JPH08282972A - Low head space crane - Google Patents

Abstract

PURPOSE: To perform weight lifting work even in a part with a head space limit. CONSTITUTION: In a low head space crane 1, a prescribed boom supporter 4 is turnably mounted around a horizontal axial line in an upper part turn unit 3 mounted turnably in a running unit 2 of crawler or the like, also to secure a prescribed boom 6 to the boom supporter 4 in the vicinity of its center or in the center a little to the rearward, and to connect a part in the vicinity of a rear end of the boom 6 and the upper part turn unit 3 by a prescribed boom derricking cylinder 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low head crane which is suitable for use in places where the head is limited.

[0002]

2. Description of the Related Art Mobile cranes are classified into truck cranes, crawler cranes, etc. according to their traveling types, and are classified into lattice type and box type boom types according to their boom structures. Here, for example, the lattice type is often used in large machines because it is lightweight and stable.

On the other hand, in addition to high lift, high weight and large working radius, the mobile crane is often required to be compact so that it can be easily worked even in a narrow field. Rough terrain cranes are representative of such compact cranes, and have high ability to penetrate narrow spaces.

[0004]

However, in all of these types of cranes, a heavy object is hoisted in a state where the boom is raised and lowered to a predetermined angle, and the height of an empty head is about several meters or less. For example, in a marshalling yard, there is a problem in that the boom cannot be sufficiently undulated because the tip of the boom interferes with an overhead overhead wire, and as a result, a heavy object cannot be suspended.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a low head crane capable of lifting work even in a place where the head is limited.

[0006]

In order to achieve the above object, the low-head crane according to the present invention has a predetermined structure on an upper swing body which is swingably mounted on a traveling body such as a crawler as described in claim 1. A boom support is attached rotatably around a horizontal axis, and a predetermined boom is fixed to the boom support near its center or at a position slightly rearward of the center,
The vicinity of the rear end of the boom and the upper swing body are connected by a predetermined boom hoisting cylinder.

[0007]

In the low head crane of the present invention, the boom is supported by the boom support near the center thereof or slightly rearward of the center thereof, and is supported by the boom hoisting cylinder near the rear end thereof. Therefore, support the boom 2
The distance between the points is much wider than with conventional cranes, and the structure is able to withstand even larger moments. Therefore, it is possible to support a considerable lifting load even when the boom is horizontal.

[0008]

Embodiments of the low head crane of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a low head crane 1 according to this embodiment.
FIG. 2 is a plan view and a side view. As can be seen from these figures, in the low head crane 1 of the present embodiment, an upper revolving structure 3 is rotatably mounted on a crawler type traveling structure 2 and a substantially inverted triangular shape is mounted on the upper revolving structure 3. A boom support 4 is attached. Here, the boom support 4 is
For example, it is formed of a truss, and its lower end 5 is hinged to the upper swing body 3. Then, the hinge can be rotated about a horizontal axis.

The traveling body 2 and the upper revolving structure 3 can be constructed by using, for example, an all-hydraulic crawler crane with a suspension of about 50 tons as a base machine.

On the other hand, a telescopic boom 6 is arranged above the upper swing body 3. The telescopic boom 6 is supported by the boom support 4 from the vicinity of the center thereof to a position slightly rearward of the center, and the lower boom 7 fixed to the boom support 4 and the boom telescopic cylinder 8 guided by the lower boom 7 axially move the boom. It is composed of an upper boom 9 which is telescopically driven.

A boom hoisting cylinder 11 is arranged behind the boom support 4, and its tip is connected to the vicinity of the rear end of the lower boom 7. With such a structure, when the empty head has a margin, the boom hoisting cylinder 11 is actuated to hoist the telescopic boom 6 by about 15 °, so that the lift can be secured even if it is slight.

Further, a winch 10 for winding a wire rope is arranged substantially in the center of the upper swing body 3, and
A hydraulic unit 12, which serves as a hydraulic pressure source for the boom telescopic cylinder 8 and the boom hoisting cylinder 11, is provided on the rear side.
A cable reel 13 and a hydraulic hose reel 14 are attached to the rear of the telescopic boom 8. In consideration of use in a narrow space, it is preferable to make the hydraulic unit 12 compact as a drive system by the main motor and reduce the turning radius.

In the low head crane 1 of this embodiment,
The telescopic boom 6 is supported by the boom support 4 from the vicinity of the center thereof to a position slightly rearward of the center, and is supported by the boom hoisting cylinder 11 near the rear end thereof. Therefore, the distance between the two points supporting the telescopic boom 6 is considerably wider than that of the conventional crane, and the structure can withstand a large moment.

Therefore, the low head crane 1 of this embodiment
1 (b), it is possible to sufficiently support the load of, for example, the suspended excavator 21 used for underground wall construction in a state in which the telescopic boom 6 is horizontal without undulations. it can.

When the empty head has a margin, as shown in FIG. 2, the boom hoisting cylinder 11 is operated to hoist the telescopic boom 6 by about 15 ° to ensure a predetermined lift. In addition, if there is a margin around,
As shown in FIG. 5, the boom telescopic cylinder 8 can be operated to extend the upper boom 9 by about 3 m with respect to the lower boom 7 to ensure a predetermined working radius.

As described above, according to the low head crane according to the present embodiment, a considerable suspension load can be supported in a state where the telescopic boom is horizontal without being undulated.

Therefore, in a place where the empty head is limited to about several meters, such as under an overhead line, under a road, or in an underground parking lot, for example, a suspended excavator can be suspended to excavate a continuous underground wall. However, it is possible to perform all other crane work.

[0019]

As described above, in the low head crane of the present invention, a predetermined boom support is attached to the upper swing body which is swingably attached to a traveling body such as a crawler so as to be rotatable about a horizontal axis. At the same time, a predetermined boom is fixed to the boom support near the center or slightly rearward of the center, and the vicinity of the rear end of the boom and the upper revolving structure are connected by a predetermined boom hoisting cylinder, so that the boom can be moved horizontally. It is possible to support a predetermined suspension load in
Lifting work can be performed even in places where there are restrictions on empty heads.

[0020]

[Brief description of drawings]

FIG. 1A is a plan view of a low head crane according to this embodiment, and FIG. 1B is a side view of the same.

FIG. 2 is a side view showing a state in which a telescopic boom is raised and lowered in the low-head crane according to the present embodiment.

FIG. 3 is a side view showing a state in which the telescopic boom is undulated and extended in the low head crane according to the present embodiment.

[Explanation of symbols]

 1 Low-head crane 2 Crawler (running body) 3 Upper swing body 4 Boom support 6 Telescopic boom (boom) 8 Boom telescopic cylinder 11 Boom hoisting cylinder

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuhiro Nakajima 2-3 Chome, Kandaji-cho, Chiyoda-ku, Tokyo Obayashi Corporation Tokyo Head Office

Claims (1)

[Claims] 1. A predetermined boom support is rotatably mounted around a horizontal axis on an upper revolving structure rotatably mounted on a traveling body such as a crawler, and a predetermined boom is attached to the boom support near the center thereof. Alternatively, the low head crane is characterized by being fixed at a position slightly rearward of the center and connecting the vicinity of the rear end of the boom and the upper swing body with a predetermined boom hoisting cylinder.