JPH0324556Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a crane jib hoisting device for hoisting a jib without using a hoisting winch.

[Prior art]

As shown in FIGS. 1 and 2, a conventional crane has a jib 1 whose one end 1a is pivotally attached to a part of a rotating part 2 in a vertical plane, and an upper end connected in a plane parallel to the vertical plane. A pair of fixed frames 5, 5 consisting of first and second frames 3 and 4 whose lower ends are fixed to the rotating part 2, a luffing winch 6 and a hoisting winch 7 which are fixed to the rotating part 2, A hoisting wire rope 9 and a sheave are stretched between the tip 1b of the jib 1 and the hoisting winch 6 via a sheave 8 that is pivotally supported at the pivot points of the first and second frames of the fixed frame 5. 8 and the hoisting fitting 18 and the hoisting winch 7 via the tip portion 1a.
and a hoisting wire rope 10 that connects the jib 1, the jib 1 is hoisted by operating the hoisting winch 6 to wind in or pay out the hoisting wire rope 9, and rotate the jib 1 around its one end 1a. That's how it goes. Note that the rotating part 2 is the mast 11
The mast 11 is rotatably supported on the top of the mast 11, and the mast 11 can be climbed or raised by a hydraulic cylinder 13 powered by a hydraulic power unit 12.

Therefore, a hoisting winch and a hoisting wire are required, which results in wear and tear on the hoisting wire rope, and requires the dangerous work of attaching the hoisting wire rope to the jib during assembly. There were other problems.

For example, in Japanese Utility Model Publication No. 55-17753, in order to raise and lower the boom of a truck crane, etc., a sheave is attached to the tip of a telescopic frame, and a pendant rope guided by the sheave is provided, so that the telescopic frame can be extended and contracted. A technique has been disclosed in which the extension state of a pendant rope is changed by operation, thereby raising the boom. Even if a telescopic frame is provided in this way, the pendant rope engages with the sheave and moves when the boom is raised and lowered, so the pendant rope is worn out in the same way as the raising and lowering wire. Although such known techniques pose few problems for supporting booms such as truck cranes, they are inconvenient for large cranes such as jib cranes.

[Problem to be solved]

Therefore, the purpose of the present invention is to provide a crane jib hoisting device in which the rope for hoisting the jib does not engage with a sheave, etc., so that the rope is not damaged during hoisting work, and there is no dangerous work during assembly. is to provide.

[Means to solve the problem]

According to the present invention, there is provided a swiveling part that is rotatably supported on the top of the mast, a swiveling part that has a base pivoted to the swivel part, and a swivel part that has a base pivoted to the swivel part in a vertical plane. In a crane jib hoisting device equipped with a jib that can be raised and lowered, the first frame has one end pivoted to the tip end side of the jib from the position where the jib is pivoted to the revolving part, and the other end of the first frame a second frame pivotally connected to one end and the other end pivotally connected near the root of the jib of the swivel part, and at least one of the first and second frames is extendable and retractable by a hydraulic cylinder. , a pendant rope stretched between the pivot points of the first and second frames and the tip of the jib.

[Function and effect of the idea]

Therefore, when either one of the undulating frames expands or contracts, the pivot points of the first and second frames rotate around the pivot points of the first frame and the pivoting section, and as a result, the first A jib, the tip of which is connected to the second pivot point via a pendant rope, rises and falls about the pivot point with the swing section. As a result, a hoisting winch and a hoisting wire rope are no longer necessary, and wear and tear on the hoisting wire rope and unsafe preparation work in conventional cranes can be eliminated.

Moreover, the points and the like that accompany these can be omitted. In addition, the hydraulic power unit, which is only used when climbing, that is, when raising the swing section through the mast, can be used, improving the efficiency of equipment use. Furthermore, guide rollers for pulling the jib onto the revolving part are provided in the revolving part, so that the jib can be assembled and dismantled without using any other equipment. And if a sheave is provided at the pivot points of the first and second frames as necessary,
It can be used as a small crane.

When implementing the present invention, it is preferable that the telescopic second frame of the undulating frame is constituted by a hydraulic cylinder whose power source is a hydraulic power unit used during climbing.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings from FIG. 3 onwards. In these drawings, parts corresponding to those in FIG. 1 are designated by the same reference numerals and redundant explanation will be omitted.

In FIG. 3 and FIG. 4, the turning section 2 includes:
A first frame 1 whose one end 14a is pivotally connected to the distal end side of the jib 1 of the rotating section 2, that is, a part of the right side in the drawing, in a plane parallel to the undulating vertical plane of the jib 1.
4 and one end is the other end 14b of the first frame 14
A pair of undulating frames 16, 16 are erected, each consisting of a retractable second frame 15, which is pivoted at the base of the jib 1 of the revolving section 2, that is, a part of the left side in the drawing, at the other end 15a. ing. This second frame 15 is composed of a hydraulic cylinder, and expands and contracts using the above-mentioned hydraulic power unit 12 for climbing as a power source, and moves the pivot point 14b of the first and second frames 14 and 15 to the first Position A around the frame 14 and the pivot point 14a of the rotating section 2
It is designed so that it can be rotated from position B to position B within the range of angle α. In the illustrated embodiment, the second frame 15 is configured to be extendable and retractable using a hydraulic cylinder, but the first frame 14 or both may be extendable and retractable. Between this pivot point 14b and the tip 1b of the jib 1,
The pendant rope 17 is stretched, and by rotating the aforementioned pivot point 14b, the pendant rope 17 is stretched.
Position jib 1 around pivot point 1a via 7
It is designed so that it can be raised and lowered within the range of angle α' from A' to position B'. In addition, the hoisting winch 7 is
The counter jib 19 is housed inside a counter jib 19 that is fixed to the rotating portion 2 on the side facing the jib 1.

With this structure, when the second frame 15 of the undulating frame 16 is expanded and contracted using the hydraulic power unit 12 as a power source, the pivot point 14b of the first and second frames 14 and 15 is moved to the first frame. 14 and the pivot point 14a of the rotating part 2 from position A to position B within the range of angle α,
As a result, the jib 1 whose tip end 1b is connected to the pivot point 14b via the pendant rope 17,
Using the pivot point 1a with the rotating part as a fulcrum, the position
It undulates within the range of angle α' from A' to position B'. As a result, the need for a hoisting winch and the wire rope for hoisting are eliminated, and wear and tear on the rope and preparation work can be eliminated. Further, the inspection work associated with this can be eliminated. Furthermore, the usage efficiency of the hydraulic power unit can be improved. Furthermore, as shown in Fig. 3, guide rollers 20 are provided in the revolving part 2 to pull the jib 1 onto the revolving part 2, so that the jib 1 can be assembled and disassembled without using any other machinery. can do.

〔effect〕

As described above, according to the present invention, the first and second
A pendant rope is stretched between the pivot point of the frame and the tip of the jib, and the rope does not engage with any other parts other than its ends, and the luffing operation is
Since this is done by expanding and contracting the first or second frame, the ropes are not worn out and are safe. Additionally, since a hoisting winch is not used, there is no need for dangerous wire preparation work when assembling the crane. In particular, since the first and second frames are configured in a triangular shape together with the rotating part, the first frame is pulled and the second frame is compressed, but the strength is sufficient to withstand the ups and downs of the jib. It can be designed to withstand high temperatures, making it ideal for large jib cranes.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a conventional crane, FIG. 2 is a plan view thereof, FIG. 3 is a side view showing one embodiment of the present invention, and FIG. 4 is an explanatory diagram of the operation. DESCRIPTION OF SYMBOLS 1... Jib, 2... Swivel part, 14... First frame, 14b... Pivoting point of the first and second frames, 15... Second frame, 16... Lifting frame, 17... ...pendant rope.

Claims (1)

[Scope of utility model registration request] In a crane jib hoisting device, the jib is equipped with a swivel part that is rotatably supported on the top of a mast, and a jib that is pivotally connected to the swivel part and can be raised and lowered in a vertical plane. A first frame with one end pivoted to the tip of the jib from the position where a second frame, at least one of which is extendable and retractable by a hydraulic cylinder, and between the pivot points of the first and second frames and the tip of the jib. A crane jib hoisting device characterized by being provided with a stretched pendant rope.