JP3121802B2 - Forklift mast device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mast device for a forklift capable of switching to traverse traveling.

[0002]

2. Description of the Related Art Conventionally, vehicles having a traversing system are found in large-sized transport vehicles, some loaders, and the like, and in forklifts, reach-type electric vehicles exist. However, there is no counter-type engine type forklift capable of traversing in addition to normal work and having the same function as a side fork. In order to establish such a forklift, the front wheels, which are drive wheels, must be steered laterally.

That is, a conventional forklift 1 shown by a solid line in FIG. 3 has a pair of left and right front wheels (drive wheels) 3 provided at a front portion of a vehicle body 2 and a pair of left and right rear wheels 4 provided at a rear portion. A driver's seat 5 is provided in front of the vehicle body 2 and above. At the front end of the vehicle body 2, a mast 6 that can expand and contract in the vertical direction is attached via a connecting shaft 7 in the vehicle width direction so as to be rotatable in the front-rear direction, and a tilt cylinder 8 that rotates back and forth is provided. It is provided between the vehicle body 2 and the mast 6.

The mast 6 comprises a pair of left and right outer frames 9 on the forklift 1 side, and a pair of left and right inner frames 10 which are guided by the outer frame 9 and can move up and down.
0 is provided with a lift cylinder 11. In addition, a lift bracket 12 that is guided by the inner frame 10 and that can move up and down is provided.
A pair of left and right forks 13 is provided via a pair of upper and lower finger bars.

[0005] The driver's seat 5 is provided with a seat 15 and a handle 16 positioned in front of the seat 15.
A head guard 19 is disposed above the head guard 19 via a front pipe 17 and a rear pipe 18 erected from the main body 2 side. Further, a counterweight 20 is provided on the main body 2 behind the seat 15. In the conventional forklift 1 shown by a solid line in FIG.
Because the mast 6 is located between the
Since the vehicle cannot be turned 0 degrees, the vehicle cannot traverse. In order to make such a conventional forklift 1 travel in a lateral direction, the mast 6 is attached to the front of the front wheel 3 and the front wheel 3 is turned 90 degrees as shown by a virtual line in FIG. Must.

[0006]

However, when the mast 6 is mounted in front of the front wheel 3 as described above, the front overhang increases from 1 to L as compared with the conventional case (solid line in FIG. 3). There is. Accordingly, an object of the present invention is to provide a mast device of a forklift capable of turning a front wheel by 90 degrees while having a mast positioned between left and right front wheels. It is.

[0007]

According to a first aspect of the present invention, there is provided a mast device for a forklift, comprising: a pair of left and right front wheels and a pair of left and right rear wheels; Masts are provided in such a manner that they can be turned by 90 degrees, and between the left and right front wheels at the front end side of the vehicle body, the mast is moved in the front-rear direction via a connection shaft positioned above the front wheels and in the vehicle width direction. A rotatable driving device is provided between the vehicle body and the mast so as to be rotatably mounted, and is provided between the vehicle body and the mast. When the mast is rotated by the rotatable driving device, a lower portion of the mast is a front wheel. Is moved to a turning non-interference position.

According to the first aspect of the present invention, the mast is in an upright posture during normal running, and the lower side of the mast is located between the left and right front wheels, so that the forklift has a long front overhang. Can form without. When switching from normal driving to traversing driving,
The mast is rotated (tilted) around the connecting shaft by the operation of the rotary drive device, and the lower portion is moved to the turning non-interference position of the front wheels, and then the front wheels are turned 90 degrees with respect to the vehicle body (sideways). (Converted to). At that time, the turning can be performed smoothly without any trouble because the lower part of the mast is moved to the turning non-interference position. After performing this turning, the mast is turned around the connecting shaft by the reverse operation of the rotary driving device to be in an upright posture, and the lower part thereof can be opposed to the side surface of the front wheel from the front, so that the forklift is In addition, the vehicle can be traversed without increasing the front overhang.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Note that, in the embodiment, the same components or almost the same components as those in the above-described conventional example (FIG. 3) are denoted by the same reference numerals, and the details are omitted. That is, 1 is a forklift, 2 is a car body, 3
Is the front wheel, 4 is the rear wheel, 5 is the driver's seat, 6 is the mast, 7 is the connecting shaft, 8 is the tilt cylinder, 9 is the outer frame, 10 is the inner frame, 11 is the lift cylinder, 12 is the lift bracket, 13 is Fork, 15 for seat, 16 for handle, 1
7 is a front pipe, 18 is a rear pipe, 19 is a head guard, and 20 is a counterweight.

A pair of left and right front wheels 3 and a pair of right and left rear wheels 4
Are provided so as to be able to turn 90 degrees with respect to the vehicle body 2 (to be able to turn sideways). The front wheel 3 is a drive wheel (the drive structure is not shown), and further includes an actuator (not shown) for turning 90 degrees. The mast 6 located at the front end side of the vehicle body 2 has its lower side positioned between the left and right front wheels 3 in an upright posture. The mast 6 is attached to the vehicle body 2 via a connecting shaft 7 positioned above the front wheel 3 and in the vehicle width direction so as to be rotatable in the front-rear direction.

A tilt cylinder 8, which is an example of a rotation driving device for rotating the mast 6 back and forth, is provided between the vehicle body 2 and the mast 6. When the mast 6 is rotated by the tilt cylinder 8, the lower part of the mast 6 is swung forward and moved to the turning non-interference position of the front wheel 3. The operation of the above embodiment will be described below.

The solid line in FIG. 1 shows a normal running time. At this time, the mast 6 is in an upright posture due to the contraction of the tilt cylinder 8, and its lower side is located between the left and right front wheels 3. Therefore, forklift 1 can be formed without long front overhang. Such a forklift 1 can travel when an operator sitting on the seat 15 of the driver's seat 5 operates the handle 16. Then, operate the lift lever and lift cylinder 1
By operating the fork 1, the fork 13 can be moved up and down via the lift bracket 12 and the like, so that the intended fork operation can be performed. The mast 6 is connected to the connecting shaft 7 by operating the tilt lever 8 by operating the tilt lever.
Can be rotated (tilted) around the lift bracket 1
The attitude of the fork 13 can be changed via the second or the like.

When switching from the normal traveling to the traversing traveling, the traversing mode switch (not shown) is first operated to greatly extend the tilt cylinder 8. The mast 6 is rotated (tilted) around the connecting shaft 7 by the extension operation of the tilt cylinder 8, and the lower part of the mast 6 is swung forward from between the front wheels 3 as shown by the phantom line in FIG. 1. Is moved to the turning non-interference position of the front wheel 3.

Then, a turning lever (not shown) is operated, and the front wheel 3 is turned 90 degrees with respect to the vehicle body 2 as shown by a virtual line in FIG. (Turned sideways). At that time, the 90-degree turning of the front wheels 3
Since the lower part of the mast 6 is moved to the turning non-interference position, it can be smoothly performed without any trouble. After the desired turning is performed in this way, the tilt cylinder 8 is contracted by feedback from the sensor. As a result, the mast 6 can be turned around the connecting shaft 7, and as shown in FIG. 2, the mast 6 can be in an upright posture, with its lower part facing the side surface of the front wheel 3 from the front. Forklift 1 does not have a long front overhang,
It may be possible to traverse.

In the above-described embodiment, the tilt cylinder 8 is shown as the rotary drive, but this may be a screw drive type or a link type.

[0016]

According to the first aspect of the present invention, a forklift can be formed without a long front overhang during normal running. The switching from the normal running to the transverse running is performed by rotating (tilting) the mast around the connecting shaft by the operation of the rotary driving device, and moving the lower portion thereof to the turning non-interference position of the front wheel, and then moving the mast to the front position. The forklift turns the wheels by turning the wheels 90 degrees (turning sideways) with respect to the vehicle body and turning the mast around the connecting shaft by the reverse operation of the rotary drive device to bring the mast upright. Direction can be smoothly performed without any hindrance, and traversing can be performed without long front overhang.

[Brief description of the drawings]

FIG. 1 shows an example of an embodiment of the present invention, and is a side view of a forklift during normal traveling.

FIG. 2 is a side view of the forklift at the time of traversing.

FIG. 3 is a side view of a forklift, showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Forklift 2 Body 3 Front wheel 4 Rear wheel 5 Driver's seat 6 Mast 7 Connecting shaft 8 Tilt cylinder (rotation drive) 9 Outer frame 10 Inner frame 11 Lift cylinder 13 Fork 15 Seat 20 Counter weight

Claims (1)

(57) [Claims] 1. A pair of left and right front wheels and a pair of left and right rear wheels are provided on a vehicle body so as to be able to turn 90 degrees, respectively, and between the left and right front wheels on the front end side of the vehicle body with respect to the front wheels. A mast is attached rotatably in the front-rear direction via a connection shaft positioned above and in the vehicle width direction, and a rotation drive device for performing front-rear rotation is provided between the vehicle body and the mast, A mast device for a forklift, wherein a lower portion of the mast is moved to a turning non-interference position of a front wheel when the mast is rotated by the rotation driving device.