JPH0155144B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an axle extension/contraction device for a self-propelled working vehicle such as a self-propelled aerial work vehicle or a self-propelled crane vehicle.

In self-propelled work vehicles that are subject to overturning moments during work, the axles are made extendable and retractable in order to ensure the stability of the vehicle body supported by the wheels and to facilitate transportation. It is. However, with conventional axle extension and contraction, the axle is extended and retracted by pressing the tip of the work vehicle's boom against the ground surface and lifting the vehicle body to lift the wheels off the ground, which can cause excessive force to be applied to the boom, etc., and cause internal damage. Or, if work is carried out despite the deformation, there is a risk of damage or other accidents, and if the strength of the boom is increased to withstand excessive force, the weight of the boom will increase. It was hot.

The present invention was made in view of the above circumstances, and it is possible to avoid applying excessive force to the boom etc.
The object of the present invention is to provide an axle extension/retraction device for a self-propelled work vehicle that can safely and smoothly extend/retract the axle.

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a self-propelled aerial work vehicle, in which a swivel base is mounted on a chassis 1 equipped with four wheels 2, 2', 3, 3' on the front, rear, left and right sides via a swivel ring 4. A stand 5 is provided, and one end of a telescopic boom 6 is pivotally supported on the rotating base 5. The telescopic boom 6 is extended and contracted by a built-in telescopic cylinder (not shown), and is raised and lowered by a lifting cylinder 7. A work platform 8 is held in equilibrium at the tip of the telescopic boom 6, and when the telescopic boom 6 is in a retracted state, the center of gravity of the working vehicle is located at a position offset from the center of the vehicle platform 1 to the rear of the swing base 5.

The four wheels 2, 2', 3, 3' have outer boxes 10, 11 provided at the front and rear of the chassis 1, and inner boxes 12, 12', 13, which are telescopically fitted into the outer boxes 10, 11, respectively. 1
The inner box 12,1 of the axle consists of 3' and
Each inner box 12, 12', 13, 13' is attached to the outer box 10, 11 by expansion and contraction of a built-in telescopic cylinder 14, 14', 15, 15'. It expands and contracts.

Note that the wheels of at least one of the front and rear axles are connected to a drive motor (not shown).

A cylinder 9 is provided in the center of the chassis 1 so as to expand and contract vertically downward, and as the cylinder 9 expands, the front or rear wheels of the wheels rise up. A plate 16 is swingably attached to the tip of the cylinder 9.

With the self-propelled aerial work vehicle having the above structure,
When extending the axle of the work vehicle from the contracted state,
Fully retract the telescopic boom 6 and position it in front of the vehicle chassis 1, rotate the swing base 5 to a position where the axis of the telescopic boom 6 is parallel to the longitudinal center line of the vehicle chassis 1, and move the center of gravity to the rear of the vehicle chassis 1. Then, as shown in FIG. 3, the cylinder 9 provided in the center of the chassis 1 is extended to raise the front of the chassis 1, the front wheels 2, 2' are lifted off the ground, and the inner boxes 12, 12' and the outer box 10 are raised. Unfix the telescopic cylinder 1.
4, 14' and inner box 12, 1.
2' is made to protrude from the outer box 10, and in this state, the inner boxes 12, 12' are fixed to the outer box 10 with pins or the like to maintain the extended state of the axle. Next, after contracting the cylinder 9, the rotating base 5 is rotated 180 degrees as shown in FIG.
By positioning the vehicle to the rear, the center of gravity of the work vehicle is placed in front of the chassis 1, and the cylinder 9 provided in the center of the chassis 1 is extended again to raise the rear of the chassis 1, and the rear wheels 3, 3' are placed on the ground. Then, release the fixation between the inner boxes 13, 13' and the outer box 11, extend the telescopic cylinders 15, 15', and move the inner boxes 13, 13' to the outer box 1.
1, and in this state, insert the inner box 1.
3 and 13' are fixed to the outer box 11 with pins or the like to keep the axle in an extended state.

When the axle is contracted from the extended state, the wheels 2 and 2 are moved by moving the center of gravity by moving the turning base 5 and by elongating the cylinder 9 provided in the center of the chassis 1, in the same way as when extending the axle described above. ',3,
3' from the ground one after another, respectively, inner boxes 12, 12', 13, 13' and outer box 1.
Release the fixation with 0 and 11, and remove the telescopic cylinder 14,
14', 15, and 15' are contracted to sequentially contract the inner box into the outer box, and in this state, the inner box is fixed to the outer box with a pin or the like to maintain the axle in the contracted state.

As described above, according to the present invention, a self-propelled work vehicle with a simple structure can safely and smoothly extend and retract the front and rear axles without applying excessive force to the boom etc. A vehicle axle extension device is provided.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a side view of a self-propelled aerial work vehicle, FIG. 2 is a plan view of FIG. 1,
FIGS. 3 and 4 are explanatory diagrams of axle expansion and contraction. 1... Chassis, 2, 2', 3, 3'... Wheels, 5...
... Rotating base, 9... Cylinder, 10, 11... Outer box, 12, 12', 13, 13'... Inner box, 14, 14', 15, 15'... Telescopic cylinder.

Claims (1)

[Claims] 1. A self-propelled type consisting of a vehicle chassis that has a telescopic axle with wheels at both ends at the front and rear, a rotating base mounted approximately in the center of the chassis, and a boom with one end pivoted to the rotating base so that it can rise and fall freely. In a work vehicle, the center of gravity of the work vehicle is located at a position offset from the center of the undercarriage to the rear of the swivel base when the telescoping boom is retracted, and the undercarriage is located at the center of four wheels provided on the front, rear, left and right sides of the undercarriage. An axle expansion and contraction device for a self-propelled work vehicle, characterized in that a single cylinder that expands and contracts vertically downward is provided in the center of the vehicle.