JP2997445B2 - Lifting device for the loading platform - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lifting device for lifting and lowering a loading table to carry in and out a load, and more particularly to a safe and reliable operation of the loading table and a receiving apparatus which follows front, rear, left and right inclined surfaces. The present invention relates to an elevating device for performing an operation of a table.

[0002]

2. Description of the Related Art As shown in FIGS. 1 and 2, a lifting device A is generally mounted at the rear of a vehicle B such as a lorry, and when not in use or while traveling, raises a load receiving table C to use the device. At times, the load receiving table C is moved up and down while maintaining the horizontal position, thereby facilitating the loading and unloading of the load.

[0003] Such a lifting device is as shown in Fig. 3 (for example, see Japanese Patent Application No. 8-272922).
The lifting device 1 includes a bracket 2 ′ supported by a chassis 2,
It is attached to a frame 3 fixed to 2 '. Elevating arms 5, 5 are fixed to both ends of a shaft 4 rotatably penetrating the frame 3 (support point a), and the other end of the arm is supported by a pin below the load receiving table 6 (support point b) (rotation point). (Attached freely) (shown by a broken line in FIG. 4). A bumper 7 is attached to this arm, and both arms are integrated.

[0004] As shown in FIG.
At one lower end of 2 ′, one end of a tilt cylinder 8 is supported by a pin (supporting point d), and the other end is supported by a pin below the receiving table 6 (supporting point c). As shown in FIG. 5, one end of the lifting cylinder 9 is pin-supported at the lower end of the other bracket 2 ', and the other end is pin-supported below the load receiving platform (support point b' (this point). The point is a point on the opposite side of the loading tray corresponding to the support point b)).

[0005] As shown in FIGS. 4 and 5, the loading table 6 is kept horizontal (at this time, the supporting points a, b, d and c form a parallelogram). As shown, when the tilt cylinder 8 expands and contracts, the receiving table 6 swings around the support point b (b '). When the lifting cylinder 9 is extended and contracted as shown in FIG. 5 while maintaining the parallelogram formed by the support points, the loading table is maintained horizontally and the topmost position (from the loading table to the vehicle). It moves up and down between the lowermost position (the position where the horizontal loading platform is in contact with the ground) and the lower position (the position where the load receiving platform is in contact with the ground).

When the tilting cylinder 8 is contracted as shown in FIG. 6 when the loading tray is grounded, the loading tray rotates around the support point b '(b) and tilts (the neck). Swing) and so on the ground, facilitating the transfer of luggage from or to the loading dock.

[0007]

In such an elevating device, the loading tray can be rocked and raised and lowered by two cylinders. However, since the cylinder is used instead of the arm, rigidity is required for the cylinder. .

[0008] In addition, there is a limit to the use of this type of device for connecting the support points by means of the cylinder due to the limitation of the extension of the cylinder.

Further, in order to raise and lower the loading tray by one cylinder, it is necessary to strengthen the connection between the arm and the loading tray, so that the clearance at each support point must be reduced, so that a smooth operation can be achieved. It may be difficult to do so. Connecting a pair of arms by a bumper to make them integral is also beneficial for smooth operation, but when the ground where the loading platform contacts the ground is inclined (left or right) with respect to the frame (such The surface is referred to as an “inclined contact surface”), and the arm, cylinder, and the cradle are rigidly connected. Therefore, it is difficult to make the cradle follow the inclined contact surface.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a lifting and lowering device for a loading tray having a mechanism for ensuring that each support point forms a parallelogram during lifting and lowering of the loading tray. To provide.

It is another object of the present invention to provide a lifting and lowering device for a loading tray which can lift and lower and tilt the loading tray with one kind of cylinder.

It is a further object of the present invention to provide a lifting device for a loading tray that starts swinging the loading tray when the loading tray is completely grounded.

Still another object of the present invention is to provide an apparatus for lifting and lowering a loading tray which can follow a grounding surface inclined forward, backward, left and right.

Still another object of the present invention is to provide a lifting device for a loading tray which can follow the inclined loading surface even when the arm is integrated with a bumper or a member. is there.

It is a further object of the present invention to provide a lifting device for a load receiving pallet in which the load on a lifting cylinder for raising and lowering the load receiving pallet is reduced and the mechanism is compact.

[0016]

Means for Solving the Problems] receiving platform of the lifting device attached to a vehicle of the present invention to achieve the above object, is attached to the chassis of the vehicle, a pair of first play that facing
And each of the first and second plates and facing
Then, a pair of second plates attached to the chassis, and each of the second plates is rotatably supported by a lever support pin facing each of the second plates , but rotation is limited by a stopper portion. A pair of levers, one end of each of which is supported by a first pin on each of the first plates, and the other end of which is connected to a link capable of supporting the loading platform by a second pin which supports the link to the loading platform. A pair of first arms supported by pins, one end of each arm supported by a third pin on each link, and the other end supported by a fourth pin on each lever, below the first arm A pair of second arms located at a position, one end of which is pin-supported by the second arm and the other end of which is pin-supported by a lever. To rotate the second arm And the cylinder, and a.

Here, the receiving table can swing and tilt about the second pin.

When the lever is in contact with the stopper, the first, second, third and fourth pins form a parallelogram, and the position of the lever support pin is determined by the lever being moved by the stopper. And when the receiving platform is at the bottom,
The position of the fourth pin is determined to be located on a first straight line passing through the lever support pin and the third pin.

From the above, the lever comes into contact with the stopper portion while the loading tray moves up and down from the uppermost position to the lowermost position by the rotation of the second arm about the fourth pin due to the expansion and contraction of the double-acting cylinder. The first, second, third and fourth pins form a parallelogram, and the links abut the loading cradle to support the loading cradle horizontally. Therefore, during the elevating, the parallelogram is not collapsed, and the loading cradle is reliably kept horizontal. When the lever is rotated by contraction of the double-acting cylinder so that the position of the fourth pin is located above the first straight line when the carrier is at the lowest position, the weight of the carrier and the load on it The lever rotates further, so
The receiving platform can be inclined along a ground surface having a step in front, rear, left and right.

The other lifting device of the loading tray mounted on the vehicle according to the present invention has one end on each of a set of second plates mounted on the chassis of the vehicle instead of the set of levers in the above device. A pair of levers that are pin-supported by a lever support pin but whose rotation is restricted by a stopper, and a lever whose one end is pin-supported by a connecting pin at the other end of the lever but whose rotation is restricted by the stopper And a unit.

Here, the other end of each of the pair of second arms is supported by a fourth pin on each of the other ends of the lever. One end of the double-acting cylinder is pin-supported by the second arm by a first cylinder support pin, and the other end is pin-supported by a lever portion by a second cylinder support pin.

When the lever and the lever portion come into contact with the stopper portion and the load receiving table is located at the lowest position, the position of the lever support pin is determined by the position of the fourth pin passing through the lever support pin and the third pin. Is determined to be located on or near the straight line of.

The position of the connection pin is determined such that the second cylinder support pin is located on or near a second straight line passing through the connection pin and the first cylinder support pin.

As described above, the lever and the lever portion are in contact with the stopper portion while the loading tray is moved up and down from the uppermost position to the lowermost position by the rotation of the second arm about the fourth pin due to the expansion and contraction of the double-acting cylinder. The abutment, the first, second, third and fourth pins form a parallelogram, and the link abuts the cradle to support the cradle horizontally. When the lever is rotated through the lever by contraction of the double-acting cylinder so that the position of the fourth pin is located above the first straight line when the loading tray is at the lowest position, The lever is further rotated, so that the carrier can be tilted along a stepped front-to-left and right-to-left surface.

The second arms may be connected by bumpers or members, and the first plate and the second plate may be the same or separate.

A double acting cylinder may be mounted on each of the second arms.

Further, the link may be composed of two members whose one ends are supported by pins. In this case, the other end of one member of the link is supported by the load receiving pedestal by the second pin, and the other end of the other member is supported by one end of the second arm by the third pin. A stopper is provided to limit the relative rotation of the members so that the first, second, third and fourth pins form a parallelogram when the lever abuts the stopper.

[0028]

FIG. 7 is a side view showing a state in which the loading / unloading device 10 of the present invention is attached to the lower rear end of the chassis 13 of the truck B, and the loading tray C is horizontal. Since the truck B carries in and out the cargo from the back of the carton, the lifting device 10 is provided at the rear of the car. However, in the case of a car that carries in and out the cargo from the side of the carton, , Can be mounted on the side of the vehicle.

As will be described below, the lifting device 10 raises the receiving table C when not in use (see FIG. 2), and keeps the receiving table C horizontal when in use, and the uppermost and lowermost positions. Raise and lower between. When the receiving table C comes into contact with the ground, a platform having a predetermined height, or the like, the receiving table C is inclined along the ground surface.

The lifting device 10 is fixed to the chassis 13 via frames 12 attached to a set of plates 11, respectively. The loading table C mounted on the lifting device is shown in FIG.
As shown in FIG. 3, a pair of triangular reinforcing members 14 are attached in a vertical direction, and
Are preferably provided in the lateral direction. Thereby, the receiving table is made rigid by these reinforcing members. Further, the mounting plate 14 "is attached to the receiving table C so as to be aligned with the reinforcing member 14.
A substantially triangular link 16 is pin-supported (rotatably supported) by a second pin 19 on a receiving plate 14 "(a plate on the near side is omitted in FIG. 7). The side surface of the ring 16 can contact the side surface of the reinforcing member 14 '.

A pair of inner (first) mounting plates 17 are fixed to the frame 12, and one end of a pair of first arms 18 is supported by the first pins 15 on the plates 17 (a rotatable support). ) Has been. The other end of each first arm 18 is pin supported by a link 16 by a second pin 19.

A substantially triangular lever 20 is pin-supported by a lever support pin 21 between an outer (second) mounting plate 17 ′ (a front side is omitted in FIG. 7) outside the mounting plate 17. . Therefore, this lever 20 is
, But the rotation is restricted by a stopper 12 ′ provided on the frame 12. As described below, when the loading table C moves up and down between the uppermost position and the lowermost position, the lever 20 comes into contact with the stopper portion 12 '.

One end of each of a pair of second arms 22 located below the first arm 18 is supported by a third pin 23 on each link 16. The other end of each of the arms 22 is supported by the lever 20 by a fourth pin 24.

When the lever 20 is in contact with the stopper portion 12 ', the first pin 15, the second pin 19, the third pin 23, and the fourth pin 24 form a parallelogram, and Link 16
The position of each pin is determined so that abuts against the side wall of the reinforcing member 14 'of the loading tray C and supports the loading tray C horizontally.

Below the second arm 22, an elevating cylinder 25 is provided, one end of which is supported by a first cylinder support pin 25a and the other end of which is supported by a lever 20 by a second cylinder support pin 25b. ing. This cylinder
Numeral 25 is for rotating the second arm 22 about the fourth pin 24 mainly by its expansion and contraction (that is, by the extension force of the cylinder), and raising and lowering the loading tray C.

A bumper 26 is further attached to the second arm 22, and the two second arms 22 are integrated. The bumper 26 protects the vehicle and also prevents a small vehicle or the like from sneaking into the vehicle from behind, and is not an essential component of the lifting device of the present invention.

Since the bumper integrates the arm (the same applies to the member that integrates the arm), the load receiving table is made to follow the inclined ground plane (left and right) with respect to the frame (this is referred to as the inclined ground plane). Although it was considered to be incompatible with the mechanism, in the lifting device of the present invention, even if the bumper (or member) was fixed to the arm, as described below, the loading tray was moved to the inclined ground surface. Can follow.

As described above, the loading tray C is required to be upright when not in use or when traveling. For this purpose, the tilting cylinder 14a is housed in the reinforcing member 14, and its tip is connected to the loading tray C. The pin is supported on the lower surface of the
Pin supported. Therefore, as shown in FIG. 7 (A), when the cylinder 14a is extended, the load receiving table C rotates about the second pin 19 and can stand up.

As described above, each pin (15, 19, 23, 2
The position of 4) is determined so as to form a parallelogram, but in order to maintain the parallelogram, the lever 20 must be in contact with the stopper 12 '. When in contact,
The second arm 22 is extended by extension of the lifting cylinder 25,
While maintaining the parallelogram formed by each pin, the pin rotates around the fourth pin 24, and the loading table is raised and lowered while being horizontal.

As shown in FIG. 7, the receiving table C is
Due to its own weight (and the weight of the luggage placed on it), it tries to rotate around the second pin 19, and its rotational force becomes a rotational moment acting on the position of the fourth pin 24,
An attempt is made to rotate the lever 20 about the lever support pin 21. Therefore, the position of the fourth pin is below the straight line passing through the lever support pin 21 and the third pin 23,
When the position of the lever support pin 21 is determined, the above rotational moment pushes the lever 20 against the stopper portion 12 'so as to come into contact therewith. Therefore, by determining the position of the lever support pin 21 as described above, the parallelogram formed by each pin is maintained, and the load receiving table C horizontally supported by the link 16 can be moved up and down.

On the other hand, when the receiving table C comes into contact with the ground or the like (at the lowest position), as shown in FIG.
In order to facilitate the movement of the load, it is necessary to break the parallelogram, which keeps the loading tray C horizontal, and to tilt the loading tray C so that it is on the ground. This means that the parallelogram has only to be maintained when the loading tray is moved up and down from the highest position to the lowest position.

From the above, as shown in FIG. 9, when the receiving table C is located at the lowest position, the position of the fourth pin 24 is the same as the position of the lever supporting pin 21 and the third position of the lever supporting pin 21 as shown in FIG. Is determined so as to be on a straight line passing through the pin 23.

As described above, when the position of the lever support pin 21 is determined, the lever 20 comes into contact with the stopper 12 ', and when the elevating cylinder 25 is extended and contracted (that is, by supplying or discharging oil to the cylinder), The loading platform moves up and down while being kept horizontal.

As shown in FIG. 9, the receiving table C is
When it comes into contact with the ground, the lever support pin 21 and the fourth pin 2
4. The third pin 23 is in a straight line. Therefore, the rotation force about the second pin 19 of the receiving platform is
In the axial direction of the second arm 22 is not a force for rotating the second arm 22 around the fourth pin 24 (therefore, no force is generated in the lifting cylinder 25 to contract it),
In addition, it does not provide a force for rotating the lever 20 about the lever support pin 21. Even at this position, the loading table C held horizontally by the link 16 remains horizontally.

As shown in FIG. 10, the lift cylinder 25 is further contracted (when the cylinder 25 has a receiving platform at the lowest position, no contraction force acts on the lift cylinder. For further contraction, this cylinder must be a double-acting cylinder (a cylinder that supplies oil to the opposite side (extension side) of the internal piston to perform further contraction), and the lever 20 is a lever support pin.
Rotate around 21 (counterclockwise in the figure) so that the position of the fourth pin 24 is located on the first straight line passing through the lever support pin 21 and the second pin 23 .

At this time, the above-mentioned rotational force acting on the position of the fourth pin 24 and rotating about the second pin 19 of the load receiving table C moves the lever 20 away from the stopper portion 12 '. Rotate as shown. Therefore, the cylinder 22 receives the contraction force again. Thus, when the cylinder 22 is caused to contract (ie, by draining the oil so that it contracts), the lever 20 rotates and the fourth pin
The position 24 also rotates around the lever support pin 21. At the same time, the second arm 22 rotates the link 16 around the second pin 19 (clockwise in the figure), and the position of the third pin 23 moves backward (left side in the figure) (FIG. 10).
(A)). As a result, the parallelogram collapses, and the receiving table C is no longer supported horizontally, and rotates about the second pin 19 and tilts (swings) along the ground contact surface.

As described above, since the double-acting cylinder is activated after the loading tray C has touched the ground, the tilting (swinging) of the loading tray starts after the landing, and the double-acting cylinder contracts further. As a result, the lever rotates and the load receiving table tilts, so that the safety of carrying the load is maintained.

If the position of the fourth pin is positioned on the above-mentioned straight line before the receiving table is positioned at the lowest position (for example, when the load to be loaded on the vehicle is light, the position of the fourth lowest pin is actually lower). (The position may decrease.) As described above, since the tilting operation starts from that point, the tilting operation is caused by the grounding of the loading tray. It is desirable to determine the position of the lever support pin so that the position of the pin is slightly below the above-mentioned straight line (this is referred to as near the lower side).

The lifting of the receiving table can be achieved by performing the above operation in reverse. That is, when the lifting cylinder is extended, the lever 20 rotates about the lever support pin 21 and
While being in contact with the stopper portion 12 ', the second arm 22 is pushed out, the link 16 is rotated about the second pin 19, and the link 16 is brought into contact with the side wall of the reinforcing member 14' of the loading tray C, and the loading tray C is leveled. Move to Then, when each pin forms a parallelogram, when the elevating cylinder is further extended, the loading tray C rises from the lowest position to the highest position while being kept horizontal.

The above operation has been described with respect to the case where the bottom is set when the receiving platform is in contact with the ground surface such as the ground, and the lifting and lowering and tilting (swinging) of the receiving platform between the highest level and the lowest level. However, even if the cradle touches the ground at a predetermined height (when the cradle is at a position higher than the lowest position, the cradle is naturally kept horizontal because the parallelogram is maintained), A tilt operation can be performed.

As shown in FIG. 9 (A), it is assumed that the receiving platform is in contact with a platform having a predetermined height. At this time, when the lifting cylinder 25 (in this figure, the cylinder is shown by a broken line so as not to complicate the figure) is contracted, the lever 20 tries to rotate about the lever support pin 21. However, as described above, in this position, the position of the fourth pin 24 is located below the first straight line passing through the lever support pin 21 and the third pin 23, so that the rotation of the lever 20 causes As shown in FIG. 10, in order to position the fourth pin 24 on the straight line, the second arm must be pushed out. At this time, since the link 16 rotates around the second pin 19 (counterclockwise in the figure), the load receiving platform once rotates upward.

Further, when the lever 20 rotates, the position of the fourth pin 24 is located above a straight line passing through the lever support pin 21 and the third pin 23. At this time, as in FIG. 10, the lever rotates due to the weight of the loading tray or the like, the parallelogram formed by each pin collapses, and the second arm 22 rotates the link 16 clockwise about the second pin 19. And the receiving platform can be tilted.

In this embodiment, since the second arm is integrally connected by a bumper, if the lifting cylinder is connected to either one of the second arms, the above-described lifting operation and tilting operation can be performed. It can be performed.
However, it is desirable to connect a lifting cylinder to each of the second arms for smooth operation.

The description so far has been about the case where the ground contact surface is parallel to the frame. However, when the ground contact surface is inclined left and right with respect to the frame, loading and unloading of luggage may be performed. is there. In such a case, the inclination of the loading tray following the inclined contact surface can improve the smooth loading of cargo,
Necessary for unloading. On the other hand, if a bumper is provided on the arm, it is considered that it is difficult for the arm to be integrated and to make the receiving table follow the inclined contact surface.

However, the apparatus of the present invention having the above-described configuration
Even if the second arms are connected by a bumper,
The loading cradle can follow such an inclined contact surface. This will be described with reference to FIG.

As shown in FIG. 11A, it is assumed that the ground contact surface is inclined left and right with respect to the frame 12.

The lift cylinders 25, 25 'are contracted with respect to such a ground contact surface (the contraction force acts on the cylinders, so that the cylinder is contracted by discharging the oil). Even if the link is lowered and touched, the link on one side (in this example, the link on the left (FIG. 11B)
) Is grounded, but the opposite link (see FIG. 11 (C) (elements corresponding to those shown in FIG. 11 (B) are denoted by the same reference numerals with “′”)) is in a floating state. It is in.

Subsequently, when the lifting / lowering cylinders 25, 25 'are contracted (in this case, no compression force acts on the cylinders, oil is supplied to the opposite side (contraction side) of the internal piston to further contract. ), The levers 20, 20 'rotate as described above, and the position of the fourth pins 24, 24'
It is located on a first straight line passing through the lever support pins 21, 21 'and the third pins 23, 23'. then,
As described in the tilting (swinging) operation, the force acting on the fourth pins 24, 24 'tends to further rotate the levers 20, 20', and the contracting force acts on the lifting cylinder 25. Therefore, by discharging the oil so that the lifting cylinder contracts, the levers 20, 20 'rotate, and the second arms 22, 22' rotate the links 16, 16 '.

The rotation of the links 16 and 16 'causes the loading table C to tilt (swing), but does not touch the floating side of the loading table even if the swing is performed. 'Further attempts to rotate about the second pin 19, with the result that a retracting force still acts on the lifting cylinder 25'.

When the second arms are not connected and are independent of each other, if the ascending / descending cylinder 25 'on which the compressive force is applied continues to be contracted, the link rotates and the first arm and the second arm are rotated. Arm also inclines, so that the floating side of the load receiving table C also inclines following the inclined (right and left) contact surface.

In this embodiment, the second arms are connected to each other by a bumper (or a member), and it seems that it is difficult to perform the above-mentioned inclination integrally. Since the clearance is provided for smooth operation and easy installation, if the oil of the lifting cylinder 25 ′ is continuously drained, the lever 20 ′ rotates and the second arm 22 ′ is connected to the link 16. 'Rotate.

At this time, since the arms 22, 22 'are connected to each other by the bumper, the height of the third pins 23, 23' hardly changes, but the link 1 on the floating side as described above.
6 'rotates and the second pin 19' on the floating side is the second pin 1
It will be lower than 9 position.

Thus, the second pin 19 on the non-floating side
Although the height of the second pin 19 'on the floating side changes little due to the further rotation of the link 16',
Lowering, the cradle inclines following the inclined ground surface, and the tip of the cradle can also contact the ground surface inclined left and right.

Even if the inclination of the ground contact surface (inclination with respect to the frame) is various, it is desirable that the receiving table follows the inclination. FIG. 12 further shows a configuration that allows such tracking.

In this embodiment, the links 16 are two links 16
a and 16b, which are pin supported. The tip of the link 16a is pin-supported by the second pin 19 on the mounting plate 14 ", and the tip of the link 16b is pin-supported by the third pin 23 on the second arm 22. A stopper 16a 'is provided to prevent the links from rotating relative to each other while C moves up and down between the highest and lowest positions.

With this two-link configuration, when the loading table is grounded and the lifting cylinder 25 contracts, not only does the lever rotate as described above, but also the link rotates.
16b also rotates about the point where the links support the pins.
Therefore, as shown in FIG. 12A, the distance between the second pin 19 and the fourth pin 23 is different from one link (in this case, the distance between the pins does not change). , Become shorter. Therefore, when such two links are provided, the position 19 of the second pin can be further lowered, and FIG.
It is possible to follow the inclined surface of the receiving table more than described in 1.

In the embodiment described, the lifting cylinder expands and contracts to rotate the second arm in order to raise and lower the loading table, but such rotation involves the connection between the cylinder and the second arm. The corners should be as large as possible. Such an angle can be increased by forming the lever into a U-shape, but the overall shape of the lever becomes large and is not suitable for mounting on the lower part of a vehicle. Therefore, it is desirable that the lever is as small as possible and that the angle between the second arm and the cylinder can be increased.

Such a lever will be described with reference to FIG. 13 (FIG. 13A shows a cylinder, FIG. 13B shows a first arm and a cylinder, and FIG. 13C shows a first arm and a cylinder). , For clarity of illustration).

Since the embodiment of FIG. 13 and the embodiment of FIG. 7 differ only in the lever, the lever will be described. The lever 20 includes a substantially triangular lever 20a and a lever portion 20b supported by a pin. The top of the lever 20a is pin-supported by a lever support pin 21 between the plates 17 '. The other end of the second arm 22 is pin-supported by a fourth pin 24 at the other top of the lever 20a. Further, one end of the lever portion 20b is pin-supported on the other top of the lever 20a by a connection pin 20c, and the other end of the lever portion 20b is pin-supported on the other end of the lifting / lowering cylinder 25 by a cylinder support pin 25b.

The position of the lever support pin 21 is changed to the fourth pin 24 when the receiving table C comes to the lowest position as in the embodiment of FIG.
Is determined to be on a first straight line passing through the lever support pin 21 and the third pin 23. At this time, the lever 20a comes into contact with the recess formed in the frame 12 (therefore, it functions as a stopper), and the first, second, and
The third and fourth pins form a parallelogram.

At this time, the lever portion 20b is also brought into contact with the concave portion formed in the frame 12 (therefore, this also functions as a stopper). However, the position of the connecting pin 20c that supports the two levers is the second position. Cylinder support pin 2
5b is determined to be below a straight line passing through the connecting pin 20c and the first cylinder support pin 25a. In order to support the lever whose pin position is determined in this way,
The shape of the recess formed in the frame 12 is determined. If two levers can be supported, it is not necessary to form a recess in the frame, and a stopper having a recess may be provided on the frame.

In order to allow the second arm to rotate smoothly by extending the lifting cylinder, the tip of the lever portion should be separated from the second arm as far as possible in response to the demand for compactness. It is desirable to do.

It is desirable that the position of the first cylinder support pin 25a be as close to the second arm as possible. In the embodiment of FIG. 13, the second arm 22 has a U-shaped cross section, and the first cylinder support pin is located therein.

In this embodiment, FIG.
As shown in (B) and (C), the lifting of the receiving platform
This is performed by the expansion and contraction of the lifting cylinder 25. When the cradle is tilted, the lifting cylinder is further contracted when the cradle is in contact with the ground and at the lowest position. At this time, since the lever portion 20b rotates the lever 20a around the lever support pin 21 (counterclockwise in the figure),
The fourth pin 24 is located above the first straight line passing through the lever support pin 21 and the third pin. In this case, unlike the above-described embodiment, at the second cylinder support pin 25b,
Since it bends, substantially no compressive force acts on the cylinder. Lever 20a due to the weight of the loading platform
Rotates, and the link 16 rotates about the second pin 19 (clockwise in the figure). As a result, the receiving table is inclined along the ground contact surface (FIG. 14A).

Also in this embodiment, the receiving table can follow the inclined (left and right) contact surface. Also, as in FIG. 12, by providing two links (16a, 16b) (FIG. 14B), it is possible to further follow the inclined ground surface.

[0076]

According to the present invention, the components (the positions of the respective pins) form a parallelogram during the raising and lowering of the loading tray, and therefore, the loading tray reliably supports the horizontal. Then, the loading tray descends due to the contraction of the lifting cylinder, and when it touches down, the lifting cylinder further contracts, so that the loading tray tilts along the ground contact surface. The same applies to the ascending from the inclination). In addition, since the loading table is tilted after being grounded, work safety is ensured.

Further, since the loading tray can be raised and lowered and tilted (swinged) by one kind of the lifting cylinder, the structure and the control can be simplified.

Furthermore, even when the ground contact surface is inclined forward, backward, left and right, the position of the pin supporting the load receiving table is lowered only by contracting the cylinder, and the load receiving table can follow the inclined contact surface. This means that in the apparatus of the present invention, even if the arms supporting the receiving table are connected and integrated by a bumper or the like, the receiving table can follow the inclined ground surface.

Further, with the two links incorporated in the present invention, the loading tray can be made to follow the inclined contact surface even more.

Further, with the two levers incorporated in the present invention, the device can be made more compact and the guesswork of the cylinder can be made smaller.

[Brief description of the drawings]

FIG. 1 is a side view of a vehicle having a prior art loading / unloading platform lifting device mounted rearward.

FIG. 2 is a rear view of a vehicle in which a prior art loading / unloading device is mounted at the rear.

FIG. 3 is a perspective view of a prior-art lifting and lowering device for a loading tray.

FIG. 4 shows a side view of a swinging state of a loading tray in a prior art lifting device.

FIG. 5 shows a side view of the lifting device of the prior art in a state where the receiving table is raised and lowered.

FIG. 6 shows a side view of a prior art lifting device in a state in which the loading tray is tilted (swinged).

FIG. 7 is a side view of the lifting / lowering device of the loading tray according to the present invention attached to a vehicle, and FIG. 7 (A) is a partial side view of the raised loading tray.

FIG. 8 is a rear view of the lifting / lowering device of the loading tray of the present invention mounted on a vehicle.

FIG. 9 is a side view of the lifting and lowering device of the loading tray according to the present invention in a state where the device is lifted and grounded.

FIG. 10 shows the inclination (swinging) of the lifting / lowering device of the receiving table of the present invention.
FIG. 10A is a partial side view of the state, and FIG. 10A is an enlarged view of a link of the loading tray.

FIG. 11A is a schematic view of an arm in a state in which a receiving platform follows an inclined (left-right) ground contact surface;
FIG. 11B is a partial left side view of the lifting device in a state where the loading tray follows the inclined ground surface, and FIG. 11C is a partial right side view of the lifting device in a state where the loading tray follows the inclined ground surface. FIG.

FIG. 12 is a partial side view of the lifting / lowering device of the loading tray according to the present invention in which another link configuration is adopted and the loading tray is inclined;
FIG. 2 (A) is a partially enlarged view of the link of the loading tray of FIG. 12.

FIG. 13 shows the lifting and lowering of the loading tray in the lifting device of the loading tray of the present invention employing another lever configuration.

14 (A) is a partial side view of the lifting device when the loading tray of FIG. 13 is inclined, and FIG. 14 (B) is the loading tray of the present invention of FIG. 13 using the link of FIG. 12; FIG. 5 is a partial side view of a platform elevating device.

[Explanation of symbols]

 15 First pin 19 Second pin 20 Lever 21 Lever support pin 22 Second arm 23 Third pin 24 Fourth pin 25 Elevating (double acting) cylinder

Claims (9)

(57) [Claims] 1. A lifting device for a load carrier mounted on a vehicle, comprising: a set of facing first plates mounted on a chassis of the vehicle ; and a first plate adjacent to each of the first plates.
And face-to-face, and a pair of second plate attached to the chassis, said second plate is rotatably pin supported by face-to-face and lever support pin each, said chassis
A pair of levers whose rotation is limited by stoppers attached to the first and second plates, each end of which is pin-supported by a first pin on each of the first plates, and the other end of each of which is a link capable of supporting a loading table ;
A pair of first arms that are pin-supported by a second pin that pin supports the link to the loading tray; one end of each link is pin-supported by a third pin on each link; A pair of second arms located below the first arm, each pin being supported by a fourth pin on each lever, and one end being pin supported by the second arm on the first cylinder support pin; A double-acting cylinder, the other end of which is pin-supported by the lever by a second cylinder support pin, and which is located below the second arm and rotates the second arm by expansion and contraction of the double-acting cylinder. The loading table can swing and tilt about the second pin, and when the lever is in contact with the stopper, the first, second, third, and second pins can be moved. Four pins are parallelograms The position of the lever support pin is such that when the lever comes into contact with the stopper portion and the load receiving table is located at the lowest position, the position of the fourth pin is the position of the lever support pin and the third pin. The lifting / lowering device for a loading tray, which is determined to be located on or near a first straight line passing therethrough. 2. The lifting device for a loading tray according to claim 1, wherein there are two double-acting cylinders, each of which is pin-supported by each of said second arms and each of said levers. The lifting device for the receiving platform. 3. A lifting device for a loading cradle mounted on a vehicle, comprising: a set of facing first plates mounted on a chassis of the vehicle ; and a plurality of first plates adjacent to each of the first plates.
And face-to-face, and a pair of second plate attached to the chassis, said second plate is rotatably pin supported by face-to-face and lever support pin each, said chassis
A pair of levers whose rotation is restricted by a stopper attached to the lever, one end of which is pin-supported by a connecting pin at the other end of the lever, and a lever whose rotation is restricted by the stopper; There is a pin supported by the first pin to the first plate, each link each other end, for supporting the receiving platform, its
With a second pin that pin supports the link to the carrier,
A pair of first arms that are pin-supported, each end of which is pin-supported by each link by a third pin, and each other end of which is pin-supported by a fourth pin to the other end of the lever; A pair of second arms located below one arm, one end of which is pin-supported by the second arm by a first cylinder support pin, and the other end of which is provided by a second cylinder support pin to the lever portion. And a double-acting cylinder positioned below the second arm supported by a pin and rotating the second arm by expansion and contraction of the double-acting cylinder. swings around, tiltable, when said lever and said lever portion is in contact with the stopper portion, the first, the second, form the third and the fourth pin is parallelogram and, the lever and the Les When the loading portion is in contact with the stopper portion and the loading tray is positioned at the lowest position, the position of the lever support pin is determined by the position of the fourth pin passing through the lever support pin and the third pin. A lifting device for a receiving platform, which is determined to be located on or near a straight line. 4. The lift device according to claim 3, wherein the position of the connection pin is such that the second cylinder support pin passes through the connection pin and the first cylinder support pin. A lifting device for a loading tray, wherein the lifting device is determined to be located on or below a second straight line. 5. The lifting device for a loading tray according to claim 3, wherein the lever has two levers, one end of each of which is pin-supported by each of the levers by a connecting pin, and wherein the double-acting cylinder has two levers. One end of each of the double-acting cylinders is pin-supported by each of the second arms by a first cylinder support pin, and the other end of each of the double-acting cylinders is connected to the other end of each of the lever portions by a second cylinder. A lifting device for a loading tray, which is supported by a support pin. 6. The lifting / lowering device according to claim 1, further comprising a bumper or a member for connecting the second arms to each other. 7. The lifting device for a loading tray according to claim 1, wherein the first plate and the second plate are the same. 8. The lifting / lowering device for a loading tray according to claim 1, wherein one end of the loading tray is pin-supported by the loading tray, and the other end is pin-supported by the link. A swinging cylinder for swinging the swinging cylinder about the loading tray support pin by expansion and contraction of the swinging cylinder. 9. The lifting device for a loading tray according to claim 1, wherein said link is composed of two members each having one end supported by a pin, and the other end of said member being connected to said second member. The other end of the other member is supported by one end of the second arm by the third pin, and the link is further supported by the lever when the lever comes into contact with the stopper. A lifting device for a loading tray, comprising a stopper for restricting relative rotation between said members so that said first, second, third and fourth pins form a parallelogram.