JPH0229549B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention consists of a pair of left and right telescopic telescoping beams that are integrally fixed with the base outer cylinders adjoining the front and back so that they can extend to both sides, and jacks attached to the ends of the telescopic beams. This invention relates to a truck crane in which an outrigger is fixed to a vehicle body and a turntable for swinging the crane is located above the rear wheels.

In such a truck crane, outriggers must be installed before and after the safe limit circle of the center of gravity of the entire truck crane including the suspended load, whereas the crane revolving body consisting of a telescopic boom and swivel base is mounted on the vehicle body. Even if it is removably attached to a crane and transported disassembled while driving on the road, the maximum lifting capacity of the crane is limited to a certain limit (applicant's experience Therefore, it is not possible to increase the amount by more than 75 tons.
This is because an increase in lifting capacity, together with an increase in the weight of the crane revolving body such as a telescopic boom, significantly increases the radius of the safety limit circle. This is because not only does the length have to be increased, but also the increased strength of the vehicle body and outriggers causes an increase in the weight of the vehicle.

The present invention addresses this problem and aims to increase the maximum lifting capacity of a crane beyond the above-mentioned limit relative to the external dimensions of an automobile.

In order to achieve the above object, the present invention consists of a pair of left and right telescopic telescoping beams that are integrally fixed with the base outer cylinders adjoining the front and rear so as to be able to extend to both sides, and a jack attached to the tips of the telescopic beams. In a truck crane in which the base outer cylinders of the outriggers are each fixed to the vehicle body, and the supporting turntable of the crane revolving body is removably attached to the vehicle body above the rear axle, the front outriggers are installed behind the front wheels and at the rear. The outriggers are installed behind the rear wheels and approximately adjacent to each other, so that the rear part of the safety limit circle at the center of gravity of the entire truck crane including the suspended load intersects with the center line connecting the jacks on both sides of the extended rear outrigger. At the rear end of the outer cylinder at the base of the vehicle body or rear outrigger, a swing arm is provided with a rear end jack having a larger supporting force than the front and rear outrigger jacks at its tip, and the jack center on both sides of the rear outrigger from which the rear end jack extends is Pivotably pivotable between an extended position located behind the intersection of tangents to the safety limit circle and a retracted position within the vehicle width along the rear end of the base outer cylinder of the vehicle body or rear outrigger. Means for fixing the swing arm in the extended position and the retracted position is provided on the vehicle body side.

An embodiment of the present invention in which the maximum lifting capacity of the crane is increased to approximately 120 tons will be described below with reference to the drawings. The vehicle body 1 of the truck crane has a box-shaped body frame 1a running longitudinally through the center, and a crane rotating body 4 is mounted on the vehicle body via a turntable 3 located directly above the two-axle rear wheels 2 of the body frame 1a. It is mounted so that it can rotate 360 degrees around the center 0 or the crane rotation axis 0-0. The crane revolving body 4 includes all structures and equipment supported on the turntable 3, such as a telescopic boom 5 consisting of five box-shaped boom tubes and a swivel base 6 that supports the telescopic boom in a cantilever manner so that the boom can be raised and lowered. including.

A vehicle body frame 1a is installed substantially adjacent to the rear wheel 2.
The rear outrigger attached to the lower part of the rear end consists of a pair of left and right telescopic telescoping beams 7 that are fixed together with box-shaped base outer cylinders 7a adjacent to each other in the front and rear, and hydraulically operated jacks that are installed perpendicularly to the tips of the telescopic beams 7. Consists of 8. As shown in FIG. 3, each telescopic beam 7 has a box-shaped middle cylinder 7b slidably inserted into a base outer cylinder 7a, and a box-shaped inner cylinder 7c slidably inserted into the middle cylinder. Built-in multi-stage hydraulic cylinder (not shown)
The base outer cylinder 7a is expandable and retractable.
The tops of the thickened portions 7a' at both ends are welded and fixed to both sides of the vehicle body frame 1a via box-shaped brackets 7d. As in the prior art, a ground plate 8a is removably attached via a spherical joint to the lower end of the piston rod of the jack 8 whose cylinder side is fixed to the tip of the inner tube 7c.

The front and rear outriggers, which are attached to the lower part of the vehicle body frame almost adjacent to the back of the front wheels 9, are also attached perpendicularly to the tips of a pair of left and right telescopic telescopic beams 10, which have exactly the same configuration as the rear outriggers 7 and 8. It consists of a hydraulically operated jack 11,
The configuration for attaching it to the vehicle body frame is also similar.

Therefore, the jacks 8, 11 on both sides of the front and rear outriggers in the illustrated extended position are located at the vertices of a parallelogram as shown in FIG. 2, and the center line 12 connecting the jacks 8, 8 on the rear outrigger side, A center line 13 connecting both jacks 11, 11 on the front outrigger side intersects a safety limit circle 14 at the center of gravity of the entire truck crane including the suspended load.

Reference numeral 15 denotes a swing arm whose base end is pivotably pivoted by a vertical pin 16 at a portion slightly left of the center of the rear end of the vehicle body, and a hydraulically operated rear end jack 17 is vertically attached to the tip of the swing arm 15. Installed. The swing arm 15 can be fixed in the extended position shown in solid line in FIG.
It can also be folded into the storage position shown by the dashed lines in the same figure, and secured to the vehicle body 1 as appropriate.

Rear end jack at swing arm extended position 17
is a circle 20 concentric with the safety limit circle 14 and tangent to the center line 19 connecting the front and rear jacks 8, 11 on each side.
It is located on the intersection of tangent lines 21 and 22 drawn from the center of 8, and equalizes the fall prevention function of the truck crane when it is lifted from the side and when it is lifted from the rear.

Reference numeral 23 denotes a hydraulically operated front end jack installed vertically at the center of the front end of the strong part of the vehicle body frame 1a, and the front end jack 23 is connected to the jacks 11 and 1 on both sides.
Tangent lines 24 and 25 drawn from the center of 1 to the circle 20
However, in order to reduce the jerking capacity and prevent interference with the front wheel steering mechanism, it is located approximately at the front end of the front wheels 9. The front and rear end jacks 23, 17 are different from other jacks in that their cylinders are fixed to the vehicle body or the swing arm side, and ground plates 23a, 17a are removably attached to the lower end of the piston rod via a spherical joint. It is similar to

During cargo handling work, the locus of the center of gravity of the entire truck crane in an unloaded state is a concentric circle with a radius smaller than the safety limit circle 14, and is located between the front and rear center lines 12 and 13 regardless of whether the crane revolving body 4 turns. First, extend the telescopic beams 7, 10 on both sides and the swing arm 15 as shown in Fig. 2, then support the vehicle body 1 on the ground with the jacks 8, 11 on both sides, and then lower the vehicle body 1 with the jacks 17, 23 at the front and rear ends. After supporting the vehicle on the ground and adjusting the expansion and contraction of each jack using a level on the vehicle body so that the vehicle body is horizontal, cargo handling work is carried out.

When the telescopic boom 5 lifts a load 26 to its full lifting capacity, the locus of the center of gravity G of the entire truck crane becomes a safety limit circle 14. For example, if the telescopic boom 5 is performing side-hanging cargo handling work at a turning angle that is located within the lateral vertical plane of the vehicle body 1, as shown in FIG. 2 or 4, the turning center of the vehicle body 0 The weight load W of the entire truck crane including the suspended load, and the moment load M in the lateral vertical plane corresponding to the product of the weight load and the horizontal distance from the center of gravity 0 to the center of gravity G act. Rear outrigger 7,
8 and the center of the front outriggers 10 and 11, respectively.
The weight load Wa, Wb and the moment load Ma are inversely proportional to the horizontal distance between this and the center of rotation 0,
Mb will act, but the weight load before and after
Since Wb and Wa are substantially supported by the jacks 23 and 17 at the front and rear ends, the front and rear outriggers only need to receive the moment loads Mb and Ma.

As the telescopic boom 5 turns from this turning angle position to any arbitrary turning angle position such as rear suspension or front suspension, a moment load component in the vertical plane in the longitudinal direction acts on the vehicle body. The bending rigidity of is significantly greater than that of the telescopic beams 7 and 10, and the supporting force of the front and rear end jacks 23 and 17 is greater than that of the side jacks 8 and 11, so there is no problem. A relief valve is appropriately connected to the high-pressure side cylinder chamber when the supporting force of the front and rear end jacks 23, 17 is generated.
7 contracts to some extent and transmits a part of the vertical load to the side jacks 8, 11.
It is also possible to reduce the load capacity of the front and rear end jacks.

Therefore, there is no risk that the front and rear outriggers will receive weight loads and moment loads at the same time as in conventional truck cranes.
10 (in particular, the inner cylinder 7c), the telescopic beam 7 of the rear outrigger, which receives particularly large loads among the front and rear outriggers, is deflected significantly more than the telescopic beam 10 of the front outrigger. , there is no risk of deterioration in crane lifting performance due to the inclination of the swivel base 6.

The case of a full-swing type crane in which the lifting capacity is constant regardless of the rotation angle of the crane revolving body has been described above. is behind the rear wheel, and the front outrigger is approximately adjacent to the rear of the front wheel 9. Since the ratio of the distance to Furthermore, while the rear outrigger is attached to the rear end of the car body, which has been reinforced to accommodate the crane revolving body 4 and the rear wheels and has become a torsionally rigid body, the crane revolving body attachment part and the front outrigger are Since the torsional rigidity of the vehicle body between the attachment parts is relatively low, the moment load applied to the rear outriggers increases even more, and if front lifting is prohibited or the center of gravity of the entire truck crane is For example, when the load to be lifted at the time of front suspension is limited so as to be located behind the center line 13, the front end jack 23 can be removed.

Since the present invention has the above configuration, the following effects are achieved.

During cargo handling work with the swing arm fixed in the extended position, the front outriggers are approximately adjacent to the rear of the front wheels, and the rear outriggers are approximately adjacent to the rear of the rear wheels.
This is due to the fact that the support turntable of the crane revolving body is located above the rear axle because the amount of protrusion of the safety limit circle 14 rearward from the center line 12 connecting the jacks on both sides of the extended rear outrigger is small. It is possible to prevent the deflection of the telescopic beam of the rear outrigger from becoming significantly larger than that of the telescopic beam of the front outrigger by using a rear end jack with a large supporting force attached to a short swing arm that can be stored within the width of the vehicle. Therefore, the lateral extension length of the front and rear outriggers can be reduced while preventing an increase in the bending rigidity of the telescoping beam of the rear outrigger and the resulting increase in the weight of the vehicle, in which the outrigger weight or axle load is suppressed to 10 tons or less per axle. In addition, when a car is driven on the road with the crane revolving body removed, which should be transported separately, the revolving arm is fixed in the retracted position, and the rear wheels are adjusted according to the increase in the lateral extension length of the front and rear outriggers. By eliminating the need to increase the length of the rear vehicle body or vehicle, the maximum lifting capacity of the crane can be increased to approximately 120 tons at once within the limits set by automobile-related laws and regulations.

[Brief explanation of drawings]

FIG. 1 is a side view of an embodiment of the present invention when the outriggers are extended; FIGS. 2 and 3 are a plan view and a rear view of the vehicle body portion thereof; and FIG. 4 is a perspective view showing the load distribution of the overturn prevention device. It is a diagram. 1...Vehicle body, 2...Rear wheel, 3...Turntable,
4...Crane revolving body, 5...Telescopic boom, 7,10
...Telescopic telescopic beam, 8, 11... Jacket, 9... Front wheel, 12... Center line, 14... Safety limit circle, 15... Swivel arm, 17... Rear end jack.

Claims (1)

[Scope of Claims] 1. The bases of the front and rear outriggers, which consist of a pair of left and right telescopic telescopic beams that are integrally fixed with the base outer cylinders adjoining the front and back so that they can be extended to both sides, and jacks attached to the tips of the beams, respectively. In a truck crane in which the outer cylinders are respectively fixed to the vehicle body and the supporting turntable of the crane revolving body is removably attached to the vehicle body above the rear axle, the front outriggers are attached behind the front wheels and the rear outriggers are attached to the rear. A safety limit circle 1 of the center of gravity of the entire truck crane including the suspended load is provided approximately adjacent to each other behind the wheels.
The rear part of the rear outrigger 4 intersects the center line 12 connecting the jacks 8, 8 on both sides of the protruding rear outrigger, and the rear end of the outer cylinder of the base of the vehicle body or the rear outrigger is connected to the jacks 11, 8 of the front and rear outriggers. The swing arm 15, which has a rear end jack 17 with a large supporting force at its tip, is installed behind the intersection of tangents to the safety limit circle 14, which pass through the jack centers on both sides of the rear outriggers from which the rear end jack 17 extends. The swing arm is pivotably pivoted between an extended position and a retracted position within the vehicle width along the rear end of the base outer cylinder of the vehicle body or rear outrigger, and the swing arm is fixed in the extended position and the retracted position, respectively. A toppling prevention device for a truck crane, characterized in that a means for preventing the overturning of a truck crane is provided on the vehicle body side. 2 Center line 19, 1 connecting the front and rear jacks 11, 8 on the left and right sides of the extended front and rear outriggers
9 is configured so that it touches a concentric circle 20 having a larger diameter than the safety limit circle 14 at the center of gravity of the entire truck crane including the suspended load, and the rear end jack 17 of the protruding swing arm and the jacks 8 on both sides of the protruding rear outrigger are The overturn prevention device for a truck crane according to claim 1, wherein the extending position of the swing arm is set so that the center lines 21 and 22 connecting the two concentric circles are in contact with the concentric circles.