JPH09194189A - Jib rising and falling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of a terrible accident such a case that a jib falls down with a rising and falling rope broken. SOLUTION: A lattice jib 23 is pivotally caught by a turning frame 30, and one end of a pendant rope 31 is mounted to the tip end of the lattice jib. One end of a rising and falling mast 29 is pivotally supported by the turning frame 30, and the other end of the pendant rope 31 is mounted to the other floating end of the aforesaid mast. Besides, one end of a hydraulic cylinder 32 is pivotally supported by the turning frame 30, and the other end of it is also pivotally supported by the rising and falling mast 29. The mast 29 rises and falls by letting the hydraulic cylinder 32 be extended/contracted, the pendant rope 31 is pulled up by letting the mast 26 rise and fall, and thereby let the lattice jib 23 rise and fall. Therefore, let the lattice jib 23 rise and fall without using a rising and falling rope and a rising and falling drum as in the past.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jib hoisting device for hoisting a jib mounted on a construction machine such as a crane.

[0002]

2. Description of the Related Art Conventionally, as this type of jib undulating device,
For example, there is one used in the crawler crane shown in FIG.

An upper revolving structure 2 having a revolving frame is mounted on a crawler type lower traveling structure 1. A lattice jib 3 is pivotally supported in front of the upper swing body 2, and a hook 4 for hanging a load is hung at the tip of the lattice jib 3. Further, a mast 5 is provided behind the upper swing body 2.
An A frame 5 consisting of a and 5b is attached.
A bail 6 is attached to the tip of the A frame 5, and a bridle 8 is attached to the tip of the live mast 7. An undulating rope 9 is wound between the bail 6 and the bridle 8, and an end of the undulating rope 9 is wound around an undulating drum 10. Further, one end of the pendant rope 11 is attached to the tip of the live mast 7, and the other end of the pendant rope 11 is attached to the tip of the lattice jib 3.

In such a structure, the undulating drum 10
By winding the up-and-down rope 9 around the bridle 8, the bridle 8 is pulled toward the bail 6, and the distance between the bridle 8 and the bail 6 is shortened. Therefore, the live mast 7 is pulled to the A frame 5 side, and the pendant rope 11 is also pulled to the A frame 5 side accordingly. As a result, the lattice jib 3 is pulled and caused by the pendant rope 11, and the lattice jib 3 is undulated. When the lattice jib 3 is undulated, the working radius R of the crane is increased.
Is adjusted. The load to be hooked on the hook 4 is hoisted by winding the hoisting rope 12 around the main winding drum 13 and the auxiliary winding drum 14. The third drum 15 is for winding an unillustrated auxiliary jib hoisting rope or the like.

The live mast 7 is used to further connect a jib such as a luffing jib (not shown) to the lattice jib 3 to lengthen the entire length of the jib and increase the working radius R. If the working radius R does not have to be increased in this way, the live mast 7 is not used. In this case,
As shown in FIG. 13, the bridle 8 is a pendant rope 1.
Attached directly to 1. In the figure, the same parts as those in FIG. 12 are designated by the same reference numerals and the description thereof will be omitted.

Further, in the lattice jib type crane in which the tip of the lattice jib 3 is supported by the pendant rope 11, in order to change the posture of the crane body, the undulating rope 9 wound around the undulating drum 10 is fed out, and the lattice jib is extended. 3 is once dropped to the ground. Then, after the lattice jib 3 is divided into the necessary length of jib, the bridle 8 is attached to, for example, the floating end of the lower basic jib 3a as shown in FIG. Incidentally, in FIG. 12 and FIG.
The same parts as those in 3 are assigned the same reference numerals and explanations thereof will be omitted. When the undulating rope 9 is wound around the undulating drum 10 in this state, the distance between the bridle 8 and the bail 6 is reduced, and the lower basic jib 3a is lifted. As a result, the attitude of the machine body is changed from the working attitude shown in FIGS. 12 and 13 to the transportation attitude shown in FIG.

[0007]

In the above-mentioned conventional jib hoisting device, hoisting ropes 9 wound around a large number of sheaves between bridle 8 and bail 6 are wound or unwound on hoisting drum 10. Thus, the lattice jib 3 is undulated as described above. Therefore, the undulating rope 9 rubs against many sheaves and is easily damaged. Further, when the undulating rope 9 is wound around the undulating drum 10, the undulating rope 9 may not be regularly wound around the undulating drum 10, but may be disorderly wound around the undulating drum 10. When the undulating rope 9 is wound around in this manner, the undulating rope 9 is easily damaged. Therefore, in the configuration of the conventional jib hoisting device, the hoisting rope 9 may be fatigued and its durability may be deteriorated, resulting in breakage. If the undulating rope 9 breaks, there will be nothing to support the lattice jib 3 and the lattice jib 3 will collapse and a major accident will occur.

[0008]

The present invention has been made to solve the above problems, and includes a pendant rope having one end attached to a jib pivotally supported by a swing frame. In a jib hoisting device for hoisting a jib by pulling the end, one end is pivotally supported by the swivel frame, and the other end of the floating is attached to the other end of the pendant rope, one end is the swivel frame, and the other end is this mast. And a cylinder for undulating the mast by expanding and contracting,
The jib undulating device was constructed.

A sheave for guiding the hoisting rope is provided at the free end of the mast.

Further, one end is connected to one end of the pendant rope detached from the jib, and the other end is connected to a floating end of the jib which is divided into a transportation posture and remains at the front part of the swing frame. An extension rope and an attitude holding rope having a predetermined length, one end of which is connected to the connecting portion of the mast and the cylinder and the other end of which is connected to the rear portion of the revolving frame, are further provided in the jib hoisting device, and the mast is provided. Composed of elastic links.

Further, one end of the mast is replaced with a revolving frame, and one end of each of the masts is pivotally supported by a link pivotally supported by the revolving frame and a connecting portion of each of the other ends of the second cylinders.

According to such a construction, the mast is undulated by the expansion and contraction of the cylinder, and the pendant rope is pulled by the mast undulation, and the jib is undulated without using the conventional undulating rope and undulating drum. .

Further, by providing the sheave on the mast, the hoisting rope is guided from the turning frame side to the tip of the jib, and a hook hoisting path is formed.

Further, the cylinder is contracted to deposit the jib on the ground, and one end of the pendant rope is removed from the jib. Then, one end of the extension rope is connected to one end of the removed pendant rope, and the other end of the extension rope is connected to the floating end of the jib which is divided in the transportation posture and remains in the front portion of the swing frame. Then, extend the cylinder and tilt the cylinder rearward of the swivel frame, supporting it with the pendant rope and extension rope. Next, the mast is allowed to expand and contract, and the cylinder and the mast are contracted while the cylinder is tilted to the rear of the revolving frame by its own weight. When they are contracted, the connecting portion of the cylinder and the mast approaches the rear portion of the revolving frame, so that the posture holding rope is connected between this connecting portion and the rear portion of the revolving frame. By extending the cylinder in this state, the tip of the cylinder rotates rearward of the revolving frame while being regulated by the posture holding rope. Therefore, the floating end of the jib remaining in the front part of the swing frame is pulled by the pendant rope and the extension rope connected to the connecting portion of the cylinder and the attitude holding rope to be lifted from the ground, and the attitude of the aircraft changes from the working attitude to the transportation attitude. Is changed to.

The attitude change of the machine body from the transport attitude to the work attitude is performed in the reverse procedure.

Further, one end of the mast is pivotally supported on the link and the connecting portion of the second cylinder instead of the swing frame.
When the second cylinder is expanded or contracted, the link between the link and the second cylinder, that is, the pivot of the mast moves to the front and the rear of the swing frame. Therefore, when the second cylinder is expanded / contracted and the pivot point of the mast is moved to the rear of the revolving frame, the jib is moved by the amount by which the pivot point of the mast is moved backward without extending the undulating cylinder. get up. Therefore, the amount of extension of the undulating cylinder required for the jib to rise to the highest position can be small.

When the pivot of the mast moves to the rear of the revolving frame, the angle formed by the mast and the undulating cylinder becomes large. Even if the same force is applied from the pendant rope to the connecting portion between the mast and the undulating cylinder, the larger the angle, the smaller the moment force applied to each of the mast and the undulating cylinder.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a first embodiment in which the jib hoisting device according to the present invention is applied to a crawler crane will be described.

FIG. 1 is a side view of a crawler crane having a jib undulating device according to this embodiment. An upper revolving structure 22 is mounted on the crawler-type traveling body 21, and the entire mechanism of the upper revolving structure 22 is partly illustrated in the revolving frame 3
It is loaded with 0. In front of the upper swing body 22,
The lattice jib 23 is rotatably supported on the swivel frame 30. A main hook 25 is suspended by a main hoisting rope 24 at the tip of the lattice jib 23. Further, the auxiliary hook is suspended by the auxiliary hoisting rope 26. This sub-hook is behind the main hook 25 in the figure and is not shown in the drawing. The main hoisting rope 24 is wound on the main hoisting drum 27 loaded on the upper swing body 22, and the auxiliary hoisting rope 26 is wound on the auxiliary hoisting drum 28.

An undulating mast 29 is provided behind the upper revolving structure 22. One end of the undulating mast 29 is pivotally supported on the swivel frame 30. The other end of the undulating mast 29 floats around this pivot point, and one end of a pendant rope 31 is attached to this floating end. The other end of the pendant rope 31 is attached to the tip of the lattice jib 23. The rod end of the hydraulic cylinder 32 is pivotally supported above the jib-side middle abdomen of the undulating mast 29.
The tube end is pivotally supported on a swivel frame 30 between the lattice jib 23 and the undulating mast 29. The hydraulic cylinder 32 freely expands and contracts by being fed with oil.
The jib undulating device according to the present embodiment is provided with the undulating mast 2 described above.
9, a hydraulic cylinder 32 and a pendant rope 31.

A first guide sheave 33 is pivotally attached to the free end of the undulating mast 29, and a second guide sheave 34 is pivotally attached to the back side of the middle abdomen. An auxiliary jib winding rope 35 is hung on these guide sheaves 33 and 34. This auxiliary jib hoisting rope 35
One end of the third winding drum 36 loaded on the upper swing body 22.
The other end is guided to an auxiliary jib (not shown) provided at the tip of the lattice jib 23.

FIG. 2 shows details of the jib undulating apparatus according to the present embodiment described above. 1A is a side view of the crawler crane shown in FIG. 1, and FIG. 1B is a view of the pendant rope 31 viewed from the direction B shown by the arrow. Further, FIG. 7C is a view of the hydraulic cylinder 32 seen from the C direction shown by the arrow, and FIG. 8D shows the undulating mast 29 from the D direction shown by the arrow.
It is the figure which looked at.

As shown in FIG. 2B, the pendant ropes 31 are stretched in pairs. One end of each pendant rope 31 is attached by pins 41, 42 on both sides of the free end of the undulating mast 29, and the other end is attached by pins 43, 44 on both sides of the tip of the lattice jib 23.
Installed by. An auxiliary jib winding rope 35 is stretched between the pendant ropes 31. This auxiliary jib hoisting rope 35 is provided with an undulating mast 29.
It is hung on the first guide sheave 33 on the side, and is hung on the jib point idler sheave 45 on the tip side of the lattice jib 23.

A pair of hydraulic cylinders 32 are also provided, as shown in FIG. The tube end of each hydraulic cylinder 32 has pins 46,
It is pivoted by 47, and the rod end thereof is pivoted by pins 48, 49 above the jib-side middle abdomen of the undulating mast 29.

Further, as shown in FIG. 3D, the undulating mast 29 has a bifurcated end on the side of the revolving frame 30, and the end of the revolving mast 29 is pinned by pins 50 and 51.
It is pivoted to zero. A second guide sheave 34 around which an auxiliary jib hoisting rope 35 is hung is provided on the back side of the abdomen of the undulating mast 29.

FIG. 3 is a side view showing a state in which the lattice jib 23 is undulated by the jib undulating device according to this embodiment. In this figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted. The lattice jib 23 is normally assembled and disassembled in the horizontal position A. In the lattice jib 23 assembled at this position A, the hydraulic cylinder 32 is extended and the mast 29 is raised,
The pendant rope 31 is pulled and raised to the position B. The lattice jib 23 is raised to the maximum position C. In the working range a, the raising angle of the lattice jib 23 is adjusted by expanding and contracting the hydraulic cylinder 32, and the working radius R is set to a desired size. It should be noted that the range b is a range in which the boom is raised and is a range necessary for assembling the crane, and the crane work is not performed in this range.

According to the jib hoisting device of this embodiment, as described above, the mast 29 is hoisted by the expansion and contraction of the hydraulic cylinder 32, and the pendant rope 31 is pulled by the hoisting of the mast 29. Lattice jib 23 is triggered. Therefore, in this embodiment, the lattice jib 23 is undulated without using the conventional undulating rope and undulating drum. For this reason,
In the jib hoisting device according to the present embodiment, unlike the conventional case, a situation in which the hoisting rope is cut due to wear or damage of the hoisting rope does not occur.

Further, the sheaves 33, 34 are attached to the undulating mast 29.
With the provision of, the auxiliary jib hoisting rope 35 is guided by the sheaves 33 and 34 from the turning frame 30 side to the tip of the lattice jib 23. Therefore, the auxiliary hook winding path is formed, and the auxiliary jib winding rope 35
Is wound around the third winding drum 36, and an auxiliary hook (not shown) is hung up.

In the above embodiment, the case where the jib hoisting device according to the present invention is applied to a crawler crane has been described, but the present invention is not limited to this. For example, it can be applied to construction machines such as fixed cranes as well as mobile cranes such as truck cranes and floating cranes, and in this case, the same effects as those of the above-described embodiment can be obtained.

Next, a second embodiment in which the jib hoisting device according to the present invention is applied to a crawler crane will be described.

FIG. 4 is a side view of a crawler crane to which the jib hoisting device according to this embodiment is applied. Also in the crawler crane according to the present embodiment, the crawler type traveling body 6
The upper revolving structure 62 is mounted on 1. Upper swing body 62
At the front portion of the, a lattice jib 63 is pivotally supported by a swivel frame (not shown) so as to be up and down. This lattice jib 6
3 comprises a lower basic jib 63a and an upper basic jib 63b. In the illustrated state, the lattice jib 63 is raised to the highest position.

Further, a link 64 which constitutes an undulating mast is provided behind the upper swing body 62. The link 64 can be freely expanded and contracted by inserting and removing pins. It may be configured to be stretchable by folding. One end of the link 64 is pivotally supported by the swivel frame, and the other end of the link 64 floats around this pivot point. One end of the pendant rope 65 is attached to the floating end, and the other end of the pendant rope 65 is attached to a bracket 66 provided at the tip of the lattice jib 63. This attachment is usually done by connecting pins. Further, the rod end of the hydraulic cylinder 67 is pivotally supported on the floating end of the link 64, and the tube end thereof is
It is pivotally supported on a swivel frame between the lattice jib 63 and the link 64. The hydraulic cylinder 67 freely expands and contracts by feeding oil.

The hook, the hoisting rope and the like are mounted on the crane as in the above-mentioned embodiment, but they are omitted in the figure.

In this embodiment, as in the above embodiment, the hydraulic cylinder 67 expands and contracts to undulate the link 64, and the undulation of the link 64 pulls the pendant rope 65 to cause the lattice jib 63. . Therefore, also in the present embodiment, the lattice jib 63 is raised and lowered without using the conventional undulating rope and the undulating drum, and the situation in which the undulating rope is cut by abrasion or damage of the undulating rope unlike the conventional case does not occur.

The jib hoisting device according to the present embodiment is configured such that, in addition to the hoisting mast being constituted by the expandable link 64, an extension rope 68 and a posture holding rope 69 having a predetermined length which will be described later are further provided. , Which is different from the jib undulating device according to the first embodiment described above. According to the jib hoisting device according to the present embodiment as described above, the posture of the crane can be changed safely and easily. Next, a procedure for changing the working posture of the crane to the transporting posture will be described with reference to FIGS.

When the crane is transported, first, in the work posture shown in FIG. 4, the hydraulic cylinder 67 is contracted, the lattice jib 63 is tilted forward of the machine, and the ground 7 is moved as shown in FIG.
Deposited at 0. Next, the pin connecting the bracket 66 and the pendant rope 65 is pulled out, and one end of the pendant rope 65 attached to the tip of the lattice jib 63 is removed.

Next, one end of the extension rope 68 stored at the time of crane work is connected to one end of this pendant rope 65 removed from the tip of the jib. Then, as shown in FIG. 6, the other end of the extension rope 68 is divided into the transportation postures, and the lower basic jib 63 left in the front part of the swing frame is left.
It is connected to the floating end of a. This connection is for the lower basic jib 6
This is performed by inserting a connecting pin into a bracket 71 provided at the floating end of 3a. In most cases, only the lower basic jib 63a is left on the airframe during transportation of the crane. Therefore, the extension rope 68 is connected to the lower basic jib 63a in this embodiment.

Next, one end of the posture holding rope 69 stored together with the extension rope 68 during the crane work is connected to the connecting portion between the link 64 and the hydraulic cylinder 67. At this time, the other end of the suspended posture holding rope 69 is in a floating state. Next, the hydraulic cylinder 67 is extended. Due to the extension of the hydraulic cylinder 67, the connecting portion between the link 64 and the hydraulic cylinder 67 rotates rearward of the machine body along an arc having a radius of the length of the link 64 with the pivot point of the link 64 and the swing frame as the center. Move. By this rotation of the connecting portion between the link 64 and the hydraulic cylinder 67, the pendant rope 65 and the extension rope 68 are pulled toward the rear of the machine, and the state shown in FIG. 6 immediately before the lower basic jib 63 a leaves the ground 70 is obtained.

In this state, the extension rope 68 is set to a predetermined length so that the hydraulic cylinder 67 reaches a position where the hydraulic cylinder 67 is sufficiently tilted rearward of the machine body due to its own weight. Further, at this time, the hydraulic cylinder 67 includes the pendant rope 65 and the extension rope 6
It is extended to a position where it falls at a constant angle determined by the ratio of the sum of the lengths of 8 and the length of the link 64.

Next, the pin that fixes the length of the link 64 is pulled out, and the length is changed. Next, the hydraulic cylinder 67 is contracted. Hydraulic cylinder 67
While being supported by the pendant rope 65 and the extension rope 68, the vehicle falls rearward due to its own weight. At this time, the link 64 is simultaneously contracted by the weight of the hydraulic cylinder 67. In the hydraulic cylinder 67, the free end of the posture holding rope 69 is connected to the connecting portion 7 provided on the swing frame of the machine body.
It is further contracted to the position shown in FIG. Then, the free end of the posture holding rope 69 is connected to the connecting portion 72.

Next, the hydraulic cylinder 67 is extended. Due to the extension of the hydraulic cylinder 67, the connecting portion between the hydraulic cylinder 67 and the posture holding rope 69 is changed to the posture holding rope 6.
Around the connecting portion 72 to the turning frame of 9, the posture holding rope 69 is turned rearward along the arc having the length as the radius. At this time, the link 64 extends simultaneously with the extension of the hydraulic cylinder 67. Therefore, the floating end of the lower basic jib 63a at the front of the machine is pulled by the pendant rope 65 and the extension rope 68 connected to this connecting portion and the ground 7
Lifted from zero. As a result, the attitude of the crane body is changed from the working attitude to the transportation attitude.

On the other hand, the change of the body posture from the transport posture to the working posture is performed in the reverse order of the above-mentioned procedure.

That is, when changing the posture from the transportation posture to the working posture, first, the hydraulic cylinder 67 is contracted, and as shown in FIG.
The lifted lower basic jib 63a shown in FIG. 7 is deposited on the ground 70 as shown in FIG. Next, the posture holding rope 69 and the connecting portion 72 of the machine body are disconnected, the posture holding rope 69 is removed, and then the hydraulic cylinder 67 is extended. During the extension work of the hydraulic cylinder 67, a pin is inserted into the link 64, and the length of the multistage link 64 is fixed in order. This fixing process of the length of the link 64 is performed at an easy-to-work position where the pin insertion position on the link 64 does not become much higher than the workbench. Link 64
The length of the link 64 is finally fixed when the length becomes maximum, and the state shown in FIG. 6 is obtained.

Next, the hydraulic cylinder 67 is contracted, and the hydraulic cylinder 67 is tilted forward as shown in FIG.
Next, the extension rope 68 is removed, and the lower basic jib 63
The upper basic jib 63b is connected to a. The end of the pendant rope 65 is connected to the bracket 66 of the upper basic jib 63b. Finally, the hydraulic cylinder 67 is extended to change the posture of the crane body to the working posture shown in FIG.

In the conventional crane equipped with the jib hoisting device shown in FIGS. 12 and 13, as described above, the attitude can be changed by winding the jib hoisting rope of the fixed length on the drum and unwinding it. In the above-described first embodiment, there is no rope wound around the drum in this way. Therefore, in order to change the attitude of the machine body in the crane including the jib hoisting device of the first embodiment described above, it is necessary to use another auxiliary crane to change the attitude. Therefore, the posture of the machine body cannot be easily changed in the above-described first embodiment.

However, the undulating mast has a flexible link 6
In the crane including the jib hoisting device according to the present embodiment, which is configured by No. 4 and has the extension rope 68 and the posture holding rope 69, the posture of the machine body can be easily changed as described above. That is, in the crane including the jib hoisting device according to the present embodiment, the posture can be easily and safely changed by itself without the help of the force of the other auxiliary cranes when the posture of the machine is changed.

Next, a third embodiment in which the jib hoisting device according to the present invention is applied to a crawler crane will be described.

FIG. 9 is a side view of a crawler crane having a jib undulating device according to this embodiment. 4, the same parts as those in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted. The jib hoisting device according to the present embodiment is configured by adding a link 81 and a second hydraulic cylinder 82 to the jib hoisting device including the link 64, the hydraulic cylinder 67 and the pendant rope 65 shown in FIG.

In the jib hoisting device shown in FIG. 4, one end of the link 64 constituting the mast is pivotally supported by the swivel frame, but in the jib hoisting device according to this embodiment, the link 64 is provided.
Has one end pivotally connected to the connecting portion between the link 81 and the second hydraulic cylinder 82. These links 81 and second
One end of each of the hydraulic cylinders 82 is pivotally supported by the revolving frame, and the other ends thereof are connected to each other to form a pivot point 83 of the link 64.

In this way, one end of the link 64 is replaced by the swing frame, and the link 81 and the second hydraulic cylinder 82 are replaced.
When the second hydraulic cylinder 82 is expanded and contracted by being pivotally supported by the connecting portion of the above, the pivot point 83 of the link 64 moves to the front and rear of the revolving frame. Therefore, when the second hydraulic cylinder 82 is extended and the pivot point 83 of the link 64 is moved to the rear of the swing frame, the jib 63 moves the hydraulic cylinder 6 for undulation.
Get up to some extent without stretching 7.

FIG. 10 shows a side view of the crawler crane in a state ready for crane work. 9, the same parts as those in FIG. 9 are denoted by the same reference numerals, and the description thereof will be omitted. In the work preparation state shown in the figure, the second hydraulic cylinder 82 is in a contracted state. At the beginning of the work preparation state, the tip of the jib 63 is in a position in contact with the ground 70. When the undulating hydraulic cylinder 67 is extended from this state, the tip of the jib 63 is separated from the ground 70,
The angle θa formed by the jib 63 and the ground horizontal line becomes large.
Crane work can be started when this angle θa becomes larger than about 30 degrees. Second hydraulic cylinder 82
Is held in a retracted position until the jib 63 rises to this angle.

When the undulating hydraulic cylinder 67 is extended and the jib 63 is raised to the beginning of the working state, the operation of the undulating hydraulic cylinder 67 is stopped. Next, the second hydraulic cylinder 82 is extended. By this extension of the second hydraulic cylinder 82, the pivot point 83 of the link 64 moves to the rear of the machine body as shown in FIG. 11, and the jib 63 moves by the amount corresponding to the movement amount of the pivot point 83 to the rear of the machine body. get up. This figure shows a side view of the crawler crane in a crane working state. In the figure, the same parts as those in FIG. 10 are designated by the same reference numerals, and the description thereof will be omitted.

In the jib undulating apparatus according to this embodiment, the second
Since the jib 63 has been previously raised to some extent by the extension of the hydraulic cylinder 82, the amount of extension of the undulating hydraulic cylinder 67 required for the jib 63 to rise to the same position as the highest position shown in FIG. 4 is small. . The maximum position of the jib 63 is often set to a position where the angle θa is about 80 degrees, and the jib 63 has a range from the lowest position where the tip of the jib 63 contacts the ground 70 to the highest position determined as the performance of the crane. Is undulated by. Therefore, when the jib 63 rises to the maximum position, the angle at which the undulating hydraulic cylinder 67 falls rearward of the machine body becomes small, and the amount of movement of the tip end portion of the undulating hydraulic cylinder 67 rearward of the machine body is suppressed.

That is, in the jib undulating device shown in FIG.
When the jib 63 is raised to the highest position shown in the figure,
The tip of the undulating hydraulic cylinder 67 is located rearward of the rearmost end of the crane body. Therefore, in this jib hoisting device, the tip of the hoisting hydraulic cylinder 67 is located outside the rear of the crane body, which is difficult for the operator of the crane to visually recognize, and is preferable in safely performing the crane operation. Absent.

However, in the jib hoisting device according to the present embodiment, as described above, the amount of movement of the tip end portion of the hoisting hydraulic cylinder 67 rearward of the machine body is larger than that in the case of the jib hoisting device according to the above-described embodiment. It is suppressed and the tip of the undulating hydraulic cylinder 67 is always kept within the operator's field of view. Therefore, according to the jib hoisting device according to the present embodiment, not only the lattice jib 63 can be hoisted without using the conventional hoisting rope and hoisting drum, but also the tip end of the hoisting hydraulic cylinder 67 causes the obstacle around the work site. It is possible to safely operate the crane without colliding with the.

Further, the link 64 and the undulating hydraulic cylinder 6
The angle θb shown in FIG. 10 formed by 7 and 7 is as shown in FIG. 1 when the pivot point 83 of the link 64 moves to the rear of the airframe.
It becomes large as shown in 1. Even if the same force is applied from the pendant rope 65 to the connecting portion between the link 64 and the undulating hydraulic cylinder 67, the larger the angle θb, the smaller the moment force applied to each of the link 64 and the undulating hydraulic cylinder 67. Therefore, the acting force acting on each part is reduced.

Therefore, by extending the second hydraulic cylinder 82 to move the pivot point 83 of the link 64 rearward of the machine body, the link 64 and the undulating hydraulic cylinder 67 are moved.
The limit of the force acting on each of the parts, that is, the structural strength can be increased as compared with the case of the jib undulating device according to the above-described embodiment. Therefore, in the jib undulating device according to the present embodiment, each of these parts can be downsized.
Further, if the sizes of the link 64 and the undulating hydraulic cylinder 67 are maintained at the same size as before, it is possible to increase the specification value of the load bearing strength.

That is, the force exerted on each part is smaller when the crane work is performed in the state shown in FIG. 11 in which the pivot point 83 of the link 64 is moved to the rear of the machine than when the crane work is performed in the state shown in FIG. And is structurally advantageous.

Further, the jib 63 cannot be grounded on the ground 70 if the pivot point 83 of the link 64 is left behind the machine body as shown in FIG. In other words, pivot point 8
3 is located at the rear of the fuselage, and the hydraulic cylinder for undulation 6
Even if 7 is contracted to the minimum, the jib 63 does not come into contact with the ground due to the structural limitation of the expansion / contraction range of the undulating hydraulic cylinder 67. For this reason, when the jib 63 is grounded during disassembly and assembly, it is necessary to retract the second hydraulic cylinder 82 to return the pivot point 83 to the position in the work preparation state shown in FIG. To lower the jib 63 to the ground 70.

In the above embodiment, the case where the second hydraulic cylinder 82 for moving the pivot point 83 is provided in front of the machine body with respect to the link 81 has been described. But the second
The relative positional relationship between the hydraulic cylinder 82 and the link 81 may be opposite to that described above, that is, the link 81 may be provided at the front of the machine body and the second hydraulic cylinder 82 may be provided at the rear of the machine body. However, in this case, the second hydraulic cylinder 82 must be contracted in order to move the pivot point 83 to the rear of the machine body. Even when the jib undulating device is configured as described above, the same operation as that of the above-described embodiment is performed, and the same effect is obtained.

[0061]

As described above, according to the present invention, when the cylinder expands and contracts, the mast is undulated, and when the mast is undulated, the pendant rope is pulled, and the jib uses the conventional undulating rope and undulating drum. Can be undulated without any effort. Therefore, a safe jib hoisting device is provided in which a serious accident such as breakage of the hoisting rope and falling of the jib does not occur.

Further, by providing the sheave on the mast, the hoisting rope is guided from the turning frame side to the tip of the jib, and the hook hoisting path is formed. Therefore, it is possible to provide a jib hoisting device to which a hook rope guide function is added in addition to the jib hoisting function.

Further, by constructing the mast with a retractable link and providing the extension rope and the posture holding rope, it is possible to change the posture of the machine body safely and easily.

Further, one end of the mast is pivotally supported on the link and the connecting portion of the second cylinder instead of the swing frame.
By extending and contracting the second cylinder, the amount of extension of the undulating cylinder required for the jib to rise to the highest position can be reduced. For this reason, when the jib rises to the highest position, the angle at which the undulating cylinder falls rearward becomes small, and the tip end of the undulating cylinder protruding to the rear part of the machine body is always kept within the range of the operator's view. Therefore, it is possible to safely operate the crane.

When the pivot point of the mast moves to the rear of the revolving frame, the angle formed by the mast and the undulating cylinder becomes large, and the force acting on each part of the mast and the undulating cylinder becomes small. Therefore, the structural strength of the mast and the undulating cylinder can be increased by expanding and contracting the second cylinder to move the pivot point of the mast to the rear of the revolving frame, and these parts can be downsized. It is possible. Further, if the sizes of the mast and the undulating cylinder are kept the same as before, the specification value of load bearing strength can be increased.

[Brief description of the drawings]

FIG. 1 is a side view of a crawler crane including a jib undulating device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing details of the jib undulating device according to the first embodiment.

FIG. 3 is a side view showing how the lattice jib is undulated using the jib undulating device according to the first embodiment.

FIG. 4 is a side view of a crawler crane to which a jib hoisting device according to a second embodiment of the present invention is applied.

FIG. 5 is a side view showing a first process of posture change using the jib undulating device according to the second embodiment.

FIG. 6 is a side view showing a second step of posture change using the jib undulating device according to the second embodiment.

FIG. 7 is a side view showing a third step of posture change using the jib undulating device according to the second embodiment.

FIG. 8 is a side view showing a fourth step of posture change using the jib undulating device according to the second embodiment.

FIG. 9 is a side view of a crawler crane including a jib undulating device according to a third embodiment of the present invention.

FIG. 10 is a side view of a crawler crane including a jib undulating device according to a third embodiment in a work preparation state.

FIG. 11 is a side view of the crawler crane including the jib undulating device according to the third embodiment in a working state.

FIG. 12 is a side view of a crawler crane with a live mast including a conventional jib undulating device.

FIG. 13 is a side view of a crawler crane without a live mast having a conventional jib undulating device.

FIG. 14 is a side view of a crawler crane including a conventional jib hoisting device in a transporting posture.

[Explanation of symbols]

 21, 61 ... Crawler-type lower traveling body 22, 62 ... Upper revolving structure 23, 63 ... Lattice jib 24 ... Main hoisting rope 25 ... Main hook 26 ... Supplementary hoisting rope 27 ... Main winding drum 28 ... Supplementary winding drum 29 ... Undulating mast 30 ... Revolving frame 31, 65 ... Pendant rope 32, 67, 82 ... Hydraulic cylinder 33, 34 ... Guide sheave 35 ... Auxiliary hook winding rope 36 ... Third winding drum 64, 81 ... Link 68 ... Extension rope 69 ... Posture holding rope 83 … Link 64 pivot

Claims (4)

[Claims] 1. A jib hoisting device having a pendant rope, one end of which is attached to a jib pivotally supported by a swivel frame, for hoisting the jib by pulling the other end of the pendant rope, wherein one end is attached to the swivel frame. A mast having the other end of the pendant rope attached to the other end that is pivotally supported and floating; one end of the mast; and a cylinder that undulates the mast by expanding and contracting the other end pivotally supported by the mast. A jib undulating device characterized by being configured as follows. 2. The jib hoisting device according to claim 1, further comprising: a sheave that guides a hoisting rope at a free end of the mast. 3. A predetermined one is connected to one end of the pendant rope detached from the jib, and the other end is connected to a floating end of the jib which is divided into a transportation posture and remains in the front part of the swing frame. The mast further includes a long extension rope and an attitude holding rope having a predetermined length, one end of which is connected to a connecting portion of the mast and the cylinder, and the other end of which is connected to a rear portion of the revolving frame. The jib undulating device according to claim 1, wherein 4. One end of the mast is pivotally supported instead of the revolving frame, and one end of each of the mast is pivotally supported by a link pivotally supported by the revolving frame and a connecting portion of each of the other ends of the second cylinders. The jib undulating device of claim 1, characterized in that