JPH1159255A - Loading and unloading device provided on deck of truck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use one thrust force of right and left tilting cylinder mechanisms to turn a platform 1 and to use both thrust forces to operate the platform 1 in the horizontal state loaded with load because the large thrust force is required. SOLUTION: This device is provided with a lift arm 4 and a lift cylinder mechanism 6 for lifting the lift arm 4 between a vehicle body and each of right and left sides of a platform 1. On either side of the platform 1, a tilting cylinder mechanism is provided comprising a short cylinder 9, a rod 10 extending from the short cylinder 9, and an empty cylinder 11 fitted which the rod 10. The other side of the platform 1 uses a tilting cylinder mechanism having a long stroke. The tilting cylinder mechanism is operated to set the platform 1 in a vertical retracted position (b). At this time the short cylinder 9 side follows it. Both thrust forces are used to lift the platform 1 in the horizontal states (a), (c).

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 side or rear of a carrier such as a van-type truck.

[0002]

2. Description of the Related Art FIG. 4 is a perspective view of a van type vehicle equipped with a lifting device for loading and unloading, as viewed from the rear. FIG.
FIG. 2 is a perspective view showing a conventional elevating device. Reference numeral 1 denotes a platform for loading cargo. Reference numeral 2 denotes a chassis mounting bracket provided symmetrically. The mounting portion of the chassis mounting bracket 2 is used by being mounted on two main frames of a vehicle chassis. The bearing portions 3 are arranged so as to bridge the two brackets 2 for mounting the chassis, and one bracket 7 and two brackets 8 are mounted on both ends of the bearing portion 3 symmetrically. The lift arm 4 that supports the platform 1, the tilt cylinder mechanism 5, and the base end of the lift cylinder mechanism 6 are attached to the bearing 3 via brackets 7 and 8, respectively. A stabilizer 20 for synchronizing the operations of both lift arms 4 is attached between the ends of both lift arms 4.

The operation mechanism of the lifting device will be described with reference to FIG. The base end of the lift arm 4 is attached to the bracket 8 with a pin B. An enlarged portion is provided at a distal end of the lift arm 4, and an upper portion of the enlarged portion is attached to a base upper portion of the platform 1 with a pin A. The proximal end of the tilt cylinder mechanism 5 is attached to the bracket 7 with a pin C, and the distal end of the rod of the tilt cylinder mechanism 5 is attached to the lower portion of the base end of the platform 1 with a pin D. Lift cylinder mechanism 6
Is attached to the lower portion of the bracket 8 with a pin E, and the tip of the rod of the lift cylinder mechanism 6 is attached to the lower portion of the enlarged portion at the tip of the lift arm 4 with a pin F. With this configuration, a parallelogram link mechanism that connects the pins A, B, C, and D is formed, and the platform 1 can be moved up and down while maintaining a horizontal state by the link mechanism.

FIG. 6A shows a state in which the rod of the lift cylinder mechanism 6 is extended, and the parallelogram link mechanism raises the platform 1 to the upper limit position.
The platform 1 is flush with the loading platform, so that it will not rise any further. FIG. 6B shows a state in which the rod of the lift cylinder mechanism 6 is retracted. The parallelogram link mechanism lowers the platform 1 to the lower limit position, and the platform 1 abuts the base end on the ground.

The platform 1 can perform an opening / closing operation and a tilting operation in addition to the lifting / lowering operation. Based on FIGS. 7 and 8, two operating mechanisms of opening / closing and tilting will be described. In addition, in order to make it easy to understand, members and structures are schematically illustrated in each drawing. FIG. 8A shows a state where the empty platform 1 is stored. The rod of the tilt cylinder mechanism 5 is extended, and the platform 1 is rotated from the horizontal position in the vertical direction facing the rear section opening and stored. The operation of turning from the horizontal position to the vertical position or from the vertical position to the horizontal position is referred to as opening and closing operation. FIG.
(B) shows a tilting movement in which the platform 1 is leveled and the tip side is moved up and down for loading and unloading of the cargo with the platform 1 side. FIG. 8C shows an operation of lowering the platform 1 in a horizontal state to bring the base end into contact with the ground, and then tilting the tip, that is, tilting down, to eliminate a step with the ground. After removing the steps, unload the cargo.

As is clear from FIGS. 7 and 8, the operation stroke of the tilt cylinder mechanism 5 is short in the tilting operation and extremely long in the opening and closing operation. Further, since there is no cargo on the platform 1 at the time of opening / closing operation, only the driving force of its own weight is sufficient as the thrust of the tilt cylinder mechanism 5. When performing the tilting movement, a large thrust corresponding to the nominal loading capacity is required.

[0007]

If an attempt is made to drive such an operation in which the stroke and the thrust are significantly different from each other by using a cylinder having the same diameter, not only an excessive thrust occurs at the time of opening and closing, but also a large amount of tank oil is required. As a result, there is a problem that the installation space and cost of the power unit device are wasted. Conversely, if the thrust is suitable for opening and closing operation,
The tilting operation results in insufficient thrust. Conventionally, in order to solve this problem, the use of a cylinder having a different diameter or a differential cylinder has been devised. However, each of these methods has a problem that the cost of the cylinder is high, the structure is complicated for control, and maintenance is not easy.

An object of the present invention is to provide a lifting device capable of operating an opening / closing operation and a tilting operation with a cylinder thrust and an operating speed suitable for each operation.

[0009]

In the lifting device according to the present invention, the conventional tilt cylinder mechanism 5 is used on one of the left and right sides of the platform 1 and the short cylinder 9 is used on the other side. The amount of oil required for this is almost halved. Therefore, assuming that the pressure receiving areas of the left and right cylinders are constant, the speed of the platform 1 remains unchanged in the stroke of the short cylinder 9, that is, in the range of the tilting operation, but exceeds the range of the tilting operation when performing the opening and closing operation. And the hydraulic pressure acts only on one of the tilt cylinders, so that the speed of the platform 1 is accelerated. By such an operation, the operation time of the stroke can be shortened in the opening / closing operation, and the speed can be reduced in the range of the tilting operation requiring the position adjustment. Further, when performing the tilting operation of the platform 1 on which a load of a certain load or more is placed, the short cylinder 9 having the same thrust as the conventional tilt cylinder is provided.
If the angle is set to about 0 °, there is no thrust to incline more than that, so there is no possibility that the load is inclined and fall.

[0010]

The lift device according to the first aspect of the present invention comprises a lift arm 4 and a tilt cylinder mechanism 5 which are vertically arranged on one of the right and left sides of the platform 1 so that the lift arm 4 and the tilt cylinder mechanism are arranged. 5 is attached to the vehicle body side by pins B and C, respectively, and the tip side of both is attached to the platform 1 side by pins A and D, and a parallelogram link connecting the pins A, B, C, and D A mechanism is formed, and a similar structure is formed on the other side of the platform 1. However, instead of using the tilt cylinder mechanism 5, the base end side of the short cylinder 9 having a short stroke is attached to the vehicle body side with the pin C.
A rod 10 extending from the short cylinder 9 is inserted into the empty cylinder 11 and the tip of the empty cylinder 11 is attached to the platform 1 with a pin D.

According to the second aspect, instead of using the tilt cylinder mechanism 5 on the other side of the platform 1, the base end of the short cylinder 9 having a short stroke is attached to the vehicle body with the pin C, and the short cylinder 9 The tip of the rod 10 extending from inside is connected to the short link 12
And the other end of the link 12 is attached to the platform 1 side with the pin A together with the tip of the lift arm 4.

According to the third aspect, instead of using the tilt cylinder mechanism 5 on the other side of the platform 1, the short end of the short cylinder 9 having a short stroke is attached to one end of the short link 12 with a pin C. The other end of the link 12 is attached to the vehicle body with the pin B together with the base end of the lift arm 4, and the rod 10 extending from the short cylinder 9 is inserted into the empty cylinder 11 and the empty cylinder 1
1 is attached to the platform 1 side with a pin D.

[0013]

Embodiment 1 Embodiment 1 will be described with reference to FIG. In the lifting device according to the present invention, one of the pair of left and right tilt cylinder mechanisms uses the conventional tilt cylinder mechanism 5. On the other hand, the tilt cylinder mechanism shown in FIG. 1 is used. That is, the short cylinder 9 having a short stroke
Is attached to the chassis mounting bracket 2 side with the pin C, the rod 10 extending from the short cylinder 9 is inserted into the empty cylinder 11, and the tip of the empty cylinder 11 is
And is attached to the base end of the platform 1.
During the opening / closing operation, the short stroke of the short cylinder 9 is linked with the long stroke of the other tilt cylinder mechanism 5, and then the rod 10 slides in the empty cylinder 11 to follow the long stroke of the tilt cylinder mechanism 5. During the tilting operation, the short cylinder 9, the rod 10, and the empty cylinder 11 work together with the other tilt cylinder mechanism 5 while supporting the load on the platform 1.

The tilt cylinder mechanism according to the present invention is provided on one of the right and left sides, but cannot be provided on both sides. Stabilizer 20 providing left-right synchronization function
May be provided between the ends of the lift arms 4 or between the center portions.

The operation of the first embodiment will be described in more detail. FIG. 1A shows a state in which the platform 1 is leveled from the retracted state by opening and closing operation. Or, a state in which the platform 1 on which a load is placed is raised to the height of a bed such as a truck is shown. The platform 1 is held at the upper limit position in a horizontal state by a parallelogram link mechanism. The rod 10 is pushed out of the short cylinder 9, and the tip of the rod 10 is in contact with the innermost end in the empty cylinder 11. The short cylinder 9, the rod 10, and the empty cylinder 11 are in a state of supporting the load on the platform 1 together with the other tilt cylinder mechanism 5. FIG. 1B shows that the platform 1 is driven by the driving force of the tilt cylinder mechanism 5 after the cargo handling operation is completed.
Is rotated upward, and is stored vertically along the rear section opening. The short cylinder 9, the rod 10, and the empty cylinder 11 follow the movement of the tilt cylinder mechanism 5. In the retracted state, the rod 10 extends from the inside of the short cylinder 9 to the maximum, and the empty cylinder 11 extends from the rod 10, and a maximum gap is formed inside the empty cylinder 11. The tilt cylinder mechanism on this side does not support the platform 1 at all.

The opening and closing of the platform 1 can be sufficiently performed if there is a thrust for opening and closing only the platform 1.
It is opened and closed only by the thrust of one tilt cylinder mechanism 5. Since strong thrust is not used, the platform 1 can be operated at a safe opening / closing speed without giving a strong impact. The operation of the tilt cylinder mechanism 5 is transmitted to the other side by a parallelogram link mechanism and a stabilizer 20, so that the left and right are synchronized. Therefore, a stable operation can be performed.

FIG. 1C shows a state in which the platform 1 is grounded and a load is unloaded. The oil in the short cylinder 9 is discharged in conjunction with the other tilt cylinder mechanism 5, and the rod 10 is, for example, 20 mm.
It has receded a little distance. The tip of the rod 10 has reached the innermost end in the empty cylinder 11.

Embodiment 2 Embodiment 2 will be described with reference to FIG. The base end of the short cylinder 9 is mounted on the chassis mounting bracket 2 with pins C. The tip of a rod 10 extending from inside the short cylinder 9 is attached to the lower end of a short link 12 with a pin D. The upper end of the link 12 is attached to the base end of the platform 1 with a pin A together with the tip of the lift arm 4.

FIG. 2A shows a state where the platform 1 is horizontally supported at an upper position. The base end of the platform 1 contacts the front end face of the link 12, and supports the load of the platform 1 by the thrust of the short cylinder 9 together with the other tilt cylinder mechanism 5. FIG.
(B) shows a storage state in which the platform 1 is vertical and the rear department entrance is closed. During the opening and closing operation of the platform 1 from (a) to (b), the thrust of the other tilt cylinder mechanism 5 follows. The base edge of the platform 1 is separated from the front end face of the link 12, and the rod 10 extends from inside the short cylinder 9. FIG. 2C shows a state where the platform 1 is tilted down after being leveled. The rod 10 is retracted into the short cylinder 9, and the base edge of the platform 1 contacts the front end face of the link 12, and supports the load of the platform 1 together with the other tilt cylinder mechanism 5.

Embodiment 3 Embodiment 3 will be described with reference to FIG. The upper end of the short link 12 is mounted on the chassis mounting bracket 2 together with the base end of the lift arm 4 with a pin B. The base end of the short cylinder 9 is attached to the lower end of the link 12, and the rod 10 extending from inside the short cylinder 9 is inserted into the empty cylinder 11. The tip of the empty cylinder 11 is attached to the platform 1 with a pin D. The operation of the third embodiment is as follows.
Since it is clear from the description of the first and second embodiments, the description is omitted.

[0021]

According to the present invention, the short cylinder 9 having a short stroke is used for the tilt cylinder mechanism on one side, and the amount of driving oil is reduced by almost half. For this reason, the oil tank capacity of the power unit could be reduced. Further, at the time of the opening / closing operation or the tilting operation of the platform 1, the fine adjustment operation of the horizontal position and the like is facilitated. Furthermore, the cost is lower,
Lighter weight was also achieved.

[Brief description of the drawings]

FIG. 1 is a front view showing an operation of a first embodiment.

FIG. 2 is a front view showing the operation of the second embodiment.

FIG. 3 is a front view showing a third embodiment.

FIG. 4 is a perspective view showing a lifting device attached to a truck or the like.

FIG. 5 is a perspective view showing a lifting device.

FIG. 6 is a front view showing the operation of a conventional elevating device.

FIG. 7 is a front view showing a conventional elevating device.

FIG. 8 is a front view showing the operation of a conventional elevating device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Platform 4 ... Lift arm 5 ... Tilt cylinder mechanism 6 ... Lift cylinder mechanism 9 ... Short cylinder 10 ... Rod 11 ... Empty cylinder 12 ... Link A / B / C / D ... Pin

Claims (3)

[Claims] 1. A lift arm (4) and a tilt cylinder mechanism (5), wherein a lift arm (4) and a tilt cylinder mechanism (5) are arranged vertically parallel on one of the left and right sides of the platform (1). Are mounted on the vehicle body side with pins (B) and (C), respectively, and the distal ends of both are mounted on the platform (1) side with pins (A) and (D), respectively, and the pins (A) (B) ( C) A parallelogram link mechanism connecting (D) is formed, and the same configuration is provided on the other side of the platform (1), except that a short stroke is used instead of using the tilt cylinder mechanism (5). The base end of the short cylinder (9) is attached to the vehicle body with the pin (C), and the rod (10) extending from inside the short cylinder (9) is attached to the empty cylinder (1).
1) Insert the empty cylinder (11) into the pin (D)
A lifting device for loading and unloading a carrier such as a truck, using a device mounted on the platform (1) side. 2. A lift arm (4) and a tilt cylinder mechanism (5) by vertically disposing a lift arm (4) and a tilt cylinder mechanism (5) on one of the left and right sides of the platform (1). Are mounted on the vehicle body side with pins (B) and (C), respectively, and the distal ends of both are mounted on the platform (1) side with pins (A) and (D), respectively, and the pins (A) (B) ( C) A parallelogram link mechanism connecting (D) is formed, and the same configuration is provided on the other side of the platform (1), except that a short stroke is used instead of using the tilt cylinder mechanism (5). The base end of the short cylinder (9) is attached to the vehicle body with a pin (C), and the tip of a rod (10) extending from inside the short cylinder (9) is attached to one end of a short link (12) by a pin ( D) and attach the link (1
The other end of 2) is a lifting / lowering device for loading / unloading a bed such as a truck, using the other end of the lift arm (4) together with the pin (A) attached to the platform (1) side. 3. A lift arm (4) and a tilt cylinder mechanism (5) by vertically disposing a lift arm (4) and a tilt cylinder mechanism (5) on one of the left and right sides of the platform (1). Are mounted on the vehicle body side with pins (B) and (C), respectively, and the distal ends of both are mounted on the platform (1) side with pins (A) and (D), respectively, and the pins (A) (B) ( C) A parallelogram link mechanism connecting (D) is formed, and the same configuration is provided on the other side of the platform (1), except that a short stroke is used instead of using the tilt cylinder mechanism (5). The base end of the short cylinder (9) is attached to one end of a short link (12) by a pin (C), and the other end of the link (12) is connected to the vehicle body by a pin (B) together with the base end of a lift arm (4). To the short cylinder (9) and extend the rod (10) extending from the inside of the short cylinder (9) to the empty cylinder (1).
1) Insert the empty cylinder (11) into the pin (D)
A lifting device for loading and unloading a carrier such as a truck, using a device mounted on the platform (1) side.