JPH11334376A - Van type truck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cargo box door jumping up device for a van type truck, which has high durability and can secure a large cargo box volume. SOLUTION: This cargo box door jumping up device, which is disposed inside a cargo box door 30, comprises an arm A1, an arm B2, a lever 4, a shaft 5, and elastic means 7. An end of the arm A1 is fixed inside the cargo box door 30, while the other end of the arm A1 is linked to an end of the arm B2. The other end of the arm B2 is linked to an end 4a of the lever 4 with an intermediate part 4b of the lever 4 pivotally mounted to a cargo box side, while the other end 4c of the lever 4 is linked to an end of shaft 5. The elastic means 7 connected to the other end of the shaft 5 are elastically provided between the other end of the shaft 5 and a cargo box side pivotally supporting member 8. The elastic means 7 are expanded and contracted by a stroke of the shaft 5 caused by opening and closing of the cargo box door 30 such that a moment caused by the elastic means 7 operates in a direction to jump up or close the cargo box door 30 according to a turning position of the cargo box door 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cargo box door flipping device, and more particularly to a van type truck provided with the device.

[0002]

2. Description of the Related Art FIGS. 19 and 20 are external views of various van-type trucks. In FIG. 19, a rear door of a packing box is used. Thereby, the packing box is opened. 2. Description of the Related Art Conventionally, a packing box main body and a gas damper connected to the packing box door are mounted inside the packing box as a packing box lifting device. In addition, the present inventors have proposed in Japanese Patent Application No. 9-365729 a packing box door flip-up device of a type to be mounted on the roof of a packing box door.

[0003]

However, the conventional box door flip-up device using a gas damper has a problem that gas leaks frequently occur from the gas damper, resulting in low durability and high cost.

[0004] In addition, in the case of the type of box door flip-up device of the type proposed by the present inventors in Japanese Patent Application No. 9-365729, which is mounted on the roof of a package door, the height of the vehicle is increased by the height of the flip-up device. Due to legal restrictions on the vehicle height, there is a case where the height of the packing box must be reduced by installing this type of flip-up device, and as a result, the packing box volume is reduced. In addition, when the height of the cargo entrance is low, there is a possibility that a van-type truck provided with this type of flip-up device cannot enter.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cargo box door flipping device of a van type truck which has high durability and can secure a large cargo box volume.

[0006]

The present invention has the following items from each viewpoint. First viewpoint: Arm A, arm B, lever, shaft, and elastic means are arranged inside the packing box door (inside the packing box). One end of the arm A is fixed inside the packing box door. The other end of the arm A is connected to one end of the arm B. The other end of the arm B is connected to one end of the lever. The intermediate portion of the lever is pivotally supported on the packing box side. One end of the shaft was connected to the other end of the lever. The elastic means is connected to the other end of the shaft and is elastically mounted between the other end of the shaft and a member pivoting with the shaft.

Second viewpoint: Arm A, arm B, lever, rod, shaft, rod guiding means, and elastic means are arranged inside the packing box door (inside the packing box). One end of the arm A is fixed inside the packing box door. Arm A
Is connected to one end of the arm B. The other end of the arm B is connected to one end of the lever. The middle part of the lever is pivoted to the packing box. One end of the rod was connected to the other end of the lever. The guide means guides the rod in a stroke and rotatable manner. One end of the shaft is connected to the other end of the rod. The elastic means is connected to the other end of the shaft and is elastically mounted between the other end of the shaft and a member fixed to the packing box.

Third viewpoint: A stopper that defines the maximum opening of the packing box door by abutting the lever at a predetermined pivot position of the lever and locking the lever. In a third aspect, preferably, there is provided means for fixing the stopper so that the mounting position of the stopper is displaceable along the pivot direction of the lever.

Fourth viewpoint: a seal member provided with a seal member between a side edge of a packing box door and an opening edge of the packing box. A plate member that is provided near the seal member and fixes the arm A to the packing box door. Along the horizontal direction, the mounting position of the arm A is closer to the inner wall of the packing box than the mounting center of the plate member for mounting the arm A to the packing box door.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

[First Embodiment] A packing box flip-up device according to an embodiment of the present invention is disposed inside a packing box of a van type truck, and is provided between an inner wall of the packing box of the van type truck and an inside of a rear packing box door. It is attached between.

FIG. 1 is a sectional view of the first embodiment in which the device cover 43 is broken.
FIG. 2 is a view of the packing box flip-up device according to the embodiment viewed from the side, and FIG. 2 is a view of the device shown in FIG. FIG. 3 is an operation diagram of the apparatus shown in FIG. 1, showing a state where the packing box door 30 is fully opened, and FIG. 4 is a view of the apparatus shown in FIG.

Hereinafter, the structure of the cargo box door flipping device according to the first embodiment will be described. Referring to FIG. 1, one end of an arm A1 is fixed to a packing box door 30 via a bracket mechanism 15. The other end of the arm A1 is rotatably connected to one end of an arm B2 via a pin 31.
The other end of the arm B2 is rotatably connected to one end (first corner) 4a of the lever 4 via a pin 32. Lever 4
The intermediate portion (second corner portion) 4b of the pin 3 is attached to the lever mounting member 44 fixed to the fixing plate 9 fixed to the packing box side, and the pin 3
It is pivoted through 3. One end of a shaft 5 is rotatably connected to the other end (third corner) 4c of the lever 4 via a pin 34. In the closed position of the packing box door 30, the pivot point (pin 33) of the lever 4 and the arm B2
, The shaft 5 extends. At the maximum open position of the packing box door 30 (see FIG. 3), the pivot point (pin 33) of the lever 4 is located between the shaft 5 and the arm B2.

The spring receiver 8 is pivotally supported on the nose of the fixed plate 9 via a pin 35. The shaft 5 is supported by a sleeve 8c integral with the spring support 8 so as to be able to stroke with respect to the spring support 8 and to be rotatable integrally with the spring support 8. The shaft 5 is inserted through a bore of the coil spring 7 housed in the spring receiver 8. At the other end of the shaft 5, a spring seat 6 is held between a nut 45 and a coil spring 7. The position of the spring seat 6 in the axial direction of the shaft 5 can be displaced by changing the screwing position of the nut 45 to the shaft 5. The coil spring 7
Compression interposition (elastic) between the spring seat 6 and the inner surface of the spring receiver 8
Have been.

As shown in FIG. 1, the entire flip-up device is housed in a device cover 43 fixed to the side wall of the packing box, and the mechanism (moving part) of the flip-up device and the load even when a large amount of loads are loaded. The interference with is prevented. FIG.
1 shows an enlarged view of the device cover 43 as viewed from below in FIG.

Next, details of each member will be described.

[Fixing Plate 9] Referring to FIGS. 1 and 6, the fixing plate 9 has a pair of parallel plates 9a, 9b and 9a, 9 having a surface extending in the vertical direction.
b, an L-shaped packing box door side mounting plate 9c arranged on the packing box door 30 side and a horizontal plate 9d provided on the other end side of the parallel plates 9a and 9b are integrated. The packing box door-side mounting plate 9c is fixed to members extending downward from the packing box ceiling on the rear surface of the packing box by bolts 38a and 38b. The parallel plate 9a is fixed to the inner wall of the packing box by bolts 39a, 39b (not shown, 39b is located below the bolt 39a) via a mounting plate 40 (see FIG. 15) extending in the vertical direction. .

The other ends of the lever 4 and the pair of L-shaped plates 12, 13 extend between the pair of parallel plates 9a, 9b. The other ends of the pair of parallel plates 9a and 9b are connected to a pair of forked portions 8 formed at one end of the spring receiver 8.
a and 8b, and are rotatably connected to each other by a pin 35. Further, a sleeve 8c is formed at a central portion on one side of the spring receiver 8, and the sleeve 8c receives the shaft 5 so as to be freely stroked. By the sleeve 8c, the shaft 5 and the spring receiver 8 rotate integrally about the pin 35.

As shown in FIG. 6, instead of fixing the parallel plate 9a to the packing box side wall via the mounting plate 40, as shown in FIG. May be fixed to the ceiling wall of the packing box.

[Stopper Mechanism 10] FIG. 8 is an enlarged view of the stopper mechanism 10 shown in FIG. 1 as viewed from above. Referring to FIG. 3 and FIGS. 6 to 8, a stopper mechanism 10 is provided on the upper surface of the horizontal plate 9 d of the fixed plate 9. In the stopper mechanism 10, a pair of L-shaped plates 12, 13 are provided so as to sandwich a plate 11 fixed or integrated with the horizontal plate 9d. Slots 11a, 11b formed in plate 11 and L-shaped plates 12, 1
The L-shaped plates 12 and 13 are fixed to the plate 11 by inserting and fastening the bolts 14 a and 14 b into the holes formed in the plate 3. In addition, the long holes 11a, 11b
Is larger than the bolts 14a, 14b, and the mounting position of the L-shaped plates 12, 13 can be adjusted along the pivoting direction of the lever 4. By this adjustment, the maximum opening degree of the packing box door 30 can be changed.

The bent other end of the pair of L-shaped plates 12 and 13 extends downward, and the other end (the second end) of the lever 4 (comprising a pair of plates 4e and 4f shown in FIG. 13). A contact surface (contact plate) 4d formed on the corner portion 4b and the third corner portion 4c) and a stopper surface 10d extending in the vertical direction facing the rotation direction of the lever 4 are respectively provided. Have. The maximum opening of the packing box door 30 is defined by the rotation of the packing box door 30 and the engagement of the contact surface 4d of the lever 4 with the stopper surface 10d.

[Arm A1] FIG. 9 is a sectional view taken on line B- in FIG.
It is B sectional drawing and has shown the connection part of arm A1 and arm B2. FIG. 10 shows the bracket mechanism 15 shown in FIG.
It is the figure which looked at from the top. FIG. 11 is a side view of FIG. 9 to 11, the arm A1 includes a pair of plates 1a and 1b, and one ends of the pair of plates 1a and 1b are fixed to the upper inside of the packing box door 30 via the plate 19. At the other end of the arm A1, one end of the arm B2 penetrates between the pair of plates 1a and 1b, and is rotatably connected to each other via a pin 31.

[Bracket Mechanism 15] Referring to FIGS. 2, 10 and 11, the bracket mechanism 15 for fixing the arm A1 to the packing box door 30 will be described. The bracket mechanism 15 has a pair of plates 19 and 20 facing each other across the packing box door 30. A pair of plates 19, 2
0 is determined by bolts 21a, 21b, 21c and 21d.
The packing box door 30 is fixed to the inside and outside of the door so as to sandwich it.

Referring to FIG. 1, the packing box door 30 is attached to the upper edge of the packing box opening via a hinge 37. The hinge 37 has a portion that projects horizontally from the side edge of the packing box door 30. Further, referring to FIG. 10, a sealing member (seal rubber, H rubber, packing, or the like) 41 is attached to a side edge of the packing box door 30 and / or a packing box opening side edge so that the packing box is sealed. I have. The plates 19 and 20 on the inside and outside of the packing box door 30 are attached to the center side of the packing box door 30 so as to avoid the overhang because the sealing member 41 protrudes on the packing box door 30 surface. ing.

Referring to FIGS. 2 and 10, along the horizontal direction, the arm A1 (the pair of plates 1a and 1b) is closer to the inner wall of the packing box than the mounting center of the pair of plates 19 and 20. It is fixed to the packing box door 30. Further, a link system such as the arm B2, the lever 4, and the shaft 5, an elastic system such as the coil spring 7, and a device cover 43 for accommodating them are provided as a whole with a pair of plates 19 and 2.
It is located closer to the inner wall of the packing box than the center of attachment.
For this reason, the effective volume of the cargo box in which the cargo can be substantially loaded is increased.

[Arm B2] Referring to FIGS. 1 and 9,
One end of the arm B2 penetrates into a pair of plates 1a and 1b constituting the arm A1 and is rotatably connected to each other via a pin 31. The other end of the arm B2 enters a forked portion (or between a pair of plates) formed at the one end 4a of the lever 4, and the pin 32 is inserted through the other end of the arm B2 and the forked portion. Are rotatably connected to each other.

[Lever 4] FIG. 12 is a sectional view taken along the arrow C- in FIG.
It is C sectional drawing and has shown the connection part of the lever 4 and the shaft 5. FIG. Referring to FIGS. 1 and 12, at one end (third corner) 4c of lever 4, one end of shaft 5 enters between a pair of plates 4e and 4f constituting lever 4,
The pin 34 is inserted through the other end 4c of the pair of plates 4e and 4f and the one end bearing portion of the shaft 5 so as to be rotatably connected to each other.

[Lever Mounting Member 44] FIG. 13 is a sectional view taken along the line DD in FIG. With reference to FIGS. 1 and 13, one end of a lever mounting member 44 fixed to the fixing plate 9 fixed to the packing box side is a pair of forked portions, and the lever 4 is provided between the pair of forked portions. The pair of plates 4e and 4f respectively enter, and the lever 4 is pivotally supported by the lever mounting member 44 by the pair of pins 33.

[Spring Receiver 8] Referring to FIG. 1, both ends of the spring receiver 8 are opened to allow a stroke of the shaft 5, and the shaft 5 is housed in the spring receiver 8 through an opening on one side. Of the coil spring 7 thus cut out. FIGS. 1 and 6 show the nose of the fixing plate 9 on which the spring receiver 8 is pivotally supported via a pair of pins 35. FIG. 14 is a sectional view taken along the line EE in FIG.
And the bearing of the shaft 5 are shown.

Referring to FIG. 1, FIG. 6 and FIG. 14, one end of spring support 8 is formed as a pair of forked portions 8a and 8b, and a pair of forked portions 8a and 8b constituting fixed plate 9 is provided in the pair of forked portions 8a and 8b. The other ends (nose) of the parallel plates 9a, 9b of the above-mentioned intrude, and the pair of pins 35, 35 attach the spring receiver 8 to the fixed plate 9.
Is pivoted.

At the center of one end of the spring receiver 8, a sleeve 8
c is provided integrally with the plates 8b, 8b. The shaft 5 is inserted into the sleeve 8c and is supported so as to be able to stroke. By this sleeve 8c, the shaft 5 and the spring receiver 8 rotate integrally about the pin 35 as a central axis.

The operation of the above-described flip-up device will be described. 5 (A) to 5 (C) are operation diagrams of the packing box door flip-up device according to the present embodiment. FIG. 5 (A) shows the packing box door closed state, and FIG. 5 (B) shows the packing box door opened about 45 °. State, (C)
Indicates a state in which the packing box door is opened to the maximum. With reference to FIGS. 1, 3 and 5, the packing box door 30 is operated by operation.
Is rotated, the arms A1 and B2 move while rotating toward the outside of the packing box. As a result, the lever 4 rotates around the pin 33 counterclockwise in FIG. At the same time, when the shaft 5 strokes to the other side of the shaft 5, the coil spring 7 expands, and the stored elastic energy is released.

Since the pivot point (pin 33) of the lever 4 is located above the axis of the shaft 5 from the initial position of the packing box to a predetermined opening, the coil spring 7 moves toward the other side of the shaft 5. The acting elastic force acts as a moment for rotating the lever 4 clockwise in FIG. But,
After the predetermined opening degree, the pivot point (pin 33) of the lever 4 is located below the axis of the shaft 5, and the elastic force acting on the other side of the shaft 5 by the coil spring 7 is opposite to that of FIG.
In the middle, it acts as a moment to rotate the lever 4 counterclockwise. Therefore, after the packing box door 30 is manually opened to a predetermined opening degree (for example, about 45 ° as shown in FIG. 5B), the packing box door 30 pops up by itself. By adjusting the mounting position of the spring seat 6 with respect to the shaft 5, it is possible to adjust the relationship between the elastic energy released from the coil spring 5 and the potential energy obtained by the packing box door 30. Box door 30
Can be stopped.

When the packing box door 30 further pops up by itself by the elastic force of the coil spring 7, FIGS.
With reference to (C), the contact surface 4d provided on the other side of the lever 4 contacts the stopper surface 10d and is locked. That is, the further counterclockwise pivoting of the lever 4 in FIG. 3 is prevented, so that the packing box door 30 connected to the lever 4 via the arms A1 and B2 cannot rotate any more. Thus, the maximum opening degree of the packing box door 30 is set. As described above, it is possible to arbitrarily set the maximum opening degree of the packing box door 30 by adjusting the mounting position of the pair of L-shaped plates 12 and 13.

The flipped-up packing box door 30 can be pressed down by pulling a string or the like attached to the packing box door 30 and can be closed. In the closing stroke, when the packing box door 30 is pushed down to a predetermined opening degree, the moment generated by the coil spring 7 acts as a moment acting in the clockwise direction in FIG. 1, and the packing box door 30 is automatically closed. Close on your own.

[Second Embodiment] A flip-up device according to another embodiment of the present invention will be described. FIG. 17 is a side view of a van type truck flip-up device according to a second embodiment of the present invention. Hereinafter, differences between the apparatuses according to the first and second embodiments will be described. Parts having the same configuration are as described above.

Referring to FIG. 17, in the second embodiment, a rod 5a and a shaft 5b connected to each other are provided. One end of the rod 5a is rotatably connected to the other end (third corner) 4c of the lever 4 via a pin 34. The other end of the rod 5a is rotatably connected to one end of the shaft 5b via a pin 50. A roller 51 pivotally supported by a fixed plate 52 is disposed between the rod 5 a and the lever mounting member 44. The roller 51 is in sliding contact with the rod 5a. Also, the spring receiver 5
3 is fixed to the fixing plate 52.

Hereinafter, the operation of the device according to the second embodiment will be described. FIG. 18 is an operation diagram of the device shown in FIG. 17, showing a state where the packing box door is fully opened. FIG. 17 and FIG.
8, as the packing box door 30 is opened, the rod 5a strokes toward the coil spring 7 while rotating counterclockwise in FIG. As shown in FIG. 18, at the maximum opening of the packing box door 30, the rod 5a and the shaft 5b are substantially aligned, and can be regarded as an integral rigid body. As described above, the direction of the elastic force exerted by the coil spring 7 can be changed by connecting the rod 5a and the shaft 5b and further providing the means (roller 51) for guiding the rod 5a. The spring receiver 53 can be a non-rotating member.

Hereinafter, advantages of the flip-up device according to the first and second embodiments of the present invention will be described. (1) Since the turning radius of the flip-up device in the packing box is extremely small, opening and closing of the packing box door is facilitated without substantially reducing the packing box volume. In the opening stroke, a small operation force is applied to the packing box door to a certain opening degree, so that the packing box door is lifted by itself. On the contrary, in the closing stroke, the packing box door is closed by itself from a certain opening degree. (2) The spring force of the packing box door is obtained by the coil spring. Since the coil spring has a longer life than a gas damper used as a spring force generating mechanism in a conventional device, the device according to the present embodiment reduces the overall cost in consideration of maintenance. (3) The maximum opening of the packing box door is regulated by restricting the pivotal movement of the lever as the driving force transmitting member. Therefore, the cargo box door can be safely stopped as compared with the case where the rotation of the heavy cargo box door is restricted. Further, since the lever is located inside the flip-up device, the space occupied by the flip-up device does not increase by providing the packing box door maximum opening setting mechanism (stopper mechanism). (4) Since the entire lifting device accommodated in the packing box is mounted close to the inner wall of the packing box, the reduction in the volume of the packing box due to the attachment of the lifting device is very small.

In the second embodiment, the roller 51 is supported on the fixed plate 52 to guide the rod 5a. On the other hand, in another preferred embodiment, a pair of rods (FIG. 1)
7 (see FIG. 17), and a pin (see FIG. 17) that is inserted through one end of a shaft (see FIG. 17 shaft 5b) penetrating between the other ends of the pair of rods and rotatably connects the two. Rollers are supported at both ends of the pin 50). Then, a member fixed to the packing box side, for example, FIG.
Are provided as a pair, and rails for guiding these rollers are provided on their facing surfaces. Such embodiments also provide the above-described advantages.

In the embodiment described above, fixing means such as screws may be used in place of the bolts. A tension spring can be used instead of a compression spring. Further, the flip-up device of the present invention can be attached to any of a rear packing box door and a side door of a van type truck, and is applied to a vehicle other than the van type truck and other devices having a flip-up type door. Can also. Further, it may be attached to a door that opens in a vertical direction. The flip-up device of the present invention may be mounted on one side of the door or on both sides (preferably at both ends), depending on the weight of the door, one or more flip-ups at the door end or middle. A device may be attached.

The present invention is mainly applied to a truck or trailer-equipped cargo box door having a flip-type packing box door, but can be attached to another flip-type door. Note that the shape of the members, the form of receiving the pins that connect or pivot the members, and the like are not limited to the forms described above, and various forms can be adopted as long as the principles of the present invention are followed.

[0043]

According to the lifting device of the present invention, the lifting operation of the packing box is facilitated and a large packing box volume is secured. Since the moment for flipping or closing the packing box door is obtained from the elastic means (particularly, a coil spring), the durability of the apparatus is high. Further, by providing a mechanism for stopping a lever which is much smaller than the packing box door, the maximum opening of the packing box door is set safely, and the adjustment of the maximum opening is also facilitated.

[Brief description of the drawings]

FIG. 1 is a side view of a van-type truck flip-up device according to a first embodiment of the present invention.

FIG. 2 is a rear view of the apparatus of FIG. 1;

FIG. 3 is an operation diagram of the device shown in FIG. 1, showing a state in which a packing box door is fully opened.

FIG. 4 is a rear view of FIG. 3;

5 (A) to 5 (C) are operation views schematically showing the entire apparatus shown in FIG. 1; FIG. 5 (A) is a closed state of a packing box door, and FIG. 45 ° open, (C)
Indicates a state in which the packing box door is opened to the maximum.

FIG. 6 is a view as seen from an arrow indicated by an arrow F in FIG. 1, and is a view of the flip-up device as viewed from above.

FIG. 7 is a side view for explaining another mounting mode of the fixing plate.

8 is a cross-sectional view taken along the line AA in FIG. 1, and is a view of the stopper mechanism as viewed from above.

FIG. 9 is a cross-sectional view taken along the line BB in FIG. 1 and shows a connecting portion between the arm A and the arm B.

10 is a view of the arm A and the packing box door shown in FIG. 1 as viewed from above.

FIG. 11 is a side view of FIG. 10;

FIG. 12 is a cross-sectional view taken along a line CC in FIG. 1, showing a connecting portion between the lever and the shaft.

FIG. 13 is a cross-sectional view taken along the line DD in FIG. 1, showing a pivotal support portion of the lever.

FIG. 14 is a cross-sectional view taken along the line EE in FIG. 1, showing a pivot portion of the spring receiver and a receiving portion of the shaft.

FIG. 15 is an enlarged perspective view of the mounting plate shown in FIG. 6;

FIG. 16 is an enlarged perspective view showing the device cover shown in FIG. 1;

FIG. 17 is a side view of a van type truck flip-up device according to a second embodiment of the present invention.

FIG. 18 is an operation diagram of the device shown in FIG. 17, showing a state where the packing box door is fully opened.

FIG. 19 is an external view of a van type truck in which a packing box rear door is opened and closed.

FIG. 20 is an external view of a van type truck in which a packing box side door is opened and closed.

[Explanation of symbols]

1 Arm A 1a, 1b A pair of plate arms B 4 Lever 4a One end (first corner) 4b Middle part (second corner) 4c Other end (third corner) 4d Contact surface (contact plate) 4e, 4f A pair of plates 5 Shaft 5a Rod 5b Shaft 6 Spring seat 7 Coil spring 8 Spring receiver 8a, 8b Fork, 8c Sleeve 9 Fixing plate 9a, 9b Parallel plate 9c Packing box door side mounting plate, 9d Horizontal plate 10 Stopper mechanism 10d Stopper surface 11
Plate 11a, 11b Slot 12, 13 A pair of L-shaped plates 14a, 14b Bolt 15 Bracket mechanism 19, 20 Plate 21a, 21b, 21c, 21d Bolt 30 Packing box door 31, 32, 33, 34, 35 Pin 37 Hinge 38a, 38b, 39a, 39b Bolt 40 Mounting plate 41 Sealing member (H rubber) 42 Escape 43 Device cover 44 Lever mounting member 45 Nut 50 Pin 51 Roller 52 Fixed plate 53 Spring receiver 54 Mounting plate

Claims (4)

[Claims] 1. A packing box, a packing box door which is opened and closed by rotating about one side of the packing box, and an arm A, an arm B, a lever, and a shaft disposed inside the packing box door. And one end of the arm A is fixed to the inside of the packing box door, the other end of the arm A is connected to one end of the arm B, and the other end of the arm B is One end of a lever is connected, an intermediate portion of the lever is pivotally supported on the packing box side, one end of the shaft is connected to the other end of the lever, and the elastic means is connected to the other end of the shaft. The elastic means is elastically mounted between the other end of the shaft and a member pivotally supported on the packing box side, and the elastic means expands and contracts by a stroke of the shaft accompanying the opening and closing operation of the packing box door, and is attached to the packing box door. Characterized by generating an acting moment A van type truck equipped with a packing box flip-up device. 2. A packing box, a packing box door which is opened and closed by rotating about one side of the packing box, and an arm A, an arm B, a lever and a rod arranged inside the packing box door. , A shaft, and an elastic means, and a guide means for guiding the rod so as to be able to stroke and rotate when the packing box door is opened and closed is provided. One end of the arm A is fixed inside the packing box door. The other end of the arm A is connected to one end of the arm B; the other end of the arm B is connected to one end of the lever; an intermediate portion of the lever is pivotally supported on the packing box side; The other end of the rod is connected to one end of the rod, the other end of the rod is connected to one end of the shaft, and the elastic means is connected to the other end of the shaft and fixed to the other end of the shaft and the packing box. Is mounted between the member and A van type equipped with a box door flip-up device, wherein, when the box door is opened and closed, the rod makes a stroke while rotating, and the elastic means expands and contracts to generate a moment acting on the box box door. truck. 3. A stopper for regulating the maximum opening of the packing box door by contacting the lever and locking the lever at a predetermined rotation position of the lever. Item 3. The cargo box door flip-up device according to Item 1 or 2. 4. A packing member is provided between a side edge of the packing box door and an opening edge of the packing box, and a plate member for fixing the arm A to the packing box door is provided near the sealing member. The packing box according to any one of claims 1 to 4, wherein the mounting position of the arm A is closer to the inner wall of the packing box than the mounting center of the plate member along the horizontal direction. Door jumping device.