JP2011241003A - Crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit reduction of forward moment around a jib foot without degrading crane performance, without making assembly difficult, without creating a need for much modification to a conventional crane, or without incurring much cost.SOLUTION: A lower part spreader 70 for jib derricking (a lower part spreader) includes a mounting part 73 for mounting itself on a tower boom 20, and is fitted to (a bracket 22 of) the tower boom 20 in a rotatable manner around the mounting part 73 when the upper part rotary body (a rotary body) is viewed from the side. (A fall-preventive means connecting part 79 of) the lower spreader 70 for jib derricking and (a fall-preventive means connecting part 23 of) the tower boom 20 are connected with each other by a fall-preventive means 80.

Description

  The present invention relates to a crane having a jib attached to the tip of a tower boom.

  FIG. 4 shows a conventional crane 101 (tower specification crane) in which the jib 40 is attached to the tip 21t of the tower boom 20. In the crane 101, the jib 40 is raised and lowered using the jib raising and lowering means 50. The jib hoisting means 50 includes a jib guy line 51 with one end attached to the tip of the jib 40, a strut 52 attached with the other end of the jib guy line 51, a strut guy line 53 with one end attached to the strut 52, and the other end of the strut guy line 53. The jib hoisting rope 55 connected to the upper end, the winch 54 for winding and unwinding one end side of the jib hoisting rope 55, and the upper spreader 60 for jib hoisting and the other end side of the jib hoisting rope 55 and the jib hoisting rope And a lower spreader 70. When the jib hoisting rope 55 is wound and unwound by the winch 54, the distance between the jib hoisting upper spreader 60 and the jib hoisting lower spreader 70 changes. This causes the jib 40 to undulate. Also, a backstop 42 is attached to the jib 40 to prevent the jib 40 from turning backwards.

In this type of crane, when the undulation angle of the jib 40 is increased (causing the jib 40), the forward moment around the jib foot 41f is reduced. This is particularly noticeable when the tower boom 20 is long and the jib 40 is short.
The smaller the forward moment around the jib foot 41f, the smaller the tension of the jib hoisting rope 55 and the more likely the turbulent winding occurs in the winch 54.
In addition, when the forward moment around the jib foot 41f is small, there is a risk that the jib 40 may be reversed backward depending on conditions such as the wind hitting the jib 40, the inclination of the ground on which the crane 101 is installed, and the speed at which the jib 40 is raised. There is also. Therefore, the following techniques are known.

  (1) First, there is a technique in which a point weight is attached to the tip of the jib 40. This point weight increases the forward moment around the jib foot 41f. Further, the tension of the jib hoisting rope 55 is increased by this point weight.

  (2) There is a technology in which the backstop 42 is strengthened. That is, there is a technique in which the backstop 42 is lengthened and the spring attached to the backstop 42 is reinforced (increasing the number of turns of the spring, increasing the diameter of the spring, etc.). In this technique, the tip of the backstop 42 comes into contact with the receptacle from a state where the angle of the jib 40 is small. Therefore, the angle of the jib 40 does not increase, and the forward moment around the jib foot 41f does not decrease. Further, the tension of the jib hoisting rope 55 is not reduced.

  Patent Document 1 discloses a technique for a spreader (60, 70) for jib undulations.

Japanese Patent Laid-Open No. 11-11874

  However, the above technique has the following problems.

(1) First, in the technique in which a point weight is attached to the tip of the jib 40, the crane capacity is reduced as compared with a case where the point weight is not provided. That is, the ability to lift the suspended load is reduced by the mass of the point weight.
In addition, when the weight of the point weight is excessive, the jib 40 and the tower boom 20 may not be able to stand on their own.

  (2) Further, the technology in which the backstop 42 is strengthened has the following problems. There is a limit to lengthening the backstop 42 (e.g., too long can cause the jib 40). Further, when the backstop 42 is lengthened or the spring attached to the backstop 42 is strengthened, the assembly becomes complicated as compared with the case where the normal backstop is attached to the jib 40.

  Further, since the jib hoisting lower spreader 70 is pivotably attached to the tower boom 20, the jib hoisting lower spreader 70 is tilted rearward as it is, and the jib hoisting rope 55 is placed on the jib hoisting lower spreader. A weight of 70 is added. As a result, the forward moment around the jib foot 41f decreases (the backward moment increases).

  An object of the present invention is a crane capable of suppressing a decrease in the forward moment around the jib foot without lowering the crane capacity, without making it difficult to assemble, with few changes compared to the conventional crane, and without high cost. Is to provide.

  A crane according to the present invention is attached to a swivel body, a tower boom attached to the swivel body so as to be able to undulate, a jib attached to a tip part of the tower boom so as to be able to undulate, and a tip part of the tower boom. Attached to the tower boom, a jib guy line connecting the tip of the jib and the strut, a strut guy line having one end attached to the strut, an upper spreader to which the other end of the strut guy line is attached, and the tower boom A lower spreader, and a winch attached to the swivel body. One end side is wound and unwound by the winch, and the other end side is provided with a jib hoisting rope hung around the upper spreader and the lower spreader. The lower spreader includes an attachment portion for attachment to the tower boom, and is attached to the tower boom so as to be rotatable around the attachment portion when the swivel body is viewed from the side. Further, the lower spreader and the tower boom are connected by a fall-preventing means.

The lower spreader of the crane includes an attachment portion for attachment to the tower boom, and is attached to the tower boom so as to be rotatable around the attachment portion when the swivel body is viewed from the side. Therefore, the lower spreader can fall to the rear side as it is.
Further, in this crane, the lower spreader and the tower boom are connected by a fall-preventing means. Therefore, the lower spreader is prevented from falling backward. As a result, it is possible to suppress the weight of the lower spreader from being added to the jib hoisting rope hung around the upper spreader and the lower spreader. As a result, a decrease in forward moment (increase in backward moment) around the jib foot is suppressed.

Since the decrease in the forward moment around the jib foot is suppressed, the jib undulation rope tension is suppressed from becoming smaller. As a result, it is possible to suppress the winding of the winch that unwinds and winds the jib undulation rope.
Moreover, since the reduction | decrease of the front moment around a jib foot is suppressed, it can suppress that a jib reverse | inverts back.
In the above configuration, it is not necessary to attach a point weight to the jib tip. Therefore, it is not necessary to lower the crane capacity.
Moreover, in the said structure, it is not necessary to lengthen the back stop attached to the jib, or to strengthen the spring of this back stop. Therefore, the assembly of the crane is not complicated.
Moreover, in the said structure, it is not necessary to attach a point weight to a jib front end, and it is not necessary to lengthen the said back stop and to strengthen the said spring. Therefore, it is possible to suppress a decrease in the forward moment around the jib foot with a small change from the conventional crane and without high costs. Moreover, since there are few changes, the conventional crane after shipment can be easily changed to the structure of this invention.

1 is an overall view of a crane. It is a figure which shows the periphery of the upper spreader and lower spreader which are shown in FIG. 1, and is F2 arrow line view shown in FIG. It is an enlarged view of the lower spreader periphery (F3 part) shown in FIG. . It is a conventional crane.

  Hereinafter, an embodiment of a crane 1 according to the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the crane 1 is a tower-type mobile crane. The crane 1 includes a lower traveling body 11, an upper revolving body 12 (revolving body) attached to the lower traveling body 11, a tower boom 20 attached to the upper revolving body 12, and a tower boom raising / lowering means for raising and lowering the tower boom 20. 30, a jib 40 attached to the tip of the tower boom 20, and jib hoisting means 50 for raising and lowering the jib 40.

  The lower traveling body 11 is a portion used for traveling of the crane 1. The lower traveling body 11 is, for example, a crawler traveling type (may be a wheel traveling type).

  The upper revolving unit 12 (revolving unit) is a part that is attached to the upper side of the lower traveling unit 11 and revolves with respect to the lower traveling unit 11. A tower boom 20 is attached to the upper swing body 12 near the front end, a gantry 31 constituting the tower boom hoisting means 30 is attached to the rear side of the tower boom 20, and a winch 54 constituting the jib hoisting means 50. Is attached. In addition, when referring to “front-rear direction”, “front side”, “rear side”, or “lateral direction”, the upper swing body 12 is used as a reference.

  The tower boom 20 is a lattice boom that is attached to the vicinity of the front end of the upper swing body 12 so as to be raised and lowered. During the crane operation, the tower boom 20 is arranged so that the axial direction is about 90 ° with respect to the ground G (so that the axial direction is substantially vertical) (even if the axial direction is inclined forward). good). During the crane operation, the tower boom 20 is not normally raised or lowered. In addition, the tower boom 20 includes a tower boom body 21 having a lattice structure, a bracket 22 attached to the tower boom body 21 and a fall-preventing means connecting portion 23 (see FIG. 3). In FIG. 1, the ratio of the length of the tower boom 20 to the jib 40 is shown as about 3: 2, but the tower boom 20 may be made longer than the jib 40 (for example, the above ratio is 3). : 1 etc.)

  As shown in FIGS. 1 to 3, the bracket 22 is, for example, a plate-like member for attaching the lower spreader 70 for raising and lowering the jib. As shown in FIGS. 1 and 3, the bracket 22 has a rear surface 21b of the tower boom 20 (a rear surface 21b of the tower boom body 21 in a state where the tower boom 20 is raised, specifically, a main pillar 21a. ). As shown in FIG. 2, one bracket 22 is attached to each end of the tower boom main body 21 in the horizontal direction, for example (two in total). As shown in FIG. 3, the bracket 22 includes a jib undulation lower spreader mounting portion 22a (described later).

  The fall prevention means connecting portion 23 is a part to which the fall prevention means 80 is attached, and is, for example, a plate-like member provided with a through hole. The fall prevention means connecting portion 23 is attached to a rear surface 21 b (for example, the main column 21 a) of the tower boom body 21. As shown in FIG. 2, the fall-preventing means connecting portions 23 are attached to each end of the tower boom main body 21, for example, one at a time (two in total) (one may be attached at the center in the horizontal direction). In addition, you may attach the fall prevention means connection part 23 to the tower boom main body 21 of the conventional crane 101 (refer FIG. 4) after shipment. For example, welding or a U-bolt can be used for attachment.

  The tower boom raising / lowering means 30 is a part which raises / lowers the tower boom 20 as shown in FIG. The tower boom hoisting means 30 includes a gantry 31 attached to the upper swing body 12. The tower boom raising / lowering means 30 includes a guy line 32 and a tower boom raising / lowering rope 33 that connect the tip end portion 21 t of the tower boom 20 and the gantry 31. The tower boom hoisting rope 33 is hung around the tower boom hoisting spreader 34. Then, the tower boom 20 is raised and lowered by unwinding and winding the tower boom hoisting rope 33 with a winch (not shown).

  Jib 40 is attached to tip part 21t of tower boom 20 so that raising and lowering is possible. The base end portion (jib foot 41 f) of the jib 40 is attached to the distal end portion of the tower boom 20. The jib 40 is arranged so that the tip end portion (jib top 41t) of the jib 40 is located on the front side of the tower boom 20. The jib 40 is raised and lowered by the jib raising and lowering means 50. The jib 40 includes a lattice-structured jib main body 41 and a backstop 42 attached to the jib main body 41 in the vicinity of the jib foot 41f. The backstop 42 is a member that prevents the jib 40 from being reversed backward.

  The jib hoisting means 50 is a part for raising and lowering the jib 40. The jib hoisting means 50 includes a jib guy line 51, a strut 52, a strut guy line 53, a jib hoisting upper spreader 60 (upper spreader), a jib hoisting rope 55, and a jib hoisting lower spreader 70 (lower spreader) in this order from the tip of the jib 40. , And a winch 54.

  The jib guy line 51 is a guy line (impossible to wind and unwind) connecting the tip end part (jib top 41t) of the jib 40 and the strut 52.

  The strut 52 is a member attached to the tip end portion 21 t of the tower boom 20. The strut 52 includes a front strut 52f disposed on the front side, a rear strut 52r disposed on the rear side, and a connecting member 52c that connects the distal end portion of the front strut 52f and the distal end portion of the rear strut 52r. . And the whole strut 52 can be rotated centering | focusing on the base end part (tip part 21t of the tower boom 20). That is, when the strut 52 connected to the jib 40 through the jib guy line 51 rotates, the jib 40 is raised and lowered.

  The strut guy line 53 is a guy line having one end attached to the strut 52 and the other end attached to the upper spreader 60 for raising and lowering the jib. That is, the strut guy line 53 is a guy line that connects the tip part of the rear strut 52r and the upper spreader 60 for raising and lowering the jib.

  The winch 54 is attached to the upper swing body 12. The winch 54 winds and unwinds one end side of the jib hoisting rope 55.

  One end side of the jib hoisting rope 55 is wound and unwound by the winch 54, and the other end side is wound around the jib hoisting upper spreader 60 and the jib hoisting lower spreader 70. In addition, the direction of the jib hoisting rope 55 can be changed using the sheave 56 attached to the gantry 31 (the direction does not need to be changed).

  As shown in FIGS. 1 and 2, the jib hoisting upper spreader 60 is a member to which the end of the strut guy line 53 is attached and the jib hoisting rope 55 is hung. As shown in FIG. 2, the jib undulation upper spreader 60 includes an upper spreader frame 61 and a plurality of sheaves 62 attached to the upper spreader frame 61. A jib hoisting rope 55 is hung on the sheave 62.

  The jib hoisting lower spreader 70 is a member on which the jib hoisting rope 55 is hung, as shown in FIGS. 1 and 2. As shown in FIG. 3, the jib hoisting lower spreader 70 includes a mounting portion 73 for mounting to the tower boom 20 and is rotatable about the mounting portion 73 when the upper swing body 12 is viewed from the side. It is attached to the tower boom 20. As shown in FIGS. 2 and 3, the lower spreader 70 for raising and lowering the jib is attached to the lower spreader frame 76, the plurality of sheaves 77 attached to the lower spreader frame 76, and the lower spreader frame 76 and to the attachment portion 73. The link member 71 provided with is provided.

The link member 71 is a member that connects the bracket 22 of the tower boom 20 and the lower spreader frame 76. As shown in FIG. 2, for example, two link members 71 (a total of four) are attached to the lateral ends of the lower spreader frame 76 (may be one each). In order to avoid complication, only one of the four link members shown in FIG.
As shown in FIGS. 2 and 3, the lower end portion (attachment portion 73) of the link member 71 is rotatable when the upper swing body 12 (see FIG. 1) is viewed from the side (the side of the upper swing body 12 is sideways). The tower boom 20 is attached to the lower spreader attachment portion 22a for raising and lowering the jib. Specifically, the attachment portion 73 and the jib undulation lower spreader attachment portion 22a are through holes, and the attachment is performed by inserting a pin 71p into the through hole.
The upper end 72 of the link member 71 is attached to a link member attachment portion 78 of the lower spreader frame 76 so as to be rotatable when the upper swing body 12 (see FIG. 1) is viewed from the side. For this attachment, the pin 71p is used in the same manner as the lower end (attachment portion 73). This attachment may not be rotatable. That is, the link member 71 and the lower spreader frame 76 may be integrated.

  The lower spreader frame 76 is a member to which a plurality of sheaves 77 (for example, two so as to be arranged in the horizontal direction when viewed from the rear) are attached. As shown in FIG. 2, a jib hoisting rope 55 is hung on the sheave 77. The lower spreader frame 76 includes link member mounting portions 78 that protrude downward from the lower end, one at each lateral end (two in total). A link member 71 is attached to the link member attachment portion 78. As shown in FIG. 3, the lower spreader frame 76 includes two plate-like members that face each other in the thickness direction of the sheave 77. Of the two plate-like members, the member on the tower boom 20 side is referred to as a plate-like member 76a.

  The fall-preventing means connecting portion 79 is a portion for connecting the fall-preventing means 80 and is, for example, a plate-like member having a through hole. The fall prevention means connecting portion 79 is attached to the lower spreader frame 76 so as to protrude from the surface (plate-like member 76a) facing the tower boom 20 of the lower spreader frame 76 to the tower boom 20 side (front side). As shown in FIG. 2, the fall prevention means connecting portions 79 are provided, for example, one at each lateral end of the lower spreader frame 76 (two in total) (one may be provided at the lateral center). In addition, you may attach the fall prevention means connection part 79 to the lower spreader frame 76 of the conventional crane 101 (refer FIG. 4) after shipment using welding, a volt | bolt, etc.

  As shown in FIG. 3, the fall-preventing means 80 connects the jib hoisting lower spreader 70 and the tower boom 20 to prevent the jib hoisting lower spreader 70 from falling backward (see arrow A <b> 1). It is a member. The fall prevention means 80 is disposed above the attachment portion 73 (the rotation center of the jib undulation lower spreader 70). One end of the fall prevention means 80 is attached to the fall prevention means connecting portion 23 of the tower boom 20. The other end of the fall prevention means 80 is attached to the fall prevention means connecting portion 79 of the lower spreader frame 76 of the lower spreader 70 for raising and lowering the jib. In addition, as shown in FIG. 2, a total of two anti-falling means 80 are arranged near the both ends of the tower boom 20 and the lower spreader frame 76 (one may be provided in the central portion in the lateral direction). In FIG. 2, the fall-preventing means 80 is schematically shown. Moreover, as shown in FIG. 3, the fall prevention means 80 does not need to suppress the jib hoisting lower spreader 70 from moving forward (see arrow A2).

  Moreover, the fall prevention means 80 is specifically provided with, for example, a wire rope 81 and shackles 82 (two in total) attached to both ends of the wire rope 81. Both ends of the wire rope 81 are formed into a ring shape, and a shackle 82 is attached to the ring-shaped portion. And the shackle 82 is attached to the through-hole of the fall prevention means connection parts 23 and 79. As a result, the fall prevention means 80 is attached to the fall prevention means connecting portions 23 and 79.

  Further, the length of the anti-falling means 80 (distance between the anti-falling means connecting portions 23 and 79) can be set variously. That is, since the above-described problem occurs when the weight of the lower spreader 70 for raising / lowering the jib is applied to the jib raising / lowering rope 55 (see FIG. 1), the weight is not applied (or no problem occurs even if the weight is applied). In this way, the length of the fall prevention means 80 may be set. Specifically, for example, when the undulation angle of the jib 40 (see FIG. 1) is a predetermined angle (such as an angle at which turbulent winding is likely to occur in the winch 54), the mounting portion 73, the jib undulation lower spreader 70, and the jib undulation upper portion The length of the anti-falling means 80 is set so that the lower spreader 70 for raising and lowering the jib does not fall backward (A1 side) than when the spreader 60 (see FIG. 1) is arranged on a straight line.

(Characteristics of crane of this embodiment)
The crane 1 of this embodiment has the following characteristics. As shown in FIG. 3, the jib hoisting lower spreader 70 includes an attachment portion 73 for attachment to the tower boom 20, and the attachment portion 73 is centered when the upper swing body 12 (see FIG. 1) is viewed from the side. It is attached to the tower boom 20 (the bracket 22 thereof) so as to be rotatable. Therefore, the jib hoisting lower spreader 70 can be tilted to the rear side (arrow A1 side) as it is.
Further, in this crane 1, the jib hoisting lower spreader 70 (the anti-falling means connecting portion 79) and the tower boom 20 (the anti-falling means connecting portion 23) are connected by the anti-falling means 80. Therefore, the jib hoisting lower spreader 70 is prevented from falling backward (arrow A1 side). As a result, the weight of the jib hoisting lower spreader 70 is suppressed from being applied to the jib hoisting rope 55 (see FIG. 1) hung around the jib hoisting upper spreader 60 and the jib hoisting lower spreader 70. As a result, a decrease in forward moment (increase in backward moment) around the jib foot 41f shown in FIG. 1 is suppressed.

As shown in FIG. 1, since the decrease in the forward moment around the jib foot 41f is suppressed, it is possible to suppress the tension of the jib hoisting rope 55 from being reduced. As a result, the winding of the winch 54 that unwinds and winds the jib hoisting rope 55 can be suppressed.
Moreover, since the reduction | decrease of the front moment around the jib foot 41f is suppressed, it can suppress that the jib 40 reverses backward.
In the above configuration, it is not necessary to attach a point weight to the tip of the jib 40 (jib top 41t). Therefore, it is not necessary to lower the crane capacity.
Moreover, in the said structure, it is not necessary to lengthen the back stop 42 attached to the jib 40, and it is not necessary to strengthen the spring of this back stop 42. FIG. Therefore, the assembly of the crane 1 is not complicated. Further, since there is no need for the above, it is possible to suppress a decrease in the forward moment around the jib foot 41f with a small change with respect to the conventional crane 101 (see FIG. 4) without incurring high costs. Moreover, since there are few changes, the conventional crane 101 (refer FIG. 4) after shipment can be easily changed into the structure of this invention.

(Modification)
The structure of the fall-preventing means 80 shown in FIG. 3 and the method of attaching the fall-preventing means 80 to the fall-preventing means connecting portions 23 and 79 can be variously modified. For example, the wire rope 81 may be changed to a link (a bar or long plate connected), a chain, or the like. Moreover, it may replace with the attachment using the shackle 82, and may deform | transform into the method using a pin, the method using a hook, etc. Three or more fall prevention means 80 may be provided.

1 Crane 12 Upper swing body (revolving body)
20 Tower boom 40 Jib 52 Strut 51 Jib guy line 53 Strut guy line 54 Winch 55 Jib hoisting rope 60 Upper spreader for jib hoisting (upper spreader)
70 Lower spreader for lowering of jib (lower spreader)
73 Mounting part 80 Fall prevention means

Claims (1)

A swivel,
A tower boom attached to the swivel body in a undulating manner;
A jib attached to the tip of the tower boom so that it can be raised and lowered;
A strut attached to the tip of the tower boom;
A jib guy line connecting the tip of the jib and the strut;
A strut guy line with one end attached to the strut;
An upper spreader to which the other end of the strut guy line is attached;
A lower spreader attached to the tower boom;
A winch attached to the swivel body;
A jib hoisting rope having one end side wound and unwound by the winch and the other end side wound around the upper spreader and the lower spreader,
The lower spreader includes an attachment portion for attachment to the tower boom, and is attached to the tower boom so as to be rotatable around the attachment portion when the swivel is viewed from the side,
A crane in which the lower spreader and the tower boom are connected by a fall-preventing means.

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