JP2001199679A - Tower crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tower crane capable of maintaining an upright property of a boom when increasing a ground angle of a jib, and suppressing a change in the ground angle of the jig when derricking the boom. SOLUTION: This tower crane has the boom 8 pivotally supported to a revolving superstructure 3 by a boom foot pin 9; the jib 22 pivotally supported on the bottom 8 by a jib foot pin 23 parallel to the boom foot pin 9; a strut 25 capable of derricking relatively to the boom 8 together with the jib 22; a winch 6 mounted in the revolving superstructure 3 and wound with a jib derricking rope 29; and a guide sheave 35 pivotally supported on the revolving superstructure 3 such that the guide sheave 35 is positioned close to the boom foot pin 9. The guide sheave 35 is wrapped around with the jib derricking rope 29.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a tower crane.

[0002]

2. Description of the Related Art FIG. 5 shows an example of a tower crane using a crawler self-propelled crane as a base machine. This tower crane is required to have a high head and a long turning radius as in a building construction work. Suitable for lifting work.

[0003] Reference numeral 1 denotes a lower traveling body.
Has a pair of right and left crawlers 2.

[0004] Reference numeral 3 denotes an upper rotating body.
Is provided on the upper surface of the lower traveling body 1 so as to be pivotable,
A bracket 4 is fixed to a center portion of the upper surface of the upper rotating body 3 at a front end thereof, and a cab 5 is mounted on a portion of the upper rotating body 3 closer to the right side of the upper surface front end.

Reference numeral 6 denotes a winch. The winch 6 is housed in a machine room 7 provided near the rear end of the upper surface of the upper swing body 3 together with an engine (not shown) as a drive source.

Reference numeral 8 denotes a boom. The boom 8 is formed by connecting an inner boom 8a having a steel pipe truss structure, an appropriate number of insert booms 8b, and an outer boom 8c in series. The base end of the inner boom 8a is A boom foot pin 9 extending substantially horizontally in the width direction of the upper swing body 3 is pivotally supported by the bracket 4.

The back side of the portion near the tip of the outer boom 8c (the surface that faces upward when the boom 8 has a small undulation angle and faces rearward when the boom 8 has a large undulation angle). The main winding guide sheave 10 and the auxiliary winding guide sheave 11 are in a parallel state,
It is pivotally supported by a sheave pin 10a extending in a direction parallel to the boom foot pin 9.

Further, the abdominal surface of the distal end portion of the outer boom 8c (the surface facing the lower side when the boom 8 has a small up-and-down angle and facing the front side of the upper revolving unit 3 when the boom 8 has a large up-and-down angle). , Four main winding point sheaves 12 are pivotally supported in parallel by sheave pins 12 a extending in a direction parallel to the boom foot pin 9.

Further, on the back side of the outer boom 8c near the main winding point sheave 12, the main winding horizontal sheave 13 is provided with a sheave pin 1 of the main winding point sheave 12.
It is arranged to be parallel to 2a.

Reference numeral 14 denotes an A frame (an undulating cord supporting frame).
The telescopic link 14a having a telescopic structure whose base end is pivotally supported by a portion near the rear end of the upper swing body 3 so that the A frame 14 can move in the front-rear direction of the upper swing body 3.
And a bracket 15 whose base end is provided near the center of the upper swing body 3 so that the upper swing body 3 can swing back and forth.
A link 14b pivotally supported at the distal end of the telescopic link 14a, and a base end pivotally supported by the bracket 15 and a distal end pivotally supported by an intermediate portion of the link 14b. When the fluid pressure is applied to the head-side fluid chamber or the rod-side fluid chamber of the undulating cylinder 14c, the A frame 14 undulates with respect to the upper rotating body 3. ing.

The telescopic link 14a of the A frame 14
The guide sheave 16 is pivotally supported and an A-frame yoke 17 having a plurality of sheaves is connected to a portion where both ends of the and the link 14b are pivotally supported.

Reference numeral 18 denotes a boom support pendant rope. One end of the boom support pendant rope 18 is locked on the back side of the distal end of the outer boom 8c.
The other end of the boom support pendant rope 18 is connected to an equalizer 19 having a plurality of sheaves.

Reference numeral 20 denotes a boom hoisting rope. The boom hoisting rope 20 is wound around a boom drum (not shown) of the winch 6 described above.

A portion of the boom hoisting rope 20 near the payout end is wound around a guide sheave 16 pivotally supported by an A frame 14 and is also a sheave of an equalizer 19 connected to a boom support pendant rope 18. Frame yoke 17 connected to A frame 14
Are wound alternately around the sheaves of the A frame yoke 17.

Numeral 21 denotes a stabilizer of a telescopic structure in which an elastic body such as a spring is housed, and one end of the stabilizer 21 is connected to the bracket 1.
5 and the other end of the stabilizer 21 is pivotally supported on the rear side of the vicinity of the distal end of the inner boom 8a.

Reference numeral 22 denotes a jib. The jib 22 is formed by connecting an inner jib 22a of a steel pipe truss structure, an appropriate number of insert jib 22b, and an outer jib 22c in series, and the base end of the inner jib 22a is turned upward. By the jib foot pin 23 extending substantially horizontally in the width direction of the body 3, the abdominal surface (the boom 8
When the up-and-down angle of the boom 8 is small, it is pivoted to the front side of the upper swing body 3).

An auxiliary winding point sheave 24 is pivotally supported at the tip of the outer jib 22c.

Reference numeral 25 denotes a strut.
Reference numeral 5 denotes an A strut 25a whose base end is pivotally supported by the distal end of the outer boom 8c so as to be able to swing in the front-rear direction of the upper swing body 3, and is disposed so as to be located behind the A strut 25a. In addition, a B strut 25b whose base end is pivotally supported by the distal end of the outer boom 8c so as to be able to swing in the front-rear direction of the upper swing body 3, one end is connected to the distal end of the A strut 25a, and the other end is connected to B strut. It is composed of a C strut 25c connected to the tip of the strut 25b.

Reference numeral 26 denotes a jib-supporting pendant rope. One end of the jib-supporting pendant rope 26 is engaged with the back side of the distal end of the outer jib 22c, and the other end of the jib-supporting pendant rope 26 is provided. Is locked to the tip of the A strut 25a.

Reference numeral 27 denotes a strut supporting pendant rope. One end of the strut supporting pendant rope 27 is locked to the tip of the B strut 25b.
The other end of the strut support pendant rope 27 is connected to an equalizer 28 having a plurality of sheaves.

Reference numeral 29 denotes a jib hoisting rope. The jib hoisting rope 29 is wound around a jib drum (not shown) of the winch 6 described above.

The portion of the jib hoisting rope 29 near the payout end is a sheave of an equalizer 28 connected to a strut supporting pendant rope 27 and a sheave of a post yoke (not shown) provided on the upper swing body 3. And the delivery end is locked by a post yoke (not shown) provided on the upper swing body 3.

Numeral 30 denotes a hoisting rope. The base end of the hoisting rope 30 is engaged with the above-mentioned hoisting drum (not shown) of the winch 6. The portion near the base end of 30 is wound around the auxiliary winding drum so as to be able to be fed out.

The portion near the payout end of the hoisting rope 30 is wound around a hoisting guide sheave 11 pivotally supported by the outer boom 8c and a hoisting point sheave 24 pivotally supported by the outer jib 22c. It hangs down from the front end of the outer jib 22c, is further wrapped around the sheave of the auxiliary winding hook block 31 from below, and is locked at the front end of the outer jib 22c.

Reference numeral 32 denotes a main winding rope. The base end of the main winding rope 32 is engaged with the above-described main winding drum (not shown) of the winch 6 and is connected to the main winding rope 32. The portion near the base end is wound around the main winding drum so as to be able to be fed out.

The parts of the main winding rope 32 extended from the main winding drum are the main winding guide sheave 10, the main winding point sheave 12, the sheave of the main winding hook block 33, and other main winding ropes. The point sheave 12 is wound around the main winding horizontal sheave 13, and further, the payout end of the main winding rope 32 is locked at a predetermined position of an outer boom 8 c constituting the boom 8.

In this tower crane, when the boom hoisting rope 20 is wound around the boom drum of the winch 6,
A frame yoke 17 connected to A frame 14
Then, the equalizer 19 connected to the boom support pendant rope 18 comes closer to increase the up-and-down angle of the boom 8.

Conversely, when the boom hoisting rope 20 is extended from the boom drum of the winch 6, the equalizer connected from the A frame yoke 17 connected to the A frame 14 to the boom support pendant rope 18. As a result, the undulation angle of the boom 8 decreases.

When the jib hoisting rope 29 is wound around the jib drum of the winch 6, the equalizer 28 connected to the strut supporting pendant rope 27 comes close to the post yoke provided on the upper swing body 3. The displacement of the strut 25 rotating rearward is transmitted to the jib 22 via the jib supporting pendant rope 26, so that the up-and-down angle of the jib 22 increases.

Conversely, when the jib hoisting rope 29 is extended from the jib drum of the winch 6, the upper revolving unit 3
The equalizer 28 connected to the strut-supporting pendant rope 27 is separated from the post yoke provided at the jig 22, and the displacement of the strut 25 that rotates forward due to the weight of the jib 22 is changed via the jib-supporting pendant rope 26. By being transmitted to the jib 22, the undulation angle of the jib 22 is reduced.

Further, when the auxiliary rope 30 is wound around the auxiliary winding drum of the winch 6, the auxiliary hook block 31 rises toward the tip of the outer jib 22c, and the auxiliary winding rope is wound from the auxiliary winding drum of the winch 6. When the winding rope 30 is extended,
The auxiliary hook block 31 descends with respect to the tip end of the outer jib 22c.

Similarly, when the main winding rope 32 is wound around the main winding drum of the winch 6, the main winding hook block 33 is raised toward the tip of the outer boom 8c, and the main winding hook block 33 is moved from the main winding drum of the winch 6. When the main winding rope 32 is extended,
The main winding hook block 33 descends with respect to the tip of the outer boom 8c.

[0033]

However, in the tower crane shown in FIG. 5, the jib hoisting rope 29 is directly connected to the strut supporting pendant rope 27 from the winch 6 mounted near the rear end of the upper swing body 3. Since it is extended, the upper revolving unit 3, the boom 8, the B strut 25b, the pendant rope 27 for supporting the strut, and the rope 29 for raising and lowering the jib are used to extend and retract the boom foot pin 9 and the rope 29 for raising and lowering the winch. Thus, a quadrilateral link having a fixed side between them is formed.

For this reason, if the jib hoisting rope 29 is wound up while the boom 8 is standing upright to shorten the feeding length and increase the angle of the jib 22 with respect to the ground, the boom 8 is not moved. A moment for pulling the boom 8 rearward acts, which makes it difficult to maintain the uprightness of the boom 8.

When the extension length of the boom hoisting rope 20 is increased or decreased while the extension length of the jib hoisting rope 29 is kept constant, the ground of the jib 22 follows the hoisting operation of the boom 8. The angle changes.

The present invention has been made in view of the above-described circumstances, and is a tower capable of maintaining the uprightness of a boom when increasing the ground angle of the jib and suppressing a change in the ground angle of the jib when raising and lowering the boom. It is intended to provide cranes.

[0037]

In order to achieve the above object, a tower crane according to a first aspect of the present invention has a boom pivotally supported on an upper swing body by a boom foot pin whose base end extends substantially horizontally. A jib whose base end is pivotally supported by the boom by a jib foot pin parallel to the boom foot pin; a strut that can be raised and lowered with respect to the boom together with the jib; and a jib hoisting rope mounted on the upper rotating body and wound around the jib. And a guide sheave pivotally supported on the upper revolving structure so as to be located close to the boom foot pin. A jib hoisting rope fed out from the winch is wound around the guide sheave, and the feed-out end is wound. It is connected to the strut via a pendant rope.

In the tower crane according to the second aspect of the present invention, in addition to the configuration of the tower crane according to the first aspect of the present invention, a plurality of rollers are rotatably fitted to a support pin parallel to the boom foot pin. A guide device is provided on the rear surface of a portion near the base end of the boom so that the jib hoisting rope can touch the roller.

In any one of the tower cranes according to the first and second aspects of the present invention, a jib hoisting rope is wound around a guide sheave pivotally supported in the vicinity of the boom foot pin, and the upper rotating body, the boom, The strut, the pendant rope, and the jib hoisting rope form a quadrilateral link similar to a triangular link having a fixed side between the boom foot pin and the jib hoisting rope wrapping position of the guide sheave, thereby reducing the jib ground angle. The uprightness of the boom at the time of enlargement is maintained, and the change in the ground angle of the jib when the boom is raised and lowered is suppressed.

In the tower crane according to the second aspect of the present invention, when the jib is hung down from the boom such that the tip thereof is located below the base end, the portion of the jib hoisting rope closer to the boom base end. Of the guide device is brought into contact with the roller of the guide device, and the roller is rotated by the jib hoisting rope wound around the winch when the jib stands up, thereby avoiding damage to the jib hoisting rope due to sliding friction.

[0041]

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

FIGS. 1 to 4 show an embodiment of a tower crane according to the present invention, in which the same reference numerals as in FIG. 5 denote the same components.

In this tower crane, the boom 8 whose base end is pivotally supported by the bracket 4 of the upper swing body 3 by the boom foot pin 9 and the jib foot pin 23 whose base end is parallel to the boom foot pin 9 are used to form the boom 8. A jib 22 pivotally supported on the abdominal surface in the vicinity of the distal end, a strut 25 pivotally supported at the distal end of the boom 8 so as to be able to undulate with the boom 8 together with the jib 22, and mounted on the upper rotating body 3; A winch 6 having a jib drum 34 around which a jib hoisting rope 29 is wound;
, And three sets of guide devices 36 attached to the back surface near the base end of the boom 8.

The guide sheave 35 is connected to the boom foot pin 9.
The inner boom 8a is pivotally supported by a bracket provided on the rear side of the base end portion by a sheave pin 37 parallel to the inner boom 8a.

A jib hoisting rope 29 drawn out from the jib drum 34 is wound around the guide sheave 35 from below.

The portion of the jib hoisting rope 29 near the extended end is a sheave 38b pivotally supported by a bracket on the rear side of the base end portion of the inner boom 8a so as to be located close to the sheave 38a of the equalizer 28 and the guide sheave 35. , And the pay-out end is locked to the bracket.

Thus, the jib hoisting rope 29 wound around the guide sheave 35 pivotally supported near the boom foot pin 9, the strut supporting pendant rope 27 connected to the jib hoisting rope 29, and the upper swing body 3 , Boom 8, strut 25 and boom foot pin 9
A quadrilateral link similar to a triangular link having a fixed side between the guide sheave 35 and the jib hoisting rope 29 winding position is formed.

The guide device 36 includes left and right brackets 39 provided on the back surface of the portion near the base end of the boom 8, a support pin 40 supported by the bracket 39 and parallel to the boom foot pin 9, and It is composed of a plurality of rollers 41a and 41b rotatably fitted.

Of the three sets of guide devices 36, the one located at the center in the back and right direction of the boom 8 is a long roller 41a fitted on the left and right portions of the support pin 40, and the long roller 41a.
And a plurality of short rollers 41b fitted to the intermediate portion of the support pin 40 so as to be located between the support rollers 40 (see FIG. 3).

In the guide device 36 located on the left and right sides of the back of the boom 8, the support pins 4 are used instead of the short rollers 41b.
The long roller 41a is fitted in the middle portion of the zero.

In the tower crane shown in FIGS. 1 to 4,
As described above, the boom foot pin 9 and the guide sheave 35 are wrapped around the jib hoisting rope 29 by the upper swing body 3, the boom 8, the strut 25, the strut supporting pendant rope 27, and the jib hoisting rope 29. Is formed as a quadrangle link that is similar to a triangular link having a fixed side between the jib, the jib hoisting rope 29 is wound up while the boom 8 is standing upright, the feeding length is shortened, and the jib Even if the ground angle of 22 is increased, the moment for pulling the boom 8 backward is hardly applied to the boom 8, and the uprightness of the boom 8 can be maintained.

Also, while the extension length of the boom hoisting rope 20 is increased or decreased while the extension length of the jib hoisting rope 29 is kept constant, the angle of the boom 8 can be adjusted. Since the position where the jib hoisting rope 29 is wound around the guide sheave 35 and the guide sheave 35 is close, the ground angle of the jib 22 hardly changes.

Further, when the jib 22 is hung down from the boom 8 such that the tip end thereof is located below the base end, the jib hoisting rope 29 extends along the back surface of the portion near the base end of the boom 8. The rollers 41a and 41 of the guide device 36
Touch b.

Therefore, when the jib 22 is swung up, the rollers 41a, 4
1b rotates, and damage to the jib hoisting rope 29 due to sliding friction can be avoided.

In addition, a plurality of short rollers 41 are attached to the guide device 36 located at the center of the back of the boom 8 in the left-right direction.
When the plurality of jib hoisting ropes 29 adjacent to each other between the sheaves 35 and 38a and between the sheaves 38a and 38b move vertically, the two jib hoisting ropes 29 are the same. The short roller 41b surely rotates without touching the short roller 41b.

It should be noted that the tower crane of the present invention is not limited to the above-described embodiment, and it is needless to say that various changes can be made without departing from the gist of the present invention.

[0057]

As described above, according to the tower crane of the present invention, the following various excellent effects can be obtained.

(1) In any of the tower cranes according to the first or second aspect of the present invention, a jib hoisting rope is wound around a guide sheave pivotally supported near the boom foot pin, and Boom, strut,
The pendant rope and the jib hoisting rope form a quadrilateral link similar to a triangular link having a fixed side between the boom foot pin and the jib hoisting rope winding position of the guide sheave, so that the angle of the jib to the ground is increased. The uprightness of the boom at that time can be maintained, and the change in the ground angle of the jib when the boom is raised and lowered can be suppressed.

(2) In the tower crane according to the second aspect of the present invention, the portion of the jib hoisting rope extending along the back surface of the portion near the base end of the boom is brought into contact with the roller of the guide device, and the jib is raised when the jib is raised. Since the roller is rotated by the jib hoisting rope to be wound, damage to the jib hoisting rope due to sliding friction can be avoided.

[Brief description of the drawings]

FIG. 1 is a side view schematically illustrating a tower crane of the present invention.

FIG. 2 is a perspective view of a guide sheave and a guide device arranged near a base end of a boom related to FIG. 1;

FIG. 3 is a front view of the guide device related to FIG. 1;

FIG. 4 is a view taken in the direction of arrows IV-IV in FIG. 3;

FIG. 5 is a side view schematically showing an example of a conventional tower crane.

[Explanation of symbols]

3 Upper Revolving Structure 6 Winch 8 Boom 9 Boom Foot Pin 22 Jib 23 Jib Foot Pin 25 Strut 27 Pendant Rope (Pendant Rope) for Strut Support 28 Equalizer 29 Rope for Jib Up / Down 35 Guide Sheave 36 Guide Device 40 Support Pin

Claims (2)

[Claims] A boom having a base end pivotally supported by an upper revolving structure by a boom foot pin extending substantially horizontally; a jib having a base end pivotally supported by a boom foot pin parallel to the boom foot pin. A strut that can be raised and lowered with respect to the boom together with the jib, a winch mounted on the upper swing body and around which a jib hoisting rope is wound, and pivotally supported by the upper swing body so as to be located close to the boom foot pin. A tower crane comprising: a guide sheave; a jib hoisting rope extended from a winch wound around the guide sheave; and the extended end connected to a strut via a pendant rope. 2. A guide device having a plurality of rollers rotatably fitted on a support pin parallel to a boom foot pin, wherein the guide device can be in contact with the back surface of a portion near the base end of the boom, and a jib hoisting rope can be in contact with the rollers. The tower crane according to claim 1, wherein the tower crane is mounted as follows.