JP5840558B2 - Cargo box tilting device for dump vehicle - Google Patents

Description

  The present invention relates to a packing box tilting device provided in a dump vehicle.

  A dump vehicle is provided with a cargo box tilting device that tilts a cargo box (loading platform) provided on the vehicle body frame up and down with respect to the vehicle body frame. The packing box tilting device is provided with a tilting cylinder for tilting the packing box, and the packing box rises and falls on the vehicle body frame by expansion and contraction of the tilting cylinder.

  Specifically, the tilting cylinder is disposed between the body frame and the cargo box. When the tilting cylinder contracts, the attitude of the cargo box lying down substantially horizontally on the body frame (for example, FIG. 1). Reference). On the other hand, when the tilting cylinder is extended, the cargo box is in a standing posture (see, for example, FIG. 4) standing upright on the body frame. By placing the packing box in a lying position, it is possible to load and transport the load in the packing box, and by tilting the packing box in an upright position, the load loaded in the packing box can be loaded. It can be discharged through the rear door (tailgate).

  Conventionally, a driving force of an engine is taken out by a power take-out device (PTO device) to drive a tilting cylinder (see, for example, Patent Documents 1 and 2). Recently, there is also known a cargo box tilting device that does not include a PTO device and drives a tilting cylinder using a power source (for example, a battery) different from the engine.

Japanese Utility Model Publication No. 62-15038 JP-A-58-202121

  By the way, some dump vehicles tilt the cargo box upward by locking the tailgate at the open position where the tailgate is opened when discharging the cargo loaded in the cargo box. In such a dump vehicle, with the tailgate open without locking the cargo box tailgate (for example, when an operator forgets to lock the tailgate after opening the tailgate) If the packing box is tilted upward, the tailgate may interfere with the ground and be damaged during the tilting operation of the packing box.

  In addition, since the container box tilting device that does not include the PTO device can tilt the container box independently of the traveling system of the dump vehicle, the container box can be tilted even during the traveling of the dump vehicle. It is possible to perform operations. However, in the case of the packing box tilting device not provided with the PTO device, unlike the packing box tilting device provided with the PTO device, the sound generated during the tilting operation of the packing box is small. For this reason, when the operator performs the tilting operation of the cargo box unintentionally while driving the dump vehicle, the operator is difficult to notice the tilting operation of the cargo box, and the cargo box tilts to the maximum tilt angle. There is a possibility that it may end up.

  The present invention has been made in view of such problems, and is capable of suppressing damage to the tailgate due to interference with the ground during the upward tilting operation of the cargo box, and is excellent in safety. An object of the present invention is to provide a cargo box tilting device for a vehicle.

In the present invention, means for solving the above-described problems are configured as follows. That is, the present invention has a tailgate, which is tiltably mounted on a vehicle body frame, an electric motor driven by battery power, and is expanded and contracted by driving the electric motor. A dumping carton tilting device including a tilting cylinder for tilting the packing box up and down and a control device for controlling the driving of the electric motor, wherein the control device tilts the packing box up and down. An operation device, and a detection unit that detects whether or not the tilt angle of the packing box is smaller than a maximum tilt angle and is equal to or larger than a preset angle, and the packing box by the operation device is moved upward. During the operation of the lifting operation to tilt, when the tilt angle of the cargo box becomes equal to or larger than the set angle, the lifting operation of the cargo box is stopped, and the operation device has the operation position of the operation member as the operation position. Packing box At least a raising position for performing a bending operation, a lowering position for tilting the packing box downward, and a neutral position for stopping the tilting operation of the packing box, and the operating device is configured such that the operating member is in the neutral position. When the operating member is in the raised position or the lowered position, and when the operating member is in the raised position or the lowered position, the operating force to the operating member can be applied to the operating member. It is configured to automatically return to the neutral position when the operation force is released, and when the operation member is held at the raised position, the tilt angle of the packing box is equal to or greater than the set angle. and if it becomes stops raising operation of the packing box, the elapsed time from the tilt angle of the packing box has become the set angle or more is detected, the set time or a preset If it becomes, even the operating device is operated, it is characterized by stopping the raising operation of the packing box.

  According to the above configuration, when the packing box is raised, when the packing box reaches the set angle smaller than the maximum tilt angle, the lifting operation of the packing box is forcibly stopped. The state of the tailgate can be confirmed in the middle of the process, and damage to the tailgate due to interference with the ground can be suppressed. In other words, it is possible to check whether the tailgate is locked during the lifting operation of the packing box. As a result, if the tailgate is locked, the operating device is operated immediately. Then, the lifting operation of the packing box can be resumed. On the other hand, if the tailgate is not locked, after the tailgate is locked, the tailgate interferes with the ground and is damaged by operating the operating device and restarting the cargo box lifting operation. Can be avoided. Then, by operating the operating device and restarting the lifting operation of the packing box, the packing box can be easily tilted to the maximum tilting angle.

  Also, even when the operator accidentally operates the operating device while driving the dump vehicle, the lifting operation of the packing box is compulsory when the tilting angle of the packing box reaches the set angle. Therefore, the lifting operation of the packing box can be stopped before the packing box is tilted to the maximum tilting angle. Therefore, it is possible to provide a cargo box tilting device with excellent safety.

Further , when the elapsed time is equal to or longer than the set time, for example, when the tilt angle of the packing box is near the set angle, the operation of the operating device to the raised position and the operation to the neutral position are performed in a short time. Even if it is repeatedly performed, the lifting operation of the packing box can be reliably stopped.

  According to the present invention, during the lifting operation of the packing box, when the packing box reaches the set angle smaller than the maximum tilt angle, the lifting operation of the packing box is forcibly stopped. The state of the tailgate can be confirmed in the middle of the process, and damage to the tailgate due to interference with the ground can be suppressed. Also, even when the operator accidentally operates the operating device while driving the dump vehicle, the lifting operation of the packing box is compulsory when the tilting angle of the packing box reaches the set angle. Therefore, it is possible to provide a cargo box tilting device excellent in safety.

It is a side view showing a schematic structure of a dump vehicle provided with a packing box tilting device according to an embodiment. It is a top view of a dump vehicle. It is a rear view of a dump vehicle. It is a side view which shows the dump vehicle at the time of tilting operation of a packing box. It is a block diagram showing typically a schematic structure of a packing box tilting device concerning an embodiment. It is a perspective view which shows an example of the operating device of a packing box tilting apparatus. It is a side view which shows an example of the limit switch of a packing box tilting apparatus. It is a figure which shows typically an example of the power unit of a packing box tilting apparatus.

  Embodiments of the present invention will be described with reference to the accompanying drawings.

  First, a schematic configuration of the dump vehicle 1 including the packing box tilting device 100 according to the embodiment will be described with reference to FIGS.

  As shown in FIGS. 1 to 4, the dump vehicle 1 includes a cab 2, a vehicle body frame 3, a cargo box (loading platform) 4 provided on the vehicle body frame 3, and a cargo box 4 with respect to the vehicle body frame 3. And a packing box tilting device 100 that tilts the box up and down. Although not shown, the dump vehicle 1 is equipped with an engine (prime mover) and a transmission connected to the engine via a clutch, and the driving force of the engine shifts to the drive system of the drive wheels. It is transmitted through the machine.

  The vehicle body frame 3 has a configuration in which a subframe 32 is placed on a chassis frame 31. A rotation shaft 5 is provided at the rear end portion of the sub frame 32, and the cargo box 4 is rotatably provided around the rotation shaft 5. The rotating shaft 5 extends substantially horizontally in the left-right direction, and both ends thereof are rotatably supported by the left and right subframes 32.

  The cargo box 4 includes a floor surface and four side walls on the front, rear, left and right sides. Of the four side walls of the packing box 4, the rear wall body constitutes a rear door (tailgate) 41, and the other three side walls constitute fixed walls 42, 43, 44. In this embodiment, the rear door 41 is composed of two tailgates 41a and 41b divided into right and left, and is a so-called double door opening / closing door. That is, the left and right tailgates 41a and 41b are provided to be rotatable in the horizontal direction via the hinges 42a and 43a with respect to the rear end portions of the left and right fixed walls 42 and 43 along the front-rear direction of the cargo box 4. ing. The left and right tailgates 41a and 41b are provided with locking means 45 and 46 for restraining the tailgates 41a and 41b in the closed position (position shown in FIG. 2).

  The left and right tailgates 41a and 41b have a rotation range of about 270 degrees around the hinges 42a and 43a, as shown by the broken lines in FIG. When the left and right tailgates 41a and 41b are rotated about 270 degrees around the hinges 42a and 43a from the closed position, the left and right tailgates 41a and 41b are along the outer wall surfaces of the left and right fixed walls 42 and 43 of the cargo box 4, respectively. Locking means (not shown) is provided on the outer wall surfaces of the left and right fixed walls 42 and 43 to restrain the tailgates 41a and 41b in an open position rotated approximately 270 degrees from the closed position.

  In this embodiment, opening and closing of the tailgates 41a and 41b of the packing box 4 are performed manually by an operator. Specifically, when opening the left and right tailgates 41a and 41b from the closed state, the operator manually releases the locking means 45 and 46 provided on the tailgates 41a and 41b, 41a and 41b are rotated around hinges 42a and 43a. Then, the locking means provided on the fixed walls 42 and 43 are manually moved to lock the tailgates 41a and 41b in the open position rotated approximately 270 degrees from the closed position. On the other hand, when closing the left and right tail gates 41a and 41b from the opened state, the operator manually releases the locking means provided on the fixed walls 42 and 43, and the tail gates 41a and 41b are hinged. The tail gates 41a and 41b are locked in the closed position by rotating the locking means 45 and 46 manually by rotating about 270 degrees around 42a and 43a.

  The packing box 4 is tilted up and down by a tilting cylinder 110 provided in the packing box tilting device 100. For example, a hydraulic cylinder is used as the tilting cylinder 110. The tilting cylinder 110 is expanded and contracted by a power unit 120 (see FIGS. 5 and 8) described later.

  More specifically, as shown in FIG. 4, one end of a pair of left and right lift arms 6 is rotatably connected to the lower center of the cargo box 4. One end of a pair of left and right tension links 7 is rotatably connected to the other end of the lift arm 6, and the other end of the tension link 7 is rotatably connected to a sub frame 32 of the vehicle body frame 3. Between the left and right tension links 7, a tilting cylinder 110 for tilting the packing box 4 is disposed. The bottom side of the tilting cylinder 110 is rotatably connected to the sub-frame 32, and the rod side of the tilting cylinder 110 is rotatably connected to the lift arm 6.

  Then, the packing box 4 is erected and laid down on the vehicle body frame 3 by the expansion and contraction of the tilting cylinder 110. In this case, when hydraulic oil is supplied to the tilting cylinder 110 and the tilting cylinder 110 is extended, the cargo box 4 tilts upward with respect to the vehicle body frame 3 and stands upright. Thereafter, when hydraulic oil is discharged from the tilting cylinder 110 and the tilting cylinder 110 is contracted, the cargo box 4 tilts downward and returns to a substantially horizontal lying posture.

  Next, the packing box tilting device 100 provided in the dump vehicle 1 will be described with reference to FIGS.

  As shown in FIG. 5, the cargo box tilting device 100 includes the tilting cylinder 110, the power unit 120, the battery 130, and the control device 140 described above. The power unit 120 includes an electric motor 121, a hydraulic pump 122, a solenoid valve 123, a magnet switch 124, and the like (see FIG. 8). The control device 140 includes an ignition switch 141, an operation device 142, a limit switch 143, a timer 144, a relay (not shown), and the like, and these are connected in a control circuit (not shown). This will be specifically described below.

  The control device 140 controls driving of the electric motor 121 of the power unit 120 based on the operation position signal output from the operation device 142. The control device 140 is supplied with power from the battery 130.

  The operation device 142 of the control device 140 is an operation means for manually operating the tilting operation of the cargo box 4, and is disposed in front of the driver's seat in the cab 2. For example, as shown in FIG. 6, the operating device 142 moves the lever 142 a to the raised position P <b> 1 (position indicated by a one-dot chain line), the neutral position P <b> 2 (position indicated by a solid line), and the lowered position P <b> 3 (indicated by two-dot chain line). It is possible to operate to any one of three operation positions. Then, the operating device 142 outputs an operation position signal corresponding to the operated position of the operated lever 142a. The raising position P1 is an operation position for performing a tilting operation for tilting the cargo box 4 upward. The neutral position P2 is an operation position where the tilting operation of the cargo box 4 is stopped (the cargo box 4 is stopped). The lowered position P3 is an operation position for performing a tilting operation for tilting the cargo box 4 downward. The operation of the cargo box 4 by the operating device 142 is allowed only when the ignition switch 141 is on, and is prohibited when the ignition switch 141 is off.

  In this embodiment, the operating device 142 is configured as an automatic return type toggle switch, and the lever 142a as an operating member is configured to automatically return to the neutral position P2 that is the home position. That is, while the lever 142a is operated to the raising position P1 or the lowering position P3 and is held at the positions P1 and P3, the upward movement or the downward movement of the cargo box 4 is performed. On the other hand, for example, when the operator releases his / her hand from the lever 142a and the operating force on the lever 142a is released, the lever 142a automatically returns from the positions P1 and P3 to the neutral position P2, and the cargo box 4 Is tilted.

  Further, the operating device 142 is provided with a safety device 142b so as not to inadvertently tilt the cargo box 4 while the dump vehicle 1 is traveling, for example. FIG. 6 shows a state where the safety device 142b is released. In a state where the operation of the lever 142a is restricted by the safety device 142b, the lever 142a is fixed at the neutral position P2, and the lever 142a cannot be operated to the raised position P1 or the lowered position P3. When the safety device 142b is released, the lever 142a can be moved from the neutral position P2, and the operation of the lever 142a to the raised position P1 or the lowered position P3 is allowed.

  The limit switch 143 is detection means for detecting whether or not the tilt angle α (see FIG. 4) of the cargo box 4 is equal to or larger than a preset set angle α1, and has a configuration as shown in FIG. 7, for example. ing.

  The limit switch 143 is pushed upward by a roller 143a attached to the rear end portion of the sub-frame 32 of the vehicle body frame 3 in contact with a pressing member 143f attached to the left end portion of the rotation shaft 5 of the cargo box 4. Thus, it is detected whether or not the tilt angle α of the packing box 4 is equal to or larger than the set angle α1. The limit switch 143 is configured to be turned off when the tilt angle α of the cargo box 4 is less than the set angle α1, and to be turned on when the tilt angle α of the cargo box 4 is equal to or larger than the set angle α1. Has been.

  Specifically, a stay 143b is fixed to a rear end portion of the subframe 32 that rotatably supports the rotation shaft 5 of the cargo box 4, and one end of an arm 143c is connected to the stay 143b. The arm 143c is pivotable about a pivot shaft 143d supported by the stay 143b. A roller 143a is rotatably supported at the other end of the arm 143c. The arm 143c is arranged to extend in a substantially horizontal direction when the roller 143a and the pressing member 143f are not in contact with each other. The arm 143c is urged in a direction to rotate downward about the rotation shaft 143d by an urging means such as a spring (not shown).

  In addition, an upper portion of a bracket 143g is fixed to a rear end portion of the cargo box frame (loading frame) 4a integrally attached to the bottom portion of the cargo box 4, and the lower portion of the bracket 143g attaches the subframe 32. It is fixed to the left end portion of the pivot shaft 5 that has penetrated. A pressing member 143f is integrally attached to the lower end portion of the bracket 143g, and the pressing member 143f and the bracket 143g are rotatable about the rotation shaft 5 integrally with the cargo box 4. . For this reason, the rotation angle around the center C1 of the rotation shaft 5 of the pressing member 143f coincides with the tilt angle α of the cargo box 4. The pressing member 143f has a shape that surrounds the outer periphery of the rotation shaft 5 from one side in a side view, and when the cargo box 4 is in the lying posture (see FIG. 1), the center C1 of the rotation shaft 5 On the other hand, a pressing member 143f is arranged diagonally to the left. At this time, the pressing member 143f is disposed at a position separated from the roller 143a.

  Detection of whether the tilt angle α of the cargo box 4 by the limit switch 143 is equal to or larger than the set angle α1 is performed as follows. Here, in this embodiment, the maximum tilt angle αmax of the packing box 4 is set to 55 degrees, and the packing box 4 can be tilted within the range of the tilt angle α of 0 to 55 degrees. The set angle α1 is set to 45 degrees, for example. This set angle α1 is set so that the tailgates 41a and 41b that protrude obliquely downward and rearward when the cargo box 4 is lifted without locking the tailgates 41a and 41b during the cargo box 4 lifting operation. This value is set based on the amount of protrusion (L1 in the example shown by the two-dot chain line in FIG. 4), and is set as a safe tilt angle so that the tailgates 41a and 41b do not interfere with the ground. The set angle α1 can be adjusted by changing the attachment position of the pressing member 143f to the bracket 143g. In FIG. 7, the state when the tilt angle α of the packing box 4 is 0 degrees is indicated by a solid line, the state when the tilt angle α is α1 (45 degrees) is indicated by a one-dot chain line, and the tilt angle α is αmax. A state at (55 degrees) is indicated by a two-dot chain line.

  When the lever 142a of the operation device 142 described above is operated to the raised position P1 from the state where the packing box 4 is in the lying posture, the tilting operation of the packing box 4 is performed and the tilting angle of the packing box 4 is increased. α gradually increases from 0 degrees. At this time, the pressing member 143f rotates around the center C1 of the rotation shaft 5 by the same angle as the tilt angle α of the packing box 4. As the rotation angle of the pressing member 143f increases, the pressing member 143f approaches the roller 143a. When the rotation angle of the pressing member 143f further increases, the pressing member 143f contacts the roller 143a and the roller 143a is moved by the pressing member 143f. It will be pushed up. Even if the pressing member 143f contacts the roller 143a, the limit switch 143 is off while the rotation angle of the pressing member 143f is less than α1 (45 degrees). However, when the rotation angle of the pressing member 143f becomes α1 (45 degrees) or more, the limit switch 143 is turned on, and it is detected that the tilt angle α of the cargo box 4 is equal to or more than the set angle α1.

  Thereafter, when the lever 142a of the operating device 142 is operated to the lowered position P3, the downward movement of the cargo box 4 is performed, the inclination angle α of the cargo box 4 gradually decreases, and the rotation angle of the pressing member 143f. Becomes smaller. Then, the pressing of the roller 143a by the pressing member 143f is released, the pressing member 143f is separated from the roller 143a, and the roller 143a returns to the initial position (the position shown in FIG. 7).

  Subsequently, the power unit 120 extends and retracts the tilting cylinder 110 by a battery 130 as a power source independent of an engine that is a power source for traveling of the dump vehicle 1. For example, as shown in FIG. It has become a structure. In FIG. 8, the solenoid 123 a of the electromagnetic valve 123 is connected to the operation device 142 of the control device 140. In addition, the input side of the magnet switch 124 is connected to the battery 130, the operation device 142 of the control device 140, and the limit switch 143.

  The electric power of the battery 130 is supplied to the electric motor 121 via the magnet switch 124. Specifically, when the magnet switch 124 is on, the electric power of the battery 130 is supplied to the electric motor 121 and the electric motor 121 is driven. By driving the electric motor 121, the hydraulic pump 122 is operated, and the hydraulic oil stored in the oil tank 125 is supplied to the tilting cylinder 110. On the other hand, when the magnet switch 124 is off, the electric power of the battery 130 is not supplied to the electric motor 121 and the electric motor 121 is not driven. For this reason, the hydraulic pump 122 does not operate, and hydraulic oil is not supplied to the tilting cylinder 110.

  The magnet switch 124 is turned on when the lever 142a of the operating device 142 is operated to the raised position P1 and the limit switch 143 is turned off, and in other cases (the lever 142a of the operating device 142 is in the neutral position P2 or the lowered position). When operated by P3 or when the limit switch 143 is on), it is turned off.

  The electromagnetic valve 123 is a switching valve that switches communication or blocking of a discharge oil passage 126 that discharges hydraulic oil from the tilting cylinder 110 to the oil tank 125. When the solenoid valve 123 is switched to the shut-off position 123b (in the state shown in FIG. 8), the discharge oil passage 126 is shut off and the discharge of hydraulic oil from the tilting cylinder 110 is prohibited. On the other hand, when the solenoid valve 123 is switched to the communication position 123c, the discharge oil passage 126 is connected, and the discharge of the hydraulic oil from the tilting cylinder 110 is allowed. As a result, the hydraulic oil in the tilting cylinder 110 is returned to the oil tank 125 via the discharge oil passage 126. A throttle 127 for limiting the return amount (flow rate) of the hydraulic oil to the oil tank 125 is provided on the downstream side of the electromagnetic valve 123 in the discharge oil passage 126.

  The electromagnetic valve 123 is switched to the cutoff position 123b when the lever 142a of the operating device 142 is operated to the raised position P1 or the neutral position P2. On the other hand, when the lever 142a of the operating device 142 is operated to the lowered position P3, the solenoid valve 123 is switched to the communication position 123c by operating the solenoid 123a.

  Next, the tilting operation of the packing box 4 by the packing box tilting device 100 having the above configuration will be described.

  First, the raising operation of the packing box 4 that tilts the packing box 4 upward from the state of the lying posture shown in FIG. 1 will be described. When the cargo loaded in the cargo box 4 is discharged along with the lifting operation of the cargo box 4, the worker first manually opens the tailgates 41a and 41b of the cargo box 4 as described above. Next, the operator releases the safety device 142b of the operating device 142 and operates the lever 142a from the neutral position P2 to the raised position P1. Then, the magnet switch 124 of the power unit 120 is turned on, and the electric motor 121 is driven. The hydraulic pump 122 is actuated by driving the electric motor 121, hydraulic oil is supplied to the tilting cylinder 110, and the cargo box 4 is tilted upward. While the lever 142a is held at the raised position P1, the driving of the electric motor 121, the operation of the hydraulic pump 122, the supply of hydraulic oil to the tilting cylinder 110, and the tilting operation of the packing box 4 are continued. As a result, the tilt angle α of the packing box 4 gradually increases from 0 degree.

  When the operator releases the lever 142a during the raising operation of the cargo box 4 and the lever 142a is returned to the neutral position P2, the magnet switch 124 is turned off, the electric motor 121 is stopped, and the cargo box 4 is Raising operation is stopped. The cargo box 4 is stationary while being tilted by the tilt angle α. On the other hand, when the lever 142a is operated again to the raising position P1 while the lifting operation of the packing box 4 is stopped, the magnet switch 124 is turned on, the electric motor 121 is driven, and the lifting operation of the packing box 4 is resumed. .

  Here, while the tilt angle α of the packing box 4 is less than the set angle α1, the limit switch 143 is off, and the lifting operation of the packing box 4 is performed according to the operation of the lever 142a to the lifting position P1. Done. However, when the tilt angle α of the packing box 4 reaches the set angle α1, the limit switch 143 is turned on, the magnet switch 124 is turned off, the electric motor 121 is stopped, and the lifting operation of the packing box 4 is stopped. That is, even if the lever 142a is held at the raised position P1, when the tilt angle α of the cargo box 4 reaches the set angle α1, the raising operation of the cargo box 4 is forcibly stopped (automatically). .

  When the lever 142a is returned to the neutral position P2 after the cargo box 4 stops at the set angle α1, the magnet switch 124 is turned on when the lever 142a is operated again to the raised position P1, and the electric motor 121 is turned on. Is driven, and the lifting operation of the packing box 4 is resumed.

  In the vicinity of the tilt angle α of the packing box 4 being the set angle α1, the operation of the lever 142a of the operating device 142 to the raised position P1 and the operation to the neutral position P2 are repeated in a short time (for example, , Repeated at intervals of 0.2 seconds), there is a concern that malfunctions may occur. In order to avoid such a malfunction, a timer 144 is provided. The timer 144 sets in advance the elapsed time from the time when it is detected that the tilt angle α of the cargo box 4 is equal to or larger than the set angle α1, that is, the elapsed time from the time when the limit switch 143 is turned on. It is detected whether or not the set time (for example, 0.5 seconds) is exceeded. When the elapsed time from when the limit switch 143 is turned on becomes equal to or longer than the set time, the timer 144 is turned on. Even when the lever 144a is repeatedly operated as described above when the timer 144 is on, the lifting operation of the cargo box 4 is surely stopped after the set time has elapsed.

  Next, the lowering operation of the packing box 4 for tilting the packing box 4 downward from the state where the packing box 4 is tilted at a tilt angle α and is stationary will be described.

  When the lever 142a of the operating device 142 is in the neutral position P2, the electric motor 121 is stopped. However, since the solenoid valve 123 is switched to the cutoff position 123b and the hydraulic oil is not discharged from the tilting cylinder 110, the cargo box 4 is tilted by the tilt angle α without tilting downward. At rest.

  In this state, the operator operates the lever 142a of the operating device 142 from the neutral position P2 to the lowered position P3. Then, the solenoid 123a of the electromagnetic valve 123 of the power unit 120 is activated, and the electromagnetic valve 123 is switched from the cutoff position 123b to the communication position 123c. As a result, the discharge oil passage 126 is communicated, the hydraulic oil can be discharged from the tilt cylinder 110, and the cargo box 4 tilts downward due to its own weight. At this time, the tilting cylinder 110 contracts, and the hydraulic oil in the tilting cylinder 110 is returned to the oil tank 125 via the discharge oil passage 126. Note that the speed of the lowering operation of the cargo box 4 can be adjusted by a throttle 127 provided in the discharge oil passage 126.

  In this embodiment, when it is detected by the limit switch 143 that the tilt angle α of the cargo box 4 is equal to or larger than the set angle α1 during the operation of the lifting operation of the cargo box 4 by the operation device 142 in the dump vehicle 1. In this case, the lifting operation of the packing box 4 is stopped. Thereby, the following effects can be obtained.

  That is, the tailgates 41a and 41b of the packing box 4 are double doors, and the tailgates 41a and 41b are not locked (for example, after the operator opens the tailgates 41a and 41b, For example, when forgetting to lock 41a and 41b), when the cargo box 4 is lifted, the tailgates 41a and 41b protrude obliquely downward and rearward as shown by the two-dot chain line in FIG. . Then, the tailgates 41a and 41b may interfere with the ground and be damaged during the raising operation of the packing box 4.

  However, according to this embodiment, during the raising operation of the cargo box 4, when the cargo box 4 reaches the set angle α1 smaller than the maximum tilt angle αmax, the raising operation of the cargo box 4 is forcibly stopped. Therefore, the state of the tailgates 41a and 41b can be confirmed during the raising operation of the packing box 4, and damage to the tailgates 41a and 41b due to interference with the ground can be suppressed. That is, it is possible to confirm whether or not the tailgates 41a and 41b are locked during the raising operation of the packing box 4, and as a result, when the tailgates 41a and 41b are locked, The operation device 142 may be operated immediately to resume the lifting operation of the cargo box 4. On the other hand, when the tail gates 41a and 41b are not locked, the tail gates 41a and 41b are locked, and then the operation device 142 is operated to resume the lifting operation of the cargo box 4 to It can be avoided that the gates 41a and 41b interfere with the ground and are damaged. Then, by operating the operation device 142 and restarting the lifting operation of the cargo box 4, the cargo box 4 can be easily tilted to the maximum tilt angle αmax.

  Furthermore, when working in a place where the ceiling height is relatively low, the distance between the packing box 4 and the ceiling can be confirmed during the raising operation of the packing box 4, and the packing box 4 interferes with the ceiling. Can be suppressed.

  Further, unlike the packing box tilting device provided with the PTO device, in this embodiment, the packing box tilting device 100 is independent of the traveling system of the dump vehicle 1 and is a battery 130 as a power source different from the engine. Is configured to drive the tilting cylinder 110. For this reason, it is possible to tilt the cargo box 4 even while the dump vehicle 1 is traveling. That is, it is possible to intentionally perform the tilting operation of the cargo box 4 by operating the lever 142a after releasing the safety device 142b of the operating device 142. However, if the operator unintentionally operates the lever 142a while the safety device 142b is released while the dump vehicle 1 is traveling, the cargo box 4 may tilt to the maximum tilt angle αmax. Concerned.

  According to this embodiment, even in such a case, when the tilt angle α of the packing box 4 reaches the set angle α1, the lifting operation of the packing box 4 is forcibly stopped. The lifting operation of the packing box 4 can be stopped before 4 is tilted to the maximum tilt angle αmax. Therefore, it is possible to provide the cargo box tilting device 100 with excellent safety.

-Other embodiments-
The present invention is not limited only to the above-described embodiments, and all modifications and applications within the scope of the claims and within the scope equivalent to the scope are possible.

  In the above embodiment, the power unit 120 includes the electric motor 121 and the hydraulic pump 122, but the power unit may include only the electric cylinder.

  The configurations of the tilting cylinder 110, the operating device 142, and the limit switch 143 described in the above embodiment are merely examples, and other configurations may be employed. For example, the operation device 142 may be configured to use a push button switch, a rotary switch, or the like. Further, instead of the limit switch 143, a proximity switch or the like may be used.

  In the above-described embodiment, the packing box 4 is configured to have the double-spread type tailgates 41a and 41b. However, the packing box may be configured to have a bottom-opening type tailgate. In this case, the tailgate is provided so as to be rotatable around a hinge provided at the upper end of the rear part of the cargo box, for example. In the case of a packing box with a bottom-open tailgate, the longer the distance between the rotation axis of the packing box and the rear end of the packing box (the lower end of the closed tailgate) is, the higher the packing box is lifted. In this case, the tailgate easily interferes with the ground. Therefore, in the case of a packing box having a downwardly opening type tailgate, as in the case of the above-described embodiment (in the case of the packing box 4 having the double door type tailgates 41a and 41b), the packing box is being lifted. Thus, it is effective to automatically stop the lifting operation of the packing box when the tilt angle of the packing box reaches the set angle.

  INDUSTRIAL APPLICABILITY The present invention is applicable to a dump carton tilting device for a dump vehicle that does not include a PTO device and that drives a tilting cylinder by a power source different from the engine.

DESCRIPTION OF SYMBOLS 1 Dump vehicle 3 Body frame 4 Cargo box 32 Subframe 41a, 41b Tailgate 100 Cargo box tilting device 110 Tilt cylinder 120 Power unit 121 Electric motor 122 Hydraulic pump 130 Battery 140 Control device 142 Operation device 143 Limit switch α Tilt angle α1 setting Angle αmax Maximum tilt angle

Claims (1)

A cargo box that has a tailgate and is tiltably mounted on the body frame;
An electric motor driven by the power of the battery;
A tilting cylinder that is expanded and contracted by driving the electric motor and tilts the packing box up and down by the expansion and contraction;
A dumping carton tilting device provided with a control device for controlling the driving of the electric motor,
The controller is
An operating device for tilting the packing box up and down;
A detection unit that detects whether the tilt angle of the packing box is smaller than the maximum tilt angle or greater than a preset set angle;
During the operation of the lifting operation to tilt the packing box upward by the operating device, when the tilting angle of the packing box is equal to or larger than the set angle, the lifting operation of the packing box is stopped,
The operating device has, as operating positions of the operating member, a raised position for raising the cargo box, a lowered position for tilting the cargo box downward, and a neutral position for stopping the tilting action of the cargo box. At least provided,
When the operating member is in the neutral position, the operating device can be operated to the raised position or the lowered position by an operating force applied to the operating member, and the operating member is moved to the raised position or When in the lowered position, it is configured to automatically return to the neutral position by releasing the operating force on the operating member,
When the operation member is held at the raised position, when the tilt angle of the packing box is equal to or larger than the set angle, the lifting operation of the packing box is stopped ,
When the elapsed time from the time when it is detected that the tilt angle of the packing box is equal to or greater than the set angle is equal to or greater than a preset time, even if the operating device is operated, A cargo box tilting device for a dump vehicle, wherein the lifting operation of the cargo box is stopped .

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