JPH01267295A - Boom center-folding device in crane - Google Patents

Abstract

PURPOSE:To make any load at the time of working so as not to be imposed on a center-folding linkage device by installing two tension bars between the upper part of a tip side boom and that of a tower and between the upper part of a body side boom connected to the body side boom via a hinge of a center- folding part and that of the tower, respectively. CONSTITUTION:Using two tension bars 7, 10, a mounting position of the tension bar 7 to a tip side boom 2b is set to the more outside than an outreach L doing ordinary work. For this reason, at the time of ordinary work, any load is not imposed on a first link 13, a second link 14 and a third link 15 for center- folding use, so that it is merely enough to support dead load of the tip side boom 2b at a tip of a center-folding part 6. Consequently, when a boom 2 is supported by these tension bars 7 and 10 at boom horizontality, each side of these center-folding links 13-15 is released, but since the links 13-14 consist of a wire rope, compressive force can be opened. If the center-folding boom is uplifted with a winch, the tip side boom 2b is supported by these links 13-15 and thereby uprighted.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a mid-folding device for a crane boom subject to height restrictions. In container yards, etc., if an airport is nearby, the overall height of the crane is restricted due to aviation restrictions.
A mechanism to fold the boom in the middle is required.

The present invention relates to a device that allows a boom to be folded in the middle without using complicated mechanical devices.

(Prior Art) Near airports, container cranes and the like must be kept within limits even when their booms are hoisted so as not to obstruct air routes.

In this way, examples of booms that can be bent in the middle to keep the boom within the height limit are disclosed in Japanese Utility Model Publication No. 59-183490 and Japanese Patent Publication No. 62-184.
Publication No. 74, Japanese Patent Publication No. 61-58397, Japanese Patent Publication No. 1983
Techniques such as Japanese Patent Publication No. 1-188393, Japanese Patent Publication No. 58-20875, and Japanese Patent Publication No. 44-22268 are known.

However, in these systems, the main load during cargo handling is normally shared by a folding link mechanism, or the tip of the boom is lowered at the same time as the lifting and lowering, and there are problems such as restrictions on the mounting position of the tension bar.

(Problems to be Solved by the Invention) It is an object of the present invention to provide a safe and reliable center-folding device that does not use complicated mechanical devices, has a simple configuration, and does not apply a load during work to a center-folding link mechanism.

(Means for Solving the Problems by the Invention) It consists of an upright tower, a boom on the main body side that is pivotally supported on the crane main body, and a boom on the tip side that is pivotably supported on the main body side boom in a downwardly bendable manner. In the center-folding boom that can be raised and lowered by a wire, a first tension bar is provided between the top of the tip side boom and the top of the front tower, and a second tension bar is provided between the top of the main body side boom and the top of the tower.
a first link made of a wire rope that loads the load during work with a tension bar and has one end attached to the top of the boom on the tip side; a third link having rigidity that is attached to the top of the boom on the main body side; One end was attached to the top of the first and third links, and the second link, which was made of a wire rope and the other end was attached to the tower side, constituted a center-fold link that maintains the tip side boom horizontally.

In addition, the center-fold link was stretched between the bracket provided at the upper part of the center-fold part of the boom on the tip side and the middle part of the tower, and was constructed with a wire rope.

(First Example) This will be explained based on FIG. 1. 1 is a tower for a container crane or the like. 2 is a center-folding boom, and a boom 2a on the main body side is pivotally supported on the crane main body 3 with a pin 4.

It consists of a tip side boom 2b which is pivotally supported by the main body side boom 2a with a pin 5 and can be bent downward. When the main body side boom 2a and the distal end side boom 2b are pivotally supported by a pin 5, the center-folding part 6 is in a state of metal contact to prevent reverse bending when both are in contact and become horizontal.

Reference numeral 7 designates a first tension bar, one end of which is pivotally connected to the top of the tip side boom 2b with a pin 8, and the other end is pivotally connected to a bracket attached to the top of the tower 1 with a pin 9, and can be bent in the middle. It has multiple joints. 10 is a second tension bar, one end of which is attached to the upper bracket of the boom 2a on the main body side with a pin 11.

The other end is pivotally connected to the upper part of the tower 1 with a pin 12, and this also has a plurality of bendable joints in the middle.

13, one end is the upper part of the tip side boom 2b, and
A first link made of a wire rope is pivotally connected with a pin 16 at a position rearward from the pivot portion of the tension bar 7, and a second link 14 also made of a wire rope is connected to the first link with a pin 17. The other end of the second link 14 is pivotally attached to the middle part of the tower 1 with a pin 18. 15 is the third
The link is compressible, and its upper end is pivotally connected to the joint between the first link 13 and the second link 14, and its lower end is connected to the upper part of the boom 2a on the main body side, rearward of the center folding part 6 (to the crane main body). (closer side) with pin 19.

Reference numeral 20 denotes a levitation wire, which has one end fixed to the upper part of the tower 1, and is located above the boom 2a on the main body side, and is provided at an intermediate position between the third link 15 and the pivot point of the second tension bar 10. It is wrapped around the car 21-, and further the tower 1
It can be hoisted up by a winch (not shown) via a rope wheel 22 provided at the top of the holder.

23 is a lifting device installed at the lower part of the tip side boom 2b, and the crane outreach L is smaller than the distance fiA from the position of the pivot pin 8 of the first tension bar 7 to the tower 1, that is, the distance to the crane main body side. Only Ha is included. That is, A =
L + a) L.

As shown in the above section, two first tension bars 7 and second tension bars 10 are used, and the attachment position of the first tension bars 7 to the tip side boom 2b is set outside of the outreach L where normal work is performed. Therefore, during normal work, the first
No load is applied to the link 13, the second link 14, and the third link 15, and they only need to support the weight of the distal end side boom 2b at the distal end of the folded portion 6.

Therefore, when the boom 2 is supported by the tension bars 7 and 10 when the boom is horizontal, the
4.15 side is released, but since the first link 13 and the second link 14 are made of wire rope, the compressive force can be released.

When the winch is wound and the center-folding boom 2 is lifted by the hoisting wire 20, the tension bar is released and breaks at the joint, and the tip side boom 2b is attached to the center-folding link 13,
14.15, and rises while maintaining a substantially parallel state.

(Second embodiment) This will be explained based on FIG. 2. In this case, there is only one link 24 made of wire rope instead of the first link 13, second link 14, and third link 15 in the first embodiment. One end of the link 24 is pivotally connected to the rear end of a bracket 25 provided at the upper part of the folded part of the tip side boom 2b by a pin 26, and the other end is pivotally connected to the intermediate part of the tower 1 by a pin 27.

Since the other machines are completely the same as those in the first embodiment, their explanation will be omitted.

As mentioned above, since one flexible link 24 is used as the center-folding link, as in the first embodiment, no load is applied to the link 24 during normal work.
The link 24 only needs to support the weight of the distal end boom 2b. Further, when the boom is horizontal, the boom 2 is supported by the tension members 7 and 10, but the folding link 24 is released and the compressive force can be released.

When the winch is wound and the boom 2 is hoisted up by the hoisting wire 20, the tension bar is released from tension and breaks at the joint, and the distal end boom 2b is supported by the center-folding link 24 and is in a substantially parallel state as shown in Fig. 2. maintain.

(Effect) The main body side boom 2 is connected between the upper part of the tip side boom 2b and the upper part of the tower, and to the tip side boom via the hinge at the center fold.
Two tension bars are provided between the upper part of a and the upper part of the tower, and the attachment position of the tension bar supporting the tip side boom 2b is located outside of the outreach L where normal work is performed. As a result, each center-folding link is not loaded with any load during normal operation, so the weight of the link can be reduced.

Since the upper part of the folded part is prevented from bending backward due to metal contact during cargo handling, a strong linear boom that can reliably maintain a straight state during cargo handling can be constructed.

Since the first and third links of the center-folding links are made of flexible wire ropes, the center-folding links can be easily released when the boom is supported by a tension bar.

Furthermore, since the center-folding link is constructed from one wire rope as in the second embodiment, the center-folding link can be constructed more simply.

[Brief explanation of the drawing]

FIG. 1 is a side view of a first embodiment of a boom folding device according to the present invention. FIG. 2 is a side view of the second embodiment. In the figure: 1 Tower 2 Center-folding boom 2a Main body side boom 2b Tip side boom 3 Crane main body
4 Pin 5 Pin 6 Center folded part 7 First tension bar 8 Pin 9 Pin lO Second tension bar 11 Pin 12 Pin 3 1st
Link 14 Second link 15 Third link 16.17, 18.19 Pin 20 Hoisting wire 21 Rope car 22 Rope car
23 Lifting device 24 Link 25
Bracket 26 Pin 27 Application for bottle or more Person: Isamu Ohashi, sub-agent, patent attorney, Sumitomo Heavy Industries, Ltd.

Claims (1)

[Claims] 1) Consisting of an upright tower, a boom on the main body side that is pivotally supported on the crane main body, and a boom on the tip side that is pivotably supported on the main body side boom so that it can be bent downward, In a center-folding boom that can be raised and lowered by a wire, a first tension bar provided between the top of the tip side boom and the top of the tower, and a second tension bar provided between the top of the main body side boom and the top of the tower. Carrying the load during work,
a first link made of a wire rope with one end attached to the top of the tip side boom; a third link having rigidity attached to the top of the main body side boom; and one end attached to the tops of the first and third links. A boom center-folding device for a crane, characterized in that a second link made of a wire rope whose other end is attached to the tower side constitutes a center-folding link that maintains the boom on the tip side horizontally. 2) The crane according to claim 1, wherein the center-folding link is constituted by a single link made of a wire rope stretched between a bracket provided at the upper part of the center-folding part of the tip side boom and a middle part of the tower. boom center folding device.