JP7760901B2 - crane - Google Patents

Description

The present invention relates to a crane.

Conventionally, cranes equipped with a crane body and a boom are known. 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 left and right backstops interposed between the boom and the crane body to prevent the boom from tipping backward. A support member for receiving the backstops is located in the center of the crane body in the fore-and-aft direction.

In this technology, each backstop has an outer tube, an inner tube inserted into the outer tube, and a contractible spring member interposed between the outer and inner tubes. The length of the backstop changes as the spring member expands and contracts. The base end of the backstop is supported by the boom. When the boom is raised relative to the crane body, the tip of the backstop eventually abuts against the support member attached to the crane body, and the spring member contracts. The contraction energy of this spring member functions to push the boom back in an upside-down direction when the crane is disassembled. If the boom is blown backward by strong winds or other factors during crane operation, the backstop's spring member contracts to its minimum dimension, reducing the backstop to its minimum length. Supporting the boom from behind, it prevents the boom from tipping over backward (swinging).

JP 2012-232822 A

In recent years, the wind-receiving surface area of a crane's hoisting structure has tended to increase due to factors such as the lengthening of booms and the increase in accessories attached to the structure. In this case, the force required of the backstop to support the structure from behind to prevent it from tilting during normal operation tends to be greater than the force required to push the structure back in the direction of collapse when the crane is disassembled. For this reason, conventional technology such as that described in Patent Document 1 has the problem of increasing the strength and cost required of the backstop's spring members.

The present invention was made in consideration of the above problems, and aims to provide a crane that can reliably prevent the hoisting body from tipping over due to strong winds during normal operation, even if the wind-receiving area of the hoisting body increases, without increasing the strength or cost of the components supporting the hoisting body, and that can push the hoisting body back in an upside-down direction when the crane is disassembled.

A crane according to one embodiment of the present invention comprises a crane body, a hoisting body including a hoisting body fulcrum supported by the crane body so as to be rotatable in the hoisting direction around a horizontal rotation center axis, a support member having an outer tube and an inner tube inserted into the outer tube, and being extendable between a maximum length and a minimum length, and which is interposed between the hoisting body and the crane body when the hoisting body is in an upright position relative to the crane body and supports the hoisting body from the rear while applying a forward biasing force to the hoisting body, and a restricting member which is interposed between the crane body and the hoisting body to receive the load of the hoisting body to prevent the hoisting body from tipping backward when the hoisting body is in the upright position and the length of the support member is a predetermined restricting length between the maximum length and the minimum length.

With this configuration, the restricting member can prevent the cranes from tipping backward before the support members retract to their minimum length. This prevents the maximum load of the cranes from being applied to the support members. As a result, even if the wind-receiving area of the cranes increases due to an increase in the length of the cranes or an increase in the number of accessories attached to the cranes, it is possible to reliably prevent the cranes from tipping over due to strong winds during normal operation without increasing the strength or cost of the support members, and to push the cranes back in an upside-down direction when the crane is disassembled.

In the above configuration, it is desirable that the support member further includes a spring member disposed between the outer tube and the inner tube and capable of contracting between a maximum spring length and a minimum spring length, and when the descent body is in an upright position and the spring member is contracted below the maximum spring length, the support member is disposed between the descent body and the crane body, and supports the descent body from the rear while applying a forward biasing force to the descent body; and when the descent body is in the upright position and the length of the spring member is contracted to a length between the maximum spring length and the minimum spring length and the length of the support member is set to the restricting length, the restricting member is disposed between the crane body and the descent body, and receives the load of the descent body to prevent the descent body from tipping backward.

With this configuration, the restricting member can prevent the hoisting body from tipping backward before the spring members of the support members contract to their minimum length. This prevents the maximum load of the hoisting body from being applied to the support members, including the spring members. As a result, even if the wind-receiving area of the hoisting body increases due to an increase in the length of the hoisting body or an increase in the number of accessories attached to the hoisting body, it is possible to reliably prevent the hoisting body from tipping over due to strong winds during normal operation without increasing the strength or cost of the spring members, and it is also possible to push the hoisting body back in an upside-down direction when the crane is disassembled.

In the above configuration, it is desirable that the regulating member be positioned between the crane body and the elevator, between the support member and the elevator support point when viewed in a direction parallel to the central axis of rotation.

With this configuration, the restricting member is positioned closer to the fulcrum of the undulating body than the support member, which reliably restricts the undulating body from tipping backward and more reliably prevents the maximum load of the undulating body from being applied to the rear support member.

In the above configuration, it is desirable that the regulating member has a base end supported by the derrick and a tip end opposite the base end, and is positioned to protrude from the derrick, and the crane body has a regulating member receiving portion capable of receiving the tip end of the regulating member, and when the derrick is in the upright position and the length of the spring member is set to the regulating length, the tip end of the regulating member abuts against the regulating member receiving portion, thereby causing the regulating member to receive the load of the derrick.

With this configuration, the restricting member receiving portion receives the tip of the restricting member, thereby reliably preventing the undulating body from tipping over due to strong winds during normal operation.

In the above configuration, it is desirable that the crane body has a rotating frame and a support frame that is arranged at the front end of the rotating frame and includes a hoisting body support part that rotatably supports the hoisting body fulcrum part, and that the restricting member receiving part is arranged on the support frame.

With this configuration, the restricting member receiving portion is located on a support frame with high strength to rotatably support the fulcrum portion of the elevation unit, which further stably prevents the elevation unit from tipping over due to strong winds during normal operation.

In the above configuration, the crane may further include a mast that supports the hoisting body from behind, the mast having a mast base end that is rotatably supported on the crane body behind the hoisting body, the crane body having a swivel frame, the swivel frame having a mast support portion that rotatably supports the mast base end, and the restricting member receiving portion being disposed on the mast support portion.

With this configuration, the restricting member receiving portion is located on the mast support section, which has high strength to support the base end of the mast, making it possible to more reliably prevent the eruption body from collapsing due to strong winds during normal operation.

In the above configuration, it is desirable that the elevation body be separable into multiple components, have at least an elevation body lower member including the elevation body fulcrum portion, and that the base end of the regulating member be supported by a portion of the elevation body lower member closer to the elevation body fulcrum portion than the longitudinal center of the elevation body lower member.

This configuration prevents interference between the restricting member and other components arranged at the tip of the lower member of the undulating body, increasing the degree of freedom in the layout of components on the lower member of the undulating body.

This invention provides a crane that can reliably prevent the rafter from tipping over due to strong winds during normal operation, even if the wind-receiving area of the rafter increases, without increasing the strength or cost of the components supporting the rafter, and can also push the rafter back in an upside-down direction when the crane is disassembled.

1 is a side view of a crane according to an embodiment of the present invention. FIG. FIG. 2 is a side view of a lower boom portion, a boom support, and a boom stop when the boom of the crane according to one embodiment of the present invention is in a lowered position. FIG. 2 is a side view of the crane body and the crane elevation unit according to the embodiment of the present invention. FIG. 2 is a rear view of the boom support receiver of the crane according to the embodiment of the present invention. FIG. 10 is a side view of the elevation body and crane body of a crane according to a modified embodiment of the present invention.

Each embodiment of the present invention will be described below with reference to the drawings. Figure 1 is a side view of a crane 10 (work machine) according to one embodiment of the present invention. Note that although the directions "up," "down," "front," and "rear" are indicated in each figure hereafter, 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 usage of the crane according to the present invention.

The crane 10 comprises an upper rotating body 12 and a lower running body 14, which correspond to the crane body, a cab 15 attached to the upper rotating body 12, a boom 16 which functions as a hoisting body, 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 that it can rotate around a central rotation axis extending in the vertical direction.

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 foot support 12S (Figure 3) of the upper rotating unit 12 so as to be rotatable in the hoisting direction. The boom 16 shown in Figure 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, 16D, and an upper boom 16E.

The lattice mast 17 comprises 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 that it can be raised and lowered around 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 Figure 1, a first mast sheave 171 and a second mast sheave 172 are located at the mast tip end 17Q of the lattice mast 17. A boom hoisting 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.

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 each abut against the upper rotating body 12 when the lattice mast 17 reaches the upright position shown in Figure 1. This abutment prevents the lattice mast 17 from being blown backward by strong winds, etc.

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

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 positioned a predetermined distance in front of the lower spreader 18. 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 Figure 1. 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 lines 20 include guy links (metal plates), guy ropes, guy wires (metal wires), etc.

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

The boom hoist winch 38 is located on the mast base end 17P side of the lattice mast 17. The boom hoist winch 38 winds in and unwinds the boom hoist rope 22 to change the distance between the lower sheave block 181 of the lower spreader 18 and the upper sheave block 191 of the upper spreader 19, thereby raising and lowering the boom 16 while rotating the boom 16 relative to the lattice mast 17.

The box mast 21 has a base end and a pivot end (tip), and is pivotally connected to the upper rotating body 12 behind the lattice mast 17. The box mast 21 has a rectangular cross-sectional shape. 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's elevation.

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 the paper in Figure 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 arranged on the upper rotating body 12 and has multiple sheaves arranged in the width direction, and a sheave block 25, which is arranged at the rotating end of the box mast 21 and has multiple sheaves arranged in the width direction.

The mast hoisting winch 30 is located at the base end of the box mast 21. The mast hoisting winch 30 winds in and pays out the mast hoisting rope 26. The winding and paying out operation of the mast hoisting 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, causing the box mast 21 and lattice mast 17 to rotate together relative to the upper rotating body 12, raising and lowering the lattice mast 17.

In addition to the mast hoist winch 30 and boom hoist winch 38 mentioned 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 of this embodiment, the main hoist winch 34 and auxiliary hoist winch 36 are both installed on the lower boom 16A of the boom 16. The winches 34 and 36 of the crane 10 may also be mounted on the upper rotating body 12.

The main hoisting winch 34 hoists and lowers a load using a main hoisting rope 51 (Figure 1). For this main hoisting, a main hoisting guide sheave (not shown) is rotatably mounted at the boom tip 16Q of the boom 16. Furthermore, a main hoisting sheave block, with multiple main hoisting point sheaves arranged in the width direction, is mounted adjacent to the main hoisting guide sheave. A main hook 53 for the load is connected to the main hoisting rope 51 hanging down from the main hoisting sheave block. The main hoisting rope 51 pulled out from the main hoisting winch 34 is then hooked onto 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.

Similarly, the auxiliary winch 36 hoists and lowers the load using the auxiliary hoisting rope 52. This auxiliary hoisting is equipped 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, the auxiliary hook for the load (not shown), which is connected to the end of the auxiliary hoisting rope 52, is hoisted or lowered.

A counterweight 40 is mounted on the rear of the upper rotating body 12 to adjust the balance of the crane 10, and a pallet weight 41 is also located behind the upper rotating body 12. The pallet weight 41 serves as a SHL (Super Heavy Lifting) weight that allows 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.

Figure 2 is a side view of the lower boom 16A, boom support 45, and boom stop 70 when the boom 16 of the crane 10 according to this embodiment is in a lowered position. Figure 3 is a side view of the lower boom 16A (boom 16) and upper rotating body 12 of the crane 10 according to this embodiment. Figure 4 is a rear view of the boom support receiver 121 of the crane 10 according to this embodiment.

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.

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. As shown in FIG. 2 and other figures, they extend from near the boom foot 16S toward the tip of the lower boom 16A so that the spacing between them increases. The lower frame 160 is a plate-shaped 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 multiple lattice pipes 165 connect the first main pipe 161 and the second main pipe 162, the left and right pairs of first main pipes 161, and the left and right pairs of second main pipes 162 to each other at multiple locations.

Furthermore, the lower boom 16A has a pair of left and right boom support supports 161S. The pair of left and right boom support supports 161S are arranged on the first main pipe 161 (the back surface of the lower boom 16A) at a position closer to the tip of the boom foot 16S, more specifically, closer to the tip of the longitudinal center of the lower boom 16A. The boom support support parts 161S support the boom support base end 452S of the boom support 45 described below.

The crane 10 further includes a pair of left and right boom supports 45 (support members) and a pair of left and right boom stops 70 (restraining members). Note that the left and right structures of these members are the same, so the following description will focus on the structure of the right side.

The boom support 45 is attached to the lower boom 16A. When the boom 16 reaches the upright position (working position) shown in FIG. 1 relative to the upper rotating body 12, the boom support 45 abuts against the upper rotating body 12, thereby interposing itself between the boom 16 and the upper rotating body 12 and supporting the boom 16 from the rear. The boom support 45 is also extendable and has the function of pushing the boom 16 forward, i.e., in an inverted direction, when the crane 10 is disassembled.

As shown in FIG. 2, the boom support 45 is disposed on the first main pipe 161. The boom support 45 has a lower boom support 451 (also referred to as an inner cylinder), an upper boom support 452 (also referred to as an outer cylinder), and a boom support spring 453 (spring member). The lower boom support 451 and the upper boom support 452 have a cylindrical structure, with the lower boom support 451 inserted into the cylindrical interior of the upper boom support 452 so as to be able to expand and contract. The boom support spring 453 is contractibly mounted between flanges F ( FIG. 2 ) provided on the lower boom support 451 and the upper boom support 452, respectively. The boom support spring 453 is disposed between the lower boom support 451 and the upper boom support 452, and can contract between a predetermined maximum spring length (free length) and a predetermined minimum spring length. When the boom support spring 453 is at its maximum spring length, the boom support 45 is at its maximum length, and when the boom support spring 453 is at its minimum spring length, the boom support 45 is at its minimum length.

The lower boom support 451 has a boom support abutment portion 451S, and the upper boom support 452 has a boom support base end portion 452S. The boom support base end portion 452S corresponds to the base end portion of the boom support 45, and the boom support abutment portion 451S corresponds to the tip end portion of the boom support 45 opposite the boom support base end portion 452S. The boom support abutment portion 451S has a bifurcated protrusion (Figure 4). The boom support base end portion 452S is rotatably supported (attached) to a boom support support portion 161S (Figure 2) that is located closer to the tip end portion (boom tip portion 16Q) of the lower boom 16A than the boom foot 16S.

The crane 10 also has a support column 60. The support column 60 is connected to a fixed portion 65 located on the first main pipe 161 and to a supported portion 452T located on the boom support upper portion 452 by connecting pins (not shown). As a result, the boom support 45 is in an upright position as shown in Figure 2. When the support column 60 is removed, for example when disassembling the crane 10, the boom support 45 can be lowered to a position closer to the first main pipe 161 than in Figure 2, directly above the boom stop 70.

The boom support 45 described above is positioned between the boom 16 and the upper rotating body 12 when the boom 16 is in an upright position relative to the upper rotating body 12 and the boom support spring 453 is compressed, and supports the boom 16 from behind while applying a forward biasing force to the boom 16.

The boom stop 70 is positioned between the upper rotating body 12 and the boom 16 when the boom 16 is in an upright position and the length of the boom support spring 453 of the boom support 45 is contracted to a predetermined length between the maximum spring length and the minimum spring length (when the length of the boom support 45 is a predetermined restricted length between the maximum length and the minimum length), and receives the load (dead weight) of the boom 16 to prevent the boom 16 from tipping backward.

The boom stop 70 is disposed on the first main pipe 161, similar to the boom support 45. Specifically, a boom stop support portion 166 is disposed on the first main pipe 161 near the boom foot 16S. The boom stop 70 extends (protrudes) from the boom stop support portion 166 in approximately the same direction as the boom support 45 in an upright position. The boom stop 70 has a boom stop abutment portion 70S and a boom stop base end portion 70H. The boom stop abutment portion 70S corresponds to the tip end of the boom stop 70. Note that the boom stop abutment portion 70S also has a bifurcated protrusion similar to the boom support abutment portion 451S. The boom stop base end portion 70H is the base end of the boom stop 70 opposite the boom stop abutment portion 70S, and is fixed to the boom stop support portion 166.

Referring to Figure 3, the upper rotating body 12 includes a rotating frame 120. The rotating frame 120 is supported by the lower running body 14 so that it can rotate. The rotating frame 120 is a member that extends in the front-rear and left-right directions, and is, for example, made of a frame made of joined steel members.

The upper rotating body 12 further has a pair of left and right boom foot support portions 12S, a pair of left and right boom support receiving portions 121, a pair of left and right box-shaped supports 122, a pair of left and right boom stop receiving portions 123 (restriction member receiving portions), and a pair of left and right mast support portions 124.

A pair of left and right boom foot supports 12S rotatably support the boom foot 16S of the boom 16. Each boom foot support 12S has a pin hole that penetrates 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 turn, allowing the boom 16 to be supported on the upper rotating body 12 so that it can be raised and lowered.

A pair of left and right boom support receivers 121 are fixed to the revolving frame 120 behind the boom foot support 12S. Each boom support receiver 121 is a U-shaped receiver that opens forward and upward. Each boom support receiver 121 receives (supports) the boom support abutment 451S of the boom support 45. As shown in Figure 4, the boom support receivers 121 are positioned so that they protrude outward from the revolving frame 120 to the left and right. As a result, interference between the boom support 45 and the winch 30 (Figure 1) and other devices positioned in the left and right central section (center section) of the upper revolving body 12 is prevented.

A pair of left and right supports 122 are arranged on the swivel frame 120 immediately rearward of the boom foot support 12S. Each support 122 is a box-shaped member having an upper surface, a lower surface opposite the upper surface, right and left sides connecting the upper and lower surfaces, and a front and rear surface. The lower surface and the inner left and right sides of the supports 122 are supported by the swivel frame 120. This box-like shape of the supports 122 increases the rigidity and strength of the supports 122 compared to when the supports 122 are made of a single plate material. Like the swivel frame 120, the supports 122 are also made of steel.

The pair of left and right boom stop receiving portions 123 are fixed to the upper surface of the support body 122 and are U-shaped receiving portions that open forward and upward. Each boom stop receiving portion 123 has the function of receiving the boom stop abutment portion 70S of the boom stop 70 (described below).

The pair of left and right mast support sections 124 are part of the revolving frame 120 and are positioned above the support body 122. Each mast support section 124 rotatably supports the mast base end section 17P (Figure 1) of the lattice mast 17. Each mast support section 124 has a pin hole 124H.

In the state shown in Figure 2, when the intermediate booms 16B, 16C, 16D, and upper boom 16E (Figure 1) are connected in this order to the lower boom 16A to form the boom 16, the lattice mast 17 pulls the boom 16 via the guy lines 20, causing the boom 16 to rise relative to the upper rotating body 12. As shown in Figure 3, when the angle θ between the center line of the boom 16 and the horizontal line reaches, for example, 85 degrees, the boom support abutment 451S of the boom support 45 first abuts against the boom support receiver 121, and the boom support spring 453 begins to contract. When the boom support spring 453 contracts to a predetermined length, the boom 16 rises to the angle required for normal operation. At this time, the boom stop abutment 70S of the boom stop 70 does not abut against the boom stop receiver 123.

On the other hand, if the boom 16 is blown backward by a strong wind or the like while the crane 10 is operating and the angle θ of the boom 16 reaches, for example, 90 degrees (maximum angle), the boom stop abutment portion 70S of the boom stop 70 abuts against the boom stop receiving portion 123. As a result, the boom stop 70 is positioned between the upper rotating body 12 and the boom 16 while receiving the maximum load (maximum reaction force) of the boom 16, preventing the boom 16 from tipping backward.

At this time, the boom support spring 453 of the boom support 45 has not contracted to its minimum length. In other words, the boom support 45 has not bottomed out. This prevents the large weight (load) of the boom 16 from being applied to the boom support 45 and the boom support receiving portion 121. Furthermore, once the strong winds around the crane 10 subside, the boom 16 is pushed back by the biasing force of the boom support spring 453, and the boom stop abutment portion 70S moves away from the boom stop receiving portion 123.

On the other hand, when the boom hoist winch 38 (see Figure 1) pays out the boom hoist rope 22 during disassembly of the crane 10, the boom 16 begins to collapse forward. At this time, the elastic energy of the boom support spring 453 of the boom support 45 is released, and the boom support 45 exerts a force pushing the boom 16 forward. As a result, the boom 16, which is a heavy object, can be guided into a collapsed position.

As described above, in this embodiment, the crane 10 includes a boom support 45 and a boom stop 70. The boom stop 70 prevents the boom 16 from tipping backward before the boom support spring 453 of the boom support 45 retracts to its minimum length. Therefore, the boom support 45, including the boom support spring 453, only needs to generate a force to push back the boom 16 when the crane is disassembled, preventing the boom support 45 from bearing the maximum load of the boom 16. As a result, even if the boom 16's wind-receiving area increases due to an increase in the length of the boom 16 or an increase in the number of accessories attached to the boom 16, the boom 16 can be reliably prevented from tipping over due to strong winds during normal operation and can be pushed back in an inverted direction when the crane is disassembled. Furthermore, the boom support spring 453 of the boom support 45 can be designed based on the push-back force, thereby reducing its size and cost. As a result, the outer diameter and plate thickness of the lower boom support 451 and upper boom support 452 of the boom support 45 can be reduced compared to when the boom support 45 bears the maximum load of the boom 16. Furthermore, if it is necessary to detect the reaction force received by the boom support 45 using a load cell (not shown), the capacity of the load cell can also be reduced.

In addition, in this embodiment, the boom stop 70 is positioned between the boom support 45 and the boom foot 16S when viewed from a direction parallel to the rotation center axis, so as to be interposed between the upper rotating body 12 and the boom 16. In this way, the boom stop 70 is positioned closer to the boom foot 16S than the boom support 45, which reliably prevents the boom 16 from tipping backward and more reliably prevents the maximum load of the boom 16 from being applied to the rear boom support 45.

In addition, unlike conventional backstops, this embodiment does not use a single component to both prevent the boom 16 from tipping backward and push the boom 16 forward. This reduces the need to significantly increase the rigidity and strength of this single component, even if the wind-receiving area of the boom 16 increases. Furthermore, because the boom supports 45 and boom stops 70, each with a predetermined size and strength, are dispersedly positioned on the revolving frame 120, it is possible to increase the degree of freedom in the placement of components on the revolving frame 120. Furthermore, the structure of the boom support receiver 121 can be simplified compared to a backstop receiver that receives the tip of a conventional backstop. Furthermore, in this embodiment, the boom stop 70 does not need to be rotatably supported by the boom support support part 161S, and the relative angle of the boom stop 70 with respect to the lower boom 16A may be constant.

Furthermore, in this embodiment, when the boom 16 is in the upright position and the length of the boom support 45 is set to the regulated length, the boom stop abutment portion 70S abuts against the boom stop receiving portion 123, causing the boom stop 70 to receive the load of the boom 16. In this way, the boom stop receiving portion 123 provided on the upper rotating body 12 receives the boom stop abutment portion 70S, thereby reliably preventing the boom 16 from tipping over due to strong winds during normal operation, etc.

In particular, in this embodiment, the boom stop receiving portion 123 is disposed on the support body 122, which has high strength to rotatably support the boom foot 16S, which further stably prevents the boom 16 from tipping over due to strong winds during normal operation.

Furthermore, in this embodiment, the boom stop support portion 166 is positioned 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 boom stop 70 and other components positioned at the tip of the lower boom 16A, such as the winches 34 and 36 in Figure 1. As a result, even when the lower boom 16A supports the boom stop 70, the degree of freedom in the layout of component placement on the lower boom 16A can be increased.

The above describes a crane 10 according to one embodiment of the present invention. However, the present invention is not limited to these embodiments. The following modified embodiments are possible with the present invention.

(1) The present invention is not limited to the above-described embodiments. Figure 5 is a side view of the boom 16 and upper rotating body 12 of the crane 10 according to a modified embodiment of the present invention. In the above-described embodiment, the boom stop receiving portion 123 that receives the boom stop 70 is disposed on the support body 122, but the present invention is not limited to this. In the embodiment shown in Figure 5, the boom stop receiving portion 125 is disposed on the mast support portion 124 provided at the front end of the rotating frame 120.

Meanwhile, the boom stop 80 is supported by a boom stop support portion 167 provided on the lower boom 16A. As the boom 16 is raised, the boom stop abutment portion 80S of the boom stop 80 abuts against and is received by the boom stop receiving portion 125.

In this modified embodiment, the boom stop 80 can also prevent the boom 16 from tipping backward before the boom support spring 453 of the boom support 45 retracts to its minimum length. Therefore, the boom support 45, including the boom support spring 453, only needs to generate a force to push back the boom 16 when the crane is disassembled, preventing the boom support 45 from being subjected to the maximum load of the boom 16. As a result, even if the wind-receiving area of the boom 16 increases due to an increase in the length of the boom 16 or an increase in the number of accessories attached to the boom 16, it is possible to reliably prevent the boom 16 from tipping over due to strong winds during normal operation and to push back the boom 16 in an upside-down direction when the crane is disassembled, without increasing the strength or cost of the boom support spring 453.

In addition, in this modified embodiment, the boom stop receiving portion 125 is disposed on the mast support portion 124, which has high strength to support the mast base end portion 17P of the lattice mast 17, and this further stably prevents the boom 16 from tipping over due to strong winds during normal operation. Furthermore, in the case of the boom stop 80, its length can be shortened compared to the boom stop 70 described above.

On the other hand, in the case of the boom stop 70 described above, the abutment portion between the boom stop abutment portion 70S and the boom stop receiving portion 123 is located at the same position as both ends of the lower boom 16A in the left-right direction, making it easy to position the boom stop support portion 166 on the first main pipe 161. In contrast, the boom stop support portion 167 (Figure 5) that supports the boom stop 80 may be located on a second connecting pipe (not shown) that connects the left and right first main pipes 161 (Figure 2) together in the left-right direction. Furthermore, in another embodiment, the crane 10 may be equipped with both the boom stop 70 and boom stop 80 described above in addition to the boom support 45.

(2) 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, rather than the SHL structure. In this case, the sheave block may not be provided, and the tip of the box mast and the tip of the boom may be directly connected by a guy link. Furthermore, both general-purpose cranes and large cranes may have a jib or strut attached to the tip of the boom.

(3) In the above embodiments, the boom support 45 has a boom support spring 453, and the length of the boom support 45 changes as the boom support spring 453 contracts. However, the present invention is not limited to this. As an example, the boom support 45 may have a hydraulic cylinder structure that expands and contracts under hydraulic pressure. In this case, the lower boom support 451 constitutes the cylinder body of the hydraulic cylinder, and the upper boom support 452 constitutes the cylinder rod of the hydraulic cylinder. The cylinder rod has a piston portion and divides the cylinder body into a head chamber and a rod chamber. When hydraulic oil is received in the head chamber and discharged from the rod chamber, the cylinder rod extends relative to the cylinder body. When hydraulic oil is received in the rod chamber and discharged from the head chamber, the cylinder rod contracts relative to the cylinder body. In the above configuration, the lower boom support 451 may constitute the cylinder rod of the hydraulic cylinder, and the upper boom support 452 may constitute the cylinder body of the hydraulic cylinder.

Even with this configuration, the boom stop 70 receives the load of the boom 16 before the boom support 45 hydraulically retracts to its minimum length (before it bottoms out), preventing a large load from being applied to the boom support 45. This reduces the need to expand the cylinder diameter or rod diameter of the hydraulic cylinder-configured boom support 45 to support a large load. It also reduces the need to install equipment and piping within the hydraulic circuit that can withstand large pressures.

10 Crane 12 Upper rotating body (crane body)
120 Swing frame 121 Boom support receiving portion 122 Support body (support frame)
123, 125 Boom stop receiving portion (restriction member receiving portion)
124 Mast support portion 124H Mast foot support portion 12S Boom foot support portion 16 Boom (elevating body)
160 Lower frame 161 First main pipe 161S Boom support support portion 162 Second main pipe 163 First connecting pipe 165 Lattice pipe 166 Boom stop support portion 167 Boom stop support portion 16A Lower boom (lower member of the boom raising body)
16S Boom foot (elevating body support part)
17 Lattice mast (mast)
17P Mast base end 45 Boom support (support member)
451 Boom support lower part 451S Boom support abutment part 452 Boom support upper part 452S Boom support base end part 452T Supported part 453 Boom support spring 60 Support column 65 Fixing parts 70, 80 Boom stop (restricting member)
70H, 80H Boom stop base end (base end of restricting member)
70S, 80S Boom stop contact part (tip of restricting member)

Claims (7)

The crane body,
a hoisting body including a hoisting body fulcrum supported by the crane body so as to be rotatable in a hoisting direction around a horizontal rotation center axis;
a support member having an outer tube and an inner tube inserted into the outer tube, which is extendable between a maximum length and a minimum length, and which is interposed between the derricking body and the crane body when the derricking body is in an upright position relative to the crane body, and which applies a forward biasing force to the derricking body while supporting the derricking body from the rear;
a restricting member that is interposed between the crane body and the rafter and receives the load of the rafter so as to restrict the rafter from tipping backward when the rafter is in the upright state and the length of the support member is set to a predetermined restricted length between the maximum length and the minimum length;
Equipped with
The crane body has a support member receiving portion and a regulating member receiving portion,
The support member has a support member base end portion rotatably supported on the undulating body and a support member abutment portion opposite to the support member base end portion,
a crane in which the regulating member is fixed to the derricking body so that when the derricking body is raised to an angle during normal operation at which the support member abutment portion abuts the support member receiving portion, the regulating member does not abut the regulating member receiving portion, and when the derricking body rotates further rearward from the angle during normal operation, the regulating member abuts the regulating member receiving portion when the length of the support member is set to the specified regulating length . The support member further includes a spring member disposed between the outer tube and the inner tube and capable of contracting between a maximum spring length and a minimum spring length, and when the rafter is in an upright position and the spring member is contracted below the maximum spring length, the support member is disposed between the rafter and the crane body and applies a forward biasing force to the rafter, supporting the rafter from behind;
2. The crane according to claim 1, wherein the regulating member is interposed between the crane body and the rafter and receives the load of the rafter so as to prevent the rafter from tipping backward when the rafter is in the upright state and the length of the spring member has contracted to a length between the maximum spring length and the minimum spring length and the length of the support member is set to the regulating length. The crane described in claim 2, wherein the restricting member is positioned between the crane body and the hoist, between the support member and the hoist fulcrum, when viewed in a direction parallel to the central axis of rotation. The crane body,
a hoisting body including a hoisting body fulcrum supported by the crane body so as to be rotatable in a hoisting direction around a horizontal rotation center axis;
a support member having an outer tube and an inner tube inserted into the outer tube, which is extendable between a maximum length and a minimum length, and which is interposed between the derricking body and the crane body when the derricking body is in an upright position relative to the crane body, and which applies a forward biasing force to the derricking body while supporting the derricking body from the rear;
a restricting member that is interposed between the crane body and the rafter and receives the load of the rafter so as to restrict the rafter from tipping backward when the rafter is in the upright state and the length of the support member is set to a predetermined restricted length between the maximum length and the minimum length;
Equipped with
The support member further includes a spring member disposed between the outer tube and the inner tube and capable of contracting between a maximum spring length and a minimum spring length, and when the rafter is in an upright position and the spring member is contracted below the maximum spring length, the support member is disposed between the rafter and the crane body and applies a forward biasing force to the rafter, supporting the rafter from behind;
the regulating member is interposed between the crane body and the hoisting body and receives the load of the hoisting body so as to regulate the hoisting body from tipping backward when the hoisting body is in the upright state and the length of the spring member is contracted to a length between the maximum spring length and the minimum spring length and the length of the support member is set to the regulated length;
the regulating member has a regulating member base end supported on the undulating body and a regulating member tip end opposite to the regulating member base end, and is disposed so as to protrude from the undulating body;
The crane body has a regulating member receiving portion capable of receiving the tip end of the regulating member,
A crane in which, when the elevation body is in the upright position and the length of the spring member is set to the regulated length, the tip of the regulating member abuts against the regulating member receiving portion, thereby causing the regulating member to receive the load of the elevation body. The crane body is
A rotating frame;
a support frame including a hoist support portion disposed at a front end of the swivel frame and rotatably supporting the hoist support portion;
and
The crane according to claim 4 , wherein the restricting member receiving portion is disposed on the support frame. The crane further includes a mast having a mast base end portion rotatably supported on the crane body at the rear of the hoisting body, and supporting the hoisting body from the rear,
The crane body has a rotating frame,
the rotating frame has a mast support portion that rotatably supports the mast base end portion,
The crane according to claim 4 , wherein the restricting member receiving portion is disposed on the mast support portion. 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,
A crane according to any one of claims 4 to 6, wherein the base end of the regulating member is supported by a portion of the lower member of the elevation structure that is closer to the elevation structure fulcrum portion than the longitudinal center of the lower member of the elevation structure.