection result of the tilt angle θ by the angle signal S1 and the seating by the seating signal S2 The detection result of the state is different.

  On the other hand, when it is determined that the seating signal S2 is not output and the seating state is determined, it is determined whether the inclination angle θ based on the angle signal S1 is larger than the minimum seating angle θb (θ> θb). At this time, when the inclination angle θ is larger than the minimum separation angle θb, the inclination angle θ becomes a value within the separation range shown in FIG. 6, so that the detection result of the inclination angle θ by the angle signal S1 and the seating signal S2 are used. The detection result of the seating state matches. On the other hand, when the tilt angle θ is smaller than the minimum seating angle θb, the tilt angle θ becomes a value outside the seating range shown in FIG. 6, and therefore the detection result of the tilt angle θ by the angle signal S1 and the seating signal S2 Is different from the detection result of the seating state.

  If “YES” is determined in Step 5, the detection result of the inclination angle θ based on the angle signal S1 and the detection result of the sitting state based on the seating signal S2 coincide. For this reason, it is determined that both the angle sensor 20 and the seating sensor 21 are normal, and the process proceeds to step 9.

  On the other hand, when “NO” is determined in Step 5, the detection result of the inclination angle θ by the angle signal S1 is different from the detection result of the sitting state by the seating signal S2. For this reason, it is determined that an abnormality has occurred in at least one of the angle sensor 20 and the seating sensor 21, and the process proceeds to step 6.

  In step 6, the indicator 24 in the cab 6 is used to indicate that an abnormality has occurred in either one of the sensors 20 and 21, and in step 7, the alarm buzzer 23 is activated to alert the driver. Arouse. Finally, in step 8, the abnormality of the sensors 20, 21 is recorded in the storage device 25, and the process proceeds to step 9.

  Then, in step 9, it is determined whether or not an engine switch (not shown) has been turned off. If "NO" is determined, the process returns to step 1, and if "YES" is determined, the series described above. This completes the detector abnormality determination process.

  Thus, according to the present embodiment, the angle sensor 20 is used to detect the inclination angle θ of the loading platform 8, and therefore the controller 22 performs protection control that suppresses the increase in the inclination angle θ using this detection result. Can do. In addition, since the seating state of the loading platform 8 is detected using the seating sensor 21, the seating state of the loading platform 8 can be accurately determined even when it is difficult to detect whether the seating state is detected by the angle sensor 20 due to vibration of the loading platform 8 or the like. I can grasp it. For this reason, the controller 22 can determine, for example, whether to allow the vehicle 2 to travel according to the seating state of the loading platform 8.

  The controller 22 determines that the two sensors 20 and 21 are normal when the detection result by the angle sensor 20 and the detection result by the seating sensor 21 match, and at least one of the sensors 20 and 21 when they are different. It is determined that one of them is abnormal. For this reason, when the controller 22 determines that an abnormality has occurred, the angle sensor 20 and the seating sensor 21 can be inspected, repaired, exchanged, and the like, and control based on an erroneous detection result can be prevented.

  Further, the controller 22 determines whether or not the angle sensor 20 and the seating sensor 21 are normal when the operation lever device 18 outputs a command signal for swinging the loading platform 8 upward and downward. I do. For this reason, when the loading platform 8 switches between the seating state and the seating state, the controller 22 determines whether or not each sensor 20, 21 is normal. Thus, the normality and abnormality of each sensor 20, 21 can be confirmed, and the detection accuracy of the abnormal state can be improved.

  Next, FIG. 7 shows a second embodiment of the present invention, and the feature of this embodiment is that an inclination angle detector is configured using a stroke sensor that detects the stroke length of the hoist cylinder. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  Reference numeral 31 denotes a stroke sensor as an inclination angle detector that indirectly detects the inclination angle of the loading platform 8, and the stroke sensor 31 is attached to the hoist cylinder 10, for example. The stroke sensor 31 detects the displacement amount of the piston rod 10C or the piston 10D relative to the outer cylinder portion 10A when the piston rod 10C of the hoist cylinder 10 expands and contracts, and outputs a displacement amount signal corresponding to the displacement amount. Output to the controller 22. At this time, the controller 22 calculates the inclination angle θ of the loading platform 8 based on the displacement amount signal. Then, the controller 22 performs protection control and detector abnormality determination processing (detector abnormality determination means) for suppressing the lift of the loading platform 8 based on the calculated inclination angle θ.

  Thus, in the second embodiment, it is possible to obtain substantially the same operational effects as those in the first embodiment.

  In each of the above embodiments, the dump truck 1 in which the loading platform 8 is supported by the wheel-type vehicle body 2 having the front wheels 3 and the rear wheels 4 is illustrated. However, the present invention is not limited to this, and can be applied to, for example, a transport vehicle in which a loading platform is supported on a crawler-type vehicle body.

It is a front view which shows the dump truck to which the 1st Embodiment of this invention was applied. It is a front view which shows the state which inclined the loading platform of the dump truck. It is a hydraulic circuit diagram for driving a hoist cylinder. It is a flowchart which shows the detector abnormality determination process by a controller. It is explanatory drawing which shows the seating range of an inclination angle. It is explanatory drawing which shows the seating range of an inclination angle. It is a front view which shows the dump truck by 2nd Embodiment.

Explanation of symbols

1 Dump truck (transportation vehicle)
2 Car body 8 Loading platform 10 Hoist cylinder (loading platform tilting device)
10C piston rod (rod)
10D piston 20 angle sensor (tilt angle detector)
21 Seating sensor (sitting detector)
22 Controller (control device)
31 Stroke sensor (Inclination angle detector)

Claims (4)

A self-propelled vehicle body, a cargo bed that can be tilted on the vehicle body, a cargo bed tilting device that is provided between the cargo bed and the vehicle body and tilts the cargo bed diagonally, and detects the tilt angle of the cargo bed In a transport vehicle comprising: a tilt angle detector that controls and a control device that controls the loading platform tilt device using a detection result of the tilt angle detector;
A seating detector for detecting a state in which the cargo bed is seated on the vehicle body;
The controller is
When the detection angle by the tilt angle detector matches the detection state by the seating detector, it is determined that both the tilt angle detector and the seating detector are normal,
Detector abnormality determining means for determining that at least one of the inclination angle detector and the seating detector is abnormal when the detection angle by the inclination angle detector is different from the detection state by the seating detector; A transport vehicle characterized by comprising a configuration. Command signal output means for outputting a command signal for swinging the cargo bed upward and downward with respect to the cargo bed tilting device,
2. The detector abnormality determining unit is configured to determine whether or not the inclination angle detector and the seating detector are normal when the command signal output unit outputs a command signal. The transport vehicle described in 1.   The transport vehicle according to claim 1 or 2, wherein the tilt angle detector is configured using an angle sensor that directly detects the tilt angle of the loading platform. The loading platform tilting device is configured using a hoist cylinder that moves the loading platform upward and downward by extending and contracting a rod,
The transport vehicle according to claim 1, wherein the tilt angle detector is configured using a stroke sensor that indirectly detects a tilt angle of the loading platform from a displacement amount of a rod or a piston of the hoist cylinder.

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