JPH106843A - Steering mechanism for trackless industrial vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a steering mechanism for a trackless running truck used in a heavy object conveyance field. SOLUTION: Traveling steering mechanisms 17 are arranged on both the front and rear sides in the traveling direction at the car body 12 of a conveyance vehicle 11. A running steering mechanism 17 is formed such that when the conveyance vehicle 11 turns, a turning center 16 is positioned on extension of the axis of a rigid axle 15 and the normals of inner and outer wheels 14 and 13 always coincide with each other. Since a difference between the inner and outer wheels 14, 13 is not provided for the steering angles γ of the inner and outer wheels 14 and 13, a need for control of each wheel is eliminated and steering of a shaft unit may be always controlled on the rigid axle 15 and a mechanism for steering is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering mechanism for a trackless industrial vehicle used for conveying heavy objects.

[0002]

2. Description of the Related Art Conventionally, as a trackless industrial vehicle, in the field of transporting heavy goods such as freight containers, metal strip coils, slabs and billets which are lump of metal material, and steel raw materials, for example, there are various types of vehicles. A transportation vehicle as shown in 1-444380 is used. FIG. 9 shows a schematic configuration of an all-wheel steering transport cart. Transport vehicle 1
Is loaded on the upper surface of the vehicle body 2 and used for distribution in a container yard or a factory. The transport vehicle 1 is provided with a steering mechanism so that the traveling direction can be freely changed in a predetermined area. In order to reduce the turning radius in the case of changing the direction, it is necessary to perform control to change the steering angles α and β between the outer wheel 3 and the inner wheel 4 during turning. For this reason, the steering joint 5 is used to steer at an angle such that the outer wheel 3 and the inner wheel 4 pass on a concentric circle centered on the turning center 6. In the conventional transport vehicle 1, a method of independently steering each wheel by such a kingpin method is often used. In addition, Japanese Patent Publication No. 50-39288 discloses a prior art for a cargo handling vehicle.

[0003]

The method of independent steering of each wheel by the kingpin method as shown in FIG. 9 requires correction control for each wheel in order to eliminate the influence of inner and outer wheel differences.
The steering mechanism becomes complicated. Although the steering mechanism using the kingpin method is widely used in ordinary automobiles and the like, especially in the transport vehicle 1 which needs to carry heavy objects and change directions with a small turning radius, it can withstand a large load for each wheel. , A mechanism for steering while correcting the angle must be provided.

[0004] It is an object of the present invention to provide a steering mechanism for a trackless industrial vehicle which can easily eliminate the influence of a difference between the inner and outer wheels at the time of turning and can easily steer.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a pair of wheels which are grounded on a road surface and whose tangential directions on the outer periphery are parallel to each other, the center of each wheel is connected, an axle parallel to the road surface, and a center between the wheels. so,
A steering mechanism for turning an axle around an axis perpendicular to a road surface. According to the present invention, since the steering means turns the axle around the axis perpendicular to the road surface at the center between the wheels, the turning center exists on the axial extension of the axle, and the inner ring and the outer ring are located with respect to the turning center. Normals coincide. Since there is no difference between the inner and outer wheels in the normal direction, the steering mechanism can be simplified and can easily withstand the transport of heavy objects.

In the present invention, the pair of wheels, axle and steering means are provided on both sides of the vehicle body in the traveling direction. According to the present invention, since a configuration capable of steering by turning the axle at the center between the wheels is provided on both sides in the traveling direction of the vehicle body, steering with a small turning radius can be performed.

Further, according to the present invention, wheels on both sides of the axle are
It is characterized by having a differential gear mechanism for compensating and driving the difference between the inner and outer wheels during turning. According to the present invention, since the axle has a differential gear mechanism for driving while compensating for the difference between the inner and outer wheels during turning, the axle is turned at the center between the wheels while driving the wheels for traveling,
The direction of the vehicle can be changed.

In the present invention, the steering means is fixed to the vehicle body, and has a fixed gear through which a shaft for turning the axle passes through the center, and a planetary gear engaged with the fixed gear and performing planetary motion along the outer periphery of the fixed gear. And a motor that rotationally drives the planetary gears, and a support member that supports the planetary gears, the motor and the axle. According to the invention, when the planetary gear and the prime mover are supported by the support member and the planetary gear is driven to rotate by the prime mover, the planetary gear meshes with the fixed gear, so that planetary motion occurs along the outer periphery of the fixed gear.
This planetary motion is also transmitted to the axle via the support member,
At the same time, it is turned around an axis perpendicular to the road surface. The direction of the vehicle can be changed so that the turning center exists on the extension of the axle without changing the mounting angle of the wheel with respect to the axle.

[0009]

FIG. 1 shows a schematic configuration of a transport vehicle 11 according to an embodiment of the present invention. The wheels that support the vehicle body 12 include an outer wheel 13 and an inner wheel 14 that are outside and inside a turning radius at the time of direction change.
The turning center 16 is located on the axial extension of the rigid axle 15, that is, on the extension of the normal to each wheel. A traveling steering mechanism 17 is provided near the center of the rigid axle 15. The traveling steering mechanism 17 causes the rigid axle 15 to pivotally displace around the axis perpendicular to the road surface at the center of the rigid axle 15 so that the pivoting center 16 is positioned on the axial extension of the rigid axle 15. Can be. The traveling steering mechanism 17 also includes a mechanism for rotationally driving the outer wheel 13 and the inner wheel 14 for traveling. Even if the vehicle is turned at a large angle γ around an axis 17a perpendicular to the road surface, the traveling steering mechanism 17 has The tangential directions are always parallel, and the outer wheel 13 and the inner wheel 14 can be driven while the difference between the inner and outer wheels is eliminated, so that the transport vehicle 11 can travel.

FIG. 2, FIG. 3, FIG. 4 and FIG. 2 is a front view, FIG. 3 is a plan view, FIG. 4 is a cross-sectional view taken along section line IV-IV in FIG. 3, and FIG. 5 is a cross-sectional view taken along section line VV in FIG. . The vehicle body 12 includes a chassis 18 and bumpers 19 provided at both ends in the traveling direction. Chassis 18
Near the center of the diesel engine 20
The radiator unit 21, the air cleaner 22, the flywheel 23, the hydraulic pump 24, the silencer 25, the fuel tank 2
6, battery 27, accumulator 28, valve block 2
9 and a control device 30 are arranged. The radiator unit 21 cools the diesel engine 20, and the air cleaner 22 cleans the combustion air supplied to the diesel engine 20. Flywheel 23
Smoothes the rotational output of the diesel engine 20, the hydraulic pump 24 is driven by the rotational output of the diesel engine 20, and supplies hydraulic oil to the traveling steering mechanism 17.
The silencer 25 is provided in an exhaust system for exhaust gas from the diesel engine 20 to reduce noise. The fuel of the diesel engine 20 is stored in a fuel tank 26. Battery 27 serves as a power source for electrical control. The working oil supplied from the hydraulic pump 24 is temporarily stored in the accumulator 28. The hydraulic oil is supplied from the accumulator 28 to the traveling steering mechanism 17 via the valve block 29. The opening and closing control of various valves in the valve block 29 is performed by the control device 30. Transport vehicle 1
The running condition 1 is controlled by remote control via a radio or the like.

The traveling steering mechanism 17 has a fixed gear 31, a planetary gear 32, a steering hydraulic motor 33, a support member 34, a differential gear mechanism 35, and a traveling hydraulic motor 36. From the differential gear mechanism 35, an axle 37 and an axle tube 38 extend on both sides of the rigid axle 15 in the axial direction.
The two tires 39 and 40 are mounted respectively, and support the load in a double tire system. Differential gear mechanism 35 and support member 3
4, a suspension 41 is provided by a leaf spring. In this embodiment, a steering system using a hydraulic motor is used, but electric or pneumatic can be used in addition to hydraulic pressure, and a cylinder system can be used in addition to the motor system.

FIG. 6, FIG. 7 and FIG.
7 shows a detailed configuration. 6 is a front view, FIG. 7 is a plan view, and FIG. 8 is a right side view of FIG. The steering hydraulic motor 33 and the traveling hydraulic motor 36 are driven to rotate in accordance with the pressure of the operating oil controlled by the valve block 29 described above. A planetary gear 32 is mounted on the output shaft of the steering hydraulic motor 33 and meshes with the fixed gear 31. When the planetary gear 32 is driven to rotate, the fixed gear 3
A planetary motion is performed along the outer periphery of the road surface 1, so that the support member 34 can be displaced around the turning axis 17 a perpendicular to the surface of the road surface 42. The differential gear mechanism 35 is rotationally driven by a traveling hydraulic motor 36, and is suspended below the support member 34 by a suspension 41 together with an axle 37 and an axle tube 38 on both sides in the axial direction as the rigid axle 15. Double tire specification tires 39 and 40
However, when the traveling direction is changed, a difference in the number of rotations occurs due to a difference in the turning radius, and when the rotation is performed at the same speed, the vehicle slips and the load increases. The differential gear mechanism 35 is used to eliminate the difference in the number of rotations of the drive wheels between the inner and outer wheels, similarly to a differential device used in a general automobile. Since the difference between the inner and outer wheels occurs even between the tires 39 and 40 of the double tire specification, the tires 39 and 40 are used to eliminate the difference between the inner and outer wheels.
Only one of them is driven, and the other is in a free rotation state so as to bear only the load.

When a cylinder type steering mechanism is used,
For example, a pair of cylinders are respectively arranged between the vehicle body 12 and both sides in the axial direction near the center of the rigid axle 15. Extending one and contracting the other allows the rigid axle 15 to pivot about an axis perpendicular to the road surface.

In the embodiment described above, the traveling steering mechanisms 17 are provided on both sides of the vehicle body 12 in the traveling direction, and steering control with a large steering angle and a small turning radius is enabled by all-wheel steering. Front-wheel steering in which only the front side is steered in the traveling direction and rear-wheel steering in which only the rear side is steered are possible. Further, at the time of all-wheel steering, it is also possible to make the one steering direction different from the other steering direction, and to make the transport vehicle 11 run obliquely at an angle deviated from the center line of the vehicle body 12. In the embodiment of FIG. 1, the steering angle γ by the traveling steering mechanism 17 can be up to about ± 45 °, and various steering controls can be performed in various modes.

In the embodiment shown in FIG. 1, the same traveling steering mechanism 17 is used on both sides in the traveling direction of the vehicle body 12 to perform all-wheel steering and all-wheel drive. It can also be an axle.
By providing the traveling steering mechanism 17 only on one side, the capacity of the hydraulic pump 24 and the like can be reduced, and the weight of the transport vehicle 11 can be reduced. In addition, the transport vehicle 11 can be applied not only to heavy load transport but also to light and medium load transport fields. At the time of transporting light and medium-weight materials, instead of the steering hydraulic motor 33 and the traveling hydraulic motor 36, electric motors may be used, and the battery 27 may be operated as an energy source without using a prime mover such as the diesel engine 20. it can.

[0016]

As described above, according to the present invention, the normals of the inner and outer wheels coincide with the turning center on the extension of the axle,
Since there is no difference between the inner and outer rings, the direction can be changed smoothly as it is. Since it is not necessary to control the steering angle for each wheel, and the direction can be constantly changed by the steering control for each axle, the steering mechanism can be simplified and the control can be easily performed.

According to the present invention, the wheels provided on both sides in the traveling direction of the vehicle body can be turned around the axis perpendicular to the road surface at the center between the wheels. By doing so, the steering angle can be increased and the turning radius can be reduced.

According to the present invention, the wheels on both sides of the axle can be driven while compensating for the difference between the inner and outer wheels by the differential gear mechanism, so that not only the direction of the wheels but also the rotational speed can be adjusted, and the inner and outer wheels can be adjusted. The difference can be eliminated.

Further, according to the present invention, it is possible to fix the fixed gear to the vehicle body, generate planetary motion along the outer periphery of the fixed gear by the planetary gear, change the direction of the axle via the support member, and perform steering. Therefore, the steering mechanism can be simply configured, and can easily withstand a heavy load when a heavy object is conveyed.

[Brief description of the drawings]

FIG. 1 is a simplified plan view showing a basic configuration of an embodiment of the present invention.

FIG. 2 is a front view of the transport vehicle 11 of FIG.

FIG. 3 is a plan view of the transport vehicle 11 of FIG.

FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 3;

FIG. 5 is a cross-sectional view taken along the line VV of FIG. 2;

FIG. 6 is a front view of the traveling steering mechanism 17 of the embodiment of FIG.

7 is a plan view of the traveling steering mechanism 17. FIG.

8 is a right side view of the traveling steering mechanism 17. FIG.

FIG. 9 is a simplified plan view of a conventional transport vehicle 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Conveyance vehicle 12 Body 13 Outer ring 14 Inner ring 15 Rigid axle 16 Turning center 17 Traveling steering mechanism 17a Axis line 20 Diesel engine 24 Hydraulic pump 26 Fuel tank 27 Battery 30 Control device 31 Fixed gear 32 Planetary gear 33 Steering hydraulic motor 34 Support member 35 Differential gear mechanism 36 Traveling hydraulic motor 37 Axle 39,40 Tire 42 Road surface

Claims (4)

[Claims] 1. A pair of wheels which are grounded on the road surface and whose tangential directions of the outer circumference are parallel to each other, and which connect the centers of the respective wheels to each other, an axle parallel to the road surface, and a center between the wheels around an axis perpendicular to the road surface. A steering mechanism for turning an axle. 2. The trackless industrial vehicle steering mechanism according to claim 1, wherein said pair of wheels, axle and steering means are provided on both sides of the vehicle body in the traveling direction. 3. The trackless industrial vehicle according to claim 1, further comprising a differential gear mechanism for driving wheels on both sides of the axle while compensating for a difference in inner and outer wheels during turning. Steering mechanism. 4. A steering gear fixed to a vehicle body, a fixed gear through which a shaft for turning the axle passes through the center, a planetary gear meshing with the fixed gear and performing planetary motion along the outer periphery of the fixed gear; The steering mechanism for a trackless industrial vehicle according to any one of claims 1 to 3, further comprising a motor that rotationally drives the planetary gears, and a support member that supports the planetary gears, the motor and the axle.