JP3104340B2 - Steering wheel direction indicator for industrial vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering wheel direction indicating device for informing a driver in a driver's seat of a steering wheel direction in an industrial vehicle such as a reach type forklift.

[0002]

2. Description of the Related Art Generally, in the case of a reach-type forklift 1 as shown in FIG. 3, the steering angle of a driving wheel (hereinafter, referred to as "steering wheel") 2 as a steering wheel is reduced to improve turning performance. 1
It is set to 80 degrees. Further, since the steered wheels 2 have a vehicle body structure that cannot be seen from the driver's seat, it is difficult to determine the direction of the steered wheels 2 when starting. Therefore, when starting the reach-type forklift 1 particularly at the corner of the passage, the driver checks the direction of the steered wheels 2 before riding and takes a slight motion first for safety. You have to check the direction of travel
Work efficiency may be reduced.

Therefore, conventionally, a steered wheel direction indicating device in which a direction indicating plate 3 which rotates in conjunction with a steered wheel 2 is provided on an instrument panel 4 is used.
As shown in FIG. 4, a conventional general steered wheel direction indicating device converts a movement of a chain 8 attached between a steering shaft 5 and a rotation shaft 7 of a power steering device 6 into a rotational motion by a sprocket 9. Convert and cable 1
The information is transmitted to the direction indicating plate 3 of the display unit 11 via the “0”. The display unit 11 is a speed reduction mechanism (not shown).
Cable 10 so that the amount of rotation of the steering wheel 2 about the support shaft and the amount of rotation of the direction indicating plate 3 match.
Is appropriately decelerated. Therefore, the direction of the steered wheels 2 is displayed by the direction indicating plate 3 of the display unit 11.

[0004]

However, the conventional steering wheel direction supporting device as described above has a problem that it is difficult to see because the display portion is located on the instrument panel and at a position away from the steering wheel. . Also,
Since space for installation, such as cable layout, is required, the layout inside the machine is also limited.

An object of the present invention is to provide a steering wheel direction indicating device which can solve such a problem.

[0006]

SUMMARY OF THE INVENTION Therefore, a steering wheel direction indicating apparatus according to the present invention is provided with a steering shaft having a hollow structure to which a steering wheel is attached, and provided in the steering shaft and engaged with an inner surface of the steering shaft. An inner pipe which moves in the axial direction with respect to the rotation of the steering shaft, and which is provided in the inner pipe and engages with the inner pipe, and around the axis thereof with respect to the axial movement of the inner pipe. A rotating indicator shaft,
A direction indicator plate fixed to one end of the indicator shaft, wherein the direction indicator plate rotates so as to match the direction of the steered wheels based on the rotation of the steering shaft.

[0007]

In the above construction, the direction support plate is disposed at the center of the steering wheel, so that the driver can easily recognize the direction.

[0008] The amount of rotation of the steered wheels or the direction thereof is uniquely determined by the amount of rotation of the steering wheel. Therefore, in the present invention, the rotation of the steering wheel is transmitted by the steering shaft, the transmission mechanism, and the reduction mechanism to rotate the direction indicating plate. However, by appropriately setting the reduction ratio of the reduction mechanism, the direction indicating plate is rotated. The direction indicates the direction of the steering wheel.

[0009]

1 and 2 show a preferred embodiment of a steering wheel direction indicating apparatus according to the present invention applied to a reach type forklift. This steering wheel direction indicating device is interlocked with a steering system of a reach type forklift, and the steering system is rotatably supported by a bearing device 21 fixed to a steering plate 20, similarly to a conventional general system. Steering shaft 22, a steering wheel 23 integrally attached to the upper end of the steering shaft 22, a sprocket 24 provided below the steering shaft 22, and a rotating motion of the steering wheel 23 wound around the sprocket 24. And a chain 25 for transmitting to a rotation shaft (not shown) of the power steering device.

The steering wheel direction support device according to the present invention incorporates a transmission / deceleration mechanism in the steering shaft 22,
A direction indicating plate 26 is arranged at the center of the steering wheel 23. More specifically, as shown in FIG.
Has a hollow cylindrical structure, and a female screw portion 27 is formed on the inner peripheral surface thereof. An inner pipe 28 is coaxially arranged inside the steering shaft 22, and an outer thread portion 29 is formed on an outer peripheral surface of the inner pipe 28 so as to be screwed with a part of the female thread portion 27. I have.
Further, a straight spline portion 30 is formed on an inner peripheral surface at a lower portion of the inner pipe 28, and a support pipe 31 coaxially disposed therein is spline-coupled to the straight spline portion 30 of the inner pipe 28. It extends downward. The lower part of the support pipe 31 is the steering plate 2
No. 0 is fixed to a bracket 32 bolted to the bearing device 21 by welding or the like.

At the center of the lower end of the support pipe 31, there is a through hole 33, in which an indicator shaft 34 is rotatably supported. The indicator shaft 34 extends coaxially upward in the support pipe 31 and the inner pipe 28, slightly projects from the upper end of the steering shaft 22, and the center of the direction indicator plate 26 is screwed to the upper end surface. Indicator shaft 34
An oblique spline portion 35 is formed slightly above the center of the inner pipe 28 and meshes with spline teeth 36 formed on the inner peripheral surface of the inward flange at the upper end of the inner pipe 28. Reference numeral 37 denotes a transparent cap for protecting the direction indicating plate 26.

In such a configuration, when the steering wheel 23 is in the straight-ahead position, the spline teeth 36 of the inner pipe 28 are located substantially at the middle of the oblique spline portion 35 of the indicator shaft 34 in the vertical direction (FIG. 1).
State). When the steering wheel 23 is turned in this state, the steering shaft 22 rotates integrally, and the power steering device is driven via the chain 25 to rotate the steered wheels (not shown). At the same time, the inner pipe 28 in the steering shaft 22 moves upward or downward. Since the inner pipe 28 is spline-coupled to the fixed-side support pipe 31, the inner pipe 28 cannot rotate. Therefore, the inner pipe 28 moves only in the vertical direction due to the rotation of the steering shaft 22. On the other hand, the inner pipe 28
The spline teeth 36 at the upper end of the indicator shaft 34
When the inner pipe 28 moves upward or downward, a vertical force and a rotational force act on the indicator shaft 34 due to the movement of the inner pipe 28. However, since the indicator shaft 34 is rotatably supported by the support pipe 31 and cannot be moved in the vertical direction, the indicator shaft 34 only rotates clockwise or counterclockwise. Thus, the direction indicating plate 26 is rotated by the rotation operation of the steering wheel 23.

Here, in a general reach type forklift, the relationship between the rotation speed of the steering wheel 23 and the rotation speed of the steered wheels is in a proportional relationship. For example, the steering wheel 23 is steered for about 6 full rotations. The wheel is about 1 /
It is set so as to make two rotations. Therefore, in this example, if the pitch of the threaded portions 27 and 29 or the inclination of the oblique spline portion 35 is designed so that the ratio between the rotational speed of the steering wheel 23 and the rotational speed of the direction indicating plate 26 is about 12, Steering wheel direction and direction indicator plate 26
Can be matched with the direction of Further, in the reach type forklift, when the steering wheel 23 is rotated clockwise, the steered wheels rotate counterclockwise, so that the direction indicator plate 26 also rotates counterclockwise so that the direction of the screw portions 27, 29 and It is necessary to determine the inclination of the oblique spline section 35.

In the above embodiment, the steering wheel 2
The speed reduction / transmission mechanism for transmitting the rotation operation of the third rotation to the direction indicating plate 26 while reducing the speed of rotation is provided by the inner pipe 28, the support pipe 31, the threaded portions 27, 29 and the spline portion 30 of the indicator shaft 34 disposed in the steering shaft 22. , 35, and 36, other types of transmission mechanisms and reduction mechanisms can be used as long as they can be built into the steering shaft 22. For example, the spline teeth 36 at the upper end of the inner pipe 28
Instead, a single engaging pin is formed therein, and an oblique groove into which the engaging pin is fitted is provided in the indicator shaft 34, and the same function is obtained.

[0015]

As described above, according to the present invention, since the direction support plate indicating the direction of the steered wheels is located at the center of the steering wheel, it is easy for the driver in the driver's seat to see, and Since the traveling direction can be checked instantaneously, the driving operation in a narrow passage, a corner portion or the like becomes extremely easy, and the work efficiency is improved.

Further, since most of the components are housed compactly in the steering shaft, there is no need to consider the installation space, and there is also an effect that the degree of freedom in the layout inside the machine is increased.

Although the present invention is particularly suitable for a reach type forklift in which steered wheels are hardly seen from a driver's seat, it is needless to say that the present invention may be applied to other industrial vehicles.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a steering wheel direction indicating device according to the present invention.

FIG. 2 is a plan view showing a steered wheel direction indicating device according to the present invention.

FIG. 3 is a schematic view showing a conventional general reach-type forklift and a conventional steered wheel direction indicating device.

FIG. 4 is an enlarged view showing the conventional steered wheel direction indicating device of FIG. 3;

[Explanation of symbols]

 Reference Signs List 22 steering shaft 23 steering wheel 26 direction indicator plate 27 female thread 28 inner pipe 29 male thread 30 straight spline 31 support pipe 34 indicator shaft 35 oblique spline 36 spline teeth

Claims (1)

(57) [Claims] 1. A steering shaft having a hollow structure to which a steering wheel is attached, and an inner pipe provided in the steering shaft, engaging with an inner surface of the steering shaft, and moving in an axial direction with respect to rotation of the steering shaft. An indicator shaft provided in the inner pipe and engaging with the inner pipe and rotating around its axis for axial movement of the inner pipe; and a direction indicator fixed to one end of the indicator shaft. A steering wheel direction indicating device for an industrial vehicle, wherein the direction indicating plate rotates so as to match the direction of the steered wheels based on the rotation of the steering shaft.