JP5431107B2 - Underfloor retractable lifting device - Google Patents

Description

  The present invention relates to a lifting device that is mounted on the rear part of a vehicle such as a lorry to facilitate loading and unloading of cargo by lifting and lowering the platform, and in particular, it can be stored under the floor in a structure in which the platform is folded and stored under the vehicle floor. Relates to the device.

  Conventionally, as an elevating device to be mounted on a truck, it has been common to use a rear gate of a truck as a platform and lift a platform also serving as a rear gate with a link mechanism.

  By the way, in a structure in which the body of a lorry has no gate, for example, a structure having a double door, a slide door, an accordion door, a side-open roof, etc., the structure in which the platform also serves as the gate of the body is rather inconvenient.

  Therefore, in the lifting device disclosed in Patent Document 1 proposed by the present applicant, the platform is configured to be folded, and the platform is folded and stored under the vehicle body floor.

JP 2003-175760 A

  By the way, in the case of Patent Document 1, the lifting platform has a three-plate structure including a main plate, an intermediate plate, and a tip side plate, and is manually folded. Further, the operation of unfolding from a folded state onto a single flat platform is also manual. For this reason, when the lifting platform is soiled with mud or the like, the operator's hand is soiled by a manual unfolding operation, which may cause inconvenience of handling food items or the like with the soiled hand.

  The present invention has been made in view of such a situation. The purpose of the present invention is to automatically fold the lifting platform and store it under the floor, and to automatically unfold it from the folded state into a flat plate shape. An object of the present invention is to provide an underfloor retractable lifting device that does not bother a hand and saves labor in cargo handling work.

  Another object of the present invention is to provide an underfloor retractable lifting device that automates the folding and folding operations of the lifting platform and the flat plate by using an opening / closing cylinder and a simple link mechanism.

  Furthermore, another object is to provide an underfloor retractable lifting device that can be mounted on a small vehicle having a small underfloor storage space by folding the elevating platform compactly.

  Other objects and novel features of the present invention will be clarified in embodiments described later.

In order to achieve the above object, an underfloor retractable lifting apparatus according to an aspect of the present invention includes a main body frame that is slidable in the front-rear direction with respect to the chassis side of the vehicle,
A slide drive mechanism for pulling the main body frame under the floor of the vehicle;
A main plate, a distal end plate rotatably connected to a distal end side of the main plate by a first double hinge, and a proximal end side rotatably connected to a proximal end side of the main plate by a second double hinge; An elevating platform consisting of a plate and having a flat top surface in the unfolded state;
An elevating drive link mechanism for connecting the main body frame side and the base end side plate to drive the platform up and down;
First and second opening / closing cylinders disposed on the back side of the main plate,
One end of the first opening / closing cylinder is attached to the back side of the main plate, and one end of the first opening / closing link is pivotally attached to the other end of the first opening / closing cylinder. The other end is pivotally attached to the tip side plate,
One end of the second opening / closing cylinder is attached to the back side of the main plate, and one end of the second opening / closing link is pivotally attached to the other end of the second opening / closing cylinder. The other end is pivotally attached to the proximal plate,
When the first opening / closing cylinder is extended, the front end side plate is turned over to be in a first folded state where it overlaps the main plate,
When the second opening / closing cylinder is extended, the main plate is turned over to be in a second folded state in which the main plate is overlapped with the base end side plate.

  In the above aspect, the pivot points of the both ends of the first opening / closing link are positioned on or near a straight line in the axial direction of the first opening / closing cylinder in the unfolded state of the platform. In the initial stage, the tip side plate may rotate with a pivot point of the first connecting link of the first double hinge to the tip side plate as a rotation fulcrum.

  In the above aspect, the first opening / closing link may be bent so as to avoid contact of the main plate and the tip side plate with the double hinge by the double hinge.

  In the above aspect, the pivot points of the both ends of the second opening / closing link in the deployed state of the platform are on or near a straight line in the axial direction of the second opening / closing cylinder, and the main plate is folded. Initially, the main plate may be configured to rotate with a pivot point of the second connecting link of the second double hinge with respect to the base plate as a rotation fulcrum.

  In the above aspect, the second opening / closing link may be bent so as to avoid contact of the main plate and the base end side plate with the connection side edge by the second double hinge.

  It should be noted that any combination of the above-described constituent elements, and those obtained by converting the expression of the present invention between methods and systems are also effective as aspects of the present invention.

  According to the underfloor retractable lifting device according to the present invention, the lifting platform can be automatically folded and stored under the floor, and can be automatically expanded into a flat shape from the folded state so as not to bother the operator. Thus, labor saving of cargo handling work can be achieved. In addition, the folding operation of the lifting platform and the flattening operation can be automated by the opening / closing cylinder and a simple link mechanism. Further, by folding the lifting platform compactly, there is an advantage that it can be mounted on a small vehicle having a small underfloor storage space.

It is embodiment of the underfloor retractable raising / lowering apparatus which concerns on this invention, Comprising: A cylinder accommodating part is a side view explaining the raising / lowering operation | movement of the raising / lowering platform made into the cross section. It is a side view (cylinder storage part was made into the section) which shows the state before storage by folding operation of the raising / lowering platform in an embodiment. It is a side view which shows the storage completion state of the raising / lowering platform in embodiment. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation platform and an accompanying mechanism in an embodiment, wherein (A) is a side sectional view showing a first opening / closing hydraulic cylinder and a first opening / closing link, and (B) is a second opening / closing hydraulic cylinder and a second opening / closing hydraulic cylinder. 2 is a side sectional view showing a link for opening and closing, etc. FIG. 4C is a bottom view showing the arrangement of first and second opening / closing hydraulic cylinders in a cylinder housing portion on the back side of the main plate. It is a bottom view which shows arrangement | positioning of the main plate of the raising / lowering platform in embodiment, a front end side plate, and a cylinder accommodating part. It is a side view which mainly shows the link mechanism part for raising / lowering in embodiment. It is a hydraulic circuit diagram in an embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or equivalent component, member, process, etc. which are shown by each drawing, and the overlapping description is abbreviate | omitted suitably. In addition, the embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

  1 to 3 show an overall configuration of an embodiment of the present invention. In these drawings, a box-shaped vehicle body 2 is mounted and fixed on a chassis 1 of a lorry, and a fixed frame 4 of an underfloor retractable lifting device is fixed to a rear portion of the chassis 1 of the lorry. . A rectangular pipe-shaped slide guide 5 with slits is fixed to both sides of the chassis 1 in the horizontal direction on the fixed frame 4. The slits of the square pipe-shaped slide guide 5 are provided for passing a runner 14 described later.

  As shown in FIGS. 1 to 6, the main body frame 10 of the underfloor retractable lifting device has a pair of a square pipe 11 as a connecting member, brackets 12 and 13 fixed to both sides thereof, and a pair on the inner side of the brackets on both sides. The lower part of the runner 14 is fixed to the outer periphery of the square pipe 11.

  A runner 14 integrated with the main body frame 10 is provided so as to be slidable in the lateral direction (front-rear direction of the vehicle) with respect to the slide guide 5. That is, a rectangular plate-like sliding member 14a having a wear resistance and a small friction coefficient, such as nylon resin, slidably in contact with the upper and lower inner surfaces of the slide guide 5 is fixed to both ends of the upper portion of the runner 14. Slides smoothly in the slide guide 5 without rattling. The lower portion of the runner 14 extends downward through the slit of the slide guide 5 and is connected to the square pipe 11.

  A slide drive hydraulic cylinder 15 for moving the runner 14 in the lateral direction (front-rear direction) is attached between the fixed frame 4 side, that is, between the extended end of the slide guide 5 and the runner 14. A slide drive mechanism that drives the main body frame 10 in the lateral direction (front-rear direction) is constituted by a runner 14 that slides in the slide guide 5. That is, in the extended state of the piston rod of the cylinder 15, the main body frame 10 (runner 14) approaches the rear end side of the floor portion 3 of the vehicle body 2 as shown in FIGS. Then, as shown in FIG. 3, the main body frame 10 is pulled into the back direction below the vehicle body floor.

  As shown in FIGS. 4A and 4B, the elevating platform 60 connected to the main body frame 10 via the elevating drive link mechanism is connected to the main plate 61 and the distal end side and the proximal end side thereof. The main plate 61 and the distal end side plate 62 are each folded by a first double hinge (double hinge having two rotation fulcrums) 64. The distal end side plate 62 and the proximal end side plate 63 are rotatably connected to each other. The main plate 61 and the base end side plate 63 are connected by a second double hinge (double hinge having two rotation fulcrums) 84 so as to be foldable. That is, one of the first connecting small links 65 included in the first double hinge 64 is connected to the upper portion of the front end of the main plate 61 at a pivot point (rotation fulcrum) 66, and the other is a tip at the pivot point (rotation fulcrum) 67. It is connected to the upper part of the base end portion of the side plate 62. Similarly, one of the second small connecting links 85 included in the second double hinge 84 is connected to the upper portion of the base end portion of the main plate 61 at a pivot point (rotation fulcrum) 86, and the other is pivot point (rotation fulcrum) 87. And is connected to the upper portion of the distal end portion of the proximal end side plate 62.

  The main plate 61, the distal end side plate 62, and the proximal end side plate 63 are in a flattened state, the reinforcing material 61a on the back side of the main plate 61 and the reinforcing materials 62a, 63a on the back side of the distal end side and the proximal end side plates 62, 63. (Or, the end surfaces of the plates 61, 62, and 63) are abutted with each other and function as a single flat platform having a flat upper surface. In the folded state, the first plate 62 is turned over and superimposed on the main plate 61, and then the main plate 61 is turned over and folded over the base plate 63. It will be in a folded state.

  4 (A), (B), (C) and FIG. 5, in order to automatically open and close the lifting platform 60, the back side of the main plate 61 (the lower surface side when the lifting platform 60 is deployed in a flat plate shape). The first and second opening / closing hydraulic cylinders (double-acting hydraulic cylinders) 70 and 90 are disposed in the cylinder housing portion 100. The cylinder storage portion 100 is formed as an inner space of a cover 101 fixed to the back side of the main plate. The cover 101 is disposed at a position where it does not interfere with the slide guide 5 fixed to the chassis 1 when the platform 60 is folded and stored as shown in FIG. Usually, the cover 101 is positioned outside the slide guide 5 as shown in FIG. 3 so as not to interfere with the underfloor storage operation.

  As shown in FIG. 4A, the end of the main body of the first opening / closing hydraulic cylinder 70 is fixedly attached to the back surface of the main plate 61 with a fixture (for example, pivotally attached to a bracket fixed to the back surface side with a pin 70a). One end of the first opening / closing link 71 is pivotally attached to the tip of the piston rod of the first opening / closing hydraulic cylinder 70, and the other end of the first opening / closing link 71 is a bracket 72 integrated with the lower portion of the proximal end of the distal end side plate 62. It is pivotally attached to. Here, the pivot points 71a and 71b at both ends of the first opening / closing link 71 are on a straight line X1 in the axial direction of the first opening / closing hydraulic cylinder 70 in the deployed state of the platform 60 (or in the vicinity of the straight line X1). FIG. 4A shows an example in which the pivot point 71b is slightly above the straight line X1. A roller 75 is pivotally mounted coaxially with the link 71 at the piston rod tip position of the first opening / closing hydraulic cylinder 70 (the pivot point 71a of the first opening / closing link 71). It is guided so as to move substantially linearly by a guide rail 76 fixed to the back side.

  Therefore, at the initial stage of the first stage of the platform folding operation in which the first opening / closing hydraulic cylinder 70 starts to extend, the pivot point 67 of the first double hinge 64 on the distal end side plate 62 of the first connecting small link 65 is set. The tip side plate 62 rotates as a rotation fulcrum. Thereby, it is possible to prevent the first opening / closing link 71 from hindering the rotation of the distal end side plate 62. Further, the first opening / closing link 71 is curved in an arc shape so as to avoid contact of the main plate 61 and the tip side plate 62 with the first double hinge 64 on the connection side edge (when the platform is deployed). The intermediate portion of the first opening / closing link 71 has a lowered shape.

  As shown in FIG. 4B, the end of the main body of the second opening / closing hydraulic cylinder 90 is attached and fixed to the back surface of the main plate 61 with a fixture (for example, pivotally attached to a bracket fixed to the back surface side with a pin 90a). One end of the second opening / closing link 91 is pivotally attached to the tip of the piston rod of the second opening / closing hydraulic cylinder 90, and the other end of the second opening / closing link 91 is a bracket 92 integral with the lower end of the proximal end side plate 63. It is pivotally attached to. Here, the pivot points 91a and 91b at both ends of the second opening / closing link 91 are on a straight line X2 in the axial direction of the second opening / closing hydraulic cylinder 90 in the deployed state of the platform 60 (or in the vicinity of the straight line X2). FIG. 4B shows an example in which the pivot point 91b is slightly below the straight line X2. A roller 95 is pivotally mounted coaxially with the link 91 at the piston rod tip position of the second opening / closing hydraulic cylinder 90 (the pivot point 91a of the second opening / closing link 91). It is guided so as to move substantially linearly by a guide rail 96 fixed to the back side of the guide.

  Therefore, at the initial stage of the second stage of the platform folding operation where the second opening / closing hydraulic cylinder 70 begins to extend, the pivot point 87 of the second double hinge 84 to the proximal end plate 63 of the second connecting small link 85. The main plate 61 rotates about the rotation fulcrum. Thus, the second opening / closing link 91 can be prevented from obstructing the rotation of the main plate 61. The second opening / closing link 91 is curved in an arc shape so as to avoid contact of the main plate 61 and the base end side plate 63 with the second double hinge 84 on the connection side edge (in the platform deployed state). Sometimes the middle part of the second opening / closing link 91 is lowered.

  When the first opening / closing hydraulic cylinder 70 is extended from the unfolded state of the platform 60, the distal side plate 62 initially starts to rotate with the pivot point 67 as a rotation fulcrum, but thereafter the first connecting small link 65 Rotation about the pivot point 66 on the main plate 61 side is also added, and finally the tip side plate 62 is turned over so that it is in a first folded state where it overlaps the main plate 61 (see FIG. 2A). . In addition, the operation | movement which makes this 1st folding state is performed, for example when the platform 60 of FIG.

  Next, when the second opening / closing hydraulic cylinder 90 is extended from the first folded state, the main plate 61 initially has the pivot point 87 on the base end side plate as a rotation fulcrum as shown in FIG. The rotation starts as indicated by the arrow R, but after that, the rotation of the second connecting small link 85 around the pivot point 86 on the main plate 61 side is also added. Finally, the main plate 62 is turned over and the base side plate is turned. The second folded state overlapped with 63 and the main arm 25 and the sub-arm 35 are lifted to a substantially horizontal state, and the floor is ready for storage (see FIG. 2B).

  The operation of the platform 60 from the folded state to the unfolded state is performed by lowering the tips of the main arm 25 and the sub-arm 35, and by reversing the second opening / closing hydraulic cylinder 90 and then by the reverse movement of the first opening / closing hydraulic cylinder 70. It can be carried out.

  As shown in FIG. 6, the upper end of the small arm 20 is pivotally attached (rotatably mounted) to the bracket 12 of the main body frame 10 by a pin 21, and the lower contact portion 20 a of the small arm 20 faces the square pipe 11 side. The stopper portion 16 is provided in contact with the stopper portion 16. A base end portion of the main arm 25 is pivotally attached to a midway position of the small arm 20 by a pin 26. The proximal side plate 63 is integrally formed with a reinforcing member 63 a that also serves as a bracket for connecting the main arm 25 and the sub arm 35, and the distal end portion of the main arm 25 is pin 31 above the reinforcing member 63 a of the proximal side plate 63. It is pivotally attached. An elevating hydraulic cylinder 27 is pivotally attached by pins 28 and 29 between the lower end of the small arm 20 and a position near the tip of the main arm 25. Further, a sub arm 35 is pivotally connected by pins 36 and 37 between the bracket 13 of the main body frame 10 and the lower portion of the reinforcing member 63a of the base end plate 63. The main arm 25 and the sub arm 35 constitute a lifting drive link mechanism, and when the lower contact portion 20a of the small arm 20 is maintained in contact with the stopper portion 16 on the square pipe 11 side, The pins 26 and 31 at both ends and the pins 36 and 37 at both ends of the sub arm 35 are positioned at the apexes of the parallelogram, respectively, and the lift platform 60 in the unfolded state maintains a horizontal state. When the lifting hydraulic cylinder 27 is contracted, the tip of the main arm 25 is lowered (the platform 60 is lowered), and when it is extended, the tip of the main arm 25 is in the raised position (the platform 60 is in the raised position). The rotation of the small arm 20 due to the reaction force when the cylinder 27 is extended is prevented by the lower contact portion 20a contacting the square pipe side stopper portion 16.

  Next, the operation of the embodiment of the underfloor retractable lifting device will be described.

  When performing normal cargo handling work, as shown in FIGS. 1A and 1B, the slide drive hydraulic cylinder 15 is extended, and the runner 14 and the main body frame 10 slide close to the floor end of the vehicle body 2. The main plate 61, the distal end side plate 62, and the proximal end side plate 63 constituting the lifting platform 60 are deployed in a flat plate shape (the deployment operation of the lifting platform 60 is performed by the contraction of the second opening / closing hydraulic cylinder 90). Operation, and then by a contraction operation of the first opening / closing hydraulic cylinder 70). Then, by extending or contracting the lifting hydraulic cylinder 27 that drives the main arm 25 included in the lifting drive link mechanism, the main arm 25 and the sub arm 35 in the parallel link state are rotated, and the platform 60 is shown in FIG. While maintaining the horizontal state from the landing state of the imaginary line (A) to the position of the solid line (B) of the height of the floor surface 3A (the upper surface of the floor 3) of the vehicle body 2, the height of the floor surface 3A The platform 60 can be lowered to the landing state, and by using such a lifting and lowering operation of the platform 60, a cargo handling operation from the ground to the vehicle body floor surface or from the vehicle body floor surface to the ground can be performed.

  When the lifting hydraulic cylinder 27 is further contracted in the landing state of the lifting platform 60, the lower contact portion 20a of the small arm 20 is separated from the stopper portion 16 on the square pipe 11 side (see FIG. 6), and the main arm Since the 25 mounting fulcrums (pins 26) move to the rear side of the vehicle body 2, the lifting platform 60 is tilted as shown by the phantom line (c) in FIG. 1 to load the luggage onto the platform 60 in the landing state. It is also possible to efficiently carry in or carry out.

  The platform retracting operation after normal cargo handling is completed as follows. In the state shown in FIG. 1A, that is, in a state where the lifting platform 60 is deployed at the positions where the ends of the main arm 25 and the sub arm 35 are lowered, the first opening / closing hydraulic cylinder 70 is first extended, The tip side plate 62 is turned around the point 67 as a rotation fulcrum, and thereafter, the turning is performed around the pivot point 66 on the main plate 61 side of the first connecting small link 65. Finally, the tip side plate 62 is turned over. It is set as the 1st folded state piled up on the main plate 61 (refer FIG. 2 (A)).

  Next, the second opening / closing hydraulic cylinder 90 is extended, and the main plate 62 is initially rotated as indicated by the arrow R in FIG. 2A with the pivot point 87 as a rotation fulcrum. In addition, the link 85 is turned around the pivot point 86 on the main plate 61 side, and finally the main plate 61 is turned over so as to be overlapped with the base end plate 63, and further for storage. The main arm 25 and the sub arm 35 are set in a substantially horizontal state (see the storage preparation state in FIG. 2B).

  By retracting the slide drive hydraulic cylinder 15 shown in FIG. 1 from the storage preparation state shown in FIG. 2B, the lift platform 60 folded as shown in FIG. 3 is drawn under the floor of the vehicle body 2 and stored. .

  The operation of unfolding the lifting platform 60 from the retracted state shown in FIG. 3 so as to be capable of cargo handling is the reverse of the retracting operation. First, the slide drive hydraulic cylinder 15 is extended to move the runner 14 and the main body frame 10 to the vehicle body 2. It is moved to the rear end side of the floor portion 3 (see FIG. 2B), and the tips of the main arm 25 and the sub arm 35 are lowered. Thereafter, the second opening / closing hydraulic cylinder 90 is contracted to bring the lifting platform 60 in the second folded state into the first folded state (as shown in FIG. 2A), the main plate 61 and the proximal end plate. 63). Then, the first open / close hydraulic cylinder 70 is contracted to develop the first folded lift platform 60 into a flat plate shape to form a single flat platform shape (the main plate 61, the tip side plate 62, and the like). The base plate 63 is flattened). Thereafter, the lifting / lowering hydraulic cylinder 27 can be contracted or extended to drive the platform 60 up and down via the main arm 25 and the sub arm 35.

  FIG. 7 shows a hydraulic circuit for driving the slide driving hydraulic cylinder 15, the lifting hydraulic cylinder 27, and the first and second opening / closing hydraulic cylinders 70 and 90. In this figure, the hydraulic oil discharge side port of the power unit is indicated by P, and the return side port is indicated by T. 2A, 2B, 2C, 2D, 2H, 2X, and 2Y are solenoid valves, and 4A, 4D, and 4H are shuttle valves.

  The slide drive hydraulic cylinder 15 is driven by exciting the solenoid valve 2A or 2B. If the solenoid valve 2A is excited and opened, and hydraulic fluid is supplied from the hydraulic oil discharge side port P to one port of the slide drive hydraulic cylinder 15 through the path of the solenoid valve 2A and the shuttle valve 4A, the slide drive hydraulic cylinder 15 Contracts. Conversely, when the solenoid valve 2B is excited and opened and hydraulic fluid is supplied to the other port of the slide drive hydraulic cylinder 15 through the solenoid valve 2B, the slide drive hydraulic cylinder 15 extends.

  The raising / lowering hydraulic cylinder 27 is driven by exciting the solenoid valve 2H. When the solenoid valve 2H is excited and opened and hydraulic fluid is supplied to the lift hydraulic cylinder 27 through the path of the shuttle valve 4H and the solenoid valve 2H, the lift hydraulic cylinder 27 extends. Conversely, by returning the hydraulic oil to the return side port T through the path of the electromagnetic valve 2H and the shuttle valve 4H in the opened state, the lifting hydraulic cylinder 27 can be contracted.

  The first and second open / close hydraulic cylinders 70 and 90 are driven by selective excitation of the solenoid valves 2C, 2D, 2X, and 2Y. When folding the lift platform 60 in the unfolded state, the solenoid valve 2C and the solenoid valve 2X are excited and opened, and hydraulic fluid is supplied to one port of the first opening / closing hydraulic cylinder 70 through the path of the solenoid valve 2C and the solenoid valve 2X. In this case, the first opening / closing hydraulic cylinder 70 is extended, and the distal end side plate 62 is rotated to be in the first folded state. At this time, the hydraulic oil pressure is also applied to one port of the second opening / closing hydraulic cylinder 90, but since the load of the first opening / closing hydraulic cylinder 70 is lighter, the first opening / closing hydraulic cylinder 70 first extends. To do. Further, by continuing to supply the hydraulic oil, the second opening / closing hydraulic cylinder 90 can be extended and the main plate 61 can be rotated with respect to the base end side plate 63 to be in the second folded state.

  Since the folding operation is performed at the lowered position (landing position) of the platform 60 in which the tips of the main arm 25 and the sub arm 35 are lowered, the main arm 25 and the sub arm 35 are moved to the storage ready state shown in FIG. The tip is lifted to be substantially horizontal, but the posture of the main plate 61 with respect to the proximal end plate 63 changes during this operation. In order to cope with the change in the posture of the main plate 61, the electromagnetic valve 2Y is excited and opened, and one port and the other port of the second opening / closing hydraulic cylinder 90 are connected through the electromagnetic valve 2Y. The posture of the main plate 61 after being folded can be changed, and the main arm 25 and the sub arm 35 are allowed to rotate.

  When the folded platform 60 is deployed, the solenoid valves 2X and 2Y are returned to the closed state, the solenoid valve 2D is energized and opened, and the other side of the second opening / closing hydraulic cylinder 90 through the path of the solenoid valve 2D and the shuttle valve 4D. The hydraulic oil is supplied to this port, and the second opening / closing hydraulic cylinder 90 is contracted to bring the lifting platform 60 in the second folded state into the first folded state. Next, the solenoid valve 2X is energized and opened, so that hydraulic oil is supplied to the other pot of the first opening / closing hydraulic cylinder 70, and the first opening / closing hydraulic cylinder 70 is contracted to be in the first folded state. The raised / lowered platform 60 is set in the unfolded state.

  According to this embodiment, the following effects can be obtained.

(1) The elevator platform 60 formed by connecting the main plate 61 and the distal end plate 62 with the first double hinge 64 and the main plate 61 and the proximal end plate 63 with the second double hinge 84 is automatically folded. It can be stored under the floor of the vehicle body 2 and can be automatically unfolded from a folded state into a flat plate shape so as not to bother the operator's hand and to save labor in cargo handling work.

(2) The elevating platform 60 has a structure in which the main plate 61, the distal end side plate 62, and the proximal end side plate 63 are folded, and can be folded compactly and stored under the floor of the vehicle body. It can also be installed.

(3) The first and second opening / closing hydraulic cylinders 70 and 90 and a simple link mechanism can automate the folding and unfolding operations of the lifting platform 60. Specifically, the main bodies of the first and second opening / closing hydraulic cylinders 70 and 90 are attached to the back side of the main plate 61. One end of the first opening / closing link 71 is pivotally attached to the tip of the piston rod of the first opening / closing hydraulic cylinder 70, and the other end of the first opening / closing link 71 is pivotally attached to the tip side plate 62. Further, the pivot points 71a and 71b at both ends of the first opening / closing link 71 in the deployed state of the platform 60 are located on a straight line in the axial direction X1 of the first opening / closing hydraulic cylinder 70 or in the vicinity of the straight line X1. By forming the first opening / closing link 71 into an arcuate shape, the first opening / closing link 71 is connected to the edge of the main plate 61 and the tip side plate 62 by the double hinge 64 during the opening / closing operation of the platform 60. To avoid touching. The same applies to the second opening / closing link 91 connected to the second opening / closing hydraulic cylinder 90.

(4) The platform can be lifted and lowered only by the lifting hydraulic cylinder 27 and the lifting link mechanism. That is, the base end portion of the main arm 25 is not directly pivotally attached to the main body frame 10 but is connected to the main body frame 10 via the small arm 20, and the lifting / lowering hydraulic pressure after the main plate 61 of the platform 60 is in the landing state. When the cylinder 27 is further contracted, the small arm 20 is separated from the stopper portion 16 on the main body frame 10 side, and the position of the base end portion of the main arm 25 is moved (moved toward the rear of the vehicle body). It is possible to perform a tilting operation in which the tip of the heel is lowered.

  Although the embodiments of the present invention have been described above, it will be obvious to those skilled in the art that the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the claims.

  For example, it is possible to use an electric cylinder (electric actuator) instead of the hydraulic cylinder.

DESCRIPTION OF SYMBOLS 1 Chassis 2 Car body 3 Floor part 4 Fixed frame 5 Slide guide 10 Main body frame 11 Square pipe 12, 13 Bracket 14 Runner 15 Slide drive hydraulic cylinder 16 Stopper 20 Small arm 25 Main arm 27 Lifting hydraulic cylinder 35 Sub arm 60 Lifting platform 61 Main plate 62 Front end side plate 63 Base end side plate 64 First double hinge 70 First opening / closing hydraulic cylinder 71 First opening / closing link 84 Second double hinge 90 Second opening / closing hydraulic cylinder 91 Second opening / closing link

Claims (5)

A body frame slidable in the front-rear direction with respect to the chassis side of the vehicle;
A slide drive mechanism for pulling the main body frame under the floor of the vehicle;
A main plate, a distal end plate rotatably connected to a distal end side of the main plate by a first double hinge, and a proximal end side rotatably connected to a proximal end side of the main plate by a second double hinge; An elevating platform consisting of a plate and having a flat top surface in the unfolded state;
An elevating drive link mechanism for connecting the main body frame side and the base end side plate to drive the platform up and down;
First and second opening / closing cylinders disposed on the lower surface side of the main plate,
One end of the first opening / closing cylinder is attached to the lower surface side of the main plate, and one end of the first opening / closing link is pivotally attached to the other end of the first opening / closing cylinder. The other end is pivotally attached to the tip side plate,
One end of the second opening / closing cylinder is attached to the lower surface side of the main plate, and one end of the second opening / closing link is pivotally attached to the other end of the second opening / closing cylinder. The other end is pivotally attached to the proximal plate,
When the first opening / closing cylinder is extended, the front end side plate is turned over to be in a first folded state where it overlaps the main plate,
An underfloor retractable lifting device, wherein when the second opening / closing cylinder is extended, the main plate is turned over to be in a second folded state where the main plate is overlapped with the base end side plate.   2. The underfloor retractable lifting device according to claim 1, wherein the pivot points at both ends of the first opening / closing link are located on or near a straight line in the axial direction of the first opening / closing cylinder in the deployed state of the platform. In the initial stage of the folding operation of the front end side plate, the front end side plate rotates about the pivot point of the first connecting link of the first double hinge to the front end side plate as a rotation fulcrum. apparatus.   The underfloor retractable lifting device according to claim 1 or 2, wherein the first opening / closing link is bent so as to avoid contact with an edge on a connection side by the double hinge of the main plate and the tip side plate. Underfloor retractable lifting device.   The underfloor retractable lifting device according to claim 1, 2, or 3, wherein the pivot points at both ends of the second opening / closing link are on a straight line in the axial direction of the second opening / closing cylinder or the Under the floor, in the vicinity of the main plate, at the initial stage of the folding operation of the main plate, the main plate rotates around the pivot point of the second connecting link of the second double hinge to the base side plate as a rotation fulcrum Retractable lifting device.   5. The underfloor retractable lifting device according to claim 4, wherein the second opening / closing link is bent so as to avoid contact of the main plate and the base end side plate with the connection side edge by the second double hinge. Underfloor retractable lifting device.

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