JPH0752148Y2 - Crane jib - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a crane jib.

[Prior Art] FIG. 3 shows an example of a conventional crane jib, which is composed of a beam member 2, a boom 5, a tension member 7, an intermediate member 8, a boom tilting member 9, and the like.

The beam member 2 is pivotally supported at its base end on a support member 23 provided on the upper part of the upper swing body 1.

The boom 5 is formed by connecting a plurality of lattice booms, and the base end portion thereof is pivotally supported by the pin 6 at the tip end portion of the beam member 2.

As shown in FIG. 4, the tension member 7 is composed of two members, and is 2 when the pin 24 is pulled out.
To allow relative displacement in the longitudinal direction of the two members,
Further, in the state where the pin 24 is fitted in the hole formed in each of the two members, the relative displacement of the two members in the longitudinal direction is restricted.

The base end of the tension member 7 is pivotally supported by the support member 23.

The tip of the intermediate member 8 is near the tip of the beam member 2 (near the portion that pivotally supports the base end of the boom 5).
Is pivoted to.

The boom tilt stop member 9 has its tip end pivotally supported on the rear part 10 of the boom 5.

The tip end portions of the tension member 7, the intermediate member 8 and the boom tilt stop member 9 described above are rotatably connected to the upper end connecting portion 11, and the tension member 7, the intermediate member 8 and the boom tilt stop member 9 enable An A frame 22 having a triangular side surface is formed.

The upper connecting portion 11 and the tip 12 of the boom 5 are connected by a pendant cable 13.

In the crane jib having such a structure, the elevation angle is changed by operating the elevation cylinder 3 provided between the beam member 2 and the upper swing body 1.

Furthermore, the hoist drum 15 provided in the upper swing body 1
A hoist cable 14 is extended, and the hoist cable 14 is wound around a guide sheave 16 provided on the upper connecting portion 11 and hangs down from a sheave block 17 provided on the tip 12 of the boom 5, A lifting hook (not shown) is connected to the tip portion.

In the above-described crane having the crane jib, the crane jib is long, and therefore the crane jib needs to be disassembled into individual member units and transported.

For this reason, when assembling the crane jib at the work site, first, the beam member 2, the boom 5, the tension member 7, and the intermediate member in a state where the two members forming the tension member 7 can be relatively displaced in the longitudinal direction. 8. A state in which members such as the boom tilt stop member 9 are connected to each other and the boom 5 is bent so that its tip faces downward with respect to the beam member 2 as shown by the chain double-dashed line in FIG. 3 (non-working state). )
Assemble to b.

Further, a hook block 18 of another crane (not shown) is connected to the boom 5 to lift the boom 5 to a state (working state) a shown by a solid line in FIG. 3, and a tension member is provided by a pin 24 shown in FIG. The relative displacement in the longitudinal direction of the two members forming part 7 is restricted, and the mutual position of each member forming the crane jib is set to the working state a described above.

[Problems to be Solved by the Invention] However, in the conventional crane jib shown in FIG.
When installing a crane having this crane jib, another crane is required to erect the boom 5 from the non-working state b to the working state a after connecting the members forming the crane jib to each other. When another crane having the crane jib is withdrawn, another crane is also required, which increases the cost required for the assembly work and the withdrawal work.

Further, when performing the above-described assembly work and withdrawal work, a place for placing another crane is required, so that it is particularly difficult to perform the assembly work and the withdrawal work at an uneven work site such as a mountain area.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a crane jib that allows easy assembly and removal of the crane.

[Means for Solving the Problems] In order to achieve the above object, the crane jib of the present invention is
A beam member 2 supported by an upper swing body 1 so as to be capable of undulating,
A boom 5 having a base end pivotally supported by the beam member 2 and an intermediate member 8 having one end pivotally supported at the tip end of the beam member 2.
A boom tilt stop member 9 whose one end is pivotally supported by the boom 5, and a tension member 19 whose one end is pivotally supported by the base end portion of the beam member 2.
In the crane jib in which the A frame 22 is formed by pivotally supporting the intermediate member 8 and the boom tilt preventing member 9 at the tip end thereof, a fluid pressure cylinder is used as the tension member 19.

[Operation] After the fluid pressure cylinder forming the tension member 19 is extended in its entire length, the beam member 2, the boom 5, the tension member 19, the intermediate member 8, and the boom tilting member 9 are connected to each other, When the fluid pressure cylinder forming the tension member 19 is contracted, the boom 5 stands up against the beam member 2.

Further, when the fluid pressure cylinder forming the tension member 19 is extended, the boom 5 lowers with respect to the beam member 2.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

1 and 2 show one embodiment of the crane jib of the present invention. The basic construction of the crane jib of this embodiment is substantially the same as that shown in FIG. The parts denoted by the same reference numerals as those shown in the figure represent the same things.

In this embodiment, a tension member 19 is used instead of the tension member 7 shown in FIG.

The tension member 19 is a fluid pressure cylinder having a cylinder body 20 and a piston rod 21 and the like, and the piston rod 21 is displaced with respect to the cylinder body 20 by applying fluid pressure.

The cylinder body 20 that constitutes the tension member 19 is pivotally supported by a support member 23 provided on the upper part of the upper swing body 1.

Further, the tip end portion of the piston rod 21 that constitutes the tension member 19 is rotatably connected to the upper end connecting portion 11 together with the tip end portions of the intermediate member 8 and the boom tilt stop member 9, and these tension member 19 and the intermediate member The member 8 and the boom tilt stop member 9 form an A frame 22 having a triangular side surface.

In the crane jib having the above-described configuration, the beam member 2, the boom 5, the tension member 19, the intermediate member 8, and the beam member 2, as shown in FIG. 1, with the piston rod 21 of the tension member 19 pushed out with respect to the cylinder body 20. Members such as the boom tilt stop member 9 are connected to each other.

Then, by applying fluid pressure to the cylinder body 20 of the tension member 19, as shown in FIG.
When is pulled back to the cylinder body 20, the boom 5 rotates around the pin 6 and the boom 5 stands up.

When the boom 5 is erected in a predetermined state, the relative displacement between the piston rod 21 and the cylinder body 20 is restricted by an appropriate means.

In addition, the undulation of the crane jib itself having the above configuration is
Similar to that shown in FIG. 3, this is done by operating the elevation cylinder 3.

Further, when disassembling the crane jib, the piston rod 21 is pushed out to the cylinder body 20 as shown in FIG. 1 by applying a fluid pressure to the cylinder body 20 of the tension member 19 contrary to the above-mentioned procedure. , Boom 5 is pin 6
The boom 5 lowers by rotating around.

As described above, in the present embodiment, the boom 5 can be raised or lowered by displacing the piston rod 21 of the tension member 19 with respect to the cylinder body 20, so that crane assembly work or withdrawal work is performed. At this time, it is not necessary to prepare another crane, so that the cost required for the work can be reduced, and the assembling work and the withdrawing work at an uneven work site such as a mountain area can be easily performed.

The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[Effect of the Invention] As described above, in the crane jib of the present invention,
When the fluid pressure cylinder forming the tension member 19 is expanded / contracted, the boom 5 is raised / lowered with respect to the beam member 2. Therefore, it is not necessary to prepare another crane for raising / lowering the boom 5, and thus the cost required for the work is increased. In addition to reducing the number, it is possible to achieve an excellent effect that the assembling work and the withdrawing work can be easily performed at an uneven work site such as a mountain area.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view showing a state before a boom is erected with respect to a beam member in an embodiment of the crane jib of the present invention, and FIG. 2 is a view showing a boom member of the crane jib in an embodiment of the present invention. Is a partially cutaway side view showing a state after standing upright, FIG. 3 is a side view showing an example of a conventional crane jib, and FIG. 4 is a detailed view of a tension member shown in FIG. In the figure, 1 is an upper swing body, 2 is a beam member, 5 is a boom,
8 is an intermediate member, 9 is a boom tilting member, 19 is a tension member, and 22 is an A frame.

Claims (1)

[Scope of utility model registration request] 1. A beam member (2) supported by an upper revolving structure (1) so as to be capable of undulating, a boom (5) whose base end is pivotally supported by the beam member (2), and one end of which is the beam described above. Material (2)
Member (8) pivotally supported at the tip of the boom and boom tilt stop member (9) pivotally supported at one end by the boom (5).
And a tension member (19) whose one end is pivotally supported by the base end of the beam member (2), and the intermediate member (8) and the boom tilting member ( A crane jib in which the tip portion of 9) is pivotally supported to form an A frame (22), wherein a fluid pressure cylinder is used for the tension member (19).