JPH09194190A - 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 its rising and falling rope broken. SOLUTION: One end of a first pendant rope 25 is mounted to the tip end of a lattice jib 23, and the other end of it is connected with one end of a second pendant rope 26. The other end of the second pendant rope 26 is locked onto a turning frame. Besides, one end of a telescopic cylinder box 27 is pivotally supported by the turning frame, and the other end of it is floated around the pivotally supporting point. This floating end is locked onto the connecting part of the first pendant rope 25 with the second pendant rope 26. The aforesaid connecting part is pressed/drawn by letting the cylinder box 27 be extended/ contracted, and the first pendant rope 25 is pulled up, so as to let the lattice jib 23 thereby 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. 14, the bridle 8 is a pendant rope 1.
Attached directly to 1. In the figure, the same parts as those in FIG. 13 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 unwound and the lattice jib is moved. 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. In addition, in FIG. 13 and FIG.
The same parts as those in FIG. 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. 13 and 14 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, a second pendant rope having one end locked to a swivel frame and the other end connected to the other end of the pendant rope, and one end pivotally supported by the swivel frame. The jib undulating device is configured with an extensible cylinder box having a cylinder that holds the floating other end at the connecting portion of the pendant rope and the second pendant rope and pushes and pulls the connecting portion by expanding and contracting. .

A sheave for guiding the hoisting rope is provided at the free end of the telescopic cylinder box.

Further, a locking tool provided on the body of the telescopic cylinder box, a second cylinder whose one end is pivotally supported at the rear part of the revolving frame, and one end on the revolving frame in front of this second cylinder. A link that is pivotally supported and has the other end connected to the free end of the second cylinder; and a work rope that has one end connected to the second cylinder and the connecting portion of this link and the other end connected to a lock. , One end is connected to the other end of this work rope which is disconnected from the locking device, and the other end is connected to the floating end of the jib which is divided into the transport position and remains in the front part of the swing frame A rope and a jib undulating device were also provided.

Further, one end of the second pendant rope is replaced with a revolving frame, and one end of each of the second pendant ropes is locked to a connecting portion of the other end of the second link and the third cylinder pivotally supported by the revolving frame. It was configured to let.

According to this structure, the cylinder box expands and contracts to allow the pendant rope and the second
The pendant rope connection is pushed and pulled, the pendant rope is pulled, and the jib is raised and lowered without the use of conventional undulating ropes and undulating drums.

Further, since the telescopic cylinder box is provided with the sheave, the hoisting rope is guided from the turning frame side to the tip of the jib, and the hook hoisting path is formed.

Further, the telescopic cylinder box is contracted to store the jib on the ground, and one end of the pendant rope is removed from the jib. Then, the second cylinder is extended to reduce the distance between the second cylinder and the connecting portion of the link and the locking tool, and the work rope is connected therebetween. Next, the second cylinder is contracted, the work rope is pulled, and the telescopic cylinder box is lifted. When the telescopic cylinder box is lifted, the second pendant rope loosens, so the connection of the second pendant rope with the swing frame is released. When the second cylinder is extended in this state, the telescopic cylinder box falls forward of the swing frame while being supported by the work rope, and is placed on the jib that remains in front of the swing frame after being divided into the transportation posture.

Next, release the connection between the work rope and the locking tool,
Connect the end of the loosened work rope to one end of the posture-maintaining rope. The other end of the posture holding rope is connected to the free end of the jib remaining on the front part of the swing frame. When the second cylinder is contracted in this state, the floating end of the jib remaining at the front part of the revolving frame is pulled from the ground by the work rope and posture holding rope connected to the connecting portion between the second cylinder and the link. Lifted, the attitude of the aircraft changes from the working attitude to the transportation attitude.

The posture change of the machine body from the transport posture to the work posture is performed by the reverse procedure.

Further, one end of the second pendant rope is
When the third cylinder is expanded and contracted by engaging with the connecting portion of the second link and the third cylinder instead of the revolving frame, the connecting portion of the second link and the third cylinder, that is, the second pendant rope. The locking points of move to the front and back of the swivel frame. Therefore, if the third cylinder is expanded and contracted and the locking point of the second pendant rope is moved to the rear of the revolving frame, the jib will move to the locking point of the second pendant rope without extending the elastic cylinder box. Will get up by the amount of moving backwards. Therefore, the amount of extension of the telescopic cylinder box required for the jib to rise to the highest position can be small.

When the locking point of the second pendant rope moves to the rear of the revolving frame, the angle formed by the second pendant rope and the telescopic cylinder box increases. Even if the same force is applied from the pendant rope to the connecting part between the second pendant rope and the telescopic cylinder box,
The larger this angle, the smaller the moment force applied to each of the second pendant rope and the telescopic cylinder box.

[0019]

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 structure 21, and the entire mechanism of the upper revolving structure 22 is loaded on a revolving frame (not shown). In front of the upper revolving structure 22, the lattice jib 23 is rotatably supported by the revolving frame.
The lattice jib 23 is prevented by the jib back stop 24 from falling due to tilting when a load is dropped or while traveling. Further, one end of the first pendant rope 25 is attached to the tip of the lattice jib 23, and the other end of the first pendant rope 25 is connected to one end of the second pendant rope 26. The other end of the second pendant rope 26 is locked to the swing frame.
An extendable cylinder box 27 is provided between the lattice jib 23 of the upper swing body 22 and the second pendant rope 26. One end of this telescopic cylinder box 27 is pivotally supported by the swivel frame, and the other end is free to move around this pivot point. This floating end is locked to the connecting portion between the first pendant rope 25 and the second pendant rope 26. The jib undulating device according to the present embodiment is composed of the first and second pendant ropes 25 and 26 and the telescopic cylinder box 27.

A guide sheave 28 is pivotally attached to the free end of the telescopic cylinder box 27. A main hoisting rope 29 and a supplementary hoisting rope 30 are hung on the guide sheave 28, and the ropes 29 and 30 are moved from the turning frame side by the sheave 28 to the lattice jib 2.
It is led to the tip of 3. A main hook 31 is suspended at one end of the main hoisting rope 29 on the jib tip side,
The other end on the turning frame side is wound around the main winding drum 32. Further, a sub hook is suspended at one end of the auxiliary hoisting rope 30 on the jib tip side. This sub-hook is behind the main hook 31 in the figure and is not shown in the drawing. The other end of the auxiliary hoisting rope 30 on the side of the turning frame is wound around the auxiliary hoisting drum 33.

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 first pendant rope 25 seen from the direction B shown by the arrow. Further, FIG. 7C is a view of the telescopic cylinder box 27 seen from the C direction of the arrow, and FIG. 7D is a view of the second pendant rope 26 seen from the D direction of the arrow.

As shown in FIG. 2B, the first pendant ropes 25 are stretched in a pair. One end of each pendant rope 25 is attached by pins 41, 42 on both sides of the free end of the telescopic cylinder box 27, and the other end is attached by pins 43, 44 on both sides of the tip of the lattice jib 23. Also,
A main hoisting rope 29 and an auxiliary hoisting rope 30 are stretched between the pendant ropes 25. The main hoisting rope 29 and the auxiliary hoisting rope 30 are hooked on the guide sheaves 28 on the telescopic cylinder box 27 side, and on the jib point idler sheaves 45 on the tip end side of the lattice jib 23.

Further, as shown in FIG. 3C, the telescopic cylinder box 27 has a built-in hydraulic cylinder 27a. The telescopic cylinder box 27 is telescopically configured to be telescopic. The bifurcated end of the telescopic cylinder box 27 on the turning frame 46 side is pivotally supported on the turning frame 46 by pins 47 and 48. Further, the hydraulic cylinder 27a freely expands and contracts by being fed with oil. The tube end of the hydraulic cylinder 27a has a pin 4 on the inner wall of the telescopic cylinder box 27.
9 is pivotally supported, and its rod end is pivotally supported by the pin 50 on the floating end of the telescopic cylinder box 27.

Further, as shown in FIG. 3D, the second pendant ropes 26 are also stretched in pairs. One end of each of the second pendant ropes 26 has pins 51,
They are locked by 52 and are respectively connected to the first pendant ropes 25. The other end of the second pendant rope 26 is attached to the swivel frame 46 by the pins 53, 54.
It is locked by. Further, as described above, the main hoisting rope 29 and the auxiliary hoisting rope 30 are hung on each guide sheave 28.

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 telescopic cylinder box 27 is extended, and the first pendant rope 25
The first pendant rope 25 is pulled up to the position B by pushing the connecting portion between the first pendant rope 25 and the second pendant rope 26 backward. The lattice jib 23 is raised to the maximum position C. In the working range a,
By expanding and contracting the cylinder box 27, the angle at which the lattice jib 23 is raised is adjusted, 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 the present embodiment, the first and second pendant ropes 2 are expanded and contracted by the cylinder box 27 as described above.
The connecting portions of 5 and 26 are pushed and pulled, the first pendant rope 25 is pulled, and the lattice jib 23 is undulated. Therefore, in this embodiment, the lattice jib 23
Can be undulated without the use of conventional undulation ropes and undulation drums. Therefore, 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, since the telescopic cylinder box 27 is provided with the sheave 28, the main hoisting rope 29 and the auxiliary hoisting rope 30 are guided by the sheave 28 from the turning frame side to the tip of the lattice jib 23. Therefore, a hook winding path is formed, and the main winding rope 29 and the auxiliary winding rope 30 are wound around the main winding drum 32 and the auxiliary winding drum 33, so that the main hook 31 and the auxiliary hook are 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.

One end of the first pendant rope 65 is attached to the bracket 66 at the tip of the lattice jib 63, and the other end of the first pendant rope 65 is connected to one end of the second pendant rope 64. . The other end of the second pendant rope 64 is locked to the connecting portion 68 of the turning frame. Further, between the lattice jib 63 of the upper swing body 62 and the second pendant rope 64,
Telescopic cylinder box 6 containing the first hydraulic cylinder
7 are provided. One end of this telescopic cylinder box 67 is pivotally supported on the revolving frame, and its free end is
The first pendant rope 65 and the second pendant rope 64 are locked to the connecting portion. The telescopic cylinder box 67 freely telescopes by sending oil to the built-in first hydraulic cylinder.

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 well, as in the above-described embodiment, the connecting portion between the first and second pendant ropes 65 and 64 is pushed and pulled by the expansion and contraction of the cylinder box 67, and the first pendant rope 65 is formed. Is pulled and the lattice jib 63 is undulated. 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 provided with a hook 69, which is a metal fitting provided on the body of the telescopic cylinder box 67, a second hydraulic cylinder 70, which will be described later, a link 71, a work rope 72, and a posture. The jib undulating device according to the above-described embodiment is different in that a holding rope 73 is further provided. 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 transportation posture will be described with reference to FIGS.

When the crane is transported, first, the telescopic cylinder box 67 is contracted in the work posture shown in FIG. 4, the lattice jib 63 is tilted forward of the machine body, and it is stored on the ground 74 as shown in FIG. Next, the pin connecting the bracket 66 and the first pendant rope 65 is pulled out,
One end of the first pendant rope 65 attached to the tip of the lattice jib 63 is removed. In most cases, only the lower basic jib 63a is left on the airframe during transportation of the crane. Therefore, the case where the lower basic jib 63a is divided and left in this embodiment will be described.

As shown in FIG. 6, one end of a second hydraulic cylinder 70 is pivotally supported at the rear of the revolving frame. Further, one end of a link 71 is pivotally supported on the swing frame in front of the second hydraulic cylinder 70 with respect to the machine body. The other end of the link 71 is connected to the floating end of the second hydraulic cylinder 70. Next, the second hydraulic cylinder 70 is extended, and the connecting portion of the second hydraulic cylinder 70 and the link 71 rotates about the pivot point of the link 71 with respect to the turning frame. By this rotation, the distance between the connecting portion of the second hydraulic cylinder 70 and the link 71 and the locking tool 69 is shortened, and the work rope 72 is connected between them. The work rope 72 is stored during crane work.

Next, the second hydraulic cylinder 70 is contracted, the work rope 72 is pulled by the connecting portion, and the telescopic cylinder box 67 is lifted. When the telescopic cylinder box 67 is lifted, the second pendant rope 6
Since 4 is loosened, the connection between the end of the second pendant rope 64 and the connecting part 68 of the swivel frame is broken by pulling out the pin. Then, the second pendant rope 64 and the first pendant rope 65 are removed from the machine body.

In this state, the second hydraulic cylinder 70 is extended so that the connecting portion of the second hydraulic cylinder 70 and the link 71 is centered on the pivot point of the link 71 with respect to the turning frame, and the length of the link 71 is increased. Rotate forward of the revolving frame along an arc having a radius of. Therefore, the telescopic cylinder box 67 is supported by the work rope 72 and falls toward the front of the machine body, and is placed on the lower basic jib 63a which is divided into the transportation posture and remains in the front of the machine body as shown in FIG. The telescopic cylinder box 67 mounted on the lower basic jib 63a is fixed by the fixture 75.
It is fixed to 3a. By this fixing, the telescopic cylinder box 67 is held by the lower basic jib 63a during transportation.

After that, the connection between the work rope 72 and the locking tool 69 is released, and the end of the work rope 72 released is connected to one end of the posture holding rope 73 shown in FIG. This posture holding rope 73 is attached to the lattice jib 63 during crane work. The other end of the posture holding rope 73 is connected to a flange 76 provided at the free end of the lower basic jib 63a. When the second hydraulic cylinder 70 is contracted in this state, the lower basic jib 6 remaining at the front of the machine body
As shown in FIG. 9, the floating end of 3a is pulled by a work rope 72 and a posture holding rope 73 connected to the connecting portion between the second hydraulic cylinder 70 and the link 71, and the ground 74
Lifted from. 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 second hydraulic cylinder 70 is extended, and the lifted lower basic jib 63a shown in FIG.
As shown in FIG. 8, it is deposited on the ground 74. Next, the posture holding rope 73 is removed, and the end portion of the work rope 72 is locked by the locking tool 69 of the telescopic cylinder box 67 as shown in FIG.
Connected to. In this state, the second hydraulic cylinder 70 is contracted, and the telescopic cylinder box 67 placed on the lower basic jib 63a is raised.

Next, the second pendant rope 64 is connected between the tip of the telescopic cylinder box 67 and the connecting portion 68 on the main body side as shown in FIG. Further, the first pendant rope 6 is attached to the tip of the telescopic cylinder box 67.
One end of 5 is connected. Then, the second hydraulic cylinder 70 is extended to loosen the work rope 72, and the telescopic cylinder box 67 is supported by the second pendant rope 64. Next, the work rope 72 is removed and the state shown in FIG. 5 is obtained. Then, the lattice jib 63 is assembled, and the other end of the first pendant rope 65 is connected to the flange 66 at the tip of the upper basic jib 63b.

When the telescopic cylinder box 67 is extended in this state, the lattice jib 63 is raised from the ground surface 74. As a result, the crane body is changed to the work posture shown in FIG.

In the conventional crane equipped with the jib hoisting device shown in FIGS. 13 and 14, the posture can be changed by winding the jib hoisting rope of fixed length on the drum and unwinding it, as described above. In the above-described embodiment, there is no rope wound around the drum. Therefore, in order to change the attitude of the machine body in the crane equipped with the jib hoisting device of the above-described embodiment, it is necessary to use another auxiliary crane to change the attitude. Therefore, in the above-described embodiment, the posture of the machine body cannot be easily changed.

However, a locking tool 69 is provided on the body of the telescopic cylinder box 67, and the second hydraulic cylinder 7
In the crane including the jib hoisting device according to the present embodiment having the 0, the link 71, the work rope 72, and the attitude holding rope 73, the attitude 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. 10 is a side view of a crawler crane equipped with the jib hoisting 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 a jib hoisting device including a second pendant rope 64, a telescopic cylinder box 67 and a first pendant rope 65 shown in FIG. 4, a second link 81 and a third hydraulic pressure. The cylinder 82 is provided.

In the jib hoisting device shown in FIG. 4, one end of the second pendant rope 64 is locked to the connecting portion 68 of the revolving frame, but in the jib hoisting device according to this embodiment, the second pendant rope 64 is provided. One end of is locked to the connecting portion of the second link 81 and the third hydraulic cylinder 82. One end of each of the second link 81 and the third hydraulic cylinder 82 is pivotally supported by the swing frame, and the other ends thereof are connected to each other to form the second pendant rope 6
The four locking points 83 are formed.

As described above, one end of the second pendant rope 64 is locked to the connecting portion of the second link 81 and the third hydraulic cylinder 82 in place of the swing frame, and the third end of the third pendant rope 64 is locked.
When the hydraulic cylinder 82 is expanded and contracted, the locking point 83 of the second pendant rope 64 moves to the front and rear of the swing frame. Therefore, the third hydraulic cylinder 82 is extended and the second hydraulic cylinder 82 is extended.
When the locking point 83 of the pendant rope 64 is moved to the rear of the revolving frame, the jib 63 rises to some extent without extending the telescopic cylinder box 67.

FIG. 11 shows a side view of the crawler crane in a state ready for crane work. In the figure, the same parts as those in FIG. 10 are designated by the same reference numerals and the description thereof is omitted. In the work preparation state shown in the figure, the third 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 74. When the telescopic cylinder box 67 is extended from this state, the tip of the jib 63 separates from the ground 74, and the angle θa formed by the jib 63 and the ground horizontal line increases. Crane work can be started when this angle θa becomes larger than about 30 degrees. Third hydraulic cylinder 8
2 is kept in a retracted state until the jib 63 rises up to this angle.

When the telescopic cylinder box 67 is extended and the jib 63 is raised to the beginning of the working state, the operation of the telescopic cylinder box 67 is stopped. Next, the third hydraulic cylinder 82 is extended. Third hydraulic cylinder 82
Due to this extension, the locking point 83 of the second pendant rope 64 moves to the rear of the machine as shown in FIG. 12, and the jib 6
3 rises by an amount corresponding to the amount of movement of the locking point 83 to the rear of the machine body. This figure shows a side view of the crawler crane in the crane working state. In the figure, the same parts as those in FIG. 11 are designated by the same reference numerals, and the description thereof will be omitted.

In the jib undulating apparatus according to this embodiment, the third
Since the jib 63 is previously caused to some extent by the extension of the hydraulic cylinder 82, the extension amount of the telescopic cylinder box 67 required for the jib 63 to rise up to the same position as the highest position shown in FIG. 4 can be small. The highest 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 74 to the highest position determined as the performance of the crane. Is undulated by. For this reason, when the jib 63 rises to the maximum position, the angle at which the telescopic cylinder box 67 falls rearward of the machine body becomes small, and the amount of movement of the tip end of the telescopic cylinder box 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 telescopic cylinder box 67 is located rearward of the tail end of the crane body. Therefore, in this jib hoisting device, the tip of the telescopic cylinder box 67 is located outside the rear of the crane body, which is difficult for the operator of the crane to visually recognize, which is not preferable in safely operating the crane. .

However, in the jib hoisting device according to the present embodiment, as described above, the amount by which the tip end portion of the telescopic cylinder box 67 moves rearward of the machine body is suppressed as compared with the case of the jib hoisting device according to the above-described embodiment. Thus, the tip of the telescopic cylinder box 67 is always kept within the operator's field of view. Therefore, according to the jib hoisting device of the present embodiment, not only the jib 63 can be hoisted without using the conventional hoisting rope and hoisting drum, but also the tip end of the cylinder box 67 collides with an obstacle around the work site. It is possible to safely carry out the crane operation without the need to do so.

The angle θb shown in FIG. 11 formed by the second pendant rope 64 and the telescopic cylinder box 67.
When the locking point 83 of the second pendant rope 64 moves to the rear of the machine body as described above, becomes large as shown in FIG. The first pendant rope 65 is attached to the connecting portion between the second pendant rope 64 and the telescopic cylinder box 67.
Even if the same force is applied from, the larger the angle θb is, the smaller the moment force applied to each of the second pendant rope 64 and the telescopic cylinder box 67 becomes,
The acting force acting on each part is reduced.

Therefore, by extending the third hydraulic cylinder 82 and moving the locking point 83 of the second pendant rope 64 to the rear of the machine, the respective parts of the second pendant rope 64 and the telescopic cylinder box 67 are moved. The limit of the force exerted on the structure, 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 second pendant rope 64 and the telescopic cylinder box 67 are kept the same as before, it is possible to increase the specification value of the load bearing strength.

That is, rather than performing the crane work in the state shown in FIG. 11, the locking point 8 of the second pendant rope 64
When the crane 3 is moved to the rear of the machine and the crane operation is performed in the state shown in FIG. 12, the force acting on each part becomes smaller, which is advantageous in structure.

Further, if the locking point 83 of the second pendant rope 64 remains positioned at the rear of the machine as shown in FIG. 12, the jib 63 cannot be grounded on the ground 74.
That is, even if the telescopic cylinder box 67 is contracted to the minimum with the locking point 83 being located at the rear of the machine body, the jib 63 does not come into contact with the ground due to the structural limitation of the telescopic cylinder box 67 in the telescopic range. Therefore, when the jib 63 is grounded during disassembly and assembly, the third hydraulic cylinder 82
Must be retracted to return the locking point 83 to the position of the work preparation state shown in FIG.
To lower the jib 63 to the ground 74.

In the above embodiment, the case where the third hydraulic cylinder 82 for moving the locking point 83 is provided in front of the machine body with respect to the second link 81 has been described. However, the relative positional relationship between the third hydraulic cylinder 82 and the second link 81 is the reverse of the above description, that is, the second link 81 is provided at the front of the machine and the third hydraulic cylinder 82 is provided at the rear of the machine. May be However, in this case, the third hydraulic cylinder 82 must be contracted in order to move the locking point 83 rearward 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, the connecting portion of the pendant rope and the second pendant rope is pushed and pulled by the expansion and contraction of the cylinder box, and the pendant rope is pulled, so that the jib can be kept in the conventional state. It can be undulated without using undulating ropes and drums. 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 expandable cylinder box with the sheave, 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 providing a locking tool on the body of the telescopic cylinder box, and further by providing the second cylinder, the link, the work rope and the posture holding rope, the posture of the machine body can be changed safely and easily. It will be possible.

In addition, one end of the second pendant rope is
By engaging the connecting portion of the second link and the third cylinder instead of the swing frame and extending and contracting the third cylinder, the extension amount of the telescopic cylinder box required for the jib to rise to the maximum position is small. I'm done. For this reason, when the jib rises to the maximum position, the angle at which the telescopic cylinder box falls backward becomes small, and the tip of the telescopic cylinder box that was overhanging at the rear of the machine was always kept within the operator's field of view. Become.
Therefore, it is possible to safely operate the crane.

When the locking point of the second pendant rope moves to the rear of the revolving frame, the angle formed by the second pendant rope and the telescopic cylinder box increases, and the second pendant rope and the telescopic cylinder box move. The force acting on each part is small. Therefore, the third
By extending and retracting the cylinder of the second pendant rope to move the locking point of the second pendant rope to the rear of the swing frame,
The structural strength of the pendant rope and telescopic cylinder box can be increased, and these parts can be downsized. Further, if the sizes of the second pendant rope and the telescopic cylinder box are kept the same as before, it becomes possible to increase the specification value of the load bearing strength.

[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 showing a fifth step of posture change using the jib undulating device according to the second embodiment.

FIG. 10 is a side view of a crawler crane including a jib undulating device according to a third embodiment of the present invention.

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

FIG. 12 is a side view of the crawler crane including the jib undulating device according to the third embodiment in a working state.

FIG. 13 is a side view of a crawler crane with a live mast including a conventional jib undulating device.

FIG. 14 is a side view of a crawler crane without a live mast that includes a conventional jib undulating device.

FIG. 15 is a side view of a crawler crane equipped with a conventional jib hoisting device in a transporting posture.

[Explanation of symbols]

 21, 61 ... Crawler-type lower traveling body 22, 62 ... Upper revolving body 23, 63 ... Lattice jib 24 ... Jib back stop 25, 65 ... First pendant rope 26, 64 ... Second pendant rope 27, 67 ... Telescopic cylinder Boxes 27a, 70, 82 ... Hydraulic cylinder 28 ... Guide sheave 29 ... Main hoisting rope 30 ... Supplementary hoisting rope 31 ... Main hook 32 ... Main winding drum 33 ... Supplementary winding drum 46 ... Revolving frame 69 ... Engaging tool 71, 81 ... Link 72 ... Work rope 73 ... Posture holding rope 83 ... Locking point of the second pendant rope 64

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 second pendant rope that is locked and the other end of which is connected to the other end of the pendant rope, and one end of which is pivotally supported by the swivel frame and which is free to move is connected to the pendant rope and the second pendant rope. A jib hoisting device, comprising a telescopic cylinder box having a built-in cylinder that pushes and pulls the connecting portion by being locked and expanded. 2. The jib hoisting device according to claim 1, further comprising a sheave that guides a hoisting rope at a free end of the telescopic cylinder box. 3. An engaging member provided on a body portion of the telescopic cylinder box, a second cylinder having one end pivotally supported by a rear portion of the revolving frame, and one end of the second cylinder in front of the second cylinder. A link pivotally supported by the swivel frame, the other end of which is connected to the free end of the second cylinder; one end of which is connected to the second cylinder and the connecting portion of the link, and the other end of which is connected to the locking device. A work rope to be connected, one end of which is connected to the other end of this work rope that has been disconnected from the locking tool, and the other end of which is divided into a transport position and which remains on the front part of the revolving frame. The jib hoisting device according to claim 1, further comprising a posture holding rope connected to the free end. 4. One end of the second pendant rope is
2. Instead of the revolving frame, one end of each of the second frame and the third cylinder is pivotally supported by the revolving frame, and is locked to a connecting part of the other end of each of the third cylinders. Jib undulating device.