JPH11292490A - Electric cargo handling vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve energy efficiency by driving a drive motor with a battery power supply without making energy conversion, and directly lifting or lowering a lifter. SOLUTION: When the prescribed switch of an operation device is tuned on, an electric motor is rotatively driven. The drive power for the motor is directly fed from a battery used for a vehicle body travel. A first gear 21 supported on a gear housing 34 is rotated by the rotative drive of the motor, and second and third gears 38, 39 meshed with it are also rotated. A meshing chain 1 is slid downward along a first chain guide 33 and pushes up support brackets connected together at the center. An inner mast 12 is fixed to the brackets via a stay 35 and the lower bracket 32, and the mast 12 starts rising along an outer mast 11. When the mast 12 rises, a sprocket 36 supported on its upper end also rises, thus a roller chain 40 lifts a lifter 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric cargo handling vehicle represented by a battery-powered forklift, and more particularly to a structure of a lifting device in the vehicle.

[0002]

2. Description of the Related Art A conventional forklift has a mast standing in front of a vehicle body, and a lifter for loading a load is provided so as to be able to move up and down along the mast. The vehicle body is provided with an elevating device for driving the lifter up and down. For this purpose, a hydraulic cylinder is often used. The cylinder is extended by pressure oil supplied from a hydraulic pump provided on the vehicle body, and raises the lifter.

[0003] Such a hydraulic elevating device supplies hydraulic oil from a hydraulic pump to a cylinder by a pipe or a hose, and thus has a wide degree of freedom in the distance between the pump and the cylinder, the number of cylinders to be used, and the like. On the other hand, there are various problems such as high hydraulic noise, high production cost due to the need for a hydraulic pressure control valve circuit, and furthermore, pressure oil is scattered at the time of failure to contaminate the surroundings. . Especially in battery-powered forklifts,
Since the electric energy stored in the battery is converted into hydraulic energy, there is a major problem that energy loss is large.

[0004] In order to solve the above-mentioned problems, a device for directly raising and lowering by electricity without using hydraulic pressure has been studied.

[0005] One of the representative examples studied is to erect a worm gear along a mast and fix a socket having a ball screw meshing with the gear to the lifter. When the worm gear is rotationally driven by a motor provided on the vehicle body side, the lifter having the socket moves up and down. This mechanism has a problem that the worm gear becomes long because the worm gear becomes long, making it difficult for the socket to slide, and is not suitable for a device for lifting and lowering a load of several tons over several meters.

As another example, a lifter is suspended from a top end of a mast by a chain or the like, and the lifter is raised and lowered by winding the chain by a motor. However, in this case, since the lifter is suspended, there is a problem that it is difficult to control the lift speed of the lifter.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a new cargo-handling vehicle capable of directly controlling the lifting and lowering of a lifter by electric power used for running the vehicle. .

[0008]

Means for Solving the Problems As a first invention to solve this problem, a mast provided upright on a vehicle body, a lifter provided to be able to move up and down along the mast,
An elevating device for driving the lifter up and down with respect to the mast, the elevating device comprising two meshing chains each having one end connected to the lifter, and a sprocket provided on the mast and engaging with each of the chains. And an electric motor for rotating the sprocket, and a guide that guides the two chains so as to mesh with each other from one end and travel in a predetermined direction with the rotation of the sprocket. suggest.

According to a second aspect of the present invention, there is provided a first mast provided upright on a vehicle body, a second mast provided up and down along the first mast, and a second mast provided on the second mast. A lifter provided so as to be able to move up and down along with the first mast, and an elevating device that drives the second mast up and down with respect to the first mast. The elevating device has one end connected to the second mast. A double-meshed chain, a sprocket provided on the first mast and engaging with each of the chains, an electric motor for rotating the sprocket, and the two chains meshing with each other from the one end with the rotation of the sprocket. And a guide that guides the vehicle to travel in a predetermined direction.

In the first and second inventions described above, a meshing chain is used as a means for raising and lowering the lifter. This meshing chain is also called a chuck chain, a push-pull chain, or the like, and is formed as a rod-shaped rigid body by meshing two flexible chains with each other, and examples thereof are shown in FIGS. 9 and 10. .

FIG. 9 shows a part of a meshing chain. The chain 1 has two link plates 2 on each of the front and back sides.
Are connected to each other through. Each plate 2 is abbreviated
It is C-shaped and has two holes 4,4. The front side plate 2 and the back side plate 2 are shifted from each other by a half pitch, overlapped in the front and rear two rows, and are mutually rotatably connected by a pin 5 inserted in the center of the roller 3. The front and rear plates 2 are symmetrically arranged so as to face the same direction.

FIG. 10 shows a state in which two meshing chains 1, 1 are meshed and connected to each other. Each chain 1,1
Are opposed to each other in opposite directions, and the projections 6 of one plate 2 and the recesses 7 of the other plate 2 are fitted with each other, so that they are meshed or combined with each other to form a single rod-like shape. Become rigid. In the present specification, the meshing chain is
In this manner, two chains are engaged with each other to form one rigid body.

According to a first aspect of the present invention, the meshing side end of the meshing chain is connected to a lifter, and the chain is driven to travel by using an electric motor and a sprocket, so that the lifter is formed by a meshed rigid body. It is designed to be pushed upward. Note that the mast in the first invention is not limited to a mast fixed to the vehicle body, but includes a mast provided to be able to move up and down with respect to the vehicle body.

According to a second aspect of the present invention, a first mast is provided on a vehicle body, a second mast is provided on the first mast so as to be able to move up and down, and a lifter for loading a load on the second mast. Are provided so as to be able to move up and down. In the second invention, the lifting device having the meshing chain is provided between the first mast and the second mast, and the second mast moves up and down with respect to the first mast. In addition, in the case of the second invention as well, it is assumed that the second mast is provided so as to be able to move up and down with respect to the vehicle body.

In the first and second aspects of the present invention, the lifter refers to a means for loading and lifting a load, and does not particularly limit the structure and shape of the lifter.
Therefore, in the second invention, the lifter is the third third lifter.
May be provided, and the means for lifting and lowering the lifter is not limited.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to examples. In the following description, the structure of the meshing chain which has already been described is treated as the same, and the reference numerals indicating the respective parts are used without change.

[0017]

1 shows a side view of a forklift according to the present invention. This forklift is of a counterbalance type driven by a battery B mounted thereon. An outer mast 11 is erected in front of a vehicle body 10, and an inner mast 12 (see FIG. 2) is moved along the outer mast 11. A lifter 13 is provided to be able to move up and down along 12.

The lifter 13 includes a lift bracket 14 slidably supported by the inner mast 12 and two forks 15 having an L-shape in side view attached to the bracket 14.
When the fork 15 is inserted into the pallet P, the load W is lifted and transported together with the pallet P.

At the rear of the vehicle body 10, there are provided a seat 16 on which the worker M sits and a driving operation device 17 for the worker M to drive the vehicle body 10. Reference numeral 18 denotes a head guard for protecting a worker on the seat 16 from falling objects.
6 is detachably mounted below 6.

An electric motor 20, which is rotationally driven by a battery B, is fixed inside the vehicle body 10. The rotational force of the motor 20 is connected to a shaft of a first gear 21 fixed to the outer mast 11 via a speed reducer. You.

FIGS. 2 to 6 show the outer mast 1 described above.
1, the main parts of the inner mast 12 and the lifter 13 are shown.

The outer mast 11 and the inner mast 12 are provided upright on the left and right sides of the vehicle body 10, respectively, and the inner mast 12 is provided with rollers 22, 2 inside the outer mast 11.
3 slidably provided.

The lift bracket 14 of the lifter 13
Are plates 24, 2 fixed to the bracket 14.
Rollers 26, 27 provided via 4, 25, 25
The inner mast 12 is provided so as to be freely slidable up and down.

The outer masts 11, 11 are connected and fixed to each other by an upper bracket 28, a center bracket 29, and a lower bracket 30, and the inner masts 12, 12 are connected and fixed to each other by an upper bracket 31 and a lower bracket 32.

The upper ends of two first chain guides 33, 33 for vertically guiding the two meshing chains 1 are fixed to a central bracket 29 fixed to the outer mast 11. The gear housing 34 is fixed.

An upper bracket 31 fixed to the inner mast 12 fixes an upper end of a prism-shaped stay 35 disposed at the center of the chain guides 33, 33, and supports sprockets 36, 36 which can rotate freely. A support bracket 37 for fixing the lower end of the stay 35 is fixed to the lower bracket 32.
7, one end of each of the meshing chains 1 and 1 is connected.

The gear housing 34 has the first
A gear 21 is rotatably supported, and a second gear 38 meshing with the gear 21 and a third gear meshing with the second gear 38 on the plate.
The gears 39 are rotatably supported.

On the upper surface of the housing 34, the first
The lower end of the chain guide 33 is fixed, and one end of each of the roller chains 40, 40 wound around the sprocket 36 is fixed to both left and right ends. The other end of the roller chain 40 is fixed to a fixture 41 of the lift bracket 14 as shown in FIG.

As shown in FIG. 6, sprockets 42 and 43 are fixed to the front ends of the second and third gears 38 and 39, respectively. The first chain guide 33 is formed with a guide groove 44 for sequentially guiding the rollers 3 of the meshing chain 1. The meshing chains 1, 1 arranged along the groove 44 respectively correspond to the sprockets 4.
The support bracket 37 is guided by the support bracket 37 by being wound around the U-shaped member 2 and 43 and bent.

A second chain guide 45 is fixed to the front surface of the gear housing 34. The guide 45 guides the engagement chains 1, 1 into engagement with the respective sprockets 42, 43, and also connects the engagement chains 1, 1 to the sprockets 4 and 43.
Along the rotation of the wheels 2 and 43, the vehicle runs along a predetermined route, and the two are smoothly connected or separated as shown in the figure.

The operation of the forklift will be described. The operation of raising the load W mounted on the pallet P from the state shown in FIG. 1 or 2 by the lifter 13 is performed as follows.

When a predetermined switch of the operating device 17 is turned on, the electric motor 20 is driven to rotate. As a result, the first gear 21 supported by the gear housing 34 rotates, and the second and third gears 38 and 39 meshing with the first gear 21 rotate, and the sprocket 4 fixed to the gears 38 and 39 rotates.
2, 43 rotate in the direction of arrow A in FIG.

By the rotation of the sprockets 42, 43, the meshing chains 1, 1 slide downward along the first chain guides 33, 33, and are connected to each other at the center to form a single rod-shaped rigid body to form the support bracket 37. Push up.

Since the inner mast 12 is fixed to the bracket 37 via the stay 35 and the lower bracket 32, the mast 12 starts to rise along the outer mast 11.

When the inner mast 12 rises, the sprocket 36 supported on the upper end thereof also rises, so that the lifter 13 is pulled up by the roller chain 40. Therefore, the lifter 13 removes the load W and the pallet P from the inner mast 1.
2 along the mast 12 at twice the speed of the mast 12, FIG.
The state shown by the chain line is shown in FIG.

The lowering of the lifter 13 is performed by rotating the motor 20 in the reverse direction. When the motor 20 rotates in the opposite direction, the sprockets 42 and 43 also rotate in the direction opposite to the arrow A, pulling the interlocking chains 1 and 1 downward, separating them from each other, and separating them from each other. Each of the chains 1, 1 is pushed upward from the second chain guide 45 to the first chain guide 33.

According to the forklift described above, the lifter 13 is driven up and down by the two rigid meshing chains 1, 1, and the driving force is given by the electric motor 20. Therefore, both lift and lower of the lifter are freely controlled by the motor 20, and a desired lifting speed is realized.

The driving power of the motor 20 is supplied by a battery B used for running the vehicle. That is, the present forklift directly drives the traveling of the vehicle body and the lifting and lowering of the load using the electric energy of the common battery B, and does not have a process of converting the energy into other energy such as hydraulic pressure.

Further, the meshing chains 1 employed in the present forklift are connected to each other to form a rigid body. However, unlike a mere metal rod, they have a strong resistance to bending. It has the advantage of not being easily damaged.

In the above embodiment, a so-called two-stage mast forklift having the outer mast 11 and the inner mast 12 has been described. However, the present invention is not limited to this, and is applicable to a one-stage mast or a three-stage mast. It is.

As shown in FIGS. 7 and 8, for example, a one-stage mast type can be easily realized by partially changing the above embodiment. That is, only one mast 50 is erected on the vehicle body 10 in place of the two masts 11 and 12, and the support bracket 51 connected to the meshing chain 1 is deformed so that the mast 50 is replaced with the plate 24 fixed to the lifter 13. Stick. The upper end of the first chain guide 33 is fixed to the central bracket 52 of the mast 50. The roller chain 39 and the sprocket 35 are not required because they are unnecessary. By doing so, the lifter 13 moves up and down along the mast 50 as the meshing chains 1 and 1 run.

[0042]

As described above, according to the electric cargo handling vehicle according to the present invention, the lifter can be directly moved up and down by driving the electric motor by the battery power without any energy conversion. Energy-efficient cargo handling vehicles can be realized. Further, since the engagement chain is employed in the lifter lifting / lowering device, the lifting / lowering speed of the lifter can be surely adjusted by controlling the rotation of the motor.

[Brief description of the drawings]

FIG. 1 is a side view of a forklift according to the present invention.

FIG. 2 is a front view showing a main part of the forklift according to the present invention.

FIG. 3 is a side view showing a main part of the forklift according to the present invention.

FIG. 4 is a sectional view taken along line XX in FIG.

FIG. 5 is a sectional view taken along line YY in FIG.

FIG. 6 is an enlarged view of a main part in FIG. 2;

FIG. 7 is a front view corresponding to FIG. 2, showing another embodiment of the present invention.

FIG. 8 is a side view corresponding to FIG. 3 showing another embodiment of the present invention.

FIG. 9: Diagram of the meshing chain.

FIG. 10 is a diagram showing a meshing state of a meshing chain.

[Explanation of symbols]

 1: meshing chain 10: body 11: outer mast 12: inner mast 13: lifter 14: lift bracket 15: fork 20: electric motor 33: first chain guide 42: sprocket 43: sprocket 45: second chain guide B: battery M: Worker P: Pallet W: Load

Claims (2)

[Claims] 1. A mast provided upright on a vehicle body, a lifter provided to be able to move up and down along the mast, and an elevating device for driving the lifter up and down with respect to the mast.
The lifting device includes two meshing chains each having one end connected to the lifter, a sprocket provided on the mast and engaging with each of the chains, an electric motor for rotating and driving the sprocket, and rotating the sprocket. An electric cargo handling vehicle comprising: a guide that guides both chains from one end to mesh with each other and to travel in a predetermined direction. 2. A first mast provided upright on a vehicle body, and a second mast provided up and down along the first mast.
A mast, a lifter provided so as to be able to move up and down along the second mast, and an elevating device that drives the second mast up and down with respect to the first mast, the elevating device comprising:
A double-meshed chain having one end connected to the second mast, a sprocket provided on the first mast and engaging with each of the chains, an electric motor for driving the sprocket to rotate, and rotating the sprocket And a guide for guiding both chains so as to mesh with each other from one end and travel in a predetermined direction.