JPH05147557A - Steering wheel direction indication device in industrial vehicle - Google Patents

Abstract

PURPOSE:To arrange a direction indicating plate at the center of a steering wheel at the position of which the plate can be viewed easily by a driver, and reduce the installation space as possible as can. CONSTITUTION:A steering shaft 22 on which a steering wheel 23 is mounted is formed in a hollow structure. At the center at an upper end of the steering shaft 22 a direction indication plate 26 is mounted so as to turn freely. In the shaft 22, transmission and deceleration mechanism 28, 31, 34 are provided respectively for decelerating the turning action of the shaft 22 by a specified ratio and transmitting it to the plate.

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 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 drive wheels (hereinafter referred to as "steering wheels") 2 which are steering wheels is increased to improve turning performance. 1
It is set to 80 degrees. Further, since the steering wheel 2 has a vehicle body structure that cannot be seen from the driver's seat, it is difficult to determine the direction of the steering wheel 2 at the time of starting. Therefore, when starting the reach type forklift 1 especially at the corner of the passage, for safety, the driver looks at the direction of the steered wheels 2 in advance and then gets on the vehicle, or first performs the fine movement motion. You have to check the direction of travel by doing
The work efficiency was sometimes lowered.

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

[0004]

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

An object of the present invention is to provide a steering wheel direction indicator which can solve such problems.

[0006]

Therefore, in the steering wheel direction indicator according to the present invention, the steering shaft to which the steering wheel is attached has a hollow structure, and the direction indicator plate is rotatably attached to the center of the upper end of the steering shaft. A steering mechanism including a transmission mechanism and a reduction mechanism for decelerating the rotational movement of the steering shaft at a predetermined ratio so as to transmit the steering wheel to the direction indicating plate so that the direction of the steering wheel and the direction of the direction indicating plate match. It is characterized by being installed in the shaft.

[0007]

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

Further, the amount of rotation of the steering wheel or its direction is uniquely determined by the amount of rotation of the steering wheel. Therefore, according to the present invention, the rotating motion of the steering wheel is transmitted by the steering shaft, the transmission mechanism, and the speed reduction mechanism to rotate the direction indicating plate. However, by appropriately setting the reduction ratio of the speed reducing mechanism, The direction indicates the direction of the steering wheel.

[0009]

1 and 2 show a preferred embodiment of a steering wheel direction indicator according to the present invention applied to a reach type forklift. This steering wheel direction indicator is linked 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, like a conventional steering system. The steering shaft 22, the steering wheel 23 integrally attached to the upper end of the steering shaft 22, the sprocket 24 provided at the lower portion of the steering shaft 22, and the rotation movement of the steering wheel 23 wound around the sprocket 24. And a chain 25 that transmits the rotation shaft (not shown) of the power steering device.

The steering wheel direction support device according to the present invention incorporates a transmission / reduction mechanism in the steering shaft 22.
The steering wheel 23 is characterized in that a direction indicating plate 26 is arranged at the center thereof. More specifically, as shown in FIG. 1, the steering shaft 22
Has a hollow cylindrical structure, and an internal thread 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 having a length to be screwed into a part of the female thread portion 27 is formed on an outer peripheral surface of the inner pipe 28. There is.
Further, a straight spline portion 30 is formed on the inner peripheral surface of the lower portion of the inner pipe 28, and a support pipe 31 coaxially arranged 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
It is fixed to a bracket 32 bolted to the bearing device 21 of No. 0 by welding or the like.

A through hole 33 is formed in the center of the lower end of the support pipe 31, and the indicator shaft 34 is rotatably supported by the through hole 33. The indicator shaft 34 coaxially extends upward in the support pipe 31 and the inner pipe 28 and slightly protrudes from the upper end of the steering shaft 22. The center of the direction indicating plate 26 is screwed to the upper end surface thereof. 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 of the upper end of the inner pipe 28. Reference numeral 37 is a transparent cap for protecting the direction indicating plate 26.

In such a structure, when the steering wheel 23 is in the straight-ahead position, the spline teeth 36 of the inner pipe 28 are located substantially in the middle of the diagonal spline portion 35 of the indicator shaft 34 in the vertical direction (FIG. 1).
Condition). When the steering wheel 23 is rotated in this state, the steering shaft 22 integrally rotates, 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. The inner pipe 28 cannot be rotated because it is spline-coupled to the fixed side support pipe 31, and therefore the inner pipe 28 moves only in the vertical direction by the rotation of the steering shaft 22. On the other hand, the inner pipe 28
The spline teeth 36 on the upper end of the indicator shaft 34
Since it is meshed with the diagonal spline portion 35, when the inner pipe 28 moves upward or downward, the movement causes a vertical force and a rotational force to act on the indicator shaft 34. However, since the indicator shaft 34 is rotatably supported by the support pipe 31, it cannot be moved in the vertical direction, so the indicator shaft 34 only rotates clockwise or counterclockwise. In this way, the direction indicating plate 26 is rotated by the rotation operation of the steering wheel 23.

In a general reach type forklift, the rotation speed of the steering wheel 23 is proportional to the rotation speed of the steering wheel. The ring is about 1 /
It is set to rotate twice. Therefore, in this example, if the pitch of the screw portions 27 and 29 or the inclination of the oblique spline portion 35 is designed so that the ratio of the rotation speed of the steering wheel 23 to the rotation speed of the direction indicating plate 26 is about 12, Direction of steering wheel and direction indicator plate 26
The orientation of can be matched. In the reach type forklift, when the steering wheel 23 is rotated to the right, the steered wheels rotate to the left, so that the direction indicating plate 26 also rotates to the left. It is necessary to determine the inclination of the diagonal spline portion 35.

In the above embodiment, the steering wheel 2
The speed reduction / transmission mechanism that transmits the rotational movement of No. 3 to the direction indicating plate 26 while decelerating the rotation is performed by the inner pipe 28, the support pipe 31, and the screw portions 27 and 29 of the indicator shaft 34 and the spline portion 30. , 35, 36, but any other type of transmission mechanism or reduction mechanism can be used as long as it can be built in the steering shaft 22. For example, the spline teeth 36 at the upper end of the inner pipe 28
Alternatively, a single engagement pin may be formed on the indicator shaft 34, and an oblique groove into which the engagement pin is fitted may be provided on the indicator shaft 34 to function similarly.

[0015]

As described above, according to the present invention, since the direction support plate indicating the direction of the steering wheel 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 confirmed in an instant, driving operation in a narrow passage or a corner portion becomes extremely easy and work efficiency is improved.

Further, since most of the constituent elements are compactly accommodated 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 layout within the machine base is increased.

The present invention is particularly suitable for a reach type forklift in which the steered wheels are hard to see from the driver's seat, but it goes without saying that it may be applied to other industrial vehicles.

[Brief description of drawings]

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

FIG. 2 is a plan view showing a steering wheel direction indicator according to the present invention.

FIG. 3 is a schematic view showing a conventional general reach type forklift and a conventional steering wheel direction indicator.

FIG. 4 is an enlarged view of the conventional steering wheel direction indicator of FIG.

[Explanation of symbols]

 22 Steering Shaft 23 Steering Wheel 26 Direction Indicator Plate 27 Female Thread Part 28 Inner Pipe 29 Male Thread Part 30 Straight Spline Part 31 Support Pipe 34 Indicator Shaft 35 Oblique Spline Part 36 Spline Teeth

Claims (1)

[Claims] 1. A steering shaft to which a steering wheel is attached has a hollow structure, and a direction indicating plate is rotatably attached to the center of the upper end of the steering shaft so that the direction of a steering wheel and the direction of the direction indicating plate coincide with each other. A steering wheel direction indicating device in an industrial vehicle having a transmission mechanism and a speed reduction mechanism for decelerating the rotational movement of the steering shaft at a predetermined ratio and transmitting the speed to the direction indicating plate.