JPH107397A - Cargo handling device for forklift - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cargo handling device for forklift which can attain a simple structure and highly efficient work regardless of temperature. SOLUTION: When a cargo handling motor 19 disposed below a side mast 12 is driven, a pair of chain winding drums 21 fitted at both the ends of a motor shafts rotate together, a chain 18 is wound around the drum 21 through a chain wheel 17 at the upper of the side mast or delivered from the drum 21, so that a fork 15 rises or lowers together with a lift bracket 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cargo handling device for a forklift, and more particularly to a cargo handling device for lifting an attachment such as a fork using an electric motor.

[0002]

2. Description of the Related Art In a conventional forklift, FIG.
As shown in FIG. 1, a pair of outer masts 2 are provided upright in front of the vehicle body frame 1, and a pair of inner masts 3 are provided along the inside of the outer masts 2 so as to be able to move up and down. Further, a lift bracket 4 is provided to be able to move up and down along the inner mast 3, and a fork 5 is fixed to the lift bracket 4. A hydraulic cylinder 6 is erected on the back of the outer mast 2, and a chain wheel 8 is provided on the top of a piston rod 7 of the hydraulic cylinder 6. A chain 9 is suspended from the chain wheel 8. One end of the chain 9 is fixed to the hydraulic cylinder 6, and the other end is fixed to the lift bracket 4.

When hydraulic oil is supplied to the hydraulic cylinder 6 by a hydraulic circuit (not shown) to raise the piston rod 7,
The chain wheel 8 also rises, but since one end of the chain 9 is fixed to the hydraulic cylinder 6, the lift bracket 4 connected to the other end of the chain 9
And rises along the inner mast 3 at a speed twice as high as that of the inner mast. When the upper end of the piston rod 7 hits the tie beam 10 of the inner mast 3, the inner mast 3 moves up along with the piston rod 7 along the inner surface of the outer mast 2.

[0004]

However, such a conventional forklift requires a sliding mechanism for the inner mast 3 along the outer mast 2, a lift bracket 4 by the hydraulic cylinder 6, and a lifting and lowering mechanism for the inner mast 3. Therefore, a hydraulic circuit for operating the hydraulic cylinder 6 is required, and the structure is complicated and the manufacturing cost is high. Furthermore, because of the use of hydraulic pressure, work efficiency is low,
There is also a problem that the elevating performance is affected by the oil temperature, that is, it is difficult to obtain required performance when the oil temperature is low.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide a forklift loading and unloading apparatus which has a simple structure and can operate efficiently regardless of temperature.

[0006]

According to the present invention, there is provided a cargo handling apparatus for a forklift for lifting an attachment such as a fork or the like, comprising: a side mast provided upright on a vehicle body frame; A lift bracket that is provided to be able to move up and down and holds an attachment, a chain wheel fixed to the upper part of the side mast, a chain suspended on the chain wheel and one end of which is fixed to the lift bracket, and a lower part of the side mast And a chain winding drum that is rotated by the cargo handling motor and winds the other end of the chain.

[0007] A pair of side masts, a chain wheel, a chain, and a chain winding drum can be provided on the left and right, respectively, and the pair of chain winding drums can be attached to both ends of a motor shaft of a loading motor. Further, as each chain winding drum, a drum having a substantially conical shape with the motor shaft of the cargo handling motor as a central axis and having chain convolution teeth spirally arranged on a conical surface can be used.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a forklift provided with a cargo handling device according to an embodiment of the present invention. A pair of left and right side masts 12 are provided upright in front of the vehicle body frame 11, and a lift bracket 13 is provided along the side masts 12 so as to be able to move up and down.
A backrest 14 is fixed to the lift bracket 13, and a fork 15 is held on the backrest 14 as an attachment. As shown in FIG. 2, the upper portions of the pair of side masts 12 are connected to each other by upper brackets 16.
The upper bracket 16 is provided with a pair of chain wheels 17 rotatably. A chain 18 is suspended from each chain wheel 17, and one end of the chain 18 is fixed to the lift bracket 13.

An electric cargo handling motor 19 fixed to the body frame 11 is disposed below the side mast 12, and as shown in FIG. 3, motor shafts 20 project from both ends of the cargo handling motor 19, This motor shaft 2
A chain-wound drum 21 is attached to each end of the “0”. The chain winding drum 21 is mounted on the motor shaft 2.
4, and has a substantially conical shape with its center axis at 0. As shown in FIG.
2 are spirally arranged and the other end of the chain 18 is connected to a small diameter portion at the tip. The teeth 22 of the left and right chain winding drums 21 are arranged in a spiral shape in opposite directions, so that when the motor shaft 20 rotates both drums 21 at the same time, the chains 18 wound on the respective drums 21 Are wound together,
Or they are sent together.

Further, as shown in FIG. 3, a brake disk 2 is mounted on a motor shaft 20 of the loading motor 19.
3 is mounted, and a brake device 24 for preventing rotation of the brake disk 23 is disposed near the brake disk 23.

A battery (not shown) is mounted on the forklift. When the motor shaft 20 is rotated by supplying electric power from the battery to the loading motor 19, a pair of chain windings provided at both ends of the motor shaft 20 are provided. The drums 21 rotate simultaneously and, for example, the chains 18 of the helically arranged teeth 22 of these drums 21
Is wound up, and the fork 15 moves up together with the lift bracket 13. When the motor shaft 20 is rotated in the reverse direction,
The chain 18 wound around both chain winding drums 21 is sent out, whereby the fork 15 descends. The lifting and lowering of the fork 15 can be stopped by stopping the rotation of the fork 15 with the brake device 24 sandwiching the brake disk 23.

Here, since the other end of the chain 18 is connected to a small diameter portion at the end of each chain winding drum 21, when the drum 21 is rotated, the conical drum 21 is rotated.
Chain 18 from small diameter section to large diameter section
Is wound, and a heavy load can be lifted with a small motor torque. In this embodiment, the chain winding drum 21 is directly attached to the motor shaft 20 of the cargo handling motor 19, but if the drum 21 is connected to the cargo handling motor 19 via a reduction gear, a heavier load can be obtained. Can be lifted. Further, if a motor having a large torque is used as the cargo handling motor 19, it is possible to use a chain-shaped drum having a cylindrical shape instead of a conical shape.

When a step, that is, a difference in height occurs between the left and right forks 15 in accordance with the use of the cargo handling device, the step can be easily changed only by changing the attachment position of the chain 18 to the chain winding drum 21. Can be eliminated.

Since the fork 15 is raised and lowered by winding or feeding out the chain 18 by the loading motor 19, a quick operation becomes possible and the loading motor 1
The height of the fork 15 can be detected by the number of rotations of 9, and the operability of the cargo handling device is improved.

In the above-described embodiment, the fork 15 is held by the backrest 14, but the present invention is not limited to the fork, and another attachment may be held.

As described above, according to the present invention,
This eliminates the need for a hydraulic circuit that has been conventionally used, simplifies the structure of the forklift, and enables efficient cargo handling operations without being affected by temperature. Furthermore, the manufacturing cost can be reduced with the simplification of the structure.

[Brief description of the drawings]

FIG. 1 is a partially broken side view showing a forklift provided with a cargo handling device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an upper portion of a side mast.

FIG. 3 is a front view showing a cargo handling motor on which a chain winding drum and a brake disk are mounted.

FIG. 4 is a perspective view showing a chain winding drum attached to the cargo handling motor.

FIG. 5 is a side view showing a forklift provided with a conventional cargo handling device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Body frame 12 Side mast 13 Lift bracket 14 Backrest 15 Fork 16 Upper bracket 17 Chain wheel 18 Chain 19 Motor 20 Motor shaft 21 Chain winding drum 22 Teeth 23 Brake disc 24 Brake device

Claims (3)

[Claims] 1. A loading and unloading device for a forklift for lifting an attachment such as a fork, comprising: a side mast provided upright on a body frame; and a lift bracket provided to be able to move up and down along the side mast and holding the attachment. A chain wheel fixed to an upper portion of the side mast; a chain suspended on the chain wheel and one end of which is fixed to the lift bracket; a loading motor disposed at a lower portion of the side mast; And a chain winding drum which is rotated by a motor and winds the other end of the chain. 2. The side mast, a chain wheel,
2. The cargo handling device according to claim 1, wherein a pair of chains and a chain winding drum are provided on left and right sides, respectively, and a pair of chain winding drums are attached to both ends of a motor shaft of the cargo handling motor. 3. 3. Each of the chain winding drums has a substantially conical shape with the motor shaft of the cargo handling motor as a central axis, and chain winding teeth are spirally arranged on a conical surface. The cargo handling device according to claim 2, characterized in that: