A telescopic boom and a crane

Abstract

The present invention discloses a telescopic boom, which includes N sections of arms sleeved and arranged in sequence from outside to inside. The boom locking device is arranged on any one of two adjacent sections of arms or simultaneously arranged on two adjacent sections of arms for locking or unlocking the relative positions of two adjacent sections of arms. The telescopic boom further includes: an extension rope, a retraction rope, a rope guide, and an extension and retraction rope winding and unwinding device arranged on the boom barrel; the extension rope is led out from the extension rope winding and unwinding device, then successively bypasses the rope guides at the head of the first section of arm, and all the rope guides at the heads and roots of the second to the (N - 1)th sections of arms, and the other end is fixed to the root of the Nth section of arm. The retraction rope is led out from the retraction rope winding and unwinding device, and the other end is directly fixed to the Nth section of arm. The driving rope winding and unwinding device can realize the telescopic movement of the telescopic boom in any order, and the telescopic mechanism does not bear the lifting load, greatly simplifying the telescopic mechanism and improving the lifting capacity and efficiency of the crane.

Description

Technical Field

[0001] The present invention relates to the technical field of telescopic boom of cranes, and particularly to a telescopic boom and a crane. Background Art

[0002] At present, there are mainly two forms of telescoping of crane telescopic booms. One is the single-cylinder pin telescoping method suitable for large-tonnage cranes. In this method, since the oil cylinder does not bear the lifting weight, the oil cylinder can be made relatively thin and the structure is compact. The single-cylinder pin is also beneficial to optimizing the telescoping sequence of the boom segments and improving the lifting capacity of the boom. However, the disadvantage of the single-cylinder pin is slow speed, high machining accuracy requirements, complex control, and inconvenient maintenance. The other telescoping form is the linkage of the driving oil cylinder and the rope row to achieve multi-stage boom synchronous telescoping, such as Patent Document 1 (Publication No.: CN101575075A) and Patent Document 2 (Publication No.: CN202481966U). This is a traditional telescoping method. This method has a simple principle and fast speed, and is still a widely used telescoping technology in the industry. In this telescoping method of the driving oil cylinder plus the rope row, since there is no locking device provided between two adjacent telescopic booms, the oil cylinder and the rope row have to bear a huge axial force caused by the lifting weight during the lifting process. Therefore, the diameter of the driving oil cylinder is large, the number of strands of the rope row is large, the internal layout is complex, it is difficult to optimize the boom cylinder, and the lifting capacity is limited. In addition, in the existing telescopic boom of the driving oil cylinder plus the rope row, when the number of telescopic booms is greater than 4, usually two oil cylinders are required to achieve this. For example, the crane boom disclosed in Patent Document 2 (Publication No.: CN202481966U) includes two oil cylinders. The second oil cylinder is located between the third boom and the fourth boom. In the case where the oil cylinder bears the lifting weight, the weight of the oil cylinder itself is also large, thus increasing the self-weight of the boom and reducing the lifting capacity.

[0003] The invention patent with the application number CN201811579829.6 applied by the applicant earlier discloses a telescopic boom that uses a drum to wind and unwind a rope to achieve arbitrary sequence telescoping of multiple boom segments. This solution has a simple structure, is flexible and fast. However, the technical problems existing in this technical solution are: if the rope on the drum is disordered, it will cause uneven stress on the rope, and there are already many drums on the turntable of the crane itself, and it is difficult to arrange an additional drum for boom telescoping on the turntable. Summary of the Invention

[0004] In view of the problems in the current boom telescoping technology, such as the load-bearing limitation of the oil cylinder plus rope row telescoping device, simple combination method, while the single-cylinder pin mechanism has high precision requirements, complex operation, and slow speed. As for using a drum as a rope winding and unwinding device to achieve arbitrary sequence telescoping of multiple boom segments, there are also problems of disordered rope on the drum and inconvenient arrangement. The present invention provides a telescopic boom that will adopt a new rope winding and unwinding device to achieve arbitrary sequence telescoping of multiple boom segments, simplify the telescoping structure of the telescopic boom, and improve the flexibility of boom telescoping. The specific technical solutions are as follows.

[0005] A telescopic boom, which includes N sections of booms sleeved and arranged in sequence from outside to inside, where N is greater than or equal to 3. The outermost section is the first boom, and the innermost section is the Nth boom. The telescopic boom further includes a boom locking device, which is arranged on any one of two adjacent booms or on both adjacent booms simultaneously, and is used to lock or unlock the relative positions of the two adjacent booms. It is characterized in that the telescopic boom further includes: a boom extension rope, a rope guide, and a boom extension rope retracting and releasing device. The boom extension rope retracting and releasing device is arranged on the first boom or the turntable of the crane and is used to store or release the boom extension rope;

[0006] The head of the first boom, as well as the heads and roots of the second to the (N - 1)th booms, are all provided with the rope guides; one end of the boom extension rope is fixed to the rope retracting and releasing device, and the other end sequentially bypasses the rope guides at the head of the first boom, as well as all the rope guides at the heads and roots of the second to the (N - 1)th booms, and is fixed to the root of the Nth boom. Herein, the root is the end on the upstream side of the extending direction of a boom section, and the head is the end on the downstream side of the extending direction of a boom section.

[0007] Further, the boom extension rope retracting and releasing device adopts a boom extension pulley block mechanism. The boom extension pulley block mechanism includes a boom extension fixed pulley block, a boom extension movable pulley block, and a driving oil cylinder. The rod of the driving oil cylinder is connected to the first boom. At least on one of the boom sections, there is a guiding component for guiding the cylinder barrel to move along the telescopic direction of the boom and preventing it from rotating. The boom extension fixed pulley block is fixedly arranged at the root of the first boom, and the boom extension movable pulley block is fixedly arranged on the cylinder barrel; one end of the boom extension rope bypasses at least one fixed pulley of the boom extension fixed pulley block and at least one movable pulley of the boom extension movable pulley block and is fixedly connected to the pulley frame of the boom extension movable pulley block or the pulley frame of the boom extension fixed pulley block; when the driving oil cylinder extends, the distance between the boom extension fixed pulley block and the boom extension movable pulley block increases, and the boom extension rope is stored in the pulley space of the retracting and releasing device, and the unlocked boom sections extend. When the driving oil cylinder shortens, the distance between the boom extension fixed pulley block and the boom extension movable pulley block decreases, and the boom extension rope is released.

[0008] Further, the guiding component is a guide rod and / or a guide groove.

[0009] Further, the rope guide is a pulley, or an arc-shaped array of rotating shafts, or an arc-shaped guide groove.

[0010] Further, the telescopic boom rope winding and unwinding device adopts a sprocket and chain belt mechanism, which includes a chain belt and at least two parallelly arranged sprockets, where at least one sprocket is a driving sprocket. The chain belt is sleeved on the sprockets, and the sprockets are arranged on the first boom section through sprocket brackets; multiple rope channels are provided on the chain belt. One end of the telescopic boom rope is fixedly connected to a rope channel of the chain belt. When the driving sprocket rotates forward, the telescopic boom rope winds around the rope channel, and the unlocked boom section extends. When the driving sprocket rotates reversely, the telescopic boom rope is released.

[0011] Further, the telescopic boom further includes a retracting boom rope and a retracting boom rope winding and unwinding device. One end of the retracting boom rope is fixedly connected to the retracting boom rope winding and unwinding device, and the other end is fixedly connected to the Nth boom section.

[0012] Further, the retracting boom rope winding and unwinding device adopts a retracting boom sprocket and chain belt mechanism, a retracting boom drum mechanism or a retracting boom pulley block mechanism.

[0013] Further, the retracting boom pulley block mechanism includes a retracting boom fixed pulley block, a retracting boom movable pulley block and the driving oil cylinder. The retracting boom pulley block mechanism shares the same driving oil cylinder with the telescopic boom pulley block mechanism. The retracting boom fixed pulley block is arranged at one end near the head on the first boom section, and the retracting boom movable pulley block is fixedly arranged on the cylinder barrel; one end of the retracting boom rope bypasses at least one fixed pulley of the retracting boom fixed pulley block and at least one movable pulley of the retracting boom movable pulley block and then is fixedly connected to the pulley bracket of the retracting boom movable pulley block or the pulley bracket of the retracting boom fixed pulley block; when the driving oil cylinder shortens, the distance between the retracting boom fixed pulley block and the retracting boom movable pulley block increases, and the unlocked boom section retracts. When the driving oil cylinder extends, the distance between the retracting boom fixed pulley block and the retracting boom movable pulley block decreases, and the retracting boom rope is released.

[0014] Further, the retracting boom sprocket and chain belt mechanism includes a retracting boom rope and the above-mentioned sprocket and chain belt mechanism. One end of the retracting boom rope is fixedly connected to a rope channel on the chain belt, and the other end is fixedly connected to the Nth boom section. The winding direction of the telescopic boom rope on the sprocket and chain belt mechanism is opposite to the winding direction of the telescopic boom rope on the sprocket and chain belt mechanism. When the sprocket rotates, the retracting and telescoping of the retracting boom rope is realized.

[0015] Further, the chain belt is a common link type chain belt. When the sprocket rotates, the sprocket teeth push the chain belt to rotate around the sprocket.

[0016] Further, the chain belt is a rope and bead type chain belt. When the sprocket rotates, the beads embedded in the sprocket tooth grooves drive the chain belt to rotate around the sprocket. In fact, the rope and bead type chain belt can be a part of the root of the telescopic boom rope or the retracting boom rope, that is, only need to add beads to a section of the root of the telescopic boom rope or the retracting boom rope and then tie it into a ring and sleeved on the sprocket.

[0017] Furthermore, the rope bead chain belts can be arranged side by side or separately. For example, the rope bead chain belts can be arranged in the gaps on both sides of the first and second boom segments.

[0018] Furthermore, the rope retracting and releasing device can be a combination of a drum mechanism, a pulley block mechanism or a sprocket chain belt mechanism.

[0019] The present invention also relates to a crane having the telescopic boom described above.

[0020] Based on the introduction of the arm end locking device, the present invention uses a rope retracting and releasing device to drive the telescoping of the boom segments. Compared with the telescoping method using an oil cylinder and a rope row, the driving force is greatly reduced. Compared with the single-cylinder pin telescoping method, since it can telescope step by step continuously from bottom to top without pause, and can also adjust the extended length of a given boom segment in real time under any boom length condition, not only the retracting resistance of the boom is minimized, but also the continuity and flexibility of the telescoping process are greatly improved. The present invention is beneficial to optimizing the telescoping sequence of the boom segments, the telescoping mechanism does not bear load during operation, and the lifting capacity is improved. In particular, by using a rope retracting and releasing device that can be arranged inside the boom cylinder, the boom telescoping device is completely placed inside the boom cylinder, the structure is more compact, and the overall vehicle layout is simplified. Since the space in the cylinder in the boom extension direction is not limited, the rope only needs to be wound two or three times to achieve full extension of the boom, and there will be no rope entanglement, making the telescoping process smoother and more reliable.

[0021] In short, this fundamentally breaks through the limitations of the existing telescoping technology, provides a new type of efficient and reliable boom telescoping technology, and enhances the market competitiveness of crane products. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of the telescopic boom of Embodiment 1 of the present invention (the boom is in the extended state);

[0023] Figure 2 is a schematic diagram of the telescopic boom of Embodiment 2 of the present invention (the boom is in the extended state);

[0024] Figure 3 is a schematic diagram of a common link chain belt;

[0025] Figure 4 is a schematic diagram of a rope bead chain belt;

[0026] Figure 5 is a schematic diagram of the telescopic boom of Embodiment 3 of the present invention (the boom is in the extended state);

[0027] Figure 6 is a schematic diagram of the telescopic boom of Embodiment 4 of the present invention (the boom is in the extended state).

[0028] In the figure: the first boom section Ⅰ, the second boom section Ⅱ, the third boom section Ⅲ, the fourth boom section Ⅳ, the fifth boom section Ⅴ, the boom extension rope 1, the boom retraction rope 2, the boom extension fixed pulley block 3, the boom extension movable pulley block 4, the boom locking device 5, the drive oil cylinder 6, the rope guide 7, the chain belt 8, the sprocket 9, the support rod 10, the sprocket bracket 11, the pulley bracket 12, the boom retraction fixed pulley block 13, the boom retraction movable pulley block 14, the drum mechanism 15. Detailed implementation mode

[0029] The present invention will be further described in detail below with reference to the accompanying drawings.

[0030] Embodiment 1

[0031] Refer to Figure 1 , a telescopic boom, which includes the first boom section Ⅰ, the second boom section Ⅱ, the third boom section Ⅲ, the fourth boom section Ⅳ and the fifth boom section Ⅴ which are sleeved and arranged in sequence from outside to inside. The telescopic boom includes a boom locking device 5, and the boom locking device 5 is arranged on two adjacent boom sections and is used to lock or unlock the relative positions of the two adjacent boom sections. The boom locking device 5 can be the boom locking device described in the utility model patent with the publication number of CN209411651U, which will not be elaborated here. Of course, the boom locking device can also adopt other structural forms as long as it can lock two adjacent boom sections and unlock them when needed.

[0032] The telescopic boom of this embodiment further includes a boom extension rope 1, a boom retraction rope 2, a rope guide 7, and a boom extension rope retracting and releasing device and a boom retraction rope retracting and releasing device disposed inside the first boom section Ⅰ. In this embodiment, both the boom extension rope retracting and releasing device and the boom retraction rope retracting and releasing device adopt pulley block mechanisms. The pulley block mechanism includes: a driving oil cylinder 6, a support rod 10, a boom fixed pulley block 3, a boom movable pulley block 4, a boom retraction fixed pulley block 13, and a boom retraction movable pulley block 14. The piston rod of the driving oil cylinder 6 is connected to the first boom section. A guiding component for guiding the movement of the cylinder barrel of the driving oil cylinder to prevent the cylinder barrel from rotating and swinging is provided on at least one boom section. The support rod 10 and the boom fixed pulley block 3 are fixedly disposed at the root of the first boom section. The boom retraction fixed pulley block 13 is fixedly disposed at one end of the support rod 10 close to the head of the first boom section. The boom movable pulley block 4 and the boom retraction movable pulley block 14 are both fixedly disposed on the cylinder barrel. One end of the boom extension rope 1 bypasses at least one fixed pulley of the boom fixed pulley block 3 and at least one movable pulley of the boom movable pulley block 4 and is fixedly connected to the pulley frame 12 of the boom fixed pulley block 3 or the pulley frame 12 of the boom movable pulley block 4. A rope guide 7 is provided at the head of the first boom section Ⅰ. Rope guides 7 are also provided at the heads and roots of the second boom section Ⅱ, the third boom section Ⅲ, and the fourth boom section Ⅳ. One end of the boom extension rope 1 is fixedly connected to the pulley frame 12, and the other end is fixed to the root of the fifth boom section Ⅴ. The middle of the boom extension rope 1 sequentially bypasses the rope guide at the head of the first boom section Ⅰ, the rope guide at the root of the second boom section Ⅱ, the rope guide at the head of the second boom section Ⅱ, the rope guide at the root of the third boom section Ⅲ, the rope guide at the head of the third boom section Ⅲ, the rope guide at the root of the fourth boom section Ⅳ, and the rope guide at the head of the fourth boom section Ⅳ. The root is the end on the upstream side of the extending direction of the boom section, and the head is the end on the downstream side of the extending direction of the boom section.

[0033] One end of the boom retraction rope 2 bypasses the boom retraction fixed pulley block 13 and the boom retraction movable pulley block 14 and is fixedly connected to the pulley frame 12 of the boom retraction fixed pulley block 13 or the pulley frame 12 of the boom retraction movable pulley block 14. The other end of the boom retraction rope 2 is fixedly connected to the fifth boom section Ⅴ.

[0034] When the driving oil cylinder 6 extends, the distance between the boom movable pulley block 4 and the boom fixed pulley block 3 increases, the boom extension rope 1 is received between the pulley blocks, and the unlocked boom section is pulled out. The distance between the boom retraction movable pulley block 14 and the boom retraction fixed pulley block 13 decreases, and the boom retraction rope 2 is released. When the driving oil cylinder 6 shortens, the distance between the boom retraction movable pulley block 14 and the boom retraction fixed pulley block 13 increases, the boom retraction rope 2 is received between the pulley blocks, and the unlocked boom section is pulled back. The distance between the boom movable pulley block 4 and the boom fixed pulley block 3 decreases, and the boom extension rope 1 is released.

[0035] Preferably, the rope guide 7 is a pulley, an arc array rotating shaft or a chute, so as to ensure that the telescopic boom rope 1 slides on the rope guide with relatively small resistance.

[0036] Preferably, the fixed pulley or movable pulley in the telescopic boom pulley group mechanism and the retractable boom pulley group mechanism can be a single pulley, or can be a mechanism composed of several arc array rotating shafts to play the role of a pulley.

[0037] The specific telescopic operation process is as follows: In the fully retracted state (not shown), each arm section is locked bidirectionally. When telescoping the boom, starting from the second arm section, unlock the mutual position locking between the first arm section Ⅰ and the second arm section Ⅱ, drive the oil cylinder 6 to extend, the cylinder barrel drives the telescopic boom movable pulley group 4 to move, the distance between the telescopic boom fixed pulley group 3 and the telescopic boom movable pulley group 4 increases, the telescopic boom rope 1 is pulled and received between the fixed pulley group 3 and the movable pulley group 4, and the second arm section Ⅱ is pulled out by the telescopic boom rope 1. At the same time, the distance between the retractable boom fixed pulley group 13 and the retractable boom movable pulley group 14 decreases, and the retractable boom rope 2 is released. Since the third arm section Ⅲ, the fourth arm section Ⅳ, and the fifth arm section Ⅴ are in a mutually locked state and no relative movement will occur, when the second arm section Ⅱ extends in place, re-lock its positional relationship with the first arm section Ⅰ. Similarly, unlock the remaining arm sections in sequence (unlock only one arm section at a time), drive the oil cylinder 6 to extend, and the extension of each arm section can be achieved in sequence. When each arm extends in place, re-lock each arm section to perform the hoisting operation.

[0038] When it is necessary to retract the boom, in the reverse order of telescoping the boom, unlock the locked state of each arm section, drive the oil cylinder 6 to shorten, the distance between the retractable boom fixed pulley group 13 and the retractable boom movable pulley group 14 increases, the retractable boom rope 2 is pulled and received between the retractable boom fixed pulley group 13 and the retractable boom movable pulley group 14, and the unlocked arm section retracts. At the same time, the distance between the telescopic boom fixed pulley group 3 and the telescopic boom movable pulley group 4 decreases, and the telescopic boom rope is released.

[0039] In this solution, it is also possible to independently control the locking and unlocking of a certain arm section in each arm section. By telescoping the drive oil cylinder, the telescoping of the specified arm section can be achieved; when the boom is in any working boom length state, if it is necessary to change the extended length of a certain arm section, as long as the locking of this arm section is released and the telescoping drive oil cylinder is operated, the extension or retraction of this arm section can be achieved.

[0040] It should be noted that in this embodiment, a telescopic boom with 5 arm sections is adopted, but those skilled in the art can understand that the number of arm sections of the telescopic boom of the present invention can be any number greater than or equal to 3, such as the telescopic boom includes 3, 4, 5, 6, 7 or 8 arm sections, etc. Those skilled in the art can understand that: the retractable boom rope and the retractable boom pulley group described in this embodiment can be cancelled, and each arm section can automatically retract under the action of gravity.

[0041] When the telescopic boom is in the operation of lifting a load, all the boom locking devices are in the locked state. The locking devices bear all the loads of the boom, while the extension ropes and retraction ropes do not bear the loads. This is beneficial to reducing the requirements for the extension ropes.

[0042] In the above embodiment, only one set of extension rope 1 is shown. However, those skilled in the art can understand that two or more sets of extension ropes can be arranged inside the telescopic boom to improve balance and reliability.

[0043] Adopting the pulley block mechanism to store the extension rope 1 has at least the following advantages.

[0044] 1. The extension moving pulley block 4 moves along the telescopic direction of the boom driven by the oil cylinder, and does not occupy too much lateral space inside the first boom section. The extension moving pulley block 4 and the telescopic oil cylinder 6 can be arranged inside the first boom section and the second boom section, which is beneficial to reducing the volume of the first boom section and the second boom section, and does not require major modifications to the existing boom structure.

[0045] 2. The pulley block mechanism can be completely located inside the first boom section, with little influence from the external environment, which is beneficial to stable operation; it does not require major modifications to the turntable of the existing telescopic boom, and the modification cost is low.

[0046] 3. Due to the arrangement of the extension moving pulley block, the amplification effect of the stroke of the telescopic oil cylinder can be achieved. When the extension rope 1 bypasses one moving pulley in the extension moving pulley block, when the telescopic oil cylinder 6 extends 1 m, the end of the extension rope 1 connected to the fifth boom rises at least 2 m, that is, the whole telescopic boom extends 2 m; when the extension rope 1 bypasses two moving pulleys in the extension moving pulley block, when the telescopic oil cylinder 6 extends 1 m, the end of the extension rope 1 connected to the fifth boom rises at least 4 m, that is, the whole telescopic boom extends 4 m. Therefore, a telescopic oil cylinder with an appropriate length can be used to complete the full extension of the entire telescopic boom.

[0047] Embodiment 2

[0048] See Figure 2, different from Embodiment 1, both the extending arm and retracting arm rope winding and unwinding devices adopt a sprocket chain mechanism. The sprocket chain mechanism includes a chain 8 and at least two parallelly arranged sprockets 9, where at least one sprocket is a driving sprocket, and the driving sprocket is connected to a driving motor for driving the sprocket to rotate. The chain 8 is sleeved on the sprockets 9, and the sprockets 9 are arranged in the cylinder of the first boom section through a sprocket bracket 11; multiple mutually parallel rope channels are provided on the chain 8. One end of the extending arm rope 1 is fixedly connected to the chain 8 and wound around a rope channel of the chain, and then sequentially bypasses the rope guides 7 at the head and tail of the relevant boom sections, and the other end is connected to the root of the last boom section; one end of the retracting arm rope 2 is fixedly connected to the chain 8 and reversely wound around another rope channel of the chain, and the other end is directly connected to the last boom section; when the telescopic boom needs to extend, the driving sprocket 9 rotates, and the chain 8 rotates around the sprocket, thereby recovering and winding the extending arm rope 1 on the chain 8, thereby pulling the unlocked boom sections to extend. And the retracting arm rope is released; when the telescopic boom needs to retract, the driving sprocket 8 rotates reversely, and the chain 8 rotates reversely around the sprocket, thereby recovering and reversely winding the retracting arm rope 2 on the chain 8, thereby pulling the unlocked boom sections to retract. And the extending arm rope is released; if there is more than one extending arm rope, additional rope channels can be opened on the chain 8, and multiple rope channels can be opened on one chain to accommodate multiple strands of extending arm ropes.

[0049] Preferably, the chain is a common link type chain ( Figure 3 ), when the sprocket rotates, the sprocket teeth push the chain to rotate around the sprocket.

[0050] Preferably, the chain is a rope bead type chain ( Figure 4 ), when the sprocket rotates, the beads embedded in the sprocket grooves drive the chain to rotate around the sprocket. In fact, the rope bead type chain can be a part of the root of the extending arm rope or the retracting arm rope, that is, only by adding beads to a section of the root of the extending arm rope or the retracting arm rope and then tying it into a ring and sleeving it on the sprocket.

[0051] Embodiment 3

[0052] See Figure 5 , in Embodiment 2, the extending arm rope 1 and the retracting arm rope 2 are wound around the same sprocket chain mechanism. In this embodiment, the extending arm rope 1 and the retracting arm rope 2 respectively adopt different sprocket chain mechanisms. As Figure 5 shown, two sets of extending arm sprocket chain mechanisms and one set of retracting arm sprocket chain mechanisms are provided. The extending arm sprocket chain mechanisms are located in the gap between the two sides of the cylinders of the first and second boom sections, and the retracting arm sprocket chain mechanism is located in the cylinder. The driving sprockets of the three sets of sprocket chain mechanisms can be coaxially installed or driven by the same motor.

[0053] Embodiment 4

[0054] See Figure 6, on the basis of Embodiment 1, the retractable boom rope winding and unwinding device of Embodiment 1 is replaced with a drum mechanism 15. The drum mechanism is arranged on the turntable of the boom or inside the first boom section. One end of the retractable boom rope 2 is wound around the drum mechanism 15, and the other end is fixedly connected to the end boom. The retractable boom rope 2 is wound or unwound by the forward and reverse rotation of the drum mechanism. It should be noted that the retractable boom rope winding and unwinding device in Embodiment 1 can also be replaced with the sprocket chain belt mechanism in Embodiment 2, and the sprocket chain belt is used to wind or unwind the retractable boom rope 2.

[0055] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. Without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other. The present invention is not limited to the above specific embodiments. For example, the rope winding and unwinding device can be a hybrid of a drum mechanism, a pulley block mechanism or a sprocket chain belt mechanism. The rope winding and unwinding device can be arranged either inside or outside the boom cylinder. In the schematic diagrams of Embodiments 1 and 2, only one telescopic boom rope is drawn, but in fact, two or more telescopic boom ropes can be arranged. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can make more forms without departing from the spirit and scope of the present invention defined by the claims. All of these fall within the protection scope of the present invention.

Claims

1. A telescopic boom, which comprises N sections of booms sleeved and arranged in sequence from outside to inside, where N is greater than or equal to 3, the outermost is the first section of boom, and the innermost is the Nth section of boom. The telescopic boom further includes a boom locking device, which is arranged on any one of two adjacent sections of booms or simultaneously arranged on two adjacent sections of booms for locking or unlocking the relative positions of two adjacent sections of booms; it is characterized in that, The telescopic boom further includes: a boom extension rope, a rope guide, and a boom rope retracting and extending device. The boom rope retracting and extending device is arranged on the first boom section or the turntable of the crane and is used for storing or releasing the boom extension rope; The head of the first boom section, as well as the heads and roots of the second to the (N - 1)th boom sections, are all provided with the rope guides. One end of the boom extension rope is fixed to the rope retracting and extending device, and the other end sequentially passes around the rope guides at the head of the first boom section, as well as all the rope guides at the heads and roots of the second to the (N - 1)th boom sections, and is fixed to the root of the Nth boom section. Herein, the root is the end on the upstream side in the extending direction of a boom section, and the head is the end on the downstream side in the extending direction of a boom section; The boom rope retracting and extending device adopts a boom pulley block mechanism. The boom pulley block mechanism includes a boom fixed pulley block, a boom movable pulley block, and a driving oil cylinder. The rod of the driving oil cylinder is connected to the first boom section. At least on one of the boom sections, there is a guiding component for guiding the cylinder barrel of the driving oil cylinder to move along the telescopic direction of the boom to prevent it from rotating. The boom fixed pulley block is fixedly arranged on the first boom section, and the boom movable pulley block is fixedly arranged on the cylinder barrel. One end of the boom extension rope passes around at least one fixed pulley of the boom fixed pulley block and at least one movable pulley of the boom movable pulley block and is fixedly connected to the pulley frame of the boom movable pulley block or the pulley frame of the boom fixed pulley block. When the driving oil cylinder extends, the distance between the boom fixed pulley block and the boom movable pulley block increases, and the boom extension rope is stored in the pulley space of the retracting and extending device, and the unlocked boom sections extend. When the driving oil cylinder shortens, the distance between the boom fixed pulley block and the boom movable pulley block decreases, and the boom extension rope is released; Alternatively, the boom rope retracting and extending device adopts a sprocket chain belt mechanism. The sprocket chain belt mechanism includes a chain belt and at least two parallelly arranged sprockets, wherein at least one sprocket is a driving sprocket. The chain belt is sleeved on the sprockets, and the sprockets are arranged on the first boom section through sprocket frames. The chain belt is provided with a plurality of rope channels. One end of the boom extension rope is fixed to a rope channel of the chain belt. When the driving sprocket rotates forward, the boom extension rope is wound on the rope channel, and the unlocked boom sections extend. When the driving sprocket rotates reversely, the boom extension rope is released.

2. The telescopic boom according to claim 1, wherein, The guiding component is a guide rod and / or a guide groove.

3. The telescopic boom according to claim 1, wherein, The rope guide is a pulley or an arc-shaped array of rotating shafts or an arc-shaped guide groove.

4. The telescopic boom according to any one of claims 1-3, characterized in that The telescopic boom further includes a boom retraction rope and a boom retraction rope retracting and extending device. One end of the boom retraction rope is fixedly connected to the boom retraction rope retracting and extending device, and the other end is fixedly connected to the Nth boom section.

5. The telescopic boom according to claim 4, wherein The boom retraction rope retracting and extending device adopts a boom retraction sprocket chain belt mechanism, a boom retraction drum mechanism, or a boom retraction pulley block mechanism.

6. The telescopic boom according to claim 5, wherein, The boom retracting pulley block mechanism includes a boom retracting fixed pulley block, a boom retracting movable pulley block, and the driving oil cylinder. The boom retracting pulley block mechanism shares the same driving oil cylinder with the boom extending pulley block mechanism. The boom retracting fixed pulley block is arranged at one end of the first boom section close to the head. The boom retracting movable pulley block is fixedly arranged on the cylinder barrel. One end of the boom retracting rope bypasses at least one fixed pulley of the boom retracting fixed pulley block and at least one movable pulley of the boom retracting movable pulley block and is fixedly connected to the pulley frame of the boom retracting movable pulley block or the pulley frame of the boom retracting fixed pulley block. When the driving oil cylinder shortens, the distance between the boom retracting fixed pulley block and the boom retracting movable pulley block increases, the boom retracting rope is stored in the pulley space of the winding and unwinding device, and the unlocked boom section retracts. When the driving oil cylinder extends, the distance between the boom retracting fixed pulley block and the boom retracting movable pulley block decreases, and the boom retracting rope is released.

7. The telescopic boom according to claim 6, wherein The boom retracting sprocket chain belt mechanism includes a boom retracting rope and the above-mentioned sprocket chain belt mechanism. One end of the boom retracting rope is fixedly connected to a rope channel on the chain belt of the sprocket chain belt mechanism, and the other end is fixedly connected to the Nth boom section. The winding direction of the boom retracting rope on the sprocket chain belt mechanism is opposite to the winding direction of the boom extending rope on the sprocket chain belt mechanism. When the sprocket rotates, the winding and unwinding of the boom retracting rope and boom retraction are realized.

8. A crane, characterized in that, It has a telescopic boom as described in any one of claims 1-7.

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