JP2003112554A - Loading deck elevating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a loading deck elevating device which is simple in structure and can lift the deck easily at storage. SOLUTION: A tip end link mechanism (CDEF) in the shape of a parallelogram is connected to a base link mechanism (ABCD) in the shape of an inequilateral quadrangle, and by inclining the side CD and the side EF against the side AB with rotation of an arm, elevation and tilting are executed at the same time. By bringing a stopper provided at the deck 18 into contact with a tip end connecting member 15, upward rotation of the deck is regulated.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loading / unloading device mounted on the rear or side of a lorry and used for loading and unloading luggage. 2. Description of the Related Art Among conventional loading tray lifting devices mounted on a truck, a loading tray is raised and lowered based on the rotation of an arm to which power such as hydraulic pressure is applied. In general, the attitude of the load receiving platform during ascending and descending is kept horizontal by using parallel links. Further, in such a loading tray lifting device, the loading tray is tilted (tilted) in order to smoothly load and unload the load between the ground and the loading tray.
In some cases, an operating structure is employed. To attach the receiving platform so that it can cope with both the horizontal and tilt,
A structure in which the receiving table is pivotally mounted on the arm is conceivable. However, if a structure for performing a tilt operation precisely besides the parallel link is employed, the entire apparatus becomes considerably complicated. In addition, when the loading cradle with the shaft attached thereto is lifted on the end side with respect to the shaft during storage, the loading cradle is turned around and is very difficult to lift. [0003] In view of the above-described conventional problems, an object of the present invention is to provide a loading tray lifting device that has a simple structure and can easily lift the loading tray during storage. [0004] A loading tray lifting device according to the present invention is provided on a vehicle body in a pair of left and right sides, each of which is provided around a pair of upper and lower fulcrums A and B provided on the vehicle body side. A pair of arms rotatable in a range, and a base connecting member connected between action points C and D on the respective rotating end sides of these arms.
The quadrangle having the apex is the side CD with the rotation of the arm.
And a pair of left and right sides provided with respect to the vehicle body, each of which is rotatable within a predetermined range around the action points C and D, respectively. , And a tip connecting member connected between action points E and F on the respective rotating end sides of these arms, and a quadrangle having four vertices C, D, E, and F is a parallelogram. A drive unit for driving the base link mechanism, a load receiving platform having one end pivotally mounted on the application point E or F side of the pair of left and right front end link mechanisms, A restricting device for restricting upward rotation of the load receiving table with respect to the link mechanism. [0005] In the lifting device of the loading tray configured as described above, the arm of the distal link mechanism connected to the rotating end of the arm rotates according to the rotation of the arm of the base link mechanism, and the loading tray moves up and down. Operate. The side CD tilts with respect to the side AB with the rotation of the arm in the base link mechanism.
The loading tray also tilts in parallel with the side CD, and the load receiving table performs a tilt operation based on the tilting of the side CD until the base link mechanism reaches the rotation lowering end. In this case, the tilt operation is not performed separately from the elevating operation, but is performed integrally with the elevating operation. In addition, the restricting device restricts the upward rotation of the loading tray when the loading tray is lifted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an explanation will be given of a loading tray lifting apparatus employing an arm structure according to an embodiment of the present invention with reference to the drawings. FIGS. 1 and 2 are a rear view and a side view, respectively, showing a loading tray elevating device 1 attached below a packing box 102 at a rear portion of a body 101 of a truck.
In FIG. 2, the chassis 104 behind the rear wheel 103
A bracket 2A is attached to each of both side surfaces of the
The support member 2B is attached to this. The loading table lifting device 1 is attached to the support member 2B. 2 is in a running state stored in the lower part of the vehicle body 101. And at the time of use,
From the state shown in FIG. 3, FIG. 4, and FIG.
01 and is unfolded. Next, the structure of each part of the loading tray lifting device 1 will be described with reference to FIG. Basically, the loading / unloading device 1 has a two-stage arm structure including a base arm (base lower arm 4, base upper arm 8) and a tip arm (tip lower arm 13, tip upper arm 16). are doing. In FIG. 4, the base lower arm 4 is
A pin 5 provided at the left end portion can be pivoted in a predetermined range around the pin 5 as a fulcrum.
It is supported by. The right end of the base lower arm 4 is connected to a base connecting member 7 via a pin 6 as an action point. On the other hand, the base upper arm 8 is rotatable within a predetermined range around a pin 9 provided at the left end as a fulcrum, and the pin 9 is supported by the support member 2B. The right end of the base upper arm 8 is connected to the base connecting member 7 via a pin 10 as an action point. Here, the pins 9 and 5 are a pair of upper and lower fulcrums A and B, and the pins 10 and 6 are action points C and D corresponding to the fulcrums A and B, respectively.
Then, the lower base arm 4, the base connecting member 7, and the upper base arm 8 have A, B, C, and D as the four vertices, and the side CD
Is longer than the side AB, and the side BD is a base link mechanism composed of a scalene rectangle longer than the side AC. A hydraulic cylinder 30 is provided on the base upper arm 8.
(Shown only in FIG. 4) is connected, and when the base upper arm 8 rotates by the supply of hydraulic pressure, the base lower arm 4 also rotates accordingly. The base upper arm 8 is formed by fixing two steel materials of the same shape arranged in the vehicle body width direction to each other with a channel material 11. This channel material 11
Functions to reinforce the base upper arm 8 and also controls the rotation of the distal upper arm 16. That is, in the retracted state of FIG.
7) is in contact with the upper surface of the channel material 11, thereby restricting further rotation of the distal end upper arm 16 in the counterclockwise direction. Next, referring to FIG.
Is pivotally attached to the base lower arm 4 by a pin 6, and is attached so as to be rotatable in a predetermined range in a counterclockwise direction from a position shown in the figure. The right end of the distal end lower arm 13 is connected to a distal end connecting member 15 via a pin 14 as an action point. Further, the L-shaped tip upper arm 16 is pivotally mounted on the base upper arm 8 by the pin 10 and is rotatable counterclockwise within a predetermined range, and conversely, clockwise from the illustrated position. Is detented. The right end of the distal end upper arm 16 is connected to the distal end connecting member 15 via a pin 17 as an action point. Here, pin 1
Assuming that points 7 and 14 are action points E and F, respectively, the tip lower arm 13, the tip connecting member 15, and the tip upper arm 16 are formed of parallelograms having C, D, E, and F as four vertices. This constitutes a partial link mechanism. In the base link mechanism (ABCD), the tip link mechanism (CDEF), and the loading tray 18 supported by the tip link mechanism, the position indicated by the solid line in FIG. The position is the rising end. The tip link mechanism (CDEF) can be folded as shown in FIGS. 3 and 2 by rotating counterclockwise with respect to the base link mechanism (ABCD). On the other hand, in FIG. 5, the receiving table 18 also has a foldable structure, and includes a main plate 19 and a sub-plate 20. Sub plate 20
Is rotatable counterclockwise with respect to the main plate 19 from the illustrated position (see FIG. 4). The main plate 19 is attached so as to be rotatable in a counterclockwise direction from the position shown in the figure with the pin 17 as a support point. The adjustment bolt 21 attached to the main plate 19 is
It is in contact with the right end surface of the distal end connecting member 15. Also, a guide plate 22 protruding from the left end of the main plate 19 is provided.
Plays a role in filling a gap between the floor of the packing box 102 and the receiving tray 18 when loading and unloading luggage. Guide roller 23
Engages with the receiving table 18 when the receiving table lifting / lowering device 1 is stored, and guides it. The guide roller 23 is rotatably supported by a guide roller support member 24 fixed to the support member 2B. Next, a description will be given of the lifting mechanism of the loading table 18. FIG. 6 is a side view principally showing the load receiving table 18 and an arm structure including a base link mechanism and a distal end link mechanism for raising and lowering the same.
5 to FIG. The base linkage is represented by a trapezoidal ABCD, where A and B are fixed points, C and D
Is a movable point. The tip link mechanism is represented by a parallelogram CDEF, and all vertices C, D, E, and F are movable points. When the lower base arm 4 and the upper base arm 8 rotate within the range shown in the figure, the distal end portion is connected to the rotation end side and is provided with the base upper arm 8 being prevented from rotating in the clockwise direction. The upper arm 16 rotates integrally,
Following this, the tip lower arm 13 also rotates. Edge CD
And the side EF are always parallel to each other, and the receiving table 18 always maintains a constant attitude with respect to the side EF. Therefore, the inclination of the receiving tray 18 is determined by the inclination of the side CD. Conversely, as long as the inclination of the side CD is constant, the attitude of the loading table 18 is constant and always horizontal. For example, the receiving table 18 in the state shown in FIG. 3 is different from the state shown in FIG. 5 in that the sub-plate 20 is folded, but the inclination of the side CD is unchanged. Therefore, the attitude of the loading tray 18 (the inclination of the main plate 19) is completely the same between the state shown in FIG. 3 and the state shown by the solid line in FIG. As shown in FIG. 6, the distal end link mechanism (CDEF) has a steeper inclination angle at the rising end of the upper base arm 8 than the inclination angle of the upper base arm 8, so that the side CD is On the other hand, it plays the role of further pushing up the side EF and the loading tray 18. Therefore, it is possible to push up the receiving tray 18 to a predetermined height while suppressing the rotation range of the base link mechanism (ABCD). In addition, interference between the base arm and the like and the packing box 102 can be avoided at the rising end of the receiving table. Conversely, at the lower end of the upper base arm 8, the distal end link mechanism has a gentler inclination angle than the inclination angle of the upper base arm 8, and suppresses the lowering of the side EF and the loading tray 18 with respect to the side CD. Plays a role. The relationship between the lengths of the sides AB, CD, AC and BD of the base link mechanism (ABCD) in the present embodiment is such that AB <CD and AC <BD. Such a magnitude relationship between the two opposing sides affects the link operation. FIG. 7 is a diagram showing how the magnitude relationship between the sides AB and CD in a generally inequilateral quadrangular link mechanism affects the link operation, apart from the actual arrangement shown in FIG. (A) shows a link operation when AC <BD and AB <CD, and (b)
Indicates a link operation when AB> CD. In (a), in the state shown by the solid line, both sides AB and CD are vertical, but the side CD is inclined to the left as shown by the two-dot chain line as the pivot side of the link mechanism rises. I do. Further, the side CD is inclined rightward as the pivot side of the link mechanism descends. On the other hand, in the state (b), in the state shown by the solid line, the sides AB and CD are both vertical, but the side CD inclines rightward as shown by the two-dot chain line when the pivot side of the link mechanism rises. . Also, when the rotating side of the link mechanism is lowered, the side CD is lowered.
Tilts to the left. That is, in (a) and (b),
The direction of inclination of the side CD associated with the rotation of the link mechanism has an opposite relationship. Further, if AC> BD in (a), the inclination angle of the side CD with respect to the vertical at the time of ascent and descent is reduced. Conversely, when AC <BD, the inclination angle of the side CD with respect to the vertical at the time of ascending and descending increases. In (b), if AC> BD,
At the time of ascent and descent, the inclination angle of the side CD with respect to the vertical increases. Conversely, if AC <BD, the inclination angle of the side CD with respect to the vertical at the time of ascending and descending decreases. From the above, based on the magnitude relationship between AB and CD (including the case where they are equal), if necessary, the magnitude relationship between AC and BD (including the case where they are equal).
The side C with respect to the side AB generated with the rotation of the link by configuring the inequilateral quadrangular link mechanism in consideration of
The slope of D can be adjusted to a desired degree. In the present embodiment, the relationship of AB <CD and AC <BD is adopted as described above. Returning to FIG. 6, a base link mechanism (ABCD)
At the rising end of the side, the side CD and the side EF are inclined leftward. In this state, the receiving table 18 is supported substantially horizontally. When the base link mechanism moves downward from this state, the side CD and the side EF tilt gently. At the lower end, the inclination angles of the side CD and the side EF become smaller than at the upper end, and the load receiving table 18 is in a tilted state. In this manner, the tilting operation of the receiving table 18 is not performed separately from the elevating operation, but is performed integrally with the elevating operation. Therefore, a dedicated structure for the tilt operation is not required, and the structure is simple. Further, this tilt operation is performed extremely smoothly, and does not involve an impact. Therefore, it is possible to prevent the load from falling or falling. Conversely, when moving from the descending end to the ascending end, similarly, the loading table 18 changes its posture from the tilted state to the horizontal very smoothly. Next, the arm structure will be described in more detail. FIG. 8 is an exploded perspective view of the arm structure (an example on the left side when viewed from the rear of the vehicle body). In the figure, the base upper arm 8 is composed of two plates as described above, and the distal upper arm 16 composed of a single plate is connected between the ends of the two plates. On the other hand, the tip lower arm 13 is composed of two plates,
A base lower arm 4 made of a single plate between the ends of the two plates
(However, pipe-shaped members are welded to both ends.)
Connection has been made. Further, as described above, the above-described CD is connected by the base connecting member 7, and the EF is connected by the distal connecting member 15. That is, the upper arm (the base upper arm 8 and the distal end upper arm 1
6) and the lower arm (the lower base arm 4 and the lower end arm 13) both have a structure in which a two-plate arm and a one-plate arm are connected. FIG. 9 shows the loading tray 1 at the lower end position shown in FIG.
FIG. 8 is an enlarged detail view of the periphery of a distal end connecting member 15 in FIG. In the figure, an adjusting bolt 21 is a female screw member 21a welded to a mounting base 19a of a main plate 19.
Is screwed in a double nut state via a nut 21b. The adjustment bolt 21 abuts on the right end surface of the distal end connecting member 15 of the distal end link mechanism, and is adjusted so that the loading table 18 at the raised end position is in a substantially horizontal posture. Accordingly, the downward rotation (clockwise rotation) of the load receiving table 18 with respect to the distal end connecting member 15 of the distal end link mechanism is restricted in the range from the rising end to the falling end. On the other hand, a stopper 25 is welded to the left end side of the mounting base 19a. In a state where the adjustment bolt 21 is in contact with the right end surface of the distal end connecting member 15, a gap G is provided between the left end surface of the distal end connecting member 15 and the stopper 25.
Is provided, whereby the receiving table 18 can be slightly rotated counterclockwise from the position shown in the figure. However, when the gap G is closed by a slight rotation, the stopper 25 contacts the distal end connecting member 15. Therefore, the receiving table 18 cannot rotate further in the counterclockwise direction. That is, the stopper 25 attached to the load receiving table 18 serves as an upward rotation restricting device that restricts the upward rotation of the load receiving table 18 with respect to the distal end connecting member 15 of the distal end link mechanism within a predetermined range. Further, such a device includes a distal end connecting member 1 which is a member of a distal end link mechanism.
5 is also used as a contact member for the stopper 25, so that a simple and inexpensive configuration is achieved. FIG. 10 is a cross-sectional view of the tip of the sub-plate 20 in the loading tray 18. In the figure, a concave portion 20a extending in the width direction (a direction perpendicular to the paper surface) and a columnar pivot portion 20 extending in the width direction are provided at the tip of the sub-plate 20.
b. The cart stopper 201 is a member having a cross-sectional shape as illustrated and extending in the width direction, and is rotatably mounted around the pivot 20b. A torsion spring 202 is mounted between the cart stopper 201 and the recess 20a, whereby the cart stopper 201 is urged clockwise. The cart stopper 201 is pushed into the concave portion 20a by the load placed on the load receiving table 18, and further loads the load on the load receiving table 1.
When the baggage comes off by sliding the baggage 8 deeper (to the side of the main plate 19), the baggage is lifted by the torsion spring 202 to prevent the baggage from falling. To drop the load on the ground, the operator steps on the cart stopper 201 and pulls the load toward the front while placing the load on the cart stopper 201. FIG. 11 is a view of the unfolded receiving tray 18 viewed from the lower surface side. FIG. 12 is a detailed view of the folded loading tray 18 as viewed from the side. FIG.
In FIGS. 1 and 12, a step member 26 made of a U-shaped metal pipe is attached near the connection between the main plate 19 and the sub-plate 20 so as to project rearward of the vehicle body. In a state where the loading tray 18 is stored (FIG. 2), when the operator gets into the loading box (or gets off the loading box), the step member 26 can be used as a step platform. When the loading tray 18 is stored (FIGS. 4 to 3), the loading tray 18 can be easily stored by grasping and lifting the step member 26.
At this time, the sub-plate 20 is fixed to the main plate 1 by a securing device (not shown, which can be released by manual operation).
9, the sub-plate 20 does not open even if the step member 26 is gripped and lifted. Receiving platform 1
8 is lifted, the loading platform 18
Attempts to rotate upward in the counterclockwise direction around (E).
5 restricts the upward rotation. Therefore, the receiving table 18 does not rotate, and shifts from the state of FIG. 4 to the state of FIG. 3 (or vice versa) together with the tip end link mechanism (CDEF). As a result, the receiving table 18 is securely stored (or vice versa).
can do. The lifting / lowering device 1 configured as described above
Will be described with reference to FIG. 2 to FIG. First, after stopping the vehicle and applying the parking brake, the hydraulic cylinder 30 (FIG. 4) is driven from the state shown in FIG. 2 to rotate the upper base arm 8 and the lower base arm 4 clockwise to the lower end. Let it. Accordingly, the receiving table 18 is moved to the guide roller 23.
The tip lower arm 13 and the tip upper arm 16 are slightly opened clockwise about the pins 6 and 10, respectively, to reach the state shown in FIG. Next, the operator pulls out the folded receiving tray 18 by hand. As a result, the distal end lower arm 13 and the distal end upper arm 16 rotate clockwise around the pins 6 and 10, respectively. During this rotation,
The parallelogram CDEF formed by the pins 10, 6, 17, and 14 changes its shape, but maintains a parallel relationship between the side CD and the side EF. Accordingly, the loading tray 18 descends while maintaining a constant posture, and reaches near the floor as shown in FIG. Thereafter, the operator raises and rotates the sub-plate 20 of the loading tray 18 by hand, and unfolds the sub-plate 20 as shown in FIG. When unloading the load, the hydraulic cylinder 30 (FIG. 4) is driven to rotate the base upper arm 8 and the base lower arm 4 counterclockwise. According to this,
The tip upper arm 16 and the tip lower arm 13 also rotate,
The receiving platform 18 is raised. During the ascent, the side CD of the base link mechanism (ABCD) gradually tilts with respect to the side AB, so that the side EF of the tip link mechanism (CDEF) also tilts, and the loading tray 18 is tilted. It gradually becomes horizontal from the state. Thus, the receiving table 18 and the packing box 10
The loading table 18 is raised to the rising end indicated by the two-dot chain line in FIG. Here, the operator transfers the package from the packing box 102 to the receiving table 18. After the transfer, the hydraulic cylinder 30 (FIG. 4) is driven to rotate the base upper arm 8 and the base lower arm 4 clockwise. Accordingly, the distal end upper arm 16 and the distal end lower arm 13 also rotate, and the load receiving table 18 is lowered. During the downward movement, the side CD of the base link mechanism is gradually tilted with respect to the side AB, so that the side EF is also tilted, and the load receiving table 18 gradually shifts from the substantially horizontal state to the tilt state. Reach the falling edge. Therefore, no impact is applied to the load, and the load can be prevented from falling or falling. When loading the luggage in the packing box 102, the above-described operations are performed in reverse order. Next, when the loading tray lifting device 1 is to be stored, the operator folds the sub-plate 20 from the state shown by the solid line in FIG. 5 to the state shown in FIG. And return to the state shown in FIG. At this time, the stopper 25 (FIG. 9) comes into contact with the distal end connecting member 15 to prevent the rotation of the load receiving table 18, so that the load receiving table 18 can be reliably lifted. Here, the hydraulic cylinder 30 (FIG. 4) is driven to rotate the base upper arm 8 and the base lower arm 4 counterclockwise. As a result, the receiving table 18 is in the state shown in FIG. In the above embodiment, the stopper 2
5 may be provided at a place other than the mounting base 19a. For example, as shown in FIG. 13, a stopper 25 may be provided on the distal end lower arm 13 while securing a slight gap G between the mounting base 19a and the lower left end surface. Also in this case, the receiving table 18 cannot rotate counterclockwise beyond closing the gap G. In the above embodiment, the loading tray lifting device 1 has been described as being pulled out to the rear of the vehicle body 101. However, a configuration in which the loading tray lifting device 1 is pulled out to the side is also applicable. Further, although the main plate 19 of the loading tray 18 is rotatably mounted with the pin 17 as a support point, the main plate 19 may be rotatably mounted with a pin provided separately from the pin 17 as a support point, or It is also possible to pivotally mount the pin 14 as a supporting point. According to the lifting device of the present invention configured as described above, the loading table is tilted based on the tilt of the side CD until the base link mechanism reaches the rotation lowering end. It operates, and the tilt operation is not performed separately from the lifting operation,
It is performed integrally with the elevating operation. Therefore, a dedicated structure for the tilt operation is not required, and the structure is simple. In addition, the restricting device restricts the upward rotation of the receiving tray when the receiving tray is lifted, so that the receiving tray can be reliably lifted and stored.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a rear view of a state in which a loading tray elevating device including an arm structure according to an embodiment of the present invention is mounted below a packing box at a rear part of a body of a truck. FIG. 2 is a side view of the loading tray elevating device, showing a state where it is stored in a vehicle body. FIG. 3 is a side view of the lifting / lowering device, showing a state in which the loading / unloading device is being deployed or stored. FIG. 4 is a side view of the loading tray elevating device, showing a state in which a leading end link mechanism is expanded with respect to a base link mechanism and the loading tray is folded. FIG. 5 is a side view of the loading tray elevating device, showing a state in which the leading end link mechanism and the loading tray are expanded and moved up and down. FIG. 6 is a side view principally showing a loading tray in the loading tray lifting device and an arm structure including a base link mechanism and a tip link mechanism for lifting and lowering the loading tray. FIG. 7 shows a side A in a generally inequilateral quadrangular link mechanism.
FIG. 9 is a diagram illustrating how the magnitude relationship between B and CD affects the link operation. FIG. 8 is an exploded perspective view of the arm structure shown in FIGS. 2 to 6 (an example on the left side as viewed from the rear of the vehicle body). 9 is an enlarged detail view of a periphery of a leading end connecting member in the loading tray at the lowered end position shown in FIG. 5; FIG. 10 is a cross-sectional view of a tip end of a sub plate in the loading tray. FIG. 11 is a view of the unfolded receiving tray viewed from the lower surface side. FIG. 12 is a detailed view of the folded loading tray viewed from the side. FIG. 13 is a diagram illustrating an example in which a stopper is provided at a position different from that in FIG. 9; [Description of Signs] 1 Receiving-table lifting device 4 Base lower arm 5 pin (B) 6 pin (D) 7 Base connecting member 8 Base upper arm 9 pin (A) 10 pin (C) 13 Tip lower arm 14 pin (F ) 15 Tip connecting member 16 Tip upper arm 17 Pin (E) 18 Loading table 25 Stopper (Regulator) 30 Hydraulic cylinder (Drive device) 101 Body ABCD Base link mechanism CDEF Tip link mechanism

Claims (1)

Claims: 1. A pair of left and right arms provided on a vehicle body, each pair of arms being rotatable within a predetermined range around a pair of upper and lower fulcrums A and B provided on the vehicle body side. And a base connecting member connected between action points C and D on the respective rotating end sides of these arms, and a quadrangle having four vertices A, B, C and D is used for the rotation of the arms. A base link mechanism, which is a trapezoidal side that tilts the side CD with respect to the side AB, and a pair of left and right sides are provided with respect to the vehicle body. A quadrangular shape including a pair of movable arms and a tip connecting member connected between action points E and F on the respective rotating end sides of these arms, and having C, D, E, and F as four vertices. Is a parallelogram. And click mechanism, a driving device for driving the base link mechanism, the point of action of the pair of left and right distal link mechanism E or F
A load receiving table lifting and lowering device, comprising: a load receiving table having one end pivotally mounted on a side thereof; and a regulating device that restricts upward rotation of the load receiving table with respect to the distal end link mechanism.