JP6925854B2 - Jib and crane - Google Patents

Description

The present invention relates to a jib having a lattice structure and a crane provided with the jib.

As shown in FIG. 4, the conventional lattice-structured jib 20 (hereinafter, abbreviated as “conventional jib 20”) provided in the crane 200 is joined by the base jib 1, the plurality of intermediate jib 2, and the top jib 4. It is composed of together.

Further, one end of the undulating pendant wire 102 is attached to the tip of the top jib 4, and the other end of the undulating pendant wire 102 is fixed to the first relay sheave 107. Further, the undulating wire 103 is wound by the undulating winch 104 via the first relay sheave 107 and the second relay sheave 109 attached to the upper ends of the relay frame 108. The conventional jib 20 is undulated by winding the undulating wire 103. When the working radius of the crane 200 becomes long, the number of intermediate jib 2 is increased to lengthen the total length of the conventional jib 20.

However, when the total length of the conventional jib is increased, the buckling length is increased by the lengthening, and the slenderness ratio and the buckling coefficient are increased, so that the portion that bends due to its own weight increases. As a measure to avoid this phenomenon, it is conceivable to increase the strength of the jib components by making them larger and thicker. However, if the components are made larger and thicker, the weight will be heavier by that amount, and as a result, the jib will be larger due to its own weight. It bends.

The present invention has been made in view of each of the above problems, and an object of the present invention is to reduce the weight of the jib and suppress bending regardless of the length of the working radius of the crane.

In order to solve the above problems, the jib according to one aspect of the present invention is a jib having a lattice structure provided on a crane, and a plurality of intermediate jibs corresponding to the main body of the jib and the tip of the jib. A top jib corresponding to a portion and an intermediate pendant jib arranged between the intermediate jib and the top jib are provided, and an undulating pendant wire for supporting the jib is attached to the intermediate pendant jib. It is characterized in that a mounting portion is provided.

According to the above configuration, the undulating pendant wire can be attached to the attachment portion of the intermediate pendant jib arranged between the intermediate jib and the top jib. Therefore, when the undulating pendant wire is attached to the attachment portion of the intermediate pendant jib, the portion of the jib on the tip side of the intermediate pendant jib becomes a so-called cantilever, and the load applied to the tip of the jib causes the portion on the tip side. Bending moment is applied. This bending moment cancels the bending (based on its own weight) of the tip side portion. Therefore, for example, even if the total length of the jib is long due to the long working radius of the crane, the part where the jib is bent (based on its own weight) is compared with the case where the undulating pendant wire is attached to the mounting part of the top jib. Can be reduced.

Further, when the undulating pendant wire is attached to the attachment portion of the intermediate pendant jib, the portion of the jib where buckling may occur due to the support of the undulating pendant wire is reduced as compared with the case where the undulating pendant wire is attached to the attachment portion of the top jib. Therefore, since the buckling length is shortened and the slenderness ratio and the buckling coefficient are reduced, it is not necessary to make the jib components large and thick in order to obtain strength against buckling, and the weight of the intermediate jib and top jib is reduced. Can be planned. Therefore, for example, even when the working radius of the crane is long, the work can be safely performed by using the jib according to one aspect of the present invention in which weight reduction is realized.

On the other hand, when the working radius of the crane is short, one aspect of the present invention has realized weight reduction while avoiding deformation of the tip side portion due to bending moment by attaching the undulating pendant wire to the mounting portion of the top jib. The work can be safely performed using the jib according to the above. As described above, according to the jib according to one aspect of the present invention, the weight of the jib can be reduced and the bending of the jib can be suppressed regardless of the length of the working radius of the crane.

Further, in the jib according to one aspect of the present invention, the intermediate pendant jib is arranged between the intermediate jib arranged on the tip end side of the jib most among the plurality of intermediate jibs and the top jib. Is also good. According to the above configuration, when the undulating pendant wire is attached to the attachment portion of the intermediate pendant jib, the bending moment is applied only to the top jib due to the load applied to the tip of the jib, and the magnitude of the bending moment becomes small. Therefore, it is possible to reduce the weight of the jib and suppress the bending of the jib regardless of the length of the working radius of the crane while suppressing the deformation of the jib due to the bending moment.

Further, in the jib according to one aspect of the present invention, the mounting portion may be arranged at a position vertically below the central axis of the jib in a state where the jib is horizontal. If the mounting part of the intermediate pendant jib is arranged at the same position as the central axis of the jib or at a position vertically above the central axis when the jib is horizontal, the undulating pendant attached to the mounting part. The bearing capacity of the wire promotes the deflection of the jib based on its own weight.

In that respect, according to the above configuration, the supporting force of the undulating pendant wire attached to the attachment portion of the intermediate pendant jib acts on the jib so that the jib bends vertically upward. Therefore, the deflection of the jib based on its own weight is canceled by the above-mentioned bearing capacity, so that the deflection is promoted. Regardless of the length of the working radius of the crane, it is possible to reduce the weight of the jib and further suppress the bending of the jib.

Further, it is preferable that the crane according to one aspect of the present invention is provided with the above jib. According to the above configuration, it is possible to realize a crane in which the weight of the jib is reduced and the bending is suppressed regardless of the length of the working radius.

According to one aspect of the present invention, it is possible to reduce the weight of the jib and suppress bending regardless of the length of the working radius of the crane.

It is a side view which shows the outline of the structure of the crane and jib which concerns on one Embodiment of this invention. (A) is a plan view which shows the outline of the structure of the intermediate pendant jib which concerns on one Embodiment of this invention. (B) is a side view showing the outline of the structure of the first mounting portion of the intermediate pendant jib, the second mounting portion of the top jib, and the tip portion of the undulating pendant wire. It is the ability diagram of the said jib. It is a schematic diagram which shows the structure of the conventional jib.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. Hereinafter, for convenience of explanation, the same reference numerals may be added to other items for configurations having the same functions as those described in one item, and the description thereof may be omitted.

[Crane and jib structure]
FIG. 1 is a schematic view showing the structures of a crane 100 and a jib 10 according to an embodiment of the present invention. FIG. 2A is a plan view showing an outline of the structure of the intermediate pendant jib 3 according to the embodiment of the present invention. FIG. 2B is a schematic view showing the structure of the first mounting portion 3a of the intermediate pendant jib 3, the second mounting portion 4a of the top jib 4, and the tip end portion 102a of the undulating pendant wire 102.

(Crane structure)
As shown in FIG. 1, the crane 100 includes a jib 10, a swivel frame 101, an undulating pendant wire 102, an undulating wire 103, an undulating winch 104, a hoisting wire 105, a hoisting winch 106, a first relay sheave 107, and a relay frame 108. , The second relay sheave 109, the tip sheave 110, and the hook portion 111 are provided.

The jib 10 is an arm of a crane 100 undulatingly provided on the swivel frame 101, and has a lattice structure. The swivel frame 101 is provided on the crane 100 so as to be swivelable. An undulating winch 104 for winding and unwinding the undulating wire 103, a hoisting winch 106 for winding and unwinding the hoisting wire 105, and a relay frame 108 are installed on the upper surface of the swivel frame 101. At the upper end of the relay frame 108, a second relay sheave 109 that relays the undulating wire 103 and two second relay sheaves 109 that relay the hoisting wire 105 are provided.

Further, one end of the undulating pendant wire 102 is attached to the tip of the top jib 4 in the jib 10, and the other end of the undulating pendant wire 102 is fixed to the first relay sheave 107. Further, the undulating wire 103 is wound by the undulating winch 104 via the first relay sheave 107 and the second relay sheave 109. The undulating pendant wire 102 is a wire for supporting the jib 10. The undulating wire 103 is a wire for supporting and undulating the jib 10.

Further, at the tip of the top jib 4, two tip sheaves 110 that relay the hoisting wire 105 are provided. Specifically, as shown in FIG. 2A, a cylindrical second axis 4b penetrates both side walls of the tip of the top jib 4 and is exposed in the space between the both side walls. Two tip sheaves 110 are provided at the portion of the biaxial 4b. Further, as shown in FIG. 1, the hoisting wire 105 having one end fixed to the upper surface of the swivel frame 101 is provided at the hook portion 111 via one of the second relay sheave 109 and one of the tip sheave 110. It is hung on a pair of hook site sheaves (not shown).

As shown in FIGS. 1 and 2A, the hook portion 111 includes a hook portion main body 111a, a hook 111b arranged below the hook portion main body 111a for suspending a load, and a hook portion main body 111a. It is composed of a pair of hook part sheaves arranged in the space inside the. The hook portion 111 is suspended by a hoisting wire 105 via a pair of hook portion sheaves. The hoisting wire 105 hooked on the pair of hook site sheaves is wound up by the hoisting winch 106 via the other of the tip sheave 110 and the other of the second relay sheave 109.

(Jib structure)
As shown in FIG. 1, the jib 10 includes a base jib 1, a plurality of intermediate jib 2, an intermediate pendant jib 3, and a top jib 4. Specifically, the jib 10 is configured by joining each of the base jib 1, a plurality of intermediate jib 2, the intermediate pendant jib 3, and the top jib 4, and can be disassembled into these four types of members. ing. Further, as the molding material for the base jib 1, the plurality of intermediate jib 2, the intermediate pendant jib 3, and the top jib 4, for example, high hardness steel can be exemplified.

The base jib 1 has an end portion on the side corresponding to the base of the jib 10 undulatingly attached to the swivel frame 101. The intermediate jib 2 is a member arranged between the base jib 1 and the intermediate pendant jib 3 or between the base jib 1 and the top jib 4 according to the working radius of the crane 100, and corresponds to the main body of the jib 10. do. A maximum of five intermediate jib 2s can be spliced together. The intermediate pendant jib 3 is a member arranged between the intermediate jib 2 arranged on the tip end side of the jib 10 most among the plurality of intermediate jibs 2 and the top jib 4, and when the working radius of the crane 100 is long. Used for. The top jib 4 is a member corresponding to the tip end portion of the jib 10.

When performing the work, the number of intermediate jib 2 to be joined is increased or decreased according to the length of the working radius of the crane 100, and the total length of the jib 10 is adjusted so as to match the working radius. When the working radius of the crane 100 is short, the intermediate pendant jib 3 is not used, and the jib 10 is composed of the base jib 1, the plurality of intermediate jibs 2, and the top jib 4.

In the present embodiment, the number of intermediate jib 2 is 5 in total, but this number is only an example and may be increased or decreased as appropriate according to the maximum working radius of the crane 100. Further, the intermediate pendant jib 3 does not necessarily have to be arranged between the intermediate jib 2 arranged on the tip end side of the jib 10 most among the plurality of intermediate jib 2 and the top jib 4. The intermediate jib 2 may be arranged between the intermediate pendant jib 3 and the top jib 4.

When the working radius of the crane 100 is long, as shown in FIG. 2A, the tip portion 102a of the undulating pendant wire 102 is attached to the first attachment portion 3a (attachment portion) provided on the intermediate pendant jib 3. The first mounting portion 3a is a member for mounting the undulating pendant wire 102 to the intermediate pendant jib 3, and is attached to each of the portions of the first shaft 3b protruding outward from both side walls of the intermediate pendant jib 3. It is provided. The first shaft 3b has a cylindrical shape and penetrates both side walls of the intermediate pendant jib 3.

Specifically, as shown in FIG. 2B, the first mounting portion 3a is composed of a disk-shaped connecting portion 3a-1 and a plate-shaped mounting portion 3a-2. As shown in FIG. 2A, the portion of the first axis 3b penetrates the connecting portion 3a-1, and the connecting portion 3a-1 and the portion of the first axis 3b are connected to each other. There is. As shown in FIGS. 2A and 2B, the mounting portion 3a-2 protrudes from the surface of the connecting portion 3a-1 facing the intermediate jib 4, and the mounting portion 3a-2 has a longitudinal direction of the first. It substantially coincides with the stretching direction of the central axis (not shown) of the uniaxial 3b. Further, the mounting portion 3a-2 is formed with a through hole to the extent that a bolt (not shown) can be inserted.

As shown in FIG. 2B, the tip portion 102a of the undulating pendant wire 102 has a U-shape in a side view so that the mounting portion 3a-2 of the first mounting portion 3a can be sandwiched. .. Further, through holes having substantially the same diameter as the through holes formed in the attachment portion 3a-2 are formed on the two walls of the tip portion 102a, respectively. The central axes of these two through holes are common.

When attaching the undulating pendant wire 102 to the first attachment portion 3a, attach the attachment portion 3a-2 so that the central axis of the through hole of the attachment portion 3a-2 and the central axis of the through hole of the tip portion 102a coincide with each other. It is sandwiched by the tip portion 102a. Then, by passing a bolt through these through holes and tightening with a nut (not shown), the tip portion 102a is fixed to the mounting portion 3a-2 as shown in FIG. 2A.

On the other hand, when the working radius of the crane 100 is short, the undulating pendant wire 102 is attached to the second attachment portion 4a shown in FIG. 2A provided on the top jib 4. The second mounting portion 4a is a member for mounting the undulating pendant wire 102 to the top jib 4, and is provided at each of the portions of the second shaft 4b protruding outward from both side walls of the top jib 4. ..

As shown in FIG. 2B, the second mounting portion 4a has the same shape and size as the first mounting portion 3a, and has a disk-shaped connecting portion 4a-1 and a plate-shaped mounting portion 4a-. It is composed of 2. The method of attaching the undulating pendant wire 102 to the second attachment portion 4a is the same as the attachment method to the first attachment portion 3a described above. When the working radius of the crane 100 is short, the jib 10 shown in FIG. 2A does not have the intermediate pendant jib 3, that is, the intermediate jib 4 and the top jib 4 arranged on the tip end side of the jib 10 are the most. The configuration is directly spliced (not shown).

Here, as shown in FIG. 1, the jib 10 has a structure in which the center of gravity axis G of the jib 10 is arranged vertically below the central axis T of the jib 10, and the first mounting portion 3a Is arranged on the center of gravity axis G in the intermediate pendant jib 3 in a side view. Similarly, the second mounting portion 4a is arranged on the center of gravity axis G in the top jib 4 in a side view.

Specifically, the central axis of the first axis 3b (not shown) and the central axis of the second axis 4b (not shown) intersect with the center of gravity axis G, and the connecting portion 3a- of the first mounting portion 3a The connecting portion 3a-1 is connected to the first axis 3b so that the central axis of 1 (not shown) and the central axis of the first axis 3b coincide with each other. Similarly, the connecting portion 4a-1 is connected to the second axis 4b so that the central axis (not shown) of the connecting portion 4a-1 of the second mounting portion 4a and the central axis of the second axis 4b coincide with each other. There is.

By arranging the first and second mounting portions 3a and 4a as described above, the undulating pendant wire 102 can be mounted on any of the first and second mounting portions 3a and 4a (the working radius of the crane 100 is long). Deflection of the jib 10 based on its own weight is suppressed (whether short or short). That is, regardless of whether the undulating pendant wire 102 is attached to any of the first and second attachment portions 3a and 4a, the supporting force of the undulating pendant wire 102 is the portion of the jib 10 from the root of the jib 10 to the attachment location of the wire 102. Acts to bend vertically upward.

The arrangement of the first and second mounting portions 3a and 4a described above is not essential. However, from the viewpoint of suppressing the bending of the jib 10 due to its own weight, at least the first mounting portion 3a is arranged at a position vertically below the central axis T of the jib 10 in a state where the jib 10 is horizontal. It is preferable to have.

Further, in the present embodiment, the first mounting portion 3a and the second mounting portion 4a have the same shape and size, but this is just an example, and the shapes and sizes of the two mounting portions may be different from each other. .. However, since the crane 100 has a structure in which the attachment location of the tip portion 102a of the undulating pendant wire 102 is different depending on the working radius, the shape and size of the attachment portion 3a-2 and the attachment portion 4a-2 It is preferable that the shapes and sizes of the above are at least substantially the same.

Further, in the present embodiment, both the mounting portions 3a-2 and 4a-2 have a plate shape, but this is also an example only, so as to match the shape and size of the tip portion 102a of the undulating pendant wire 102. , Another shape may be adopted as appropriate.

[Jib ability]
FIG. 3 is a capability diagram of the jib 10. When it is necessary to increase the overall length of the jib 10, the intermediate pendant jib 3 is incorporated into the jib 10 and the undulating pendant wire 102 is attached to the first attachment portion 3a as described above, so that the jib 10 is compared with the conventional jib 20. , The maximum total length of the jib 10 can be made longer. That is, the crane 100 can handle a longer working radius.

That is, in the case of the conventional jib 20, since the undulating pendant wire 102 is always attached to the second attachment portion 4a of the top jib 4, the substantially total length of the conventional jib 20 is the buckling length. Therefore, the longer the working radius, the larger the slenderness ratio and buckling coefficient, and the entire conventional jib 20 is greatly bent by its own weight. Therefore, in the conventional jib 20, the maximum total length of 45 m is the limit.

In that respect, since the jib 10 attaches the undulating pendant wire 102 to the first attachment portion 3a of the intermediate pendant jib 3 when the working radius of the crane 100 becomes long, the buckling length of the jib 10 is larger than the total length of the jib 10. Will also be shorter. Therefore, even if the working radius of the crane 100 becomes long, the slenderness ratio and buckling coefficient can be suppressed to a certain value, and the bending of the jib 10 based on its own weight can be suppressed. Specifically, the slenderness ratio can be reduced by about 15% to 20% and the buckling coefficient can be reduced by about 40% as compared with the conventional jib 20.

Here, the top jib 4 is in a so-called cantilever state, and a bending moment based on the weight of the load suspended on the hook portion 111 acts on the top jib 4. However, as shown in FIG. 3, the weight of the load that can be lifted by the jib 10 becomes lighter as the total length of the jib 10 becomes longer (for example, the rated load of the load is 2 tons at the maximum total length of the jib 10 of 55 m). The top jib 4 can withstand the bending moment without considering the strength so much. By obtaining these effects, it has become possible to extend the working radius of the crane 100 (maximum total length of the jib 10) to 55 m in the jib 10, as shown in FIG.

On the other hand, when the total length of the jib 10 may be short, the undulating pendant wire 102 is attached to the second attachment portion 4a of the top jib 4 without using the intermediate pendant jib 3, so that the jib is not considered to be strong. The 10 allows a relatively heavy load to be lifted.

That is, since the total length of the jib 10 is short, the buckling length is short even if the undulating pendant wire 102 is attached to the second attachment portion 4a, and the slenderness ratio and buckling coefficient can be suppressed to a small value. Therefore, the bending of the jib 10 based on its own weight is suppressed. Further, the top jib 4 does not become a so-called cantilever, and no bending moment acts on the top jib 4. By obtaining these effects, as shown in FIG. 3, in the jib 10, even if the maximum working radius of the crane 100 (total length of the jib 10) is 33 m when the intermediate pendant jib 3 is not used, the jib 10 is 6.8 t. Can lift loads up to heavy.

[Additional notes]
The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

2 Intermediate jib 3 Intermediate pendant jib 3a 1st mounting part (mounting part)
4 Top jib 10 Jib 100 Crane 102 Undulating pendant wire T Central axis

Claims (4)

A lattice-structured jib installed on a crane.
A plurality of intermediate jib corresponding to the main body of the jib, and
The top jib corresponding to the tip of the jib and
It comprises an intermediate pendant jib disposed between the intermediate jib and the top jib.
The intermediate pendant jib is provided with a mounting portion to which an undulating pendant wire for supporting the jib is mounted.
The mounting portion is arranged outside the side walls of the intermediate pendant jib.
The undulating pendant wire has a shape in which the tip portion can sandwich the mounting portion, and a first through hole into which a bolt can be inserted is formed in the tip portion.
A second through hole into which the bolt can be inserted is formed in the mounting portion.
A jib characterized in that the central axis of the first through hole and the central axis of the second through hole coincide with each other in a state where the mounting portion is sandwiched between the tip portions. The jib according to claim 1, wherein the intermediate pendant jib is arranged between an intermediate jib arranged on the tip end side of the jib most among the plurality of intermediate jibs and the top jib. A lattice-structured jib installed on a crane.
A plurality of intermediate jib corresponding to the main body of the jib, and
The top jib corresponding to the tip of the jib and
It comprises an intermediate pendant jib disposed between the intermediate jib and the top jib.
The intermediate pendant jib is provided with a mounting portion to which an undulating pendant wire for supporting the jib is mounted.
The jib is characterized in that the mounting portion is arranged at a position vertically below the central axis of the jib in a state where the jib is horizontal. A crane comprising the jib according to any one of claims 1 to 3.

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