JPH0848489A - Installation of rear post supporting cable in jib crane - Google Patents

Abstract

PURPOSE:To facilitate the installation work for the rear post supporting cable on a jib crane and improve the workability and safety. CONSTITUTION:A rear post supporting cable is half divided, and one end part 11 is jointed with a rear post 8, and the other end part 12 is installed on a tower bottom 4. The tower bottom 4 is set to a horizontal state, and the rear post 8 is suspended by an auxiliary crane 22, and the rear post 8 and a bottom head 5 are connected by a rear post supporting cylinder 9. The rear post supporting cylinder 9 is contracted to tilt the rear post 8 to the tower boom 4 side, and two rear post supporting cables 11 and 12 are connected. The rear post supporting cylinder 9 is extended by the hydraulic pressure, and the rear post 8 is erected in a specific angle, and after the rear post supporting cables 11 and 12 are laid, the tower boom 4 is erected and put to a working attitude.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jib crane, and more particularly to a method of assembling a rear post support cable in a jib crane having a rear post.

[0002]

2. Description of the Related Art A method of assembling a rear post supporting cable in a conventional jib crane will be described. First, at the time of assembling the jib crane, the boom pivotally attached to the traveling machine body is tilted horizontally. Then, the rear post pivotally attached to the boom head is erected almost vertically, and the rear post supporting strut is interposed between the rear post and the boom. The rear post supporting strut is formed so that a compression coil spring is interposed in a slidable double tube to support a compression load. Then, attach one end of the rear post support cable to the tip of the rear post in advance, pull the rear post support cable toward the base of the boom with an auxiliary crane, and attach the other end of the rear post support cable to the cable link provided near the base of the boom. After locking, the boom stands up to a predetermined angle and is in a working position.

[0003]

Conventionally, when assembling the rear post support cable, the auxiliary post crane pulls the rear post support cable laterally against the repulsive force of the rear post support strut so that the end portion of the rear post support cable is pulled. Since it is connected to the boom, labor is required for pulling and connecting the cables, and there is a risk of accidents due to high-risk work. Therefore, there is a technical problem to be solved in order to facilitate the work of assembling the rear post support cable, improve the workability, and eliminate the risk, and the present invention solves the above problem. With the goal.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention has a rear post of a jib crane and a boom, wherein a hydraulic cylinder is interposed between the rear post and the rear post so that the rear post is rotatable and the rear post support cable is divided into two parts. One end of one rear post support cable is locked to the tip of the rear post, and one end of the other rear post support cable is locked to the boom cable attachment part, and the hydraulic cylinder is contracted to bring the rear post to the boom side. After assembling the rear post support cable in the jib crane, the hydraulic cylinder is extended after connecting the two rear post support cables, and the rear post is erected at a predetermined angle. It is a proposal.

[0005]

According to the present invention, a hydraulic cylinder is used as a rear post supporting device interposed between the rear post and the boom to support the load of the rear post and the jib / elevation rope. When assembling the rear post support cable, the rear post support cylinder is contracted to tilt the rear post standing upright with respect to the boom in the horizontal state. As a result, the distance between the tip of the rear post and the cable attachment portion of the boom is reduced, and the rear post support cables locked to the rear post and the boom can be easily connected. When the rear post support cylinder is extended after connecting the cables, the rear post stands up at a predetermined angle and the rear post support cable is stretched.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a jib crane 1, in which a tower boom 4 is pivotally attached to an upper revolving structure 3 of a traveling body 2, and a boom head 5 of the tower boom 4 which has stood upright has a jib 6 and a front post 7.
And the rear post 8 is pivotally attached. A telescopic type rear post support cylinder 9 is interposed between the rear post 8 and the boom head 5, and two rear post support cables 11 and 12 are connected in series with a tip end of the rear post 8 and a cable link 10 near the base of the tower boom 4. Connected and linked. Further, the front end of the jib 6 and the front post 7 are connected by a jib support cable 13, and the jib elevation rope 16 is wound around the pulley devices 14 and 15 provided at the front end portions of the front post 7 and the rear post 8, respectively. The end of the jib raising / lowering rope 16 is fixed to the jib undulating drum 17 of the upper swing body 3.

In the rear post supporting cylinder 9, the inner cylinder 19 is fitted in the outer cylinder 18, and the inner cylinder 1
9 is expandable and contractible by hydraulic pressure. Further, the piston and piston rod 2 loosely fitted in the internal cylinder 19
0 is cut off from the hydraulic system and expands and contracts according to external force.

Next, a method of assembling the rear post support cables 11 and 12 in the assembly process of the jib crane 1 will be described. First, the rear post 8, the front post 7, and the jib 6 are attached to the boom head 5 of the tower boom 4 which has been tilted horizontally. Then, one end of one rear post support cable 11 is coupled to the tip of the rear post 8. Further, one end of the other rear post support cable 12 is connected to the cable link 10 of the tower boom 4, the rear post support cable 12 is laid on the tower boom 4, and the other end is arranged on the rear post 8 side.

As shown in FIG. 2, a piston rod 20 of a rear post support cylinder 9 is pivotally attached to an intermediate portion of the rear post 8, and the rear post support cylinder 9 is housed in the rear post 8 in a contracted state. Then, the hydraulic unit is connected to the rear post support cylinder 9, the inner cylinder 19 is extended while the rear post support cylinder 9 is supported by the auxiliary crane or the winch of the traveling machine body, and the link 21 pivotally attached to the rear post support cylinder 9 is connected. The end portion is connected to the rear post 8 to hold the rear post support cylinder 9 at a predetermined angle.

Next, as shown in FIG. 3 and FIG. 4, the jib elevation rope 16 is extended to maintain the horizontal position of the front post 7, and the rear post 8 is lifted up substantially vertically by the auxiliary crane 22 or winch. The bottom of the support cylinder 9 is pivotally attached to the boom head 5. Then, the rear post support cylinder 9 is contracted by the hydraulic unit 21 while further feeding out the jib raising and lowering rope 16, and the rear post 8 is tilted backward about 45 degrees as shown by a chain line in FIG. As a result, the lower end of the rear post support cable 11 locked to the rear post 8 approaches the tip of the rear post support cable 12 on the tower boom 4 side, and the two rear post support cables 11 and 12 can be connected. here,
The rear post support cables 11 and 12 are connected to extend the rear post support cylinder 9, and the rear post 8 is erected at a predetermined angle (about 85 ° ± 3 °) with respect to the tower boom 4 as shown by the solid line in FIG. Then, the rear post support cables 11 and 12 are installed. Then, after removing the hose from the hydraulic unit 23 connected to the rear post support cylinder 9 and connecting the contraction side port of the rear post support cylinder 9 to the spare tank 24 provided in the boom head 5, the tower boom 4 is raised. The work posture is shown in FIG.

In the working posture, the rear post 8, the rear post supporting cables 11 and 12, and the jib elevation rope 16 are provided.
Is supported by the rear post support cylinder 9,
The piston rod 20 of the rear post support cylinder 9 is contracted by the load, and the load is applied to the internal cylinder 19 via the piston rod 20. This load compresses the pressure oil in the expansion-side oil chamber of the external cylinder 18, but since the contraction-side port communicates with the auxiliary tank 24, negative pressure due to load fluctuation does not occur.

During lifting work, the jib supporting cable 13, the jib raising and lowering rope 16 and the rear post supporting cables 11 and 12 are stretched by the load of the suspended load, and the rear post 8 rotates in the upright direction. The piston rod 20 of the cylinder 9 extends along with the rotation of the rear post 8, does not hinder the movement of the rear post 8, and the rear post 8 and the rear post support cylinder 9 are not overloaded.

When the suspended load is released, the rear post 8 pivots in the descending direction as the jib supporting cable 13, the jib raising and lowering rope 16 and the rear post supporting cables 11 and 12 contract, and the rear post supporting cylinder 9 moves. The piston rod 20 returns to the most contracted position and returns to the initial state.

The present invention should not be limited to the above-mentioned embodiment, but various modifications can be made without departing from the spirit of the present invention, and the present invention covers those modifications. Is natural.

[0015]

As described in detail in the above-mentioned embodiment, the present invention contracts the rear post supporting cylinder which is a hydraulic cylinder to tilt the rear post, and thereby the tip of the rear post and the rear post supporting cable mounting portion of the boom are connected. By making the distances closer, the rear post support cable can be connected very easily. Further, since the tensioning process of the rear post supporting cable by the conventional auxiliary crane is not necessary, the danger at the time of connecting work is eliminated, and it is possible to contribute to the improvement of workability and safety.

[Brief description of drawings]

FIG. 1 is a side view of a jib crane.

FIG. 2 is an explanatory view showing a process of assembling the rear post support cylinder, showing a state before the cylinder is attached.

FIG. 3 is an explanatory view showing a process of assembling the rear post support cylinder, showing a state after the cylinder is attached.

FIG. 4 is an explanatory diagram showing a connection and tension process of a rear post support cable.

[Explanation of symbols]

 1 Jib Crane 4 Tower Boom 5 Boom Head 6 Jib 8 Rear Post 9 Rear Post Support Cylinder 10 Cable Link 11, 12 Rear Post Support Cable 13 Jib Support Cable 16 Jib Depth Rope 18 External Cylinder 19 Inner Cylinder 20 Piston Rod 21 Link 23 Hydraulic Unit 24 Spare Tank

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Masao Kuno, 6-1, Asahi-machi, Obu-shi, Aichi Prefecture Sumitomo Construction Machinery Co., Ltd. Nagoya factory (72) Inventor, Seiichiro Kuwamori 6-1-1, Asahi-cho, Obu-shi, Aichi Sumitomo Construction Machinery Co., Ltd. Nagoya factory

Claims (1)

[Claims] 1. A rear cylinder and a boom of a jib crane are equipped with a hydraulic cylinder to allow the rear cylinder to freely rotate, and one end of one of the rear cylinder support cables divided into two is attached to the tip of the rear cylinder. Stop, one end of the other rear post support cable is locked to the cable attachment portion of the boom, the hydraulic cylinder is contracted, the rear post is tilted to the boom side, and after connecting the two rear post support cables, A method of assembling a rear post support cable in a jib crane, wherein a hydraulic cylinder is extended, the rear post is erected at a predetermined angle, and the rear post support cable is installed.