JP2010137777A - Load receiving platform lifting gear for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a load receiving platform from interfering a packaging case, and to prevent damage to the packaging case or the load receiving platform while shortening a time until the start of loading work in a cargo handling vehicle allowing the loading/unloading of a load by horizontally deploying the load receiving platform from an erected storing attitude. <P>SOLUTION: The loading receiving platform G is made to perform both deploying motion and descending motion simultaneously after the load receiving platform G is tilted by approximately 30° while maintaining a storing position and is separated from the packaging case V. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle cradle lifting apparatus, and more particularly to a cargo cradle lifting apparatus in which a deployment operation from a storage position of the cargo cradle and a lowering operation thereof are performed in parallel.

Conventionally, in a vehicle, in order to load and unload cargo between a cargo box and the ground, a load receiving platform that has been deployed in a substantially horizontal deployment posture is brought into contact with a lowered position where the lift cylinder contacts the ground and the floor surface of the cargo box. A load receiver that is driven up and down between a substantially parallel raised position, and when the load receiving table is not in use, the load receiving stand is turned upright from the raised position by a tilt cylinder so as to be turned upright in a substantially vertical storage posture. A table raising / lowering device is known from Patent Document 1 described later.
JP 2006-143217 A

  By the way, in such a load receiving platform elevating device, as a preparatory work for starting the loading operation of the load into the cargo box, the unfolding operation of unfolding the substantially vertically stowed load receiving stand to the substantially horizontal unfolding posture, A descent operation is performed to descend to the ground, and the cargo receiving platform is stopped at the descent position where it is grounded.

  However, when the unloading operation of unfolding the load receiving platform by the tilt cylinder is completed after the unfolding operation of unfolding the load receiving platform from the substantially vertical storage posture to the substantially horizontal unfolding posture, the load loading work time is reduced. There is a problem that it becomes longer and the work efficiency is lowered.

  In order to solve this problem, the lift cylinder and the tilt cylinder are operated at the same time, and the unloading operation and the lowering operation are simultaneously performed to shorten the preparation work time. As a result, the load receiving platform may start to descend while being stowed in a substantially vertical position (because the load receiving stand in the substantially vertical storing position is deployed while contracting the tilt cylinder by its own weight). In addition, the force for contracting the tilt cylinder is weak, and the rotational moment for deploying the load receiving table in the retracted position is small. On the other hand, the contraction of the lift cylinder for deploying the load receiving table is caused by the load receiving platform and the parallel link mechanism. Since the force for contracting the lift cylinder is substantially constant, the contraction of the lift cylinder has priority over the contraction of the tilt cylinder).

  By the way, when the load receiving platform is in a substantially vertical storing posture, the load receiving table is arranged adjacent to the rear wall of the load box, so that the load receiving table descends along the rear wall of the load box. Thus, when the load receiving platform is lowered, this may interfere with the rear wall of the cargo box. In particular, a vehicle having an opening / closing door provided on the rear wall of the cargo box (for example, disclosed in Japanese Patent Laid-Open No. 8-193447). ), The load receiving table may be lowered while the lock device locking the open / close door in the closed position and the load receiving table are in contact with each other, resulting in damage or breakage of the lock device or the load receiving table. There is a problem that the tendency becomes even more prominent when the load receiving platform descends without the operator accidentally locking the locking device.

  The present invention has been made in view of such a situation, and as a preparatory operation for the loading operation, the time until the loading operation is started by simultaneously performing the lowering operation and the unfolding operation of the loading platform in the retracted position is shortened. On the other hand, it is an object of the present invention to provide a novel vehicle load receiving device lifting / lowering device capable of preventing damage and breakage of a load receiving table and a packing box.

In order to achieve the above object, the invention according to claim 1 is characterized in that the vehicle body frame is held in an unfolding posture capable of loading and unloading luggage and can be moved up and down between a lowered position and an elevated position, and the unfolded posture. A vehicle cradle lifting device provided with a cradle that is erected and rotated and is held in a retracted posture,
A lift cylinder that drives the load receiving table up and down, a tilt cylinder that opens and closes the load receiving table between a deployed posture and a retracted posture, and detects an interference avoidance posture while the load receiver moves from the retracted posture to the deployed posture. And a control means for driving and controlling the lift cylinder and the tilt cylinder, the control means until the load receiving platform is deployed from the retracted position and the detecting means detects the interference avoidance attitude. After driving and controlling only the tilt cylinder and the detecting means detects the interference avoidance posture, the tilt cylinder and the lift cylinder are both driven and controlled so that the unloading operation and the lowering operation of the load receiving table are performed in parallel. It is characterized by.

  According to the first aspect of the present invention, as a preparatory operation for the loading operation, the load receiving platform in the retracted posture is lowered and unfolded simultaneously to shorten the time required to start the loading operation, while receiving the load. It is possible to prevent the platform from interfering with the cargo box, and to prevent damage or breakage of the cargo cradle or the cargo box.

  Embodiments of the present invention will be specifically described below based on the embodiments of the present invention illustrated in the accompanying drawings.

  FIG. 1 is a side view of a cargo handling vehicle equipped with a cargo receiving platform lifting device of the present invention, FIG. 2 is a rear view of the cargo handling vehicle as viewed in the direction of arrows 2 in FIG. 1, and FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 3, FIG. 5 is a side view of the load receiving stand taken along line 5-5 of FIG. 2, and FIG. 6 is a view taken along arrow 6 of FIG. FIGS. 7 and 7 are hydraulic circuit diagrams of the load receiving table, and FIGS. 8 to 12 are operation explanatory views of the load receiving table.

  1 and 2, a covered cargo box V is mounted on the body frame F of the cargo handling vehicle, and an entrance / exit provided on the rear wall of the cargo box V is opened / closed by a kannon-type opening / closing door D. A lock device LO for locking the open / close door D in the closed position is provided on the outer surface of the open / close door D, and the lock device LO slightly protrudes from the outer surface of the open / close door D. On the rear part of the vehicle body frame F, a load receiving table G is supported so as to be movable up and down via a lifting device E composed of a parallel link mechanism Li. After opening the entrance / exit of the cargo box V, as shown by the chain line in FIG. 1, the cargo carrier V is lifted and lowered between the floor and the ground by holding the cargo receiving platform G in a substantially horizontal unfolded posture. Can be loaded and unloaded. Further, when the cargo handling vehicle is traveling, the load receiving platform G is erected and held in a substantially vertical retracted position adjacent to the outer surface of the closed door opening / closing door D as indicated by a solid line in FIG.

  As shown in FIGS. 3 and 4, support brackets 2 and 3 are welded to the left and right sides of the cross member 1 fixed to the rear portion of the vehicle body frame F. The base ends of the upper link 4 and the lower link 5 constituting the parallel link mechanism Li of E are pivotally connected 6 and 7 so as to be pivotable in the vertical direction, respectively. The base ends of a pair of lift cylinders LC for lifting and lowering are pivotally connected 10 so as to be rotatable. Further, the ends of the upper link 4 and the lower link 4 are pivotally connected 8 and 9 to the front link 12. The base end of the load receiving platform G is pivotally supported by the pivotal connection 8 part of the upper link 4 and the front link 12 so as to be rotatable. One end of the piston rod of the tilt cylinder TC is pivotally connected 13 to the protrusion 12P of the front link 12. The front portions of the left and right parallel link mechanisms Li are connected by a connecting rod 15.

  Reference numerals 17, 18 and 19 denote left and right and central rear bumpers supported by the vehicle body frame F via the cross member 1.

  As shown in FIGS. 2 to 6, the load receiving table G includes a load receiving body 20 having a square plate shape and a flat receiving surface. The left and right stiffeners 21 </ b> L and 21 </ b> R form a pair. It is reinforced by. The left and right stiffeners 21L and 21R are fixed to the back surface of the load receiving body 20 by a plurality of bolts 22 and extend in the front-rear direction parallel to each other at intervals in the left and right directions of the load receiving body 20 and from the proximal end to the distal end. The tilt cylinders TC are housed in the base ends thereof, respectively. In each tilt cylinder TC, one end of the cylinder barrel is pivotally connected 14 to the left and right stiffeners 21L and 21R, and the tip of the cylinder rod protrudes outside from the stiffeners 21L and 21R and is pivotally connected 8 to the upper link 4. The load receiving table G can be opened and closed by the expansion and contraction operation of the tilt cylinder TC. When the load receiving table G is in the contracted state, the load receiving table G is held in a vertical storage posture, and the load receiving surface is loaded with the load receiving surface. Adjacent to the rear wall of the box V and held substantially parallel to the rear wall of the box V, and when the tilt cylinder TC is extended, the load receiving platform G rotates about the eight pivotal connection points to a substantially horizontal deployed posture. Retained. A stopper 23 is provided on each of the base end surfaces of the left and right stiffeners 21L and 21R. When the load receiving table G is rotated to the deployed position, the stopper 23 contacts the parallel link mechanism Li so that the load receiving table G is substantially horizontal. It is prevented from rotating downward from a proper deployment posture.

  As shown in FIG. 6, an inclination angle sensor 24 as a detecting means is fixed to one of the pair of stiffeners 21L and 21R, in this embodiment, on the inner surface of the base of the left stiffener 21L. The inclination angle sensor 24 detects that the load receiving base G starts to rotate from a substantially vertical retracted position to a substantially horizontal deployed position, and detects that the retracted position is inclined to an interference avoidance position, that is, about 30 °, and the detection signal Thus, the control means C described later is operated (see FIG. 8).

  Next, the control means C for controlling the operation of the cargo receiving platform G will be described with reference to FIG.

  The outlet port P1 of the hydraulic power unit PU is connected to the pair of lift cylinders LC, LC composed of a single-acting hydraulic cylinder via electromagnetic open / close valves SOLC, SOLC, and the outlet port P2 of the power unit PU is connected to the outlet port P2 of the power unit PU. A pair of tilt cylinders TC, TC composed of a single acting hydraulic cylinder is connected. The power unit PU includes a hydraulic pump P driven by a motor M, an oil tank T, and electromagnetic switching valves SOLA and SOLB. The suction side of the hydraulic pump P is communicated with the oil tank T, and on the discharge side thereof. The discharge oil passage 30 to be connected is branched into first and second hydraulic oil passages 32 and 33 via a check valve 31, and the first hydraulic oil passage 32 is connected to the outlet port P1, and the second hydraulic oil. The path 33 is connected to the outlet port P2 via the electromagnetic switching valve SOLB and the opening / closing control valve 34. A branch oil passage 35 branched from the discharge oil passage 30 is connected to the oil tank T via an electromagnetic switching valve SOLA and a variable throttle valve 36, and another branch oil passage 37 branched from the discharge oil passage 30 is relief. It is connected to the oil tank T via a valve 38. The other branch oil passage 37 is connected to the open / close control valve 34 via a check valve 39.

  The operation of the load receiving table G is performed by controlling the operation of the lift cylinder LC and the tilt cylinder TC by the control of the control means C based on the operation of the wired remote control switch RS shown in FIG.

  The remote control switch RS includes an “open / close” switch 41, an “UP” switch 42, and a “DOWN” switch 43.

  Next, the operation control of the load receiving table G by the control means C based on the operation of the remote control switch RS will be described with reference to FIGS.

8 to 12, ○ indicates driving of the motor M of the hydraulic pump P and excitation (conduction) of the electromagnetic switching valves SOLA, SOLB and SOLC, and X indicates stopping of the motor M of the hydraulic pump P and the electromagnetic switching valve SOLA, The de-excitation (cut-off) of SOLB and SOLC is shown, respectively.
"Preparation operation for loading work from the stowed position of the receiving platform G" (see Fig. 8)
1. When the operator presses the “DOWN” switch 43 in a state where the cargo receiving table G is in the retracted posture, the operation of the cargo receiving table G is started. The control means C stops driving of the motor M of the hydraulic pump P and excites both the electromagnetic on-off valves SOLA and SOLB (switching on the left side in FIG. 7). Thereby, only the tilt cylinder TC communicates with the oil tank T, and the hydraulic oil in the tilt cylinder TC returns to the oil tank T. At this time, the tilt cylinder TC contracts in response to the weight of the load receiving table G, and the load receiving table G starts only the unfolding operation from the retracted position to the unfolding (FIG. 8A).

2. The unfolding operation of the loading platform G is continued, and it is tilted around 8 points of pivot connection about 30 ° to be in an interference avoidance posture (tilt posture). When the tilt angle sensor 24 detects this, the motor M is driven. The electromagnetic switching valve SOLC is excited (switched on the right side in FIG. 7) while maintaining the stop state and the electromagnetic switching valves SOLA and SOLB are maintained in the excited state, and the lift cylinder LC is communicated with the oil tank T. At this time, the lift cylinder LC contracts in response to the weights of the load receiving table G and the parallel link Li, and the load receiving table G starts to descend while continuing the unfolding operation. The load receiving platform G is located at a position far from the rear wall of the load box V, and the load receiving table G does not interfere with the rear wall of the load box V even if it continues to descend. (Fig. 8 (B))
3. The unloading operation of the load receiving table G stops when the stopper 23 at the base end of the load receiving table G comes into contact with the parallel link mechanism Li while the load receiving table G descends. When the tip of the parallel link mechanism Li is grounded, the descending of the load receiving platform G stops.

  Thereby, the preparation operation for the loading operation is completed.

“Ascending movement when loading / unloading the loading platform G” (see FIG. 9)
4). When the operator presses the “UP” switch 42 in a state where the load receiving platform G is in the lowered position, the control means C drives the motor M of the hydraulic pump P, and turns off the electromagnetic switching valves SOLA, B, and C. Excitation control is performed. As a result, the pressure oil from the hydraulic pump P is supplied only to the lift cylinder LC, and only the lift cylinder LC is extended until the load receiving stand G is substantially flush with the floor surface of the cargo box V in the deployed posture. Ascending, the cargo on the receiving platform G can be loaded into the packing box.

"Descent movement when loading / unloading the cargo receiving table G" (see Fig. 10)
5). When the operator presses the “DOWN” switch 43 in a state where the load receiving table G is in the raised position, the lowering operation of the load receiving table G is started. The control means C stops driving the motor M and excites the electromagnetic switching valves SOLA and SOLC. As a result, the lift cylinder LC communicates with the oil tank T, while the electromagnetic switching valve SOLB is non-excited, and the tilt cylinder TC remains filled with hydraulic oil, so the lift cylinder LC is parallel to the load receiving table G. It receives the weight of the link mechanism Li and contracts, the load receiving table G is lowered and grounded, and the load on the load receiving table G can be wholesaled to the ground.

"Operation when storing the receiving platform G" (see Fig. 11)
6). When the operator presses both the “open / close” switch 41 and the “UP” switch 42 in a state where the load receiving platform G is in the lowered position, the storing operation is started. The control means C drives the motor M of the hydraulic pump P and excites the electromagnetic switching valve B while de-energizing the electromagnetic switching valves SOLA and SOLC. Thereby, the pressure oil of the hydraulic pump P is supplied to both the lift cylinder LC and the tilt cylinder TC, but in this embodiment, the lift cylinder LC is extended in preference to the tilt cylinder TC. The inner diameter dimensions and the load applied to them are set (the pressure receiving area of the lift cylinder LC is larger than that of the tilt cylinder TC, and the rotation moment by which the lift cylinder LC lifts and rotates the parallel link mechanism Li is more tilt cylinder. Since TC is smaller than the turning moment for raising and lowering the load receiving stand G, the load receiving stand G rises while maintaining the unfolded state without raising and turning (FIGS. 11A and 11B). )).

  7). When the load receiving platform G is raised to the highest position, that is, until it is substantially flush with the floor surface of the cargo box V, the parallel link mechanism Li abuts on the vehicle body side to prevent further upward rotation. When the LC is prevented from extending, the pressure oil discharged from the hydraulic pump P is supplied to the tilt cylinder TC. As a result, the tilt cylinder TC extends and the load receiving platform G rises and rotates in the retracted direction (FIG. 11C).

  8). When the load receiving table G is rotated to the retracted posture, the load receiving table G comes into contact with the load box V and is prevented from rising up in the retracted posture, and the load receiving table G is held in the retracted posture.

  As a result, the operator can automatically and continuously switch the ascending operation of the load receiving table G and its upright turning operation without switching between the raising operation of the load receiving table G and its upright turning operation. Easy to operate.

“Unfolding operation from the stowed position of the receiving platform G” (see FIG. 12)
9. In this operation, the loading platform G is expanded from a substantially vertical storage posture to a substantially horizontal deployment posture without moving up and down, and the loading platform G is bridged between the cargo box V and the platform and a load is loaded between them. In the case of wholesale, the operator presses both the “open / close” switch and the “DOWN” switch 43. Thereby, the unloading operation of the cargo receiving platform G is started from the retracted posture. This operation is the same as the “preparation operation for loading work from the stowed posture of the load receiving table”, but even if the load receiving table G is tilted by 30 °, the tilt angle sensor 24 is in an inoperative state, The excitation of the electromagnetic switching valves SOLA and SOLB is continued, and the electromagnetic switching valve SOLC is not excited. The load receiving stand G continues only the unfolding operation, and its stopper 23 comes into contact with the link mechanism Li to complete its unfolding, and its tip reaches the platform.

  As mentioned above, although the Example of this invention was described, this invention is not limited to the Example, A various Example is possible within the scope of the present invention.

  For example, in the above-described embodiment, an inclination angle sensor is used as the detection means. However, a proximity sensor, a limit switch, and other known sensors or switches may be used instead. It is also possible to provide a dog on the other of them and to detect that the cargo box and the cargo cradle are separated. A sensor or switch is provided on one of the arms of the load carrier or the parallel link mechanism, and a dog is provided on the other of them. The load carrier is separated from the cargo box due to a change in the relative posture between the arm of the parallel link mechanism and the load carrier. You may make it detect. Furthermore, by detecting the stroke of the tilt cylinder, it may be detected indirectly that the load receiving table is separated from the cargo box. Furthermore, in the above-described embodiment, the load receiving table is moved up and down by the parallel link mechanism, but instead of this, a vertical lifting type in which the load receiving table can be moved up and down along the vertical lifting column may be used.

Side view of a cargo handling vehicle equipped with a cargo receiving platform lifting device Rear view of the cargo handling vehicle as viewed in the direction of the arrow 2 in FIG. Enlarged view of the phantom line encircled portion in FIG. Sectional view along line 4-4 in FIG. Side view of the receiving platform along line 5-5 in FIG. 6 arrow view of FIG. Working hydraulic circuit diagram of the loading platform Illustration of the operation of the receiving platform Illustration of the operation of the receiving platform Illustration of the operation of the receiving platform Illustration of the operation of the receiving platform Illustration of the operation of the receiving platform

Explanation of symbols

24 Detection means (tilt angle sensor)
F Body frame G Loading platform LC Lift cylinder TC Tilt cylinder

Claims (1)

The body frame (F) is held in an unfolded posture capable of loading and unloading luggage, can be moved up and down between a lowered position and a raised position, and is stood up from the deployed position and held in a retracted position. (G) is a vehicle cradle lifting device,
A lift cylinder (LC) that drives the load receiving table (G) to move up and down, a tilt cylinder (TC) that drives the load receiving table (G) to open and close between an unfolded position and a retracted position, and the load receiving table (G). A detection means (24) for detecting an interference avoidance posture in the middle of moving from the retracted posture to the deployed posture, and a control means (C) for driving and controlling the lift cylinder (LC) and the tilt cylinder (TC),
The control means (C) drives and controls only the tilt cylinder (TC) until the load receiving platform (G) is deployed from the retracted position and the detection means (24) detects the interference avoidance position. Further, after the detection means (24) detects the interference avoidance posture, both the tilt cylinder (TC) and the lift cylinder (LC) are driven and controlled so that the unloading operation and the lowering operation of the load receiving platform (G) are performed in parallel. A vehicle cradle raising and lowering device characterized by that.

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