JP4889229B2 - Mobile crane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile crane X equipped with a pair of masts 20 arranged at a jib 14 being inclined to the left and right about the boom rising and falling surface Y, a pair of first tension members 21 to couple the tips of the masts 20 with the tip 18 of the jib, and a pair of second tension members 22 to couple the tips of the masts 20 with an upper revolving body 12, wherein the constitution is arranged able to suppress the spread of the masts 20 at the time of jib working effectively without bringing about a large-scale arrangement nor involving a weight increase. <P>SOLUTION: An inter-mast coupling member 24 is installed to couple the masts 20 with each other, whereby the external force willing to widen the space between the masts 20 can be absorbed efficiently by this inter-mast coupling member. This enables the construction of the whole device to be simple and lightweight because there is no risk that the arrangement becomes large scaled nor the strength of the masts themselves must be heightened. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a mobile crane equipped with a device that absorbs part and all of the longitudinal and lateral bending moments acting on the jib and the telescopic boom when the jib is attached to the tip of the telescopic boom.

  There has been proposed a device that absorbs the bending moment in the vertical and horizontal directions of the telescopic boom in a crane working posture in which the telescopic boom is extended and has a large undulation angle (see, for example, Patent Document 1). However, although the device described in Patent Document 1 is effective for boom work using only the telescopic boom, the longitudinal and lateral directions of the jib and the entire telescopic boom in the jib work with the jib attached to the tip of the telescopic boom. A sufficient effect could not be expected for the absorption of bending moment.

Therefore, the applicant of the present invention absorbs part or all of the bending moments in the vertical and horizontal directions acting on the entire jib and the telescopic boom with the jib attached to the distal end of the telescopic boom, thereby increasing the maximum lifting load. The mobile crane provided with the device which can increase a value is proposed (for example, refer to patent documents 2 ).

The entire mobile crane Z described in Patent Document 2 is shown in FIG. 4, and its C arrow view is shown in FIG. As shown in FIG. 4, the mobile crane Z is pivotally attached to the lower traveling body 1, the upper revolving body 2 that is turnably mounted on the lower traveling body 1, and the upper revolving body 2 so as to be raised and lowered. The telescopic boom 3 and the jib 4 attached to the tip of the telescopic boom are provided. The jib 4 includes a jib support 31 that is detachably attached to the telescopic boom tip 30 and a jib body 32 that is pivotally attached to the jib support 31 so as to be raised and lowered.

  The mobile crane Z is a pair of first masts 37 that are inclined to the left and right sides with respect to the boom raising / lowering surface Y and are disposed on the jib 4, and a pair of first mast 37 that connects the tip of the mast 37 and the jib tip 35. A tension member 39 and a pair of second tension members 40 that connect the tip of the mast 37 and the upper swing body 2 are provided.

With the above configuration, the inclination of the mast 37 is selected so as to absorb part or all of the bending moments in the vertical and horizontal directions acting on the jib 4 and the telescopic boom 3. As shown in FIG. 5, the mast 37 is connected to the jib support 31 via a swinging member 61, and the swinging member 61 is an undulating surface about a tilting shaft 60 parallel to the telescopic boom 3. It is possible to tilt with respect to. Further, the mast 37 is rotatable with respect to the swing member 61 about a rotation shaft 62 orthogonal to the tilting shaft 60. Reference numeral 63 denotes a tilting hydraulic cylinder in which both ends of the jib support 31 and the swinging member 61 are pivotally attached. The tilting angle α of the mast 37 is changed to an optimum angle, and during the jib operation, the mast 37 The inclination angle α is kept constant.
JP 2001-58791 A (page 4-5, FIG. 1) Japanese Patent Application No. 2003-403279 (page 4-5, FIG. 2, FIG. 6)

  However, as shown in FIG. 4, when the jib 4 is not on the extension of the axis of the telescopic boom 3 and the jib 4 is bent with respect to the telescopic boom 3, the portion excluding the tip of the mast 37 is The first tension member 39 and the second tension member 40 deviate from the triangular plane formed. Therefore, when the resultant force due to the tension generated in the first tension member 39 and the second tension member 40 acts on the mast 37, it does not act only as an axial compressive force of the mast 37, and further in a direction in which the mast 37 is inclined. The component force which tries to defeat acts. That is, when tension is generated in the tension member, an external force is applied to the pair of masts 37 in such a direction that the distal ends thereof open to each other. The external force for opening the mast tip tends to increase as the tilt angle of the jib 4 with respect to the telescopic boom 3 increases and as the tension of the tension member increases.

  As shown in FIG. 5, if it is attempted to prevent the opening of the mast 37 by the tilting hydraulic cylinder 63 pivotally attached to the rocking member 61 at the base end portion of the mast 37, the tilting hydraulic cylinder 63 must support a large load. Therefore, the structure becomes large. Further, since the bending moment acts on the entire mast 37, the cross-section of the mast 37 is increased in order to withstand the bending moment, and the weight of the entire mast 37 is increased.

Therefore, the present invention has a configuration capable of effectively suppressing the spread of the mast without adding a large scale and increasing the weight by improving the apparatus described in Patent Document 2 . The mobile crane which increases the maximum value of the lifting load by the device is to be proposed.

A mobile crane described in claim 1 of the present application includes a lower traveling body, an upper swinging body that is turnably mounted on the lower traveling body, and an extendable boom pivotally attached to the upper swinging body. And a jib that can be attached to and detached from the tip of the telescopic boom. In such a mobile crane, with the jib attached to the distal end of the telescopic boom, the base end is connected to the jib base end or the telescopic boom distal end, and the distal end is laterally lateral to the boom undulation surface. A pair of masts that are inclined to each other, a pair of first tension members that connect the mast tip and the jib tip, and a pair of mast that connects the tip of the mast and the telescopic boom base end or the upper swing body. A second tension member and a wire as an inter-mast connecting member for connecting the masts are provided.

  The mobile crane described in claim 2 of the present application is characterized in that the jib includes a jib support that is detachable from the distal end portion of the telescopic boom, and a jib body that is pivotally attached to the jib support so as to be raised and lowered. Is characterized in that its proximal end is connected to the jib support.

  The mobile crane described in claim 3 of the present application is characterized in that the mast connecting member includes a mast distance changing means capable of changing a distance between the masts.

In the mobile crane described in claim 4 of the present application, the mast is a first mast, a second mast located on the rear side of the first mast, the first mast tip portion, and the second mast tip. An inter-mast tension member for connecting the first mast tip to the first mast tip and the second tension member to the second mast tip. .

The mobile crane described in claim 1 has a base end portion connected to a jib base end portion or a telescopic boom tip portion, and a tip portion of the mobile crane inclined to the left and right sides with respect to the boom hoisting surface. Since the wire as a mast connecting member for connecting the masts is provided, an external force for spreading the mast can be efficiently absorbed by the mast connecting member. Therefore, it is not necessary to make a large-scale device, and it is not necessary to increase the strength of the mast itself, so that the entire device can be simple and lightweight.

  In the mobile crane according to claim 2, since the mast is connected to the jib support that can be attached to and detached from the distal end of the telescopic boom, the mast-related device including the inter-mast connecting member is integrated into the jib support. Can be arranged. For this reason, disassembly, transportation, and assembly relating to the jib are facilitated, and workability can be improved.

  The mobile crane described in claim 3 is provided with an inter-mast distance changing means capable of changing the distance between the masts in the inter-mast connecting member, so that the inclination angle of the mast with respect to the undulating surface of the telescopic boom as required. Can be changed. Therefore, it is possible to easily adjust to the optimum mast inclination angle that changes according to the jib length, the boom length, the dibutylt angle with respect to the telescopic boom, or the like.

  According to a fourth aspect of the present invention, the mast includes a first mast, a second mast, and an inter-mast tension member, and an inter-mast connecting member between the pair of left and right first masts. In addition, an inter-mast connecting member is provided between the pair of left and right second masts. For this reason, in the first mast and the second mast, it is possible to efficiently absorb an external force that attempts to expand the space between the masts generated by the tension of the tension member connected to each mast.

  FIG. 1 shows a mobile crane X according to an embodiment of the present invention. The mobile crane X includes a lower traveling body 11, an upper revolving body 12 that is turnably mounted on the lower traveling body 11, a telescopic boom 13 pivotally attached to the upper revolving body 12, and the telescopic movement. And a jib 14 attached to the tip of the boom. The jib 14 includes a jib support 16 that is detachably attached to a telescopic boom tip 15 and a jib body 17 that is pivotally attached to the jib support 16 so as to be raised and lowered.

  The jib support 16 of the jib 14 is connected to a base end portion of a pair of masts 20 inclined to the left and right sides with respect to the boom hoisting surface. A pair of first tension members 21 that connect the tip of the mast 20 and the jib tip 18 and a pair of second tension members 22 that connect the tip of the mast 20 and the upper swing body 12 are disposed. Has been. The wire constituting the second tension member 22 is fed from the drum of the winch 26 disposed on the swivel base 12, and the tilt angle of the jib 14 relative to the telescopic boom 13 can be changed by operating the winch 26. It has become. The second tension member 22 may be connected to the telescopic boom base end portion 19 and provided with a means for changing its length separately.

Reference numeral 24 denotes an inter-mast connecting member that connects the tip portions 23 of the pair of left and right masts 20. From the jib tip 18, a jib work wire 100 fed from a winch (not shown) arranged on the upper swivel is suspended, and a suspended load 25 is hung from the tip of the jib work wire 100. Yes. Due to the weight of the suspended load 25, a large tension is generated in the first tension member 21 and the second tension member 22.

  Since the mast connecting member 24 for connecting the masts as described above is provided, it is possible to efficiently absorb the component force that attempts to widen the mast generated by the tension of the tension members 21 and 22. it can. For this reason, it is not necessary to use a large-scale device and it is not necessary to increase the strength of the mast itself, so that the entire mast can be made simple and lightweight. The inclination of the mast 20 with respect to the boom undulation surface is selected so as to absorb part or all of the longitudinal and lateral bending moments acting on the jib 14 and the telescopic boom 13, thereby increasing the strength of the jib and boom. The maximum lifting load during jib work can be increased without increasing the height.

  FIG. 2 is a view taken in the direction of arrow A in FIG. 1 and illustrates details of the inter-mast connecting member 24 disposed on the mast 20. In FIG. 2, the left and right sides are identified by attaching L or R to the end of the numbers for the members arranged in a pair on the left and right. As shown in FIG. 2, the right mast 20 </ b> R is connected to the jib support 16 via a right swing member 27 </ b> R, and the right swing member 27 </ b> R has a right tilt shaft 50 </ b> R parallel to the telescopic boom 13. It can be tilted with respect to the relief surface as the center. Further, the right mast 20R is rotatable with respect to the right swing member 27R about a right rotation shaft 51R perpendicular to the right tilt shaft 50R. The left mast 20L has the same configuration as the right mast 20R, and has a symmetrical shape with the telescopic boom undulation surface Y as the center.

Reference numeral 24 denotes an inter-mast connecting means for connecting the left mast tip 23L and the right mast tip 23R. The mast connecting means 24 includes a winch device 52 (corresponding to “mast distance changing means” described in the claims), a wire 54 fed out from the drum 53 of the winch device 52, and the like. 55 is a sheave rotatably disposed on the right mast tip 23R, and 56 is a wire engaging portion disposed on the left mast tip 23L. After the wire 54 fed out from the drum 53 is wound around the sheave 55, the tip thereof is locked to the wire locking portion 56. The winch 52 is equipped with a drum lock device so that drum rotation can be locked at an arbitrary wire feed amount.
When tension F is generated in the first tension member 21 and the second tension member 22, a moment M is generated in the mast 20 in a direction in which the mast 20 tends to spread outward as shown in FIG. However, since the left and right mast tip portions 23 are connected to each other by the wire 54 constituting the inter-mast connecting means 24, a tension against the moment M is generated on the wire 54, and the mast 20 is in a balanced state. The angle α inclined from the undulating surface Y is maintained. In addition, the distance between the masts can be easily changed by operating the winch 52 and feeding or feeding the wire 54. Thus, the inclination angle α of the mast 20 with respect to the undulating surface Y of the telescopic boom can be changed as necessary, and the angle can be maintained. As described above, it is possible to select an optimum mast inclination angle that changes in accordance with the jib length, the boom length, the tilt angle of the jib 14 with respect to the telescopic boom 13, or the like.

FIG. 3 shows a mobile crane W according to another embodiment. The mobile crane W is a mast that connects the first mast 70, the second mast 71 located on the rear side of the first mast 70, and the first mast tip and the second mast tip. The mobile crane W comprised including the intermediate tension member 72 is shown. The first tension member 39 is connected between the first mast tip and the jib tip , and the second tension member 40 is connected between the second mast tip and the upper swing body .

  The triangle formed by the first mast 70, the second mast 71, and the inter-mast tension member 72 maintains a constant shape regardless of changes in the tilt angle of the jib body 32 with respect to the jib support 31. Even if the tilt angle becomes a large angle, a sufficient arm length for generating a moment can be secured. Therefore, the jib work with a wide range of dibutylt angles with respect to the telescopic boom 3 becomes possible.

The first mast 70 and the second mast 71 in FIG. 3 are each composed of a pair of masts inclined to the left and right sides with respect to the telescopic boom undulation surface Y, as shown in FIG. Provided with a mast linkage member between the pair of first mast 70, a mast between coupling member to between the pair of second mast 71. Thereby, in the 1st mast 70 and the 2nd mast 71, the component force which is going to expand between the right and left mast which generate | occur | produces with the tension | tensile_strength of the tension member connected with each mast can be absorbed efficiently.

It is a figure showing mobile crane X concerning an embodiment of the invention. FIG. 2 is a view as seen from an arrow A in FIG. 1. The mobile crane W which concerns on other embodiment is shown. 1 is an overall view of a mobile crane Z described in Patent Document 2. FIG. It is C arrow line view of FIG.

Explanation of symbols

11: Lower traveling body 12: Upper turning body 13: Telescopic boom 14: Jib 20: Mast 21: First tension member 22: Second tension member 24: Mast connecting member 16: Jib support 17: Jib body 52: Winch 54 : Wire 70: first mast 71: second mast 72: inter-mast tension member W, X: mobile crane Y: boom hoisting surface

Claims (4)

A lower traveling body, an upper revolving body that is pivotably mounted on the lower traveling body, a telescopic boom pivotably attached to the upper revolving body, and a jib that is detachably attached to a distal end portion of the telescopic boom And a mobile crane with
With the jib attached to the telescopic boom distal end, a pair of masts whose base end is connected to the jib base end or telescopic boom distal end and whose distal end is inclined to the left and right sides with respect to the boom undulation surface; A pair of first tension members that connect the mast tip and the jib tip, a pair of second tension members that connect the tip of the mast and the telescopic boom base end or upper swing body, and the mast A mobile crane comprising a wire as a connecting member between masts for connecting together.   The jib includes a jib support that can be attached to and detached from the distal end of the telescopic boom, and a jib body that is pivotally attached to the jib support so that the mast can be raised and lowered. The base end of the mast is connected to the jib support. The mobile crane according to claim 1.   The mobile crane according to claim 1, wherein the inter-mast connecting member includes an inter-mast distance changing unit capable of changing a distance between the masts.   The mast includes a first mast, a second mast located behind the first mast, and an inter-mast tension member that connects the first mast tip and the second mast tip, The mobile crane according to claim 1, wherein the first tension member is connected to the first mast tip, and the second tension member is connected to the second mast tip.

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