JP2000142208A - Elevating device for load receiving deck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a load receiving surface of a predetermined size, prevent a load receiving deck from interfering in car body. SOLUTION: An elevating device for a load receiving deck is so constituted that a link body 13 for constituting a part of a load receiving surface is connected to top end sides of a lower arm 9 and an upper arm 14 for constituting a parallel link. Moreover, a load receiving deck 29 is rotated around a pin 26 provided on the link body separately from a point of action of the parallel link to fold against the link body 13, and the load receiving deck 29 (a main plate 30 and a sub plate 31) is composed of the load receiving surface with the link body 13 at the time of developing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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.

[0002]

2. Description of the Related Art FIG.
FIG. 9 is a side view of a conventional loading tray elevating device described in Japanese Patent Publication No. 9-No. In the figure, a main frame 202 of a loading tray elevating device is attached to a rear portion of a vehicle body 201 so as to be slidable in the vehicle longitudinal direction. This mainframe 202
To the main arm 203 and the sub arm 2 via pins and the like.
04 and a hydraulic cylinder 205 for lifting. The loading tray 206 is composed of a main plate 207 and a foldable sub-plate 208. The sub-plate 208 is unfolded (shown by a two-dot chain line on the right) when a load is to be placed, and folded when stored. This is indicated by a solid line). The receiving table 206 is connected to the main arm 203 by a pin 210 at a bracket 209 provided at the base of the main plate 207. Therefore, the receiving table 206 rotates about the pin 210 integrally with the bracket 209. The link body 211 sharing the pin 210 with the bracket 209 is
2 is connected to the sub arm 204. The tip of the lifting hydraulic cylinder 205 is connected to the main arm 203 by a pin 213.

[0003]

In the above-described conventional loading / unloading device, the loading / unloading pedestal 20 has a pin 210 as a center.
6 (refer to the two-dot chain line), the turning end of the loading tray 206 is moved to the vehicle body 201 due to a difference in vehicle height or the like.
There was a case where it could not be stored by hitting the rear part of. Therefore, in order to avoid interference with the vehicle body 201,
The depth (in the longitudinal direction of the vehicle) had to be limited. Therefore, large luggage cannot be placed, and
There was a problem that the work space on the 06 was narrow.
In view of the above-mentioned conventional problems, an object of the present invention is to provide a loading tray elevating device that secures a loading surface of a predetermined size and prevents interference of the loading tray with a vehicle body.

[0004]

According to a first aspect of the present invention, there is provided a lifting and lowering device for a receiving pallet, comprising: a support base supported by a vehicle body; two arms constituting a parallel link supported by the support base and performing a vertical movement; A lifting / lowering drive mechanism that drives the arm, a link body connected to the distal end side of the arm, including an action point of the parallel link, and forming a part of a load receiving surface;
A main plate rotatably connected to a rotation fulcrum provided on the link body separately from the action point, and rotatably connected to a distal end side of the main plate and foldable on the main plate A sub-plate, which is foldable with respect to the link body as a whole in a state in which the sub-plate is folded, and a unloading table that forms a receiving surface together with the link body when unfolded. (Claim 1). In the loading stand lifting device configured as described above, the receiving surface is formed by the link body, the main plate, and the sub plate, and a predetermined size is secured. Because the loading platform with the sub-plate folded can be folded around the link body around a separate pivot point that is not the point of action of the parallel link,
The turning radius at the time of folding does not include a dimension corresponding to the link body. Therefore, the turning radius is reduced accordingly.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 22 are views showing a lifting / lowering device for a receiving tray according to an embodiment of the present invention, and FIG.
It is a side view which shows the loading stand raising / lowering apparatus 1 attached below the packing box 102 in the rear part of the body 101 of a truck.
First, in FIG. 1, the chassis 1 behind the rear wheel 103
An angle-shaped mounting member 2 is vertically mounted on each of both side surfaces of 04, and a slide rail 3 made of I-shaped steel is horizontally fixed to the mounting member 2. The slide rail 3 supports a movable member, which will be described later, of the loading tray lifting device 1, and guides the sliding movable member horizontally. The support bases of these movable members are a first support plate 4, a thick (about 25 mm) second support plate 5, and a rectangular tubular connection pipe 6.

[0006] The first support plate 4 arranged adjacent to the slide rail 3 is connected to the slide rail 3 via a sliding member (a side pad 69 described later (FIGS. 16 and 17B)).
, And can slide horizontally along the slide rail 3. The first support plates 4 provided on the left and right sides (both sides) of the vehicle body are welded to the outer peripheral portion of a connection pipe 6 horizontally arranged in the width direction of the vehicle body. Further, the second support plate 5 is externally inserted into the connection pipe 6 and is welded to the outer periphery of the connection pipe 6 at a predetermined position outside the first support plate 4 in the vehicle width direction. Therefore, the left and right pair of the first support plate 4 and the second support plate 5 and the connecting pipe 6 constitute a structurally integrated support base.

[0007] A switch box 7 containing operation switches, control circuits, and the like of the loading / unloading device 1 is provided only on the left side of the vehicle body. The switch box 7 is fixed to the second support plate 5 and protrudes most outward in the vehicle width direction. When the cover 7a is opened to the front, the key switch S1,
An elevating switch S2 is provided. Key switch S
1 has three positions of “OFF”, “ON” and “ST”, and in the “OFF” and “ON” positions, the key can be held at that position even if the hand is released,
In the "ST" position, the key returns to "ON" when the hand is released. The elevating switch S2 is a toggle switch of a neutral position automatic return type, and has three positions of “up” and “down” across the neutral position. The lifting switch S2 is connected to a retractable cable and can be pulled out from the switch box 7 for operation. On the other hand, a power unit box 8 (shown by a broken line) containing a hydraulic pump, a valve, and the like is provided only on the right side of the vehicle body, and is fixed to the second support plate 5 on the right side.

FIG. 2 is a diagram showing the structure of the switch box 7 shown in FIG.
FIG. 2 is a view mainly showing a structure related to a slide mechanism and a lifting mechanism of the loading tray lifting device 1, omitting illustration of a power unit box 8. 3 to 6 are side views sequentially showing a process of pulling out and unfolding the loading / unloading device 1 in the state of FIG. In FIG. 2, the lower arm 9 having a substantially linear shape is rotatable within a predetermined range around a pin 10 provided at the left end.
Is attached to the support section 11 fixed to the support section. The right end of the lower arm 9 is connected to a link (vertical link) 13 via a pin 12.

The upper arm 14, which forms a parallel link together with the lower arm 9, is rotatable within a predetermined range around a pin 15 provided at the left end. Installed. Upper arm 1
The right end of 4 is connected to link 13 via pin 17. The upper arm 14 includes a root portion 14a having a side shape such as a long sword, and a substantially L-shaped tip portion 14b. The base 14a is connected to the second support plate 5
, A hydraulic cylinder (hereinafter, referred to as a lift cylinder) 20 as an elevation drive mechanism is disposed between the pair of steel plates.

The auxiliary link 16 is rotatable around a pin 18 within a predetermined range. The pin 18 is attached to the second support plate 5. A stopper 19 composed of a bolt, a nut, and the like is attached to the lower left end of the auxiliary link 16. The head of the stopper 19 (the head of the bolt) abuts on the second support plate 5, whereby the auxiliary link is provided. 1
6 is restricted from rotating in the clockwise direction. Both ends of the lift cylinder 20 are connected to the auxiliary link 16 and the upper arm 14 by pins 21 and 22, respectively.
The pair of left and right upper arms 14 are connected to each other by a connecting pipe 23 horizontally arranged in the width direction of the vehicle body at a tip portion 14b. Also, the trunk 14 of the upper arm 14
A short angle member 24 is welded to the upper end surface of a, and a stopper 25 composed of a bolt, a nut or the like is attached to the angle member 24. This stopper 2
5 comes into contact with the second support plate 5 so that the upper arm 1
4 is prevented from rotating counterclockwise beyond the allowable rotation range.

A hinge 27 that rotates about a pin 26 is attached to the link 13. The hinge 27 is also connected to a load receiving platform (platform) 29 via another pin 28, and is a double hinge having two pivot points. Therefore, the receiving table 29 can rotate about the pin 28 and also about the pin 26. The receiving table 29 includes a main plate 30
And a sub-plate 31. The main plate 30 and the sub plate 31 are connected to each other by a hinge 32 which is a double hinge similar to the hinge 27 described above.

FIG. 9 is a view of the unloading table 29 in the unfolded state (see FIG. 7) viewed from the back side (the surface on which the load is placed is the front surface). 2 or 9, a pair of “U” -shaped guides 33 are provided on the rear surface side of the main plate 30 so as to face the slide rails 3 with their opening sides facing inward (rear). See also FIG. 11 above). The pair of guides 33 engage with the corresponding slide rails 3 to support the load receiving table 29 when the load receiving table elevating device 1 is stored, and also have a function as a reinforcing member for the main plate 30. On the back side of the main plate 30, a pair of backing plates 34 made of an elastic member (rubber or the like) are provided.
The abutment plate 34 comes into contact with the ground when the load receiving table 29 is unfolded to serve as a cushion (see FIGS. 5 and 6), and stabilizes the load receiving table 29. Similarly, a pair of backing plates 35 are provided on the back surface of the sub plate 31. Also, the sub plate 31
On one side, 49 is attached.

Next, in FIG. 4, a switch mounting plate 36 is provided to project slightly upward from the upper end surface of the lower arm 9, and a detection switch 37 is mounted on the switch mounting plate 36. Dog 3 for operating detection switch 37
8 is provided adjacent to the backing plate 35 of the sub-plate 31. When the folded receiving tray 29 is overlaid on the upper arm 14 (see FIG. 3), the contact plate 35 comes into contact with the switch mounting plate 36 to act as a stopper, and the dog 38 operates the detection switch 37.

An angle 39 is horizontally mounted between the left and right slide rails 3 in the vehicle width direction, and a mounting plate 40 is fixed to a central portion of the angle 39. A hydraulic cylinder (hereinafter, referred to as a slide cylinder) as a slide drive mechanism is provided on the mounting plate 40 via a pin 41.
The distal end of the piston rod 42a is supported.
A cylinder support member 43 containing the cylinder portion of the slide cylinder 42 is horizontally arranged in the front-rear direction of the vehicle body,
It is welded to the connecting pipe 6 at a position crossing the connecting pipe 6.

A lock member 44 having a plurality of holes 44a is attached to the right end of the cylinder support member 43. The triangular guide roller support member 45 is
A pin 46 attached to the right end of the cylinder support member 43
And a guide roller 48 is rotatably supported by a pin 47 provided on the right end side. The hole 44a of the lock member 44 is formed on a circumferential orbit drawn by a hole 45a provided on the left end side of the guide roller support member 45 centering on the pin 46. Therefore, the hole 45a of the guide roller support member 45 is
The guide roller support member 45 can be mounted at a desired mounting angle by bolting together with 4a.

When the slide cylinder 42 expands and contracts in accordance with the supply and discharge of hydraulic pressure, the connecting pipe 6 slides with respect to the pin 41. Therefore, connecting pipe 6
All the members directly or indirectly supported by the first member are movable members. That is, the mounting member 2, the slide rail 3, the angle 39, the mounting plate 40, and the pin 41 are fixed members of the loading / unloading device 1 and include a piston rod 42a serving to connect with the fixed member. The remaining members are movable members. The loading tray lifting device 1 is manufactured separately from the vehicle body, and is mounted as a unit by fixing the mounting member 2 to the chassis 104 of the completed vehicle. Therefore, the mounting is simple.

FIG. 14 is a view of the loading / unloading device 1 which is folded and stored as viewed from the rear of the vehicle body. Link body 13
The rear end face is substantially vertical and continuous in the vehicle width direction,
It can also be used as a rear bumper (rush prevention device). Therefore, there is no need to provide a separate rear bumper, and no rear bumper mounting member is required. Further, since there is no need to provide a separate rear bumper, it is possible to secure a sufficient size of the load receiving platform 29 in the vehicle longitudinal direction. Further, since the link body 13 is a member that is continuous in the vehicle body width direction, there is an effect of preventing the upper arm 14 and the lower arm 9 from being twisted between each pair of left and right. When it is desired to provide the rear bumper a little above, a metal plate may be attached to the rear end face 30a of the main plate 30 above the hinge 27 shown in FIG. 2 to form the rear bumper.

Next, the detailed structure of the folded portion of the loading tray 29 will be described. As shown in FIG. 9, a pair of hinges 32 connecting the main plate 30 and the sub-plate 31 are provided.
Are equipped with torsion bars 50, respectively.
FIG. 10 is a side view of the connection portion, and shows the main plate 3.
0 indicates that the sub-plate 31 is upright. FIG. 11 shows the hinge 3 of the receiving table 29 in the folded state.
FIG. 6 is a view of the periphery of the device 2 viewed from the rear (for example, the rear of FIG. 5).
As shown in FIG. 11, four torsion bars 50 are mounted on one hinge 32, and two upper torsion bars are fixed at one bent end to the sub-plate 31, and the other bent end is at the center of the hinge 32. It is inserted slightly above and fixed. Further, the lower two pieces are fixed at one end to the main plate 30, and the other ends are hinged at the hinge 32.
Is inserted and fixed slightly below the central part of the.

The torsion bar 50 is mounted on the sub plate 31 shown in FIG. That is, the torsion bar 50 is free in this state. Therefore, when the sub-plate 31 is rotated from this state, a force is evenly applied to the rear surface of the hinge 32 from the four torsion bars 50. As a result, the hinge 32 always follows the sub-plate 31 with a rotation corresponding to half the rotation angle of the sub-plate 31. For example, in the state shown in FIG. 10, the rotation amount of the sub-plate 31 from the folded state or the expanded state is 90 degrees, while
The rotation amount of No. 2 is 45 degrees.

If the above-mentioned torsion bar 50 is not used, the sub-plate 31 rotates around only one pin of the hinge 32, so that the so-called hinge 32 is bent and the hinge 32 smoothly rotates. Movement is impeded. Thus, by using the torsion bar 50 as described above, the hip plate can be prevented from breaking and the side plate 31 can be smoothly rotated. In both the unfolded state shown in FIG. 9 and the folded state shown in FIG. 11, the torsion bar 50 is in a state of being twisted to the maximum, and the sub-plate 31 moves in the direction of returning to the state shown in FIG. Being energized. Therefore, the force required to raise the sub-plate 31 from the folded state or the unfolded state of the loading tray 29 can be reduced.

Next, the link body 13 and the main plate 30
A detailed structure of a connection portion with the device will be described. 12 and 13 are cross-sectional views of the connection portion (the upper arm 14 and the lower arm 9 are indicated by imaginary lines). In the figure, the torsion spring 51 is provided so as to be wound around the pin 28 of the hinge 27 (see also FIG. 9). One end of the torsion spring 51 is fixed to the main plate 30, and the other end is fixed to the hinge 27. In the folded state (the state shown in FIG. 2 and FIG. 3) of the loading tray 29 in which the main plate 30 has a 90-degree positional relationship with the hinge 27, the torsion spring 51 is in a free state.

When the loading table 29 is lifted from the folded state, the main plate 30
There is a possibility of turning around the pin 6 or the pin 28. However, the rotation about the pin 26 is not limited at all, whereas the rotation about the pin 28 is limited because it receives the load of the torsion spring 51. As a result, the hinge 27 rotates about the pin 26 following the rotation of the main plate 30 until the main plate 30 is lifted upright as shown in FIG. Therefore, the so-called hinge break does not occur, and the main plate 30 is not bent.
Can be smoothly rotated.

When the main plate 30 stands upright, the hinge 27 hits the link body 13 and further rotation is restricted. Therefore, after this, the main plate 30
The rotation of the torsion spring 51 is performed with the torsion spring 51 being charged. In the unfolded state of the main plate 30 shown in FIG. 13, the torsion spring 51 is in a maximum torsion state. Conversely, when the main plate 30 is folded from the unfolded state, the main plate 30 is
8 and around the pin 26 from the upright state to the folded state.

Next, the hydraulic system of the lifting / lowering device 1 will be described. FIG. 15 is a hydraulic circuit diagram. The hydraulic circuit includes a pair of lift cylinders 20 and a slide cylinder 4
2. hydraulic pumps 81, 2 driven by a motor 80
It is composed of four electromagnetic valves 82 to 85 as position valves, a pair of electromagnetic valves 86 performing the same operation, a reservoir tank 87, a pressure reducing valve 88 and other elements shown in the drawing. Elements other than the lift cylinder 20 and the slide cylinder 42 are mainly stored in the power unit box 8 (FIG. 1). The operation of the hydraulic circuit is in four modes corresponding to the extension (drawing) and contraction (retraction) of the slide cylinder 42 and the extension (up) and contraction (down) of the lift cylinder 20.

First, when the slide cylinder 42 is extended, the hydraulic pump 81 is driven and all the solenoid valves 82 to 86 are de-energized. As a result, oil pressure is supplied to the piston rod side chamber 42r of the slide cylinder 42, and oil pressure is also supplied to the piston head side chamber 42h via the electromagnetic valve 84. Here, the hydraulic pressure P supplied to the piston rod side chamber 42r is equal to the hydraulic pressure P supplied to the piston head side chamber 42h. However, depending on the presence or absence of the piston rod 42a, the piston pressure receiving area Sr of the piston rod side chamber 42r is smaller than the piston pressure receiving area Sh of the piston head side chamber 42h. Therefore, the driving force applied to both surfaces of the piston head is P · (S
h-Sr), which is the driving force for the piston rod 42a in the extension direction.

Further, by receiving the driving force based on the pressure receiving area difference as described above, even when an excessive resistance is applied to the extension of the slide cylinder 42, an excessive compression force is applied to the piston rod 42a. Will not join. Therefore, buckling of the piston rod 42a can be reliably prevented. Since the solenoid valve 83 is in the non-excited state, no hydraulic pressure is supplied to the lift cylinder 20 by the internal check valve.

When the slide cylinder 42 is contracted, the hydraulic pump is driven and only the solenoid valves 84 and 85 are excited. Therefore, the hydraulic pressure is supplied only to the piston rod side chamber 42r, and the oil liquid in the piston head side chamber 42h is supplied to the reservoir tank 87 via the electromagnetic valve 85 in a communicating state.
Is returned to. As a result, the piston rod 42a receives the driving force in the return direction, and the slide cylinder 42 contracts.
The driving force in this case is substantially represented by P · Sr. Usually Sr
Is approximately 1/2 of Sh, the driving force P · Sr is substantially equal to the driving force P · (Sh−Sr) at the time of extension. Therefore, the speed at the time of extension and the speed at the time of contraction are substantially the same. As described above, according to the configuration in which the slide cylinder 42 is expanded and contracted by utilizing the pressure receiving area difference, since the two solenoid valves 84 and 85 required for operation are all required to be two-position valves, an expensive three-position valve is required. There is no need to use it and it is economical.

On the other hand, when the lift cylinder 20 is extended after the extension operation of the slide cylinder 42, the hydraulic pump 81 is driven and only the solenoid valve 83 is excited. When the electromagnetic valve 83 is excited, hydraulic pressure is supplied to the lift cylinder 20 via the electromagnetic valves 83 and 86, and the lift cylinder 20 is extended. At this time, hydraulic pressure is continuously supplied to the slide cylinder 42. on the other hand,
Even after the hydraulic pump 81 is stopped after the lift cylinder 20 is extended, the check cylinder 2
The oil liquid in 0 does not return. Therefore, the lift cylinder 20
Are held in an extended state. The lift cylinder 20
Is contracted, the hydraulic pump 81 is stopped, and only the solenoid valves 82 and 86 are excited. Therefore, the oil liquid in the lift cylinder 20 is supplied from the communicating solenoid valve 86 to the solenoid valve 8.
After passing through 3, it is returned to the reservoir tank 87 through the electromagnetic valve 82 in a communicating state.

Next, the slide lock device will be described. Although not shown in FIGS. 1 to 7 for simplification of the drawings, a slide lock device 60 shown in FIG. 16 is provided near the connecting pipe 6. (A) of FIG.
Is a horizontal cross-sectional view of a main part of the slide lock device 60, and (b) is a vertical cross-sectional view. 16 and 17, the lock bar 61 penetrates the second support plate 5 and is attached to the second support plate 5 by a mounting plate 62 so as to be rotatable around the axis. An engagement pin 64 is attached to the distal end side of the lock rod 61 via a compression spring 63 so as to be movable in the axial direction. The distal end of the engaging pin 64 is tapered, and the distal end including the tapered portion 64a has a storage position hole 3b (see FIGS. 3 and 4) provided on the slide rail 3 and a drawer position hole 3a (see FIGS. 1 and 2). The draw-out position holes 3a are provided at a plurality of positions so that the draw-out position can be adjusted according to the rear overhang (the distance from the center of the rear wheel to the rear surface of the vehicle body). A lock slide pad 68 having tapered portions 68a at both ends is attached between the storage position hole 3b and the extraction position hole 3a.

A side pad 69 as a sliding member is attached to the first support plate 4 facing the slide rail 3 (see FIGS. 16 and 17B). The side pad 69 is connected to the stopper 3 provided on the slide rail 3.
The position corresponding to c (FIG. 16) is the extraction position. FIG.
When the side pad 69 attached to the position shown in FIG. 6 hits the stopper 3c, the engagement pin 64 engages with the rightmost drawing position hole 3a in the figure. The mounting position of the side pad 69 can be shifted rightward from the position shown in the figure, and by shifting the mounting position of the side pad 69 in accordance with the rear overhang, the center pull-out position hole 3a or the leftmost position is obtained. The engaging pin 64 can be engaged with the pull-out position hole 3a.

A handle 66 is attached to the lock bar 61 via a connecting handle 65. The rotation range of the lock rod 61 and the handle 66 is 180 degrees, and FIG.
FIG. 17 shows a state in which the handle 66 is lowered directly below. One end of the tension spring 67 is locked to a part of the handle 66, and the other end is attached to the mounting plate 62. Therefore, in order to rotate the handle 66 located immediately below, the handle 66 is rotated counterclockwise against the tension spring 67. When rotated in this way,
The handle 66 is held in the position directly above by being urged again by the tension spring 67. When the handle 66 is directly above, the direction of the tapered portion 64a of the engaging pin 64 is opposite to that in FIG. 17A (the lower side in the figure is the tapered portion). Therefore, the handle 66 is operated depending on whether the sliding operation is the storage direction or the pull-out direction.
Turn to. Further, at the time of pulling out, the tapered portion 64a is turned in the pulling out direction.

When the slide operation is started after the handle 66 has been set to the pull-out position or the storage position, the slide lock device 60 starts to slide together with the second support plate 5 and the like, and the tapered portion 64a of the engaging pin 64 is pressed. You. As a result, the engagement pin 64 comes out of the pull-out position hole 3a or the storage position hole 3b while compressing and compressing the compression spring 63, so that the slide lock device 60 can be moved. Engaging pin 6
4 further slides on the lock slide pad 68.

In the case of sliding in the storage direction, the engagement pin 64 is engaged with the storage position hole 3b at the end of the contraction operation of the slide cylinder 42 (FIGS. 1 to 7). Once engaged,
Unless the tapered portion 64a is directed in the pull-out direction, the engaging pin 64 does not come off naturally. Therefore, it is possible to prevent the movable member of the loading tray elevating device 1 from being pulled out due to the vibration while the vehicle is running. On the other hand, in the case of sliding in the pull-out direction, the side pad 69 contacts the stopper 3c to stop the sliding operation, and the engaging pin 6
4 engages with the corresponding drawer position hole 3a. Once engaged, the engagement pin 64 does not come off spontaneously unless the tapered portion 64a is oriented in the storage direction. Therefore, when the vehicle is unloaded with the vehicle body lowered forward on a slope, it is possible to avoid the danger caused by the falling of the luggage due to the pulled out movable member moving in the storage direction due to gravity.

Next, a securing device for the loading tray 29 will be described. The loading tray 29 is provided with a securing device for maintaining the folded state. FIG.
9 is a diagram showing only a portion 9, in which a male engaging portion 70 is attached to a main plate 30, and a female engaged portion 73 is attached to a sub plate 31. Receiving platform 29
In a state before the is folded ((a) in the figure), the engaging portion 70 slightly protrudes from the upper surface of the main plate 30. In a state where the sub-plate 31 is folded ((b) in the figure), the engaging portion 70 is in an engagement holding state with the engaged portion 73, and the sub-plate 31 is
It is held at 0.

FIG. 19 is a sectional view showing details of the securing device. In the figure, the engaging portion 70 includes a mounting seat 71 and a pin 72 having a mushroom-shaped tip. The female engaged portion 73 includes a housing 74, an engagement piece 75 with the pin 72, a compression spring 76, one spring receiver 77, and the other spring receiver 7.
8 and a push button 79 (see also FIG. 9) integrally attached to the spring receiver 78. Engagement piece 75
Consists of a combination of three split members, and the upper and lower ends of the engagement piece 75 housed in the housing 74 are inwardly contracted in a natural state. In the state of FIG.
The lower end of the engagement piece 75 is pushed open by the spring receiver 77, and the opening 75a is large enough to receive the pin 72. The upper end side of the engagement piece 75 is inwardly tapered. FIG. 21A shows the shape of the engagement piece 75 at this time as viewed from the bottom surface on the side of engagement with the pin 72.

When the pin 72 is relatively pushed into the engaged portion 73 by folding the sub-plate 31 on the main plate 30, the spring receiver 77 is pushed up by the pin 72. Further, as shown in FIG. 20, the pin 72 pushes up the spring receiver 78 via the compression spring 76, so that the upper side of the spring receiver 78 is pushed out of the housing 74, and the push button 79 projects. As a result, the engaging piece 75 is pushed and opened with the upper end thereof being externally inserted into the large diameter portion of the spring receiver 78. On the other hand, the lower end of the engagement piece 75 is released from being pushed open by the spring receiver 77, and is in a state of being recessed (see FIG. 21B). Thus, the head of the pin 72 is held in a state of being engaged with the engagement piece 75. Also, the pin 72 is stably held by receiving the bias of the compression spring 76.
Therefore, the sub plate 31 is fixed to the main plate 30 and does not come off naturally.

In order to release the engagement (locking), the push button 79 is pressed. When the push button 79 is pressed,
The engagement piece 75 is disengaged from the large-diameter portion of the spring receiver 78, and the state of being pushed open is released. As a result, the upper end of the engagement piece 75 contracts inward. Therefore, it is easy to spread at the lower end. Further, the spring receiver 77 is pressed downward by the pressing force of the push button 79 via the compression spring 76, and the engagement piece 7
The lower end of 5 is pushed open to enlarge the opening 75a. In this state, when the sub-plate 31 is lifted while the push button 79 is being pressed, the pin 72 comes off from the engagement piece 75, and the locked state is released.

Next, the elevating mechanism of the loading table 29 will be described in detail. FIG. 8 is a side view showing only the main parts related to the elevating operation, and the reference numerals of the respective parts are common to FIGS. In FIG. 8, (a) shows a state in which the loading tray 29 is raised so as to be flush with the floor surface of the cargo box of the vehicle body,
(B) shows a state where the receiving platform 29 is horizontal on the ground, and (c) shows a state where the receiving platform 29 is inclined on the ground. Here, the pin 18 is a pivot point of the auxiliary link 16 and a fixed point in the movable member. On the other hand, the pins 15 and 21 are movable points that move according to the rotation of the auxiliary link 16. The pin 10 is a fixed point that is fixed independently of the auxiliary link 16. Other pins 12, 1
7, 22, and 28 move according to the elevating operation.

First, the ascending operation from the state (c) to the state (a) will be described. In (c), the lift cylinder 20 is in a contracted state, and the auxiliary link 16 is
Assuming that the state shown in (1) is vertical, the state is free to rotate slightly counterclockwise. When the lifting operation is performed from this state and the lift cylinder 20 starts to extend, the auxiliary link 16 slightly rotates clockwise via the pin 21. By this rotation, the pin 15 also slightly rotates in the same direction. Therefore, the pin 17 is slightly pulled to the left of the drawing via the upper arm 14. On the other hand, since the pin 10 is a fixed point, the pin 12 does not move at this point and is fixed. Therefore, the link 13 and the load receiving table 29 rotate counterclockwise around the pin 12 as a rotation fulcrum, and the upper surface 13a of the link 13 and the load receiving table 29 become horizontal as shown in FIG. At this time, the position of each pin is designed so as not to rotate further than horizontal, and the stopper 1
9 (see FIG. 7) is adjusted in advance.

The above-described tilting operation of the receiving table 29 (operation from tilt to horizontal or vice versa) is performed when the pin 18 is at the point A, the pin 15 is at the point B, and the pin 21 is at the point C, To B
There is a point and there is a point C below the point B. Further, the distance AC is larger than the distance AB. Thereby, the rotation distance of the point B with respect to the stroke amount of the lift cylinder 20 is
AB / AC is substantially achieved, and the tilt operation is slower than the operation of the lift cylinder 20. Pin 17 is set at point D,
Assuming that the pin 12 is the point E, the angle at which the line segment AB intersects with the line segment BD is slightly larger than 90 degrees in the state of FIG.
In the state of (b), it is slightly smaller than 90 degrees. That is,
In the state change from (c) to (b), the angle is 9
It changes around 0 degrees. This has an effect that the rotation speeds at the points B and D become substantially constant from the start to the end of the rotation. For example, when a package is placed on the receiving table 29,
If the tilt operation is accelerated or decelerated from the state of (c) to the state of (b) in an accelerated or decelerated manner, a situation may occur in which the luggage swings or falls over with excessive momentum. According to the operation, there is no such fear.

When the auxiliary link 16 reaches the state shown in (b), the stopper 19 comes into contact with the second support plate 5, and the auxiliary link 16 cannot rotate any more. Here, pin 1
Assuming that 0 is the point F, the points B, D, and E are:
The line segment BF and the line segment DE are parallel to each other, and the line segment BD and the line segment FE are parallel to each other. That is, the quadrilateral BDEF is a parallelogram and the upper arm 14
The lower arm 9 and the lower arm 9 constitute a parallel link having the points B and F as pivot points and the points D and E as points of action. This parallel relationship is then maintained up to the raised position. Therefore, the upper surface 13a of the link body 13 and the receiving tray 29 maintain a horizontal state.

When the lift cylinder 20 further extends from the state shown in FIG. 4B, a driving force is applied to the pin 22 located in the parallelogram with the pin 21 located below the parallelogram as a fulcrum. Rotates in the counterclockwise direction about the points B and F, and the receiving table 29 is raised. When the floor surface of the packing box, the upper surface 13a of the link 13 and the receiving table 29 are flush with each other, the stopper 25 (see FIG. 7) comes into contact with the second support plate 5 and the rotation of the upper arm 14 stops. And
The lifting of the receiving table 29 stops. After the ascent is stopped, the hydraulic pressure generated by the hydraulic pump 81 increases, but this hydraulic pressure is released by the pressure reducing valve 88 (see FIG. 15).

It is also possible to stop the lifting of the load receiving table 29 by applying the link 13 or the upper arm 14 to a part of the packing box 102. However, the packing box 102 is generally made of aluminum, and the link body 13 and the upper arm 14
Is an iron-based metal such as iron or stainless steel. When the iron-based metal having a higher hardness than aluminum is applied to the cargo box 102 to stop the rise of the loading table 29, the cargo box 102 is damaged. Therefore, it is necessary to separately provide reinforcement at the contact portion of the packing box 102, which is troublesome. In this regard, as described above, the configuration in which the stopper 25 is applied to the second support plate 5 is simple and robust.

Next, the lowering operation from the state (a) to the state (c) will be described. In the state of (a),
When the lowering operation is performed and the lift cylinder 20 starts contracting, the operation reverse to that at the time of the upward movement is performed, and the state shown in FIG. Here, the tip of the lower link 9 lands and stops rotating.
At this point, the total weight of the link body 13 and the load receiving platform 29 and the load placed thereon acts as a force in the direction of rotating the pin 17 clockwise about the pin 12. Here, when the lift cylinder 20 further contracts,
The auxiliary link 16 slightly rotates counterclockwise about the pin 18. As a result, the pin 15 rotates counterclockwise about the pin 18. Due to the rotation of the pin 15, the pin 17 rotates clockwise around the pin 12, and the load receiving platform 29 performs a tilt operation to lower its tip. As in the case of ascending, the tilting operation is performed at a rotation distance of AB / AC approximately with respect to the contraction of the lift cylinder 20,
And it is performed at a substantially constant speed. Accordingly, the receiving table 29 is slowly inclined at a substantially constant speed. Therefore, the situation where the luggage swings or falls over too much does not occur.

Next, a series of operations and operations (storage / drawing and lifting / lowering) in the loading / unloading device 1 configured as described above will be described with reference to FIGS. First, after stopping the vehicle and pulling the parking brake, the occupant gets off and sets the handle 66 (FIGS. 16 and 17) to "pull out". Next, switch box 7 (FIG. 1)
Is turned from "OFF" to "ON", and further turned to and held at the "ST" position where the sliding operation is performed. As a result, the slide cylinder 42 is extended, and the movable side member of the loading tray elevating device 1 slides rightward in the figure (FIG. 3). With this slide, the switch box 7 also moves rightward, so that the operator follows and walks. It is rather preferable that the operator walks following the vehicle from the viewpoints of operability and safety such as backward confirmation. When the side pad 69 attached to the first support plate 4 comes into contact with the stopper 3c (see FIG. 16), the slide stops, and at the same time, the slide lock device 6
Since the zero engagement pin 64 engages with the corresponding hole 3a, it is locked in both directions of drawing and storing.

Next, the operator operates the up / down switch S2 provided on the switch box 7 to "down".
As a result, the lift cylinder 20 starts to contract, and the upper arm 14 and the lower arm 9 rotate clockwise. FIG.
As shown in (2), when the lower arm 9 lands on the ground, the rotation stops, so that the lowering operation is stopped. Along with this operation, the load receiving table 29 is relatively pressed by the guide roller 48 and is separated from the link body 13, and becomes slightly upright so as not to reach vertical.

Next, the operator grasps 49 (FIG. 9) and manually raises and rotates the loading tray 29 to fall down on the ground (FIG. 5). As a result, the main plate 30 of the loading tray 29 is completely unfolded with respect to the link body 13. In addition, at the time of the falling operation of the load receiving table 29, the load receiving table 29 is slightly erected in advance as described above, so that the burden of the force required by the operator is small. Subsequently, the operator presses the push button 79 (FIG. 19) to release the securing state of the loading tray 29 and opens the sub-plate 31 (FIG. 6).
In this way, when the receiving table 29 is unfolded, a receiving surface of a predetermined size that is linearly continuous from the upper surface 13a of the link body 13 is formed, and is ready for loading. Here, the abutting plates 34 and 35 are provided between the ground and the receiving tray 29 to serve as a cushion and stabilize the receiving tray 29.

When the luggage has been placed on the cargo receiving table 29, the operation of lifting is performed. As a result, first, the above-described tilting operation is performed, and the link body 13 and the receiving tray 29 become horizontal (FIG. 7).
Are indicated by two-dot chain lines. ). Further, when the lift cylinder 20 is extended, the link body 13 and the receiving tray 29 are raised to a height that matches the floor of the packing box 102 while being kept horizontal (FIG. 7). Here, the worker transfers the luggage to the packing box 102. When unloading the luggage from the packing box 102, the above operation is performed in the reverse order from the state of FIG. 7 to the state of FIG.

FIG. 6 shows a case where the loading tray lifting device 1 is stored.
, The operator takes the 49 (FIG. 9) and folds the sub-plate 31. Upon folding, the sub-plate 31 is automatically secured and remains folded unless the push button 79 (FIG. 20) is pressed (FIG. 5). Next, the operator lifts the folded loading tray 29 and leans it against the guide roller 48 (FIG. 4). As a result, the receiving table 29 as a whole is
3 is folded to some extent. That is, the receiving surface, which is a single plane continuous from the link body 13, is also folded at the connection point between the link body 13 and the receiving table 29. Note that the receiving table 29 in the state shown in FIG.
The force required to lift the torsion
(FIGS. 12 and 13) are assisted, and slightly lighter than the actual weight. Therefore, it is possible to easily stand up with the force of holding the 49 with one hand.

As described above, when the state shown in FIG. 5 changes to the state shown in FIG.
Are rotated about the pin 28 until they have a positional relationship of about 90 degrees with each other, and then rotated about the pin 26. The pin 26 is located at a position separate from the pins 17 and 12 serving as the action points of the parallel link. Therefore, the rotating loading tray 2
4 does not include the depth of the upper surface 13a of the link body 13 (length in the front-rear direction of the vehicle body) when the vehicle 9 is closest to the rear part of the vehicle body 102 and reaches the state shown in FIG. It is the length up to the turning tip of 29. This allows
The turning radius becomes compact, and the turning tip of the loading tray 29 does not interfere with the vehicle body 101. Here, supplementing the degree of compactness, it is assumed that the receiving tray 29 shown in FIG. 5 is integrated (folded) with the same member as the link body 13 around the pin 17 which is the point of action of the parallel link. ), The radius of rotation is extremely large, and the difference from the above configuration is apparent.

Next, the user operates the handle 66 of the slide lock device 60 to set the slide lock device 60 to "storage". Then, an ascending operation is performed while the key switch S1 is maintained at “ON”. As a result, the upper arm 14 and the lower arm 9 rotate counterclockwise, and the load receiving table 29 rolls down against the guide roller 48 and falls counterclockwise. Falling loading platform 2
9 is a switch mounting plate 36 as a stopper.
, The detection switch 37 is operated by the dog 38 (FIG. 3). When the detection switch 37 is operated, the ascent is stopped, and the lift cylinder 20 is connected to the solenoid valve 86 (FIG. 1).
The oil liquid supply state at that time is maintained by the check action of 5). Subsequently, the retracting operation due to the contraction of the slide cylinder 42 is automatically performed.

When the slide cylinder 42 reaches the contraction end and the movable member of the loading / unloading device 1 reaches a predetermined storage position, the engaging pin 64 (FIG. 17) is moved to the storage position hole 3b.
(FIG. 3) and the movable member is automatically locked. Further, a guide 33 provided on the load receiving table 29 is engaged with the slide rail 3. In this way, the storage of the loading / unloading device 1 is completed, and the vehicle can be driven. The engagement of the engagement pins 64 prevents the loading tray elevating device 1 from being unintentionally pulled out even with vibration during traveling. Also,
Due to the engagement between the guide 33 and the slide rail 3, even if the lift cylinder 20 leaks oil,
There is no danger that the movable members such as the arm 9 and the arms 9 and 14 will descend. Further, since the backing plate 35 made of an elastic body is in contact with the switch mounting plate 36 mounted on the lower arm 9, the load receiving table 29 is stably supported by the lower arm 9, and the load receiving table 29 in the storage position. Rattle is prevented.

Next, the position adjustment of the guide roller 48 will be described with reference to FIGS. Guide roller 4
The position 8 is, as described above, the guide roller support member 45.
It is possible to adjust by rotating.
FIG. 22 shows a vehicle height H1 higher than the vehicle height H0 of the vehicle shown in FIG.
FIG. In this case, the hole 45a of the guide roller support member 45 is shifted to the clockwise direction from the position shown in FIG. As a result, the guide roller 48 rotates clockwise about the pin 46, and is lower than the case of FIG.
Go to Thereby, the inclination rising angle of the load receiving table 29 leaning against the guide roller 48 with respect to the ground becomes almost the same as in the case of FIG. That is, the guide roller 4
By adjusting the position of 8, it is possible to maintain the inclination and upright posture of the loading tray 29 substantially the same regardless of the vehicle height. Accordingly, regardless of the vehicle height, the force required to lower the load receiving table 29 from the inclined standing state can be made substantially constant, and the work is easy. Conversely, even when the loading tray 29 is raised and leans against the guide roller 48, it can be stably leaned regardless of the vehicle height. The guide roller 48 is rotated as described above, so that the position adjustment in both the horizontal direction and the vertical direction is performed simultaneously. If the inclination erecting angle is maintained only by adjusting in the horizontal direction, the tip of the receiving tray 29 may interfere with the rear part of the vehicle body 101 during the operation of storing the receiving tray 29 from the state shown in the drawing. It is preferable to perform the vertical adjustment simultaneously.

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.

[0055]

The present invention configured as described above has the following effects. According to the loading tray elevating device of the first aspect, the loading surface of the predetermined size is constituted by the link body, the main plate, and the sub-plate, and the loading tray with the sub-plate folded is the point of action of the parallel link. However, since the link body can be folded around a separate pivot point, the pivot radius at the time of folding does not include a dimension corresponding to the link body, and the pivot radius is reduced accordingly. Therefore, it is possible to prevent the load receiving table from interfering with the vehicle body while securing a predetermined size of the load receiving surface.

[Brief description of the drawings]

FIG. 1 is a side view of a loading tray lifting device according to an embodiment of the present invention.

FIG. 2 is a side view of FIG. 1 with some parts omitted.

FIG. 3 is a side view showing the loading tray elevating device in a state of being pulled out rearward.

FIG. 4 is a side view showing the loading / lifting device in a state where the tip of the lower arm lands and the loading tray leans against a guide roller and stands upright.

FIG. 5 is a side view showing the loading / unloading device in a state where the tip of the lower arm lands and the loading tray is folded down and laid down;

FIG. 6 is a side view showing the loading / unloading device in a state where the loading tray is completely unfolded and along the ground.

FIG. 7 is a side view showing an elevating operation of the loading tray elevating device.

FIG. 8 is a diagram showing in detail the elevating operation of the loading tray elevating device.

FIG. 9 is a bottom view of the unfolded loading tray in the loading tray lifting device.

FIG. 10 is a side view showing a hinge portion of the loading tray in the loading tray lifting device.

FIG. 11 is a view of the folded hinge of the loading tray in the loading tray lifting device as viewed from the rear side of the vehicle.

FIG. 12 is a cross-sectional view showing a hinge structure of a base portion of the loading tray in the loading tray elevating device, showing a standing state of the loading tray.

FIG. 13 is a cross-sectional view showing a hinge structure of a base of the loading tray in the loading tray elevating device, showing the loading tray in a laid state.

FIG. 14 is a view of a part of the loading tray lifting device as viewed from the rear of the vehicle.

FIG. 15 is a hydraulic system diagram of the loading tray elevating device.

FIG. 16 is a side view showing a slide lock device of the loading tray elevating device.

FIG. 17 is a horizontal sectional view and a vertical sectional view of the slide lock device.

FIG. 18 is a side view showing a securing structure of the loading tray in the loading tray lifting device.

FIG. 19 is a sectional view showing details of the securing structure, showing a state before securing.

FIG. 20 is a sectional view showing details of the securing structure, showing a state after securing.

FIG. 21 is a bottom view showing an engagement piece in the securing structure.

FIG. 22 is a side view similar to FIG. 4, showing a state in which the position of a guide roller is adjusted according to the vehicle height.

FIG. 23 is a side view showing a schematic structure of a conventional loading tray elevating device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Receiving stand raising / lowering apparatus 2 Mounting member 3 Slide rail 4 1st support plate 5 2nd support plate 6 Connecting pipe 9 Lower arm 10,15 pin (rotation fulcrum) 12,17 pin (working point) 13 Link body 14 Upper arm Reference Signs List 20 lift cylinder 29 loading table 30 main plate 31 sub plate 42 slide cylinder 102 body 104 chassis

Claims (1)

[Claims] 1. A support base supported by a vehicle body, two arms constituting a parallel link supported by the support base and performing a vertical movement, a lifting drive mechanism for driving the arm, and a tip end side of the arm And a link body that includes a point of action of the parallel link and forms a part of the load receiving surface, and is connected rotatably about a pivot point provided on the link body separately from the point of action. A main plate, and a sub-plate rotatably connected to the distal end side of the main plate and foldable on the main plate. When the sub-plate is folded, the whole is folded with respect to the link body. A load receiving platform elevating device which is capable of forming a load receiving surface together with the link body when deployed.