JP2022190553A - Backstop posture changing device for crane - Google Patents

Abstract

To provide a backstop posture changing device for a crane that easily and safely changes the posture of a backstop of a crane between a supporting posture and a retracted posture.SOLUTION: A backstop lifting device 60 includes a first arm 61, a second arm 62, a lifting cylinder 66 and a stopper 63. The first arm 61 and the second arm 62 are rotatably connected to a backstop and a lower boom, respectively. When a cylinder rod 662 of the lifting cylinder 66 is extended against a cylinder body 661, a push-up member 67 pushes up the first arm 61, expanding the relative angle between the first arm 61 and the second arm 62, and the backstop changes its posture from a retracted posture on the lower boom to a supporting posture that can support the boom. An arm fixing pin P2 of the stopper 63 engages with an engagement groove 621D of a guide groove portion 621B, and the postures of the first arm 61 and the second arm 62 are held.SELECTED DRAWING: Figure 8

Description

The present invention relates to a crane backstop attitude changing device.

2. Description of the Related Art Conventionally, as a crane, a crane is known that includes a crane main body and undulating bodies such as a boom, a jib and a mast. The hoisting body is supported by the crane body so that it can be hoisted around a horizontal central axis of rotation. Further, such a crane is known to further include a pair of left and right backstops interposed between the hoisting body and the crane body in order to prevent the hoisting body from falling backward. Each backstop is telescopic, and its base end is rotatably supported by the undulating body. When the crane is assembled, each backstop is in a supporting position that intersects the back surface of the undulating body and supports the undulating body. When the undulating body is erected with respect to the crane body while each backstop is in the supporting posture, the leading end of each backstop eventually comes into contact with the backstop receiving portion provided on the crane body. As a result, the pair of backstops supports the hoisting body, preventing further rotation of the hoisting body, that is, preventing it from collapsing backward.

On the other hand, when the crane is transported or stored, each of the backstops as described above is rotated about its base end portion as a fulcrum, and placed in a retracted posture so as to overlap the back surface of the undulating body. As a result, less space is required for the relief on the transport vehicle or in the storage area.

Patent Document 1 discloses a tower boom, a rear post rotatably supported at the tip of the tower boom, and a backstop cylinder interposed between the tower boom and the rear post to maintain the posture of the rear post. and a crane is disclosed. The crane further includes a cylinder holding device that supports the backstop cylinder so that the backstop cylinder can change its posture between a supporting posture and a retracted posture. The cylinder holding device includes a first link connected to the central portion of the backstop cylinder, a second link connected to the rear post, and a coupler connecting the first link and the second link to each other. have The first link and the second link can bend and extend with respect to each other with the connector as a fulcrum, and the posture of the backstop cylinder can be changed by the bending and stretching motion of the links.

Japanese Patent Application Laid-Open No. 2007-290782

In the technique described in Patent Document 1, when the crane is assembled, the operator rotates the backstop cylinder so that the tip of the backstop cylinder, which is in a retracted posture in advance, is separated from the rear post. changes position to the support position. At this time, the cylinder holding device follows the rotation of the backstop cylinder, and the first link and the second link extend relative to each other with the connector serving as a fulcrum. When the crane is disassembled, contrary to the above, the operator rotates the backstop cylinder so that the tip of the backstop cylinder in the supporting posture approaches the rear post, and the backstop cylinder is in the retracted posture. change. As described above, in this technology, since the posture of the backstop cylinder is manually changed, it has been desired to reduce the burden on workers and improve safety in assembling and disassembling cranes.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a crane backstop posture changing device capable of easily and safely changing the posture of a crane backstop between a supporting posture and a retracted posture. for the purpose.

Provided by the present invention is a crane backstop reorientation device. The backstop posture changing device includes a crane body, a base end portion of the elevating body supported by the crane body so as to be rotatable in the elevating direction, and a tip end portion of the elevating body on the side opposite to the base end portion of the elevating body. an undulating body, a backstop base end portion supported rotatably about a horizontal reference rotation center axis at a portion of the undulating body closer to the tip end portion of the undulating body than the base end portion of the undulating body, and the backstop; It is attachable to a crane having a backstop including a proximal end and a backstop distal end located opposite the proximal end. The backstop posture changing device can change the posture of the backstop between a supporting posture and a retracted posture by rotating the backstop with the backstop base end as a fulcrum. The supporting posture is a posture in which the backstop can restrict the undulating body from falling backward. On the other hand, the retracted posture is a posture in which the tip of the backstop of the backstop is arranged at a position closer to the undulating body than the support posture. In addition, the backstop posture changing device of the crane includes a first base end portion connected to the backstop so as to be rotatable about a first rotation center axis parallel to the reference rotation center axis; a first support member having a first pivoting end opposite to the base end and a pushed portion disposed between the first base end and the first pivoting end; a second proximal end portion rotatably connected to the undulating body; and a second rotating end portion connected so as to be relatively rotatable about an intermediate rotation center axis parallel to the rotation center axis, wherein the second support member is connected to the second rotation center axis. A first straight line connecting the first rotation center axis and the intermediate rotation center axis and a second straight line connecting the second rotation center axis and the intermediate rotation center axis are arranged so as to form a first angle. While the backstop is in the supporting posture together with the first supporting member, the first straight line and the second straight line are arranged to form a second angle that is acute and smaller than the first angle. a second support member that allows the backstop to be in the retracted posture together with the first support member; and a push-up that is interposed between the first support member and the second support member A mechanism comprising a cylindrical cylinder body, a cylinder rod inserted into the cylinder body so as to be able to expand and contract with respect to the cylinder body, and the cylinder rod extending with respect to the cylinder body. a push-up member capable of pushing up the pushed portion of the first support member so as to rotate the first support member relative to the second support member about the intermediate rotation center axis; a connecting member rotatably supported by one of the first supporting member and the second supporting member; and one of the first supporting member and the second supporting member. and a guide groove disposed in the other support member different from the one support member. The connection member has a connection member base end supported by the one support member so as to be rotatable about a third rotation center axis parallel to the reference rotation center axis, and a side opposite to the connection member base end. and a connecting shaft arranged in and extending parallel to the reference rotation center axis. The guide groove is a main guide groove that extends along the longitudinal direction of the other support member and movably receives the connecting shaft, and the guide groove is a main guide groove that movably receives the connecting shaft as the cylinder rod contracts with respect to the cylinder main body. a groove base end portion for receiving the connecting shaft; and a groove distal end portion disposed opposite to the groove base end portion for receiving the connecting shaft as the cylinder rod extends with respect to the cylinder body. a main guide groove and an engaging groove extending so as to intersect the main guide groove and communicating with the groove tip portion of the main guide groove, wherein the cylinder rod extends with respect to the cylinder body. an engaging groove is formed to receive the connecting shaft that has passed through the groove tip portion and to engage with the connecting shaft so as to hold the backstop in the supporting posture.

According to this configuration, when the cylinder rod of the push-up mechanism extends with respect to the cylinder main body from the state where the backstop is in the retracted posture on the undulating body, the push-up member pushes up the push-up portion of the first support member, thereby pushing up the first support member. The support member can be rotated relative to the second support member to change the posture of the backstop to the support posture. Therefore, it is easier and safer to change the posture of the backstop of the crane from the storage posture to the support posture compared to the case where the posture of the backstop is changed by other auxiliary cranes or the posture of the backstop is changed manually by the operator. It is possible to Further, when the backstop is in the supporting posture, the connecting member connects the first supporting member and the second supporting member to each other, and the relative posture of both members can be maintained. Even if the weight is applied to the backstop, application of a large force to the cylinder portion of the push-up mechanism is suppressed, and damage to the cylinder portion is suppressed. Furthermore, when the first support member extends relative to the second support member as the cylinder of the push-up mechanism expands and contracts, the connecting shaft of the connecting member engages with the engagement groove of the guide groove, thereby supporting the backstop. Can be held in position. Therefore, it is not necessary for the operator to attach pins for connecting the first support member and the second support member to each other at a high place. Therefore, it is possible to improve the work efficiency of the worker in the assembly and disassembly work of the crane, and reduce the work load.

In the above configuration, the guide groove is further formed with a sub-guide groove communicating with the groove tip portion of the main guide groove on the side opposite to the engagement groove, further comprising a restrictor, When the cylinder rod extends with respect to the cylinder main body while the connecting shaft is engaged with the engaging groove, the connecting shaft moves from the engaging groove to the auxiliary guide through the groove tip. It is arranged to face the groove tip of the main guide groove so as to allow the connecting shaft to enter the groove, but to restrict the connecting shaft, which has entered the sub-guide groove, from entering the engaging groove. It is desirable that

According to this configuration, when the posture of the backstop is changed from the supporting posture to the retracted posture, the restrictor restricts the connecting shaft from re-entering the engaging groove after being separated from the engaging groove. It can be guided to the groove base end side of the guide groove. Therefore, even if an engaging groove extending in a direction different from that of the main guide groove is provided to hold the backstop in the supporting posture, the posture of the backstop can be easily and reliably changed.

In the above configuration, the restrictor has a guide plate and an urging member that urges the guide plate toward the end of the connecting shaft, and the guide plate is configured so that the connecting shaft engages with the connecting shaft. When the connecting shaft moves from the engaging groove toward the tip of the groove due to the extension of the cylinder rod with respect to the cylinder body in a state of being engaged with the matching groove, the end portion of the connecting shaft It is inclined with respect to the axial direction of the connecting shaft so as to allow the connecting shaft to climb over the guide plate and enter the groove tip portion while contracting the biasing member by the force received from the connecting shaft. and a restricting surface disposed on the opposite side of the inclined surface and abutting against the connecting shaft so as to restrict the connecting shaft from entering the engaging groove.

According to this configuration, the connecting shaft can be reliably guided in the appropriate direction by the structure of the restricting tool including the inclined surface and the restricting surface.

In the above configuration, the first support member and the undulating body can be connected to each other so that the backstop is held in the retracted posture when the cylinder rod is contracted with respect to the cylinder body. It is desirable to further provide a storage connection.

According to this configuration, it is possible to maintain the relative posture of the first support member and the second support member in the retracted posture of the backstop, and the backstop does not spring up from the derricking body when the derricking body is transported. is prevented.

In the above configuration, the storage connecting portion is supported by one structure of the first support member and the undulating body, and is spaced apart from each other in a direction parallel to the reference rotation center axis. a pair of retracting engagement pins each including pin tip portions arranged in the same direction as each other; an urging portion; and an engaging portion disposed on a structure other than the one of the first support member and the undulating body, wherein the cylinder rod is engaged with the cylinder main body. and the backstop changes its posture from the supporting posture to the retracted posture, and when the engaging portion enters between the tip end portions of the pair of pins, the pair of retracting engaging pins is attached to the pin. While contracting the force portion, the pair of pin tip end portions can be engaged with the engaging portions, respectively, and the engaging portions are contracted by the thrust of the cylinder rod extending with respect to the cylinder main body. detached from the pin tip of the undulator and allowed to move upwardly relative to the undulator.

According to this configuration, since the first support member can be automatically attached to and detached from the undulating body, an operator attaches a pin for connecting the first supporting member and the undulating body to each other at a high place. you don't have to.

In the above configuration, with the connecting member holding the relative posture between the first supporting member and the second supporting member, the push-up portion moves along with the contraction of the cylinder rod with respect to the cylinder body. can be separated from the pushed part.

According to this configuration, the cylinder rod can be accommodated in the cylinder body while the backstop is in the supporting posture. Therefore, even if the weight of the undulating body is applied to the backstop during crane operation, application of a large force to the cylinder portion of the lifting mechanism is suppressed, and damage to the cylinder portion is suppressed. Furthermore, it is possible to prevent the cylinder rod from being left for a long period of time in a state in which it is extended from the cylinder body, thereby preventing the cylinder rod from being rusted.

ADVANTAGE OF THE INVENTION According to this invention, the backstop attitude|position change apparatus of the crane which can change the attitude|position of the backstop of a crane easily and safely between a support attitude|position and a storage attitude|position is provided.

1 is a side view of a crane according to a first embodiment of the invention; FIG. FIG. 4 is a plan view of a lower boom and a backstop of the crane according to the first embodiment of the present invention in a state in which the boom is laid down; Fig. 2 is a side view of the lower boom and backstop of the crane according to the first embodiment of the present invention in a state in which the boom is in a laid down posture, and is a side view in a state in which the backstop is in a retracted posture by the backstop posture changing device; is. FIG. 5 is a side view of the crane according to the first embodiment of the present invention in which the backstop is in a supporting posture by the backstop posture changing device; FIG. 4 is a side view of the crane according to the first embodiment of the present invention, in which the backstop is set to a supporting posture by the backstop posture changing device and the boom is erected; FIG. 4 is a side view showing the appearance of the backstop attitude changing device in a state where the backstop is in the retracted attitude in the crane according to the first embodiment of the present invention; Fig. 7 is a side cross-sectional view of the backstop repositioning device of Fig. 6; FIG. 4 is a side view showing a state in which the telescopic cylinder of the backstop position changing device is extended from the state in which the backstop is in the retracted position in the crane according to the first embodiment of the present invention; FIG. 4 is a side view showing the appearance of the backstop posture changing device in a state where the backstop is in a supporting posture in the crane according to the first embodiment of the present invention; FIG. 10 is a side view showing how the telescopic cylinder of the backstop posture changing device contracts from the state of FIG. 9 ; FIG. 4 is a side view showing the state of the backstop posture changing device when the backstop is changed from the supporting posture to the retracted posture in the crane according to the first embodiment of the present invention; FIG. 4 is a side view showing the state of the backstop posture changing device when the backstop is changed from the supporting posture to the retracted posture in the crane according to the first embodiment of the present invention; FIG. 4 is a side view showing the state of the backstop posture changing device when the backstop is changed from the supporting posture to the retracted posture in the crane according to the first embodiment of the present invention; FIG. 10 is a cross-sectional view of the backstop attitude changing device of FIG. 9 taken along arrows XIV-XIV; 11 is a cross-sectional view showing how the connecting shaft moves from the state shown in FIG. 10; FIG. FIG. 17 is a cross-sectional view showing how the connecting shaft moves from the state shown in FIG. 16; 18 is a cross-sectional view showing how the connecting shaft moves from the state shown in FIG. 17; FIG. FIG. 19 is a sectional view showing how the connecting shaft moves from the state shown in FIG. 18; FIG. 7 is a cross-sectional view of the backstop attitude changing device of FIG. 6 taken along the arrow XIX-XIX; FIG. 11 is a side view showing the appearance of the backstop attitude changing device in a state where the backstop is in the retracted attitude in the crane according to the second embodiment of the present invention; FIG. 11 is a side view showing how the telescopic cylinder of the backstop position changing device extends from the state in which the backstop is in the retracted position in the crane according to the second embodiment of the present invention. FIG. 11 is a side view showing the state of the backstop attitude changing device in a state where the backstop is in the supporting attitude in the crane according to the second embodiment of the present invention; FIG. 23 is a side view showing how the telescopic cylinder of the backstop posture changing device contracts from the state of FIG. 22 ; FIG. 10 is a side view showing the state of the backstop posture changing device when the backstop is changed from the supporting posture to the retracted posture in the crane according to the second embodiment of the present invention; FIG. 10 is a side view showing the state of the backstop posture changing device when the backstop is changed from the supporting posture to the retracted posture in the crane according to the second embodiment of the present invention; FIG. 10 is a side view showing the state of the backstop posture changing device when the backstop is changed from the supporting posture to the retracted posture in the crane according to the second embodiment of the present invention;

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 (working machine) according to one embodiment of the present invention. Hereinafter, directions such as "up", "down", "front" and "rear" are shown in each figure, and the directions are the same as the structure and assembly method of the crane 10 according to the present embodiment. , and does not limit the moving direction of the crane or the manner of use of the backstop position changing device according to the present invention.

The crane 10 includes an upper revolving body 12 corresponding to a crane main body, a lower traveling body 14 that supports the upper revolving body 12 so as to be able to revolve and can travel on the ground G, and a boom 16 that functions as an elevating body. a backstop 45, a lattice mast 17 which is a boom hoisting member, and a box mast 21.

The boom 16 has a boom base end 16P (elevating body base end) supported by the upper rotating body 12 so as to be rotatable in the hoisting direction, and a boom arranged on the opposite side of the boom base end 16P in the longitudinal direction. and a tip portion 16Q (tip portion of the undulating body). In this embodiment, a boom foot 16S provided at the boom base end 16P is rotatably supported by a pivotal support (not shown) of the upper swing body 12. As shown in FIG. The boom 16 shown in FIG. 1 is of a so-called lattice type, and includes a lower boom 16A including a boom foot 16S, one or more (three in the example shown) intermediate booms 16B, 16C, and 16D, and an upper boom 16E. Consists of A pair of left and right backstops 45 are provided on the lower boom 16A. These backstops 45 come into contact with the upper rotating body 12 when the boom 16 reaches the standing posture (working posture) shown in FIG. This abutment prevents the boom 16 from being blown backward by strong winds or the like. The structure of the backstop 45 will be detailed later.

The lattice mast 17 includes a mast proximal end portion 17P and a mast distal end portion 17Q. The mast base end portion 17P is attached to the upper revolving body 12 so as to be able to rise and fall around a rotation axis parallel to the rotation axis of the boom 16 at a position on the rear side of the boom 16 . That is, the lattice mast 17 is also rotatable in the same direction as the boom 16 is raised and lowered. The mast front end portion 17Q is the front end portion of the lattice mast 17 arranged on the side opposite to the mast base end portion 17P in the longitudinal direction. As shown in FIG. 1, a first mast sheave 171 and a second mast sheave 172 are arranged at the mast tip portion 17Q of the lattice mast 17. As shown in FIG. The first mast sheave 171 and the second mast sheave 172 are hooked with a boom hoisting rope 22 which will be described later. The lattice mast 17 serves as a support for pivoting the boom 16 .

A pair of left and right backstops 46 are provided on the mast base end portion 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 FIG. This abutment prevents the lattice mast 17 from being blown rearward by a strong wind or the like.

Further, the crane 10 includes a lower spreader 18 , an upper spreader 19 , a guy line 20 , a boom hoisting rope 22 and a boom hoisting winch 38 .

The lower spreader 18 has a lower sheave block 181 . A plurality of sheaves are arranged in the width direction (horizontal direction) of the lower sheave block 181 .

The upper spreader 19 is arranged in front of the lower spreader 18 at a predetermined distance. The upper spreader 19 is connected via a guy line 20 to the boom tip 16Q. The upper spreader 19 has an upper sheave block 191 . A plurality of sheaves are arranged in the width direction (horizontal direction) in the upper sheave block 191 . A pair of guylines 20 are arranged in the left-right direction orthogonal to the plane of FIG. 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 a guy link (a plate made of metal), a guy rope, a guy wire (a wire made of metal), and the like.

The boom hoisting rope 22 is pulled out from the boom hoisting winch 38, and after being hung on the first and second mast sheaves 171 and 172 of the mast tip portion 17Q, a plurality of boom hoisting ropes 22 are arranged between the lower sheave block 181 and the upper sheave block 191. It is hung around. The tip of the boom hoisting rope 22 after being wound around the lower sheave block 181 and the upper sheave block 191 is fixed to the mast tip 17 Q of the lattice mast 17 .

The boom hoisting winch 38 is arranged on the mast base end portion 17</b>P side of the lattice mast 17 . The boom hoisting winch 38 winds and unwinds the boom hoisting 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 the boom 16. The boom 16 is raised and lowered while being rotated relative to the lattice mast 17. - 特許庁

The box mast 21 has a base end and a rotating end (tip), and is rotatably connected to the upper revolving body 12 on the rear side of the lattice mast 17 . The box mast 21 has a rectangular shape when viewed in cross section. The pivot axis of the box mast 21 is arranged parallel to the pivot axis of the boom 16 and substantially at the same position as the pivot axis of the lattice mast 17 . That is, the box mast 21 is also rotatable in the same direction as the boom 16 is raised and lowered.

Further, the crane 10 includes a guy line 23 , a mast hoisting rope 26 and a mast hoisting winch 30 . A pair of guylines 23 are arranged in the left-right direction orthogonal to the plane of FIG. The guy line 23 connects the mast tip portion 17Q of the lattice mast 17 and the pivoting end portion of the box mast 21 . This connection coordinates the rotation of lattice mast 17 and box mast 21 . The mast hoisting rope 26 consists of a sheave block 24 arranged on the upper rotating body 12 and having a plurality of sheaves arranged in the width direction, and a sheave block 24 arranged at the rotating end of the box mast 21 and having a plurality of sheaves arranged in the width direction. The sieve block 25 is wound multiple times.

The mast hoisting winch 30 is arranged on the base end side of the box mast 21 . The mast hoisting winch 30 winds up and lets out the mast hoisting rope 26 . Winding and unrolling operations of the mast hoisting winch 30 change 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 revolving body 12 . As the box mast 21 and the lattice mast 17 rotate integrally, the lattice mast 17 rises and falls.

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

The main hoisting winch 34 hoists and lowers the suspended load by the main hoisting rope 51 (FIG. 1). For this main hoisting, a main hoisting guide sheave (not shown) is rotatably provided at the boom tip 16Q of the boom 16, and a plurality of main hoisting point sheaves are provided at positions adjacent to the main hoisting guide sheave in the width direction. A main hoist sheave block is provided. A main hook 53 for a suspended load is connected to the main hoisting rope 51 suspended from the main hoisting sheave block. Then, the main hoisting rope 51 pulled out from the main hoisting winch 34 is sequentially hung on the main hoisting guide sheave, and the sheave of the main hoisting sheave block and the sheave of the sheave block provided on the main hook 53 are connected. passed between. Therefore, when the main hoisting winch 34 winds up or lets out the main hoisting rope 51, the main hook 53 is hoisted up and lowered.

Similarly, the auxiliary hoisting winch 36 hoists and lowers the suspended load with the auxiliary hoisting rope 52 . The auxiliary winding has a structure (not shown) similar to that of the main winding. When the auxiliary hoisting winch 36 winds or unwinds the auxiliary hoisting rope 52, an unillustrated auxiliary hook for hanging load connected to the end of the auxiliary hoisting rope 52 is hoisted or lowered.

A counterweight 40 for adjusting the balance of the crane 10 is loaded on the rear part of the upper swing body 12 , and a pallet weight 41 is further arranged behind the upper swing body 12 . The pallet weight 41 has a function of keeping the balance of the crane 10 as an SHL (Super Heavy Lifting) weight provided for the crane 10 to lift a heavy object. The pallet weight 41 is connected to the mast tip portion 17Q of the lattice mast 17 by a weight line 42. As shown in FIG.

2 and 3 are a plan view and a side view of the lower boom 16A and the backstop 45 of the crane 10 according to this embodiment when the boom 16 is laid down. FIG. 4 is a side view of the crane 10 according to the present embodiment in which the backstop 45 is in the supporting posture by the backstop lifting device 60 (backstop posture changing device). FIG. 5 is a side view of the crane 10 according to the present embodiment, in which the backstop 45 is set in the supporting posture by the backstop lifting device 60 and the boom 16 is erected.

2 to 5, when the boom 16 (lower boom 16A) is laid down with respect to the upper revolving structure 12, the lower boom 16A includes a pair of left and right lower frames 160 and a pair of left and right second booms. 1 main pipe 161 , a pair of left and right second main pipes 162 , a pair of left and right first connection pipes 163 , a pair of upper and lower second connection pipes 164 , 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. It extends so that the mutual interval widens toward the tip side. The lower frame 160 is a plate-like member that connects the base ends of the first main pipe 161 and the second main pipe 162 on both left and right sides of the lower boom 16A. A pair of left and right first connection pipes 163 connect respective tip portions of the first main pipe 161 and the second main pipe 162 to each other. The pair of upper and lower second connection pipes 164 connect the tip portions of the pair of left and right first main pipes 161 and the tip portions 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 points.

Furthermore, the lower boom 16A has a pair of left and right brackets 161S. A pair of left and right brackets 161S are arranged on the first main pipe 161 between the boom foot 16S and the tip of the first main pipe 161, more specifically, at a position near the tip of the first main pipe 161. there is The bracket 161S rotatably supports a backstop fulcrum portion 452S of the backstop 45 described later.

In addition, as described above, the crane 10 includes a pair of left and right backstops 45 . The crane 10 further includes a pair of left and right backstop lifting devices 60 (backstop posture changing device) that can be mounted between the backstop 45 and the boom 16 of the crane 10 . Each backstop 45 is arranged on a pair of left and right first main pipes 161 . Since the structure and function of the pair of left and right backstops 45 and the pair of left and right backstop lifting devices 60 are the same, the backstop 45 and the backstop lifting device 60 on the right side (the front side of the paper surface of FIG. 2) will be described below. .

The backstop 45 has a backstop lower portion 451 , a backstop upper portion 452 and a backstop spring 453 . The backstop lower part 451 and the backstop upper part 452 have a cylinder structure, and the backstop lower part 451 is inserted into the tubular interior of the backstop upper part 452 so as to be expandable and contractable. Backstop spring 453 is compressively mounted between flanges F (FIG. 3) provided on backstop lower portion 451 and backstop upper portion 452, respectively.

Further, the backstop lower portion 451 has a backstop contact portion 451S, and the backstop upper portion 452 has a backstop fulcrum portion 452S. The backstop fulcrum portion 452S corresponds to the base end portion of the backstop 45 (backstop base end portion), and the backstop contact portion 451S corresponds to the tip portion of the backstop 45 on the side opposite to the backstop fulcrum portion 452S. top tip). As described above, the backstop fulcrum portion 452S is arranged on the bracket 161S arranged at the tip portion (boom tip portion 16Q) side of the lower boom 16A from the boom foot 16S. rotation center axis extending in the direction, reference rotation center axis).

Referring to FIG. 5, the upper swing body 12 includes a swing frame 120. The swing frame 120 includes a support portion 12S that rotatably supports a boom foot 16S, a pair of left and right backstop receiving portions 121, have In addition, in FIG. 5, only the backstop receiving portion 121 on the right side (the front side of the paper surface) appears.

The backstop lifting device 60 rotates the backstop 45 with the backstop fulcrum portion 452S as the fulcrum in the collapsed state of the boom 16 in which the boom 16 is collapsed with respect to the upper revolving body 12, thereby lifting the backstop 45. can be changed between a supporting posture (Fig. 4) and a retracted posture (Fig. 3). The support posture is such that the backstop contact portion 451S of the backstop 45 comes into contact with the backstop receiving portion 121 of the upper rotating body 12 as the boom 16 rises from the collapsed state. The backstop 45 extends obliquely upward from the boom 16 (lower boom 16A) in the fallen state so that the boom 16 can be restrained from falling backward (see FIG. 4). On the other hand, the retracted posture is a posture in which the backstop contact portion 451S of the backstop 45 is arranged at a position closer to the lower boom 16A (boom 16) than the support posture. Therefore, as shown in FIGS. 3 and 4, the backstop lifting device 60 is arranged in the space between the backstop 45 and the first main pipe 161 of the lower boom 16A.

FIG. 6 is a side view showing the state of the backstop lifting device 60 with the backstop 45 in the retracted posture in the crane 10 according to this embodiment. FIG. 7 is a side sectional view of the backstop lift device 60 of FIG. FIG. 8 is a side view showing how the elevating cylinder 66 of the backstop elevating device 60 extends from the state in which the backstop 45 is in the retracted posture in the crane 10 according to this embodiment. FIG. 9 is a side view showing the state of the backstop lifting device 60 with the backstop 45 in the supporting posture in the crane 10 according to the embodiment. FIG. 10 is a side view showing how the elevating cylinder 66 of the backstop elevating device 60 contracts from the state of FIG. 11 to 13 are side views showing the state of the backstop lifting device 60 when the backstop 45 in the crane 10 according to this embodiment changes its posture from the supporting posture to the retracted posture. FIG. 14 is a cross-sectional view of the backstop lifting device 60 of FIG. 9 taken along arrows XIV-XIV. FIG. 15 is a sectional view showing how the arm fixing pin P2 sequentially moves from the state shown in FIG. 16, 17, and 18 are cross-sectional views showing how the arm fixing pin P2 sequentially moves from the state shown in FIG. 19 is a cross-sectional view of the backstop attitude changing device of FIG. 6 taken along arrows XIX--XIX.

The backstop lifting device 60 includes a first arm 61 (first support member, one support member), a second arm 62 (second support member, other support member), and a pair of left and right stoppers 63 (connecting members). , a support portion 60T including a second arm support portion 64 and a first arm fixing portion 65 (connecting portion for storage), an elevating cylinder 66 (push-up mechanism), and a guide groove portion 621B (guide groove).

The first arm 61 and the second arm 62 are connected at an arm fulcrum portion 60S (FIG. 8) so as to be relatively rotatable about a central axis of rotation extending in the left-right direction.

The first arm 61 is a member extending in a predetermined longitudinal direction, and has a substantially U-shaped cross section in a cross section perpendicular to the longitudinal direction. Specifically, the first arm 61 includes a first base portion 611, a pair of left and right first side portions 612, an arm end portion 613 (first rotating end portion), and a first connecting portion 614 (first base portion). end) and .

In FIG. 7, the first base portion 611 constitutes the upper surface portion of the first arm 61 and connects the pair of left and right first side portions 612 to each other in the left-right direction. That is, the first base portion 611 and the pair of left and right first side portions 612 form the U-shaped cross section. Here, as shown in FIG. 7, a pushed portion 611T is formed in a region near the arm fulcrum portion 60S on the lower surface (rear surface) of the first base portion 611. As shown in FIG. The pushed-up portion 611T has a function of being pushed up by a push-up portion 67T (FIG. 7) of a push-up member 67 described later.

The arm end portion 613 constitutes the tip portion (rotating end portion) of the first arm 61 .

The first connecting portion 614 constitutes the base end portion of the first arm 61 . The first connecting portion 614 has a substantially triangular shape when viewed from the side, and includes a connecting opening 614A and a fixing opening 614B arranged near the vertex of the first connecting portion 614. . The connecting opening 614A is an elongated hole opened substantially in the center of the first connecting portion 614, and the connecting opening 614A and the bracket 451T (FIG. 4) of the backstop lower portion 451 (not shown) are opened. By inserting a connecting pin (not shown) into the hole, the first connecting portion 614 of the first arm 61 is rotatable about the rotation center axis extending in the left-right direction to the backstop 45 (backstop lower portion 451). Supported. On the other hand, the fixing opening 614B is an opening for detachably fixing the first connecting part 614 to the first arm fixing part 65 with a later-described storage fixing pin P1 (FIGS. 4 and 7).

In other words, the first arm 61 is provided at a portion of the backstop 45 closer to the backstop abutment portion 451S than the backstop fulcrum portion 452S to the first arm parallel to the reference rotation center axis. A first connecting portion 614 (first base end portion) connected so as to be rotatable about the central axis of rotation, and an arm end portion 613 (first rotating end portion) opposite to the first connecting portion 614 ( FIG. 7 ), and a pushed portion 611 T arranged between the first connecting portion 614 and the arm end portion 613 .

The second arm 62 is a member extending in a predetermined longitudinal direction, and has a substantially U-shaped cross section in a cross section orthogonal to the longitudinal direction. Specifically, the second arm 62 has a pair of left and right second side portions 621 and a second base portion 622 (FIG. 7).

6 and 7, the second base portion 622 constitutes the lower surface portion of the second arm 62 and connects the pair of left and right second side portions 621 to each other in the left-right direction. That is, the second base portion 622 and the pair of left and right second side portions 621 form the U-shaped cross section. The width of the second arm 62 in the left-right direction is set smaller than the width of the first arm 61 in the left-right direction. For this reason, as shown in FIG. 6, the first arm 61 and the second arm 62 which are rotatable with respect to the arm fulcrum portion 60S are arranged so that the second arm 62 can be accommodated inside the first arm 61. As shown in FIG. have a dimensional relationship.

In addition, the second base portion 622 has a dimension that protrudes laterally outward from the pair of left and right second side portions 621 , and the portion that protrudes laterally outward from the second side portions 621 is A later-described restrictor 625 (FIG. 14) is fixed.

Further, second arm fulcrum portions 62S are arranged at the proximal end portions of the pair of left and right second side portions 621 (FIG. 7). The second arm fulcrum portion 62S is supported by the bearing portion 64S of the second arm support portion 64 so as to be rotatable about a rotation center axis extending in the left-right direction. 7, the second arm 62 further has a cylinder support portion 62T that rotatably supports a cylinder fulcrum portion 66S of an elevation cylinder 66, which will be described later.

In other words, the second arm 62 is a portion (second arm A second arm fulcrum portion 62S (second base end portion) connected to the support portion 64) so as to be rotatable about a second rotation center axis parallel to the reference rotation center axis, and a second arm fulcrum portion. 62S and is connected to the arm end 613 of the first arm 61 so as to be relatively rotatable about an intermediate rotation center axis parallel to the reference rotation center axis ( a second pivot end) (FIG. 8);

Here, further mentioning the relationship between the first arm 61 and the second arm 62, the second arm 62 is arranged between the first straight line connecting the first rotation center axis and the intermediate rotation center axis and the second rotation center axis. The backstop 45 is held in the supporting posture together with the first arm 61 by arranging so that the second straight line connecting the intermediate rotation center axis forms a first angle θ1 (FIG. 4). On the other hand, the second arm 62 is arranged so that the first straight line and the second straight line form an acute second angle θ2 (FIG. 3) that is smaller than the first angle. Together with 61, the backstop 45 is held in the retracted position.

As shown in FIGS. 6 and 7, the lifting cylinder 66 is arranged between the pair of left and right second side portions 621 of the second arm 62 so as to be interposed between the first arm 61 and the second arm 62. It is The elevating cylinder 66 has a cylinder body 661 , a cylinder rod 662 and a push-up member 67 . The cylinder body 661 and the cylinder rod 662 constitute a hydraulic cylinder. The cylinder main body 661 is made of a cylindrical (tubular) member. The cylinder body 661 includes a base end portion supported by the second arm 62 so as to be rotatable around a cylinder fulcrum portion 66S (first cylinder rotation center axis) parallel to the reference rotation center axis. On the other hand, the cylinder rod 662 is inserted into the internal space of the cylinder body 661 so as to be able to expand and contract with respect to the cylinder body 661 on the side opposite to the base end portion of the cylinder body 661 .

A push-up member 67 ( FIG. 7 ) is arranged at the tip of the cylinder rod 662 . The push-up member 67 extends the cylinder body 661 with respect to the cylinder rod 662 from the state in which the first arm 61 (first straight line) and the second arm 62 (second straight line) form the second angle θ2. Accordingly, the first arm 61 is rotated relative to the second arm 62 about the arm fulcrum portion 60S (intermediate rotation central axis), and the first arm 61 and the second arm 62 are rotated at the first angle. It is possible to push up the pushed-up portion 611T (FIG. 7) of the first arm 61 so as to form θ1.

The push-up member 67 has a first fulcrum portion 671 (first supported portion), a second fulcrum portion 672 (second supported portion), and a push-up portion 67T. The first fulcrum portion 671 is supported by the distal end portion of the cylinder rod 662 so as to be rotatable around a rotation center axis (second cylinder rotation center axis) parallel to the reference rotation center axis. The second fulcrum portion 672 is supported by the arm end portion 623 of the second arm 62 so as to be rotatable about the arm fulcrum portion 60S (intermediate rotation center axis).

The push-up portion 67T is arranged between the first fulcrum portion 671 and the second fulcrum portion 672, and pushes up the pushed-up portion 611T of the first arm 61 as the cylinder rod 662 extends with respect to the cylinder body 661. It is a flat part that can be used.

Further, a pair of left and right second side portions 621 of the second arm 62 are formed with guide groove portions 621B (FIG. 6).

Each guide groove portion 621B has a length that is approximately half the total length of the second arm 62 . The guide groove portion 621B includes a main guide groove 621C, an engagement groove 621D, and a sub-guide groove 621E.

The main guide groove 621</b>C is a long groove formed to extend along the longitudinal direction of the second arm 62 . The main guide groove 621C movably receives an arm fixing pin P2 of the stopper 63, which will be described in detail later. That is, the arm fixing pin P2 is fitted in the main guide groove 621C so as to move along the main guide groove 621C. The main guide groove 621C includes a groove proximal end portion and a groove distal end portion. The base end of the main guide groove 621C is one end of the main guide groove 621C, and the first arm 61 moves such that the first straight line and the second straight line form the second angle. The arm fixing pin P2 is received along with (FIG. 6). The tip of the main guide groove 621C is the other end of the main guide groove 621C, and the first arm 61 moves such that the first straight line and the second straight line form the first angle. As a result, the arm fixing pin P2 is received (see FIG. 8).

The engagement groove 621D extends to intersect the main guide groove 621C and communicates with the groove tip of the main guide groove 621C. The engagement groove 621D receives an arm fixing pin P2 that has passed through the tip of the groove as the cylinder rod 662, which will be described later, extends with respect to the cylinder body 661, and holds the backstop 45 in the supporting posture. has a function of engaging with the arm fixing pin P2.

The sub-guide groove 621E communicates with the groove tip of the main guide groove 621C on the side opposite to the engaging groove 621D. The sub-guide groove 621E has a function of receiving the arm fixing pin P2 that has detached from the engaging groove 621D. The sub-guide groove 621E communicates with the groove tip so as to have a slight length along the longitudinal direction of the main guide-groove 621C. In other words, the width of the tip of the main guide groove 621C is partially widened by the sub guide groove 621E. Further, as shown in FIG. 6, the end portion of the sub guide groove 621E on the side of the groove base end portion is formed with an inclined surface that is inclined so as to approach the main guide groove 621C. The inclined surface can smoothly guide the arm fixing pin P2.

A pair of left and right stoppers 63 ( FIG. 8 ) are rotatably supported on both left and right sides of the first arm 61 . Each of the stoppers 63 is arranged such that the first arm 61 and the second arm 62 form a first angle θ1 and the backstop 45 maintains the support posture. 62 are connected to each other. Specifically, as shown in FIG. 6, the stopper 63 has a link shape extending in a direction perpendicular to the left-right direction, and stopper fulcrum portions 631 (connecting member base end portions) disposed at both ends thereof. and an arm fixing pin P2 (connecting shaft).

The stopper fulcrum portion 631 is provided at a portion of the first side portion 612 of the first arm 61 spaced from the arm fulcrum portion 60S toward the first connecting portion 614 side, and the rotation center axis (reference rotation center axis) extending in the left-right direction. is rotatably supported around a third rotation center axis parallel to the .

The arm fixing pin P2 is a pin (connection shaft) that is arranged at the tip of the stopper 63 on the side opposite to the stopper fulcrum portion 631 and extends in the left-right direction (direction parallel to the reference rotation center axis). The arm fixing pin P2 engages with the guide groove 621B of the second arm 62 so as to be movable along the guide groove 621B.

The support portion 60T (FIG. 6) is fixed to the first main pipe 161 of the lower boom 16A. The support portion 60T has a pair of left and right second arm support portions 64 . Each of the second arm support portions 64 includes a bearing portion 64S that supports the second arm fulcrum portion 62S of the second arm 62 so as to be rotatable about the rotation center axis extending in the left-right direction, as described above.

Further, the support portion 60T has a first arm fixing portion 65. As shown in FIG. The first arm fixing portion 65 is arranged between the pair of left and right second arm supporting portions 64 and has a function of temporarily fixing the first connecting portion 614 of the first arm 61 .

Referring to FIG. 19, the first arm fixing portion 65 has a support frame 65C, a pair of left and right storage fixing pins P1 (storage engagement pins), and a pair of left and right springs 65D (pin biasing portions). .

The support frame 65C is supported by a second arm support portion 64 (FIG. 6) fixed to the first main pipe 161 of the lower boom 16A. The support frame 65C supports a pair of left and right storage fixing pins P1.

A pair of left and right storage fixing pins P1 are supported by the upper end portion of the support frame 65C so as to be slidable in the left-right direction. The pair of left and right storage fixing pins P1 each include pin tip portions that are arranged to face each other with a gap in the direction parallel to the reference rotation center axis. A tapered surface P1T (tapered portion) is formed at the tip of each pin.

A pair of left and right springs 65D urge the pair of retracting fixing pins P1 inward in the left-right direction so that the pin tip portions of the pair of retracting fixing pins P1 approach each other. Even when each retracting fixing pin P1 is urged by each spring 65D, each retracting fixing pin is prevented from interfering with a part of the support frame 65C and a flange (not shown) provided on each retracting fixing pin P1. The inner position of P1 in the left-right direction is regulated. At this time, the distance between the pin tip portions of the pair of left and right storage fixing pins P1 is set to be smaller than the plate thickness of the first connecting portion 614 (engagement portion) of the first arm 61 (FIG. 19). ).

As described above, the connecting opening 614A and the fixing opening 614B are formed in the first connecting portion 614 (FIG. 7) (engaging portion) of the first arm 61, respectively. The connecting opening 614A is a pin hole for connecting the first arm 61 to the backstop 45 . On the other hand, when the backstop 45 changes its posture from the supporting posture to the retracted posture, the fixing opening 614B fits between the pair of left and right retracting fixing pins P1 in FIG. That is, the fixing opening 614B functions as an engaging hole with which the pin tip portions of the pair of retracting fixing pins P1 can be engaged from both sides.

Referring to FIG. 15, restrictor 625 is fixed to second base portion 622 of second arm 62 . When the posture of the backstop 45 is changed from the supporting posture to the retracted posture, that is, when the first arm 61 and the second arm 62 are bent according to the operation of the lifting cylinder 66, the restricting member 625 engages with the above-mentioned engagement. It has a function of preventing the arm fixing pin P2, which has been separated from the groove 612D, from entering the engagement groove 621D again.

The restrictor 625 has a pair of left and right restriction guide plates 625A (guide plates) and a pair of left and right springs 625B (biasing members). The regulation guide plate 625A is supported by a frame erected from the second base portion 622 so as to be slidable along the left-right direction. The pair of left and right springs 625B are elastic spring members capable of urging each regulation guide plate 625A inward in the left-right direction toward the end of the arm fixing pin P2.

In other words, the left and right pair of springs 625B urge the left and right regulation guide plates 625A so that the left and right regulation guide plates 625A approach each other. An inclined surface 625C inclined at a predetermined angle is formed on the lower surface of the regulation guide plate 625A (the upper surface side with respect to the arm fixing pin P2 at the time of contact). A regulation surface 625D parallel to the reference rotation center axis is formed on the lower surface side of the control pin P2. The functions of the inclined surface 625C and the restricting surface 625D will be detailed later. In another embodiment, the restrictor 625 may have one restriction guide plate 625A and one spring 625B on one of the left and right sides.

Next, the elevating operation (position changing operation) of the backstop 45 by the backstop elevating device 60 will be described.

When the backstop 45 changes its posture from the storage posture shown in FIG. 3 to the support posture shown in FIG. to extend. At this time, first, the push-up portion 67T of the push-up member 67 in FIG. 7 contacts the pushed-up portion 611T of the first arm 61 from below. The push-up portion 67T pushes up the first base portion 611 in accordance with the extension operation of the cylinder rod 662, so that the first arm 61 moves upward while rotating relative to the second arm 62. do.

At this time, when the first connecting portion 614 of the first arm 61 attempts to move upward due to the thrust of the lifting cylinder 66, the pair of left and right storage fixing pins P1 (FIG. 19) move outward in the left and right direction due to the inclination of the tapered surface P1T. It is pushed out and detached from the fixing opening 614B. As a result, the backstop 45 connected to the first connecting portion 614 of the first arm 61 rotates upward around the backstop fulcrum portion 452S (FIG. 4). As the elevating cylinder 66 extends, as shown in FIG. 8, the arm fixing pin P2 of the stopper 63 reaches the tip of the main guide groove 621C of the guide groove 621B.

Next, the cylinder rod 662 of the lifting cylinder 66 contracts with respect to the cylinder body 661 . At this time, as shown in FIG. 9, the first arm 61 slightly moves downward under the weight of the backstop 45, and the arm fixing pin P2 of the stopper 63 engages from the tip of the main guide groove 621C. It enters the groove 621D and engages its lower end (bottom). After that, the cylinder rod 662 is fully retracted while the push-up portion 67T of the lifting cylinder 66 is separated from the pushed-up portion 611T (FIG. 10).

Through the above operations, as shown in FIG. 4, the angle formed by the first arm 61 and the second arm 62 reaches the aforementioned first angle θ1. At this time, since the arm fixing pin P2 is engaged with the engaging groove 621D, the relative position of the first arm 61 with respect to the second arm 62 is regulated, and the backstop 45 is held in the supporting posture.

When the backstop 45 changes its posture from the supporting posture shown in FIG. 4 to the retracted posture shown in FIG. 3, the cylinder rod 662 extends again from the state shown in FIG. do. Eventually, when the push-up portion 67T pushes up the pushed-up portion 611T, the first arm 61 extends relative to the second arm 62, and the stopper 63 is pulled upward. As a result, as shown in FIG. 11, the arm fixing pin P2 is separated from the engagement groove 621D and attempts to enter the groove tip portion of the main guide groove 621C again.

15, 16, 17 and 18, both ends of the arm fixing pin P2 come into contact with the inclined surfaces 625C of the pair of left and right regulation guide plates 625A, compressing the springs 625B. 625A, the arm fixing pin P2 climbs over the pair of left and right regulation guide plates 625A and enters the groove tip of the main guide groove 621C.

At this time, since the sub-guide groove 621E communicates with the upper side of the groove tip of the main guide groove 621C, the arm fixing pin P2 enters the sub-guide groove 621E (FIG. 11).

When the cylinder rod 662 contracts further with respect to the cylinder body 661, the arm fixing pin P2 of the stopper 63 attempts to move downward, but is blocked (regulated) by the regulation surfaces 625D of the pair of left and right regulation guide plates 625A. Therefore, the arm fixing pin P2 is prevented from entering the engaging groove 621D. As a result, as the cylinder rod 662 contracts, the arm fixing pin P2 moves along the main guide groove 621C (FIGS. 12 and 13) and reaches the base end of the main guide groove 621C (FIGS. 6 and 6). Figure 7).

At this time, while receiving the weight of the backstop 45, the first connecting portion 614 of the first arm 61 pushes out the pair of left and right storage fixing pins P1 of the first arm fixing portion 65 (FIG. 19) laterally outward. Each storage fixing pin P1 biased inward in the left-right direction by each spring 65D engages with each fixing opening 614B. As a result, the backstop 45 is held (locked) in the retracted posture.

As described above, in this embodiment, when the cylinder rod 662 of the lifting cylinder 66 extends with respect to the cylinder main body 661 from the state where the backstop 45 is in the retracted posture on the lower boom 16A, the boost member 67 is moved to the first position. By pushing up the pushed-up portion 611T of the arm 61, the first arm 61 can be rotated relative to the second arm 62, and the posture of the backstop 45 can be changed to the supporting posture. Therefore, compared to the case where the attitude of the backstop 45 is changed by another auxiliary crane or the case where the operator manually changes the attitude of the backstop 45, the backstop 45 of the crane 10 can be adjusted between the supporting attitude and the retracted attitude. It is possible to easily and safely change the posture between them.

Further, when the first arm 61 extends with respect to the second arm 62 as the elevating cylinder 66 expands and contracts, the arm fixing pin P2 of the stopper 63 engages with the engagement groove 621D of the guide groove portion 621B. A backstop 45 can be held in a supporting position. Therefore, it is not necessary for the worker to mount a pin for connecting the first arm 61 and the second arm 62 at a high place. Therefore, it is possible to improve the working efficiency of the worker in the assembling and disassembling work of the crane 10 and reduce the burden of the work.

In addition, since the relative posture of the first arm 61 and the second arm 62 can be maintained in this way, even if the weight of the boom 16 is applied to the backstop 45 during work of the crane 10, the cylinder of the lifting cylinder 66 can be lifted. A large force is prevented from being applied to the portion, and damage to the cylinder portion is prevented. Also, the need to increase the strength of the lifting cylinder 66 to receive the weight of the boom 16 is reduced.

Furthermore, in the present embodiment, the first connecting portion 614 enters between the pair of storage fixing pins P1 as the first arm 61 bends with respect to the second arm 62, thereby contracting each spring 65D. while the pin tips of the pair of retracting fixing pins P1 are engaged with the fixing openings 614B, respectively. On the other hand, as the first arm 61 extends with respect to the second arm 62, at least the thrust force of the lifting cylinder 66 is received, and the pin tip portions of the pair of storage fixing pins P1 are separated from the fixing openings 614B. One arm 61 extends with respect to the second arm 62 . A tapered surface P1T is formed at each of the pin tip portions of the pair of storage fixing pins P1 so as to allow such an operation.

According to such a configuration, the first connecting portion 614 of the first arm 61 can be automatically attached to and detached from the first arm fixing portion 65 on the lower boom 16A as the elevating cylinder 66 expands and contracts. Since it is possible, it is not necessary for the worker to attach a pin for connecting the first arm 61 and the first arm fixing portion 65 to each other at a high place.

Furthermore, in this embodiment, the guide groove portion 621B has a sub-guide groove 621E, and the backstop lifting device 60 has a restrictor 625. As shown in FIG. Specifically, the restrictor 625 is configured such that the cylinder rod 662 extends with respect to the cylinder main body 661 in a state in which the arm fixing pin P2 is arranged at the groove base end portion of the main guide groove 621C, so that the arm fixing pin P2 is After reaching the tip of the groove, as the cylinder rod 662 contracts with respect to the cylinder body 661, the arm fixing pin P2 is allowed to enter the engagement groove 621D. On the other hand, when the arm fixing pin P2 is engaged with the engagement groove 621D, the cylinder rod 662 extends with respect to the cylinder body 661 so that the restrictor 625 moves from the engagement groove 621D to the main guide groove 621C. to enter the sub-guide groove 621E. On the other hand, the restrictor 625 restricts the arm fixing pin P2 entering the sub guide groove 621E from entering the engaging groove 621D, and the arm fixing pin P2 is prevented from entering the groove base end portion of the main guide groove 621C. Allow to move towards. The restrictor 625 is arranged to face the groove tip of the main guide groove 621C of the guide groove 621B so that the above operation can be realized.

According to such a configuration, the arm fixing pin P2 of the stopper 63 is engaged by extending the elevating cylinder 66 from the supporting posture of the backstop 45 and moving the first arm 61 relative to the second arm 62. It can move from the groove 621D to the sub-guide groove 621E through the restrictor 625. On the other hand, when the elevating cylinder 66 is contracted, the movement of the arm fixing pin P2 to the engagement groove 621D is restricted by the restrictor 625, and the arm fixing pin P2 is guided to the main guide groove 621C. Therefore, even if an engagement groove 621D extending in a direction different from that of the main guide groove 621C is provided to hold the backstop 45 in the supporting posture, the posture of the backstop 45 can be easily and reliably changed.

In particular, regulation guide plate 625A includes inclined surface 625C and regulation surface 625D. When the cylinder rod 662 extends with respect to the cylinder body 661 while the arm fixing pin P2 is engaged with the engaging groove 621D, the inclined surface 625C moves the arm fixing pin P2 from the engaging groove 621D to the main guide groove 621C. When moving toward the tip of the groove, the arm fixing pin P2 climbs over the regulation guide plate 625A while contracting the spring 625B by the force received from the arm fixing pin P2 in contact with the end of the arm fixing pin P2. It is inclined with respect to the axial direction of the arm fixing pin P2 so as to allow the arm fixing pin P2 to enter into the groove tip portion. On the other hand, the restricting surface 625D is arranged on the opposite side of the inclined surface 625C, and contacts the end of the arm fixing pin P2 that has entered the sub guide groove 621E from the engaging groove 621D via the groove tip of the main guide groove 621C. The contact arm fixing pin P2 extends along a direction intersecting the inclined surface 625C so as to restrict re-entry into the engagement groove 621D.

In this way, when the arm fixing pin P2 of the stopper 63 is moved from the position where it is engaged with the engaging groove 621D of the guide groove portion 621B to the main guide groove 621C, the arm fixing pin P2 moves toward the inclination of the regulation guide plate 625A. By abutting on the surface 625C, the regulating guide plate 625A biased by the spring 625B can be pushed out while entering the groove tip portion of the main guide groove 621C and the sub-guide groove 621E. Conversely, when the arm fixing pin P2 attempts to enter the engagement groove 621D again, the regulation surface 625D of the regulation guide plate 625A comes into contact with the arm fixing pin P2, thereby preventing the arm fixing pin P2 from entering. be done. Therefore, the structure of the restricting member 625 (inclined surface 625C, restricting surface 625D) can reliably guide the arm fixing pin P2 in an appropriate direction.

In this embodiment, the push-up member 67 is rotatably supported by the rod tip portion 662S of the cylinder rod 662 and the second arm 62 at the first fulcrum portion 671 and the second fulcrum portion 672, respectively. Therefore, the direction in which the push-up portion 67T pushes up the pushed-up portion 611T of the first arm 61 can be changed relative to the direction in which the cylinder rod 662 expands and contracts with respect to the cylinder body 661. It is possible to reliably change the posture of the backstop 45 by changing the relative angle between the first arm 61 and the second arm 62 according to the telescopic motion in one direction.

Further, in the present embodiment, the push-up member 67 is pushed up as the cylinder rod 662 contracts with respect to the cylinder main body 661 while the stopper 63 maintains the relative posture of the first arm 61 and the second arm 62 . It rotates around the first fulcrum portion 671 and the second fulcrum portion 672 so that the push-up portion 67T can be separated from the pushed-up portion 611T. Therefore, the cylinder rod 662 can be accommodated in the cylinder main body 661 while the backstop 45 is in the supporting posture. Therefore, the cylinder rod 662 is prevented from being left for a long period of time in a state of being extended from the cylinder main body 661, and the occurrence of damage such as rust on the cylinder rod 662 is prevented. In addition, since the cylinder rod 662 can be maintained in the oil-immersed state for a long period of time inside the cylinder body 661, the occurrence of rust and the like is further reduced. Since the push-up portion 67T can be separated from the pushed-up portion 611T, the cylinder rod 662 including the push-up member 67 may contract under its own weight.

Further, in the present embodiment, when the cylinder rod 662 is contracted with respect to the cylinder main body 661, the first coupling of the first arm 61 is performed so that the pair of left and right storage fixing pins P1 hold the backstop 45 in the storage posture. It is possible to lock the part 614 . Therefore, the relative posture of the first arm 61 and the second arm 62 can be maintained in the retracted posture of the backstop 45, and the backstop 45 does not spring up from the boom 16 when the boom 16 is transported. prevented.

Further, in the present embodiment, since the stopper fulcrum portion 631 of the stopper 63 is rotatably supported by the first arm 61, the stopper 63 may be detached from both the first arm 61 and the second arm 62. In comparison, transportation and storage of the backstop lifting device 60 are facilitated.

Next, a second embodiment of the invention will be described. FIG. 20 is a side view showing the state of the backstop lifting device 60 with the backstop 45 in the retracted posture in the crane 10 according to this embodiment. FIG. 21 is a side view showing how the elevating cylinder 66 of the backstop elevating device 60 extends from the state in which the backstop 45 is in the retracted posture in the crane 10 according to this embodiment. FIG. 22 is a side view showing the state of the backstop lifting device 60 with the backstop 45 in the supporting posture in the crane 10 according to this embodiment. FIG. 23 is a side view showing how the lifting cylinder 66 contracts from the state shown in FIG. 24, 25, and 26 are side views showing the state of the backstop lifting device 60 when the backstop 45 in the crane 10 according to this embodiment changes its posture from the supporting posture to the retracted posture. In this embodiment, differences from the first embodiment will be mainly described, and descriptions of common points will be omitted.

In this embodiment, a pair of left and right first side portions 612 of the first arm 61 (the other support member) are formed with guide grooves 612B similar to the guide grooves 621B of the first embodiment. The guide groove portion 612B includes a main guide groove 612C, an engagement groove 612D, and a sub-guide groove 612E.

On the other hand, the stopper fulcrum portions 631 of the pair of left and right stoppers 63 are rotatably supported by the pair of left and right second side portions 621 of the second arm 62 (one supporting member). Further, the arm fixing pin P2 on the opposite side of the stopper fulcrum portion 631 of each stopper 63 is engaged with the guide groove portion 612B so as to be movable along the guide groove portion 612B.

A restrictor 615 is fixed to the pair of left and right first side portions 612 of the first arm 61 so as to face the tip of the main guide groove 612C. The structure of the restrictor 615 is the same as the restrictor 625 of the first embodiment.

Also, the connection structure between the first connecting portion 614 provided at the tip of the first arm 61 and the first arm fixing portion 65 is the same as that of the first embodiment.

In this embodiment, when the backstop 45 changes its posture from the storage posture shown in FIG. 3 to the support posture shown in FIG. to the cylinder body 661 in order. Also at this time, first, the push-up portion 67T of the push-up member 67 provided at the tip of the cylinder rod 662 comes into contact with the pushed-up portion 611T (FIG. 20) of the first arm 61 from below. The push-up portion 67T pushes up the first base portion 611 in accordance with the extension operation of the cylinder rod 662, so that the first arm 61 moves upward while rotating relative to the second arm 62. do.

At this time, when the first connecting portion 614 of the first arm 61 attempts to move upward due to the thrust of the lifting cylinder 66, the pair of left and right storage fixing pins P1 (FIG. 19) move outward in the left and right direction due to the inclination of the tapered surface P1T. It is pushed out and detached from the fixing opening 614B. As a result, the backstop 45 connected to the first connecting portion 614 of the first arm 61 rotates upward about the backstop fulcrum portion 452S. As the elevating cylinder 66 extends, as shown in FIG. 21, the arm fixing pin P2 of the stopper 63 reaches the tip of the main guide groove 612C of the guide groove 621B.

Next, the cylinder rod 662 of the lifting cylinder 66 contracts with respect to the cylinder body 661 . At this time, as shown in FIG. 22, the first arm 61 slightly moves downward under the weight of the backstop 45, and the arm fixing pin P2 of the stopper 63 moves upward from the tip of the main guide groove 612C. It enters the extending engagement groove 612D and engages with its upper end (bottom). After that, the cylinder rod 662 is fully retracted while the push-up portion 67T of the lifting cylinder 66 is separated from the pushed-up portion 611T (FIG. 23).

Through the above operations, as shown in FIG. 4, the angle formed by the first arm 61 and the second arm 62 reaches the aforementioned first angle θ1. As a result, the relative position of the first arm 61 with respect to the second arm 62 is regulated, and the backstop 45 is held in the supporting posture.

When the backstop 45 changes its posture from the supporting posture shown in FIG. 4 to the retracted posture shown in FIG. 3, the cylinder rod 662 extends from the state shown in FIG. 23 to the cylinder body 661 as shown in FIG. . Eventually, when the push-up portion 67T pushes up the pushed-up portion 611T, the first arm 61 extends relative to the second arm 62 with the stopper 63 left. As a result, the arm fixing pin P2 moves downward away from the engaging groove 612D and attempts to enter the groove tip portion of the main guide groove 612C again.

At this time, as in the first embodiment, both ends of the arm fixing pin P2 abut on the inclined surfaces 625C of the pair of left and right regulation guide plates 625A, and each regulation guide plate 625A is moved laterally while compressing each spring 625B. Pushed outward, the arm fixing pin P2 climbs over the pair of left and right regulation guide plates 625A and enters the groove tip of the main guide groove 612C.

Since the sub-guide groove 612E communicates with the lower side of the groove tip of the main guide groove 612C, the arm fixing pin P2 enters the sub-guide groove 612E (FIG. 24).

Next, when the cylinder rod 662 begins to contract with respect to the cylinder main body 661, the arm fixing pin P2 of the stopper 63 tries to move upward relative to the first arm 61, but the pair of left and right regulation guides Since it is blocked (regulated) by the regulation surface 625D of the plate 625A, it is prevented from entering the engagement groove 612D. As a result, as the cylinder rod 662 contracts, the arm fixing pin P2 moves along the main guide groove 612C (FIGS. 25 and 26) and reaches the base end of the main guide groove 612C (FIG. 20). .

At this time, while receiving the weight of the backstop 45, the first connecting portion 614 of the first arm 61 pushes out the pair of left and right storage fixing pins P1 of the first arm fixing portion 65 (FIG. 19) laterally outward. Each storage fixing pin P1 biased inward in the left-right direction by each spring 65D engages with the fixing opening 614B. As a result, the backstop 45 is held (locked) in the retracted posture.

As described above, also in the present embodiment, when the cylinder rod 662 of the lifting cylinder 66 extends relative to the cylinder main body 661 from the state in which the backstop 45 is in the retracted posture on the lower boom 16A, the push-up member 67 is pushed upward. By pushing up the pushed portion 611T of the first arm 61, the first arm 61 can be rotated relative to the second arm 62, and the posture of the backstop 45 can be changed to the supporting posture. Therefore, compared to the case where the attitude of the backstop 45 is changed by another auxiliary crane or the case where the operator manually changes the attitude of the backstop 45, the backstop 45 of the crane 10 can be adjusted between the supporting attitude and the retracted attitude. It is possible to easily and safely change the posture between them.

Further, when the first arm 61 extends relative to the second arm 62 as the elevating cylinder 66 expands and contracts, the arm fixing pin P2 of the stopper 63 engages with the engagement groove 612D of the guide groove portion 612B. A backstop 45 can be held in a supporting position. Therefore, it is not necessary for the worker to mount a pin for connecting the first arm 61 and the second arm 62 at a high place. Therefore, it is possible to improve the working efficiency of the worker in the assembling and disassembling work of the crane 10 and reduce the burden of the work. Other effects are the same as those of the first embodiment.

The backstop lifting device 60 of the crane 10 according to each embodiment of the present invention has been described above. In addition, this invention is not limited to these forms. In the present invention, the following modified embodiments are possible.

(1) In the above embodiment, the backstop 45 is arranged on the boom 16, but the backstop 46 in FIG. In this case, the backstop lifting device 60 is arranged so as to be interposed between the lattice mast 17 and the backstop 46 . The backstop whose posture is changed by the backstop lifting device 60 may be a jib or strut (not shown) that maintains the posture. That is, the present invention can also be applied to backstops provided on masts (such as lattice masts), struts (rear struts, front struts), and jibs.

(2) In the above embodiment, the second arm 62 supports the cylinder body 661 . It may also be one that expands and contracts relatively. In this case, a push-up portion 67T is arranged at the tip of the cylinder main body 661 .

(3) In the above embodiment, the crane 10 shown in FIG. 1 was used, but the present invention is not limited to this, and can be applied to cranes having other structures. That is, the crane to which the present invention is applied may be a general-purpose crane, provided with a gantry instead of the lattice mast, and the hoisting winch may be arranged on the upper frame (rear side) of the upper swing body 12 . As a large-sized crane, instead of the SHL structure, a structure in which the boom is raised and lowered by raising and lowering the box mast may be used. 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. Moreover, both general-purpose cranes and large-sized cranes may have a jib or strut attached to the tip of the boom.

(4) In the above embodiment, the first connecting portion 614 (engaging portion) of the first arm 61 has fixing openings with which the pin tip portions of the pair of retracting fixing pins P1 can be engaged from both sides. The portion 614B (engagement hole) is formed, and the tapered surface P1T (tapered portion) is formed at the distal end portion of the pair of left and right storage fixing pins P1 (storage engagement pin). However, the present invention is not limited to this. The tapered surface P1T may not be formed on the distal end portion of the pair of left and right retraction fixing pins P1 (engagement pins for retraction). Alternatively, a pair of left and right pressing members may be biased inward in the left and right direction, and hold the first connecting portion 614 by sandwiching the first connecting portion 614 from both sides.

10 crane 12 upper revolving body (crane body)
120 swing frame 121 backstop receiving portion 16 boom (elastic body)
160 lower frame 161 first main pipe 16A lower boom 16P boom base end (resting body base end)
16Q boom tip (tip of hoisting body)
16S Boom foot 45 Backstop 451 Backstop lower part 451S Backstop contact part 452 Backstop upper part 452S Backstop fulcrum part 453 Backstop spring 60 Backstop lifting device (backstop posture changing device)
60S arm fulcrum portion 60T support portion 61 first arm (first support member)
611 First base portion 611T Pushed portion 612 First side portion 612B Guide groove portion (guide groove)
612C Main guide groove 612D Engagement groove 612E Sub-guide groove 613 Arm end (first rotation end)
614 first connecting portion (first base end portion)
614A Connecting opening 614B Fixing opening 615 Regulating tool 615A Regulating guide plate 615B Spring 615C Inclined surface 615D Regulating surface 62 Second arm (second support member)
621 second side portion 622 second base portion 523 arm end portion (second rotating end portion)
62S Second arm fulcrum (second proximal end)
63 stopper (connecting member)
631 stopper fulcrum (connection proximal end)
64 Second arm support portion 65 First arm fixing portion (connecting portion for storage)
66 lift cylinder (push-up mechanism)
661 cylinder main body 662 cylinder rod 67 push-up member 671 first fulcrum portion (first supported portion)
672 second fulcrum portion (second supported portion)
67S Push-up portion P1 Storage fixing pin P1T Tapered surface (tapered portion)
P2 Arm fixing pin (connecting shaft)

Claims (6)

a crane body;
an elevating body including an elevating body base end portion rotatably supported in the elevating direction by the crane main body, and an elevating body distal end portion opposite to the elevating body base end portion;
a backstop base end portion supported rotatably about a horizontal reference rotation center axis at a portion of the elevating body that is closer to the tip end of the elevating body than the base end of the elevating body; and the base end of the backstop. A backstop attitude changing device mountable to a crane, comprising: a backstop tip positioned opposite to the
By rotating the backstop around the base end of the backstop as a fulcrum, it is possible to change the posture of the backstop between a supporting posture and a retracted posture. While it is a posture in which the body can be restrained from lying backward, the retracted posture is a posture in which the tip of the backstop of the backstop is arranged at a position closer to the derrick body than in the support posture. ,
a first base end connected to the backstop so as to be rotatable about a first rotation center axis parallel to the reference rotation center axis; and a first rotation opposite to the first base end. a first support member having an end portion and a pushed portion disposed between the first base end portion and the first rotating end portion;
a second base end connected to the undulating body so as to be rotatable about a second rotation center axis parallel to the reference rotation center axis; a second rotating end connected to the first rotating end of the first support member so as to be relatively rotatable about an intermediate rotation center axis parallel to the reference rotation center axis; 2 support member, wherein the second support member is a first straight line connecting the first rotation center axis and the intermediate rotation center axis and a second straight line connecting the second rotation center axis and the intermediate rotation center axis are arranged to form a first angle so that the first support member and the backstop are in the support posture, while the first straight line and the second straight line are arranged to form a first angle. a second support member arranged at a small acute second angle to allow the backstop with the first support member to assume the retracted position;
A push-up mechanism arranged to be interposed between the first support member and the second support member, comprising: a cylindrical cylinder body; The inserted cylinder rod and the extension of the cylinder rod with respect to the cylinder body cause the first support member to rotate relative to the second support member about the intermediate rotation center axis. a push-up mechanism having a push-up member capable of pushing up the pushed portion of the first support member;
a connecting member rotatably supported by one of the first supporting member and the second supporting member;
a guide groove disposed in the other support member different from the one support member of the first support member and the second support member;
with
The connecting member is
a base end of a connecting member supported by the one support member so as to be rotatable around a third rotation center axis parallel to the reference rotation center axis;
a connecting shaft arranged on the side opposite to the base end of the connecting member and extending parallel to the reference central axis of rotation;
In the guide groove,
A main guide groove that extends along the longitudinal direction of the other support member and movably receives the connecting shaft, the groove receiving the connecting shaft as the cylinder rod contracts with respect to the cylinder body. a main guide groove including a base end portion and a groove distal end portion disposed opposite to the groove base end portion and receiving the connecting shaft as the cylinder rod extends with respect to the cylinder body;
An engaging groove extending to intersect the main guide groove and communicating with the groove tip of the main guide groove, wherein the groove tip is formed as the cylinder rod extends with respect to the cylinder body. an engaging groove that receives the connecting shaft that has passed through and engages with the connecting shaft so as to hold the backstop in the supporting posture;
A backstop attitude changer for a crane, each formed by The guide groove is further formed with a sub-guide groove communicating with the groove tip portion of the main guide groove on the side opposite to the engagement groove,
Equipped with additional controls,
The regulator is
When the cylinder rod extends with respect to the cylinder body while the connecting shaft is engaged with the engaging groove, the connecting shaft enters the auxiliary guide groove from the engaging groove through the groove tip portion. is arranged opposite to the groove tip of the main guide groove so as to allow the connection shaft to enter the sub-guide groove while restricting the connecting shaft from entering the engagement groove; The crane backstop posture changing device according to claim 1. The regulator is
a guide plate,
a biasing member that biases the guide plate toward the end of the connecting shaft;
has
The guide plate is
When the cylinder rod extends with respect to the cylinder body while the connecting shaft is engaged with the engaging groove, the connecting shaft moves from the engaging groove toward the tip of the groove. The connecting shaft is arranged so as to allow the connecting shaft to climb over the guide plate and enter the tip of the groove while contracting the biasing member due to the force received from the connecting shaft in contact with the end of the connecting shaft. an inclined surface inclined with respect to the axial direction;
a restricting surface disposed on the opposite side of the inclined surface and in contact with the connecting shaft so as to restrict the connecting shaft from entering the engaging groove;
3. A crane backstop reorientation device according to claim 2, comprising: A retracting connecting portion capable of connecting the first support member and the undulating body to each other so that the backstop is held in the retracted posture when the cylinder rod is contracted with respect to the cylinder body. 4. The crane backstop attitude changing device according to any one of claims 1 to 3, further comprising: The storage connecting portion is
A pair of pin tip portions each supported by one of the first support member and the undulating body and arranged facing each other with a gap in a direction parallel to the reference rotation center axis. a retraction engagement pin;
a pin biasing portion that biases the pair of engagement pins for storage such that the pin tip portions of the pair of engagement pins for storage approach each other;
an engaging portion arranged on the other structure different from the one of the first support member and the undulating body;
including
When the cylinder rod contracts with respect to the cylinder main body and the backstop changes its posture from the supporting posture to the retracted posture, the engaging portion enters between the tip end portions of the pair of pins. The retracting engagement pin allows the pair of pin tip portions to engage with the engagement portion while contracting the pin biasing portion, while the cylinder rod extends with respect to the cylinder body. 5. The crane backstop posture changing device according to claim 4, wherein the engaging portion is disengaged from the tip end portions of the pair of pins and moved upward with respect to the hoisting body by a thrust force. With the connecting member holding the relative posture between the first support member and the second support member, the push-up portion moves toward the pushed-up portion as the cylinder rod contracts with respect to the cylinder body. 6. A crane backstop attitude changing device according to any one of claims 1 to 5, wherein the backstop attitude changing device is capable of moving away from the .

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