crane

Abstract

To provide a crane capable of making an expansion stroke of a backstop smaller than a conventional one and increasing a member layout freedom in a crane body.SOLUTION: A crane 10 comprises: a revolving super structure 12; a boom 16; and a backstop 45. The boom 16 is disposed closer to a tip side than a boom foot 16S, and has a backstop support 161S that supports one end of the backstop 45. The revolving super structure 12 has a boom support 122A that supports the boom foot 16S to be rotatable about a horizontal rotational center axis, and a backstop receiver 122B that supports the other end of the backstop 45 before a turning center axis.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a crane. [Background technology]

[0002] Conventionally, a crane has been known that includes a crane body and a boom. The boom is supported by the crane body so that it can be raised and lowered around a horizontal rotation axis. Patent Document 1 discloses a crane that further includes a pair of backstops, one on each side, interposed between the boom and the crane body to prevent the boom from tipping backward.

[0003] In this technology, each backstop is extendable and retractable, and its base end is supported by the crane. When the crane rises up relative to the crane body, the tip of each backstop eventually abuts against a fixed member provided on the crane body. As a result, the pair of backstops support the crane, preventing further rotation of the crane and preventing the crane from tipping backward. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-232822 Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology described in Patent Document 1, the boom has a lower boom, and the base end of the backstop is supported closer to the tip than the longitudinal center of the lower boom. Meanwhile, the fixing member that receives the tip of the backstop is located near the longitudinal center of the crane body. With this configuration, the backstop's retraction stroke is large from the time the tip of the backstop abuts the fixing member until the backstop supports the boom from the rear. This increases the cost of the spring member required to ensure the backstop's stroke. Additionally, when the boom is lowered relative to the crane body, the backstop extends a long distance from the lower boom. This increases the overall length of the backstop, posing a problem of the backstop occupying a large amount of space when transporting the boom and backstop together, or when transporting the backstop detached from the lower boom. Furthermore, because engines and other components are often located near the longitudinal center of the crane body, there is a problem of limited space available for fixing members on the crane body.

[0006] The present invention has been made in consideration of the above problems, and aims to provide a crane that can reduce the extension and retraction stroke of the backstop compared to conventional methods and increase the degree of freedom in the layout of components in the upper rotating body. [Means for solving the problem]

[0007] A crane according to one embodiment of the present invention includes a lower traveling body, an upper rotating body arranged above the lower traveling body, a slewing bearing arranged between the lower traveling body and the upper rotating body, which enables the upper rotating body to rotate about a rotation center axis extending in a vertical direction relative to the lower traveling body, a hoisting body including a hoisting body fulcrum supported on the upper rotating body so as to be rotatable in a hoisting direction, and a hoisting body having one end and the other end, which is arranged between the hoisting body and the upper rotating body when the hoisting body is upright relative to the upper rotating body. and an extendable backstop that supports the escalating body from the rear, the escalating body being positioned further forward than the escalating body fulcrum and having a backstop first support part that supports one end of the backstop, and the upper rotating body having an escalating body support part that rotatably supports the escalating body fulcrum part around a horizontal rotation center axis, and a backstop second support part that is positioned forward of the rotation center axis and rearward of the escalating body support part in the fore-and-aft direction of the upper rotating body and supports the other end of the backstop.

[0008] According to this configuration, the backstop second support portion, which supports the other end of the backstop, is disposed forward of the rotation center axis and rearward of the hoisting body support portion in the fore-and-aft direction of the upper rotating body. Therefore, the extension / retraction stroke of the backstop can be made smaller compared to when the backstop second support portion is disposed rearward of the rotation center axis. Furthermore, by disposing the backstop second support portion forward of the rotation center axis, the degree of freedom in the layout of the central portion of the upper rotating body can be increased. Furthermore, the area of ​​the upper rotating body forward of the rotation center axis is where the hoisting body support portion is disposed in addition to the rotation bearing, so high rigidity and strength are necessarily required. Therefore, by disposing the backstop second support portion in this area, the hoisting body can be stably supported by the backstop.

[0009] In the above configuration, it is preferable that the upper rotating body further includes a box-shaped support body including the elevation body support portion and the backstop second support portion.

[0010] According to this configuration, the backstop second support part is disposed on the same box-shaped support as the undulating body support part, and is therefore disposed closer to the undulating body support part in the fore-and-aft direction. As a result, the stroke of the backstop contracting after it begins to support the undulating body is reduced. In addition, by disposing the backstop second support part close to the undulating body support part, the degree of freedom in the layout of the central part of the upper rotating body can be further increased. Furthermore, because the backstop second support part is disposed on the box-shaped support that supports the undulating body, the undulating body can be stably supported due to the lightweight and high-strength characteristics of the box shape.

[0011] In the above configuration, it is preferable that the support body has an upper surface, and the backstop second support portion is disposed on the upper surface.

[0012] According to this configuration, the backstop second support portion is disposed on the upper surface of the support body, so that the backstop second support portion can more stably receive the load of the undulating body.

[0013] In the above configuration, it is desirable that the undulating body support portion is disposed at the front end of the support body, and the backstop second support portion is disposed at the rear end of the support body.

[0014] According to this configuration, the perpendicular distance between the fulcrum of the undulating body and the backstop on the support body can be maximized.

[0015] In the above configuration, it is desirable that the upper rotating body has a bottom plate rotatably supported on the lower running body and a vertical plate erected on the bottom plate so as to extend in the fore-and-aft direction, and that the support body has a lower surface supported on the bottom plate on the opposite side to the upper surface, and a side surface connecting the upper surface and the lower surface and connected to the vertical plate.

[0016] According to this configuration, the support is disposed at the portion where the bottom plate and the vertical plate intersect, and the support can be stably supported by the bottom plate and the vertical plate.

[0017] In the above configuration, it is desirable that one end of the backstop is connected to the backstop first support part so that the backstop rotates integrally with the elevation body relative to the upper rotating body, and when the elevation body stands upright relative to the upper rotating body, the other end of the backstop abuts against the backstop second support part, thereby restricting further rearward rotation of the elevation body.

[0018] According to this configuration, the backstop can be removed from the upper rotating body together with the elevation body, so that the elevation body and the backstop can be transported and stored as a unit.

[0019] In the above configuration, it is desirable that the one end of the backstop be supported by the backstop first support portion so that the relative posture of the backstop with respect to the undulating body is maintained when viewed from a direction parallel to the rotation center axis.

[0020] According to this configuration, the backstop can be kept in the same position when the crane is in use and when it is disassembled, reducing the need for position change work and the devices involved in this process as in the past.

[0021] In the above configuration, the elevation body is separable into multiple members, and has at least a lower elevation body member including the elevation body fulcrum portion, and when the elevation body is upright relative to the upper rotating body so that the center line of the elevation body extends vertically, it is desirable that the other end of the backstop is positioned forward of the rear end of the lower elevation body member.

[0022] According to this configuration, when the lower member of the elevation body is lowered, the backstop fits within the maximum height of the lower member of the elevation body, so the backstop can be transported together with the lower member of the elevation body while satisfying the transport height restrictions without changing the position of the backstop or removing it.

[0023] In the above configuration, it is desirable that the other end of the backstop is connected to the backstop second support part so that the elevation body rotates relative to the backstop and the upper rotating body, and that when the elevation body stands upright relative to the upper rotating body, the one end of the backstop abuts against the backstop first support part, thereby restricting further rearward rotation of the elevation body.

[0024] According to this configuration, the backstop is disposed on the upper rotating body side, which further increases the degree of freedom in the layout of the members attached to the elevation body.

[0025] In the above configuration, it is desirable that the elevation body be separable into multiple components and have at least an elevation body lower member including the elevation body fulcrum portion, and that the backstop first support portion be arranged on the elevation body lower member closer to the elevation body fulcrum portion than the longitudinal center of the elevation body lower member.

[0026] According to this configuration, interference between the backstop first support portion and other components arranged at the tip side of the lower member of the elevation body is prevented, thereby increasing the degree of freedom in the layout of component arrangement in the lower member of the elevation body. [Effects of the Invention]

[0027] According to the present invention, a crane is provided in which the extension and retraction stroke of the backstop can be made smaller than conventional ones and the degree of freedom in the layout of components in the upper rotating body can be increased. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a side view of a crane according to an embodiment of the present invention. FIG. [Figure 2] FIG. 2 is a side view of a lower boom portion and a backstop of a crane according to an embodiment of the present invention, with the boom in a lowered position. [Figure 3] FIG. 2 is an enlarged side view of a portion of the upper rotating body of the crane according to the embodiment of the present invention. [Figure 4] FIG. 2 is an enlarged perspective view of a portion of the upper rotating body of the crane according to the embodiment of the present invention. [Figure 5] FIG. 2 is a plan view of a rotating frame of an upper rotating body of the crane according to one embodiment of the present invention. [Figure 6] FIG. 1 is a side view of a conventional crane compared to a crane according to an embodiment of the present invention. [Figure 7] FIG. 1 is a side view of a lower boom and a backstop of a conventional crane when the boom is in a lowered position. [Figure 8] FIG. 1 is a side view of a lower boom and a backstop of a conventional crane in a state where the backstop is raised from a state where the boom is in a lowered position. [Figure 9] FIG. 1 is a side view of a lower boom, an upper rotating body, and a backstop of a conventional crane with the boom in an upright position. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a side view of a crane 10 (work machine) according to one embodiment of the present invention. Note that, although the directions of "up," "down," "front," and "rear" are shown in each drawing hereinafter, these directions are shown for the convenience of explaining the structure and assembly method of the crane 10 according to this embodiment, and do not limit the direction of movement or the manner of use of the crane according to the present invention.

[0030] The crane 10 comprises an upper rotating body 12 and a lower running body 14 which correspond to the crane body, a cab 15 provided on the upper rotating body 12, a boom 16 which functions as a hoisting body, a pair of left and right backstops 45, a lattice mast 17 which is a member for raising and lowering the boom, and a box mast 21. The lower running body 14 is capable of traveling on the ground (on a running surface), and the upper rotating body 12 is supported by the lower running body 14 so as to be rotatable about a rotation center axis which extends in the vertical direction.

[0031] The boom 16 has a boom base end 16P (hoisting unit base end) supported on the upper rotating unit 12 so as to be rotatable in the hoisting direction, and a boom tip end 16Q (hoisting unit tip end) located on the opposite side of the boom base end 16P in the longitudinal direction. In this embodiment, a boom foot 16S (hoisting unit fulcrum) provided at the boom base end 16P is supported on a boom support section 122A (FIGS. 3 and 4) of the upper rotating unit 12 so as to be rotatable in the hoisting direction. The boom 16 shown in FIG. 1 is a so-called lattice type and can be separated into multiple members. More specifically, the boom 16 is composed of a lower boom 16A (hoisting unit lower member) including the boom foot 16S, one or more (three in the illustrated example) intermediate booms 16B, 16C, and 16D, and an upper boom 16E. A pair of left and right backstops 45 is provided on the lower boom 16A. These backstops 45 come into contact with the upper rotating body 12 when the boom 16 reaches the upright posture (working posture) shown in Fig. 1 relative to the upper rotating body 12, thereby being interposed between the boom 16 and the upper rotating body 12 and supporting the boom 16 from the rear. As a result, the boom 16 is prevented from being blown backward by strong winds, etc. The structure of the backstops 45 will be described in detail later.

[0032] The lattice mast 17 includes a mast base end 17P and a mast tip end 17Q. The mast base end 17P is attached to the upper rotating body 12 at a position behind the boom 16 so as to be able to rise and fall about a rotation axis parallel to the rotation axis of the boom 16. In other words, the lattice mast 17 can also rotate in the same direction as the boom 16. The mast tip end 17Q is the tip of the lattice mast 17, located on the opposite side of the mast base end 17P in the longitudinal direction. As shown in FIG. 1, a first mast sheave 171 and a second mast sheave 172 are disposed at the mast tip end 17Q of the lattice mast 17. A boom hoist rope 22, described below, is hung around the first mast sheave 171 and the second mast sheave 172. The lattice mast 17 serves as a support for the rotation of the boom 16.

[0033] A pair of left and right backstops 46 are provided on the mast base end 17P side of the lattice mast 17. These backstops 46 come into contact with the upper rotating body 12 when the lattice mast 17 reaches the upright position shown in Figure 1. This contact prevents the lattice mast 17 from being blown backward by strong winds, etc.

[0034] The crane 10 further includes a lower spreader 18, an upper spreader 19, guy lines 20, a boom hoist rope 22, and a boom hoist winch 38.

[0035] The lower spreader 18 has a lower sheave block 181. The lower sheave block 181 has multiple sheaves arranged in the width direction (left-right direction). The upper spreader 19 is arranged in front of the lower spreader 18 at a predetermined interval. The upper spreader 19 is connected to the boom tip 16Q via guy lines 20. The upper spreader 19 has an upper sheave block 191. The upper sheave block 191 has multiple sheaves arranged in the width direction (left-right direction). A pair of guy lines 20 are arranged in the left-right direction perpendicular to the plane of the paper in FIG. 1.

[0036] The rear end of the guy line 20 is connected to the upper spreader 19, and the front end of the guy line 20 is detachably connected to the boom tip 16Q. The guy line 20 includes guy links (metal plates), guy ropes, guy wires (metal wires), etc.

[0037] The boom hoist rope 22 is pulled out from the boom hoist winch 38, and is then hooked around the first mast sheave 171 and the second mast sheave 172 of the mast tip 17Q, and then wound around multiple times between the lower sheave block 181 and the upper sheave block 191. After being hooked around the lower sheave block 181 and the upper sheave block 191, the tip of the boom hoist rope 22 is fixed to the mast tip 17Q of the lattice mast 17.

[0038] The boom hoist winch 38 is disposed on the mast base end 17P side of the lattice mast 17. The boom hoist winch 38 changes the distance between the lower sheave block 181 of the lower spreader 18 and the upper sheave block 191 of the upper spreader 19 by winding in and letting out the boom hoist rope 22, thereby raising or lowering the boom 16 while rotating the boom 16 relative to the lattice mast 17.

[0039] The box mast 21 has a base end and a pivot end (tip end), and is pivotally connected to the upper rotating body 12 behind the lattice mast 17. The box mast 21 has a rectangular shape in cross section. The pivot axis of the box mast 21 is parallel to the pivot axis of the boom 16 and is located at approximately the same position as the pivot axis of the lattice mast 17. In other words, the box mast 21 can also pivot in the same direction as the boom 16 is raised and lowered.

[0040] The crane 10 also includes guy lines 23, a mast hoisting rope 26, and a mast hoisting winch 30. A pair of guy lines 23 are arranged in the left-right direction, perpendicular to the plane of FIG. 1 . The guy lines 23 connect the mast tip 17Q of the lattice mast 17 to the rotating end of the box mast 21. This connection coordinates the rotation of the lattice mast 17 with the rotation of the box mast 21. The mast hoisting rope 26 is reeled in multiple times between a sheave block 24, which is disposed on the upper rotating body 12 and has multiple sheaves arranged in the width direction, and a sheave block 25, which is disposed on the rotating end of the box mast 21 and has multiple sheaves arranged in the width direction.

[0041] The mast hoist winch 30 is located on the base end side of the box mast 21. The mast hoist winch 30 winds in and pays out the mast hoist rope 26. The winding and paying out operation of the mast hoist winch 30 changes the distance between the sheave block 25 at the tip of the box mast 21 and the sheave block 24 at the rear end of the upper rotating body 12, and the box mast 21 and the lattice mast 17 rotate together relative to the upper rotating body 12, causing the lattice mast 17 to rise and fall.

[0042] In addition to the mast hoist winch 30 and boom hoist winch 38 described above, the crane 10 is also equipped with a main hoist winch 34 and an auxiliary hoist winch 36 for hoisting and lowering a load. In the crane 10 according to this embodiment, the main hoist winch 34 and the auxiliary hoist winch 36 are both installed on the lower boom 16A of the boom 16. The winches 34, 36 of the crane 10 may also be mounted on the upper rotating body 12.

[0043] The main winch 34 hoists and lowers a load using a main hoisting rope 51 (FIG. 1). For this main hoisting, a main hoisting guide sheave (not shown) is rotatably mounted at the boom tip 16Q of the boom 16. A main hoisting sheave block, in which multiple main hoisting point sheaves are arranged in the width direction, is also mounted adjacent to the main hoisting guide sheave. A main hook 53 for the load is connected to the main hoisting rope 51 suspended from the main hoisting sheave block. The main hoisting rope 51 pulled out from the main hoisting winch 34 is looped around the main hoisting guide sheaves in order and is stretched between the sheave of the main hoisting sheave block and the sheave of the sheave block mounted on the main hook 53. Therefore, when the main hoisting winch 34 winds or unwinds the main hoisting rope 51, the main hook 53 is hoisted or lowered.

[0044] Similarly, the auxiliary winch 36 hoists and lowers the load using the auxiliary hoisting rope 52. This auxiliary hoisting is provided with a structure (not shown) similar to that of the main hoisting described above. When the auxiliary hoisting winch 36 winds or unwinds the auxiliary hoisting rope 52, an auxiliary hook (not shown) for the load, which is connected to the end of the auxiliary hoisting rope 52, is hoisted or lowered.

[0045] A counterweight 40 for adjusting the balance of the crane 10 is also loaded on the rear of the upper rotating body 12, and a pallet weight 41 is also disposed behind the upper rotating body 12. The pallet weight 41 serves as an SHL (Super Heavy Lifting) weight provided for the crane 10 to lift heavy loads, and has the function of maintaining the balance of the crane 10. The pallet weight 41 is connected to the mast tip 17Q of the lattice mast 17 by a weight line 42.

[0046] FIG. 2 is a side view of the lower boom 16A and the backstop 45 when the boom 16 of the crane 10 according to this embodiment is in a lowered position.

[0047] Referring to Figure 2, when the boom 16 (lower boom 16A) is viewed in a state where it is lowered relative to the upper rotating body 12, the lower boom 16A has a pair of left and right lower frames 160, a pair of left and right first main pipes 161, a pair of left and right second main pipes 162, a pair of left and right first connecting pipes 163, a pair of upper and lower second connecting pipes (not shown), and a plurality of lattice pipes 165.

[0048] The pair of left and right first main pipes 161 and the pair of left and right second main pipes 162 are pipes that define the outer shape of the lower boom 16A, and as shown in FIG. 2, they extend from the vicinity of the boom foot 16S toward the tip of the lower boom 16A so that the distance between them increases. The lower frame 160 is a plate-like member that connects the base ends of the first main pipes 161 and the second main pipes 162 to each other on both the left and right sides of the lower boom 16A. The pair of left and right first connecting pipes 163 connect the tips of the first main pipes 161 and the second main pipes 162 to each other, respectively. Note that a pair of upper and lower second connecting pipes (not shown) connect the tips of the pair of left and right first main pipes 161 to each other and the tips of the pair of left and right second main pipes 162 to each other. The plurality of lattice pipes 165 connect the first main pipe 161 and the second main pipe 162, the pair of left and right first main pipes 161, and the pair of left and right second main pipes 162 to each other at a plurality of locations.

[0049] Furthermore, the lower boom 16A has a pair of left and right backstop support portions 161S (first backstop support portions). The pair of left and right backstop support portions 161S are respectively disposed on the pair of left and right first main pipes 161 (rear surfaces of the lower boom 16A) at positions closer to the tip end than the boom foot 16S, more specifically, closer to the boom foot 16S than the longitudinal center of the lower boom 16A. The backstop support portions 161S support a backstop base end portion 452S (one end portion) of the backstop 45 described below.

[0050] As described above, the crane 10 is equipped with a pair of left and right backstops 45. Each backstop 45 is disposed on a pair of left and right first main pipes 161. Since the pair of left and right backstops 45 have the same structure and function, hereinafter, only the backstop 45 on the right side (the front side of the paper in FIG. 2) will be described.

[0051] The backstop 45 has a backstop lower part 451 (also referred to as an inner cylinder), a backstop upper part 452 (also referred to as an outer cylinder), and a backstop spring 453 (also referred to as a spring member). The backstop lower part 451 and the backstop upper part 452 have a cylindrical structure, and the backstop lower part 451 is inserted into the cylindrical interior of the backstop upper part 452 so as to be able to expand and contract. The backstop spring 453 is attached between flanges F (FIG. 2) provided on the backstop lower part 451 and the backstop upper part 452 so as to be able to contract and deform.

[0052] The backstop lower portion 451 has a backstop abutment portion 451S (other end portion), and the backstop upper portion 452 has a backstop base end portion 452S (one end portion). The backstop base end portion 452S corresponds to the base end portion of the backstop 45, and the backstop abutment portion 451S corresponds to the tip end portion of the backstop 45 opposite the backstop base end portion 452S. As described above, the backstop base end portion 452S is supported (attached) to the backstop support portion 161S, which is located closer to the tip end portion (boom tip portion 16Q) of the lower boom 16A than the boom foot 16S.

[0053] 3 and 4 are a side view and a perspective view showing an enlarged portion of the upper rotating body 12 of the crane 10 according to this embodiment. FIG. 5 is a plan view of the rotating frame 120 of the upper rotating body 12 according to this embodiment. The upper rotating body 12 has a rotating frame 120. The rotating frame 120 includes a bottom plate 125 and a pair of left and right vertical plates 121 fixed on the bottom plate 125. The crane 10 also has a slewing bearing 12S. The slewing bearing 12S is disposed between the lower traveling body 14 and the upper rotating body 12, and enables the upper rotating body 12 to rotate about a rotation center axis CL extending in the vertical direction relative to the lower traveling body 14. In FIG. 5, the outer diameter of the slewing bearing 12S is indicated by a dashed line.

[0054] The bottom plate 125 is rotatably supported by the lower traveling body 14. The bottom plate 125 is a member extending in the front-rear and left-right directions, and is made, for example, of a frame formed by joining steel materials. The pair of left and right vertical plates 121 are each plate-shaped members extending long in the front-rear direction, and are fixed (standing) to the bottom plate 125 at a distance in the left-right direction, and are also made of steel materials or the like. Note that in Figures 3 and 4, only the vertical plate 121 on the right side (the front side of the paper) is visible.

[0055] Furthermore, the upper rotating body 12 has a pair of box-shaped supports 122 on the left and right, and a pair of mast supports 123 on the left and right. Each support 122 is disposed outside the vertical plate 121 at the tip end side of the vertical plate 121. The pair of mast supports 123 are disposed at the tip and upper end of each vertical plate 121, and rotatably support the mast base end 17P (FIG. 1) of the lattice mast 17 described above.

[0056] The following describes in more detail the structure surrounding the right-side support 122, as shown in FIGS. 3 and 4. The structure surrounding the left-side support 122 is symmetrical to the structure on the right side. The support 122 is a box-shaped member having an upper surface 122T, a lower surface opposite the upper surface 122T, right and left side surfaces connecting the upper and lower surfaces, and a front and rear surface. As shown in FIG. 4, the lower surface of the support 122 is supported by a bottom plate 125. The left side surface of the support 122 is connected to a vertical plate 121. As shown in FIG. 3, the front portion of the support 122 has a triangular shape that protrudes forward. The box-shaped support 122 can enhance the rigidity and strength of the support 122 compared to a support 122 made of a single plate. Like the bottom plate 125, the support 122 is made of steel.

[0057] The support body 122 has a boom support portion 122A (elevating body support portion), a backstop receiving portion 122B (backstop second support portion), and a cab support portion 122C.

[0058] The boom support part 122A supports the boom foot 16S so that it can rotate about a horizontal rotation center axis that extends in the left-right direction. The boom support part 122A is located at the front end of the support body 122, particularly in the triangular portion. The boom support part 122A has pin holes that penetrate the support body 122 in the left-right direction. Similar pin holes are also formed in the boom foot 16S of the boom 16, and with both pin holes aligned, connecting pins (not shown) are inserted into each pin hole in order, thereby supporting the boom 16 on the upper rotating body 12 so that it can be raised and lowered. Although not shown in the figure, the same is true for the left support body 122.

[0059] The backstop receiving portion 122B is disposed rearward of the boom support portion 122A and supports the backstop abutment portion 451S of the backstop 45. The backstop receiving portion 122B is disposed at the rear end of the support body 122. More specifically, the backstop receiving portion 122B is disposed at the rear end of the upper surface 122T of the support body 122 and is a U-shaped receiving portion that opens forward and upward. When the boom 16 is in the upright position shown in FIG. 1, the backstop receiving portion 122B supports the backstop abutment portion 451S of the backstop 45 and receives the weight of the boom 16 via the backstop 45. The backstop receiving portion 122B shown in FIGS. 3 and 4 is disposed on the revolving frame 120 forward of the revolving central axis CL in FIG. 5 in the fore-and-aft direction of the upper revolving body 12.

[0060] The cab support portion 122C is disposed on the upper surface of the support body 122 in a portion forward of the backstop receiving portion 122B. The cab support portion 122C has a function of supporting the cab 15, the step 15H, etc. via other supports, etc.

[0061] FIG. 6 is a side view of a conventional crane 10Z compared with the crane 10 according to this embodiment. FIG. 7 is a side view of a lower boom 16AZ and a backstop 45Z when the boom 16Z of the conventional crane 10Z is in a lowered position. FIG. 8 is a side view of a lower boom 16AZ and a backstop 45Z when the backstop 45Z has been raised from a position where the boom 16Z of the conventional crane 10Z is in a lowered position. FIG. 9 is a side view of a lower boom 16AZ, an upper rotating body 12Z, and a backstop 45Z when the boom 16Z of the conventional crane 10Z is in an raised position. Note that in FIGS. 6 to 9, components common to those in FIG. 1 are designated by the same reference numerals followed by a letter Z.

[0062] The crane 10Z has a backstop 45Z. The backstop 45Z is supported on the lower boom 16AZ so as to be able to rise up. The backstop 45Z is supported on the lower boom 16AZ so as to be able to rotate. The backstop 45Z has a backstop lower part 451Z, a backstop upper part 452Z, and a backstop spring 453Z. The backstop lower part 451Z has a backstop abutment part 451SZ. In addition, the backstop upper part 452Z has a backstop base end part 452SZ and a supported part 452T.

[0063] 7, the lower boom 16AZ includes a boom foot 16SZ, a backstop support portion 161SZ, and a backstop fixing portion 65. The backstop support portion 161SZ supports a backstop base end portion 452SZ of the backstop 45Z so that the backstop 45Z can rotate about a rotation center axis extending in the left-right direction. When the backstop 45Z is held by the lower boom 16A, as shown in FIG. 7, the backstop 45Z is fixed by inserting a pin 65P into pin holes formed in the supported portion 452T and the backstop fixing portion 65. On the other hand, as shown in FIG. 8, when the backstop 45Z is raised relative to the lower boom 16AZ, the support member 60 is interposed between the supported portion 452T and the backstop fixing portion 65, thereby maintaining the raised posture of the backstop 45Z relative to the lower boom 16AZ.

[0064] Referring to FIG. 9, in such a conventional crane 10Z, a backstop receiver 150 is disposed on the upper rotating body 12Z at a position rearward of the boom foot 16SZ. When the boom 16Z is raised relative to the upper rotating body 12Z, the backstop abutment portion 451SZ of the backstop 45Z abuts against the backstop receiver 150, thereby supporting the boom 16Z from behind. In this configuration in which the backstop 45Z is supported by the backstop support portion 161SZ disposed at the tip end of the lower boom 16AZ and the backstop receiver 150 disposed at the center of the bottom plate 125Z, the free length of the backstop 45Z is inevitably long. In other words, as the boom 16Z is raised, the contraction stroke required for the backstop spring 453Z to contract and deform to its minimum length after the backstop abutment portion 451SZ abuts against the backstop receiver 150 is increased. As an example, this stroke may be required to be approximately 500 mm. In this case, the cost of the backstop spring 453Z for ensuring the extension and retraction stroke of the backstop 45Z is likely to be high. Also, when the boom 16Z is lowered relative to the upper rotating body 12Z, the total length of the backstop 45Z extending from the lower boom 16AZ becomes long, as shown in Figures 7 and 8. This poses a problem in that the space occupied by the backstop 45Z increases when the boom 16Z and the backstop 45Z are transported together, or when the backstop 45Z is detached from the lower boom 16AZ and transported. Also, as shown in Figures 7 and 8, a mechanism (support member 60) for changing the position of the backstop 45Z is required.

[0065] In addition, as shown in Fig. 6, components such as winches 34, 36 and guy links (not shown) are arranged closer to the tip of the lower boom 16AZ than the longitudinal center, which tends to limit the space available for arranging the backstop support portion 161SZ that supports the backstop base end portion 452SZ. Furthermore, because an engine and other components are often arranged around the longitudinal center of the upper rotating body 12Z, there is a problem that the space available for arranging the backstop receiver 150 shown in Fig. 9 is limited. In this case, the shape of the backstop receiver 150 becomes complex in order to avoid interference with surrounding components, and additional reinforcing members may be required to stably support the weight of the boom 16Z.

[0066] On the other hand, in this embodiment, when the boom 16 including the lower boom 16A shown in FIG. 2 is raised, the backstop abutment portion 451S of the backstop 45 abuts against and is supported by the backstop receiving portion 122B (FIGS. 3 and 4) of the support body 122 (FIG. 1). The backstop receiving portion 122B is disposed forward of the revolving central axis CL (FIG. 5) and rearward of the boom support portion 122A in the longitudinal direction of the upper rotating body 12. Therefore, the extension / retraction stroke of the backstop 45 can be made smaller than when the backstop receiving portion 122B is disposed rearward of the revolving central axis CL. Furthermore, by disposing the backstop receiving portion 122B forward of the revolving central axis CL in this manner, the degree of freedom in the layout of the central portion of the upper rotating body 12 can be increased. Furthermore, since the boom support portion 122A is disposed in addition to the revolving bearing 12S in the region of the upper rotating body 12 forward of the revolving central axis CL, high rigidity and strength are necessarily required. Therefore, by utilizing such an area to arrange the backstop receiving portion 122B, the boom 16 can be stably supported by the backstop 45.

[0067] Furthermore, in this embodiment, the backstop receiving portion 122B is disposed on the same support body 122 as the boom support portion 122A, and is therefore disposed closer to the boom support portion 122A in the fore-and-aft direction. As a result, the contraction stroke required for the backstop spring 453 to deform to its minimum length after the backstop abutment portion 451S abuts against the backstop receiving portion 122B is shortened. As an example, this stroke is approximately 100 mm to 200 mm. Furthermore, as shown in FIGS. 3 and 4, the backstop receiving portion 122B is disposed closer to the boom support portion 122A, which further increases the degree of freedom in the layout of the central portion of the upper rotating body 12, specifically, the area surrounding the mast hoisting winch 30 in FIG. 1, making it easier to arrange a power unit such as an engine than before.

[0068] 1, in this embodiment, the backstop 45 is positioned close to the boom foot 16S, so a larger load is likely to be applied to the backstop receiving portion 122B to prevent the boom 16 from tipping backward. However, in this embodiment, the backstop receiving portion 122B is similarly arranged on the box-shaped support body 122 on which the boom support portion 122A for supporting the boom 16 is arranged, so the boom 16 can be stably supported from behind due to the lightweight and high-strength characteristics of the support body 122.

[0069] In particular, since the backstop receiving portion 122B is disposed on the upper surface 122T of the support body 122, the backstop receiving portion 122B can receive the load of the boom 16 more stably.

[0070] In addition, since the boom support portion 122A is positioned at the front end of the support body 122 and the backstop receiving portion 122B is positioned at the rear end of the support body 122, the perpendicular distance between the boom foot 16S and the backstop 45 on the support body 122 can be maximized.

[0071] In this embodiment, the lower surface of the support body 122 is supported by the bottom plate 125, and the side surface of the support body 122 is supported by the vertical plate 121. Therefore, the support body 122 is disposed at the intersection of the bottom plate 125 and the vertical plate 121, and the support body 122 can be stably supported by the bottom plate 125 and the vertical plate 121.

[0072] Furthermore, in this embodiment, the backstop base end 452S of the backstop 45 is connected to the backstop support portion 161S so that the backstop 45 rotates integrally with the boom 16 relative to the upper rotating structure 12. When the boom 16 stands upright relative to the upper rotating structure 12, the backstop abutment portion 451S of the backstop 45 abuts against the backstop receiving portion 122B, thereby restricting further rearward rotation of the boom 16. With this configuration, the backstop 45 can be removed from the upper rotating structure 12 together with the boom 16, allowing the lower boom 16A and the backstop 45 to be transported and stored as a unit.

[0073] In this embodiment, the backstop base end 452S of the backstop 45 is fixed to the backstop support portion 161S so that the relative orientation of the backstop 45 with respect to the lower boom 16A (boom 16) is maintained when viewed in a direction parallel to the central axis of rotation of the boom 16 (FIG. 2). In other words, in this embodiment, the backstop 45 does not need to be supported rotatably with respect to the lower boom 16A over a large movable range as in the past. Therefore, the orientation of the backstop 45 can be maintained the same when the crane 10 is in use and when it is disassembled, reducing the need for the conventional orientation change work and the associated devices.

[0074] In this embodiment, the boom 16 is separable into multiple components and includes at least a lower boom 16A including a boom foot 16S. When the boom 16 is raised relative to the upper rotating structure 12 so that the centerline of the boom 16 extends vertically, the backstop abutment portion 451S of the backstop 45 is located forward of the rear end of the lower boom 16A. This is equivalent to the backstop 45 being located within the maximum height of the lower boom 16A when the lower boom 16A is lowered, as shown in FIG. 2 . Furthermore, when the boom 16 is in an upright position facing vertically upward, and the lower boom 16A is projected onto the upper rotating structure 12 in a plan view, the backstop abutment portion 451S is located forward of the rear end of the projected area. This configuration allows the backstop 45 to be transported together with the lower boom 16A while satisfying the transport height limit without removing the backstop 45 from the lower boom 16A or significantly changing the position of the backstop 45.

[0075] Furthermore, in this embodiment, the backstop support portion 161S is disposed on the lower boom 16A closer to the boom foot 16S than the longitudinal center of the lower boom 16A. This prevents interference between the backstop 45 and components disposed on the tip side of the lower boom 16A, such as the winches 34 and 36 in Fig. 1, and increases the degree of freedom in the layout of component arrangement on the lower boom 16A.

[0076] The crane 10 according to one embodiment of the present invention has been described above. However, the present invention is not limited to these embodiments. The following modified embodiments are possible in the present invention.

[0077] (1) In each of the above embodiments, the backstop base end 452S of the backstop 45 is supported by the lower boom 16A, and the backstop abutment portion 451S abuts against the backstop receiving portion 122B on the upper rotating body 12 side as the boom 16 is raised. However, the present invention is not limited to this.

[0078] (2) The backstop 45 may be supported in advance by the upper rotating body 12. That is, the backstop base end 452S (other end) of the backstop 45 may be connected to a backstop support portion (backstop second support portion) that is provided on the support body 122 and has a shape similar to that of the backstop support portion 161S so that the boom 16 can rotate relatively to the backstop 45 and the upper rotating body 12. In this case, when the boom 16 stands upright relative to the upper rotating body 12, the backstop abutment portion 451S (one end) of the backstop 45 abuts against a backstop receiver portion (backstop first support portion) that is provided on the lower boom 16A and has a shape similar to that of the backstop receiver 122B, thereby restricting further rearward rotation of the boom 16.

[0079] According to this configuration, the backstop 45 is disposed on the upper rotating body 12 side, which further increases the degree of freedom in the layout of accessories for the lower boom 16A.

[0080] (3) Furthermore, while the above embodiments have been described using the crane 10 shown in FIG. 1 , the present invention is not limited to this and can also be applied to cranes with other structures. That is, a crane to which the present invention is applied may be a general-purpose crane equipped with a gantry instead of the lattice mast, and the hoisting winch may be located on the upper frame (rear side) of the upper rotating body 12. Furthermore, a large crane may have a structure in which the boom is hoisted by hoisting a box mast instead of the SHL structure. In this case, the tip of the box mast and the tip of the boom may be directly connected by a guy link, without the sheave block. Furthermore, both general-purpose cranes and large cranes may have a jib or strut attached to the tip of the boom.

[0081] (4) In the above embodiment, the backstop 45 extends along the first main pipe 161 of the lower boom 16A as shown in Fig. 2. However, the backstop 45 may be disposed so as to intersect with the first main pipe 161 at a larger angle. When the backstop 45 is disposed so as to be perpendicular to the first main pipe 161, the backstop 45 can efficiently support the weight of the boom 16.

[0082] (5) In the above embodiment, the backstop receiving portion 122B is disposed forward of the slewing center axis CL, i.e., in the front half of the slewing bearing 12S. However, the present invention is not limited to this. For example, when the crane 10 is small, medium, or large, the backstop receiving portion 122B may be disposed in a predetermined area forward of the slewing center axis CL. Alternatively, the backstop receiving portion 122B may be disposed in a predetermined area rearward of the front end of the slewing bearing 12S. In this case, the length of each predetermined area in the front-rear direction is preferably two-thirds of the length from the slewing center axis CL to the front end of the slewing bearing 12S.

[0083] Furthermore, if the crane 10 is large, the backstop receiver 122B may be disposed in a predetermined region (near the area where the vertical plate 121 and the slewing bearing 12S contact or intersect) in front or behind the slewing center axis CL as the starting point. In this case, the length of the predetermined region in the front-rear direction is preferably two-thirds of the length from the slewing center axis CL to the front end or rear end of the slewing bearing 12S. Furthermore, it is also preferable that the support body 122 or the backstop receiver 122B be disposed in a region including the slewing center axis CL in the front-rear direction (a region overlapping with the slewing center axis CL). In these regions, the slewing bearing 12S is located at the left-right end, so the backstop receiver 122B can be disposed stably and firmly.

[0084] (6) In the above embodiment, the backstop receiving portion 122B is disposed on the box-shaped support body 122. However, the backstop receiving portion 122B may not be disposed on the support body 122. The support body 122 may have a shape other than a box shape. As an example, the boom support body 122A may be composed of one or more plate-shaped portions, and the backstop receiving portion 122B may be another structure disposed near the boom support body 122A. In this case, the structure may be composed of a combination of plate-shaped members or a bracket structure.

[0085] (7) In the previous embodiment, the backstop spring 453 is disposed on the backstop base end 452S side as shown in FIG. 2. However, the backstop spring 453 may be disposed on the backstop abutment portion 451S (FIG. 2) side as shown in FIG. 7. [Explanation of symbols]

[0086] 10 Crane 12 Upper rotating body 120 Swivel Frame 121 Vertical board 122 Support 122A Boom support part (elevating body support part) 122B Backstop receiving part (backstop second support part) 122C cab support 122T top surface 123 Mast support 125 Bottom plate 12S slewing bearing 14 Undercarriage 15 Cab 15H step 16. Boom 161S Backstop support part (backstop first support part) 16A Lower boom (lower member of the boom) 16S Boom foot (elevating body support part) 45 Backstop 451 Backstop bottom 451S Backstop contact part (other end) 452 Backstop Top 452S Backstop base end (one end) 453 Backstop Spring

Claims

1. a lower running body; an upper rotating body disposed above the lower traveling body; a slewing bearing disposed between the lower traveling body and the upper rotating body, the slewing bearing enabling the upper rotating body to rotate about a rotation center axis extending in the vertical direction relative to the lower traveling body; a hoisting body including a hoisting body fulcrum portion rotatably supported in a hoisting direction on the upper rotating body; an extendable backstop having one end and the other end, interposed between the elevation body and the upper rotating body in a state where the elevation body is upright relative to the upper rotating body, and supporting the elevation body from behind; Equipped with The undulating body is separable into a plurality of members, a lower member of the undulating body including at least the fulcrum portion of the undulating body, the lower member having a first main pipe and a second main pipe that define the outer shape of the lower member of the undulating body and extend so that the distance between them increases toward the tip side of the lower member of the undulating body; a backstop first support portion that is disposed on the first main pipe on the back surface of the lower member of the elevation structure at a position closer to the tip end than the elevation structure fulcrum portion and that supports the one end of the backstop; The upper rotating body is a support portion for supporting the support portion for pivoting about a horizontal pivot axis; a backstop second support portion that is disposed forward of the rotation central axis and rearward of the elevation body support portion in the front-to-rear direction of the upper rotating body and supports the other end of the backstop, the backstop first support portion is disposed on the first main pipe on the back surface of the lower member of the undulating body at a position closer to the undulating body fulcrum portion than the longitudinal center of the lower member of the undulating body, The backstop is arranged to extend from the backstop first support portion along the first main pipe when the elevation body lower member is in a lowered state.

2. 2. The crane of claim 1, wherein the upper rotating body further comprises a box-shaped support including the elevation body support portion and the backstop second support portion.

3. the support has an upper surface; The crane of claim 2 , wherein the backstop second support is disposed on the upper surface.

4. A lower running body; an upper rotating body disposed above the lower traveling body; a slewing bearing disposed between the lower traveling body and the upper rotating body, the slewing bearing enabling the upper rotating body to rotate about a rotation center axis extending in the vertical direction relative to the lower traveling body; a hoisting body including a hoisting body fulcrum portion rotatably supported in a hoisting direction on the upper rotating body; an extendable backstop having one end and the other end, interposed between the elevation body and the upper rotating body in a state where the elevation body is upright relative to the upper rotating body, and supporting the elevation body from behind; Equipped with The undulating body has a backstop first support portion that is arranged on the tip side of the undulating body fulcrum portion and supports the one end portion of the backstop, The upper rotating body is a support portion for supporting the support portion for pivoting about a horizontal pivot axis; a backstop second support portion that is disposed forward of the rotation central axis and rearward of the elevation body support portion in the front-to-rear direction of the upper rotating body and supports the other end portion of the backstop; a box-shaped support including the relief support portion and the backstop second support portion; the support has an upper surface; the backstop second support portion is disposed on the upper surface; the relief support is located at the front end of the support; The backstop second support is disposed at the rear end of the support.

5. The upper rotating body is a bottom plate rotatably supported on the lower traveling body; a vertical plate provided on the bottom plate so as to extend in the front-rear direction; and The crane according to claim 3 or 4, wherein the support body has a lower surface supported by the bottom plate on the opposite side to the upper surface, and a side surface connecting the upper surface and the lower surface and connected to the vertical plate.

6. The one end of the backstop is connected to the backstop first support portion so that the backstop rotates integrally with the elevation body relative to the upper rotating body, 6. The crane according to claim 1, wherein when the hoisting body is raised relative to the upper rotating body, the other end of the backstop abuts against the backstop second support portion, thereby restricting further rearward rotation of the hoisting body.

7. 7. The crane according to claim 6, wherein the one end of the backstop is fixed to the backstop first support portion so that the relative attitude of the backstop with respect to the elevation body is maintained when viewed in a direction parallel to the pivot center axis.

8. A lower running body, an upper rotating body disposed above the lower traveling body; a slewing bearing disposed between the lower traveling body and the upper rotating body, the slewing bearing enabling the upper rotating body to rotate about a rotation center axis extending in the vertical direction relative to the lower traveling body; a hoisting body including a hoisting body fulcrum portion rotatably supported in a hoisting direction on the upper rotating body; an extendable backstop having one end and the other end, interposed between the elevation body and the upper rotating body in a state where the elevation body is upright relative to the upper rotating body, and supporting the elevation body from behind; Equipped with The undulating body has a backstop first support portion that is arranged on the tip side of the undulating body fulcrum portion and supports the one end portion of the backstop, The upper rotating body is a support portion for supporting the support portion for pivoting about a horizontal pivot axis; a backstop second support portion that is disposed forward of the rotation central axis and rearward of the elevation body support portion in the front-to-rear direction of the upper rotating body and supports the other end of the backstop, The one end of the backstop is connected to the backstop first support portion so that the backstop rotates integrally with the elevation body relative to the upper rotating body, When the hoisting body stands upright relative to the upper rotating body, the other end of the backstop abuts against the backstop second support portion, thereby restricting further rearward rotation of the hoisting body, The one end of the backstop is fixed to the backstop first support portion so that the relative posture of the backstop with respect to the undulating body is maintained when viewed in a direction parallel to the pivot central axis, The undulating body can be separated into a plurality of members, and has at least an undulating body lower member including the undulating body fulcrum portion, When the elevation body is upright relative to the upper rotating body so that the center line of the elevation body extends vertically, the other end of the backstop is positioned forward of the rear end of the elevation body lower member.

9. The other end of the backstop is connected to the backstop second support portion so that the elevation body rotates relative to the backstop and the upper rotating body, 6. The crane according to claim 1, wherein when the hoisting body is raised relative to the upper rotating body, the one end of the backstop abuts against the backstop first support portion, thereby restricting further rearward rotation of the hoisting body.

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