JP5505954B2 - Loading platform lifting device - Google Patents

Description

  The present invention relates to a load receiving platform lifting / lowering device that supports a loading / unloading operation of a load on a loading platform and can stand behind a vehicle.

  As a load receiving table lifting device provided at the rear of the vehicle, the load receiving stand is in an upright state when the vehicle is traveling, and when loading and unloading, the load receiving table is rotated from the standing state to the horizontal state and then lifted and lowered. When the loading / unloading is completed, there is one that returns the receiving platform from the horizontal state to the standing state.

  The lifting and lowering operation of the load receiving table is performed based on the expansion and contraction of the hydraulic cylinder, and there are those having a stopper member that abuts the load receiving table at a predetermined position in order to switch these operations at an appropriate position. is there. In this case, in order to control the speed at which the load receiving table comes into contact with the stopper member and suppress the impact force and the collision sound at the time of contact, a detection device for detecting the position of the moving load receiving table is arranged. The amount of hydraulic oil supplied to and discharged from the hydraulic cylinder is appropriately controlled by the detection signal of the detection device, and the moving speed of the load receiving table is reduced, so that the impact force and collision noise between the load receiving table and the stopper member at the time of contact are reduced. Suppression and improvement of safety.

  In order to suppress the movement speed of the load receiving table in the rotation operation and the lifting operation, it is necessary to detect at a plurality of locations. However, the increase in the number of detection devices avoids a complicated configuration and a significant increase in cost. In order to do this, a load receiving table lifting device in which only one detection device is installed and speed control is performed based on the detection signal has also been proposed (Patent Document 1).

  In addition, regarding the operation of the load receiving platform, various approaches have been made not only for speed control but also for preventing erroneous operation. For example, in order to ensure safety and prevent falling of the load, there is a restriction that cannot be switched between the turning operation and the lifting operation unless the load receiving tray is in a horizontal state ( Patent Document 2).

JP 2004-142706 A Japanese Patent No. 3935888

  As described above, the safety improvement and the simplification of the configuration are individually addressed. However, the present inventors have used the load receiving platform lifting device in various external situations as follows. Attention was also paid to the need to combine these different types of functions.

  First, in the case of a load receiving device lifting apparatus related to a vehicle that travels with the load receiving stand as described above in an upright state, even if the vehicle is subjected to large vibrations while running, the load receiving stand does not rattle. The posture is maintained by firmly pressing the load receiving table in front of the vehicle against the stopper member. Depending on the environment in which the vehicle is stopped, the worker may be required to quickly load and unload the load, and may perform a lowering operation before the load receiving table is rotated. When such an erroneous operation occurs, damage to the load receiving table or the like is caused by the above-described pressing that increases the certainty of maintaining the posture of the load receiving table.

Secondly, when the condition that the load receiving platform is in the horizontal state is used as a switching condition between the rotation operation and the lifting operation, for example, when loading / unloading a heavy load, the load remains in the set horizontal state. When carrying out the lowering operation of the load receiving table with the load placed thereon, the load receiving table may not be in a horizontal state, and the load may slide off the load receiving table. In addition, when the vehicle is stopped on an inclined ground, if the surface direction substantially the same as the loading platform floor is set as the horizontal direction, the load receiving platform is actually inclined when the load is loaded in the set state. There is a fear that the safety of loading and unloading work may be insufficient. Furthermore, even if an operator attempts to make the loading / unloading work safety by finely adjusting the posture of the loading platform by his / her own operation, the lifting / lowering operation of the loading platform cannot be performed unless the above set condition is satisfied. If it is controlled, there may be a situation where the lifting / lowering operation itself cannot be performed even if the safety of loading / unloading operations can be ensured.
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a load receiving platform lifting / lowering device that has a function that can appropriately cope with various environments and conditions and suppresses the complexity of the configuration.

  In the present invention, a load receiving table lifting device having the following configuration is used.

A parallel link mechanism provided at the rear of the vehicle and driven by a lifting cylinder or a rotation cylinder, and connected to the link mechanism, and is lifted and lowered between the ground and the loading platform floor height position, and the loading platform floor height In the load receiving platform lifting device having a load receiving platform that is rotated between a vertical position and a position that stands up behind the vehicle, the rotation of the load receiving platform between the height position of the loading platform floor and the standing position In the range, the rotation position detection means for detecting that the load receiving platform is located in a partial area thereof or an area different from the partial area, and the rotation position detection that the load receiving stand is positioned in the partial area. Based on the detection by the means, the extension control means for controlling the extension speed of the rotation cylinder, and the rotation position detection means detects that the load receiving base is located in the different area, For rotation Comprising a Linda shrinkage rate, and a shrinkage control means for performing at least one of the control of the contraction speed of the lifting cylinders, contraction of the lift cylinder, the consignee in the different areas by the rotation position detecting means This is performed based on detection of the position of the table .

  In this cargo bed lifting / lowering device, the extension control means causes the rotation speed of the cargo bed along the rotation direction from the height position of the cargo bed floor surface to the standing position in the partial area. It is set to be smaller than the rotational speed of the load receiving table in the different areas along the direction. The “rotation speed of the load receiving table along the rotation direction” indicates the speed of the load receiving table when rotating.

  In addition, as described above, when the position of the load receiving table is detected by the rotation position detecting unit, the lifting cylinder is set to be drivable by the contraction control unit. preferable.

  Furthermore, in this load receiving table lifting device, the rotation speed of the load receiving table along the rotation direction from the standing position to the height position of the load carrier floor surface in the different region is adjusted by the shrinkage control means. It is also preferable to adopt a configuration that is set to be smaller than the rotational speed of the load receiving table in the partial region along the direction.

  The partial area is an area from a desired position between the height position of the cargo bed floor surface and the standing position to the standing position, and the different area is the desired floor position from the desired position. This is the area up to the height position.

  The partial area may be an area spaced from the loading floor surface height position and the standing position, and the different area may be an area from the loading floor surface height position to the partial area. Absent.

  The load receiving table elevating device as described above includes operation means for outputting commands for raising and lowering the load receiving table and rotating operation, and the operating means includes a rotating operation unit that outputs a command for rotating operation. The extension speed is controlled by the detection of the rotation position detection means and the output signal of the rotation operation unit. Further, the operation means has an elevating operation section for outputting an elevating operation command, and the contraction control means is controlled by detection of the rotational position detecting means and an output signal of the elevating operation section. It does not matter as a configuration.

  According to the configuration of the present invention, the rotation position detection means is also used as the detection means for controlling the expansion and contraction of the rotation cylinder and the contraction operation of the lift cylinder. Can be suppressed.

  Further, when the rotation position detecting means detects that the load receiving platform is located in a partial area, the rotation speed can be suppressed before the standing state by controlling the extension speed of the rotation cylinder. . On the other hand, since it is possible to control at least one of the contraction speeds of the rotating cylinder and the lifting cylinder when detecting that the load receiving platform is located in an area different from the partial area, the load receiving platform is set in the different area. The cradle cannot be lowered until is positioned. Thereby, generation | occurrence | production of the misoperation which causes damage to a goods receiving stand etc. can be prevented. Also, since the load receiving table can be lowered when the load receiving table is located in the different area, it is possible to realize a highly safe lifting operation of the load receiving table corresponding to the environment where the vehicle is stopped.

  Furthermore, when controlling the contraction speed of the rotation cylinder when detecting that the load receiving table is located in the different area, the rotation speed can be suppressed before the load receiving table is in a horizontal state. In addition to suppressing impact force and collision noise when in a horizontal state, the desired tilt angle for shifting from a turning operation to a lifting operation is slightly different depending on the location where the vehicle stops and the type of luggage In addition, it is easy to adjust appropriately.

It is a side view which shows the operation state of a cargo receiving stand raising / lowering apparatus. It is a schematic diagram which shows the detection range of the rotation position of a load receiving stand. It is a circuit diagram of a control device and a hydraulic device connected to the load receiving table lifting device. It is a timing chart figure of operation which operates a receiving stand from a standing state to a horizontal state. It is a side view which shows the goods receiving stand which has a fine rotation angle just before becoming a horizontal state. It is a timing chart figure of operation which operates a load receiving stand from a horizontal state to a standing state. It is a schematic diagram for examining the inclination angle of the boundary line in the detection range of the rotational position of the cargo cradle. It is a sequence circuit diagram of the control apparatus which concerns on 3rd Embodiment. It is a schematic diagram which shows the rotation position detection range of the cargo receiving stand which concerns on 4th Embodiment.

Embodiments according to the present invention will be described with reference to the drawings.
(First embodiment)
1-1. Configuration of lifting platform

  FIG. 1 is a side view of a load receiving table lifting apparatus 100 according to the present embodiment. The load receiving table lifting / lowering device 100 is attached to a rear portion of a vehicle body frame including a main frame of the vehicle via a support member 1, and has a load receiving table 2 and a pair of left and right tilt links 3, a lift arm 4, and a tilt cylinder. 5. A lift cylinder 6 and a sensor 8 for detecting the rotation angle of the load receiving table are provided.

  The support member 1 includes a frame member 11 extending in the vehicle width direction below the rear end portion of the vehicle body frame, a pair of left and right fixing brackets 12 for fixing the frame member 11 to the rear end portion of the vehicle body frame, and the frame member 11. And support brackets 13 provided at both right and left ends. A loading platform is mounted on the body frame.

  The tilt link 3 is formed in a substantially U-shaped cross section that opens to the rear of the vehicle and extends in the vertical direction. An upper portion of the tilt link 3 is rotatably connected to an upper portion of the support bracket 13 via a pin 31, and a lower portion thereof is It is formed to swing forward and backward.

  The lift arm 4 is pivotally connected to the upper part of the tilt link 3 via a pin 41 at the base end. The tip of the lift arm 4 is rotatably connected to the upper end of the load receiving platform 2 via a pin 42.

  The tilt cylinder 5 has a function as a hydraulic cylinder for rotating the load receiving platform 2, and is disposed below the lift arm 4. The base end of the tilt cylinder 5 is rotatably connected via a pin 51 between the support bracket 13 and the bracket 14 facing the support bracket 13 from the outside. The tip of the tilt cylinder 5 is rotatably connected to the lower end of the load receiving platform 2 via a pin 52.

  The lift cylinder 6 has a function as a hydraulic cylinder for raising and lowering the load receiving platform 2, and is disposed below the tilt cylinder 5. The base end of the lift cylinder 6 is rotatably connected to the lower part of the tilt link 3 via 61. The tip of the lift cylinder 6 is rotatably connected to the intermediate portion of the lift arm 4 via a pin 62.

A known proximity sensor is used as the sensor 8 for detecting the rotation angle of the load receiving platform 2, and a detection piece 81 provided on the tip of the lift arm 4 and the pin 42 used for connecting the load receiving platform 7. And a detection unit 82 provided on the cargo receiving platform 2 by detecting the detection piece 81. The detection piece 81 is rotatably provided on the pin 42 that is the rotation center of the load receiving table 2 and is connected to the load receiving table by a connecting member (not shown) so as to rotate in conjunction with the rotation operation of the load receiving table 2. Has been. Further, the detection unit 82 is fixed to the pin 42 that is the rotation center of the load receiving platform 2, and is provided on the load receiving table by a connecting member (not shown) so as not to be interlocked with the rotation of the load receiving table 2. That is, the detection piece 81 is provided so as to be relatively close to or separated from the detection unit 82.

  The load receiving platform lifting apparatus 100 having the above-described configuration is such that the load receiving stand 2 is erected as shown in FIG. At this time, the tilt cylinder 5 and the lift cylinder 6 are in an extended state, and when in the standing state, the load receiving platform 2 is brought into contact with a member projecting rearward of the load platform (not shown). The load receiving platform 2 is pressed in front of the vehicle against the provided member.

  In order to perform loading / unloading work after the vehicle stops, the standing load receiving platform 2 has a height position substantially equal to the height position of the loading platform floor surface 7 as shown by the solid line portion in FIG. It is in a horizontal state. At this time, the lift cylinder 6 remains unchanged and the tilt cylinder 5 is contracted, and the load receiving platform 2 is rotated as shown in the figure by the contraction operation of the tilt cylinder 5.

  When loading / unloading a load between the ground and the loading platform floor surface 7, the horizontal loading platform 2 is lowered until it is in a grounded state as indicated by a one-dot chain line in FIG. At this time, the tilt cylinder 5 is in a contracted state and the lift cylinder 6 is also contracted. If the tilt cylinder 5 is extended in this state, the tilt cylinder 5 can be tilted until the tip of the load receiving platform 2 comes into contact with the ground.

Note that an operating device (not shown) for performing the expansion / contraction operation of the tilt cylinder 5 and the lift cylinder 6 is provided in a side portion on the rear side of the vehicle, so that an operator can visually check the operating state of the load receiving platform 2.
1-2. Detection Range of Sensor Next, detection of the rotation angle of the load receiving platform 2 by the sensor 8 will be described with reference to FIG.

  The range of the rotation operation of the load receiving platform 2 performed between the horizontal state and the standing state is such that the position of the load receiving platform 2 is detected by the sensor 8 with a virtual line L inclined obliquely upward toward the rear of the vehicle. It is divided into a rotation range A and a rotation range B that is not detected.

  When the load receiving platform 2 is located within the rotation range A shown in FIG. 2A, a signal for detecting the load receiving platform 2 is output by the sensor 8 and the load receiving platform 2 is positioned within the rotation range B. The signal output by the sensor 8 is not performed.

As shown in the schematic diagram of the main part of FIG. 2 (b), when the load receiving table 2 is rotated in the order of angle a and angle b from the standing state (solid line portion), the detection piece 81 also rotates the load receiving table 2 as shown in FIG. It rotates in conjunction with the movement.
In a state where the load receiving platform 2 is rotated by an angle a (a chain line portion), the detection piece 81 has a region (shaded portion in FIG. 2B) overlapping with the detection unit 82. At this time, the sensor 8 detects that the load receiving platform 2 is in a state of straddling the boundary line L between the rotation range A and the rotation range B and is located in the rotation range A. When the load receiving platform 2 is further rotated by an angle b (two-dot chain line portion), the detection piece 81 does not have an overlapping portion with respect to the detection portion 82, and the rotation range A is defined as the load receiving platform 2. Is detected as a state of being removed. At this time, it is assumed that the load receiving platform 2 is located in the rotation range B, and no detection signal from the sensor 8 is output.

The sensor 8 is provided on the load receiving platform 2 as shown in the figure, but may be provided at the base end portion of the lift arm 4 or other place. The type of detection by the sensor 8 may be any of a non-contact type detection device such as an induction type, a capacitance type, an ultrasonic type, a photoelectric type, or a magnetic type, or a contact type detection device.
1-3. Control device and hydraulic circuit relating to operation of loading platform 2

The load receiving table lifting device 100 includes a control device that controls the expansion and contraction of the tilt cylinder 5 and the lift cylinder 6 based on the detection signal of the sensor 8. The control device will be described with reference to FIG. 3. As shown in FIG. 3A, the sensor 8 is connected to the controller 9, and a detection signal (ON signal) from the sensor 8 is input to the controller 9. . The controller 9 includes an opening / closing switch SW2 provided in the operating means C for changing the posture of the load receiving platform 2 from the standing state to the horizontal state (opening operation) or changing the posture from the horizontal state to the standing state (closing operation); An up switch SW3 for raising the load receiving platform 2 in the horizontal state and a lowering switch SW4 for lowering the load receiving platform 2 in the horizontal state are also connected. Further, the controller 9 is energized by the ON operation of the opening / closing switch SW2 and the lowering switch SW4 to open the solenoid SOL4 which contracts the tilt cylinder 5, and is excited by the ON operation of the opening / closing switch SW2 and the raising switch SW3. A closing solenoid SOL3 to be extended is connected to a lowering solenoid SOL2 that is excited by an ON operation of only the lowering switch SW4 and contracts the lift cylinder 6. Further, the controller 9 is connected to a relay CT that is closed by an ON operation of the opening / closing switch SW2, and the opening / closing of a connection circuit to the motor M connected to the battery is controlled by the relay CT. The motor M drives a hydraulic pump that supplies and discharges hydraulic oil that performs the contracting operation of the tilt cylinder 5 and the lift cylinder 6.

  Each of the solenoids SOL4, SOL3, and SOL2 is disposed as shown in FIG. 3B in a power unit 90 that is disposed at a predetermined position on the side of the vehicle. The power unit 90 has a configuration in which the motor M and the hydraulic pump P are connected to the tilt cylinder 5 or the lift cylinder 6 via a hydraulic oil supply path or the like.

The suction side of the hydraulic pump P communicates with the oil tank T, and the discharge side communicates with the bottom side of each lift cylinder 6 through the first supply path 91. One end of a second supply path 92 having a closed solenoid SOL3 is connected to the first supply path 91, and the other end communicates with the bottom side of the tilt cylinder 5. In the first supply path 91, a first discharge path 93 provided with a lowering solenoid SOL <b> 2 is connected to the lift cylinder 6 side of the connection portion with the second supply path 92. In the second supply path 92, a second discharge path 94 including an open solenoid SOL4 is connected to the tilt cylinder 5 side of the closed solenoid SOL3. Both the first and second discharge passages 93 and 94 communicate with the oil tank T. In addition, a throttle valve 103 that restricts the maximum flow rate of the hydraulic fluid flowing through the first discharge path is disposed downstream of the lower solenoid SOL2 in the first discharge path 93, and regulates the maximum value of the discharge pressure of the hydraulic pump. A relief valve 101 is provided.
1-4. Changing the attitude of the receiving platform 2 from the standing state to the horizontal state

  By outputting the rotation command and the elevation command to the control device and the hydraulic circuit, the load receiving table is operated, that is, the tilt cylinder 5 and the lift cylinder 6 are expanded and contracted as follows. .

  First, the relationship between the operation switches SW2 to SW4 and the switching positions of the solenoids SOL2 to SOL4 when the load receiving platform 2 rotates from the standing state to the horizontal state will be described with reference to the timing chart of FIG. The response of the lowering solenoid SOL2 varies depending on whether or not the sensor 8 detects the cargo receiving platform 2 (time T3). In FIG. 4, the main switch SW1 (see FIG. 3A) is turned on.

In order to perform the opening operation of rotating the load receiving stand 2 in the horizontal state, the lowering switch SW4 is also turned on (time T2) immediately after the opening / closing switch SW2 is turned on (time T1). The lowering switch SW4 may be turned on simultaneously with the opening / closing switch SW2. As rotational operation for commanding the turnable operation receiving platform 2, opening and closing switch SW2, and the signal output of the up switch SW3 or lowering switch SW4 is performed, at the time of opening operation, opening and closing switch SW2 and down switches SW4 Upon receiving both ON signals, the open solenoid SOL4 is turned on, and the open solenoid SOL4 is switched to the communication position among the shut-down solenoids SOL2, SOL3, and SOL4. At this time, the motor M is not driven, and the hydraulic oil is pushed away from the bottom side of the tilt cylinder 5 by its own weight, and the tilt cylinder 5 is contracted to open the load receiving base 2. At this time, the sensor 8 detects that the load receiving platform 2 is located within the rotation range A (see FIG. 2), and the controller 9 receives an ON / OFF switch while receiving the ON signal of the sensor 8. Receiving the ON signals of both SW2 and the lowering switch SW4 is set as a condition for operating the cargo receiving platform 2.

  Specifically, when the operator accidentally turns off only the opening / closing switch SW2 while the cargo receiving platform 2 is positioned within the rotation range A (for example, time T2 to T3), FIG. As indicated by the dotted line S1, the open solenoid SOL4 is also in a shielding state. Therefore, the cargo receiving platform 2 is brought into a stopped state without operating. That is, when the load receiving platform 2 is located within the rotation range A, the lowering operation is not performed even if only the lowering switch SW4 is ON.

On the other hand, when the load receiving platform 2 is rotated until it is positioned in the rotation range B (see FIG. 2), the load receiving platform 2 can be operated without receiving the ON signal of the opening / closing switch SW2. Is set to When the operator mistakenly turns off only the opening / closing switch SW2 while the load receiving platform 2 is positioned in the rotation range B (for example, time T3 to T4), as shown by a dotted line S2 in FIG. Although relays CT and opens the solenoid SOL4 is also a cutoff state, only solenoid SOL 2 is lowered by receiving the signal of the lower switch SW 4 that maintains the oN state is switched to the communicating position, the lift due to the weight of such receiving platform 2 The hydraulic oil is pushed away from the bottom side of the cylinder 6. As a result, the lift cylinder 6 is contracted to lower the load receiving platform 2. Further, when the lowering switch SW4 is turned off (T4) and the opening / closing switch SW2 is also turned off, the operation of the cargo receiving platform 2 is stopped. It should be noted that the OFF operation of the lowering switch SW4 may be performed simultaneously with the OFF operation of the open / close switch SW2.

  As described above, the cradle 2 can be lowered when it is located in the rotation range B, so that an appropriate inclination angle for loading and unloading of the luggage can be set corresponding to the stop position of the vehicle and the surrounding environment. It becomes possible to select. For example, as shown in FIG. 5 (a), the load receiving platform 2 when loading and unloading the load is set to a state (solid line portion) slightly tilted upward from the horizontal state (dotted line portion). Can be lowered. When loading and unloading a heavy load, the load receiving platform 2 is tilted upward immediately before loading so that the load receiving platform 2 on which the load is placed does not tilt downward from the horizontal state. To do. Thereby, the load receiving stand 2 can be made into a horizontal state in the state in which the luggage | load was loaded, and fall of a luggage | load etc. can be prevented.

In addition, the rear end of the vehicle is inclined as shown in FIG. 5B, for example, when the vehicle is stopped on a sloping ground or when the vehicle is stopped with the vehicle rear wheel positioned on the low ground side of the stepped portion. In the state, the standing cradle 2 may be slightly deviated from the vertical direction. According to the present embodiment, even in such a case, the load receiving platform 2 can be lowered as a horizontal state or a state inclined slightly upward from the horizontal state (dotted line portion). It is possible to prevent the cargo loaded in the box from falling.
1-5. Elevating / lowering operation of the horizontal loading tray 2

  Only the lowering switch SW4 is turned ON for the load receiving platform 2 whose posture has been changed to the horizontal state, whereby the lowering solenoid SOL2 is switched to the communication position, and only the lowering solenoid SOL2 is in the communication state, and the lift cylinder 6 The hydraulic oil is pushed away from the bottom side of the cylinder and the lift cylinder 6 is contracted. As a result, the cargo receiving platform 2 is lowered and grounded.

When the load is placed on the grounded load receiving platform 2 and the lifting operation is performed up to the height of the loading platform floor, only the raising switch SW3 is turned on. As a result, the motor M is driven to drive the hydraulic pump P, and hydraulic oil is supplied to the bottom side of the lift cylinder 6 via the first supply path 91. The lift cylinder 6 is extended and the load receiving platform 2 is raised.
1-6. Changing the posture of the receiving platform 2 from the horizontal state to the standing state

  An operation for loading a load on the loading platform after the horizontal loading platform 2 has been raised to the height of the loading platform floor and storing the loading platform 2 in an upright state will be described with reference to the timing chart of FIG.

When the load receiving platform 2 is in the horizontal state, the sensor 8 is not detected because it is located in the rotation range B, and the sensor 8 is in the OFF state. When the open / close switch SW2 is pressed (time T11) and then the raising switch SW3 is pressed (time T12), the relay CT is turned on and the closed solenoid SOL3 is switched to the communication position. When the raising switch SW 3 is pressed, the motor M is driven and the hydraulic pump P is driven, so that hydraulic oil is supplied to the bottom side of the tilt cylinder 5 via the second supply path 92. As a result, when the opening / closing switch SW2 and the raising switch SW3 serving as the rotation operation unit are turned ON, the tilt cylinder 5 is extended and rotated in the direction in which the load receiving platform 2 is raised. Note that the opening / closing switch SW2 and the raising switch SW3 may be turned ON simultaneously.

  When the load receiving platform 2 is rotated from the rotation range B to the rotation range A (see FIG. 2), the position of the load receiving platform 2 is detected by the sensor 8, and the output signal of the sensor 8 is turned on (time). T13). In response to the output signal of the sensor 8, the lower solenoid SOL2 is switched to the communication position via the controller 9. As a result, a part of the hydraulic oil from the hydraulic pump P is returned from the first supply passage 91 to the oil tank T via the first discharge passage 93, so that the amount of hydraulic oil supplied to the tilt cylinder 5 is reduced. The extension speed of the tilt cylinder 5 is suppressed. That is, the rotation speed in the locus indicated by the arrow in the rotation range A as compared with the rotation speed in the rotation range B when rotating in the locus as indicated by the arrow in FIG. Becomes smaller. As described above, the rotation speed of the load receiving table 2 is automatically reduced when the sensor detects that the load receiving table 2 is positioned in the rotation range A only by rotating the load receiving table 2. The collision force and the collision noise between the load receiving table 2 and the contact member when the load receiving table 2 is in the standing state can be suppressed.

As a condition for the lowering solenoid SOL2 to be in communication, at least both the raising switch SW3 and the sensor 8 are in the ON state. Therefore, when the raising switch SW3 is turned off as indicated by the dotted line S4, the motor drive is stopped, the closed solenoid SOL3 is turned off, and the lowering solenoid SOL2 is also turned off. The insertion state of the discharge path 93 is blocked, and the load receiving platform 2 is stopped without being rotated.
1-7. Detecting range of rotation angle of load receiving table 2 by sensor 8

  As described above, the position of the load receiving platform 2 is detected by the sensor 8, and the lowering operation of the load receiving platform 2 is controlled based on the detection signal. Regarding the rotation angle (the rotation angle from the standing position of the load receiving platform 2) of the rotation range A (see FIG. 2) in which the detection signal is output, the load receiving platform 2 in the rotating operation from the horizontal state to the standing state. Is set after appropriately considering the reduction rate of the predetermined collision force and the rotation speed with the stopper member that abuts. That is, if the rotation angle of the rotation range A is too large, it takes too much time to bring the load receiving stand 2 into an upright state, and if the rotation angle is too small, the rotation speed is not sufficiently suppressed. Is appropriately set.

However, when the standing cradle 2 is slightly opened (rotated to the horizontal state), the members related to the cradle lifting device 100 are buffered when the cradle 2 is lowered. There is. For example, as shown in the schematic side view of the load receiving platform lifting device 100 in FIG. 7A, the load receiving platform 2 is provided with a side guard 21 to prevent the loaded cargo from dropping from the side. In some cases, the cargo bed floor surface is provided with an overhanging portion that fills the gap between the cargo bed floor surface and the cargo receiving platform and extends rearward from the cargo bed floor surface. In this case, when the region of the rotation range A in which the rotation position of the standing cradle 2 is detected is set as a range from the position of the standing state to the virtual line L1 indicated by the one-dot chain line, When the cargo receiving platform 2 is lowered at the position where the rotation angle is L1, as shown in FIG. 7B, the side guard 21 and the overhanging portion 71 interfere with each other, causing damage or destruction of these members. End up. Therefore, the rotation angle of the boundary line L between the rotation range A and the rotation range B is preferably set to a size that does not cause interference between the side guard 21 and the overhang portion 71.
(Second Embodiment)

  The present embodiment is different from the first embodiment in the control means for changing the posture of the load receiving platform 2 from the standing state to the horizontal state, but the other configurations are the same, and therefore the control means is the center. Explained.

  In the present embodiment, the load receiving platform 2 is raised by providing a hydraulic circuit having a configuration in which the open solenoid SOL4 shown in FIG. 3B used in the description of the first embodiment is replaced with a flow proportional valve. The rotation speed can be suppressed not only immediately before the state is set but also immediately before the level state is set.

When the load cradle 2 is opened from the standing state to the horizontal state, the flow proportional valve is switched to the communication position, so that the hydraulic oil on the bottom side of the tilt cylinder 5 is pushed away by its own weight. While the tilt cylinder 5 is being contracted, the rotation position of the load receiving platform 2 moves from the rotation range A detected by the sensor 8 to the rotation range B that is not detected, so that a detection signal from the sensor 8 is input. On the condition that it disappears, the hydraulic pressure of the hydraulic fluid sent to the second discharge passage 94 is limited through the flow rate proportional valve. That is, when the detection signal of the sensor 8 is not input (see FIG. 3A), the contraction speed of the tilt cylinder 5 is suppressed, and the rotation speed until the load receiving platform 2 becomes horizontal is reduced.
(Third embodiment)

This embodiment is different from the control means and the first and second embodiment uses a sequence control, since other configurations etc. are the same, will be described with reference to FIG. 8 about the different portions.
In the present embodiment, it operates as follows by the sequence control shown in FIG.

  When the operator connects the main switch SW installed in the cab (ON operation), electric power is supplied from the battery power source mounted on the vehicle to the sensor 8, and the sensor 8 becomes operable.

  When the opening / closing button B1 and the lowering button B3 are pressed and turned on to start the opening operation for changing the posture to the horizontal state with respect to the standing cradle 2, the relay coil R22 is excited and the normally open relay The contact R22a is turned on. As a result, the opening solenoid SOL4 is switched to the communication position, the tilt cylinder 5 is contracted, and the load receiving platform 2 is rotated in the opening direction to be in a horizontal state. On the other hand, the normally closed relay contact R22b is turned off, so that the lowering solenoid SOL2 is not switched to the communication position.

  In this state, since the load receiving platform 2 is located in the rotation range A, it is detected by the sensor 8, and the relay coil R11 is excited and the normally open relay contact R11a is turned on. When only the lower button B3 is pressed without pressing, or when only the open / close button B1 is released while both the open / close button B1 and the lower button B3 are being pressed, the relay coil R22 is de-energized. Thus, the lowering solenoid SOL2 is not switched to the insertion position. That is, the load receiving platform 2 is neither rotated nor lowered.

  Further, when the load receiving platform 2 is located within the rotation range B, it is not detected by the sensor 8. Therefore, the relay coil RA is de-energized, and when only the lowering button B3 is pressed as described above, or opening / closing If only the opening / closing button B1 is released while both the button B1 and the lowering button B3 are being pressed, only the lowering solenoid SOL2 is switched to the communication position.

  Next, when only the lowering button B3 is pressed to perform the lowering operation with respect to the horizontal load receiving platform 2, only the lowering solenoid SOL2 is switched to the communication position because the normally closed relay contacts R22b and R11a are in the ON state. When only the raising button B2 is pressed to perform the ascending operation, the normally closed relay contact R12 is in the ON state, so that the contactor relay coil RCT is excited, the contactor is turned ON, and the motor M is driven.

  When the opening / closing button B1 and the raising button B2 are pressed and turned on in order to start the closing operation for changing the posture to the standing state with respect to the horizontal load receiving platform 2, the relay coil R21 is excited and the normally open relay contact R21a is turned ON, and the closed solenoid SOL3 is switched to the insertion position. On the other hand, the normally closed relay contact RA1 is turned off, so that the lower solenoid SOL2 is not switched to the communication position.

In this state, when the cargo cradle 2 is located in the rotation range B, the cargo cradle 2 is not detected by the sensor 8 and the relay coil RA is not excited, but the cargo cradle 2 is in the rotation range. When it is located within A, it is detected by the sensor 8 and the relay coil RA is excited. Thereby, the normally open relay contact RA1 is turned ON, and the lowering solenoid SOL2 is switched to the communication position. That is, part of the hydraulic oil supplied from the hydraulic pump is also supplied to the first discharge passage 93, and the extension operation of the tilt cylinder 5 is suppressed.
(Fourth embodiment)

  This embodiment differs from the first to third embodiments in that the detection range of the rotation position of the load receiving platform 2 is different, but based on a detection signal from a sensor that detects the rotation position of the load receiving platform 2, Since the other structure etc. by which the stand 2 is operated are the same, it demonstrates using FIG. 9 focusing on the said detection range.

In this embodiment, the rotation range in which the posture of the load receiving platform 2 is changed from the standing state to the horizontal state is divided into rotation ranges C, D, and E as shown in FIG. As shown in the figure, a rotation range D is formed in the central portion that is separated from the standing position (solid line portion) and the horizontal position (one-dot chain line portion) of the load receiving platform 2. A sensor (not shown) is installed so as to output a detection signal when is located. Like the sensor 8 according to the first embodiment, the sensor is configured to include a detection piece and a detection unit, but in order to detect the position of the boundary line (two-dot chain line) that forms the rotation range D, The detection unit is configured by two detection units (a first detection unit and a second detection unit). Depending on the output of the rotation direction (opening operation direction or closing operation direction) to the load receiving platform 2 and the detection signal from either one of these two detection units, the load receiving table 2 is in any of the rotation ranges C, D, E. It is detected whether it is located.
When the load receiving platform 2 is located in the rotation range D, the procedure shown in FIG. 9B is controlled.

  First, a rotation command is output (C2) to the load receiving platform 2 in the opening operation or the closing operation in a state (C1) located in the rotation range D. (C3), specifically, when the open / close button is pressed and the lift button is pressed, the posture of the load receiving platform 2 is changed so as to be in an upright state (C4). When the load receiving platform 2 is positioned within the rotation range C, the sensor of the present embodiment stops outputting the detection signal, receives the above closing operation command and the stop of the detection signal, and closes the load receiving platform 2. The deceleration control is performed. That is, based on the output of the detection signal indicating that the position is within the rotation range D, the closing operation command for the load receiving platform 2 is further output, so that not only the closing solenoid SOL3 but also the lowering solenoid SOL2 is connected to the communication position. The extension speed of the tilt cylinder 5 is suppressed.

Next, based on the output of the detection signal located within the rotation range D, when a rotation command in the opening direction is output to the cargo receiving platform 2 (C13), specifically, opening / closing When the down button is pressed while the button is pressed, the attitude of the load receiving platform 2 is changed so as to be horizontal (C14). When the load receiving platform 2 is located within the rotation range E, the sensor stops signal output, and the control that can start the lowering operation of the load receiving platform 2 or the deceleration control of the opening operation is performed.
(Other matters)

  When the load receiving platform 2 is located within the rotation range B, the control means (the lowering operation of the load receiving platform 2 and the deceleration operation of the load receiving platform 2) according to the first embodiment and the second embodiment are provided respectively. However, a configuration including both of these control means is also possible. In particular, when performing the lowering operation of the load receiving platform 2, if the tilt angle is very small when it is tilted upward without being in a horizontal state, it has a deceleration function of the load receiving platform 2. This is preferable because the fine angle can be easily adjusted.

  In each embodiment, operating both the opening / closing switch SW2 and the raising switch SW3 or the lowering switch SW4 is a condition for the opening / closing operation (rotation operation) of the load receiving table 2. The raising switch SW3 or the lowering switch SW4 is configured to perform the closing operation by subsequently turning on the raising switch SW3 after raising the loading platform 2 from the ground contact state to the height position of the loading platform floor. You may set so that a rotation operation may be performed only by.

  In addition, when each operation command is output (ON operation of each switch), the expansion / contraction control of the tilt cylinder 5 or the lift cylinder 6 is performed immediately. The setting may be made such that the above control is performed after the elapse of a desired time later.

Further, when the load receiving platform 2 is detected by the sensor 8, it is output as an ON signal from the sensor 8. For example, it is output as an ON signal that the load receiving platform 2 is not located in the rotation range A, It may be set to perform expansion / contraction control of each of the cylinders 5 and 6 centering on a state where the sensor 8 does not detect so that the load receiving platform 2 can be lowered.
In addition, a configuration that adjusts the supply and discharge of the hydraulic oil by a known technique such as motor control and a configuration in the tilt cylinder 5 or the lift cylinder 6 can be appropriately applied.

  According to the present invention, since the load receiving platform lifting apparatus capable of performing the load receiving platform work in an appropriate posture can be realized with a simple configuration in accordance with various places and environments, it has a plurality of different types of operation modes. It is useful for the cargo receiving platform lifting device.

DESCRIPTION OF SYMBOLS 1 Support member 2 Cargo stand 3 Tilt link 4 Lift arm 5 Tilt cylinder 6 Lift cylinder 7 Cargo floor 8 Sensor 9 Controller 81 Detection part 82 Detection piece 90 Power unit
100 Loading platform lifting device

Claims (7)

A parallel link mechanism provided at the rear of the vehicle and driven by a lifting cylinder or a rotation cylinder, and connected to the link mechanism, and is lifted and lowered between the ground and the loading platform floor height position, and the loading platform floor height A load receiving table lifting device having a load receiving table rotated between a vertical position and a position standing behind the vehicle,
In the rotation range of the load receiving platform between the loading platform floor height position and the standing position, the cargo receiving platform may be in a partial area thereof or in a region closer to the loading platform floor height position than the partial area. Rotation position detection means for detecting the position of the table,
An extension control means for controlling the extension speed of the turning cylinder based on the fact that the turning position detecting means detects that a load receiving table is located in the partial area;
Control of at least one of the contraction speed of the rotating cylinder and the contraction speed of the elevating cylinder is performed based on the detection of the rotational position detecting means that the load receiving table is located in the different area. Contraction control means;
Equipped with a,
The load receiving device lifting / lowering apparatus according to claim 1, wherein the lifting / lowering cylinder contracts based on detection of the load receiving table being positioned in the different area by the rotation position detecting means . By the extension control means, the rotation speed of the load receiving table along the rotation direction from the loading platform floor surface height position to the standing position in the partial area is the different area along the rotation direction. The load receiving device lifting / lowering device according to claim 1, wherein the load receiving device lifting / lowering device is set to be lower than a rotation speed of the load receiving table. By the contraction control means, the rotation speed of the load receiving table along the rotation direction from the standing position to the height position of the loading platform floor in the different area is changed in the partial area along the rotation direction. The load receiving table lifting / lowering device according to claim 1, wherein the load receiving table lifting / lowering device is set smaller than a rotation speed of the load receiving table. The partial region is a region from a desired position between the loading floor surface height position and the standing position to the standing position,
The said receiving area is an area | region from the said desired position to the said loading platform floor surface height position. The cargo receiving platform raising / lowering apparatus of Claim 1 characterized by the above-mentioned. The partial region is a region separated from the loading floor surface height position and the standing position,
The cargo receiving platform lifting apparatus according to claim 1, wherein the different area is an area from a height position of the cargo bed floor to the partial area. An operation means for outputting commands for raising and lowering and rotating the load receiving table;
The operation means has a rotation operation unit that outputs a rotation operation command,
The cargo receiving platform elevating device according to any one of claims 1 to 5 , wherein the extension speed is controlled by detection of the rotation position detection means and an output signal of the rotation operation unit. An operation means for outputting commands for raising and lowering and rotating the load receiving table;
The operation means has an elevating operation unit that outputs an elevating operation command,
The load receiving platform lifting / lowering device according to any one of claims 1 to 5 , wherein the contraction control device is controlled by detection of the rotation position detecting device and an output signal of the lifting / lowering operation unit.