JPH05139693A - Crane - Google Patents

Abstract

PURPOSE:To reduce a space required for extension/housing of a Jib and eliminate exclusive parts for jib extension/support. CONSTITUTION:A sheave block 3 is rotatably installed with respect to a tip end 2a of a boom main body 2 between a boom operation position wherein a main winding sheave 12 is protruded under the boom main body 2 in a boom horizontal state and a jib operation position wherein the sheave 12 is positioned above a jib installation shaft 4a in a boom horizontal state by adapting a horizontal shaft 11 as a center. At the time of jib operation, by substituting the sheave block 3 for a strut, a jib 27 is extended and housed by means of the main winding rope 7 and supported for variable angle in an extending state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crane which has a jib extended from the tip of a boom and which supports the jib with a variable angle in the extended state.

[0002]

2. Description of the Related Art In a crane with a jib, the jib is stored on the side surface or the bottom surface of the boom during boom operation without using the jib, and the jib is moved from the retracted position to the extended position of the boom tip during the jib operation. ..

Conventionally, a method of utilizing the hoisting force of a main hoisting rope used during boom work has been known as a method of extending the jib.

More specifically, the jib is stored vertically on the side of the boom, hung down from this storage position, then twisted and then swung forward by the main winding rope (so-called jib twist system = Japanese Patent Publication No. 63, for example). -3827
No. 3-16877) and a jib that is horizontally stored on the bottom surface of the boom, hangs down from this storage position, and then swings forward with a main winding rope. There is.

On the other hand, as means for supporting the thus-protruding jib in a variable angle, (a) actual open sho 63-161293
As shown in the publication, etc., after the jib is extended by the main rope, the suspension rod is suspended between the boom tip and the jib to support the jib, and the jib is lifted by the cylinder incorporated in this suspension rod. As described in (B) Japanese Utility Model Laid-Open No. 59-140285, a strut is attached to the tip of the boom, and the main winding rope is passed through the sheave of the strut and fixed to the jib. A means for supporting the jib by the main winding rope so that the angle of the jib can be changed after the extension is known is known.

[0006]

However, in the means (a) using the suspension rod, after the jib is extended by the main rope, the boom is laid horizontally on the ground.
It is necessary to set the suspension rod and remove the main rope from the jib.

For this reason, a space above the boom and jib is required, which makes it impossible to overhang in a narrow space or in an urban area with electric wires.

On the other hand, the means using the strut (b) requires a large part for supporting the jib called a strut, which increases the weight of the boom tip and lowers the lifting capacity accordingly.

Also, when switching between boom work and jib work,
The main winding rope had to be hung between the state where it passed through the main winding sheave at the tip of the boom and the state where it passed through the sheave of the strut, so the conversion operation was troublesome.

Incidentally, as a modification of (b), the actual development number is 59-
As disclosed in Japanese Patent No. 140280, a jib is extended from a lower stage boom of a tip boom of a telescopic boom,
Although a means for supporting the jib by a main winding rope in the form of using the tip boom as a strut has been proposed, this causes a problem that the lifting range during jib work is reduced.

Therefore, according to the present invention, the jib can be extended and stored, and the jib can be supported at a variable angle in the extended state without using the suspension rod and the strut and without the adverse effect of reducing the lifting height. It provides a crane.

[0012]

The invention according to claim 1 comprises a boom and a jib extended from the tip of the boom,
The boom is a crane in which a sheave block having a main winding sheave through which a main winding rope is passed and a supplementary sheave through which a supplementary winding rope is passed is provided at a tip of the boom main body. In the lower part of the boom in the horizontal state at the tip of the jib, the jib mounting shaft to which the base end of the jib is connected when the jib is extended, the upper part is provided with a horizontal shaft orthogonal to the boom length direction, and the sheave block is A boom working position in which the main winding sheave protrudes below the boom main body in a boom horizontal state around the horizontal axis,
The main winding sheave is rotatably attached to a jib working position located above the jib attachment shaft in a horizontal state of the boom, and includes block fixing means for fixing the sheave block to the two positions. It is a thing.

According to a second aspect of the present invention, in the structure of the first aspect, a main hoisting rope guide member for guiding the main hoisting rope is provided at a tip end portion of the boom body so as to protrude below the jib mounting shaft in a horizontal state of the boom. It is provided in the state.

According to a third aspect of the present invention, in the structure of the first or second aspect, a spring for pushing up the sheave block toward the jib working position is provided between the tip of the boom body and the sheave block.

[0015]

According to the above construction, during jib work (when the jib is extended), the sheave block is moved from the boom work position to the jib work position so that the sheave block can be used as a strut and the jib is extended by the main rope. ,
It can be stowed and supported variable in the extended state. That is, the suspension rod and the strut as a part dedicated to overhanging and supporting the jib are unnecessary.

Therefore, since it is not necessary to horizontally tilt the boom for attaching and detaching the suspension rod, a long ground space for extending the jib is unnecessary. Therefore, the jib can be extended and stored even in a narrow area or in an urban area where there are obstacles such as electric wires.

Since the sheave block is substituted for the strut, there is no inconvenience that the weight of the boom tip is significantly increased as in the case of using a dedicated strut, and the trouble of hanging the main winding rope at the time of work conversion. further,
Even if the tip boom of the telescopic boom is used instead of the strut, there is no adverse effect such as a reduction in the lifting height.

According to the second aspect of the present invention, when the jib is extended, the main winding rope is erected by the main winding rope guide member in the boom horizontal state even when the boom is largely erected to reduce the overhanging space. Is guided to the lower position. That is, it is possible to secure the moment arm necessary for stretching the jib with the main winding rope.

On the other hand, according to the third aspect of the invention, the sheave block can be easily set in the jib work position with a small force by the spring force.

[0020]

Embodiments of the present invention will be described with reference to the drawings.

In this embodiment, a crane that uses a jib twist system as a system for projecting and storing a jib is taken as an example.

Reference numeral 1 denotes a telescopic boom, which comprises a boom body 2 composed of a plurality of stages of booms fitted in a telescope shape, and a sheave block 3 attached to the tip of the boom body 2 (tip of the tip boom). It is composed by.

A frame 2a for attaching a sheave block is fixed to the boom body 2 at its tip.

A horizontal shaft 4 is fixed to the lower end of the frame 2a in a horizontal state of the boom in a state of horizontally penetrating the frame 2a and projecting to the left and right sides as shown in FIG. The left and right protrusions 4a and 4b serve as both left and right jib mounting shafts.

A bracket 5 is fixed to the frame 2a in a state of protruding downward from the jib mounting shafts 4a, 4b, and a roller for a main winding rope guide (may be a fixing pin) is provided at the tip of the bracket 5. 6 is provided.

The sheave block 3 has a main winding on one end side,
Two idler sheaves 9, 10 through which auxiliary ropes 7, 8 (pulled out from a winch mounted on a crane body or boom body 2 not shown) pass are horizontal idler sheaves orthogonal to the boom length direction. It is rotatably supported by the shaft 11.

On the other hand, on the other end side, a plurality of main winding main sheaves 12 ... And one auxiliary winding main sheave 13 are displaced in the front and rear and up and down in the horizontal state of the boom, and the idler sheave is moved. An idler sheave 9 for main winding is rotatably supported by main sheave shafts 14 and 15 parallel to the shaft 11.
The main winding rope 7 from the main winding main sheave 12 ...
, And the sheave 17 of the main winding hook 16 are multiply threaded, and the auxiliary winding rope 8 that has come out from the idler sheave 10 for auxiliary winding passes through the main sheave 13 for auxiliary winding, and the terminal ends the auxiliary winding hook 18. Be stopped by.

The sheave block 3 has the idler sheave shaft 11 fixed to the upper end portion of the frame 2a of the boom body 2 in the horizontal state of the boom, so that the idler sheave shaft 11 is centered around the idler sheave shaft 11. As shown in FIGS. 1 and 2, the idler sheaves 9 and 10 are the upper part, the main sheaves 12 ...
3 is located in the lower part, and the main sheaves 12 ..., 13 are projected below the boom body. As shown in FIGS. 3, 5 and 6, the main sheave 12 ...
13 is attached to the frame 2a in a state in which it can rotate between a jib work position (jib extension) located above the jib attachment shafts 4a and 4b in a boom horizontal state.

A torsion spring 19 is provided around the idler sheave shaft 11, one end of which is attached to the frame 2a.
The other ends are fixed to the sheave blocks 3, respectively. The spring 19 pushes up the sheave block 3 toward the jib work position so that the sheave block 3 can be easily set to the jib work position with a small force.

The sheave block 3 and the frame 2a have fixed pin holes 20 and 21 which coincide with each other at the jib work position.
Is provided, as shown in FIG. 3, both fixing pin holes 20,
The sheave block 3 is fixed to the jib work position by inserting the fixing pin 22 across the portion 21.

On the other hand, as a means for fixing the sheave block 3 at the boom working position, a latch mechanism (not shown in other figures) shown in FIG. 4 is provided.

This latch mechanism includes a latch 23 rotatably provided on the sheave block 3 side and a latch 24 with a lever 24a rotatably provided on the frame 2a side.
And springs 25 and 26 that apply spring force to the latch 23 and the latch 24 in the direction in which they engage with each other,
When the sheave block 3 is set to the boom working position, the latch 23 engages with the hook 24 and the sheave block 3
Are fixed in the same position.

In this state, the latch 24 is rotated downward as shown by the arrow in FIG.
However, the sheave block 3 is released from being fixed by being pushed by the pushing piece 24b provided on the hooking device 24 to rotate.

The sheave block 3 can be rotated only between the boom working position and the jib working position by a stopper (not shown).

As shown in FIGS. 1 and 3, the jib 27 is stored vertically on the side surface of the boom body 2 when not in use.

At the base end of the jib 27, a bifurcated rotary jib foot 28 which is rotatable around an axis X (shown in FIG. 1) in the length direction of the jib at the bottom in the retracted state, and a bifurcated upper jib. Fixed jib feet 29 are provided respectively.

The jib 27 is stored in such a positional relationship that the rotating jib foot 29 engages with the left jib mounting shaft 4a when the boom body 2 is in a fully contracted state.

Next, the operation will be described.

A. During boom work During boom work, the jib 27 is retracted to the side of the boom as shown in FIG. 1, while the sheave block 3 is set to the boom work position. In this state, the main hoist rope 7 and the main hoist hook 16 are used. The winding operation and the auxiliary winding operation using the auxiliary winding rope 8 and the auxiliary winding hook 18 are performed.

In this case, since both the main winding main sheaves 12 and the auxiliary winding main sheaves 12 and 13 project below the boom body, the main winding and auxiliary winding ropes 7 and 8 are kept even when the boom 1 is maximally erected. Does not come into contact with the lower surface of the boom body 2 in the horizontal state of the boom.

B. During jib work When the jib 27 is extended during jib work, the sheave block 3 is unfixed to the boom work position and the block 3 is moved from the boom work position to the jib work position shown in FIG. 3 with the help of the spring 19. Reposition and fix.

The boom main body 2 is in a fully contracted state, and the left jib mounting shaft 4 a is engaged with the rotating jib foot 28 of the jib 27, and is prevented from coming off by a pin (not shown).

As is well known (for example, Japanese Patent Publication No. 63-
3827) and the jib 27 with the connection point between the left jib mounting shaft 4a and the rotary jib foot 28 as a fulcrum.
As shown by the phantom line, the wire is then twisted by approximately 270 ° in the direction of arrow a in the figure to obtain the solid line state. In this state, the fixed jib foot 29 of the jib 27 moves to the right jib mounting shaft 4
It engages with b (this state is not shown).

In FIG. 5, the auxiliary winding rope 8 is passed through the jib tip sheave 30 and the main winding hook 16 is hooked on the jib tip portion in the state of the phantom line or in the state of the solid line (31 in FIGS. 5 and 6 is 31). A ring for hooking the main winding hook).

By winding up the main winding rope 7 in this state, the jib 27 is swung up in the direction of arrow B in FIG. 5 to obtain the state of FIG.

In this case, in order to reduce the required upper space, the boom 1 should be stood as much as possible. Thus, the main winding main sheave 12 is located rearward of the jib swinging fulcrum (jib mounting shaft 4) in the boom upright state, but at this time, as shown by the phantom line in FIG.
Is guided by the roller 6 forward of the jib swinging fulcrum, so that the moment arm required for swinging up the jib is secured.

As described above, the extension of the jib 27 is completed, and the jib work is performed by the auxiliary winding rope 8 and the auxiliary winding hook 18 while the jib 27 is supported by the main winding rope 7 in a variable angle.

During this jib work, the main sheave 1 for the main winding
2 (main winding rope 7) is located rearward of the jib attachment shafts 4a and 4b in the boom upright state, and a grip angle θ required to support the jib 27 is secured.

The jib 27 can be stored in the reverse order of the above.

Thus, during jib work (when the jib is extended)
In order to move the sheave block 3 from the boom work position to the jib work position, the sheave block 3 can be used as a strut instead of extending the jib 27 by the main winding rope 7, and the jib 27 can be supported at a variable angle in the extended state. You can Therefore, it is not necessary to horizontally tilt the boom for attaching and detaching the suspension rod as in the conventional case.

Therefore, a long aboveground space for overhanging the jib is not required, so that the jib can be overhanged and stored even in a narrow space or in an urban area where there are obstacles such as electric wires.

Further, since the sheave block 3 is replaced with a strut, there is no inconvenience that the boom tip weight is significantly increased as in the case of using a strut as an exclusive jib overhanging / supporting part, and the main winding rope 7 is used at the time of work conversion.
There is no need for the troublesome work of changing over.

Further, there is no adverse effect such as the reduction of the lifting height as in the case where the tip boom of the boom body 2 is used instead of the strut.

By the way, during jib work in the state of FIG.
In order to avoid interference between the auxiliary winding rope 8 and the main winding hook 16, the auxiliary winding rope guide sheave or roller may be provided on the hook 16.

Further, in the above embodiment, the sheave block 3
Although the latch mechanism is used as a means for fixing the to the boom working position, a pin fixing means may be used as in the case of fixing to the jib working position. Alternatively, conversely, a latch mechanism may be used as the fixing means at the jib working position.

Further, in the above-described embodiment, the rotating jib foot 28 is attached to the base end portion of the main girder of the jib 27, and the rotating jib foot 28 is connected to the left jib mounting shaft 4a. The case of hanging and twisting has been described as an example, but as shown in JP-A-3-158393, etc., on one side of the jib base end portion,
While the jib foot is fixed to the main girder base end, a jib overhanging / storing connector may be provided separately and the jib may be suspended with the connection point between the jib foot and the jib mounting shaft as a fulcrum.

The present invention can also be applied in the same manner to a crane in which the jib is stored on the lower surface of the boom, and the jib is hung from the storage position and then swung upward.

[0058]

As described above, according to the present invention, the boom working position is such that the sheave for the main winding projects below the boom main body in the horizontal state of the boom about the horizontal axis with respect to the tip of the boom main body. And the main winding sheave is rotatably mounted between the jib work position located above the jib mounting shaft in the boom horizontal state, and the jib work position is set during jib work (when the jib is extended). By setting this sheave block to a strut, the jib is extended by the main winding rope, stored, and supported in a variable angle in the extended state. No need for struts.

Therefore, since it is not necessary to horizontally tilt the boom for attaching and detaching the suspension rod, a long ground space for extending the jib is unnecessary. For this reason,
Jibs can be extended and stored even in narrow spaces or in urban areas with obstacles such as electric wires.

Further, there is no inconvenience that the weight at the tip of the boom is significantly increased as in the case of using a strut exclusively used for supporting a jib, and the trouble of hanging the main winding rope when changing work. Further, there is no adverse effect such as a decrease in the lifting height, which occurs when the tip boom of the telescopic boom is used instead of the strut.

On the other hand, according to the second aspect of the present invention, when the jib is extended, the main winding rope is erected by the main winding rope guide member in a boom horizontal state even when the boom is largely erected to reduce the overhang space. Is guided to the lower position. That is, it is possible to secure the moment arm necessary for stretching the jib with the main winding rope.

According to the third aspect of the invention, the sheave block can be easily set in the jib working position with a small force by the spring force.

[Brief description of drawings]

FIG. 1 is a side view of a boom tip portion showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a side view showing a state in which the sheave block has been moved to the jib working position from the state shown in FIG.

FIG. 4 is a side sectional view showing a latch mechanism for fixing the sheave block to a boom working position in the embodiment.

FIG. 5 is a schematic side view showing a state where the jib is being projected in the example.

FIG. 6 is a schematic side view of the jib overhanging state.

[Explanation of symbols]

1 boom 2 boom main body 2a sheave block mounting frame provided at the tip of the boom main body 3 sheave blocks 4a, 4b jib mounting shaft 7 main winding rope 8 auxiliary winding rope 11 as a horizontal axis around which the sheave block rotates Idler sheave shaft 12 Main sheave for main winding 13 Main sheave for auxiliary winding 20,21 Pin hole for fixing sheave block to jib working position 22 Same fixing pin 23 Latch mechanism for fixing sheave block to boom working position 24 The same latching tool 24a The lever of the same latching tool 24b The same pushing piece 25,26 The same spring 6 The roller as the main winding rope guide member 19 The spring which pushes up the sheave block to the jib working position 27 Jib

Claims (3)

[Claims] 1. A boom, and a jib that extends from the tip of the boom, wherein the boom has a main winding sheave through which a main winding rope is passed and a supplementary winding rope that is passed through a tip of a boom body. In a crane provided with a sheave block provided with a sheave for auxiliary winding, a jib mounting shaft to which a base end portion of the jib is connected when the jib is extended at a lower portion of the boom main body in a horizontal state of the boom, A horizontal axis orthogonal to the boom length direction is provided at each of the upper portions, and the sheave block is centered on the horizontal axis. The winding sheave is rotatably attached to the jib work position located above the jib attachment shaft in the boom horizontal state, and the sheave block is fixed to the two positions. A crane comprising block fixing means for 2. A main winding rope guide member for guiding the main winding rope is provided at a tip end portion of the boom body in a state of protruding below the jib mounting shaft in a horizontal state of the boom. The listed crane. 3. The crane according to claim 1, further comprising a spring provided between the tip of the boom body and the sheave block to push up the sheave block toward the jib working position.