JP4286368B2 - Mobile crane with luffing jib - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a luffing jib mounted on a mobile crane, and more particularly to a tension member thereof.
[0002]
[Prior art]
FIG. 5 shows a working state in which a mobile crane is equipped with a luffing jib. Reference numeral 1 denotes a vehicle portion of the mobile crane, and 2 denotes a swivel mounted on the vehicle portion 1 so as to be freely turnable. Reference numeral 3 denotes an extendable telescopic boom supported on the swivel base 2 by a hoisting cylinder 10 so as to be raised and lowered. Reference numeral 4 denotes a jib support attached to the distal end portion of the telescopic boom, and a luffing jib 5 formed by connecting a plurality of divided jibs 19 is pivotally supported at the distal end portion of the jib support 4 so as to be raised and lowered. Reference numeral 7 denotes two tension members, which are composed of a tension rod 28 formed by connecting a plurality of split rods and a wire rope 29, and are provided on the left and right in the vicinity of the leading end of the luffing jib 5 and the tip of the first mast 8 described later. The left and right are connected. The reason why the wire rope 29 is configured to be connected to the first mast 8 as a part of the tension member is to improve the workability when assembling the raffin bujib 5 and the tension member 7.
[0003]
Reference numeral 6 denotes a back tension device, which includes a first mast 8, a second mast 9, a connecting link 11, a back stopper cylinder 12, a connecting rod 17, a wire 15, a winch 13, an aerial sheave 14, and a fixed sheave 16. Has been. The aerial sheave 14 and the fixed sheave 16 are composed of a plurality of sheaves. After the wire 15 from the winch 13 is wound around the aerial sheave 14 and the fixed sheave 16, the end of the wire 15 is attached to the bracket of the fixed sheave. It is connected.
[0004]
The tension member 7 and the back tension device 6 have a back tension generated by the weight of the luffing jib 5 and the load of the suspended load with the above-described configuration, and wind the wire 15 from the winch 13 and feed it out to extend the telescopic boom 3 of the luffing jib 5. By changing the relative angle to the working radius, the working radius and the lift are made necessary.
[0005]
Reference numeral 18 denotes a support wire, which connects the upper surface of the intermediate portion in the longitudinal direction of the luffing jib 5 and the intermediate portion in the longitudinal direction of the tension rod 28. In the case of a long luffing jib as shown in FIG. 5, it is effective for reducing the deflection of the luffing jib 5 due to its own weight.
[0006]
[Problems to be solved by the invention]
As described above, since the part of the tension member 7 on the mast side is constituted by the wire rope 29, when the tension is applied to the wire rope 29 by the crane work by the luffing jib, the twist is returned as the characteristic of the wire rope, and the tension rod 28 is Rotation occurs by the amount of play at that connection. Since the two wire ropes 29 are twisted wire ropes in the same direction, the two tension rods 28 described above rotate in the same direction, so that the parallelism between the tension rods 28 is not only lost. There was also a risk that the entire luffing jib 5 was twisted.
[0007]
In particular, when using supporting example wire 18 described above, the connection portion is rotated in the same direction, since the imbalance of the tension rod 28 to the luffing jib 5 by supporting example wire 18 is transmitted, the tendency is more pronounced There was a problem of appearing.
[0008]
The invention of the present application provides a configuration of a tension member that can solve the above-described problem while using a wire rope for a part of the tension member because of its assembling property.
[0009]
[Means for Solving the Problems]
In the invention of claim 1 of the present application, a jib support is attached to the distal end portion of the telescopic boom, a base end portion of a luffing jib formed by connecting a plurality of divided jibs is pivotally attached to the jib support, and the vicinity of the rafting jib base end portion or A mast is erected on the jib support, the right and left in the vicinity of the luffing jib tip and the left and right of the tip of the mast are connected by two tension members, respectively, and the mast is supported by a back tension device. In the mobile crane with a luffing jib for supporting a luffing jib, at least a part of the tension member is constituted by a wire rope, and the twisting direction of the wire rope is different between right and left tension members, and the luffing jib Supports the upper surface of the longitudinal intermediate portion and the intermediate portion of the tension member. It is characterized in that a spherical bearing is interposed between the support wire and the intermediate portion of the tension member .
[0010]
With this configuration, even if tension acts on the wire rope of the tension member and the twist returns, the tension rod rotates by the same amount in the opposite direction on the left and right, so that the balance as a whole is maintained. . Further, the rotation of the tension member is absorbed by the spherical bearing, so that an excessive force is not applied to the support wire, and the rotation is not transmitted to the split jib of the luffing jib.
[0011]
In addition to the invention of claim 1, the invention of claim 2 of the present application is configured such that the tension member is formed by connecting a tension rod formed by connecting a plurality of split rods and a wire rope, and the intermediate portion in the longitudinal direction of the luffing jib The upper surface and the split rod connecting portion at the middle portion in the longitudinal direction of the tension rod are connected by a support wire, and a spherical bearing is interposed between the support wire and the split rod connecting portion.
[0012]
With this configuration, the rotation of the tension rod is absorbed by the spherical bearing, and the rotation is not transmitted to the split jib of the luffing jib.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
In describing the embodiment of the present invention, an example in which the present invention is applied to a mobile crane with a luffing jib shown and described in FIG. 5 in the prior art will be described. Accordingly, portions common to the present invention and the conventional ones will be described below using the same reference numerals and omitting detailed description.
[0014]
FIG. 1 shows a luffing jib according to an embodiment of the present invention. In this figure, in order to make the wire rope 20 in the tension member 7 easy to understand, the number of the divided jibs 19 of the luffing jib 5 will be described in a short state.
[0015]
FIG. 2 is a view of the tension member 7 of FIG. 1 as viewed from the direction of arrow B. Reference numeral 21 denotes a connecting member provided on the upper portion of the first mast 8, and the tension links 11, 11 and the wire ropes 20a, 20b are connected to each other. The wire ropes 20a and 20b are wire ropes having different twist directions. For example, if the 20a wire rope is S-twisted, the 20b wire rope is Z-twisted. Of course, the opposite may be true. Tension rods 28, 28 are connected to the ends of the wire ropes 20 a, 20 b to constitute the tension member 7.
[0016]
With the above configuration, even if the tension is applied to the wire rope 20 in the crane work by the luffing jib and the twist is returned as the characteristic of the wire rope, the two wire ropes 20 are rotated even if the tension rod 28 is rotated by the backlash of the connecting portion. Are twisted wire ropes in different directions, so that the two tension rods 28 described above rotate in different directions and are balanced as a whole, and the parallelism between the tension rods 28 is not lost. The entire twist does not occur.
[0017]
Figure 3 is a detailed view of a portion A showing a supporting example wire in FIG. The tension rods 28 and 28 are pin-connected via the connecting member 22. Bottom and one end of the supporting example wire 18 of the connecting member 22 is connected, the other end of the supporting example wire 18 is connected to the connecting portion of the divided jib 19.
[0018]
4A is a detailed view of the connecting portion between the connecting member 22 and the support wire 18 of FIG. FIG. 4A is a cross-sectional view taken along the line D in FIG. Which is one end end portion 23 of the supporting example wire 18 through the spherical bearing 24 is coupled with the coupling member 22.
[0019]
Since more supporting example wires 18 as being connected to the connection member 22 through the spherical bearing 24, also the tension rod 28 is rotated about its axis, it eliminates that excessive force is applied to the supporting example wire It is. Further, even if the tension is applied to the wire rope 20 of the tension member 7 and the twist is returned and the tension rod 28 is rotated, the influence is not transmitted to the split jib 19 of the luffing jib. This balance is maintained.
[0020]
【The invention's effect】
In the luffing jib of the mobile crane of the present invention, even if the tension acts on the wire rope of the tension member and the twist returns, the right and left sides of the tension rod are reversed in the opposite direction. Since the rotation is the same amount, the balance of the tension rod as a whole is maintained.
[0021]
Also in luffing jib long as using a supporting example wires, also rotates and the twist back tension rod acts tension on the wire rope tension member, the impact is not transmitted to the split jib luffing jib The balance of the luffing jib as a whole is maintained.
[Brief description of the drawings]
FIG. 1 is a side view of a luffing jib of a mobile crane according to the present invention.
FIG. 2 is a view taken in the direction of arrow B in FIG.
FIG. 3 is a detailed view of part A in FIG. 5;
4 is a detailed view of a portion C in FIG. 3. FIG.
FIG. 5 is an overall view of a mobile crane equipped with a luffing jib.
[Explanation of symbols]
3 telescopic boom 4 support 5 luffing jib 6 back tension device 7 Tension member 8 first mast 9 second mast 10 derricking cylinder 11 the tension link 18 supported e wire 19 divided jib 20, 20a, 20b, 29 a wire rope 21 connecting member 23 End 24 Spherical bearing 28 Tension rod

Claims (2)

A jib support is attached to the distal end of the telescopic boom, a base end of a luffing jib formed by connecting a plurality of divided jibs is pivotally attached to the jib support, and a mast is erected in the vicinity of the base end of the luffing jib or on the jib support. A mobile crane with a luffing jib for supporting the luffing jib by connecting the right and left in the vicinity of the luffing jib tip and the left and right of the mast tip by two tension members, and supporting the luffing jib by a back tension device supporting the mast. The tension member is at least partially composed of a wire rope, and the wire rope has different twisting directions between right and left tension members, and the upper surface of the luffing jib longitudinal direction intermediate portion and the tension member And connect the support wire with the support wire. A mobile crane with a luffing jib, characterized in that a spherical bearing is connected to the connection between the tension member and the intermediate portion of the tension member .  The tension member is configured by connecting a tension rod formed by connecting a plurality of split rods and the wire rope, an upper surface of the luffing jib longitudinal intermediate portion, and a split rod connecting portion of a longitudinal intermediate portion of the tension rod; The mobile crane with a luffing jib according to claim 1, wherein the support crane and the split rod connecting portion are connected via a spherical bearing.

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