JPH10310370A - Crane with luffing jib - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve erection and workability of a crane by preventing a third mast for raising a luffing jib, from getting in the way during nonuse. SOLUTION: A third mast 30 for raising first and second masts 24, 25 for supporting a luffing jib is provided with first and second links 30A, 30B, and the first and second links 30A, 30B are equipped with a roller 31 for winding a tension rope, with the oscillating end pivotally supported. The first link has an oscillating fulcrum 32 at a luffing jib fitting base 20 at the tip of an expansion boom 21, and the second link has an oscillating fulcrum at a base jib section 22. The oscillating end can fall in onto the tip side of the base jib section 22 when the base jib section 22 and the luffing jib fitting base 20 are in a parallel state. When the base jib section 22 hangs down from the luffing jib fitting base 20 at the time of vertical erection, the first link stands up being pulled by the base jib section 22, so that the second link is raised to position the roller frontward from the rotating fulcrum of the base jib section 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crane with a luffing jib, and more particularly, to a mechanism for erecting a luffing jib when assembling the luffing jib to a boom tip by an upright method.

[0002]

2. Description of the Related Art As is well known, a luffing jib is a crane used for unloading or unloading work at a high head or at a remote position. The luffing jib is, for example, a base jib attached to the tip of a boom mounted on a truck crane, and a plurality of split jib and a sheave for suspending a hook block at the tip of the split jib according to working conditions with respect to the base jib. It is configured by connecting the mounted top jib. The split jib is configured such that an intermediate jib section is formed between the base jib and the top jib by being connected to a plurality of jib.Lattice jib which can achieve weight reduction compared to the number of connection stages in such an intermediate jib section is frequently used. The longitudinal ends of the lattice gibs are connected to each other. As a configuration for connection, a lug-shaped portion facing each other is formed on one of the longitudinal ends of the lattice jib, and a piece formed on the other side in the longitudinal direction is inserted into this lug-shaped portion, and the lug is inserted. There is a configuration in which a pin is inserted into an insertion hole formed in each of the shape portion and the piece portion (for example, JP-A-7-69585).

Incidentally, when assembling a luffing jib, the present applicant has proposed an assembling method called an upright assembly method which can reduce the ground space required for assembling (for example, the prior application of the present application). No. 2,524,141). This assembling method is a method in which the split jib is connected while being sequentially suspended from the end of the boom while extending the telescopic boom. When assembling the luffing jib by the vertical assembly method, there are provided first and second masts for supporting the luffing jib at an arbitrary undulation angle and a third mast for erecting the luffing jib together with each of these masts. FIG. 4 shows an example of a luffing jib equipped with the first to third masts. In the drawing, a roughing jib 1 is composed of a base jib section 2, an intermediate jib section 3 and a top jib section 4. The jib section 2 is composed of a divided jib pivotally supported on a luffing jib mounting base 7 attached to the tip of a boom 6 mounted on a truck crane 5. The intermediate jib section 3 is configured by connecting a number of divided jib according to the work content, and the top jib section 4 is provided with a tension rod 8 for raising and lowering a luffing jib and a sub-rope winding sheave at the tip. Have been.

On the other hand, the first and second masts 9, 10
A swingable member whose base end is pivotally supported by the base jib section 2, and the third mast 11 is fixed to the luffing jib mounting base 7 at a position close to the front end thereof in a state of standing upright. ing. The first and second masts 9 and 10 can be interlocked by a bendable tension rod 13 connected to the ends thereof. A roller is provided at the tip of the third mast 11, and a second
The tension rope 12 and the sub rope 14 hung on the tip of the mast 10 can be hung. The state shown in FIG. 4 corresponds to the point in time when the connection of the jib sections 2, 3, and 4 in the vertical manner has been completed.
In this state, the winch mounted on the swivel base is hoisted to raise the luffing jib. In other words, the winch winding operation pulls the tension rope 12 wrapped around the third mast 11 to cause the second mast 10, and causes the first mast 9 to interlock with the first mast 9 through the tensioning operation of the tension rod 14. The luffing jib 1 is raised by raising the second masts 9 and 10.

[0005]

However, in order to raise the luffing angle and raise the luffing jib with the third mast 11, the tension rope 12 is lifted in the middle to raise the luffing jib. It is necessary to secure a moment at which the second mast 10 can be swung out. Therefore, conventionally, the luffing jib mounting base has been long, and the position of the swinging fulcrum axis of the duffing jib has been often arranged above the center line of the boom. This leads to an increase in the size of the structure at that portion, which also increases the moment borne by the boom. For this reason, there is a possibility that the work performance at the time of the turning and raising / lowering operation of the boom may be reduced. In addition, since the third mast 11 is fixed to the luffing jib mounting base 7 and is erected, when the swing angle of the second mast 10 is large, the third mast 11 is likely to interfere with the second mast 10 and during transportation. Get in the way when not in use. Meanwhile, the third
If the mast 11 is erected while being fixed, the contents of the assembling work may be affected. That is, in the assembling work, there is a work of guiding the sub-rope to the tip of the base jib section 2 before erecting.
This is performed by sequentially walking on the upper, luffing jib mounting base 7 and the second mast 10 to reach the base jib section. At that time, it is necessary to walk while avoiding the third mast 11, and smooth walking for work is hindered. Therefore, a configuration has been proposed in which the third mast is provided so as to be able to be turned upside down (for example, Japanese Patent Application Laid-Open No. Hei 7-215672 related to the earlier application of the present application). However, in the case of such a configuration, a dedicated hydraulic cylinder for performing the raising / lowering operation is required, which increases the weight and complicates the structure.

SUMMARY OF THE INVENTION In view of the above-mentioned problems in the conventional crane with a luffing jib, it is an object of the present invention to prevent the third mast used when raising the luffing jib from being obstructed when not in use, and to assemble and work the crane. An object of the present invention is to provide a crane with a luffing jib having a configuration capable of improving the performance.

[0007]

In order to achieve this object, according to the first aspect of the present invention, there is provided a base jib in which divided jib are connected while being sequentially suspended from the end of the boom while extending a telescopic boom. The section and the intermediate jib section or the top jib section are sequentially connected, and after the connection, the first and second masts arranged in the front-rear direction of the telescopic boom near the base jib section to hold the luffing jib at an arbitrary angle are pulled. In a crane with a luffing jib having a third mast that raises the luffing jib, the third mast has first and second links, and the first and second links have pivoting ends that are pivotally connected to each other. And a roller for hanging a tension rope, and a first link is provided at the end of the telescopic boom. When the swinging fulcrum is provided on the finning jib mounting base, the second link has a swinging fulcrum on the base jib section, and the base jib section and the luffing jib mounting base are substantially parallel to each other. The swing end is capable of falling down to the distal end side of the base jib section, and the first link is attached to the base jib section when the base jib section is hung from the luffing jib mounting base during the vertical assembly. By being pulled and standing, the second link is raised to position the roller forward of the rotation fulcrum of the base jib section.

According to a second aspect of the present invention, in the crane with a luffing jib according to the first aspect, the third mast is disposed inside the first and second masts in a width direction of the luffing jib. I have.

According to a third aspect of the present invention, in the crane with a luffing jib according to the first aspect, the third mast is provided with first and second links when the luffing jib mounting base and the base jib section are connected. Swinging fulcrum is attached.

According to a fourth aspect of the present invention, in the crane with a luffing jib according to the first aspect, the first and second masts have a range corresponding to a rising locus of the third mast. It is characterized by that.

According to a fifth aspect of the present invention, in the crane with a luffing jib according to the first aspect, a walking platform is provided on a back surface of the third mast.

[0012]

According to the first aspect of the present invention, the first link has a swing fulcrum on the luffing jib mounting base and the second link has a swing fulcrum on the base jib section. A state in which the third mast has fallen and a state in which the third mast is standing can be selectively set according to the form. In particular, when the base jib section is not in an upright position substantially parallel to the luffing jib mounting base, the third mast is in an inclined state to reduce the protruding height, and from this state the base jib section is suspended. At the time of assembling, the standing rope is automatically erected according to the swing of the base jib section so that the tension rope can be wound.

According to the second, fourth and fifth aspects of the present invention, the third mast is located inside the first and second masts. When the mast is erected, the third mast does not interfere with the first and second masts. In addition, since the pedestal is on the back surface of the third mast that does not interfere with the first and second masts, it is possible to walk on the third mast.

According to the third aspect of the present invention, since the first to third masts are assembled at the same time, when assembling the luffing jib, it is only necessary to connect the first to third masts in advance. The work of assembling the third mast is not required.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; FIG. 1 is a diagram showing a base jib section and a luffing jib mounting base used in a crane with a luffing jib. In FIG. 1, a luffing jib mounting base 20 is pin-coupled at four points, up, down, left, and right at the tip of a telescopic boom 21. ing. Since the configurations of the telescopic boom 21 and the luffing jib mounting base 20 are the same as those shown in FIG. 4, detailed description thereof will be omitted. The base jib section 22 has its base end supported by a luffing jib mounting base 20 via a rotating support shaft 23 in advance and is integrated with the luffing jib mounting base 20 so that the base jib section 22 can rotate up and down in a vertical plane. Has become. The base jib section 22 is provided with a frame having a lattice structure, like this type of jib. In the longitudinal direction of the frame, the base jib section 22 has an upper and lower end opposite to the support end with the luffing jib mounting base 20. Receiving portions 22A made of lug pieces are provided at left and right corners, and are fitted to end portions (not shown) made of a pair of lug pieces provided in the intermediate jib section or the top jib section. It is designed to be pin-coupled.

On the other hand, at the base end side of the base jib section 22, as shown in FIG.
2 is provided with first and second masts 2 for supporting the luffing jib at an arbitrary undulation angle.
Reference numerals 4 and 25 are attached via swing pivot shafts. Each of the first and second masts 24 and 25 has a configuration in which two right and left columns and a reinforcing member arranged between the columns are connected to each other. A range corresponding to the rising locus of the mast 30 is a space, and is a passage space for the third mast.

A back stopper device 26 is provided between the luffing jib mounting base 20 and the base jib section 22. The back stopper device 26 is
First and second swinging when erecting a luffing jib
It is provided in order to prevent the luffing jib from inadvertently swinging backward in conjunction with the masts 24 and 25. For this reason, the back stopper device 26 is provided with the hydraulic cylinder 2 provided on the base jib section 24 side.
7, a main link 28 having one end connected to the plunger of the hydraulic cylinder 27 and the other end pivotally supported on the roughing jib mounting base 20 side, and a longitudinal end between the plunger and the base jib section 22. And a secondary link 29 pivotally supported. When connecting the divided jib by the extension and raising operations of the telescopic boom 21, the back stopper device 26 extends the plunger of the hydraulic cylinder 27 in a state where the jib section in the connected state is suspended, and the jib section is moved. The plunger of the hydraulic cylinder 27 contracts in accordance with the raised angle, and the entire contraction restricts the base jib section 22 from swinging backward more.
Main link 28 used for the back stopper device 26
Functions as a stopper when the plunger of the hydraulic cylinder 27 contracts.
The hydraulic cylinder 27 and its plunger function as a regulating member for preventing the hydraulic cylinder 27 and the plunger from being displaced downward by an external force from above. The sub-link 29 maintains a state in which a third mast 30, which will be described later, falls down, and abuts against a roller of the third mast 30 to prevent rotation.

The third mast 30 has the following configuration. In FIG. 1, the third mast 30 includes a first link 30A and a second link 30B in which a swing end is pivotally supported and a roller 31 for hanging a tension rope is supported on the same axis. . 1st link 30A
Is supported by a support shaft 32 serving as a swing fulcrum in a support bracket 20B provided on the luffing jib mounting base 20, and the second link 30B swings at a tip end of a support 33 whose base is fixed to the base jib section 22. It is supported by a support shaft 34 serving as a fulcrum. Third
As shown in FIG. 3, the support bracket 20B and the support 33 on the side of the luffing jib mounting base 20 that support the first and second links 30A and 30B of the mast 30 are provided with the second mast 25 in the width direction of the luffing jib. The interval in the width direction is set so as to be located inside the installation width range, and when the first and second masts 24 and 25 are raised, they interfere with the first and second masts 24 and 25. Has been prevented.

In FIG. 1, the support base 33 has a tip extending from a base fixed to the base jib section 22 and a luffing jib mounting base 20 and a telescopic boom 2.
The first link 30A extends toward the connection position side, and is located near the support shaft 32 serving as a swing support point of the first link 30A. For this reason, the first link 30A and the second link 30
Since the position of the swing fulcrum (support shafts 32 and 34) of B is located on the same side behind the position of the rotation support shaft 23 of the base jib section 22, the third mast 30 shown in FIG. At this time, the first and second links 30A and 30B can be folded in a substantially horizontal state. The horizontal state of the first and second links 30A and 30B is determined by the back stopper device 2
6 and the first and second links 30
It can be obtained by setting the supporting positions of the swinging fulcrums (support shafts 32, 34) of A and 30B to approximate heights in the vertical height direction.

FIG. 3 is a local plan view showing the back surface of the third mast 30, showing a state in which a part of the upper part is opened at the center line in the vertical direction. The reinforcing material forming the lattice structure is omitted for convenience. In the figure,
Third having a first link 30A and a second link 30B
On the back of the mast 30, a walking platform 35 is provided.
Although such a walking member is not shown, there is a walking step provided on the back surface of the hydraulic cylinder 27 in the back stopper device 26.

Since the present embodiment has the above configuration,
When assembling the luffing jib using the upright method,
At the work site, the luffing jib mounting base 20, the base jib section 22, the intermediate jib section or the top jib section are sequentially connected to the telescopic boom 21 and assembled. Before that, the luffing jib mounting base is transported to the work site. 20 is connected to the split jib forming the base jib section 22. When the base jib section 22 is connected to the luffing jib mounting base 20, the first to third masts 24, 2
5, 30 are mounted in the required support positions. That is,
The first and second masts 24 and 25 are attached to a bracket 20A on the base end side of the base jib section 22 via a swing fulcrum shaft.
A is supported by a support shaft 32 serving as a swing fulcrum at a support bracket 20B of the luffing jib mounting base 20, and a second link 30B is provided at a tip of a support base 33 whose base is fixed to the base jib section 22 at a swing fulcrum. Is supported by the supporting shaft 34. At this time, the back stopper device 26 and the third mast 30
The walking platform 35 located at the back of the vehicle is also supported at a position where the members constituting the same are required. FIG. 1 shows the luffing jib mounting base 20, the base jib section 22 and the members related thereto in an assembled state, and can be transported in this state. As shown in FIG. 1, the third mast 30 is in a state where the luffing jib mounting base 20 and the base jib section 22 are substantially parallel (the swing fulcrum shaft 2).
The swing angle of the base jib section 22 is almost 0 with respect to 3.
When the first and second links 30A and 30B are conveyed in a state corresponding to degrees, the pivot ends of the first and second links 30A and 30B are centered on the positions of the pivot points (support shafts 32 and 34). The back stopper device 26 is maintained by the hydraulic cylinder 27 of the back stopper device 26 and the auxiliary link 29 supporting the same. Accordingly, the third mast 30 does not protrude upward because it is substantially parallel to the base jib section 22 at the upper portion of the base jib section 22, and the occupancy in the height direction is reduced. This is advantageous in terms of height restrictions during transportation. In addition, the roller 31 of the third mast 30 comes into contact with the sub-link 29 of the back stopper device 26 and is prevented from rotating.

On the other hand, the sub rope is pulled out from the sub winch, and the tip of the rope is connected to the base jib section 22.
Is guided to the tip side. When guiding the sub-rope,
The operator guides the end of the rope by holding it with his / her hand. From the telescopic boom 21 to the base jib section 22, the walking platform 35 and the back stopper device 26 arranged on the back of the third mast 30 are provided. Can be easily and safely moved by the pedestal 35 and the step even if the part has poor scaffolding from the end of the boom to the base jib section 22. Furthermore, the walking platform 3 included in the third mast 30
The roller 31 located in the vicinity of the roller 5 is prevented from rotating by the sub-link 29 of the back stopper device 26, and does not rotate even if the worker makes an excessive contact with the roller 31. Accidents such as dropping or stepping off can be prevented.

When connecting the divided jib which forms the intermediate jib section or the top jib section to the tip of the base jib section 22, the base jib section 22 which has been in a substantially horizontal state by each operation of extending and raising the telescopic boom 21. Is suspended to be substantially vertical. FIG.
Shows a state in which the base jib section 22 is suspended. In this state, when the base jib section 22 rotates downward about the rotation fulcrum, the support 33 integrated therewith rotates. . When the support base 33 rotates, the first link 30A forming the pivot point of the support shaft 32 provided at the tip of the support base 33 is pulled, and as shown in FIGS. When the first link 30A stands, the second link 30B, whose pivot end is pivotally supported, is also pulled and raised together with the first link 30A, and the position of the roller 31 at the pivot end is determined by the rotation fulcrum of the base jib section 22. Is located ahead of the boom. Since the position of the roller 31 is located forward of the position of the rotation fulcrum of the base jib section 22, the arm length around the rotation support shaft 23 when the mast is raised is increased, and the second mast tip and the air sheave are connected to each other. Can be shortened.

On the other hand, the first and second masts 24 and 25 pass through the position occupied by the third mast 30 when they are raised by pulling the tension rope. Since the passage space for the third mast 30 is formed, the first and second masts 24 and 25, particularly the second mast 25, are raised without interfering with each other.

According to the present embodiment, the roller 31 of the third mast 30 can be supported by the hydraulic cylinder 27 and the auxiliary link 29 of the back stopper device 26, so that at least the luffing jib mounting base 20 and the base jib section. In a state where the axis is parallel to 22, the third mast can be stored within the height range of the luffing jib mounting base 20. In addition, since the positions of the pivot points (support shafts 32, 34) of the first and second links 30A, 30B are arranged on the same side, the third mast 30 can be in a state where the links are folded. In addition, the position of the swinging fulcrum is the
Since it is inserted into the base end side from the tip end, a part of the length occupied by each link can be taken in as a part of the length of the luffing jib mounting base 20. The space occupied by the third mast 30, that is, the space in the height direction and the length direction can be reduced.

[0026]

According to the first aspect of the present invention, the first link has a swing fulcrum on the luffing jib mounting base and the second link has a swing fulcrum on the base jib section. Third depending on the operation mode of the jib section
A state in which the mast has fallen and a state in which the mast is standing can be selectively set. In particular, when the base jib section is not upright and the luffing jib mounting base is substantially parallel,
The protruding height is reduced by the mast being in the fall state, and the base jib section is suspended from this state. It can be turned. As a result, it is possible to eliminate an inadvertent height when not in use and not to be an obstacle. In addition, when the first and second masts are raised, it is only necessary to link them to the base jib section without using a special driving source, so that the structure is prevented from becoming complicated and the increase in the moment borne by the boom is suppressed. This makes it possible to improve the work performance of the crane work.

According to the second, fourth and fifth aspects of the present invention, the third mast is located inside the first and second masts. When the second mast is erected, the third mast does not interfere with the first and second masts. In addition, since the pedestal is on the back surface of the third mast that does not interfere with the first and second masts, it is possible to walk on the third mast. Thereby, workability at the time of assembling the roughing jib can be improved.

According to the third aspect of the present invention, since the first to third masts are assembled at the same time, when assembling the luffing jib, it is only necessary to connect the first to third masts in advance. This eliminates the need for assembling the third mast again. This makes it possible to improve the efficiency of assembly work.

[Brief description of the drawings]

FIG. 1 is a view showing a part of a jib section used for a roughing jib according to the first to fifth aspects of the present invention.

FIG. 2 is a view for explaining an intermediate stage of assembling the jib section shown in FIG. 1;

FIG. 3 is a plan view of a main part of the jib section shown in FIG.

FIG. 4 is a view for explaining an example of a roughing jib having a third mast. It is a figure for explaining a part like an example shown in a figure.

[Explanation of symbols]

 Reference Signs List 1 luffing jib 20 luffing jib mounting base 21 telescopic boom 22 base jib section 24 first mast 25 second mast 26 back stopper device 30 third mast 30A first link 30B second link 31 roller 32 Support shaft 34 Support shaft that forms the pivot of the second link 35 Walking platform

Claims (5)

[Claims] 1. A jib which is divided while extending an extendable boom is connected in a state of being sequentially suspended from the end of the boom to sequentially connect a base jib section and an intermediate jib section or a top jib section. In a crane with a luffing jib having a third mast that pulls up a first mast and a second mast disposed in the front-rear direction of the telescopic boom near the base jib section to hold the luffing jib near the base jib section, The three masts include first and second links, the first and second links being pivotally supported at their swinging ends and equipped with rollers for looping a tension rope, Has a rocking fulcrum on a luffing jib mounting base provided at the end of the telescopic boom,
The link has a swing fulcrum at the base jib section, and when the base jib section and the luffing jib mounting base are substantially parallel to each other, the swing end can fall down to the tip side of the base jib section. When the base jib section is suspended from the luffing jib mounting base during the upright assembly, the first link is pulled by the base jib section and stands up, thereby raising the second link. A crane with a roughing jib, wherein the roller is positioned forward of a fulcrum of rotation of the base jib section. 2. The crane with a luffing jib according to claim 1, wherein the third mast is disposed inside the first and second masts in a width direction of the luffing jib. 3. The crane with a luffing jib according to claim 1, wherein the third mast is a first mast when the luffing jib mounting base is connected to the base jib section.
A crane with a roughing jib, wherein a swing support point of the second link is attached. 4. The crane with a luffing jib according to claim 1, wherein the first and second masts have a range corresponding to a rising locus of the third mast as a passage space of the third mast. A crane with a roughing jib. 5. The crane with a luffing jib according to claim 1, wherein a walking platform is provided on a back surface of the third mast.